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Biomedical subjects

P Kirschner

Publications and source records attributed to P Kirschner.

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

Mycobacteria of Runyon groups I, II and IV do not play an aetiological role in Crohn's disease.

OBJECTIVE: In addition to Mycobacterium paratuberculosis, other slow-growing as well as rapid-growing mycobacteria were isolated from mucosa or full thickness samples of intestine from patients with Crohn's disease. The meaning of these data remained unclear. To investigate the possible aetiological role of these rapid- and slow-growing mycobacteria, serosa and mesenteric lymph nodes were also cultivated in the present study. DESIGN AND METHODS: Mucosa, lymph nodes and serosa of 23 patients with Crohn's disease and 23 patients with other intestinal afflictions were incubated at 37 degrees C on Löwenstein-Jensen medium and Herrold egg yolk medium. These methods allow the cultivation of most atypical mycobacteria, including Mycobacterium paratuberculosis. In addition, full thickness samples of some of these patients were analysed for mycobacterial DNA using polymerase chain reaction. RESULTS: Despite lack of decontamination of 60% of lymph nodes and serosa, no mycobacterial growth was observed over a long incubation period (an average of 718 days in Crohn's disease and 552 days in controls) on Löwenstein-Jensen medium. Polymerase chain reaction was based on the amplification of 16S ribosomal DNA sequences specific for mycobacteria of tissues derived from four patients with Crohn's disease and one control was negative. CONCLUSIONS: These findings suggest that mycobacteria, such as M. fortuitum and M. chelonei, which are widespread in the environment, are not involved in the aetiology of Crohn's disease but, rather, should be considered as environmental opportunists.

Adolescent↗
PubMed1995

Phylogeny of the Mycobacterium chelonae-like organism based on partial sequencing of the 16S rRNA gene and proposal of Mycobacterium mucogenicum sp. nov.

The Mycobacterium chelonae-like organism (MCLO) is a recently described member of the Mycobacterium fortuitum complex which causes posttraumatic skin infections and catheter sepsis. This taxon is a distinct group biochemically and has a unique mycolic acid profile as determined by high-performance liquid chromatography. Its phylogenetic relationships to other mycobacteria, however, have not been studied previously. We sequenced 1,062 bp of the 16S rRNA genes from three MCLO strains obtained from the American Type Culture Collection and compared our results with the sequences of previously described taxa of rapidly growing and slowly growing mycobacteria. Two biochemically typical strains (ATCC 49650T [T = type strain] and ATCC 49651) had identical sequences, while the sequence of a biochemically atypical strain (ATCC 49649) differed by 4 bp from the sequence of the two typical strains. The Hamming distances between these MCLO strains and related rapidly growing mycobacteria are comparable to the Hamming distances among taxa of rapidly growing mycobacteria established as species by DNA-DNA hybridization. We propose the name Mycobacterium mucogenicum sp. nov. for this new taxon because of the highly mucoid nature of most isolates on solid media.

Base Sequence↗
PubMed1995

[Wound drainage with a continuous high vacuum drainage system and a drainage system with variable vacuum].

A study of 120 total hip replacements showed the advantages of the variable vacuum drainage system over the continuous high vacuum drainage system. Better wound healing, less severe hematomas and less occlusion of drains confirmed the higher effectiveness of secretion draining. With regard to hygienic aspects, and especially to wound infection, the continuous closed drainage system is an improvement of the intermittent closed drainage system.

Adult↗
PubMed1995

[Gorham-Stout massive ostelysis. A case report].

One case of massive osteolysis Gorham-Stout is presented. Idiopathic osteolysis is a rare disease. The coincidental radiological diagnosis following minor trauma or a few months' history of mild pain involving joints is characteristic. The disease process has a sudden onset. Bones undergo partial or complete resorption, which may spread across joints to contiguous bones. The osteolytic process eventually ceases spontaneously, but generally not before severe deformation and destruction of bone has occurred. Usually radiotherapy is not successful and is followed by local resection of the osteolytic process. Based on our presented case, we suggest early operative treatment to prevent severe damage.

