The limitation of mitral echocardiography in combined mitral lesions

In combined mitral stenosis and incompetence, the mitral echocardiogram is able to estimate the degree of mitral stenosis (i. e. mitral valve area) without being able to detect or quantify mitral incompetence. A diastolic closure rate of 20 mm/sec or less does not exclude significant mitral incompetence as claimed by others. Cardiac catheterization is still necessary in mitral stenosis, where concominant mitral incompetence is suspected clinically, to confirm its presence and quantify its degree.     

Early prostaglandin release from the ischemic myocardium in the dog

Cellular consequences of myocardial ischemia were studied in anesthetized dogs. Confirmation of myocardial ischemia was provided by electrocardiographic and biochemical indexes. Prostaglandin F2alpha release into coronary venous blood was significantly elevated during myocardial ischemia, whereas indomethacin treatment prevented this increase in coronary venous prostaglandin F2alpha concentrations. No significant increase in prostaglandin E2 release was observed in response to myocardial ischemia, but indomethacin treatment significantly reduced coronary venous prostaglandin E2 concentrations below those of control values. Within one hour after occlusion of the coronary artery, the S-T segment was significantly altered, and coronary venous prostaglandin F2alpha had increased significantly above the control concentration. These changes persisted during four hours of myocardial ischemia. Plasma creatine phosphokinase activity increased significantly after two hours of myocardial ischemia and remained elevated for the subsequent two hours of ischemia. After four hours of myocardial ischemia, myocardial creatine phosphokinase activity of ischemic myocardium was significantly reduced, and labilization of myocardial treatment prevented increases in prostaglandin release but did not influence other biochemical changes or the electrocardiographic response to ischemia. Thus, prostaglandin release by ischemic myocardial tissue is an early response to the ischemic stimulus.     

Three-area epidemiological study of geographic differences in stroke mortality. I. Background and methods

An epidemiological study was conducted to determine the geographical variations in stroke mortality among three U.S. areas. They were Savannah, Georgia (high stroke rates), Hagerstown, Maryland (intermediate stroke rates) and Pueblo, Colorado (low stroke rates). In each area samples were drawn of the population in the 35--54 age group. The subjects were interviewed and examined to obtain the information required on medical conditions and/or living habits which would characterize each area. A brief medical and family history, as well as demographic and personal data, were obtained by interview. The medical examination included blood pressure, ECG, blood and urine chemistry, height and weight. In all three cities the response rate in the final sample selected was 90% (2,375 individuals) interviewed and 74% (1.939 individuals) examined.     

Evolution of ascorbic acid and peroxidase during industrial processing of broccoli

The ascorbic acid content and peroxidase activity of raw, canned and frozen (after blanching times of 60, 90, 120 and 150 s) broccoli florets and stems were determined. The ascorbic acid content represented 1.12 and 0.78 g kg⁻¹ fresh weight in raw florets and stems respectively. After blanching (for different times) and freezing, the ascorbic acid content decreased to values of 0.55–0.56 g kg⁻¹ fresh weight in florets and 0.35–0.36 g kg⁻¹ fresh weight in stems. The industrial processing involved in canning decreased the ascorbic acid content to 0.18 g kg⁻¹ fresh weight in florets. The peroxidase activity observed in the florets and stems of raw broccoli was 308.8 and 278.6 µmol min⁻¹ per 100 g fresh weight respectively. The peroxidase activity remaining in frozen florets varied from 0.9 to 0.2%, while that in stems showed values of between 7.5 and 8.4%. These values for stems were within the range recommended for residual activity after blanching and freezing. The peroxidase activity of canned broccoli florets was practically undetectable. © 2000 Society of Chemical Industry     

Rapid detection of a Schistosoma mansoni circulating antigen excreted in urine of infected individuals by using a monoclonal antibody

Schistosoma circulating antigens were used to indicate the infection intensity and to assess cure. An immunoglobulin G2a (IgG2a) mouse monoclonal antibody was used in a fast dot-enzyme-linked immunosorbent assay (ELISA; FDA) for rapid and simple diagnosis of schistosomiasis in the field. Seven hundred Egyptians were parasitologically examined for Schistosoma mansoni and other parasitic infections. A rectal biopsy was done as a "gold standard" for individuals showing no S. mansoni eggs in their feces. Egg counts were obtained by the Kato smear method for only 100 of 152 individuals with eggs in their feces. Specific anti-schistosome IgG antibodies were evaluated in sera by ELISA. Urine samples from the 700 individuals were tested by FDA for detection of the circulating antigen. The assay showed a sensitivity of 93% among 433 infected individuals and a specificity of 89% among 267 noninfected individuals. FDA showed the highest efficiency of antigen detection (91%) compared with the efficiency of antibody detection by ELISA (75%) and stool analysis (60%). In addition, FDA detected infected patients with 20 eggs/g of feces. Also, the sensitivity of FDA ranged from 90 to 94% among samples from patients with different clinical stages of schistosomiasis. All the assay steps can be completed within 30 min at room temperature for 96 urine samples. The monoclonal antibody identified a 74-kDa antigen in different antigenic extracts of S. mansoni and Schistosoma haematobium and in the urine of infected individuals. In addition, a 30-kDa degradation product was identified only in the urine samples. On the basis of these results, FDA should be used as a rapid tool for the sensitive and specific diagnosis of Schistosoma infection.     

Constrained evolution of human immunodeficiency virus type 1 protease during sequential therapy with two distinct protease inhibitors

Human immunodeficiency virus type 1 (HIV-1) variants that have developed protease (PR) inhibitor resistance most often display cross-resistance to several molecules within this class of antiretroviral agents. The clinical benefit of the switch to a second PR inhibitor in the presence of such resistant viruses may be questionable. We have examined the evolution of HIV-1 PR genotypes and phenotypes in individuals having failed sequential treatment with two distinct PR inhibitors: saquinavir (SQV) followed by indinavir (IDV). In viruses where typical SQV resistance mutations were detected before the change to IDV, the corresponding mutations were maintained under IDV, while few additional mutations emerged. In viruses where no SQV resistance mutations were detected before the switch to IDV, typical SQV resistance profiles emerged following the introduction of IDV. We conclude that following suboptimal exposure to a first PR inhibitor, the introduction of a second molecule of this class can lead to rapid selection of cross-resistant virus variants that may not be detectable by current genotyping methods at the time of the inhibitor switch. Viruses committed to resistance to the first inhibitor appear to bear the "imprint" of this initial selection and can further adapt to the selective pressure exerted by the second inhibitor following a pathway that preserves most of the initially selected mutations.     

Securing urethral catheters in patients undergoing urethrovesical anastomosis

OBJECTIVE: Securing urethral catheters for the optimal healing of and prevention of extravasation at the urethrovesical anastomosis. METHOD: This article describes the technique that we use to help secure Foley catheters or replace them if necessary. CONCLUSION: In the rare patients where disruption of the anastomosis or loss of the catheter prematurely takes place, the nylon suture can be used to replace the catheter without jeopardizing the anastomotic line.