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J Varga

Publications and source records attributed to J Varga.

At least 91 records · Page 5Linked to original sources
PubMed1998

Comparison of ultrasonography, bovine pregnancy-specific protein B, and bovine pregnancy-associated glycoprotein 1 tests for pregnancy detection in dairy cows.

At Days 26 to 58 after AI, 138 Holstein-Friesian dairy cows were repeatedly examined by ultrasonography, using a 7.5 MHz linear-array rectal transducer. The total calving rate was 37.6% (52/138), and late embryonic mortality occurred 8.6% of the cows (12/138). On the days of ultrasound scanning, blood samples were drawn from the jugular vein for measuring the concentration of bovine pregnancy-specific protein B (bPSPB) and bovine pregnancy-associated glycoprotein 1 (bPAG 1). When compared with calving results, there were no significant differences in accurate diagnosis of pregnant cows were found between the 3 methods. However, when recognition of an embryo proper with a beating heart was used as the criterion for positive ultrasonographic diagnosis significantly fewer (P < 0.001) pregnant cows were correctly identified than by the other 2 tests. When compared with the noncalving cows, significantly fewer (P < 0.001) false positive diagnoses were made by the 2 ultrasonographic tests than by the PSPB and bPAG 1 tests, while significantly fewer (P < 0.001) false positive diagnoses were made by the bPSPB test than by the bPAG 1 test. The accuracy of detecting nonpregnant animals by both protein tests was limited by the relatively long half-life of these proteins after calving and by early embryonic mortality.

Animals↗
PubMed1998

Evaluation of false ultrasonographic diagnoses in cows by measuring plasma levels of bovine pregnancy-associated glycoprotein 1.

Between days 27 and 59 after artificial insemination (AI), 189 ultrasonographic pregnancy diagnoses were made in 56 dairy cows using a 7.5 MHz linear-array rectal transducer. Blood samples were withdrawn from a jugular vein on the day of AI, on day 21, and after each ultrasonographic examination between days 27 and 31, days 34 and 38, days 41 and 45 and days 55 and 59 after AI. Plasma concentrations of bovine pregnancy-associated glycoprotein 1 (bPAG-1) were measured by radioimmunoassay. The results showed that before day 31, ultrasonographic scanning was not very sensitive because six of the 30 calving cows were incorrectly diagnosed as non-pregnant. In five of these animals, the uterus was located far cranial to the pelvic inlet. Five of the cows examined between days 27 and 31 were pregnant on the basis of plasma bPAG-1 levels on the same day, using 0.5 ng/ml as the cut-off point. Plasma levels of bPAG-1 and progesterone proved that four of the cows which had early positive ultrasonographic diagnoses but did not produce a calf, were pregnant when they were examined.

Animals↗
PubMed1998

Modulation of cellular tryptophan metabolism in human fibroblasts by transforming growth factor-beta: selective inhibition of indoleamine 2,3-dioxygenase and tryptophanyl-tRNA synthetase gene expression.

