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PubMed1999

[The prevalence of pain in the German population: results of population-based studies with the Giessen Subjective Complaints List (Giessener Beschwerdebogen GBB)].

OBJECTIVE: Pain is one of the most frequent physical complaints worldwide. Empirical data on the prevalence of chronic pain is considerable. However, compared with the large number of epidemiological studies published in North America, Great Britain and particularly in Scandinavia, there has been relatively little equivalent research in Germany to date. METHODS: In two separate population-based cross-sectional studies conducted in 1975 (n=1.597, 18-60 years) and 1994 (n=2.148, 18-60 years) using the Giessen Subjective Complaints List (Giessener Beschwerdebogen GBB), data was collected on current pain in various parts of the body (limbs, back, neck, head, stomach). RESULTS: The frequency scores for pain varied according to localization between 32.4% (stomach pains 1975) and 67.3% (headaches 1994). Between the two measurement dates there was an increase in overall prevalence particularly for pains in the neck, head and limbs. At the same time we found a decrease in the proportion of severe pain symptoms. There were also considerable variations in pain experience according to age and gender: the frequency of pain increases with age (especially in limbs, back and neck). Women register more pain than men (particularly in head and neck), although the influence of gender decreases from 1975 to 1994. There are other sociodemographic variables like marital status, educational level, occupation or living in East/West Germany which influence the pain prevalence. CONCLUSIONS: Pain in differing parts of the body is a serious problem in the German population. However, the prevalence of pain is strongly dependent on sociodemographic factors (especially age, gender and living in East/West Germany), the localization of pain in the body and the grading of pain. Future epidemiological research should take these differential aspects into account.

English Abstract↗
PubMed1981

Investigations on radiosensitive and radioresistant populations of Drosophila melanogaster. VIII. The system of relative radioresistance in immature oocytes of the irradiated population ROI4.

Prophase I oocytes of the irradiated population ROI4 of Drosophila melanogaster are radioresistant relative to those of a control population (+K). The system of relative radioresistance is apparently dose-modifying and can be described by Dose-Reduction Factors (DRFs). At least 3 constituent components of the system can be distinguished, as follows. The genetic factor rar-1 contributes to the system with respect to the induction of dominant (DRF = 1.31) and sex-linked recessive lethals (DRF = 1.31) in a way that is inhibited by caffeine. The factor rar-2, independently reduces both types of lethal to the same amount as does rar-1, but also affects the production of X-chromosome loss (DFR = 1.72). The results of several different approaches allow, as a working hypothesis, the interpretation that rar-2 reduces the association of heterologous, chiasmatic chromosomes in the chromocentre in time and/or space and thus minimizes the preconditions for the production of certain types of interchange and of non-disjunction. A third factor, rar-3, is postulated to contribute, independently from the others, to the system of relative radioresistance with respect to dominant lethals (DRF = 1.58), interchanges and non-disjunction (DRFs = 1.58), and sex-linked recessive lethals (DRF = 1.87).

Animals↗
PubMed1991

A comparison of selected health-related data from surveys of a general population and a sporting population.

This paper presents a comparison of health-related data from two surveys of British adults. Respondents from one survey formed a representative sample of the British population, whilst respondents from the other were characterised by their participation in sport. Statistical analysis revealed that sports participants had significantly lower body mass index values, lower blood pressures and lower resting pulse rates (P less than 0.05). In addition, sports participants possessed better self-perceived health and perceived themselves overall to be more active than members of the general population. When controls were introduced for gender and age, many of these differences remained, particularly among females. It is concluded that despite the cross-sectional nature of these data, evidence is provided that supports the health-promoting case for sport.

Adolescent↗
PubMed2005

Association between serum C-reactive protein levels and pulse wave velocity: a population-based cross-sectional study in a general population.

Arterial stiffness as determined by aortic pulse wave velocity (PWV) has been shown to predict cardiovascular events in high-risk subjects such as those with hypertension or end-stage renal disease. Although it is suspected that low-grade inflammation as represented by increased C-reactive protein (CRP) plays an important role in the progression of atherosclerosis, it is not yet known whether serum CRP levels are associated with PWV. To examine the relationship between brachial-ankle PWV (baPWV) and serum CRP levels, several cardiovascular risk factors including these two markers (baPWV and CRP) were measured in 870 participants (mean age 59 years) randomly selected from a general population. Age, male gender, systolic blood pressure, heart rate, diabetes, and serum CRP levels increased with the quartiles divided by baPWV (all, p<0.01). By multiple regression analysis, age (p<0.001), systolic blood pressure (p<0.001), heart rate (p<0.001), body mass index (p<0.001), and CRP (p<0.01) were significant and independent predictors for baPWV. In conclusion, this cross sectional study has demonstrated in the general population that the arterial stiffness marker baPWV was independently correlated with serum CRP levels after adjustment for other established cardiovascular risks factors. This result suggests that baPWV may be a surrogate marker for atherosclerotic vascular damages including an inflammatory component.

