Acute caecal volvulus

Forty-one cases of acute caecal volvulus have been analysed. The diagnosis is rarely made on clinical grounds alone but plain radiography of the abdomen should suggest the diagnosis in nearly 90 per cent of cases. Prompt surgery is imperative. When the bowel is viable, simple caecopexy combined with tube caecostomy is effective in fixing and decompressing the bowel in the short term and prevents recurrence.

Mk in three generations of an English family

Mk was demonstrated in three generations of an English family. The propositus was detected as a result of an incompatibility in cross-match. General serological, biochemical and biophysical aspects have been studied.

Isolated liver perfusion: the choice of anaesthetic

Perfused livers isolated from rats under halothane anaesthesia produced greater amounts of bile, released smaller amounts of aspartate aminotransferase, and had a much greater ability to maintain a constant concentration of glucose in perfusates than those obtained with ether or pentobarbitone. Little or no effect was shown on the ability of the liver to synthesize urea and to retain potassium within the organ. It appears, therefore,that halothane is the anaesthetic of choice when removing the liver from the laboratory rat.

Lung injury induced by leukocytic proteases

Human polymorphonuclear neutrophilic leukocytes (PMNs) contain large amounts of neutral proteases that can degrade elastin, collagen, proteoglycan, and basement membrane. The instillation of one of the purified enzymes (elastase) into dog lungs in vivo causes degradation of elastic fibers and other alveolar septal components and results in anatomic changes similar to those of human pulmonary emphysema. Cigarette smoking is a major risk factor associated with pulmonary emphysema in man. One mechanism for this association may be interference with the regulation of PMN elastase activity by alveolar antiproteases. This possibility is supported by the observation that the oxidizing activity of tobacco smoke inactivates alpha 1-proteinase inhibitor in vitro. Macrophages also secrete an elastolytic protease, albeit at low levels. The short-term exposure of cultured mouse macrophages to cigarette smoke augments the rate of elastase secretion by these cells. Mouse macrophage elastase is not inhibited by alpha 1-proteinase inhibitor or alpha 2-macroglobulin. This unusual property of macrophage elastase may facilitate its attack upon elastin over prolonged intervals despite very low levels of macrophage elastase production. A unified hypothesis of lung injury in pulmonary emphysema is presented, involving both PMN and macrophage elastases and the actions of cigarette smoke. (Am J Pathol 97:111--136, 1979).

Improved performance of the isolated rat liver when perfused with purified bovine serum albumin

Three groups of isolated rat livers were perfused at 35 C with Krebs-Ringer bicarbonate buffer containing commercial bovine serum albumin (BSA) which had been purified by gel filtration on a column of Sephacryl S-200 and used within 12 hr of purification, or BSA which had been purified by gel filtration and stored at -70 C until used. The ability of livers to produce bile, retain potassium, and to maintain a constant level of glucose in the perfusate was greatly improved in the presence of purified albumin which had not been frozen. Such livers also showed the highest rates of urea synthesis, but the rate of release of aspartate aminotransferase (GOT) from cells and the bile salt content of the bile produced were similar to those found with unpurified BSA. Livers perfused with purified albumin which had been stored in the frozen state were slightly inferior to those perfused with nonfrozen albumin in their ability to produce bile and urea, to retain potassium and GOT within cells, and to maintain a constant concentration of glucose in perfusates. The concentration of bile salts in the bile produced by this group was also lower than that found with the other two groups. Overall, isolated rat livers benefited from perfusion with purified albumin, although freeze storage of this material rendered it slightly inferior to the nonfrozen material in its ability to support the liver.

The danger of hemolysis in shock

Intravascular hemolysis is sometimes harmful and often fatal. Other times it is harmless. Dogs were paired and subjected to hemorrhagic shock. One of the pair was given 2 ml/kg of autologous hemolyzed blood before bleeding. The other of the pair was given 2 ml/kg of heparinized autologous blood. All of the animals given heparinized blood survived, whereas, all of the animals given hemolyzed blood died. The animals given hemolyzed blood developed coagulation changes indicative of Disseminated Intravascular Coagulation (DIC), whereas, the dogs given nonhemolyzed blood did not. It is concluded that hemolysis in the presence of shock (slow capillary flow) causes DIC and death. Hemorrhagic shock alone or hemolysis alone was harmless.

