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PubMed2001

Geographical distribution of elderly people in Croatia.

The authors outlined the geographical distribution of individuals displaying longevity in the Republic of Croatia. Elderly people, aged 80 years and older, have been the subject of this study and were viewed in several aspects including the number of elderly people and age-specific mortality rate by districts. Data for the years 1981 and 1991 were reviewed. In 1981 there were 73,052 (1.6%) persons aged 80 or older. Ten years later in 1991 their number had increased to 107,256, which was 2.2% of the whole population. Most of the elderly people live on the islands, in the district of Dubrovnik and in Lika, which is in the continental part of Croatia. There are more women than men among those aged 80 years and older Age-specific mortality rate in 1981 in Croatia was 170 and in 1991 151 per 1,000 elderly people. In women the rate was 162 in 1981 and 141 in 1991, per 1,000 elderly people. The death rate was higher in men; in 1981 it was 201 and in 1991, 172 per 1,000 elderly people. We can see that the specific mortality rate had fallen in 1991 compared to 1981. The age specific mortality rate varies from district to district. In 1991 the lowest, 110 per 1,000, was in Lika, and the highest in the districts of Varazdin (182 per 1,000), Bjelovar (178 per 1,000) and Zagorje (175 per 1,000). The death rate was higher amongst elderly men (172.31 per 1,000) than elderly women (141.65 per 1,000). The smallest number of those aged 80 years and older with a high death rate is found in Slavonia. The opposite--a high number of elderly people and a low specific mortality rate--can be seen in the district of Lika. On the islands the number of elderly people is high, especially women, and surprisingly, the specific mortality rate is relatively high as well.

Aged↗

PubMed2001

Burkholderia, a genus rich in plant-associated nitrogen fixers with wide environmental and geographic distribution.

The genus Burkholderia comprises 19 species, including Burkholderia vietnamiensis which is the only known N(2)-fixing species of this bacterial genus. The first isolates of B. vietnamiensis were recovered from the rhizosphere of rice plants grown in a phytotron, but its existence in natural environments and its geographic distribution were not reported. In the present study, most N(2)-fixing isolates recovered from the environment of field-grown maize and coffee plants cultivated in widely separated regions of Mexico were phenotypically identified as B. cepacia using the API 20NE system. Nevertheless, a number of these isolates recovered from inside of maize roots, as well as from the rhizosphere and rhizoplane of maize and coffee plants, showed similar or identical features to those of B. vietnamiensis TVV75(T). These features include nitrogenase activity with 10 different carbon sources, identical or very similar nifHDK hybridization patterns, very similar protein electrophoregrams, identical amplified 16S rDNA restriction (ARDRA) profiles, and levels of DNA-DNA reassociation higher than 70% with total DNA from strain TVV75(T). Although the ability to fix N(2) is not reported to be a common feature among the known species of the genus Burkholderia, the results obtained show that many diazotrophic Burkholderia isolates analyzed showed phenotypic and genotypic features different from those of the known N(2)-fixing species B. vietnamiensis as well as from those of B. kururiensis, a bacterium identified in the present study as a diazotrophic species. DNA-DNA reassociation assays confirmed the existence of N(2)-fixing Burkholderia species different from B. vietnamiensis. In addition, this study shows the wide geographic distribution and substantial capability of N(2)-fixing Burkholderia spp. for colonizing diverse host plants in distantly separated environments.

Bacterial Proteins↗

PubMed2004

Epidemiology of non-Hodgkin's lymphoma (NHL): trends, geographic distribution, and etiology.

While for most cancers incidence and mortality are decreasing, those of non-Hodgkin's lymphoma (NHL) are steadily increasing. Research to define reasons for this increase is extensive, but has not yet resolved them. We have conducted a literature analysis on trends regarding changes in the incidence, geographic distribution, and etiologic factors of NHL. From our own and previous analyses, an increasing NHL incidence at a rate of 3-4% per year was observed for the 1970s and 1980s. This stabilized in the 1990s, nevertheless still with an annual rise of 1-2%, resulting in almost a doubling of the NHL incidence. This rise has been noted worldwide, particularly in elderly persons >55 years. Concerning gender subgroups, a male predominance throughout all age groups is apparent. Although the NHL incidence has historically been higher in whites than blacks, disproportional increases have recently been observed in the latter group. Increases in high-grade NHL and extranodal disease are predominant. Differences in geographic distribution are striking for follicular lymphoma, which is more common in Western countries than elsewhere. Asians have higher rates of aggressive NHL, T-cell lymphomas, and extranodal disease. In the Middle East, high rates of intestinal extranodal disease are observed, whereas in Africa, endemic Burkitt's lymphoma accounts for a substantial proportion. Risks for developing NHL include immunosuppression and a causal link between infectious agents, and lymphomagenesis has also been determined, particularly for human T-cell leukemia/lymphoma virus type 1 (HTLV-1), Epstein-Barr virus (EBV), and Helicobacter pylori infections. Exposure to environmental agents and occupational risks have been studied; however, their significance is as yet uncertain.

