Development of Plant Embryology in China

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.

Accurate diagnosis of prenatal cleft lip/palate by understanding the embryology

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.

Embryology of Iris sanguinea Donn ex Horn. and its systematic relationship

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.

Synthetic Human Embryo-Like Structure: A New Paradigm for Human Embryology

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.

Online and Offline Integrated Teaching of Histology and Embryology Based on Concept of "Golden Course"

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.

Embryology of the nose:The evo-devo concept

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.

Comprehensive Review of Thyroid Embryology,Anatomy,Histology,and Physiology for Surgeons

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.

Contribution of Tibetan Medicine To Embryology

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.

Anatomy and embryology of umbilicus in newborns： a review and clinical correlations

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.

The embryology of persistent cloaca and urogenital sinus malformations

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.

Exploratory practice of bilingual education integrated with the PBL model in the teaching of histology and embryology

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.

Experimental Embryology of Sexual and Asexual Reproduction in Mammals

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.

Embryological Studies on Facultative Apomixis in Apluda mutica (Gramineae)

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.

Expression of Cx genes in liver and stomach of different embryonic stages

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.

Embryological Studies on In Vitro Pollination in Rice

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.

Cancer of the uncinate process of the pancreas:surgical anatomy and clinicopathological features

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.

Principle of relative positioning of structures in the human body

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.

Does cranial-medial mixed dominant approach have a unique advantage for laparoscopic right hemicolectomy with complete mesocolic excision?

BACKGROUND Complete mesocolic excision(CME)with central vascular ligation(CVL)was proposed by Hohenberger in 2009.The CME principle has gradually become the technical standard for colon cancer surgery.How to achieve CME with CVL in laparoscopic right hemicolectomy(LRH)is controversial,and a unified standard approach is not yet available.In recent years,the authors’team has integrated the theory of membrane anatomy,tried to combine the cephalic approach with the classic medial approach(MA)for technical optimization,and proposed a cranialmedial mixed dominant approach(CMA).AIM To explore the feasibility of operational approaches for LRH with CME.METHODS In this retrospective cohort study,the clinical data of 57 patients with right-sided colon cancer(TNM stage I,II,or III)who underwent LRH with CME from January 2016 to June 2020 were collected and summarized.There were 31 patients in the traditional MA group and 26 in the CMA group.RESULTS There were no significant differences in baseline data between the two groups.The operation was shorter and the number of lymph nodes dissected was higher in the CMA group than in the MA group,but there was no significant difference in the number of positive lymph nodes,intraoperative blood loss,postoperative exhaust time,feeding time,postoperative hospital stay or postoperative complication incidence.CONCLUSION Our study shows that the CMA is a safe and feasible procedure for LRH with CME and has a unique advantage.

Klippel-feil:A syndrome in the occipital-cervical spine field and its dentofacial manifestations

Klippel-Feil syndrome(KFS) is defined by congenital cervical vertebral spine fusion and is seen with a wide spectrum of dental manifestations and craniofacial profiles. Previous studies on lateral cephalograms have documented an association between fusion of the cervicalvertebrae and deviations in the craniofacial profile in non-syndromic patients with severe malocclusion. To our knowledge, no previous studies have described the craniofacial profile including the cranial base of KFS patients on lateral cephalograms. Therefore KFS and its craniofacial and dental manifestations were described according to existing literature and additionally the craniofacial profile and cranial base was analysed on lateral cephalograms of two patients with KFS. According to the literature the dental manifestations of KFS-patients included oligodontia, overjet, cross bite, open bite and deep bite. The craniofacial profile was clinically described as reduced lower facial height, midfacial hypoplasia, and mandibular prognathia. The analyses of the two lateral cephalograms showed increased mandibular inclination, increased vertical jaw-relationship, increased jaw angle and maxillary retrognathia. The cranial base was normal in both cases. The sagittal jaw relationship and mandibular prognathia varied between the two cases. The literature review and the analyses of the two lateral cephalograms have shown that deviations in the occipital and cervical spine field as KFS were associated with deviations in the teeth and craniofacial profile.