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Biomedical subjects

M Maiwald

Publications and source records attributed to M Maiwald.

At least 55 records · Page 3Linked to original sources
PubMed1995

[Natural epidemiology of Lyme borreliosis with reference to clustered incidence of illnesses in the suburbs of a North Baden community].

Human infection with Borrelia burgdorferi, the causative agent of Lyme disease, is unusually common in the "Scheelkopf" area of the town Bruchsal in north Baden (Germany), a situation which has led to considerable publicity and public concern. This study was carried out in order to clarify this situation by determining the prevalence of B. burgdorferi in both the free-living tick populations (Ixodes ricinus) and the rodent population from the "Scheelkopf" as well as from surrounding control areas. The polymerase chain reaction (PCR) was used to determine the presence of infection in whole tick preparations and in mouse bladders. The prevalence of B. burgdorferi in freeland ticks ranged from 19% to 44% and in mice from 6% to 29% depending on the area studied. The "Scheelkopf", with prevalences for ticks and mice of 33% and 10% respectively, was not significantly different from the control areas. Our results indicate that there is a high risk of human infection throughout the study area. This is probably related to the intensive use of the area for gardens and the related recreational behaviour of the human population in conjunction with the high rate of infection prevailing in I. ricinus.

Animals↗
PubMed1994

[Self-measurement of blood pressure in hypertensive subjects in Germany. Results of a questionnaire in Spring/early Summer 1993].

The 'cardiovascular hotline' in Heidelberg, established in April 1992, provides data concerning the self-measurement of blood pressure. For this purpose 277 hypertensives were asked from 15 April to 15 July 1993. 195 (70%) of those questioned (47% men, 53% women) practised home-recording, but only 17% on recommendation of their physician. Only 22% were introduced to the technique by experienced personnel; just 50% were adequately controlled. At least 35% of hypertensives used an oscillometric device and not more than 10% an auscultation device. 5 to 14% of the patients reported to have difficulties in handling their device. Approximately 60% of the patients practicing home-recording stated that this method enabled them to cope better with their disease. Compared with the 1987 pilot study in the Hamburg area, this percentage did not increase; however, it could be confirmed that only approximately 10% of the patients are unsuited for home-recording. 75% of the hypertensives measuring their own blood pressure documented their values, but in only 47% of all cases physicians drew conclusions from the data. 31% of the patients were unable to say whether their medication was adjusted on the basis of self-measured blood pressure values. In conclusion, many hypertensives practice self-measurement of blood pressure. Despite this fact, home-readings are not yet sufficiently accepted by physicians as a possible and desirable method to optimize high blood pressure treatment. This situation should be improved since compliance of physicians is the basis for a better education of hypertensive patients, thus optimizing patient compliance.

Adult↗
PubMed1994

[Reinfection with Borrelia burgdorferi in an immunocompetent patient].

A 54-year-old patient with an intact immune system developed Lyme disease three times within 4 years. The first time an erythema migrans occurred, which was successfully treated with oral doxycycline (100 mg twice daily for 20 days). Specific antibodies were subsequently demonstrated. Re-infection nonetheless occurred a year later, again as erythema migrans. Oral doxycycline in higher dosage (three times 100 mg daily for 20 days) failed to prevent generalization of the infection with rigor, head and neck aches, myalgia, fatigue and subfebrile temperatures. There was a marked increase in Borrelia-specific antibody titre. Parenteral treatment with cefotaxime (twice daily 3 g for 12 days) was curative. But 2 years later yet another re-infection occurred with classic erythema migrans, which regressed under doxycycline. The course of the disease in this case demonstrates that Borrelia-specific antibodies do not always protect against re-infection. This may have consequences for the possible development of a vaccine.

Animals↗
PubMed1994

Characterization of contaminating DNA in Taq polymerase which occurs during amplification with a primer set for Legionella 5S ribosomal RNA.

An amplification product that occurred in negative controls of a PCR using a primer system for Legionella 55 ribosomal RNA was characterized by direct sequencing. The amplification product did not hybridize to a Legionella specific oligonucleotide. It was derived from bacterial DNA contaminating Taq DNA polymerase, a phenomenon that was previously reported for amplification reactions with universal primer sets for bacterial 16S rRNA. The sequence of the 5S ribosomal fragment had close homology to the 5S-rRNA of the species Pseudomonas fluorescens, Pseudomonas aeruginosa, Alcaligenes faecalis, and Azotobacter vinelandii. These findings confirm that the DNA contaminations in Taq DNA polymerase belong to other species than Thermus aquaticus or Escherichia coli.

