Melatonin promotes the development of the secondary hair follicles by regulating circMPP5

Background The quality and yield of cashmere fibre are closely related to the differentiation and development of secondary hair follicles in the skin of cashmere goats.The higher the density of secondary hair follicles,the higher the quality and yield of cashmere from the fleece.Development of secondary hair follicles commences in the embryonic stage of life and is completed 6 months after birth.Preliminary experimental results from our laboratory showed that melatonin(MT)treatment of goat kids after their birth could increase the density of secondary hair follicles and,thus,improve the subsequent yield and quality of cashmere.These changes in the secondary hair follicles resulted from increases in levels of antioxidant and expression of anti-apoptotic protein,and from a reduction in apoptosis.The present study was conducted to explore the molecular mechanism of MT-induced secondary hair follicle differentiation and development by using whole-genome analysis.Results MT had no adverse effect on the growth performance of cashmere kids but significantly improved the character of the secondary hair follicles and the quality of cashmere,and this dominant effect continued to the second year.Melatonin promotes the proliferation of secondary hair follicle cells at an early age.The formation of secondary hair follicles in the MT group was earlier than that in the control group in the second year.The genome-wide data results involved KEGG analysis of 1044 DEmRNAs,91 DElncRNAs,1054 DEcircRNAs,and 61 DEmiRNAs which revealed that the mitogen-activated protein kinase(MAPK)signaling pathway is involved in the development of secondary hair follicles,with key genes(FGF2,FGF21,FGFR3,MAPK3(ERK1))being up-regulated and expressed.We also found that the circMPP5 could sponged miR-211 and regulate the expression of MAPK3.Conclusions We conclude that MT achieves its effects by regulating the MAPK pathway through the circMPP5 sponged the miR-211,regulating the expression of MAPK3,to induce the differentiation and proliferation of secondary hair follicle cells.In addition there is up-regulation of expression of the anti-apoptotic protein causing reduced apoptosis of hair follicle cells.Collectively,these events increase the numbers of secondary hair follicles,thus improving the production of cashmere from these goats.

Effects of N-acetylcysteine on growth,viability and reactive oxygen species levels in small antral follicles cultured in vitro

Objective:To investigate the effects of different concentrations of N-acetylcysteine on follicular growth and morphology,as well as on viability,levels of reactive oxygen species(ROS)and meiotic progression of oocytes from in vitro cultured bovine early antral follicles.Methods:Isolated early antral follicles(about 500μm)were cultured in TCM-199+alone or supplemented with 1.0,5.0 or 25.0 mM N-acetylcysteine at 38.5℃with 5%CO_(2) for 8 days.Follicle diameters were evaluated at day 0,4 and 8 of culture.At the end of culture,the levels of ROS,chromatin configuration and viability(calcein-AM and ethidium homodimer-1 staining)were investigated in the cumulus-oocyte complexes.Comparisons of follicle diameters between treatments were performed.Data on percentages of morphologically normal follicles,growth rates and chromatin configuration in different treatments were compared.Results:An increase in follicular diameters after culture in all treatments was observed,except for follicles cultured with 25.0 mM N-acetylcysteine.Fluorescence microscopy showed that oocytes cultured in all treatments were stained positively with calcein AM,and that 5.0 mM N-acetylcysteine reduced fluorescence for ethidium homodimer-1.Intracellular levels of ROS in oocytes from follicles cultured with 1.0 mM N-acetylcysteine showed a significant reduction compared to other treatments.The presence of N-acetylcysteine in culture medium did not influence the rates of oocyte at the germinal vesicle stage.Conclusions:N-acetylcysteine at concentrations of 1.0 and 5.0 mM reduces ROS levels and staining for ethidium homodimer-1 in in vitro cultured follicles,respectively,while 25.0 mM N-acetylcysteine decreases follicular growth and the percentages of continuously growing follicles.

