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1.
Tissue Antigens ; 79(4): 287-90, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22256791

RESUMO

Human leukocyte antigen (HLA)-E is an inhibitory ligand of natural killer cells and γ/δ T-cells. Differential expression of HLA-E alleles on the cell surface has been reported to influence outcome of hematopoietic stem cell transplantation (HSCT). We performed HLA-E genotyping in 116 HSCT patients and their HLA-matched unrelated donors. The impact of HLA-E genotypes on patient's overall survival (OS), disease free survival (DFS), cumulative incidences for relapse, transplant-related mortality (TRM) and acute graft vs host disease (aGvHD) was assessed. Neither univariate nor multivariate analysis showed any influence of HLA-E polymorphisms on the investigated endpoints of HSCT in our cohort. We could not confirm any of the previous observations in our cohort and consider it unlikely that HLA-E polymorphisms affect outcome of HSCT.


Assuntos
Transplante de Células-Tronco Hematopoéticas , Antígenos de Histocompatibilidade Classe I/genética , Polimorfismo Genético , Adolescente , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Resultado do Tratamento , Antígenos HLA-E
2.
J Biotechnol ; 134(1-2): 121-6, 2008 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-18282625

RESUMO

The effect of oxygen transfer rate (OTR) on the synthesis of mycosubtilin, a non ribosomal lipopeptide antifungal biosurfactant, was investigated in the respiration activity monitoring system (RAMOS) for two Bacillus subtilis strains. These cultures were performed under definite oxygen-limited conditions without the adding of any anti-foam in the culture medium. By using four different filling volumes (FV) in the shaken bioreactors, different levels (20, 14, 9 and 7 mmol O(2)l(-1)h(-1)) of oxygen-limited growth could be obtained. A 25-fold increase of the specific productivity of mycosubtilin was observed for B. subtilis ATCC6633 in the case of the most severe oxygen limitation. But nearly no effect could be found with strain BBG100 carrying the constitutive P(repU) promoter instead of the natural P(myc) promoter. Transcript analysis of the fenF gene belonging to the myc operon indicated that the P(myc) promoter regulation could be slightly oxygen sensitive. Additionally, different patterns of the synthetised mycosubtilin homologues were obtained for different level of oxygen-limited growths. At the present state of investigation, oxygen regulation was thus shown to act at different levels suggesting the existence of a complex regulatory system of NRPS lipopeptide synthesis in the natural B. subtilis ATCC6633 strain.


Assuntos
Bacillus subtilis/metabolismo , Lipoproteínas/biossíntese , Oxigênio/metabolismo , Reatores Biológicos/microbiologia , Lipopeptídeos , Lipoproteínas/metabolismo , Peptídeos Cíclicos/metabolismo , Transcrição Gênica/genética
3.
Andrology ; 5(6): 1115-1123, 2017 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-28980413

RESUMO

There is currently no effective medical therapy for men with infertility due to oligoasthenozoospermia. As men with abnormal sperm production have lower concentrations of 13-cis-retinoic acid in their testes, we hypothesized that men with infertility from oligoasthenozoospermia might have improved sperm counts when treated with isotretinoin (13-cis-retinoic acid). We conducted a single-site, single-arm, pilot study to determine the effect of therapy with isotretinoin on sperm indices in 19 infertile men with oligoasthenozoospermia. Subjects were men between 21 and 60 years of age with infertility for longer than 12 months associated with sperm concentrations below 15 million sperm/mL. All men received isotretinoin 20 mg by mouth twice daily for 20 weeks. Subjects had semen analyses, physical examinations, and laboratory tests every 4 weeks during treatment. Nineteen men enrolled in the study. Median (25th, 75th) sperm concentration increased from 2.5 (0.1, 5.9) million/mL at baseline to 3.8 (2.1, 13.0) million/mL at the end of treatment (p = 0.006). No significant changes in sperm motility were observed. There was a trend toward improved sperm morphology (p = 0.056). Six pregnancies (three spontaneous and three from intracytoplasmic sperm injection) and five births occurred during the study. Four of the births, including all three of the spontaneous pregnancies, were observed in men with improvements in sperm counts with isotretinoin therapy. Treatment was well tolerated. Isotretinoin therapy improves sperm production in some men with oligoasthenozoospermia. Additional studies of isotretinoin in men with infertility from oligoasthenozoospermia are warranted.


