Sensory lateralization in pain subjective perception for noxious heat stimulus

The aim of the present study was to identify and characterize hemispheric lateralization for pain intensity perception. A sample of 351 healthy volunteers was tested by the immersion of the right hand for 10 s followed by the same test for the left hand (RL group; n = 199) or in a random sequence (RND group; n = 152) into a water bath (48 degrees C, 15 s). Pain intensity was self-reported by the Visual Analogue Scale (VAS). The motor hemispherical Lateralization Index (LI) was obtained by the Edinburgh Inventory. Gender, hand skin fold, interstimulus time and menstrual cycle data in case of female subjects were recorded. The sample, 60.7% females and 39.3% males, 20.4 +/- 0.18 (mean +/- SEM) years old, showed 92.1% right-handed subjects. Left hand VAS was significantly higher than right hand VAS for RL (7.24 +/- 1.31 vs 6.74 +/- 1.52; p < 0.01) and RND (7.24 +/- 0.82 vs 6.73 +/- 1.25; p < 0.01) both for right- and left-handed subjects. A low but significant correlation for VAS scores and LI was found (r = 0.14; p < 0.05 or r = 0.18; p < 0.05, for left or right hand, respectively). Skin fold was statistically similar in both hands (p > 0.05) being highly correlated with each other (r = 0.68; p < 0.05). Pain subjective perception was not correlated to interstimulus time (r = -0.01; p > 0.05). Females showed significantly higher values than males for both left and right hand VAS scores. Periovulatory phase VAS value was significantly higher than luteal phase VAS only for the right hand test (7.57 +/- 0.20 vs 6.47 +/- 0.33; p < 0.01). The results of the present study suggest a lateralization of pain intensity perception to the right hemisphere not correlated with the motor hemispheric lateralization.     

Proteolysis in hyperthermophilic microorganisms

Proteases are found in every cell, where they recognize and break down unneeded or abnormal polypeptides or peptide-based nutrients within or outside the cell. Genome sequence data can be used to compare proteolytic enzyme inventories of different organisms as they relate to physiological needs for protein modification and hydrolysis. In this review, we exploit genome sequence data to compare hyperthermophilic microorganisms from the euryarchaeotal genus Pyrococcus, the crenarchaeote Sulfolobus solfataricus, and the bacterium Thermotoga maritima. An overview of the proteases in these organisms is given based on those proteases that have been characterized and on putative proteases that have been identified from genomic sequences, but have yet to be characterized. The analysis revealed both similarities and differences in the mechanisms utilized for proteolysis by each of these hyperthermophiles and indicated how these mechanisms relate to proteolysis in less thermophilic cells and organisms.     

New strategies for treatment of Candida vaginal infections

New strategies for treatment of vaginal candidiasis have been recently exploited, due to widespread occurrence of this disease, in particular as recurrent infections, limitations of safe and efficacious antifungals as well as the lack of reliable preventative approaches. In this review new chemotherapeutic and immunotherapeutic strategies, based on the improved understanding of the immunopathogenesis of this prevalent human infection, will be discussed. The role of killer antibodies (or their molecular derivatives), i.e. antibodies that show antibiotic activity bearing the internal image of a yeast killer toxin (KT), characterized by a wide spectrum of microbicidal activity, and of the specific cell wall KT receptor as putative new therapeutic agents and preventative or therapeutic vaccines, respectively, will be particularly outlined.     

Characterization of Paracoccidioides brasiliensis atypical isolates by random amplified polymorphic DNA analysis

Two atypical Paracoccidioides brasiliensis strains (yeast form at room temperature) have been isolated from chronically infected patients living in Brazil. Different random primers were used to characterize these isolates and compare them to typical strains. The RAPD patterns allowed the differentiation of all the selected isolates. Their genetic distance ranged from 5% to 80% of non-shared bands depending on the strains and the primer used. The RAPD data were used to build a Wagner phenogram, which showed two major branched with more than 56% of genetic distance separating them. No significant difference was observed between the atypical isolates and the others suggesting that specific genes are involved in the dimorphism phenomenon.     

