E. Clinton Texter

Comparison of Direct Effects of Angiotensin and Other Vasoactive Agents on Small and Large Blood Vessels in Several Vascular Beds

ATHOROUGH STUDY of a vasoactive agent should inelude effects on resistance to blood flow (influences arterial pressure and rate of blood flow), storage of blood (influences effective eircuilating volume and, hence, venous return, cardiac output, and arterial pressure), capillary patency (iinfluences diffusion distances and, therefore, rates of movement of material and heat), and filtration pressure (influences storage of water in tissues). This paper presents a comparison of the local effects of angiotensin and other vasoactive agents on resistance to blood flow through the dog forelimb and gut beds and on Cfiltration pressure in the dog forelimb and rabbit ear. Preliminary observations on blood storage in the dog forelimb are also mentioned. Inasmuch as the data contained in the paper were derived from a number of studies conducted over the last 10 years, the methods utilized are summarized as each study is presented.

Response of the Physiologic Gastroesophageal Sphincter to Increased Intra-abdominal Pressure

A zone of increased intraluminal pressure interposed between the tubular esophagus and presumed to be due to tonically contracted circular muscle fibers was described by Fyke, Code, and Schlegel (1) in 1956. Frequently only the narrow abdominal portion of this sphincter imposes a pressure barrier between the gastric and esophageal lumina when the pleuroperitoneal pressure gradient is increased (2-6). Reflux in patients with sliding hiatal hernia has been attributed to the upward displacement of the sphincter and the absence of the abdominal segment (7, 8). Although there is agreement concerning the importance of the compression effect of increased intra-abdominal pressure during inspiration in the maintenance of sphincter competency, the role of the diaphragmatic crura remains controversial. Monges (9) showed that a balloon filled with radiopaque liquid in the esophagogastric area is compressed during deep inspiration in a ring-like fashion that he attributed to right crural contraction. Our studies were designed to contrast the effects of passive abdominal compression and deep inspiration on intraluminal pressure and pH and thereby to differentiate a crural (pinchcock) action from a dome (intra-abdominal pressure) action of the diaphragm.

The natural history of ulcerative colitis

Abstract Chronic ulcerative colitis is used to designate a group of serious maladies which may have varying etiologies. However, when the known etiologic factors are excluded, the majority of cases remain without a specific known cause. It is probable that the entity, idiopathic ulcerative colitis, is the result of the interaction of several etiologic factors including infection, allergy, vascular alterations, and an imbalance between the autonomic nervous systems. The important temporal relation between psychic trauma and the development of ulcerative colitis has been emphasized. Gross pathologic changes include hyperemia of the mucosa, edema, superficial abscesses, and coalescence of abscesses with the formation of larger ulcers. These processes appear to be the result of two processes: vasculitiss with ischemia of the mucosa and submucosa, and the development of crypt abscesses which rupture into the submucosa. The most characteristic feature of the clinical course of ulcerative colitis is its variability. The onset may be sudden or insidious. It may pursue an intermittent or continous course for a period varying from a few weeks to many years. Certain factors are of value in predicting the subsequent clinical course. Factors suggesting a poor subsequent prognosis are: onset in either the very young of rery old, a severe initial attack which carries a higher mortality rate, lack of response to treatment, segmental or right-sided involvement of the bowel, lack of improvement in the proctoscopic appearance, and the development of complications. Local complications include polyps, stricture, perirectal and perianal complications, hemorrhage, perforation, and an increased susceptibility to carcinoma. The systemic complications may be related directly to the disease or secondary to the nutritional and metabolic disorders secondary to ulcerative colitis. Important among these are nutritional problems, an increased incidence of liver disease, arthritis, and skin complications, notably erythema nododum and pyoderma gangrenosum. Although improvement initially is usually noted regardless of the type of therapy employed, there are few data to suggest that any therapeutic agents now in use greatly alter the long-term course of the disease.

