Detection and Analysis of Candida Albicans Enolase Antigen-Specific T Cells in Heathy Individuals by ELISPOT Assay / 现代检验医学杂志

Objective To observe the T cells immune response to Enolase (Eno),an immunodominant antigen of Candida albicans.Methods Determined the frequencies of positive spot-forming cells (SFCs) of Eno antigen-specific T cells secreting IFN-γ,IL-4 and IL-17A in the PBMCs of 25 healthy individuals by ELISPOT assay.Results After Eno stimulation,the SFCs of IFN-γ,IL-4 and IL 17A in 25 healthy persons were 14.00(8.50,39.00),0(0,0) and 2(1,4.50),respectively.Either the SFCs of IFN-γ or those of IL-17A were significantly higher than those of IL-4 (P＜0.05).The difference between SFCs of IFN-γ and those of IL-17A was also significant (P=0).The response rates of IFN-γ,IL-4 and IL-17A were 100％ (25/25),4.00％ (1/25) and 88.00％ (22/25),respectively.The difference between either IFN-γor IL 17A and IL-4 was significant (values all P＜0.05).Eno induced strong response (SCFs≥20) for IFN-γ in 10 healthy individuals (40.00％,10/25),but failed to induce strong response for IL-17A and IL-4 in all the volunteers.Major healthy individuals (84.00％,21/25)showed both Th1 and Th17 cells response against Eno,12.00％ (3/25) showing Th1 cells response in isolation,and none showed Th2 or Th17 cells response individually.Conclusion Eno of Candida albicans could induce immunodominant responses of Th1 and Th17 cells,which was considered to provide protection to IC.Eno might be a potential protective vaccine against IC.

Lipopolysaccharide affects testicular histology and reproductive endocrine function in male rats / 中华男科学杂志

<p><b>OBJECTIVE</b>To study the influence of lipopolysaccharide (LPS)-induced inflammation on the testicular histology and reproductive endocrine function in male rats and investigate the possible mechanism of inflammation affecting male fertility.</p><p><b>METHODS</b>Thirty-six male SD rats were randomly divided into a control group (A) and three LPS intervention groups (B, C, and D) to receive saline and LPS (5 mg/kg i. p, once), respectively. The animals in groups B, C, and D were killed by anesthesia at 12, 24, and 72 hours after treatment. Histopathological changes in the left testis of the rats were observed by HE staining and the levels of the reproductive hormones T, FSH, and LH in the serum were determined by ELISA.</p><p><b>RESULTS</b>Compared with group B, group A showed clear structure of seminiferous tubules, orderly arrangement of spermatogenic cells, a slightly decreased number of sperm in some seminiferous tubular lumens, and shed spermatogenic cells in the rat testis tissue; group C exhibited thinner seminiferous epithelia, disordered structure of seminiferous tubules, irregular arrangement of spermatogenic cells, decreased number of mature sperm and obvious shedding of spermatogenic cells in seminiferous tubular lumens; group D manifested similar findings to those of group C, with even more shed spermatogenic cells that blocked the tubular lumens. The levels of serum T, LH, and FSH were (0.490 +/- 0.028) ng/ml, (6.290 +/- 0.515) ng/L, and (1.837 +/- 0.127) IU/L in group A, (0.460 +/- 0.024) ng/ml, (5.881 +/- 0.124) ng/L, and (1.707 +/- 0.098) IU/L in group B, (0.417 +/- 0.021) ng/ml, (5.123 +/- 0.271) ng/L, and (1.620 +/- 0.115) IU/L in group C, and (0.378 +/- 0.021) ng/ml, (4.504 +/- 0.279) ng/L and (1.562 +/- 0.216) IU/L in group D, all decreased in group B as compared with A (P > 0.05). The decreases of T and LH were extremely significant (P < 0.01) and that of FSH was significant in groups C and D (P < 0.05) in comparison with A.</p><p><b>CONCLUSION</b>LPS-induced inflammation affects the testicular tissue and reproductive endocrine function of male rats, resulting in decreased levels of serum T, LH, and FSH.</p>

Meiotic analysis of spermatogenic cells in severe oligoasthenoteratozoospermia with chromosome 13 rearrangement / 中华男科学杂志

