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Biomedical subjects

G Wahl

Publications and source records attributed to G Wahl.

At least 55 records · Page 3Linked to original sources
PubMed1992

[The microbial colonization of implant elements made of plastics and titanium].

12 edentate subjects wearing lower complete dentures stabilized by an IMZ-implant-supported Dolder bar took part in the experiment. Elastic (POM) and titanium connection parts were alternatingly inserted. After the removal of 24 POM and titanium elements from each of the patients, a qualitative analysis of the microbial flora was performed. Except for actinomycetes, aerobic as well as anaerobic microorganisms were found less frequently with titanium than with POM elements.

Actinomycetales↗
PubMed1992

The effects of epidural versus parenteral opioid analgesia on postoperative pain and pulmonary function in adults who have undergone thoracic and abdominal surgery: a critique of research.

Studies comparing epidural and parenteral opioid analgesia for patients experiencing thoracic or abdominal surgery are analyzed with respect to differences in postoperative pain and pulmonary function. Although most studies suggest that epidural analgesia is superior for postoperative pain relief, few clearly demonstrate an improvement in pulmonary function attributable to epidural analgesia. Recommendations for future research are proposed to improve the design, measurement, analysis, and reporting of studies. Research relevant to the nursing care of patients receiving epidural analgesia is suggested.

Abdomen↗
PubMed1991

Hydroxyurea accelerates loss of extrachromosomally amplified genes from tumor cells.

Gene amplification is one mechanism mediating the resistance of tumor cells to antineoplastic agents and the overexpression of a variety of oncogenes in diverse tumor types. There is mounting evidence that acentric extrachromosomal elements such as double minute chromosomes are common intermediates in the amplification process. These acentric structures partition unequally at mitosis and can be lost in the absence of selection. In the present study, we used human and hamster cell lines documented to contain extrachromosomally amplified drug resistance genes to investigate the feasibility of enhancing the loss rate of the extrachromosomally amplified genes to make the cells more sensitive to drug treatment. The results show that treatment of each of these lines with hydroxyurea accelerates the loss of the extrachromosomally amplified drug resistance genes. Loss of these extrachromosomal genes was associated with a corresponding increase in the drug sensitivity in the cases examined. The mechanism of accelerated loss does not appear to involve a differential effect on the replication of extrachromosomal DNA sequences. The results suggest that hydroxyurea treatment may provide a valuable tool for the general accelerated elimination of extrachromosomally amplified genes.

Aspartate Carbamoyltransferase↗
PubMed1991

Anaerobic degradation of sorbic acid by sulfate-reducing and fermenting bacteria: pentanone-2 and isopentanone-2 as byproducts.

Strictly anaerobic bacteria were enriched and isolated from freshwater sediment sources in the presence and absence of sulfate with sorbic acid as sole source of carbon and energy. Strain WoSo1, a Gram-negative vibrioid sulfate-reducing bacterium which was assigned to the species Desulfoarculus (formerly Desulfovibrio) baarsii oxidized sorbic acid completely to CO2 with concomitant stoichiometric reduction of sulfate to sulfide. This strain also oxidized a wide variety of fatty acids and other organic compounds. A Gram-negative rod-shaped fermenting bacterium, strain AmSo1, fermented sorbic acid stoichiometrically to about equal amounts of acetate and butyrate. At concentrations higher than 10 mM, sorbic acid fermentation led to the production of pentanone-2 and isopentanone-2 (3-methyl-2-butanone) as byproducts. Strain AmSo1 fermented also crotonate and 3-hydroxybutyrate to acetate and butyrate, and hexoses to acetate, ethanol, hydrogen, and formate. The guanine-plus-cytosine content of the DNA was 41.8 +/- 1.0 mol%. Sorbic acid at concentrations higher than 5 mM inhibited growth of this strain while strain WoSo1 tolerated sorbic acid up to 10 mM concentration.

Bacteria, Anaerobic↗
PubMed1991

The development of Onchocerca dukei and O. ochengi microfilariae to infective-stage larvae in Simulium damnosum s.l. and in members of the S. medusaeforme group, following intra-thoracic injection.

Neonate Simulium females from an endemic area of human and bovine onchocerciasis in North-Cameroon were injected in one set of experiments with microfilariae (mff) of Onchocerca dukei and in another with mff of O. ochengi. Onchocerca dukei was found to develop to infective third-stage larvae in Simulium flies: 148 third-stage larvae (28.1% of injected mff) were recovered in S. hargreavesi, seven (10.4% of injected mff) in S. vorax, and 12 (1.3%) in S. damnosum s.l. Onchocerca ochengi mff developed in S. hargreavesi at a rate of 17.3% and in S. damnosum s.l. at 16.1%, yielding a total of 77 and 32 third-stage larvae respectively. Onchocerca dukei infective larvae had a mean length of 717.3 microns and a mean maximum diameter of 17.5 microns, and were slightly shorter and conspicuously thinner than those of O. ochengi (748.3 microns x 20.4 microns). All larval stages of O. dukei typically had an attenuated anterior end. The implications of these findings for the epidemiology of human onchocerciasis are discussed.

