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Biomedical subjects

E Wolner

Publications and source records attributed to E Wolner.

464 records · Page 26Linked to original sources

Prophylactic use of hyperimmunoglobulin for cytomegalovirus infection in heart transplantation.

Cytomegalovirus (CMV) infection in solid organ recipients can endanger the immunosuppressed patient and increase vulnerability to secondary infections and the high risk of rejection triggered by the viral disease. The effect of passive immunization against CMV was examined in 69 heart transplant patients. The patients received weekly administrations of 1 ml/kg of CMV hyperimmunoglobulin from the day of transplantation until the 30th postoperative day. Forty-four of the patients were monitored clinically and serologically up to the 120th postoperative day. Nine patients showed clinical and serologic signs of CMV infection; in 15 the only evidence of CMV infection was a rise in antibody titers. The remaining 20 patients showed no clinical or serologic signs of CMV infection. Three patients who were seronegative preoperatively remained seronegative until the end of the observation period. The results indicate a potential therapeutic benefit of hyperimmunoglobulin prophylaxis to prevent infectious complications due to CMV in heart transplant patients.

Adolescent↗

Neopterin as a new marker to detect acute rejection after heart transplantation.

Neopterin is excreted at high levels in the course of activation of the immunologic system during allograft rejection or viral infection. This pteridine therefore may be considered as a specific indicator of T cell-mediated immunity. With radioimmunoassay we analyzed both serum and urine levels of neopterin in 43 patients after orthotopic heart transplantation. These data were correlated to the histologic finding at routine endomyocardial biopsies (EMB). In case of rejection (that is, grades I to II or more in EMB) serum levels of neopterin increased about 156% +/- 94% within 1 week before EMB, whereas urine levels increased about 215% +/- 137%. The most marked increase was seen 2.8 days before the corresponding EMB. The predictive value theory was used to elaborate the reliability of the correlation between an increase of neopterin levels and the occurrence of an acute rejection episode. With regard to serum levels, sensitivity and specificity were 0.872 and 0.815, respectively. The positive predictive value was 0.41 and the negative predictive value was 0.977. We found similar results in urine levels.

Acute Disease↗

Impacts of low-dose steroids and prophylactic monoclonal versus polyclonal antibodies on acute rejection in cyclosporine- and azathioprine-immunosuppressed cardiac allografts.

The ideal combination of immunosuppressants after heart transplantation that safely prevents graft rejection and maintains a low rate of infections and toxic side effects is still a topic of discussion. Between March 1984 and March 1988, 76 patients underwent orthotopic heart transplantation. Sixty-five patients received either double-drug (cyclosporine + azathioprine) or triple-drug (cyclosporine + azathioprine + steroids) maintenance therapy. In addition all patients with double-drug protocol (group 1, n = 13) and the majority with triple-drug protocol (group 2, n = 39) received prophylactic antithymocyte globulin (ATG); 13 patients with triple-drug protocol (group 3) received prophylactic monoclonal antibody (murine antihuman mature T cell [OKT3]). Recipients with perioperative or intraoperative deaths, maintenance protocol without cyclosporine, or previous total artificial heart bridge were excluded from the study. Cyclosporine was given in low doses according to a trough whole blood high-performance liquid chromatography target level of 200 to 400 ng/ml in the first month, 150 to 250 ng/ml from the second to sixth month, and 100 to 150 ng/ml after the sixth month. Azathioprine dose was adjusted to a leukocyte count of approximately 4,000 cells/mm3. In patients with triple-drug protocol, prednisolone (0.2 mg/kg/day) was added. The mean follow-up (group 1, 12.75 months; group 2, 12.84 months) was comparable between the groups who received ATG perioperatively. The mean follow-up for group 3 was 3.46 months.(ABSTRACT TRUNCATED AT 250 WORDS)

Actuarial Analysis↗

Noninvasive assessment of acute rejection after orthotopic heart transplantation: value of changes in cardiac volume and cardiothoracic ratio.

Since 1984, 47 orthotopic heart transplantations (HTX) were carried out in 45 patients. In 29 long-term survivors cardiac volume as well as cardiothoracic ratio were measured during their routine follow-up. These two parameters of cardiac size were evaluated from posterior-anterior (pa) and lateral chest x-rays by using conventional technics. Changes of these parameters were correlated to the histological grading of endomyocardial biopsies (EMB). Increases of cardiac volume of more than 10 percent or 100 ml compared with the last measurement and simultaneous increases of cardiothoracic ratio of more than 2 percent were assumed to represent rejection equivalents. Sensitivity and specificity were 0.759 and 0.969, respectively. Predictive values of a positive or negative test for the presence or absence of disease came to 0.815 and 0.957.

