Genes coding for transporters showed a rapid and sharp increase in their expression in response to lead, in the aquatic fern (Salvinia minima Baker).

Salvinia minima was assessed for its ability to accumulate lead (Pb) by exposing it to concentrations of 40µM Pb(NO3)2 during 24h. At the same time, the expression levels were quantified, of four genes coding for transporters: SmABCC (ABCC-MRP), SmATPase (ATPase-P3A), SmNhaD (Type-Na+/H+) and SmABCG (ABCG-WBC). In the absence of lead, S. minima had very low expression of those genes, when plants were exposed to the metal however, those genes showed a rapid (in just three hours or less) and sharp increase (up to 60 times) in their expression, particularly the SmNhaD (Type-Na+/H+) gene. This sharp increase in expression levels of the genes studied, occurred at the same time that the plant accumulated the highest content of lead in its tissues. The first two genes, are apparently implicated in detoxification and lead accumulation mechanisms, while the other two genes are apparently involved in maintaining cell balance (homeostatic control) and membrane integrity. Our results confirmed that S. minima is efficient for phytoremediation of water bodies contaminated by lead, as it is efficient in accumulating this metal in its tissues (bioconcentration factor; BCF) values greater than 1000, in short times of exposure. More importantly, our data on the expression profiles of four genes coding for transporters, represent a first sight scenario of the molecular basis for understanding the different mechanism of detoxification, apparently present in this aquatic fern.

Impact of functional mandibular advancement appliances on the temporomandibular joint - a systematic review.

BACKGROUND: Although many orthodontists have no doubts about the effectiveness of functional appliances for mandibular advancement, the impact on the temporomandibular joint (TMJ) is still in dispute. The objective of this systematic review is to examine the main effects on the TMJ of using functional appliances, both in healthy patients and in patients with a pre-existing disorder. MATERIAL AND METHODS: A systematic review of the literature was conducted in accordance with the PRISMA guidelines. Only systematic reviews, meta-analyses, randomized clinical trials (RCTs), case-control studies and cohort studies were included. A detailed language-independent electronic search was conducted in the Pubmed, Scopus, Cochrane Library and Embase databases. All studies published between 2000 and 2015 were included. RESULTS: A total of 401 articles were identified. Of these, 159 were duplicates and were excluded. On reading the title and abstract, 213 articles were excluded because they did not answer the research question, leaving a total of 29 articles. These articles were read and assessed. Following critical reading of the full text, eight articles were excluded: seven because they were considered of low quality and one because it published redundant data. As a result, 21 articles were included. CONCLUSIONS: After treatment with functional appliances, the condyle was found to be in a more advanced position, with remodelling of the condyle and adaptation of the morphology of the glenoid fossa. No significant adverse effects on the TMJ were observed in healthy patients and the appliances could improve joints that initially presented forward dislocation of the disk.

MiR-320e is a novel prognostic biomarker in colorectal cancer.

BACKGROUND: Advances in early detection and treatment have improved outcomes in patients with colorectal cancer (CRC). However, there remains a need for robust prognostic and predictive biomarkers. We conducted a systematic discovery and validation of microRNA (miRNA) biomarkers in two clinical trial cohorts of CRC patients. METHODS: We performed an initial 'discovery' phase using Affymetrix miRNA expression arrays to profile stage III CRC patients with and without tumour recurrence (n=50 per group) at 3-years of follow-up. All patients received adjuvant 5-fluorouracil (5-FU) plus oxaliplatin, that is, FOLFOX, treatment. During 'validation', we analysed miRNAs using qRT-PCR in an independent cohort of 237 stage II-IV CRC patients treated with 5-FU-based chemotherapy, as well as in normal colonic mucosa from 20 healthy subjects. Association with disease recurrence, disease-free survival (DFS) and overall survival (OS) was examined using Cox proportional hazard models. RESULTS: In the discovery cohort, miR-320e expression was significantly elevated in stage III colon cancers from patients with vs without recurrence (95% confidence interval (CI)=1.14-1.42; P<0.0001). These results were then independently validated in stage II and III tumours. Specifically, increased miR-320e expression was associated with poorer DFS (hazard ratio (HR)=1.65; 95% CI=1.27-2.13; P=0.0001) and OS (HR=1.78; 95% CI=1.31-2.41; P=0.0003) in stage III CRC patients. CONCLUSIONS: In two clinical trial cohorts, a systematic biomarker discovery and validation approach identified miR-320e to be a novel prognostic biomarker that is associated with adverse clinical outcome in stage III CRC patients treated with 5-FU-based adjuvant chemotherapy. These findings have important implications for the personalised management of CRC patients.

Transcriptome analysis reveals key defense-related genes upon SA induction in Cocos nucifera L.

