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Biomedical subjects

L Varga

Publications and source records attributed to L Varga.

At least 73 records · Page 4Linked to original sources
PubMed1994

[Hepatitis B and C markers in alcoholic liver diseases].

Hepatitis B and C virus contamination of 240 patients with alcoholic liver disease was studied. Hepatitis B virus core antibodies were present in 58 alcoholic patients (24%) and hepatitis C virus antibodies in 30 alcoholic patients (12.5%). Both antibodies were present in 17 patients (7.1%). The prevalence of antibodies was more frequent in alcoholic female patients than in males. Data concerning the hepatitis B virus contamination in alcoholic liver patients with or without cirrhosis were similar. The frequency of hepatitis C virus antibodies in cirrhotic patients was more than in patients without cirrhosis. Female cirrhotic patients were more frequently C virus antibody positive than males. In female alcoholics the frequency of C virus antibodies was more in patients with cirrhosis than in the patients without cirrhosis. The viral serology and follow up of patients with alcoholic liver disease may be useful in detection of the early stage hepatocellular carcinoma.

Adult↗
PubMed1994

[Comparative evaluation of dipyridamole and dobutamine 2-dimensional echocardiography in ischemic heart disease].

Dipyridamole and dobutamine stress were performed in the same 41 angiographically controlled patients. Both tests were followed by 2 dimensional-echocardiography. The dose of dipyridamole was 0.56 mg/kg/4 min. or 0.84 mg/kg over 10 min., while the dose of dobutamine was 10-20-30-40 and 40 micrograms/kg/min. over 3 min. each step. In addition, to reach the submaximal heart rate 0.25 mg/min Atropine was also injected for 4 minutes in 13 cases. One vessel disease was found in 15 cases, and 2 vessel disease was in 2 cases. The number of coronarography negative cases was 24. The sensitivity, specificity, positive and negative predictive values for both tests were 70%, 91%, 85% and 81%, respectively. False positive results were observed in 2 cases and false negative ones were found in 5 cases, mainly at left anterior descendent stenosis. There was a good agreement between the wall motion abnormality and the anatomic localization of stenoses. Both non-invasive tests are suitable for the diagnosis of ischaemic heart disease.

Adult↗
PubMed1994

An indirect effect of an antibody on complement deposition and lysis of differently sensitized surrounding cells.

Lysis of papain-treated group A and B erythrocytes by human complement was studied by an anti-A (BRIC. 131) and an anti-B (BRIC. 30) IgM monoclonal antibody in 51Cr release assays. The indirect effect of membrane-bound antibody, i.e. its influence on complement binding to sensitized surrounding cells, was examined in a cold target competition test in which sensitized, non-labelled cells are present along with sensitized labelled cells and complement. The mode by which anti-A antibodies indirectly suppressed lysis of sensitized B cells up to 20-fold was studied by following C1q and C3b binding. C1q binding to both types of erythrocytes was not altered in mixed populations of erythrocytes in the presence of both antibodies. Binding of C3b to a mixture of both cell types was, however, suppressed, when both antibodies were present. C3b deposition in mixed cell populations did not reach a significantly higher extent than deposited to one type of erythrocyte alone. This was consistent with the results from competitive lysis and suggests that the anti-A captured most C3b at high anti-A concentrations and deprived the similarly sensitized B erythrocytes of complement. We think that this phenomenon is not due to an uneven removal of complement regulatory proteins from A and B erythrocytes by papain. Instead, the phenomenon might be due to an inherent property of anti-A mAb to better produce nucleation sites for C3 convertases which, upon binding factor B, better compete for the limiting factor D. A mathematical analysis of cold target competition experiment (containing 2430 individual measurements) also shows that the distribution of complement between the competing A and B erythrocyte population is uneven, since it predicts that in any given antibody combination the majority of complement is bound to A erythrocytes. This is consistent with the measured average percentage of lysis.

ABO Blood-Group System↗
PubMed1994

Cholecystokinin type B receptor antagonist PD-136,450 is a partial secretory agonist in the stomach and a full agonist in the pancreas of the rat.

