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Biomedical subjects

G Ruckdeschel

Publications and source records attributed to G Ruckdeschel.

At least 37 records · Page 2Linked to original sources
PubMed1995

The influence of the pH-value on the growth of Brevibacterium epidermidis in continuous culture.

Brevibacterium epidermidis is a major component of the bacterial flora of certain skin surface biotopes, characterized by a comparatively high pH-value. The presence of Brevibacterium epidermidis seems to be linked to the production of malodour. Skin surface pH has been found to be a major factor of bacterial growth on the skin. In order to find out if this might also apply to Brevibacterium epidermidis, this microorganism was grown in vitro in continuous culture using a chemostat. Specific growth rate and density of colony forming units were well correlated. While the organism grew readily from pH 5.5 to 8.5, this was not the case with a pH of 5.0. Thus pH-shifts induced by cosmetic procedures can only prevent unpleasant body odour due to abundant growth of bacteria if the pH-value is decreased to 5.0 or less.

Brevibacterium↗
PubMed1994

[Respiratory tract infections: how frequent is antibiotic resistance? In vitro activity of older and recent antibiotics against the significant pathogens].

Presumably influenced by the new cost-saving health care regulations, more of the long-established antibiotics are now being prescribed. This fact prompted the present study on the current resistance profiles of such antibiotics used to treat major pathogens responsible for airway infections. A total of 202 strains of Streptococcus pneumoniae, Streptococcus pyogenes, Moraxella catarrhalis and Haemophilus influenzae were investigated. Sensitivity was determined using the agar dilution test for doxycycline, erythromycin, penicillin G, amoxicillin-clavulanic acid and cefpodoxime. In the case of such older antibiotics as doxycycline, erythromycin and amoxicillin, certain shortcomings in their efficacy against these common pathogens were found, while the bacteria were all sensitive to a combination of amoxicillin and clavulanic acid and to the oral cephalosporin, cefodoxime. In order to avoid the risk of ineffectivity in the treatment of infection of the airways, it is recommended that in Germany a new oral cephalosporin or a combination of an aminopenicillin and a beta-lactamase inhibitor be used.

Anti-Bacterial Agents↗
PubMed1994

Detection by PCR of human polyomaviruses BK and JC in immunocompromised individuals and partial sequencing of control regions.

Immunocompromised individuals were tested for the presence of the human polyomaviruses JC (JCV) and BK (BKV) by the polymerase chain reaction (PCR). The use of appropriate primers in a nested PCR allowed the detection of both viruses simultaneously. Viruses were differentiated by restriction fragment length analysis of amplified DNA fragments. Both BKV and JCV DNA were detected in the urine of an AIDS patient with progressive multifocal leukencephalopathy. In autopsy materials from this patient, JCV- but not BKV-DNA was found in brain and kidney tissue, whereas lung tissue was negative for both virus DNAs. To evaluate the methodology further, hybridization-positive urines from three recipients of bone marrow transplants and a positive urine of an acute myeloid leukemia patient were analyzed by this PCR method. One case was positive both for BKV and JCV, two cases were positive only for BKV, and one was negative for both. Parts of the control regions of JCV and BKV were sequenced directly from PCR-derived fragments. The JCV sequence from urine of the AIDS patient compared to sequences from a bone marrow transplant recipient and to archetypical reference strains showed two nucleotide (nt) exchanges out of 250 nt. The BKV sequences from the AML and the AIDS patients showed five nt exchanges out of 265 nt in the control region and were identified as BKV WW or WWT3 strains. In the agnogene region five exchanges were detected, two of them resulting in non-conservative amino acid exchanges. The possibility of testing clinical specimens of different origins by this PCR method is important for elucidating often unclear clinical courses in immunocompromised patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Acquired Immunodeficiency Syndrome↗
PubMed1994

Does yogurt enriched with Bifidobacterium longum affect colonic microbiology and fecal metabolites in health subjects?

