Biomedical subjects

J Nemeth

Publications and source records attributed to J Nemeth.

At least 37 records · Page 2Linked to original sources

PubMed1999

[Preoperative evaluation of gastric adenocarcinomas: comparison of CT results with surgical and patholgic results].

PURPOSE: The objective of our study was to reassess the value of CT scan in the preoperative evaluation of gastric adenocarcinoma, using surgical and pathologic findings as the reference standard. MATERIALS AND METHODS: Forty-five patients who had preoperative CT scan for gastric carcinoma were retrospectively included in the study. Images were analyzed by two readers working in consensus with respect to tumor detection, tumor location, depth of invasion, involvement of adjacent organs, lymph node involvement and presence of peritoneal carcinomatosis. RESULTS: Gastric tumor was visible in 91% of cases. Accurate tumor localization was obtained in 50% of cases. Depth of tumor penetration was correctly evaluated in 40% of the cases. Evaluation of regional and distant lymph node metastases was correct in 54% and 64% of cases, respectively. Peritoneal carcinomatosis was depicted in 17% of cases. CONCLUSION: CT scan allows detection of gastric adenocarcinoma in the majority of cases. However, this technique markedly underscores the extent of gastric adenocarcinoma. Therefore, CT scan should not be used to determine the preoperative staging of gastric adenocarcinoma.

Adenocarcinoma↗

PubMed1998

Improvement of nitrergic relaxation by farnesol of the sphincter of Oddi from hypercholesterolaemic rabbits.

Field stimulation relaxed the rabbit sphincter of Oddi muscle rings after incubation with atropine (1 microM) and guanethidine (4 microM) with a threefold increase in tissue cyclic cGMP content, a response previously shown to be essentially nitrergic. Preparations from hypercholesterolaemic rabbits (1.5% dietary cholesterol load over 8 weeks increasing serum total cholesterol from pre-diet 1.4+/-0.3 to 22.6+/-3.8 mmol/l) exhibited contractions with no change in cyclic GMP content under the same conditions. The nitrergic relaxation was recaptured with a twofold increase in tissue cyclic GMP content in preparations from hypercholesterolaemic rabbits undergone a treatment with 30 microM/kg farnesol i.v. twice a day over the last 3 days of the dietary period. We conclude that farnesol treatment restores nitrergic relaxation of the sphincter of Oddi in hypercholesterolaemia.

Animals↗

PubMed1998

Assessing the effectiveness of mesorectal excision in rectal cancer: prognostic value of the number of lymph nodes found in resected specimens.

PURPOSE: The aim of this study was to determine whether the number of involved or uninvolved lymph nodes in resected specimens can be used to predict the effectiveness of surgical resection for rectal cancer. METHODS: Local recurrence and survival rates for 118 patients undergoing curative resection for rectal carcinoma, without adjuvant therapy, were retrospectively studied. RESULTS: Mean follow-up was 62+/-37 months. Mean number of involved or uninvolved lymph nodes per resected specimen was 12+/-7. Overall local recurrence rate was 15.2 percent. In patients without involved lymph nodes (N0 patients) and with T1 or T2 tumors, the local recurrence rate ranged from 0 to 8 percent (not significant), depending on the number of lymph nodes on the specimen. In patients without involved lymph nodes and those with T3 tumors, the actuarial survival rate at ten years was significantly lower (P < 0.05), and the local recurrence rate was higher (P < 0.02) in patients with fewer than ten lymph nodes than in those with more than ten nodes. In patients with involved lymph nodes, the mean number of nodes on the resected specimen correlated closely with the mean number involved by the tumor. CONCLUSION: The assessment of the effectiveness of rectal excision for cancer is in part helped by the number of involved or uninvolved lymph nodes found on the resected specimen. This is of particular interest in patients without involved lymph nodes and those having infiltrating T3 tumors, for whom the long-term survival and local recurrence rates were significantly better when more than ten lymph nodes were present. On the other hand, when fewer than ten nodes were found, whatever the cause, adjuvant radiotherapy had to be considered, because of the high risk of local failure rate.

