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Biomedical subjects

M Feldmann

Publications and source records attributed to M Feldmann.

At least 37 records · Page 2Linked to original sources
PubMed1992

HER2 (c-erbB-2) oncoprotein expression in colorectal adenocarcinoma: an immunohistological study using three different antibodies.

Paraffin wax sections of 70 surgically resected colorectal adenocarcinomas were examined for the overexpression of HER2/c-erbB-2 oncoprotein using three different specific antibodies and the avidin-biotin immunoperoxidase technique. The patients included 38 men and 32 women aged between 47 and 80 years. The tumours were derived from various parts of the large intestinal tract, and represented all three stages of Dukes' classification and the three histological grades of differentiation. Many tumour sections also included adjacent normal or transitional mucosa. Eight tubular adenomas found in the colectomy specimens in association with some carcinomas were also examined. No positive membrane staining was seen in any of the 70 carcinomas, four adenomas, two hyperplastic polyps, nor in the adjacent normal or transitional mucosa. It is suggested that the overexpression of c-erbB-2 gene product is unlikely to be as common and as pronounced in colorectal adenocarcinoma as it is in ductal carcinoma of the breast.

Adenocarcinoma↗
PubMed1992

[Neonatal Campylobacter fetus septicemia: a case secondary to maternal-fetal contamination].

A favourable outcome of a severe Cambylobacter fetus sepsis in a neonate is reported. The transmission was probably vertical. His mother experienced diarrhoea 15 days before birth. No infecting organism was isolated from maternal stools, but maternal antibody response was significant. Such a perinatal infection with meningitis and septicemia is uncommon. Bacteriological diagnosis requires an enriched medium and a long incubation. The diagnosis should be evoked in view of an anamnestic context, a negative culture or a resistance to antimicrobial drugs.

Bacteremia↗
PubMed1992

[Bourneville tuberous sclerosis manifested by prenatal finding of intracardiac tumors].

Neonatal cardiac rhabdomyoma is the most frequent cardiac tumour in the newborn, and a classical way to diagnose tuberous sclerosis (Bourneville's disease). The authors report 4 cases, including 2 antenatal diagnosis: 2 of them had arrhythmia, one with asystolic cardiac failure and the other with cyanosis due to a right-left shunt; the tumour was asymptomatic in the 2 others. The 4 babies had clinical and radiological neurologic signs of tuberous sclerosis, initially or during the course of the disease. The authors discuss the polymorphism of the clinical presentation of tuberous sclerosis in the newborn. Although tuberous sclerosis is transmitted through a dominant gene, the expressivity and the penetrance are very variable. The authors discuss the examination and investigation of at risk family members. The genetic counsel is difficult but very important because of the poor neurologic prognosis of the disease.

Female↗
PubMed1992

Detection of in vivo production of tumour necrosis factor-alpha by human thyroid epithelial cells.

We have established previously that human thyroid epithelial cells (TEC) from patients with autoimmune thyroiditis are able to synthesize cytokines, such as interleukin-1 (IL-1) and interleukin-6 (IL-6). This paper examines TEC in sections from autoimmune thyroiditis for the in vivo production of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) using the combined techniques of in situ hybridization and immunohistochemistry. Thyroid tissue from patients with Graves' disease, Hashimoto's disease and non-toxic goitre was examined and both mRNA and the protein of TNF-alpha were detected in TEC on frozen sections. Representative figures of only Graves' samples are illustrated in this paper. In contrast, using the same methods, IFN-gamma was detected only in the infiltrating cells and not in TEC of thyroid tissue from the patients.

Epithelium↗
PubMed1992

[Droperidol versus metoclopramide. Prevention of emesis following strabismus surgery in children].

