Prospective Molecular Epidemiological Study on Transmission of Pulmonary Tuberculosis and Migration (MuT Study)

Introduction: In Western Europe prevalence and incidence of tuberculosis in the indigenous population is declining and TB in migrants from high prevalence countries is becoming a major issue of TB control. Resulting changes in transmission patterns need to be investigated to adapt control strategies. The MuT (Migration and Tuberculosis) study a co-operation among federal and local public health services (ÖDG), the National Surveillance Center (RKI) and the University has been established in Baden-Wuerttemberg to address these issues.

Objectives: The goal of this ongoing study is to determine the transmission dynamics of TB in Baden-Wuerttemberg. Here, we present the first set of data on TB cases and their contacts and discuss strategies to overcome arising difficulties.

Methods: Prospective data collection of culture positive pulmonary tuberculosis cases and their contacts. Analysis of (1) routine data, (2) spatial data, (3) social interaction data, (4) molecular typing data, and (5) observational data of the implementation phase.

Results: The study demonstrates the capability of the study consortium to identify clusters. It provides valuable insights into current case detection and case management procedures and shows ways to improve. A set of factors has been identified that (a) facilitate and (b) discourage study participation.

Conclusion: Collaboration among federal and local public health services (ÖGD), National Surveillance Center (RKI) and the University is a promising approach to investigate and improve TB control. This model has potentials for other infectious disease control.

Outcome of tuberculosis treatment in Hamburg: a survey, 1997-2001

SETTING

Federal State of Hamburg, Germany, 1997-2001.

OBJECTIVE

To determine risk factors affecting the treatment outcome for tuberculosis according to the WHO/IUATLD classification.

DESIGN

Prospective evaluation among patients with culture-confirmed pulmonary disease due to Mycobacterium tuberculosis during the period 1997-1999.

RESULTS

Five hundred and eighteen (467 new and 51 re-treatment) cases started a course of treatment (average duration 36.1 +/- 15.5 weeks), resulting in cure for 416 (80.3%) and treatment completed for three (0.6%) patients; 449 patients (86.7%) initially received a three-drug regimen. Treatment interruption occurred in 54 (10.4%), and failure in 12 (2.3%) cases; 32 (6.2%) patients died (irrespective of cause). Alcohol dependence appeared to be the strongest risk factor for persistence of disease, followed by homelessness and unemployment. The risk of treatment interruption was six times higher among alcoholics (OR = 6.0), five times higher among drug abusers (OR = 5.2) and three times higher among the homeless (OR = 3.0) than in other patients.

CONCLUSION

Although the current treatment management in Hamburg is considered to be effective, a further improvement in the proportion of patients who complete treatment can be achieved by increased public health surveillance of subpopulations with the above-mentioned risk factors.

Mycobacterium africanum subtype II is associated with two distinct genotypes and is a major cause of human tuberculosis in Kampala, Uganda

The population structure of 234 Mycobacterium tuberculosis complex strains obtained during 1995 and 1997 from tuberculosis patients living in Kampala, Uganda (East Africa), was analyzed by routine laboratory procedures, spoligotyping, and IS6110 restriction fragment length polymorphism (RFLP) typing. According to biochemical test results, 157 isolates (67%) were classified as M. africanum subtype II (resistant to thiophen-2-carboxylic acid hydrazide), 76 isolates (32%) were classified as M. tuberculosis, and 1 isolate was classified as classical M. bovis. Spoligotyping did not lead to clear differentiation of M. tuberculosis and M. africanum, but all M. africanum subtype II isolates lacked spacers 33 to 36, differentiating them from M. africanum subtype I. Moreover, spoligotyping was not sufficient for differentiation of isolates on the strain level, since 193 (82%) were grouped into clusters. In contrast, in the IS6110-based dendrogram, M. africanum strains were clustered into two closely related strain families (Uganda I and II) and clearly separated from the M. tuberculosis isolates. A further characteristic of both M. africanum subtype II families was the absence of spoligotype spacer 40. All strains of family I also lacked spacer 43. The clustering rate obtained by the combination of spoligotyping and RFLP IS6110 analysis was similar for M. africanum and M. tuberculosis, as 46% and 49% of the respective isolates were grouped into clusters. The results presented demonstrate that M. africanum subtype II isolates from Kampala, Uganda, belong to two closely related genotypes, which may represent unique phylogenetic branches within the M. tuberculosis complex. We conclude that M. africanum subtype II is the main cause of human tuberculosis in Kampala, Uganda.