Environmental Exposure↗

PubMed1976

Infantile cystinosis in France: genetics, incidence, geographic distribution.

A national distribution of 66 French patients, from 49 sibships, has been studied. Segregation analysis, using the maximum likelihood method, was found to agree with the theoretical values expected in recessive autosomal inheritance. The birthplaces of these patients show an unequal geographic distribution of cystinosis, the incidence being higher in Western France. Compared with the total number of live births during the period 1959 to 1972, the minimum incidence of the condition in the province of Brittany is 1 per 25 909, and the gene frequency 0.0062. In the rest of France, the minimum incidence is 1 per 326,440 and the gene frequency 0.0018. Application of Dahlberg's formula gives a similar result. The mean inbreeding coefficient is 530 X 10(-5), a figure 23 times higher than the mean coefficient of France. An indirect test of inbreeding, the distance between parental birthplaces, was studied, first using the French administrative boundaries, second by using kilometers. This distance was constantly smaller for the parents of patients than for the parents of controls. Analysis of two erythrocyte polymorphisms (ABO and Rh) showed a large excess of group A patients when compared with overall French data. These findings are difficult to interpret on genetic grounds. The genetic reasons for the unequal geographic distribution of cystinosis in France are discussed.

ABO Blood-Group System↗

PubMed1984

Phylogeny and geographical distribution of the genus Boettcherisca Rohdendorf (Diptera: Sarcophagidae).

The phylogeny of the genus Boettcherisca Rohdendorf was investigated by numerical techniques. The phenetic and phyletic dendrograms were obtained by mean character difference (MCD) and Russell and Rao's coefficient (SRR) proximity analyses and unweighted pair-group (UPGA) cluster analysis, and then related to the classification of the species group and the geographical distribution of the group. Two monophyletic and one paraphyletic groups were recognized: peregrina-group, septentrionalis-group and karnyi-group, respectively. A biological evolution was postulated commencing with a hypothetical ancestor having occurred in Sundaland and involving two lines of specialization, the peregrina-group found in and around Sundaland and the septentrionalis-group in Far East, Walacea and Papualand. On the basis of the cladogram and the present geographical distribution, a Sundaland origin was postulated for the genus.

Animals↗

PubMed1988

Geographic distribution and biting behaviour of four species of the Anopheles dirus complex (Diptera: Culicidae) in Thailand.

A cytogenetic analysis of the species status of members of the Anopheles dirus group, from natural populations, over a six-year period has produced biogeographic and behavioural data which are presented herein. Species A, B, C and D have quite distinct geographic distributions in Thailand. Species A is the only species in most of the mainland but is absent from the southern half of the peninsula. Species B is dominant in the far south of the peninsula giving way to species C on the north-east side and rarely occurring on the west side of the peninsula; it is unknown from the northern half or the rest of the country. Species C is known from the middle eastern side of the peninsula and from a site far to the north along the Burmese border. Species D occurs down the mountains along the Burmese/Thai border and along the north half of the western peninsula. Each species appears to have distinct times of biting during the night. They also appear to have differential seasonal abundance. These data together with the differing geographic distributions suggest some implications for Plasmodium transmission and that care should be taken to identify these genetic species during malariometric studies.

Animals↗

PubMed1997

Socioeconomic level, sedentary lifestyle, and wine consumption as possible explanations for geographic distribution of cerebrovascular disease mortality in Spain.

BACKGROUND AND PURPOSE: The geographic distribution of cerebrovascular disease (CVD) mortality in Spain spans a wide range, from provinces where mortality is low (70/100,000) and close to that of the United States and other Anglo-Saxon countries, to others where mortality is high (180/100,000) and more akin to that of Portugal and the Mediterranean and central European countries. This report seeks to identify the socioeconomic and lifestyle factors that most contribute to the geographic pattern of CVD mortality in Spain. METHODS: We performed a study using data collected at a provincial level. Mortality data were taken from official vital statistics, and data on risk factors were obtained from surveys of representative large Spanish population samples. Correlation and multiple linear regression analyses were performed on standardized CVD mortality ratios and potential determinants of mortality for the period 1989 to 1993. RESULTS: CVD mortality, unemployment and illiteracy rates, blond cigarette smoking, and sedentary lifestyle proved substantially higher in the south and east (Mediterranean coast) of Spain. Saturated fatty acid intake and wine consumption were both lower in these regions, however. Illiteracy, wine consumption, sedentary lifestyle, high blood pressure, blond cigarette smoking, prevalence of diabetes, and body mass index > or = 30 explained 59% of the variation in CVD mortality. Only illiteracy, sedentary lifestyle, and wine consumption registered a statistically significant relationship (P < .05) with CVD mortality. Whereas lower consumption of wine showed a negative association with CVD mortality, higher consumption revealed a positive association. CONCLUSIONS: Socioeconomic level, as measured by illiteracy, sedentary lifestyle, and wine consumption, may partly explain the higher CVD mortality registered for regions situated in the south and east of Spain.