Alterations in the rate of cellular tryptophan metabolism are involved in mediating important biological activities associated with cytokines and growth factors. Indoleamine 2,3-dioxygenase (IDO) and tryptophanyl-tRNA synthetase are enzymes of tryptophan metabolism whose expression in a variety of cells and tissues is highly inducible by interferon-gamma (IFN-gamma). Transforming growth factor-beta (TGF-beta) antagonizes many cellular responses to IFN-gamma. The interaction of these two cytokines plays an important role in maintaining homeostasis during inflammation and repair. In human skin and synovial fibroblasts in vitro, TGF-beta caused time- and dose-dependent abrogation of IFN-gamma-stimulated expression of IDO and tryptophanyl-tRNA synthetase mRNAs. The inhibition was selective and did not appear to be due to down-regulation of IFN-gamma signaling by TGF-beta. In parallel with its effect on IDO mRNA expression, TGF-beta caused a marked reduction in intracellular IDO protein levels and abrogated IDO activity and tryptophan catabolism in these cells induced by IFN-gamma. IFN-gamma caused a rapid and striking increase in the amount of IDO heterogeneous nuclear pre-mRNA and induced transcription of the IDO gene, as demonstrated by transient transfection assays. TGF-beta partially reversed this stimulation. IFN regulatory factor (IRF)-1 and stat1 are cellular intermediates in IFN signaling. Both are implicated in activation of IDO transcription in response to IFN-gamma. The stimulation by IFN-gamma of IRF-1 protein and mRNA expression was not prevented by treatment of fibroblasts with TGF-beta. Furthermore, gel mobility shift assays indicated that TGF-beta did not inhibit the induction of stat1 and IRF-1 binding activity to their cognate DNA recognition sites in the IDO gene promoter. In contrast, the stability of IDO mRNA transcripts was reduced in fibroblasts treated with TGF-beta, as shown by determination of mRNA half-lives following blockade of transcription with 5,6-dichlorobenzimidazole riboside. The findings indicate that TGF-beta prevents the induction of IDO and tryptophanyl-tRNA synthetase gene expression in fibroblasts. The repression of IDO expression by TGF-beta is mediated at both transcriptional and posttranscriptional levels. These results implicate TGF-beta in the negative regulation of tryptophan metabolism, provide evidence for the molecular basis of this regulation, and indicate that cellular tryptophan metabolism is under tight immunological control.

Adult↗
PubMed1998

Oral iloprost treatment in patients with Raynaud's phenomenon secondary to systemic sclerosis: a multicenter, placebo-controlled, double-blind study.

OBJECTIVE: To evaluate the efficacy and tolerability of an oral preparation of iloprost, a prostacyclin analog, in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (scleroderma). METHODS: A multicenter, randomized, parallel-group, placebo-controlled double-blind study was performed at university and community-based medical centers. Patients were randomly assigned to receive either 50 microg of iloprost orally twice daily or an identical gelatin-coated capsule containing placebo for 6 weeks. Outcome measures included average total daily duration of RP attacks, average number of RP attacks, and RP condition scored via a standardized daily diary. RESULTS: Three hundred eight patients with scleroderma (272 women, 36 men, mean age 49 years [range 18-80]) were enrolled. One hundred fifty seven were assigned to receive iloprost and 151 to receive placebo. One hundred forty-three patients in the iloprost group (91.1%) and 144 in the placebo group (95.4%) completed the 6-week treatment phase. Fifteen of these treated patients (8 iloprost, 7 placebo) failed to complete all of the followup visits. The mean reduction in the average duration of attacks from baseline to week 5-6 was 24.32 minutes in the iloprost group and 34.34 minutes in the placebo group (P = 0.569). Likewise, the mean reduction from baseline to week 5-6 in the daily frequency of attacks was 1.02 in the iloprost group and 0.83 in the placebo group (P = 0.459). The Raynaud's condition score, a patient-completed assessment of the severity of RP attacks, was reduced by 1.32 in the iloprost group and 1.00 in the placebo group (P = 0.323). The lack of significant difference between treatment groups did not change when a variety of factors, including use of other vasodilators, duration of disease, classification of scleroderma (limited versus diffuse), or number of baseline digital ulcers were taken into account. Premature withdrawal from the study due to adverse events occurred in 10 patients (6.4%) in the iloprost group and 3 (2.0%) in the placebo group (P = 0.058). CONCLUSION: Oral iloprost at a dosage of 50 microg twice daily is no better than placebo for management of RP secondary to scleroderma, either during 6 weeks of treatment or during 6 weeks of posttreatment followup.

Administration, Oral↗
PubMed1998

Identification of elements in the promoter region of the alpha1(I) procollagen gene involved in its up-regulated expression in systemic sclerosis.