Gender bias in the assessment of physical activity in population studies

OBJECTIVES

Despite their generally more health promoting behaviours, women are found to participate less in physical activity than men. This study explores possible gender bias in measurement of physical activity in population studies.

METHODS

Data collected by telephone (CATI) from the Berne Lifestyle Panel in 1996 is utilised. A representative samples of the population of the city of Berne comprised N = 1119 cases. Gender differences are assessed for the weekly frequency of three measurements of physical activities.

RESULTS

An indicator of sport and exercise showed higher physical activity among men, while the indicator of habitual physical activity showed higher rates of daily walking and biking among women. A combined indicator of general physical activity showed no significant gender differences.

CONCLUSIONS

The results provide empirical evidence on potential risk of underestimation of physical activity among women and of misclassification with respect to high or low risk behaviour patterns.

ACRC codes for a novel nuclear protein with unusual acidic repeat tract and maps to DYT3 (dystonia parkinsonism) critical interval in xq13.1

We searched for novel genes as candidates of X-linked dystonia parkinsonism (XDP) in the critical interval of Xq13.1 that harbors the disease locus (DYT3). A gene, ACRC (acidic repeat containing), was discovered by a combination of in silico and "wet" experiments. ACRC is composed of at least 12 exons and 11 introns. It is expressed in all tissues tested, including skeletal muscle, liver, kidney, pancreas, heart, lung, and brain. Highest levels of expression are found in skeletal muscle. The ACRC protein is characterized by a previously undescribed acidic repeat tract of 21 units of 8-10 amino acids. The N-terminal portion of the protein is highly acidic (pI=3.2), and the C-terminal region is basic (pI=10.2). There are nuclear localization signals in its C-terminal portion. Extensive mutation analysis of the transcribed region of the gene, including intron-exon boundaries and the 5' and 3' untranslated intervals, did not reveal a mutation in XDP patients. Exclusion of a mutation in the transcribed portion of this and all other known genes within the DYT3 critical interval suggests that XDP is most likely caused by a mutation in a regulatory region of a gene within the critical interval, or by a structural rearrangement.

Assignment of PGL3 to chromosome 1 (q21-q23) in a family with autosomal dominant non-chromaffin paraganglioma

We performed a whole genome scan in a family with maternally transmitted paraganglioma (PGL3). The family included five patients with histologically proven paraganglioma and one patient with imaging findings consistent with a paraganglioma. In addition, there were 33 clinically unaffected family members. Of these eight could be examined by magnetic resonance imaging. Our investigations indicate that PGL3 is located in 1q21-q23 for several reasons: 1) two-point linkage analysis yielded the highest LOD score of 2.25 at 1q21-q23 (marker D1S2675); 2) haplotype analysis was most consistent for 1q21-q23 markers; and 3) the locus was excluded from more than 97% of the genome using a total of 381 highly polymorphic markers.

Mycobacterium microti llama-type infection presenting as pulmonary tuberculosis in a human immunodeficiency virus-positive patient

A rare case of Mycobacterium microti infection in a human immunodeficiency virus-positive patient is described. Because of unusual morphological and cultural features, the pathogen was analyzed by spoligotyping and identified as the Mycobacterium microti llama type. Although culture of M. microti is difficult, drug susceptibility testing could be performed, which correlated with the clinical outcome.

