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  • 1
    Electronic Resource
    Electronic Resource
    Occupational exposure to hexachlorocyclohexane (1981)
    Springer
    International archives of occupational and environmental health 48 (1981), S. 81-87 
    Details
    ISSN: 1432-1246
    Keywords: Pesticides ; Hexachlorocyclohexane ; Lindane ; Health supervision ; Benzenehexachloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixty male workers in a lindane (y-hexachlorocyclohexane)-producing factory were examined with regard to health in comparison with an external control group of 20 clerks. Case history, physical examination, neurologic status, and ECG revealed no significant differences between groups. However, the following significant differences in clinical-chemical blood tests were ascertained: higher polymorphonuclear leukocyte count, lower lymphocyte count, higher reticulocyte count, lower prothrombin (Quick's) test, and lower blood concentrations of creatinine and uric acid. No significant differences were observed in total red and white blood cell as well as platelet counts, hemoglobin content, the other counts of differential blood picture, γ-GT, GOT, GPT, LDH, cholinesterase, triglycerides, cholesterol, and urea. In spite of a pronounced exposure to the α-, β-, and γ-isomers of hexachlorocyclohexane, no signs of severe impairment of health were observed; only small deviations in some laboratory tests were found having no pathologic significance. However, biological monitoring and health supervision of HCH-exposed workers should be carried out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00405934
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  • 2
    Electronic Resource
    Electronic Resource
    Occupational exposure to hexachlorocyclohexane (1981)
    Springer
    International archives of occupational and environmental health 48 (1981), S. 165-172 
    Details
    ISSN: 1432-1246
    Keywords: Pesticides ; Hexachlorocyclohexane ; Lindane neurological findings ; Benzenehexachloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary Sixty male workers in a lindane (γ-hexachlorocyclohexane) producing factory were examined with regard to functions of nervous system in comparison with two external control groups having no contact with hazardous substances. Examinations of reflexes and sensibility revealed no pathological signs. Mean values of amplitude and frequency of forefinger tremor were found at about 20 μm and 10 Hz respectively without significant differences between groups. Manual skill tested by means of a tracking task was nearly the same in HCH-workers and a control group of dairy workers. On the contrary, a control group of clerks showed significantly better results in the tracking test, a probable consequence of their occupational practice. In electromyography no pathologic patterns were observed. The maximal motor nerve conduction velocity of ulnar nerves showed nearly identical mean values of 59.5 m/s in HCH-workers and controls. Neuromuscular conduction as revealed by distal latencies was not impaired. Furthermore, electroencephalographic recordings taken in spot-checks of HCH-workers and controls did not show any specific pathological signs. Only small abnormalities in rhythm could be observed in some cases of workers as well as of control persons indicating no increased incidence in the HCH exposed group. In conclusion, even after years or decades of occupational HCH exposure, in this study no signs of neurological impairment or perturbation of “neuromuscular function” could be ascertained.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00378437
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  • 3
    Electronic Resource
    Electronic Resource
    Occupational exposure to hexachlorocyclohexane (1980)
    Springer
    International archives of occupational and environmental health 47 (1980), S. 119-127 
    Details
    ISSN: 1432-1246
    Keywords: Pesticides ; Hexachlorocyclohexane ; Biological monitoring ; Lindane ; Benzenehexachloride
