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Biomedical subjects

J Kern

Publications and source records attributed to J Kern.

At least 37 records · Page 2Linked to original sources
PubMed2001

Phosphorus retention capacity of iron-ore and blast furnace slag in subsurface flow constructed wetlands.

The suitability of iron-ore and blast furnace slag for subsurface flow (SSF) constructed wetlands was studied over a period of four months. Dairy farm wastewater (TP 45 mg l(-1)) was percolated through buckets planted with reed (volume 9.1 l; hydraulic load 151 m(-2) d(-1)). One group of buckets was kept under aerobic conditions and the other group under anaerobic conditions, monitored by continuous redox potential measurements. Even at high mass loading rates of 0.65 g P m(-1) d(-1) the slag provided 98% removal efficiency and showed no decrease in performance with time. However, phosphorus fractionation data indicate that the high phosphorus retention capacity under aerobic conditions is to a great extent attributable to unstable sorption onto calcium compounds (NH4Cl-P). Phosphorus sorption of both the slag (200 microg P g(-1)) and the iron-ore (140 microg P g(-1)) was promoted by predominantly anaerobic conditions due to continuous formation of amorphous ferrous hydroxides. None of the substrates had adverse affects on reed growth.

Adsorption↗
PubMed2000

Characterization of three-phonon states in 110Cd

The three-phonon structure of 110Cd has been studied with the (n, n(')gamma) reaction. The measurements consisted of gamma-ray excitation functions and angular distributions, and lifetimes of proposed three-phonon quadrupole states in 110Cd have been measured using the Doppler-shift attenuation method. Moreover, decay of the three-phonon 2(+) state in 110Cd at 2356 keV to a two-phonon state is observed for the first time. The experimental results allow the determination of transition rates of decays from the three-phonon excitations, and the collectivity of these states is established. The experimental B(E2) values are compared to different theoretical descriptions.

Journal Article↗
PubMed2000

Genome-wide scan for adult onset primary open angle glaucoma.

Adult onset primary open angle glaucoma is a leading cause of blindness throughout the world. The disease results in an apoptotic death of retinal ganglion cells that is usually associated with an elevation of intraocular pressure. Familial aggregation of the disorder provides evidence for strong genetic influences that are likely to be the result of multiple susceptibility genes. A two-stage genome scan to identify the genomic locations of glaucoma susceptibility genes was performed using an initial pedigree set of 113 affected sibpairs and a second pedigree set of 69 affected sibpairs. Linkage analysis was performed using both model-dependent (lod score) and model-independent affected relative pair and sibpair methods. Twenty-five regions identified by the initial scan were further investigated using the second pedigree set. In the combined data analysis, regions located on chromosomes 2, 6, 9, 11, 14, 17 and 19 continued to produce model-dependent lod scores and/or an MLS >1.0, while five regions (2, 14, 17p, 17q and 19) produced an MLS >2. 0. Multipoint analysis using ASPEX also showed significant results on chromosomes 2, 14, 17p, 17q and 19. These results are an important step towards the identification of genes responsible for the genetic susceptibility to this blinding condition.

Age of Onset↗
PubMed2000

Respiratory findings in chemical workers exposed to low concentrations of organic and inorganic air pollutants.

BACKGROUND: Occupational exposure to respiratory irritants may effect respiratory function in workers exposed to ambient air pollutants in the workplace. METHODS: We studied 567 male and 135 female workers employed in two chemical plants in Zagreb, Croatia. Measurements of the ambient concentrations of air pollutants were performed. The mean age of the men was 37 years and mean duration of employment was 12 years; a majority of these workers were smokers. The mean age of the women was 37 years with a mean duration of employment of 14 years; only one-third of the women smoked. An unexposed group of 340 male and 110 female unexposed workers was also studied. Acute and chronic work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves. RESULTS: There were higher prevalences for all chronic respiratory symptoms in exposed than in unexposed workers particularly among women, a majority of which were nonsmokers. Occupational asthma was recorded in three (0. 5%) of the men and in two (1.5%) of the women workers. Logistic regression analysis indicated that the presence of chronic respiratory symptoms among exposed workers was primarily associated with the amount of smoking. Additionally, there were high prevalences of acute symptoms during the work shift. Among the chemical workers these were greatest for eye irritation (male: 43. 9%; female: 51.9%), dryness of the throat (male: 43.4%; female: 57. 0%) and irritation of the throat (male: 37.4%; female: 56.6%). Ventilatory capacity data among the chemical workers demonstrated that most of the measured tests, particularly the FVC and FEV1 were significantly decreased compared to predicted (P < 0.01 or P < 0. 05)). In particular nonsmoking women exhibited abnormal lung function. The effect of smoking among exposed workers was demonstrated on all ventilatory capacity tests by regression analysis for all measured respiratory parameters. Both length of exposure and age were correlated with lung function loss for FVC. Measured pollutant levels were for the most part within acceptable standard limits. CONCLUSIONS: Our data suggest that in this population of chemical workers exposed to low levels of pollutants respiratory symptoms were primarily associated with smoking. Environmental effects, possibly due to an interaction of pollutants were also suggested.

