956 resultados para sperm antibody


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BACKGROUND: Recent studies have shown that a low clinical pretest probability may be adequate for excluding heparin-induced thrombocytopenia. However, for patients with intermediate or high pretest probability, laboratory testing is essential for confirming or refuting the diagnosis. Rapid assessment of anti-PF4/heparin-antibodies may assist clinical decision-making. OBJECTIVES: To evaluate the performance of rapid ID-H/PF4-PaGIA. In particular, we verified reproducibility of results between plasma and serum specimens, between fresh and frozen samples, and between different ID-H/PF4-polymer lots (polystyrene beads coated with heparin/PF4-complexes). PATIENTS/METHODS: The samples studied were 1376 plasma and 914 corresponding serum samples from patients investigated for suspected heparin-induced thrombocytopenia between January 2000 and October 2008. Anti-PF4/heparin-antibodies were assessed by ID-H/PF4-PaGIA, commercially available ELISAs and heparin-induced platelet aggregation test. RESULTS: Among 914 paired plasma/serum samples we noted discordant results (negative vs. low-titre positive) in nine instances (1%; 95%CI, 0.4-1.6%). Overall, agreement between titres assessed in plasma vs. serum was highly significant (Spearman correlation coefficient, 0.975; P < 0.0001). Forty-seven samples tested both fresh and after freezing/thawing showed a good agreement, with one discordant positive/negative result (Spearman correlation coefficient, 0.970; P < 0.0001). Among 1376 plasma samples we noted a strikingly variable incidence of false negative results (none - 82%; 95%CI, 66-98%), depending on the employed ID-H/PF4-polymer lot. Faulty lots can be recognized by titrating commercial positive controls and stored samples of HIT-patients. CONCLUSION: Laboratories performing the assay should implement stringent internal quality controls in order to recognize potentially faulty ID-H/PF4-polymer lots, thus avoiding false negative results.

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OBJECTIVE: To evaluate whether intravaginal application of seminal plasma at the time of follicle aspiration in IVF or intracytoplasmic sperm injection treatment cycles has the potential to increase pregnancy rate. To calculate the number of patients needed to achieve significance in a multicenter trial. DESIGN: Double-blind, placebo-controlled randomized pilot study. SETTING: University department of gynecological endocrinology and reproductive medicine. PATIENT(S): One hundred sixty-eight patients undergoing IVF or intracytoplasmic sperm injection treatment. INTERVENTION(S): Cryopreserved seminal plasma from the patient's partner or sodium chloride (placebo) was injected into the cervix and the posterior fornix of the vagina just after follicle aspiration. MAIN OUTCOME MEASURE(S): Clinical-pregnancy rate. RESULT(S): One hundred sixty-eight patients agreed to participate in the study. Participation was limited to one treatment cycle. Thirty-one patients (18%) were excluded from the study, mainly as a result of canceled embryo transfers. Seventy patients received placebo, and 67 received seminal plasma. The clinical-pregnancy rate was 25.7% (18/70) in the placebo group. The clinical-pregnancy rate in the seminal plasma group reached 37.3% (25/67), corresponding to a relative increase of 45%. CONCLUSION(S): Even though significance was not reached in this pilot study, the data suggest that seminal plasma has the potential to improve pregnancy rate. It is estimated that around 450 patients need to be recruited to reach significance in a multicenter study.

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We assessed the serological responses over 10 years to repeated immunization of cystic fibrosis (CF) patients with an O-polysaccharide (OPS)-toxin A conjugate vaccine against Pseudomonas aeruginosa. A retrospective analysis was performed with sera from 25 vaccinated and 25 unvaccinated children treated at the same CF centre and matched for clinical management, age and gender. Yearly immunization led to sustained elevations of serum immunoglobulin G (IgG) antibody levels to all vaccine components. Eighteen unvaccinated patients but only eight vaccinated ones developed chronic pseudomonal lung infections. Infection rapidly caused further marked elevations of polysaccharide- but not toxin A-specific serum IgG in both immunized and nonimmunized patients, indicating that protection did not depend on the quantity of IgG present. However, qualitative analyses revealed that the protective capacity of specific serum IgG antibodies was linked to high affinity and to specificity for OPS serotypes rather than for lipopolysaccharide core epitopes.

