Clinical Use of a New Mitral Disc Valve

A disc valve of new design was used successfully for the replacement of the mitral valve in patients with rheumatic mitral valve disease. This valve would appear to have the following advantages over the mitral ball valve prosthesis:• Lower left atrial pressure after replacement.• Elimination of the hazard of left ventricular outflow tract obstruction with mitral valve replacement.• Decreased incidence of thromboembolization.• Abolition of possibility of ventricular septal irritation.Despite the better outlook for this valve compared with the ball valve for mitral valve substitution, the mitral valve should always be repaired whenever feasible. Repair is possible in the majority of patients.     

Electron microscopic and pharmacological studies on the rat median eminence

Summary The rat median eminence contains at least three kinds of granules or vesicles: 1. large electron-dense granules (perhaps carriers of neurohypophysial hormones), 2. small electron-dense granules with or without haloes (perhaps carriers of catecholamines) and 3. synaptic vesicle-like structures (perhaps carriers of acetylcholine). The former two electrondense granules exist in separate axons but they coexist with the latter vesicles in the same axons.The pars nervosa shows basically a similar structure to the median eminence. However, the axons containing the small electron-dense granules are very few. In the pars tuberalis, there are at least two types of cells: the cells of one type contain much cytoplasm with large round nuclei and those of the other type contain a small amount of cytoplasm with polymorphic nuclei. The cells of the former include multivesicular bodies and secretory granules, but those of the latter do not. Some of capillaries of the primary plexus are surrounded by the cells of the pars tuberalis on one side and by neurosecretory axon endings on the other side.The median eminence contains high concentration of acetylcholine or an acetylcholine-like substance and shows neurohypophysial hormone activity.Aided by Grant A-3678 from the United States National Institute of Arthritis and Metabolic Diseases. The authors are indebted to Dr. Welsh, Harvard University, for the kind gift of Mytolon.     

Establishment of five human myeloma cell lines

Summary Five human myeloma cell lines, KMM-1, KMS-5, KMS-11, KMS-12- PE, and KMS-12-BM, have been established at Kawasaki Medical School since 1980. As the KMS-12-PE and KMS-12-BM lines were obtained from the same patient, these five cell lines have been derived from four patients with multiple myeloma. The five myeloma cell lines are stably growing at present in RPMI 1640 medium supplemented with 10% fetal bovine serum. They can also grow in a defined culture medium without serum. That these cell lines were, human myeloma cells was confirmed by the following findings. Ultranstructually, all five cell lines showed features characteristic of plasma cells. KMM-1 and KMS-11 cells secreted lambda and kappa chains into the culture medium, respectively, but the other cell lines produced no immunoglobulins. KMM-1 expressed cytoplasmic lambda antigen, KMS-5 showed cytoplasmic delta, and KMS-11 expressed surface kappa, whereas KMS-12-PE and KMS-12-BM cells showed no surface or cytoplasmic immunoglobulins. Regarding reaction with a monoclonal plasma cell antibody (PCA-1), four of the five lines were positive, the exception being KMS-5. Another monoclonal antibody (CD38), which also recognizes plasma cells, reponded to KMM-1, KMS-12-PE, and KSM-12-BM. KMS-5 cells expressed acute lymphoblastic leukemia antigens (CALLA). These data suggest that such lines as KMM-1, KMS-11, KMS-12-PE, and KMS-12-BM represent later stages of B-cell differentiation, and that KMS-5 represents a relatively early stage of B-cell differentiation. All the cell lines lacked Epstein-Barr virus nuclear antigen, showed abnormal karyotypes of human origin, and differed from each other in the isozyme patterns examined. Only KMS-5 was tumorigenic when transplanted subcutaneously into nude mice.     

Quantitative analysis of serum IL-6 and its correlation with increased levels of serum IL-2R in HIV-induced diseases

We have devised a luminescence sandwich ELISA for the quantification of IL-6 in both sera and cell culture supernatants, which had a detection limit of 100 fg/ml of test sample. By using the luminescence sandwich-ELISA, low but measurable levels of IL-6 (9.5 pg/ml on average) were found in the sera from normal individuals. The serum levels of IL-6 were elevated in HIV-seropositive asymptomatic carriers (55.5 pg/ml on average), and the IL-6 levels were correlated with the degree of HIV-induced disease progression (AIDS-related complex 106.8 pg/ml on average and (AIDS 283 pg/ml). IL-6 immunoreactivity in the sera of AIDS patients eluted at a 25,000 m.w. major peak, which was biologically active and heat-stable, and a 500,000 m.w. minor peak in size-exclusion HPLC. Interestingly, a significant correlation was observed between the serum IL-6 levels and soluble IL-2R levels. In vitro, HIV infection of PHA-activated PBMC led to enhanced release of IL-6 into the culture supernatants. Moreover, soluble IL-2R release was markedly increased by adding exogenous IL-6, whereas it was decreased by adding the neutralizing anti-IL-6 mAb to the cultures. These results demonstrate that increased IL-6 levels are significantly associated with sIL-2R levels, and suggest a cause of the increased levels of this receptor in patients with HIV infection. Furthermore, both serum IL-6 and serum IL-2R levels in HIV infection reflect the stage of the HIV-induced disease.     

