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Biomedical subjects

R D Cook

Publications and source records attributed to R D Cook.

At least 37 records · Page 2Linked to original sources

Common variable hypogammaglobulinemia with T-cell nodular lymphoid interstitial pneumonitis and B-cell nodular lymphoid hyperplasia: different lymphocyte populations with a similar response to prednisone therapy.

Intestinal lymphoid hyperplasia and recurrent pulmonary infections by pyogenic bacteria are well-recognized accompaniments of common variable (late onset) hypogammaglobulinemia. A 35-yr-old woman with this illness had progressive pulmonary insufficiency caused by nodular lymphoid interstitial pneumonitis, rather than by infectious lung damage, and intestinal lymphoid nodular hyperplasia. B cells were abundant in the intestinal nodules but absent in the pulmonary nodules by immunoperoxidase staining. Pulmonary lymphocytes isolated in single-cell suspension from the biopsy were 0.5% B cells and 82% T cells. Prednisone therapy improved pulmonary function and decreased the intestinal lymphoid nodules. Lymphocytic interstitial pneumonitis should be considered in patients with hypogammaglobulinemia and restrictive lung disease.

Adult↗

Hepatic damage in sheep fed annual ryegrass, Lolium rigidum, parasitised by Anguina agrostis and Corynebacterium rathayi.

Annual ryegrass (Lolium rigidum) parasitised by Anguina agrostis and Corynebacterium rathayi causes neurological signs and brain lesions thought to be associated with a vasoconstrictor effect of the toxic grass. In three separate experiments of six to 112 days duration parasitised ryegrass was fed to 21 adult sheep. The concentrations of many blood constituents were examined, liver biopsies taken, necropsies performed and tissues other than brain examined by light and electron microscopy. The invariable finding was liver damage indicated by increased plasma concentrations of liver specific enzymes and bilirubin. There was diffuse vacuolation of hepatocytes due to gross distension of cisternae of rough endoplasmic reticulum, as well as necrosis of individual hepatocytes, fatty change, biliary hyperplasia and hepatocytic regeneration. The changes were not typical of experimental hepatic ischaemia and may have been due to a cytopathic effect of toxic annual ryegrass.

Animal Feed↗

Infantile and late onset form of generalised glycogenosis type II in cattle.

A herd of cattle which produces calves with generalised glycogenosis type II has been established. Seven affected animals have been born and their disease status as indicated by a decreased acid alpha-glucosidase activity and excessive glycogen deposition in muscle, can be detected on the day of birth. Two animals have died of heart failure aged 3 and 5 months and have shown cardiomegally. Five animals were clinically normal until 9 months of age when they failed to maintain weight gain, showed muscle weakness and four were killed aged between 12 and 16 months after showing difficulty in rising. All affected animals had abnormal ECG tracings and had elevated levels of CK, LDH and HBDH in serum. Excessive amounts of glycogen were deposited in voluntary, cardiac and smooth muscle, and in cells of the nervous system. The muscles showed a vacuolar myopathy. Both the infantile and late onset forms of generalised glycogenosis type II are present in this herd of cattle. The condition appears to be controlled by a recessive allele at a single autosomal locus.

Animals↗

Multiple sclerosis: is the domestic cat involved?

Recent evidence suggests a possible viral aetiology of multiple sclerosis (MS). The present hypothesis proposes a relationship between MS and a demyelinating condition in the central nervous system of cats from which a paramyxovirus has been isolated. The theory attempts to relate the distribution and incidence of MS with the keeping of cats as household pets. The incidence of MS is explained on the basis of a human susceptibility factor, perhaps the histocompatibility antigens and the onset, remissions and relapse of MS are considered to be related to stressful situations which trigger a persistent virus.

Adolescent↗

An ultrastructural and morphometric study of the liver of normal and copper-poisoned sheep.

In sheep given copper (Cu) at the level of 10 ml of a 0.2% solution of CuSO4.5H2O/kg body weight, the volume density of nuclei and cytoplasm of hepatocytes increased and the volume density of the sinusoids and the space of Disse decreased. These changes were interpreted as an indication of cellular swelling. There was a significant increase in volume density, number, and absolute volume of lysosomes when Cu was given. The greatest increase in number occurred during the pre-hemolytic period (mean = 48 days), and the highest increase in volume occurred thereafter. Thus, the most extensive proliferation of lysosomes occurred in livers of the pre-hemolytic sheep, and the hemolytic sheep had the largest and heaviest lysosomes. The liver necrosis in sheep undergoing hemolysis was possible caused by hydrolytic enzymes released by the rupture of the enclosing lysosomal membranes. The significant increase in volume density of mitochondria observed in livers of sheep given Cu was due to an increase in volume (swelling) rather than an increase in number.

Animals↗

The altrastructure of Auerbach's plexus in the guinea-pig. I. Neuronal elements.

The ultrastructural features of nerve cell bodies and axon profiles within Auerbach's plexus in the stomach, ileum, caecum and colon of the guinea-pig have been examined. Nerve cell bodies have been tentatively classified into nine different types according to their size, distribution of organelles, location and relationship to satellite cells. Except for cell size, no attempt has been made to correlate ultrastructual with light microscopical observations. On the basis of vesicular size, shape and content, eight morphologically distinct types of axon profile have been identified as well as two profile types which are thought to reflect different physiological conditions. The axons contained various populations of small, mostly granular vesicles; small, round agranular vesicles; small, flattened vesicles; large flattened or elongated vesicles; and three types of large vesicle with granular contents distinguished by size. Some correlation between types of axon profile and two types of nerve cell body was recognized. However, more than one type of axon profile usually formed synapses with one type of cell body, and a precise correlation was not determined.

Animals↗

The ultrastructure of Auerbach's plexus in the guinea-pig. II. Non-neuronal elements.

The ultrastructural features of non-neuronal cells associated with Auerbach's plexus in the stomach, ileum and colon of the guinea-pig have been examined. Apart from Schwann, mast and interstitial or fibroblast-like cells, two other cell types are described that do not appear to have been reported previously. Of these two cell types, one was found external, but close to, the plexus and contained large granular vesicles. The other cell type contained numerous glycogen-like granules, was situated close to or within axon bundles and had processes that extended within and peripheral to nerve bundles as well as being close to smooth muscle cells. Although axon varicosities were opposed to both the processes and cell body of the second type of cell, synaptic-like contacts were not observed.

Animals↗