Correction to: Inhibition of cathepsin B by caspase-3 inhibitors blocks programmed cell death in Arabidopsis.

We thank D Nicholson for initial advice on caspase activity purification and B Turk for advice on recombinant cathepsin B. We thank N Atanasova for cell death assays. The Bioimaging Facility microscopes used in this study were purchased with grants from BBSRC, Wellcome Trust and the University of Manchester Strategic Fund. Special thanks go to D Knight in the Faculty Biomolecular Analysis facility. We thank P Birch and M Kim for improving the manuscript. The project was partially funded by BBSRC Grants 34/P14516, BB/K009478/1 and China National High-Tech Research and Development Programme(863 programme)NO. 2015AA020903.

Inhibition of cathepsin B by caspase-3 inhibitors blocks programmed cell death in Arabidopsis.

Programmed cell death (PCD) is used by plants for development and survival to biotic and abiotic stresses. The role of caspases in PCD is well established in animal cells. Over the past 15 years, the importance of caspase-3-like enzymatic activity for plant PCD completion has been widely documented despite the absence of caspase orthologues. In particular, caspase-3 inhibitors blocked nearly all plant PCD tested. Here, we affinity-purified a plant caspase-3-like activity using a biotin-labelled caspase-3 inhibitor and identified Arabidopsis thaliana cathepsin B3 (AtCathB3) by liquid chromatography with tandem mass spectrometry (LC-MS/MS). Consistent with this, recombinant AtCathB3 was found to have caspase-3-like activity and to be inhibited by caspase-3 inhibitors. AtCathepsin B triple-mutant lines showed reduced caspase-3-like enzymatic activity and reduced labelling with activity-based caspase-3 probes. Importantly, AtCathepsin B triple mutants showed a strong reduction in the PCD induced by ultraviolet (UV), oxidative stress (H2O2, methyl viologen) or endoplasmic reticulum stress. Our observations contribute to explain why caspase-3 inhibitors inhibit plant PCD and provide new tools to further plant PCD research. The fact that cathepsin B does regulate PCD in both animal and plant cells suggests that this protease may be part of an ancestral PCD pathway pre-existing the plant/animal divergence that needs further characterisation.

Estrogenic alkylphenols induce cell death by inhibiting testis endoplasmic reticulum Ca(2+) pumps.

Industrial alkylphenols in the environment may act as "xenoestrogens" to disrupt testicular development and decrease male fertility. Amongst possible targets for these compounds are testicular Sertoli cells, which nurture the developing sperm cells. We demonstrate that SERCA 2 and 3 Ca(2+) pumps are relatively abundant in rat testis microsomal membranes, and also in Sertoli, myoid, and TM4 cells (a Sertoli cell line). A number of estrogenic alkylphenols such as nonylphenol, octylphenol, bisphenol A, and butylated hydroxytoluene all inhibit testicular Ca(2+) ATPase in the low micromolar concentration range. These agents also mobilize intracellular Ca(2+) in intact TM4 cells in a manner consistent with the inhibition of ER Ca(2+) pumps. Alkylphenols dramatically decrease the viability of TM4 cells, an effect that is reversed by either a caspase inhibitor or by BAPTA, and is therefore consistent with Ca(2+)-dependent cell death via apoptosis. We postulate that alkylphenols disrupt testicular development by inhibiting ER Ca(2+) pumps, thus disturbing testicular Ca(2+) homeostasis.

The impact of a helicopter emergency medical services program on potential morbidity and mortality.

INTRODUCTION: The evaluation of the effectiveness of helicopter emergency medical services is currently a major focus of air transport research, and dispatch judgment likely will play a significant role in any research aimed at measuring outcome or impact. SETTING: Two rotor-wing programs in Alberta, Canada. METHODS: A panel of experts evaluated the effectiveness of a helicopter service in Canada. Four hundred sequential patient records were examined and categorized into four risk levels. Level 1 included patients who required critical intervention. Level 2 included patients in whom a major deterioration of vital signs could be expected. Level 3 patients were those for whom transport by an advanced life support ground unit would have been adequate. Level 4 was strictly for missions in which patient transport by any other means would have been impractical, such as remote locations (these cases were double-rated). RESULTS: Risk level 1 included 98 cases (24.5%); risk level 2, 266 cases (66.5%); risk level 3, 36 cases (9%); and risk level 4, 16 cases, two of which were rated level 1, 11 rated level 2, and three rated level 3. CONCLUSION: The results indicate that in 91% of the reviewed cases, helicopter transport was appropriate, representing a reasonable and judicious use of a helicopter emergency medical service.

