Electron probe x-ray microanalysis of a normal centriole.

A scanning spectrometer with lithium fluoride, ammonium dihydrogen phosphate, and gypsum crystals was used to detect the x-ray spectrum of a normal centriole, the transmitted electron image of which was used to focus the exciting electron beam to the size, shape, and position of the centriole in a 700-angstrom section of intact tissue.

Platelet studies in patients with hypertrophic cardiomyopathy.

Because of a shared abnormality of platelet and muscle in some neuromuscular diseases, platelets were investigated in five cases of hypertrophic cardiomyopathy, a disease likely to be primarily myogenic. Morphometric and chemical differences from normal were found consisting of increased cell size, decreased phosphorus concentrations and increased permeability to cations. The findings suggest membrane and energy metabolism aberrations.

X-ray microanalysis of zinc and calcium in ultrathin sections of human sperm cells using the pyroantimonate technique.

X-ray microanalysis of pyroantimonate-fixed sperm cells indicates the retention of calcium and zinc subcellularly in similar proportions to air dried cells. The ultrastructure is well preserved and is corelated with the analysis. Sodium, potassium and chlorine are all removed during the fixation. CAlcium and zinc are found present intracellularly both in association with and independent of antimonate precipitation. There thus appears to be a varying degree of binding of those elements subcellularly, precipitation occurring where binding is reduced.

Localization of a thrombin-sensitive calcium pool in platelets.

Electron microscopic x-ray microprobe analysis of pyroantimonate precipitates in platelets fixed in osmium tetroxide-pyroantimonate revealed calcium localization in the nucleoids of alpha-granules. This pool of calcium had largely disappeared within 10 sec after stimulation of platelets by thrombin. Such a rapid change suggests that this calcium pool may have a regulatory role in stimulus-response coupling.

Correlation between elemental composition and motility of human spermatozoa.

X-ray microanalysis of human sperm cells in donor semen having a range of motilities from 0% to 85% showed that elemental composition is not strongly correlated with spermatozoal motility. Only copper in the midpiece was positively correlated with motility when high- and low-fertility groups were compared. Aging of cells in semen caused large changes in subcellular elemental concentrations as motility decreased, notably with uptake of zinc, but these changes were not reflected in the range of motilities in the clinical samples. Electrolyte balance as measured by sodium to potassium ratios also appeared not to be correlated with motility. Subcellular elemental distribution is not a major factor in determining sperm motility in normal human semen.

PIP: A possible correlation between the elemental composition of human spermatozoa and sperm motility was investigated. X-ray microanalysis did not reveal any strong correlation between sperm motilities of C-85% and elemental composition. However, when high- and low-fertility samples were compared, a significant (p less than .025) correlation was found between copper in the midpiece region and motility. As cells aged and motility decreased, there were considerable changes in subcellular elemental concentrations, particularly with regard to zinc uptake. However, these changes were not correlated with the range of motilities. No apparent correlation was found between electrolyte balance, as determined by sodium to potassium ratios, and motility. It is concluded that the subcellular distribution of elements in semen is not a determining factor in sperm motility.

Toxicity and uptake of heavy metals by human spermatozoa.

The effects of metallic copper on human spermatozoa are described. Incubation with the metal caused a fall on the percentage of motile sperm, which was directly related to the surface area of copper employed and to the copper content of whole semen. These changes were accompanied by a decrease in semen zinc levels and an uptake of copper by individual sperm cells, as determined by X-ray microanalysis. Low concentrations of ionic copper caused a less marked fall in sperm motility, although the metal was generally more toxic than zinc or cadmium ions. All three metals were accumulated by spermatozoa on incubation, with cadmium causing a decrease in sperm nuclear zinc concentrations.

A study of the host selection patterns of the mosquitoes of the Kisumu area of Kenya.

The results of 12,168 precipitin tests on blood meals of mosquitoes of the Kano Plain caught by a variety of catching techniques indicate that to gain an accurate overall picture of feeding patterns both the indoor and the outdoor biotope must be sampled. CDC light traps operated inside houses and Monkswood type light traps operated under the outside eaves of houses were found to collect larger numbers of blood fed specimens from a wider range of species than battery driven aspirators collecting from natural resting sites. The results indicated that 7 mosquito species entered houses to bite man in appreciable numbers in the Kisumu area. These were Anopheles gambiae s.l., A. funestus, A. pharoensis, Mansonia uniformia, M. africana, Culex antennatus, and C. univittatus. Eight mosquito species were found to bite man and domestic animals in the outdoor biotope in large numbers. These were: A. pharoensis, A. ziemanni, M. uniformis, M. africana, C. antennatus, C. univittatus, Aedes circumluteolus, and Ae. ochraceus. From an epidemiological point of view, species with a narrow range of hosts are most likely to be of importance as vectors of parasitic diseases such as malaria and into this category fall the major man biting anophelines A. gambiae and A. funestus. Those mosquito species which switch from one group of hosts to another according to local circumstances are most likely to be involved in arbovirus transmission and in this group the following species must be considered: A. pharoensis, A. ziemanni, M. uniformia, M. africana, C. antennatus, C. univittatus and Ae. circumluteolus.

Arbovirus isolations from mosquitoes: Kano Plain, Kenya.

Arbovirus isolation attempts on 324,486 mosquitoes captured over a four-year period on the Kano Plain, Kenya, yielded 15 isolates including Pongola (six strains), Ilesha (three strains), Germiston (two strains), Sindbis (one strain), Barur (one strain) and two viruses which could not be characterized. Mansonia uniformis, Anopheles gambiae and Culex antennatus constituted 70% of the total collection and accounted for all of the isolates except one, which came from Anopheles funestus.