<p><b>OBJECTIVE</b>To explore the possible mechanisms of spermatogenic arrest in severe oligoasthenoteratozoospermia induced by supernumerary, ring-neocentric 13q12.3 --> 13q22 chromosome and reciprocal deletion.</p><p><b>METHODS</b>We performed a genomic-wide high-density oaCGH analysis for a case of oligoasthenoteratozoospermia with abnormal chromosome 13 to characterize the breakpoints of the chromosome involved or the gene deletion caused by the rearrangement. We also conducted a fluorescence in situ hybridization analysis on the germ cells using probes of 13q14/13qter to observe the pairing condition of homologous chromosome 13.</p><p><b>RESULTS</b>We identified by oaCGH analysis a microdeletion of 4 consecutive probes (A_16_P19757882, A_16_P02744617, A_14_ P108858 and A_16_P02744687 at chr13q12.3: 27979261 --> 28039191) with 59.93 kb between the FLT1 and POMP genes, with no annotated genes in the deleted region. The signals of 13q14 and 13qter were separated from each other in 90% of all the primary spermatocytes examined, indicating the unpairing of homologous chromosome 13 or synapse failure.</p><p><b>CONCLUSION</b>Chromosomal rearrangement-induced spermatogenesis failure is caused by the unpairing of the homologous chromosomes involved in the first meiotic division of germ cells.</p>

Application of Online Mendelian Inheritance in Man to medical genetics / 中华男科学杂志

Online Mendelian Inheritance in Man (OMIM, http://omim. org/) is a comprehensive, authoritative, practical and timely knowledgebase of human genes and genetic disorders. OMIM, as a genetic encyclopedia, provides an easy and straightforward access to information on human genetics to students, researchers and clinicians. This article presents an overview on the contents of OMIM and its application to medical genetics.

Research progress of Wif1 in development of nervous system / 浙江大学学报·医学版

Wnt inhibitor factor-1 (WIF-1) is an extracellular antagonist of Wnts secreted proteins, first characterized as an expressed sequence tag in the human retina. WIF-1 belongs to the secreted Frizzled-related protein (sFRP) class, which can directly bind to Wnt proteins, prevent Wnts from binding to their receptors in vertebrates. Wif1 is expressed in the nervous system of mouse, Xenopus, zebrafish and human. It has been shown that WIF-1 affects the formation of somites in Xenopus embryos and inhibits rod production in retinal histogenesis by binding to Wnt4 in mice. Histological information of Wif1 expression during the development of the central nervous system has been reported in mouse, Xenopus and zebrafish and the strong embryonic expression suggests Wif1 may play an essential role in the spatial and temporal regulation of Wnt signals in development of central nervous system. The Wnt pathway plays a key role in the patterning of the nervous system. However, insights into the function of Wif1 in the development of the central nervous system are rather limited. Selecting suitable stage and target according to the expression pattern may contribute to understanding the function of Wif1.

Comparison of four methods for sperm counting / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the accuracy and precision of 4 methods including Hemacytometer, Makler chamber, Cell-VU chamber, and computer-aided semen analysis for determining sperm concentration.</p><p><b>METHODS</b>Latex bead solutions with concentrations known as (35 +/- 5) x 10(6)/ml and (18.0 +/- 2.5) x 10(6)/ml and semen samples (n = 54) were counted by the above 4 methods and the results were then compared.</p><p><b>RESULTS</b>Mean bead concentrations for Hemacytometer, Makler, Cell-VU chambers and CASA were (44.84 +/- 4.86), (52.36 +/- 7.78), (39.70 +/- 4.76), (28.53 +/- 2.06) x 10(6)/ml respectively for the standard solution containing (35 +/- 5) x 10(6)/ml, and (21.04 +/- 1.87), (24.54 +/- 3.67), (19.09 +/- 2.02), (14.62 +/- 0.95) x 10(6)/ml respectively for a standard solution containing (18 +/- 2.5) x 10(6)/ml. The results of Cell-VU chamber were consistently similar and close to the standard solutions, while those of Hemacytometer, Makler chambers were overestimated, and those of CASA were underestimated. The coefficients of variation for Hemacytometer, Makler, Cell-VU chambers and CASA were 10.81%, 14.86%, 12.80%, and 7.22% respectively for a higher standard solution, while 8.89%, 14.96%, 10.58%, and 6.50% respectively for a lower standard solution. CASA has the lowest CV%. When semen samples were counted, the results of Hemacytometer, Makler, Cell-VU chambers and CASA were (76.98 +/- 59.90), (63.89 +/- 53.84), (45.28 +/- 34.52), (41.96 +/- 31.93) x 10(6)/ml respectively. There wasn't any significant difference either between Cell-VU chamber and CASA (P = 0.71), or between Hemacytometer and Makler chamber (P = 0.14), while there was significant difference between Cell-VU chamber or CASA and Hemacytometer or Makler chamber (P < 0.05 or P <0.01).</p><p><b>CONCLUSION</b>When counting semen sample, there wasnt any significant difference between Cell-VU chamber and CASA. Each laboratory can select its own proper method for manual or computer-aided analysis.</p>