Frequency of rpoB mutations inside and outside the cluster I region in rifampin-resistant clinical Mycobacterium tuberculosis isolates

The prevalence of recently described mutation V176F, located in the beginning of the rpoB gene and associated with rifampin resistance and the wild-type cluster I sequence, was determined by analyzing the distribution of rpoB mutations among 80 rifampin (RIF)-resistant Mycobacterium tuberculosis strains isolated in Germany during 1997. The most frequent rpoB mutations were changes in codon 456 (52 isolates, 65%), followed by changes in codon 441 (13 isolates, 16%) and codon 451 (11 isolates, 14%). The V176F mutation was detected in one isolate of the study population and in 5 of 18 RIF-resistant strains with no cluster I mutation from six previously published studies. In three isolates, a mixture of resistant and susceptible subpopulations (heteroresistance) prohibited the detection of rpoB mutations in the initial analysis; however, in these isolates, cluster I mutations could be verified after a passage on RIF-containing medium. IS6110 DNA fingerprinting of 76 strains revealed eight clusters comprising 27 strains with identical restriction fragment length polymorphism patterns that mainly also show identical rpoB mutations and identical or similar drug resistance patterns. In conclusion, our results indicate that the V176F mutation should be included in molecular tests for prediction of RIF resistance in M. tuberculosis. We further demonstrated that heteroresistance caused by a mixture of mycobacterial subpopulations with different susceptibilities to RIF may influence the sensitivity of molecular tests for detection of resistance.

Mutations in SDHC cause autosomal dominant paraganglioma, type 3

Nonchromaffin paragangliomas (PGLs) are usually benign, neural-crest-derived, slow-growing tumours of parasympathetic ganglia. Between 10% and 50% of cases are familial and are transmitted as autosomal dominant traits with incomplete and age-dependent penetrance.

Differentiation of clinical Mycobacterium tuberculosis complex isolates by gyrB DNA sequence polymorphism analysis

The discriminatory power of gyrB DNA sequence polymorphisms for differentiation of the species of the Mycobacterium tuberculosis complex (MTBC) was evaluated by sequencing and restriction fragment length polymorphism (RFLP) analysis of a 1,020-bp fragment amplified from clinical isolates of M. tuberculosis, Mycobacterium bovis (pyrazinamide [PZA] resistant as well as PZA susceptible), Mycobacterium africanum subtypes I and II, and Mycobacterium microti types vole and llama. We found sequence polymorphisms in four regions described previously and at one additional position. These differences in the gyrB sequences allow an accurate discrimination of M. bovis, M. microti, and M. africanum subtype I. The PZA-susceptible subtypes of M. bovis shared the M. bovis-specific substitution at position 756 with the PZA-resistant strains, but can be unambiguously differentiated by a characteristic substitution at position 1311. As a drawback, M. tuberculosis and M. africanum subtype II showed an identical gyrB sequence that facilitates discrimination from the other species, but not from each other. A PCR-RFLP technique applying three restriction enzymes could be shown to be a rapid and easy-to-perform tool for the differentiation of the members of the MTBC. Based on these results, we present a clear diagnostic algorithm for the differentiation of species of the MTBC.

Stability of IS6110 restriction fragment length polymorphism patterns of Mycobacterium tuberculosis strains in actual chains of transmission

The stability of IS6110 restriction fragment length polymorphism (RFLP) patterns of Mycobacterium tuberculosis strains in actual transmission chains has been assessed by analyzing the variability of IS6110 RFLP patterns of strains in fingerprint clusters that have been confirmed by classical epidemiological data. Forty susceptible and 35 drug-resistant (including 17 multidrug-resistant) M. tuberculosis strains obtained from 75 patients living in Germany have been analyzed. The epidemiological relationship among strains within the fingerprint clusters has been verified by family contacts (14 clusters) or by contact tracing of the public health offices (7 clusters). The time spans between the first and the last isolate of one cluster ranged from less than 1 to 29 months. Of the 75 strains only 1 showed a one-band variation when compared to the other nine isolates grouped in the same cluster, corresponding with a rate of change of approximately 1.9% per possible transmission (one index patient per cluster was subtracted from the total number of isolates). These results confirm a high degree of stability of IS6110 RFLP patterns of transmitted M. tuberculosis strains. Furthermore, the data presented indicate that isolates with identical IS6110 DNA fingerprint patterns are a good indicator for the rate of recent transmission in a study population.

