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Biomedical subjects

W Vogel

Publications and source records attributed to W Vogel.

At least 379 records · Page 21Linked to original sources

Detection of BrdUrd incorporation in mammalian chromosomes by a BrdUrd antibody. III. Demonstration of replication patterns in highly resolved chromosomes.

A bromodeoxyuridine antibody staining technique (BAT) was applied for the analysis of human chromosomes of different chromosomal band resolution. For this purpose lymphocyte cultures were synchronized and labeled with bromodeoxyuridine during the second half of the S-phase. Generally BAT was found comparable to GTG banding though some prominent GTG bands and the constitutive heterochromatin exhibit less intense staining with this technique.

Antibodies, Monoclonal↗

Continuous-plus-on-demand epidural infusion of buprenorphine versus morphine in postoperative treatment of pain. Postoperative epidural infusion of buprenorphine.

In a randomized, double-blind study, buprenorphine was compared with morphine in the treatment of pain after major abdominal operations by means of continuous-plus-on-demand epidural infusion for constant analgesia. The patients received bolus epidural injections of 0.15 mg buprenorphine or 2 mg morphine-HCl prior to an on-demand epidural infusion of 0.03% buprenorphine or 0.25% morphine HCl at a basal rate of 0.06 ml/h. Over 50 h, mean buprenorphine consumption was 0.85 +/- 0.08 mg, and mean morphine consumption was 6.4 +/- 0.5 mg. Under the treatment, no discomfort or side-effects necessitating treatment occurred. We conclude that buprenorphine is a useful substitute for morphine in the treatment of pain after major abdominal operations by continuous-plus-on-demand epidural infusion, and that the relative analgesic potency ratio of epidural buprenorphine is 8.

Adolescent↗

Heterogeneous distribution of transferrin receptors on parenchymal and nonparenchymal liver cells: biochemical and morphological evidence.

To investigate which cells of the liver express the receptor for transferrin, isolated rat liver cells produced by collagenase perfusion were fractionated by repeated differential centrifugation to produce hepatocytes (95% + 1%, mean +/- SD, n = 4) and nonparenchymal cells (97% + 1%, n = 3). Saturable, high-affinity binding of 125I-transferrin was demonstrated on intact cells at 4 degrees C, with average receptor numbers 20,900 +/- 3,160 (mean + SD, n = 4) for hepatocytes and 5,500 + 1,520 (n = 3) for nonparenchymal cells. Total cellular receptors measured in detergent permeabilized hepatocytes were 42,000 +/- 18,330 (mean +/- SD, n = 3) per cell and 14,760 +/- 7,120 (n = 3) per cell in the nonparenchymal fraction. Immunocytochemical demonstration of transferrin using antitransferrin, peroxidase antiperoxidase complex confirmed that both cell types bound transferrin. There was heterogeneity of the staining reaction since there was no detectable staining on 40% of hepatocytes and 60% of nonparenchymal cells. Microdensitometric analysis of the staining product corroborated the biochemical evidence that hepatocytes have, on average, more than three times more transferrin receptors than do nonparenchymal cells. These findings support the concept that the hepatocyte has a central role in the uptake and storage of transferrin iron.

Animals↗

[The effect of stress ulcer prevention on the incidence of pneumonia in artificial respiration].

The role of stress ulcer prophylaxis in increasing the risk of pneumonia in ventilator patients was analyzed prospectively in 142 artificially ventilated patients at a medical and surgical intensive care unit (104 males, 38 females, mean time of ventilation 7.9 days, mean age 46.5 years). The pH of gastric aspirate and bacterial counts in gastric fluid and tracheal secretions were investigated daily. Identical isolates from gastric aspirates and tracheal secretions were typed by agglutination, bacteriocin, or phage typing. An average of 2.1 bacterial species were isolated in 80.5% of all gastric aspirates. Bacterial counts increased with rising gastric aspirate pH, which was especially true for Gram-negative and less so for Gram-positive organisms; colony counts of Candida sp. decreased slightly. In 31.6% of patients identical bacterial species were first isolated from gastric aspirates and 1 to 2 days later from tracheal secretions. Of these microbes that were first isolated from gastric aspirate and later from tracheal secretions, 50.3% were Gram-negative, 37.5% Gram-positive, and only 4.2% Candida sp. One-half of all bacterial aspirations occurred between the 2nd and 7th day of ventilation; 80% occurred within 11 days of ventilation. Only 20% of all migrations of Gram-positive organisms from stomach to respiratory tract lead to pneumonia, as compared with 60% of Gram-negatives. At a gastric pH below 3.4 the incidence of ventilation pneumonia was 40.6%; above pH 5.0 the incidence was 69.2% (P less than or equal to 0.05). As pH increased, the organism causing pneumonia was significantly more often isolated first from the gastric aspirate and 1 to 2 days later from the tracheal secretion of the same patient.