Aged↗

PubMed1996

Widespread geographical distribution of mitochondrial haplotypes in rock-dwelling cichlid fishes from Lake Tanganyika.

The spectacularly diverse cichlid fish species flocks of the East African Rift Lakes have elicited much debate on the potential evolutionary mechanisms responsible for the origin of these adaptive radiations. An historical perspective on population structure may offer insights into the processes driving population differentiation and possibly speciation. Here, we examine mitochondrial DNA (mtDNA) sequence variation in two endemic species of rock-dwelling cichlids, Simochromis babaulti and S. diagramma, from Lake Tanganyika. Phylogeographic analyses were used to infer what factors might have been important in the genetic structuring of Simochromis populations. Patterns of mtDNA differentiation in Simochromis were compared to those of other rock-dwelling cichlids to distinguish between competing hypotheses concerning the processes underlying their evolution. In striking contrast to previous findings, populations of Simochromis, even those separated by up to 300 km, were found to share mitochondrial DNA haplotypes. There is no correspondence between mtDNA genealogies and the geographical distribution of populations. Only S. babaulti, but not S. diagramma was found to have a significant association between genetic and geographic distance. These phylogeographic patterns suggest that the evolutionary effects of abiotic and biotic factors shaping population genetic structure may differ substantially even among closely related species of rock-dwelling cichlids. Physical events and barriers to gene flow that are believed to have had a major impact on the geographical distribution and intralacustrine speciation of Tropheus do not seem to have equally strongly affected its close relative Simochromis. These findings emphasize that no single mechanism can be responsible for the formation of population structure, speciation, and the adaptive radiation of all cichlid fishes.

Africa, Eastern↗

PubMed1987

More on the geographical distribution of physicians.

This paper presents more empirical evidence on the geographical distribution of physicians. Probit procedure and data for the Province of Quebec were used. The results are consistent with the standard location theory and therefore with those of Newhouse et al. (1982a). They also show that quality of leisure, distance to central city areas, average income and presence of a hospital are significant in explaining the probability that at least one physician (specialist or general practitioner) is present in a given town. Other variables were also considered.

Demography↗

PubMed1990

Geographical distribution of insanity in America: evidence for an urban factor.

The geographic distribution of insanity and schizophrenia in the United States is examined for 9 separate years between 1880 and 1963. A concentration of these conditions in Northeastern and Pacific Coast States was remarkably consistent over the 83 years. States with a high prevalence rate had approximately three times more insanity and schizophrenia than those with a low prevalence rate. There is a direct regional correlation of insanity/schizophrenia with urbanization, which is consistent with previous studies. There is also a direct regional correlation of schizophrenia with socioeconomic status, which contradicts previous studies carried out in large cities in which the schizophrenic rates were inversely correlated with socioeconomic status. The apparent discrepancy can be explained by postulating that the direct regional correlations are due to correlations of urbanization and socioeconomic status (cities have higher mean incomes than rural areas) whereas, within a particular city, schizophrenia is more prevalent among lower socioeconomic groups because of drift and other factors. Social, stress and crowding, genetic, and biological factors are discussed as possible explanations for the urban factor associated with insanity/schizophrenia.

Cross-Sectional Studies↗

PubMed1995

[Mortality from ischemic cardiopathy in Spain: the trends and geographic distribution].