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a lindane (γ-hexachlorocyclohexane =γ-benzenehexachloride)-producing factory 57 workers were studied with regard to their blood levels of the three hexachlorocyclohexane isomers:α-, β-, andγ-HCH. The TLV-TWA (MAK value 1979) forγ-HCH of 0.5 mg/m3 was not exceeded at any of the workplaces where HCH is synthesized and purified to lindane. Additionally, in some of the workers samples of s.c. adipose tissue were taken for determination of HCH-isomer content. An external group of 20 clerks was examined in the same way for control purposes. In contrast to the control persons, none of whom had HCH-concentrations in serum above the respective detection limits, the values determined in serum of the exposed workers were in the following ranges:α-HCH: 10–273 μg/l,β-HCH: 17–760 μg/l, andγ-HCH: 5-188 μg/l. Of special interest is the observation of a significant increase ofβ-HCH-concentration in serum with the time of employment in lindane production, indicating a pronounced accumulation of this substance in the human organism. Concentrations of this isomer in s.c. adipose tissues were about 300-fold higher than in serum. A significant correlation between both parameters could be established. The results of this study show that adherence to the TLV-TWA ofγ-HCH is not sufficient for control of HCH-exposure. Furthermore, biological monitoring of exposed workers is necessary taking into account the three more important isomersα-, β-, andγ-HCH.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00716371
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  • 4
    Electronic Resource
    Electronic Resource
    Occupational exposure to hexachlorocyclohexane (1981)
    Springer
    International archives of occupational and environmental health 48 (1981), S. 283-287 
    Details
    ISSN: 1432-1246
    Keywords: Pesticides ; Hexachlorocyclohexane ; Lindane benzenehexachloride ; Sex hormones
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Summary In a lindane (γ-hexachlorocyclohexane)-producing factory 54 male workers (mean age 40 years, mean duration of exposure 8 years) were studied with regard to their blood levels of testosterone, LH, and FSH. Twenty clerks of nearly the same age were examined for control purposes in the same way. Serum-LH concentrations of the exposed workers were significantly higher than in controls. Geometric mean values were 8.8 mIU/ml and 5.7 mIU/ml respectively. On the other hand, FSH levels were insignificantly higher. Concerning testosterone concentrations in serum, these were found to be slightly lower in the group of workers than in control persons but this difference could not be proved to be statistically significant. These results indicate certain perturbations in sex hormone regulation probably as a consequence of HCH-exposure. To judge the pathological significance of these alterations further investigation will be necessary.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00405615
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  • 5
    Electronic Resource
    Electronic Resource
    Kinetische Studien derd-Glucoseresorption im proximalen Konvolut der Rattenniere (1969)
    Springer
    Pflügers Archiv 305 (1969), S. 139-154 
    Details
    ISSN: 1432-2013
    Keywords: d-Glucose ; Microperfusion ; Proximal Tubule ; Active Reabsorption ; Kinetic Study ; d-Glucose ; Mikroperfusion ; proximaler Tubulus ; aktive Reabsorption ; kinetische Studien
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Proximale Konvolute von Rattennieren wurden bei fehlendem Nettofluß von Natriumionen und Wasser kontinuierlich mit Lösungen perfundiert, die eined-Glucosekonzentration zwischen 0,5 und 2,0 mmol/l enthielten. Der Abfall der intraluminalend-Glucosekonzentration entlang eines Konvolutes wurde durch Absaugen der perfundierten Lösung in abnehmender Entfernung von der Perfusionsstelle verfolgt. Die pro innere Tubulusoberfläche und Zeit transportierted-Glucosemenge wird mit Abnahme der intraluminalen Glucosekonzentration kleiner. Dieses Verhalten läßt sich durch eine 2-parametrige Gleichung analog der Michealis-Menten-Kinetik beschreiben. Es errechnet sich eine maximale Transportrate,V max, von 6 · 10−10 mol · cm−2 · sec−1 und eine Halbsättigungskonzentration,K m, von 0,6 mmol/l. Die so beschriebene aktive Resorption und die von uns gefundene passive Permeabilität des proximalen Konvolutes fürd-Glucose reichen, nach angestellten Computerberechnungen zu schließen, allein nicht aus, um den Nettoglucosetransport der Gesamtniere unter Freiflußbedingungen quantitativ zu beschreiben.