Adult↗
PubMed2000

Respiratory findings in mail carriers.

The results of the recording of respiratory symptoms and the measurement of lung function in 136 male postal workers employed as mail carriers were studied. In addition, the prevalence of chronic respiratory symptoms in 87 male nonexposed control workers was also examined. There was a significantly higher prevalence of chronic bronchitis (25.0%) and sinusitis (38.9%) in mail carriers than in control workers (13.8%; P < 0.05 and 2.3%; P < 0.01). A logistic regression analysis performed on the results of the study of chronic respiratory symptoms of mail carriers indicated a significant (P < 0.001) effect of smoking in this cohort, with the exception of occupational asthma. Mail carriers who smoked had a significantly higher prevalence of chronic cough (45.3%), chronic phlegm (39.1%), chronic bronchitis (39.1%) and sinusitis (53.1%) than mail carriers who were nonsmokers (18.1%; 12.5%; 12.5% and 26.4% respectively.) (P < 0.01). A high prevalence of acute symptoms developing during the work-shift was recorded, in both smokers and nonsmokers, being highest for upper airway symptoms, headache (50.0%), nasal catarrh (42.6%), and eye irritation (57.4%). The results of tests for average measured ventilatory capacity (as a percentage of predicted capacity) were significantly lower than expected, particularly for maximum flow rates at the last 25% of the vital capacity (FEF25), in both smokers (68.5%) and in nonsmokers (74.2%). A multivariate analysis of lung function parameters indicated a significant effect of employment conditions. The only major identifiable occupational exposure of mail carriers was to ambient air pollution for an average of 6 h per day as well as to adverse meteorological conditions. The measured ambient concentrations of major outdoor pollutants, primarily total suspended particulates, sulfur dioxide (SO2) and black smoke exceeded considerably the recommended Croatian maximum air quality standards over the past 10 years. Our study of mail carriers demonstrated that these workers were subject to respiratory symptoms associated with their smoking habits. Lung function findings suggested that occupational exposures, possibly to atmospheric pollution in combination with adverse meteorological conditions, may have led to lung function impairment in these workers.

Adolescent↗
PubMed2000

Prevention of venous thromboembolism after injury: an evidence-based report--part I: analysis of risk factors and evaluation of the role of vena caval filters.

BACKGROUND: Trauma surgeons use a variety of methods to prevent venous thromboembolism (VT). The rationale for their use frequently is based on conclusions from research on nontrauma populations. Existing recommendations are based on expert opinion and consensus statements rather than systematic analysis of the existing literature and synthesis of available data. The objective is to produce an evidence-based report on the methods of prevention of VT after injury. METHODS: A panel of 17 national authorities from the academic, private, and managed care sectors helped design and review the project. We searched three electronic databases (MEDLINE, EM-BASE, and Cochrane Controlled Trial Register) to identify articles relevant to four key questions: methods of prophylaxis, methods of screening, risk factors for VT, and the role of vena caval filters. The initial 4,093 titles yielded 73 articles for meta-analysis. A random-effects model was used for all pooled results. Study quality was evaluated by previously published quality scores. In this article (part I), we report on the question ranked by the experts as the most important, i.e., Which is the best method to prevent VT?, and also on the incidence of deep venous thrombosis and pulmonary embolism in trauma patients. RESULTS: The incidence of deep venous thrombosis and pulmonary embolism reported in different studies varies widely. The pooled rates are 11.8% for deep venous thrombosis and 1.5% for pulmonary embolism. Only a few randomized controlled trials have evaluated the methods of VT prophylaxis among trauma patients, and combining their data is difficult because of different designs and preventive methods used. The quality of most studies is low. Meta-analysis shows no evidence that low-dose heparin, mechanical prophylaxis, or low-molecular-weight heparin are more effective than no prophylaxis or each other. However, the 95% confidence intervals of many of the comparisons are wide; therefore, a clinically important difference may exist. CONCLUSION: The trauma literature on VT prophylaxis provides inconsistent data. There is no evidence that any existing method of VT prophylaxis is clearly superior to the other methods or even to no prophylaxis. Our results cast serious doubt on the existing policies on VT prophylaxis, and we call for a large, high-quality, multicenter trial that can provide definitive answers.