Arthrodesis↗
PubMed1994

[Application possibilities of MR arthrography in diseases of the shoulder joint].

In a prospective study possible indications for MR arthrography of the shoulder were evaluated. 37 patients were examined before and after intraarticular administration of a 2-mmolar solution of Gd-DTPA. MR arthrography was performed if there was no joint effusion and/or an uncertain finding concerning the rotator cuff or the capsulolabral complex on plain MR images. MR arthrography leads to a better demonstration of labrum pathology in 11/22 patients and to a superior delineation of the capsuloligamentous apparatus in 20/22 cases. In 9/15 patients with impingement lesions MR arthrography allowed a differentiation of severe tendinitis from partial and small full-thickness tears of the rotator cuff. MR arthrography of the shoulder joint enhances the accuracy of MR in case of an uncertain finding on plain MR images.

Adolescent↗
PubMed1994

Mycobacterium genavense. Autopsy findings in three patients.

The authors report on the pathologic findings in three cases of disseminated infection with Mycobacterium genavense, a recently described nontuberculous mycobacterium, in human immunodeficiency virus (HIV)-I-positive patients. The mycobacterium was identified by amplification of a 16S rDNA gene fragment and subsequent sequence determination. The organs mainly involved were the small intestine, spleen, liver, and lymph nodes. In contrast, lungs, myocardium, and kidneys were not involved, or only minimally involved, in this generalizing disease. Histopathologically, infection with Mycobacterium genavense in HIV-positive patients was mostly characterized by masses of foamy histiocytes and, depending on the immunologic reactivity of the host, by ill-formed granulomas, rarely with small foci of necrosis. The pathologic findings and clinical features were similar to those presented by patients who had generalized infection with Mycobacterium avium-intracellulare complex. To obtain more precise information about the specific course of infection with Mycobacterium genavense, scrupulous microbiologic investigations, including molecular biologic techniques, are necessary in cases with mycobacterial infections.

AIDS-Related Opportunistic Infections↗
PubMed1994

Genetic alterations in streptomycin-resistant Mycobacterium tuberculosis: mapping of mutations conferring resistance.

We report on the identification of mutations associated with streptomycin resistance in Mycobacterium tuberculosis. Two isolates (3656 and 3976) showed a wild-type ribosomal protein, S12, but exhibited a single point mutation at 16S rRNA position 491 (C-->T) or 512 (C-->T), respectively. Sequence analysis of a third isolate (2438) revealed a single base change at 16S rRNA position 904 (A-->G). This position is equivalent to invariant position 913 of the Escherichia coli 16S rRNA gene, an A-->G transition of which has been shown previously to impair streptomycin binding and streptomycin-induced misreading in vivo. Surprisingly, strain 2438 harbors an additional mutation in the ribosomal protein S12 (Lys-88-->Gln).

Base Sequence↗
PubMed1994

Identification of mutations in 23S rRNA gene of clarithromycin-resistant Mycobacterium intracellulare.

Clarithromycin is a potent macrolide that has been used for treating infections with nontuberculous mycobacteria. Pairs of susceptible and resistant Mycobacterium intracellulare strains were obtained from patients with chronic pulmonary M. intracellulare infections undergoing monotherapy with clarithromycin. Nucleotide sequence comparisons of the peptidyltransferase region in 23S rRNAs from parental and resistant strains revealed that in three of six resistant strains, for which the MIC was > 32 micrograms/ml, a single base was mutated (Escherichia coli equivalent, A-2058-->G, C, or U). As the modification of adenine 2058 by dimethylation is a frequent cause of macrolide resistance in a variety of different bacteria, we suggest that mutation of A-2058 confers acquired resistance to clarithromycin in M. intracellulare.

