Venous thromboprophylaxis in UK medical inpatients.

We prospectively assessed the implementation of venous thromboembolism (VTE) prophylaxis guidelines and the impact of grand round presentation of the data in changing clinical practice. Two NHS teaching hospitals were studied for 24 months from January 2003. Patients were risk stratified according to the THRIFT (thromboembolic risk factor) consensus group guidelines and compared with the recommendations of the THRIFT and ACCP (American College of Chest Physicians) consensus groups. Six months following presentation of the initial results, a further analysis was made to assess changes in clinical practice. 1128 patients were assessed of whom 1062 satisfied the inclusion criteria for thromboprophylaxis. 89% of all patients were stratified as having high or moderate risk of developing VTE. Of these only 28% were prescribed some form of thromboprophylaxis-4% received the THRIFT-recommended and 22% received the ACCP-recommended thromboprophylaxis. The vast majority (72%) received no thromboprophylaxis at all. Reassessment, following data presentation at grand rounds, showed a significant increase to 31% inpatients receiving THRIFT (P<0.0001) and ACCP (P=0.002) recommended thromboprophylaxis. However,the proportion of patients receiving no form of prophylaxis barely changed (72% to 69%: P=0.59). We found a gross underutilization of thromboprophylaxis in hospitalized medical patients. A simple grand-round presentation of the data and recommended guidelines to clinicians significantly increased the proportion of patients receiving recommended thromboprophylaxis but did not increase the overall proportion of patients receiving it. We therefore conclude that a single presentation of guidelines is not enough to achieve the desired levels. Such presentations may only serve to make DVT (deep venous thromboembolism) aware clinicians prescribe prophylaxis more accurately.

Dose- and sex-dependent effects of the neurotoxin 6-hydroxydopamine on the nigrostriatal dopaminergic pathway of adult rats: differential actions of estrogen in males and females.

Epidemiological and clinical studies provide growing evidence for marked sex differences in the incidence of certain neurological disorders that are largely attributed to the neuroprotective effects of estrogen. Thus there is a keen interest in the clinical potential of estrogen-related compounds to act as novel therapeutic agents in conditions of neuronal injury and neurodegeneration such as Parkinson's disease. Studies employing animal models of neurodegeneration in ovariectomised female rats treated with estrogen support this hypothesis, yet experimental evidence for sex differences in the CNS response to direct neurotoxic insult is limited and, as yet, few studies have addressed the role played by endogenously produced hormones in neuroprotection. Therefore, in this study we aimed to determine (1) whether the prevailing levels of sex steroid hormones in the intact rat provide a degree of protection against neuronal assault in females compared with males and (2) whether sex differences depend solely on male/female differences in circulating estrogen levels or whether androgens could also play a role. Using the selective, centrally administered neurotoxin 6-hydroxydopamine, which induces a lesion in the nigrostriatal dopaminergic pathway similar to that seen in Parkinson's disease, we have demonstrated a sexually dimorphic (male-dominant), dose-dependent susceptibility in rats. Furthermore, following gonadectomy, dopamine depletion resulting from a submaximal dose of 6-hydroxydopamine (1 microg) was reduced in male rats, whereas in females, ovariectomy enhanced dopamine depletion. Administration of the nonaromatizable androgen dihydrotestosterone to gonadectomized animals had no significant effect on 6-hydroxydopamine toxicity in either males or females, whereas treatment of gonadectomized males and females with physiological levels of estrogen restored the extent of striatal dopamine loss to that seen in intact rats, viz, estrogen therapy reduced lesion size in females but increased it in males. Taken together, our findings strongly suggest that there are sex differences in the mechanisms whereby nigrostriatal dopaminergic neurones respond to injury. They also reveal that the reported clinically beneficial effects of estrogen in females may not be universally adopted for males. While the reasons for this gender-determined difference in response to the activational action of estrogen are unknown, we hypothesize that they may well be related to the early organizational events mediated by sex steroid hormones, which ultimately result in the sexual differentiation of the brain.

Neoantigen formation and clastogenic action of HCFC-123 and perchloroethylene in human MCL-5 cells.