Gastrin (cholecystokinin type B (CCK-B)) receptor antagonists may help to elucidate the physiological role of gastrin, have therapeutic potential as acid antisecretory drugs, and may be of use as adjuvant therapy for gastrin sensitive tumours. In binding studies, the gastrin receptor antagonist PD-136,450 had at least 1000 fold greater affinity for gastrin (CCK-B) than CCK-A receptors. In this study the biological activity of PD-136,450 was evaluated in conscious and anaesthetised rats. PD-136,450 antagonised gastrin stimulated acid secretion after subcutaneous (IC50: 0.28 mumol/kg; conscious rats) and intravenous (IC50: 0.17 mumol/kg; anaesthetised rats) administration. In basal secreting fistula animals, the compound stimulated acid output to 30 (5)% of the maximal response to gastrin. Stimulant activity was not caused by gastrin release. As an agonist PD-136,450 was about 350 times less potent than gastrin-17 on a molar basis. In addition, PD-136,450 was a powerful agonist of pancreatic secretion in anaesthetised rats. The specific gastrin antagonist L-365,260 inhibited the (partial) agonist activity of PD-136,450 in the stomach and the specific CCK-A receptor antagonist L-364,718 inhibited the agonist activity of PD-136,450 in the pancreas. It is concluded that the agonist effect of PD-136,450 is mediated via interaction with the gastrin (CCK-B) receptor in the stomach and the CCK-A receptor in the pancreas.

Animals↗
PubMed1994

Antacid provides better restoration of glandular structures within the gastric ulcer scar than omeprazole.

Mucosa of healed gastric ulcers displays histological abnormalities that are possibly the basis of ulcer recurrence. The influence of antacid and omeprazole treatment was studied on the quality of ulcer healing. Sixty four rats with gastric cryoulcers were treated daily either with placebo, antacid, omeprazole, or antacid plus omeprazole. Ulcer size was measured three times per week with a novel video endoscopic method. Prostaglandin generation (day 6), cell proliferation (day 8 and 15), height and cell composition of ulcer margin (day 8), and mucosal scar (day 15) were quantitatively assessed. Antacid, omeprazole, and antacid plus omeprazole significantly accelerated ulcer healing predominantly during days 3-8. Compared with placebo, the height of ulcer margin and mucosal ulcer scar was significantly increased in antacid (+7 and +9% respectively) and significantly decreased in omeprazole (-33 and -22% respectively) and antacid plus omeprazole (-26 and -18% respectively) treated rats. The number of bromodeoxyuridine labelled cells (+42%, day 8), epithelial cell mass (+42%, day 15), and the ratios of epithelial cells/connective tissue (+73%, day 15) and epithelial cells/gland lumen (+100%, day 15) were significantly increased in antacid treated rats. In conclusion, both antacid and omeprazole accelerate ulcer healing but antacid provides a better quality of healing. This advantage is lost by cotreatment with omeprazole.

Aluminum Hydroxide↗
PubMed1993

[New strategy for thyroid function testing].

The authors used a new protocol, based upon a supersensitive TSH assay, to examine the thyroid status of 1720 patients. Based upon the serum hormone levels, the patients were divided into different clinical groups. The biochemical relationship between the different hormone levels, and the rate of occurrence of various thyroid diseases were studied. 76.1% of the new patients hadn't received any previous treatment. 15.5% of those patients who had received treatment had hyperthyroidism, while 8.4% of those had hypothyroidism. 76% of the new patients, 38.3% of those who had hyperthyroidism, and only 29.7% of those who had hypothyroidism, were euthyroid. Undetectable TSH levels (< 0.03 mU/L) where observed in 51.8% of the new hyperthyroid patients, and in 33.8% of those who had subclinical hyperthyroidism. Similar results were obtained with those who had been previously treated for hyperthyroidism. The new protocol has the following advantages: it's more convenient to the patients, it's quick, it's economical. With this method it is possible to reduce the assays per patient by 31%. The algorithm was supplemented with results of free hormone levels. By doing this the authors were able to measure free-T4 and T3 hormone levels of 150 more patients. According to the authors, the free-T4 test is more informative than the free-T4-index, especially in the border-line cases and in treated hyperthyroidism. Primarily the free-T3 test is most necessary when examining patients treated with methimasol.

