[Role of glucocorticoids in pneumocystis pneumonia in patients with non-HIV infection/AIDS (HIV/AIDS) and related mechanisms].

Pneumocystis pneumonia (PCP) is an opportunistic infection caused by Pneumocystis carinii and is the most common fungal infection in HIV/AIDS patients. With the routine use of antiretroviral therapy (ART), the incidence of PCP infection in HIV/AIDS patients has decreased and the prognosis has improved significantly. On the other hand, the use of chemoradiotherapy and immunotherapy in patients with cancer, post-transplantation and autoimmune diseases are increasing dramatically, which has led to a similar increase in the incidence of PCP in these non-HIV/AIDS patients. There is a global shift in research on PCP from HIV-infected co-infected PCP (HIV-PCP) to non-HIV-infected co-infected PCP. The clinical course of non-HIV-PCP is rapid and severe, and the morbidity and mortality rates are higher than those of HIV-PCP. Studies have shown that 90% of non-HIV-PCP patients have a history of glucocorticoid use prior to infection, such as in patients with hematologic malignancies, solid organ transplants, and rheumatic diseases, and that long-term high-dose glucocorticoid use is an important risk for PCP susceptibility. Clinical practice has shown that PCP often occurs during the tapering of glucocorticoids, and a higher proportion of patients develop diffuse pulmonary lesions and, in more severe cases suffer from life-threatening acute respiratory failure. The pathogenesis of non-HIV infections associated with PCP is not yet clarified, and there is a lack of effective therapeutic practices that require further investigation.

[A randomized controlled study on the long-term efficacy of intra-cervical lymphatic immunotherapy for adult allergic rhinitis].

Objective: To determine the long-term efficacy and safety of intra-cervical lymphatic immunotherapy (ICLIT) for adult allergic rhinitis (AR) by comparing it with subcutaneous immunotherapy (SCIT). Methods: A total of 100 adult AR patients with dust mite allergy in Department of Otorhinolaryngology, First People's Hospital of Foshan from Feb 2018 to Dec 2019 were randomly divided into two groups, 50 in SCIT group [including 42 males and 8 females, aging (32.55±9.72) years] and 50 in ICLIT group [including 45 males and 5 females, aging (31.33±9.84) years]. The changes in total symptom score (total system score, TSS), nasal symptom score (total nasal symptom score, TNSS), eye symptom score (total ocular scoring system, TOSS), drug score (total medication score, TMS), and quality of life score of the two groups of patients were evaluated before and after treatment, and the adverse reactions of all patients during the treatment period were recorded. The changes in the level of dust mite specific IgE (sIgE) in the serum were evaluated. GraphPad Prism 9.0 software was used for statistical analysis. Results: In the SCIT group, 38 patients completed treatment and follow-up, with a dropout rate of 24%. In the ICLIT group, 48 patients completed treatment and follow-up, with a dropout rate of only 4%. The scores of TSS, TNSS, TOSS, TMS, and quality of life in the ICLIT group before treatment were 32.1±3.0, 27.3±3.1, 4.8±2.8, 2.3±0.9, and 68.1±28.7, respectively; After 36 months of treatment, the scores were 21.8±11.4, 18.1±9.4, 3.7±2.9, 1.3±1.1, and 36.0±26.7, respectively, which were significantly lower than those before treatment (all P<0.001). After 36 months of treatment, the TSS of the ICLIT group improved by 10.3±11.2 compared to before, while the TSS of the SCIT group improved significantly by 21.9±11.0 compared to before, with statistically significant differences between the groups (P<0.001). No serious systemic adverse reactions occurred in both groups of patients. Conclusions: ICLIT treatment for adult AR has long-term efficacy, high safety, and high compliance, but its long-term efficacy is not as good as SCIT. ICLIT can be considered as a new complementary option for AR immunotherapy.

[Study of the negative regulation of transforming growth factor beta type II receptor to inhibit the occurrence and development of liver fibrosis with miR-217].

