The role of K+ and H+ transport systems during glucose‐ and H2O2‐induced cell death in Saccharomyces cerevisiae

Glucose, in the absence of additional nutrients, induces programmed cell death in yeast. This phenomenon is independent of yeast metacaspase (Mca1/Yca1) and of calcineurin, requires ROS production and it is concomitant with loss of cellular K⁺ and vacuolar collapse. K⁺ is a key nutrient protecting the cells and this effect depends on the Trk1 uptake system and is associated with reduced ROS production. Mutants with decreased activity of plasma membrane H⁺‐ATPase are more tolerant to glucose‐induced cell death and exhibit less ROS production. A triple mutant ena1‐4 tok1 nha1, devoid of K⁺ efflux systems, is more tolerant to both glucose‐ and H₂O₂‐induced cell death. We hypothesize that ROS production, activated by glucose and H⁺‐ATPase and inhibited by K⁺ uptake, triggers leakage of K⁺, a process favoured by K⁺ efflux systems. Loss of cytosolic K⁺ probably causes osmotic lysis of vacuoles. The nature of the ROS‐producing system sensitive to K⁺ and H⁺ transport is unknown. Copyright © 2010 John Wiley & Sons, Ltd.     

Competition,regulation, and pricing behaviour in the Spanish retail gasoline market

The restructuring of the Spanish oil industry produced a highly concentrated oligopoly in the retail gasoline market. In June 1990, the Spanish government introduced a system of ceiling price regulation in order to ensure that “liberalization” was accompanied by adequate consumer protection. By 1998, prices were left to the “free” market. This paper examines the pricing behaviour of the retail gasoline market using multivariate error correction models over the period January 1993 (abolishment of the state monopoly)–December 2004. The results suggest that gasoline retail prices respond symmetrically to increases as well as to decreases in the spot price of gasoline both over the period of price regulation (January 1993–September 1998) and over the period of free market (October 1998–December 2004). However, once the ceiling price regulation was abolished, cooperation emerged between the government and the major operators, Repsol-YPF and Cepsa-Elf, to control the inflation rate. This resulted in a slower rate of adjustment of gasoline retail prices when gasoline spot prices went up, as compared with the European pattern. Finally, the Spanish retail margin was by the end of our timing period of analysis, as in the starting years after the abolishment of the state monopoly, above the European average. This pattern confirms our political economic hypothesis, which suggests that the Spanish government and the oil companies were working together in reducing the inflation, in periods of rising oil and gasoline prices. It is also inferred that explaining the pricing pattern in energy markets may require different hypothesis than the classical perspective, involving just firms taking advantage of market power.     

Volatile fraction and sensory characteristics of Manchego cheese. 2. Seasonal variation

An automatic purge and trap apparatus, coupled to a GC-MS was used to study the seasonal variability of the volatile fraction of raw milk Manchego cheese. Both season and dairy significantly affected abundance of most volatile compounds. Most aldehydes, methyl ketones, n-alcohols, and secondary alcohols reached significantly higher concentrations in spring cheeses. Branched chain alcohols showed significantly higher concentrations in autumn and winter cheeses, while significantly higher amounts of diketones were found in summer cheeses. Most ethyl esters reached higher concentrations in spring and winter cheeses and lower in autumn cheeses. Lower concentrations of alpha-pinene were found in spring cheeses, and higher amounts of limonene were observed in winter cheeses. Heptane and octane were significantly more abundant in summer cheeses. No significant seasonal differences were found either for quality or intensity scores.     

Bugzilla, ITracker, and other bug trackers

Bug-tracking helps the software developers in knowing what the error is, resolving it, and learning from it. Working on a software project includes managing the bugs we find. At first, we might list them on a spreadsheet. But when the number of bugs becomes too large and a lot of people must access and input data on them, we have to give up the spreadsheet and instead use a bug- or issue-tracking system. Many software projects reach this point, especially during testing and deployment when users tend to find an application's bugs. Nowadays we can choose among dozens of bug-tracking systems. This paper looks at two specific open source products and provides useful hints for working with any bug-tracking tool.     

A stability-indicating HPLC method to determine cyproterone acetate in tablet formulations

A simple and accurate liquid chromatographic method was developed to estimate cyproterone acetate (CA) in pharmaceuticals. The drug was chromatographed on a reversed-phase C18 column. Eluents were monitored at a wavelength of 254 nm utilizing a mixture (60:40) of acetonitrile and water. Solution concentrations were measured on a weight basis to avoid the use of an internal standard. The method was statistically validated for linearity, accuracy, precision, and selectivity. Due to its simplicity and accuracy, we believe that the method can be used for routine quality control analysis. No specific sample preparation is required except for the use of a column guard and a suitable prefilter attached to the syringe.     

Structure functional expression and spatial distribution of a cloned cDNA encoding a rat 5-HT1D-like receptor

Using polymerase chain reaction (PCR) a complementary DNA (cDNA) encoding a 5-hydroxytryptamine (5-HT) receptor was isolated from rat forebrain. The amplified cDNA specifies an open reading frame of 374 amino acids comprising seven putative transmembrane regions. Expression of the cloned cDNA in human embryonic kidney cells (HEK 293) was used to establish the pharmacological profile of the encoded receptor polypeptide. Membranes containing the cloned receptor showed high affinity binding of [3H]-5-HT. Competition binding experiments with a variety of serotonin receptor ligands displayed a rank order of affinities corresponding to a 5-HT1D subtype: 5-CT > 5-HT = metergoline > CGS 12066 > methysergide > sumatriptan > mianserin = (-)alpha-Me-5-HT = yohimbine > 8-OH-DPAT > or = rauwolscine > spiperone > DOI > propranolol > or = 2-Me-5-HT > or = ICS 205930. Ketanserin and ritanserin displaced [3H]-5-HT-binding in a biphasic manner. In situ hybridization revealed highest expression of the corresponding mRNA in the pyramidal layer of the olfactory tubercle and the nucleus caudatus and accumbens.     