OBJECTIVE: To identify regulatory elements in the promoter region of the alpha1(I) procollagen gene (COL1A1) involved in the transcriptional activation of this gene in systemic sclerosis (SSc), and to identify the transcription factors interacting with these regulatory elements. METHODS: Dermal fibroblasts from 6 patients with diffuse SSc of recent onset and from 6 healthy individuals were studied. The transcriptional regulation of COL1A1 was examined by transient transfections with deletion constructs containing portions of the COL1A1 promoter. The DNA binding activity of nuclear proteins recognizing the regulatory regions in the COL1A1 promoter was examined by gel mobility shift assays. A procedure was established to allow the quantitative determination of the amount of DNA binding proteins interacting with the COL1A1 promoter, employing DNA binding protein and DNA titration experiments analyzed by gel mobility shift assays. RESULTS: Maximal chloramphenicol acetyltransferase activity was observed with a -174-bp to +42-bp COL1A1 promoter construct in both normal and SSc cells; however, the activity driven by this construct was 70-260% higher in SSc fibroblasts. Most of the transcriptional activity of the COL1A1 promoter was contained in a minimal promoter region encompassing -174 bp to -84 bp. Electrophoretic mobility shift assays performed with oligonucleotides corresponding to the regions spanning -129/-107 bp and -104/-78 bp of the COL1A1 promoter revealed marked increases in the intensities of DNA-protein complexes formed with both oligonucleotides in nuclear extracts prepared from each of the SSc cell lines in comparison with normal fibroblasts. Competition experiments showed that each of these regions contained elements recognized by Sp1 and nuclear factor 1 (NF-1) binding proteins. A quantitative determination of DNA binding activity recognizing the Sp1 binding element within the -129/-107-bp region showed that it was 23.6 nM in SSc fibroblasts compared with 6.9 nM in normal fibroblasts. CONCLUSION: The results demonstrate that a short region in the proximal promoter of COL1A1 containing 2 tandem NF-1/Sp1 elements displays up-regulated transcriptional activity in SSc fibroblasts, and that SSc fibroblasts contain 3.4-fold greater DNA binding activity recognizing these elements than normal cells.

Binding, Competitive↗
PubMed1998

Recombination of mitochondrial DNA without selection pressure among compatible strains of the Aspergillus niger species aggregate.

Previous mitochondrial transmission experiments between oligomycin-resistant and oligomycin-sensitive incompatible strains of the A. niger aggregate bearing various mtDNA RFLP profiles resulted in a great variety of mitochondrial recombinants under selection pressure. Apart from the recombinant mtDNAs, resistant clones harbouring unchanged RFLP profiles of resistant donor mtDNAs with the recipient nuclear backgrounds were rarely isolated. These strains were anastomosed with nuclearly isogenic oligomycin-sensitive recipient partners and the mitochondria of the resulting progeny were examined under non-selective conditions. These experiments provide insights into events which are possibly similar to those occurring in nature. The heterokaryons obtained formed both oligomycin-resistant and -sensitive sectors, most of which were found to be homoplasmons. Progenies harbouring oligomycin-resistant and -sensitive mtDNAs may originate either from individual recombination events or be due to parental segregation. MtDNA recombination might take place in the heterokaryons without selection by oligomycin. The most frequent recombinant types of mtDNA RFLP profiles were indistinguishable from those recombinant mtDNAs which were frequently obtained under selection pressure from directed transfer experiments between incompatible strains. We present evidence that mixed mitochondrial populations may influence the compatibility reactions in the presence of an isogenic nuclear background, that recombination may take place without selection pressure, and that the process does not require specific nuclear sequences of both parental strains.

Anti-Bacterial Agents↗
PubMed1998

Beneficial effects of pentoxifylline treatment of experimental acute pancreatitis in rats.