Female↗

PubMed1998

Differential efficacy of vasodilators in hypercholesterolaemic rabbits.

The effects of hypercholesterolaemia on the endothelium-dependent and -independent vascular reactivity of the superior mesenteric artery has been examined in anaesthetized rabbits in-vivo. Rabbits were fed with either standard or cholesterol-enriched diet for 24 weeks. Plasma lipids and changes in the endothelin content of plasma and vascular tissue were measured in the superior mesenteric artery and in the thoracic aorta. The functional severity of atherosclerosis was determined by examining vascular responses in the isolated thoracic aorta. The blood flow in the superior mesenteric artery was measured by transit-time flowmetry and drugs were injected through an intra-abdominal aortic catheter. Acetylcholine (5, 10, 20 microg kg(-1)) elicited dose-dependent, mesenteric vasodilation in normocholesterolaemic rabbits. In hypercholesterolaemic animals the response to acetylcholine was completely abolished and even became a vasoconstriction. Endothelin levels in plasma and in the vascular tissue were significantly elevated in hypercholesterolaemic animals compared with controls. Cromakalim at a dose of 3 microg kg(-1), elicited similar mesenteric vasodilation in hypercholesterolaemic and normocholesterolaemic animals. These experiments show that the endothelium-dependent responses of the superior mesenteric artery to acetylcholine are functionally impaired by prolonged hypercholesterolaemia, that this altered vascular reactivity is associated with the elevation of endothelin levels in the circulation and in vascular tissues, and that in hypercholesterolaemia the mesenteric vasodilator effect of the K+-channel opener cromakalim is entirely preserved, suggesting that severe hypercholesterolaemia does not depress the function of ATP-sensitive potassium channels in mesenteric vascular smooth muscle.

Acetylcholine↗

PubMed1997

Effect of Yersinia pestis YopM on experimental plague.

YopM of Yersinia pestis has previously been shown to be necessary for full virulence in mice and to be able to bind human alpha-thrombin. This activity prompted the hypothesis that YopM, functioning extracellularly during plague, might be accessible to neutralization by antibody and hence might be a protective antigen. This study tested this hypothesis and found that YopM was not protective, either by passive or active immunization, in inbred or outbred mice. These findings showed that either YopM-specific antibody does not have access to YopM during experimental plague or the function of extracellular YopM is not neutralizable by antibody. Exogenously supplied YopM partially restored virulence to a YopM- strain of Y. pestis while having no effect on lethality of Listeria monocytogenes. These findings indicate that YopM does not significantly alter host defenses important for resistance against heterologous infection (Listeria monocytogenes) but raise the possibility that YopM has a minor extracellular function specific to homologous infection (Y. pestis).

Animals↗

PubMed1996

Discrimination between constitutive secretion and basal secretion from the regulated secretory pathway in GH3 cells.

The present experiments were undertaken to characterize basal release from vesicles of the regulated secretory pathway. In transfected GH3 cells, progastrin was released by the constitutive route, and mature, bioactive, amidated gastrin by the regulated secretory pathway. Studies using brefeldin A and bafilomycin A1 which inhibit progression through the Golgi complex suggested that both basal and stimulated release of amidated gastrin originated from mature secretory granules. Basal, but not stimulated, secretion of amidated gastrin was strongly inhibited at 22 degrees C. Mature secretory vesicles therefore support both basal and evoked secretion although the mechanisms underlying the two processes differ in their temperature sensitivity.

Amides↗

PubMed1996

Ileal pouch/anal anastomosis for Crohn's disease.