Evaluation of an immunohistochemical test with polyclonal antibodies raised against mycobacteria used in formalin-fixed tissue compared with mycobacterial specific culture

OBJECTIVES: In neurogenic dysphagia a good cough is important for airway protection. If triggering of cough, or its effectiveness, is impaired this might result in an increased aspiration risk. Capsaicin, an agent which induces cough through sensory nerve stimulation, was used to test cough sensitivity in groups of patients with and without neurogenic dysphagia. METHODS: On the basis of swallowing speed (ml/s) in a validated water test 28 alert neurological inpatients (16 women, aged 22-71 years) were classified into 13 with abnormal and 15 with normal swallowing (median swallowing speed 23% and 99%, median volume/swallow 43% and 106% of that predicted for age and sex respectively: p<0.001). Capsaicin nebulised on air in saline was inhaled via a low resistance valve using a mouthpiece and noseclip. Up to seven incremental concentrations of capsaicin ranging from 0.07-20.0 x 10(-4) mol/l were each inhaled for up to a minute. A pneumotachograph connected to the expiratory limb gave a paper recording of expiratory air flow. Coughs were recorded as high flow expirations of short duration. Capsaicin concentrations at first cough (threshold) were recorded; concentrations at frequencies of 10 and 20 coughs/minute were interpolated from the dose-response curve. RESULTS: Cough threshold tended to be lower in those with abnormal swallowing (non-significant): the (log) concentration of capsaicin producing 10 or 20 coughs/ minute also tended to be lower (p=0.12 and 0.07 respectively) in those with abnormal swallowing. CONCLUSION: Contrary to expectation, these results suggest that cough responsiveness is enhanced in alert patients with neurogenic dysphagia even after allowing for diagnostic category, the possible presence of a bulbar upper motor neuron lesion, or voluntary respiratory capacity. It is concluded that these patients with neurogenic dysphagia do not have a reduced sensitivity of cough triggering.     

Endothelin ET(B) receptors counteract venoconstrictor effects of endothelin-1 in anesthetized rats

The inhibitory effects of BQ 788 (3 mg/kg, i.v., ET(B)-receptor antagonist) on endothelin-1 (ET-1)- or IRL 1620 (ET(B)-receptor agonist)-induced changes in mean arterial pressure (MAP), mean circulatory filling pressure (MCFP, driving force of venous return), arterial resistance (RA), venous resistance (RV) and cardiac output (CO) were characterized in 6 groups of pentobarbital-anesthetized rats. ET-1 or IRL 1620 (0.5, 1 and 2 nmol/kg, i.v.) dose-dependently increased MAP, RA, RV and MCFP and decreased CO. Maximum changes in RA, RV and CO elicited by ET-1 were greater than those by IRL 1620. Equimolar doses of ET-1 and IRL 1620 also caused similar initial transient decreases in MAP. BQ 788 alone slightly elevated MCFP, but did not alter other variables. The ET(B)-blocker abolished all changes elicited by IRL 1620, but only partially inhibited its responses on MCFP, showing the presence of BQ 788-insensitive receptors. BQ 788 also abolished ET-1's depressor response, partially inhibited its effect on MCFP, and markedly augmented its effects on RA, RV and CO. Thus, ET(B)-receptors counteract the sustained constrictor effects of ET-1 on arterial and venous resistance vessels Our results indicate a substantial arterial and venous dilator role for ET(B) receptors.     

Histopathology of coronary lesions with early loss of minimal luminal diameter after successful percutaneous transluminal coronary angioplasty: is thrombus a significant contributor?

BACKGROUND: Early loss of minimal luminal diameter of >0.3 mm after successful percutaneous transluminal coronary angioplasty (PTCA) is associated with a higher incidence of restenosis. The underlying mechanism of this early loss is unknown and thrombus may be a contributing factor. METHODS: We performed a prospective study using quantitative computerized planimetry on coronary tissue specimens obtained by directional coronary atherectomy of 24 lesions in which early loss occurred 22+/-9 minutes after successful PTCA. RESULTS: Thrombus was present in 9 (37%) of 24 coronary specimens. Segmental areas (mm2) and percentage of total area were distributed as follows: sclerotic tissue, 4.07+/-0.7 mm2 (63%+/-6%); fibrocellular tissue, 0.97+/-0.27 mm2 (16%+/-4%); hypercellular tissue, 0.99+/-0.29 mm2 (12%+/-3%); atheromatous gruel, 0.18+/-0.07 mm2 (3%+/-0.1%); and thrombus, 0.24+/-0.15 mm2 (6%+/-0.4%). There was no difference in the relative early loss index between lesions with or without thrombus (35%+/-7% vs 26%+/-2%, respectively; P= .87). Multiple stepwise regression analysis did not identify any histologic predictors of relative early loss index. CONCLUSION: Histopathologic analysis of coronary lesions with early loss after successful PTCA suggests that thrombus may not play a significant role in this angiographic phenomenon.     

Convolutional Codes of Goppa Type

A new kind of Convolutional Codes generalizing Goppa Codes is proposed. This provides a systematic method for constructing convolutional codes with prefixed properties. In particular, examples of Maximum-Distance Separable (MDS) convolutional codes are obtained.This research was partially supported by the Spanish DGI through research project BFM2003-00078 and by the Junta de Castilla y León through research projects SA071/04 and SA032/02.