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Biomedical subjects

J Kern

Publications and source records attributed to J Kern.

At least 19 recordsLinked to original sources
PubMed1998

Respiratory findings in synthetic textile workers.

We studied 308 female and 92 male textile workers employed in a factory that produced synthetic fiber hosiery. The mean age of the women was 38 years, their mean duration of employment 16 years. The mean age of the men was 39 years with a mean duration of employment of 16 years. A control group of 160 female and 78 male nonexposed workers was also studied. Chronic and acute work related symptoms were recorded for all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves from which the forced vital capacity (FVC), the 1-sec forced expiratory volume (FEV1) and maximum expiratory flow rates at 50% and the last 25% (FEF50, FEF75) were read. There was a higher prevalence of all chronic respiratory symptoms in exposed than in control workers, although the differences were statistically significant only for dyspnea, sinusitis, and nasal catarrh (P < 0.01) in female synthetic textile workers, and for nasal catarrh (P < 0.01) in male synthetic textile workers. Occupational asthma was recorded in 3 (0.9%) of the women textile workers, and in 1 (1.1%) of male textile workers. There was a high prevalence of acute symptoms during the work shift, which was greatest for cough (female: 46%; male: 59%), dryness of the throat (female: 49%; male: 40%), dryness of the nose (female: 53%; male: 43%) and eye irritation (female: 46%; male: 36%). Ventilatory capacity data among the synthetic textile workers demonstrated significantly decreased FEF75 compared to predicted (P < 0.05). Our data suggest that inhalation of dust in synthetic textile plants causes the respiratory impairment.

Adult↗
PubMed1998

Oral iloprost treatment in patients with Raynaud's phenomenon secondary to systemic sclerosis: a multicenter, placebo-controlled, double-blind study.

OBJECTIVE: To evaluate the efficacy and tolerability of an oral preparation of iloprost, a prostacyclin analog, in patients with Raynaud's phenomenon (RP) secondary to systemic sclerosis (scleroderma). METHODS: A multicenter, randomized, parallel-group, placebo-controlled double-blind study was performed at university and community-based medical centers. Patients were randomly assigned to receive either 50 microg of iloprost orally twice daily or an identical gelatin-coated capsule containing placebo for 6 weeks. Outcome measures included average total daily duration of RP attacks, average number of RP attacks, and RP condition scored via a standardized daily diary. RESULTS: Three hundred eight patients with scleroderma (272 women, 36 men, mean age 49 years [range 18-80]) were enrolled. One hundred fifty seven were assigned to receive iloprost and 151 to receive placebo. One hundred forty-three patients in the iloprost group (91.1%) and 144 in the placebo group (95.4%) completed the 6-week treatment phase. Fifteen of these treated patients (8 iloprost, 7 placebo) failed to complete all of the followup visits. The mean reduction in the average duration of attacks from baseline to week 5-6 was 24.32 minutes in the iloprost group and 34.34 minutes in the placebo group (P = 0.569). Likewise, the mean reduction from baseline to week 5-6 in the daily frequency of attacks was 1.02 in the iloprost group and 0.83 in the placebo group (P = 0.459). The Raynaud's condition score, a patient-completed assessment of the severity of RP attacks, was reduced by 1.32 in the iloprost group and 1.00 in the placebo group (P = 0.323). The lack of significant difference between treatment groups did not change when a variety of factors, including use of other vasodilators, duration of disease, classification of scleroderma (limited versus diffuse), or number of baseline digital ulcers were taken into account. Premature withdrawal from the study due to adverse events occurred in 10 patients (6.4%) in the iloprost group and 3 (2.0%) in the placebo group (P = 0.058). CONCLUSION: Oral iloprost at a dosage of 50 microg twice daily is no better than placebo for management of RP secondary to scleroderma, either during 6 weeks of treatment or during 6 weeks of posttreatment followup.

Administration, Oral↗
PubMed1998

Respiratory findings in workers employed in the brick-manufacturing industry.