A case of atypical polyagglutinability due to Tk-transformation

A case of acquired transient polyagglutinability in a group O, Rh(D) positive female patient, Wa, is described. An unusual finding in the preliminary serological investigation was the non-reaction of the cells with peanut (Arachis hypogaea) extract. The patient's red cells were strongly agglutinated by normal human and rabbit sera from which anti-T had been removed. Electrophoretic mobility studies and tests with polybrene indicated that their sialic acid content was normal. The use of a specific antiserum raised in a rabbit to Wa cells and cross-absorption tests showed that the patient's erythrocytes shared similar antigenic determinants to red cells treated with supernatants from pure cultures of Bacteroides fragilis. The in vitro-modified red cells reacted strongly with BS II lectin prepared from Bandeiraea simplicifolia seeds thus providing confirmatory evidence for Tk transformation on Wa cells. It is concluded that the Tk receptor is probably a more frequent feature of acquired transient polyagglutinability than has hitherto been recognized.

Aedes aegypti in Puerto Rico: environmental determinants of larval abundance and relation to dengue virus transmission

In order to understand adquately the dynamics of vector-borne disease, one must understand how and why vector populations change over time. We describe a long-term, cooperative study of seasonal fluctuation in populations of the Aedes aegypti mosquito in Puerto Rico. During each month of the first 3 years of the project, A. aegypti was found breeding in all five communities studied. Mosquito density was positively correlated with rainfall, the relationship being more marked in the dry, south-coastal part of the island. Discarded tires and animal watering pans were the two most common larval breeding sites. In general, houses in Puerto Rico harbor more potential A. aegypti breeding sites than those in other tropical locations, probably because Puerto Rico is relatively more affluent.

The effect of insulin and hydrocortisone on the isolated rat liver

Isolated rat livers were perfused at 35 degrees C with bovine serum albumin (40 g/l) in Krebs Ringer bicarbonate buffer, or with the same solution containing insulin (0.22 x 10(-6) mol/l), hydrocortisone (0.068 x 10(-3) mol/l), or both hormones together. Observations on the synthesis of bile and on perfusate levels of potassium, aspartate aminotransferase, urea and glucose showed that the presence of insulin and/or hydrocortisone had no beneficial effect on the perfused rat liver in vitro. There is little justification of the isolated liver.

Techniques for arteriography and hydraulic analysis of coronary stenoses in unsedated dogs

This report describes techniques for obtaining pressure flow characteristics and arteriograms of controlled coronary stenoses in unsedated, trained dogs. Coronary flow velocity was recorded by calibrated Doppler velocity transducers linear to three times maximum coronary flow velocity. Pressure losses across stenoses were measured by a differential pressure transducer through small catheters implanted in the distal and proximal left circumflex coronary artery or ascending aorta, a system that was linear within +/-5% to 30 Hz. Coronary stenoses were produced by saline-filled, perivascular cuff constrictors inflated to constant pressure by a pressure regulator. Catheters were implanted in the pulmonary artery for injection of intravenous drugs or diffusible radionuclides and in the left atrium for injection of radionuclide microspheres. Contrast medium was injected through the proximal coronary catheter, and high-resolution arteriograms were obtained by single-spot filming on ultra detail X-ray film and cassettes at end diastole by triggering X-ray exposures from the electrocardiogram. In 13 dogs studied consecutively, the surgical mortality was 15.4%. All implanted instruments functioned for an average of 8 wk per dog.

Myelomatosis and the hyperviscosity syndrome

Eleven patients are described in whom myelomatosis was complicated by the laboratory and clinical features of the hyperviscosity syndrome (HVS). The myeloma type was IgA in nine and IgG3 in two. In those patients with IgA myeloma the HVS was related to the presence of high molecular weight complexes in the serum. Remission of clinical features was obtained in all patients by plasma exchange. Clinical improvement coincided with reduction of whole blood viscosity and in those patients with IgA myeloma, with a parallel reduction of the high molecular weight complexes. The relationship between the IgA complexes and blood viscosity has been examined by physicochemical analysis of purified IgA monomer and polymers and evidence is presented to show that the IgA polymer has a higher intrinsic viscosity and axial ratio than the larger IgM molecule. The significance of these observations is discussed.