Taking construction of the online and offline integrated first-class undergraduate curriculum teaching modes of Histology and Embryology in Guangxi as an opportunity,under the guidance of student-centered teaching con...Taking construction of the online and offline integrated first-class undergraduate curriculum teaching modes of Histology and Embryology in Guangxi as an opportunity,under the guidance of student-centered teaching concept,efforts were made to innovate online and offline integrated teaching mode to overcome the shortcomings and dilemma of traditional Histology and Embryology teaching,with attention paid to the competence education in students including schematic knowledge,professional techniques,analytical thinking,and ideological and political theories,which would be of great significance for the cultivation of high-quality professionals specialized in traditional Chinese medicine.展开更多
The development of plant embryology in China can be roughly divided into three stages: (1) the initial stage, (2) the stage of establishing plant embryology as a branch of plant sciences, and (3) the stage when plant...The development of plant embryology in China can be roughly divided into three stages: (1) the initial stage, (2) the stage of establishing plant embryology as a branch of plant sciences, and (3) the stage when plant embryology evolves into plant reproductive biology with its vigorous development. It is in the third stage that research work in this field in China has developed rapidly and many of the significant achievements obtained are described in more details in this review. Researches of experimental embryology are not included in this paper.展开更多
Cleft lip with or without cleft palate(CP) is one of the most common congenital malformations. Ultrasonographers involved in the routine 20-wk ultrasound screening could encounter these malformations. The face and pal...Cleft lip with or without cleft palate(CP) is one of the most common congenital malformations. Ultrasonographers involved in the routine 20-wk ultrasound screening could encounter these malformations. The face and palate develop in a very characteristic way. For ultrasonographers involved in screening these patients it is crucial to have a thorough understanding of the embryology of the face. This could help them to make a more accurate diagnosis and save time during the ultrasound. Subsequently, the current postnatal classification will be discussed to facilitate the communication with the CP teams.展开更多
Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesi...Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesis, gametogenesis, fertilization and embryogenesis of I. sangumea, we developed fl owering regulation and control breeding. I. sangumea fl ower bud differentiation was observed in April for 21 days; in this stage, the early differentiation process was slow, temperature was more than 5 °C, if the temperature is shorter than this, most fl ower bud will have no differentiation, and turn to vegetative growth; later differentiation is faster and required temperature is from 5 to 8 °C and gradually rose to 10-12 °C. The temperature in April plays the defi nitely role in the number of bud differentiation. Three stamina contain tetrasporangiate anthers and a glandular tapetum. The anther wall is composed of four cell layers inclduding the epidermis, the endothecium, one middle layer and the secretory tapetum. The type of anther wall development the dicotyledonous type. After pollen maturation, the anther wall forms a double-layer containing only epidermis and endothecium. Simultaneous cytokinesis is of the continuous type during meiosis of microspore mother cell results in a zygomorphous or tetragonal tetrad. Mature pollen grains are two-celled. I. sangumea ’s stylar canal is hollow, open type style, and the gynoecium has three carpels. The ovaries have axial placentas. The ovule is anatropous, bitegmic and crassinucellate. The primary sporogenous cell differentiates directly as the megaspore. The megaspore tetrads are linear, T-shaped or juxtaposed. Generally, the fi rst of the tetrad megaspores at the chalaza becomes functional while the other three degenerate. A mature embryo sac with seven cells and eight nuclei embryo sac is of the polygonum type. For dichogamy, the male gametophyte matures about 2 days earlier than the female gametophyte. The pollen tube entered into the embryo sac for 22–24 h after pollination. The dormancy stage of fertilized ovules is 5-6 days, and the fusion of sperm and egg nucleus is of the premitotic type. The primary endosperm cell has shorter dormancy of 4-6 days, and endosperm formation is of the nuclear type.展开更多
Early human embryonic development remains mysterious due to drastic species divergences between humans and othermammalian models and limited accessibility to human embryo samples. Recent studies from my laboratory and...Early human embryonic development remains mysterious due to drastic species divergences between humans and othermammalian models and limited accessibility to human embryo samples. Recent studies from my laboratory and others haveshown that under suitable culture conditions human pluripotent stem cells ( hPSCs) can undergo intricate morphogenetic eventsand self-organize to form patterned human embryo-like structures in vitro. These synthetic human embryonic tissueshold great promises for advancing human embryology and reproductive medicine. In this talk,I will describe a hPSC-based,synthetic 3D model of human post-implantation development that recapitulates key developmental landmarks successively,including pro-amniotic cavity formation,amniotic ectoderm-epiblast patterning,primordial germ cell specification,and developmentof the primitive streak with controlled anteroposterior polarity ( Fig.1) . We further show that the amniotic ectoderm,as the first lineage that segregates from the epiblast upon implantation of the human embryo,functions as a signaling centerto trigger primitive streak development in the epiblast. Together,our research has developed a powerful synthetic embryologicalmodel and provided new understandings of previously inaccessible but critical embryogenic events in human development.展开更多