Evaluation of the determination of seminal ACP and gamma-GT activities and correlation between seminal ACP or gamma-GT activity and semen parameters / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the determination of seminal acid phosphatase (ACP) and gamma-glutamyltranspeptidase (gamma-GT) activity, and analyze the correlation between seminal ACP or gamma-GT and semen parameters.</p><p><b>METHODS</b>ACP and gamma-GT activities in 133 samples of seminal plasma were measured. Two of the samples were randomly selected for intra-assay, one for the detection of ACP activity and the other for gamma-GT activity. And another four were selected the same way for the same purpose, two for the detection of ACP activity and the other two for gamma-GT activity. The semen volume, pH, sperm concentration, motility, and grade-a and -b motility were analyzed by CASA system and so were the correlation between seminal ACP or gamma-GT activity and semen parameters.</p><p><b>RESULTS</b>There was significant positive correlation between ACP and gamma-GT activities (r = 0.570, P = 0.000). The intra-CV of ACP was 13.72%, and inter-CVs of ACP were 13.80% and 15.49%. The intra-CV of gamma-GT was 7.68%, and inter-CVs of gamma-GT were 7.76% and 9.73%. Both seminal ACP and gamma-GT activities had significant negative correlation with pH (r = -0.330, P = 0.000 vs r = - 0. 388, P = 0.000). There was obvious correlation between gamma-GT activity and sperm concentration (r = 0.165, P = 0.045), but not between ACP activity and sperm concentration (r = 0.048, P = 0.546). Neither of seminal ACP and gamma-GT activity was correlated with sperm motility, grade-a and -b motility, semen volume, abstinence time and age.</p><p><b>CONCLUSION</b>The precision of the measurement of gamma-GT activity in seminal plasma was higher than that of ACP. The correlation between seminal gamma-GT activity and semen parameters was similar to that between seminal ACP activity and semen parameters. Thus, the determination of gamma-GT activity was a more reliable marker than that of ACP activity for the evaluation of prostate function.</p>

Etiologic analysis of globozoospermia: a 1-case report / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the etiologic factors of globozoospermia.</p><p><b>METHODS</b>Routine semen analysis, sperm DNA special staining and chromosomal karyotype detection of peripherical blood lymphocytes were performed in a globozoospermia patient.</p><p><b>RESULTS</b>Round-headed spermatozoa were lack of acrosome and the acrosin activity was low. Meanwhile, there was an additional band located in the Y chromosomal short arm.</p><p><b>CONCLUSION</b>Lack of acrosome, low acrosin activity and abnormality of chromosome may be the main reasons for globozoospermia.</p>

Application of distilled water in sperm counting and hypoosmotic swelling test / 中华男科学杂志

<p><b>OBJECTIVE</b>To evaluate the application of distilled water in sperm-counting and hypoosmotic swelling test.</p><p><b>METHODS</b>Thirty-seven semen samples were collected and each was diluted by distilled water and sodium acid carbonate-formaldehyde solution, respectively. Then the hemacytometer was used for sperm counting. Meanwhile, the percentage of swelled sperm diluted by distilled water was compared with the result of hypoosmotic swelling test recommended by WHO. Another 26 semen samples were diluted by distilled water and hypoosmotic swelling solution respectively, and the percentages of the swelled sperm were compared.</p><p><b>RESULTS</b>There was no significant difference either between the sperm concentrations obtained by distilled water and sodium acid carbonate-formaldehyde solution (P > 0.05) or between the percentages of the swelled sperm diluted by distilled water and hypoosmotic swelling solution.</p><p><b>CONCLUSION</b>Distilled water can not only replace sodium acid carbonate-formaldehyde solution for sperm-counting dilution but also be used as a hypoosmotic swelling solution.</p>

Comparison and evaluation of two methods for measuring acid phosphatase activity in seminal plasma / 中华男科学杂志