Animals↗
PubMed1991

Development of Onchocerca volvulus microfilariae injected into Simulium species from Cameroon.

Microfilariae (mff) of the savanna and forest strains of Onchocerca volvulus (Leuckart) were injected intrathoracically into adult females of Simulium damnosum Theobald sensu stricto, S.sirbanum Vajime & Dunbar, S.squamosum Enderlein and S.mengense Vajime & Dunbar. Nine days post infection (pi) 27-29% of the savanna mff and 31-38% of the forest strain had developed to third-stage larvae (L3), irrespective of the fly species, size or injection dose (5, 10 or 15 mff). Savanna flies supported the development of forest O.volvulus better than forest flies, in contrast to the results after per os infections. Therefore, in these four species of the S.damnosum complex from Cameroon, the peritrophic membrane is considered to be the main factor limiting the success rate of microfilarial development following the ingestion of blood infections, while the fly's haemolymph and intracellular environment play minor roles.

Animals↗
PubMed1991

Transmission of Onchocerca dukei by Simulium bovis in North-Cameroon.

"Wild" Simulium bovis females were collected after they had taken blood on a bait oxen with skin microfilariae (mf) of Onchocerca dukei and Onchocerca ochengi. Flies ingested O. dukei mf in high numbers (13.1 mf per blood fed fly) but rarely mf of O. ochengi (3 mf in 60 flies). In 32 flies dissected 14 to 17 hours after the blood meal, a total of 130 O. dukei mf but no of O. ochengi had migrated to the thorax. Six to 9 days after the blood meal, a total of 203 third stage larvae (L3) were found in 61 surviving flies. Invasive larvae from the head measured 738.0 x 17.8 microns and resembled those of O. dukei obtained by intrathoracic injection of mf in a previous study, but were shorter and thinner than O. ochengi L3. Thus, S. bovis can be seen as an efficient natural vector of O. dukei. Its role in the transmission of bovine and human onchocerciasis in North Cameroon is discussed.

Animals↗
PubMed1991

[Soft laser in postoperative care in dentoalveolar treatment].

After removal of lower third molars a postoperative treatment with a low energy laser (6mW-HeNe) was investigated to compare different parameters of wound healing with a control group. A positive influence of wound granulation seems to be possible; no side effects could be observed. There was neither interindividual nor intraindividual any statistical significance for the efficiency of this sort of laser-application.

Adolescent↗
PubMed1991

[Direct radiographic magnification in experimental research on the stomatognathic system].

A new X-ray tube with a less than 10 microns microfocus enables investigations supported by direct radiological magnification. It allows the nondestructive examination of mineralized structures up to microscopic dimensions. For experimental research on bony tissue, teeth and in the field of dental material science, new and interesting areas have been opened. Examples demonstrate possibilities of this special radiographic method.

Animals↗
PubMed1990

Blunt-end and single-strand ligations by Escherichia coli ligase: influence on an in vitro amplification scheme.

A ligase-based, in vitro DNA amplification system (LAR) has been described by Wu and Wallace [Genomics 4 (1989) 560-569]. This strategy is based on the ability of a DNA ligase to join the 5' phosphate of one DNA molecule to the 3' hydroxyl of a second during a nick-closing reaction. Escherichia coli DNA ligase has been used in place of the T4 DNA ligase in our study in order to limit template-independent ligation activities, which lower the sensitivity of this amplification procedure. The results of this study indicate that E. coli ligase also joins blunt-ended DNA molecules and some single-stranded oligodeoxyribonucleotides, in the absence of a complementary template, with an efficiency which is sensitive to both the concentrations of DNA substrate and enzyme.

Base Sequence↗
PubMed1990

Hippuric acid and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid in serum and urine. Analytical approaches and clinical relevance in kidney diseases.

Hippuric acid (HA) and 3-carboxy-4-methyl-5-propyl-2-furanpropionic acid (FA) were determined in serum, plasma, ultrafiltrate and urine by gas chromatography (GC), high-performance liquid chromatography and GC with mass-selective detection, and the methods were compared. As determined by affinity chromatography and analysis of serum and ultrafiltrate, 0.5% of FA in serum occurs free and 99.5% is bound to albumin. In haemodialysed patients with chronic renal failure, the plasma levels of HA and FA are elevated in comparison with normal controls and hospital patients without kidney diseases: HA, 11.1 +/- 5.7 mg/dl (n = 86); FA, 1.9 +/- 1.2 mg/dl (n = 86). Gradual increases in HA in serum, depending on the creatinine concentrations, are found in non-dialysed patients with chronic renal failure. By haemodialysis and haemofiltration the HA levels are lowered (53-66 and 30-36%, respectively), whereas FA is not dialysable.

