Changes of neoplasm concentration with geographical co-ordinates.

We investigated the regional differences in diversity--from another respect concentration--of causes of cancer mortality in England and Wales. Statistical analyses of published mortality data were done, using the jackknifed estimate of the Shannon index, for each region, sex and age group and year of death. In males diversity of cancer death causes is secularly increasing whilst it is decreasing in females. Latitude was negatively associated with diversity in male 45+ year age groups and longitude negatively associated with diversity in male 65+ age groups. Although, there were some significant associations in the female groups, there was no general trend across age groups as found in males. These trends remained after accounting for regional variation in past smoking behaviour. We suggest that the observed patterns may be related to prior occupational exposures and non-identified environmental and socioeconomical factors. It is concluded that techniques drawn from population ecology have a potential value in epidemiological studies of human disease. Ecological methods by themselves are likely to be of value in hypothesis generation rather than hypothesis testing.

[Analyzing changes in cause-specific mortality by age using dissimilarity indices]. / A halaloki struktura valtozasainak vizsgalata disszimilaritasi indexekkel.

PIP: "Cause of death structure exhibits considerable changes with age. Calculating dissimilarity indices for pairs of five year age groups of cause of death statistics, we obtained a picture on the age dependence of the scalarized structural changes. Some dissimilarity measures accentuate mainly the differences between case numbers in the range of dominant causes of death. Others are sensitive also to changes in smaller frequencies.... We performed calculations on causes of death statistics of some European countries." (EXCERPT)^ieng

A typical interdisciplinary topic: questions of the mortality dynamics.

Dynamic characteristics of mortality experience are intensely studied in demography and in experimental gerontology. The classic Gompertz-Makeham function is also a significant starting point of numerous investigations in this topic. By comparative analysis of human vital statistics, one can observe characteristic secular and topological variations of the Gompertz parameters. Some of these findings are reviewed briefly in the article. Some other related questions are also touched upon. For example, the concept of the maximum life span is criticised. A thorough overview of literature data makes it clear that the general male mortality excess is by far not so unambiguous as is widely supposed. Surprisingly simple stochastic models, published by one of us in the recent past, can serve as theoretical background for the Gompertz law. Further studies would be necessary to check the biological relevance of these models.

[Fatal accidents classified according to their causes]. / A halalos balesetek okok szerinti koncentraltsaga.

PIP: The author analyzes accidental deaths in Hungary according to cause. The impact of age and environmental factors is considered. (SUMMARY IN ENG)^ieng

Applying the jackknife method to significance tests of diagnostic diversity.

The sample theory of normal diversity indices is complex. Distribution free methods, such as the jackknife method, can easily be used to determine confidence intervals and testing diversity. Jackknife estimates and their variances for a number of different diversity indices are described in this paper. A simple numerical example is given for demonstrating this method. Discrimination based on confidence intervals is also discussed. It is assumed that there is a special correlation between the sensitivity parameter m and the relative width of confidence intervals in the Hurlbert index family. It is shown that the usual estimation of the Hurlbert index coincides with the relating jackknife estimate. For demonstration, diagnoses registered in a set of death certificates are used. There is a considerable diversity in diagnoses among different diagnostic groups: the diversity is largest in autopsy reports, whereas it is non-significant in GP's reports and in reports of physicians authorized to issue death certificates. Knowing that autopsy reports tend to be fairly accurate, our research findings seem to confirm the hypothesis that there is a correlation between reliability and diversity of diagnoses.

A latitudinal diversity gradient in virus infections in humans in England and Wales.

This paper reports the presence of a latitudinal diversity gradient in reports of human viral infections in the various health regions of England and Wales. The data used in this study are reports of the laboratory diagnosis of virus infections made to the Public Health Laboratory Service Communicable Disease Surveillance Centre. Two indices of diversity were calculated from the data--Fisher's and Simpson's. Both indices were shown to correlate with latitude but not longitude. Possible mechanisms for this diversity gradient are discussed. It is suggested that such a gradient in the class of human viruses is more likely to be due to increasing environmental stress in colder climates, than to the after-effects of major climatic change.

Comparative analysis of death cause diversity curves in various countries.