Base Sequence↗
PubMed1994

Bias of culture techniques for diagnosing mixed Mycobacterium genavense and Mycobacterium avium infection in AIDS.

Disseminated Mycobacterium avium infection is a common complication in late-stage AIDS. We describe a patient seropositive for human immunodeficiency virus with a disseminated infection caused by mycobacteria. Acid-fast rods were visible by microscopy in stool and bone marrow and in specimens from skin, liver, spleen, lung, and lymph nodes. Using molecular biology techniques and standard culture techniques, we found evidence of a mixed mycobacterial infection with M. genavense and M. avium. We suggest that the prevalence of M. genavense infection in patients with AIDS is underestimated because of the bias toward M. avium when using standard techniques for the detection and identification of mycobacteria.

AIDS-Related Opportunistic Infections↗
PubMed1993

[Mycobacterium genavense infection in AIDS].

Fever, loss of weight, anaemia, hepatosplenomegaly and lymphadenopathy developed in two HIV-infected patients. At first malignant lymphoma with septicaemia was thought to be the cause. In both patients Salmonella enteritidis was isolated by blood culture and found to be sensitive against the antibiotics that were given (5 g azlocillin and 2 g cefotaxime, three times daily each; additionally in case 2, metronidazole, 500 mg three times daily). Because bone-marrow biopsy demonstrated acid-fast rods, antimycobacterial treatment was started (isoniazid 300 mg/d, rifampicin 600 mg/d, ethambutol 1,200 mg/d and pyrazinamide 2 g/d). Despite this the patients died of septic shock. Histological examination revealed massive amounts of acid-fast rods in spleen, liver, gut and bone marrow. Polymerase chain reaction and sequencing identified the structure as that of the recently discovered M. genavense.

AIDS-Related Opportunistic Infections↗
PubMed1993

Invasive infection with Mycobacterium genavense in three children with the acquired immunodeficiency syndrome.

Three children with human immunodeficiency virus infection and invasive infection with Mycobacterium genavense are reported. Fever spikes, abdominal cramps and distension, diarrhea or ileus, and anemia were the predominant symptoms in the severely immunodeficient patients (CD4 lymphocytes < 0.04 x 10(9)/l). Numerous acid-fast bacilli were readily detectable by microscopy in stool samples and in lymph node biopsies, but cultures for mycobacteria remained negative. Mycobacterium genavense should be sought when invasive non-tuberculous mycobacteriosis is suspected and mycobacterial cultures from blood or other sites show limited growth. Multiple-drug regimens including amikacin, ethambutol, rifampin, and clarithromycin may be of benefit in controlling the infection, as observed in two patients.

AIDS-Related Opportunistic Infections↗
PubMed1993

Transoesophageal echocardiography and the intraoperative diagnosis of left atrial invasion by carcinoid tumour.

A 41-yr-old woman with pulmonary carcinoid tumour presented for thoracotomy and lung resection. However, intraoperative transoesophageal echocardiography (TEE) revealed that the tumour had invaded the left atrium, and the planned resection was aborted to allow resection under cardiopulmonary bypass at a later date. Although the incidence of cardiac involvement by lung cancer at the time of pulmonary resection is unknown, transoesophageal echocardiography can be useful in identifying the extension of hilar lung tumours. This should preferentially be done preoperatively, but can be done intraoperatively as described in this case report.

Adult↗
PubMed1993

Excretion of urinary enzymes after extracorporeal shock wave lithotripsy: a critical reevaluation.

The excretion of the urinary enzymes alanine aminopeptidase, alkaline phosphatase, gamma-glutamyl-transferase and N-acetyl-beta-D-glucosaminidase, and the 99mtechnetium-diethylenetriaminepentaacetic acid isotope clearance were studied in 35 patients treated with extracorporeal shock wave lithotripsy (ESWL*). Enzyme measurements were made before and consecutively on days 1, 2 and 5, and at 3 months after treatment. A control group investigated at the same intervals was included. Posttreatment enzyme values were not significantly different from those before treatment except for alkaline phosphatase on day 1 after ESWL. Some individuals had short-term increases of enzymuria that were greater than biological variations in the control group. The transient changes of enzymuria after ESWL had no predictive value for kidney function, since no decreased renal function was observed in individual patients with high enzyme excretions after ESWL.