Cardiac Volume↗

Nine year experience with the clinical use of total artificial hearts as cardiac support devices.

One hundred sixteen total artificial hearts (TAH) were implanted in 113 patients by 29 centers between April 4, 1969 and March 1, 1988. Five were permanent and 111 were temporary implants (3 patients received second implants). Eight different types of TAHs have been used. The ages ranged from 15 to 62 (mean age: permanent 57, temporary 42). Sixty-seven percent (72/108) of patients receiving the TAH for temporary support were transplanted; 6 patients were waiting for a transplant. Forty-seven percent (34/72) were alive after transplantation. Of the 92 patients receiving the Jarvik TAH (the most frequently used device) as a temporary device, 67% (62/92) were transplanted (6 currently supported) and 55% were alive after transplantation; 85% were back to work, with a normal life-style. The thromboembolic rate for patients who received the device as a temporary support was 10%, with 3 patients having residual sequellae. No deaths resulted from mechanical failure. Experience to date suggests that the use of the TAH as a temporary device can be beneficial if patients are carefully selected.

Adolescent↗

A new flush solution for extended lung preservation.

BACKGROUND: The aim of this study was to compare the effect of the most frequently used clinical preservation solution (Euro-Collins, group I) with a newly composed low potassium, glucose- and insulin-containing preservation solution (141 mmol/L sodium, 6.4 mmol/L potassium, 119 mmol/L chloride, 5 mmol/L magnesium, 10 gm/L glucose, 10 gm/L dextrane and 20 U/L insulin) (group II) on postischemic lung function. METHODS: We studied 12 isolated New Zealand White rabbit lungs in a closed circuit model during the first 4 hours of reperfusion after 24 hours of ischemic hypothermic storage. RESULTS: Oxygenation capacity, defined by the difference between the arterial and venous oxygen tension was significantly higher in group II compared with group I after 10 (58.7 +/- 5.8 versus 34.9 +/- 7.5 mm Hg), 30 (63.5 +/- 7.8 versus 27.3 +/- 10.4 mm Hg) and 180 minutes (77.7 +/- 7.2 versus 8.8 +/- 5.6 mm Hg). Ventilatory pressure was significantly lower in group II after 1 minute (11.3 +/- 1.3 mm Hg versus 13.7 +/- 0.5 mm Hg, p < 0.05), with no significant difference thereafter. No significant difference was found in pulmonary vascular resistance except after 20 minutes (30.8 +/- 1.2 dyns/cm5 [group I] versus 27.1 +/- 1.1 dyns/cm5 [group II], p < 0.05). CONCLUSION: These data suggest that this new solution provides superior lung function after 24 hours ischemic time compared with Euro-Collins solution.

Animals↗

Platelet function after total artificial heart replacement: clinical application and experiment.

Clinical application of artificial blood pumps for mechanical circulatory support has been hampered by thromboembolic events. The underlying mechanisms are complicated and may differ from patient to patient. Because the calf is commonly used for artificial heart studies, the object was to determine the value of data gained in an animal model. To this end, the average of 10 calf experiments was compared with three clinical applications of an orthotopically implanted total artificial heart in patients with terminal heart failure. Platelet reactivity was investigated in vitro by collagen-induced whole blood aggregometry, radioimmunoassay methods, and scanning electron microscopy over a 10-day period. An analogous periodicity of platelet function was found in human and animal recipients. Improvement of platelet function preceded that of platelet counts in the early postoperative phase. Exaggerated responses to aggregative agents were observed at days 3 and 7. On the basis of our data, we believe that we can comment about the prospective course of the function and number of human platelets, which may contribute to the identification of critical phases of such treatment, during total artificial heart replacement.

Adult↗

Artificial heart driven by an automatic driving system.

Thrombi formation within artificial ventricles is caused by the effects of biomaterials, stagnation areas, and major turbulences. During systolic and diastolic cycles, stagnation area increase in hearts that are properly designed. Stagnation areas may also occur in properly designed artificial hearts that are not working with a maximum stroke volume. The ellipsoid heart avoids stagnation areas and major turbulences because all the inside surfaces have an adequate washout with blood. The optimum washout of these surfaces is obtained by driving the heart with a constant maximum stroke volume. The cardiac output is regulated according to Starling's law by adjusting the frequency according to the venous return.