<p><b>OBJECTIVE</b>To compare the routine method and the kit method for the measurement of acid phosphatase activity in seminal plasma, and to explore the possibility of the kit method for routine measurement.</p><p><b>METHODS</b>Seventy-nine seminal plasma samples were assayed by routine method and kit method respectively for acid phosphatase. One sample was detected 10 times for within-run analysis, and an other two were measured by both the methods once a day for 10 days for between-run analysis. Acid phosphatase activities in another 10 seminal plasma samples collected at random were measured immediately or 30 min after dilution by two technicians, respectively.</p><p><b>RESULTS</b>There were significant positive correlations between the acid phosphatase activities measured by routine and kit methods (r = 0.745, P = 0.000). In the within-run assay, the coefficient of variation for the kit method (13.72%) was similar with that for the routine method (10.66%). But in the between-run assay, the coefficients of variation for the kit method (13.8% and 15.49%) were obviously lower than those for the routine method (24.43% and 21.04%). Compared with the acid phosphatase activities in seminal plasma measured immediately after dilution, those measured after 30-min standing were notably lower for either of the methods (P < 0.05). However, there wasnt significant difference in the acid phosphatase activities detected by the routine method between the two technicians (P = 0.165).</p><p><b>CONCLUSION</b>The kit method is superior and preferable to the routine method for the measurement of acid phosphatase in seminal plasma.</p>

Effect of inflammatory chronic pelvic pain syndrome on the levels of prostatic specific antigen / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the levels of prostatic specific antigen (PSA) in patients with chronic prostatitis.</p><p><b>METHODS</b>Forty-five patients with diagnosed inflammatory chronic pelvic pain syndrome (NIH category III A prostatitis) were inquired about the history symptoms and signs of prostatitis, and underwent digital rectal examination of the prostate as well as analysis of expressed prostatic secretions (EPS). Bacterial infection was also analyzed by pre- and post- massage test (PPMT), and PSA in the blood was detected. Thirty healthy males without inflammation in EPS were selected as controls.</p><p><b>RESULTS</b>In 45 cases of the patients with NIH category III A prostatitis, the PSA level in the blood was 2.41 +/- 0.64 microg/L, and that in the control group was 0.93 +/- 0.52 microg/L, with significant difference (P < 0.05). And among the 45 patients there were 6 (13.3%) whose PSA levels were over 4.0 microg/L, but there was only 1 in the 30 control males (3.3%). In III A prostatitis, the PSA level was elevated with the increase of inflammation in EPS, but with no significant difference.</p><p><b>CONCLUSIONS</b>In the diagnosis of prostate diseases, it should be taken into account that chronic non-bacterial prostatitis might elevate the level of PSA to a certain extent.</p>

Chinese traditional medicine yi kang ling to treat immunity infertility caused by anti-sperm antibody: the experimental research. I / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the effects of Chinese traditional medicine Yi Kang Ling (YKL) on immunity infertility caused by anti-sperm antibodies (AsAb).</p><p><b>METHODS</b>Based on the animal model of immunity infertility, seventy-five pairs of New Zealand rabbits were divided into three groups: YKL treatment group (sub-divided into mini-, midi- and maxi-dosage groups), prednisone treatment group and non-treatment group. Five pairs of normal rabbits were used as control. The AsAb from the rabbit serum were detected on the 15th, 30th and 45th day of treatment respectively. The sperm density, activity, the mobility and AsAb of seminal plasma from the obedient rabbits were determined.</p><p><b>RESULTS</b>Statistics showed that on the 45th day in mini- and maxi-YKL and prednisone treatment groups the positive serum AsAb reversing ratio reached 100%, and the seminal plasma AsAb reversing ratios were 85% in mini- and maxi-YKL group, 83% in midi-YKL and prednisone groups, while in non-treatment group the reversing ratios of the positive serum AsAb and seminal plasma AsAb were only 20% and 25% respectively. There were also remarkable differences (P < 0.05) in both serum AsAb and seminal plasma AsAb on the 45th day of treatment between YKL, prednisone treatment groups and the non-treatment group.</p><p><b>CONCLUSIONS</b>YKL can effectively reverse the AsAb positive results, hence increasing sperm mobility and improving sperm quality.</p>

Chinese traditional medicine yi kang ling to treat immunity infertility caused by anti-sperm antibody: the experimental research II / 中华男科学杂志