In this study, the metabolic activation of 2,2-dichloro-1,1,1-trifluoroethane (hydrochlorofluorocarbons-123, HCFC-123), halothane or 1,1-dichloro-1-fluoroethane (HCFC-141b) was compared to that of perchloroethylene, using lymphoblastoma derived cell lines expressing human CYP1A1, CYP1A2, CYP2E1, CYP2A6 and CYP3A4 (MCL-5 cells). A dose dependent increase in micronucleus formation was detected over a nominal concentration range of 0.05-2 mM for HCFC-123 and halothane, but this was not seen with HCFC-141b. No dose response for HCFC-123 was seen in a control cHo1 cell line not expressing this cytochrome P450's. Cell lines expressing individual human cytochrome P-450 (CYP) forms were also used to define the enzymes responsible for the clastogenic events and to investigate the formation of immunoreactive protein by microsomal fractions. It was shown that CYP2E1 or CYP2B6 catalysed the clastogenic response, but CYP2D6, CYP3A4, CYP1A2 or CYP1A1 all appeared to be inactive. The formation of neoantigenic trifluoroacetylated protein adducts by microsomal mixtures incubated with HCFC-123 and NADPH was catalysed primarily by CYP2E1 and to a lesser extent by CYP2C19, whereas, only trace levels of immunoreactive protein were seen with microsomes expressing CYP2B6 or CYP2C8. With perchloroethylene as a substrate, the extent of activation was low in comparison with HCFC-123, as judged by the absence of micronuclei formation in the MCL-5 cell line and the weak immunoreactivity of proteins following Western blotting. CYP1A2, CYP2B6 and CYP2C8 appeared to be responsible for perchloroethylene immunoreactivity and in contrast to the findings with the HCFC's, no activation of perchloroethylene by CYP2E1 could be detected. These results show that even though both saturated and unsaturated halocarbons can result in neoantigen formation, there is a marked difference in the specificity of the CYP enzymes involved in their metabolic activation.

The results of basal and post pentagastrin gastric secretory studies in apparently healthy subjects, a preliminary communication.

Pentagastrin stimulated gastric secretory studies were carried out in 26 apparently healthy subjects. Each specimen of gastric juice was analysed for volume, pH, total acidity and major electrolytes. The data was analysed and compared with other published reports.

An investigation into the behaviour of the electrolytes in presence of ionic urfactants.

The effect of various concentrations of Sodium Chloride and Lithium Sulphate in presence of Carbonate-bicarbonate buffer at pH 9.20 on the base-catalyzed hydrolysis of procaine was investigated. The whole study was done in the presence of different concentration of cetyltrimethyl ammonium bromide (CTAB) and Sodium dodecyl Sulphate (SDS) at 60 degrees C. Addition of different electrolytes suppressed the maxima in the Surfactant Effect Ratio (SER). The presence of these additives increase the inhibitory effect with a corresponding in their concentrations SDS/SO4, appeared to be most effective inhibitory amongst SDS/Li2SO4, SDS/NaCl, CTAB/Li2SO4, and CTAB/NaCl systems.

B-lymphocytic hairy cells contain no HTLV-II DNA sequences.

HTLV-II has been found in some cases of the rare T-cell form of hairy-cell leukemia (HCL) and in a leukopenic chronic T-cell leukemia mimicking HCL. We asked whether the virus is implicated in the more frequent B-cell form of HCL. DNA extracted from the mononuclear cells derived from spleen (eight cases) or peripheral blood (eight cases) of 16 patients with the B-cell form of HCL was probed. No viral sequences were detected at levels of sensitivity as low as one viral genome in five cells. Therefore HTLV-II may not be involved in the B-cell form of HCL.

Rapid dot blot quantitation of viral DNA and amplified genes in less than 1,000 human cells.

The copy number of intracellular DNA sequences can be quantitated rapidly with great sensitivity in 100 to 1,000 cells as starting material. The method applies DNA from lysed cells to a charged nylon membrane that permits successive hybridizations with probes for different genes or DNA sequences. This method was tested with eight types of human cells, including leukemic cells, and has detected Epstein-Barr virus (DNA virus) in immortalized cells, integrated HTLV-I (RNA retrovirus) in infected cells, and determined copy numbers of the amplified multiple drug-resistant gene in human cells resistant to various cytotoxic agents. It could also be used for estimating copy number of transfected DNA in human or other mammalian cells. The described method is not as sensitive as polymerase chain reaction may potentially prove, but is easily quantitated for accurate clinical diagnosis where sensitive and quantitative assays must be carried out on a limited number of cells. Examples of the method's clinical application are the staging of human neuroblastomas and the evaluation of oncogene amplification, which has prognostic value for both overall survival and relapse time in breast cancer patients.

A continuous fluorometric assay for gamma-glutamyltranspeptidase.

The synthesis of gamma-glutamyl-7-amino-4-(trifluoromethyl)coumarin and its use as a substrate for gamma-glutamyltranspeptidase is described. The reaction product 7-amino-4-(trifluoromethyl)coumarin was fluorescent at neutral pH values and with excitation and emission wavelengths of 400 and 490 nm, respectively, concentration was linearly related to fluorescence over the range of 10 to 300 pmol/3 ml reaction mixture. At pH 8.4, the optimum for purified gamma-glutamyltranspeptidase, continuous fluorometric determination of enzyme activity with time could be carried out. This permitted accurate estimations to be made of initial reaction rates. Low levels of gamma-glutamyltranspeptidase activity could be shown in isolated rat hepatocytes (1 x 10(5) cells). Such activity could be inhibited by the addition acivicine (alpha-amino-3-chloro-5-isoxazoleacetic acid), suggesting the absence of peptidase-like activity. Following 2-week pretreatment of rats with the antiestrogen, tamoxifen, a fourfold increase in gamma-glutamyltranspeptidase activity was observed. The present method offers a convenient, sensitive method for the determination of gamma-glutamyltranspeptidase activity without the need for elaborate workup procedures.