Assuntos
Isotretinoína/uso terapêutico , Oligospermia/tratamento farmacológico , Motilidade dos Espermatozoides/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos , Adulto , Humanos , Masculino , Projetos Piloto , Análise do Sêmen , Contagem de Espermatozoides
4.
J Immunol Methods ; 81(1): 137-46, 1985 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-4020146

RESUMO

A monoclonal antibody to the testicular sulfatoxygalactosylglycerolipid has been raised following in vitro stimulation of lymphocytes with glycolipid immobilized on glass beads by means of a photoactivatable heterobifunctional crosslinking agent. The antibody can distinguish between glycerol and sphingosine-based sulfoglycolipids.


Assuntos
Anticorpos Monoclonais/biossíntese , Glicolipídeos/imunologia , Sulfoglicoesfingolipídeos/imunologia , Animais , Bovinos , Feminino , Vidro , Hibridomas/imunologia , Imunização , Imunoglobulina M/biossíntese , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos , Testículo/imunologia
5.
Am J Cardiol ; 87(6): 782-5, A8, 2001 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-11249905

RESUMO

In this analysis of ischemic and hemorrhagic strokes after acute myocardial infarction (AMI) in 21,330 consecutively included patients with AMI, we found an incidence of stroke after AMI of 1.2% and a very poor prognosis. Previous stroke, atrial fibrillation, and older age were the strongest predictors of stroke after AMI; thrombolysis was a borderline risk factor and early therapy with aspirin was associated with a reduction in stroke after AMI.


Assuntos
Infarto do Miocárdio/complicações , Acidente Vascular Cerebral/etiologia , Idoso , Feminino , Alemanha/epidemiologia , Mortalidade Hospitalar , Humanos , Incidência , Modelos Logísticos , Masculino , Infarto do Miocárdio/tratamento farmacológico , Prognóstico , Estudos Prospectivos , Fatores de Risco , Acidente Vascular Cerebral/epidemiologia , Acidente Vascular Cerebral/mortalidade , Taxa de Sobrevida , Terapia Trombolítica
6.
Obstet Gynecol ; 71(5): 685-90, 1988 May.
Artigo em Inglês | MEDLINE | ID: mdl-3357655

RESUMO

Seventy-four men of infertile couples, for whom a female infertility factor had been excluded, were followed for up to three years after semen analyses that included the sperm penetration assay, an in vitro test of sperm function. At 156 weeks after a normal sperm penetration assay, the cumulative pregnancy rate was 68%, versus only 27% when an abnormal assay was noted. Cumulative pregnancy percents at one year varied significantly (P less than .02) according to the magnitude of the assay result (0%, 1-10%, 11-15%, 16% or greater). However, differences between 0% versus 1-10%, and 11-15% versus 16% or greater, were not statistically significant. Only one of 14 men effected conception after an assay result of 0%. These findings were little altered when analysis of the sperm penetration assay was restricted to men with normal sperm concentration (20 X 10(6) sperm mL-1 or greater) and motility (60% or greater). The presence of pyospermia (six or more white blood cells per 100 spermatozoa) was associated with continued infertility, but neither abnormal sperm concentration nor motility were associated significantly with lower cumulative pregnancy percents. When performed for infertile men according to standard protocol, the sperm penetration assay enhances prediction of future pregnancy.


Assuntos
Infertilidade Masculina/fisiopatologia , Interações Espermatozoide-Óvulo , Adulto , Feminino , Seguimentos , Humanos , Infertilidade Masculina/etiologia , Masculino , Pessoa de Meia-Idade , Gravidez , Contagem de Espermatozoides , Motilidade dos Espermatozoides
7.
Obstet Gynecol ; 75(5): 800-4, 1990 May.
Artigo em Inglês | MEDLINE | ID: mdl-2325963