<p><b>OBJECTIVE</b>To observe the effects of Chinese traditional medicine Yi Kang Ling (YKL) on immunity infertility caused by anti-sperm antibodies (AsAb).</p><p><b>METHODS</b>With the AsAb infertile rabbit as the experimental model, seventy-five pairs of New zealand rabbits were divided into three group including YKL treatment group (sub-divided into mini-, midi- and maxi-dosage groups), prednisone treatment group and non-treatment group. Rabbits of the YKL treatment sub-groups were further divided into M+F- (male positive, female negative), M-F+, (male negative, female positive) and M+F+ (male positive, female positive) pairs according to their initial AsAb detection results. The control group consisted of five pairs of normal rabbits. When the expected AsAb reversing ratio was achieved, the rabbits were matted and observed for the number of the pregnant and the weight of the newborn.</p><p><b>RESULTS</b>Statistics showed that in M+F- pairs both the midi-dosage of YKL and prednisone treatment groups had fertility, in the mini- and maxi-dosage of YKL treatment groups, 20% of the female rabbits failed to be pregnant, while in the non-treatment group, 60% female rabbits remained sterile. The sterile ratios of the M-F+ pairs in the mini-, midi- and maxi-dosage of YKL and prednisone treatment groups were 0, 20%, 25% and 25%, respectively, while the sterile ratio in the non-treatment M-F+ group was 40%. In M+F+ groups, the sterile ratios of the three YKL sub-groups, prednisone treatment and non-treatment groups were 20%, 20% and 60% respectively. In the control group the sterile ratio was 20%. The weight of the newborn rabbits were around 50 grams with no visible malformation.</p><p><b>CONCLUSIONS</b>YKL can effectively reverse the AsAb positive results, and restore the fertility of female rabbits. Mini-dosage of YKL for 45 days produced the best results and maxi-dosage of YKL had no negative effects on the weight of the newborn rabbit.</p>

Inhibin B levels of serum and seminal plasma in fertile and infertile males / 中华男科学杂志

<p><b>OBJECTIVES</b>To investigate the possible differences in the inhibin B levels of seminal plasma and serum between fertile and infertile males and to obtain information on the relation between serum inhibin B or seminal plasma inhibin B and spermatogenesis.</p><p><b>METHODS</b>Semen and blood samples were collected from fertile(n = 20), oligospermia(n = 20), asthenospermia(n = 22) and non-obstructive azoospermia(NOA) (n = 20) males at 8:00 am = 10:00 am. Semen parameters were analyzed. Levels of inhibin B in seminal plasma and serum, ACP, Fru, alpha-Glu in seminal plasma, serum levels of FSH, T, LH were determined.</p><p><b>RESULTS</b>Both levels of serum inhibin B and levels of seminal plasma inhibin B correlated significantly negatively with serum FSH(r = -0.536, P < 0.001 vs r = -0.288, P = 0.01), and statistically positively with sperm concentration(r = 0.49, P < 0.001 vs r = 0.48, P < 0.001). There was positive correlation between levels of seminal plasma inhibin B and activity of alpha-Glu in seminal plasma (r = 0.377, P = 0.001). The difference in levels of seminal plasma inhibin B was found only between fertile males or asthenospermia and NOA (P < 0.01 and P < 0.05, respectively). However, significant differences in levels of serum inhibin B were found not only between males with normal sperm concentration (including fertile males and asthenospermia) and NOA (P < 0.01), fertile males and oligospermia (P < 0.05), but also between oligospermia and NOA (P < 0.05). There was no correlation between serum inhibin B and seminal plasma inhibin B.</p><p><b>CONCLUSIONS</b>Both levels of serum inhibin B and seminal plasma inhibin B could reflect testis spermatogenesis status. Levels of seminal plasma inhibin B could also reflect the function of seminiferous duct, but the wide range of values limited its applicability.</p>

Examination and significance of semenial prostate specific antigen in infertile patients / 中华男科学杂志

<p><b>OBJECTIVE</b>To investigate the significance of prostate specific antigen (PSA) examination in seminal plasma of infertile patients.</p><p><b>METHODS</b>Eighty-five infertile patients were collected randomly. The level of PSA in seminal plasma was detected by ELISA method. The correlations between PSA and several seminal parameters including sperm density, motility and acid phosphatase (ACP) were analyzed.</p><p><b>RESULTS</b>The PSA, ACP concentrations and sperm motility in 65 cases of abnormal liquefaction patients were obviously lower than those in normal liquefaction patients(P < 0.01). But there were no significant differences in sperm density among the three groups(P > 0.05). PSA levels were significantly correlated with ACP and sperm motility(P < 0.01).</p><p><b>CONCLUSIONS</b>The seminal PSA in infertile patients is markedly correlated with semen liquefaction. The abnormal quality and quantity of PSA can result in a depression of sperm motility and subinfertility.</p>

Isolation and identification of spermatids in semen of male infertile patients / 中华男科学杂志