Aim was to gather relevant knowledge in evolution and development to find a rational explanation for the intricate and elaborate anatomy of the nose. According to classic embryology, the philtrum of the upper lip, nas...Aim was to gather relevant knowledge in evolution and development to find a rational explanation for the intricate and elaborate anatomy of the nose. According to classic embryology, the philtrum of the upper lip, nasal dorsum, septum and primary palate develop from the intermaxillary process, and the lateral walls of the nasal pyramid from the lateral nasal processes. The palatal shelves, which are outgrowths of the maxillary processes, form the secondary palate. The median nasal septum develops inferiorly from the roof of the nasal cavity. These valuable embryologic data do not explain the complex intricacy of the many anatomical structures comprising the nose. The evo-devo theory offers a rational explanation to this complex anatomy. Phylogenically, the nose develops as an olfactory organ in fish before becoming respiratory in tetrapods. During development, infolding of the olfactory placodes occurs, bringing the medial olfactory processes to form the septolateral cartilage while the lateral olfactory processes form the alar cartilages. The olfactory fascia units these cartilages to the olfactory mucosa, that stays separated from brain by the cartilaginous olfactory capsule(the ethmoid bone forerunner). Phylogenically, the respiratory nose develops between mouth and olfactory nose by rearrangement of the dermal bones of the secondary palate, which appears in early tetrapods. During development, the palatal shelves develop into the palatine processes of the maxillary bones, and with the vomer, palatine, pterygoid and inferior turbinate bones form the walls of the nasal cavity after regression of the transverse lamina. Applying the evolutionary developmental biology(evo-devo) discipline on our present knowledge of development, anatomy and physiology of the nose, significantly expands and places this knowledge in proper perspective. The clinicopathologies of nasal polyposis, for example, occurs specifically in the ethmoid labyrinth or, woodworker's adenocarcinomas, occurring only in the olfactory cleft can now be explained by employing the evo-devo approach. A full understanding of the evo-devo discipline, as it pertains to head and neck anatomy, has profound implications to the otolaryngologist empowering his skills and abilities, and ultimately translating in improving surgical outcomes and maximizing patient care.展开更多
Emil Theodor Kocher and Theodor Billroth pioneered the surgical management of thyroid disease. Their surgical techniques, knowledge of thyroid anatomy, embryology, histology, physiology, and antisepsis practices trans...Emil Theodor Kocher and Theodor Billroth pioneered the surgical management of thyroid disease. Their surgical techniques, knowledge of thyroid anatomy, embryology, histology, physiology, and antisepsis practices transitioned a life-threatening operation to one with acceptable morbidity. The modern head and neck surgeon should have a meticulous surgical technique, combined with a thorough understanding of thyroid embryology and anatomy that is central to the understanding and treatment of the different disease processes of the thyroid gland and the consequences of thyroid gland surgery. In this manuscript we will be examining thyroid gland embryology, anatomy, histology, and physiology that is essential to the practicing thyroid surgeon.展开更多
Tibetan medicine has a history of some 2,000 years. It is a shining pearl in the cultural treasure house of the great motherland. In the prolonged process of combating disease, the Tibetans came to understand the part...Tibetan medicine has a history of some 2,000 years. It is a shining pearl in the cultural treasure house of the great motherland. In the prolonged process of combating disease, the Tibetans came to understand the parts of animals and plants, and the mineral ores which have medical effect for certain kinds of pain and suffering. With the deepening of understanding of nature, and with the development of production, they started to study the human body.展开更多
Umbilicus is considered a mirror of the abdomen in newborns. Despite its importance, the umbilicus has been stated in literature and textbooks as discrete subjects with many body systems, such as the urinary, digestiv...Umbilicus is considered a mirror of the abdomen in newborns. Despite its importance, the umbilicus has been stated in literature and textbooks as discrete subjects with many body systems, such as the urinary, digestive, and cardiovascular ones. This article aimed to address the basic knowledge of the umbilicus in relation to clinical disorders under one integrated topic to aid physicians and surgeons in assessing newborns and infants. The umbilicus appears as early as the fourth week of fetal life when the folding of the embryonic plate occurs. The umbilicus appears initially as a primitive umbilical ring on the ventral aspect of the body. The primitive umbilicus contains the connecting stalk, umbilical vessels, vitelline duct and vessels, allantois, and loop of the intestine. Changes occur to form the definitive cord, which contains three umbilical vessels, namely, "one vein and two arteries," embedded in Wharton's jelly. After birth, the umbilical vessels inside the body obliterate and gradually form ligaments. Congenital disorders at the umbilicus include herniation, bleeding, and discharge of mucous, urine, or feces. Some of these disorders necessitate emergent surgical interference, whereas others may be managed conservatively. The umbilicus has many embryological remnants. Thus, the umbilicus is prone to various clinical disorders. Detecting these disorders as early as possible is essential to prevent or minimize possible complications.展开更多