Animals↗

Racial variation in lung cancer.

Lung cancer claimed about 153,000 lives in 1994 in the United States. Despite research overall lung cancer survival has still not improved during the last 20 years, with 5-year relative survival remaining about 13%. In addition several epidemiologic and molecular studies showed a difference in the incidence of lung cancer in the three major races. The aim of our study was to investigate the variations of race in lung cancer patients, in order to identify potential risk factors linked to the different racial status. In this light we compared a 10 years lung cancer data of black population from Howard University Hospital, Washington D.C., U.S.A. and a 20 years data of white population from the Vienna University Hospital, Austria. Our results did not show any significant difference in mean age or tumor localization in both groups, but highlighted a remarkable difference in the incidence of the lung cancer histological types also according to the sex. In this respect it could be more successful to consider carcinogenesis like a protracted process of gene function deregulation in response to cell injury from exposure to genotoxic substances with individual specificity.

Adult↗

Ethnic variations in lung cancer.

Cancer of the lung is the most frequent cancer in the world, but with wide geographical variation in risk. It is most spread among males of all races worldwide, the only exception being its incidence among Chinese women aged 70 years and older. When comparing the different ethnic groups we have to consider that besides inhaling cigarette smoke actively or as a passive smoker the exposure to occupational carcinogens varies considerably according to different work places. In our study we compared 10 years of data from African-Americans in Howard University Hospital, Washington D.C. with 20 years of data from the white population in the University Hospital of Vienna, Austria. Ethnic patterns are generally consistent within each group in terms of both incidence and mortality. The difference in susceptibility between the sexes, the three major racial groups and already proven differences in genetic variations indicate the difference between individuals concerning the initiation and progression of lung cancer.

Adenocarcinoma↗

Prognostic role of proliferating cell nuclear antigen in lung cancer: an immunohistochemical analysis.

Proliferating cell nuclear antigen (PCNA) is a 36 kDa protein acting as a subunit of DNA polymerase delta, and is therefore associated with DNA replication. Its involvement in DNA excision repair after DNA sub-lethal damage has been reported. We assessed the immunohistochemical expression of PCNA in 94 lung cancer specimens in order to evaluate its potential relationship with clinical history and the outcome of the evaluated patients. We found PCNA protein expressed in all the evaluated neoplastic specimens, but with different expression levels. In addition, our results showed a subgroup of patients (high expressors) having a statistically significant worse outcome compared to the other two groups of patients, independently of' any other clinico-pathological feature. In conclusion, our data highlight the central role of PCNA and estimation of the proliferation rate in the prediction of the prognosis of lung cancer patients.

Adenocarcinoma↗

The Windkesselventricle with guiding balloon as a new approach for assisted circulation.

A simple method was developed to aid the patient with low cardiac output syndrome following cardiac surgery. The concept was shown to be feasible in electric circulatory analog studies and verified in 20 dog experiments. A Dacron graft (end-to-side) through the right second intercostal space connects the ascending aorta to the subcutaneously implanted, ellipsoidal-shaped artifical ventricle. A spherical polyurethane balloon is positioned in the aorta distal to the Dacron graft via the femoral artery. The ventricle and balloon are pneumatically driven synchronously with the ECG. In natural systole the balloon is inflated, occluding the aorta, and the artificial ventricle sucks the entire stroke volume. In natural diastole the balloon deflates and the artificial ventricle ejects the blood into the peripheral arteries. With this system it is possible to maintain a normal systemic pressure and have high hemodynamic efficiency. The left ventricular systolic pressure is 85 percent unloaded. The systolic wave is turned 180 degrees to the natural. After treatment, the device can be removed without thoracotomy.

Animals↗

RB growth control evasion in lung cancer.

We evaluated the expression of pRb by immunohistochemistry in 98 lung cancer specimens already characterized for their p16 and cyclin D1 status. We found the absence of pRb expression to be dependent upon the histological type, being more frequent in SCLCs than in NSCLCs (p < .00005). On the other hand, we failed to find any correlation between the expression of pRb and p16. In addition, we found a positive correlation between the expression of pRb and cyclin D1 (p = .0001). Therefore, we hypothesize that pRb growth control may be overcome by two different mechanisms in lung carcinogenesis: loss of pRb expression or overexpression of cyclin D1.

Adenocarcinoma↗