Copolymerization of N-carboxy-α-amino acid anhydride with propylene oxide

The copolymerization of N-carboxy-L(+)-alanine anhydride (L(+)-alanine NCA) with DL-propylene oxide was examined using diethylzinc or triethylaluminum as catalysts. Analytical data, IR and NMR-spectra indicate that dioxane soluble copolymers contain various kinds of linkage such as amide, ester, ether, and urethane in their polymer chains. Optical rotatory dispersion curves of the copolymers measured in benzene or chloroform were analyzed in terms of the one term DRUDE equation and of the MOFFITT-YANG equation. The copolymerization of L(-)-β-phenylallanine NCA with DL-propylene oxide was also examined. The sign of the optical rotation of the copolymer prepared with diethylzinc catalyst was opposite to that of the copolymer prepared with triethylaluminum.     

Numerical aberrations of chromosome 9 in bladder cancer. A possible prognostic marker for early tumor recurrence

Bilharzial bladder cancer is one of the most common types of malignancy in both men and women in several developing countries including Egypt. It has several unique clinical, epidemiological, and histological characteristics, suggesting that it is an entity distinct from bladder cancer seen in Western countries. Genetic alterations in bilharzial-related bladder cancer have been studied infrequently, especially in the advanced stages of disease, that is, T3 and T4 classifications. The objective of this study was to extend establishing the baseline cytogenetic profile of this type of malignancy to early T1 and T2 classifications. For this purpose, fluorescence in situ hybridization was applied to interphase nuclei of frozen-stored samples with biotinylated repetitive DNA probes specific for all chromosomes to detect numerical chromosome changes in 35 patients presenting with relatively early-stage pT1 and pT2 disease. Eleven cases had squamous cell carcinoma (SCC) and 24 had transitional cell carcinoma. Six of 24 transitional cell carcinomas had diploid chromosome counts with all the probes. Numerical chromosome aberrations were detected in 18 cases (75%). In 12 cases, a loss of chromosome 9 was observed. In three cases, an additional loss of chromosome 17 was detected. One case demonstrated a loss of chromosome 10, whereas another two cases showed a gain of chromosome 7, next to a loss of chromosome 9. Loss of chromosome Y was observed in nine of the 27 male cases studied (33.3%), in which only one case showed an abnormality whereas four cases were detected next to loss of chromosome 9, and one case showed gain of chromosome 7. Five cases showed loss of chromosome 19 whereas gain of chromosome 4 was detected in two cases. Two of 11 samples of SCC had normal diploid chromosome counts with all the probes used. In four of 11 cases (36.4%) underrepresentation of chromosome 9, compared with the other chromosomes, was detected. An additional loss of chromosome 17 and gain of chromosome 7, next to loss of chromosome 9, was detected in three cases. One case showed loss of chromosome 17 as the only numerical aberration. Loss of the Y chromosome was detected in three cases of which one case had gain of chromosome 7 and one case had loss of chromosome 19. No correlation was found between any of the clinicopathologic parameters examined in this study and the presence or absence of any numerical chromosomal aberrations except for the significant association between schistosomal history and loss of Y chromosome (P=0.007).     

Genetic polymorphisms of orosomucoid and alpha-2-HS-glycoprotein in Thai,Sri Lankan and Paraguayan populations

The genetic polymorphism of orosomucoid (ORM) and alpha-2-HS-glycoprotein (AHSG) were studied in Thai, Sri Lankan and Paraguayan populations using isoelectric focusing. Gene frequencies in these populations were compared with those in other populations. Four new ORM variants were detected:ORM1 ^* 15 in Thai,ORM1 ^* 16 in Paraguayan,ORM2 ^* 21 andORM2 ^* 22 in Sri Lankan.     

HISTOPATHOLOGICAL STUDY ON PROGRESSIVE MUSCULAR DYSTROPHY—REPORT OF A CASE WITH AUTOPSY FINDINGS—

A typical case of the D uchenne type of progressive muscular dystrophy with autopsy findings was presented. Changes in the myocardial and smooth muscle of many organs were found, and the skeletal muscles also revealed florid changes.
Histopathological examination of the skeletal muscle was made in detail through light and electron microscopic observation.     