The Large Isoform of Myelin-Associated Glycoprotein Is Scarcely Expressed in the Quaking Mouse Brain

Two polypeptide isoforms of myelin-associated glycoprotein (MAG) with molecular masses of 72 and 67 kDa are produced by alternative splicing of the exon 12 portion. Our previous work has demonstrated that in the quaking mouse brain this alternative splicing is lacking and that the mRNA coding the large MAG isoform (L-MAG) is scarcely expressed, whereas that of small MAG isoform (S-MAG) is overexpressed. In the present study, we prepared antisera specific to the S-MAG and L-MAG amino acid residues, respectively. Immunoblots showed that the L-MAG band was scarcely detectable in the quaking mouse brain, whereas the S-MAG band had an apparently higher molecular mass than in the normal control. Our immunohistochemical study also showed that L-MAG was scarcely stained in the quaking mouse brain. These results seemed to reflect a reduction in content of L-MAG mRNA and abnormal glycosylation in the quaking mouse brain.     

Identification of alpha 2-macroglobulin as a carrier protein for IL-6

In this report we demonstrate that alpha 2-macroglobulin (alpha 2M) is a carrier protein for IL-6. IL-6 was found to bind plasma proteins and an immunoblot analysis revealed that the complex between IL-6 and plasma proteins contains alpha 2M. Furthermore, purified alpha 2M bound IL-6. alpha 2M did not inhibit IL-6 activity or its binding to homologous receptor. IL-6 bound to alpha 2M retained its biologic activity and became resistant to treatment with proteases, although free IL-6 was easily degraded. These findings indicate that alpha 2M plays an important role as a carrier protein for IL-6 in serum and makes IL-6 produced at the local inflammatory site available to lymphocytes, hepatocytes, and hematopoietic stem cells, resulting in the induction of the coordinate systemic host defense reactions, such as immune response, acute phase reaction, and hematopoiesis.     

Effects of a New Calcium Channel Blocker, KB-2796, on Protein Synthesis of the CA1 Pyramidal Cell and Delayed Neuronal Death Following Transient Forebrain Ischemia

The effects of a new calcium channel blocker, 1-[bis(4-fluorophenyl)methyl]-4-(2,3,4-trimethoxybenzyl)-piperazine dihydrochloride (KB-2796), on delayed neuronal death (DND) in the hippocampus were examined in gerbils in comparison with those of pentobarbital and flunarizine. The neuronal density in the hippocampal CA1 subfield was counted on the seventh day of recirculation following 5 min of bilateral carotid occlusion, and protein biosynthesis in the brain was also determined at 1, 2, 4, 24, and 72 h following occlusion. The drugs were intraperitoneally administered after recirculation. KB-2796 (10 mg/kg) significantly prevented DND in the CA1 subfield. Pentobarbital (40 mg/kg), but not flunarizine (3 and 10 mg/kg), inhibited DND. Protein synthetic activity in the CA1 subfield was reduced by ischemia and the reduction was not restored even at 72 h after recirculation. KB-2796 did not ameliorate the reduction of protein synthesis in the CA1 subfield by 24 h after recirculation, but in one of three animals restoration of protein synthesis was observed at 72 h of recirculation. Pentobarbital also restored the reduced protein synthesis in two of three animals at 72 h. These results suggest that calcium influx into neurons participates in the pathogenesis of DND, and also that KB-2796 might prevent both morphological and functional cell damage in CA1 neurons induced by transient ischemia.     

Intravesical treatment of bladder cancer with recombinant human interferon-β

Summary In order to examine its clinical efficacy, recombinant human interferon- (rIFN-) was instilled intravesically into 51 patients with superficial bladder cancer. Ten patients, who received intermittent intravesical instillation at a dose of (3–36) × 10⁶ U rIFN- on days 1–3 every week, showed no response. Thirty-two patients received intravesical instillation at a dose of (3–36) × 10⁶ U every day for 10–20 days. Eight patients showed partial response, indicating an efficacy rate of 25%. Nine patients received divided doses of 18 × 10⁶ U twice a day every day for 10–20 days. Six patients showed partial response, indicating an efficacy rate of 67%. This value was significantly higher than that obtained by administering divided doses. The response to intravesical instillation therapy with rIFN- varies with treatment protocol. Frequent and longer exposure to rIFN- may induce better regression of superficial bladder cancer. Six incidences of side-effects were found in five cases (9.8%): pollakiuria in one, pain on micturition in two, fever in two, and eruption in one case. All of these side-effects were slight and reversible after drug withdrawal. Laboratory tests showed only a few changes with low severity. Thus, rIFN- is potentially a new drug for instillation therapy of superficial bladder cancer, in view of the absence of adverse effects.