Vomiting after strabismus surgery is a major problem that remains as yet unsolved, especially in children. Droperidol and metoclopramide, both known as powerful antiemetic drugs, were compared in this study. METHODS. One hundred ASA class I and II children ranging from 3 to 10 years of age were studied in a double-blind, randomised fashion. They were assigned to three groups: group D (n = 33) received 0.075 mg/kg droperidol, group M (n = 33) 0.15 mg/kg metoclopramide, and group N (n = 34) 0.1 ml/kg NaCl i.v. upon arrival in the post-anaesthesia recovery room (PARR). After oral premedication with 0.4 mg/kg midazolam, anaesthesia was induced via a face mask by inhalation of halothane, nitrous oxide, and oxygen. Barbiturates, atropine, and succinylcholine were not used; 0.05 mg/kg vecuronium was given to facilitate intubation. Gastric contents were aspirated by a gastric tube at the end of the operation. Vomiting and retching were recorded for 24 h; recovery from anaesthesia was assessed by a modified Steward score. RESULTS. The three groups were comparable regarding age, body weight, duration of anaesthesia, number of repaired eye muscles, and occurrence of the oculocardiac reflex (OCR). During the first 24 h postoperatively 21/33 (64%) patients of group D vomited, 24/33 (73%) of group M, and 33/34 (97%) of group N. The differences between groups D and N and between M and N were significant (P less than 0.01); comparison of groups D and M showed no statistical significance. Droperidol was more effective in reducing severe vomiting. Of the group N children, 47% vomited more than 6 times in 24 h compared to 18% of group M and 0% of group D. Age, sex, duration of anaesthesia, number of repaired eye muscles, and occurrence of the OCR had no influence on postoperative vomiting. Despite being administered at the end of the operation, droperidol did not prolong the patients' stay in the PARR. The post-anaesthetic scores for group D children were only slightly lower compared to groups M and N. CONCLUSIONS. Droperidol (0.075 mg/kg) and metoclopramide (0.15 mg/kg) both reduce postoperative vomiting after strabismus surgery. Droperidol seems to be more effective in reducing severe vomiting. Postoperative sedation after droperidol was not a major problem in our experience.

Child↗
PubMed1991

Regulatory interactions among autologous T cell clones. Human bifunctional T cell clones regulate the activity of an autologous T cell clone.

In contrast to the ease of cloning and characterizing, at the molecular level, helper and cytotoxic T cells, suppressor T cells remain an enigma, and their existence as discrete entities is being increasingly challenged. Here we review evidence that CD4+ regulatory clones, capable of expressing both helper and suppressor functions, may account for much of the suppressor function. It is suggested that a single T cell clone, depending on the signals it receives from its environment, may release either helper or suppressor cytokines. Studying such clones under defined conditions (providing suppressor signals), may preclude detection of their helper capacity. Since some therapeutic approaches in various human diseases are based on the manipulation of helper and suppressor functions, the question whether committed suppressor cells exist has important practical implications in medicine.

Clone Cells↗
PubMed1991

Platelet-derived interleukin 1 induces human endothelial adhesion molecule expression and cytokine production.

Interleukin 1 (IL-1) plays a central role in the regulation of the body's response to infectious and inflammatory stimuli. Recent evidence has shown that human platelets express a cell associated form of this proinflammatory cytokine very rapidly following activation. Since one of the earliest events in inflammation is frequently the rapid adhesion of platelets to injured endothelium, it was of interest to determine whether platelets express IL-1 in a functionally relevant form that can alter the phenotype of human endothelial cells in vitro. Thrombin activated platelets induced significant expression of the adhesion molecule intercellular adhesion molecule 1, as well as secretion of the IL-1 inducible cytokines IL-6 and granulocyte macrophage colony stimulating factor by cultured human umbilical cord and saphenous vein endothelial cells. This was inhibited by prior treatment of the platelets with antibody specific for IL-1. These results suggest that platelet delivered IL-1 might initiate and regulate some of the earliest phases of the inflammatory response. An additional observation of interest was differential induction of endothelial leucocyte adhesion molecule 1 by activated platelets on saphenous vein but not umbilical vein but not umbilical vein endothelial cells, which suggests functional heterogeneity of the endothelial cells.

