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Biomedical subjects

W Lange

Publications and source records attributed to W Lange.

At least 91 records · Page 5Linked to original sources
PubMed1995

Cecum of guinea pig is a reservoir and sigmoid is a high-resistance conduit.

We compared the filling responses of the cecum and the sigmoid of the guinea pig using volumes up to 60 ml and 2.5 ml, respectively. In the isolated cecum, each 1-cm increment of hydrostatic pressure above zero led to accommodation of 10 ml volume; in the sigmoid, the yield pressure (at which accommodation first occurred) was 6 cm H2O, and pressure increments up to 20 cm H2O produced volume increments of less than 0.5 ml. Resting pressure at half-maximal filling was 5.0 +/- 0.7 cm H2O for the sigmoid and 1.7 +/- 0.6 cm H2O for the cecum. K+ depolarization led to a significant upward shift in the pressure curves of both segments. Ca2+ withdrawal decreased sigmoid and cecal pressures at some volumes. Distension of the cecum triggered intermittent contractions, which began with the shortening of the teniae and were associated with low-amplitude pressures and expulsion of a 5- to 10-ml volume. Distension of the sigmoid produced propagating contractions that were associated with high-amplitude pressures and lengthening; compartmentalization in the sigmoid prevented efflux from it, and volume inflow was not affected by pressure waves. Our observations indicate that its large capacity and great distensibility make the cecum suitable for reservoir functions, whereas its narrowness and lack of distensibility make the sigmoid a high-resistance conduit.

Animals↗
PubMed1995

Simultaneous immunoenzymatic staining of catecholamines, catecholamine-biosynthesizing enzymes, and bromodeoxyuridine in adrenal medullary cells of the rat.

The rat adrenal medulla consists mainly of low proliferating, highly differentiated parenchymal cells. By immunocytochemical techniques, two types of parenchymal cells can be identified, norepinephrine (NE)- and epinephrine (E)-storing cells. Bromodeoxyuridine (BrdU), a thymidine analogue often used to identify proliferating cells, can also be detected by immunocytochemical techniques. We developed double- and triple-labeling procedure(s) for simultaneous visualization of NE, E, dopamine beta-hydroxylase (DBH), phenylethanolamine-N methyltransferase (PNMT), and BrdU in rat adrenal medulla. BrdU was administered to 7-week-old Wistar rats by mini-osmotic pumps. Tissues were fixed by perfusion with 4% paraformaldehyde and embedded in paraffin. By immunocytochemistry, first NE, E, DBH, and/or PNMT was detected by an indirect immunoalkaline phosphatase technique with Fast Red or Fast Blue as substrate. Next, incorporation of BrdU was detected with an indirect immunoperoxidase procedure using diaminobenzidine (DAB). Both NE- and E-storing cells, as well as endothelial cells, can incorporate BrdU, i.e., are able to divide. Occasionally, we also found BrdU-stained mitotic figures in E, PNMT and DBH immunoreactive cells. No BrdU incorporation was found in the post-ganglionic neurons of the adrenal medulla. The procedures described enable a detailed cell kinetic study of the NE- and E-storing cells in the adrenal medulla, particularly in the rat, which can lead to a better understanding of cell renewal in the adrenal medullary tissue under normal and pathological conditions.

Adrenal Medulla↗
PubMed1995

Influenza vaccination in older patients. Immunogenicity, epidemiology and available agents.

Excess hospitalisation and deaths attributable to influenza virus infections often occur during epidemics and even in interepidemic periods. Influenza vaccines in current use are inactivated preparations that contain 15 micrograms each of the most recently circulating influenza A (H3N2 and H1N1) and B viruses. At present, 3 types of inactivated influenza virus vaccines are available: (a) whole virus vaccines; (b) split virus vaccines; and (c) subunit vaccines. All 3 types are similarly immunogenic in primed patients. Vaccine efficacy depends on a close antigenic match between the vaccine composition and the influenza strains circulating in the human population. The continuous antigenic drift of the viral membrane antigens (haemagglutinin and neuraminidase) necessitates an update of the vaccine composition each year according to the recommendations of the World Health Organization (WHO). Subunit and split virus vaccines cause fewer systemic reactions than whole virus vaccines. At present, live attenuated influenza virus vaccines are not licensed. In perspective, combined administration of live and inactivated vaccines seems to be advantageous. Influenza vaccine is approximately 75% effective in reducing deaths in elderly and high risk persons. Several studies have shown that the antiviral agent amantadine is a useful adjunct to vaccination for preventing influenza A in institutional settings. Currently, the proper use of inactivated vaccine according to the recommendations of public health authorities is the only way to reduce the annual influenza-associated medical and economic burden.