UNLABELLED: The purposes of this study were to determine the tumor necrosis factor (TNF) and interleukin-6 (IL-6) levels after the induction of acute necrotizing pancreatitis, and to establish the effects of pentoxifylline on cytokine production. METHODS: acute pancreatitis was induced by the retrograde injection of 200 microliters taurocholic acid into the pancreatic duct in male Wistar rats. The serum amylase activity, the wet pancreatic weight/body weight ratio, and the TNF and IL-6 levels were measured. Seven mg/kg pentoxifylline were administered intraperitoneally at the time of operation 6, 12 or 24 h later. Rats were killed 6, 24, 48 or 72 h after the operation. RESULTS: the TNF bioassay revealed high levels of TNF (30.2 +/- 5.4 U/ml, 35.0 +/- 5.0 U/ml and 36.6 +/- 6.0 U/ml) in the control group at 6, 24 and 48 h and (54.1 +/- 20 U/ml and 10.9 +/- 4.2 U/ml) in the pentoxifylline-treated group at 6 and 24 h, respectively, whereas the level had decreased to zero in the pentoxifylline-treated group at 48 h. The IL-6 bioassay likewise demonstrated high levels of IL-6 in the control group at 48 h and in the pentoxifylline-treated group at 6 and 24 h, and markedly decreased levels in the pentoxifylline-treated group at 48 h (7083 +/- 2844 pg/ml, 6463 +/- 1307 pg/ml, 10,329 +/- 5571 pg/ml vs 137.5 +/- 85.5 pg/ml, respectively, P < 0.05). The high mortality observed in the pancreatitis group (43%) was decreased by pentoxifylline administration to 11%. CONCLUSION: these results demonstrate that pentoxifylline very effectively inhibits cytokine production in acute pancreatitis.

Acute Disease↗
PubMed1998

Biochemical characteristics, serogroup distribution, antibiotic susceptibility and age-related significance of Campylobacter strains causing diarrhoea in humans in Hungary.

During August and September 1995, 111 thermopilic campylobacters from stool samples of patients suffering from diarrhoea were cultured and f1amined. Biochemical characteristics, serological distribution and antibiotic susceptibility of the strains were examined and the age distribution of the patients affected was recorded. Most of the strains, i.e. 101 isolates (91%) proved to be Campylobacter (C.) jejuni, whereas 10 strains (9%) were C. coli. On the basis of their heat-stable antigens, 66 strains (65.3%) of C. jejuni could be assigned to 17 serogroups, of which serogroups 2 (15 strains, 14.8%) and 8 (10 strains, 9.9%) occurred most frequently. All isolates examined were susceptible to erythromycin whereas susceptibility to other antibiotics varied greatly. Children under five years of age (59 cases = 53.1%) were most frequently affected. During 1995, altogether 11,976 human Campylobacter cases were recorded in Hungary which means a prevalence of 114/100,000. The results suggest that the great majority of cases of Campylobacter diarrhoea is caused by C. jejuni strains while C. coli strains have much less significance. The serotype distribution of C. jejuni strains causing diarrhoea is very wide. If treatment is needed the best choice at present seems to be erythromycin.

Adolescent↗
PubMed1998

Modulation of basal expression of the human alpha1(I) procollagen gene (COL1A1) by tandem NF-1/Sp1 promoter elements in normal human dermal fibroblasts.

We previously demonstrated that a segment of the human alpha1 type I procollagen gene (COL1A1) promoter encompassing nt -174 to -84 is responsible for the highest transcriptional activity in collagen producing cells in vitro. Here, we identified two almost identical tandem NF-1/Sp1 binding sites located between nt -129 to -107 (distal element) and nt -104 to -77 (proximal element) that are responsible for the basal regulation of COL1A1 transcription in normal human dermal fibroblasts. Transient transfection studies revealed that 85% of the basal COL1A1 promoter activity resides within the distal element; however, site-directed mutagenesis within the CCAAT motif in the proximal element resulted in a 98% decrease of the COL1A1 promoter activity. We conclude that each of the NF-1/Sp1 tandem binding sites has a different function. The distal element drives the transcriptional activity of the COL1A1 promoter but is not sufficient for its basal expression, whereas the NF-1 binding site in the proximal element is essential for in vitro COL1A1 gene transcription.