Cloacal malformations are characterized by the confluence of the lower urinary tract,the female reproductive tract,and the rectum to create a common channel with a single opening on the perineum.The presence of a cloa...Cloacal malformations are characterized by the confluence of the lower urinary tract,the female reproductive tract,and the rectum to create a common channel with a single opening on the perineum.The presence of a cloaca is a normal phase of early human embryological development.Between the 4^th and 7^th weeks of gestation,the cloaca undergoes subdivision to form the hindgut and urogenital sinus.Failure of this process results in the congenital anomaly termed persistent cloaca(PC).The term urorectal septum malformation sequence(URSMS)is also used to describe this anomaly.The classic description of this process which is still cited in many standard textbooks dates from the 19th century.However,this has been increasingly called into question by the findings of studies using modern scientific methodology.Urogenital sinus anomalies are defined by the confluence of the urethra and vagina to form a common channel of varying length with a single perineal opening.In this condition,the anorectal canal opens separately on the perineum.The presence of a urogenital sinus represents a transient phase of the normal development of the lower genital tract in the female fetus.However,the form of urogenital sinus most commonly encountered in the developed world is a feature of disordered sexual differentiation and does not arise simply from the persistence of the anatomical structure which is a feature of normal fetal development.展开更多
The bilingual education integrated with PBL method is a new teaching model which gives consideration to knowledge,ability and professional foreign language.It reflects the international integration for the reform idea...The bilingual education integrated with PBL method is a new teaching model which gives consideration to knowledge,ability and professional foreign language.It reflects the international integration for the reform idea of medical education.The teaching practice indicated this model might be feasible in histology and embryology.It brings not only the classic medical knowledge but also the latest medical developments to the classroom.This new teaching model plays a role in the cultivation of the ability to solve problems independently and team spirit for students.It helps students to improve their knowledge,skills,level of foreign language and quality.展开更多
This research was carried out in the area of experimental embryology, which covers from animal fertilization to cloning. Two achievements in the field of reproductive bilogy have created major influence in the past 50...This research was carried out in the area of experimental embryology, which covers from animal fertilization to cloning. Two achievements in the field of reproductive bilogy have created major influence in the past 50 years, One is the discovery of sperm capacitation and the establishment of in vitro fertilization technology, and the other is the birth of somatic cell nuclear transfer animals. Although researches in reproductive bilogy have developed very quickly and a lot of literatures have been published. many basic theoretical questions are still remained illusive. This paper gives a brief description of our researches during the past decade.展开更多
The blood supply to the most of abdominal organs is provided by the branches of CT. The SMA supply caecum, ascends colon, all of the small bowels except the upper part of duodenum. Knowledge of variable anatomy of cel...The blood supply to the most of abdominal organs is provided by the branches of CT. The SMA supply caecum, ascends colon, all of the small bowels except the upper part of duodenum. Knowledge of variable anatomy of celiac axis and SMA may be useful in planning and executing radiological interventions such as celiacography and chemoembolization of hepatic and pancreatic tumors. In this study, the uncommon or low percentage cases of CT and SMA are presented in the light of clinical and embryological information. The celiac axises of a total of 30 adult corpses were examined. Dissections of abdominal region were performed in detail according to Cunningham’s manual. Angiographic images of 100 consecutive adult patients who underwent celiac MDCT angiography were evaluated. During autopsies, an incomplete celiac trunk or bifurcation of celiac trunk associated with the hepatomesenteric and gastrosplenic trunks (0.7%) and a celiacomesenteric trunk associated with high origin superior mesenteric artery and gastrosplenic trunk were detected (0.7%). During MDCT angiography, a case of total absence of celiac trunk associated with a hepatosplenomesenteric trunk (0.7%) and also a case of total absence of celiac trunk alone were observed (0.7%). The persistence or unusual development of ventral splanchnic arteries (VSAs) or ventral longitudinal anastomosis may result in variations or the unusual trunks related to celiac axis and SMA. The anomalous trunks of the CT may be result of either the persistence of some parts of the VSAs or ventral longitudinal anastomose that normally disappear or disappearance of parts that normally persist. The prevalence of unusual trunks of celiac axis and SMA in this study is quite low in literature. These abnormal vessels pose problems for surgeons and radiologists. Such vascular anomalies may cause clinical complications following surgical and radiological procedures such as resection of tumor of the pancreatic head, lymphadenectomy, coeliacography, aortic replacement with reimplantation of the trunk and coembolization of pancreatic and liver tumors.展开更多
