Slippage of water past superhydrophobic carbon nanotube forests in microchannels

We present in this Letter an experimental characterization of liquid flow slippage over superhydrophobic surfaces made of carbon nanotube forests, incorporated in microchannels. We make use of a particle image velocimetry technique to achieve the submicrometric resolution on the flow profile necessary for accurate measurement of the surface hydrodynamic properties. We demonstrate boundary slippage on the Cassie superhydrophobic state, associated with slip lengths of a few microns, while a vanishing slip length is found in the Wenzel state when the liquid impregnates the surface. Varying the lateral roughness scale L of our carbon nanotube forest-based superhydrophobic surfaces, we demonstrate that the slip length varies linearly with L in line with theoretical predictions for slippage on patterned surfaces.

GW572016, gemcitabine and GW572016, gemcitabine, oxaliplatin, a two-stage, phase I study for advanced pancreaticobiliary cancer

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Background: GW572016 is an orally active small molecule that reversibly inhibits ErbB1 and ErbB2 tyrosine kinases. ErbB1 is commonly expressed in pancreaticobiliary cancers. ErbB2 is the preferred heterodimer partner for other ErbB receptors. Baerman et al demonstrated that GW572016 was active against pancreatic cancer cell lines (ASCO GI 2005). We have completed a two-stage, phase I evaluation of GW572016 and gemcitabine (gem), and GW572016 with the combination of gemcitabine and oxaliplatin (GEMOX). Methods: Patients with advanced adenocarcinoma of the pancreas or bile ducts were treated with GW572016 and either weekly gemcitabine (1gm/m2/week, 3 weeks on, 1 week off) or GEMOX (gemcitabine 1g/m2 over 100 minutes and oxaliplatin 100 mg/m2, every 14 days). Cohort 1: Weekly gem + GW572016, 1000mg/day. Cohort 2: Weekly gem + GW572016, 1500 mg/day. Cohort 3: GEMOX + GW572016 1000 mg/day. Cohort 4: GEMOX + GW572016 1500 mg/day. Results: Twenty-one patients have been treated; pancreatic cancer (n=15), biliary cancer (n=6). The median age was 64 (41–78). One of six patients in cohort 2 had grade 3 diarrhea. Dose limiting grade 3 nausea occurred in 2 of 5 patients in cohort 4. Two patients had a temporary decrease in cardiac ejection fraction. Five of 20 evaluable patients (25%) responded. Conclusions: GW572016 1500 mg/day can be administered will full dosage gem. The MTD of GW572016 is 1000mg/day with GEMOX. Dramatic responses have been demonstrated in patients with diffuse liver and peritoneal metastases suggesting that erbB1/erbB2 signaling is important in pancreaticobiliary cancers. Further evaluation of GW572016 in pancreaticobiliary cancer is indicated.

[Table: see text]

Conversion of Lactococcus lactis cell envelope proteinase specificity by partial allele exchange

AIMS

To determine whether conversion of lactocepin substrate binding regions by gene replacement can alter lactocepin specificity in Lactococcus lactis starter bacteria without affecting other important strain properties.

METHODS AND RESULTS

We utilized two-step gene replacement to convert substrate-binding determinants in the L. lactis prtP genes encoding group h (bitter) lactocepin in two industrial strains into the corresponding group b (nonbitter) variant. Analysis of lactocepin activity toward alpha(s1)-casein (f 1-23) by reversed-phase high-pressure liquid chromatography demonstrated enzyme specificity among isogenic derivatives had been altered in a manner that was consistent with predicted amino acid substitutions in substrate binding regions. Milk acidification properties of some mutants were not statistically different (P > 0.05) from wild-type parent strains, and strain propensity for autolysis was also not significantly (P > 0.05) changed.

CONCLUSIONS

Conversion of lactocepin substrate binding regions by allele exchange can effectively alter lactocepin specificity in industrial strains of L. lactis without significantly affecting other important strain properties.

SIGNIFICANCE AND IMPACT OF THE STUDY

Methodology outlined in this study can be used to alter lactocepin specificity in commercial starter cultures with a propensity for bitter flavour defect, and prtP derivatives developed by this approach should be suitable for commercial application.

