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Biomedical subjects

I Varga

Publications and source records attributed to I Varga.

At least 19 recordsLinked to original sources
PubMed1999

Immunogenicity of three oocyst extracts of Cryptosporidium baileyi in experimentally infected chickens.

The immunogenic properties of water-soluble and detergent-extracted components of Cryptosporidium baileyi oocysts were studied. Oocyst cytosol antigen (OCA) containing hydrophilic proteins was obtained by freeze-thaw cycles in liquid nitrogen. This was followed by Triton X-114 extraction of remaining oocyst fragments to dissolve membrane-bound proteins (TRE). The remainder of the pellet was solubilized with sodium dodecyl sulfate and treated with 2-mercaptoethanol to reduce disulfide-linked oocyst wall proteins (BME). The immune recognition of these three extracts was evaluated during the course of experimental cryptosporidiosis in chickens using ELISA, immunoblotting, and the lymphocyte stimulation test (LST). Four groups of chickens were infected at various times with different doses of C. baileyi and one group with the mammalian parasite C. parvum. Analysis of the data revealed that OCA proteins are well recognized by serum antibodies during the infection and to a limited extent by sera from chickens infected with C. parvum. Humoral responses of chicken groups to this antigen did not correlate well with the length of patency in contrast with its cellular recognition in LST. TRE gave lower values than OCA in both ELISA and LST, though it was still specifically recognized by samples from C. baileyi-infected chickens. Antibodies reacted aspecifically with BME, since only samples of birds which were immunocompetent at the time of their infection were able to recognize this extract as antigen. Immunoblotting revealed more specific components in OCA than in TRE or BME.

Animals↗
PubMed1999

Study on the course of Cryptosporidium baileyi infection in chickens treated with interleukin-1 or indomethacin.

The effects exerted by human recombinant interleukin-1 beta (hrIL-1 beta) and the prostaglandin inhibitor indomethacin on the course of Cryptosporidium baileyi infection in chickens were studied. Daily oocyst shedding was monitored by a quantitative method throughout the experiment. Humoral immune response to C. baileyi was assessed by ELISA at 3 weeks of age while the level of cellular immune response to phytohaemagglutinin-P (PHA-P) by a skin test at 23 days of age. Parenteral application of hrIL-1 beta decreased oocyst shedding to 62%, but the infection ran a similar course in treated and control birds. The PHA-P skin test demonstrated increased cellular immune reaction in chickens receiving IL-1 beta, but there was no significant difference in the humoral responses of the two groups as detected by ELISA. On the other hand, indomethacin mixed to the feed lessened oocyst shedding to 13.7% and also shortened its duration. Immunological parameters as reflected by PHA-P skin test and ELISA results indicated enhanced cellular but unaltered humoral immune response. These data suggest that the systemic application of interleukin-1 can induce partial protection against C. baileyi in chickens and that prolonged, abundant oocyst shedding is due to an indomethacin-sensitive immunodepression via the prostaglandin pathway.

Animals↗
PubMed1999

Human Dirofilaria repens infection in Hungary: a case in the spermatic cord and a review of the literature.

Orchiectomy was performed in a 37-year-old Hungarian man exhibiting a swelling in his right testicle. Histology revealed a nodule attached to the spermatic cord, consisting of a granulomatous tissue around sections of a nematode. The worm was identified as Dirofilaria repens, an uncommon parasite in Hungary. As the patient had been abroad only in Italy where cases of dirofilariosis in dogs and humans are relatively frequent, it is assumed that the infection might have been acquired in that country 5 years earlier. This is the fifth case, published so far in the world, of such a localization in a human. The human cases of dirofilariosis reported in Hungary are reviewed.

Adult↗
PubMed1998

[Preventive treatment in internal medicine by low-molecular-weight heparin (nadroparine calcium)].

On the basis of literature data the authors discuss the preventive treatment of the low-molecular-weight heparin in various non-surgical disorders. The method was compared with unfractionated heparin in the treatment of 20 high risk patients. The efficacy of the two different heparins was examined on the liver and renal function, blood lipids and the hematologic and hemostaseologic parameters. The thromboembolic and hemorrhagic complications were observed. Significant difference was not found with the comparison of the two preparations. The authors emphasize the simplicity, safety, home treatment possibility of the low-molecular-weight heparin and the regular control of thrombocyte-count only, too.