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KBPA-101 is a human monoclonal antibody of the immunoglobulin M isotype, which is directed against the O-polysaccharide moiety of Pseudomonas aeruginosa serotype O11. This double-blind, dose escalation study evaluated the safety and pharmacokinetics of KBPA-101 in 32 healthy volunteers aged 19 to 46 years. Each subject received a single intravenous infusion of KBPA-101 at a dose of 0.1, 0.4, 1.2, or 4 mg/kg of body weight or placebo infused over 2 h. Plasma samples for pharmacokinetic assessments were taken before infusion as well as 0.25, 0.5, 1, 2, 2.5, 4, 6, 8, 12, 24, 36, and 48 h and 4, 7, 10, and 14 days after start of dosing. Plasma concentrations of KBPA-101 were detected with mean maximum concentrations of drug in plasma of 1,877, 7,571, 24,923, and 83,197 ng/ml following doses of 0.1, 0.4, 1.2, and 4.0 mg/kg body weight, respectively. The mean elimination half-life was between 70 and 95 h. The mean volume of distribution was between 4.76 and 5.47 liters. Clearance ranged between 0.039 and 0.120 liters/h. At the highest dose of 4.0 mg/kg, plasma KBPA-101 levels were greater than 5,000 ng/ml for 14 days. KBPA-101 exhibited linear kinetics across all doses. No anti-KBPA-101 antibodies were detected after dosing in any subject. Overall, the human monoclonal antibody KBPA-101 was well tolerated over the entire dose range in healthy volunteers, and no serious adverse events have been reported.

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DNA methylation patterns at the IGF2-H19 locus were investigated in sperm DNA from Swiss Landrace (SL) and Swiss Large White (LW) boars. The putative IGF2 differentially methylated regions (DMR) 0, 1 and 2, a quantitative trait nucleotide (QTN) region in the intron 3 and a CpG island in the intron 4 of the IGF2 gene as well as three regions around porcine CTCF binding sites within the H19 differentially methylated domain (DMD) were selected for the DNA methylation analysis. In both breeds putative IGF2 DMR0, 1, 2 and H19 DMD were hypermethylated. Significant differences in DNA methylation content were found between the two breeds in the two DMD regions proximal to the H19 gene. The IGF2 QTN region and the CpG island in the IGF2 intron 4 were hypomethylated in sperm DNA of both breeds. The methylation analysis revealed significantly more methylated CpG sites in the intron 4 of sperm from the LW breed than in that from SL. No difference was found in global DNA methylation between the two breeds. These results indicate differences in DNA methylation patterns between breeds and it remains to be established whether variation in DNA methylation patterns impacts on phenotypic traits.

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Respiratory disease in beef calves has been associated with the stress of weaning. Management practices commonly delay vaccination of calves to this time, and weaning stress could potentially suppress the immune response. To reduce this stress we have been experimenting with a procedure termed “pasture weaning” in which the dams are removed and the calves remain on pasture. Observation suggests that calves weaned with this approach adapt to the weaned state much better than those held in drylot. Consequently, one would expect less stress-mediated effects including those on the immune system. Calves were weaned and assigned to groups that were pasture or drylot weaned, and calves within the groups were vaccinated with one of two inactivated virus vaccines by either the intramuscular or subcutaneous route. Weaning placement did not affect antibody responses to the viruses included in the vaccines. The route of administration did not influence responses with subcutaneous injection inducing responses equivalent to the intramuscular site. Utilization of this route for vaccination could be advantageous because it precludes the tissue damage and hidden abscessation that sometimes results from intramuscular injections. A distinct difference was noted in the immunogenicity of the vaccines with the Vira Shield product yielding significantly better responses to all viral entities.