BACKGROUND: Patients with Crohn's disease (CD) are not commonly considered as candidates for ileal pouch/anal anastomosis (IPAA). This approach has been avoided because of the poor results observed, retrospectively, in patients with an initial diagnosis of ulcerative colitis who were found to have CD on examination of the resected specimen. However, in 1985, we decided to investigate an alternative to coloproctectomy with definitive end-ileostomy by a prospective study of IPAA for selected patients with CD. METHODS: Between 1985 and 1992, 31 patients with CD, but with no evidence of anoperineal or small-bowel disease, were recruited to our study. They comprised 15 men and 16 women whose mean age was 36 years (SD 14; range 16-72). All CD patients underwent IPAA. The short-term and long-term functional results of this procedure were compared with those of 71 ulcerative colitis patients who also underwent IPAA during the same period in our unit. Mean follow-up was 59 (SD 25) months. FINDINGS: No significant differences were observed between patients with CD and ulcerative colitis in the postoperative complication rate. Of the 31 CD patients, six (19%) experienced specific complications 9 months to 6 years after surgery: three had pouch-perineal fistulas, which required pouch excision in two cases; one had a pouch-vaginal fistula that was treated by gracilis muscle interposition; and one had an extrasphincteric abscess, which was treated surgically. Two patients (6%), one of whom was treated for an extrasphincteric abscess, experienced CD recurrence on the reservoir, and were treated successfully with azathioprine. At 5-year follow-up, there were no significant differences between patients with CD and ulcerative colitis in stool frequency (5.0 [2.0] vs 4.7 [1.4] per day; p=0.68), continence, gas/stool discrimination, leak or need for protective pads, and sexual activity. INTERPRETATION: Our results show that in selected cases of CD without anoperineal or small-bowel manifestations, IPPA can be recommended as an alternative to coloprotectomy with definitive end-ileostomy, when rectal resection is essential.

Adult↗

PubMed1996

Small bowel fistulae in Degos' disease: a case report and literature review.

Degos' disease (malignant atrophic papulosis) is a rare, progressive, small- and medium-size arterial occluding disease, leading to tissue infarction and initially involving the skin. We report a case with bowel involvement followed by enterocutaneous fistulae. Diagnostic laparoscopy with jejunal biopsy was followed by jejunal perforations, peritonitis, and fistulae leading to death after a 4-month course in the intensive care unit. The usual treatment of enterocutaneous fistula by somatostatin and parenteral nutrition was ineffective in this case. The course of the disease in our patient was not usual, as can be seen in a literature review underlining the specific features of Degos' disease. Laparoscopy and bowel biopsy should be avoided in this context. Degos' disease should be considered in the differential diagnosis of a primary ulceration of the small intestine.

Adult↗

PubMed1995

Antibodies to capsular polysaccharides are not protective against experimental Staphylococcus aureus endocarditis.

The protective efficacy of antibodies to the Staphylococcus aureus capsular polysaccharide was examined in a rat model of catheter-induced endocarditis. Capsular antibodies were induced either by active immunization with killed S. aureus or by passive immunization with hyperimmune rabbit antiserum to S. aureus. Control rats were injected with phosphate-buffered saline or passively immunized with normal rabbit serum or rabbit antiserum to a nonencapsulated strain. Animals with indwelling catheters were challenged intravenously with 5 x 10(4) to 4 x 10(6) CFU of the homologous S. aureus strain (capsular serotype 5 strain Reynolds or serotype 1 strain SA1 mucoid). Both immunized and control rats developed S. aureus endocarditis. The numbers of S. aureus cells recovered from the blood and aortic valve vegetations of immunized rats were similar to those of control rats, indicating that capsule-specific antibodies were not protective. To determine whether the presence of an indwelling catheter interfered with antibody-mediated protection against S. aureus endocarditis, catheters were removed 2 h after insertion in additional groups of rats. An inoculum of 10(8) CFU of strain Reynolds was needed to provoke endocarditis in rats catheterized for 2 h, compared with 5 x 10(4) CFU for rats with indwelling catheters. Passively transferred capsular antibodies were not protective since both immunized and nonimmunized animals developed endocarditis, and quantitative cultures of blood and valvular vegetations revealed no differences between immunized and control animals. The findings of this study indicate that antibodies to the capsular polysaccharide are not protective in the rat model of experimental S. aureus endocarditis.

Animals↗

PubMed1995

Accelerated gastric epithelial proliferation.