RESUMO

Bacteria can be isolated from most seminal fluid samples, but the significance of these microorganisms is uncertain because most men lack symptoms associated with bacterial infection of the reproductive tract. We obtained semen samples from 37 men attending a Special Infertility Clinic and assessed the relationship between seminal fluid microorganisms and seminal fluid analysis including sperm motility, morphology, and concentration; the numbers of polymorphonuclear leukocytes and other white blood cells; and the hamster zona-free oocyte sperm penetration assay. Aerobic and/or anaerobic bacteria were recovered from 36 of the 37 samples. One hundred eighty-eight isolates (113 aerobes, 74 anaerobes, and one yeast) were recovered, with a mean of 5.2 isolates per semen specimen. The microorganisms recovered from the samples included: coagulase-negative staphylococci (89%), viridans streptococci (65%), diphtheroids (86%), Peptostreptococcus sp (62%), Bacteroides sp (27%), Gardnerella vaginalis (19%), Lactobacillus sp (16%), Actinomyces sp (16%), Enterococcus (11%), and Veillonella (11%). Other microorganisms including group B streptococcus, Hemophilus, Escherichia coli, Mobiluncus, and Clostridium were each recovered from fewer than 10% of the specimens. When the microbiology of seminal fluid specimens with or without polymorphonuclear leukocytes was compared, the presence of polymorphonuclear leukocytes in the semen was not associated with the isolation of staphylococci (33 versus 25%), viridans streptococci (33 versus 28%), Bacteroides sp (17 versus 37%), or Peptostreptococcus (31 versus 33%) (P greater than .05 for each comparison). The proportion of semen samples yielding bacterial isolates was similar after categorization by normal motility (more than 60%), pyospermia (six or more leukocytes per 100 sperm), sperm concentration, morphology, and a normal sperm penetration assay (11% or more).(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Bactérias/isolamento & purificação , Infertilidade Masculina/microbiologia , Sêmen/microbiologia , Adulto , Feminino , Humanos , Infertilidade Masculina/patologia , Infertilidade Masculina/fisiopatologia , Masculino , Pessoa de Meia-Idade , Sêmen/citologia , Contagem de Espermatozoides , Motilidade dos Espermatozoides , Interações Espermatozoide-Óvulo , Espermatozoides/patologia
8.
Science ; 183(4123): 368, 1974 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-17781918
9.
Science ; 164(3876): 197-8, 1969 Apr 11.
Artigo em Inglês | MEDLINE | ID: mdl-5774196
10.
Science ; 165(3891): 415-6, 1969 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-5789440
11.
Science ; 173(3995): 462-3, 1971 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-17770453
12.
Fertil Steril ; 62(3): 580-4, 1994 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-7520396

RESUMO

OBJECTIVE: To identify men with leukocytospermia and prostatitis in an infertility practice and evaluate the effect of various treatments and recurrence rates after treatment. DESIGN: A prospective randomized trial of men with leukocytospermia. SETTING: Academic tertiary infertility clinic. PATIENTS: One hundred two men with leukocytosperimia identified on smear of semen using Bryan-Leishman stain and in expressed prostatic secretion. INTERVENTIONS: Treatment groups were no treatment group; antibiotic treatment alone group; frequent ejaculation alone group; and antibiotic treatment with frequent ejaculation group. MAIN OUTCOME MEASURE: Resolution of leukocytospermia on semen smear. RESULTS: Significant resolution of leukocytospermia occurred in all treatment groups at 1 month compared with no treatment. The resolution was sustained at 2 and 3 months only in those who took antibiotics and frequently ejaculated. CONCLUSIONS: Antibiotic treatment, frequent ejaculation, and antibiotic treatment with frequent ejaculation effectively treat leukocytospermia immediately after the treatment phase. However, only antibiotic treatment coupled with frequent ejaculation is effective 3 months after treatment.


Assuntos
Infertilidade Masculina/patologia , Infertilidade Masculina/terapia , Leucócitos/patologia , Prostatite/complicações , Sêmen/citologia , Adulto , Antibacterianos/uso terapêutico , Ejaculação , Humanos , Infertilidade Masculina/etiologia , Contagem de Leucócitos , Masculino , Estudos Prospectivos , Recidiva , Coloração e Rotulagem , Fatores de Tempo
13.
Fertil Steril ; 59(3): 629-38, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8458468