Adult↗
PubMed1991

Autoantigen recognition by thyroid-infiltrating T cells in Graves disease.

Graves disease is a common form of human autoimmune thyroiditis. It shares many pathological features and HLA associations with other, less easily studied, organ-specific autoimmune conditions such as insulin-dependent diabetes mellitus, and hence it is also a useful model for understanding these other diseases. We have previously shown that thyroid-infiltrating T cells in Graves disease that have been recently activated in vivo specifically recognize autologous thyroid epithelial cells. However, the autoantigens involved were not defined. In this study, we have made use of antigen-independent T-cell cloning techniques to show that at least three different thyroid antigens, three different epitopes on a single antigen, and two HLA class II elements are involved in this recognition process in a single individual. This demonstrates that T cells that are present and activated at the site of a human autoimmune disease may show considerable heterogeneity in their recognition of autoantigen on the target tissue. This contrasts with the limited heterogeneity recently reported in some animal models and has potentially important implications for both our understanding of the autoimmune process in humans and the design of immunotherapies to reverse it.

Adult↗
PubMed1991

Localization of tumor necrosis factor alpha in synovial tissues and at the cartilage-pannus junction in patients with rheumatoid arthritis.

Using immunoaffinity-purified polyclonal anti-human recombinant tumor necrosis factor alpha (TNF alpha) F(ab')2 fragments and immunohistochemical techniques, the cells that make TNF alpha were localized in the inflamed synovial tissue of patients with rheumatoid arthritis (RA) and osteoarthritis (OA). Anti-TNF alpha antibody-stained cells were demonstrated in 9 of 11 RA and 2 of 4 OA but none of 5 normal synovial membranes examined. In RA, 26-64% of the lining layer cells were positive for TNF alpha. In the interaggregate area, 10-30% of the cells contained TNF alpha, often in a perivascular distribution, and up to 19% of the cells in lymphoid aggregates stained for TNF alpha. Some endothelial cells also stained with these antibodies. In OA tissues, the TNF alpha-containing cells were found predominantly in the deeper layer. Cells containing TNF alpha were also found at the cartilage-pannus junction in all 4 RA specimens examined. Double immunofluorescence analysis demonstrated that most TNF alpha-secreting cells in the RA synovial membrane expressed the monocyte/macrophage marker antigens CD11b and CD14, and a few expressed the T cell marker CD3. Our findings provide histologic evidence that TNF alpha is locally produced in the lining and deeper layers of the synovium by cells of the monocyte/macrophage lineage, supporting its role in inflammation. Further, our findings demonstrate that TNF alpha is produced by cells at the cartilage-pannus junction, which could affect chondrocyte metabolism, leading to the cartilage degradation in RA.

Antibodies↗
PubMed1991

Interleukin 4 induces interleukin 6 production by endothelial cells: synergy with interferon-gamma.

Interleukin (IL)4 induces IL6 production by human umbilical vein endothelial cells (HUVEC) in a dose-dependent manner, as shown by bioassay and immunoprecipitation. Interferon (IFN)-gamma, which antagonizes IL4 effects on leukocytes, synergized with IL4 in the induction of IL6 production by HUVEC. Contamination with endotoxin was excluded by heat-inactivated IL4, preincubating with anti-IL4 polyclonal antibody and the use of polymyxin B. The presence of IL4 receptors on HUVEC was shown by affinity cross-linking with 125I-IL4, revealing a 110-kDa binding protein. However, compared with the amount seen on T cells the 60-70-kDa cross-linked doublet was present at much lower levels. Additional lower molecular weight cross-linked proteins were isolated only with HUVEC, but the origin of these is unclear. IL6 is a pluripotent cytokine produced by many cells which promotes the differentiation and growth of lymphocytes and the production of acute phase protein by hepatocytes, and is important in the regulation of immunity at the systemic and local levels. Since IL4 and IFN-gamma are produced by T cells, which are frequently associated with vascular endothelium during chronic inflammation, IL4 is likely to be an important cytokine in the regulation of IL6 and perhaps other cytokine production by endothelium in vivo.

