Josef Dolejs

Single parameter of inverse proportion between mortality and age could determine all mortality indicators in the first year of life

Mortality increase with age in adult population has been studied and modeled by many authors, but relatively little attention has been given to mortality decrease with age after birth. Data split in more detailed age categories can newly test mortality decrease with age. Age trajectories of mortality are studied in 20 age categories in the specific age interval 1-365 days. Four basic models mentioned in literature are tested here. The linear model and the linear model with the specific slope -1 in the log-log scale represent the most successful formalism. Mortality indicators describing the first year could be determined by a single parameter of the model with slope -1 in the log-log scale. All conclusions are based on published data which are presented as a supplement.

Small carcinomas involving less than one-quarter of the rectal circumference: local excision is still associated with a high risk of nodal positivity

A study was carried out to determine the relationship between mesorectal lymph nodal involvement and T stage in a group of patients with a rectal cancer involving less than one‐quarter of the rectal circumference, such as might be selected for local excision.

Factors Affecting the Number of Visitors in National Parks in the Czech Republic, Germany and Austria

In the context of national-level strategies, the importance of tourism in national parks is on the rise. The objective of this study is to investigate the relationship between the number of visitors to national parks and five variables: area, number of employees, budget, average employee salary and number of researchers in 12 national parks in the Czech Republic, Germany and Austria. Analysis of factors influencing the number of visitors to national parks uses the method of retrospective analysis of the data contained in internal documents and questionnaires among managers of national parks. The number of candidate predictors is relatively high when compared with the number of observations. Due to this fact, the Gilmour method for statistical analysis is used. Statistical results represented by the parameter β2 for number of employees is −33,016 (95% CI, −50,592–−15,441) and by the parameter β3 for budget is 0.586 (95% CI, 0.295–0.878), showing that the number of visitors increases with budget, while it decreases with the number of employees. The results of this study are a useful starting point for managers in their efforts to focus on developing key areas in an appropriate way. In conclusion, results show that increasing the economic benefits accruing from national parks regional policy could aim at a qualitative upgrading of tourist services, increased marketing of the unique national park label and the promotion of a diverse regional supply base.

Neopterin, kynurenine and tryptophan as new biomarkers for early detection of rectal anastomotic leakage

Introduction At present, there are no strong predictors, nor a useful scoring system, that clearly identifies patients at risk for anastomotic leakage. Aim This study aimed to investigate a new method that assesses this risk by monitoring levels of neopterin, tryptophan, and kynurenine, in bodily fluids. Material and methods This prospective study included patients who underwent elective rectal resection for carcinoma. The basic condition for inclusion was rectal anastomosis using the double-stapling technique. Preoperative levels of neopterin, tryptophan, kynurenine, and their ratios, were assessed with blood and urine samples. These levels were then monitored for 6 postoperative days in venous blood, urine, and abdominal drainage fluid. Results A total of 42 patients were enrolled in the study. Thirty-six patients underwent a laparoscopic resection and 6 patients had an open procedure. No differences were found among neopterin, tryptophan, and kynurenine serum levels. However, the groups were observed to have significant differences in the urinary neopterin/creatinine ratio: the preoperative neopterin/creatinine ratio was 139.5 μmol/mol in the group with leakage, vs 114.8 μmol/mol in the group without complications, p = 0.037. The same results were observed during the postoperative period, p = 0.012. Additionally, the group with complications had a higher mean value of neopterin in drainage fluid, p = 0.048. Conclusions Our study demonstrated that high preoperative levels of urinary neopterin could be interpreted as a risk for anastomotic leakage. Moreover, pathological levels of neopterin in urine and abdominal drainage fluid could be useful for early identification of anastomotic leakage during the postoperative period prior to its clinical development.

