Traffic of T and B Lymphocytes in the Normal Spleen

The occurrence of C3b and C3d complement receptors and of Fc and E receptors in normal splenic tissue was studied in cryostat sections incubated with specific marker cells. Thereby the topographic distribution of T and B lymphocytes in the splenic tissue was mapped: T^E lymphocytes are found especially in the periarteriolar sheaths, B lymphocytes in eccentric zones around the arterioles. The cells in the splenic pulp carry especially Fc, but also C3b receptors, whereas C3d receptors appear to be specific of lymphocytes. The basic lymphocyte traffic behind the mapped distribution of the lymphocyte subpopulations in the spleen was elucidated by lymphocyte kinetic studies using autologous ⁵¹Cr-labelled reinfused lymphocytes. These studies were performed partly on normal persons and partly on splenectomized persons without immune defects. The results indicate the presence of an exchangeable pool of T as well as of B lymphocytes in the spleen, the T cell pool being larger and making up in normals about 30 % of the total exchangeable T lymphocyte mass. The matrix for the T lymphocyte pool in the spleen is the periarteriolar sheaths. The difference in structure between the lymph nodes and the lymphoid tissue of the spleen, including differences in the distribution of lymphocyte subpopulations, are explained by the special vascular arrangement in the spleen.     

Preparation and structure-property relationships of polymeric materials containing arylenevinylene segments — perspectives for new light-emitting materials

Well defined oligo(arylenevinylene)s were prepared by Pd-catalyzed coupling of dibromoarenes and styrenes. The mixing behavior of these oligo(arylenevinylene)s with polymers is significantly influenced by the structure of the oligo(arylenevinylene)s. Potential consequences for optical properties are discussed. Segmented polymers with arylenevinylene segments in the main chain are presented and discussed in detail. Light-emitting thermotropic polymers were obtained with modified distyrylbenzene segments in the main chain. These thermotropic light-emitting polymers show polarized photoluminescence on orientation on rubbed polyimide substrates. Light-emitting amorphous polymers with high fluorophore concentrations and high glass transition temperatures were obtained by polymers with arylenevinylene segments in the side chain.     

Myasthenia gravis antibodies to skeletal muscle cell surface antigens

Sera from 28 of 137 patients with myasthenia gravis (MG) (i.e. 20%) contained antibodies which stained the surface of skeletal muscle cells in an indirect immunofluorescence test. Forty of the 137 sera (i.e. 30%) contained cross-striational antibodies. Absorption experiments showed that the antibodies staining the muscle cell surface were different from those staining the cross-striational bands. Twenty of the sera (i.e. 15%) contained antibodies which agglutinated sheep erythrocytes (SE) coated with a citric acid extract of skeletal muscle (CAE). These antibodies were closely associated with the presence of a thymoma. There was a positive correlation between the antibodies agglutinating CAE-coated SE and those staining the muscle cell surface. Absorption experiments indicated that the antibodies to CAE were directed against muscular antigens located in or near the sarcolemma.     

Therapy of metastatic prostatic cancer by orchiectomy plus Anandron versus orchiectomy plus placebo. Initial results of a randomized multicenter study

In the course of a randomized double blind trial conducted by 7 Swiss urological centres, 51 patients with advanced, not pretreated carcinoma of the prostate were included. Following orchiectomy the patients were either administered 300 mg Anandron daily (Roussel RU 23908) or Placebo. Twelve months later the Anandron-group shows a slightly better objective response whereas there is no difference in survival rates. The adverse effects of Anandron-treatment are described.     

Effect of dexmedetomidine, a selective and potent alpha 2-agonist, on cerebral blood flow and oxygen consumption during halothane anesthesia in dogs

The effect of the alpha 2-agonist dexmedetomidine on the cerebral blood flow (CBF) and the metabolic rate for oxygen was studied by a sagittal sinus outflow technique in dogs during halothane anesthesia. Dexmedetomidine was given in a dose (10 micrograms/kg) reported to reduce the anesthetic requirement of halothane by 90%. During 0.9% halothane anesthesia dexmedetomidine caused a significant reduction in CBF without influencing the metabolic rate for oxygen. Reducing the halothane concentration to 0.1% caused no further change in CBF, but increased the metabolic rate for oxygen 19%. The cerebral vasoconstrictive effect, combined with the 90% reduction in MAC for halothane, indicates that dexmedetomidine might be a useful adjunct to inhalation anesthetics during neurosurgery in situations where an increase in CBF should be avoided.     

Reduced Global Cerebral Blood Flow in Non-Demented HIV Positive Patients

Twelve non-demented HIV positive men with different degrees of immunodeficiency were examined with single photon emission computed tomography (SPECT). Reduction in relative global cerebral blood flow was found in HIV positive patients compared to healthy HIV negative controls (p = 0.014). In the patients there was also a change in cerebral flow distribution, with lower global flow compared to central flow (p = 0.01), most pronounced in patients with early disease. In the patients with advanced HIV disease the relative cerebral blood flow was lower than in the controls in 108 of 116 (93%) regions investigated.     

Cyclosporine toxicity in renal transplant recipients detected by nailfold capillaroscopy with Na-fluorescein

BACKGROUND: Cyclosporine represented a major advance in the medical management of patients with organ transplantation, but its use is limited by the frequent occurrence of hypertension and renal toxicity diagnosed by invasive renal biopsy. Renal histology shows a specific arteriolopathy. It was hypothesized that cyclosporine may also induce subclinical microvascular changes in the skin that might be detected noninvasively by a combination of dynamic capillaroscopy [capillary blood cell velocity (CBV)] with and without intravenous Na-fluorescein (NaF) injection and laser Doppler fluxmetry (LDF). METHODS: The nailfold skin microcirculation was evaluated in 112 consecutive renal transplant recipients (54 +/- 11 years old; 70 males and 42 females) receiving cyclosporine. The investigation was made the same day as a routine renal biopsy performed in all patients more than two years after transplantation. Renal biopsies were blindly classified as positive (N = 33) when significant specific signs of cyclosporine toxicity were clearly observed (AH2-AH3) and were otherwise negative (AH0-AH1, N = 79) according to the Banff classification. RESULTS: Time to fluorescence peak after NaF injection (tpNaF) was significantly longer in patients with positive biopsies than in patients with negative biopsies (13.9 +/- 8.1 vs. 17.5 +/- 9.4 sec, P = 0.009). All patients but three with negative biopsies (93%) had a tpNaF less than 10 seconds (sensitivity 91%, negative predictive value 93%). On the other hand, CBV, LDF, plasma levels of cyclosporine, and endothelin were similar in the two groups. CONCLUSION: Nailfold fluorescence capillaroscopy is an accurate and simple mean to rule out cyclosporine toxicity in renal transplant recipients. A normal test could avoid invasive renal biopsy in about 40% of the patients. Renal biopsy would, however, still be indicated when the test is abnormal.