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Biomedical subjects

J Jokela

Publications and source records attributed to J Jokela.

32 records · Page 2Linked to original sources
PubMed1997

Dental services utilization between 1977 and 1995 by Finnish adolescents of different socioeconomic levels.

Equal distribution of health care services has long been a major goal of health policy in the Nordic countries. According to these guidelines, every child is expected to have an examination and treatment at least every second year. The aim of this study was to analyze the trends and, in particular, the socioeconomic differences in dental visits between 1977 and 1995. The data were collected as part of a nationwide research program, the Adolescent Health and Lifestyle Survey, which began in 1977. Every second year a self-administered questionnaire was mailed to a representative sample of 14-, 16- and 18-year-old Finns. The sample sizes in the surveys varied from 2422 to 9556, making a total of 56,605 subjects in the whole study. The response rates in different years varied from 77% to 88%. The percentage of adolescents visiting a dentist increased between 1977 and 1981 and thereafter remained stable. Dental visits seemed to correlate with the occupational and educational status of the parents up to 1983, but not after that. The Finnish primary oral health care policy seems to have gained a major objective by eliminating social inequality in dental service utilization among adolescents.

Adolescent↗
PubMed1996

Direct and correlative phenotypic selection on life-history traits in three pre-industrial human populations.

Because natural selection acts simultaneously on several correlated traits, can be under both direct and correlative selection simultaneously. Correlative selection may either weaken or magnify the association between a trait and fitness. Direct effect of a single trait on fitness can be assessed by removing the effects of correlative selection with multivariate techniques. We studied the phenotypic selection on demographic life-history traits in three pre-industrial human populations, which experienced different mortality environments. We used path-analysis to estimate direct and correlative selection on different traits in females and males. Our results indicate substantial differences among the sexes in the force of phenotypic selection on key life-history traits. For females, the most important component of reproductive success was the age at first reproduction. Most important component of fitness for males was the quality of mate. In addition, our analysis revealed considerable among-population variation in the selection on life-history traits. These differences are in accord with the historical notes of among-population variation in the lifestyle and harshness of the environment, suggesting that among-population variation in life-history traits may have been a response to the environmental variation.

Age Factors↗
PubMed1995

A simple method for monitoring mutans streptococci in young children.

The study assessed the practicability of the Dentocult-SM STRIP MUTANS test in children, using dental floss to transfer the dental plaque to the strip. The subjects were children of 2-3 yr (n = 365) and 5-6 yr (n = 398). The mutans streptococci count on the strip was found to be a good indicator of infection and was surprisingly accurate in the prediction of the 3-yr caries increment.

Chi-Square Distribution↗
PubMed1995

Organic halogens in the environment: studies of environmental biodegradability and human exposure.

Organic halogens from chlorobleaching of kraft pulp were not as biorecalcitrant as has been assumed. Fifty percent were removed during biotreatment of wastewater, and 50% of the remaining organohalogens faded in fresh water ecosystems in 200 to 400 days. Molecular size seemed not to hinder biodegradation up to sizes of approximately 2000 daltons. Anoxic biodegradation was of prime importance for halomineralization of pulp bleaching organohalogens but could also lead to toxic metabolites such as vinyl chloride from tri- and tetrachloroethene in anoxic soil. Indigenous soil microbes were unable to clean old organohalogen pollution but had converted chlorophenols into polymeric substances, chlorohumus, which were found bioaccumulable by earthworms in spite of the large (up to 5000 g/mole) molecular sizes. Because of the danger of formation of toxic metabolites, the biochemistry of the xenobiotic degradation must be elucidated before active bioremediation is practiced on polluted soil or water. Groundwater pollution by chlorophenols led to increased disease among the exposed population in one well-studied case. Two further cases of potential environmental health impact are described.

Biodegradation, Environmental↗
PubMed1994

Sensitivity of the central visual field in 70- to 81-year-old male athletes and in a population sample.

The sensitivity of the central visual field (0 degree-30 degrees) was studied using an automatic Octopus 500E perimeter in elderly male athletes and in a population sample of men of corresponding age. The athletes (N = 96) were endurance and power athletes, who were still active in competitive sports with training histories spanning tens of years. The athletes' results were compared with those of a sample of men of the same age (70-81 years, N = 41) randomly selected from the local population register. The sensitivity values of the athletes, and the endurance athletes in particular, were significantly better than those of the controls, with differences varying from 1 to 2.5 dB in the different areas of the central visual field. Multivariate analyses of the background factors of visual field sensitivity showed that the most important were age, amount of annual training, number of chronic diseases, HDL-cholesterol level, and vital capacity. The results suggest that a long training history, especially of the aerobic type, may be beneficial with respect to the sensitivity of the visual system.

Aged↗
PubMed1994

Retinal light sensitivity of the central visual field among 70- to 81-year-old men and women.

Retinal light sensitivity of the central visual field (0-30 degrees), visual acuity, intraocular pressure and pupillary size were screened in 42 men and 42 women aged 70 to 81 years. The subjects were randomly selected from the population register. After excluding the diagnosed glaucoma cases, the men had better visual field light sensitivity values than the women. They also had lower intraocular pressure and a wider pupillary diameter than the women, whereas there were no differences in visual acuity between the sexes. When the effect of pupillary size was controlled the differences in visual field light sensitivity values between men and women became non-significant. Among these elderly people there was a negative correlation between retinal light sensitivity and age among the men but not among the women.