Base Sequence↗
PubMed1994

Rapid presumptive identification of medically relevant yeasts to the species level by polymerase chain reaction and restriction enzyme analysis.

A method for the rapid presumptive differentiation of a panel of 12 clinically relevant yeasts to the species level was developed on the basis of evaluation by the polymerase chain reaction (PCR) of the gene coding for the small ribosomal subunit 18S-rRNA. The method involved restriction enzyme analysis of PCR products obtained with primers common to all fungi. Using six restriction enzymes, AluI, BanI, BbsI, DraII, Eco147I and NheI, characteristic PCR-restriction enzyme patterns were obtained for Candida albicans, Candida tropicalis, Candida krusei, Candida kefyr, Candida lusitaniae, Candida guilliermondii, Candida glabrata and Saccharomyces cerevisiae, as well as for the pairs Candida parapsilosis/Candida viswanathii and Trichosporon beigelii/Cryptococcus neoformans. The procedure does not involve hybridization steps or the use of radioactivity and can be completed within one working day.

Base Sequence↗
PubMed1994

Comparison of polymerase chain reaction and conventional culture for the detection of legionellas in hospital water samples.

A detection system for Legionella spp. based on the polymerase chain reaction (PCR) was used to assess the diagnostic value of PCR for the surveillance of contamination of man-made water systems by legionellas. A previously-published primer system was chosen to amplify a fragment of the 5S-ribosomal gene of Legionella spp. A total of 78 water samples from various sources were examined by PCR and culture on MWY Legionella selective agar. Fifty-seven of 78 water samples were positive by both test systems (73%), nine were positive by PCR only (11.5%), another nine were positive by culture but negative by PCR (11.5%), and three were negative by both techniques (3.8%). The PCR was inhibited when large amounts of rust were present in the samples. Culture failed to detect legionellas in samples that contained large numbers of other bacteria capable of overgrowing the legionellas. These results show that PCR is a rapid and sensitive technique for the detection of legionella contamination in water samples and that PCR and culture complement each other in monitoring of environmental water samples.

Base Sequence↗
PubMed1994

[Lyme borreliosis--an infectious disease with interdisciplinary demands].

Lyme borreliosis is an infectious disease with various clinical manifestations, caused by the bacterium Borrelia burgdorferi. Although symptoms of the disease have been described since more than 100 years ago, it was not until 1982 that the causative organism was discovered. In Europe, Lyme borreliosis is the most common tick-borne disease, and in endemic regions, a considerable number of clinical cases can be found. The course of the disease is in stages and involves various organ systems, such as skin, nervous system, heart, and joints. Laboratory diagnosis is considered to be difficult and relies mainly on the determination of antibodies. A vaccine for use in humans is not yet available, but experimental data support the feasibility of a vaccine development.

Animals↗
PubMed1993

[Whipple's disease associated with opportunistic infections].

A 36-year-old man, with a history of recurrent respiratory infection, dermatomycosis, arthralgia and abnormal stools for 12 years, developed a febrile illness (up to 40 degrees C). A Serratia marcescens septicaemia responded to antibiotics. Four months later cervical and abdominal lymph-adenopathies were noticed. Cervical lymph node biopsy revealed lymphadenitis with epithelioid cell nests. Duodenoscopy with biopsy demonstrated Whipple's disease associated with lambliasis. Electron-microscopy showed rod-shaped bacteria typical of Whipple's disease, and Giardia lamblia. Using the polymerase chain reaction, Whipple-specific DNA fragments of 284 base pairs from the genome of the Whipple bacterium (Tropheryma whippelii) were demonstrated. Antibiotic treatment with Ampicillin (2 g three times daily) and ceftriaxone (2 g once daily) i.v. for 21 days, followed by oral ofloxacin (200 mg daily) and co-trimoxazole (three times daily 800 mg sulfamethoxazole and 160 mg trimethoprim), brought about remission of Whipple's disease. Long-term antibiotic treatment was continued with co-trimoxazole. Lambliasis recurred after 3 and 5 months, despite treatment with metronidazole, 250 mg three times daily for 7 days.