Regulation of membrane fusion by the membrane-proximal coil of the t-SNARE during zippering of SNAREpins

We utilize structurally targeted peptides to identify a "tC fusion switch" inherent to the coil domains of the neuronal t-SNARE that pairs with the cognate v-SNARE. The tC fusion switch is located in the membrane-proximal portion of the t-SNARE and controls the rate at which the helical bundle that forms the SNAREpin can zip up to drive bilayer fusion. When the fusion switch is "off" (the intrinsic state of the t-SNARE), zippering of the helices from their membrane-distal ends is impeded and fusion is slow. When the tC fusion switch is "on," fusion is much faster. The tC fusion switch can be thrown by a peptide that corresponds to the membrane-proximal half of the cognate v-SNARE, and binds reversibly to the cognate region of the t-SNARE. This structures the coil in the membrane-proximal domain of the t-SNARE and accelerates fusion, implying that the intrinsically unstable coil in that region is a natural impediment to the completion of zippering, and thus, fusion. Proteins that stabilize or destabilize one or the other state of the tC fusion switch would exert fine temporal control over the rate of fusion after SNAREs have already partly zippered up.     

Seasonal transmission of Leishmania (Leishmania) mexicana in the state of Campeche, Yucatan Peninsula, Mexico

In the Yucatan Peninsula, Mexico, localized cutaneous leishmaniasis (LCL) caused by Leishmania (Leishmania) mexicana is a typical wild zoonosis restricted to the forest, and humans are only accidentally involved. The transmission of L. (L.) mexicana has been related to the patient's occupation: "chicleros" (gum collectors) and agricultural workers. The objective of this study was to document L. (L.) mexicana seasonally of transmission in endemic areas of LCL in the state of Campeche, Yucatan Peninsula, Mexico. The timing of incidence of LCL in humans during 1993-1994, as well as the rate and time of infection in rodents and sand flies between February 1993 and March 1995 were analyzed. Rodents and sand flies were found infected between November and March, when men carried out their field activities and are exposed. Based on results analyzed, it is concluded that L. (L.) mexicana in the endemic area of LCL in the state of Campeche, Yucatan Peninsula, Mexico, presents a seasonal transmission restricted to the months of November to March. The knowledge of the timing of the transmission cycle in an endemic area of leishmaniasis is very important because intervention measures on the high-risk focus and population might be restricted.     

Induction of a Crassulacean acid like metabolism in the C4 succulent plant,Portulaca oleracea L.: physiological and morphological changes are accompanied by specific modifications in phosphoenolpyruvate carboxylase

The induction of a Crassulacean acid like metabolism (CAM) was evidenced after 21–23 days of drought stress in the C₄ succulent plant Portulaca oleracea L. by changes in the CO₂ exchange pattern, in malic acid content and in titratable acidity during the day–night cycle. Light microscopy studies also revealed differences in the leaf structure after the drought treatment. Following the induction of the CAM-like metabolism, the regulatory properties of phosphoenolpyruvate carboxylase (PEPC, EC 4.1.1.31), the enzyme responsible for the diurnal fixation of CO₂ in C₄ plants but nocturnal in CAM plants, were studied. The enzyme from stressed plants showed different kinetic properties with respect to controls, notably its lack of cooperativity, higher sensitivity to L-malate inhibition, higher PEP affinity and lower enzyme content on a protein basis. In both conditions, PEPC's subunit mass was 110 kDa, although changes in the isoelectric point and electrophoretic mobility of the native enzyme were observed. In vivo phosphorylation and native isoelectrofocusing studies indicated variations in the phosphorylation status of the enzyme of samples collected during the night and day, which was clearly different for the control and stressed groups of plants. The results presented suggest that PEPC activity and regulation are modified upon drought stress treatment in a way that allows P. oleracea to perform a CAM-like metabolism. This revised version was published online in August 2006 with corrections to the Cover Date.     