Adult↗
PubMed2004

The annual incidence and course of neck pain in the general population: a population-based cohort study.

Although neck pain is a common source of disability, little is known about its incidence and course. We conducted a population-based cohort study of 1100 randomly selected Saskatchewan adults to determine the annual incidence of neck pain and describe its course. Subjects were initially surveyed by mail in September 1995 and followed-up 6 and 12 months later. The age and gender standardized annual incidence of neck pain is 14.6% (95% confidence interval: 11.3, 17.9). Each year, 0.6% (95% confidence interval: 0.0-1.1) of the population develops disabling neck pain. The annual rate of resolution of neck pain is 36.6% (95% confidence interval: 32.7, 40.5) and another 32.7% (95% confidence interval: 25.5, 39.9) report improvement. Among subjects with prevalent neck pain at baseline, 37.3% (95% confidence interval: 33.4, 41.2) report persistent problems and 9.9% (95% confidence interval: 7.4, 12.5) experience an aggravation during follow-up. Finally, 22.8% (95% confidence interval: 16.4, 29.3) of those with prevalent neck pain at baseline report a recurrent episode. Women are more likely than men to develop neck pain (incidence rate ratio=1.67, 95% confidence interval 1.08-2.60); more likely to suffer from persistent neck problems (incidence rate ratio=1.19, 95% confidence interval 1.03-1.38) and less likely to experience resolution (incidence rate ratio=0.75, 95% confidence interval 0.63-0.88). Neck pain is a disabling condition with a course marked by periods of remission and exacerbation. Contrary to prior belief, most individuals with neck pain do not experience complete resolution of their symptoms and disability.

Adult↗
PubMed1980

Study of kinetics of epithelial cell populations in normal tissues of the rat's intestines and in carcinogenesis. I. A comparison of enterocyte population kinetics in different segments of the small intestine and colon.

The peculiarities of enterocyte proliferation in the duodenum, jejunum, ileum, caecum, ascending, transverse and descending colon in the rat were studied by different methods of analysis of cell population kinetics (percentage-labelled mitosis curves, cumulative labelling curves, distribution of labelling index curves, etc.). The majority of proliferating cells in the small intestine are homogenous, as far as mitotic cycle mean duration (11-12 hrs) is concerned. All proliferating cells in all the zones of the colonic crypts and the bottom of the small intestine crypts are divided into subpopulations, having different mean durations of the mitotic cycle. It is suggested that, in the crypt bottom in all intestines as well as the crypt's maximum proliferation zones in most of the colonic segments, a considerable fraction of cells has a very long mitotic cycle or enters resting phase R1. The average value of the mean durations of the mitotic cycle of all colonic enterocyte subpopulations is 18-22 hours. On the basis of the authors' findings and literature data, a model for the enterocyte life cycle is proposed, according to which the cell flux is branched during the mitotic cycle and the crypt develops from a stem enterocyte population located at its bottom.

Animals↗
PubMed2002

Chronic angle-closure with glaucomatous damage: long-term clinical course in a North American population and comparison with an Asian population.

PURPOSE: To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients. DESIGN: A retrospective, interventional case-control study series. PARTICIPANTS: Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI). METHODS: The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period. MAIN OUTCOME MEASURES: The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. RESULTS: The mean presenting IOP was higher in the Singapore eyes (40 +/- 15 mmHg) compared with the New York eyes (31 +/- 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery. CONCLUSIONS: Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients.

Aged↗
PubMedDate not supplied

IgG subclasses serum concentrations in a population of children with Down syndrome: comparative study with siblings and general population.