Diet-induced changes in the colonic microflora seem to play a role in colon carcinogenesis. In this study the effects of a yogurt (500 mL/d for 3 wk) enriched with Bifidobacterium longum and 5 g lactulose/L (A) on the fecal bacterial flora and various risk indexes for colon carcinogenesis were tested in 12 healthy volunteers and compared with a conventional yogurt (B). Increased excretion of bifidobacteria (P < 0.017) was found after consumption of both yogurts compared with the prestudy periods, whereas cultural counts of aerobes and anaerobes were not different. Breath-hydrogen exhalation was elevated and mouth-to-cecum transit time was accelerated in the period of yogurt A ingestion (P < 0.05) whereas no differences were found for oral-anal mean transit time, stool weight and pH, and fecal concentrations of short-chain fatty acids, bile acids, and neutral sterols. The results generally indicate great stability of the human fecal flora to this kind of dietary intervention.

Adult↗
PubMed1994

Healing of protein losing hypertrophic gastropathy by eradication of Helicobacter pylori--is Helicobacter pylori a pathogenic factor in Ménétrier's disease?

Hypertrophic gastropathy--that is, Ménétrier's disease--was found, in a retrospective analysis, to be associated with Helicobacter pylori in more than 90% of patients. It is proposed that hypertrophic gastropathy represents a special form of H pylori gastritis in these patients. A case is described of a 28 year old woman with Ménétrier's disease associated with proved protein loss from the stomach. Treatment with cimetidine for more than three years had little benefit when colonisation by H pylori was detected. Density of H pylori colonisation and activity of gastritis, which was also present in the first biopsy specimens taken five years ago, were more pronounced in the body than in the antrum, which is in agreement with the characteristics of H pylori gastritis found in other cases with Ménétrier's disease. A 14 day antibacterial treatment course with 750 mg amoxicillin three times a day combined with 40 mg omeprazole three times a day was started in April 1991. This resulted in eradication of H pylori and the return to normal of giant folds and the mucosal histology. Serum protein concentrations returned to normal within six weeks and remained normal at two endoscopies during a two year follow up. This case report suggests that a subgroup of the patients with Ménétrier's disease may be healed by the eradication of H pylori.

Adult↗
PubMed1994

[Diagnosis of pathogens in nosocomial pneumonia].

Due to the rising number of immunosuppressed patients, the spectrum of pathogens in nosocomial pneumonias has expanded considerably. This has led to increased demands on both the methods and the quantity of microbiological diagnostics. Most important is still the detection of the pathogen through cultivation, the success of which depends mostly on the quality of the test material. Progress in this area is therefore, to a considerable extent, dependent on invasive methods of gaining clean tracheobronchial secretion. Apart from the long-known serological test methods for viruses, mycoplasma, chlamydia, legionella and other bronchopulmonary pathogens, a series of new investigational methods have meanwhile been established. These include microscopy with direct immunofluorescence, immunological detection of antigenic components of pathogens in blood or urine and lately the new methods of molecular biology: gene probes and polymerase chain reaction. The latter promise higher sensitivity and specificity as well as a more rapid diagnosis.

Cross Infection↗
PubMed1993

Imaging of leukocyte-endothelium interaction using in vivo confocal laser scanning microscopy during the early phase of experimental pneumococcal meningitis.

Confocal laser scanning microscopy (CLSM) was used to investigate dynamic aspects of rhodamine 6G-labeled leukocytes in the pial microcirculation during the early phase of pneumococcal meningitis. Closed cranial windows were implanted into anesthetized rats without removing the dura mater. Leukocyte behavior was studied every hour after intracisternal (ic) injection. The number of adherent and extravasated leukocytes was determined during playback of videotaped images. Compared with results in controls, the number of adherent leukocytes increased significantly (P < .05) within 1 h after ic pneumococcal challenge, followed by a further increase up to 6 h after infection. In untreated infected rats, the number of extravasated leukocytes progressively increased from 3 to 6 h after infection. Leukocyte adherence to microvascular endothelium occurred in pial venules but not in arterioles. Dexamethasone pretreatment significantly (P < .05) attenuated leukocyte adherence and transendothelial passage of leukocytes.