RESUMO

OBJECTIVE: To determine if one mechanism of albumin-mediated support of human sperm capacitation is lipid (cholesterol) transfer activity and contamination of albumin with Lipid Transfer Protein-I (LTP-I). DESIGN AND MAIN OUTCOME MEASURES: Measure lipid transfer activity in various bovine and human albumin preparations, relate this activity to albumin-supported capacitation (measured by zona-free hamster oocyte sperm penetration assay) and acrosome reactions; and attempt to detect LTP-I in active albumins. Remove LTP-I from albumin which supports capacitation and reassess this support. Reconstitute capacitation support by addition of purified LTP-I. SETTING AND SUBJECTS: Healthy sperm donors with normal semen analyses were recruited by the Reproductive Biology-Andrology Laboratory in a university medical center. RESULTS: Albumin preparations that effectively support capacitation have high levels of lipid transfer activity and of LTP-I, a protein responsible for lipid transfer activity. Preparations with lower levels of capacitation support have less lipid transfer activity. Removal of LTP-I from supportive albumin significantly reduces the capacitation support, and this is restored by purified LTP-I. Progesterone concentrations in these preparations are negligible. CONCLUSIONS: The variable abilities of albumin preparations to support in vitro sperm capacitation are largely dependent on the presence of contaminating LTP-I. The cholesterol transfer activity of this protein, which is present in human serum and follicular fluid, may be one mechanism in the process of capacitation.


Assuntos
Proteínas de Transporte/fisiologia , Albumina Sérica/fisiologia , Capacitação Espermática , Acrossomo/fisiologia , Animais , Western Blotting , Proteínas de Transporte/análise , Cricetinae , Feminino , Masculino , Mesocricetus , Albumina Sérica/análise , Interações Espermatozoide-Óvulo
14.
Fertil Steril ; 52(6): 891-905, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2687028

RESUMO

Clinical and laboratory attempts to alter the sex ratio require more complete and thorough study. Improved identification of Y-bearing sperm through chromosome evaluation rather than by F-body identification is critical to provide a more precise definition. The tentative conclusions stated below are based on an assessment of literature from which it is generally difficult to draw conclusions: 1. The timing of intercourse in relation to ovulation and subsequent fertilization appears to influence the sex ratio. More females are conceived when coitus occurs relatively close to ovulation, and more males are conceived when the sperm or egg is in the reproductive tract for a relatively longer time before conception. The influence of coital timing on the sex ratio is overall quite subtle and is not a practical method to alter the sex ratio for individual couples. 2. The use of ovulation-inducing medications slightly favors female offspring. A decrease in sex ratio of 5% to 10% has been shown in multiple studies. 3. Artificial insemination with fresh donor or homologous spermatozoa results in more male births with a reported 7% to 10% increase in the sex ratio. It appears that ovulation induction combined with artificial insemination cancels the respective influences of each on the sex ratio. 4. Sperm separation techniques using albumin (for selection of Y-bearing sperm) or Sephadex column filtration (for selection of X-bearing sperm) are the only techniques that have been reported to alter the sex ratio to a degree that is clinically relevant. Although clinical birth data are just beginning to accumulate, these methods appear to have a 70% to 80% success for selection of assumed Y-bearing sperm and a 75% to 80% success for selection of assumed X-bearing sperm. The validity of these results will remain questionable until fully detailed accounts are published and successfully repeated. Free-flow electrophoresis appears to achieve significant separation; however, the depressed postprocedure spermatozoa motility presently limits the usefulness of this procedure. 5. There is a potential to combine clinical and laboratory methods to maximize the efficiency of sex selection for interested couples. Modern methods to identify ovulation (e.g., urinary LH kits, ultrasonography) may help the timing of coitus for sex selection. Clomiphene citrate may enhance female sex preselection when Sephadex column filtration is also employed. 6. The priority of sex preselection in terms of medical, social, and demographic consideration remains to be determined. The avoidance of sex-linked genetic disorders is a reasonable and desirable goal.(ABSTRACT TRUNCATED AT 400 WORDS)


Assuntos
Engenharia Genética , Pré-Seleção do Sexo , Separação Celular , Coito , Eletroforese , Feminino , Humanos , Técnicas Imunológicas , Inseminação Artificial , Masculino , Ovulação , Sêmen/citologia , Razão de Masculinidade , Fatores Socioeconômicos , Motilidade dos Espermatozoides
15.
Fertil Steril ; 71(3): 547-51, 1999 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10065796