Uncoupling of myelin assembly and schwann cell differentiation by transgenic overexpression of peripheral myelin protein 22

We have generated previously transgenic rats that overexpress peripheral myelin protein 22 (PMP22) in Schwann cells. In the nerves of these animals, Schwann cells have segregated with axons to the normal 1:1 ratio but remain arrested at the promyelinating stage, apparently unable to elaborate myelin sheaths. We have examined gene expression of these dysmyelinating Schwann cells using semiquantitative reverse transcription-PCR and immunofluorescence analysis. Unexpectedly, Schwann cell differentiation appears to proceed normally at the molecular level when monitored by the expression of mRNAs encoding major structural proteins of myelin. Furthermore, an aberrant coexpression of early and late Schwann cell markers was observed. PMP22 itself acquires complex glycosylation, suggesting that trafficking of the myelin protein through the endoplasmic reticulum is not significantly impaired. We suggest that PMP22, when overexpressed, accumulates in a late Golgi-cell membrane compartment and uncouples myelin assembly from the underlying program of Schwann cell differentiation.

Self-rated health, life satisfaction and personal characteristics of post-menopausal women under estrogen replacement therapy

OBJECTIVES

To describe the prevalence of oestrogen replacement therapy (ERT)-use among post-menopausal women in relation with personal and socio-economic characteristics and to examine the association of ERT-use with self-rated health and selected aspects of life satisfaction.

METHODS

Population survey data were derived from a cohort study of 511 Bernese women, aged 55-65 years. Data were collected by means of telephone interviews. Overall prevalence of ERT-use, and selected associations with personal and socio-economic characteristics were investigated using descriptive statistical methods and logistic regression. The relations of ERT-use with five self-reported health measures were explored using Spearman's correlation coefficients. The associations of ERT-use with six dichotomous variables on satisfaction with various aspects of life were tested with chi-square tests in cross tabulations.

RESULTS

The overall prevalence of self reported ERT-use was 17.6%. ERT was more prevalent women younger than 61 years than in women in the older age group. Women with a body mass index (BMI) under 25 reported ERT-use significantly more frequently than women with higher BMI (OR=3.16, CI 1.87-5.34). ERT-use was more prevalent in women with relatively high education: OR=2.01, CI 1.18-4.00. The self-reported health measures and the satisfaction items were not significantly associated with ERT-use.

CONCLUSIONS

ERT-use among post-menopausal women was found to be associated with higher educational level and lower BMI. ERT-users did not report better health or life-satisfaction.

Differentiation among members of the Mycobacterium tuberculosis complex by molecular and biochemical features: evidence for two pyrazinamide-susceptible subtypes of M. bovis

The variations in biochemical as well as molecular characteristics among several members of the Mycobacterium tuberculosis complex that are not M. tuberculosis have been assessed to facilitate an unambiguous species identification. Altogether, 96 M. tuberculosis complex strains including 52 M. bovis isolates and 44 M. africanum isolates were analyzed by spoligotyping. The strains could be clustered into five spoligotype groups. All M. bovis isolates showed the typical absence of the spacers 39 to 43 and typical biochemical properties. However, within these strains we found a group of strains that had a spoligotype pattern which is clearly defined by the additional absence of spacers 3 to 16 and that were uncommonly susceptible to pyrazinamide (PZA). This spoligotype pattern has previously been described as being typical for a caprine genotype because of its predominant isolation from sheep and goats. Due to the clinical importance of PZA resistance, we propose two M. bovis subtypes: M. bovis subtype bovis, which is resistant to PZA, and M. bovis subtype caprae, which is susceptible to PZA. Two additional strains that clustered in group 3 showed biochemical and genetic properties typical for M. bovis and were also sensitive to PZA; thus, they may represent a third PZA-susceptible M. bovis subtype. The M. africanum isolates could be clustered into two spoligotype groups which can be differentiated from M. bovis by hybridization to spacers 39 to 43. These groups correspond to the previously described M. africanum subtypes I and II and can be clearly distinguished from each other by spoligotyping and resistance to thiophen-2-carboxylic acid hydrazide. Our results demonstrate that spoligotyping is a useful tool for differentiation of M. bovis and M. africanum. Moreover, we describe two PZA-susceptible M. bovis subtypes and describe a method that facilitates an unambiguous differentiation of the two M. africanum subtypes.