Base Sequence↗
PubMed1998

Abnormal uptake of Tc-99m MIBI, a novel myocardial imaging agent, in the lungs of patients with systemic sclerosis.

OBJECTIVE: Fibrosing alveolitis is a prominent feature of systemic sclerosis (SSc), and accounts for much of the morbidity and mortality of this disease. Sensitive techniques for the detection and monitoring of fibrosing alveolitis could target patients for early therapeutic intervention. The objective of this small pilot study was to assess the frequency and clinical significance of abnormal lung uptake of Tc-99m MIBI, a novel radionuclide imaging agent that selectively accumulates in cells rich in mitochondria. METHODS: Sixteen patients with SSc and evidence of pulmonary involvement were studied. The uptake of radionuclide in the lungs, and the ratio of pulmonary to cardiac uptake were evaluated after intravenous injection of Tc-99m MIBI. Results were correlated with clinical and laboratory parameters. RESULTS: Lung uptake of Tc-99m MIBI was increased in all 16 SSc patients compared to control patients with coronary heart disease but no evidence of pulmonary abnormality. The degree of isotope uptake in the lungs was correlated with the extent of maximal skin induration and with radiologic evidence of interstitial lung disease, but not with other clinical or laboratory parameters of disease activity or extent of pulmonary involvement. The ratio of pulmonary to cardiac uptake of isotope was also increased in patients with SSc compared to controls. CONCLUSION: Accumulation of Tc-99m MIBI is abnormally elevated in the lungs of SSc patients with pulmonary involvement. Isotope accumulation in the lungs may be related to activation of fibroblasts or endothelial cells. The specificity and sensitivity of Tc-99m MIBI scanning in the detection and monitoring of pulmonary involvement, and its potential role in the management of SSc, deserve further investigation.

Coronary Disease↗
PubMed1998

Carbon dioxide laser resurfacing of peri-oral rhytids in scleroderma patients.

BACKGROUND: The short pulse duration high-energy carbon dioxide (CO2) lasers have been used in the past for treating cutaneous pathology and more recently for cosmetic improvements of rhytids, photo-aging, and acne. OBJECTIVE: This study was undertaken to determine the benefits of CO2 laser resurfacing on the severe peri-oral rhytidosis commonly seen in patients with systemic scleroderma. METHODS: Three patients were studied and evaluated for satisfactory wound healing, improved cosmetic result, and lack of complications. RESULTS: All three patients experienced significant improvement following laser resurfacing. CONCLUSION: The study demonstrated the safe and effective treatment for peri-oral rhytidosis in patients with generalized scleroderma utilizing CO2 laser resurfacing.

Aged↗
PubMed1998

Cerebral effects of a single dose of intravenous vinpocetine in chronic stroke patients: a PET study.

The effects of vinpocetine (Cavinton) on the cerebral glucose metabolism of chronic stroke patients are studied with positron emission tomography. The regional and global cerebral metabolic rates of glucose (CMRglu) and the kinetic constants related to them are quantified before and after single-dose intravenous vinpocetine treatment. These measurements are completed with transcranial Doppler sonography and single photon emission computed tomography to explore the possible mechanisms underlying the resulting changes in glucose uptake and metabolism in the brain. The authors' findings indicate that a single-dose vinpocetine treatment, although it does not affect significantly the regional or global metabolic rates of glucose, improves significantly the transport of glucose (both uptake and release) through the blood-brain barrier in the whole brain, the entire contralateral hemisphere, and in the brain tissue around the infarct area of the symptomatic hemisphere. These changes are in accord with increased blood flow in the entire contralateral hemisphere as well as decreased blood flow velocity and increased peripheral vessel resistance in the entire symptomatic hemisphere.

Aged↗
PubMed1998

Double-stranded RNA mycoviruses in species of Aspergillus sections Circumdati and Fumigati.