During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rat...During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rates of the house cricket, Acheta domesticus. In particular, the experiment tested what colors of visible light provide the best incubation conditions to ensure cricket embryo viability. The concept was to use house cricket embryos to represent human embryos. Cricket embryos were chosen as their eggs have soft outer membrane casings and resemble human embryos during the first few days after fertilization. During the experiment, the adult crickets laid their eggs into one of six soil-filled boxes called substrates. Each substrate was placed into one of six storage containers filled with adult crickets and lit with a different colored visible light (red, yellow, green, blue, white, or no light). After two days of breeding, the egg-filled substrates were removed from the adult crickets and placed in another storage container of the same color light. After incubation under heat-emitting lamps and under one of six light colors, nymphs were counted after hatching to determine embryo viability. After three trials, the red light provided the significantly highest viability rate, with yellow and no light being comparable seconds. The green, blue, and white lights showed significantly lower viability rates than no visible light. My results raise the speculation that exposing fertilized mammal eggs to visible light colors might have the same effects during the in vitro fertilization process.展开更多
A cytological study on Apluda mutica L. revealed that this species was a facultative apomict with 60.74% of apomictic embryo sac formation. Its sexual reproduction exhibited the characteristics of polygonum_type embry...A cytological study on Apluda mutica L. revealed that this species was a facultative apomict with 60.74% of apomictic embryo sac formation. Its sexual reproduction exhibited the characteristics of polygonum_type embryo sac formation. After the 3 megaspores at the micropylar end had degenerated, leaving only the chalazal megaspore in the nucellus, a nucellar cell adjacent to the megaspore differentiated into an aposporous initial, which later developed into a panicum_type embryo sac. It was an aposporous 4_nucleate embryo sac without chromosome reduction and composed of an egg, a single synergid and a central cell with 2 polar nuclei. The chalazal megaspore degenerated before the onset of the division in the aposporous initial cell.展开更多
AIM To explore the relationship between the rules of Cx gene expression and cellular differentiation in organs of different embryonic stages. METHODS A series of Cx gene serving as molecular probes and the Northern...AIM To explore the relationship between the rules of Cx gene expression and cellular differentiation in organs of different embryonic stages. METHODS A series of Cx gene serving as molecular probes and the Northern blot hybrydization were employed to study the Cx gene expression. RESULTS Cx31, Cx31 1, Cx46 did not express while other Cx genes expressed in the embryonic liver and stomach. The Cx gene expression in the liver and stomach showed different state at different embryonic stages. The Cx gene expression had organic diversity. The expression of Cx26 gene was overlapping in the above organs. Cx43 did not express in the human liver after birth, but it expressed in the embryonic stage. CONCLUSION The expression state of Cx genes is concordant with cellular differentiation. It might be a key candidate gene to regulate some differentiational events associated with cellular differentiation, proliferation, and morphogenesis in the early embryo.展开更多
In. vitro pollination and its embryological studies were carried out in two japonica cultivars of rice (Oryza sativa L.), 'Chunjiang 05' and '95046'. N-6 basic medium supplemented with different exogen...In. vitro pollination and its embryological studies were carried out in two japonica cultivars of rice (Oryza sativa L.), 'Chunjiang 05' and '95046'. N-6 basic medium supplemented with different exogenous hormones was used for ovary culture after in vitro pollination. The main results were as follows: (1) both cultivars were induced to set kernels after in vitro pollination. The frequency of seedset was 52.1%, including 28.4% normal embryo development, 2.2% abnormal embryo development and 21.5% callus formation. (2) The processes of embryo and endosperm development after in vitro pollination were basically as normal as those in vivo, except there was some retardation in the first division of zygotes and primary endosperm nuclei as well as in their subsequent development. However, both kernels and plantlets could be produced finally. (3) A few abnormal embryos were observed, for instance, proembryos with elongated suspensor and vacuolated proembryos. (4) Two types of calli in the cultured ovaries appeared, namely, the compact callus and the fragile callus, which were able to differentiate into adventitious buds and roots.展开更多
BACKGROUND:The clinicopathological features of uncinate process pancreatic cancer(UPPC) are poorly described.Furthermore the anatomy of the uncinate process and its division during surgery are central to pancreaticodu...BACKGROUND:The clinicopathological features of uncinate process pancreatic cancer(UPPC) are poorly described.Furthermore the anatomy of the uncinate process and its division during surgery are central to pancreaticoduodenectomy for UPPC.We set out to describe the embryology and anatomy of the uncinate process and the clinicopathological features of UPPC.DATA SOURCES:All published case series of UPPC were reviewed and included in this review.RESULTS:The true incidence of UPPC is difficult to quantify,with the reported incidence ranging from 2.5% to 10.7% of pancreatic cancer.There are 5 published series of UPPC including 117 patients,72 males and 45 females,aged from 45-53 years to 61-84 years.The median survival was 5 or 5.5 months in 3 of the series,12.1 months in another based only on potentially resectable lesions and 17 months in another based only on resected cases.CONCLUSIONS:The number of reported series of UPPC is limited,with vague symptoms as the predominant presenting features of the disease.The prognosis is poor with synchronous venous resection demonstrating a survival advantage.展开更多
