Novel function of metallothionein in photoprotection: metallothionein-null mouse exhibits reduced tolerance against ultraviolet B injury in the skin

The alien hand sign refers to a group of signs which include a feeling that the hand is foreign together with autonomous activity, as if the hand is driven by an external agent. These features are commonly associated with frontal and callosal lesions. We report the alien hand sign in a man with left medial cortical infarct, presenting with autonomous grasping and groping with his right upper limb, denial of ownership of his limb, and dissociative phenomena including self restriction and intermanual conflict.     

Temporary internal fixation of the scaphotrapezio-trapezoidal joint for the treatment of Kienb?ck''s disease: a preliminary study

Gene transfer into a panel of non-small cell lung cancer (NSCLC) cells by adenoviral (Ad) and retroviral (RV) vectors was studied. Indexed to multiplicity of infection (MOI), Ad vectors transduce squamous, adenosquamous, and malignant mesothelioma cells with greater efficiency than large cells or adenocarcinoma cells. Transduction-sensitive cells bind the Ad vector with specificity for the Ad fiber knob, and internalize vector efficiently. Transduction-refractory cells bind and internalize vector by less efficient pathways. Like Ad vectors, there is heterogeneity in RV transduction efficiencies of different NSCLC subtypes. With respect to the most common cell type metastatic to the pleural space (adenocarcinoma), amphotropic retroviral vectors transduce cells of this subtype more efficiently (at a lower MOI) than Ad. RV transduction is not solely dependent on cellular replication, and both permissive and refractory cell lines express the mRNA for the amphotropic RV receptor. These observations suggest that neither Ad nor RV vectors will suffice a priori as the optimal gene transfer vehicle, and successful gene therapy of lung cancer may require tumor-specific or patient-specific vectors.     

Transcellular transport of benzoic acid across Caco-2 cells by a pH-dependent and carrier-mediated transport mechanism

2-Amino-3-methylimidazo[4,5-f]quinoline (IQ) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) are two members of a family of carcinogenic heterocyclic amines (HAs) found in cooked meats that form DNA adducts after activation to N-acetoxy derivatives. The ability of IQ- and PhIP-DNA adducts to inhibit gene expression was investigated using a human growth hormone (hGH) reporter gene in a pUC12-based mammalian expression vector under the control of either the herpes simplex virus-1 thymidine kinase promoter or the human immunodeficiency virus-1 long terminal repeat. The plasmids were treated in vitro with 0, 5, 10, or 40 microM N-hydroxy-IQ or N-hydroxy-PhIP in the presence of a 10-fold molar excess of acetic anhydride to generate the N-acetoxy derivatives in situ. The adduct levels in the plasmids were quantitated by the 32P-postlabeling method. The adducted (and control) plasmids were each transfected into repair-deficient or -proficient Chinese hamster ovary cells, and expression of hGH was measured by immunoassay of growth hormone secreted into the cell medium. The results showed that IQ- and PhIP-DNA adducts inhibited gene expression in both plasmids and that the degree of inhibition of hGH production was proportional to the levels of IQ- and PhIP-DNA adducts. The degree of inhibition, however, was independent of the promoter, despite the differences in the strengths of the two promoters to drive hGH production. Repair capacity influenced the extent of inhibition of gene expression by HA adducts since, in general, fewer adducts were needed to inhibit reporter gene expression in repair-deficient cells than in repair-proficient cells. In both cell lines, DNA adducts of PhIP appeared to be more potent in inhibiting hGH expression than adducts of IQ. Whether alteration of gene expression by HA adducts plays a role in the carcinogenicity of these compounds deserves further study.     

Proton-cotransport of pravastatin across intestinal brush-border membrane

PURPOSE: The purpose of the present study is to clarify the intestinal brush-border transport mechanism of a weak organic acid, pravastatin, an HMG-CoA reductase inhibitor. METHODS: The transport of pravastatin was studied by using intestinal brush-border membrane vesicles prepared from rabbit jejunum, and uptake by the membrane vesicles was measured using rapid filtration technique. RESULTS: The initial uptake of [14C]pravastatin was markedly increased with decreases in extravesicular pH and showed a clear overshoot phenomenon in the presence of a proton gradient (pHin/out = 7.5/5.5). A protonophore, carbonylcyanide p-trifluoromethoxyphenylhydrazone, significantly reduced the uptake of [14C]pravastatin. In addition, an ionophore for sodium, potassium and proton, nigericin, stimulated the uptake of [14C]pravastatin in the presence of a potassium gradient ([K+]in/[K+]out = 0/145 mM). On the other hand, neither the imposition of an inwardly directed sodium gradient nor an outwardly directed bicarbonate gradient stimulated the uptake of [14C]pravastatin. In the presence of a proton gradient (pHin/out = 7.5/5.5), the initial uptake of pravastatin was saturable with the apparent Kt of 15.2 +/- 3.2 mM and Jmax of 10.6 +/- 1.21 nmol/mg protein/10 sec. The uptake of pravastatin was significantly inhibited by monocarboxylic acid compounds such as acetic acid and nicotinic acid in a competitive manner but not by di- or tricarboxylic acids, or acidic amino acid. CONCLUSION: It was concluded that a pH-dependent transport of pravastatin across the brush-border membrane occurs by a proton-gradient dependent carrier-mediated mechanism rather than by simple diffusion of its unionized form.     