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Respiratory disease resulting from infection of calves with Haemophilus somnus (H. somnus) is an annual occurrence in fall calves at the McNay Farm. Previous observations of skin test reactivity to H. somnus antigens suggested a role for this phenomenon in the pathogenesis of the disease. Groups of calves, about 90 days of age, were vaccinated with four different commercial H. somnus vaccines, and serum levels of H. somnus antibodies were determined. Antibodies of the IgG and IgE classes were detected with ELISA procedures conducted on sera collected before and after vaccination. Most of the calves had detectable H. somnus IgE class antibodies at the start of the experimentation but IgG class antibodies were minimal. Antibodies of both classes increased in nonvaccinated and vaccinated calves during the 30 day period of experimentation. However, the level of IgE class antibodies in vaccinates was lower than in controls suggesting that vaccination may limit the IgE response.

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The objective of this experimentation was to determine if circulating antibody titers to parainfluenza type-3 (PI-3) and infectious bovine rhinotracheitis (IBR) viruses could be enhanced by a combination of vaccines. The vaccines utilized were a modified live virus vaccine administered by the intranasal route and an inactivated virus vaccine injected intramuscularly. Virus neutralization tests were conducted on sera obtained at intervals before and following vaccination. Unfortunately, the calves were apparently exposed naturally to PI-3 virus, and the responses to that virus were inconclusive. However, antibody responses to IBR virus were dramatically enhanced by the combination of the two vaccines.

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Three commercial inactivated virus vaccines were evaluated for immunogenicity in young calves with residual maternal antibodies. Groups of 30 calves were administered each of the vaccines at the start of the experimentation and were administered a second dose 32 days later. Serum was obtained from these calves and 30 calves in a nonvaccinated control group prior to vaccination and at 32, 61, 99 and 125 days thereafter. Antibody responses to viruses in two of the vaccines were extremely limited. The third vaccine overcame suppression by maternal antibodies and elicited responses clearly differentiated from antibody levels in the control group of calves.

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BACKGROUND Timing is critical for efficient hepatitis A vaccination in high endemic areas as high levels of maternal IgG antibodies against the hepatitis A virus (HAV) present in the first year of life may impede the vaccine response. OBJECTIVES To describe the kinetics of the decline of anti-HAV maternal antibodies, and to estimate the time of complete loss of maternal antibodies in infants in León, Nicaragua, a region in which almost all mothers are anti-HAV seropositive. METHODS We collected cord blood samples from 99 healthy newborns together with 49 corresponding maternal blood samples, as well as further blood samples at 2 and 7 months of age. Anti-HAV IgG antibody levels were measured by enzyme immunoassay (EIA). We predicted the time when antibodies would fall below 10 mIU/ml, the presumed lowest level of seroprotection. RESULTS Seroprevalence was 100% at birth (GMC 8392 mIU/ml); maternal and cord blood antibody concentrations were similar. The maternal antibody levels of the infants decreased exponentially with age and the half-life of the maternal antibody was estimated to be 40 days. The relationship between the antibody concentration at birth and time until full waning was described as: critical age (months)=3.355+1.969 × log(10)(Ab-level at birth). The survival model estimated that loss of passive immunity will have occurred in 95% of infants by the age of 13.2 months. CONCLUSIONS Complete waning of maternal anti-HAV antibodies may take until early in the second year of life. The here-derived formula relating maternal or cord blood antibody concentrations to the age at which passive immunity is lost may be used to determine the optimal age of childhood HAV vaccination.

