In vitro radiation sensitivity of the lncap prostatic tumor cell line

Because there is extremely limited information on the intrinsic radiosensitivity of human prostatic cancer cells, we have investigated the in vitro radiation response of exponentially growing LNCaP cells. Due to the very poor colony-forming potential of the LNCaP cells, radiation survival was investigated using the dose-dependent (0-6 Gy) changes seen after X-irradiation in the shapes of regrowth curves. Survival was described using both the single-hit, multitarget (SHMT) equation and the linear-quadratic (LQ) equation. The values and 95% confidence limits of the extrapolation number (n), quasi-threshold dose (D_q), and mean lethal dose (D_o) in SHMT terminology were respectively: 0.9 (0.7-1.0), 0.0 Gy, and 1.39 (0.11) Gy. The LQ alpha and beta parameters were respectively 6.80 (1.13) and -0.53 (2.89). The X-ray dose response of the LNCaP line is, therefore, purely exponential. The mean survival at the clinically relevant dose of 2 Gy (S₂) was 51.2% for the LNCaP line. Comparison of the S₂ value for the LNCaP line with previous investigations with other human prostatic cancer cell lines (DU145 and PC-3) indicates a mean S₂ value of 47.6%, which suggests that human prostate cancer cells might lie toward the resistant side of the spectrum for various classes of human neoplasms. © 1994 Wiey-Liss, Inc.     

髂骨截骨延长术下肢延长量计算方法的探讨

髂骨截骨延长术下肢的延长量及其测算方法报道不一。根据手术的生物力学原理和肢体延长的机理,认为肢体的延长量是由患肢绝对延长和相对延长两部分组成的,它与髂骨截骨间距密切相关,经数学推算,其方法为测量X线片髂骨截骨撑开的梯形中心间距(cm),减去X线片的放大值(cm)再除以0.7;手术时髂骨需要撑开的宽度(cm)为肢体短缩数(cm)乘以0.7。经临床103例手术验证,这种计算方法是准确的。     

湖南省12家医院1996年心血管类国家基本药物的用药分析

根据国家制定的基本药物目录，就湖南省12家医院1996年心血管类药物的购入情况进行分析，了解到心血管类药物的使用信息，讨论了制定国家基本药物的合理性。随着医药水平的发展，国家基本药物目录有必要进行定期调整，以引导临床心血管类药物的合理使用。     

Suppressive Effect of Pregnancy on the Development of Experimental Allergic Encephalomyelitis in Rabbits

ABSTRACT: In the present study we have investigated the influence of pregnancy on the induction and development of experimental autoimmune encephalomyelitis (EAE) in rabbits in relation to the time of gestation. Randomly bred rabbits were immunized with encephalitogenic bovine brain homogenate in complete Freund's adjuvant before or during pregnancy. The appearance of EAE was delayed and occurred only after delivery, abortion, or fetal resorption. The incidence of the disease was lower and the duration longer. The levels of antibodies to myelin basic protein, an autoantigen of EAE, as measured by solid phase radioimmunoassay, were lower in the pregnant rabbits as compared to the nonpregnant animals. The suppressive influence of pregnancy on the induction and the development of EAE confirms previous reports demonstrating amelioration of autoimmune diseases and other immunological reactions during the second half of human pregnancy. This effect might be partially attributed to the increased level of alpha-fetoprotein (AFP) and/or other pregnancy-associated factors in maternal serum.     

Dental care expenditures in the Netherlands and the USA: a design for historical and international comparison

Policymakers face the problem that virtually no standards are available to judge whether the amount of dental care provided is satisfactory or to weight the interests of dental care against other health and economic interests. It is suggested that international comparison of a number of standardized indicators and analyses of their development over time constitutes a practical approach to the partial solution of these problems. A specific set of basic data and seven indicators are suggested. Of the indicators, two serve as measures for the total volume of dental care available to the individual, two could help to assess the productivity of dental care workers, and three are intended to put the expenditures for dental care in the perspective of health care expenditures in general and the national economy at large. The practicality of the approach is subsequently demonstrated by the comparison of the basic data and the indicators for the Netherlands and the USA over the period 1972 through 1979.     

Effect of epidermal growth factor on the labeling of the various RNA species and of nuclear proteins in primary rat astroglial cell cultures

This study investigated the effects of epidermal growth factor (EGF) on the labeling of various RNA species and of nuclear proteins in primary rat astroglial cell cultures. After 12 hours of EGF treatment in serum-free medium or chemically defined medium, significant increase in RNA labeling, and also in acid-soluble radioactivity and RNA content, was observed. The ratio RNA/DNA was significantly higher in EGF-treated cultures compared with controls. Ribosomal RNAs (28S and 18S), polyadenylated, and nonpolyadenylated RNAs showed a higher specific radioactivity in EGF-treated cultures. Among the nuclear proteins, the labeling of basic proteins was enhanced by EGF treatment, whereas that of total nuclear acidic protein (NHPs) was less modified, except for some NHPs separated by gel electrophoresis with a molecular weight (MW) approximately 95-83 and 44 kd, which were significantly more labeled in EGF-treated cultures.     