Objective: To observe the effect of miR-217 on angiotensin II (AngII)-induced hepatic stellate cells (HSCs) activation, and carbon tetrachloride (CCl4)-induced overexpression in mice, so as to clarify miR-217 role in liver fibrosis. Methods: HSCs were stimulated with AngⅡ and the changes condition in the expression level of miR-217 were detected. HSCs were divided into control group, AngII-treated group and AngⅡ+miR-217-treated group. The expression levels of alpha-smooth muscle actin, fibroblast-specific protein 1 and collagen Ⅰ (Collagen Ⅰ) in each group were detected. The target gene of mir-217 was screened and verified by Targetscan and Dual luciferase gene reporter assay. Real-time quantitative PCR and Western blot were used to detect the effect of miR-217 on the expression level of transforming growth factor beta type Ⅱ receptor (TGFBR2). A CCl4-induced mouse liver fibrosis model was constructed. Masson staining and Sirius red staining were used to detect the effect of miR-217 overexpression on the progression of liver fibrosis in CCl4 mice. Data of two groups were compared using t-test. Data of multiple groups were statistically analyzed with one-way ANOVA. Results: The expression level of miR-217 was downregulated by AngⅡ-stimulated HSC cells. The expression levels of α-smooth muscle actin, fibroblast-specific protein 1 and Collagen Ⅰ induced by AngⅡ was inhibited by miR-217 mimics transfection. The 3'-UTR of TGFBR2 had specifically bind miR-217. The mRNA and protein expression levels of TGFBR2 was inhibited with miR-217 mimics transfection in HSCs. The overexpression of miR-217 had inhibited the expression levels of Collagen Ⅰ and Ⅲ in CCl4 mice and alleviated the progression of liver fibrosis . Conclusion: miR-217 regulates liver fibrosis by targeting TGFBR2, inhibits AngII-induced HSC activation, and slows down the process of liver fibrosis in CCl4 mice, suggesting that miR-217 may have an inhibitory effect on liver fibrosis.

LINC00106 prevents against metastasis of thyroid cancer by inhibiting epithelial-mesenchymal transition.

OBJECTIVE: Thyroid cancer (TC) is a common malignant tumor of the endocrine system, and its morbidity and mortality are in the high places. Recent studies have focused on exploring biological markers and targeted therapy for TC. This research aims to elucidate the role of LINC00106 in the progression of TC and the regulatory mechanisms. PATIENTS AND METHODS: Differential level of LINC00106 in a downloaded profile containing TC and normal tissues from GEPIA database was analyzed. Subsequently, its level in TC tissues and cell lines was detected by quantitative Real Time-Polymerase Chain Reaction (qRT-PCR). The relationship between LINC00106 level and clinical data of TC patients was assessed, including age, tumor staging, lymphatic metastasis, and overall survival. After transfection of si-LINC00106, TC cell metastasis was evaluated by wound healing and transwell assay. Relative levels of E-cadherin, N-cadherin, ß-catenin, and Vimentin regulated by LINC00106 were determined using qRT-PCR and Western blot. RESULTS: LINC00106 was downregulated in TC tissues than normal ones. Its level was correlated to tumor staging, lymphatic metastasis and overall survival in TC patients. The knockdown of LINC00106 in BCPCP and TPC-1 cells enhanced migratory and invasive abilities and triggered the process of epithelial-mesenchymal transition (EMT). CONCLUSIONS: LINC00106 is lowly expressed in TC specimens, which attenuates migratory and invasive abilities in TC by inhibiting EMT as a tumor suppressor.

Inhibitory effect of TGF-ß gene modified human amniotic mesenchymal stem cells on rejection after xenotransplantation of peripheral nerves.

OBJECTIVE: To explore the inhibitory effect of transforming growth factor-beta (TGF-ß) gene modified human amniotic mesenchymal stem cells on rejection after xenotransplantation of peripheral nerves. MATERIALS AND METHODS: In this study, 6 placentas collected in our hospital were selected as the source of human amniotic mesenchymal stem cells. A total of 60 C57BL/6 experimental mice (mouse sciatic nerves were removed before the experiment) were taken as research objects. Mice were randomly divided into experimental group 1, experimental group 2 and experimental group 3 (xenogenous peripheral nerves were introduced to all experimental groups), and a control group (autologous peripheral nerves were introduced). Among them, TGF-ß gene modified (overexpression) human amniotic mesenchymal stem cells were introduced to experimental group 1; TGF-ß gene modified (inhibition) human amniotic mesenchymal stem cells were introduced to experimental group 2; normal human amniotic mesenchymal stem cells were introduced to experimental group 3; and autologous sciatic nerves were introduced to control group. The messenger ribonucleic acid (mRNA) and protein expressions of the TGF-ß in different human amniotic mesenchymal stem cells were detected by quantitative polymerase chain reaction (qPCR) and Western blotting, respectively. Mouse sciatic nerve function in each group after 2 weeks of procedures was detected via the CatWalk system. Expression level of interleukin-22 (IL-22) in the peripheral tissues of transplanted nerves and blood was detected using immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). Its mRNA level was examined via fluorescence quantitative PCR. RESULTS: TGF-ß1 was highly expressed in mice of experimental group 1, but lowly expressed in experimental group 2 relative to that of experimental group 3 (p<0.05). CatWalk test results revealed that the main indexes in experimental group 1 were superior to those in other groups, while the main indexes in experimental group 2 were inferior to those in other groups. According to immunohistochemistry and ELISA results, there were significant differences in the expression level of IL-22 in mice of different treatment groups (p<0.05). IL-22 level was the lowest in control group [(5.05±0.15) pg/mL], followed by that in experimental group 1 [(6.52±0.24) pg/mL], and it was the highest in experimental group 2 [(9.47±0.31) pg/mL]. CONCLUSIONS: Human amniotic mesenchymal stem cells overexpressing TGF-ß can inhibit rejection after xenotransplantation of peripheral nerves.