BACKGROUND: Salicylic acid (SA) is an important regulator of genes involved in plant defense and pathogen-triggered systemic acquired resistance (SAR). Coconut is an important crop affected by several pathogens. Reported evidence suggests SA involvement in defense responses, including SAR in coconut. OBJECTIVE: To identified differentially expressed genes in leaf and root tissues of coconut plantlets, as a result of SA, that might be involved in coconut defense responses. METHODS: Comparative transcriptomic analysis by RNA-Seq of leaf and root tissues from in vitro coconut plantlets unexposed and exposed to SA 2.5 mM for 48 h. And in silico validation of gene expression by qRT-PCR. RESULTS: We identified 4615 and 3940 differentially expressed unigenes (DEUs) in leaf and root tissues respectively. Our GO analysis showed functional categories related to the induction of defense responses, such as "systemic acquired resistance" and highly enriched hormone categories, such as abscisic acid. The most abundant KEGG pathway in our results was "Biosynthesis of antibiotics". Our findings support that exogenous application of SA to plantlets induced the activation of PRs, RGAs, ICS2, NLTP2, PER4, TRXM and some WRKYs mediated by NPR1-dependent pathways. Also, we found DEUs, such as BZR1, HSL1, and WHY2 that support that SA could regulate defense-related genes through NPR1-independent pathways. CONCLUSION: The present study of massive data analysis carried out on coconut plantlets exposed to SA, generates valuable information that increases our understanding of defense molecular mechanisms in coconut and open new venues for research for the improvement of management of coconut diseases.

Detection of 16SrIV-A phytoplasma DNA in Colpoptera sp. (Hemiptera: Nogodinidae) insects in Yucatan Peninsula, Mexico.

Lethal yellowing (LY) is a disease that affects coconut and other palm species. It is associated to phytoplasmas of the group 16SrIV and the only reported insect vector for this pathogen so far is Haplaxius crudus. H. crudus is present in Mexico and has been associated to 16SrIV phytoplasmas, however, it was not detectable during a LY outbreak in the coast of Yucatan, Mexico, suggesting the existence of other vector species. To test this hypothesis a survey of insects was carried out and a total of 3074 insects were captured during a year of monthly sampling. Ten taxonomic orders were identified in this sample, Hemiptera being the most abundant (N=2094), and these were classified into nine families. The leafhopper Colpoptera sp. from to the Nogodinidae family was de most abundant representing 56% of the total number of insects sampled and 23% of these samples resulted positive for LY phytoplasma by PCR detection. The BLAST comparison, virtual RFLP and phylogenetic analyses of the sequenced amplicons relate the detected phytoplasma to the subgroup 16SrIV-A. The findings presented herein suggest that Colpoptera sp. could be considered as a new putative vector of the LY-causing phytoplasmas in Mexico and a candidate for further research.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico.

Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Regulation of α2-adrenoceptor gene expression by chronic lithium treatment in rat brain.

One of the approaches for the treatment of bipolar disorder involves the coadministration of lithium, a mood stabilizer, with α2-adrenoceptor antagonists possessing an antidepressant effect. Since lithium accelerates the recovery of α2(D)-adrenoceptors following their irreversible inactivation with N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), our aim was to examine if it could be to some changes in Adra2A gene expression which codifies these adrenoceptors. Animals were treated with lithium chloride (120 mg/kg i.p.) or saline once a day for 10 days. A group of lithium- or saline-treated rats was killed 48 h after the last injection. The remaining animals were treated with EEDQ and were killed at 0.25, 4 and 14 days following this administration. Total RNA was extracted from cerebral cortex and Adra2A gene expression was measured by RT-QPCR. The results show that chronic lithium raised the Adra2A gene expression (P < 0.05), and after EEDQ administration this expression decreased to the basal level. No change in Adra2A gene expression was detected in the saline-treated group. However, EEDQ administration produced an insignificant increase in α2-adrenoceptors mRNA levels followed by a progressive decrease until basal levels. Lithium produced an overexpression of the Adra2A gene after chronic treatment that made the neuron ready to produce α2-adrenoceptors to deal with their inactivation.

[Sleep-disordered breathing as a consequence of vagus nerve stimulation]. / Alteraciones respiratorias durante el sueño a consecuencia de la estimulación del nervio vago.

INTRODUCTION: Vagus nerve stimulation (VNS) is indicated in cases of refractory epilepsy. Its side effects are frequently minor, however, breathing disturbances during sleep have been previously reported. CASE REPORTS: Our three cases are representative of sleep-disordered breathing that occurred as a consequence of VNS activity in patients with refractory epilepsy. Sleep apnoea was observed in two patients and stridor in one patient. CONCLUSIONS: Given the high prevalence of sleep apnoea-hypopnoea syndrome in patients with refractory epilepsy, implantation of VNS should be ideally preceded by an assessment of the breathing during sleep. Furthermore, sleep-disordered breathing should be considered as a rare complication of VNS, and sleep apnoea should be investigated alongside data regarding VNS firing.

