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Biomedical subjects

C Schmid

Publications and source records attributed to C Schmid.

At least 271 records · Page 15Linked to original sources
PubMed1992

Differential regulation of insulin-like growth factor binding protein (IGFBP)-2 mRNA in liver and bone cells by insulin and retinoic acid in vitro.

Isolated cells produce insulin-like growth factors (IGFs) and their binding proteins (IGFBPs). Two distinct cell types were studied with regard to IGFBP-2 expression: (i) rat hepatocytes, which produce IGF I at a high rate and thus regulate its plasma concentration; and (ii) rat osteoblasts, which are targets of IGF I action. IGFBP-2 expression is low in hepatocytes prepared from normal adult rats and high in calvaria cells from newborn rats. Retinoic acid stimulates IGFBP-2 production by liver cells. Insulin suppresses both basal and retinoic acid-induced IGFBP-2 mRNA expression in hepatocytes and has no such effect on osteoblasts. Retinoic acid and insulin regulate IGFBP-2 expression in a tissue-specific manner.

Animals↗
PubMed1992

Prostaglandin E2 stimulates synthesis of insulin-like growth factor binding protein-3 in rat bone cells in vitro.

Prostaglandin E2 is produced by bone cells and increases cyclic AMP in these cells. Like PTH and dibutyryl cyclic AMP, PGE2 is a potent stimulator of IGF-I synthesis in cultured rat osteoblasts and inhibits DNA synthesis and type I procollagen gene expression. In addition, PGE2 inhibits the response of the cells toward IGF-I after 1 day but not after 4 days of incubation. Rat calvaria osteoblasts constitutively release IGFBPs into the culture medium, in particular IGFBP-2 and IGFBP-3. Like growth hormone, PGE2 stimulates the accumulation of IGFBP-3. PGE2 rapidly increases IGF-I and IGFBP-3 mRNA expression in calvaria cells, with a time course clearly different from that observed in response to growth hormone. Thus, PGE2 modifies not only the synthesis of IGF-I but also that of IGFBP-3 in skeletal tissue.

Animals↗
PubMed1992

Epstein-Barr virus latent membrane protein expression by Hodgkin and Reed-Sternberg-like cells in acute infectious mononucleosis.

In the light of reports of latent membrane protein (LMP) expression by Hodgkin and Reed-Sternberg (HRS) cells, paraffin sections of tonsil (two cases), lymph nodes (eight cases; three cervical, one axillary, and four inguinal) and spleen (four cases) from 14 patients with acute infectious mononucleosis (IM) have been examined for the presence of HRS-like cells and immunostained with an antibody to LMP. Sections of the tonsils and one lymph node were also stained with a panel of antibodies which characterize HRS cells of Hodgkin's disease. The tonsils contained abundant HRS-like cells, mainly adjacent to the crypts, which were highlighted by strong LMP expression. The immunophenotype of these cells closely, but not completely, resembled that of HRS cells of Hodgkin's disease. The lymph nodes and spleens showed the typical changes of acute IM but only few LMP-positive HRS-like cells were present in the cervical lymph nodes and hardly any were present in the inguinal nodes and spleen. These findings suggest that tonsillar crypt squamous epithelium may play a role in the formation of LMP-positive HRS-like cells; these cells could be progenitors of Hodgkin's disease HRS cells and, if so, this might explain the restricted sites of presentation of Hodgkin's disease.

Acute Disease↗
PubMed1992

Proliferating cell nuclear antigen (PCNA) expression in Hodgkin's disease.