Drug Synergism↗
PubMed1991

Induction of the interleukin 1 receptor antagonist protein by transforming growth factor-beta.

Transforming growth factor-beta 1 (TGF-beta 1) mediates many immunosuppressive effects on immune cells and can inhibit the production of tumor necrosis factor and interleukin 1 (IL 1). However, TGF-beta 1 can stimulate the production of IL 6 and platelet-derived growth factor, indicating that TGF-beta 1 initiates complex effects on the production of cytokines. In this report we show that treatment of peripheral blood monocytes with TGF-beta 1 leads to the induction of a recently described IL 1 receptor antagonist protein (IRAP). The effect of TGF-beta 1 was both dose and time dependent. TGF-beta 1 induced de novo synthesis of IRAP, as Northern blotting experiments indicated a rapid and transient induction of the mRNA encoding IRAP. The induction of IRAP suggests a potential mechanism by which some of the inhibitory effects of TGF-beta 1 are mediated.

Cells, Cultured↗
PubMed1991

Cloning, expression and cross-linking analysis of the murine p55 tumor necrosis factor receptor.

Tumor necrosis factor (TNF) mediates its pleiotropic effects via high-affinity cell surface receptors. In man, molecular cloning has identified two distinct, independent TNF receptors (TNFR) of 55 and 75 kDa. It is unclear, however, whether the multiple effects of TNF are suggested between the receptor types. In the mouse, previous studies had shown functional heterogeneity of TNFR, since the WEHI 164 fibroblast line is sensitive to the cytotoxic effects of both murine and human TNF, whereas the murine T cell line, CT6, proliferates in response to murine but not human TNF. In this study, the cloning of a cDNA encoding the murine homologue of the p55 TNFR is reported. This receptor binds murine and human TNF with equal affinity and is expressed on WEHI 164 and a number of other cell lines, but only low levels of mRNA and no protein is detectable on CT6 cells. CT6 cells, however, express a second TNFR of approximately 75 kDa, identified by cross-linking analysis, which is also found on WEHI 164 cells, and binds only murine TNF. These studies establish that there are also two TNFR in the mouse, and suggests that there may be segregation of the cytotoxic and proliferative responses between different receptors, at least in these cell lines.

Amino Acid Sequence↗
PubMed1991

Expression of granulocyte-macrophage colony-stimulating factor in rheumatoid arthritis: regulation by tumor necrosis factor-alpha.

Granulocyte-macrophage colony-stimulating factor (GM-CSF), in addition to being a growth factor for granulocytes and macrophages, is an activator of cells of the monocyte/macrophage lineage and induces HLA class II expression and cytokine synthesis in these target cells. Macrophage activation and class II expression are prominent features in rheumatoid arthritis (RA) joints, but the mechanism of their stimulation is not understood, since interferon-gamma, the major stimulus of class II expression, is not usually detectable at the protein level in synovial cell culture supernatants. We have, therefore, studied GM-CSF expression in cultures of cells derived from joints affected by RA and osteoarthritis (OA), and show that GM-CSF is produced spontaneously both by RA synovial cells and to a lesser extent by OA synovial cells in the absence of extrinsic stimuli. GM-CSF production continues for the 5-day duration of the culture period. Using neutralizing antibodies to tumor necrosis factor (TNF)-alpha we demonstrated that GM-CSF production in RA synovial cell cultures is dependent on the continued presence of active TNF-alpha. This result supports our concept that continued activation of the cytokine network is a marked feature of RA, and that TNF-alpha plays a pivotal role in this network, by regulating the production of other pro-inflammatory cytokines, such as interleukin 1, as demonstrated previously, and GM-CSF.