We studied 233 male workers employed in two brick-manufacturing plants and 149 matched control workers. The mean age of the brick workers was 35 years, with a mean duration of employment in this industry of 16 years. The prevalence of chronic respiratory symptoms as well as acute symptoms during the work shift were recorded. Lung function was measured on Monday during the work shift by recording maximum expiratory flow-volume (MEFV) curves, from which the forced vital capacity (FVC), the one-second forced expiratory volume (FEV1) and flow rates at 50% and the last 75% of the FVC (FEF50, FEF75) were measured. The results of periodic chest roentgenograms were reviewed. There was a significantly higher prevalence of chronic cough (31.8%), chronic phlegm (26.2%), and chest tightness (24.0%) in exposed workers, compared with control workers (20.1%; 18.1%; 0%) (P < 0.05). This increased symptom frequency was also documented among nonsmokers studied by age and by length of employment, suggesting a work-related effect. Among work shift-related symptoms, high prevalences were noted for upper respiratory tract symptoms (e.g., dry throat, eye irritation, throat irritation). The measured FVC and FEV1 were significantly lower than predicted for brick workers and suggested a restrictive pattern. The mean FVC (as a percent of predicted) was 78.1% and FEV1 was 88.1%. The FEF50 and FEF25 were not significantly decreased. A multiple regression analysis with age, exposure, and smoking as predictors and lung function parameters as response variables showed a significant effect between exposure and FVC. Significant chest roentgenographic abnormalities were not documented. These findings of a restrictive lung function pattern in brick workers with normal chest roentgenograms may suggest early interstitial disease. Additionally, a bronchitic component, as suggested by the respiratory symptoms, may also be present.

Adult↗
PubMed1998

Respiratory function and immunological status in paper-recycling workers.

The respiratory function and immunological status of workers employed in the paper recycling industry were studied. The mean age of the 101 studied workers was 41 years, and the mean duration of their exposure was 17 years. A group of 87 unexposed workers of similar age, duration of employment, and smoking history was studied for the prevalence of chronic respiratory symptoms. Lung function in the paper workers was measured by recording maximum expiratory flow volume (MEFV) curves and recording forced vital capacity (FVC), 1-second forced expiratory volume (FEV1), and maximum expiratory flow rates at 50% and the last 25% of the FVC (FEF50, FEF25). Immunological studies were performed in all 101 paper workers and in 37 control workers (volunteers). These included skin-prick tests with paper-dust extracts and other nonoccupational allergens, as well as the measurement of total serum immunoglobulin E. Significantly higher prevalences of all chronic respiratory symptoms were found in paper compared with control workers (P < 0.01). The highest prevalences were found for chronic cough (36.6%), chronic phlegm (34.7%), chronic bronchitis (33.7%), sinusitis (31.7%), and dyspnea (18.8%). Occupational asthma was diagnosed in four (4.0%) of the paper workers. A logistic regression analysis performed on chronic respiratory symptoms of paper workers indicated significant effects of smoking and exposure, with the smoking effect being the most important. Multivariate analysis of lung-function parameters indicate significant effects of exposure. For paper workers, the measured FEF50 and FEF25 were significantly decreased, compared with predicted values, suggesting obstructive changes located primarily in smaller airways. Among 101 tested paper workers, 16 (15.8%) had positive skin-prick tests to at least one of the paper extracts; none of the control workers reacted to these extracts. Increased serum IgE levels were found in 21% of the paper workers and in 5% of control workers (P < 0.05). Paper workers with positive skin-prick tests to any of the paper and/or other tested extracts had higher prevalences of chronic respiratory symptoms and lower measured lung-function tests compared with predicted than did those with negative skin-prick tests, but the differences were not statistically significant. The measured concentrations of total and respirable dust in this industry were higher than those recommended by Croatian standards. Our study suggests that work in the paper-recycling industry is associated with respiratory impairment and that sensitive workers employed in this industry may be at particular risk of developing chronic respiratory abnormalities.

Adult↗
PubMed1998

Gln368STOP myocilin mutation in families with late-onset primary open-angle glaucoma.

PURPOSE: To examine families ascertained for late-onset primary open-angle glaucoma (POAG) to determine mutations in the gene coding for myocilin. METHODS: The diagnosis of late-onset POAG was defined as age at diagnosis more than 35 years, intraocular pressure (IOP) 22 mm Hg or more in both eyes or 19 mm Hg or more while the patient was taking two glaucoma medications, glaucomatous optic neuropathy in both eyes, and visual field loss consistent with optic nerve damage in at least one eye of the proband. Two of three criteria were required in other family members. DNA from all families was screened for polymorphisms in myocilin using single-strand conformation polymorphism analysis. All polymorphisms were sequenced for mutations. RESULTS: Eighty-three affected people in 29 families with late-onset POAG were screened for mutations. Three mutations, two novel missense (Thr377Met and Glu352Lys) and one nonsense (Gln368STOP), were identified. The missense mutations did not segregate with the disease phenotype in these families. The nonsense mutation was found in 3 of 29 unrelated families with POAG. All affected family members and 8 of 12 in whom glaucoma was suspected had the Gln368STOP mutation. All people with this mutation had elevated IOP, and 78% had POAG by age 70. CONCLUSIONS: Three mutations were identified in the gene coding for myocilin in families with late-onset POAG. Of these, the Gln368STOP mutation was highly associated with the development of glaucoma. All people with this mutation had glaucoma or elevated IOP by age 70. In the United States, the Gln368STOP mutation in myocilin is strongly associated with the development of late-onset POAG. However, factors in addition to the presence of this mutation seem to play a role in the development of ocular hypertension and glaucoma in these families.