Chromatography, Gas↗
PubMed1990

Distribution of microfilariae of Onchocerca lienalis and Onchocerca gutturosa in the skin of cattle in Germany and their development in Simulium ornatum and Culicoides nubeculosus following artificial infestation.

Onchocerca microfilariae were isolated form the umbilicus and neck of 438 cow hides at the abattoir in Tübingen, F.R.G. The overall Onchocerca infection rate was 40.4%. The presence of Onchocerca lienalis and O. gutturosa microfilariae, which are difficult to distinguish by morphological criteria, was retrospectively demonstrated after artifically infesting Simulium ornatum and Culicoides nubeculosus and identifying the infective larvae recovered. Nine of 16 samples of umbilical microfilariae fed to C. nubeculosus through a latex membrane developed to O. gutturosa third stage larvae (L3). Six of seven umbilical samples injected into the thorax of S. ornatum yielded O. lienalis L3. In six infestation trials in which microfilariae were introduced both into S. ornatum and C. nubeculosus, O. lienalis L3 were recovered exclusively from simuliids, while O. gutturosa L3 developed only in midges. Of six umbilical skins tested by cross-infestation, one contained exclusively O. gutturosa microfilariae, four only O. lienalis microfilariae and one was infected with both species. Developmental success of O. lienalis microfilariae to L3 in S. ornatum following intrathoracic injection was 22% of the mean inoculum. O. gutturosa microfilariae, ingested by C. nubeculosus through a latex membrane, developed to L3 at a rate of 2.3% of the mean microfilarial uptake.

Animals↗
PubMed1990

[The efficacy of paracetamol (Tylenol) and acetyl salicylic acid (Aspirin) in treating postoperative pain].

In a randomized, double-center, double-blind, parallel group study the analgesic effect of a single dose of paracetamol (1000 mg) and acetyl salicylic acid (1000 mg) was compared with placebo in patients with moderate to severe postoperative pain following the surgical removal of a wisdom tooth. The most important finding was the statistically significantly shorter period until the onset of the action of paracetamol as against acetyl salicylic acid.

Acetaminophen↗
PubMed1989

Morphological and immunological changes of hairy cell leukemia during alpha-2-interferon therapy.

We describe a patient who presented with the clinical picture of hairy cell leukemia (HCL). Bone marrow and peripheral blood lymphoma cells showed morphological and immunological features of HCL. Under recombinant alpha-2-interferon (alpha-2-IF) therapy the characteristic morphology changed from HCL to prolymphocytic leukemia (PLL). At diagnosis the lymphoma cells expressed CD24 and FMC7 surface antigen, but stained negative for surface immunoglobulins, light chains and anti-CD5. During alpha-2-IF treatment surface antigen expression changed to CD24, CD5 and FMC7. Surface IgD and lambda light chains became strongly positive. Southern Blot analysis of peripheral blood mononuclear cells showed two rearranged immunoglobulin bands at diagnosis but only one upon alpha-2-IF therapy. These data suggest, that this patient suffered from a biclonal lymphoma, HCL and PLL. While undergoing alpha-2-IF treatment the HCL came into remission, whereas the PLL clone proved to be poorly sensitive to alpha-2-IF therapy.

Aged↗
PubMed1988

[Imipenem/cilastatin as monotherapy in neutropenic patients with fever].

We treated 20 febrile episodes in 14 patients with granulocytopenia under 1.0 x 10(9)/L. 6 episodes were pretreated, in 14 Imipenem/Cilastatin was the initial therapy. The age was between 36 and 78 years, mean 57 years. Predominant underlying disease was acute leukemia. 8 out of 20 episodes became afebrile. Counting only proven bacterial infections the response rate was 6 out of 12. There was a statistical difference between not pretreated and pretreated patients. The treatment had no success in the latter. There was also a significant difference between febrile episodes of patients with granulocytes increasing under treatment to those remaining unchanged. 5 of 6 of the first group but none of the 9 episodes of the second group resolved. 7 patients died while on treatment between the 9th and 32nd day after therapy had started. There was no connection between the Imipenem treatment and the deaths. Tolerance of therapy was good. The most common side effect was nausea, which was reversible with reduction of the infusion rate. Most important advantage of imipenem is the easy handling and the low inconvenience to the patient. We had only moderate efficacy in our series.

Adult↗