The arrangement of various biological structures should generally ensure the safety of crucial structures and increase their working efficiency; however, other principles governing the relative positions of structures...The arrangement of various biological structures should generally ensure the safety of crucial structures and increase their working efficiency; however, other principles governing the relative positions of structures in humans have not been reported. The present study therefore investigated other principles using nerves and their companion vessels in the human body as an example. Nerves and blood vessels usually travel together and in the most direct way towards their targets. Human embryology, histology, and gross anatomy suggest that there are many possible positions for these structures during development. However, for mechanical reasons, tougher or stronger structures should take priority. Nerves are tougher than most other structures, followed by arteries, veins, and lymphatic vessels. Nerves should therefore follow the most direct route, and be followed by the arteries, veins, and lymphatic vessels. This general principle should be applicable to all living things.展开更多
基金Supported by the Project for Undergraduate Education and Teaching Reform and Research at the District Level of Guangxi (2020JGB233)the Key Project for Undergraduate Education and Teaching Reform and Research of Guangxi University of Chinese Medicine (2018B07)。
文摘Taking construction of the online and offline integrated first-class undergraduate curriculum teaching modes of Histology and Embryology in Guangxi as an opportunity,under the guidance of student-centered teaching concept,efforts were made to innovate online and offline integrated teaching mode to overcome the shortcomings and dilemma of traditional Histology and Embryology teaching,with attention paid to the competence education in students including schematic knowledge,professional techniques,analytical thinking,and ideological and political theories,which would be of great significance for the cultivation of high-quality professionals specialized in traditional Chinese medicine.
文摘The development of plant embryology in China can be roughly divided into three stages: (1) the initial stage, (2) the stage of establishing plant embryology as a branch of plant sciences, and (3) the stage when plant embryology evolves into plant reproductive biology with its vigorous development. It is in the third stage that research work in this field in China has developed rapidly and many of the significant achievements obtained are described in more details in this review. Researches of experimental embryology are not included in this paper.
文摘Cleft lip with or without cleft palate(CP) is one of the most common congenital malformations. Ultrasonographers involved in the routine 20-wk ultrasound screening could encounter these malformations. The face and palate develop in a very characteristic way. For ultrasonographers involved in screening these patients it is crucial to have a thorough understanding of the embryology of the face. This could help them to make a more accurate diagnosis and save time during the ultrasound. Subsequently, the current postnatal classification will be discussed to facilitate the communication with the CP teams.
基金supported by the National Natural Science Foundation of China(No.31670344)the Fundamental Research Funds for the Central Universities(2572019DF08)
文摘Iris sangumea Dorm ex Horn. is a perennial cold-tolerant herbs of the Iris genus of Iridaceae, which has a well-formed, bright color and adaptability. Through understanding the fl ower bud differentiation, Sporogenesis, gametogenesis, fertilization and embryogenesis of I. sangumea, we developed fl owering regulation and control breeding. I. sangumea fl ower bud differentiation was observed in April for 21 days; in this stage, the early differentiation process was slow, temperature was more than 5 °C, if the temperature is shorter than this, most fl ower bud will have no differentiation, and turn to vegetative growth; later differentiation is faster and required temperature is from 5 to 8 °C and gradually rose to 10-12 °C. The temperature in April plays the defi nitely role in the number of bud differentiation. Three stamina contain tetrasporangiate anthers and a glandular tapetum. The anther wall is composed of four cell layers inclduding the epidermis, the endothecium, one middle layer and the secretory tapetum. The type of anther wall development the dicotyledonous type. After pollen maturation, the anther wall forms a double-layer containing only epidermis and endothecium. Simultaneous cytokinesis is of the continuous type during meiosis of microspore mother cell results in a zygomorphous or tetragonal tetrad. Mature pollen grains are two-celled. I. sangumea ’s stylar canal is hollow, open type style, and the gynoecium has three carpels. The ovaries have axial placentas. The ovule is anatropous, bitegmic and crassinucellate. The primary sporogenous cell differentiates directly as the megaspore. The megaspore tetrads are linear, T-shaped or juxtaposed. Generally, the fi rst of the tetrad megaspores at the chalaza becomes functional while the other three degenerate. A mature embryo sac with seven cells and eight nuclei embryo sac is of the polygonum type. For dichogamy, the male gametophyte matures about 2 days earlier than the female gametophyte. The pollen tube entered into the embryo sac for 22–24 h after pollination. The dormancy stage of fertilized ovules is 5-6 days, and the fusion of sperm and egg nucleus is of the premitotic type. The primary endosperm cell has shorter dormancy of 4-6 days, and endosperm formation is of the nuclear type.