Adult↗
PubMed1998

[Respiratory function in textile workers involved in the processing of synthetic fibers].

The study included 308 female workers employed in processing synthetic stockings and 160 controls. The mean age of the exposed workers was 38 years with the mean exposure of 16 years. Most workers did not smoke while 41% of smokers consumed about 10 cigarettes a day. The data on acute and chronic respiratory symptoms were taken from all workers. Ventilatory capacity was measured by recording maximum expiratory flow-volume (MEFV) curves with readings on forced vital capacity (FVC), one-second forced expiratory volume (FEV1), and maximum expiratory flows at 50% and the last 25% (FEF50, and FEF25, respectively). Textile workers manifested a higher prevalence of chronic respiratory symptoms than did the controls, although the differences were statistically significant only for sinusitis, dyspnoea, and nasal catarrh. Occupational asthma was found in 3 (0.9%) textile workers. The prevalence of acute symptoms in the exposed workers was particularly high during shift, especially with regard to dryness of the nose (53%), dryness of the throat (49%), headache (47%), cough (47%), and the eye irritation (46%). Textile workers showed a significantly lower FEF25 than predicted. Our study on textile workers indicates that inhalation of synthetic fiber dust may impair the respiratory function.

Adolescent↗
PubMed1998

Investigations on the pharmacokinetics of alpha-lipoic acid in healthy volunteers.

AIM: The aim of the present study was to examine the pharmacokinetics of racemic alpha-lipoic acid in twelve healthy volunteers following single oral administration of 200 and 600 mg (Thioctacid 200 film tablets). SUBJECTS, MATERIAL AND METHODS: Each film tablet contained 200 mg of alpha-lipoic acid. In addition, an injection solution containing 200 mg of alpha-lipoic acid was administered. Plasma concentrations of alpha-lipoic acid were determined using a validated reversed-phase HPLC method with electrochemical detection having a lower limit of quantitation of 1 ng/ml. The areas under curve (AUC) were 46.82 +/- 21.46 and 157.97 +/- 35.05 microg x min/ml for the oral and intravenous administration of 200 mg, respectively. RESULTS: The AUC following oral administration of 600 mg was 157.83 +/- 35.82 microg x min/ml. The difference in mean t(1/2) for the two oral doses and the i.v. dose (in the range of 25.3-32.7 min) was not statistically significant. CONCLUSION: The lack of a significant difference between values for apparent total plasma clearance for the 200 and 600 mg doses indicates non-saturable kinetics of alpha-lipoic acid in healthy volunteers in this dose range. The absolute bioavailability after the 200 mg dose was 29.1 +/- 10.3%.

Administration, Oral↗
PubMed1997

Respiratory function in vineyard and orchard workers.

A group of 174 male vineyard and orchard workers was studied for the prevalence of acute and chronic respiratory symptoms and lung function changes. In addition, 115 male control workers were studied for the prevalence of chronic respiratory symptoms. There was a significantly higher prevalence of dyspnea and chest tightness in exposed compared to control workers. In particular, exposed nonsmokers had significantly higher prevalences of dyspnea and chest tightness than controls this was found for exposed nonsmokers with both short (< or = 10 years) and long (> 10 years) exposure. Smokers exposed for more than 10 years had significantly higher prevalences of chronic cough, chronic phlegm, chronic bronchitis, and chest tightness than smokers with shorter exposures (p < 0.01 or p < 0.05). Workers employed for more than 10 years had higher prevalences of most of the acute (shipt-related) symptoms than those workers with shorter employment; however, the differences were significant only for cough in smokers (p < 0.05). Significantly lower than predicted FVC values were measured in smokers and nonsmokers after both short and long duration of employment. Differences between measured and predicted FEV1, FEF50, and FEF25 were significant for workers employed for more than 10 years. A separate analysis of individual data as a percent of predicted values demonstrated that many workers had FVC (5.2%), FEV1 (6.3%), FEF50 (27.6%), and FEF25 (40.2%) lower than 70% of predicted values. These data suggest that vineyard and orchard workers may develop acute and chronic respiratory symptoms and lung function changes which are, in part, related to environmental factors and to cigarette consumption.