TITLE: Alteraciones respiratorias durante el sueño a consecuencia de la estimulación del nervio vago.Introducción. La estimulación del nervio vago (ENV) es una terapia utilizada en casos de epilepsia refractaria. Sus efectos secundarios son, con frecuencia, leves; sin embargo, se han descrito previamente alteraciones respiratorias durante el sueño. Casos clínicos. Los tres casos incluidos son representativos de alteraciones respiratorias durante el sueño (apnea del sueño y estridor) que surgen a consecuencia de la actividad de la ENV. Conclusiones. Dada la elevada prevalencia del síndrome de apnea/hipopnea durante el sueño en pacientes con epilepsia refractaria, debería estudiarse su posible preexistencia en candidatos a ENV y considerarse su potencial aparición como consecuencia de la ENV en el seguimiento de pacientes con ENV activa.

[Sleep-related movement and behavioural disorders in adults]. / Trastornos del movimiento y de la conducta durante el sueño en el adulto.

Sleep-related movement and behaviour disorders may have an impact on sleep quality and lead to daytime symptoms. These groups of conditions include diseases such as restless legs syndrome, periodic leg movements, and REM and NREM parasomnias. The knowledge of their clinical features and management is of utmost importance for the neurologist and sleep specialist. Frequently, these patients are referred to such specialists and it is relevant to know that certain sleep disorders may be associated with other neurological conditions.

TITLE: Trastornos del movimiento y de la conducta durante el sueño en el adulto.Los trastornos del movimiento y de la conducta durante el sueño pueden tener un impacto en la calidad del sueño del paciente y dar lugar a síntomas diurnos. En estos grupos de enfermedades se incluyen entidades como el síndrome de piernas inquietas, los movimientos periódicos de las piernas y las parasomnias del sueño de movimientos oculares rápidos (REM) y no REM. El conocimiento de sus características clínicas y nociones sobre su manejo es de gran importancia para el neurólogo y especialista en sueño por su frecuencia e impacto en la calidad del sujeto. Con frecuencia, estos pacientes son referidos a dichos especialistas, y es relevante conocer que ciertos trastornos del sueño pueden asociarse a otras enfermedades neurológicas.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico

Abstract Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Resumo Isla Arena está localizada na coordenada 20°70N - 90°45W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.

Identification by molecular techniques of halophilic bacteria producing important enzymes from pristine area in Campeche, Mexico / Identificação por técnicas moleculares de bactérias halofílicas que produzem enzimas importantes em área intocada de Campeche, México

Abstract Isla Arena is located in the coordinate 20° 70´ N - 90° 45´ W, from Campeche, Mexico. In these estuaries, the ocean mixes with fresh water, and ecosystems are concentrated where petenes and pink flamingos proliferate. Crustaceans and mollusks abound in the sea. Despite its enormous marine wealth, there are no studies carried out on which halophilic microorganisms are present in these waters. In this work, the diversity and structure of the microbial community was investigated through a metagenomics approach and corroborated for sequencing of 16S rRNA genes. It was found that the phylum Fimicutes predominates with more than 50%, in almost the same proportion of the class Bacilli and with almost 41% of relative abundance of the order Bacillales. The sequencing results showed that one of the samples presented a high percentage of similarity (99.75%) using the Nucleotide BLAST program with a peculiar microorganism: Bacillus subtilis. This microorganism is one of the best characterized bacteria among the gram-positive ones. Our results demonstrate that B. subtilis can be an efficient source of proteases, lipases and cellulases, from halophilic microbial communities located in poorly explored areas.

Resumo Isla Arena está localizada na coordenada 20°70'N - 90°45'W, de Campeche, México. Nesses estuários, o oceano se mistura com a água doce e os ecossistemas se concentram onde proliferam petenos e flamingos rosa. Crustáceos e moluscos abundam no mar. Apesar de sua enorme riqueza marinha, não há estudos realizados sobre a presença de microrganismos halofílicos nessas águas. Neste trabalho, a diversidade e estrutura da comunidade microbiana foram investigadas através de uma abordagem metagenômica e corroboradas para o sequenciamento de genes 16S rRNA. Verificou-se que o filo Fimicutes predomina com mais de 50%, quase na mesma proporção da classe Bacilli e com quase 41% de abundância relativa da ordem Bacillales. Os resultados do sequenciamento mostraram que uma das amostras apresentou alto percentual de similaridade (99,75%) pelo programa Nucleotide BLAST com um microrganismo peculiar: Bacillus subtilis. Nossos resultados demonstram que B. subtilis pode ser uma fonte eficiente de proteases, lipases e celulases, provenientes de comunidades microbianas halofílicas localizadas em áreas pouco exploradas.

