Perflubron emulsion improves tolerance to low-flow ischemia in isolated rabbit hearts.

The efficacy of the temporary oxygen carrier perflubron emulsion (PFC) in maintaining oxygen delivery, tissue oxygenation, high-energy phosphates (HEPs), and myocardial function was investigated during low-flow ischemia. Perfusion rate, oxygen tensions, and cardiac function were measured during stabilization (5 min), controlled-flow (22 ml/min x 20 min), and low-flow (0.22 ml/min x 120 min) periods in isolated rabbit hearts. Hearts were perfused with Krebs-Henseleit (KH) solution (Control), or 10 or 20% PFC (vol/vol; n = 8 per group) 5 min before and throughout the low-flow period. Myocardial tissue was then frozen for biochemical and metabolic measurements. Myocardial oxygenation was measured at incremental flow rates by using 20% PFC (n = 4) or KH (n = 6). In PFC hearts, oxygen delivery and intramyocardial tissue Po2 were improved at all evaluated time points and flow rates, respectively (p < 0.05). In Control hearts, left ventricular end-diastolic pressure was elevated at 60, 90, and 120 min of low-flow ischemia (p < 0.05). Tissue lactate was higher (p < 0.05) and HEPs lower (p < 0.05) in Control hearts during low-flow ischemia. These results indicate that PFC treatment improves myocardial oxygenation, maintains HEPs, prevents ischemic contracture, and may increase the margin of safety during low-flow ischemia in isolated rabbit hearts.     

Ewing's sarcoma of the bone. Anatomoclinical study of 424 cases]

The clinic-epidemiologic and prognostic features of 424 cases of Ewing sarcoma observed at "Rizzoli" Institute between 1972-1990 are reported. The incidence of the tumor was higher in the second decade of life with slight predominance in the male sex. The primary lesion was especially localized in the extremity and the ratio lower/upper extremity was 5/1. We did not find, in contrast with other Authors, differences in height or in incidence of congenital malformations when compared to controls. The pain was the first common symptom at debut (90%) followed by swelling (50%) and fever (40%). Diagnosis was made 5.5 months after the first symptom and the delay was due to wrong diagnosis at debut in 3/4 of the patients. Laboratory tests showed anemia in about half of the patients and increased value of ESR (60%) and LDH (40%). Seventy-one of the patients were metastatic at presentation, none of these patients were still living after three years. At a median follow-up of 9 years 43% of the patients with localized disease, treated with adjuvant and neo-adjuvant chemotherapy remained continuously disease free, 53% developed metastatic disease and/or local recurrences and 2% had a second malignancy. In 24% of the patients metastases and/or local recurrences appeared three years after the beginning of treatment. Better prognosis was observed in female patients, without fever at diagnosis, with tumor localized at extremities and with normal value of hemoglobin, ERS and LDH. Regarding the type of treatment, better results were obtained by surgery of the primary tumor and by chemotherapy with four drugs (vincristine, cyclophosphamide, adriamycin dactinomycin) in comparison to radiotherapy of the primary tumor and chemotherapy with three drugs (vincristine, cyclophosphamide, adriamycin).     

Managers: function and form in the new organization

Nurse executives, administrators, and managers are constantly being challenged by the changes in healthcare. Although it sometimes seems there is really nothing new, proactive visionary nurse administrators can rediscover, redesign, and redirect their own and others' activities to achieve organizational effectiveness. Such approaches require periodic examination of all strategies and practices--past, present, and future--for their relevance, practicality, and success. The editors of "Executive Development" reflect on topics important to organizational life.     

Effects of cardioplegic solutions and their components on human saphenous vein contractility.

Cardioplegic solution administration into the vein graft is an established method to ensure cardioplegic distribution beyond coronary artery stenoses. The ultrastructural demonstration of severe endothelial damage after cardioplegic exposure suggests that intravenous cardioplegic administration can contribute to early and late graft thrombosis. The direct effect on human saphenous vein contractility of three cardioplegic solutions and their components was compared. A solution with 30 mmol/L K+ and 82 mmol/L Na+ produced intense venoconstriction. Lowering the potassium level to 10 mmol/L and increasing the sodium level to 92 mmol/L reduced its vasoconstricting action. A third solution with 16 mmol/L K+, 16 mmol/L Mg2+, and lidocaine caused venodilatation. Analysis of the single component effects showed that high potassium level, low sodium level, and the addition of lidocaine produced concentration-dependent vasoconstriction. High magnesium concentration resulted in vasodilatation. The present data suggest that cardioplegic solution composition may cause marked vasomotor effects on saphenous vein and thus influence its endothelial integrity. In the search for an "ideal solution" to the cardioplegic controversy, a venoconstrictor infusate should be avoided to improve patency rates of coronary artery bypass grafts.     

