Factors effecting recurrence of duodenal ulcers after highly selective vagotomy]

Recurrence of duodenal ulcer was diagnosed in 15 patients who underwent highly selective vagotomy before 6-13 years, i.e. in 12.2%. Factors possibly contributing to such a recurrence were analysed. Patients with ulcer recurrence were: 1) non-qualified workers, 2) tobacco smokers, 3) heavy drinkers, 4) users of ulcerogenic medicines, and 5) were involved into conflict situations.     

Operative mortality and postoperative morbidity of highly selective vagotomy.

In a world-wide survey of the results of 5539 highly selective vagotomies (HSVs) performed electively for duodenal ulcer the operative mortality was found to be 0-3%. This was lower than that found in collected series after either vagotomy with drainage (0-8%) or gastric resection with or without vagotomy (over 1%). Necrosis of the lesser curvature occurred in 10 patients (0-2%) after HSV and caused death in 5(0-1%). Such necrosis is probably ischaemic in origin. Hence reperitonealisation of the raw area on the lesser curvature and prompt laparotomy if the patient develops signs of peritonitis might lower the mortality still further. Three deaths were due to pulmonary embolism, one to mesenteric vascular occlusion, and four to myocardial infarction; such deaths might be reduced by the prophylactic use of low-dose heparin. Persisting gastric stasis requiring drainage occurred in only 0-1% of the patients in the early postoperative period and in 0-6% of the patients later. Hence drainage procedures, which produce side effects such as early dumping, bilious vomiting, and diiarrhoea, could be abandoned if the mean incidence of recurrent ulceration after HSV remains close to its present level. HSV is probably the safest operation for duodenal ulcer because the alimentary tract is not opened and there is no anastomosis, suture line, or stoma.     

Localized avascular necrosis of lesser curve of stomach complicating highly selective vagotomy.

The fourth case of localized avascular necrosis of the lesser curve of the stomach after highly selective vagotomy is reported. The pathogeneses was probably related to the relative poverty of the submucosal blood supply along the lesser curve. This complication may be prevented by peritonealizing the lesser curve before closing the abdominal wall.     

Changes in ventilatory patterns before and after vagotomy in rabbits]

Ventilatory pattern have been investigated during rebreathing experiments. Before vagotomy, a linear relation has been found between increasing tidal volume and decreasing inspiratory and expiratory durations. After vagotomy, these relations existed but expiratory duration remained almost constant.     

Effects of truncal,selective, and highly selective vagotomy on glucose tolerance and insulin secretion in patients with duodenal ulcer. Part I-Effect of vagotomy on response to oral glucose.

An oral glucose tolerance test was performed in patients who had undergone truncal vagotomy and pyloroplasty, bilateral selective vagotomy and pyloroplasty, or highly selective vagotomy without a drainage procedure at least six months earlier. The results were compared with those from patients with chronic duodenal ulcer before operation. In all three groups of patients after vagotomy more rapid rates of rise of blood glucose and higher peak concentrations were observed than in patients who were tested before operation. These differences were statistically significant only in patients who had undergone truncal or selective vagotomy with pyloroplasty and were probably due to more rapid rates of gastric emptying after these operations. Plasma insulin concentrations were lower after truncal vagotomy than after selective or highly selective vagotomy, the difference between truncal vagotomy and highly selective vagotomy being statistically significant. Truncal vagotomy resulted in a diminished insulin response to oral glucose, which could have been due to vagal denervation of the pancreas or, more probably, impaired release of small-bowel hormones which normally augment the pancreatic insulin response.     

Endocrine cells of the gastric mucosa in patients with duodenal ulcer after vagotomy]

Bioptates of the stomach mucous membrane (SMM) have been investigated in 169 patients suffering from duodenal ulcer (DU). According to the nocturnal gastric secretion test among them there are "hypersecretors" and persons with moderate elevation of acid formation. In conformity with the efficiency of the operative treatment among the patients examined, groups are defined: those with recurrent disease and those recovered after vagotomy. The DU endocrine apparatus undergoes both qualitative and quantitative alterations after vagotomy. When recovery after vagotomy takes place, the number of endocrine cells only slightly exceeds these parameters in the patients with a moderately manifested acid production. These alterations are adaptive. The recurrence of DU in patients with moderately manifested acid production before the operation can be explained by hyperplasia of G-cells. A high degree of hyperplasia of all elements of the endocrine apparatus in the "hypersecretors" can be one of the causes of the DU recurrence. The data about the state of G-, Ec- and EcL-cells before and after vagotomy can be used at prognostication the results of surgical treatment of patients with DU.     

Differential effects of selective vagotomy and tropisetron in aminoprivic feeding

Both total subdiaphragmatic vagotomy (TVAGX) and serotonin(3) receptor blockade with tropisetron or ondansetron attenuate amino acid-imbalanced diet (Imb) anorexia. Total vagotomy is less effective than tropisetron in reducing Imb-induced anorexia and also blunts the tropisetron effect. With the use of electrocautery at the subdiaphragmatic level of the vagus, we severed the ventral and dorsal trunks as well as the hepatic, ventral gastric, dorsal gastric, celiac, and accessory celiac branches separately or in combination to determine which vagal branches or associated structures may be involved in these responses. Rats were prefed a low-protein diet. On the first experimental day, tropisetron or saline was given intraperitoneally 1 h before presentation of Imb. Cuts including the ventral branch, i.e., TVAGX, ventral vagotomy (above the hepatic branch), and hepatic + gastric vagotomies (but not hepatic branch cuts alone) caused the highest (P < 0.05) Imb intake on day 1 with or without tropisetron. The responses to tropisetron were not affected significantly. On days 2-8, groups having vagotomies that included the hepatic branch recovered faster than sham-treated animals. Because the hepatic and gastric branches together account for most of the vagal innervation to the proximal duodenum, this area may be important in the initial responses, whereas structures served by the hepatic branch alone apparently act in the later adaptation to Imb.     

Morphometric studies of pancreas islets of rats after subphrenic vagotomy]

Analysis of the morphometric data showed that 7 days after vagotomy significant changes ocurred in the pancreatic islets, mainly as a result of variation in B cells. At later periods (45 and 90 days after surgery) normalization of some morphofunctional parameters is noted, however, absolute restoration is not achieved.     

Studies in the mathematical theory of excitation

The general linear two-factor nerve-excitation theory of the type of Rashevsky and Hill is discussed and normal forms are derived. It is shown that in some cases these equations are not reducible to the Rashevsky form. Most notable is the case in which the solutions are damped periodic functions. It is shown that in this case one or more—in some cases infinitely many—discharges are predictable, following the application of a constant stimulusS. The number of discharges increases withS, but the frequency is a constant, characteristic of the fiber and independent ofS.     

Critical periods in the development of spurs in light of the theory of phylembryogenesis]

Two critical periods have been established in the development of spurs representing a derivative of the corneous squama. During the first period the exposure to x-rays results in the development of the corneous squama instead of the spur, and the same exposure during the second critical period completely suppresses the development of the spur. These periods seem to correspond to the truning-points in the chain of morphogenetical processes of the spur formation associated with phylembryogeneses. Department of Embryology, Institute of Experimental Medicine, USSR Acad. Med. Sci., Leningrad.     

Biological adaptation and the mathematical theory of information

Adaptation is viewed as a tendency maximizing the Shannon entropy of an ecosystem, where the ecosystem is considered as two interacting subsystems, namely, the biota and its environment. We derive theadapted structures starting from three fundamental hypotheses and we apply this result to an ecological topic: the cryptic and aposematic behaviour.