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In search of transmittable epigenetic marks we investigated gene expression in testes and sperm cells of differentially fed F0 boars from a three generation pig feeding experiment that showed phenotypic differences in the F2 generation. RNA samples from 8 testes of boars that received either a diet enriched in methylating micronutrients or a control diet were analyzed by microarray analysis. We found moderate differential expression between testes of differentially fed boars with a high FDR of 0.82 indicating that most of the differentially expressed genes were false positives. Nevertheless, we performed a pathway analysis and found disparate pathway maps of development_A2B receptor: action via G-protein alpha s, cell adhesion_Tight junctions and cell adhesion_Endothelial cell contacts by junctional mechanisms which show inconclusive relation to epigenetic inheritance. Four RNA samples from sperm cells of these differentially fed boars were analyzed by RNA-Seq methodology. We found no differential gene expression in sperm cells of the two groups (adjusted P-value>0.05). Nevertheless, we also explored gene expression in sperm by a pathway analysis showing that genes were enriched for the pathway maps of bacterial infections in cystic fibrosis (CF) airways, glycolysis and gluconeogenesis p.3 and cell cycle_Initiation of mitosis. Again, these pathway maps are miscellaneous without an obvious relationship to epigenetic inheritance. It is concluded that the methylating micronutrients moderately if at all affects RNA expression in testes of differentially fed boars. Furthermore, gene expression in sperm cells is not significantly affected by extensive supplementation of methylating micronutrients and thus RNA molecules could not be established as the epigenetic mark in this feeding experiment.

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The objective of this study was to determine whether cancer chemotherapy induces detectable mutations in DNA of the human germline and whether minisatellite repeat number changes can be used as a sensitive indicator of genetic damage in human sperm caused by mutagens. We compared the mutation frequencies in sperm of the same cancer patients pre- and post-, pre- and during, or during and post-treatment. Small pool polymerase chain reaction (SP-PCR) (DNA equivalent to approximately 100 sperm) and Southern blotting techniques were used to detect mutations and quantify the frequency of repeat number changes at the minisatellite MS205 locus. One pre- and one post-treatment semen sample was obtained from each Hodgkin's disease patient treated with either: (1) a regimen without alkylating agents, Novantrone, Oncovin, Vinblastine, and Prednisone (NOVP), 4 patients; (2) a regimen containing alkylating agents, Cytoxan, Vinblastine, Procarbazine, and Prednisone (CVPP)/Adriamycin, Bleomycin, DTIC, CCNU, and Prednisone (ABDIC), 2 patients; and (3) a regimen containing alkylating agents, Mechlorethamine, Oncovin, Procarbazine, and Prednisone (MOPP), 1 patient. One pre- and one during treatment semen sample from each of two Hodgkin's disease patients treated with Adriamycin, Bleomycin, Vinblastine, and Dacarbazine (ABVD) were obtained. One during and one post-treatment semen sample from a Hodgkin's disease patient treated with NOVP were also obtained. At least 7900 sperm in each sample were screened for the repeat number changes at the MS205 locus by multi-aliquots of SP-PCR. The mutation frequencies of pre- and post-treatment for the four patients treated with NOVP were 0.22 and 0.18%; 0.24 and 0.16%; 0.35 and 0.28%; and 0.19 and 0.18%. With CVPP/ABDIC, they were 0.22 and 0.23%; and 0.94 and 0.98% for the two patients and with MOPP they were 0.79 and 1.14%. The mutation frequencies of pre- and during treatment with ABVD were 0.09 and 0.07%; and 0.34 and 0.27% for the two patients. The mutation frequencies of during and post-treatment with NOVP for one patient were 0.31 and 0.25%. A statistically significant increase in mutation frequency was only found in the patient treated with MOPP. According to the time of samples collected after or during treatment and the above results, we conclude that there is no effect of NOVP and CVPP/ABDIC regimens on the mutation frequency in spermatogonia. The spermatocytes are not highly sensitive to chemotherapy agents compared to spermatogonia at the minisatellite MS205 locus. MOPP treatment may increase the mutation frequency at the MS205 locus in spermatogonia. ^