Serum total IgG and subclasses were determined in three different groups of children: with Down syndrome, their siblings and general pediatric population. Several cases of IgG2 and IgG4 deficiency were identified, predominantly in children with Down syndrome. The differences, considering three age groups, were statistically significant for both groups in relation to the general population group, with an increase of IgG1 and IgG3 and a decrease in serum concentrations of IgG2 and IgG4. Down syndrome children and their siblings tend o have a similar variation of the IgG4 serum concentration levels (P < 0.05). The mechanisms of this concordance are not well understood. The results point out that an adequate strategy to improve the immune status of Down syndrome children could have a positive manifestation in the immune profile of their brothers.

Adolescent↗
PubMed2000

Haplotype frequencies and population data of nine Y-chromosomal STR polymorphisms in a German and a Chinese population.

Y-chromosomal STR loci are of increasing interest in paternity testing, forensic casework, anthropological and evolutionary studies. We participate in a cooperation to establish an international reference database of at least nine Y-chromosomal STR loci to be used for biostatistic calculations. We present frequency distributions of nine Y-chromosome specific STR polymorphisms and frequencies of compound haplotypes in two populations. We chose the loci DYS393, DYS19, DYS392, DYS385I, DYS385II, DYS390, DYS391 and DYS389I and II. Blood samples were taken from 136 unrelated male individuals from Cologne (Germany) and of 63 unrelated males from Chengdu (Sichuan Province, PR China). DNA was extracted by a salting out procedure or chelex extraction. PCR was carried out in two multiplex reactions. Fragment analysis was conducted on an ALF- or ALF-express sequencer. Frequency profiles of the German men showed no significant differences compared to most European populations. Mean exclusion chances were between 0.44 for DYS393 and 0.94 for DYS385. Haplotype diversity for the complete haplotype was 86.66% in Germans and 98% in Chinese. The Chinese men showed for all analysed loci except for DYS389I and DYS390 remarkably different allele distributions.

Asian People↗
PubMed1999

Compliance with fluvastatin treatment characterization of the noncompliant population within a population of 3845 patients with hyperlipidemia. CREOLE Study Team.

The objectives of the study were to analyze 1) compliance with an HMG-CoA reductase inhibitor, 2) the relationship between treatment compliance and sociodemographic, clinical, and psychological criteria, and 3) the effect of raising patients' awareness through distribution of an information notice. The results analyzed in this article compare the noncompliant and compliant population independently of awareness. This open-label study was conducted in two randomized parallel groups: a control group that received the information normally given by the practitioners, and an awareness group that received specific informational brochures on diet and cardiovascular risk factors and the reasons for the treatment. Male and female patients (n = 3845) aged 18 to 75 years with primary hypercholesterolemia (type IIa and IIb), not taking a cholesterol-lowering drug or for whom an ongoing treatment was poorly tolerated or ineffective, were to be included. Cholesterol levels had to be greater than 250 mg/dL (or 200 mg/dL if previous coronary history) and triglyceride levels less than 350 mg/dL. A total of 2888 subjects (75%) were defined as compliant (taking more than 90% of the prescription) and 957 (25%) noncompliant. Both populations are identical for age, sex ratio, and different risk factors, with the exception of diabetes. The adverse effects in noncompliant subjects were very clearly different, with an overrepresentation of gastrointestinal and neurologic effects and the noncompliant patients more frequently having more than one adverse effect. Noncompliant patients had an identical duration of follow-up, and the number of patients claiming to have a symptom related to hypercholesterolemia, self-evaluation of cardiovascular risk level, and source of knowledge about cholesterol and diet was similar in both groups. In contrast, in the noncompliant group, there were a larger number of symptomatic patients who thought the drug did not improve the symptoms. In practice, these results show that physicians should systematically evaluate compliance by looking for and analyzing adverse effects and by reassuring the patient when these effects are minor or probably unrelated to the treatment. Diabetics and polymedicated patients deserve special attention in this regard.

Adolescent↗
PubMed1996

The effect of nonresponse on prevalence estimates for a referent population: insights from a population-based cohort study. Atherosclerosis Risk in Communities (ARIC) Study Investigators.