"We used diversity indices to quantify the dominance conditions of death cause frequencies [in England, Finland, Hungary, Japan, and Norway]. Plotting age-diversity values, the curves exhibit large changes in the death cause diversity/concentration by age.... The differences are mostly attributed to the site and value of the characteristic maximum. In both studied sections (Neoplasms and Circulatory Diseases) the Japan diversity curves differ considerably from corresponding curves of the European countries. Characteristic departures are observable between the diversity graphs of the male and female groups." (SUMMARY IN ITA)

Effect of smoking on different biological parameters in aging mice.

To investigate the harmful effect of smoking three groups of CBA/Ca male mice of different ages were subjected to smoking for different time durations. Body weight changes and acute cold tolerance were measured throughout the experiment. Thyroid hormone levels (T4, T3), TSH and lipid peroxidation products (as malondialdehyde and lipofuscin) were determined from either the blood or some organs. There was a decrease in body weight related to aging and it was most pronounced in the oldest animals (Group III). However, significant body-weight loss due to smoking was found in the youngest animals (Group I). Similarly, smoking resulted in a body-weight loss of the other two older groups (Groups II and III) as well. The greatest change in withstanding cold stress was measured in Group I and less so in Group II, as a consequence of smoking. Simultaneously, the youngest animals (Group I) showed the most remarkable changes in thyroxine (T4) and 3,3,4-triiodothyronine (T3) serum concentrations. Both hormone levels were significantly lower in the smokers. The T3 serum levels of the oldest animals (Group III) did not differ, while the T4 levels apparently increased. The TSH blood level in the oldest group was lower (by 20%) in the smokers compared to controls. Malondialdehyde (MDA) and lipofuscin content in most of the organs were considerably higher in the aging animals than those of the younger ones. The most significant elevations of these lipid peroxidation products were found in the smokers compared to the age-matched controls. The present results indicate that smoking probably accelerates the aging process.

Effect of aging on cold tolerance and thyroid activity in CBA/Ca inbred mice.

Relationships between cold tolerance, serum levels of thyroxine (T4), thyronine (T3), and thyrotropine (TSH), and thyroid morphometry have been investigated in male CBA/Ca inbred mice at various ages through their life span. From the data obtained it appeared that there was an age-related decrease in cold tolerance up to 18 months of age which was followed by an increase, the age effect being most apparent in relation to cold resistance and cold tolerance during the recovery period following cold exposure. The age-related changes in cold tolerance appeared to be associated with changes in the serum concentrations of T3, T4, and TSH. In contrast to the T3 serum levels which showed a decrease at 36 months, the thyroxine contents showed a perceptible decrease from the age of 12-18 months onwards. A similar pattern was observed for the TSH levels, with a peak at 21 months, followed by a decline at 30 months. A relationship with age between serum T4 level and thyroid weight was indicated together with structural changes in the thyroid gland, particularly during senescence, for example the size and number of thyroid epithelial cells had become enlarged by 30 months of age.

Diversity studies of Salmonella incidents in some domestic livestock and their potential relevance as indicators of niche width.

This study attempts to determine whether or not livestock are becoming more susceptible to epidemics of salmonella infections by the analysis of published data on the annual number of reported infections in various animals. The number of incidents reported each year may be subject to a variety of biases due to temporal and geographical differences in reporting practices. This study analysed these reports by the calculation of diversity indices which are not subject to some of these potential biases. The relationship between the ecological concept of niche width and the diversity of species or types occupying that niche is discussed. The diversity of salmonella types reported in fowl has shown a highly significant decline over the 13-year period 1976-88. It is suggested that this declining diversity may be related to the declining niche width of the biotope available to this pathogen. Although speculative, this reduction in niche width could be related to a declining genetic diversity in the host animals or to an increasing intensification of animal husbandry.

Changes of organ indices of CBA/Ca inbred mice as function of age.

Weight changes of seven organs: brain, heart, lungs, liver, spleen, small intestine, and kidneys, were analyzed during aging of male CBA/Ca inbred mice. Data were collected as absolute organ weights, organ weights related to body, as well as brain weights. It was established that most organs increase their weight up to nearly two years of age, after which there is a dramatic decline. Body weight shows a distinct plateau or constancy along the lifespan of the animals; consequently, body weight seems to be generally the most favorable reference point to express some of the physiological changes and parameters of the aging organism. Variation coefficients of the organ weights generally become higher with age.