Recent progress in hair follicle stem cell markers and their regulatory roles

Hair follicle stem cells(HFSCs)in the bulge are a multipotent adult stem cell population.They can periodically give rise to new HFs and even regenerate the epidermis and sebaceous glands during wound healing.An increasing number of biomarkers have been used to isolate,label,and trace HFSCs in recent years.Considering more detailed data from single-cell transcriptomics technology,we mainly focus on the important HFSC molecular markers and their regulatory roles in this review.

Follicle-stimulating hormone is expressed in ovarian follicles of chickens and promotes ovarian granulosa cell proliferation

Follicle-stimulating hormone(FSH),an important hypothalamic-pituitary-gonadal axis(HPG)hormone,is secreted by the pituitary gland.This study confirms that FSH is expressed in chicken follicles at different stages,and positive FSHβ mRNA signals were stronger(P<0.05)in granulosa cells than in oocytes.The 369 bp coding sequence of FSHβ in ovaries is 100%identical to that in the pituitary gland.The experiment in vitro revealed that the ovary possessed FSH secretory capacity.Further,FSHβ mRNA was significantly upregulated(P<0.05)in follicles and significantly higher(P<0.05)than that in the pituitary gland by approximately 2–23 times with the development.The number of granulosa cells decreased significantly(P<0.05)in the cells with siRNA treatment,confirming that the ovarian FSH could promote granulosa cell proliferation.This view was supported by cell cycle analysis and CCND2 and CCNE2 expression.Further research indicated that no difference(P>0.05)was observed between the number of granulosa cells treated with FSHβ siRNA and in exogenous FSH.However,the number of granulosa cells without FSHβ siRNA transfection was significantly higher(P<0.05)for exogenous FSH.This finding suggests that the proliferative effect of exogenous FSH on ovarian granulosa cells depend on endogenous FSH.This study demonstrated that the FSH gene was expressed in chicken follicles and promoted ovarian granulosa cell proliferation,which enriched the theory on HPG axis.

Cyclosporine A stimulated hair growth from mouse vibrissae follicles in an organ culture model

Hypertrichosis is one of the most common side effects of systemic cyclosporine A therapy.It has been previously shown that cyclosporine A induces anagen and inhibits catagen development in mice.In the present study,to explore the mechanisms of cyclosporine A,we investigated the effects of cyclosporine A on hair shaft elongation,hair follicle cell proliferation,apoptosis,and mRNA expression of selected growth factors using an organ culture model of mouse vibrissae.In this model,cyclosporine A stimulated hair growth of normal mouse vibrissae follicles by inhibiting catagen-like development and promoting matrix cell proliferation.In addition,cyclosporine A caused an increase in the expression of vascular endothelial growth factor（VEGF）,hepatocyte growth factor（HGF）,and nerve growth factor（NGF）,and inhibited follistatin expression.Our findings provide an explanation for the clinically observed effects of cyclosporine A on hair growth.The mouse vibrissae organ culture offers an attractive model for identifying factors involved in the modulation of hair growth.

Impact of Luteinized Unruptured Follicles on Endometrial Receptivity

This study examined the impact of luteinized unruptured follicle （LUF） on endometrial receptivity. The menstrual cycle of 17 LUF patients （LUF group） and 13 ovulatory women （control group） was monitored by measuring LH level in urine and by ultrasonic examination. An endometrial biopsy at the sixth to tenth day after LH surge was taken in all the patients. The expressions of endometrial ER, PR and integrin ανβ3 were immunohistochemically determined. At the same time, the serum levels of E2 and P were detected by chemiluminescence. The results exhibited that （1） The mean serum P level in LUF group （7.32±2.56 ng/mL） was significantly lower than that in control group （11.17±3.17 ng/mL） （P0.01）. But there was no significant difference in the mean serum E2 levels between LUF group （179.35±81.60 pg/mL） and the control group （198.58±75.23 pg/mL） （P0.05）; （2） The mean expression intensities of ER, PR in endometrium of LUF group （183.86±2.43, 167.94±3.04） were significantly higher than those in control group （109.35±6.31, 105.98±4.07） （P0.01）; （3） The mean expression intensities of integrin ανβ3 in endomtrium of LUF patients （114.90±11.38） were significantly lower than those in control group （191.34±1.82） （P0.01）; （4） The change profile of integrin ανβ3 expression in the endometrium of LUF patients was in positive relation with serum P level （r=0.77, P0.01）, but bore no significant relationship with serum E2 level （r=0.01, P0.05）. It was concluded that the depression of serum P levels in LUF patients was closely related to the failure of the down-regulation of ER and PR, and the low expressions of integrin ανβ3 also suggested that the delayed implantation and the impaired endometrial receptivity had impact on embryonic implantation.