Animals↗
PubMed1993

Long-term follow-up after eradication of Helicobacter pylori with a combination of omeprazole and amoxycillin.

Early studies have suggested that omeprazole may facilitate the eradication of Helicobacter pylori. Sixty patients with duodenal ulcer and H. pylori colonization were randomly assigned to receive either omeprazole monotherapy (n = 30) or combination therapy with omeprazole and amoxycillin (n = 30) for a total duration of 6 weeks. Four patients receiving monotherapy and three receiving combination therapy had to be withdrawn from the study. All (100%) duodenal ulcers healed in patients receiving combination therapy, and 25 out of 26 (96%) healed in the group receiving monotherapy. H. pylori was eradicated in 22 out of 27 (82%) patients receiving combination therapy; only two ulcer relapses (9%) occurred within 18 months in these 22 patients. Of the five patients who remained H. pylori-positive after combination therapy, two relapsed during the 18-month follow-up. In the monotherapy group, all patients remained H. pylori-positive after treatment, and duodenal ulcer relapsed in 16 out of 25 (64%) patients within the median follow-up of 18 months. Adverse events were not reported in the group treated with combination therapy; one patient receiving monotherapy reported severe headache. These results lend further support to existing data that H. pylori eradication prevents duodenal ulcer relapse and show that combination therapy with omeprazole and amoxycillin is effective and well tolerated.

Adolescent↗
PubMed1992

[The effect of taurolin on endogenous immunity and pathogen elimination in human peritonitis].

The influence of taurolin on phagocytosis-related defense functions and on the elimination of bacteria has been investigated in a controlled study. Particle opsonisation, a prerequisite for sufficient phagocytosis, was undisturbed in presence of up to 0.1% taurolin. Intraabdominal taurolin application did not diminish the leukocyte influx into the abdominal cavity. Opsonic capacity of peritoneal exudate was low in the taurolin group. These exudates contained more severe bacterial contamination, suggesting that this deficit was due to enhanced specific consumption of opsonins. Taurolin treatment resulted in a marked reduction of bacterial growth. Thus the substance provides antiseptic capacities without afflicting the physiological defense systems.

Aged↗
PubMed1992

Effect of catalase on regional cerebral blood flow and brain edema during the early phase of experimental pneumococcal meningitis.

Previous studies have demonstrated that the radical scavenger superoxide dismutase completely blocked the increase of regional cerebral blood flow (rCBF), intracranial pressure (ICP), and brain water content during the early phase of experimental pneumococcal meningitis in the rat. To obtain information on the nature of the reactive oxygen species involved, the effect of catalase, a hydrogen peroxide scavenger, was tested. Rats injected intracisternally with live pneumococci were either untreated or received intravenous catalase. The increase of rCBF and brain water content in infected untreated rats was significantly attenuated by catalase 6 h after intracisternal challenge. ICP increased in both infected groups, with a trend toward lower ICP with catalase treatment. Cerebrospinal fluid white blood cell counts were not significantly different between infected groups. These results and previous experiments using superoxide dismutase suggest that the increase of rCBF, ICP, and brain water content is mainly caused by superoxide or superoxide reaction products.

Animals↗
PubMed1992

Establishment of a pneumococcal septicemia model in the miniature swine.

Human pneumococcal septicemia, the prominent postsplenectomy complication, was as yet difficult to study in the porcine model, since this species appeared to be fairly resistant against pneumococcal infections. We have used two strains of pneumococci (serotype 1 and 6B) both of which had been isolated from patients with systemic infection and both of which were maintained in a virulent state by regular mouse passage. After challenge with 10(9) type 1 pneumococci, however, only one of the 5 pigs developed fever, none showed profound hematological alterations and each animal exhibited a rapid clearance of bacteria from peripheral blood. By contrast, challenge of 7 animals with type 6B pneumococci resulted in a slower and incomplete bacterial clearance with persistent bacteremia for up to 24 hours. All animals developed fever and a profound leukopenia with less than 5,000 leukocytes/ml and 3 of the 7 animals died after injection of type 6B pneumococci. The results show that potentially the type 6B pneumococci can be successfully employed for studies of gram positive septicemia in the miniature swine.