Post-translational processing of thyrotropin-releasing hormone precursor in rat brain: identification of 3 novel peptides derived from pro TRH

The sequence of rat hypothalamic pro-thyrotropin releasing hormone, deduced by sequencing of cDNA, in addition to 5 TRH progenitor genitor sequences contains leader, trailer and 4 intervening sequences separated by paired basic amino acid sequences. We have developed radioimmunoassays to synthetic peptides corresponding to portions of these cryptic proTRH sequences and have used these assays to identify and partially characterize proTRH peptides, distinct from TRH, in extracts of rat brain. Two of these peptides correspond closely in size to one intervening sequence and the car☐y-terminal sequence of proTRH. Three other peptides correspond to the intact amino-terminal leader sequence and two peptides formed by a further cleavage of the leader sequence at an internal paired basic amino acid sequence.     

CHARACTERIZATION OF TURKEY MYELIN BASIC PROTEIN ISOLATED BY A SIMPLE PROCEDURE

Highly purified basic proteins have been isolated from bovine and turkey brains by a novel method employing acid-acetone extraction. The final product gave a single band on polyacrylamide gel electrophoresis at pH 4.3 and in the presence of sodium dodecyl sulfate. Both proteins have arginine at the COOH-terminus while the NH₂-terminal residue cannot be detected and is probably blocked. A higher ratio of histidine to lysine and a greater proportion of serine and valine was found for the turkey compared with the bovine protein. Both proteins contain one tryptophan and two methionine residues. However, it was found from cyanogen bromide treatment that there is a marked difference in the location of one of the methionine residues, while the tryptophan-containing peptides liberated after trypsin digestion have different mobilities on peptide maps. When dissolved in water these proteins give a typical random coil curve from circular dichroism (CD)*, whereas in 80% methyl alcohol they assume a 25% α-helix.     

Experimental allergic encephalomyelitis: Modulation by intraventricular injection of myelin basic protein

Antigen-induced suppression and therapy of experimental allergic encephalomyelitis in Lewis rats was studied using guinea pig myelin basic protein administered either intravenously or intraventricularly. A small intraventricular dose of basic protein was effective when given shortly before the onset of clinical signs (suppression) as well as when given after the disease (therapy). In contrast, the same amount of basic protein administered intravenously was effective only in the therapy of disease.     

The long term culture of bulk-isolated bovine oligodendroglia from adult brain

Oligodendroglia isolated from adult bovine brain by the method of Farooq et al. could be plated on polylysine-coated plastic dishes with an efficiency of 55–80%, and maintained in culture for as long as 4 months. The addition of cytosine arabinoside to the nutrient medium resulted in cultures that were approximately 90% oligodendroglia and 10% large fibroblasts. From 50 g of white matter 100 − 160 × 10⁶ oligodendroglia, containing approximately 6–10 mg protein, could be obtained in culture. These small round cells started to send out processes at 5 days in vitro and by 2 weeks they formed an extensive network of processes. By immunofluorescence, all cells of this morphology were positive for galactocerebroside (GC) and myelin basic protein (MBP), and negative for glial filament protein and fibronectin. Most of the large flat cells were positive for fibronectin and negative for GC, MBP and glial filament protein. As the cultures aged the oligodendroglia tented to clump and blebs formed on the surface of both perikarya and processes. By 4 months they showed evidence of degeneration and detached from the substrate. Electron microscopic examination showed that the cells had the appearance typical of oligodendroglia in situ. The somata were round to elliptical, with eccentrically placed nuclei, and were larger than freshly isolated cells. They grew directly on the substrate or on the surface of the fibroblasts. In older cultures the cells formed tight nests. The somata were enveloped by sheets of oligodendrocyte cytoplasm, sometimes having a myelin-like appearance. Gap junctions and small desmosomes were seen between oligodendroglial processes and between oligodendroglia and fibroblasts. The cytoplasm was characterized by a prominent Golgi apparatus, many mitochondria and lysosomes, scattered rough endoplasmic reticulum, free ribosomes, frequent centrioles and an abundance of microtubules. In cells from older cultures large vacuoles were common, and rarely they had multilamellar walls with alternating major and minor dense lines resembling myelin.