Gastric body mucosal proliferation was quantified and localised under conditions of increased gastrin drive using a variety of techniques. Rats were given omeprazole 400 mumol/kg/day by gavage and after 30 days mean serum gastrin rose 11-fold (p < 0.001). Total mucosal polyamines rose 220% from 15.9 to 50.9 nmol/mg protein (p < 0.001). This was associated with a 238% increase in crypt cell production rate from 0.541 to 1.83 crypt cells/h by vincristine metaphase arrest (p < 0.02). Using computer aided counting of proliferating cell nuclear antigen (PCNA) immunostained nuclei to assess epithelial proliferation in hypergastrinaemia rat stomach: mucus neck cell PCNA labelling was increased by 41% (p < 0.001) and gland cell PCNA labelling was increased by 222% (p < 0.001). PCNA/AgNOR (argyrophilic nuclear organiser regions) co-stained sections were used to assess proliferative activity in cycling and non-cycling cell populations. Data from these experiments suggest that, in addition to increasing the number of mucosal cells in cycle, cell life and cell cycle duration may be reduced in hypergastrinaemia.

Animals↗

PubMed1994

Multiple lymphomatous polyposis of the gastrointestinal tract. An extensive histopathologic and immunohistochemical study of 12 cases.

BACKGROUND: Multiple lymphomatous polyposis (LP) is a rare entity, characterized by multiple polypoid tumors involving several segments of the gastrointestinal tract. METHODS: In this large retrospective series of 12 patients with LP, histologic and immunohistochemical features were investigated from patients with multiple biopsy samples from each site (500 gastrointestinal biopsies). Immunohistochemistry was performed on paraffin embedded biopsies from 12 patients and on frozen tissue biopsies from 8 patients, for each of whom at least two different anatomic sites were studied. RESULTS: Histologic features always were characterized by nodules located in mucosa and submucosa composed of lymphomatous, small cleaved cells. B-cell phenotype of the neoplastic cells was the same phenotype as adult mantle-zone cells or fetal follicle cells (frequent coexpression of surface IgM and surface IgD, and weak expression of CD5, CD35+, CDw32+, and CD23-). Tested cases expressed bcl-2. Five to 20% of LP cells were positive for the monoclonal antibody Ki-67. Five patients died within 5-32 months after diagnosis. Frequent extradigestive sites were also identified. There were two unique findings: five cases with digestive tract lymphoepithelial lesions (LEL), and one secondary transformation to large B-cell malignant lymphoma. CONCLUSIONS: To the authors' knowledge, this is the largest series so far of LP studied with immunohistochemistry on frozen sections. Mantle-cell B cell phenotype of the nodular monotonous, small cleaved cells is confirmed. This entity may be classified as mantle-cell lymphoma with a similar aggressive clinical course, and treated as a high grade B-cell lymphoma. The authors know of no such LEL that has been reported previously, and secondary transformation has been described only briefly in one case.

Adult↗

PubMed1994

Extensive small intestinal T-cell lymphoma of low-grade malignancy associated with a new chromosomal translocation.

BACKGROUND: Primary T-cell lymphoma of the small intestine is rare, and most cases have proved rapidly fatal. METHODS: We describe a case of lymphoma involving the small intestine uniformly and extensively in a 28-year-old man on initial examination seen with long-standing diarrhea, malabsorption, and recurrent episodes of intestinal obstruction. Clinical remission was obtained with pentostatin (2'-deoxycoformycin, supplied by Professor Catovsky, London UK) after the patient had failed to improve under conventional chemotherapy. Tumor specimens as well as mesenteric lymph node, liver, and bone marrow specimens were studied with conventional pathology and immunochemistry. Additionally, mesenteric lymph nodes and peripheral blood cells were studied for T-cell receptor (TCR) gene rearrangement and karyotype. RESULTS: Lymphoma cells were small T-lymphocytes with irregular pleomorphic nuclei, bearing the CD3, CD4 and TCR alpha-beta phenotype. Peripheral-blood cytology and bone marrow biopsy were normal. Southern blot analysis of the TCR beta-chain gene revealed the same monoclonal rearrangement in the mesenteric lymph nodes and peripheral blood lymphocytes. An as yet undescribed t(4;16)(q26;p13) translocation, involving the region where the interleukin-2 (IL-2) gene has been mapped, was present in the mesenteric lymph nodes and peripheral blood lymphocytes. CONCLUSION: We believe this is the first description of an extensive, small intestinal lymphoma of low-grade malignancy made up of monoclonal T-cells with a TCR alpha-beta and helper/inducer phenotype, associated with a novel chromosomal translocation.