[Anaphylaxis after rocuronium: advantage of blood tests for early diagnosis]

A 56-year-old patient was scheduled for coronary artery bypass surgery, because of a severe coronary artery disease. Soon after induction of anaesthesia, he rapidly developed a cardiovascular collapse with bronchospasm and rash. Specific immunoglobulin E and tryptase measurements supported the diagnosis of grade III anaphylactic shock due to rocuronium bromide. A few days later, a general anaesthesia was administered without muscle relaxant and was uneventful.

Safety of oral nicorandil before coronary artery bypass graft surgery

Nicorandil is a K(ATP) channel opener used to treat angina. It is cardioprotective and a vasodilator. We conducted a prospective, randomized, double-blind, placebo-controlled study to assess oral nicorandil in patients undergoing coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). Twenty-two patients received nicorandil (10 mg twice a day) and 23 patients received placebo. Haemodynamic data were recorded before induction of anaesthesia (T0), 5 and 20 min after starting mechanical ventilation (T1, T2), before aortic cannulation (T3), after 30 min of CPB (T4), 10 min after CPB (T5) and after 3, 8 and 18 h in the intensive care unit (T6, T7, T8). Serum proteins (creatine kinase metabolite and cardiac troponin I) were measured before and 8 and 18 h after surgery. Haemodynamic values did not differ between the two groups. There was no tachycardia during the study, no significant difference in hypotensive episodes, ST segment changes and no changes in cardiac enzymes. Myocardial infarction after surgery was similar in the two groups. Vasoactive therapy was similar in the two groups. Nicorandil can be continued safely up to premedication without deleterious haemodynamic consequences, but a myocardial protective effect of nicorandil in CABG surgery was not found.

Rapid orientated cloning in a shuttle vector allowing modulated gene expression in Bacillus subtilis

An expression vector for systematic protein overproduction in Bacillus subtilis has been constructed. It derives from pDG148 and combines the main property of this vector, i.e. conditional expression of the gene in response to isopropylbeta-D-thiogalactopyranoside, with (i) rapid orientated cloning by a ligation independent procedure and (ii) a ribosome binding site of high translational efficiency. When used for overproduction of several proteins in B. subtilis, this vector gave good levels of protein synthesis.

Relentless progression of venous obstruction in a case of Budd-Chiari syndrome related to heterozygous protein C deficiency

A 28-year-old man with heterozygous protein C deficiency presented with Budd-Chiari syndrome resulting from hepatic vein obstruction. Over the next 40 months, standard oral anticoagulant therapy and multiple percutaneous interventions aimed at relieving hepatic vein obstruction could not prevent progression of the disease ultimately to cirrhosis and death. Serial angiography provided unique documentation of the relentless progression of hepatic venous obstruction, which was related to the disease and to iatrogenic factors. Operative findings obtained during unsuccessful mesocaval shunt surgery revealed that venous disease in protein C deficiency can be far more extensive than is clinically anticipated. The ineffectiveness of therapy in this patient may be related to standard oral anticoagulant therapy being insufficient to offset the risk of recurrent thrombosis and progression to an advanced stage of vascular damage.

Integration of tuberculosis screening at an HIV voluntary counselling and testing centre in Haiti

OBJECTIVE

To describe the integration of tuberculosis screening into the activities of an HIV voluntary counselling and testing (VCT) centre in a country with endemic tuberculosis.

SETTING

An HIV VCT centre in Port au Prince, Haiti.

DESIGN

All patients presenting for HIV VCT who reported cough received same-day evaluation for active tuberculosis. Of the 1327 adults presenting to the centre for the first time between January and April 1997, 263 (20%) reported cough and of these 241 (92%) were evaluated.

RESULTS

Of the 241 patients evaluated for cough, 76 (32%) were diagnosed with pulmonary tuberculosis. Of the 76 patients diagnosed with pulmonary tuberculosis, 28 (37%) had a positive smear for acid-fast bacilli (AFB), 14 (18%) had a negative AFB smear but a positive sputum culture for Mycobacterium tuberculosis, and 34 (45%) had culture-negative tuberculosis. Also, 31 out of 241 (13%) VCT clients evaluated for cough were diagnosed with bacterial pneumonia.