Study on Development of Northeast China Fine-fleece Sheep Fetal Follicles

Different gestational age fetal follicles of Northeast China Fine-fleece Sheep were histologically studied. The results showed that boundaries between medulla and cortex was ambiguous at the eighth week and became obvious at the twelfth week. Primordial follicles could be found in 8-week fetal ovaries and some follicle cells became irregular cuboid in 12-week, but primary follicles could be found until 16-week. There was significant difference between 8-week and 12-week follicles in size (P < 0.01), most mitochondria were round, some diamond, irregular and juvenile ones could be found with the development of oocytes. Some of oocytes degenerated in each stage of development. The diameter of primary oocytes, primordial follicles and primordial follicular oocytes were larger in 12-16 weeks fetal ovaries than other times.

Methionine Levels in the Diet for Pregnant Female Rabbits Affects Hair Follicles Development of Baby Rabbits

[ Objective] This experiment was conducted to study methionine level in diet for prepnant famale rabbits on the development of hair follicles of baby rabbits. [ Method] Fifty-four Angora female rabbits with similar body weight, parities and historicaly hair yield were randomly assigned to three groups with eighteen replicates in each group and one rabbit per replicate. Rabbits during pregnancy were fed diets with 0.5!%, 0.71% and 0.91% methionine, respectively. Hair follicle density and diameter in the back skin were determined at 18-day fetus. 26-day fetus, newborn and 2- month-old,and hair fiber diameter at 2-month-old was also determined. [ Result] The results showed as follows： （1） hair follicle density and diameter at each stage,coarse hair fiber diameter at 2-month. old showed a tendency of increasing with dietary methionine level（ P 〉0.05）, fine hair diameter in 0.91% group was significantly larger than that in 0.51% group at 2-month-old （ P 〈 0.05）. （2） With the development of baby rabbit,the ratio of secondary follicle and primary follicle increased gradually, at newborn of rabbits in group 0.51%, 0.71% and 0.91%were 5.84, 5.56 and 5.81, respectively, and at 2-month-old were 8.47, 7.97 and 8.03, respectively. （3） Baby rabbits in group 0.51%, 0.71% and 0.91% gained increases of primary follicle diameter by 0.58, 0.57 and 0.61pm/d from 26-day fetus to birth, and 0.11,0.11 and 0.12 prn/d from birth to 2-month-old, re- spectively; they also gained increases on secondary follicle diameter by 0.0018,0. 012 and 0. 011prn/d from birth to 2-months-old, respectively. [ Conclusion] These results indicate that increase of methionine level in diet for female rabbits during pregnancy is a stimulation factor for the development of hair follicle of baby rabbits, and can improve their hair fiber diameter.

