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Biomedical subjects

J N Cross

Publications and source records attributed to J N Cross.

At least 19 recordsLinked to original sources

Reproductive impairment in a fish inhabiting a contaminated coastal environment off Southern California.

White croaker (Genyonemus lineatus), collected from a highly contaminated site in San Pedro Bay and from a reference site 80 km away (Dana Point), were induced to spawn in the laboratory. Forty-one per cent of San Pedro Bay females and 54% of Dana Point females spawned. Examination of the ovaries of non-spwaning females revealed that spawning was imminent in the remainder of Dana Point fish but only in 16% of the San Pedro Bay fish. The remainder of the San Pedro Bay fish (43%) contained only immature, yolky oocytes. No croakers containing more than 3.8 ppm ovarian total DDT could be induced to spawn whereas 36% of a contemporaneous San Pedro Bay sample had ovarian total DDT residues in excess of 4 ppm. This suggests that the inability to induce spawning in white croaker may be associated with an ovarian total DDT threshold of about 4 ppm. These data, coupled with observed decreases in fecundity (32%), fertility (14%), and early oocyte loss (30%) relative to reference fish, could partially explain the population declines observed for many southern California fishes since the 1940s.

Journal Article↗

Spinal cord compression in thalassaemia.

Two cases of spinal cord compression resulting from extramedullary haemopoiesis in patients with thalassaemia of intermediate clinical severity are reported. The association between mild thalassaemia with long survival and the risk of spinal cord compression from extramedullary haemopoietic deposits is emphasised.

Adult↗

Supratentorial haemangioblastoma with polycythaemia.

A case is reported of a 21 year old man with polycythaemia and a vascular frontal lobe tumour that was histologically compatible with the diagnosis of haemangioblastoma. On review of the English literature no case could be found of polycythaemia associated with supratentorial haemangioblastoma.

Adult↗

Limitations of circulation time in the diagnosis of intracranial disease.

The mode circulation time was measured using intravenously injected technetium 99(m) and a collimation system devised to discriminate between the right and left sides of the head. The results in 21 normal men were used as a basis of assessing the findings in 205 patients, made up of five diagnostic groups (ischaemia, haematoma, subarachnoid haemorrhage, intracranial tumour, and head injury). The average mode circulation time in the affected hemisphere for the three groups with vascular disease was increased, but even in these groups half the patients had a mode circulation time within 1 SD of normal mean; similar results were found for asymmetry between the hemispheres. In serial measurements in 45 patients no correlation was found between change in mode circulation time and the clinical state. That so many results are within the normal range limits the value of this method.

Blood Circulation Time↗

Cerebral strokes associated with pregnancy and the puerperium.

Thirty-one cases of ischaemic cerebral stroke occurring in association with childbirth were fully investigated. The pathological basis of non-haemorrhagic carotid territory strokes in pregnant or puerperal women proved to be similar to that in non-pregnant women of the same age group. Over 70% were due to occlusive cerebral arterial disease or ischaemic lesions unrelated to thrombosis of the intracranial venous system. Comparisons are made with some other reported series in which only a minority of the patients were investigated by angiography, but in which intracranial venous occlusion was assumed to be the primary lesion. It seems likely that many of these patients may also have suffered arterial rather than venous lesions.

Adult↗