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Biomedical subjects

M Maiwald

Publications and source records attributed to M Maiwald.

At least 37 records · Page 2Linked to original sources
PubMed1997

Serum antibodies against Helicobacter pylori proteins VacA and CagA are associated with increased risk for gastric adenocarcinoma.

Infection with Helicobacter pylori is associated with the development of gastric cancer. To study whether the infection with H. pylori strains expressing the vacuolating cytotoxin (VacA) and/or the cytotoxin-associated protein (CagA) is associated with an increased risk of developing gastric adenocarcinoma, sera of 90 patients with gastric cancer and 90 matched controls with cardiovascular diseases were investigated for the presence of antibodies to VacA and CagA by immunoblot. Although no significant difference in the overall H. pylori seropositivity was found between cancer patients and controls, antibodies against VacA or CagA were significantly more frequent in cancer patients than in control subjects. Seventy-five (97.4%) of 77 H. pylori-positive patients in the cancer group, but only 60 (84.5%) of 71 H pylori-positive control patients had antibodies against either VacA or CagA (chi 2 = 6.63; relative risk, 2.00; 95% confidence interval, 1.18-3.39; P = 0.01). The presence of antibodies against VacA or CagA alone was also associated with an increased cancer risk (92.2% vs 80.3%; chi 2 = 5.30; relative risk, 1.74; 95% confidence interval, 1.08-2.78; P = 0.021, for VacA; and 87.0% vs 74.6%; chi 2 = 4.90; relative risk, 1.61; 95% confidence interval, 1.06-2.45; P = 0.037, for CagA). The relative risk for gastric cancer was mainly elevated in patients under 65 years, but not in patients at or over 65 years. There is evidence that infection with VacA- or CagA-producing H. pylori strains increases the risk of developing gastric cancer, especially in younger patients.

Adenocarcinoma↗
PubMed1997

Whipple's disease: staging and monitoring by cytology and polymerase chain reaction analysis of cerebrospinal fluid.

BACKGROUND & AIMS: Diagnostic procedures in Whipple's disease usually focus on the intestine, but symptomatic central nervous system involvement is a major threat for patients. The aim of this study was to determine the diagnostic value of cerebrospinal fluid (CSF) analysis. METHODS: A total of 39 CSF samples and 2 brain biopsy specimens that were obtained from 24 patients with Whipple's disease at various intervals after diagnosis were examined. Five patients presented with neurological symptoms, 3 of them as relapses after therapy. Thirty-two CSF samples were examined by polymerase chain reaction for Tropheryma whippelli and 20 CSF samples by cytology. Brain biopsy specimens were examined histologically. RESULTS: Positive results were obtained in 4 of 5 patients (80%) with neurological symptoms, in 7 of 10 patients (70%) without neurological symptoms examined before therapy, and in 3 of 11 patients (27%) without neurological symptoms studied during or after therapy. Conversion from positive to negative was observed in 4 patients after antibiotic treatment. CONCLUSIONS: Testing of CSF in Whipple's disease yields a high rate of positive results, even in patients without neurological symptoms. Examination of CSF is therefore potentially useful for initial staging and for monitoring of the efficiency of therapy.

Actinobacteria↗
PubMed1997

Epidemiology of Whipple's disease in Germany. Analysis of 110 patients diagnosed in 1965-95.

BACKGROUND: The epidemiology of Whipple's disease (WD) is obscure. To obtain basic data, we performed an evaluation of WD patients in Germany. METHODS: Information was collected from 110 WD patients diagnosed during 1965-95 at 5 institutions in different regions of Germany. Four items were evaluated: 1) year in which the diagnosis was made; 2) residence and 3) age at the time of diagnosis; and 4) sex. RESULTS: WD patients originated from all parts of Germany. The incidence of new cases was relatively stable, with a mean of one to two cases per year per collecting centre. In 1995, a maximum of 13 new WD patients was diagnosed. There was a significant increase in the mean age of patients (1965-75, 48.7 years; confidence interval, +/- 3.98 years; 1976-85, 50.7 years, +/- 3.69 years; 1986-95, 57.0 years, +/- 2.80 years; P < 0.01) and an increasing proportion of women (1965-85, 4%; 1986-1995, 22%). CONCLUSIONS: Whipple's disease is not quite as rare as commonly assumed. There is no obvious geographic predominance. During the past three decades, the demography of WD patients has changed.