Arthritis, Rheumatoid↗
PubMed1991

Interleukin-6 localisation in the synovial membrane in rheumatoid arthritis.

Polyclonal antibodies were raised in rabbits against Interleukin-6 (IL-6) by immunisation with a synthetic peptide of identical sequence to the amino terminal 12 amino acids of human IL-6. These antibodies reacted with recombinant IL-6 by ELISA and stained the cytoplasm of the IL-6 secreting bladder tumour cell line T24. Staining was abolished by prior incubation of the antibody with the IL-6 peptide. F(ab')2 fragments made by pepsin digestion of the IgG were immunopurified, labelled with biotin and retained activity in the biochemical and histological assays. Sections of synovial membrane from patients with rheumatoid arthritis (RA) were stained with these antibodies, using an immunoperoxidase technique, and cells containing IL-6 were domonstrated in the thickened synovial lining layer and also in a perivascular distribution in the deeper synovium. In osteoarthritis there were fewer cells in the lining layer and hence localisation appeared similar in both the interstitial area and lining layer. Double-staining techniques with mouse monoclonal antibodies against cell subset markers in five RA synovial membranes showed that up to 13% of T-cells and 19% of antibody-producing cells stained for IL-6. However, up to 70% of the macrophages contained IL-6 and these were found in close proximity to Ig-producing plasma cells. This study showed that macrophages were the major cells of the immune system in which IL-6 could be localised in RA, and suggests a role for locally produced IL-6 in the stimulation of rheumatoid factor production.

Amino Acids↗
PubMed1991

Unusual encephaloclastic lesions with paraventricular calcification in congenital rubella.

We report an unusual case of congenital rubella. The infant was suffering from a serious encephalopathy, and both prenatal echography and neonatal CT scan showed passive ventriculomegaly with a calcified periventricular border. Usually, such lesions are strongly suggestive of cytomegalovirus (CMV) infection and have never previously been reported in congenital rubella. Classic cerebral lesions in rubella are related to a prominent obstructive vasculopathy. Conversely, encephaloclastic lesions in CMV infection are likely related to a necrosis of brain parenchyma following upon an initial ventriculitis, and perhaps also to a disturbance of neuronal proliferation. Recently, Carey described a neonate with proven congenital rubella and cranial ultrasound findings typical of ventriculitis. However, in spite of the close similarity between our patient's lesions and the typical CMV lesions, we think it's impossible to assert similar pathogenic mechanisms. Actually, it's quite conceivable that only a severe or extensive vasculopathy can lead to brain atrophy with periventricular calcification in congenital rubella.

Brain Diseases↗
PubMed1991

Production of interleukin-1 and interleukin-6 by human keratinocytes and squamous cell carcinoma cell lines.

Cultured human keratinocytes and squamous cell carcinoma (SCC) cell lines were analyzed for the presence of ribonucleic acid (RNA) transcripts for the cytokines interleukin-1 and interleukin-6 and for these proteins. This study demonstrates that both cytokines are synthesized and secreted by both normal keratinocytes and SCC lines. The rate of secretion of these cytokines can be augmented in response to a variety of stimuli including tumor necrosis factor-alpha, granulocyte-macrophage colony stimulating factor, transforming growth factor-beta and the combination of lipopolysaccharide and phorbol myristate acetate. Interleukin-1 and interleukin-6 have been reported to influence the proliferation of cultured human fibroblasts. However, these cytokines had no significant effect on the proliferation of human keratinocytes or the SCC lines tested. Although it seems unlikely that interleukin-1 or interleukin-6 could directly influence keratinocyte proliferation in vivo, the capacity of these cells to synthesize and release these cytokines supports earlier observations that keratinocytes may play an important role in augmenting an immune or inflammatory response.

Carcinoma, Squamous Cell↗