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Biomedical subjects

K Zimmermann

Publications and source records attributed to K Zimmermann.

At least 37 records · Page 2Linked to original sources
PubMed2000

Funguria and Candida-specific immunoglobulins in patients with systemic candidosis.

UNLABELLED: Funguria, indirect anti-Candida haemagglutination test (C-IHT) and Candida-specific immunoglobulins C-IgM, C-IgG and C-IgA were investigated under suspicion of systemic candidosis in critically ill patients. A total of 143 urine cultures were studied for Candida from 74 adults and a median count of log 3.0 CFU ml-1 was found. Most isolated Candida species were Candida albicans and Candida glabrata. In 14 cases of candidaemia there was no regular agreement between the finding of Candida species in blood and urine. In cases with candiduria > = or log 3.0 CFU ml-1 a stronger increase of C-IHT titres and all three Candida-specific immunoglobulins after 5-7 days was observed. Some statistically significant correlations were found between the levels of urinary yeast counts and immunological parameters concerning C-IHT, C-IgA and C-IgG on the first day and after 5-7 days. Clinical findings in some cases coincided well with funguria and courses of titres before and after treatment. CONCLUSION: In critically ill patients suspected of having systemic candidosis not only blood cultures should be made. Cultural studies with specimens taken from different sites including funguria are essential for a complete specific serological investigation.

Aged↗
PubMed2000

Sensitive single-stage PCR using custom-synthesized internal controls.

A new approach for an internally controlled PCR was developed using a custom-synthesized oligonucleotide as the internal control. Three different PCR setups demonstrated the usefulness of this approach: (i) the addition of the respective internal control to samples containing ssDNA virus Parvo B19; (ii) the co-extraction of plasma samples and the respective internal control for the detection of the ssDNA virus TTV; and (iii) the addition of the respective internal control to a crude lysate of tail pieces for the genotyping of FVIII knockout mice, demonstrating that this approach is also applicable for dsDNA.

Animals↗
PubMed2000

Deoxyribonucleic acid preparation in polymerase chain reaction genotyping of transgenic mice.

BACKGROUND AND PURPOSE: In an attempt to find a rapid and reproducible method for routine polymerase chain reaction genotyping of transgenic mice, two novel approaches were developed. METHODS: One approach allowed reproducible amplification from crude lysates of tail snips, using a thermally activated polymerase. In a second approach, for situations in which non-invasive techniques are necessary, oral swab specimens were amplified after DNA extraction by use of an isolation kit. Samples from 10 transgenic factor VIII knockout mice were genotyped after processing by use of these and other methods. RESULTS: False-negative results were not obtained by use of the two novel approaches. Despite their relative simplicity, both approaches yielded results comparable to those obtained by use of procedures known to be reliable, such as organic extraction and a DNA extraction kit. CONCLUSION: Both approaches are useful for PCR-amplification of DNA from mammalian sources.

Animals↗
PubMed2000

Oesophageal candidosis in intensive care patients.

We conducted upper intestinoscopies in 124 intensive care patients, six of whom had oesophageal candidosis. Of these, two also had Candida plaque in the stomach. The patients at the intensive care unit (ICU) had a mean Apache-II score of 26.7; whereas the score was 29.5 in patients with Candida oesophagitis. A significant increase of Candida antibodies was found in 59 of 124 patients (47.6%), including all patients with oesophageal candidosis. Presumably, mycotic infections of other sites were present. The severity by which mucous membranes were affected correlated well with microscopically evident invasiveness.

Candida↗
PubMed1999

Functional characterization of the S. cerevisiae genome by gene deletion and parallel analysis.

The functions of many open reading frames (ORFs) identified in genome-sequencing projects are unknown. New, whole-genome approaches are required to systematically determine their function. A total of 6925 Saccharomyces cerevisiae strains were constructed, by a high-throughput strategy, each with a precise deletion of one of 2026 ORFs (more than one-third of the ORFs in the genome). Of the deleted ORFs, 17 percent were essential for viability in rich medium. The phenotypes of more than 500 deletion strains were assayed in parallel. Of the deletion strains, 40 percent showed quantitative growth defects in either rich or minimal medium.

Culture Media↗
PubMed1999

Differential regulation of the human nidogen gene promoter region by a novel cell-type-specific silencer element.

