An analysis of paramagnetic centers in irradiated dentin using electron spin resonance

Summary The ESR spectra produced in irradiated dentin have been studied over a range of incident radiation energies from 50 kVp to 25 MVp. The behavior of the dentin ESR signal strength is similar to that of enamel as a function of the energy of the incident radiation. The magnitude of the dentin ESR signals are, however, up to 10 times smaller than the signals of dental enamel for a given radiation energy. The possible contributions of radiation interaction coefficients, chemical structure, and crystallite size to the differences in ESR spectra are discussed.     

Bladder leiomyosarcoma following cyclophosphamide therapy for lupus nephritis

We report 2 cases of leiomyosarcoma of the bladder that occurred after long-term cyclophosphamide chemotherapy for lupus nephritis and rheumatoid arthritis. One patient had a tumor at the end of an 11-year course of chemotherapy and 1 approximately 7 years after completing a 7-year course of chemotherapy. Patient 1 underwent left partial cystectomy and patient 2 underwent cystectomy with ileal conduit urinary diversion. In patient 1 the tumor was a typical leiomyosarcoma and patient 2 had a myxoid variant. Both patients were free of disease at 4 months and 3 years, respectively. Whereas previous reports of the carcinogenic effects of cyclophosphamide have been questioned, since the induced tumors occurred in patients being treated for other neoplasms (lymphoproliferative and myeloproliferative disorders), the disease in both of our patients followed cyclophosphamide therapy for nonneoplastic disorders.     

Involvement of platelet activating factor and thromboxane A2 in the renal response to unilateral ureteral obstruction

Platelet activating factor (PAF) and thromboxane A2 (TxA2) are two vasoactive mediators which can decrease renal blood flow. Both are synthesized by various intrarenal cell types or by macrophages which may infiltrate the kidney during unilateral ureteral obstruction (UUO). In several experimental systems, PAF receptor activation is accompanied by TxA2 release; pharmacological modification of TxA2 synthesis or receptor activation modulates the response to PAF. The involvement of PAF in UUO has not been studied previously, and the role of TxA2 has not been clearly defined by previous investigations. The hemodynamic response to acute UUO is characterized by decreases in renal blood flow (RBF) and glomerular filtration rate and an acute increase in ureteral pressure. In the present experiments, the involvement of either PAF or TxA2 in the acute response to UUO was studied by determining if blockade of either the TxA2 or PAF receptor would affect the renal hemodynamic response to UUO. In addition, the effect of blockade of the TxA2 receptor on the renal response to PAF was determined. Our results indicate that only a small portion of the renal response to PAF is mediated by TxA2, and that neither PAF nor TxA2 can be implicated in the acute hemodynamic response to UUO. TxA2 or PAF involvement in the chronic response to UUO still remains to be determined.     

Factors determining prognosis in stage T1.2NoMo breast cancer

From study of data on 5- and 10-year survivals of 560 patients who underwent operation for breast cancer in stage T1.2NoMo, the authors determined the most significant prognostic factors. These were the histological form of the tumor and the degree of invasion into the adjoining tissues. The percentage of each studied factor was determined by mathematical analysis, which allowed the individual prognosis for each patient to be made and treatment planned accordingly.     

Correction of immunologic disorders in patients with burns

Addition of immunomodulating therapy with Thymalin, a thymus agent, to the multimodality therapy of burnt patients contributes to a rapid normalization of immunological parameters. The most marked immune response was observed 7-10 days after a therapy course initiated in the early periods of burn disease in patients with severely depressed T-system immunity and a high sensitivity to the drug. Inclusion of a donor blood leukomass transfusion course activates the cellular link of the immune system just after the treatment course, but fails to favour a stable normalization of thymus-dependent lymphocyte ratios.     

Early postoperative rejection crises after transplantation of the kidney from the living related donors

The frequency of the development of rejection crises in the early postoperative period in 32 recipients of allogeneic kidneys from alive related donors was analysed depending on the histocompatibility according to the antigens of the HLA-AB system and the nature of the immunosuppressant therapy. The results of the analysis showed that the frequency of rejection crises was 100% when the donor and recipient were compatible in 1-2 antigens, and 40% in compatibility according to 3-4 antigens. The incidence of rejection crises was 71.4% among patients who received the standard immunosuppressant therapy (corticosteroids + azathioprine) and 36% among those given also sandimmune. Analysis of the frequency of rejection crises according to the ABO blood group system to which the donor-recipient pair occurred, showed that rejection crises occurred most frequently among patients with A (II) blood group.     

Ultrasonic vascular scanning in the diagnosis of acute arterial obstruction

In thrombosis of the aorta and major arteries (52 cases), postthrombotic occlusion (26), arterial embolism (14), the ultrasound vascular scanning++ was performed. The method permits to define the presence and location of arterial occlusion, differentiate thrombosis and embolism, atherosclerotic and autoimmune diseases of the vessels and as well to assess the outcome of restorative and reconstructive operations in acute arterial obstruction.     

The use of laser scalpel in the surgical treatment of cholecystitis

A comparison of the results of 169 cholecystectomies with the use of a laser scalpel and 160--conventional methods was carried out. The CO2-laser was used for exposure of the gallbladder and coagulation of tissue of the liver in the region of its bed. Hemo- and cholestasis in all the cases was reliable, and due to this fact in 27% of the patients, the subhepatic recess was not drained. The incidence of complications after the elective cholecystectomy reduced by 11%, after the emergency one--by 9%, the lethality reduced considerably.     

Surgical treatment of postoperative abdominal hernia

After surgical treatment of 664 patients with postoperative abdominal hernias (PAH) within the period of from 1972 to 1983, the incidence of recurrences was 48.4%. On the basis of studying microcirculation at the area of hernioplasty and its dependence on tissue tension force in the experiment on animals and at operations by means of radiometry, rheometry and fluorimetric analysis, the technique for surgical treatment of PAH with regard to location of a defect, including the method of plasty, system of preoperative preparation and prophylaxis of the postoperative wound complications, has been developed. From 1984, 200 patients with PAH were operated on, the incidence of recurrences decreased to 2.4%.