Aged↗
PubMed1987

Thrombotic thrombocytopenic purpura in a human immunodeficiency virus (HIV)-seropositive homosexual man.

A case of thrombotic thrombocytopenic purpura (TTP) in a human immunodeficiency virus (HIV)-seropositive homosexual man is reported. The patient improved after corticosteroid and plasma exchange therapy was instituted. The case demonstrated most of the classic features of TTP, including histologic evidence of fibrin thrombi in small blood vessels. Atypical features included reduced number of megakaryocytes in the bone marrow and only partial resolution of thrombocytopenia after therapy was begun. An autoimmune thrombocytopenia has been well-characterized in HIV-antibody-seropositive homosexual men. Physicians caring for HIV-seropositive persons should also be aware of a possible association with TTP.

Acquired Immunodeficiency Syndrome↗
PubMed1987

Initial steps in the pathway for bacterial degradation of two tetrameric lignin model compounds.

We investigated the metabolic route by which a lignin tetramer-degrading mixed bacterial culture degraded two tetrameric lignin model compounds containing beta-O-4 and 5-5 biphenyl structures. The alpha-hydroxyl groups in the propane chain of both phenolic and nonphenolic tetramers were first oxidized symmetrically in two successive steps to give monoketones and diketones. These ketone metabolites were decomposed through C(alpha)(=O)-C(beta) cleavage, forming trimeric carboxyl acids which were further metabolized through another C(alpha)(=O)-C(beta) cleavage. Dehydrodiveratric acid, which resulted from the cleavage of the carbon bonds of the nonphenol tetramer, was demethylated twice. Four metabolites of the phenolic tetramer were purified and identified. All of these were stable compounds in sterile mineral medium, but were readily degraded by lignin tetramer-degrading bacteria along the same pathway as the phenol tetramer. No monoaromatic metabolites accumulated. All metabolites were identified by mass and proton magnetic resonance spectrometry. The metabolic route by which the mixed bacterial culture degraded tetrameric lignin model compounds was different from the route of the main ligninase-catalyzed C(alpha)-C(beta) cleavage by Phanerochaete chrysosporium.

Journal Article↗
PubMed1986

Correlates of vibrotactile thresholds in men of different ages.

As a part of a larger gerontological research project vibrotactile thresholds on the inner malleolus of the ankle were studied in 355 men aged 31-35, 51-55 and 71-75 years. The groups studied were random samples of men living in the town of Jyväskylä in Finland in the year 1981. The thresholds were assessed at three frequencies: 50 Hz, 100 Hz and 250 Hz. The thresholds were associated with age at all frequencies, the means of the threshold values being significantly higher in the older age groups. Within the age groups the thresholds correlated positively with height. In addition, reaction and movement time, leg extension velocity, and postural sway were associated with the thresholds. Neither general health status nor occupational or educational background, or living habits had significant influence on the thresholds within the age groups. The results suggest that the elevation of vibrotactile thresholds is an inherent manifestation of aging in the nervous system. In addition to age, the height of the respondents is among the factors that should be taken into account when interindividual comparisons are made, if the measurement is on distal parts of the body.

Adult↗
PubMed1986

Reaction and movement times in men of different ages: a population study.

Tests of psychomotor and motor speed at different levels of complexity were studied in random samples of men aged 31 to 35, 51 to 55, and 71 to 75 yr. The study was performed as a part of a larger research project on health and functional aging. Analyses indicated significantly slower responses among older men at all levels of test complexity (maximal knee extension velocity, tapping rate, simple and choice reaction and movement times). There were marked differences both between the youngest and the middle-aged groups and between the middle-aged and the oldest groups. Within the age groups high psychomotor and motor speed were associated with a favourable functioning of certain senses (vibration sensitivity and postural balance), with a high isometric muscular force, and with a high directly assessed aerobic capacity. The most important covariants of the speed functions within the age groups were, however, cognitive performance, length of education, and perceived health.

Adult↗
PubMed1986

Pure-tone thresholds, speech understanding, and their correlates in samples of men of different ages.

Pure-tone thresholds and speech understanding were studied in three samples of men of different ages (31-35, 51-55 and 71-75 years). The air-conducted pure-tone thresholds were measured at 125-8,000 Hz and speech understanding by the help of interrupted and masked speech tests. The audiological measures were related to measures of other sensory functions, psychomotor speed, cognitive functions, psychic well-being, occupational and educational background and health. The results indicated a clear decrement in all audiological measures when proceeding from younger to older age groups. The results of the speech-understanding tests correlated significantly with the pure-tone thresholds both at 4,000 Hz and at the mean of three frequencies (500, 1,000, 2,000 Hz) in the speech area. The audiological measures were not associated with other sensory functions or psychic well-being but showed significant correlations with psychomotor speed and cognitive functions. The most important predictors of the auditory functions within the age groups were occupational status, noise exposure at work, cognitive capacity, education, and number of disease symptoms, which, in addition, correlated with each other.

Adult↗