Transfection analyses of the human nidogen promoter region in nidogen-producing fibroblasts from adult skin revealed multiple positive and negative cis-acting elements controlling nidogen gene expression. Characterization of the positive regulatory domains by gel mobility-shift assays and co-transfection studies in Drosophila SL2 cells unequivocally demonstrated that Sp1-like transcription factors are essential for a high expression of the human nidogen gene. Analysis of the negative regulatory domains identified a novel silencer element between nt -1333 and -1322, which is bound by a distinct nuclear factor, by using extracts from adult but not from embryonal fibroblasts. In embryonal fibroblasts, which express significantly higher amounts of nidogen mRNA as compared with adult fibroblasts, this inhibitory nidogen promoter region did not affect nidogen and SV40 promoter activities. The silencer element seems to be active only in nidogen-producing cells. Therefore this regulatory element might function in vivo to limit nidogen gene expression in response to external stimuli. However, none of the identified regulatory elements, including the silencer, contribute significantly to cell-specific expression of the human nidogen gene. Instead we provide evidence that gene expression in epidermal keratinocytes that are not producing nidogen is repressed by methylation-specific and chromatin-dependent mechanisms.

Adult↗
PubMed1999

Fungal resistance.

Fungal resistance is caused by an acquisition of intrinsically resistant species, by selection of resistant strains from a population or by mutation of an initially susceptible strain. According to different classes of antimycotics there are different resistance mechanisms: differences in the uptake mechanisms, drug target alterations, mostly the ergosterol-biosynthesis pathway, and the efflux or pumping mechanisms to the outside.

Animals↗
PubMed1999

Genotyping of the prion protein gene at codon 129.

Sporadic, iatrogenic and new variant forms of Creutzfeldt-Jakob disease are associated with a predisposition for disease depending on a homozygosity at amino acid residue 129 of the prion protein gene (PRNP). A novel polymerase chain reaction/restriction digestion assay to screen for this polymorphism was developed and proved after comparison with a previously used method to be advantageous. Furthermore, for prevention of incorrect results an internal control for the restriction digestion was constructed. The feasibility of this method was tested in a cohort of 300 healthy Caucasian subjects. Of this normal population, 48.7% were heterozygous at codon 129, 43% homozygous for methionine and 8.3% for valine.

Codon↗
PubMed1999

A triglycine linker improves tumor uptake and biodistributions of 67-Cu-labeled anti-neuroblastoma MAb chCE7 F(ab')2 fragments.

The peptide-linked copper chelators CPTA-triglycyl-L-p-isothiocyanato-phenylalanine (CPTA-R1-NCS) as well as DOTA-triglycyl-L-p-isocyanato-phenylalanine (DOTA-R1-NCS) were synthesized and coupled to F(ab')2 fragments of the anti-neuroblastoma monoclonal antibody (MAb) chCE7. 67Cu-labeled conjugates were compared with the original CPTA- and DO3A-F(ab')2 in vitro and in vivo in mice bearing neuroblastoma xenografts. With the CPTA-R1-F(ab')2, biodistributions were improved, because radioactivity present in the kidney was reduced. With the DOTA-R1-F(ab')2, clearance from the blood was slower and tumor uptake was higher compared with the other conjugates. DOTA-R1-F(ab')2 achieved the best tumor/tissue ratios.

Animals↗
PubMed1999

Irrigating fluid absorption during percutaneous nephrolithotripsy.

BACKGROUND: The most common complication during percutaneous nephrolithotripsy (PNL) is the destruction of organ structures with extravasation of the irrigation fluid into the retroperitoneal space. Consequently, there is an increased risk of a urosepsis and a complicated therapeutic course. In this study we aimed to show that extravascular absorption could be differentiated from intravascular absorption due to their unique absorption characteristics, and that these characteristics enable a prediction of possible post-operative complications. METHODS: In a prospective study of 31 patients with PNL, ethanol was added to the irrigating fluid and blood ethanol concentration (BEC) was measured by gas chromatography during the endoscopic procedure and in the recovery room. Following the guidelines of Hahn, patients were divided into two groups: group EVA, in whom extravasation had occurred with subsequent absorption; group IVA, those with intravascular absorption. Patients' post-operative progress along with diagnoses of renal perforations or bleeding, or signs of infection or sepsis, were comprehensively listed. RESULTS: EVA was diagnosed in 19 cases, and IVA in 12 cases. Maximum BEC levels were achieved after 20 min (median) in the IVA group, and 75 min in the EVA group (P < 0.05). Apart from their significantly higher demand for opioids (P < 0.05), EVA patients had been hospitalised for a substantially and significantly longer period of time (P < 0.01). Although without statistical significance, there was a higher rate of peri-operatively confirmed complications and prolonged intensive therapeutic treatment in the extravasation group. CONCLUSION: Retroperitoneal extravasation can be identified by using ethanol monitoring during and after PNL. Afflicted patients require considerably longer hospitalisation, probably because of the additional injury to surrounding organ structures.