Adult↗
PubMed1996

Tick infestation patterns and prevalence of Borrelia burgdorferi in ticks collected at a veterinary clinic in Germany.

A total of 4803 domestic and wild animals which were presented for examination at a veterinary clinic in north Baden, Germany over a period of 1 year were examined for tick infestation. A total of 434 nymphal and adult ticks were collected from 175 hosts. Ticks found belonged to the species Ixodes ricinus (385), Ixodes hexagonus (48), and Ixodes ventalloi (one). The polymerase chain reaction was used to examine 132 I. ricinus and 21 I. hexagonus for the presence of Borrelia burgdorferi. Twenty-two per cent of adult I. ricinus were infected as were one female and one larval I. hexagonus.

Animals↗
PubMed1996

Histology of intestinal Whipple's disease revisited. A study of 48 patients.

Whipple's disease is an infectious disorder with intestinal and extra-intestinal manifestations. We reinvestigated the intestinal histology in a series of 48 patients (10 females, 38 males; mean age 56.5 years, standard deviation of the mean +/- 11.2 years). A total of 126 biopsy samples, obtained prior to, during, and after therapy, were evaluated by light microscopy. In 43 patients (90%), histology was consistent with common descriptions, while it was uncommon in 3 patients (6%), and non-diagnostic in 2 patients (4%). During treatment, several alterations occurred. Apart from a continuous decrease in PAS-positive macrophages, the pattern of mucosal infiltration changed from diffuse to patchy. Moreover, the cytological aspects of PAS-positive macrophages changed substantially, and this change was used to propose four different subtypes. Initially, subtype 1 macrophages predominated (74%), but showed a gradual decrease within a few months of therapy. After 15 months, subtype 3 and subtype 4 macrophages predominated (< 80%). In 7 of 9 patients followed over long periods some subtype 3 or subtype 4 macrophages persisted. It is concluded that at diagnosis and during treatment the intestinal histology of Whipple's disease is heterogeneous. A few PAS-positive macrophages commonly persist at long-term follow-up. This and other features suggest the presence of a persistent immune defect.

Animals↗
PubMed1996

Excess glutamate in the cerebrospinal fluid in bacterial meningitis.

We investigated possible neurotoxic components in the cerebrospinal fluid (CSF) of patients with bacterial meningitis. On murine cerebellar neuronal cell cultures, CSF exerted a dose-dependent toxic effect, which was attenuated by the NMDA receptor antagonist MK-801. Glutamate concentrations in the CSF of patients with bacterial meningitis were measured by an enzymatic assay and found to be significantly elevated (p < 0.001) as compared to viral meningitis and non-inflammatory neurological diseases. The concentration of glutamate in the CSF of patients with bacterial meningitis varied considerably and correlated with the severity of the disease as scored by the Glasgow Coma Scale. Cells in the CSF, mainly comprising polymorphonuclear granulocytes, did not release any glutamate into the culture medium, whereas blood monocytes produced remarkable amounts. These findings implicate an important role of monocytic inflammatory cells in bacterial meningitis by the release of glutamate, which may contribute to neuronal cell death.

Adult↗
PubMed1996

Diagnostic application of a polymerase chain reaction assay for the Whipple's disease bacterium to intestinal biopsies.

