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Biomedical subjects

O Jahn

Publications and source records attributed to O Jahn.

At least 37 records · Page 2Linked to original sources

[Neurologic symptoms in inhalation poisoning with metallic mercury].

Nineteen caisson workers had been exposed to metallic mercury vapours while digging tubes underneath the first district of Vienna (exposure between 470 and 2440 min; mean 1621 min). The blood mercury values on admission were between 29 and 166 micrograms/l (mean 75 +/- 34 micrograms/l). The main findings reported are clinical neurologic symptoms, psychic complaints, neurographic results and autonomic parameters (cardiovascular reflexes): 47% complained of headache and tiredness, 37% showed tremor and suffered from sleep disturbances, 26% showed hypersalivation, 16% changes in handwriting, and 11% slight dysarthria. The cardiovascular reflexes (autonomic parameters) were abnormal in 7 of 12 patients. On neurography the distal latency (median nerve) was pathologic in 47%, the distal latency (peroneal nerve) was pathologic in 26%, the antidromic sensory nerve conduction velocity (median nerve) was abnormal in 10%, the motor nerve conduction velocity, compound amplitude and vibratory threshold were normal.

Adult↗

Characterization of two ornithine carbamoyltransferases from Pseudomonas syringae pv. phaseolicola, the producer of phaseolotoxin.

Two ornithine carbamoyltransferases (OCT 1 and OCT 2) were isolated from Pseudomonas syringae pv. phaseolicola and purified by precipitation with ammonium sulfate, heat denaturation, chromatography on DEAE-Sephadex A-50 and Sephadex G-200. Molecular weights of both enzymes: 110,000; optimal activity: pH 8.5 to 9.5 (OCT 1), pH 8.4 (OCT 2); apparent Km for ornithine: 7 X 10(-4) (both enzymes); apparent Km for carbamoyl-phosphate: 7 X 10(-4) (OCT 1), 2.8 X 10(-3) (OCT 2). Both enzymes possess only an anabolic function. OCT 1 is highly inhibited by low concentrations of phaseolotoxin and Orn-P(O)(NH2)-NH-SO3H, OCT 2 is insensitive to both compounds. The inhibition of OCT 1 is reversible.

Exotoxins↗

Detection of two ornithine carbamoyltransferases in a phaseolotoxin-producing strain Pseudomonas syringae pv. phaseolicola.

The phaseolotoxin-producing Pseudomonas syringae pv. phaseolicola strain 1321 contains two ornithine carbamoyltransferases which differ in resistance to phaseolotoxin. Whereas ornithine carbamoyltransferase 1 (OCT 1) is inhibited at low concentrations of phaseolotoxin, ornithine carbamoyltransferase 2 (OCT 2) is insensitive to phaseolotoxin. The activity of the insensitive enzyme is correlated with the amount of toxin formed.

Exotoxins↗

[Comparison of 2 field studies (office and food factory)].

The results of a medical investigation of 973 volunteers (632 bank employees and 341 workers in a food factory) are compared: a marked difference exists between the two groups with regard to body-weight distribution. Significantly more persons with elevated levels of serum cholesterol, triglycerides and glucose are registered in the group of food workers; moreover, the incidence of hypertension, bad teeth and varicosis is also higher in this group.

Blood Sedimentation↗

[Anemias significant in occupational medicine].

The role of anaemia in occupational medicine is reviewed briefly. Although anaemia is an infrequent symptom, it may be important by its severeness. Irreversible bone marrow failure following exposition to benzene, is discussed more in detail and finally the importance of evaluating professional exposition to potentially myelo-toxic compounds in every patient, is emphasized.

Anemia↗

[Control studies on retired lead workers].

Nine lead-workers, with an exposure time of 26 years, are investigated 10 years, after they had retired. There are no differences in the blood-count, hemoglobin, blood-lead level, urin-delta-aminolevulinic-acid, urincoproporphyrin and delta-aminolevulinic-acid-dehydratase-activity in their blood, upon comparison with a control group without lead-exposure. The mean urinary excretion of lead (0.119 mumol/g Kreatinin = 24 microgram/g Kr.) was 8 times higher than of reached by the controls (0.014 mumol/g Kr. = 2.7 microgram/g Kr.). The injection of CaNa2-EDTA increased the lead excretion to 0.197 mumol/g Kr. = 40.8 microgram/g Kr., in the control group 0.123 mumol/g Kr. - 25.7 microgram/g Kr. (62%). Therefore these two investigations are recommended for detection of previous lead exposure.

Aged↗