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T Toth

Publications and source records attributed to T Toth.

17 recordsLinked to original sources
PubMed2000

Analysis of follicular fluid hormone concentrations and granulosa cell mRNA levels for the inhibin-activin-follistatin system: relation to oocyte and embryo characteristics.

OBJECTIVE: To explore the potential roles of inhibin, activin, and follistatin in human oocyte development by quantifying their intrafollicular biosynthesis. DESIGN: Prospective, nonrandomized study. SETTING: An IVF unit and academic research laboratory. PATIENT(S): Thirty one patients undergoing IVF. INTERVENTION(S): Human menopausal gonadotropins or human FSH (or both) were administered. Single-follicle aspirates (n = 110) were collected for analysis. MAIN OUTCOME MEASURE(S): Concentrations of dimeric, total and pro-alphaC inhibin forms; activin A; follistatin; estradiol; and progesterone were measured in follicular fluids. Granulosa-cell mRNA was analyzed for alpha, beta A, and beta B inhibin and activin subunits; follistatin; activin receptors; and beta-actin. Hormone concentrations and mRNA levels were correlated with oocytes or embryos from the same follicles. RESULT(S): Levels of progesterone and follistatin were significantly greater in follicles containing MI or MII oocytes than in those containing GV oocytes. Inhibin alpha-subunit mRNA levels were significantly higher in follicles containing maturing oocytes, the highest-quality oocytes, and oocytes that were subsequently fertilized. In contrast, inhibin alpha-subunit mRNA levels were significantly lower in follicles from which higher-quality embryos were obtained. CONCLUSION(S): Inhibin alpha-subunit biosynthesis is associated with normal oocyte and follicle maturation, but excessive alpha-inhibin is associated with poor embryo quality. None of the hormones analyzed were associated with oocyte or embryo quality.

Actins↗
PubMed1998

Preparation by differential gradient centrifugation is better than swim-up in selecting sperm with normal morphology (strict criteria).

OBJECTIVE: To evaluate two commonly used methods of sperm preparation with respect to their effects on sperm morphology (strict criteria). DESIGN: Auto-controlled, split sample study performed on the semen of 74 male partners of couples enrolled for IVF. SETTING: In vitro fertilization and andrology laboratories at a tertiary care, major teaching hospital. PATIENT(S): Seventy-four male partners of couples who were scheduled to undergo IVF. INTERVENTION(S): Equal halves of the same semen sample were evaluated for strict criteria sperm morphology before and after preparation by differential gradient centrifugation using Percoll (Pacific Andrology, Montrose, CA) and by the standard swim-up method. MAIN OUTCOME MEASURE(S): The percentage of morphologically normal sperm was assessed using strict criteria before and after the two methods of sperm preparation. Specific parameters studied were individual abnormalities of the head, midpiece, and tail. RESULT(S): Sperm preparation using differential gradient centrifugation with Percoll produced a significantly greater number of specimens with normal sperm morphology and also showed higher absolute quantitative improvement over the swim-up method. The two methods were comparable in regard to their effects on specific sperm abnormalities (i.e., head, midpiece, and tail defects). CONCLUSION(S): The differential gradient sperm separation method using Percoll is superior to the swim-up method for selecting sperm with normal morphology as assessed by strict criteria. Because sperm morphology as assessed by strict criteria is a good predictor of oocyte fertilization, this method can be recommended as the method of choice for assisted reproductive technology laboratories. Use of this method may help improve outcome by increasing fertilization rates.

Centrifugation, Density Gradient↗
PubMed1998

Characterization of inhibin/activin subunit, activin receptor, and follistatin messenger ribonucleic acid in human and mouse oocytes: evidence for activin's paracrine signaling from granulosa cells to oocytes.