Adult↗
PubMed1993

The acute infection-associated hemolytic anemia of childhood: immunofluorescent detection of microbial antigens altering the erythrocyte membrane.

The majority of acute infection-associated hemolytic diseases of infancy and childhood have been suggested to be caused by exogenic alterations of the erythrocyte surface, though laboratory methods for their further evaluation were not yet available. Investigating 96 children, the present study characterizes 72% of cases as corresponding to this type of acute acquired hemolytic anemia, which cannot be clearly related to autoantibodies against unmodified components of the host's own red cells. Using a new immunofluorescence test, the erythrocyte membrane of 80% of these children was found to be altered in vivo by nonspecific adsorption of foreign material released from the infectious micro-organisms. In 24% of cases additive binding of complement was detectable by an antiglobulin test. Thus, the adsorption of microbial antigens to the red cell surface is suggested to be one of the causes for the removal of altered erythrocytes due to phagocytosis or a complement-dependent destruction during the course of infection-associated hemolytic anemia. Especially in childhood, the immunofluorescent detection of an erythrocyte sensitization in vivo provides a further characterization of this type of mostly transient hemolytic disease, which probably can be treated without any immunosuppressive drug, merely by elimination of the underlying infection.

Adolescent↗
PubMed1993

Human brucellosis in Dhofar, Sultanate of Oman.

Sera were collected, mostly from school children, in six localities of the southern region of the Sultanate of Oman. Macro and micro-agglutination tests were used to indicate positive Brucella serology. Four of the 525 sera tested had titres of at least 1:200, which were considered positive, and two had borderline values. The frequency of serologically positive sera in the six localities ranged between zero and 2%. No relevant difference was observed between titres using antigen of B. abortus or B. melitensis.

Adult↗
PubMed1991

[Time series analysis of patient self-assessed psychophysiologic variables].

A data set of physiological (blood pressure, body weight, pulse rate) as well as psychological (adjective list by Sokolow et al.) variables collected by a patient in 1985 is analysed. Initially, by identifying time series models, subsequently, by estimating parameters and, eventually, by cross correlating all variables pair wise. With regard to different time intervals (the whole year, 2-months-intervals) several ARIMA-models apply for a description of the psychophysiological variables. Results obtained by time series analyses are confirmed by spectral analyses. For distinct time sections (i.e. Sep.--Oct., Nov.--Dec.) cross correlations reveal a seven day periodicity which corresponds to a psychophysiological pattern. Time series analyses of single case data are considered as a valuable research strategy which in some cases allows the detection of the underlying processes.

Affect↗
PubMed1990

Possible role of acetaldehyde in ethanol-related rectal cocarcinogenesis in the rat.

Prospective epidemiologic studies have reported an increased risk of rectal cancer following chronic ethanol ingestion. The effect of ethanol on chemically induced colorectal carcinogenesis is controversial depending on the experimental conditions. In the present study the effect of chronic ethanol administration on acetoxymethylmethylnitrosamine-induced rectal cancer and the possible role of acetaldehyde in this process were investigated. Chronic ethanol administration resulted in an earlier occurrence of rectal tumors in this animal model. Because the concomitant administration of cyanamide, a potent acetaldehyde dehydrogenase inhibitor, showed a positive trend toward increased incidences of tumors, acetaldehyde could be involved in the ethanol-associated carcinogenesis. To measure colonic acetaldehyde, 12 chronically ethanol-fed and control rats received an acute dose of ethanol (2.5 g/kg body wt). The mucosal concentration of acetaldehyde was significantly higher in the rectum compared with the cecum (198 +/- 23 vs. 120 +/- 23 nmoles.g colon-1, p less than 0.05), but was not affected by chronic ethanol feeding. Furthermore, 6 germ-free rats had significantly lower acetaldehyde concentrations in the rectum (84 +/- 11 vs. 234 +/- 33 nmoles.g colon-1, p less than 0.01) and in the cecum (59 +/- 13 vs. 121 +/- 33 nmoles.g colon-1, p less than 0.05) compared with 6 conventional animals, and this was paralleled by the number of fecal bacteria in the 2 intestinal segments. In addition, to determine the effect of chronic ethanol feeding on colorectal cell turnover, 30 animals were pair-fed liquid diets. Using the metaphase-arrest technique, alcohol feeding induced rectal (19.1 +/- 2.0 vs. 9.1 +/- 1.8 cells.crypt-1.h-1, p less than 0.01), but not cecal (18.9 +/- 1.3 vs. 22.2 +/- 3.3 cells.crypt-1.h-1, p greater than 0.05) hyperregeneration. This was accompanied by an increase in the crypt proliferative compartment and increased mucosal ornithine decarboxylase activity (63 +/- 18 vs. 22 +/- 6 pmoles.hr-1.mg protein-1, p less than 0.05). The data show that chronic ethanol ingestion accelerates chemically induced rectal carcinogenesis and raise the possibility that acetaldehyde probably generated through bacterial ethanol oxidation may be involved in this process. The secondary hyperregeneration of the mucosa, observed after alcohol feeding, could by itself favour carcinogenesis.