BACKGROUND & AIMS: The uncultured Whipple's disease bacterium (Tropheryma whippelii) was characterized in 1991-1992 by polymerase chain reaction (PCR) and sequencing of the bacterial 16S ribosomal RNA gene. The aim of this study was to develop a PCR assay for diagnostic purposes. METHODS: Modified primers for PCR and a specific probe for hybridization were designed. The specificity of this PCR assay was tested using 37 bacterial control strains and intestinal biopsy samples from 16 patients without Whipple's disease. The sensitivity was tested in 88 intestinal biopsy samples from 35 patients with Whipple's disease. RESULTS: PCR and hybridization were negative in all 37 bacterial controls and in all 16 patients without Whipple's disease. Before therapy, DNA of T. whippelii was detected in all 30 patients with Whipple's disease from whom formalin-fixed biopsy material was available, whereas Bouin-fixed material was negative. During and after treatment, PCR was negative in 23 of the 24 patients who were followed up. Generally, conversion to negative occurred within 1 year. Despite negative intestinal PCR, symptomatic cerebral Whipple's disease appeared in 3 patients. CONCLUSIONS: This PCR assay is specific and sensitive and is applicable as a diagnostic test. However, PCR from intestinal biopsy samples seems less helpful for monitoring the effect of treatment.

Actinobacteria↗
PubMed1996

Patient assessment of self-measurement of blood pressure: results of a telephone survey in Germany.

OBJECTIVE: To obtain information on the adoption of self-measurement of blood pressure by hypertensives and their attending physicians. METHODS: Callers to the Cardiovascular Hotline Heidelberg revealing themselves to have high blood pressure were interviewed about self-recording of blood pressure. RESULTS: Among the callers about 70% practised self-measurement. Half of them bought a device on their own initiative, one-third on recommendation or prescription by their physician. A quarter of those practising the technique were introduced to it by experienced personnel and a comparable number were adequately informed about the aims and objectives. Nevertheless, more than half of those practising self-measurement claimed to be coping better with the disease. CONCLUSIONS: The data indicate that self-monitoring is widely practised by hypertensives in Germany. In contrast to this finding, too few physicians have adopted home-recording as a useful tool in the treatment of hypertension.

Adult↗
PubMed1996

Reassessment of the phylogenetic position of the bacterium associated with Whipple's disease and determination of the 16S-23S ribosomal intergenic spacer sequence.

Whipple's disease is a rare chronic illness associated with an unculturable bacterium that is constantly present in affected tissues. This bacterium was previously characterized at the molecular level by PCR and sequencing of the 16S rRNA gene. On the basis of 1,321 nucleotides of the sequence of its gene coding for 16S rRNA (16S rDNA), a phylogenetic relationship to the actinomycetes was established. In this study, we determined an almost complete 16S rDNA sequence (1,495 nucleotides), the 16S-23S ribosomal intergenic spacer sequence, and 200 nucleotides of the 23S rRNA gene. The 16S rDNA sequence was compared with the large number of actinomycete sequences that have been added to the database since the original study. Phylogenetic analysis revealed a branching position as the deepest branch of the cluster comprising the actinomycetes with group B peptidoglycan between this group and the family Cellulomonadaceae. This provides additional information on the phylogenetic position of this bacterium and some clues as to its characteristics. The spacer region between the 16S and 23S rRNA genes is 294 nucleotides long and does not contain tRNA genes. As has been shown in other instances, the increased variability of the ribosomal intergenic spacer compared with the 16S rRNA gene makes it a potential target for use in the differentiation of strains of the bacterium associated with Whipple's disease.

Actinomycetales↗
PubMed1996

Comparison of urinary bladder and ear biopsy samples for determining prevalence of Borrelia burgdorferi in rodents in central Europe.

PCR was used to compare urinary bladder and ear biopsy samples from four European species of wild rodents for the presence of Borrelia burgdorferi sensu lato. From 60 paired comparisons of bladder and ear biopsy samples, the PCR results were concordantly positive or negative in 43 samples (71.7%). Of the 17 which differed, 14 bladder samples were positive and ear samples were negative while the converse occurred for three samples. Thus ear biopsy samples led to a significantly lower estimate of infection than bladder biopsy samples. This suggests that the use of ear biopsy samples in epidemiological studies of B. burgdorferi in Central European rodents is likely to lead to underestimates of the prevalence.