CONCLUSION

This report confirms that in areas with a high HIV and tuberculosis prevalence, a high proportion of VCT clients have active pulmonary tuberculosis. The integration of tuberculosis screening offers several benefits, including the diagnosis and treatment of large numbers of individuals with tuberculosis, a decreased risk of nosocomial tuberculosis transmission, and the opportunity to provide tuberculosis prophylaxis to HIV-positive patients in whom tuberculosis has been excluded. Future studies are needed to determine the cost-effectiveness of integrated tuberculosis and HIV VCT services, and whether integration should be recommended in all countries with high HIV and tuberculosis rates.

Gene expression profile in BALB/c-3T3 cells transformed with beryllium sulfate

Differential gene expression was studied to understand the potential molecular mechanism responsible for cell transformation and tumorigenesis induced by beryllium. Cell lines were derived from tumors developed in nude mice injected subcutaneously with BALB/c-3T3 cells morphologically transformed with beryllium sulfate. Using the Atlas mouse 1.2 cDNA expression microarray, the expression profiles of 1176 genes, belonging to several different functional categories, were studied in the tumor cells as well as in the nontransformed control cells. Expression of 18 genes belonging to two functional groups was found to be consistently and reproducibly different (at least twofold) in the tumor cells compared with the control cells. The functional groups and the differentially expressed genes are as follows: The cancer-related genes (nine genes) were the ets-related transcription factor activated by ras, colony-stimulating factor, A-myb, sky, cot1, c-fos, c-jun, c-myc, and R-ras proto-oncogenes. The DNA synthesis, repair, and recombination genes (nine genes) were the DNA replication licensing factor MCM4, the DNA replication licensing factor MCM5, the DNA mismatch repair gene PMS2, the DNA excision repair gene, the DNA mismatch repair gene MSH2, the ultraviolet excision repair gene Rad23 DNA ligase 1, Rad51, and Rad52. The differential gene expression profile was confirmed with reverse transcription-polymerase chain reaction using primers specific for the differentially expressed genes. In general, expression of the cancer-related genes was upregulated, while expression of genes involved in DNA synthesis, repair, and recombination was downregulated in the tumor cells compared with the control cells. Using c-fos and c-jun, two of the differentially expressed genes, as model genes, we have found that in the nontransformed BALB/c-3T3 cells, the beryllium-induced transcriptional activation of these genes was dependent on pathways of protein kinase C and mitogen-activated protein kinase and independent of reactive oxygen species. These results indicate that beryllium-induced cell transformation and tumorigenesis are accompanied by and are possibly a product of alterations in expression of genes related to cancer and to DNA synthesis, repair, and recombination.

Cadmium-induced cell transformation and tumorigenesis are associated with transcriptional activation of c-fos, c-jun, and c-myc proto-oncogenes: role of cellular calcium and reactive oxygen species

The molecular mechanisms of carcinogenesis by cadmium were studied using BALB/c-3T3 cell transformation and nude mouse tumorigenesis models. BALB/c-3T3 cells transformed with cadmium chloride were subcutaneously injected into nude mice to develop tumors and the cell lines derived from these tumors were used in the present study. The proto-oncogenes c-fos and c-jun were overexpressed in 100% (10 out of 10) of the cell lines, while a statistically significant overexpression of c-myc was observed in 40% (4 out of 10) of the cell lines. Analysis of tumor cells stained with fluorescent dyes specific for reactive oxygen species revealed that these cells possessed markedly higher levels of superoxide anion and hydrogen peroxide compared with the nontransformed cells. Similarly, the intracellular calcium level was higher in the tumor cells compared with the nontransformed cells. Overexpression of the proto-oncogenes in these cells was blocked by treating the cells with superoxide dismutase, catalase, and 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetra acetoxy methyl ester (BAPTA/AM), which are scavengers of superoxide anion, hydrogen peroxide, and calcium, respectively. This confirmed that the overexpression of the proto-oncogenes in the tumor cells required elevated intracellular levels of reactive oxygen species and calcium. In addition to the scavengers of reactive oxygen species and calcium, inhibitors specific for transcription (actinomycin D), protein kinase C (RO-31-8220), and MAP kinase (PD 98059) also blocked the cadmium-induced overexpression of the proto-oncogenes in the tumor cells. Exposure of the nontransformed BALB/c-3T3 cells to 20 microM cadmium chloride for 1 h caused elevated intracellular levels of superoxide anion, hydrogen peroxide, and calcium, with corresponding increases in the expression levels of c-fos, c-jun, and c-myc. As in the case of the tumor cells, treating the nontransformed cells with the various modulators prior to their exposure to cadmium chloride resulted in inhibition in the expression of the proto-oncogenes. Based on these data, we conclude that the cadmium-induced overexpression of cellular proto-oncogenes is mediated by the elevation of intracellular levels of superoxide anion, hydrogen peroxide, and calcium. Further, the cadmium-induced overexpression of the proto-oncogenes is dependent on transcriptional activation as well as on pathways involving protein kinase C and MAP kinase.