Characterization of nonrespondents, with the aim of detecting nonresponse bias, is a crucial component of prospective studies. This study was undertaken to investigate the demographic and health characteristics of nonrespondents to a population-based cohort study of cardiovascular disease, to determine whether early-stage nonrespondents differ from late-stage nonrespondents, and to estimate the bias in prevalence estimates for the source population. Sixty-seven percent of eligible subjects completed all phases of the cohort recruitment. Compared to respondents, nonrespondents were less likely to be married, less likely to be employed, and less likely to be well educated. Nonrespondents tended to describe their general health in less favorable terms and were more likely to be smokers. Their reported disease profile, however, was not dissimilar to that of respondents. For several demographic and health characteristics, including marital status, education, and smoking, early-stage nonrespondents differed from respondents more than did late-stage nonrespondents. For example, 42% of early nonrespondents were smokers compared to 37% of late nonrespondents and 22% of respondents. Overall, the bias in prevalence estimates related to nonresponse was small (< 5%) for most of the measured characteristics. Although nonresponse to health surveys is associated with typical attributes, early nonrespondents differ from respondents more than do late-stage nonrespondents. With few exceptions, however, a 33% nonresponse rate did not appear to introduce substantial bias into prevalence estimates for the source community.

Age Distribution↗
PubMed1990

Frequency distribution of lymphatic filariasis microfilariae in human populations: population processes and statistical estimation.

This paper uses simple mathematical models and statistical estimation techniques to analyse the frequency distribution of microfilariae (mf) in blood samples from human populations which are endemic for lymphatic filariasis. The theoretical analysis examines the relationship between microfilarial burdens and the prevalence of adult (macrofilarial) worms in the human host population. The main finding is that a large proportion of observed mf-negatives may be 'true' zeros, arising from the absence of macrofilarial infections or unmated adult worms, rather than being attributable to the blood sampling process. The corresponding mf distribution should then follow a Poisson mixture, arising from the sampling of mf positives, with an additional proportion of 'true' mf-zeros. This hypothesis is supported by analysis of observed Wuchereria bancrofti mf distributions from Southern India, Japan and Fiji, in which zero-truncated Poisson mixtures fit mf-positive counts more effectively than distributions including the observed zeros. The fits of two Poisson mixtures, the negative binomial and the Sichel distribution, are compared. The Sichel provides a slightly better empirical description of the mf density distribution; reasons for this improvement, and a discussion of the relative merits of the two distributions, are presented. The impact on observed mf distributions of increasing blood sampling volume and extraction efficiency are illustrated via a simple model, and directions for future work are identified.

Animals↗
PubMed2004

North American populations of Entoleuca mammata are genetically more variable than populations in Europe.

Entoleuca mammata (syn. Hypoxylon mammatum) is a damaging pathogen of Populus tremuloides and P. grandidentata in North America and P. tremula in Europe, where the fungus occurs only sporadically in alpine regions and Scandinavia. It has been hypothesized that E. mammata was introduced to Europe from North America. In this study, E. mammata isolates collected from Europe and North America were compared by a sequence analysis of two DNA markers derived from DNA fingerprints. The objective of the study was to elucidate the relationship between North American and European E. mammata populations by testing two hypotheses: (1) North American and European isolates are conspecific; and (2) the fungus was introduced between continents causing both a founder effect and a genetic bottleneck. North American populations were found to be more polymorphic, but no major phylogenetic differences between fungal isolates collected from different continents were found. This result combined with the historical observations of the disease in Europe implies that E. mammata was introduced to Europe several centuries ago.

Alleles↗
PubMed2000

The population genetics of ecological specialization in evolving Escherichia coli populations.

When organisms adapt genetically to one environment, they may lose fitness in other environments. Two distinct population genetic processes can produce ecological specialization-mutation accumulation and antagonistic pleiotropy. In mutation accumulation, mutations become fixed by genetic drift in genes that are not maintained by selection; adaptation to one environment and loss of adaptation to another are caused by different mutations. Antagonistic pleiotropy arises from trade-offs, such that the same mutations that are beneficial in one environment are detrimental in another. In general, it is difficult to distinguish between these processes. We analysed the decay of unused catabolic functions in 12 lines of Escherichia coli propagated on glucose for 20,000 generations. During that time, several lines evolved high mutation rates. If mutation accumulation is important, their unused functions should decay more than the other lines, but no significant difference was observed. Moreover, most catabolic losses occurred early in the experiment when beneficial mutations were being rapidly fixed, a pattern predicted by antagonistic pleiotropy. Thus, antagonistic pleiotropy appears more important than mutation accumulation for the decay of unused catabolic functions in these populations.

Adaptation, Physiological↗
PubMed1989

Determination of serum nickel by graphite furnace atomic absorption spectrometry with Zeeman-effect background correction: values in a normal population and a population undergoing dialysis.

