Hydroboration copolymerization

Summary Organoboron copolymers were prepared by polyaddition of diene mixture or diene/diyne mixture, respectively, with thexylborane (1). When a mixture of dienes such as 1,2-diallyloxyethane (2a) and p-diallylbenzene (2b) was polymerized with 1, the peaks in GPC using both UV and RI detectors were shifted to higher molecular weight regions with the increase of the amount of 1. The molecular weight distribution of the copolymer obtained by this method indicated clear difference from that of a mixture of two homopolymers. On the other hand, when the poymerization between 1 and 1,7-octadiene (2c) was carried out in the presence of a trace amount of 1,7-octadiyne (4), the molecular weights of organoboron polymers were found to be increased when the ratio of 4/2c was increased.     

Effects of the doping profile on current characteristics in BSITs

Proposed are two doping profiles of the conducting channel in bipolar-mode static induction transistors (BSITs) that improve the current handling capability. By using the results obtained from two-dimensional device simulations, it is shown that BSITs with the proposed profiles exhibit higher drain current density and DC current gain than conventional BSITs. Also discussed is the tradeoff between the current and voltage capabilities     

Cross-sectional and longitudinal changes in total and high-density-lipoprotein cholesterol levels over a 20-year period in elderly men: the Honolulu Heart Program

PURPOSE: The purpose of this report is to describe levels of total cholesterol and high-density-lipoprotein cholesterol (HDL-C) in a group of elderly men and to compare these levels to those that were observed 20 years earlier. METHODS: From 1965-1968, the Honolulu Heart Program began following 8006 men of Japanese ancestry living on the island of Oahu, Hawaii, in a prospective study of coronary heart disease and stroke. This report presents data for 971 men who participated in a separate fasting study of lipids and lipoproteins that first occurred from 1970-1972 and in those who received repeat examinations 10 and 20 years later. Men were aged 71-93 years at the last examination. RESULTS: Over the 20-year period, total cholesterol declined by 1.6-1.8 mg/dL per year (P < 0.001), from average baseline values of 219-222 mg/dL. Levels of HDL-C rose 0.2-0.3 mg/dL per year (P < 0.001), from average baseline values of 44-46 mg/dL. After adjustment for baseline cholesterol levels, men with prevalent coronary heart disease at the end of the 20-year follow-up experienced significantly greater reductions in total cholesterol levels than men without disease (P < 0.001). Men who developed coronary heart disease within the first 10 years of follow-up had the greatest yearly decline in total cholesterol (1.9 mg/dL), followed by men who developed heart disease later (1.8 mg/dL) and men who remained disease free (1.5 mg/dL). Differences between men with recent and earlier disease were not statistically significant, although men without coronary disease experienced a significantly smaller decrease in total cholesterol than either of these groups (P < 0.05). CONCLUSIONS: Changes in total cholesterol and HDL-C levels with advancing age may be part of a natural aging process. Some changes, however, such as large reductions in total cholesterol, may signal occult disease or declines in overall health. Selective survival may contribute to these findings since improvements in lipid and lipoprotein levels that are beneficial in younger ages were common in this long-lived cohort of men.     

An autopsy case of cytokeratin 7-positive minute adenocarcinoma of the lung with systemic metastases

We describe a 60-year-old woman with leg pain. Although metastatic bone tumor and atypical cells mimicking signet-ring cells in the bone marrow picture were observed, systemic survey revealed no primary lesion. The patient died two months after admission from systemic progress of the disease. Autopsy revealed a small focus of adenocarcinoma within the right upper lobe of the lung and systemic metastases without any particular changes in the gastrointestinal tract. The tumor cells of the lung were diffusely positive for cytokeratin 7, whereas cytokeratin 20 immunoreactivity was weak and focal, and that supported the lung origin of the present tumor. Moreover, the tumor cells in the bone marrow showed a similar pattern in immunoreactivity. These findings suggest that cytokeratin 7 and cytokeratin 20 immunoreactivity is helpful for the premortem diagnosis of the metastatic tumor of unknown origin.     

In vitro parathyroid hormone release in patients with secondary hyperparathyroidism

BACKGROUND: The purpose of this study was to determine the precise endocrine characteristics of parathyroid function in secondary hyperparathyroidism (sHPT). METHODS: We examined the effects of extracellular ionized calcium (Ca2+) varying from 0.5 to 2.0 mM on parathyroid hormone (PTH) release in parathyroid cell suspensions using a mid-regional PTH assay. Cells were obtained from 26 patients with sHPT who were divided into two groups according to the type of hyperplasia they exhibited, either nodular (n = 16) or diffuse (n = 10). For comparison, we also analyzed data from nine patients with primary hyperparathyroidism (pHPT; adenomas). RESULTS: Significant in vitro suppression of PTH release by Ca2+ was observed in the majority of subjects, regardless of the histologic abnormality. The pHPT group exhibited no significant relationship between clinical and in vitro data. In contrast, in the sHPT group (taken as a whole), suppression of PTH release by Ca2+ exhibited a plateau at a total serum calcium concentration of 2.5 mmol/L, and a parathyroid gland weight of 2 g. CONCLUSIONS: These findings suggest that there is a curvilinear relationship in sHPT, but not pHPT, between the in vitro calcium sensitivity of parathyroid cells and total serum calcium, as well as gland weight. The in vitro calcium sensitivity in sHPT remains constant when the total serum calcium concentration exceeds 2.5 mmol/L, or when the gland weight exceeds 2 g.     