Inhibin, activin, and follistatin (FS) are gonadal proteins that appear to have a role in regulating folliculogenesis through possible paracrine and/or autocrine interactions. To further examine the potential role of activin in oocyte-granulosa cell communication, we developed a sensitive reverse transcription-polymerase chain reaction protocol to analyze mRNA for the alpha, betaA, and betaB inhibin/activin subunits, FS, and the four activin receptor subtypes in individual human and mouse oocytes. The resulting expression pattern was further compared to that in human cumulus granulosa cells. Our results indicate that neither ssA nor betaB mRNA was detectable in any human or mouse oocyte, that alpha subunit was marginally present in some of the human oocytes, and that FS mRNA was detectable in human but not mouse oocytes. On the other hand, inhibin/activin subunit and FS mRNAs were abundantly expressed in cumulus cells. In addition, mRNAs for all four activin receptor subtypes (ActRIA, ActRIB, ActRIIA, and ActRIIB) were easily detectable in both oocytes and granulosa cells and appeared to be differentially expressed in oocytes during nuclear maturation. Finally, RNAs for both zona pellucida 3 and growth-differentiation factor-9, which were originally used as oocyte-specific markers, were detected in human but not mouse cumulus cells, although at lower levels than observed in oocytes. Taken together with previous studies, these results indicate that oocytes may be capable of responding to, but not synthesizing, activin.

Activin Receptors↗
PubMed1997

Characterization of intrafollicular steroid hormones, inhibin, and follistatin in women with and without polycystic ovarian syndrome following gonadotropin hyperstimulation.

The etiology of polycystic ovary syndrome (PCOS) is unexplained. Since no major deficiencies are reported in serum FSH or inhibin, we hypothesized that abnormal levels of a paracrine modulator of FSH action within the ovary may be associated with the arrest of follicular growth seen in the PCOS ovary. Follicular fluid aspirates were collected from women with (n = 7) or without (n = 17) PCOS during oocyte retrieval for in vitro fertilization. Aspirates were assayed for total inhibin, inhibin A (InhA), inhibin B (InhB), and follistatin (FS), as well as for estradiol, progesterone (P4), androstenedione, and total protein. Hormone levels were compared between women with and without PCOS using all aspirates (some of which were collected from multiple follicles at once) and also between aspirates containing fluid from a single follicle only (PCOS, n = 30; non-PCOS, n = 107). P4 levels were significantly (p < 0.01) reduced in PCOS versus non-PCOS women as evidenced by analysis of all follicles as well as in single-follicle aspirates only. In addition, InhA, P4, and FS increased with follicle volume, and InhB decreased significantly in non-PCOS, but not in PCOS, follicles. Therefore, although follicular development can be induced in PCOS patients with gonadotropins, hormonal responses within the ovary appear inappropriate in terms of concentrations or patterns of secretion. These data support the concept that PCOS is associated with a deficit in the paracrine control of folliculogenesis.

Adult↗
PubMed1995

Serum follistatin levels in women: evidence against an endocrine function of ovarian follistatin.

Follistatin is a monomeric protein first identified in and isolated from ovarian follicular fluid. Evidence that follistatin might be an ovarian endocrine hormone functioning in a negative feedback fashion to modulate pituitary FSH production is based primarily on in vitro experiments. To examine the possible role of follistatin as an endocrine agent in vivo, we sought to relate circulating levels of follistatin to ovarian activity in women. Therefore, we developed a specific and sensitive homologous RIA using antiserum generated against recombinant human follistatin for the measurement of total follistatin in the presence or absence of activin. Follistatin was measured quantitatively (106 +/- 6% recovery) using calibration standards ranging from 0.4-25 ng/tube and up to 400 microL/tube serum. Furthermore, all of the endogenous follistatin measured in human serum could be removed by adsorption to activin-coated plates. Using this homologous RIA, human follicular fluid (100-600 ng/mL; n = 75) contained 3-150 times more follistatin than serum (4-35 ng/mL), an observation consistent with the notion that serum follistatin originates from the gonad. However, further studies of follistatin levels across the normal menstrual cycle (mean +/- SE, 8.09 +/- 0.73; n = 72 daily samples from 4 women), in pregnant women (17.49 +/- 1.34; n = 8), in daily samples from 20 women undergoing ovarian stimulation by exogenous FSH (9.90 +/- 0.62; n = 119), in postmenopausal women including two ovariectomized individuals (9.57 +/- 0.43; n = 8), and in GnRH-deficient women (9.85 +/- 0.50; n = 6) failed to support the hypothesis that serum levels of follistatin reflect ovarian activity in women. Levels of follistatin measured in serum collected across normal menstrual cycles did not fluctuate. However, the roughly nanomolar concentrations of follistatin measured suggest a physiological role for this protein. Follistatin at nanomolar concentrations may be capable of binding and inactivating circulating activin and perhaps in this way limiting the biological activity of activin to local autocrine or paracrine mechanisms. Measurement of peripheral levels of follistatin apparently represents only a first, albeit crucial, step in the study of the physiological significance of this protein in human reproduction.