Qualitative and quantitative analysis of goat ovaries, follicles and oocytes in view of in vitro production of embryos

Goat ovaries were collected from the slaughterhouse and categorized as right, left, corpus luteum (CL)-present and -absent group and evaluated on the basis of weight (g), length (cm), width (cm), number of follicles, follicles aspirated and number and state of cumulus-oocyte-complexes (COCs). Comparatively higher weight [(0.66±0.02) vs (0.64±0.02) g], length [(1.17±0.02) vs (1.11±0.02) cm] and width [(0.77±0.02) vs (0.74±0.02) cm] were found in right ovaries than those of left. On the other hand significantly (P<0.05) higher weight [(0.71±0.03) vs (0.64±0.01) g] and width [(0.76±0.03) vs (0.75±0.01) cm] were found in CL-present group than those of CL-absent group of ovaries. The left ovaries contained comparatively higher number of normal COCs [(1.06±0.09) per ovary] than right ovaries [(1.03±0.10) per ovary] and the similar trend was found in total number of fol-licles [(4.51±0.25) vs (4.30±0.23) per ovary] and follicles aspirated [(2.55±0.14) vs (2.52±0.12) per ovary]. But the total COCs per ovary was almost similar in both ovaries [right and left: (1.85±0.12) and (1.85±0.11) per ovary, respectively]. Higher number of total COCs [(1.87±0.09) vs (1.76±0.16) per ovary], total number of follicles [(4.45±0.19) vs (4.16±0.37) per ovary], follicles aspirated [(2.55±0.10) vs (2.48±0.21) per ovary] and normal COCs [(1.12±0.07) vs (0.76±0.14) per ovary] were found in CL-absent group than those of CL-present group of ovaries.

Effects of Nitric Oxide on the Growth and Development of Porcine Preantral Follicles Cultured in Vitro

In order to investigate the effects of nitric oxide(NO) on the growth and development of porcine preantral follicles,we treated the follicles with different concentrations of sodium nitroprusside(SNP,0, 0.001,0.01,0.1 and 1 mmol/L),a NO donor.The results showed that the follicle diameter increased during in vitro culture,but there were no significant differences between the treatments(P】0.05);the survival rate in the 1 mmol/L SNP group was significantly lower than that in the 1μmol/L SNP group(61.61% vs 81.52%,P【0.05),but no significant differences were found between other treatments(P】0.05);the rate of antrum formation in the 1μmol/L SNP group peaked at 50%on day 4,and the rate in the 1μmol/L SNP group on day 6 was higher than that in the 0.01 mmol/L SNP group;in addition,the rate of antrum formation in the 1μmol/L SNP group was significantly higher than that in the 0.1 and 1 mmol/L SNP groups (Day 6:73.07%vs 50%,47.62%,P【0.05).After 6 days of culture,the proportion of normal oocytes in the1 mmol/L SNP group was significantly lower than that in the 1μmol/L SNP group(71.21%vs 48.18%, P【0.05),with no significant differences between other treatments(P】0.05).The recovery rate of cumulus cells oocyte complexes(COCs) in the 1μmol/L SNP group was significantly higher than that in the controls and all other treatments(37.27%vs 22.88%,25.59%,20.74%and 19.39%,P【0.05).The results indicate that during the in vitro culture of porcine preantral follicles,low concentration of NO released from SNP improves growth and development of oocytes and follicular antrum formation while high levels of NO are toxic to follicular survival.

In-vitro Maturation of Immature Oocytes from Preantral Follicles in Prepuberal Mice

Objective To observe the morphological changes in in vitro growth of preantral follicle isolated from prepuberal mice and to assess impacts of gonadotropin （Gn）, insulin transferrin selenium （ITS） and epidermal growth factor （EGF） on their development. Methods Early preantral mice follicles （90-130μm diameter） were mechanical isolated and selected from 2 weeks＇ old mice and then cultured in alpha-minimal essential medium （α-MEM） with or without Gn, ITS and EGF. The preantral follicles were cultured singly in 20 miovliters droplets for up to 14 d. The medium was replaced and the .follicles were observed everyday. Granulosa cells （GC） prolification, antrum formation and oocyte maturation were recorded. Results The medium with Gn supported preantral follicle culture in vitro, during which they retained a three-dimensional structure, maintained oocytes viability and increased in diameter and number of somatic cells＇. Preantral follicles cultured in Gn medium grew obviously, while those without Gn grew slowly and after 6 d＇s culture began to shrink and blacken. Significant increase in survival rate and maturation rate of oocytes was observed in Gn group （P〈0.01）, with 92.9% survived and 28.7%formed an antrum. Further supplementation of the Gn medium with ITS and rLH, resulted in the significant increase in survival and maturation of preantral follicle （P〈0.05） Conclusions α-MEM can be the medium for in vitro culture （IVC） of preantral follicles, but need to be added with rLH/rFSH, rHCG/rEGF to facilitate thecal cell attachment, GC proliferation and oocyte maturation.