Diverticulosis and Diverticulitis

Many people have small pouches in the linxad ing of the colon, or large intestine, that bulge outward through weak spots. Each pouch is called a diverticulum. Multiple pouches are called diverticula. The condition of having diverticula is called diverticulosis. About 10 percent of Americans older than 40 have diverticulosis.1 The condition becomes more common as people age. About half of all people older than 60 have diverticulosis.2

COMPARISON OF ESTIMATED PEPTIC ACTIVITY BY RISA AND THE HEMOGLOBIN METHODS OF CRYSTALLINE PEPSIN SOLUTIONS, OF HUMAN GASTRIC SECRETIONS AND WITH THE ADDITION OF ANTIPEPTIC SULFATED POLYSACCHARIDES*

Anson and Mirsky’s hemoglobin method’ has been most widely used in the determination of gastric peptic activity. This method requires a 50to 200times dilution of the gastric juice in order to decrease the pepsin concentration to a level suitable for reading in the spectrophotometer. Bucher et a1.2 found that dilution of the gastric juice introduced a variable error of the estimated activity. Klotz and Duvall? in 1957, introduced a new method, using radioactive albumin as the substrate, to assay gastric peptic activity. Pipe+ subsequently reported that the RISA method is simple and accurate. Carrageenin, a naturally-occurring sulfated polysaccharide, has been shown to have antipeptic and antiulcerogenic activity in experimental animals. Several synthetic sulfated polysaccharides having similar properties have become available. The evaluation of therapeutic approaches for the treatment of the patient with a peptic ulcer poses many problems. One may evaluate the therapeutic agent directly by determining its effect upon the “natural history” of the illness, or indirectly, by its effect in combating alleged causative factors. Both methods pose problems to the investigator. It is difficult to determine the effects of many agents on the “natural history” of an illness with such a variable course as peptic ulcer. Information can be obtained regarding the incidence of recurrences, the frequency of complications, or the need for surgery. Large groups of patients are required and if the differences are not large, statistically valid information will not be obtained. Another approach is to evaluate the effectiveness of an agent in combating the causative factors. The importance of the combination of hydrochloric acid and pepsin in the production of ulcer manifestations has been recognized. This approach, although an indirect one, may yield very valuable information. For several years, the effectiveness of several antipeptic agents has been studied using the RISA (radioiodinated serum albumin) and Hb (hemoglobin) methods to assay gastric peptic activity before and after administration of an antipeptic agent in patients with peptic ulcer. The estimated peptic activity measured by the RISA and Hb methods differed in a systematic fashion when the results were expressed as the amount of pepsin in gastric juice. An example is shown in FIGURE 1. Gastric juice was aspirated every 15 min and the peptic activity was determined by both methods on the same specimen. After a one-hour

Medical and Surgical Management of Duodenal Ulcer

The panelists discuss general principles of medical management of duodenal ulcer, criteria of intractability, the role of stress, the status of gastric analysis, the chances of successful medical management, and the relative merits of various surgical technics.

Hepatic coma: Presentation and discussion of case

SummaryThe neurologic symptoms accompanying severe liver disease have been termed hepatic coma. This syndrome is characterized by personality changes, inappropriate behavior, stupor, and eventually coma. The peculiar flapping tremor is the most characteristic physical finding. Abnormalities of the electroencephalogram have been correlated with the depth of coma. The neuropathologic changes accompanying hepatic coma are limited to a diffuse protoplasmic astrocytosis.The most frequent biochemical abnormality is an elevation of the blood ammonia. This results from the breakdown of nitrogenous products in the bowel which reach the brain in toxic quantities as the result of portal venous collateral circulation around the liver and/or as the result of defective liver function.Treatment is directed toward improving liver function and removing the toxic breakdown products of gastrointestinal hemorrhage from the bowel. Administration of sodium glutamate has been used with variable results. Similar observations have been reported concerning the value of adrenal steroid therapy and administration of oral antibiotics.