Endocrine Glands↗
PubMed1992

Glomerular podocyte vacuolation in idiopathic membranous glomerulonephritis.

Vacuoles in glomerular visceral epithelial cells were found in 149 of 254 patients with idiopathic membranous glomerulonephritis (IMGN). In the whole population studied, 115 patients were nephrotic, 88 (76.5%) of which were found to have intraepithelial vacuoles. Fifty (35.9%) of 139 non-nephrotic patients had vacuolated podocytes (p less than 0.01). Vacuolation occurred most frequently in stages II and III of IMGN. A few intraepithelial vacuoles were observed in stage IV. Increase in vacuolation tended to correlate with subepithelial deposits which were larger in size. From these results, we concluded that the appearance of epithelial vacuolation coincides with an increased filtration of protein in IMGN and that it is an important histological marker when diagnosing the level of severity of glomerular lesions. It was not, however, prognostic.

Adult↗
PubMed1992

Idiopathic membranous glomerulonephritis: a clinicopathologic and quantitative morphometric study.

We evaluated clinical and morphological findings in 254 patients (138 men and 116 women), with idiopathic membranous glomerulonephritis (IMGN). The mean age was 44 years. At time of biopsy proteinuria was found in 98%, nephrotic syndrome (NS) in 45.2%, hypertension in 10%, elevated serum creatinine concentration of greater than or equal to 1.4 g/dl in 24%, and markedly decreased Ccr (less than or equal to 40 ml/min) in 12.5% of the patients. Of 254 patients, 51 (20%) were classified as Stage I, 131 (52%) as Stage II, 52 (20.5%) as Stage III, 9 (3.5%) as Stage IV and 11 (4.3%) as Stage V, which was a relapsing form. Both intraglomerular, peripheral electron dense deposit-size and mean thickness of the glomerular basement membrane (GBMt) were analyzed by ultrastructural morphometric methods. In patients with NS, both the mean deposit-size and the mean GBMt were largest when compared to all others (p less than 0.01). The largest subepithelial deposits (SED), in mean, were observed in Stages II and V, while the largest incorporated deposits (ICD) were measured in Stages II and IV. The mean GBMt was largest in Stage III. Furthermore, there were strong correlations between the degree of proteinuria and the deposit-size (r = 0.603, p less than 0.001), and GBMt (r = 0.456, p less than 0.001). The GBMt showed a correlation with serum creatinine concentration (r = 0.476, p less than 0.001) and Ccr (r = 0.471, p less than 0.001). We concluded that the size of the electron dense deposits and GBM thickness play an important role in the clinical manifestation of IMGN.

Adult↗
PubMed1985

On the prognostic potential of the sequential 123-I-HDA-tomoscintigram after the first MI.