Isolates (178) belonging to Aspergillus sections Fumigati, Candidi, Clavati, and Circumdati were tested for the presence of double-stranded RNA (dsRNA) genomes. Altogether, 5.6% of the Aspergillus strains examined were infected with dsRNAs. dsRNA segments indicative of mycovirus infection were observed for the first time in Neosartorya hiratsukae, Neosartorya quadricincta, Petromyces alliaceus, and Aspergillus clavatus strains. Correlation was not observed between ochratoxin production and dsRNA content of the strains. This is the first report on the detection of naturally occurring dsRNAs in Aspergillus species that are able to reproduce sexually. The detection of dsRNA in sexual aspergilli gave us a chance to examine the transmission of these segments through ascospores. A Neosartorya hiratsukae strain transmitted the dsRNAs efficiently through sexual spores, while the stromata embedding the asci in Petromyces alliaceus did not transmit one of the dsRNA segments. The 0.6-kb dsRNA segment that was present in the single-stromatal cultures was found to be located in the mitochondrial fraction of this strain. This observation indicates that some mechanisms exist in aspergilli to exclude cytoplasmically located dsRNA molecules from stromatal structures.

Antifungal Agents↗
PubMed1998

High frequency of abnormal levels of IgA anti-beta2-glycoprotein I antibodies in patients with systemic lupus erythematosus: relationship with antiphospholipid syndrome.

OBJECTIVE: To determine the frequency of IgA, in addition to IgM and IgG, anti-beta2-GPI and anticardiolipin (aCL) antibodies in patients with systemic lupus erythematosus (SLE), and to relate the presence of these antibodies to symptoms of antiphospholipid antibody syndrome (APS). METHODS: Sera from 100 blood bank donors (controls) and 48 patients with SLE were tested by ELISA. The same enzyme conjugates were used in the measurement of aCL and anti-beta2-GPI. Medical records were reviewed for the presence of manifestations of APS: arterial occlusion, pulmonary embolism, cerebrovascular accident, transient ischemic attack, venous thrombosis (deep or superficial), hemolytic anemia, thrombocytopenia, repeated fetal loss, leg ulcers, seizures, avascular bone necrosis, cerebritis, or migraine. RESULTS: Above normal levels of antibodies of all 3 isotypes against beta2-GPI were found in 5% of controls and 73% of patients with SLE. Antibodies against cardiolipin in the 2 groups were found in 5 and 37%, respectively. IgA anti-beta2-GPI was found in 2% of controls and 58% of patients with SLE; in contrast, only 2% of patients with SLE had IgA aCL. In the 48 patients studied, thrombosis and fetal loss were present in 10 (Group 1), other manifestations of APS were present in 18 (Group 2), and none in 20 (Group 3). Antibodies to beta2-GPI of all 3 isotypes were found in a higher proportion of APS (Group 1 plus Group 2) (82%) than in Group 3 (50%) (p < 0.01, chi-squared). There was also a significantly higher proportion of patients with elevated anti-beta2-GPI in Group 1 (90%) than in Group 3 (p < 0.02). There was a significantly higher frequency (p < 0.01) and level (p < 0.05) of IgA anti-beta2-GPI in patients with APS than in those with no APS manifestations. Moreover, compared to aCL and with other isotypes of anti-beta2-GPI, the highest antibody levels were observed in IgA antibeta2-GPI. CONCLUSION: The sensitivity of the anti-beta2-GPI antibody test for APS in patients with SLE is significantly increased by measuring IgA, in addition to IgM and IgG isotype.

Adolescent↗
PubMed1998

A pilot study of intermittent intravenous cyclophosphamide for the treatment of systemic sclerosis associated lung disease.