Dynamic expression of Wnt signaling molecules and stem-cell marker CK15 in the growth cycle of rat whisker hair follicles

Objective To investigate the distribution and dynamic changes of both Wnt signaling molecules and CK15 throughoutthe three phases of the follicular cycle,and to explore the relationship between Wnt/β-catenin signaling and CK15 in rat whisker hair follicle(HF)growth cycles.Methods Hematoxylin-Eosin(HE)and immunofluorescence stains were used to characterize the expression patterns,including sites and levels of some representative proteins of both canonical and non-canonical Wnt signaling molecules,as well as HF epithelial stem cell marker CK15.Results The expression patterns of bothβ-catenin and Wnt5a were correlated with that of CK15.CK15 was only expressed in anagen.In catagen,β-catenin showed a massive depletion while Wnt5a noticeably increased.In telogen,high level expression ofβ-catenin and low level of Wnt5a were detected.Wnt10b and TCF3 were detected during the entire HF growth cycle.Conclusion These results suggest that Wnt5a is associated with the transition of anagen-catagen phase,accompanied by broad deletion ofβ-catenin and loss of CK15.WntlOb is important for the maintenance of HF activity and is related to the telogenanagen transition.

Stochastic Modelling of Relative Light Sensitivity of Hair Follicles

Relative light sensitivity (RLS) of HFs was mathematically described as the ratio of two stochastic variables presenting the durations of light sensitive and light insensitive sub-phases of the cycle according to a new theory of HF light sensitivity formulated in our previous article (Kruglikov, Am J Cosm Surg, 2012, 29:266 - 272). RLS gives possibility to rank the HFs from different body regions according to their light sensitivities. Application of proposed method for estimation of the light sensitivity of scalp hairs predicts remarkable difference in light sensitivities of HFs in alopecic and non-alopecic patients.

Three Dimensional <i>In Vitro</i>Culture of Murine Secondary Follicles in a Defined Synthetic Matrix

Ovarian follicle growth in three dimensional (3D) matrices in vitro has limitations: a) matrices don’t expand as follicles grow, b) requirements for enzyme-mediated retrieval, and c) animal-derived components prevent clinical application. Therefore, we evaluated N-Isopropylacrylamide (SFX-1), a novel synthetic 3D culture matrix, for follicle culture. Groups of three murine secondary follicles were encapsulated in 50 μL of DMEM/F12-1%ITS-10%FCS (DMEM/F12) or SFX-1 (3:2 v/v DMEM/F12) or Matrigel (1:1 DMEM/F12) and cultured for 48 h. Matrigel contains growth factors but SFX-1 has no animal-derived factors. Each culture condition was examined in 6 wells containing 18 follicles, in four replicate experiments (n = 4). Photomicrographs were used to determine follicle diameters and morphological integrity. Follicles were Live-Dead (LD) stained or disaggregated to generate cells for viability assessment using Trypan Blue (TB). Estradiol, progesterone and anti-mullerian hormone (AMH) in conditioned media were measured using Enzyme-linked Immunoassay. All culture conditions supported similar increases in follicle diameter. DMEM/F12 did not maintain morphological integrity which prevented follicle retrieval after 48 h;25% were retrieved from DMEM/F12, but 44% and 41% follicles were retrieved from SFX-1 and Matrigel respectively. Follicles retrieved from Matrigel could not be disaggregated, which prevented TB viability assessment. LD estimations of viable cells/follicle were lower than TB, but culture conditions had no effect on viability;SFX-1 64% ± 8% and DMEM/F12 69% ± 9%. SFX-1 and Matrigel supported similar levels of progesterone synthesis, only Matrigel supported estrogen synthesis, but none of the culture conditions supported AMH production. SFX-1 was not cytotoxic and was comparable to Matrigel. Further development of SFX-1 for use with human follicles is supported.