RESUMO

OBJECTIVE: To determine if a simple screening test of sperm recovery through a density gradient preparation and sperm survival after a 24-hour incubation is predictive of IUI success. DESIGN: Prospective nonrandomized descriptive study. SETTING: Tertiary assisted reproductive technology center. PATIENT(S): Four hundred fourteen couples undergoing IUI for male factor and unexplained infertility. INTERVENTION(S): An advanced semen analysis, which consisted of a basic semen analysis, sperm processing through a density gradient preparation, and a 24-hour sperm incubation, was performed on all couples before beginning IUIs. MAIN OUTCOME MEASURE(S): Cumulative and per cycle pregnancy rates (PRs) were calculated for routine semen parameters, number of sperm processed through density gradient, and percent motile sperm after a 24-hour incubation. RESULT(S): None of the basic semen analysis parameters accurately predicted IUI success. When the processed total motile sperm available for insemination was > or = 10 x 10(6) and their 24-hour survival was > or = 70%, 89% (162 of 182) of couples achieved a pregnancy with a 21.4% (162 of 757) per cycle PR compared to a 2.8% (11 of 403) per cycle PR and 4.7% total PR when survival was <70%. With use of these cutoff values for the advanced semen analysis, the test had a sensitivity of 94% and specificity of 86%. CONCLUSION(S): The number of motile sperm available for insemination and especially their 24-hour survival are highly predictive of IUI success. This advanced semen analysis is an excellent screening test to evaluate couples considering IUI.


Assuntos
Fertilização , Inseminação Artificial , Sêmen/fisiologia , Espermatozoides/citologia , Sobrevivência Celular , Estudos de Avaliação como Assunto , Feminino , Humanos , Masculino , Gravidez , Taxa de Gravidez , Estudos Prospectivos , Sêmen/citologia
16.
Fertil Steril ; 47(4): 680-3, 1987 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-3552748

RESUMO

In order to study the ability of the sperm penetration assay (SPA) to correctly classify the fertility status of men, we prospectively examined the results of the SPA performed on the semen of three groups of men of known fertility status. The groups included 67 normal men without varicoceles whose wives were pregnant (VARN), 51 men with a palpable varicocele whose wives were pregnant (VARF), and 30 infertile men with varicoceles (VARI). Two SPAs were done on each subject. Ninety-seven percent of the VARIs showed less than 15% penetration on a single test, and 91% showed less than 15% on both tests. On a single test 61% of the VARNs and 68% of the VARFs were less than 15%. If 0 penetration were used as the criteria of infertility, then 40% of the VARIs, 27% of the VARFs, and 12% of the VARNs would be classified as being infertile. These data suggest that the SPA cannot independently define male fertility status and should be used in conjunction with the standard semen analysis and clinical evaluation of the couple to assess male fertility potential.


Assuntos
Infertilidade Masculina/diagnóstico , Interações Espermatozoide-Óvulo , Varicocele/fisiopatologia , Feminino , Hormônio Liberador de Gonadotropina , Humanos , Infertilidade Masculina/etiologia , Masculino , Gravidez , Sêmen/análise , Varicocele/complicações
17.
Fertil Steril ; 48(2): 282-6, 1987 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3609339

RESUMO

Performance of spermatozoa in a hamster oocyte/human sperm penetration assay (SPA) was correlated with the results of in vitro fertilization (IVF). Forty-two patients underwent 50 IVF cycles. SPA scores were obtained before IVF cycles (screening SPA, n = 30) and, where practical, on the semen sample used for IVF (IVF SPA, n = 26). Screening SPA score did not correlate to IVF result, fertilization and cleavage rates were similar between normal (n = 17) and low (n = 13) SPA groups, pregnancy rates were 35 and 46%, respectively. In addition, SPA score at the time of IVF did not correlate with IVF result. Pregnancy rates were 33% for the normal group (n = 16) and 30% for the low SPA group (n = 10). Overall, the low SPA group (n = 16) exhibited a 78% fertilization rate and a 38% pregnancy rate, which was not different from the normal SPA group: 76 and 29%, respectively. The results of this study indicate that SPA score is a poor indicator of sperm function in IVF.