Previous studies of the proliferating cell fraction in Hodgkin's disease (HD) have been directed towards the classical Hodgkin and Reed-Sternberg cells (HRS) to the exclusion of the background population and have not included cases of nodular lymphocyte predominant Hodgkin's disease (NLPHD). Using an antibody to proliferating cell nuclear antigen (PCNA), we have determined the growth fraction of HRS cells and L&H cells in paraffin sections of 15 cases of classical HD [12 nodular sclerosis (NS), 3 mixed cellularity (MC)] and eight cases of NLPHD. By double staining with anti-PCNA and antibodies to B cells (CD20) and T cells (CD45RO), we also determined the growth fraction and immunophenotype of the background population in each case. In classical HD, 50.4 per cent of HRS cells were PCNA-positive and judged to be proliferating, which is comparable to previous studies, while in NLPHD 76.9 per cent of L&H cells were PCNA-positive. In both classical HD and NLPHD, the majority of PCNA-positive cells in the background were T cells, which showed a growth fraction of 57.8 and 68.5 per cent, respectively; in comparison, only 4 per cent of B cells were PCNA-positive in each type of HD. L&H cells are widely accepted to be B cells and there is growing evidence that HRS cells are also B cell-derived. Our results underline a relationship between classical HD and NLPHD and suggest that the characteristic histological features of both diseases may be caused by the production and release of cytokines from altered B cells.

Antigens, CD↗
PubMed1992

Malignant paraganglioma of the uterus.

We report a malignant uterine paraganglioma in a 40-year-old female, who died 7 months after the initial diagnosis. On light microscopy the tumour showed a typical zellballen pattern as well as a pronounced cellular pleomorphism. In many tumour cells hyaline globules were demonstrated within the cytoplasm. Immunohistochemically the lesion was characterized by the presence of neuron-specific enolase, protein gene product 9.5 and synaptophysin, and electron microscopically by the occurrence of neurosecretory granules.

Adult↗
PubMed1992

Distribution of cytokeratins, vimentin and desmoplakins in normal renal tissue, renal cell carcinomas and oncocytoma as revealed by immunofluorescence microscopy.

Forty-two renal cell carcinomas, one oncocytoma and normal renal tissue were studied for the presence of cytokeratins and vimentin. The investigations were performed by immunofluorescence microscopy applying a panel of mono- and polyclonal antibodies to intermediate filament proteins. In all tumours except chromophobic renal cell carcinoma (CRCC) and oncocytoma a co-expression of cytokeratins and vimentin could be shown. The intermediate filament expression was often, however, very heterogeneous particularly with respect to the distribution of cytokeratins and vimentin, to the clonality of the antibodies used and to the tumour areas studied. The latter could be impressively demonstrated by examining a whole tumour. In CRCC and oncocytoma all tumour cells expressed cytokeratins and, in addition, single tumour cells also expressed vimentin. In normal renal tissue we could show vimentin-positive epithelia of proximal and distal tubules, which is reported for the first time.

Adenoma↗
PubMed1992

Systemic recombinant tissue plasminogen activator lysis for left atrial thrombus formation after single-lung retransplantation.

This report describes a recipient of single-lung transplantation surviving extraordinary complications: (1) early graft failure mandating retransplantation; (2) left atrial thrombus formation, which resolved by recombinant tissue plasminogen activator lysis; (3) and development of a "locked-in-syndrome." Possible underlying mechanisms are discussed.

Extracorporeal Membrane Oxygenation↗
PubMed1992

Cryopreservation of cytological specimens for immunocytochemistry.

A method has been established for storage and preservation of cytological specimens in liquid nitrogen and further processing for immunocytochemistry as smears prepared from thawed cells or cryo-sections of frozen cell pellets. For the experiments cultured cells of a T-lymphoblastic leukemia cell line (ATCC CCL 119) and blood cells of the buffy coat of healthy humans were treated with a cryo-solution (fetal calf serum +5% dimethylsulfoxid) and after freezing stored in liquid nitrogen. Alternatively, cells preincubated with cryo-solution followed by suspension in fetal calf serum without cryo-additive were frozen and stored in liquid nitrogen for the production of cryo-sections. Indirect immunofluorescence and alkaline phosphatase--antialkaline phosphatase based immunoreactions were performed for the decoration of various surface antigens with a panel of monoclonal antibodies. All immunoreactions were repeated at least three times and the stored cell preparations were investigated after different periods of storage (up to four months). The immunoreactions of fresh cells in suspension (which were used as controls) were comparable with those of cryopreserved cells, e.g. cells on smears after thawing and on cryo-sections of cell pellets. The strongest immunoreactions were achieved on fixed cryo-sections. The maintenance of cell morphology of smears from cryopreserved cells was slightly better than of cells from cryo-sections. In our hands the preparation of cell pellets, which are suitable for the storage in liquid nitrogen and the production of cryosections, is a very useful method for immunocytochemical investigations of cytological specimens especially in situations where immunoreactions cannot be performed on fresh material.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1992

Transcriptional regulation and transpositional selection of active SINE sequences.