Identification of Bulge Stem Cells in Mouse and Human Hair Follicles

The skin contains various populaions of stem cells, but its characterization has been hampered by lack of markers and unclear location. The hair follicle has a niche for stem cells called a “bulge” which acts as a reservoir of multipotent stem cells. In the study reported here, an immunohistochemical and immunofluorescence analysis was performed on mouse and human tissues in order to determine the possible presence of stem cells of hair follicle through cytokeratin 15 (CK15), CD34, and CD200 markers identified as crucial to the stem cells and to identify the bulge region. Mouse (n = 7) and human (n = 7) skin samples were used. The expression of proteins was determined by the indirect immunoperoxidase technique and a secondary antibody bound to a fluorochrome. The specificity of staining was evaluated by negative controls. The results revealed that the stem cells associated with CD34 and CD200 antibodies were differentially expressed in the interfollicular epidermis, sebaceous glands, and bulge region, indicating that, in mice, CD34 and, in humans, CD200 are more specific than CK15 in detecting bulge cells. It also suggests that CD34 is specific for mouse bulge cells, while CD200 might have specificity for progenitor cells and partially differentiated cells in humans.

Evaluation of glucose metabolism in women with multiple ovarian follicles

Objective ：To investigate glucose metabolism in women with multiple ovarian follicles （MOF） and explore the relationship between glucose metabolism, insulin resistance and body weight. Methods：We evaluated 46 women with MFO and 30 normal women as controls. All the subjects were given 75g of glucose orally in order to perform the oral glucose tolerance test （OGTT） and insulin releasing test （IRT）, and they were also evaluated for insulin resistance using the insulin resistance index with homeostatic model assessment （HOMA）. Results：The occurrence of impaired glucose tolerance in women with MOF was 10.87%, which was significantly higher than that in the control group （3.33% ,P 〈 0.05）. The rate of insulin resistance was 30.43% in the study group as compared to 10.00% in the control group. The results showed that there was significant difference between the two groups（P 〈 0.05）. The levels of FSH,LH,PRL,E2,T and P between the two groups had no significant difference （P 〉 0.05）. BMI in women with impaired glucose tolerance was correlated positively to insulin resistance （r = 0.567, P 〈 0.05）. Conclusion：Abnormal glucose metabolism was observed in women with unitary multiple ovarian follicles, and this could be attributed to obesity and insulin resistance. Women with MOF and associated obesity should be subjected to OGTT so that their glucose levels can be monitored as a preventive measure.

A modified protocol for <i>in vitro</i>maturation of mouse oocytes from secondary preantral follicles

A 2-step culture system was designed and tested for the in vitro maturation efficiency of oocytes from pre-puberty preantral follicles of FVB/N inbred mice. The following modifications were made: 1) The concentration of ITS was reduced by half in the basal MIF medium to minimize uncoordinated growth between oocyte and GC cells;2) Heterogeneous preantral follicles were cultured in groups of 3 - 5 follicles in hanging drops of medium with reduced concentration of ITS for six days to induction follicular aggregation. This hanging drop method mimics a 3-D IVM culture system at the early stage of cultivation in which the sphere structure of each follicle is well maintained. It also enables follicles in each aggregate to communicate with each other, synchronize their growth, and thus prevent immature follicular rupture. 3) Medium was further supplemented with retinoic acid to enhance developmental capacity of meiotically arrested oocytes. After a 14-day culture in vitro, ~37% of the collected inbred preantral follicles completed nuclear maturation. Approximately 94% of the mature oocytes tested were able to be fertilized;and 77% of them developed into healthy embryos. These results demonstrate that our IVM system is reliable to produce a satisfactory number of high quality oocytes. In addition, multiple cytoplasmic parameters, including gene expression of key regulators, chromosome/spindle organization, mitochondrial proliferation and distribution, and total ATP content were explored to characterize the supportive and limiting components of our IVM system so that the culture system can be further optimized.