Acetylglucosaminidase↗
PubMed1993

Cervical lymphadenitis in a child caused by a previously unknown mycobacterium.

Acid-fast bacilli were isolated from lymph nodes of an immunocompetent child presenting with unilateral cervical lymphadenitis. The slowly growing mycobacterium could not be identified by traditional methods. Direct sequencing of the enzymatically amplified 16S rRNA gene revealed a unique sequence belonging to a previously unrecognized mycobacterium. Direct 16S rDNA sequencing enables definitive identification of mycobacterial isolates. The method is useful for rapid recognition of previously unrecognized pathogens.

Base Sequence↗
PubMed1993

Mycobacterium intermedium sp. nov.

Strains of a new type of slowly growing mycobacterium were repeatedly isolated from sputum from a patient with pulmonary disease. This photochromogenic organism grew at 22, 31, 37, and 41 degrees C, possessed catalase, acid phosphatase, esterase, beta-galactosidase, and arylsulfatase activities, and hydrolyzed Tween. It did not produce nicotinic acid or have nitrate reductase, acetamidase, benzamidase, isonicotinamidase, nicotinamidase, pyrazinamidase, succinidamidase, and acid phosphatase activities. Urease activity was variable. The organism is susceptible to ethambutol and resistant to isoniazid and streptomycin. A mycolic acid analysis revealed the presence of alpha-mycolates, alpha'-mycolates, and keto-mycolates. The results of comparative 16S rRNA sequencing placed this organism at an intermediate position between the rapidly and slowly growing mycobacteria. On the basis of the pattern of enzymatic activities and metabolic properties, the results of fatty acid analyses, and the unique 16S rRNA sequence, we propose that this organism represents a new species, for which we propose the name Mycobacterium intermedium. The type strain is strain 1669/91; a culture of this strain has been deposited in the Deutsche Sammlung von Mikroorganismen und Zellkulturen as strain DSM 44049.

Bacterial Typing Techniques↗
PubMed1993

Molecular basis of streptomycin resistance in Mycobacterium tuberculosis: alterations of the ribosomal protein S12 gene and point mutations within a functional 16S ribosomal RNA pseudoknot.

Multidrug-resistant strains of Mycobacterium tuberculosis have resulted in several recent outbreaks. Recognition of drug resistance is important both for treatment and to prevent further transmission. Here we use molecular biology techniques to study the basis of streptomycin resistance in single and multidrug-resistant M. tuberculosis. We demonstrate that streptomycin resistance is associated with mutations implicated in ribosomal resistance. The mutations found either lead to amino acid changes in ribosomal protein S12 or alter the primary structure of the 16S rRNA. The 16S rRNA region mutated perturbs a pseudoknot structure in a region which has been linked to ribosomal S12 protein.

Base Sequence↗
PubMed1993

Genotypic identification of mycobacteria by nucleic acid sequence determination: report of a 2-year experience in a clinical laboratory.

Clinical isolates of Mycobacterium spp. were identified by direct sequence determination of 16S rRNA gene fragments amplified by polymerase chain reaction. Identification was based on a hypervariable region within the 16S rRNA gene in which mycobacterial species are characterized by species-specific nucleotide sequences. A manually aligned data base including the signature sequences of 52 species of mycobacteria easily allowed rapid and correct identification. The results of this study demonstrate that polymerase chain reaction-mediated direct sequence determination can be used as a rapid and reliable method for the identification of mycobacteria in the clinical laboratory. In addition, the prompt recognition of previously undescribed species is now feasible.

Base Sequence↗