PubMed Health⌕ Search

Biomedical subjects

S Bender

Publications and source records attributed to S Bender.

At least 19 recordsLinked to original sources
PubMed1992

Apparent lack of N-glycosylation in the asexual intraerythrocytic stage of Plasmodium falciparum.

This study investigates protein glycosylation in the asexual intraerythrocytic stage of the malaria parasite, Plasmodium falciparum, and the presence in the infected erythrocyte of the respective precursors. In in vitro cultures, P. falciparum can be metabolically labeled with radioactive sugars, and its multiplication can be affected by glycosylation inhibitors, suggesting the capability of the parasite to perform protein-glycosylation reactions. Gel-filtration analysis of sugar-labeled malarial proteins before and after specific cleavage of N-glycans or O-glycans, respectively, revealed the majority of the protein-bound sugar label to be incorporated into O-glycans, but only little (7-12% of the glucosamine label) or no N-glycans were found. Analysis of the nucleotide sugar and sugar-phosphate fraction showed that radioactive galactose, glucosamine, fucose and ethanolamine were converted to their activated derivatives required for incorporation into protein. Mannose was mainly recovered as a bisphosphate, whereas the level of radiolabeled GDP-mannose was below the detection limit. The analysis of organic-solvent extracts of sugar-labeled cultures showed no evidence for the formation by the parasite of dolichol cycle intermediates, the dedicated precursors in protein N-glycosylation. Consistently, the amount of UDP-N-acetylglucosamine formed did not seem to be affected by the presence of tunicamycin in the culture. Oligosaccharyl-transferase activity was not detectable in a lysate of P. falciparum, using exogenous glycosyl donors and acceptors. Our studies show that O-glycosylation is the major form of protein glycosylation in intraerythrocytic P. falciparum, whereas there is little or no protein N-glycosylation. A part of these studies has been published in abstract form [Dieckmann-Schuppert, A., Hensel, J. and Schwarz, R. T. (1991) Biol. Chem. Hoppe-Seyler 372, 645].

Amidohydrolases↗
PubMed1992

En bloc caudate lobe and partial vena cava resection using a Gott shunt for retrohepatic caval bypass.

A technique of retrohepatic inferior vena cava bypass is described, useful for resection of the hepatic caudate lobe. A 77 year old female developed a solitary metastatic tumor mass in the caudate lobe compressing the Inferior Vena Cava (IVC), with cavography showing the IVC to be compressed, but patent. Without evidence of other metastatic disease radical resection of this tumor was performed. Successful resection was accomplished using a Gott shunt and porta hepatus compression for hepatic vascular isolation. No pump was used to avoid heparinization. Postoperative imaging confirmed IVC patency. The serum carcinoembryonic antigen (CEA) level fell to normal and remained so for 18 postoperative months. This introduces a new use of an atriocaval shunt for hepatic isolation during resection.

Aged↗
PubMed1992

Labeling and initial characterization of polar lipids in cultures of Plasmodium falciparum.

The present report describes the radioactive labeling of polar lipids in in vitro cultures of Plasmodium falciparum as well as their extraction with organic solvents and their partial characterization by chemical and enzymatic methods. All substances detected could be cleaved by alkali, suggesting that they were esters rather than sphingolipids or compounds containing alkyl groups. Dolichol-cycle intermediates were not detected. Phosphatidylinositol, phosphatidylethanolamine, and phosphatidylcholine were labeled by fatty acids and inositol or ethanolamine, respectively, confirming their de novo synthesis by the parasite. Metabolic labeling with glucosamine and cleavage by phosphatidylinositol-specific phospholipase C provided evidence of the formation of N-acetyl-glucosaminyl-phosphatidylinositol, an obligate precursor in the biosynthesis of glycosylphosphatidylinositol membrane anchors of proteins.

Animals↗
PubMed1990

The three carboxy-terminal amino acids of human interleukin-6 are essential for its biological activity.