Modeling the age-associated decrease in mortality rate for congenital anomalies of the central nervous system using WHO metadata from nine European countries

Background: In humans, the mortality rate dramatically decreases with age after birth, and the causes of death change significantly during childhood. In the present study, we attempted to explain age-associated decreases in mortality for congenital anomalies of the central nervous system (CACNS), as well as decreases in total mortality with age. We further investigated the age trajectory of mortality in the biologically related category “diseases of the nervous system” (DNS). Methods: The numbers of deaths were extracted from the mortality database of the World Health Organization (WHO) for the following nine countries: Denmark, Finland, Norway, Sweden, Austria, the Czech Republic, Hungary, Poland, and Slovakia. Because zero cases could be ascertained over the age of 30 years in a specific age category, the Halley method was used to calculate the mortality rates in all possible calendar years and in all countries combined. Results: Total mortality from the first day of life up to the age of 10 years and mortality due to CACNS within the age interval of [0, 90) years can be represented by an inverse proportion with a single parameter. High coefficients of determination were observed for both total mortality (R2 = 0.996) and CACNS mortality (R2 = 0.990). Our findings indicated that mortality rates for DNS slowly decrease with age during the first 2 years of life, following which they decrease in accordance with an inverse proportion up to the age of 10 years. The theory of congenital individual risk (TCIR) may explain these observations based on the extinction of individuals with more severe impairments, as well as the bent curve of DNS, which exhibited an adjusted coefficient of determination of R¯2 = 0.966. Conclusion: The coincidence between the age trajectories of all-cause and CACNS-related mortality may indicate that the overall decrease in mortality after birth is due to the extinction of individuals with more severe impairments. More deaths unrelated to congenital anomalies may be caused by the manifestation of latent congenital impairments during childhood.

Onset of mortality increase with age and age trajectories of mortality from all diseases in the four Nordic countries.

Background The answer to the question “At what age does aging begin?” is tightly related to the question “Where is the onset of mortality increase with age?” Age affects mortality rates from all diseases differently than it affects mortality rates from nonbiological causes. Mortality increase with age in adult populations has been modeled by many authors, and little attention has been given to mortality decrease with age after birth. Materials and methods Nonbiological causes are excluded, and the category “all diseases” is studied. It is analyzed in Denmark, Finland, Norway, and Sweden during the period 1994–2011, and all possible models are screened. Age trajectories of mortality are analyzed separately: before the age category where mortality reaches its minimal value and after the age category. Results Resulting age trajectories from all diseases showed a strong minimum, which was hidden in total mortality. The inverse proportion between mortality and age fitted in 54 of 58 cases before mortality minimum. The Gompertz model with two parameters fitted as mortality increased with age in 17 of 58 cases after mortality minimum, and the Gompertz model with a small positive quadratic term fitted data in the remaining 41 cases. The mean age where mortality reached minimal value was 8 (95% confidence interval 7.05–8.95) years. The figures depict an age where the human population has a minimal risk of death from biological causes. Conclusion Inverse proportion and the Gompertz model fitted data on both sides of the mortality minimum, and three parameters determined the shape of the age–mortality trajectory. Life expectancy should be determined by the two standard Gompertz parameters and also by the single parameter in the model c/x. All-disease mortality represents an alternative tool to study the impact of age. All results are based on published data.

Age trajectories of mortality from all diseases in five countries of central Europe during the last decades.

Age trajectories of total mortality represent an irreplaceable source of information about the relationship between mortality and age. Total mortality includes death from external causes. Age affects mortality from all diseases differently than it affects mortality from external causes. This study examines mortality with external causes excluded. The resulting category of all-diseases is examined as a helpful tool to better understand the relationship between mortality and age. Age trajectories of all-diseases mortality are studied in Austria, the Czech Republic, Hungary, Poland, and Slovakia. Resulting age trajectories of all-diseases mortality show a strong minimum that is hidden in all-causes mortality. Two deterministic models fit the resulting age trajectories of mortality on either side of the strong mortality minimum. The inverse proportion between mortality and age is used from birth to the age when all-diseases mortality reaches the minimum value. The Gompertz relationship fits age trajectories of all-diseases mortality in 93 out of 183 cases. When extended with a small quadratic element, the Gompertz model is used to fit the remaining 90 cases.