OBJECTIVE: Pulmonary fibrosis, a frequent manifestation of systemic sclerosis (SSc), is considered incurable. Our aim was to assess the effect of therapy with intravenous (i.v.) cyclophosphamide on the course of pulmonary fibrosis in patients with SSc. METHODS: Five patients with SSc and clinical, laboratory, or radiographic findings of interstitial lung disease were treated with cyclophosphamide (1 g) administered i.v. monthly for 48 weeks. The dyspnea score, pulmonary function tests, arterial blood oxygen content, radiologic abnormalities, and bronchoalveolar lavage (BAL) fluid cellularity were determined before and after therapy. RESULTS: The dyspnea score decreased by 42% after 48 weeks of therapy. Forced vital capacity (FVC, percentage of predicted) increased by 7%, and carbon monoxide diffusing capacity (DLCO) decreased by 12%, but these changes were not statistically significant. Arterial blood oxygenation remained unchanged. At baseline, high resolution computed tomography of the lungs showed honeycombing, reticulonodular, or ground glass patterns in each patient examined. These radiologic abnormalities did not improve during treatment. A marked decrease in BAL fluid cell number, but not in the percentage of neutrophils, was observed after therapy. Nausea and leukopenia were frequent but mild side effects. One patient developed hemorrhagic cystitis. CONCLUSION: The results suggest that intermittent treatment with i.v. cyclophosphamide reduces the severity of dyspnea, but fails to improve FVC or DLCO, or cause resolution of radiologic abnormalities, in patients with SSc.

Adult↗
PubMed1997

Evaluation of false ultrasonographic pregnancy diagnoses in sows by measuring the concentration of unconjugated estrogens in feces.

On Days 26, 28, and 30 after AI, ultrasonographic pregnancy diagnoses were performed on 207 gilts and sows by using a 3.5 MHz linear-array transducer. Fecal samples were taken from the rectum after each ultrasonographic examination, and the concentrations of unconjugated estrogens in selected samples (n = 73) were measured by RIA. Fecal unconjugated estrogen concentration of 11.7 ng/g feces or higher was indicative of pregnancy. The overall sensitivity and specificity of the ultrasonographic test was 99% for farrowing sows and 73.1% for nonfarrowing sows. With one exception, sows with a false negative diagnosis by ultrasonography on Day 26 were correctly diagnosed pregnant by elevated fecal unconjugated estrogens or repeated ultrasonographic examinations on Days 28 or 30. Return to estrus around the sampling period may cause false positive results in the unconjugated estrogen assay, while early embryonic mortality can result in false positive diagnoses in both the ultrasonographic test and estrogen assay. Although there was a positive correlation between the concentrations of unconjugated estrogens in the feces and litter size at farrowing in the selected sows, it seems very unlikely that fecal estrogens can provide an accurate tool for predicting litter size.

Journal Article↗
PubMed1997

A putative tetrapeptide antagonist prevents beta-amyloid-induced long-term elevation of [Ca2+]i in rat astrocytes.

Comparative fluorimetric studies on the long-term (8-hour) action of beta[1-42]amyloid and its shorter fragments beta[1-40], beta[25-35] and beta[31-35] on the steady-state intracellular Ca2+ concentration in primary cultures of rat astroglial cells using the Ca2+-sensitive fluorescent probe Fura-2 AM revealed higher 340/380 fluorescence excitation ratios in the treated cells as compared to the untreated controls. All the peptides were found to induce similar cellular effects, suggesting the [31-35] region as the putative active centre of the molecule. No significant alteration was detectable in Fura-2 fluorescence using the Ca2+-insensitive excitation wavelength of 367 nm, indicating that the observed changes reflect a real alteration in the Ca2+ concentration of the cells. Moreover, no considerable difference was observed in the total protein content of treated and untreated cells. Co-treatment of the cells with Pr-Ile-Ile-Gly-Leu-NH2 (Pr-IIGL) peptide, an analogue of the [31-34] region of beta[1-42]-amyloid, was found to effectively antagonize the beta[1-42]-amyloid-induced elevation of the fluorescence excitation ratio, leaving the 367-nm fluorescence unaffected. To the best of the authors' knowledge, this is the first report on an analogue of beta-amyloid peptide capable of blocking one of its physiological effects, thereby raising the possibility that this sequence could prove to be a lead compound for designing effective beta-amyloid antagonists.

Amyloid beta-Peptides↗