Seven-pinhole tomography (SPT) using 123-I-heptadecanoic acid (HDA) is highly sensitive in confirming, sizing and localizing myocardial infarcts (MIs). Its prognostic value, however, is unknown. Thirty-five consecutive patients coming for a routine SPT within 10 days after MI underwent a second examination approximately 20 weeks later. These examinations combined an early (5 min) and a late (30 min) SPT after administration of 4 mCi 123-I-HDA, as well as a first pass radiocardioangiography. Scars and infarcts without residual HDA catabolism were related to lesions which followed (from 5 min to 30 min) a cool-cool or cold-cold behaviour. Cool-warm lesions (due to low HDA uptake and prolonged washout) were considered ischaemic. This ischaemic behaviour could not be correlated to the later course of the illness: in those patients with higher initial ischaemic scores, the ejection fraction did not increase disproportionately nor was the size of the lesion significantly smaller in the later examination than in those patients with lower ischaemic scores. Only a slightly better reduction of the end-diastolic volume was found in the patients with initially predominantly ischaemic lesions. Thus, SPT with HDA seems to be of limited value for an early prognostic evaluation of patients with MI.

Coronary Disease↗
PubMed1985

Immunochemical qualitative latex agglutination test for pancreatic lipase in serum evaluated for use in diagnosis of acute pancreatitis.

In 417 patients (213 men, 204 women) consecutively hospitalized with acute abdominal pain we evaluated the clinical usefulness of a latex-agglutination test at admission to screen for concentrations of pancreatic lipase (EC 3.1.1.3) in serum greater than 300 micrograms/L. The diagnoses of acute pancreatitis (in 25 patients, 6%) and other diseases were made without knowledge of the results of the latex test or of quantification of pancreatic lipase in the serum by enzyme immunoassay. In the latex assay, when agglutination was taken as a positive test for acute pancreatitis, we found a diagnostic efficiency of 0.986 (95% confidence limits: 0.971-0.997) for acute pancreatitis. The predictive value of a positive latex test result with respect to acute pancreatitis was 0.807 (0.625-0.926); the predictive value of a negative test was 1.000 (0.991-1.000). Six patients had false-positive test results. No false-negative test results were found by enzyme immunoassay. We conclude that the latex agglutination test is useful as an emergency test for diagnosis of acute pancreatitis in patients with acute abdominal pain; negative results virtually exclude acute pancreatitis.

Acute Disease↗
PubMed1983

Replication of five bovine respiratory viruses in cultured bovine alveolar macrophages.

The replication of five bovine respiratory viruses in cultured bovine alveolar macrophages (BAM) was investigated. The bovine herpesvirus DN-599 strain did not cause cytophatic effect (CPE), extracellular virus and intracellular antigen were not demonstrated. Although a small number of bovine respiratory syncytial virions were consistently released and about 1 percent of the BAM were fluorescence antibody (FA) positive the virus caused no CPE. Infectious bovine rhinotracheitis virus caused CPE at an input multiplicity of about 0.5, and 5 percent of the BAM were FA positive. Both bovine parainfluenza-3 and bovine viral diarrhea viruses caused CPE, infective virions were released and considerable proportions of the BAM were FA positive.

Animals↗
PubMedDate not supplied

Cytokeratins 7 and 14 in special types of invasive breast carcinomas.

Cytokeratins are typical constituents of the cytoskeleton of the epithelial cells and some other cell types. In normal breast tissue the luminal epithelium of the ducts and acini consistently expresses cytokeratin 7 (as well as 8, 18 and 19) while the myoepithelial cells are consistently cytokeratin 14-positive. We studied 20 invasive lobular, 10 medullary and 10 tubular breast carcinomas on expression of cytokeratins 7 and 14 using monoclonal primary antibodies in an automatic immunochemical system. All the carcinomas were cytokeratin 7-positive, but the percentage of positively stained tumor cells varied. The tumor cells of two medullary carcinomas expressed cytokeratin 14, a finding which can be interpreted as a result of squamous differentiation. Mapping of the cytokeratin profile of the special type of breast carcinomas has a practical importance for a more successful typing of adenocarcinomas in primary and metastatic sites.

Adenocarcinoma↗