Variation in delivery of palliative radiotherapy to persons dying of cancer in nova scotia, 1994 to 1998

PURPOSE

To examine sociodemographic and clinical variables associated with provision of palliative radiotherapy (RT) to persons dying of cancer.

METHODS

The Nova Scotia Cancer Registry was used to identify 9,978 adults who were dying of cancer between 1994 and 1998 in the Canadian province of Nova Scotia. RT records from between April 1992 and December 1998 were obtained from the provincial treatment database. Multivariate analysis identified factors associated with two sequential decisions determining provision of palliative RT in the last 9 months of life: likelihood of receiving an RT consultation with a radiation oncologist and, given a consultation, likelihood of being treated with palliative RT.

RESULTS

The likelihood of having a consultation decreased with age (20 to 59 years v. 80+ years: odds ratio [OR], 4.43 [95% confidence interval, 3.80 to 5.15]), increased with community median household income (> $50,000 v. < $20,000: OR, 1.31 [1.02 to 1.70]), was higher for residents closer to the cancer center (< 25 km v 200+ km: OR, 2.47 [2.16 to 2.83]), increased between 1994 and 1998 (OR, 1.34 [1.16 to 1.56]), varied by cause of death (relative to thoracic cancers, head and neck: OR, 1.75 [1.31 to 2.33]; gynecologic: OR, 0.35 [0.27 to 0.44]), and was greater for those who had prior RT (OR, 2.20 [1.89 to 2.56]). Similar associations were observed when outcome was the provision of palliative RT given a consult, with one notable exception: prior RT was associated with a lower likelihood of receiving palliative RT (OR, 0.48 [0.40 to 0.58]).

CONCLUSION

Variations observed in delivery of palliative RT should prompt further investigation into equity of access to clinically appropriate, palliative radiation consultation and treatment.

Community mental health team management in severe mental illness: a systematic review

BACKGROUND

Community mental health teams are now generally recommended for the management of severe mental illness but a comparative evaluation of their effectiveness is lacking.

AIMS

To assess the benefits of community mental health team management in severe mental illness.

METHOD

A systematic review was conducted of community mental health team management compared with other standard approaches.

RESULTS

Community mental health team management is associated with fewer deaths by suicide and in suspicious circumstances (odds ratio=0.32, 95% Cl 0.09-1.12), less dissatisfaction with care (odds ratio=0.34, 95% Cl 0.2-0.59) and fewer drop-outs (odds ratio=0.61, 95% Cl 0.45-0.83). Duration of in-patient psychiatric treatment is shorter with community team management and costs of care are less, but there are no gains in clinical symptomatology or social functioning.

CONCLUSIONS

Community mental health team management is superior to standard care in promoting greater acceptance of treatment, and may also reduce hospital admission and avoid deaths by suicide. This model of care is effective and deserves encouragement.

Effect of post-treatment isoniazid on prevention of recurrent tuberculosis in HIV-1-infected individuals: a randomised trial

BACKGROUND

Patients with HIV-1 infection respond well to treatment for active tuberculosis, but whether such patients are at increased risk of disease recurrence after complete cure is uncertain. We did a randomised trial in Port au Prince, Haiti, to determine whether recurrent tuberculosis after curative tuberculosis treatment is more common in HIV-1-infected individuals than HIV-1-uninfected individuals, and to determine whether post-treatment isoniazid prophylaxis decreases the risk of recurrent tuberculosis.

METHODS

Patients older than 18 years who were diagnosed with a first episode of tuberculosis at the national HIV testing centre in Haiti, and who successfully completed a 6-month rifampicin-containing regimen for active pulmonary tuberculosis, were randomly assigned 1 year of post-treatment isoniazid prophylaxis or placebo. The primary outcome measure was rate of recurrent tuberculosis after at least 24 months. An intention-to-treat analysis was used.