Norfloxacin interferes with cyclosporine disposition in pediatric patients undergoing renal transplantation.

Prophylactic treatment with norfloxacin was initiated in a group of pediatric patients undergoing renal transplantation who were receiving cyclosporine and were susceptible to recurrent urinary tract infections. At discharge from the hospital, the mean daily dose of cyclosporine needed to maintain trough cyclosporine blood levels of 150 to 400 ng/ml was 4.5 mg/kg/day for the patients who received norfloxacin compared with 7.4 mg/kg/day for patients who did not receive the antibiotic. This observation suggested that the clearance of cyclosporine was decreased by the concomitant use of norfloxacin. The effect of norfloxacin on specific drug-metabolizing cytochrome P450 isozymes in vitro was examined to determine if the metabolism and subsequent clearance of cyclosporine and possibly other drugs are altered through a metabolic interaction with norfloxacin. In human liver microsomes, the activity of cytochrome P4503A4, the isozyme that metabolizes cyclosporine in humans, was inhibited by norfloxacin. In rat liver microsomes, norfloxacin inhibited the activity of cytochrome P4503A2, the isozyme responsible for cyclosporine metabolism in this species, but did not alter the activity of the rat cytochrome P450 isozymes 1A, 2E1, and 4A1. The in vitro studies suggest that the lower cyclosporine dose required by pediatric patients who were given norfloxacin was caused by inhibition of the metabolism of cyclosporine.

The influence of D.D.A.V.P. on the survival of factor VIII in severe haemophiliacs.

The effect of D.D.A.V.P. (desamino-cys'-D-arg8-Vaso-pressin) on the survival characteristics of transfused VIII concentrate was studied in six severe, adolescent, haemophiliacs (VIII:C 1 iu/dl). D.D.A.V.P. was administered at a concentration of 0.3 ug/kg immediately following or 24 hours post infusion. No significant alteration in the half disappearance (1/2 d) or biological half-life (t 1/2) was detected for either VIII procoagulant (VIII:C) or its antigenic counterpart VIII:C Ag. As anticipated there was a significant (if sub-optimal) increase in VIII:R Ag within 2-4 hours of D.D.A.V.P. administration.

The stability of VIII:C in frozen stored plasma samples--re-examined.

VIII procoagulant activity (VIII:C) was estimated by a two-stage assay method, on 100 pre- and post-transfusion samples obtained from severe haemophiliacs receiving regular treatment with a variety of VIII concentrate preparations. Close and significant correlation (r = 0.97 P less than 0.01) was obtained between freshly tested samples and samples stored for one month at -35 degrees C. No significant difference between the two samples was demonstrated by Student's paired-t-test. Forty-nine of the stored samples were also measured for VIII procoagulant antigen (VIII:C Ag) level. A similar close and significant correlation was found for this parameter (r = 0.9 P less than 0.01), when compared with the VIII:C of the freshly tested samples. On average the VIII:C Ag value was 10% lower than the corresponding VIII:C value, although the difference was not statistically significant.

The 'in vivo' survival characteristics of factor VIII procoagulant antigen (VIII:C Ag) in haemophilia A subjects.

Initial half disappearance times and biological half-lives were determined for factor VIII procoagulant antigen (VIII:C Ag) and compared with VIII procoagulant (VIII:C) survival for each of two commercial concentrates, transfused into seven severe (less than 1 i.u./dl) non-bleeding haemophiliacs. The results show that VIII:C Ag has similar half disappearance and biological half-life to that of factor VIII:C. The relevance of these results to recently published findings is discussed.

GABA and hippocampal inhibition.

Bicuculline, a specific GABA antagonist, diminishes basket cell inhibition of hippocampal pyramidal neurones, an inhibition which is not affected by strychnine.The inhibitory transmitter released by basket cells is thus probably GABA.