Fibrinolytic Agents↗
PubMed1998

Assessment of maternal immunity to Cryptosporidium baileyi in chickens.

The degree of protection to Cryptosporidium baileyi in the progeny of infected chickens was studied. Hens at the beginning of their laying period were given orally three consecutive, large doses of C. baileyi oocysts at weekly intervals. The infection became patent after 6 days and lasted for another 6 days. Increasing serum IgG, and serum, bile, lachrymal and salivary IgA were demonstrated from their samples. These immunoglobulins were transferred to the eggs, since high levels of maternally derived IgG and lower amount of IgA were present in their yolks. Hatchlings of infected hens were divided into uninfected (UY) and infected (IY) groups, the birds in the latter receiving an oral inoculum of C. baileyi oocysts on the first day of their life. Two other groups, progeny of uninfected hens served as controls (uninfected UC, and infected IC). Maternal IgG was detected in serum samples of UY hatchlings which was eliminated by the third week. The total oocyst shedding of IY chickens was 54.3% lower than that of the controls (IC), however, the prepatent and patent periods did not show significant difference. In spite of the partial protection observed in IY birds, their humoral immune response to C. baileyi was significantly lower when compared to IC. A dot-ELISA was developed to evaluate seroconversion of infected chickens which was 100% in both infected groups. The findings of the present study suggest that infection of hens with C. baileyi results in partial protection of their progeny to this parasite, and factors other than immunoglobulins may also be transferred via the eggs.

Administration, Oral↗
PubMed1998

Interaction of chicken anaemia virus and Cryptosporidium baileyi in experimentally infected chickens.

The natural occurrence of concomitant chicken anaemia virus (CAV) and Cryptosporidium baileyi infection was described earlier. In this experiment, 1-day-old chickens were infected with CAV alone (anaemia virus infected, AI) or followed by inoculation with 8 x 10(5) C. baileyi oocysts orally at 1 wk of age (anaemia virus and Cryptosporidium infected, ACI). Another group of chickens received the same dose of C. baileyi oocysts without previous virus infection (Cryptosporidium infected, CI), and two groups of uninfected chickens served as controls. Except one group (uninfected control, UC), all groups -- including the other control group (challenged control, CC) -- were challenged with an oral inoculum of 8 x 10(5) C. baileyi oocysts at the age of 4 wk. Haematological, serological, immunohistochemical and pathological findings confirmed the effect of the virus agent. The individual C. baileyi oocyst shedding did not show significant difference between group CI and ACI, however, after challenge infection the AI chickens shed approximately three times more C. baileyi oocysts than those in group CC. Mortality and the percentage of birds that developed anaemia was significantly higher among ACI than AI chickens, while haematocrit values at 2 wk of age and relative bursal weights at 4 wk of age were moderately lower in the ACI group. The results presented here suggest that concurrent CAV infection increases the reproductive potential of C. baileyi in chickens, and both pathogens have synergistic effect on each other.

Animals↗
PubMed1998

p53 protein and its messenger ribonucleic acid in human adrenal tumors.

The role of p53 tumor suppressor gene in the pathomechanism of adrenal tumors was investigated by measuring p53 protein and its messenger ribonucleic acid (mRNA) in 12 normal human adrenals as well as in 56 adrenal tumors (7 aldosterone-producing adenomas, 5 adrenocortical adenomas causing Cushing's syndrome, 19 non-hyperfunctioning adrenocortical adenomas, 5 adrenocortical carcinomas, 12 pheochromocytomas, 3 myelolipomas, 4 ganglioneuromas and 1 hemangioma). The p53 protein concentration was significantly increased in aldosterone-producing adenomas (394+/-36 pg/mg cytosolic protein, mean+/-SE, vs 266+/-18 in normal human adrenals), whereas the concentration of this protein in Cushing's adenomas, non-hyperfunctioning adrenocortical adenomas, pheochromocytomas, and in all but one adrenocortical carcinomas was similar to that measured in normal human adrenal tissues. One adrenocortical carcinoma tissue showed very high p53 protein content (3000 pg/mg cytosolic protein). By contrast, myelolipomas (23+/-20) ganglioneuromas (43+/-15) and a hemangioma (11 pg/mg cytosolic protein) had very low p53 protein content. Northern blot analysis revealed the presence of p53 mRNA in each adrenal tissue examined with highest levels in aldosterone-producing and Cushing's adenomas. It is possible that the differences in p53 protein and/or mRNA contents reflect corresponding differences in the pathogenetic importance of p53 alterations in these types of adrenal tumors.