We have constructed on the cDNA level deletion mutants of human interleukin-6 lacking one, two, three or four amino acids from the carboxy-terminus of the molecule. After in vitro transcription and translation the biological activity of these deletion mutants was determined by two independent bioassays. Both, the mouse B9 cell proliferation assay and the fibrinogen induction assay with the human hepatoma cell line HepG2 led to the following result: already the removal of the last amino acid resulted in a five-fold loss of biological activity. An additional slight reduction was seen when two amino acids were removed from the carboxy-terminus. Interleukin-6 lacking three or four C-terminal amino acids were completely inactive. The presented results emphasize the extreme importance of the carboxy-terminus of interleukin-6 for its biological function.

Amino Acid Sequence↗
PubMed1990

Interleukin-1 beta induces synthesis and secretion of interleukin-6 in human chondrocytes.

Increased concentrations of interleukin-6 (IL-6) have been found in the synovial fluid of patients with osteoarthritis, rheumatoid arthritis and crystal-related joint diseases. It is therefore of great interest to identify the cells responsible for the production of IL-6, and to investigate whether IL-6 plays a role in the pathogenesis of degenerative or inflammatory joint diseases. Here we show that human interleukin-1 beta (IL-1 beta) induces IL-6 synthesis and secretion in differentiated human chondrocytes. In organ cultures resembling closely the in vivo system 10(6) chondrocytes incubated with 100 units of interleukin-1 beta per ml of medium led to the release of 6 X 10(3) units of IL-6 within 24 h. Chondrocytes cultured in agarose or as monolayers similarly incubated with IL-1 beta produced even higher amounts of IL-6: 70 X 10(3) units per 10(6) cells within 24 h. The induction of IL-6 synthesis by IL-1 beta was also shown at the mRNA level. IL-6 secreted by stimulated chondrocytes showed heterogeneity upon Western blot analysis.

Adult↗
PubMed1990

Small increases in circulating luteinizing hormone (LH) concentrations shortly before human chorionic gonadotropin (hCG) are associated with reduced in vitro fertilization (IVF) pregnancy rate.

The effects of slight elevations in serum LH just before hCG administration on IVF cycle outcome were studied in 219 women undergoing retrieval. One hundred seven patients were stimulated using human menopausal gonadotropin (hMG), and 112 received clomiphene citrate and hMG. Serum LH, estradiol (E2), and progesterone concentrations were measured before and during controlled ovarian stimulation. Retrospectively the women were subdivided into three groups based on serum LH before hCG: Group I, less than 50% LH rise from baseline (BL) value (mean of day 2 and day 7); Group II, LH rise greater than or equal to 50% but less than 2 x BL; and, Group III, LH rise greater than or equal to 2 x BL. The fertilization and cleavage rates were similar in all groups. However, a greater than or equal to 50% rise in serum LH before hCG was associated with a significantly reduced IVF pregnancy rate.

Chorionic Gonadotropin↗
PubMed1989

Young chronic patients and substance abuse.

The prevalence of substance abuse was investigated in 100 young chronic patients consecutively admitted to a long-term private psychiatric hospital. Data were obtained from diagnostic research interviews with each subject at admission. Half of the subjects had concurrent diagnoses of psychiatric disorder and substance abuse. One-third of the dual-diagnosis patients began using substances before the onset of a diagnosable psychiatric disorder, and they more often had a diagnosis of schizophrenia. Half of the dual-diagnosis patients abused three or more drugs. Implications of the findings for treatment and community management of dual-diagnosis patients are discussed.

Adolescent↗
PubMed1988

Günther vena caval filter: results of long-term follow-up.