Adult↗

PubMed1994

In vitro comparison of bovine mastitis and fecal Escherichia coli isolates.

In vitro methods were used to test the hypothesis that Escherichia coli from bovine mastitis are essentially no different from isolates from bovine feces. Fifty E. coli isolates from bovine mastitic milk, 50 from feces of mastitic cows and 50 from feces of healthy cows were compared with respect to biochemical properties and certain potential virulence factors. There were no significant differences among the groups in tests for biotype; production of colicins, colicin V, or Vero cell cytotoxicity; and growth in 90% gnotobiotic calf serum or 90% normal milk whey. Resistance to killing in 90% gnotobiotic calf serum varied from 66 to 84%. Most isolates grew in normal whey: the percentage in a group varied from 86 to 96. Mastitic milk isolates were significantly different from the fecal isolates in adonitol fermentation (P < or = 0.006), production of aerobactin (P < or = 0.026), and ability to grow in 90% mastitic whey (P < or = 0.00004). However, only 40% of mastitis E. coli fermented adonitol and only 20% produced aerobactin. Ninety-six percent of mastitic milk E. coli grew in mastitic whey, whereas 64% and 60%, respectively, of mastitic fecal and normal fecal isolates grew in this medium. It is concluded that none of the properties that were investigated constitute potential virulence factors or markers for ability to induce mastitis; the data are consistent with the hypothesis that mastitic E. coli are simply opportunistic pathogens.

Animals↗

PubMed1994

Substance use among Hungarian students.

There is very little empirical data on drug and alcohol use among Hungarian adolescents. The purpose of this pilot project was to develop instrumentation and methods that could be used to assess legal and illegal substance use among Hungarian adolescents. A Hungarian translation of The American Drug and Alcohol Survey was developed and adapted to the unique circumstances of Hungarian patterns of use. This survey was tested with 234 students, 135 females and 99 males, from Grades 8 and 11 enrolled in public schools, in Györ, Hungary during 1991-1992. The students reported little or no substance use other than use of alcohol and tobacco. Older students were more likely than younger students to be involved with alcohol and cigarettes. Females and males were equally likely to try alcohol, but males were more likely to have been drunk than females. Despite the low reported use of substances other than alcohol and tobacco, students demonstrated attitudes toward drug use that may place them "at risk" for future use.

Adolescent↗

PubMed1994

[Bouchut tubercles and AIDS. Apropos of 3 cases].

Tuberculosis choroidal granulomas ("tubercules de Bouchut") are rare, even in patients with AIDS and active tuberculosis. The authors report the clinical and angiographical findings of three cases. Choroidal involvement was bilateral, with multiple lesions, mostly located at the posterior pole. The size of the granuloma ranged from 1/8 to 1/2 of a disc diameter. Fluorescein angiography showed early prolonged hypofluorescence and late moderate hyperfluorescence. The lesions remained stable for months despite treatment of tuberculosis, and then gradually subsided. In two cases, the choroidal granulomas were discovered before the diagnosis of disseminated tuberculosis and guided the investigations, which allowed the identification of Mycobacterium Tuberculosis bacillus in the body. In the third case, pulmonary tuberculosis had already been diagnosed. The number of tuberculosis cases is increasing together with the number of AIDS cases. This should make the observation of tuberculosis choroidal granulomas more frequent. The discovery of the typical aspects of granulomas described above during fundus examination of AIDS patients can help in diagnosing tuberculosis.

AIDS-Related Opportunistic Infections↗

PubMed1993

Primary T-cell rich B-cell lymphoma of the common bile duct.