Clinical usefulness of the measurement of plasma D-dimer levels

To evaluate the clinical usefulness of D-dimer, various effects on the measurement of D-dimer were examined. Although both fibrinolytic and fibrinogenolytic products were detected by the measurement of FDP, only fibrinolytic products were detected by the measurement of D-dimer. In patients with DIC and other thrombo-embolic diseases, plasma D-dimer levels were significantly higher than in normal persons. A significant positive correlation between plasma D-dimer and serum FDP was found in DIC patients. In patients with DIC associated with acute promyelocytic leukemia, which is thought to be an increased fibrinogenolysis state, serum FDP was higher than the plasma D-dimer which suggests that increased fibrinogenolysis affects the result of serum FDP measurement. Plasma D-dimer significantly increased 5 minutes after endoscopic embolization with thrombin in the patients with esophageal varices. However serum FDP increased 30 minutes after the treatment, which suggests that the D-dimer is more useful for rapid detection of coagulo-fibrinolytic change than serum FDP. Plasma D-dimer was significantly higher in patients with cerebral infarction and increased with age. These finding suggest the usefulness of plasma D-dimer measurement for the specific and rapid evaluation of coagulo-fibrinolytic activation and thrombo-embolic state.     

CD8+ T cells from feline immunodeficiency virus (FIV) infected cats suppress exogenous FIV replication of their peripheral blood mononuclear cells in vitro

Summary.  Feline immunodeficiency virus (FIV) isolates from domestic cats have been classified into five subtypes, designated A, B, C, D and E. Although many FIV-infected cats may have frequent contact with multiple strains of FIV, they usually become infected with a single FIV subtype. In the present study, we demonstrate that peripheral blood mononuclear cells (PBMC) of FIV infected cats were resistant to exogenous FIV (second virus) replication in vitro and that the resistance of these PBMC was mediated by CD8⁺ T cells. In cats with a low anti-FIV activity of CD8⁺ T cells, the proviral DNA of the second virus inoculated into PBMC was detected intracellularly, and both the second and the originally infecting strain (original virus) were produced in the culture supernatant. In contrast, in cats with a high anti-FIV activity of CD8⁺ T cells, both the proviral DNA of the second virus and the original virus were detected in PBMC intracellularly, but neither virus was produced in the culture supernatant. However, when PBMCs from these cats were depleted of CD8⁺ T cells, the RNA of both viruses was detected in the culture supernatant. These results suggest that CD8⁺ T cells inhibit the late phase of FIV replication after viral integration. Moreover, the inhibition was also effective against FIV strains of different subtypes from that of the original strain. It appears that the CD8⁺ T cell-mediated immune response plays important roles in the maintenance of an asymptomatic state in FIV-infected cats and their resistance to superinfection. Received December 11, 2001; accepted March 22, 2002 Published online June 21, 2002     

Activation of SiO2-supported zirconocene catalysts by common trialkylaluminiums

A modified SiO₂ was prepared by reacting SiO₂ with Cl₂Si(CH₃)₂ in toluene, on which methylaluminoxane (MAO) was supported to obtain a catalyst precursor. The mixture of the precursor and Cp₂ZrCl₂ (Cp: cyclopentadienyl) gave polyethylene in a high yield even by using common trialkylaluminiums as cocatalyst. Surprisingly, the MAO-free catalyst system composed of the modified SiO₂ and Cp₂ZrCl₂ was also found to be activated by common trialkylaluminiums.     

Pituitary Folliculo-Stellate-Like Cells Stimulate Somatotroic Pituitary Tumor Growth in Nude Mice

A new cell line (TtT/GF) established from a murine pituitary thyrotropic tumor having characteristics similar to those of pituitary folliculo-stellate cell (FS cell) was implanted into nude mice together with cells from a rat pituitary somatotrophic tumor cell line (MtT/S) to determine whether the former enhances pituitary tumor growth. For as long as 2-3 mo after implantation, MtT/S cells implanted either alone or together with fibroblasts formed either no tumors or only very small tumors in the nude mice. In contrast all of the nude mice that had received MtT/S cells implanted together with TtT/GF cells developed large tumors. Furthermore, the mice bearing the MtT/S and TtT/GF implants showed a significantly higher body weight and serum growth hormone level than those bearing only MtT/S cells or a combination of MtT/S cells and fibroblasts. The TtT/GF cell line itself had no tumorigenicity during the experimental period. Therefore, the TtT/GF cell line as a model of FS cells enhanced pituitary endocrine cell tumor formation. Additionally, immunocytochemistry showed that TtT/GF cells positive for glial fibrillary acidic protein (GFAP) or S-100 protein were present in the parenchymatous tissue elements or connective tissue surrounding the tumor nests. In the parenchymatous tissue, the TtT/GF cells exhibited a stellate appearance and surrounded neighboring tumor cells with their long cell processes. These results suggest that TtT/GF cells can serve as a model for pituitary FS cells, and are capable of stimulating pituitary tumor growth either by modifying the microenvironment or producing growth factors.