A Günther vena caval filter was implanted in the inferior vena cava in 59 patients to prevent pulmonary embolism. This newly available device, which can be inserted percutaneously via a 10-French introduction system, has three filtering planes. No complications occurred at the puncture site. Follow-up included clinical examinations (54 patients), plain radiographs (50 patients), and CT scans (41 patients); these examinations were performed up to 21 months after implantation. Caudal migration of the filter occurred in 35 (70%) of the 50 patients who had radiographs, but no cranial or oblique movement occurred. Occlusion of the filter was noted in three (7%) of 41 patients who had CT examinations. Thromboemboli were seen inside the filter in 16 (39%) of the 41 patients who had CT scans. Recurrent pulmonary embolism was not observed after filter implantation. The Günther vena caval filter seems to be a satisfactory device for preventing pulmonary embolism.

Adult↗
PubMed1988

Peer review.

Explore the source record for details and available documents.

Humans↗
PubMed1988

Chorionic villus sampling: experience with an initial 940 cases.

Of over 1000 patients referred to the Genetics & IVF Institute for chorionic villus sampling, 10% had an abnormal gestational sac at the time of initial presentation. Villus sampling could not be performed in 0.6% of cases, usually because of fibroids. Chorioamnionitis, probably related to the procedure, occurred in two patients (0.2%). The total fetal loss was 2.4%, which is not significantly different from the background fetal loss rate reported in normal pregnancies after eight weeks of gestation. The procedure-related loss was estimated as approximately 0.6%. The cytogenetic analysis routinely used was "direct" trophoblast karyotyping. There were no false-negative diagnoses. Trophoblastic mosaicism was observed in 1.3% of samples. Amniocentesis was performed in 3.5% of cases because of chorionic villus sampling failure, chorionic mosaicism, or elevated maternal serum alpha-fetoprotein (MSAFP) concentrations. Chorionic villus sampling was not associated with falsely elevated MSAFP levels at 15-18 weeks' gestation. Chorionic villus sampling has proved a safe and accurate prenatal diagnostic method associated with relatively low risk when performed by an experienced team, although additional amniocentesis will be necessary in a small percentage of pregnancies.

Adult↗
PubMed1987

Haemophilus influenzae type b opsonins of intravenous immunoglobulins.

Immunoglobulin G may be prepared by different methods for intravenous infusion and administered as replacement therapy for hypogammaglobulinemia. Intravenous immunoglobulins prepared by different methods were compared in vitro for their ability to opsonize Haemophilus influenzae type b in the absence of complement and subsequently induce neutrophil chemiluminescence. While the antibody contents, measured by an enzyme-linked immunosorbent assay and radioimmunoassay, were equivalent, the immunoglobulin prepared by a non-molecular modifying method (ion-exchange chromatography) had the greatest ability to induce bacterial-neutrophil interaction, measured by chemiluminescence, while a reduced and alkylated immunoglobulin had the least. Thus, preparative methods may have a profound effect upon the function of intravenous immunoglobulins. The biological function of immunoglobulins for clinical use can be compared easily by neutrophil chemiluminescence.

Haemophilus influenzae↗
PubMed1985

Plasmacytoid myoepithelioma of a minor salivary gland.

Plasmacytoid myoepitheliomas are rare salivary gland neoplasms that probably represent a variant of the pleomorphic adenoma. They appear to occur more frequently in the minor salivary glands of the mouth. The mean average age at time of diagnosis of intraoral lesions is 18.8 years. Cytologic pleomorphism is a frequent histologic feature, which has led to a questionable diagnosis of malignancy in five out of ten cases. Caution is advocated in the evaluation of a salivary gland neoplasm with such features, and confusion with primary squamous cell or undifferentiated carcinoma of the salivary glands should be avoided. Patients who have cytologically pleomorphic lesions should be assessed for evidence of metastases. Rapid growth, neurologic evidence of sensory or motor dysfunction, and bone invasion should be regarded as ominous clinical parameters. Therapy should be directed toward complete surgical extirpation.

Adult↗
PubMed1979

Infertility.

Explore the source record for details and available documents.

Female↗