Double infection with a resistant and a multidrug-resistant strain of Mycobacterium tuberculosis

An immunocompetent patient was dually infected with a resistant and a multidrug-resistant strain of Mycobacterium tuberculosis (TB). The multidrug-resistant strain, which belongs to the W- strain/Beijing family, was first isolated after 3 months of therapy. Inappropriate treatment led to further drug resistance and unsuccessful therapy. Thus, additional infections with resistant M. tuberculosis strains should be considered when tuberculosis therapy fails.

Two cases of Mycobacterium microti derived tuberculosis in HIV-negative immunocompetent patients

We describe two cases of Mycobacterium microti infection causing pulmonary tuberculosis (TB) in HIV-seronegative immunocompetent patients in Germany. The isolates were identified as M. microti of the llama and vole types, according to spoligotype patterns. Our data demonstrate that M. microti can cause severe pulmonary TB in immunocompetent patients.

Refined linkage disequilibrium and physical mapping of the gene locus for X-linked dystonia-parkinsonism (DYT3)

X-linked dystonia-parkinsonism (XDP) is a recessive disorder characterized by generalized dystonia with some patients exhibiting parkinsonism. The disease gene, DYT3, is located between DXS453 (DXS993) and DXS559, and strongest linkage disequilibrium is found distal to DXS7117 and proximal to DXS559. We have isolated and analyzed four novel polymorphic markers between DXS7117 and DXS559 and, by haplotype analysis, have narrowed the candidate interval to <350 kb. A sequence-ready contig of 700 kb has been constructed spanning DXS7117 to DXS559 and is composed of 35 PACs, BACs, and cosmids. Nine genes and novel ESTs have been mapped into this contig, and mutations in the coding regions and intron-exon borders of two genes have been excluded as the cause of XDP. Several of the other genes and ESTs located within the contig code for proteins implicated in normal brain development and function and are candidates for DYT3.

The "CMT rat": peripheral neuropathy and dysmyelination caused by transgenic overexpression of PMP22

We have generated a transgenic rat model of Charcot-Marie-Tooth disease type 1A (CMT1A) providing formal proof that this neuropathy can be caused by increased expression of peripheral myelin protein-22 (PMP22). Heterozygous PMP22-transgenic rats develop muscle weakness and gait abnormalities as well as reduced nerve conduction velocities and EMG abnormalities, which closely resemble recordings in patients with CMT1A. Dys- and demyelination, Schwann cell hypertrophy, and "onion bulb" formation are also similar to findings in humans. When bred to homozygosity, transgenic rats completely fail to elaborate myelin, but all myelin-forming Schwann cells segregate with axons in the normal one-to-one ratio. Although arrested at this "promyelin" stage, differentiation proceeds in homozygous rats at the molecular level, as demonstrated by high-level expression of myelin structural genes. Intracellular trafficking of the wild-type protein is not visibly impaired, even when strongly overexpressed, suggesting that PMP22 blocks myelin assembly in a late Golgi/cell membrane compartment of the affected Schwann cell.

PGL3, a third, not maternally imprinted locus in autosomal dominant paraganglioma

Paragangliomas (glomus tumors) are slowly growing, mostly benign tumors of the parasympathetic ganglia which most frequently occur in the head and neck region. Between 10% and 50% of cases are familial and follow an autosomal dominant mode of inheritance. The trait is maternally imprinted and exclusively transmitted through the paternal line. To date, two loci have been implicated in this disorder: one at 11q23 (PGL1), the other one at 11q13 (PGL2). We have analyzed a large German family with hereditary paraganglioma, but no evidence of maternal imprinting. By linkage analysis with markers flanking both PGL1 and PGL2, we demonstrate that the trait does not segregate with either of the loci at 11q. Our findings show that a third locus, PGL3, can be involved in hereditary paraganglioma.