Retroperitoneal benign schwannoma. Report of a new case

The schwannoma is a tumor resulting from the Schwann cells of neural shwath, being its retroperitoneal localization quite unusual. This tumor is clinically unspecified and in most of the cases it originates symptoms coming from the compression of the close structures when its localization is retroperitoneal. Its diagnosis is quite often fortuitous being confirmed by anatomopathological study afterwards. The treatment is surgical radical exeresis with subsequent followup. We report a new case of this uncommon retroperitoneal pathology in a female patient showing a nonspecific clinic. Two years after the surgery she remains asymptomatic without any radiological evidence of recidive.     

Hepatitis G virus infection in hemodialysis patients and its relationship with hepatitis C virus infection

Our aim was to study the characteristics of hepatitis G virus (HGV) infection in hemodialysis (HD) patients. We evaluated 108 patients from two different units (A: 67 patients; B: 41 patients). HGV RNA and HCV RNA were detected by PCR. Nineteen patients (17.6%) were HGV RNA positive (20.9% in unit A and 12.2% in unit B (NS)). HCV RNA was positive in 19 patients (17.6%) (28.4% in unit A and 0 in unit B (p < 0.01)). Eight patients were HGV RNA and HCV RNA positive (group I), 11 HGV RNA positive (group II), 11 HCV RNA positive (group III), and 78 negative for both viruses (group IV). Time on HD was 51.3 +/- 37.0 months for group I, 36.0 +/- 27.9 months for group II, 63.5 +/- 40.2 months for group III, and 26.4 +/- 27.1 months for group IV (p < 0.01 for I and III). Seven patients (87.5%) from group I, 9 (81.8%) from group II, 10 (90.9%) from group III, and 44 (56.4%) from group IV had a history of transfusion (p < 0.03 for I, II and III). Two patients (25%) from group I, none from group II, 5 (45.4%) from group III, and 6 (7.7%) from group IV had chronic ALAT elevation (p < 0.01 for I and III). We conclude that HGV infection was frequent in our HD patients, related to transfusions and independent of HCV prevalence, and that HGV infection itself was not a cause of ALAT elevation suggesting chronic hepatitis.     

Use of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy in the treatment of locally advanced head and neck cancer patients.

PURPOSE: To evaluate safety and preliminary efficacy of the humanized anti-epidermal growth factor receptor monoclonal antibody h-R3 in combination with radiotherapy (RT) in unresectable head and neck cancer patients. Secondary end points were the measurement of h-R3 serum levels and the assessment of the potential mechanisms of antitumor effect on patient biopsies. Anti-idiotypic response to h-R3 was assessed. To predict pharmacologic effect, a mathematical model for antibodies recognizing antigens expressed in tumors and normal tissues was built. PATIENTS AND METHODS: Twenty-four patients with advanced carcinomas of the head and neck received six once-weekly infusions of h-R3 at four dose levels in combination with RT. Pretreatment tumor biopsies were obtained to evaluate epidermal growth factor receptor expression as an enrollment criterion. Second biopsies were taken to evaluate the proliferative activity and angiogenesis in comparison with the pretreatment samples. Patient serum samples were collected to measure h-R3 levels and anti-idiotypic response. RESULTS: The combination of h-R3 and RT was well tolerated. Antibody-related adverse events consisted in infusion reactions. No skin or allergic toxicity appeared. Overall survival significantly increased after the use of the higher antibody doses. Immunohistochemistry studies of tumor specimens before and after treatment revealed that antitumor response correlated with antiproliferative and antiangiogenic effect. One patient developed antibodies to h-R3. The mathematical model predicted that the maximum difference between the area under the curve in tumors and normal tissues is reached when the antibody has intermediate affinity. CONCLUSION: h-R3 is a well-tolerated drug that may enhance radiocurability of unresectable head and neck neoplasms.     

Relationship between tumor recurrence and the expression of the p53 gene in primary superficial transitional carcinoma of the bladder

Contribution of 60 patients with primary surface transitional cell tumours of the bladder where nuclear expression of p53 protein was prospectively studied and compared to known prognostic factors in an attempt to find out its role in the development of relapses. An statistically significant relationship was found between the protein expression and cytology, tumoral multifocality, stage, relapse development and tumoral progression. It can be concluded that expression of this protein can be of use as relapse predictor.     

Massive lymphatic involvement secondary to prostatic adenocarcinoma

Prostatic carcinoma may be diagnosed by the clinic manifestations or by the symptoms for locoregional disemination and distance metastasis. The lymphatic system is the first metastatic station, which is affected in a high percentage of cases. Event it may simulate lymphoproliferatives process and it si uncommon the lymphatic macroaffectation at first. In theses cases, the histologic and immunohistochemical study by the determination of prostatic specific antigen in lymph nodes can provice the diagnosis. Treatment of these tumors is palliative with hormonotherapy. Prognosis is bad with a low survival at five years.