Up-regulation of miR-517-5p inhibits ERK/MMP-2 pathway: potential role in preeclampsia.

OBJECTIVE: To investigate the potential role of miRNA-517-5p in preeclampsia and its underlying mechanism. MATERIALS AND METHODS: Placenta samples were obtained from 20 women with preeclampsia and 20 women with normal pregnancies. Expression level of miR-517-5p in placenta samples and JAR cells was detected. MiRNA-517-5p mimics or inhibitor was transfected in JAR cells, followed by detection of proliferative and invasive abilities of JAR cells. In addition, the expressions of extracellular regulated protein kinases (ERK), phospho-extracellular regulated protein kinases (p-ERK) and matrix metalloproteinase-2 (MMP-2) in JAR cells were evaluated by Western blot. Meanwhile, the mRNA level of MMP-2 was evaluated by Real-time polymerase chain reaction (PCR). The luciferase assay was applied to identify the target gene of miRNA-517-5p. RESULTS: Increased level of miR-517-5p was detected in placenta samples of preeclampsia patients compared with normal pregnancies. MiRNA-517-5p could regulate proliferative and invasive abilities of JAR cells. Furthermore, miRNA-517-5p could regulate ERK/MMP-2 pathway in JAR cells, which would contribute to the pathophysiology of preeclampsia. The luciferase assay showed MMP-2 was the target gene of miR-517-5p. Further studies showed that MMP-2 was dysregulated in preeclampsia. CONCLUSIONS: MiR-517-5p is highly expressed in placenta samples of preeclampsia pregnancies, which could promote proliferative and invasive abilities of JAR cells by inhibiting ERK/MMP-2 pathway.

Usefulness of the plasma glucose concentration-to-HbA1c ratio in predicting clinical outcomes during acute illness with extreme hyperglycaemia.

AIMS: To evaluate the correlation between the plasma glucose-to-glycated haemoglobin ratio (GAR) and clinical outcome during acute illness. METHODS: This retrospective observational cohort study enrolled 661 patients who visited the emergency department of our hospital between 1 July 2008 and 30 September 2010 with plasma glucose concentrations>500mg/dL. Systolic blood pressure, heart rate, white blood cells, neutrophils, haematocrit, blood urea nitrogen, serum creatinine, liver function and plasma glucose concentration were recorded at the initial presentation to the emergency department. Data on glycated haemoglobin over the preceding 6 months were reviewed from our hospital database. The glucose-to-HbA1c ratio (GAR) was calculated as the plasma glucose concentration divided by glycated haemoglobin. RESULTS: The GAR of those who died was significantly higher than that of the survivors (81.0±25.9 vs 67.6±25.0; P<0.001). There was a trend towards a higher 90-day mortality rate in patients with higher GARs (log-rank test P<0.0001 for trend). On multivariate Cox regression analysis, the GAR was significantly related to 90-day mortality (hazard ratio [HR] for 1 standard deviation [SD] change: 1.41, 95% confidence interval [CI]: 1.22-1.63; P<0.001), but not to plasma glucose (HR: 0.89, 95% CI: 0.70-1.13; P=0.328). Rates of intensive care unit (ICU) admission and mechanical ventilator use were also higher in those with higher GARs. CONCLUSION: GAR independently predicted 90-day mortality, ICU admission and use of mechanical ventilation. It was also a better predictor of patient outcomes than plasma glucose alone in patients with extremely high glucose levels.