INTRODUCTION: In order to obtain epidemiological information for health planification, age-adjusted time series and provincial distribution of ischaemic heart disease mortality have been constructed. MATERIAL AND METHODS: Analysis of time trends includes data from 1901 to 1989. Trends have been identified by linear regression analysis. For the period 1976-1986 age-adjusted and age and sex specific mortality rates have been calculated for each province. 1984 and 1989 levels have been compared to those of the European Union countries. RESULTS: After the sharp rise of the curve in the 50-70 decades, since 1976 mortality falls with an statistically significant negative slope. This change in trends cannot be explained by time variations in prevalence of the main risk factors. Although in many European countries mortality began to fall much earlier, Spain still remains between the lowest mortality rates in Europe. Provinces showing the highest rates are the islands, Andalucia, Badajoz, Murcia, Alicante and Asturias. This clear north-south pattern is maintained after stratifying by age and sex, thus indicating that geographical distribution is related more to environmental or socio-economic factors and to accessibility to qualified health care, than to the geographical distribution of age and sex related risk factors. CONCLUSIONS: Additional studies including other variables are needed to explain these time and spatial variations. Allocation of specialized health care resources can be an effective intervention, mostly in the above mentioned provinces.

Adult↗

PubMed2001

Geographical distribution of rodent-associated hantaviruses in Texas.

The purpose of this study was to increase our knowledge of the geographic distribution and natural host range of hantaviruses in Texas, southeastern New Mexico, and Mexico. Blood samples from 3,225 wild rodents, representing 34 species, were tested for hantavirus antibody (IgG), using an enzyme-linked immunosorbent assay. Hantavirus antibody was found in one or more rodents from each of 13 counties in Texas, Otero County in southeastern New Mexico, and Mexico State (central Mexico). The 133 antibody-positive rodents included seven Peromyscus species (P. attwateri, P. boylii, P. hylocetes, P. leucopus, P. maniculatis, P. melanotis, and P. pectoralis), Sigmodon hispidus, Oryzomys palustris, two Reithrodontomys species (R. fulvescens and R. megalotis), Neotoma albigula, and Perognathus merriami. This study provides further evidence that rodent-associated hantaviruses are geographically widely distributed in Texas. The discovery of antibody in P. hylocetes and P. melanotis is evidence that peromyscine rodents in Mexico are naturally associated with viruses belonging to the genus Hantavirus.

Animals↗

PubMed1998

The Sardinian IDDM study: 1. Epidemiology and geographical distribution of IDDM in Sardinia during 1989 to 1994.

Analysis of the geographical variation of risk for a disease is a key issue in descriptive epidemiology and may provide useful suggestions for planning further studies to identify the underlying causes. We adopted a Bayesian approach to investigate the geographical distribution of insulin-dependent diabetes mellitus (IDDM) incidence rate across Sardinia. Data on incidence of IDDM in children aged under 15 years (619 IDDM cases) in Sardinia was obtained by the Sardinian Eurodiab ACE register. The overall completeness of ascertainment was: 91.3%. The average yearly standardized incidence rate for the years 1989-1994 was 33.24 per 100000 (95% C.I. 30.60, 35.88), which is the second highest in Europe after Finland. Sex and age-specific risks were higher in males than in females. Considering the variation of IDDM risk according to the age at diagnosis, the risk profile increased up to the 13th year of age for both sexes, being steeper in males. The degree of geographical variation in IDDM risk was small with a slight difference between the highest and the lowest standardized rate across the map. Indeed, even the municipalities at lowest risk in Sardinia showed a risk higher than most European countries. The Sardinian population is genetically atypical, characterized by genetic homogeneity and marked susceptibility to autoimmune diseases. Our finding of a small geographical variation within the island coupled with a marked temporal trend previously observed in data on military conscripts could be interpreted as evidence of a relatively recent environmental aetiological factor that was uniformly distributed across the island and had its effect in a genetically predisposed population.

Age Factors↗

PubMed2002

Diversity and geographic distribution of secondary endosymbiotic bacteria in natural populations of the pea aphid, Acyrthosiphon pisum.

In addition to the essential intracellular symbiotic bacterium Buchnera, several facultative endosymbiotic bacteria called collectively secondary symbionts (S-symbionts) have been identified from the pea aphid Acyrthosiphon pisum. We conducted an extensive and systematic survey of S-symbionts in Japanese local populations of A. pisum using a specific PCR detection technique. Five S-symbionts of A. pisum, PASS, PAUS, PABS, Rickettsia and Spiroplasma, and two facultative endosymbionts universally found in various insects, Wolbachia and Arsenophonus, were targeted. Of 119 isofemale strains originating from 81 localities, 66.4% of the strains possessed either of four S-symbionts: PASS (38.7%); PAUS (16.0%); Rickettsia (8.4%); and Spiroplasma (3.4%), while 33.6% of the strains contained only Buchnera. PABS, Wolbachia and Arsenophonus were not detected from the Japanese strains of A. pisum. In order to understand intra- and interpopulational diversity of S-symbiont microbiota in detail, 858 insects collected from 43 localities were examined for infection with the four S-symbionts. It was demonstrated that different S-symbionts coexist commonly in the same local populations, but double infections with two S-symbionts were rarely detected. Notably, the S-symbionts exhibited characteristic geographical distribution patterns: PASS at high frequencies all over Japan; PAUS at high frequencies mainly in the northeastern part of Japan; and Rickettsia and Spiroplasma at low frequencies sporadically in the southwestern part of Japan. These results indicate that the geographical distribution and infection frequency of the S-symbionts, in particular PAUS, might be affected by environmental and/or historical factors. Statistical analyses suggested that the distribution of PAUS infection might be related to host plant species, temperature and precipitation.