Acetaldehyde↗
PubMed1990

Prediction of clinical outcome of radiation accident victims.

On the basis of the analysis of more than 350 individuals that were exposed to ionizing radiation in the course of more than 25 radiation accidents reported world wide since 1945, a biomathematical computer model was developed that simulates the pattern of granulocyte changes seen. It allows one to calculate the number of stem cells remaining intact to initiate recovery. It is shown that the major question to be asked is whether a spontaneous stem cell recovery can be expected or not. This question can be readily answered within 3-5 days after radiation exposure on the basis of the constellation of hematopoietic findings and devised stem cell pool size calculations.

Accidents↗
PubMed1988

[Principles of a medical-psychological long-term single case study].

Using time plots of serial measurements of physiologic as well as psychologic parameters (blood pressure, body weight, pulse rate and an adjective list by Sokolow) possible evaluation strategies applicable to extended data sets are demonstrated. The data set used in this study has been compiled over a seven year period by daily sampling of the aforementioned parameters by a male patient. Preliminary findings indicate, that covariation between parameters differs, when data of distant time sections are considered.

Adult↗
PubMed1987

[The enzymatic degradation of formaldehyde by isolates of Pseudomonas aeruginosa].

The capacity of 12 Ps. aeruginosa-strains to enzymatically degrade Formaldehyde was tested. These strains, derived from environmental and patient samples, were previously passaged 25 times in increasing formaldehyde-concentrations, in a micromodification of the bacteriostasis test. The formaldehyde-degradation was detected photometrically with the sulfite-pararosaniline-method. Furthermore, in 4 of the 12 strains the activity of a formaldehyde dehydrogenase assumed to be the degrading agent was determined. The tested strains exhibited a markedly differing resistance to formaldehyde, some environmental isolates growing even at concentrations in the range of commonly used disinfectant solutions. The exponential growth phase of the inoculum and the reduction of formaldehyde-content coincided. The strains with the highest formaldehyde-resistance showed a formaldehyde-dehydrogenase activity higher by approximately a factor 100 compared with the rather sensitive ATCC-strain. This dehydrogenase activity, in addition to possible extra- and intracellular penetration barriers, could be a causal factor for an increased formaldehyde-resistance.

Aldehyde Oxidoreductases↗
PubMed1987

[Verbal interaction and heart rate in the course of the therapeutic process in a neurotic patient. A psychobiologic pilot project].

Whereas measurements of physiologic variables are widely used in investigations of psychosomatic illnesses, this proceeding is not an established strategy when dealing with the therapeutic process of neuroses which lack coarse bodily symptoms. Therefore, we investigate the heart rate response pattern and the verbal dialog during therapeutic sessions of a patient with an impulsive neurosis. Recordings are made before and after the obsessive symptoms improve. Changes are found in the heart rate response as well as in the verbal interaction between patient and therapist. While symptoms persist the patient's behavior alternates between patient and therapist. While symptoms persist the patient's behavior alternates between gross defense and a panic like disturbance. Concurrently the heart rate response shows an inconspicuous pattern interrupted by sudden heart rate increases. After the obsessive symptoms had ceased the patient has been better controlled in his behavior but is more tense. Compared to the previous state this is accompanied by more frequent and longer lasting periods of reduced heart rate variability and only moderate increases.

Adult↗