Clinical application prospects and transformation value of dental follicle stem cells in oral and neurological diseases

Since dental pulp stem cells(DPSCs)were first reported,six types of dental SCs(DSCs)have been isolated and identified.DSCs originating from the craniofacial neural crest exhibit dental-like tissue differentiation potential and neuroectodermal features.As a member of DSCs,dental follicle SCs(DFSCs)are the only cell type obtained at the early developing stage of the tooth prior to eruption.Dental follicle tissue has the distinct advantage of large tissue volume compared with other dental tissues,which is a prerequisite for obtaining a sufficient number of cells to meet the needs of clinical applications.Furthermore,DFSCs exhibit a significantly higher cell proliferation rate,higher colony-formation capacity,and more primitive and better anti-inflammatory effects than other DSCs.In this respect,DFSCs have the potential to be of great clinical significance and translational value in oral and neurological diseases,with natural advantages based on their origin.Lastly,cryopreservation preserves the biological properties of DFSCs and enables them to be used as off-shelf products for clinical applications.This review summarizes and comments on the properties,application potential,and clinical transformation value of DFSCs,thereby inspiring novel perspectives in the future treatment of oral and neurological diseases.

Isolated lymphoid follicles in colon: Switch points between inflammation and colorectal cancer?

Gut-associated lymphoid tissue is supposed to play a central role in both the organization of colonic repair mechanisms and colorectal carcinogenesis. In inflammatory conditions, the number, diameter and density of isolated lymphoid follicles (ILFs) increases. They are not only involved in immune surveillance, but their presence is also indispensable in normal mucosal regeneration of the colon. In carcinogenesis, ILFs may play a dual role. On the one hand they may support tumor growth and the metastatic process by vascular endothelial growth factor receptor signaling and producing a specific cytokine and cellular milieu, but on the other hand their presence is sometimes associated with a better prognosis. The relation of ILFs to bone marrow derived stem cells, follicular dendritic cells, subepithelial myofibroblasts or crypt formation, which are all involved in mucosal repair and carcinogenesis, has not been directly studied. Data about the putative organizer role of ILFs is scattered in scientific literature.

Incidence and localization of lymphoid follicles in early colorectal neoplasms

AIM: To investigate the incidence and localizations of lymphoid follicles (LFs) in early colorectal neoplasms in human beings.METHODS: From July 1992 to September 1999, a total of 1 324 early colorectal neoplasms were removed endoscopically or surgically at our hospital; 1 031 (77.9%)were available for analysis in this study. Localization of LFs was defined histologically: as submucosal LFs, if located under the muscularis mucosa; and as intramucosal LFs, if located across or oyer the muscularis mucosa.RESULTS: Histologically, the materials included 903intramucosal neoplasms and 128 submucosal cancers.Overall incidence of LFs was 27.2% (280/1 031). The incidence of LFs was significantly higher in females (33.6% vs 24.9%,P=0.0064), the right-sided colon (32.2% vs 25.6%, P=0.0403) and in flat or depressed type lesions (34.6% vs 25.2%, P＜0.0001)as compared to males, left-sided colon and protruding type lesions, respectively. The incidences of intramucosal neoplasms and submucosal cancers were 24.3% and 43.8%, respectively (P＜0.0001). Localizations of LFs (intramucosal LF/submucosal LF) in depressed, flat,and protruding types were 1/24, 14/36, and 131/74,respectively.CONCLUSION: The incidence of LFs in early human colorectal neoplasms significantly differs by gender,location, macroscopic type, and histology. Moreover,localization significantly differs by macroscopic type.