Application of waste activated bleaching earth containing rapeseed oil on riboflavin production in the culture of Ashbya gossypii

Waste activated bleaching earth (ABE) that contained 40% rapeseed oil and was discharged by an oil refinery plant, was used for riboflavin production in a culture of Ashbya gossypii. When 125 g/L waste ABE that contained 50 g/L rapeseed oil was added into the culture, the riboflavin concentration was 1.12 g/L, which was almost 1.6-fold as high as that of pure rapeseed oil. However, in waste ABE concentration higher than 125 g/L, the produced riboflavin concentration decreased, which was due to the difficulty in mixing due to the presence of a high amount of solid material in the culture. The surface of the waste ABE was smooth without a hitch, because of being covered with rapeseed oil. However, after the culture, the surface of the waste ABE seemed like that of new one, and the oil content was nearly zero grams per liter. The waste ABE, oily clay, and its black color gradually fade and yellow little by little, and finally the waste ABE changed to yellow powder. Of the riboflavin produced during the culture, 70% was adsorbed in the oil free waste ABE. With diluted alkali solution, extraction only two times yielded 90% recovery of riboflavin adsorbed in the waste ABE. The waste ABE containing waste vegetable oil was suitable for raw material for production of the value-added useful bioproducts, which might be a good model for reuse of the waste resource.     

Evaluation of triterpenols and sterols as organic matter biomarkers in a mangrove ecosystem in northern Brazil

Mangrove leaves, sediment, and excrementfrom the mangrove crab Ucidescordatus from the coastal areas of theBragança peninsula in North Brazil wereanalysed to determine suitable biomarkersfor mangrove-derived organic matter. Leavesof Rhizophora mangle (red mangrove),the dominant species in the area, werecharacterised by high amounts of-amyrin, germanicol, taraxerol, andlupeol. Avicennia germinans (blackmangrove) mainly contained betulin, lupeol,and -sitosterol, whereas significantquantities of -sitosterol and lupeolwere typical of Laguncularia racemosa(white mangrove), the locally leastabundant species. Except for betulin, theexcrement of U. cordatus containedall of the above substances, but moststrongly reflected the triterpenolsignature of R. mangle leaves, thepredominant diet of this crab. Surfacesediments from various mangrove locationshad relatively uniform compositions thatpossibly reflect tidal mixing. Sedimentextracts were dominated by taraxerol andcontained smaller amounts of-amyrin, germanicol, and lupeol.Only sediments in a marsh area, dominatedby Sporobolus virginicus (seashoredropseed) and Eleocharis sp. (spikerush), revealed a differentbiomarker distribution. Core samples ofsubrecent sediment (up to 4000 ¹⁴C yrBP), for which previous pollen analysisindicated vegetation dominated bymangroves, had compositions similar to thatof the surface sediment. Taraxerol was themain component in the examined mangrovesediments and may be a marker for mangrovematter in this region, although analysis ofplant material did not unequivocallysupport this. Germanicol is suggested to bea biomarker for organic matter from R.mangle in North Brazil. It was detected inolder sediments, and was not significantlyaffected by ingestion by land crabs.     

Surfactant components modulate fibroblast apoptosis and type I collagen and collagenase-1 expression

During lung injury, fibroblasts migrate into the alveolar spaces where they can be exposed to pulmonary surfactant. We examined the effects of Survanta and surfactant protein A (SP-A) on fibroblast growth and apoptosis and on type I collagen, collagenase-1, and tissue inhibitor of metalloproteinase (TIMP)-1 expression. Lung fibroblasts were treated with 100, 500, and 1,000 microg/ml of Survanta; 10, 50, and 100 microg/ml of SP-A; and 500 microg/ml of Survanta plus 50 microg/ml of SP-A. Growth rate was evaluated by a formazan-based chromogenic assay, apoptosis was evaluated by DNA end labeling and ELISA, and collagen, collagenase-1, and TIMP-1 were evaluated by Northern blotting. Survanta provoked fibroblast apoptosis, induced collagenase-1 expression, and decreased type I collagen affecting mRNA stability approximately 10-fold as assessed with the use of actinomycin D. Collagen synthesis and collagenase activity paralleled the gene expression results. SP-A increased collagen expression approximately 2-fold and had no effect on collagenase-1, TIMP-1, or growth rate. When fibroblasts were exposed to a combination of Survanta plus SP-A, the effects of Survanta were partially reversed. These findings suggest that surfactant lipids may protect against intraluminal fibrogenesis by inducing fibroblast apoptosis and decreasing collagen accumulation.