基金supported by the National Science Foundation ( CMMI 1129611 and CBET 1149401)the National Institutes of Health ( R21 HL114011 and R21 EB017078)+3 种基金the American Heart Association ( 12SDG12180025)the Department of Mechanical Engineering at the University of Michigan,Ann ArborThe Lurie Nanofabrication Facility at the University of Michigan,a member of the National Nanotechnology Infrastructure Network ( NNIN)funded by the National Science Foundation,is acknowledged for support in microfabrication
文摘Early human embryonic development remains mysterious due to drastic species divergences between humans and othermammalian models and limited accessibility to human embryo samples. Recent studies from my laboratory and others haveshown that under suitable culture conditions human pluripotent stem cells ( hPSCs) can undergo intricate morphogenetic eventsand self-organize to form patterned human embryo-like structures in vitro. These synthetic human embryonic tissueshold great promises for advancing human embryology and reproductive medicine. In this talk,I will describe a hPSC-based,synthetic 3D model of human post-implantation development that recapitulates key developmental landmarks successively,including pro-amniotic cavity formation,amniotic ectoderm-epiblast patterning,primordial germ cell specification,and developmentof the primitive streak with controlled anteroposterior polarity ( Fig.1) . We further show that the amniotic ectoderm,as the first lineage that segregates from the epiblast upon implantation of the human embryo,functions as a signaling centerto trigger primitive streak development in the epiblast. Together,our research has developed a powerful synthetic embryologicalmodel and provided new understandings of previously inaccessible but critical embryogenic events in human development.
文摘Aim was to gather relevant knowledge in evolution and development to find a rational explanation for the intricate and elaborate anatomy of the nose. According to classic embryology, the philtrum of the upper lip, nasal dorsum, septum and primary palate develop from the intermaxillary process, and the lateral walls of the nasal pyramid from the lateral nasal processes. The palatal shelves, which are outgrowths of the maxillary processes, form the secondary palate. The median nasal septum develops inferiorly from the roof of the nasal cavity. These valuable embryologic data do not explain the complex intricacy of the many anatomical structures comprising the nose. The evo-devo theory offers a rational explanation to this complex anatomy. Phylogenically, the nose develops as an olfactory organ in fish before becoming respiratory in tetrapods. During development, infolding of the olfactory placodes occurs, bringing the medial olfactory processes to form the septolateral cartilage while the lateral olfactory processes form the alar cartilages. The olfactory fascia units these cartilages to the olfactory mucosa, that stays separated from brain by the cartilaginous olfactory capsule(the ethmoid bone forerunner). Phylogenically, the respiratory nose develops between mouth and olfactory nose by rearrangement of the dermal bones of the secondary palate, which appears in early tetrapods. During development, the palatal shelves develop into the palatine processes of the maxillary bones, and with the vomer, palatine, pterygoid and inferior turbinate bones form the walls of the nasal cavity after regression of the transverse lamina. Applying the evolutionary developmental biology(evo-devo) discipline on our present knowledge of development, anatomy and physiology of the nose, significantly expands and places this knowledge in proper perspective. The clinicopathologies of nasal polyposis, for example, occurs specifically in the ethmoid labyrinth or, woodworker's adenocarcinomas, occurring only in the olfactory cleft can now be explained by employing the evo-devo approach. A full understanding of the evo-devo discipline, as it pertains to head and neck anatomy, has profound implications to the otolaryngologist empowering his skills and abilities, and ultimately translating in improving surgical outcomes and maximizing patient care.
文摘Emil Theodor Kocher and Theodor Billroth pioneered the surgical management of thyroid disease. Their surgical techniques, knowledge of thyroid anatomy, embryology, histology, physiology, and antisepsis practices transitioned a life-threatening operation to one with acceptable morbidity. The modern head and neck surgeon should have a meticulous surgical technique, combined with a thorough understanding of thyroid embryology and anatomy that is central to the understanding and treatment of the different disease processes of the thyroid gland and the consequences of thyroid gland surgery. In this manuscript we will be examining thyroid gland embryology, anatomy, histology, and physiology that is essential to the practicing thyroid surgeon.
文摘Tibetan medicine has a history of some 2,000 years. It is a shining pearl in the cultural treasure house of the great motherland. In the prolonged process of combating disease, the Tibetans came to understand the parts of animals and plants, and the mineral ores which have medical effect for certain kinds of pain and suffering. With the deepening of understanding of nature, and with the development of production, they started to study the human body.
文摘Umbilicus is considered a mirror of the abdomen in newborns. Despite its importance, the umbilicus has been stated in literature and textbooks as discrete subjects with many body systems, such as the urinary, digestive, and cardiovascular ones. This article aimed to address the basic knowledge of the umbilicus in relation to clinical disorders under one integrated topic to aid physicians and surgeons in assessing newborns and infants. The umbilicus appears as early as the fourth week of fetal life when the folding of the embryonic plate occurs. The umbilicus appears initially as a primitive umbilical ring on the ventral aspect of the body. The primitive umbilicus contains the connecting stalk, umbilical vessels, vitelline duct and vessels, allantois, and loop of the intestine. Changes occur to form the definitive cord, which contains three umbilical vessels, namely, "one vein and two arteries," embedded in Wharton's jelly. After birth, the umbilical vessels inside the body obliterate and gradually form ligaments. Congenital disorders at the umbilicus include herniation, bleeding, and discharge of mucous, urine, or feces. Some of these disorders necessitate emergent surgical interference, whereas others may be managed conservatively. The umbilicus has many embryological remnants. Thus, the umbilicus is prone to various clinical disorders. Detecting these disorders as early as possible is essential to prevent or minimize possible complications.