Adrenergic beta-Antagonists↗
PubMed1993

Interactions in the complement-mediated lysis of blood group AB erythrocytes sensitized simultaneously with anti-A and anti-B monoclonal antibodies.

The lysis of group AB erythrocytes by human complement was studied by different anti-A and anti-B IgM monoclonal antibodies (mabs) in a 51Cr-release assay. The concentration of membrane-bound immunoglobulin was detected by ELISA, and the amount of C1q and C3 bound to sensitized red cells was measured by using purified, 125I-labelled molecules. We have demonstrated that there is an exponential relationship between the concentration of the sensitizing IgM mabs and C1q binding to the sensitized AB cell. The efficiency of binding was related to the number of antibodies bound; thus, anti-A sensitized cells bound 3-6 times more C1q than anti-B sensitized cells did. AB cells, on the other hand, bound similar amounts of C3 whether anti-A or anti-B was present. The lytic efficiencies of the various IgM mabs during short incubation times were different, suggesting that the complement activation rates vary widely with different antibodies on the AB cell membrane. The binding of C1q to an antibody-sensitized target activates a cascade, whose components may migrate away from the sensitizing antibody; interactions between the activation processes generated by the anti-A and anti-B antibodies may thus occur. Choosing appropriate pairs of anti-A and anti-B mabs for the simultaneous sensitization of AB cells has indeed resulted in stimulation in some and inhibition in other combinations of mabs. It is suggested that stimulation is observed when the activated intermediates are produced in excess, whereas inhibition occurs when a shortage of activated intermediates prevents mutual utilization.

ABO Blood-Group System↗
PubMed1993

Investigation of premalignant lesions of larynx epithelium with histoautoradiography and HPV-assay.

The histological evaluation of precancerous alterations of larynx epithelium is, in transitional cases, very difficult. The differentiation of harmless metaplasia, hyperplasia and keratosis from abnormal proliferation depends on the pathologist's training and experience. Fine diagnostic lines separate the different grades of dysplastic epithelial alterations. The tritiated thymidine, 3H-TdR, labelling and histoautoradiographic procedure of biopsy specimens taken from the larynx provide the possibility to recognise the DNA synthetiser cells. The number, location and distribution of 3H-TdR labelled cells in the epithelial layers help us to distinguish with clarity the growth activity, the degree of dysplasia. After 3 weeks' exposition time of sections prepared by photoemulsion and stained with haematoxilin-eosin, the result can be assessed. In addition to histoautoradiography HPV-assay was applied, as HPV may play a role in the pathogenesis of laryngeal preneoplastic alterations.

Autoradiography↗
PubMed1993

[With primary liver carcinoma-associated cholestasis].

Icterus is among the symptoms which occur late in carcinoma of the liver. Icterus which occurs through the obstruction of the bile-ducts may be an early symptom in favourable cases. On the basis of literature and the analysis of the case material in our clinic the incidence of cholestasis, its clinical picture and treatment in carcinomas of the liver is evaluated. The differential diagnostic importance of enzymes which are typical of cholestasis--alkaline phosphatase and gamma-glutamyl transferase--and their isoenzymes are discussed. The results obtained in our clinic are compared with those in literature.

Aged↗
PubMed1992

[Treatment of carcinoid syndrome with a somatostatin analogue].

Octreotide, a long-acting somatostatin analogue has recently been introduced in the therapy of gastroenteropancreatic endocrine tumors, but home experience has been lacking. With the aim of drawing attention to this therapeutic possibility, a case of malignant carcinoid syndrome treated with octreotide for 18 months is reported. Despite the therapeutic attempts preceding the octreotide administration a gradual progression in clinical symptoms was observed and cardiac failure due to fibrotic and valvular heart disease developed. Cytotoxic chemotherapy, serotonin antagonists or repeated selective embolisation of the hepatic artery only resulted in a short transitional improvement. Octreotide in a dose of 100 micrograms three times daily by subcutaneous injection provided effective and rapid relief from episodic flushing and serious diarrhoea. Plasma level of serotonin and 24-hour urinary excretion of 5-hydroxyindolacetic acid decreased from 6 micrograms/ml to 2 micrograms/ml and from 800 mumol/day to 70 mumol/day, respectively. No changes in the number and extension of liver metastases could be seen after introducing the octreotide treatment. The patient's compensated cardiac status could be preserved and continuous therapy provided an acceptable quality of life.