Adenoma↗
PubMed1998

Coexpression of p53 and tissue transglutaminase genes in human normal and pathologic adrenal tissues.

The presence of p53 and tissue transglutaminase (tTG) gene expressions was investigated in human normal and pathologic adrenal tissues with two aims (1) to determine the tissue content of p53 protein, its messenger ribonucleic acid (mRNA) and, especially, tTG mRNA which has not been previously reported and (2) to study possible differences in the coexpression of p53 and tTG in various adrenal disorders. Using Northern blot analysis, p53 and tTG mRNAs were detected in each adrenal tissue examined including 5 normal human adrenals, 6 aldosterone-producing adenomas, 3 Cushing's adenomas, 1 primary nodular adrenocortical hyperplasia causing Cushing's syndrome in an infant, 12 non-hyperfunctioning adrenocortical adenomas, and 4 adrenocortical carcinomas. The results showed a significant positive correlation between these two mRNAs in all adrenal tissues except adrenocortical carcinomas. Compared to normal adrenals, high p53 mRNA levels were observed in aldosterone-producing and Cushing's adenomas and, most markedly, in a tissue from a primary nodular adrenocortical hyperplasia. Also, Cushing's adenomas had significantly higher tTG mRNA contents. Immunohistochemistry for wild-type and mutant p53 protein showed numerous p53 positive cells with a strong nuclear staining in a tissue from a primary nodular adrenocortical hyperplasia, whereas the p53 positive cells were absent, except those with a faint nuclear staining, in all other adrenal tissues. However, all adrenal tissues showed detectable p53 contents by the more sensitive method of luminometric immunoassay (LIA). Using this method, aldosterone-producing adenomas exhibited significantly higher p53 contents than normal adrenal tissues. These observations may support potentially important roles for p53 and tTG in adrenal pathophysiology, especially in mechanisms which influence the evolution and/or progression of aldosterone-producing and Cushing's adenomas and, most probably, hyperplasias.

Adrenal Gland Neoplasms↗
PubMed1998

Failure to differentiate Cryptosporidium parvum from C. meleagridis based on PCR amplification of eight DNA sequences.

In order to determine the specificities of PCR-based assays used for detecting Cryptosporidium parvum DNA, eight pairs of previously described PCR primers targeting six distinct regions of the Cryptosporidium genome were evaluated for the detection of C. parvum, the agent of human cryptosporidiosis, and C. muris, C. baileyi, and C. meleagridis, three Cryptosporidium species that infect birds or mammals but are not considered to be human pathogens. The four Cryptosporidium species were divided into two groups: C. parvum and C. meleagridis, which gave the same-sized fragments with all the reactions, and C. muris and C. baileyi, which gave positive results with primer pairs targeting the 18S rRNA gene only. In addition to being genetically similar at each of the eight loci analyzed by DNA amplification, C. parvum and C. meleagridis couldn't be differentiated even after restriction enzyme digestion of the PCR products obtained from three of the target genes. This study indicates that caution should be exercised in the interpretation of data from water sample analysis performed by these methods, since a positive result does not necessarily reflect a contamination by the human pathogen C. parvum.

Animals↗
PubMed1998

Detection of antibodies to Neospora caninum in bovine postabortion blood samples from Hungary.

In order to obtain data on the occurrence of the protozoan parasite Neospora caninum as a potential factor in the aetiology of reproduction problems in cattle, 97 postabortion sera were examined by ISCOM ELISA and IFAT for the presence of antibodies in N. caninum. The results showed 10% and 9% seropositivity by the ELISA and IFAT, respectively. In 2 of the 10 seropositive cases no other fetopathogenic agents (such as Chlamydia sp., Leptospira spp. or bovine viral diarrhoea virus) were detected. These data confirm the presence of N. caninum in cattle in Hungary.

Abortion, Veterinary↗
PubMed1997

[Bilateral renal artery stenosis diagnosed during pregnancy].

Bilateral renal artery stenosis was diagnosed noninvasively in the 17th gestational week, in a chronically hypertensive pregnant woman, by renal artery duplex ultrasound examination, MRI and MR angiography. Continuous monitoring of the mother and the fetus was performed. Blood pressure was stabilized by complex antihypertensive therapy, but from the beginning of the third trimester superimposed preeclampsia developed gradually. In the 34th gestational week a 1600-g newborn was delivered by elective cesarean section. The case report draws attention to the significance of the thorough examination of hypertensive women before pregnancy.