Adolescent↗
PubMed1997

Craniofacial parameters during growth from the deciduous to permanent dentition--a longitudinal study.

Data on the dynamics of craniofacial growth, obtained by simple non-invasive measurements, are scarce in comparison with those collected by cephalometric methods. The aim of this study was to measure a number of craniofacial parameters, and to evaluate their changes during transition from the deciduous to the permanent dentition. A sample of 61 subjects (32 boys and 29 girls) were followed longitudinally by annual examination from an initial mean age of 4.7 years to a final mean age of 11.8 years. Conventional anthropometric instruments were employed to measure six craniofacial variables: G-Op, Eu-Eu, Zy-Zy, Go-Go, N-Gn and N-Pr. The data were analysed using basic summary statistics and a longitudinal regression model. A difference between males and females was found for all variables during the study period. During the transition from deciduous to mixed dentition (4.7-7.5 years), the cranial breadth and length (Eu-Eu and G-Op) decreased followed by an increase during the mixed dentition. All other parameters showed a continuous increase, which was highest for the variables defining facial height.

Anthropometry↗
PubMed1997

B-cells are required for the initiation of insulitis and sialitis in nonobese diabetic mice.

Nonobese diabetic (NOD) mice spontaneously develop an acute onset of hyperglycemia reminiscent of human type I diabetes. The disease is the end result of a mononuclear cell infiltration of pancreatic islets (insulitis), culminating in the selective destruction of islet beta-cells by autoreactive T-cells. NOD mice also exhibit defects in B-cell tolerance as manifested by the presence of autoantibodies against islet cell autoantigens. Based on the potential ability of B-cells to act as antigen presenting cells, we hypothesized that autoreactive B-cells of NOD mice may be necessary for the activation of islet reactive CD4+ T-cells. In the present study, we utilized an anti-mu antibody to induce in vivo depletion of B-cells and found that B-cell depletion completely abrogates the development of insulitis and sialitis in NOD mice. In contrast, control IgG-treated NOD mice developed insulitis and sialitis by 5 weeks of age. Additionally, the discontinuation of anti-mu chain antibody treatment led to the full restoration of the B-cell pool and the reappearance of insulitis and sialitis. Thus, we conclude that B-cells are a requisite cell population for the genesis of the inflammatory lesions of the islets of Langerhans. This finding suggests that autoreactive B-cells may act as the antigen presenting cells necessary for the initial activation of beta-cell-reactive CD4+ T-cells implicated in the pathogenesis of autoimmune diabetes.

Age Factors↗
PubMed1997

ILLM--inductive learning algorithm as a method for prediction of life expectancy achieving.

The aim of the paper was to use inductive learning algorithm ILLM in the field of epidemiology, for prediction the life expectancy achieving. Data base comprised results of epidemiological investigation in some regions of Croatia. Overall accuracies for different samples and corresponding rules produced by ILLM algorithm, showed some interesting results. Algorithm can be seen as having the capacity to forecast 'achieving the life expectancy'. In the same time algorithm was not able to make a good forecast for 'not achieving the life expectancy'.

Adult↗
PubMed1997

[Respiratory function in vineyard and orchard workers].

The prevalence of acute and chronic respiratory symptoms and diseases and ventilatory capacity were studied in 174 vineyard and orchard workers. In addition, 115 nonexposed workers were studied as a control group. In vineyard and orchard workers, there was significantly higher prevalence of chronic cough, chronic phlegm, dyspnea and chest tightness in comparison to the control group. Smokers, vineyard and orchard workers employed for more than 10 years showed significantly higher prevalence of chronic cough, chronic phlegm, chronic bronchitis and chest tightness than smokers with shorter employment. In vineyard and orchard workers employed for more than 10 years there was higher prevalence of acute symptoms during work shift than in those with shorter employment, although the differences were statistically significant only for cough (p < 0.05). Most of the measured ventilatory capacity tests in vineyard and orchard workers were lower than predicted in smokers and nonsmokers. Values lower than 70% of predicted were found in 5.2% workers for FVC, in 6.3% for FEV1, in 27.6% for FEF50 and in 40.2% for FEF25. These data indicate that workers employed in vineyards and orchards may develop acute and chronic respiratory symptoms and diseases along with lung function changes which are partly related to environmental factors and partly to smoking habit.

Adolescent↗
PubMed1997

[Ventilatory capacity and respiratory symptoms in brickyard workers].