Humans↗
PubMed1992

[Helicobacter pylori allergy].

A case of a 44 year old woman with antrum gastritis and H. pylori infection was reported. After unsuccessful treatment of the disorder with bismuth and tinidazole, an auto-vaccine was prepared from the bacterium in order to eliminate the infection. After the first injection of the vaccine a generalised urticaria was observed. In the development of the skin eruptions a type I, and a type IV allergic reaction could be demonstrated using the H. pylori specific RAST-test and leukocyte migration inhibition respectively. After eradication of the bacterium by amoxycillin treatment, the clinical signs of both the gastrointestinal and allergic diseases disappeared.

Adult↗
PubMed1992

Effect of acute and chronic acid suppression on plasma gastrin release in the rat.

The mechanisms by which administration of the H+,K(+)-ATPase inhibitor B 831-78 or intragastric perfusion with NaHCO3 induces plasma gastrin release were studied in the rat. Experiments were performed after a washout of residual intragastric contents in fasted animals provided with chronic gastric fistulae. Acute and chronic administration of B 831-78 elevated plasma gastrin dose-dependently up to 5-6 times above control levels, while the increase was only twofold with intragastric NaHCO3 infusion despite similar neutralization of gastric acidity. The profound hypergastrinaemia induced by the H+,K(+)-ATPase inhibitor, after both acute and chronic treatment, was completely prevented or reversed by intragastric perfusion with physiological amounts of acid (0.15 N HCl, 2.5 ml/h). The hypergastrinaemia was, however, largely resistant to high doses of atropine (4.3 mumol/kg) and of the M1 selective muscarinic antagonist telenzepine (10 mumol/kg). In contrast, the modest increase in plasma gastrin induced by gastric perfusion with NaHCO3 was completely suppressed by the high atropine dose and was attenuated by small doses of atropine or telenzepine (0.01 mumol/kg and 1 mumol/kg). These results demonstrate that, in the rat, blockade of the H+,K(+)-ATPase can potently induce gastrin release in the absence of a meal. Moreover, they suggest that interruption of the negative feedback between acid and gastrin release is the main mechanism through which this class of drugs releases gastrin in the rat. Since a similar degree of gastrin release cannot be achieved by alkalinization of gastric contents, additional hormonal or neural regulatory factors may contribute to the drug-induced hypergastrinaemia.

Adenosine Triphosphatases↗
PubMed1992

Interaction of liquid aluminium phosphate and aluminium hydroxide with the gastric acid profile. Influence of food components and timing of meals.

AlPO4 is generally perceived as a particularly weak antacid. Its neutralizing capacity, when evaluated with the classical Fordtran test at the pH 3 standard, is several times smaller than that of Al(OH)3, which is considered a particularly potent antacid. This difference of in vitro reactivity of the two antacids is largely due to the fact that the pKa value is considerably lower for AlPO4 than for Al(OH)3. The object of this study was to evaluate in vivo and in vitro the impact of the pKa value of these antacids on their efficacy at low pH values and the modulation of their neutralizing capacity through proteins. Since both preparations display a much closer antacid activity at pH 2, we felt it appropriate to reevaluate the comparative in vivo neutralizing capacity of the two antacids at doses matched with their in vitro reactivity at pH 2. In vivo antacid effects were measured by ambulant pH-metry in 18 healthy volunteers after randomized ingestion of carbohydrate or protein meals. Antacid or placebo medication was given 1 and 3 h after meals. At pH 3.0, the standard milieu of the Fordtran test, preparation A, composed of Al(OH)3 and a small fraction of Mg(OH)2, displayed in vitro a neutralizing capacity of 4.4 mmol/ml, whereas this was 0.18 mmol/ml for preparation B, composed solely of AlPO4 (p less than 0.001). When tested at pH 1, 1.5, and 2, however, the ratio between A and B was below 2.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Improvement of the reproductive performance of sows by treatment with a GnRH superactive analogue.