Animals↗

PubMed2002

Analysis of CCR5Delta32 geographic distribution and its correlation with some climatic and geographic factors.

We studied the possible effects of climatic-geographic factors on the world distribution of the mutant allele for the chemokine receptor gene CCR5, which has a 32-bp deletion (CCR5Delta32) preventing cell invasion by the primary transmitting strain of HIV-1. New data on CCR5 polymorphisms in Russian, Ukrainian, and Moldavian populations are presented. All available data on CCR5Delta32 frequencies in the Old World (number of populations n = 77) were used for construction of a geographical gene map to analyze possible correlations between allele frequencies and eight climatic-geographic parameters. A strong positive correlation was found between the allele frequency and latitude (r = 0.72), a strong negative correlation with annual radiation balance (r = -0.66), and a weaker negative correlation with longitude (r = -0.34). Partial correlations were calculated excluding the influence of latitude. The negative correlation between the allele frequency and annual radiation balance decreased (r = -0.42), but remained large and significant. We propose that the existence of correlations between the cline of CCR5Delta32 frequencies and climatic-geographic parameters provides evidence for a possible effect of either natural environmental factors or large-scale population movements on the distribution of this allele.

Climate↗

PubMed1991

Geographic distribution of newborn HIV seroprevalence in relation to four sociodemographic variables.

The geographic distribution of newborn human immunodeficiency virus seroprevalence at zip code level was compared with the distribution of four sociodemographic variables. For New York City significant univariate correlations were found between HIV and low birthweight, drug use (as measured by hospital discharges), maternal education less than 12 years, and race/ethnicity. Less significant correlations were found for New York State exclusive of New York City. For New York City a model comprising low birthweight and all drug discharges was shown by multiple regression analysis to be most strongly associated with HIV status (r2 = .77). Elsewhere a model comprising race/ethnicity (percent Black, percent Hispanic) and cocaine drug discharges had the best, but less strong association (r2 = .39). However, because of intercorrelations, race/ethnicity added little when the other variables were included first. Knowledge of the geographic association between HIV seroprevalence and sociodemographic status can be useful in designing and focusing prevention efforts in areas at highest risk for future HIV/AIDS activity.

Analysis of Variance↗

PubMed1996

Hairy cell leukemia is infrequent in México and has a geographic distribution.

Considering that the prevalence of some hematologic malignancies may have a geographic distribution that could be related with its etiology, a group of 2,387 patients with acute leukemia (1,968 adults and 419 children) was studied along a 5-year period in six different locations within México. Twenty-seven patients (16 males and 11 females) with hairy cell leukemia (HCL) were identified. The adjusted overall proportion of HCL, after excluding data from centers reporting only adults, was 1.12% of all leukemia cases; this figure is lower than that reported in the United States or England. The proportion of adult leukemic patients with HCL was significantly higher in the northern region of the country-where there are more people devoted to farming and agricultural activities-as compared with the central or southeastern regions (3.07 vs. 1.03% vs. 0%; P < 0.05); possible explanations for these differences are briefly discussed.

Adult↗

PubMed1984

Geographical distribution of lung cancer in the USSR.

During recent years medico-geographical studies on lung cancer in the USSR have been intensified. The results of these studies are reflected in works on the geographical distribution of lung cancer and on the influence of unfavourable natural-economic factors upon lung cancer incidence. The steady increase in lung cancer morbidity and mortality throughout the world is one of the urgent problems of today. Numerous studies have been carried out, and these have identified several aetiological factors which play a certain role in lung cancer development (smoking, occupational hazards, air pollution by industry and traffic). These studies have shown lung cancer to be one of the cancers most closely associated with environmental conditions. Lung cancer is considered to be a disease of the male population inhabiting highly industrialized cities and countries. However, lung cancer incidence has also been increasing recently in the female population of different countries. (V. Merabishvili, G. Tserkovny, 1981) Different levels of morbidity and mortality from lung cancer throughout the world make it necessary to undertake comprehensive studies on the complicated and ever-changing relations between the health status of the population and the effect of natural and economic factors.

Adolescent↗