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Biomedical subjects

G R Mason

Publications and source records attributed to G R Mason.

At least 109 records · Page 6Linked to original sources
PubMed1979

Required neural involvement in control of canine migrating motor complex.

This study evaluated the effects of muscarinic, nicotinic, and adrenergic neuronal blockade on the migrating motor complex (MMC) in four unanesthetized dogs. Circular muscle contractile activity was recorded from eight strain gauge force transducers implanted on the stomach and small intestine of each dog. Both atropine sulfate and hexamethonium bromide significantly increased the period of the MMC. When the complex returned after hexamethonium administration, the period of the succeeding complexes was significantly decreased when compared to control. Guanethidine sulfate significantly increased contractile activity on the pylorus, duodenum, and jejunum with a corresponding disruption of the MMC pattern. The migrating motor complex requires the preganglionic release of acteylcholine and possibly an inhibitory input from the sympathetic nervous system for its normal appearance.

Animals↗
PubMed1979

Intraperitoneal irrigation with povidone-iodine solution for the prevention of intra-abdominal abscesses in the bacterially contaminated abdomen.

A prospective randomized investigation was undertaken, involving 168 consecutive patients undergoing laparotomy for conditions accompanying bacterially contaminated peritoneal cavities, to evaluate the effectiveness of povidone-iodine irrigation of the peritoneum in preventing the development of intra-abdominal abscesses. In the treatment group irrigated with povidone-iodine solution, 0.1 per cent available iodine, one of 80 patients had an abscess, 1.3 per cent, while, in the saline solution irrigated control group, nine of 88 patients had abscesses, 10.2 per cent, p less than 0.05. Although the serum iodine levels were elevated 24 hours after intraperitoneal irrigation with povidone-iodine solution, iodine levels returned to near normal by 72 hours. Thyroxine levels showed no major changes. No complications resulting from the use of povidone-iodine were recognized.

Abscess↗
PubMed1979

Irrigation of subcutaneous tissue with povidone-iodine solution for prevention of surgical wound infections.

Five hundred patients undergoing a variety of general surgical operative procedures were prospectively randomly allocated into a treatment group, in which the incisions were irrigated with povidone-iodine solution prior to skin closure or into a control group in which wounds were irrigated with saline solution. Wounds were classified according to the degree of bacterial contamination as clean, potentially contaminated, contaminated or dirty. For all categories of surgical incisions, povidone-iodine irrigation resulted in a significant decrease in wound infections over that for saline solution irrigation. Over-all incidence of wound sepsis in the treatment group was seven of 242 patients, 2.9 per cent, compared with the control rate of 39 wound infections of 258 patients, 15.1 per cent--p less than 0.001.

Adolescent↗
PubMed1978

Vagal influence on duodenal motor activity.

The extrinsic and intrinsic vagal influences on duodenal motor activity in the anesthetized dog were investigated. The following conclusions were derived: (1) Electrical vagal stimulation elicits gastroduodenal contractions. (2) Poststimulatory contractions, or off responses, occur on the antrum and duodenum after termination of the stimulus. (3) Denervation of the extrinsic vagal nerves to the duodenum does not eliminate the above responses. (4) Denervation of the extrinsic nerves to the duodenum and transection of the gastroduodenal junction eliminates stimulated duodenal motility and the occurrence of off responses on the duodenum. Antral responses remain unaffected. (5) The motor innervation to the duodenum is composed of extrinsic vagal fibers and intrinsic vagal nerves which appear to first enter the antrum and then cross the gastroduodenal junction to innervate the duodenum.

Animals↗
PubMed1978

Gastric ulcer: the importance of follow-up care.

One hundred forty-four gastric ulcer patients in an inner city hospital were studied retrospectively over a five year period. Emphasis was placed on patient follow-up after discharge. The length of hospitalization and the mortality were higher for the surgical group; however, the recurrence rate was higher in the medically treated group. Almost half the patients were followed for less than six months. Reasons are given for this poor follow-up. The high recurrence rates necessitate close follow-up for a prolonged period.

Female↗
PubMed1977

Volvulus of the transverse colon.

Five cases of volvulus of the transverse colon are presented. Two distinct clinical types are noted and discussed, each with a significantly different mortality. The level of volvulus dictates the limitations of diagnostic aides and appropriate treatment.

Acute Disease↗
PubMed1977

An inhibitory innervation at the gastroduodenal junction in anesthetized dogs.

Our aim was to investigate the existence of an inhibitory innervation at the gastroduodenal junction (GDJ) in the whole animal. Motility induced by vagal stimulation was monitored with strain force transducers on the gastric antrum, pylorus and duodenum. The experiments were carried out in two phases: the control phase following vagotomy (TV), and the treated phase where atropine sulfate (1 mg/Kg) was injected intravenously (TV+A). After TV, antral, pyloric and duodenal contractile activity was significantly increased (P less than 0.01) during the period of vagal stimulation. After (TV+A), spontaneous activity in the antrum and duodenum was abolished and vagal stimulation did not increase motility in these organs. Spontaneous pyloric activity present after atropine administration was inhibited by stimulation, and a concomitant relaxation of the pylorus was also demonstrated. Following the termination of the stimulus, a significant increase in contractions was noted on the pylorus. These experiments demonstrate the existence of an atropine-resistant inhibitory innervation at the GDJ in the anesthetized dog.

Animals↗
PubMed1976

Gunshot wounds of the suprarenal abdominal aorta.

A review of recent series of penetrating aortic injuries is presented. The highest mortality rates were found with injuries of the suprarenal abdominal aorta. Five patients with this injury, four of whom survived, are presented. Factors preventing rapid exsanguination in some patients are explained. Surgical management, including the controversy of arterial debridement, is discussed. The possibility of missing an aortic perforation at operation with five examples from the literature is pointed out.

Adolescent↗
PubMed1976

Care of patients with hypocalcemia after parathyroidectomy.

In this series of 56 patients diagnosed as having hyperparathyroidism, 37 per cent were found to have multiple gland involvement. The data seem to indicate that routine screening has increased the number of patients operated upon each year. Hypocalcemia in the postoperative period may be manifest by a variety of symptoms, but in general does not seem to affect the postoperative course. The postoperative low point of serum calcium seems directly temporally related to the highest preoperative levels-the higher preoperative levels take longer to reach lowest postoperative levels. Several techniques of management are described.

Adenoma↗
PubMed1976

Neonatal pancreatic beta-cell hyperplasia: report of a case with failure of diazoxide and benefit of early subtotal pancreatectomy.

A newborn infant with pancreatic beta-cell hyperplasia had persistent hypoglycemia due to hyperinsulinism. After medical management, including the use of diazoxide and constant glucose infusions had proved ineffective, a subtotal pancreatectomy was curative. Cumulative experience seems to indicate that there should be little delay in performing a subtotal pancreatectomy when aggressive medical management cannot maintain normoglycemia in a neonate.

Diazoxide↗