文摘Cloacal malformations are characterized by the confluence of the lower urinary tract,the female reproductive tract,and the rectum to create a common channel with a single opening on the perineum.The presence of a cloaca is a normal phase of early human embryological development.Between the 4^th and 7^th weeks of gestation,the cloaca undergoes subdivision to form the hindgut and urogenital sinus.Failure of this process results in the congenital anomaly termed persistent cloaca(PC).The term urorectal septum malformation sequence(URSMS)is also used to describe this anomaly.The classic description of this process which is still cited in many standard textbooks dates from the 19th century.However,this has been increasingly called into question by the findings of studies using modern scientific methodology.Urogenital sinus anomalies are defined by the confluence of the urethra and vagina to form a common channel of varying length with a single perineal opening.In this condition,the anorectal canal opens separately on the perineum.The presence of a urogenital sinus represents a transient phase of the normal development of the lower genital tract in the female fetus.However,the form of urogenital sinus most commonly encountered in the developed world is a feature of disordered sexual differentiation and does not arise simply from the persistence of the anatomical structure which is a feature of normal fetal development.
基金financially supported by National Excellent Resource Sharing Course2013(2013-382)+1 种基金Education Ability Improvement Plan for Young Teachers in Shanghai Jiao Tong University2012(YB110803)
文摘The bilingual education integrated with PBL method is a new teaching model which gives consideration to knowledge,ability and professional foreign language.It reflects the international integration for the reform idea of medical education.The teaching practice indicated this model might be feasible in histology and embryology.It brings not only the classic medical knowledge but also the latest medical developments to the classroom.This new teaching model plays a role in the cultivation of the ability to solve problems independently and team spirit for students.It helps students to improve their knowledge,skills,level of foreign language and quality.
文摘This research was carried out in the area of experimental embryology, which covers from animal fertilization to cloning. Two achievements in the field of reproductive bilogy have created major influence in the past 50 years, One is the discovery of sperm capacitation and the establishment of in vitro fertilization technology, and the other is the birth of somatic cell nuclear transfer animals. Although researches in reproductive bilogy have developed very quickly and a lot of literatures have been published. many basic theoretical questions are still remained illusive. This paper gives a brief description of our researches during the past decade.
文摘The blood supply to the most of abdominal organs is provided by the branches of CT. The SMA supply caecum, ascends colon, all of the small bowels except the upper part of duodenum. Knowledge of variable anatomy of celiac axis and SMA may be useful in planning and executing radiological interventions such as celiacography and chemoembolization of hepatic and pancreatic tumors. In this study, the uncommon or low percentage cases of CT and SMA are presented in the light of clinical and embryological information. The celiac axises of a total of 30 adult corpses were examined. Dissections of abdominal region were performed in detail according to Cunningham’s manual. Angiographic images of 100 consecutive adult patients who underwent celiac MDCT angiography were evaluated. During autopsies, an incomplete celiac trunk or bifurcation of celiac trunk associated with the hepatomesenteric and gastrosplenic trunks (0.7%) and a celiacomesenteric trunk associated with high origin superior mesenteric artery and gastrosplenic trunk were detected (0.7%). During MDCT angiography, a case of total absence of celiac trunk associated with a hepatosplenomesenteric trunk (0.7%) and also a case of total absence of celiac trunk alone were observed (0.7%). The persistence or unusual development of ventral splanchnic arteries (VSAs) or ventral longitudinal anastomosis may result in variations or the unusual trunks related to celiac axis and SMA. The anomalous trunks of the CT may be result of either the persistence of some parts of the VSAs or ventral longitudinal anastomose that normally disappear or disappearance of parts that normally persist. The prevalence of unusual trunks of celiac axis and SMA in this study is quite low in literature. These abnormal vessels pose problems for surgeons and radiologists. Such vascular anomalies may cause clinical complications following surgical and radiological procedures such as resection of tumor of the pancreatic head, lymphadenectomy, coeliacography, aortic replacement with reimplantation of the trunk and coembolization of pancreatic and liver tumors.
