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Biomedical subjects

R C Kester

Publications and source records attributed to R C Kester.

At least 127 records · Page 7Linked to original sources
PubMed1978

Evaluation of the thrombogenic potential of three types of arterial graft studied in an artificial circulation.

The thrombogenic potential of woven Dacron, expanded polytetrafluoroethylene (Gore-Tex) and gluteraldehyde-treated human femoral artery (HFA) grafts was evaluated using an artificial circulation. The differences in the platelet parameters (platelet count, adhesion and aggregation) and scanning electron microscopy (SEM) appearances before and after perfusion were used as indices of thrombogenicity. Platelet counts fell significantly with woven Dacron, moderately with HFA and no fall was observed with Gore-Tex. Platelet aggregation was unaffected by any graft, but platelet retention was significantly marked in woven dacron. SEM studies revealed minimal adherence of platelets to Gore-Tex and HFA endothelium, but marked adherences to woven Dacron, accompanied by morphological changes of the adhered platelets. In an artificial circulation, of the three types of arterial graft, woven Dacron has the greatest influence on platelet function, indicating significant thrombogenicity, whereas HFA is intermediate in its effect and Gore-Tex appears to have the lowest thrombogenic potential.

Blood Cell Count↗
PubMed1978

Early results with human umbilical cord vein allografts for haemodialysis.

Six patients requiring intermittent haemodialysis for chronic renal failure underwent construction of an arteriovenous fistula using modified human umbilical cord vein allografts. Three grafts soon showed degenerative changes and were removed--2 thrombosed and 1 became infected. Satisfactory haemodialysis was achieved with the remaining 3 grafts. Two grafts are currently patent at 9.5 and 11 months respectively, while another graft became aneurysmal after 8 months, requiring its removal.

Adult↗
PubMed1978

Pulse pressure wave analysis in the diagnosis of aorto-iliac disease.

The severity of aorto-iliac disease has been evaluated by direct pressure recording at the time of translumbar aortography. Pulse wave analysis confirmed the radiological appearance of 35 aorto-iliac segments and in one further segment, identified a normal haemodynamic pattern in the presence of marked degenerative disease. The method is safe, accurate, simple and relatively inexpensive.

Aged↗
PubMed1978

A study on tissue concentrations of cephradine achieved in patients with peripheral vascular disease.

The levels of cephradine were measured in serum, voluntary muscle and subcutaneous fat samples collected from 30 patients during surgical operations for peripheral vascular disease. Cephradine 2 g was administered in two equal doses by intramuscular and intravenous routes before each operation. The mean levels found in the serum and muscle were well above the minimum inhibitory concentrations required for most important Gram-positive and Gram-negative pathogens, in contrast to the relatively low mean level found in subcutaneous fat.

Adipose Tissue↗
PubMed1978

Reinforced expanded polytetrafluoroethylene (Gore-Tex) grafts for haemodialysis.

Twenty-five vascular grafts made of expanded reinforced polytetrafluoroethylene (PTFE) were inserted as arteriovenous fistulae in 20 patients requiring intermittent haemodialysis. Thirteen grafts were placed in the forearm, either as a looped or straight configuration, and 12 straight grafts were placed in the thigh. Whereas only 45% of the forearm grafts functioned adequately, 92% of the thigh grafts supported haemodialysis satisfactorily. It is suggested that when a vascular graft for haemodialysis is required, then an arteriovenous connection of expanded PTFE placed in the thigh achieves reasonable success.

Adolescent↗
PubMed1975

The intestinal phase of gastric secretion.

The intestinal phase hormone, elaborated by the jejunum in response to an intestinal meal or simple distension, produces profound gastric hypersecretion when it escapes hepatic degradation through a portacaval anastomosis. The hormone is released within 30 min of the application of the stimulus and rapidly reaches peak concentration in the portal blood. Intravenous infusion into a donor dog of active portal plasma from a shunted, intestinally fed dog stimulates gastric acid secretion after a delay of approximately 1 h, and requires a mean 1 1/2 h to stimulate peak secretion, which suggests that intermediate steps may be necessary before the hormone can effectively stimulate the parietal cell mass. The pig develops portacaval-shunt-related gastric acid hypersecretion in response to food comparable to that observed in the dog and in man. Porcine jejunal mucosa is thus an appropriate source for isolation of the intestinal phase hormone. Pig intestinal mucosal extract contains a heat-stable acidic peptide which is a potent stimulator of gastric acid secretion. Administration of crude intestinal mucosal extract elicits gastric acid secretion after a brief delay, again indicating that some intermediate reactions occur before the target organ--the parietal cell mass--is stimulated.

Animals↗
PubMed1971

The distribution of plasminogen activator in the male genital tract.

The distribution of fibrinolytic activity in the tissues of the male genital tract was studied by a histological technique. Preparations made from testis, epididymis, vas deferens, seminal vesicle, prostate, bulbo-urethral gland, and urethra showed that most activity was related to the blood vessels. However, inconsistent fibrinolytic activity related to epithelium was found in all parts of the genital tract. This epithelial activity was least in the testis, greater in the seminal vesicle and prostate gland, and was greatest in the bulbo-urethral gland and terminal urethra. No fibrinolytic activity could be demonstrated in relation to spermatozoa.

Adult↗
PubMed1969

Plasminogen activator in the human prostate.

The distribution of plasminogen activator in fresh human prostatic tissue has been studied, using a histological technique. The vascular endothelium consistently showed fibrinolytic activity while inconstant and lesser activity arose from the epithelial cells of glands and ducts. Increased epithelial activity was often accompanied by evidence of trauma. Activity of the secretions was insignificant. The source of the fibrinolytic activity of blood in prostatic disease and of the seminal fluid remains uncertain, and cannot yet be ascribed to the prostatic epithelium.

Epithelium↗
PubMedDate not supplied

The spring in the arch of the human foot.

Large mammals, including humans, save much of the energy needed for running by means of elastic structures in their legs and feet. Kinetic and potential energy removed from the body in the first half of the stance phase is stored briefly as elastic strain energy and then returned in the second half by elastic recoil. Thus the animal runs in an analogous fashion to a rubber ball bouncing along. Among the elastic structures involved, the tendons of distal leg muscles have been shown to be important. Here we show that the elastic properties of the arch of the human foot are also important.

Biomechanical Phenomena↗