Animals↗
PubMed1996

Evaluation of a new version of the EnviroAmp Legionella kit for the detection of legionellae in water samples by the polymerase chain reaction.

The detection of Legionella sp. in various types of environmental water samples was evaluated using a revised version of the EnviroAmp Legionella kit (Perkin-Elmer), which is based on the polymerase chain reaction (PCR). The new kit employs a modified protocol for the pretreatment of water samples, which is designed to further reduce the inhibitory action of some samples to the PCR. The results of the new kit were compared with those of culture. Seventy-four water samples were examined. Of these samples, 51 were taken from hospital water systems, 16 were household water samples, 5 were from surface water, and 2 were rain water. These samples were examined both by PCR and by culture on MWY Legionella selective agar. Of the 74 samples, 46 (62%) were positive by both test systems. Twenty-five samples (34%) were positive by PCR, but negative by culture. While 3 samples (4%) were negative by both test methods, no sample was negative by PCR and positive by culture. Statistical analysis revealed high positive predictive values of PCR, when L. pneumophila was detected or when the genus Legionella was detected at high intensity. Negative predictive values were high, when the PCR was negative or only weakly positive for the genus Legionella.

Bacteriological Techniques↗
PubMed1995

Detection of Legionella DNA in human and guinea pig urine samples by the polymerase chain reaction.

A detection system for Legionella DNA in urine samples based on the polymerase chain reaction (PCR) was developed and tested on infected guinea pigs and patients suffering from pneumonia. Results were compared with standard methods for diagnosis of Legionnaires' disease. A primer system was selected which amplifies a 108 bp DNA fragment of the 5S rRNA gene. The sensitivity of the PCR system was one femtogram of extracted Legionella DNA. Three methods were tested for pretreatment of urine samples. Of these, the Geneclean II kit (Bio 101, USA) gave the best results for artificially contaminated urine samples as well as those from infected guinea pigs or patients. Thirty-seven urine samples from 15 guinea pigs intraperitoneally infected with either Legionella pneumophila serogroup 1, 3 and 6 or Legionella micdadei, 26 urine samples of 21 patients suffering from pneumonia, and 30 control samples of patients with urinary tract infection (UTI) were tested. Legionella DNA was detected in 29 of the guinea pig urine samples; whereas, urinary antigen detection using EIA was positive in only 20 of the samples. PCR was also positive in the samples of 11 patients with pneumonia, 9 of which were confirmed by other microbiological methods, such as culture, direct fluorescent antibody test, urinary antigen detection and antibody testing. However, of the 30 control samples from patients with UTI, three samples yielded positive results. The results demonstrate that Legionella DNA is excreted in the urine of infected individuals and that the PCR shows a higher degree of sensitivity than EIA to the detection of soluble Legionella antigen in urine.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

DNA polymorphisms in strains of Legionella pneumophila serogroups 3 and 4 detected by macrorestriction analysis and their use for epidemiological investigation of nosocomial legionellosis.

Genomic DNAs of clinical and environmental isolates of Legionella pneumophila belonging to serogroups 3 and 4 were analyzed by macrorestriction analysis by pulsed-field gel electrophoresis. The restriction enzymes SfiI and NotI allowed easy visual separation of epidemiologically unrelated serogroup 3 strains. Three unrelated serogroup 3 strains that were isolated from different locations were identical by this genome mapping technique. Five unrelated serogroup 4 strains were separable by this technique. The electrophoretic patterns obtained after SfiI or NotI cleavage of the DNA of strains isolated from four patients with hospital-acquired legionellosis were identical to the patterns of strains isolated from the hot water supply systems of the buildings in which the patients were hospitalized. In conclusion, macrorestriction analysis is a valuable tool for epidemiological studies of infections caused by L. pneumophila serogroups 3 and 4.