Adjuvant Chemotherapy With Gemcitabine Plus Cisplatin for Kidney Transplant Patients With Locally Advanced Transitional Cell Carcinoma: A Single-center Experience.

BACKGROUND: The purpose of the present study was to evaluate the effects and safety of adjuvant chemotherapy with gemcitabine plus cisplatin in kidney transplant patients with locally advanced transitional cell carcinoma. METHODS: A total of 22 kidney transplant patients with locally advanced transitional cell carcinoma were assessed. Eleven patients who underwent surgery and received adjuvant chemotherapy were enrolled in the study. They were compared with 11 matched patients who were treated with surgery alone. The chemotherapy regimen was gemcitabine 800 mg/m(2) on days 1, 8, and 15 and cisplatin 70 mg/m(2) on day 2. A single treatment cycle lasted 28 days. Because of the potential concerted reaction between the immunosuppressant regimen and the chemotherapeutic agents, drug toxicities were closely observed, and a dose reduction of the chemotherapeutic agents was planned according to the toxicity grade. There was a 75% drug dose reduction for grade 2 hematologic toxicities and grade 1 nephrotoxicity, and there was a 50% drug dose reduction for grade 3 hematologic toxicity and grade 2 nephrotoxicity. Patients who developed grade 4 hematologic toxicity or grade 3 to 4 nephrotoxicities were withdrawn. RESULTS: Eleven patients completed a total of 29 cycles. At a median follow-up time of 21 months, the mean overall survival time was longer than that of the observation group (P = .043). The incidence of hematologic toxicities was higher, resulting in a dose reduction of the chemotherapeutic agents in 45.5% of patients. Gastrointestinal reactions were most common in patients with nonhematologic toxicities. Grade 1 nephrotoxicity was reported in 3 patients; no other grade of nephrotoxicity was observed. Levels of serum creatinine and blood urea nitrogen were not obviously reduced during chemotherapy. CONCLUSIONS: Our study data suggest that kidney transplant patients with locally advanced transitional cell carcinoma may derive an overall survival benefit from the administration of adjuvant chemotherapy with gemcitabine plus cisplatin after surgery. The drug toxicities were acceptable, and nephrotoxicity was mild.

Association between the pre-miR-196a2 rs11614913 polymorphism and gastric cancer susceptibility in a Chinese population.

We did a case-control study to provide a more comprehensive evaluation of the association of the pre-miR-196a2 rs11614913 polymorphism with gastric cancer. Between January 2013 and December 2014, 182 patients newly diagnosed with primary gastric cancer and 182 control subjects were recruited at Zhengzhou People's Hospital. For SNP genotyping, we used the Assay Designer 3.1 to design the primers of polymerase chain reaction. Using the chi-square test, we found that patients with gastric cancer were more likely to be alcohol drinkers (χ(2) = 4.4, P = 0.04), to have a family history of cancer in the first relatives (χ(2) = 5.29, P = 0.02), and to be infected with Helicobacter pylori (χ(2) = 23.39, P < 0.001). A significant difference in the genotype distributions of rs11614913 was observed in our study (χ(2) = 6.66, P = 0.04). By logistic regression analysis, we found that the CC genotype of rs11614913 was associated with an increased risk of gastric cancer in a codominant model (OR = 2.68, 95%CI = 1.17-6.44). By stratification analysis, we found that the CC genotype was associated with a strongly increased risk of gastric cancer in drinkers when compared with the TT+TC genotype (OR = 5.63, 95%CI = 1.54-30.76). In conclusion, the results of our study suggest an association between the rs11614913 gene polymorphism and an elevated risk of gastric cancer, especially in drinkers.

Association between ERCC5 gene polymorphisms and gastric cancer risk in a Chinese population.

We conducted a hospital-based case-control study to investigate the association between 3 common SNPs in the ERCC5 gene (rs1047768, rs751402, and rs17655) and the risk of developing gastric cancer. Between January 2013 and December 2014, samples were collected from 216 gastric cancer patients and 216 control subjects. ERCC5 rs1047768, rs751402, and rs17655 polymorphisms were genotyped by polymerase chain reaction combined with restriction fragment length polymorphism analysis. By conditional logistic regression analysis, the GG genotype of rs17655 was found to be associated with an elevated risk of gastric cancer in a codominant model, and the adjusted OR (95%CI) was 1.96 (1.10-3.50). Moreover, in a dominant model, the CG + GG genotype of rs17655 was correlated with an increased risk of gastric cancer compared to the CC genotype (OR = 1.48; 95%CI = 1.00-2.22). rs1047768 and rs751402 were not significantly correlated with an increased or decreased gastric cancer risk.