The Berne-Munich Lifestyle Panel. Background and baseline results from a longitudinal health lifestyle survey

The Berne-Munich Lifestyle Panel (BMLP) studies health relevant lifestyles among some 2000 adults in Switzerland and Germany. This paper introduces the theoretical background and empirical concept of the BMLP. Sociological theory provided the guidelines for the development of an empirical model that measures structures and dynamics of health lifestyles. Health lifestyles are explained as the product of the complex interplay between health related behaviours, orientations and social resources. Residents of Berne (Switzerland) and Munich (Germany) in the age between 55 and 65 years were contacted in 12 months periods and interviewed by telephone (CATI). The questionnaire comprised some 200 questions on selected aspects of health lifestyles and health status. Interviews were conducted in two waves in Munich (1996 and 1997) and three waves in Berne (1996/97/98). The paper reports findings from baseline data analysis and explores cultural differentiations with respect to the distribution of 1. health relevant behaviours, orientations and social resources, 2. triggers of lifestyle change (life events), 3. mediating factors (Health Locus of Control, Sense of Coherence). Initial results from the search for patterns of health behaviours are also reported. The findings show considerable differences but also impressive similarities in health lifestyle elements across the two samples. There is also preliminary evidence for meaningful patterns of health behaviours in the cohort under investigation. Moreover, the findings clearly demonstrate the need for a gender specific approach in the analysis of cultural differences in health behaviours and lifestyles.

Genetic basis of enterobacterial repetitive intergenic consensus (ERIC)-PCR fingerprint pattern in Sinorhizobium meliloti and identification of S. meliloti employing PCR primers derived from an ERIC-PCR fragment

The enterobacterial repetitive intergenic consensus (ERIC)-PCR method was employed to generate genomic amplification products of Sinorhizobium meliloti strain 2011. Eleven distinctive PCR fragments obtained in PCR reactions by using the ERIC2 primer were cloned and their partial or complete nucleotide sequences established. DNA sequences that extended past the ERIC2 primer region were not conserved among the 11 PCR fragments and showed no sequence similarity to the enterobacterial ERIC consensus sequence. Thus, repetitive ERIC or ERIC-like sequences seem not to be an integral part of the S. meliloti genome. An amplification product of S. meliloti 2011 was identified which was present in S. meliloti strains but absent in other rhizobial species. Based on the nucleotide sequence information, a pair of PCR primers was designed and used for PCR amplification of sequences of S. meliloti laboratory strains 2011, L5-30, AK631 and 102F34. Nucleotide sequence analysis of the amplification products revealed a 100% DNA sequence conservation. Database searches showed that the DNA fragment putatively encodes the C-terminal part of a protein displaying similarity to 2-hydroxyacid dehydrogenases of various organisms. The newly designed PCR primers should be useful for the rapid identification of S. meliloti isolates.

Identification of Mycobacterium kansasii by using a DNA probe (AccuProbe) and molecular techniques

The newly formulated Mycobacterium kansasii AccuProbe was evaluated, and the results obtained with the new version were compared to the results obtained with the old version of this test by using 116 M. kansasii strains, 1 Mycobacterium gastri strain, and 19 strains of several mycobacterial species. The sensitivity of this new formulation was 97.4% and the specificity was 100%. Still, three M. kansasii strains were missed by this probe. To evaluate the variability within the species, genetic analyses of the hsp65 gene, the spacer sequence between the 16S and 23S rRNA genes, and the 16S rRNA gene of several M. kansasii AccuProbe-positive strains as well as all AccuProbe-negative strains were performed. Genetic analyses of the one M. gastri strain from the comparative assay and of two further M. gastri strains were included because of the identity of the 16S rRNA gene in M. gastri to that in M. kansasii. The data confirmed the genetic heterogeneity of M. kansasii. Furthermore, a subspecies with an unpublished hsp65 restriction pattern and spacer sequence was described. The genetic data indicate that all M. kansasii strains missed by the AccuProbe test belong to one subspecies, the newly described subspecies VI, as determined by the hsp65 restriction pattern and the spacer sequence. Since the M. kansasii strains that are missed are rare and all M. gastri strains are correctly negative, the new formulated AccuProbe provides a useful tool for the identification of M. kansasii.