[Epidemiologic diversity]. / Untersuchungen zur epidemiologischen Diversität.

We summarize our results with the adaptation of the so called diversity indexes, often used in the statistical ecology. We refer to the sexual difference of the diversity of death causes, and the specific formation of the diversity of morbidity and mortality by the years of life. We mention the possible explanation of this. It is also a new observation the characteristic change in the concentration of the causes of death measured by diversity indexes. In the second part of the paper we enumerate some possible new branches of research, which should develop the investigations on the epidemiological diversity.

Effect of 2-mercaptoethanol on some metabolic indices of ageing of CBA/Ca inbred mice.

It has been shown in several studies that 2-mercaptoethanol (2-ME) improves the life span and aspects of life performance of laboratory animals. To obtain further details on the beneficial effects of 2-ME, a long-term study has been performed on male CBA/Ca inbred mice treated with this antioxidant. Four month-old mice were each given 4 micrograms of 2-ME in physiological saline via intraperitoneal (i.p.) injection 3 x per week. Measurements were made of the following: cold tolerance (heat performance), apparent total body protein turnover (T1/2), changes in the major lipid and fatty acid compositions of the liver, superoxide dismutase activity and formation of malondialdehyde and observations on a range of pathological changes. It was found that the basal rectal temperatures of the treated mice were higher and in the oldest group, heat performance capacity was better than those of the controls. After about 1 year of age the apparent biological half-life time of total body protein (T1/2) was observed to be shorter in the treated mice. Significant increases were observed to occur in the proportions of the polyunsaturated fatty acids in the lipids of the liver in the mice injected with 2-ME. Although no differences were observed in the superoxide dismutase activities, malondialdehyde concentrations in the livers of the experimental mice were significantly increased. Autopsy data showed that Dunn-sarcomas associated with amyloidoses occurred more frequently in the untreated mice.

Secular changes of the concentration of neoplasm death causes in the male population of some countries.

PIP: Using diversity indexes, concentrations of deaths caused by neoplasms are examined for the male populations of the United Kingdom, Norway, Finland, Hungary, and Japan and are compared with those of the United States for the period 1968-1975. The author finds an increase in such mortality in the United States and a decrease in the other countries. (SUMMARY IN FRE AND ITA)^ieng

Biological changes and diseases in aged CBA/Ca mice.

Cold adaptation, apparent protein metabolism, life span, body and organ weights, organ indices, mitochondrial changes in the lymphocytes, and frequency of diseases were examined in 661 (untreated) inbred CBA/Ca male mice. The rectal temperature proved to be lower in aged mice, i.e. the rectal temperature of old animals immediately after cold exposure was more distinctly decreased than that of young ones. The apparent protein metabolism measured by 75Se-selenomethionine turnover showed that biological half-life (T 1/2) values in the aged are almost linearly elevated. In very old animals the values are decreased. Body weight decreased significantly and continuously, spleen and liver indices decreased and heart index increased with age in healthy animals. The number of diseased animals increased with age peaking at the age of 751-900 days. After 900 days the number of diseased animals decreased. The most frequent diseases in the old animals are: hepatocellular carcinoma, amyloidosis and pulmonary adenocarcinoma. The mitochondria of spleen lymphocytes showed degenerative changes not associated with diseases, thus they can be considered as age-related biological changes.

On the explanation of the changes in age of the concentration of the death causes.

The high concentration of the diagnoses among the categories of death causes is called the concentration of death causes. The idea of diversity used in statistical ecology is in a sense a contrary concept. Introducing the investigation of diversity indices on epidemiological material, we have shown sexual differences and age characteristics of the latter. In the course of the investigations, there was an opportunity to measure exactly and analyse the high increase of the concentration of death causes at an older age. In this paper we related the changes due to age to the structure of the set of specific death rates and to that of hazard functions. According to our fitting investigations, the majority of the elements of the set of curves could be well approximated by the Gompertz or by the Weibull function. In this case, a mathematical explanation can be given to the increase, then decrease of Hill's diversity indices, that is, to the decrease, than increase of the concentration of death causes. Finally we point briefly to the evolutionary aspects of the discussed changes with age of this concentration.