Epipolythiodioxopiperazines from fungi: chemistry and bioactivities.

Epipolythiodioxopiperazines (ETPs), characterized by a unique bridged disulfide or polysulfide dioxopiperazine six-membered ring, occur in many fungi. Due to its broad spectra of bioactivities, ETPs have drawn wide attention in recent years. This review covers diverse natural sources that produce ETPs, the synthetic chemistry of ETPs and an overview of promising bioactivities exhibited by some well studied ETPs. The plausible biosynthetic hypotheses of ETPs and some new results on antitumor activity of ETPs are also reviewed.

Cellular immunologic response to primary cryoablation of C6 gliomas in rats.

The immunological consequences of cryoablation for gliomas are largely unknown. cryoablation is an attractive therapeutic option for tumors due to its minimally invasive nature. cryoablation is also potentially immunogenic. With an aim to explore changes in cellular immunity following argon-helium cryosurgery, we established Wistar rat models bearing subcutaneous C6 glioma and divided the rats into the normal control (30 rats), sham-operated (33 rats), surgical resection (30 rats), and cryosurgery (33 rats) groups with corresponding treatments. The tumor cell morphology was observed, and changes in the T lymphocyte subset and NK lymphocyte subset and the ratio of Th1/Th2 were assessed with flow cytometry following the cryosurgery. The results showed that subcutaneous tumor implantation was successful in all cases and this was confirmed histologically. Compared with surgical resection that caused significant reduction in CD3(+), CD4(+), CD14(+), CD16+56 cell percentages, cryosurgery resulted in significantly increased percentages of CD3(+), CD4(+), CD14(+), CD16+56 cells (P < 0.05) with a increase of the Th1/Th2 ratio 7 days after the operation. These results demonstrate that in addition to tumor cell destruction, cryosurgery also results in enhanced cellular immunity, suggesting the great potential of argon-helium cryosurgery in clinical management of gliomas.

Chemical diversity in opisthobranch molluscs from scarcely investigated Indo-Pacific areas.

Opisthobranch molluscs with both a rich variety of secondary metabolites and great biomedical potential represent the most intensively studied group of molluscs in natural product chemistry. We review here the chemical investigations into secondary metabolites of "sea slugs" from less-studied Indian, Chinese and Egyptian coasts, giving an overview of their most relevant biological activities. In addition to the biomedical interest of the metabolites, in which both structures and organisms often lose their own importance, this chapter emphasizes the phyletic and geographic distribution of the compounds in order to provide a further informational base for chemotaxonomical generalizations.

Fortisterol, a novel steroid with an unusual seven-membered lactone ring B from the Chinese marine sponge Biemna fortis Topsent.

Fortisterol (1), a novel steroid with a rare seven-membered lactone ring B, has been isolated from the marine sponge Biemna fortis and its structure gas been elucidated on the basis of spectroscopic data.

3-Oxo-axisonitrile-3, a new sesquiterpene isocyanide from the Chinese marine sponge Acanthella sp.

A new sesquiterpene isocyanide, 3-oxo-axisonitrile-3 (1), with a spiro [5,6] decane skeleton (spiroaxane) together with a known related sesquiterpene isonitrile (2), sesquiterpene isothiocyanates (3-8) and two diterpene isonitriles (9, 10) have been isolated from the Chinese marine sponge Acanthella sp. The structure of 1 has been determined on the basis of spectroscopic analysis.

O-methyl nakafuran-8 lactone, a new sesquiterpenoid from a hainan marine sponge Dysidea sp.

A new sesquiterpenoid, O-methyl nakafuran-8 lactone (1) has been isolated from a Hainan sponge Dysidea sp. and the structure of the new compound proposed by spectral data, was confirmed by X-ray diffraction analysis. The complete 1H- and 13C-NMR assignments were made on the basis of detailed 2D NMR spectral analysis. Compound 1 showed strong inhibitory bioactivity against PTP1B with IC50 value of 1.58 microM.

A new spiro-sesquiterpene from the sponge Dysidea fragilis.