Evidence-Based Medicine↗
PubMed2000

Prevention of venous thromboembolism after injury: an evidence-based report--part II: analysis of risk factors and evaluation of the role of vena caval filters.

OBJECTIVE: In part II, we describe the results of the literature search and data analysis concerning risk factors for venous thromboembolism and the role of vena caval filters (VCF) in preventing pulmonary embolism. METHODS: The methodology used in part I was used in part II. RESULTS: Spinal fractures and spinal-cord injuries increase the risk for development of deep venous thrombosis (DVT) by twofold and threefold, respectively. Patients with DVT were an average of 9 years older than patients without DVT. No specific age cut-off point for increased risk could be established because data could not be combined across studies. Patients with prophylactically inserted VCF had a lower incidence of pulmonary embolism (0.2%) compared with concurrently managed patients without VCF (1.5%) or historical controls without VCF (5.8%). These results are reported on uncontrolled studies with observational design. CONCLUSION: Spinal injuries, spinal cord injuries, and age are risk factors for development of DVT. Prophylactic placement of VCF in selected trauma patients may decrease the incidence of pulmonary embolism. Future research with well-designed studies is required to provide definitive answers.

Evidence-Based Medicine↗
PubMed2000

The effect of a compulsory curriculum on ethical attitudes of medical students.

The purpose of the present study was to assess the influence of a compulsory curriculum on first-year medical students. The ethical attitude study was performed at the School of Medicine, University of Rijeka, Croatia. The samples consisted of 171 medical students (68 males and 103 females) interviewed at the beginning of the first year of studies. Some of them, namely 143 (56 males and 87 females) were interviewed again at the end of the same academic year. Data were analysed by applying factor analysis under principal component model and varimax criterion as the rotation model. The results clearly show that the current compulsory curriculum without formal ethical education has a limited influence on first-year medical students. That points to the obvious necessity to implement the medical ethics in the course of medical education.

Attitude of Health Personnel↗
PubMed2000

Health status as geneologic burden in aging process.

UNLABELLED: Knowledge of modern molecular biology is leading to the idea that aging and diseases of the aged are two different entities. Healthy life is relatively limited by the specific number of chronic conditions which are present more in old age. Up to now the idea of aging as a process in relation to the individual, organ, tissue, cell or a molecule. There are only few studies on the influence of aging within a single family and even less of aging within several generations of the same family. Genealogic level is one way of getting into the process of family system and aging throughout time. The aim of the study was to determine the significance of genealogical burden with regard to the health status in examinees with different cognitive capabilities. The difference according to sex and age was not significant between the two groups. Health status of the examinees proband in both groups showed 34.4% healthy examinees in the group D and 65.3% in group G. The difference between the two groups was statistically significant. The difference of health status of parents (II. generation) was statistically significant in both groups. Morbidity of diseases was not statistically significant. Most of the ancestors from the grandmothers and grandfathers (III generation) died. (group G--97.5%, group D--100%). Statistically significant difference is present among the diseases of the circulatory system and those of digestive system in this generation. Data on the ancestors of the IV. generation showed that all the relatives died in both groups. CONCLUSION: The health status of the examinees with higher impairment in the test of cognitive capabilities is worse and they come from the families with worse health status.

Adult↗
PubMed2000

Family relationships in prediction of ageing.