Adult↗
PubMed1997

Unique Alzheimer's disease paired helical filament specific epitopes involve double phosphorylation at specific sites.

Alzheimer's disease (AD) paired helical filaments (PHFs), building blocks of neurofibrillary tangles (NFTs) are composed of hyperphosphorylated forms of the microtubule-associated protein tau (i.e., PHF-tau). Currently, much effort is devoted to the development of diagnostic antibodies specific for PHF-tau since elevated tau levels are found in the cerebral spinal fluid of AD patients. To this end, we have mapped the epitopes of a large panel of monoclonal antibodies (mAbs) that recognized only phosphorylation dependent epitopes on PHF-tau. These mAbs include the PHF-tau specific mAb AT10 and 12 newly developed anti-PHF mAbs that recognize PHF-tau but not autopsy-derived normal adult tau on Western-blot and enzyme-linked immunosorbent assay (ELISA). Epitope analysis, together with data on known binding sites of previously published mAbs, revealed that Ser214, Thr231, and Ser396 are immunodominant phosphorylated amino acids in PHF-tau. Six of the 12 new mAbs recognized one of these three phosphorylated sites. With the exception of AT10 and PHF-27, all the mAbs also labeled fetal tau and biopsy-derived tau. Since mAbs AT10 and PHF-27 had little or no affinity for fetal tau and biopsy tau, they can be considered as the first "true" PHF-specific antibodies capable of distinguishing tau isoforms from normal versus AD subjects, suggesting a possible utility of these mAbs as diagnostic markers. Remarkably, the true PHF-specific antibodies recognized peptide sequences phosphorylated on more than one amino acid residue. The peptide recognition of mAb AT10 required the simultaneous phosphorylation of Thr212 and Ser214, and the peptide recognition of mAb PHF-27 was markedly increased when both the primary site Thr231 and the subsite Ser235 were phosphorylated. Since AT10 and PHF-27 are the only mAbs currently available that bind specifically to PHF-tau, these data suggest that double phosphorylation at Thr212/Ser214 and Thr231/Ser235 may be unique to PHF-tau. These data may facilitate the development of mAbs that can be used as specific diagnostic reagents for the detection of altered tau in cerebrospinal fluid of AD patients.

Adult↗
PubMed1997

Effect of F-2 and T-2 fusariotoxins on experimental Cryptosporidium baileyi infection in chickens.

The course of Cryptosporidium baileyi infection in chickens fed with different doses of fusariotoxins was compared with that of control groups. F-2 toxin levels of 0.187-1.5 mg kg-1 and T-2 toxin levels of 0.187-6.0 mg kg-1 were investigated. The experimental animals were orally infected with 6 x 10(5) C. baileyi oocysts at 1 week of age. Total daily oocyst output was monitored by a quantitative method. Acquired immunity was tested at the age of 4 weeks, by ELISA and by a challenge infection with an equal number of oocysts, upon recovery from the primary infection. The results show that in chickens kept on the lower doses of F-2 and T-2 toxins, the parasite infection ran a similar course to that in the control groups, and the animals became resistant to re-infection. However, when higher doses (2.0-6.0 mg kg-1) of T-2 toxin were used, a depression of weight gain was observed with some other physiological parameters (PCV, weight of bursa, weight of thymus, skin thickness in PHA-P skin test) also indicating toxic effect and, simultaneously, the oocyst output decreased significantly and the patent period was slightly prolonged. Although certain modifications of the immune response could be revealed, the chickens became resistant to re-infection. Only early (1 week of age) parasite infection and 6 mg kg-1 T-2 toxin in the feed significantly depressed body weight gain and immunity.

Animals↗
PubMed1997

Oxidative stress and antioxidant defense mechanism in glomerular diseases.