Anesthesia↗

Further chromosomal studies on Ellobius lutescens: heteromorphism of chromosome No. 1 is not associated with sex determination.

Twelve animals of the species Ellobius lutescens from two generations were studied with various chromosomal banding techniques. This species carries 17 chromosomes in both sexes. In preceding studies chromosomal sex determination was assigned to different structural variants of chromosome No. 1. In the present study, no definite chromosomal basis for sex determination was found.

Animals↗

[Effect of adjuvant immunoglobulin therapy on infections in patients in an surgical intensive care unit. Results of a randomized controlled study].

A randomized controlled clinical trial was conducted on the effects of immunoglobulin in therapy for infections in 104 intensive care patients. At the first sign of infection, one group of 50 patients received an i.v. preparation of immunoglobulin (4 X 100 ml) combined with antibiotics. The other 54 control patients received antibiotics alone. The most common infections in these patients were pneumonia, septicemia, peritonitis and wound sepsis. Infections were significantly seldom the cause of death, especially in patients with high-risk surgery who had been treated with immunoglobulin (p less than or equal to 0.05). Likewise ventilation time in the high-risk surgery group averaged only 5.5 days for those receiving immunoglobulin as opposed to 12.7 days in controls (p less than or equal to 0.01). Whereas the control group, in particular patients with pneumonia, remained in intensive care an average of 21.5 days, those receiving immunoglobulin stayed only 14.8 days (p less than or equal to 0.01). In general, patients treated with immunoglobulin recovered more rapidly from infections than did controls (p less than or equal to 0.01).

Adult↗

Cytogenetic replication studies with short thymidine pulses in bromodeoxyuridine-substituted chromosomes of different mouse cell lines.

In normal diploid fibroblasts of the mouse, 3T3-SV-3T3-, and Meth A-cells, the chromosome replication patterns were studied by a bromodeoxyuridine (BrdU)-labelling technique. SV-3T3 is a subline of 3T3 transformed by SV 40 and Meth A is a permanent cell line from Balb c transformed by methylcholanthrene. The use of 1 h thymidine pulses permits high resolution of the S-phase after partial synchronization of the cells at G1/S in an otherwise BrdU-substituted S-phase. It could be shown that the autosomal heterochromatin of the mouse (Mus musculus) starts replication during the early S-phase (R-band replication), continues while R-band chromatin finishes, and still replicates when G-band chromatin starts. The heterochromatin finishes before the majority of G-bands have been replicated. There is no fundamental difference in the course of chromosome replication between the different cell lines studied here. It is concluded that there are no obligate changes in the course of the S-phase linked to the process of transformation.

Animals↗

Detection of bromodeoxyuridine-incorporation in mammalian chromosomes by a bromodeoxyuridine-antibody. I. Demonstration of replication patterns.

We have shown that a commercially available antibody allows the demonstration of bromodeoxyuridine (BrdU) incorporation into mammalian chromosomes by the typical immunologic staining techniques. The replication patterns obtained are comparable to those after BrdU-incorporation and FPG-staining, though with reversed staining specificity. The quality of the patterns equals that of commonly used differential staining but the sensitivity of BrdU-detection is superior. Thus the new technique may be very promising for all cytogenetic studies concerning any kind of chromosome replication.

Animals↗

Detection of bromodeoxyuridine incorporation in mammalian chromosomes by a bromodeoxyuridine antibody. II. Demonstration of sister chromatid exchanges.

A commercially available bromodeoxyuridine (BrdUrd) antibody was used to demonstrate sister chromatid differentiation (SCD) and to evaluate sister chromatid exchanges (SCEs) in V79 Chinese hamster cells. V79 cells were cultivated for one cell cycle in the presence of BrdUrd, followed by a second cell cycle in the absence of BrdUrd. Chromosome preparations were stained by a common immunologic staining technique. The staining pattern observed is similar to that after FPG (fluorescent plus Giemsa) staining, though with reverse staining specificity. The sensitivity of BrdUrd detection is enhanced by a factor of 20 compared to the FPG technique and thus allows the evaluation of SCEs at very low BrdUrd concentrations. The application of the antibody technique gives information about the origin and localization of SCEs and produces further evidence for the spontaneous occurrence of SCEs.