Aged↗
PubMed1994

Comparison of different ribozymes for efficient and specific cleavage of BCR/ABL related mRNAs.

In chronic myelogenous leukemia (CML) the reciprocal translocation of the long arms of chromosomes results in the formation of the unique BCR/ABL fusion gene which is believed to play a crucial role in the pathogenesis of CML. Different short synthetic ribozyme constructs were compared with regard to their efficiency to cleave the BCR/ABL target RNA. In the CML cell line K562 we were able to inhibit the p210BCR/ABL synthesis by a ribozyme which was about twofold more effective than the corresponding antisense molecule.

Base Sequence↗
PubMed1994

Detection of chromosome 11q23 involving translocations by pulsed field gel electrophoresis.

Translocations involving chromosome band 11q23 are associated with acute lymphocytic and myelomonocytic leukemias with poor clinical prognosis. Pulsed-field gel electrophoresis (PFGE) was used to characterize the breakpoint region that has been mapped within a 300-kb fragment between the genes CD3G and PBGD. Using CD3G as a marker on SfuI-restricted DNA separated by PFGE, we detected a rearrangement involving 11q23 in the cell line B1 with a t(4;11) and in the leukemic cells of two patients, one with a t(2;11) and one with a t(11;19). In comparison, lymphoblastoid cell lines established from normal peripheral blood lymphocytes of these two patients had a normal karyotype and showed germline configuration, thus excluding RFL polymorphisms. Digestion of DNA with BssHII or SalI showed heterogeneity of 11q23 involving breakpoints. A rearrangement in the t(4;11) containing lymphoma cell line Karpas422 was seen only with the chromosome 4 probe KIT on SalI-digested DNA. PFGE is a reliable method for the mapping and detection of complex breakpoint regions. The breakpoints on 11q23 involve different introns of the highly spliced HRX/ALL-1/MLL gene.

Acute Disease↗
PubMed1994

BCL-2 induction is part of the strategy of Epstein-Barr virus.

Epstein Barr virus can infect B lymphocytes and epithelial cells. Epithelial cells present the natural reservoir for the virus in man. In vitro, infected cells harbor the virus predominantly in a latent state with the expression of a set of nuclear (EBNA 1-6) and latent membrane genes (LMP 1-2) and virus-transformed B cells grow as permanently immortalized lymphoblastoid cell lines, that show increased resistance to various growth inhibiting factors. Here we show that the lymphoma-associated oncogene BCL-2 is upregulated by different latent Epstein-Barr virus genes in B lymphocytes as well as keratinocyte cell lines. Thus, the induction of BCL-2 gene expression seems to be part of the survival strategy of the virus independently of the host cell infected.

B-Lymphocytes↗
PubMed1993

The unusual light-harvesting complex of Mantoniella squamata: supramolecular composition and assembly.

The supramolecular properties of the chlorophyll a/b/c light-harvesting protein complex of Mantoniella squamata were analyzed. The complex is built up of at least two subunits of M(r) 20,000 and 22,000, which are encoded in the nucleus as precursor proteins of M(r) 27,000. The chlorophyll a/b/c light-harvesting complex is the dominating protein of the thylakoids and is fractured with the protoplasmic membrane face as a 7.5 nm particle. These particles form paracrystalline arrays with a purported hexagonal arrangement in native thylakoids and form similar arrays when reconstituted in liposomes. The light-harvesting complexes are supposed to be trimers with a trigonal arrangement of the subunits. Preliminary amino acid sequence data show that the chlorophyll a/b/c light-harvesting complex of M. squamata is more related to the chlorophyll a/b complex of higher plants than to the light-harvesting complexes of chromophytan algae.

Amino Acid Sequence↗