Adult↗
PubMed1995

Detection of Tropheryma whippelii DNA in a patient with AIDS.

A case of an AIDS patient infected with the Whipple's disease bacterium, Tropheryma whippelii, is reported. A DNA fragment with sequence specificity for the 16S rRNA gene of the bacterium was detected by PCR in a duodenal biopsy specimen from a 55-year-old male patient with AIDS and diarrhea. The biopsy specimen contained periodic acid-Schiff stain-positive macrophages which did not, however, resemble the sickleform-particle-containing cells characteristic of Whipple's disease. This observation raises two possibilities: either the patient had a coincidence of AIDS and Whipple's disease or Tropheryma whippelii acted as an opportunistic pathogen in this immunodeficient patient. The latter explanation is of interest in light of the ongoing discussion of immunologic abnormalities as predisposing factors for Whipple's disease.

AIDS-Related Opportunistic Infections↗
PubMed1995

Recent infection as a risk factor for cerebrovascular ischemia.

BACKGROUND AND PURPOSE: Previous infection is discussed as a risk factor for ischemic stroke in children and younger adults. We tested the hypothesis that the role of recent infection in cerebrovascular ischemia is not restricted to younger patients and investigated which infections are mainly relevant in this respect. METHODS: We performed a case-control study with 197 patients aged 18 to 80 years with acute cerebrovascular ischemia and 197 randomly selected control subjects matched for sex, age, and area of residence. RESULTS: Infection within 1 week before ictus or examination was significantly more common among patients (38 of 197) than control subjects (10 of 197; odds ratio [OR], 4.5; 95% confidence interval [CI], 2.1 to 9.7). Patients more often had febrile and subfebrile infections (> or = 37.5 degrees C) than control subjects (29 of 197 versus 5 of 197; OR, 7.0; 95% CI, 2.5 to 20). Respiratory tract infections were most common in both groups. Bacterial infections dominated among patients but not among control subjects. Infection increased the risk for cerebrovascular ischemia in all age groups; this reached significance for patients aged 51 to 60 and 61 to 70 years. The profile of vascular risk factors was similar in patients with and patients without previous infection. Infection remained a significant risk factor when previous stroke, hypertension, diabetes mellitus, coronary heart disease, and current smoking were included as covariates in a logistic model (OR, 4.6; 95% CI, 1.9 to 11.3). CONCLUSIONS: Recent infection, primarily of bacterial origin, may be a risk factor for cerebrovascular ischemia in older as well as younger patients.

Adolescent↗
PubMed1995

Impact of urbanization on detection rates of eating disorders.

OBJECTIVE: The purpose of this study was to examine the incidence of anorexia nervosa and bulimia nervosa among patients in primary care and to evaluate the impact of urbanization, age and sex differences, and changes over time. METHOD: During 1985-1989, 58 general practitioners, trained in diagnosing eating disorders, registered all of their patients who had diagnoses of anorexia nervosa and/or bulimia nervosa according to strict criteria. The study population (N = 151,781) was 1% of the population of the Netherlands; the distribution of sexes, ages, geographical locations, and degrees of urbanization in the study group was representative of the Dutch population. Main outcome measures were rates of newly detected cases and age-adjusted rate ratios. RESULTS: The crude annual incidence rate of detected cases in primary care per 100,000 person-years was 8.1 for anorexia nervosa and 11.5 for bulimia nervosa. The incidence of bulimia nervosa was lowest in rural areas, intermediate in urbanized areas, and highest in large cities (6.6, 19.9, and 37.9, respectively, per 100,000 females per year); no rural-urban differences for anorexia nervosa were found. Pronounced sex and age differences in incidence rates were observed. Over the 5-year period, there was no time trend in the incidence of anorexia nervosa, but the incidence of bulimia nervosa tended to increase. CONCLUSIONS: The incidence rates of eating disorders--as defined by detection rates in primary care--are higher than previously reported. Urbanization seems to be a risk factor for bulimia nervosa but not for anorexia nervosa.

Adolescent↗