Assuntos
Fertilização in vitro , Interações Espermatozoide-Óvulo , Adulto , Feminino , Humanos , Masculino , Gravidez , Sêmen/análise
18.
Fertil Steril ; 71(1): 80-4, 1999 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-9935120

RESUMO

OBJECTIVE: To evaluate the level of variance produced in a multicenter study with the use of a computer-assisted sperm morphology analyzer. DESIGN: A multicenter, prospective, blinded study. SETTING: Assisted reproduction research laboratories. PATIENT(S): Semen samples produced for assisted reproductive procedures. INTERVENTION(S): Hamilton Thorne Research (Beverly, MA) integrated visual optical system semen analyzers were used at five different centers to evaluate the same set of 30 slides that were prepared and numerically coded at Tygerberg Hospital in Tygerberg, South Africa. MAIN OUTCOME MEASURE(S): The percentage of normal sperm. RESULT(S): Interlaboratory coefficients of variation (CVs) ranged between 16.31% and 23.09%. One of the participating laboratories produced an approximately 14% (-6.5-7.7) limits of agreement analysis, with a CV of 11.36%, for its duplicate readings. The use of a 10% normal sperm morphology cutoff point to determine discordance levels produced rates ranging between 10% and 23.3% for the interlaboratory and intralaboratory readings. This level of discordance equates with < or = 7 of the corresponding readings from two laboratories falling into a different normal sperm morphology group (< or = 10% or >10%). CONCLUSION(S): The magnitudes of variation produced by the readings performed in our study reached the same level as for the manual evaluation of sperm morphology. A < 10% CV can be obtained if the correct quality control measures are implemented.


Assuntos
Técnicas de Laboratório Clínico/normas , Diagnóstico por Computador/normas , Sêmen/citologia , Espermatozoides/ultraestrutura , Adulto , Diagnóstico por Computador/instrumentação , Humanos , Técnicas In Vitro , Laboratórios , Masculino
19.
J Androl ; 13(5): 349-60, 1992.
Artigo em Inglês | MEDLINE | ID: mdl-1429216

RESUMO

Assuring the highest possible quality of care to the patient is the first goal of the andrology laboratory. Quality control and quality assurance as they apply to the andrology laboratory are outlined, and special problems in quality control for sperm function assays are addressed. An example of the patient review process is presented. Quality of care also depends on the ability of the laboratory to perform appropriate tests of sperm function that can diagnose sperm defects, predict success or failure of in vitro fertilization, and lead to rational therapies for sperm dysfunctions. Methods for, and diagnostic value of, sperm swim-out, enhanced sperm penetration assays, acrosome reaction assessment, motility analysis of capacitating sperm, and sperm-zona binding assays are reviewed. No single test, other than in vitro fertilization itself, is capable of providing a complete diagnosis or a highly accurate prediction. A battery of sperm function tests, arranged in an algorithm, is presented as a theoretically better approach.


Assuntos
Laboratórios/normas , Técnicas Reprodutivas/normas , Testes Diagnósticos de Rotina/normas , Feminino , Humanos , Infertilidade Masculina/diagnóstico , Masculino , Valor Preditivo dos Testes , Controle de Qualidade , Espermatozoides
20.
J Androl ; 11(3): 216-26, 1990.
Artigo em Inglês | MEDLINE | ID: mdl-2384343

RESUMO

A potentially important event during sperm capacitation is the loss of sperm membrane cholesterol. Although the exact mechanisms mediating this loss are not known, albumin and high density lipoprotein have been proposed as lipid acceptors. The authors propose that lipid transfer may be involved in capacitation as a specific mediator in the sequence of events leading to sperm membrane cholesterol loss. We present the first direct evidence of lipid transfer activity (LTA) in human follicular fluid (HFF). The redistribution of 14C-cholesteryl ester among human plasma lipoproteins was used as a measure of LTA (% Transfer [%T]). The HFF was fractionated by S-300 gel filtration chromatography and assayed for LTA. Three peaks of activity were consistently eluted from the column. Each peak of LTA also stimulated human sperm to penetrate zona-free hamster oocytes after short capacitating incubations. The peak with highest LTA (12.75 +/- 1.11%T) with an Mr approximately 68,000, gave the greatest stimulation (penetration index, PI: 3.34 +/- 0.96 fold increase above control, n = 4). The HFF also showed a significant dose response for both LTA and PI, whereas bovine serum albumin did not. These results demonstrate the existence of LTA in HFF and suggest that a specific lipid transfer protein may have a role in human sperm capacitation or acrosome reaction.


Assuntos
Proteínas de Transporte/metabolismo , Líquido Folicular/metabolismo , Metabolismo dos Lipídeos , Capacitação Espermática , Animais , Sangue/metabolismo , Membrana Celular/metabolismo , Cromatografia em Gel , Cricetinae , Feminino , Humanos , Masculino , Mesocricetus , Albumina Sérica/metabolismo , Interações Espermatozoide-Óvulo
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