Absorption↗
PubMed1999

The continuous flow culture as an in vitro model in experimental mycology.

We used the model of continuous flow culture (cfc) to study the growth of Candida species. This model allows special test conditions: a long generation time of 15-20 hs, controlled limitation of nitrogen sources and carbohydrates, comparison of the growth under aerobic and anaerobic conditions simultaneously. These conditions were used to study the effect of antimycotic drugs, mainly during a long time of 7 to 10 days. Germ tube formation as a virulence factor was more abundant and faster in cfc of strains with a stronger adherence to buccal epithelium cells. Co-cultivation of C. albicans and C. glabrata allowed conclusions for their colonization in vivo. A biofilm on the glass wall of the culture vessel led to mycelium formation by C. albicans. Concomitantly the growth of C. glabrata was favoured. Growth of C. albicans in the gastrointestinal flora was reduced by masses of bacteria and their multiple metabolic activities. A remarkable growth of C. albicans was only to be seen if the ecosystem was destroyed e.g. by antibacterial antibiotics. The influence of fluconazole in a long-term follow up study under anaerobic conditions showed an inhibition of C. albicans in 99.9%. This means fungicidal efficacy.

Candida↗
PubMed1998

Glyceraldehyde-3-phosphate dehydrogenase, the putative target of the antiapoptotic compounds CGP 3466 and R-(-)-deprenyl.

R-(-)-Deprenyl (Selegiline) represents one of the drugs currently used for the treatment of Parkinson's disease. This compound was shown to protect neurons or glias from programmed cell death in a variety of models. The mechanism of action of neuroprotection as well as inhibition of apoptosis remains elusive. CGP 3466 is a structurally related analog of R-(-)-deprenyl that exhibits virtually no monoamine oxidase type B inhibiting activity but is neuroprotective in the picomolar concentration range. We showed specific binding of CGP 3466 to glyceraldehyde-3-phosphate dehydrogenase by affinity binding, by affinity labeling, and by means of BIAcore(R) technology. Apoptosis assays based on the human neuroblastoma cell line PAJU established the importance of this interaction for mediating drug-induced inhibition of programmed cell death.

Animals↗
PubMed1998

Comparison of early events during infection of human and chimpanzee peripheral blood mononuclear cells with HIV-1.

Differences in early events during entry and integration of HIV-1 into peripheral blood mononuclear cells (PBMC) might contribute to the absence of AIDS-like disease in chimpanzees as compared to humans. To address this question, we first tested the in vitro susceptibility of human and chimpanzee PBMC for infection with the two HIV-1 isolates III B and RF. The results of these studies revealed that chimpanzee PBMC had a slightly lower capability to support the growth of HIV-1 as compared to human PBMC. This was accompanied by a delayed accumulation of proviral HIV-1 DNA in cultures of HIV-1-infected chimpanzee PBMC. However, no differences between cells of the two species were observed when very early events of HIV-1 infection were studied. Shortly (20 h) after infection chimpanzee and human cells harbored similar amounts of proviral HIV-1 DNA and PBMC of both species behaved comparably with respect to pre-integration latency (i.e. the ability to activate extrachromosomal HIV-1 intermediates in HIV-1 infected quiescent cells at various times after infection). These results strongly suggest that the absence of AIDS-like disease in chimpanzees cannot be correlated with defects in early events of the HIV-1 replicative cycle.

Animals↗
PubMed1998

Influence of ciprofloxacin and other antimicrobial drugs on different Escherichia coli strains in continuous-flow cultures under aerobic and anaerobic conditions.

In continuous-flow culture, long generation times and high bacterial counts favour survival of bacteria. A chemotherapeutic agent that achieves a bactericidal effect under these circumstances can therefore be seen as highly effective. In our continuous-flow culture we obtained bactericidal effects with ciprofloxacin 1-2 mg/L, cefotaxime 4 mg/L and mezlocillin 32 mg/L. These effects were seen irrespective of whether conditions were aerobic or anaerobic. There were no significant differences between monocultures and mixed cultures simulating faecal flora with the various Escherichia coli strains tested. Cefotaxime had an initial effect but an increase in counts was then observed as a result of regrowth of E. coli survivor strains in aerobic monoculture and mixed cultures. Mezlocillin was completely bactericidal in monocultures, but regrowth occurred in mixed cultures under anaerobic conditions. Neither the bacterial composition of this culture nor the resistance pattern explained this regrowth. These results were observed in long-term experiments followed for up to 7 days. We conclude that the antibiotics tested are highly effective against E. coli under unfavourable conditions simulating in-vivo situations.

Aerobiosis↗