Total Hip Replacement in Osteoarthrosis using the Charnley Prosthesis

Charnley low-friction arthroplasty was performed on 352 osteoarthritic hips, usually because of severe pain. Three hundred and twenty hips were reviewed at a special follow-up clinic or by postal questionnaire. After operation 89% of hips were pain-free or caused only occasional discomfort, and in 76% there was an increased range of movement. Of those patients actually seen for review 79% were judged to have a good or excellent result. The most frequent single complication was deep infection, which occurred in 5·3% of hips.     

Transmission of Salmonella montevideo in Wheat by Stored-Product Insects

Sitophilus oryzae (L.), S. granarius (L.), Tribolium castaneum (Hbst.), Oryzaephilus surinamensis (L.), Rhyzopertha dominica (F.), Tenebroides mauritanicus (L.), and Cryptolestes pusillus (Schon.) transmitted Salmonella montevideo from wheat contaminated with 10(6) organisms/g to clean wheat. The insects were fed on the contaminated grain for 21 days and were then transferred to clean grain and allowed to feed for 21 days. They were subsequently transferred to two more samples of clean wheat. All species carried S. montevideo into the initial sample of clean wheat but not into a second or third sample. Progeny of the original insects that developed in the contaminated wheat exhibited less ability than the original adults to contaminate clean wheat. Data indicated that few S. montevideo could be carried by the stored-product insects in large masses of grain.     

S-Potentials in the Skate Retina : Intracellular recordings during light and dark adaptation

The S-potentials recorded intracellularly from the all-rod retina of the skate probably arise from the large horizontal cells situated directly below the layer of receptors. These cells hyperpolarize in response to light, irrespective of stimulus wavelength, and the responses in photopic as well as scotopic conditions were found to be subserved by a single photopigment with λ_max = 500 nm. The process of adaptation was studied by recording simultaneously the threshold responses and membrane potentials of S-units during both light and dark adaptation. The findings indicate that the sensitivity of S-units, whether measured upon steady background fields or in the course of dark adaptation, exhibits changes similar to those demonstrated previously for the ERG b-wave and ganglion cell discharge. However, the membrane potential level of the S-unit and its sensitivity to photic stimulation varied independently for all the adapting conditions tested. It appears, therefore, that visual adaptation in the skate retina occurs before the S-unit is reached, i.e., at the receptors themselves.     

Repair of Alkylated Bacteriophage T4 Deoxyribonucleic Acid by a Mechanism Involving Polynucleotide Ligase

Methyl methanesulfate-induced lesions in bacteriophage T4 are repaired primarily by a mechanism involving polynucleotide ligase. Apparently, other recombinational and ultraviolet repair functions aren't involved.     

Possible mode of action of a photosynthetic inhibitor produced byPandorina morum

The mode of action of the photosynthetic inhibitor produced byPandorina morum was examined by exposingVolvox globator and isolated spinach chloroplasts to a partially purified inhibitor preparation. Oxygen evolution ofVolvox, whole chloroplasts, and broken chloroplasts (-Calvin cycle) was reduced indicating that the substances inhibit the light reactions of photosynthesis. Oxygen evolution studies of other Volvocaceae confirmed the observation thatPandorina morum is not significantly influenced by its own inhibitor. Molecular weight approximation by gel filtration established that the inhibitor has a low, molecular weight (probably below 100 mw).