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W H Brook

Publications and source records attributed to W H Brook.

8 recordsLinked to original sources
PubMed1995

Complement levels and exposure in the hypobaric chamber.

Decompression sickness sometimes occurs in routine hypobaric chamber runs. Susceptibility to decompression sickness has been correlated with increases in C3a and C5a metabolites of complement activation by air bubbles. If personnel susceptible to decompression sickness show changes in C3a and C5a after decompression, then measurement of these metabolites may be useful in assisting diagnosis. C3a and C5a metabolites of complement activation were measured in 11 male and 2 female volunteers 1 h before (A), 1 h after (B), and 24 h after (C) exposure in routine hypobaric chamber runs to 25,000 ft equivalent altitude. The results were compared with 4 controls (3 males and 1 female). A one-way analysis of variance showed no significant difference between the experimental and control groups overall (p = 0.308; p > 0.05; N = 17). T-tests at each of the results further suggest non-significant differences between the experimental and control groups (p = 0.473; p = 0.341; p = 1.051; p > 0.05; N = 17) at results A, B, and C, respectively. The C5a assay was less than 10 micrograms.L-1 in all individuals, and the particular kit used was not sensitive below 10 micrograms.L-1. As none of the participants developed decompression sickness, it would be useful to determine levels of C3a and C5a in individuals who subsequently develop decompression sickness. One member of the experimental group who had undergone many chamber runs had much higher pre- and post-chamber run levels of C3a. This raises the question of the effect of repeated exposure in low pressure chambers on complement activation, and requires further study.

Adult↗
PubMed1994

Postural hypotension and the anti-gravity suit.

An air force anti-gravity suit, as used by fighter pilots to prevent loss of consciousness, has been successfully employed to treat severe postural hypotension in a patient with Shy-Drager syndrome. The definition of postural hypotension is reviewed, and reference is made to the previous use of the anti-gravity suit in the treatment of this condition.

Female↗
PubMed1990

The development of the Australian anti-G suit.

Prof. Frank Cotton of Sydney University, Australia, designed the world's first successful gas-operated anti-G suit. Research commenced late in 1940, and a suit was designed with rubber sacs covered externally by inextensible material. The sacs automatically inflated when G forces increased during flying. Initially tested on a centrifuge specially built at Sydney University, and then flight-tested in a Hurricane, Kittyhawks, and Spitfires, the suit provided about 2 G protection. The Canadians had earlier developed a water-filled suit, which the RAF adopted, but comparative trials in 1944 by the Royal Air Force concluded that: "There is no doubt the Cotton Suit gives the best protection." By the time the Cotton Aerodynamic Anti-G Suit was operational, Japanese attacks on Darwin had virtually ceased, and the suit was never used in combat. However, the principle of gas-inflatable bladders is still used in the modern anti-G suit.

Australia↗
PubMed1983

Ultrastructure of the myocardium during development from early fetal life to adult life in sheep.

The ultrastructure of the developing fetal lamb myocardium was studied in a series of animals spanning 29 days of gestation to term, and compared with newborn and adult animals. All major ultrastructural features which characterise the adult myocyte were found in early fetal life, although with considerably different degrees of development of specific features. Notably, myofibrils at 29 days of gestation are sparse and show little organisation. With advancing gestation there is an increasing number of myofibrils and the development of well defined striations. Thus, at term, the fetal tissue is not substantially different from the adult myofibril in the appearance of sarcomere structure. The observation of contractile tissue paucity and disorder in early fetal lamb myocardium is difficult to reconcile with available physiological data, which show an extraordinary pumping performance of the heart in vivo, and requires further investigation.

Animals↗
PubMed1980

Light and electron microscopy of polytetrafluoroethylene arterial grafts in dogs.

Reinforced expanded polytetrafluoroethylene grafts with fibril lengths of approximately 17 to 25 micrometers were inserted into the infrarenal aorta of dogs for periods ranging from 24 hours to eight months. The grafts were studied by light and electron microscopy, which showed that polytetrafluoroethylene consists of ridges or nodes connected by fibrils. Initially red blood cells passed down in the pores of the polytetrafluoroethylene, and then the surface was covered with fibrin. A new endothelium developed by the twelfth day. The new intimal lining became thicker owing to the appearance of smooth muscle cells deep to the endothelial cells, forming a neointima 120 micrometers thick by eight months. Fibroblasts and collagen penetrated the graft, but vasa vasorum did not, although they were present in the external connective tissue.

Animals↗
PubMedDate not supplied

A historical review of the histology of patent autogenous vein grafts and vein patches.

The literature on the histological changes occurring in autogenous vein grafts and patches was reviewed. Over 307 grafts (235 animal and 72 human) and 30 patches (28 animal and 2 human) have been described. Grafts were investigated from patients who died on the operating table up to 22 years after operation. Intimal thickening and various changes in the media (including necrosis and replacement fibrosis) occurred. Dilatation of vein grafts has occurred, and anerysm formation has been reported. Atheroma has been described in the grafts from 5 patients.

Aneurysm↗