The effect of a Hungarian-made superactive analogue of GnRH (Ovurelin, D-Phe6-GnRH-EA, Reanal, Hungary) on the postpartal sexual function of sows was monitored. GnRH treatment was carried out on day 19 before weaning. The sows were inseminated at the first oestrus after weaning. GnRH treatment markedly increased litter size at weaning, substantially reduced (to 25 and 50%, respectively) the number of sows failing to come into oestrus after weaning, and increased the number of sows coming into oestrus within one week after weaning by 42.5% and 9%, respectively. These beneficial effects were particularly apparent on the far using closed management technology.

Animals↗
PubMed1991

[Doppler echocardiography in the examination of normally functioning artificial mitral and aortic valves].

Patients with prosthetic valves were investigated by Doppler echocardiography in 902 cases between November 1987 and February 1990. The parameters of 209 of 344 mitral and 258 of 299 aortic prosthetic valves were evaluated. No significant correlation was found between the type of aortic or mitral prosthetic valves and the measured gradient. As concerns the size of the valve and the measured gradient, a close correlation for aortic valve replacement was detected. For a normally functioning mitral prosthetic valve, a maximum early diastolic velocity of less than 2 m/s (16 mm Hg gradient) and a pressure half-time of less than 130 ms (mitral valve area 1.8 cm2) were characteristic. In cases of aortic valve replacements, the maximum velocity was less than 3 m/s (36 mm Hg gradient), except for the small-diameter valves. More than 95% of the cases met these criteria. (Even if small-diameter valves were included, a maximum velocity of more than 3 m/s occurred only in 8.9%.) Doppler echocardiography is a suitable tool for detecting normal prosthetic valve function, while colour Doppler allows the optimal alignment of jet direction and Doppler beam.

Aortic Valve Insufficiency↗
PubMed1991

Decreased inhibition of immune precipitation by sera with the C2 B allotype.

Complement-mediated precipitation inhibiting (CMPI) activity of sera of 5 individuals homozygous for C2 B was compared to that of sera of 20 individuals carrying the common C2 C allotype. Sera with the rare C2 B allotype had a depressed CMPI capacity in both the early (5 min) and the late (60 min) stages of the reaction. We have also compared the CMPI activity of seven homozygous C4A deficient (C4A*Q0) and eight C4B deficient (C4B*Q0) serum samples and did not find significant differences from the controls (no C4 null alleles) in any stage of the reaction. These results indicate that C2 is the critical component in the CMPI reaction of the two constituents of the classical pathway C3 convertase and that C2 B is less active than C2 C.

Antigen-Antibody Reactions↗
PubMed1991

Differences in the complement activation induced by preformed and nascent immune complexes.

While preformed BSA-anti-BSA immune complexes (PIC) bind efficiently to human RBC after their interaction with human complement, nascent BSA-anti-BSA immune complexes (NIC) formed in the presence of complement do not bind to autologous RBC. The same results were obtained with tetanus toxoid-anti-tetanus toxoid PIC and NIC. In order to elucidate the causes of this marked difference between the RBC-binding properties of PIC and NIC, the profile of complement activation induced by them was compared using haemolytic assays and sensitive ELISA tests. BSA-anti-BSA NIC activated C1 more efficiently than PIC. This was reflected in a higher C4 content of the isolated NIC and higher C1 INH-C1s and lower C1q-fibronectin complex level in the NIC-treated serum as compared to the PIC-treated ones. Although isolated NIC contained more C3 than isolated PIC did, there was no significant difference in the AP activation. These findings suggest that the failure of NIC to bind to RBC is not due to a lack of C4-binding, or C3-binding and/or activation, but rather to the special structure of this type of complex.

Antigen-Antibody Complex↗