The changes in red blood cell (RBC) lipid peroxidation [measured via the malonyl dialdehyde (MDA) concentration], reduced (GSH), and oxidized glutathione (GSSG) levels, hemoglobin (Hb) oxidation and antioxidant enzyme [catalase (Cat), glutathione peroxidase, and superoxide dismutase (SOD)] activities were studied in 45 pediatric patients with various glomerular diseases [minimal change nephrotic syndrome (MCNS) in relapse or in remission, lupus nephropathy (SLE), poststreptococcal glomerulonephritis (APSGN), IgA nephropathy (IGA gn)], and in 20 adult patients with IGA gn and also in 15 pediatric and 14 adult controls. The in vitro effects of hydrogen peroxide [acetyl phenylhydrazine (APH) test] on the GSH and Hb metabolisms were likewise investigated. There was an increased oxidative stress in MCNS with relapse, IGA gn, SLE gn, and APSGN, which could be detected in the GSH and Hb oxidation and in the lipid peroxidation on the peripheral RBC-s. The RBC SOD and Cat activities were significantly lower in all patients than in the controls. The RBC GSSG level was significantly elevated in all patients, with the exception of MCNS in remission. This stimulated a compensatory GSH production in MCNS with relapse and in IGA gn, but not in SLE or APSGN. The regeneration of GSH from GSSG was reduced in MCNS with relapse, SLE, and IGA gn, but not in APSGN. In remission, the GSH-GSSG redox system normalizes, but in vitro the APH test stimulates an intensive Hb oxidation. In conclusion, there is a correlation between the presence of active glomerular disease and the evidence of oxidative changes in the various parameters measured in peripheral RBCs.

Adolescent↗
PubMed1997

Detection of Cryptosporidium parvum DNA in formed human feces by a sensitive PCR-based assay including uracil-N-glycosylase inactivation.

We developed a PCR-based method that can be used to identify Cryptosporidium parvum in human feces. Fecal oocysts were concentrated by centrifugation on a sodium chloride gradient and filtration on a nitrocellulose filter prior to DNA extraction and PCR amplification of a 452-bp C. parvum-specific DNA sequence with a protocol including dUTP and uracil-N-glycosylase. All samples obtained from naturally infected humans (n = 10), calves (n = 4), and goats (n = 2) were positive. A 100% detection rate was achieved with both formed and solid stools (n = 10) seeded with 1,000 C. parvum oocysts per g. Procedures based on stool concentration by a modified Ritchie method and subsequent oocyst identification by immunofluorescent labeling or acid-fast staining require concentrations of 50,000 to 500,000 oocysts per g to achieve a 100% detection rate with formed stools. The described PCR-based assay thus has a 50- to 500-fold increase in sensitivity compared to those of the methods commonly used to analyze formed feces.

Animals↗
PubMed1997

Plasma dehydroepiandrosterone sulfate levels in patients with hyperfunctioning and non-hyperfunctioning adrenal tumors before and after adrenal surgery.

To investigate the clinical significance of plasma dehydroepiandrosterone sulfate (DHEAS) measurements, 175 patients with histologically confirmed adrenal tumors, 10 cortisol-producing adenomas, 59 aldosterone-producing adenomas, 56 non-hyperfunctioning adenomas, 13 adrenocortical carcinomas, 13 adrenal cysts, and 24 adrenomedullary tumors were studied. Plasma DHEAS levels were expressed as percentage of the mean of sex- and age-matched groups of healthy, normal subjects (DHEAS %). We found that before adrenal surgery, DHEAS % values were significantly reduced in patients with cortisol-producing (mean, 15.2% of control; 95% confidence interval (CI), 9.4-24.7%), non-hyperfunctioning (28.4%; 22.4-36.0%) as well as aldosterone-producing adrenocortical adenomas (55.4%; 47.1-65.1%) compared with controls, while values were normal in patients with adrenal cysts and in those with adrenomedullary tumors. Plasma DHEAS % values exhibited a great variability in adrenocortical carcinomas (mean, 84.0%; 95% CI, 33.2-212.5%). Death from adrenocortical carcinoma was more frequent in patients with high plasma DHEAS % values compared with those with low DHEAS %. During long-term postoperative monitoring, we found that plasma DHEAS levels of patients with aldosterone-producing and non-hyperfunctioning adenomas returned to normal in the second and fourth postoperative year respectively. In patients with cortisol-producing adenomas, plasma DHEAS remained suppressed for as long as 8 years after the operation. These findings show that except in adrenocortical carcinomas and cysts, plasma DHEAS levels are significantly decreased in all groups of adrenocortical tumors, including non-hyperfunctioning and aldosterone-producing tumors. The extent of this decrease and the postoperative persistence of suppressed plasma DHEAS levels may be related to the glucocorticoid production of adrenocortical tumors.

Adenoma↗