Alu repeats are short interspersed elements whose transposition has lead to genetic variability and heritable disorders in humans. A select subset of the nearly one million Alu sequences in human DNA actually produce new transpositions. The evolution of newly inserted Alu repeats is currently a key subject for study. Mechanisms of RNA polymerase III activity and the sequence environment into which an Alu inserts might select for transcriptional and posttranscriptional determinants of Alu transposition.

Animals↗
PubMed1992

Splenic marginal zone cell lymphoma.

We describe four female patients with primary splenic low-grade non-Hodgkin's B-cell lymphomas with the morphology and immunophenotype of splenic marginal zone lymphocytes. The patients presented with splenomegaly, anemia, and weight loss. The bone marrow was involved in all four cases. Liver involvement was found in one patient; and in another, a CT scan revealed lymphadenopathy in the chest and abdomen. The histology of the spleen was characterized by broad concentric strands of monomorphic medium-sized lymphocytes around lymphoid follicles in one case and infiltrating follicles in two cases. Selective replacement of follicles was seen in one case. Tumor in splenic hilar lymph nodes (four cases) and liver (one case) was similar. Three patients remain well 4, 9, and 12 months, respectively, after splenectomy without further treatment. One patient who received chemotherapy died 1 year after splenectomy.

Adult↗
PubMed1992

Triiodothyronine (T3) stimulates insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-2 production by rat osteoblasts in vitro.

Osteoblast-like cells prepared from neonatal rat calvariae and grown under serum-free conditions produce IGF-1 and IGFBPs. In contrast to growth hormone, T3 and PTH increased both IGF-1 mRNA expression and net IGF-1 release in calvaria cells. In addition, they stimulated net production of IGFBP-3 and of an IGFBP with an apparent molecular weight of 32 kDa which was recognized by an antiserum against rat IGFBP-2. Bone cells expressed remarkably high levels of mRNA for IGFBP-2, the predominant IGFBP in serum of newborn rats. T3 at low physiological concentrations but not growth hormone stimulated IGFBP-2 mRNA expression and IGFBP-2 production in bone cells in vitro. Thus, IGFBPs are differentially regulated by these hormones and may play an autocrine/paracrine regulatory role in bone.

Animals↗
PubMed1992

Open-heart surgery in patients requiring chronic hemodialysis.

The management and outcome of open-heart surgery in 31 patients requiring chronic hemodialysis because of end-stage renal failure are reviewed. The reasons for surgery were coronary artery disease (20 cases), mitral valvulopathy (5, including 3 with tricuspid insufficiency), aortic valvulopathy (5, including 2 with coronary artery disease) and perforation of an aortic aneurysm into the left upper lung lobe. Surgery was elective in all but the last case. Apart from double venous cannulation to avoid potassium overload after cardioplegia, and hemofiltration in the extracorporeal circulation permitting removal of 1,500-2,000 ml fluid during bypass, procedure was routine. Postoperatively fluids were restricted and serum potassium levels were not allowed to exceed the known preoperative maximum. Four patients required catecholamine support for 3-10 hours. Thirty were weaned from the respirator after 8-41 (mean 16) hours. The one perioperative death was due to complications associated with post-bypass administration of protamine. Dialysis was restarted 20-69 (mean 32) hours postoperatively. With appropriate management of fluid balance and potassium, open-heart surgery in dialysis-dependent patients need not carry heightened risk.

Adult↗
PubMed1992

[Proliferating cells in Hodgkin's disease].