This paper presents a study of the predictive value of family relationships from genealogies, and its impact on the delayed ageing. The study comprised adult population over 18 years of age of two urban family practices (N = 1700). The study sample included all patients (total = 581; 57.3% female, 42.7% male) having sought medical assistance of any kind in the period of three consecutive months. The study was performed in two stages. The selection of patients according to the results of the 25th and 75th percentiles of the memory component analysis was done in stage I. The comparison of life history and events across a genealogy in the groups of the 25th and 75th percentile memory deficit was done in stage II. The method used in stage I was a psychological test--Pictures of Object Test (POT) to test the memory deficit. In stage II, personal life histories and description of the genealogies were obtained by individuals' associations expressed in the form of a free text which was then analyzed statistically (SPAD-T), and the results were correlated to data read on the developed genogram. The statistical text analysis of life-events recall and the correlation across a genealogy showed a difference in the patterns of family relationships across a genealogy in the two study groups, and their predictive value for prevention in family practice.

Adolescent↗
PubMed2000

The Croatian telemedicine.

Telemedicine developed in Croatia in two phases. The first phase during the 1970s was limited because of insufficient technology and scarce resources. But that phase was important as a learning process and the preparatory stage for the promising future. The communications infrastructure was heavily destroyed during the 1991-92 war but it was reconstructed and rebuilt as a modern technology based on optical fibres. The new technical and technological infrastructure was the base for the development of CARNet (Croatian Academic and Research Network). CARNet was linked to the Internet and enabled the international exchange of information for the scientific community. Telemedicine projects started firstly as pilot projects around the same time as in other countries. They were financially covered mostly by the Ministry of Science either directly or through the CARNet. The telemedicine projects, like telepathology, teleradiology, teleneurosurgery, teleeducation, developed in a very sophisticated way and are now in the phase of implementation into the routine health practice. Some projects are still in the pilot phase, but thanks to highly trained professionals, they are promising and it can be expected that with the growing economic stuation they will be implemented soon.

Computer Communication Networks↗
PubMed2000

Detecting predictors of new-born survival by fuzzy sets based machine learning system.

Machine learning system based on fuzzy sets was used for detecting predictors of new-born survival within the first 15 days after birth. The system processed real-life medical data of 566 new-borns; 528 survived and were classified as "alive", the remaining 38 did not survive and were classified as "died". The state of each new-born was described by values of 112 attributes. The system detected five of the attributes as the best predictors for survival (asphyxia, apnoea, birth weight, reanimation and gestation age). To evaluate are the selected attributes relevant for prediction, the following procedure was used: 566 new-borns were divided into two groups by random selection; 396 (70%) randomly selected new-borns formed the learning group, the remaining 170 new-borns formed the test group. The system acquired prediction knowledge by processing data of the learning group new-borns. Using the knowledge thus acquired, the system predicted survival for each new-born from the test group several times, each time using another set of attributes: once, using all 112 attributes; once, using attributes detected by the system as the best predictors; once, using remaining attributes without the best predictors. After the predictions for all new-borns from the test group had been finished, classification accuracy, sensitivity (accuracy for "alive") and specificity (accuracy for "died") were calculated as measures of prediction success with particular sets of attributes. The results have shown that the best prognostic accuracies were achieved when prediction was done using those attributes which the system detected as the best predictors for new-born survival.

Artificial Intelligence↗
PubMed2000

Respiratory function in female workers occupationally exposed to organic dusts in food processing industries.

Respiratory consequences of work in food processing industry were studied in 764 female workers exposed to organic dusts associated with the processing of green and roasted coffee, tea, spices, dried fruits, cocoa and flour. A group of 387 female workers not exposed to respiratory irritants served as controls for the prevalence of acute (during work shift) and chronic respiratory symptoms. A greater prevalence of all acute and chronic respiratory symptoms was consistently found among exposed workers than among control workers. The highest prevalence of chronic respiratory symptoms was recorded for chronic cough (40%), followed by acute symptoms of dry cough (58.7%). The difference in the prevalence of chronic respiratory symptoms between the exposed and control workers was in general significant (p < 0.01 or p < 0.05). Mean acute reductions of lung function over the work shift were recorded in all of the studied groups; the mean across-shift decrease as a percentage of preshift values was particularly marked in FEF25 (-26.7%), FEF50 (-21.6%), followed by FEV1 (-9.9%) and FVC (-3.7%). The preshift (baseline) values of ventilatory capacity were decreased in comparison to the predicted ones, and were lowest for FEF50 and FEF25. This finding indicated an effect of organic dust on small airways. Our analysis suggested that both dust exposure and smoking history contributed independently to these respiratory findings. Disodium cromoglycate (DSCG) significantly diminished across-shift reductions for FEF50 and FEF25 in a subgroup of the examined workers. Our data suggested the female workers employed in food processing industry to be at risk of developing both acute and chronic respiratory symptoms as well as ventilatory capacity impairment as the result of occupational exposures.