    Notes: Summary The proximal convoluted tubule of rat kidney was continuously perfused with a steady state solution containing 0.5 to 2.0 mM ofd-glucose. The gradual decrease of intraluminald-glucose concentration was investigated with repeated collections of perfusate from the same tubule whereby the sequence of punctures proceeded towards the site of perfusion. The rate ofd-glucose transport per unit area decreased with decreasing intraluminald-glucose concentration. This relationship could be expressed by a two parameter system corresponding to the Michaelis-Menten equation. It was found that the local maximal transport rateV max equals 6×10−10 mol×cm−2×sec−1 andK m equals 0.6 mM. Our data on active resorption and passive permeability ofd-glucose in the proximal convolution have been subjected to computer analysis. The sum of both components ofd-glucose transport alone as measured under the condition of zero netflux of sodium chloride and water did not match the amount of net glucose transport found for the whole kidney under free-flow-conditions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585841
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  • 6
    Electronic Resource
    Electronic Resource
    Differenzierung zwischen aktiver und passiver Komponente desd-Glucosetransports am proximalen Konvolut der Rattenniere (1969)
    Springer
    Pflügers Archiv 305 (1969), S. 118-138 
    Details
    ISSN: 1432-2013
    Keywords: d-Glucose ; Microperfusion ; Proximal Tubule ; Active Reabsorption ; Passive Permeability ; d-Glucose ; Mikroperfusion ; proximaler Tubulus ; aktive Resorption ; passive Permeabilität
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Der Nettotransport und der unidirektionale Transport vond-Glucose wurden in Mikroperfusionsversuchen am proximalen Konvolut der Rattenniere unter der Bedingung des fehlenden Nettoflusses von Natriumchlorid und Wasser gemessen. Nach vollständiger Hemmung des aktiven Transportanteils durch Phlorrhizin (10−4 mol/l in der Perfusionslösung) läßt sich eine passive Komponente desd-Glucosetransports nachweisen. Diese ist als additives Glied zum aktiven Transportanteil auch im nicht phlorrhizin-vergifteten Zustand zu beobachten. Der aktive Transportanteil beträgt imV max Bereich 6·10−10 mol·cm−2·sec−1. Die passive Transportkomponente ist derd-Glucosekonzentrationsdifferenz zwischen Perfusat und Serum im angewandten Konzentrationsbereich direkt proportional. Zwischen den Ergebnissen der Ein- und Ausstrommessung besteht kein signifikanter Unterschied. Es wird daraus geschlossen, daß der passived-Glucosefluß ein einfacher Diffusionsprozeß ist. Der sich aus drei verschiedenen Versuchsanordnungen ergebende mittlere Permeabilitätskoeffizient der proximalen Tubuluswand für Glucose beträgt 1,7·10−5 cm ·sec−1. Es ist experimentell möglich, den aktiven Austransport durch passiven Einwärtstransport vollständig zu kompensieren. Dazu ist allerdings eine Konzentrationsdifferenz von 33 mmol/l nötig. Wird der unidirektionale Austransport mit Hilfe von14C markierter Glucose gemessen, der Nettotransport jedoch chemisch, so kann man die experimentell gemessene Änderung der spezifischen Aktivität mit den aus der Zweikomponentenhypothese (aktiver Transport + passive Diffusion) voraussagbaren Veränderungen vergleichen. Eine Übereinstimmung von Voraussage und Befund ist bei Benutzung der oben angeführten Werte gegeben. Unter normalen Freiflußbedingungen spielt die passive Transportkomponente keine wesentliche Rolle. Nur bei größeren transtubulären Konzentrationsdifferenzen — wie sie bei niedrigem Glomerulumfiltrat und hoher Serumglucosekonzentration auftreten — wird der passive Glucoseeinstrom für died-Glucoseresorption der Gesamtniere bedeutend.
    Notes: Summary Both, the net and unidirectional transport ofd-glucose across the proximal tubule of rat kidney were studied by the technique of continuous microperfusion under the condition of zero netflux of water and sodium chlorid. When the active transport component was completely abolished by 10−4 M of phlorizin a small passive component could be demonstrated. The passive component was also observed in the non-phlorizin-poisoned stat to be additive to the active transport.V max of the actived-glucose transport was 6×10−10 mol×cm−2×sec−1. The passive glucose flux is proportional to the concentration difference between perfusate and serum. There is no difference between data of influx and efflux measurements. From this it is concluded that the passived-glucose flux is a simple diffusion process. The permeability coefficient ford-glucose (P G) calculated from 3 different sets of experiments is 1.7×10−5 cm×sec−1. Active and passive glucose transport component can cancel out each other at a transtubular concentration difference of 33 mmol/l. Changes of the specific activity in the perfusate were measured under three different conditions (d-glucose concentration lumen: 〉 plasma, lumen = plasma, lumen 〈 plasma). These changes were in agreement with our theoretical prediction using the above mentioned values ofV max andP G for the calculation (see appendix). The permeability ofd-glucose across the proximal tubules is small. Therefore, under normal free flow condition the passive transport component plays no role in thed-glucose absorption. However, with greatly increasing transtubular concentration difference ofd-glucose, e.q. due to a low glomerular filtration rate and a high serumd-glucose concentration, the passive transport component may be the rate limiting factor for the net transport ofd-glucose.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00585840
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