文摘During in vitro fertilization, human embryos are incubated without light, and these conditions do not ensure embryo survival. This study explored whether environmental conditions can influence the embryo viability rates of the house cricket, Acheta domesticus. In particular, the experiment tested what colors of visible light provide the best incubation conditions to ensure cricket embryo viability. The concept was to use house cricket embryos to represent human embryos. Cricket embryos were chosen as their eggs have soft outer membrane casings and resemble human embryos during the first few days after fertilization. During the experiment, the adult crickets laid their eggs into one of six soil-filled boxes called substrates. Each substrate was placed into one of six storage containers filled with adult crickets and lit with a different colored visible light (red, yellow, green, blue, white, or no light). After two days of breeding, the egg-filled substrates were removed from the adult crickets and placed in another storage container of the same color light. After incubation under heat-emitting lamps and under one of six light colors, nymphs were counted after hatching to determine embryo viability. After three trials, the red light provided the significantly highest viability rate, with yellow and no light being comparable seconds. The green, blue, and white lights showed significantly lower viability rates than no visible light. My results raise the speculation that exposing fertilized mammal eggs to visible light colors might have the same effects during the in vitro fertilization process.
文摘A cytological study on Apluda mutica L. revealed that this species was a facultative apomict with 60.74% of apomictic embryo sac formation. Its sexual reproduction exhibited the characteristics of polygonum_type embryo sac formation. After the 3 megaspores at the micropylar end had degenerated, leaving only the chalazal megaspore in the nucellus, a nucellar cell adjacent to the megaspore differentiated into an aposporous initial, which later developed into a panicum_type embryo sac. It was an aposporous 4_nucleate embryo sac without chromosome reduction and composed of an egg, a single synergid and a central cell with 2 polar nuclei. The chalazal megaspore degenerated before the onset of the division in the aposporous initial cell.
文摘AIM To explore the relationship between the rules of Cx gene expression and cellular differentiation in organs of different embryonic stages. METHODS A series of Cx gene serving as molecular probes and the Northern blot hybrydization were employed to study the Cx gene expression. RESULTS Cx31, Cx31 1, Cx46 did not express while other Cx genes expressed in the embryonic liver and stomach. The Cx gene expression in the liver and stomach showed different state at different embryonic stages. The Cx gene expression had organic diversity. The expression of Cx26 gene was overlapping in the above organs. Cx43 did not express in the human liver after birth, but it expressed in the embryonic stage. CONCLUSION The expression state of Cx genes is concordant with cellular differentiation. It might be a key candidate gene to regulate some differentiational events associated with cellular differentiation, proliferation, and morphogenesis in the early embryo.
文摘In. vitro pollination and its embryological studies were carried out in two japonica cultivars of rice (Oryza sativa L.), 'Chunjiang 05' and '95046'. N-6 basic medium supplemented with different exogenous hormones was used for ovary culture after in vitro pollination. The main results were as follows: (1) both cultivars were induced to set kernels after in vitro pollination. The frequency of seedset was 52.1%, including 28.4% normal embryo development, 2.2% abnormal embryo development and 21.5% callus formation. (2) The processes of embryo and endosperm development after in vitro pollination were basically as normal as those in vivo, except there was some retardation in the first division of zygotes and primary endosperm nuclei as well as in their subsequent development. However, both kernels and plantlets could be produced finally. (3) A few abnormal embryos were observed, for instance, proembryos with elongated suspensor and vacuolated proembryos. (4) Two types of calli in the cultured ovaries appeared, namely, the compact callus and the fragile callus, which were able to differentiate into adventitious buds and roots.
文摘BACKGROUND:The clinicopathological features of uncinate process pancreatic cancer(UPPC) are poorly described.Furthermore the anatomy of the uncinate process and its division during surgery are central to pancreaticoduodenectomy for UPPC.We set out to describe the embryology and anatomy of the uncinate process and the clinicopathological features of UPPC.DATA SOURCES:All published case series of UPPC were reviewed and included in this review.RESULTS:The true incidence of UPPC is difficult to quantify,with the reported incidence ranging from 2.5% to 10.7% of pancreatic cancer.There are 5 published series of UPPC including 117 patients,72 males and 45 females,aged from 45-53 years to 61-84 years.The median survival was 5 or 5.5 months in 3 of the series,12.1 months in another based only on potentially resectable lesions and 17 months in another based only on resected cases.CONCLUSIONS:The number of reported series of UPPC is limited,with vague symptoms as the predominant presenting features of the disease.The prognosis is poor with synchronous venous resection demonstrating a survival advantage.
文摘The arrangement of various biological structures should generally ensure the safety of crucial structures and increase their working efficiency; however, other principles governing the relative positions of structures in humans have not been reported. The present study therefore investigated other principles using nerves and their companion vessels in the human body as an example. Nerves and blood vessels usually travel together and in the most direct way towards their targets. Human embryology, histology, and gross anatomy suggest that there are many possible positions for these structures during development. However, for mechanical reasons, tougher or stronger structures should take priority. Nerves are tougher than most other structures, followed by arteries, veins, and lymphatic vessels. Nerves should therefore follow the most direct route, and be followed by the arteries, veins, and lymphatic vessels. This general principle should be applicable to all living things.