Adolescent↗
PubMed1999

Cancer incidence in eastern Adriatic isolates, Croatia: examples from the islands of Krk, Cres, Losinj, Rab and Pag.

As an extension of previous research this study investigates the incidence of cancer in five genetic isolate island populations of the Eastern Adriatic, Croatia. Thorough anthropological research over the past three decades has established some of those populations as outstanding examples of genetic isolates. A previous study which found higher cancer incidence in 5 Eastern Adriatic islands than in a control population supported a hypothesis that among the founders of these populations there were genetic variants (especially with recessive inheritance) responsible for genetic susceptibility to certain types of cancer. This study sought to investigate cancer incidence in 5 further island populations. All cancer cases in five island populations (Krk, Cres, Losinj, Rab and Pag) over the 20-year period (1971 to 1990) was extracted from the data of the Croatian Cancer Registry. The mainland populations of Istrian and Primorsko-Goranska County, characterized by similar environmental factors but an outbred genetic structure, represented a control population. After standardization by by sex and age, cancer incidence was higher in the island populations than in the control population in both sexes. The cancer sites primarily responsible for the excess incidence were prostate, stomach and pancreatic cancer in males, and ovarian, breast, stomach, bowel, and brain cancer in females. The reasons for the increased cancer incidence are uncertain and may be due to different environmental exposure between the two populations. However, it is possible that genetic isolation and inbreeding are important factors. Further investigations of cancer in these isolate populations are warranted to explore these findings further.

Adult↗
PubMed1999

Surname as 'cancer risk' in extreme isolates: example from the island of Lastovo, Croatia.

The aim of this study was to analyze whether there are surnames which appear more frequently among the ancestors of cancer cases in a small isolate, in comparison to the ancestral surnames of the healthy controls, using the classic case-control design. The chosen setting was the island of Lastovo, Croatia, located more than 100 kilometers from the nearest coastal region. The period of study was 1970-1995, during which a total of 76 cancer cases were recorded in a population of approximately 800. The comparison of surname frequencies was performed in current and in five ancestral generations. The leading hypothesis was that, if inbreeding and common ancestry contributed to the development of the disease, then those phenomena should be reflected in increasing frequency of some surnames among ancestors, identifying the 'hidden' consanguinity, or 'following' cancer-promoting genes on the Y-chromosome. The results imply that there are surnames representing a classic "risk" for cancer, but also those "protecting" from its development, which all underscores the importance of founder effect and genetic predisposition to the disease in a small, reproductively isolated population. All of the results become more evident and increasingly significant when analyzed in more distant ancestral generations.

Case-Control Studies↗
PubMed1999

Medical informatics in the medical curriculum--when?

Undergraduate teaching of medical informatics (MI) at the Medical School University of Zagreb has been changing its position in the medical curriculum. Nowadays, this subject is positioned in the second year of the medical curriculum. The aim of this paper is to find out what the students of the second year (S2Y) and of the sixth year (S6Y) think about the position of MI in the medical curriculum. The results of students' opinions have shown that MI should be positioned: in the last two years (63% of S2Y, 36% of S6Y), in the middle (11% of S2Y, 21% of S6Y), and at the beginning of the medical curriculum (26% of S2Y, 43% of S6Y). However, analysing this question according to previous experience of the students of both groups, it can be concluded that: the S6Y with more previous experience shift the subject towards the end of the medical curriculum, and the S2Y with more previous experience shift the subject towards the beginning of the medical curriculum. According to our long-term experience and students' opinion, the most relevant MI subjects, any kind of medical application, should necessarily come at the end of the medical curriculum.

Computer Literacy↗