Stability of Mycobacterium tuberculosis IS6110 restriction fragment length polymorphism patterns and spoligotypes determined by analyzing serial isolates from patients with drug-resistant tuberculosis

The stability of Mycobacterium tuberculosis IS6110 fingerprint patterns and spoligotypes has been assessed by analyzing serial isolates from patients with drug-resistant tuberculosis. Altogether, 165 M. tuberculosis isolates obtained from 56 patients have been analyzed. The time spans between the first and the last or a changed isolate from one patient ranged from 1 to 772 days. Among the 56 patients, 5 (9%) were infected with isolates with changes in their IS6110 fingerprint patterns. According to the total number of strains analyzed, 5% of the subsequent isolates showed variations in their IS6110 restriction fragment length polymorphism patterns compared to the pattern of the first isolates. Up to 10 isolates from one patient sampled at time intervals of up to 772 days with no changes in their IS6110 patterns have been analyzed. A statistically significant correlation could be found between changes in insertion sequence (IS) patterns and the increased time intervals over which the isolates were obtained, whereas changes in IS patterns are not correlated to changes in the drug resistance of the isolates. In contrast to the observed variations in IS6110 fingerprint patterns, no changes in the spoligotypes of the isolates analyzed could be found. In conclusion, our results confirm that the IS6110 fingerprint patterns of M. tuberculosis isolates have high degrees of stability. Compared to IS6110, the direct repeat (DR) region, which is the basis for spoligotyping, has a lower rate of change. Partial deletions, e.g., deletions induced by homologous recombination between the repetitive DR elements, could not be detected in this study.

Identification of shyc, a novel gene expressed in the murine developing and adult nervous system

The embryonal carcinoma cell line P19 responds to treatment with retinoid acid by differentiation into neuronal cell types [2]. Using radioactively labeled cDNA derived from differentiating P19 cells we screened an adult mouse brain cDNA library and isolated a gene named shyc for selective hybridizing clone. The encoded protein did not reveal homology to any known protein. We used in situ hybridization on mouse embryonic and adult brain sections to study shyc expression. The developing and embryonic nervous system showed the most prominent hybridization signals. In the adult brain the olfactory pathway was marked by shyc expression.

IS6110 fingerprinting of drug-resistant Mycobacterium tuberculosis strains isolated in Germany during 1995

The epidemiological relatedness of drug-resistant Mycobacterium tuberculosis strains isolated in Germany in 1995 was evaluated by the standardized IS6110 fingerprinting method. Altogether, 196 M. tuberculosis isolates from 167 patients were analyzed. A large degree of IS6110 polymorphism was found, ranging from 1 to 20 copies. Multiple isolates from one patient generally remained stable over a period of up to 1 year. However, one strain showed an additional fragment 7 months after the first isolate was obtained. Isolates from 55 patients (33%) showed identical fingerprint patterns or fingerprint patterns that differed only in one band, and thus they were clustered in 22 fingerprint groups. Specific transmission links could be established between members of four groups, e.g., transmission by family contacts. In one case, transmission of a multidrug-resistant strain to a patient initially infected with a drug-susceptible strain could be shown. Besides these fingerprint groups, 30 of the 167 isolates (approximately 18%) could be grouped in two fingerprint clusters with a similarity of at least 78%. Approximately 60% of the patients of these two clusters were known to be immigrants from the former Soviet Union, and one patient is still living in Belarus. In conclusion, our results indicate that (i) transmission of drug-resistant strains contributes substantially to the emergence of drug-resistant tuberculosis in Germany and (ii) drug-resistant M. tuberculosis strains were presumably carried over from the former Soviet Union to Germany by immigrants.

