Biomedical subjects

Alfred Barth

Publications and source records attributed to Alfred Barth.

9 recordsLinked to original sources

PubMed2006

Application of multiplex cytometric bead array technology for the measurement of angiogenic factors in the vitreous.

PURPOSE: This study was carried out to compare cytometric bead array (CBA) technology with conventional enzyme linked immunosorbent assay (ELISA) for the measurement of both vitreous and serum concentrations of interleukin-8 (IL-8), vascular endothelial growth factor (VEGF), and angiogenin (ANG) in diabetic and non-diabetic patients. METHODS: Measurement of vitreous and serum concentrations of IL-8, VEGF, and ANG using both ELISA and CBA was performed in 26 probands (13 diabetics and 13 non-diabetic control subjects). RESULTS: Vitreous and serum concentrations of IL-8, VEGF, and ANG determined by CBA showed a strong correlation with those measured by ELISA. Vitreous levels of IL-8, VEGF, and ANG were significantly higher in diabetics compared to non-diabetic control subjects. No significant correlation between vitreous and serum levels of any of the investigated parameters were found in either diabetics or control individuals. CONCLUSIONS: The present study is the first to utilize cytometric bead array technology for the measurement of angiogenic factors in the vitreous. Measurements obtained by ELISA and CBA technologies were highly correlated for IL-8, VEGF, and ANG in both vitreous and serum samples. Diabetic individuals showed significant elevation of IL-8, VEGF, and ANG in the vitreous but not in serum samples compared to control subjects. The most striking advantage of the CBA technology is the fact that numerous parameters can be measured in parallel using a comparatively small sample volume. It is therefore more rapid and cost effective than ELISA technology. CBA technology is a new, accurate method to measure IL-8, VEGF, and ANG in the vitreous.

Aged↗

PubMed2006

Study of immobilized and extracellular saccharase of watermelon.

A simple, rapid and reproducible procedure for the identification and determination of extracellular saccharase from culture medium of watermelon cell suspension cultures is described. The culture medium (without cells) was used for the identification and determination of extracellular enzyme activity. Intracellular activity was estimated from the cell suspension. Watermelon cell suspension was permeabilized by Tween 80 and immobilized by glutaraldehyde. The highest saccharase activity was at pH 4.6 at a temperature of 50 degrees C. The hydrolysis of substrate was linear 5h after reaching 60% conversion. The cells had high saccharase activity and good stability, and in long-term storage they showed convenient physico-mechanical properties.

Cells, Cultured↗

PubMed2005

Effects of short- and long-term unemployment on physical work capacity and on serum cortisol.

AIM: To investigate whether a decrease in physical working capacity occurs during the first year of unemployment and if this is accompanied by a deterioration in mental health. METHODS: In a longitudinal study, 71 unemployed individuals were investigated for 1, 6 months and 1 year after becoming unemployed. An additional 102 individuals who have been unemployed for more than 1 year were included in the cross-sectional part of the study. Possible decrease of physical working capacity was tested by bicycle ergometry. Psycho-emotional stress was tested by serum cortisol concentrations and by the Giessen symptom questionnaire. RESULTS: In short-term unemployed (STU) individuals, a significant decrease (P=0.001) of physical working capacity (16.3%) and a significant increase (P=0.004) of cortisol levels (17.6 microg/dl) was found. The Giessen symptom questionnaire score showed an increased emotional disturbance (P=0.035) during unemployment. The comparison of long-term unemployed and STU revealed a significant decrease (P=0.012) in physical working capacity (18.2%), a significant increase in cortisol levels (P=0.001) and a significant worsening of the Giessen symptom questionnaire score (P=0.001). CONCLUSION: Unemployment has a negative effect on physical working capacity and mental health, depending on the duration of unemployment. Factors that facilitate or impede physical and mental health during unemployment should be identified in future studies.

Adult↗

PubMed2005

Study of immobilized and extracellular aminopeptidases of watermelon.

Watermelon cells after permeabilization in Tween 80 were immobilized by glutaraldehyde without any carrier. Cells immobilized by cross-linking demonstrated significantly lower aminopeptidase activities than untreated cells. Pectate and alginate hydrogels were used successfully for immobilization of watermelon cells which retained activities of some aminopeptidases. A simple and rapid procedure for determination of extracellular aminopeptidases was developed using a synthetic substrate. p-Nitroanilides of amino acids were used as substrates for the determination of the extracellular and intracellular enzymatic activities. The culture medium (without cells) was used for the identification and determination of extracellular enzyme activities, whereas intracellular activities were estimated from the cell suspension.

Alginates↗

PubMed2005

Endurance exercise training in orthostatic intolerance: a randomized, controlled trial.

Orthostatic intolerance is a syndrome characterized by chronic orthostatic symptoms of light-headedness, fatigue, nausea, orthostatic tachycardia, and aggravated norepinephrine levels while standing. The aim of this study was to assess the protective effect of exercise endurance training on orthostatic symptoms and to examine its usefulness in the treatment of orthostatic intolerance. 2768 military recruits were screened for orthostatic intolerance by questionnaire. Tilt-table testing identified 36 cases of orthostatic intolerance out of the 2768 soldiers. Subsequently, 31 of these subjects with orthostatic intolerance entered a randomized, controlled trial. The patients were allocated randomly to either a "training" (3 months jogging) or a "control" group. The influence of exercise training on orthostatic intolerance was assessed by determination of questionnaire scores and tilt-table testing before and after intervention. After training, only 6 individuals of 16 still had orthostatic intolerance compared with 10 of 11 in the control group. The Fisher exact test showed a highly significant difference in diagnosis between the 2 groups (P=0.008) at the end of the study. Analysis of the questionnaire-score showed significant interaction between time and group (P=0.001). The trained subjects showed an improvement in the average symptom score from 1.79+/-0.4 to 1.04+/-0.4, whereas the control subjects showed no significant change in average symptom score (2.09+/-0.6 and 2.14+/-0.5, respectively). Our data demonstrate that endurance exercise training leads to an improvement of symptoms in the majority of patients with orthostatic intolerance. Therefore, we suggest that endurance training should be considered in the treatment of orthostatic intolerance patients.