Animals↗

Spot-transformation with plasmids.

A method is described which allows transformation of bacterial cells on the surface of agar plates. It is suitable for transferring large numbers of different plasmids, such as gene libraries, into a new genetic background. One nanogram of plasmid DNA is sufficient for transformation.

Escherichia coli↗

Selection of bacterial pac sites recognized by Salmonella phage P22.

A gene library of chromosomal PstI fragments from Salmonella typhimurium strain DB5575 has been established. By means of phage P22 mediated transduction, ten different clones which contained inserts that promoted plasmid transduction were selected out of a total of about 7,000 clones. Seven of these clones carried inserts that stimulated transduction independently of general and int-promoted recombination and were interpreted as carrying pac analogous signals. The remaining three clones carried inserts that promoted transduction under recombination proficient conditions, whereas transduction occurred at reduced rate in the absence of recombination. These were believed to have short regions of homology with P22 DNA.

Cloning, Molecular↗

Toxin gamma of the scorpion Tityus serrulatus modifies both activation and inactivation of sodium permeability of nerve membrane.

The effects of the major neurotoxic fraction isolated from scorpion venom of Tityus serrulatus, TiTx gamma, on peripheral nerve membrane of Xenopus laevis were studied under current- and voltage-clamp conditions. 700 nmol/l TiTx gamma depolarized the membrane and induced spontaneous activity (150 s-1, maximum value), which ceased within a few minutes. It reduced the amplitude of the action potentials from 109 mV to 52 mV and increased their duration from 1.25 ms to 4.5 ms. 440 nmol/l TiTx gamma induced inward Na current flow at resting potential. The descending branch of the Na current-voltage curve was flattened and shifted approximately 10 mV to more negative potentials. Maximum Na permeability was reduced to about 20%. Both development of and recovery from inactivation of Na permeability were slowed. The steepness of the steady-state inactivation curve was decreased, but the mid-potential changed only insignificantly. No prepulse was necessary to elicit either a shift of activation or an inward current at resting potential. Expressing the toxin effect either in terms of the decrease of Na peak current or of the slowing of inactivation, half-maximum effects were found with 0.3 +/- 0.1 and 3.7 +/- 0.7 mumol/l TiTx gamma, respectively.

Action Potentials↗

In vitro effects of lymphoblastoid interferon on lymphocyte activation and cell-mediated cytolysis in patients with chronic hepatitis B virus infection.

In addition to a direct anti-viral effect, interferons have important immunological properties including effects on cell-mediated immunity and antibody production as well as cell-mediated cytolysis. In chronic hepatitis B virus infection the host immune system is important for the elimination of replicating virus and in addition to directly inhibiting hepatitis B virus replication, interferons may affect host immune responses. We investigated the effect of lymphoblastoid interferon in vitro on lymphocyte activation and cell-mediated cytolysis in patients with chronic hepatitis B virus infection. The proliferative response to the mitogen PHA was significantly impaired in patients compared to controls. In addition supernatants of cultured mononuclear cells from patients stimulated with PHA contained less interleukin-2 activity than controls while the proportion of stimulated mononuclear cells expressing the interleukin-2 receptor was also reduced in patients. Prior incubation with 10(3) U ml-1 lymphoblastoid interferon increased both interleukin-2 activity and interleukin-2 receptor expression in patients and controls, although in patients the response was less marked. In contrast the proliferative response was unaffected. Natural killer cell activity against K562 cells was similar in patients and controls which in both groups was significantly augmented by prior incubation with 10(3) U ml-1 lymphoblastoid interferon; the increase was inversely proportional to baseline activity. In contrast incubation of target or effector cells with interferon did not augment T-cell cytotoxicity against autologous hepatocytes. The effects of lymphoblastoid interferon in vitro, were modest, but subtle changes in immunological status in addition to a direct effect on viral replication may be relevant to eventual clearance of the hepatitis B virus.

Cytotoxicity, Immunologic↗

Wash off liver cytology: a complementary diagnostic tool to liver biopsy.

Parenchymal and non-parenchymal cells were harvested by washing the liver tissue core and needle after percutaneous biopsy. The cytological material obtained was suitable for morphological analysis, including showing the presence of surface and cytoplasmic antigens using labelled antibody techniques. This technique provides a combined cytological and histological approach to the diagnosis of liver disease.

Antigens↗