Evaluation of the resolving power of three different DNA fingerprinting methods to discriminate among isolates of a natural Rhizobium meliloti population

In a comparative study, the PCR-based RAPD and ERIC fingerprint methods were evaluated for their resolving power to discriminate among 21 isolates of a natural Rhizobium meliloti population. PCR fingerprint patterns were analysed by using an automated laser fluorescent (ALF) DNA sequencer, thus allowing the automated on-line storage of data. Results obtained were compared to a classification system using insertion sequence (IS) fingerprinting. Both PCR fingerprint methods were comparable in their ability to resolve differences amongst Rh. meliloti isolates. Grouping of strains on the basis of their RAPD as well as their ERIC fingerprints correlated with grouping of strains according to their IS fingerprints. Moreover, strains displaying identical PCR patterns could be further differentiated according to their IS fingerprints, thus allowing a detailed insight into phylogenetic relationship among strains. The automated evaluation of strain-specific fingerprint patterns has the potential to become a valuable tool for studies of bacterial population genetics. Moreover, the rapid identification of single strains, e.g. pathogens in epidemiological studies seems feasible.

The integration of two health systems: social stratification, work and health in East and West Germany

This is an analysis of system integration, social stratification and work for health status and health care in East and West Germany. It is based on aggregate data and representative survey data of random samples of 2554 adults in both subsystems. Findings show that there were marked differences in life-expectancy prior to unification. The integration of the two systems, which occurred almost totally with regard to terms of West German health care organization, shows adjustment problems in the East for the public Health-Care-Funds and few if any for ambulatory care. The work situation has an impact on health, but there are no significant differences for East versus West. Social stratification variables show an influence on subjective health status for education (East) and for income, social status (West), while physician utilization (despite a preference of specialists by those with higher status) is not significantly determined by stratification variables in either East or West Germany. Beyond the central focus on work and stratification determinants a major finding pertains to a comparatively worse health situation for the aged and for women in what was the former East Germany. System models of Capitalism versus Socialism fit the results and recent history of the two systems to only a limited degree, as the West German corporate health system shows clear limits in following free market principles. The East German system, regardless of its centralized organization and move towards a socialist system, never fully abandoned the traditional model of German health care. Unlike the East German health system, that of West Germany, with its general expansion to 92% of the population, shows an increasing effect for social redistribution. The latter may be a reason why standard indicators of social stratification show less of an impact on health and health care than expected, while conditions at work clearly determine the health of people-the latter being the case in both the former East and West Germany.

Neurology of adult alpha-mannosidosis

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Characterization of two bioluminescent Rhizobium meliloti strains constructed for field releases

The deliberate release of genetically engineered microorganisms requires a thorough characterization of the microbes in question. For the two bioluminescent Rhizobium meliloti strains, L1 and L33 [Selbitschka et al. (1992) Mol Ecol 1:9-19; Selbitschka et al. (1995) FEMS Microbiol Ecol 16:223-232], designated for field release, the sites of genetic modifications in the chromosomes were sequenced from amplified genomic DNA. This indicated no unexpected alterations in the nucleotide sequence. The bioluminescent phenotype was stably inherited over more than 100 generations in liquid cultures. The presence of the luciferase gene in both strains did not have secondary effects on a variety of metabolic pathways as assessed by the Biolog GN system. A specific polymerase chain reaction amplification, based on the chromosomal insertion site of the luc cassette, allowed the discrimination between the two strains and thus simplifies monitoring. The RecA-deficient strain L1 showed a strongly (more than 90%) reduced ability to nodulate alfalfa in competition with its parent strain R. meliloti 2011 and its RecA+ counterpart L33.

Head-activator and the neuroectodermal differentiation of P19 mouse embryonal carcinoma cells

P19 embryonal carcinoma cells differentiate into neuroectodermal derivates upon aggregation and treatment with retinoic acid (RA). Such RA-induced P19 cells, concomitant with neuronal differentiation, produce the neuropeptide head activator (HA) and release HA into the culture medium. The amount of HA produced by such differentiating P19 cells is more than 100-fold higher than that of uninduced P19 cells. RA-induced P19 cells respond to HA treatment with a two-fold increase in total number of neuronally differentiating P19 progeny. As early response to HA, an increase in intracellular calcium concentration is observed.