<p><b>OBJECTIVES</b>To develop a method by which large and purified populations of spermatids can be isolated in semen of male infertile patients.</p><p><b>METHODS</b>A total of fifteen ejaculates containing cellular elements from infertile patients with various andrological pathologies were obtained after a 24-hour abstinence. A modified discontinuous Percoll gradient (15%, 22%, 30%, 40%, 50%, 60%) centrifugation method was used to isolate the spermatids. After centrifugation at 2,000 r/min for 30 min at 18 degrees C, the single Percoll fractions were separated and analyzed in order to select the one with the greatest purity of spermatid. The germinal cells in each isolated fraction were counted using a Macro sperm counting chamber, then the contents of spermatids were determined by morphology (Wright-Giemsa staining method) and flow cytometry (FCM) analysis, while the contaminated leukocytes were assessed by anti-CD45 immunocytochemistry.</p><p><b>RESULTS</b>After Percoll centrifuged, six single fractions were obtained. Morphology and FCM analysis showed that the 22% fraction contained mostly spermatids [(91.85 +/- 5.18)%, P < 0.005] and the mean density in this fraction was (1.010 +/- 0.786) x 10(5)/ml. While in the 30% fraction, various immature spermatogenic cells including spermatids were present and leukocytes mostly presented in the 60% fraction.</p><p><b>CONCLUSIONS</b>A large population of relatively purified spermatids can be isolated from the ejaculates of infertile patients by using this modified discontinuous Percoll gradient centrifugation method.</p>

Detection of human sperm morphology and acrosome reaction with Coomassie brilliant blue staining / 中华男科学杂志

<p><b>OBJECTIVES</b>To evaluate the application of Coomassie brilliant blue (CBB) G250 staining for the detection of human sperm deformity rate, rate of intact acrosome and acrosome reaction.</p><p><b>METHODS</b>The smear of spermatozoa before and after capacitation and induced acrosome reaction with progesterone (P) were stained with 0.05% CBB G250 and Wright-Giemisa solution respectively, and visualized with light microscopy. The deformity rate of spermatozoa, rate of intact acrosome and acrosome reaction were calculated.</p><p><b>RESULTS</b>There was no any difference in detection of deformity rate of spermatozoa and rate of intact acrosome with CBB G250 and Wright-Giemisa staining(P < 0.05). The sperm population of acrosome reaction with induced P was divided by CBB staining into two types: positive staining with dark violet blue on acrosome cap and pale or negative staining on the same area. The rate of the latter was increasing with increasing inductive time, maybe representative of the rate of acrosome reaction. The mean rate was(75.1 +/- 3.8)% after induced for 1 h.</p><p><b>CONCLUSIONS</b>CBB G250 staining is a reliable method for assessment of the human sperm morphology and acrosome reaction.</p>

A serum marker of spermatogenesis--inhibin B / 中华男科学杂志

Inhibin B is a glycoprotein secreted by testis, consisting of two disulfide-linked subunits, an alpha-subunit and a beta B-subunit. Serum inhibin B levels are significantly negatively correlated with the serum FSH levels in males, exerting a negative feedback on FSH secretion. In males the circulating levels of inhibin B increase shortly after birth and peak at 4-12 months of age, then decrease to low levels from 3-9 year. From the onset of puberty, the levels of inhibin B gradually increase. By pubertal stage II, the adult levels of inhibin B have been reached. At stage III of puberty, a negative correlation between inhibin B and FSH levels is present and persists from stage III of puberty onward. At 20-30 year of age, the levels of inhibin B reach another peak, then gradually decline with increasing age. The men with hypospermatogenesis and spermatogenesis arrest have significantly lower levels of inhibin B than those with normal spermatogenesis. The men with Sertoli-cell-only syndrome (SCO) have extremely low levels of inhibin B. There is a closely correlation between the presence of SCO and the level of serum inhibin B. A significantly positive correlation is also observed between testis volume and inhibin B level, as well as between sperm count and inhibin B level. The inhibin B is a direct product of the seminiferous tubules, reflecting the total testicular tissue. The measurable inhibin B production in adult requires the presence of germ cells. Inhibin B is regarded as a serum marker of spermatogenesis. The determination of serum inhibin B in males can be used to assess the spermatogenesis of infertile men, to diagnose the cryptorchidism and precocious puberty, to predict the outcome of testicular sperm extraction in men with non-obstructive azoospermia, and to evaluate the damage to spermatogenesis in men after radiotherapy or chemiotherapy.