We studied 233 male brickyard workers and 149 matched non-exposed control workers. The mean age of the brickyard workers was 35 years with the mean duration of employment in this industry of 16 years. Significantly higher prevalence of chronic cough (31.8%), chronic phlegm (26.2%) and chest tightness (24.0%) was found in the exposed workers than in controls (20.1%; 18.1%; 0%) (P < 0.05). A high prevalence of acute symptoms during work shift, particularly dry throat and eye and throat irritation, were found in the brickyard workers. The measured FVC and FEV1 values were significantly lower than predicted values. On the other hand, the measured FEF50 and FEF25 were not significantly lower than predicted. This was found in the exposed smokers and nonsmokers. Dust concentrations were considerably higher than recommended for dust which contains up to 70% of SiO2. Our data suggest that the brickyard workers display a high potential to develop acute and chronic respiratory symptoms and mostly restrictive changes of lung function.

Adult↗
PubMed1997

[Disorders of the respiratory tract in workers in the chemical industry].

This paper studies the prevalence of chronic respiratory symptoms and diseases in 567 chemical workers and in 340 controls as well as their ventilatory capacity. The prevalence of all chronic respiratory symptoms was found to be significantly higher in the exposed workers than in controls (p < 0.01). Workers aged over 40 and those employed for over 10 years demonstrated higher prevalence of chronic respiratory symptoms than the workers up to 40 and those employed for up to 10 years, although the differences were not statistically significant. A large number of chemical workers complained of acute respiratory symptoms manifesting during the shift. The measured values of ventilatory capacity in chemical workers were significantly lower than those predicted. The findings were more pronounced in workers over 40 and in those employed for over 10 years. The measured values of gases and fumes in the working environment were mostly below the recommended values. Our data suggest that, in spite of low atmospheric pollution of the working environment, sensitive workers may develop respiratory impairments.

Adult↗
PubMed1996

Seasonal Denitrification in Flooded and Exposed Sediments from the Amazon Floodplain at Lago Camaleao

Denitrification processes were measured by the acetylene-blockage technique under changing flood conditions along the aquatic/terrestrial transition zone on the Amazon floodplain at Lago Camaleao, near Manaus, Brazil. In flooded sediments, denitrification was recorded after the amendment with NO3- (100 μmol liter-1) throughout the whole study period from August 1992 to February 1993. It ranged from 192.3 to 640.7 μmol N m-2 h-1 in the 0- to 5-cm sediment layer. Without substrate amendment, denitrification was detected only during low water in November and December 1992, when it occurred at a rate of up to 12.2 μmol N m-2 h-1. Higher rates of denitrification at an average rate of 73.3 μmol N m-2 h-1 were measured in sediments from the shallow lake basin that were exposed to air at low water. N2O evolution was never detected in flooded sediments, but in exposed sediments, it was detected at an average rate of 28.3 μmol N m-2 h-1 during the low-water period. The results indicate that under natural conditions there is denitrification and hence a loss in nitrogen from the Amazon floodplain to the atmosphere. Rates of denitrification in flooded sediments were one to two orders of magnitude smaller than in temperate regions. However, the nitrogen removal of exposed sediments exceeded that of undisturbed wetland soils of temperate regions, indicating a considerable impact of the flood pulse on the gaseous turnover of nitrogen in the Amazon floodplain.

Journal Article↗
PubMed1996

Airway function and respiratory symptoms in sanitation workers.

The prevalence of acute and chronic respiratory symptoms and lung-function changes was studied in a group of 81 municipal sanitation workers. In addition, the prevalence of chronic respiratory symptoms and lung function was studied in 65 control workers. There were significantly higher prevalences of all chronic respiratory symptoms among the sanitation workers than among the control workers. Sanitation workers (smokers and nonsmokers) 40 years of age or older had higher prevalences of all chronic respiratory symptoms than younger workers. In addition, sanitation workers (both smokers and nonsmokers) employed for 10 years or longer had significantly higher prevalences of chronic respiratory symptoms than control workers. There was also a high prevalence of acute symptoms, which developed among the sanitation workers during work shifts. Of these symptoms, prevalences were highest for dryness of the nose and throat, followed by throat and eye irritation. Lung-function testing demonstrated significantly diminished forced vital capacity (FVC) and 1-second forced expiratory volume (FEV1) for the 81 sanitation workers compared with control values. These differences only become significant after 10 or more years of employment in the sanitation industry and were not entirely explained by smoking. These differences were smaller and not statistically significant for maximum flow rates at 50% and the last 25% of the vital capacity. Our data suggest that sanitation worker--particularly those with long periods of work exposure--may develop acute and/or chronic respiratory symptoms accompanied by decreases in lung function (primarily FVC and FEV1).

Adult↗