We have studied the proliferation fraction of Hodgkin- and Reed-Sternberg (HRS) cells and L&H cells in paraffin sections of 15 cases of classical Hodgkin's disease (HD) (12 nodular sclerosis [NS], 3 mixed cellularity [MC]) and 8 cases of nodular lymphocyte predominant Hodgkin's disease (NLPHD) using an antibody to proliferating cell nuclear antigen (PCNA). By double staining with anti-PCNA and antibodies to B- and T-cells we also determined the growth fraction and immunophenotype of the background lymphocytes in each case. In classical HD 45.3% of HRS cells, and in NLPHD 76.9% of L&H cells were in cycle. In both classical HD and NLPHD the majority of proliferating cells in the background were T-cells with 57.8% respectively 68.5%, whereas only a few B-cells were proliferating in each type of HD.

Antigens, Neoplasm↗
PubMed1991

Intact but not truncated insulin-like growth factor binding protein-3 (IGFBP-3) blocks IGF I-induced stimulation of osteoblasts: control of IGF signalling to bone cells by IGFBP-3-specific proteolysis?

IGFBP-3 is the predominant IGFBP in serum and the major IGFBP secreted by osteoblasts. Native and recombinant IGFBP-3 and a truncated form lacking the carboxyterminal third were tested for their effects on 2 osteoblastic cell lines. Intact but not truncated IGFBP-3 blocked IGF I-stimulated DNA and glycogen synthesis. Inhibition was dose-dependent and found whenever the concentration of intact IGFBP-3 exceeded the concentration of IGF I. Truncated IGFBP-3 appears to result from proteolytic cleavage and does occur in vivo. The loss of inhibition by IGFBP-3 may be regulated at the site of IGF target cells and thus be essential for IGF I-induced osteoblast growth.

Animals↗
PubMed1991

Treatment of thrombocytosis in chronic myeloproliferative disorders with interferon alfa-2b.

Thirty-six patients with chronic myeloproliferative disorders (CMPD) with thrombocytosis (essential thrombocythaemia 19 patients, chronic megakaryocytic granulocytic myelosis five, polycythaemia vera six, chronic myelogenous leukaemia six) were treated with interferon alfa-2b to reduce the platelet count. The pre-treatment platelet count was in the range 450-700 x 10(9)/L in eight patients, 700-1000 x 10(9)/L in eight and above 1000 x 10(9)/L in 20. In the induction phase of treatment 22 patients were treated with interferon alfa-2b 3 million units (MU) daily subcutaneously for 2 months or until the platelet count returned to normal, if earlier. Fourteen patients received 5 MU interferon alfa-2b daily in the same way. In the maintenance phase the doses were reduced to 3 MU and 5 MU thrice weekly, respectively. Complete response (CR), defined as a reduction of platelet count to below 450 x 10(9)/L, was achieved in 78% of patients (within 2 months of induction in 64%). The platelet depleting effect was dose dependent: CR in 2 months in 52% on 3 MU interferon alfa-2b versus 75% on 5 MU. Reduction of interferon dose was followed by an increase in platelet count in 39% of patients. The white cell count fell by 50% in Philadelphia-negative CMPD. Side effects were common, though generally mild, but led to withdrawal of treatment in six patients. Three patients suffered cerebrovascular events during treatment and one shortly thereafter.

Adult↗
PubMed1991

Malignant mesenchymoma: a very rare tumor of the peritoneum. Case report with a review of the literature.

We report the case of an 82-year-old male patient with a malignant mesenchymoma. The tumor arose from the parietal peritoneum closely attached to the ascending colon. It consisted of a larger liposarcomatous and a smaller leiomyosarcomatous component which was demonstrated by immunohistochemistry. To our knowledge this is the first report of a malignant mesenchymoma of this histological composition originating from the parietal peritoneum. The tumor was completely removed surgically, which is the treatment of choice for such tumors. In agreement with other authors, we believe that malignant mesenchymomas arise from a primitive mesenchymal cell with the capacity for totipotent differentiation.

Aged↗