Ion beam studies of events typical of soft errors in semiconductor memories

A fast ion microbeam has been used to study phenomena associated with soft errors in semiconductor memories. A spatially small beam with a fast blanking system is used to study both alpha particle and heavy ion strikes. The heavy ion strikes are typical of the recoil from cosmic-ray-generated neutrons. Charge collection and static RAM error-rate experiments are discussed.     

Index for predicting post-operative residual liver function by pre-operative dynamic liver SPET

To predict residual liver function before hepatic resection, we devised a predictive index by combining clearance values with functional liver volume measured by liver dynamic single photon emission tomography (SPET). Forty-seven patients with liver disease underwent liver dynamic SPET with 99Tcm-Sn colloid before hepatic resection. There were no operation-related deaths. Three patients died from hepatic failure more than 1 month following the operation. Their predictive indices were 0.24, 0.33 and 0.34. When the predictive index was above 0.35, no patient had symptoms of hepatic failure or died. Our data suggest that when the predictive index is above 0.35, there is a low probability of hepatic failure after hepatectomy.     

液氦自动补加实验

一种简易的液氦自动补加装置业已制成并通过了试验。该装置由一个１００Ｌ液氦贮存容器、一个蒸发率约５Ｌ／ｄ的低温恒温器、一条１ｍ长的柔性输送管、两个电磁阀、一个５Ｗ电加热器、一个容器压力传感器和控制器以及两个液面传感器和控制器组成。它没有旁通管和输送冷却的阀门。由于用加热器通过液氦蒸发使容器的压力升高，所以安全装置具有防止超压和无液加热的作用。这一简易可靠的装置，它的工作性能已通过模型试验和正常使用所     

Nanoscale molecular cavity in crystalline polymer membranes studied by molecular dynamics simulation

The size, shape, and connectivity of cavities in the crystals of syndiotactic polystyrene were investigated by molecular dynamics simulation. Cluster analysis of the free volume in the crystals clearly reveals the cavity structures: large individual holes are in an orderly manner connected by narrow channels. We call such a cavity structure a ‘molecular cavity’. The diffusion behavior and solubility of gases in the molecular cavity were also simulated. The extremely high solubility of a larger gas and the controllable diffusion path in the narrow channels proved the applicability of the concept of the molecular cavity to high performance separation membranes.     

Nicotinic acid transport mediated by pH-dependent anion antiporter and proton cotransporter in rabbit intestinal brush-border membrane

In order to determine whether the vitamin nicotinic acid is absorbed via an anion antiporter, intestinal epithelial cell membrane transport mechanisms for nicotinic acid were characterized using isolated rabbit jejunal brush-border membrane vesicles. The uptake of nicotinic acid by the membrane vesicles showed an overshoot phenomenon in the presence of an outwardly directed bicarbonate gradient or an inwardly directed proton gradient and the uptakes were two times and six times greater, respectively, than that in the absence of any ion gradient. The bicarbonate-dependent initial uptake of nicotinic acid was increased at acidic pH, showing pH-dependent transport activity. An inhibitor of anion transport, 4,4'-diisothiocyanostilbene-2,2'-disulphonic acid, specifically reduced bicarbonate-dependent transport of nicotinic acid. The initial uptakes of nicotinic acid via the anion antiporter and the proton cotransporter were specifically inhibited by monocarboxylic acids such as acetic acid, benzoic acid, D- and L-lactic acid, pravastatin and valproic acid, but not by di- or tricarboxylic acids, bile acids or amino acids. Nicotinic acid uptake activity was, furthermore, expressed in a Xenopus laevis oocyte system after injection of messenger RNA (mRNA) derived from rabbit intestinal epithelial cells. These observations demonstrate that nicotinic acid is absorbed by two independent active transport mechanisms from small intestine, i.e. a proton cotransporter and an anion antiporter. The pH-dependence observed in the intestinal absorption of nicotinic acid might, therefore, be ascribed partly to pH-sensitive and partly to carrier-mediated transport mechanisms in the brush-border membrane.