High power and high sensitivity planar lightwave circuit moduleincorporating a novel passive alignment method

A high-power, high-sensitivity planar lightwave circuit (PLC) module, comprising a laser diode (LD) and a photodiode (PD) surface mounted on a PLC platform, has been realized by a novel passive alignment technique. We used a spot-size transformed LD and a corner-illuminated PD to form a highly efficient optical coupling between the devices and a PLC waveguide. We used the unique marker alignment method to ensure accurate positioning of them. The positioning precision achieved in the lateral direction was within 1 μm for the LD's and within 10 μm for the PD's. The rotational precision was within 0.4° for both chips. We realized high power operation (>8 mW) with a high receiver sensitivity (0.3 A/W). In this paper, we describe a high power, high sensitivity PLC incorporating a novel passive optical alignment technique for LD's and PD's     

Effect of metal cation type on the structure and properties of ethylene ionomers

Thermal properties by DSC, stiffness, melt viscosity, tensile properties, and dynamic mechanical properties were measured for the Na⁺, K⁺, Mg²⁺, Zn²⁺, Cu²⁺, Mn²⁺, and Co²⁺ salts of poly(ethylene-co-methacrylic acid) (EMAA). The changes in the structure and properties with increasing neutralization are larger in the alkaline and alkaline earth metal salts than in the transition metal salts. The stiffness shows a maximum at 33% neutralization in both the alkaline and alkaline earth metal salts, while no maxima are found up to 60% neutralization in the transition metal salts. The microphase separation of salt group aggregates is observed in both the alkaline and alkaline earth metal salts, but is not seen in the transition metal salts. These differences were attributed to both the stronger ionic interactions and the larger number of carboxyl groups associated with the alkaline and alkaline earth metal salts in the ordered structure of ionic salt groups (ionic crystallites). The mechanical properties measured at low strain, such as stiffness and yield stress, strongly depend on the degree of the crystalline order of the ionic crystallites. The high-strain properties, such as tensile strength and elongation at break, depend on the strength of the ionic interactions and the valence of the cation.     

Common clonal origin of lymphocytes and plasma cells in splenic lymphoma with villous lymphocytes

In two-thirds of patients with splenic lymphoma with villous lymphocytes (SLVL) a small amount of M-protein can be detected in association with the presence of plasma cells in the peripheral blood (PB) and/or bone marrow (BM). However, it is not known whether lymphoma cells and plasma cells originate from the same clone. In this report we describe a case of SLVL which was characterized by the presence of marked monoclonal gammopathy (IgG-kappa 90 g/l) and increased plasma cells in the BM. In an attempt to elucidate the origin of lymphoma cells and plasma cells, we performed morphological, cytogenetic and molecular studies on PB mononuclear cells (PBMNC) without plasma cells and BMMNC containing 10% plasma cells from this patient. Immunofluorescence showed that lymphoma cells and plasma cells were positive for cytoplasmic gamma heavy and kappa light chains. Well-developed endoplasmic reticulum was observed in the cytoplasmic organelles of PBMNC using an electron microscope. The mean IgG concentration in the 3 d supernatant cultures of PBMNC was 374 +/- 24 microg/l. More than 50% PBMNC differentiated into plasmacytoid cells in 6 d of liquid culture with IL-3 and IL-6. Analysis by two-colour FISH revealed that karyotypic abnormalities of monosomy X and trisomy 17 existed simultaneously in both lymphoma cells and plasma cells. JH gene rearranged bands from PBMNC and BMMNC by Southern blot hybridization were identical, whereas DNAs from PBMNC failed to hybridize with the Cmu probe. These observations strongly suggest that lymphoma cells and plasma cells originate from the same clone, and that plasma cells, as well as lymphoma cells, which have undergone class switch recombination, could produce IgG type M-protein in this case.     

Heat shock cognate protein 71-associated peptides function as an epitope for Toxoplasma gondii-specific CD4+ CTL

HLA-DR-restricted CD4+ cytotoxic T-lymphocyte (CTL) lines specific for Toxoplasma gondii (T. gondii)-infected melanoma cells have been established from peripheral blood lymphocytes (PBLs) of a patient with chronic toxoplasmosis. The role of heat shock cognate protein (HSC) 71 in antigen (Ag) processing and presentation of T. gondii-infected melanoma cells to these CD4+ CTL lines was investigated. A human melanoma cell line (P36) pulsed with T. gondii-infected P36 cell-derived HSC71 was lysed by a T. gondii-specific CD4+ CTL line (Tx-HSC-1). The Tx-HSC-1 also killed T. gondii-infected P36 cells. The lytic activity of Tx-HSC-1 against P36 cells pulsed with T. gondii-infected P36 cell-derived HSC71 was inhibited by monoclonal antibodies (mAbs) against HSC71. Anti-human leukocyte antigen (HLA)-DR mAb also partially blocked the lytic activity, whereas anti-HLA-A,B,C mAb did not block the lytic activity. In addition, a flow cytometric analysis with these specific mAbs against HSC71 showed HSC71 to be expressed on the cell surface of T. gondii-infected P36 cells as well as uninfected P36 cells. These data indicate that HSC71 molecules are expressed on human melanoma cell line P36, and that HSC71 may play a potential role in Ag presentation and processing of T. gondii-infected P36 cells to CD4+ CTL.     

A new superleak to remove He for UCN experiments

The production of superleaks to remove He³ in helium for UCN experiments is described. Using one of these superleaks, He³/He⁴ ratio was found to be less than 3 × 10⁻⁹ as indicated by the UCN storage lifetime.