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Biomedical subjects

B Kochanowski

Publications and source records attributed to B Kochanowski.

16 recordsLinked to original sources

[Polymerase chain reaction (PCR) for microbiological diagnosis in refractory infectious keratitis: a clinical study in 16 patients].

BACKGROUND: The identification of the causative pathogen in infectious keratitis is possible in only 60% of the cases. The aim of this study was to show if this number increases by the use of PCR. PATIENTS AND METHODS: In a series of 16 eyes with infectious keratitis corneal specimens were collected for culture and PCR. Serology (HSV, VZV, and Borrelia) was performed in all eyes, with exception of the 4 eyes presenting an acute form of keratitis, which obviously was bacterial origin. RESULTS: In all 4 cases of acute keratitis the causative pathogen (Pseudomonas aeruginosa) was detected by both culture and PCR. Of the remaining 12 eyes PCR was capable to identify the causative pathogen in 11 eyes. In 3 eyes herpes simplex virus was detected, in 3 eyes Moraxella catharalis, in 2 eyes Borrelia burgdorferii, in 2 eyes varizella zoster virus, and in 1 eye Bartonella henselae. Culture was positive in only 2 eyes, infected by Moraxella catharalis. CONCLUSIONS: PCR is a useful supplement in the microbiological diagnostic of infectious keratitis, in particular if only a small amount of pathogens are available (non-acute form) or if the eye has been treated by antibiotics prior to the microbiological diagnostic.

Chronic Disease↗

In vivo increase in resistance to ciprofloxacin in Escherichia coli associated with deletion of the C-terminal part of MarR.

We recovered two isolates (EP1 and EP2) of Escherichia coli from the same patient that had identical pulsed-field gel electrophoresis patterns but required different MICs of ciprofloxacin (CIP): 16 and 256 mg/liter for EP1 and EP2, respectively. Both isolates had mutations in the quinolone resistance-determining regions of GyrA (Ser83Leu and Asp87Tyr) and ParC (Ser80Ile), but not in those regions of GyrB or ParE. Isolate EP2 was also more resistant to chloramphenicol, tetracyclines, cefuroxime, and organic solvents. A deletion of adenine (A) 1821 was found in marR of isolate EP2, which resulted in an 18-amino-acid C-terminal deletion in the MarR protein. The causative relationship between DeltaA1821 and the Mar phenotype was demonstrated both by the replacement of the wild-type marR by marR DeltaA1821 in isolate EP1 and by complementation with the wild-type marR in trans in isolate EP2. In isolate EP2 complemented with wild-type marR, susceptibility to chloramphenicol was restored completely, whereas susceptibility to CIP was restored only incompletely. Northern blotting demonstrated increased expression of marA and acrAB but not of soxS in isolate EP2 compared to EP1. In conclusion, the deletion of A1821 in marR in the clinical isolate EP2 caused an increase in the MICs of CIP and unrelated antibiotics. Presumably, the C-terminal part of MarR is necessary for proper repressor function.

Anti-Infective Agents↗

[Treatment of recurrent nose bleeding caused by Rendu-Osler-Weber's disease in patients treated at the ENT department of the Regional Hospital in Opole].

The authors describe a method of surgical treatment of nosebleeds caused by Rendu-Osler-Weber's disease. Free skin graft of the thigh region was used for closure of nasal septal defects. A new dermatoplasty technique allows to cover both sides of the nasal septum with a single skin graft. The diseased septal mucosa is denuded with a scalpel, but the underlying perichondrium is preserved. Excellent exposure of the nasal septum is obtained via a modified external rhinoplasty approach. This new dermatoplasty technique described by dr Bridger is a modification of traditional Saunders dermatoplasty. In three patients treated by this method at our department the transplantation ended successful.

Epistaxis↗

[Surgical treatment of epistaxis].

The authors present 17 patients with nose bleeding who had to be treated surgically, because conservative procedures turned out unsuccessful. Causes of bleeding, types of conservative procedures, as well as types of operations are described. Surgical treatment was fully efficacious in 12 patients (70%).

Adult↗

Prevalence of precore mutants in anti-HBe-positive hepatitis B virus carriers in Germany.

Hepatitis B virus (HBV) precore mutants are associated often with highly productive infection in hepatitis B surface antigen (HBsAg) carriers lacking hepatitis B e antigen (HBeAg) but positive for anti-HBe, rendering serological identification of infectious individuals unreliable. Although considered initially to be limited mostly to the Mediterranean area, more recent studies suggest a significant presence of these mutants in northern European countries. The sequence of the precore region was determined and examined for mutations from HBV isolates of 99 German chronic HBsAg carriers positive for HBV-DNA and either HBeAg (n = 15) or anti-HBe (n = 84). In addition, clinical data of individuals carrying wild-type virus and those with precore mutants were compared. HBV precore mutants were found in more than half (44/84) of all HBeAg-negative, anti-HBe-positive virus carriers. There was no difference between carriers of wild-type and precore mutant HBV in the level of viremia or in the clinical course of chronic infection. In conclusion, HBV precore mutants are common in Germany and can therefore present a diagnostic problem for serological testing. However, precore mutants do not appear to have a detrimental effect on the course of chronic HBV infection.

