Increased incidence of postoperative localized osteitis in mandibular third molar surgery associated with patients using oral contraceptives

Current literature has noted the various side effects of oral contraceptives. Oral surgeons have recently encountered an increased incidence of postoperative localized osteitis occurring with removal of manidibular third molars. This article documents the occurrence of this phenomenon among 105 women participating in a recent study at the Clinical Center of the National Institutes of Health.     

Mycobacteriosis in a roe-deer caused by wood-pigeon mycobacteria

A mycobacterium, hitherto found only in wood-pigeons, was isolated from a roe-deer with generalized tuberculosis-like lesions. It is of great epidemiological interest that a mammal, under certain conditions, can attract this pathogen.     

Glass-ceramic-copper microwave encapsulations and mountings

Methods of preparing microwave encapsulations for gallium-arsenide diodes, using a glass-ceramic-copper combination, have been developed. These encapsulations are not only cheaper than alumina- or beryllia-based ones, but the glass ceramic used has the additional advantage of more favourable microwave properties and permits a considerably greater flexibility of design of components and encapsulations than was previously available. Selected patterns can be produced in the dielectric, over large or small areas, to the tolerances compatible with integrated-circuit technologies. This opens up new possibilities and many applications over a wide range of frequencies.     

Effect of diuresis and nephron dimensional heterogeneity on the distribution of nephron filtration rates

Conflicting data in studies of the effect of natriuresis on intrarenal single nephron glomerular filtration rate (SNGFR) redistribution may arise from the interplay of hitherto largely overlooked factors. In the present work, the effect of diuresis induced by saline, glucose or mannitol, as well as the effect of anatomical nephron heterogeneity, were studied. A highly significant positive correlation was found between the logarithm of the urine flow per gram of kidney weight (log V) and the mean superficial (S) to mean juxtamedullary (JM) SNGFR ratio. The rise in S/JM SNGFR with diuresis was primarily a function of decreased JM SNGFR. Total proximal tubular length (TPL) was used as a measure of nephron size. The distribution of nephron sizes was evaluated as S/JM TPL. The effects of urine flow and anatomical heterogeneity on S/JM SNGFR were spearated by means of multiple regression analysis, which yielded the following equation: S/JM SNGFR = -0.049 + 0.179 log V + 0.818 S/JM TPL. Both slopes were highly significant (P less than 0.001). These findings indicate that S/JM SNGFR increases with urine flow, independently of sodium homeostasis, and that anatomical heterogeneity has a marked effect and must, therefore, be controlled. Conflicting data in the literature are harmonized with the present data when appropriate correction can be made for the dimensional factor. There is no evidence that SNGFR redistributions play a role in sodium homeostasis.     

Globin synthesis in normal human bone marrow

Globin synthesis has been studied by in vitro labelling with radioactive amino acids in 60 normal human bone-marrow samples. Under the conditions routinely used to fractionate alpha and beta chains by chromatography alpha/beta production ratios ranging from 0.5 to 1.0 were obtained, depending on the method of sample treatment. This variation was due entirely to the presence of non-haem proteins derived from white cells which chromagraphy with globin on CM-cellulose. Purification of globin on Sephadex G100 and fractionation of alpha and beta globin chains by a modified chromatographic system resulted in alpha/beta ratios of unity. The relevance of these findings to the study of marrows in which there is unbalanced globin chain production is discussed.