Animals↗
PubMed1992

[Antibiotic prevention and therapy of infectious complications in ERCP].

Endoscopic retrograde cholangiopancreatography (ERCP) may be complicated by bacteremia, cholangitis, or biliary sepsis. Bacteremia during ERCP implies a potential risk of endocarditis in patients with valvular prostheses or a previous history of infectious endocarditis. For these patients antibiotic prophylaxis prior to ERCP is recommended. Cholangitis or biliary sepsis may develop after ERCP in patients with obstructed bile ducts. In these patients antibiotics should be administered until adequate drainage of biliary obstructions is achieved. Antibiotic prophylaxis and antibiotic therapy must consider the spectrum of micro-organisms which is normally found in each of these situations. Regarding bacteremias associated with ERCP gram-positive cocci predominate, whereas cholangitis and biliary sepsis are caused mainly by gram-negative rods like Escherichia coli, Pseudomonas aeruginosa, or Klebsiella spp.

Anti-Bacterial Agents↗
PubMed1992

Influence of the pH-value on the growth of Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes in continuous culture.

A cutaneous isolate of Staphylococcus epidermidis, Staphylococcus aureus and Propionibacterium acnes was grown in continuous culture at varying pH-values ranging from 5.0 to 8.5. In terms of the specific growth rate as well as the bacterial density during the plateau phase there were remarkable differences. In particular, Propionibacterium acnes grew much better in the pH 6.0 to 7.0 range than in a more acidic or alkaline milieu. Staphylococcus epidermidis resembled Staphylococcus aureus showing no major difference at pH 5.5 and 7.0. These findings substantiate the hypothesis that minor changes of the pH in the pH 5.5 to pH 6.0 range as to be induced by chemically neutral or alkaline skin cleansers on the human skin surface can increase the number of propionibacteria but not staphylococci remarkably due to the relative alkalinity by itself.

Culture Media↗
PubMed1991

Beneficial effect of liposome-encapsulated muramyl tripeptide in experimental septicemia in a porcine model.

In a porcine model of pneumococcal septicemia, animals were pretreated with 1 mg of liposome-encapsulated muramyl tripeptide phosphatidylethanolamine (MTP-PE) or with liposomes alone. After 24 h each animal received an injection of either 10(9) or 10(10) pneumococcal serotype 6B cells. MTP-PE pretreatment resulted in less pronounced leukocytopenia, with a nadir of 6,700 (versus 4,100) leukocytes per mm3 after injection of 10(9) bacteria and a nadir of 4,400 (versus 3,800) leukocytes per mm3 after injection of 10(10) bacteria. At the same time bacterial clearance was substantially improved by MTP-PE pretreatment. Finally, pretreatment with MTP-PE dramatically reduced mortality; the average death rates for both series of animals used were 55% for liposome-pretreated animals and 3% for animals pretreated with MTP-PE-containing liposomes. These results in a preclinical model suggest that treatment with MTP-PE-containing liposomes might be beneficial in controlling septicemia in patients at risk.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1991

Do cutaneous coryneform bacteria produce short-chain fatty acids in vitro?

According to an opinion shared by many, human axillary and inguinal odour is related to short-chain fatty acids produced by gram-positive bacteria. Especially coryneform bacteria are said to produce these odiferous substances. After sampling 22 different strains of coryneform bacteria we cultured them for 48 h in a rich medium. Short-chain fatty acids were extracted afterwards by shaking the liquid medium with ether. Gas chromatography was used for detection. Only one of the tested bacteria produced propionic acid. Acetic acid, (iso)butyric acid or (iso)valeric acid could never be detected. The production of substances of the short-chain fatty acid type might, however, be a consequence of the particular substrate found under physiologic conditions by these organisms in human apocrine sweat. The theory that the metabolism of these skin bacteria necessarily produces short-chain fatty acids could not be supported. Another explanation might be that unspecific secreted enzymes of the bacteria are responsible for the production of short-chain fatty acids by a cleavage of skin surface lipids.

Actinomycetales↗