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Biomedical subjects

G H Collins

Publications and source records attributed to G H Collins.

At least 73 records · Page 4Linked to original sources

Prevalence of Dirofilaria immitis and Dipetalonema reconditum in greyhounds.

Blood samples from 331 greyhounds in the Hunter Valley and nearby coastal areas of New South Wales were examined for microfilariae using a filtration technique. Species were identified by histochemical staining; 10.9% of the greyhounds were infected with Dirofilaria immitis and 3.6% with Dipetalonema reconditum. The prevalence of infection of both species was significantly greater in summer than in winter (p = less than 0.05). Infection with D. immitis was correlated with differences in age, sex, bodyweight and coat colour, and a reported lack of stamina and the presence of a cough. No significant association was found. Diethylcarbamazine citrate was used for prophylaxis in 8.8% of all the greyhounds examined.

Animals↗

An evaluation of 4 commercially available ELISA kits for the diagnosis of Dirofilaria immitis infection in dogs.

Serum samples from 100 pound dogs were used to evaluate 4 commercial ELISA kits available for the diagnosis of Dirofilaria immitis. The kits were assessed on sensitivity (the ability to identify infected dogs), specificity (the ability to identify uninfected dogs) and accuracy (sensitivity plus specificity). The kits varied in sensitivity from 36% to 86%, in specificity from 44% to 70%, and in accuracy from 53% to 65%. The sensitivity was not affected by the age of the dogs, nor by the number of circulating microfilariae. The kits were most specific when testing the youngest dogs (less than = 3 years). The problems associated with the serological diagnosis of D. immitis infection in practice are discussed.

Animals↗

Atheromatous extracranial carotid arteries: CT evaluation correlated with arteriography and pathologic examination.

Dynamic, rapid sequence, axial computed tomography (CT) was employed to evaluate the extracranial common and internal carotid arteries in 17 patients with clinical histories suggesting recent or remote ischemia in the territory supplied by the internal carotid artery. The CT findings were correlated with arteriographic observations and with gross and histologic evaluations of endarterectomy specimens. Areas of arterial wall thickening were evaluated on CT scans with regard to both degree of thickening and radiographic density (attenuation). The degree of vessel wall thickening secondary to atheromatous plaque demonstrated on CT scans corresponded closely to the severity of luminal compromise seen on arteriograms. Isodense or mildly hypodense focal mural thickening noted on CT scans of seven endarterectomy specimens proved to be primarily fibrotic (simple) atheromatous plaque on gross and histologic examination. Areas of markedly lucent focal mural thickening on CT scans of 11 specimens all demonstrated varying amounts of subintimal hemorrhage within loosely arranged and rather acellular (complex) atheromatous plaques on pathologic examination. While arteriography provides information regarding the status of the arterial lumen, CT offers the potential of accurate characterization of pathologic changes in the wall of the extracranial carotid arteries in patients with symptoms of cerebral ischemia.

Adult↗

Ipsilateral hemiplegia and the Wallenberg syndrome.

We documented the anatomic basis for hemiplegia occurring on the same side of the body as the lateral medullary infarction. Extension of the zone of ischemia into the rostral spinal cord involves corticospinal fibers after they cross from the opposite side.

Aged↗

Prenatal symmetrical thalamic degeneration with flexion spasticity at birth.

The unusual occurrence of spasticity at birth with symmetrical thalamic damage was found in a male infant delivered at 36 weeks' gestation following an episode of traumatically induced premature labor at 32 weeks. The infant was found to be spastic in flexion with increased stretch reflexes, depressed primitive reflexes, and moderate flexion contractures. Computerized tomographic scans showed bilateral nonenhancing thalamic densities. Neuropathologically, the lateral thalamic nuclei and the red nucleus showed neuron loss, astrocytosis, and, as confirmed by electron microprobe analysis, calcified neurons. The striatum was uninvolved. These findings closely resemble those reported as "symmetrical thalamic degeneration in infancy" and are strongly reminiscent of the pattern of thalamic involvement frequently seen in status marmoratus. It would appear that there is a period during perinatal life in which the lateral thalamus can be rendered vulnerable to hypoxic-ischemic injury, and that the thirty-second week of gestation must be included within this period.

Brain Ischemia↗

Sporozoa in dogs and cats.

Faecal samples from 110 dogs and 71 cats were examined for sporozoan parasites by flotation. Isospora spp were present in 5.5% dogs and 4.2% cats; Sarcocystis spp in 20.9% dogs and 1.4% cats. 74.5% dogs and 77.5% cats were fed raw meat from various sources; beef was fed most often. Animals fed raw meat were more frequently infected with protozoa. No Toxoplasma oocysts were found. The results are compared with those from other surveys in Australia and New Zealand.

Animals↗

Recurrent intracranial hypertension and a midbrain glioma.

At the age of 36, this patient's clinical picture satisfied the criteria for the diagnosis of benign intracranial hypertension. After an essentially symptom-free interval, she developed new symptoms 17 years later that proved to be the result of a associated with glial-lined cavities in the midbrain and malignant glioma in the splenium. The possibility of a relationship between these disparate events is considered.

Adult↗

Cerebral capillary telangiectasis in an infant. Coincidental Association with hypsarrhythmia.

We studied a case of cerebral capillary telangiectasis in infancy. The patient, who had received treatment with intramuscular corticotropin for hypsarrhythmia, suffered disseminated intravascular coagulation and died on the 66th day of life. Neuropathological examination disclosed the presence of two fresh hemorrhages of moderate size within the cerebral hemispheres, one of which seemed to have originated from a capillary telangiectasis within the left frontoorbital white matter.

Brain↗

Rheumatoid nodule formation within the choroid plexus. Report of a second case.

A woman with active systemic rheumatoid disease had striking neuropsychiatric manifestations; a rheumatoid nodule within the choroid plexus was the sole neuropathological finding. Although we found only one other report of findings of this type in rheumatoid disease, we suspect that this phenomenon may not be as rare as originally believed, and that it may represent another mechanism by which behavioral changes develop in this disorder.

Aged↗

The neuropathology of rheumatoid disease.

Patients with active rheumatoid disease may develop encephalopathy, myelopathy, peripheral neuropathy, and myopathy through a variety of tissue mechanisms. Brain involvement is usually characterized by the formation of rheumatoid nodules or by the development of vasculitis or its complications, and there is evidence to suggest that the trapping of immune complexes within the choroid plexus may be important in pathogenesis. Structural damage to the spinal cord and lower brain stem, on the other hand, most commonly results from narrowing of the bony canal, leading either to direct compression of neural tissue or to compromise of its vascular supply. The appearance of peripheral neuropathy generally signifies the presence either of inflammatory epineurial arterial disease or entrapment by neighboring anatomical structures. Skeletal muscle dysfunction may be due to vasculitis, myositis, or denervation atrophy. Both systemic and local anatomical factors, therefore, are of importance in determining the manner in which different parts of the nervous system may be affected in rheumatoid disease.

Brain Diseases↗