A new spiro-sesquiterpene, spirofragilin (1), along with a known related sesquiterpene, dehydroherbadysidolide (2), have been isolated from the marine sponge Dysidea fragilis collected in the South China Sea. The structure of 1 was elucidated on the basis of detailed spectroscopic analysis.

Cloning and functional expression of the mucrosobin protein, a beta-fibrinogenase of Trimeresurus mucrosquamatus (Taiwan Habu).

A venom-specific cDNA encoding for a thrombin-like enzyme designated as mucrosobin has been cloned and sequenced from the cDNA library of the venomous gland of Trimeresurus mucrosquamatus. The full-length cDNA of mucrosobin was assembled by oligonucleotide screening and 5'-rapid amplification of cDNA ends. The amino acid sequence deduced from the cDNA consists of 257 amino acid residues with a putative signal peptide of 24 residues. It is highly homologous to the other thrombin-like enzymes (batroxobin, mucofirase, and calobin), suggesting that it is a serine proteinase with a conserved catalytic triad of His(41), Asp(84) and Ser(179) in the deduced form of mucrosobin protein. Northern blot analysis revealed that the mucrosobin gene encodes an mRNA of 1.5 kb and suggested a tissue-specific expression in the venomous gland. In an effort to study the biological property of mocrosobin, we have expressed the 28-kDa protein as inclusion bodies in Escherichia coli. For analyzing enzymatic activity, the inclusion bodies were solubilized and the recombinant protein was refolded with a two-step dialysis protocol. The refolded recombinant protein exhibited a specific beta-fibrinogenolytic activity. This study offers a possibility of using genetic engineering to acquire a functional snake venom protein with therapeutic potential.

Cloning and characterization of a complementary DNA encoding a human epididymis-associated disintegrin and metalloprotease 7 protein.

Mammalian spermatozoa interact with the proteins secreted by the epididymis to develop fertility. Transmembrane proteins that possess a disintegrin and metalloprotease (ADAM) domains are shown to be closely related to spermatogenesis and fertilization. Our previous study demonstrated that GP-83, a glycoprotein secreted by the epididymis, was conjugated to mature sperm. In this study, a 2.1-kilobase (kb) GP-83-expressing insert was isolated from a cDNA library of human epididymis by immunoscreening using GP-83-specific antiserum. The 5' end rapid amplification of cDNA ends (RACE) and 3'-RACE of the 2.1-kb insert elucidated two isoforms of GP-83-encoding cDNA sequences, an alpha-form of 3451 base pairs (bp) and beta-form of 2643 bp. Both forms exhibit the same open reading frame of 2262 bp predicting a peptide of 754 amino acid residues. Deduced amino acid sequence revealed signal sequence, prodomain, metalloproteinase, disintegrin, cysteine-rich, epidermal growth factor-like, transmembrane, and cytoplasmic domains. The GP-83-encoding sequence was recognized as human ADAM7 due to significant homology to other ADAM7s. According to the DNA sequences elucidated in the Human Genome Project, h-ADAM7 was located at chromosome 8p22. Ex vivo expression confirmed that h-ADAM7 cDNA did encode GP-83. Northern blot analysis revealed two transcripts of 4 kb and 3 kb in the epididymis, but not in testis or other major tissues. These results indicate that the GP-83-encoding gene is a human epididymis-associated ADAM7 gene (human ADAM7, h-ADAM7) and may be involved in the sperm-egg interaction.

Purification of GP-83, a glycoprotein secreted by the human epididymis and conjugated to mature spermatozoa.

Epididymal secretions are critical for mammalian spermatozoa to acquire both forward motility and an ability to recognize and penetrate oocytes. Previous studies identified two glycoproteins, GP-83 and GP-39, which were secreted by the human epididymis and may be related to maturation of sperm function. In this study, GP-83 was purified from human seminal fluid by DEAE-ion exchange, gel filtration chromatography and preparative gel elution. The isoelectric point (pI) of purified GP-83 was 6.57. Monospecific antiserum to GP-83 was induced in male New Zealand rabbits and confirmed on immunoblots. GP-83 was found in fluid, tissue and sperm extracts of corpus and cauda epididymis, but not in the caput. Immunohistochemical localization identified GP-83 in the luminal contents and in the supranuclear region and cell membrane of principal cells of the corpus and cauda epididymis. GP-83 was found on the anterior acrosome in ejaculated spermatozoa, and shifted to the equatorial region after capacitation and the acrosome reaction.