A 34-year-old woman was hospitalized for the investigation of a one-month history of intestinal disorders, gastric heaviness and transitory icteric episodes. Extensive clinical investigations suggested the diagnosis of gall bladder carcinoma or sclerosing cholangitis. At laparotomy, the proximal part of common bile duct was markedly thickened by a white, firm, fish-flesh like tumour extending in to the cystic duct, gall bladder wall and to the liver. Histological study showed a diffuse lymphoid proliferation of the common bile duct mainly composed of small cells mixed with scattered large atypical cells. Immunohistochemistry revealed that most of the small cells expressed T-cell markers with predominant CD 4 and alpha-beta T-cell receptors and without phenotypic gap, whereas large atypical cells showed monotypic B phenotype with co-expression of mu and delta heavy chains and light lambda chain restriction. No evidence of primary nodal lymphoma was found during extensive clinical, radiological, sonographic or scanographic examinations. Sequential chemotherapy (MACOP-B) was instituted and the patient was still alive 4 years after diagnosis. Morphological and immunohistochemistry findings fulfilled criteria for a primary high grade B-cell lymphoma (centroblastic type, Kiel classification) from common bile duct concealed by numerous small reactive T-cells, so called T-cell rich B-cell lymphoma, not previously described in this location.

Adult↗

PubMed1993

Primary T-cell malignant lymphoma of the central nervous system. Histological, immunohistochemical and ultrastructural study of a case.

Most primary malignant lymphomas (ML) of the central nervous system (CNS) are derived from B-cells, whereas T-malignant lymphomas (T-ML) primarily arising in the CNS are extremely rare. We report on a patient with a primary T-ML of the CNS localised in the posterior fossa. On the basis of histological, ultrastructural and immunohistochemical studies, this tumour was classified as a pleomorphic T-ML, medium and large cell type with peripheral helper/inducer T-cell phenotype (CD 1-, CD 2+, CD 3+, CD 5+, CD 7-, CD 4+, CD 8-, CD 19-, CD 22-, UCHL 1+/CD 45 RO, L 26-/CD 20, LN 1-/CDW75, LN 2-/CD 74, MB 2-). Furthermore, the positivity of the markers CD 25 and HLA-DR on many medium-sized and large lymphoma cells suggests activation of these cells. The nuclear marker of proliferative activity Ki-67 was expressed in some large cells, whereas the natural killer cell-related markers CD 16 and Leu 7/CD 57 did not react with lymphoma cells. This study emphasises the value of extensive immunohistochemical investigations on frozen and paraffin sections in order to identify and characterize the T-cell malignancies, particularly in their rare CNS location.

Antigens, CD↗

PubMed1993

Identification of progastrin derived peptides in colorectal carcinoma extracts.

The possible production of gastrin by colorectal carcinomas has been studied. Extracts of 44 tumours and adjacent macroscopically normal tissue were examined in radioimmunoassay using the following antibodies: (i) L289 raised to a C-terminal fragment of progastrin which shows specificity for intact progastrin, but not the extreme C-terminal tryptic peptide; (ii) LW60 raised to a C-terminal fragment of progastrin which reacts with progastrin and its C-terminal tryptic peptide; (iii) 109-21 which was raised to, and reacts with, Gly-extended forms of heptadecapeptide gastrin--that is, biosynthetic intermediates on the pathway producing active gastrin; and (iv) L2 which reacts with amidated, biologically active gastrins. All samples contained detectable material in assays using LW60; in general, concentrations measured with this antibody were higher than with the other antibodies, and in particular there were higher concentrations in tumour compared with normal tissue extracts. Tumour extracts also contained higher concentrations of immunoreactivity compared with normal tissue, in assays using antibodies L289 and 109-21. In contrast, amidated gastrins were found in similar concentrations in tumour and normal tissue, and concentrations were the lowest of those recorded in the four assays. Separation on Sephadex G50 revealed peaks compatible with progastrin and its C-terminal flanking peptide, and two other peaks that are so far unidentified. In conclusion most colorectal carcinomas contain peptides derived from the gastrin precursor, progastrin, but for the most part these tumours do not convert progastrin into biologically active products.

Amino Acid Sequence↗