Technique and early clinical results of endoscopic variceal ligation (EVL)

Summary Endoscopic variceal ligation (EVL) is a new technique designed to be used instead of sclerotherapy. Small elastic O rings ligate varices resulting in their strangulation and eradication. During a 12-month period, EVL was employed in 53 consecutive patients, of whom 36 (68%) had alcoholic cirrhosis 17 were Child-Pugh class A, 22 class B, and 14 class C. Varices were graded from I to IV and repeat treatments were given at 1–2 week intervals until the varices were eliminated. At follow-up ranging from 6–18 months (mean 11.5), 217 EVL treatment sessions had been performed. Of the 13 patients (24%) who died during the study, 11 died during the index hospitalization. Active bleeding was controlled in 19 of 21 patients (90%). Of 40 survivors 13 patients (33%) had 1–2 (mean 1.4) recurrent variceal bleeds while 34 patients had repeat EVL treatment. Elimination of distal varices was achieved in 26 and 7 had reduction of varices from grade III–IV to grade I–II or less. Eradication required a mean of 4.4 EVL sessions in Child's A and B patients and 7.0 sessions in Child's C patients (P<0.025). No significant treatment-related complications were observed. EVL appears to control active bleeding, is associated with a low incidence of non-bleeding complications, and may be used as an alternative to sclerotherapy.     

Immunotoxicity of the Semiconductor Gallium Arsenide in Female B6C3F1 Mice

The effects of gallium arsenide (GaAs) exposure on immunocompetenceof B6C3F1 female mice were investigated. GaAs was administeredas a single intratracheal instillation at doses of 50, 100,and 200 mg/kg. Fourteen days after exposure, various cellularand humoral immune parameters were assessed. GaAs exposure increasedspleen cellularity in a dose-dependent manner. However, thepercentages of Thy 1.2 positive and 1g positive cells were decreasedand that of F4/80 positive cells was increased dose dependency.The IgM and IgG antibody-forming cell response of the spleento the T-dependent antigen sheep erythrocytes was reduced by66 and 48%, respectively, at 200 mg/kg. Levels of the serumcomplement protein, C3, were increased by as much as 16% withno significant change in CH50 levels. The mitogenic responseof splenic T cells to Con A and PHA was unaffected by GaAs,but that of B cells to LPS was increased by 52%. The delayedhypersensitivity response to keyhole limpet hemocyanin and mixedlymphocyte response were significantly reduced in a dose-dependentmanner by GaAs exposure. Natural killer cell activity againstthe YAC-1 mouse lymphoma was enhanced in treated mice. Analysisof peritoneal exudate cells (PEC) revealed a dose-dependentdecrease in number and a shift in the composition of PECs. Thepercentage of PEC monocytes increased from 53% of the populationto 81%, while the lymphocytes decreased from 46 to 20%. Theadherent PEC population demonstrated decreased phagocytosisof covaspheres and increased phagocytosis of chicken erythrocytes(CRBC). GaAs exposure had no effect on host resistance to Plasmodiumyoelii or Streptococcus pneumoniae, but dose dependency increasedresistance of the mouse to Listeria monocytogenes Treated micedemonstrated a significantly decreased resistance to the B16F10melanoma with a sevenfold increase in tumor burden at 200 mg/kg.GaAs affects both humoral and cellular immune parameters inmice and impairs the ability of the immune system to protectagainst B16F10 tumor challenge.     

Resistance of Drosophila to cadmium: biochemical factors in resistant and sensitive strains

With regard to cadmium toxicity, Drosophila strains v;bw and Austin represent extremes in resistance and sensitivity, respectively. Both strains produced metallothionein (MT) in response to Cd ions in their diet. Austin produced more metallothionein than v;bw at Cd ion levels below 0.2 mM, when both strains were allowed lifetime development on Cd2+-containing media. When the rate of MT appearance was measured for 4 days in young adults the results showed no clear trend with time within a strain or between strains. The plot of LC50 vs. MT levels for identical developmental conditions revealed that for v;bw small increases in MT corresponded to large increases in resistance whereas for the sensitive Austin even large increases in MT had comparatively little effect on increasing LC50. Results given here suggest that differences in total MT content do not explain the genetically demonstrable difference in Cd2+-resistance between v;bw and Austin. However, since two MT genes are identified in Drosophila, differences in resistance could be reflective of greater relative amounts of one "more important" MT in the resistant fly.     

基于"WD倒谱"法分析人体脾组织的超声散射微结构特征

本文提出了一种对超声散射信号分析的新方法--“WD倒谱”法,并利用该方法对人体正常脾和脾增生组织的回波信号进行了分析,对软组织中散射子的平均间距进行了估计,结果表明：两种脾组织散射子的平均同距明显不同;“WD倒谱”能有效的反映软组织的微观结构特征,说明“WD倒谱”是软组织超声散射信号分析与软组织散射子平均间距定征的一种有效方法。     

Visual cortex ablation and thresholds for successively presented stimuli in rhesus monkeys: II. Hue

Summary Rhesus monkeys were trained to discriminate successively presented hues. The smallest difference they could reliably detect was determined before and after either inferotemporal ablation, or a lesion intended to remove as much as possible of prestriate area V4 (Zeki, 1973).As a group, the animals with lesions of V4 showed good but not perfect retention of their preoperative performance, and their thresholds were unaltered. The inferotemporal group showed no retention of the simplest successive task, red versus green, but after relearning their thresholds too were unaltered. It appears that animals without inferotemporal cortex can form precise internal representations of hues, and that the basis of the inferotemporal learning impairment may depend upon the nature of the stimuli to be discriminated.     

Progress in Rhesus Histocompatibility Typing Resulting from the Second International Nonhuman Primate Histocompatibility Workshop (1973)

The Second International Nonhuman Primate Histocompatibility Workshop permitted comparison of rhesus monkey alloantisera developd in various laboratories on a single common panel of related and unrelated monkeys. Analysis of the data permits the conclusion that at least nine specificities are recognized by more than one laboratory, including six at the first locus and three at the second locus.     

DHPLC screening of cystic fibrosis gene mutations

Denaturing high performance liquid chromatography (DHPLC) using ion-pairing reverse phase chromatography (IPRPC) columns is a technique for the screening of gene mutations. In order to evaluate the potential utility of this assay method in a clinical laboratory setting, we subjected the PCR products of 73 CF patients known to bear CFTR mutations to this analytic technique. We used thermal denaturation profile parameters specified by the MELT program tool, made available by Stanford University. Using this strategy, we determined an initial analytic sensitivity of 90.4% for any of 73 known CFTR mutations. Most of the mutations not detected by DHPLC under these conditions are alpha-substitutions. This information may eventually help to improve the MELT algorithm. Increasing column denaturation temperatures for one or two degrees above those recommended by the MELT program allowed 100% detection of CFTR mutations tested. By comparing DHPLC methodology used in this study with the recently reported study based on Wavemaker 3.4.4 software (Transgenomic, Omaha, NE) [Le Marechal et al., 2001) and with previous SSCP analysis of CFTR mutations [Ravnik-Glavac et al., 1994] we emphasized differences and similarities in order to refine the DHPLC system and discuss the relationship to the alternative approaches. We conclude that the DHPLC method, under optimized conditions, is highly accurate, rapid, and efficient in detecting mutations in the CFTR gene and may find high utility in screening individuals for CFTR mutations. Hum Mutat 19:374-383, 2002. Published 2002 Wiley-Liss, Inc.