An atomic absorption spectrometric method with Zeeman-effect background correction for the determination of nickel, which requires only serum dilution with an aqueous surfactant, is described. The average nickel concentration in sera collected from 38 healthy adult volunteers was 0.14 +/- 0.09 micrograms l-1 of Ni, which is approximately four times lower than normals reported previously (0.65 +/- 0.35 or 0.46 +/- 0.26 microgram l-1 of Ni). The procedure yielded accurate results for the analysis of three different reference serum pools. A comparison of the average nickel concentrations from a patient population undergoing regular haemodialysis with our normal population showed that the average concentration of serum nickel in the dialysis patient group (n = 27 patients) was 46 times higher than normal (6.38 +/- 3.36 micrograms l-1 of Ni; n = 40 specimens).

Adult↗
PubMed1998

Studies of linkage in populations. XIII. A unique cause of linkage disequilibrium in natural populations of Drosophila robusta.

Natural populations of Drosophila robusta are polymorphic for chromosomal gene arrangements in most of its range, the deciduous forests of North America east of the Rocky Mountains. Many of the gene arrangements are the result of paracentric inversions on both arms of the metacentric second chromosome. They are frequently in linkage disequilibrium, determined in many areas largely, or entirely, by differing frequencies of cis and trans forms of the double heterokaryotypes and their component linkage combinations. Presence and degree of linkage disequilibrium in these populations varies with locality and gender, with males from southern localities exhibiting the largest deviation from equilibrium. Analysis of the extensive karyotype data encompassing the entire species range collected over the past 50 years shows that natural selection is primarily responsible for maintaining these complex polymorphisms.

Animals↗
PubMed1999

Population structure of North American beluga whales (Delphinapterus leucas) based on nuclear DNA microsatellite variation and contrasted with the population structure revealed by mitochondrial DNA variation

Beluga whales (Delphinapterus leucas) in North American waters migrate seasonally between wintering areas in broken pack ice and summering locations in estuaries and other open water areas in the Arctic and sub-Arctic. Results from our previous investigation of beluga whale mitochondrial DNA (mtDNA) revealed genetic heterogeneity among beluga from different summering locations that was interpreted as representing a high degree of summering site philopatry. However, mtDNA is maternally inherited and does not reflect mating that may occur among beluga from different summering locations in wintering areas or during annual migrations. To test the possibility that breeding occurs among beluga from different summering locations, genetic variability at five nuclear DNA (nDNA) microsatellite loci was examined in the same animals tested in the mtDNA study. Beluga samples (n = 640) were collected between 1984 and 1994 from 24 sites across North America, mostly during the summer. Whales from the various sites were categorized into eight summering locations as identified by mtDNA analysis, as well as four hypothesized wintering areas: Bering Sea, Hudson Strait (Hudson Strait, Labrador Sea, southwest Davis Strait), Baffin Bay (North Water, east Davis Strait), and St Lawrence River. Microsatellite allele frequencies indicated genetic homogeneity among animals from summering sites believed to winter together but differentiation among whales from some of the wintering areas. In particular, beluga from western North America (Bering Sea) were clearly distinguished from beluga from eastern North America (Hudson Strait, Baffin Bay, and St Lawrence River). Based upon the combined data set, the population of North American beluga whales was divided into two evolutionarily significant units. However, the population may be further subdivided into management units to reflect distinct groups of beluga at summering locations.

Journal Article↗
PubMed2001

Population parameters to compare dog breeds: differences between five Dutch purebred populations.

Differences in five purebred dog populations born in 1994 in the Netherlands were evaluated using different parameters. Numerically, the Golden Retriever was the largest breed (840 litters of 234 sires) and the Kooiker Dog (101 litters of 41 sires) the smallest. The litter per sire ratio was largest in the Bernese Mountain Dog (4.59) and lowest in the Kooiker Dog (2.46). The mean relatedness and the actual mean level of inbreeding in the studied generations were 0.102 and 0.056 respectively for the Bernese Mountain Dog, 0.041 and 0.046 for the Bouvier des Flandres, 0.087 and 0.061 for the Boxer, 0.020 and 0.018 for the Golden Retriever, and 0.146 and 0.070 for the Kooiker Dog. Quantification and visualization of population parameters for purebred dogs will facilitate the comparison of breeds and the comparison of breeds in different periods or countries. It appears unlikely that the increase in inbreeding is a major determinant of the possible increase in the frequency of genetic diseases.

Animals↗