Adult↗

Delayed facial palsy following uneventful middle ear surgery: a herpes simplex virus type 1 reactivation?

In rare cases, a facial palsy appears a few days after uneventful middle ear surgery. The reason for this delayed palsy is unclear. One hypothesis is that it results from a reactivation of herpes simplex virus type 1 (HSV-1) in the geniculate ganglion of the facial nerve. From 1987 to 1996, in the course of over 1,800 middle ear operations, we observed 7 ipsilateral delayed facial palsies and investigated 5 of them using immunologic and virologic methods, including the polymerase chain reaction (PCR). We could detect HSV-1 genome with the nested primer PCR in the tongue swabs of 4 of the 5 examined patients with delayed facial palsy. The immunologic changes in these palsies are also compatible with a reactivation of HSV-1. We conclude that minimal stimulation of the facial nerve during middle ear surgery could result in a reactivation of HSV-1 in the geniculate ganglion, which may in turn lead to a facial palsy.

Adult↗

Quantitative PCR. A survey of the present technology.

PCR-based amplification of nucleic acids has had a major impact in almost every field of basic research and has already found extensive applications in the area of clinical diagnosis. For many of these applications, quantitative data are sought to relate the quantity of amplified product to the amount of original target nucleic acid present in the sample. Since the PCR methodology with its exponential nature can be adapted for this purpose, a lot of different strategies have emerged in the last few years for sensitive and specific PCR product detection and quantification. Basic strategies, including the use of external and internal standards, are presented with respect to statistical aspects, and the advantages as well as the limitations of individual protocols are discussed. Furthermore the suitability of conventional laboratory techniques, such as gel systems or HPLC, nonradioactive labeling procedures, and the principles of advanced solid-phase-mediated strategies for the precise determination of amplification products, are outlined with the help of selected examples.

Polymerase Chain Reaction↗

Isomalto-oligosaccharide-containing lipoteichoic acid of Streptococcus sanguis. Basic structure.

The lipoteichoic acid of Streptococcus sanguis DSM 20567 and of DSM 20068 was isolated by phenol/water extraction and hydrophobic-interaction chromatography. The preparations from both strains have an identical structure: a 1,3-linked poly(glycerophosphate) chain phosphodiester-linked to Glc-(alpha 1-2)Glc(alpha 1-3)acyl2Gro as the lipid anchor. The chain is substituted with D-alanine ester and glycosyl residues which comprise mono-, di-, tri- and tetra-alpha-D-glucopyranosyl residues with (1-6) interglycosidic linkages. The glycosylglycerols were released with 48% (by mass) hydrofluoric acid, separated and characterized by a combination of chemical procedures and modern techniques of 1H-NMR and 13C-NMR spectroscopy. The alpha-isomalto-oligosaccharides add a novel motif to lipoteichoic-acid chain substituents. 1H-NMR and 13C-NMR spectroscopy also provided a detailed picture of the basic glycosylated poly(1,3-glycerophosphate) diglucosylglycerol. It proved a single unbranched chain structure, provided evidence for the chain length, the extent of glycosylation, the structure of the lipid anchor and the site of attachment of the poly(glycerophosphate) chain on the lipid anchor. Owing to its unique glycosyl substituents the lipoteichoic acid may serve as a taxonomic marker for the redefined species S. sanguis (formerly S. sanguis type I).

Carbohydrate Sequence↗

Isomalto-oligosaccharide-containing lipoteichoic acid of Streptococcus sanguis. Microheterogeneity and distribution of chain substituents.

The lipoteichoic acid of Streptococcus sanguis DSM 20567 contains a poly(glycerophosphate) chain, with 49% of the glycerophosphate residues being substituted with D-alanine ester, 35% with alpha-D-glucopyranosyl and alpha-isomalto-oligosaccharide residues. Analysis of molecular species by affinity chromatography on concanavalin A showed all chains to be substituted and alanine ester and glycosyl residues to be present on the same rather than on separate chains. Molecular species varied in the length of the poly(glycerophosphate) chain, the extent of glycosylation, and had a constant alanine-ester content. An alkali-hydrolysis procedure revealed a distribution pattern between random and regular for the glycosyl substituents and suggested a similar distribution for the alanyl residues which occupy the free positions between the glycosyl substituents.

Chromatography, Affinity↗