Adult↗

PubMed2005

No cognitive deficits in men formerly exposed to lead.

OBJECTIVES: The objective of the study was to investigate long-term cognitive effects resulting from low to moderate lead exposure below current threshold values. Executive functions, attention, visuospatial and visuomotor functioning in workers formerly exposed to lead were investigated. METHODS: 48 men formerly exposed to lead and with a mean current blood level (PbB) of 5.4 microg Pb/100 ml were investigated, together with 48 matched controls (PbB, 4.7 microg Pb/100 ml) out of a pool of 61 males. The two groups were matched for age, years spent in education, verbal intelligence and gram alcohol consumption per week. The following neuropsychological tests were used: modified Wisconsin card sorting test, block design test, visual recognition test, simple reaction time, choice reaction and digit-symbol substitution. Lead exposure was assessed using both current and cumulative measurements. RESULTS: There were no significant differences in cognitive parameters between the two groups. When analyzing dose-response relationships, negative correlations were found between PbB and performance in the block design test, and between PbB and scores in the visual recognition and digit-symbol substitution tests. High cumulative exposure (IBL, >5000; duration of exposure, >5 years) correlated only with wrong reactions in the choice reaction test. CONCLUSIONS: The results of our study indicate that cognitive deficits resulting from low-level exposure to lead are reversible. The study was limited to low-level long-term exposure (all PbB values were always below 55 microg Pb/100 ml), and extrapolation of these results to persons heavily exposed to lead is not possible.

Adult↗

PubMed2004

Laser Doppler anemometry distinguishes primary Raynaud phenomenon from VWF syndrome.

OBJECTIVES: We evaluated two microcirculatory function-tests, the Laser Doppler (LD)-Anemometry and the Laser Doppler Imager (LDI)-Flowmetry in their value to further elucidate functional behavior of the "Vibration-induced white finger syndrome" (VWF) and to distinguish between Raynaud's phenomenon (RP) of idiopathic or vibration origin. PARTICIPANTS AND METHODS: Ninety-four patients, suffering from RP were studied (78 patients with primary RP and 16 patients with VWF). Measurement of blood cell velocity (BCV) before and after provocation was obtained by nailfold capillary microscopy and an included Laser detector ("Anemometry"). Digital blood flux was recorded by LDI-Flowmetry during a standardized cooling and rewarming thermal challenge. RESULTS: "Time to peak" of BCV, a measure of maximal reactive hyperemia was longer in VWF in comparison to primary RP (30.37 versus 19.29 sec P < 0.02), respectively. CONCLUSION: Based on the fact, that prolongation of reactive hyperemia, an indicator of impaired endothelium-dependent vasodilation is also frequently found in peripheral arterial occlusive disease, it is hypothesized that VWF is not only a microcirculatory vasospastic disorder, but may also be related to atherosclerosis. Anemometry, in association with an appropriate provocation-test, could represent a useful non-invasive method for objectifying diagnosis of VWF in patients with RP.

Adult↗

PubMed2004

[Shedding tears in hospitals - a survey of medical staff and students].

A questionnaire was used to investigate the crying behavior of medical personnel and medical students in Austrian hospitals. The results from 275 respondents show that shedding tears occurs relatively frequently. Main reasons were dying patients and having to give bad news. Explicitly negative reactions are rare. Attitudes towards crying are generally tolerant, although physicians tend to be more restrictive/(reserved?).

Adult↗

PubMed2002

Reduced cognitive abilities in lead-exposed men.

OBJECTIVES: Since it is still controversial whether-low-to moderate long-term lead exposure below current threshold values causes neurobehavioural deficits in adults, we investigated executive functions of the prefrontal cortex, attention, and visuospatial and visuomotor functioning in lead-exposed subjects. METHODS: Forty-seven lead-exposed subjects with a mean blood lead (PbB) level of 30.8 microg/100 ml and 53 non-lead-exposed aged-matched subjects (PbB: 4.32 microg/100 ml) with the same socio-economic background were investigated. Both groups were also matched on verbal intelligence. Neuropsychological tests were done by the modified Wisconsin card sorting test, block design test, visual recognition test, simple reaction time, choice reaction and digit symbol substitution. Lead exposure was assessed by current and cumulative measures. RESULTS: While there were significant differences in the results of the Wisconsin, block design and visual recognition tests, no differences were found in simple reaction time, choice reaction and digit symbol substitution. Significant correlations existed between current exposure and cognitive deficits. No correlation was found between cumulative exposure measures and cognitive parameters. CONCLUSIONS: Our results show that PbB below 70 microg/100 ml reduce neurobehavioural abilities, particularly visuospatial abilities and executive functions referring to the prefrontal cortex. As neurobiological substrate of the prefrontal dysfunction, glutamatergic system disturbances are discussed.

Adult↗