Triangle-programmed coulometric nanotitrations completed by continuous flow with potentiometric detection

Coulometric nanotitrations were realized in a microchannel system using a continuous-flow titration technique with a triangle current-time profile. Redox and acid-base titrations were carried out on Fe(II) and nitric acid samples, respectively, with the same nanotitrator device. A linear relation between the concentration and the coulometric current transferred to the solution was found. The advantages of this universally applicable nanotitrator are fast response, low sample volume, high sensitivity, and high reproducibility as well as the convenience of handling an automated analyzer of the flow-through type.     

The effect of carbon monoxide on haem-facilitated oxygen diffusion

From 1965-1975 in the orthopedical Univ. Clinic Balgrist, Zurich, there were 177 reoperations after total hip prostheses necessary. In 91 replacements the interval between first and second operation was an average of 4.1 years, in 67 prosthesis-removements 2.1 years. The follow-up showed a relationship between bacteriological culture taken before and during operation and clinical results. The decision to change or remove the prostheses should be made on the positive or negative bacteriological results.     

Temephos collars for control of fleas on dogs and cats

Efficacy of polyvinyl chloride collars containing temephos [0,0'-(thiodi-4,1-phenylene) 0,0,0',0'-tetramethyl bis-(phosphorothioate)] was elevaluated in dogs and cats against the cat flea (Ctenocephalides felis). Over a period of 42 weeks, collared (treated) and control dogs were experimentally infested with 100 fleas 23 times, and control and treated cats were similarly infested 20 times during a 41-week period. Flea populations on treated dogs were reduced by 80% or more for at least 36 weeks. Initially, flea reduction by 80% occurred within 1 day, but in dogs wearing the same collars for 26 weeks, this reduction occurred in 3 to 6 or more days. Only during the first 2 weeks of wearing the collars were all fleas killed on all dogs within a 6-day period after infestation. Residual efficiency was lowest on highly active dogs and greatest on inactive dogs. The residual efficiency on cats was somewhat better than on dogs. At the end of 41 weeks, collars on cats reduced the flea population by 85 to 90% within 1 to 5 days following infestation. Collars on cats, as on dogs, were 100% efficacious only during the first 2 weeks of the trial.     

The chronic toxicity of 3-chloro-4-methyl benzamine HCl to birds

3-Chloro-4-methyl benzamine HCl (DRC-1339), an avian toxicant, was fed to five species of birds for periods up to 120 days. The 30-day LC50 of uniformly treated feed for starlings was 4.7 ppm and the 90-day LC50 was 1.0 ppm. The 28-day LC50 for coturnix was 18 ppm. The 30-day LC50 for pigeons was less than 100 ppm. Pheasants fed diets containing 2% DRC-1339 baits diluted to a rate of 286 ppm of DRC-1339 died within 22 days. Bobwhite quail fed similar diets suffered some mortality at levels as low as 2.9 ppm, but most survived 10 times this dosage level for the 120-day test period. Application of the Kenaga "Index of Chronicity", resulted in the conclusion that DRC-1339 was cumulatively toxic to birds. Reproduction in coturnix was adversely affectd by treatments at 10 ppm of DRC-1339 and above. Reproduction in pigeons was adversely affectd by a treatment of 25 ppm. In coturnix, DRC-1339 caused an increased incidence of egg breakage and decreased both egg and live chick production. In pigeons, DRC-1339 caused an increase in the proportion of infertile eggs. Reproductive ability to first generation offspring was not affected when parent coturnix and pigeons were fed DRC-1339. These data emphasize the need for care in the use of DRC-1339. The bait should be used only as registered and care exercised in storage and disposal of unused baits to avoid poisoning of nontarget species.     

Thrombocyte lactate dehydrogenase isoenzymes in patients with ischemic stroke

It was established that in the acute period of the ischemic stroke in the maiority of cases a change of isoenzyme structure of LDG thrombocytes was due to a decrease of LDG3 activity. In a number of patients the dominant change in the spectrum was determined by LDG and LDG4 fractions. The changes were of a stable character up to 10 weeks. LDG4 increase was characteristic of the isoenzymes spectrum in the patients with a severe development of the disease and in the patients in the remote period of the stroke. The obtained data can serve as a criterion for evaluating the adaptive changes in acute brain ischemia.