FINDINGS

Of 354 patients with active pulmonary tuberculosis, 274 successfully completed treatment, and 233 were randomised. Of 142 HIV-1-positive patients, 68 were assigned isoniazid and 74 placebo. Of 91 HIV-1-negative individuals, 51 were assigned isoniazid and 40 placebo. The rate of recurrent tuberculosis was 4.8 per 100 person-years in HIV-1-infected individuals and 0.4 per 100 person-years in uninfected individuals (relative risk 10.7 [95% CI 1.4-81.6]). Among HIV-1-positive patients receiving isoniazid, the tuberculosis recurrence rate was 1.4 per 100 person-years, and among HIV-1-positive patients receiving placebo, it was 7.8 per 100 person-years (0.18 [0.04-0.83]). Among HIV-1-positive individuals, all cases of recurrent tuberculosis occurred in individuals with a history of HIV-1-related symptoms before initial tuberculosis diagnosis.

INTERPRETATION

The rate of recurrent tuberculosis is higher in HIV-1-positive individuals than in HIV-1-negative individuals, and is strongly associated with a history of symptomatic HIV-1 disease before initial tuberculosis diagnosis. Post-treatment isoniazid prophylaxis decreases the risk of recurrence in HIV-1-positive individuals, and should be considered for HIV-1-positive individuals with a history of HIV-1-related symptoms at the time of tuberculosis diagnosis.

Common coding in symbolic matching tasks with humans: training with a common consequence or antecedent

The present experiments explored the importance of training with a common antecedent or consequence for common coding in symbolic matching-to-sample tasks with human subjects using reversal and transfer tests. Experiment 1 assessed common coding following training in many-to-one (MTO) and one-to-many (OTM) symbolic matching-to-sample tasks by comparing learning of partial and total reversals of these contingencies. Experiment 2 assessed common coding in MTO and OTM tasks by comparing performances in transfer tests when the common coding relations in the transfer phase were either consistent or inconsistent with those present during initial training. Evidence for common coding in the MTO and OTM discriminations was obtained in both experiments, although the amount of common coding was greater in the MTO discrimination in Experiment 1. These data are discussed in terms of associative mediational approaches to common coding phenomena. It is suggested that a basic requirement of an associative theory is that common coding should be more likely to occur when the stimuli are trained with a common consequence than when they are trained with a common antecedent, and that this requirement has been at least partly satisfied in the present studies.

Role of NAD(P)H:quinone oxidoreductase 1 (DT diaphorase) in protection against quinone toxicity

NQO1-/- mice, along with Chinese hamster ovary (CHO) cells, were used to determine the in vivo role of NAD(P)H:quinone oxidoreductase 1 (NQO1) in cellular protection against quinone cytotoxicity, membrane damage, DNA damage, and carcinogenicity. CHO cells permanently expressing various levels of cDNA-derived P450 reductase and NQO1 were produced. Treatment of CHO cells overexpressing P450 reductase with menadione, benzo[a]pyrene-3,6-quinone (BPQ), and benzoquinone led to increased cytotoxicity as compared with CHO cells expressing endogenous P450 reductase. In a similar experiment, overexpression of NQO1 significantly protected CHO cells against the cytotoxicity of these quinones. Knockout (NQO1-/-) mice deficient in NQO1 protein and activity had been generated previously in our laboratory and were used in the present studies. Wild-type (NQO1+/+) and knockout (NQO1-/-) mice were given i.p. injections of menadione and BPQ, followed by analysis of membrane damage and DNA damage. Both menadione and BPQ induced lipid peroxidation in hepatic and non-hepatic tissues, indicating increased membrane damage. Exposure to BPQ also resulted in increased hepatic DNA adducts in NQO1-/- mice as compared with NQO1+/+ mice. The skin application of BPQ alone and BPQ + 12-O-tetradecanoylphorbol-13-acetate (TPA) failed to induce papillomas, or other lesions, for up to 50 weeks in either NQO1+/+ or NQO1-/- mice. The various results from CHO cells and NQO1-/- mice indicated that NQO1 protects against quinone-induced cytotoxicity, as well as DNA and membrane damage. The absence of BPQ-induced skin carcinogenicity in NQO1-/- mice may be related to the strain (C57BL/6) of mice used in the present study and/or due to poor BPQ absorption into the skin and/or due to detoxification of BPQ by cytosolic NRH:quinone oxidoreductase 2 (NQO2).