Identification of up-regulated genes from the metal-hyperaccumulator aquatic fern Salvinia minima Baker, in response to lead exposure.

Lead (Pb) is one of the most serious environmental pollutants. The aquatic fern Salvinia minima Baker is capable to hyper-accumulate Pb in their tissues. However, the molecular mechanisms involved in its Pb accumulation and tolerance capacity are not fully understood. In order to investigate the molecular mechanisms that are activated by S. minima in response to Pb, we constructed a suppression subtractive hybridization library (SSH) in response to an exposure to 40µM of Pb(NO3)2 for 12h. 365 lead-related differentially expressed sequences tags (ESTs) were isolated and sequenced. Among these ESTs, 143 unique cDNA (97 were registered at the GenBank and 46 ESTs were not registered, because they did not meet the GenBank conditions). Those ESTs were identified and classified into 3 groups according to Blast2GO. In terms of metabolic pathways, they were grouped into 29 KEGG pathways. Among the ESTs, we identified some that might be part of the mechanism that this fern may have to deal with this metal, including abiotic-stress-related transcription factors, some that might be involved in tolerance mechanisms such as ROS scavenging, membrane protection, and those of cell homeostasis recovery. To validate the SSH library, 4 genes were randomly selected from the library and analyzed by qRT-PCR. These 4 genes were transcriptionally up-regulated in response to lead in at least one of the two tested tissues (roots and leaves). The present library is one of the few genomics approaches to study the response to metal stress in an aquatic fern, representing novel molecular information and tools to understand the molecular physiology of its Pb tolerance and hyperaccumulation capacity. Further research is required to elucidate the functions of the lead-induced genes that remain classified as unknown, to perhaps reveal novel molecular mechanisms of Pb tolerance and accumulation capacity in aquatic plants.

Pulsed electric fields versus thermal treatment: equivalent processes to obtain equally acceptable citrus juices.

Pulsed electric field treatment has been claimed to produce more acceptable chilled citrus juices than those obtained by conventional thermal treatment. The pectin methylesterase activity and the acceptability of nine juices obtained from Clementine mandarins, Valencia oranges, and Ortanique fruits (hybrid of mandarin and orange), untreated, pasteurized (85 degrees C for 10 s), and treated by pulsed electric fields (25 kV/cm for 330 micros), were evaluated. The treatments, selected to reach a similar level of pectin methylesterase inactivation, produced juices that did not differ in acceptability from each other for the three varieties and in all cases were less acceptable than the untreated juice.

Antioxidant and antibacterial activities of natural extracts: application in beef meatballs.

The antioxidant and antibacterial effect of rosemary, orange and lemon extracts was investigated in cooked Swedish-style meatballs. Activity in a lard system was established for all the extracts and further determination of the development of rancidity as thiobarbituric acid reactive substances consistently showed that about 50% of the rancidity can be controlled by the citrus preparations. Two of the rosemary extracts (water soluble and oil soluble) were more effective with practically complete elimination of rancidity (TBA values) after a period of 12 days. Rosemary extract activity against lactic acid bacteria and Listeria but not Brochothrix thermosphacta was demonstrated in an agar diffusion test, but in the product only lactic acid bacteria counts were slightly reduced. Sensory analysis results, particularly aroma and acceptability scores, indicated the significant advantages in using rosemary and citrus extracts in rancidity-susceptible meat products.

Effect of suckling on plasma prolactin and hypothalamic monoamine levels in the rat.

In lactating rats that were separated from their pups for 8 hours, suckling induced a rapid rise in plasma prolactin levels. Correlatively, it induced a depletion in dopamine (DA) and serotonin (5-HT) Concentrations within the hypothalamus as early as 5 min after the onset of suckling. This depletion lasted as long as the stimulus was maintained. A parallel increase in the level of the metabolite of 5-HT, 5-hydroxyindolacetic acid (5-HIAA), was observed. Under these conditons, the ratio of 5-HIAA/5-HT is augmented. This ratio is a good index of turnover of the transmitter. Suckling affected neither the content of noradrenaline (NA) in the hypothalamus nor the levels of any amine tested in the cerebral cortex. When pups were separated from their mother for 24 hours, suckling no longer resulted in changes in either plasma prolactin levels or hypothalamic DA, 5-HT, or 5-HIAA concentrations. We have concluded that the activation of a discrete system of 5-HT containing neurons is associated with the triggering effect of suckling on prolactin release.

Role of nitric oxide on papillary blood flow and pressure natriuresis.

This study examined whether nitric oxide synthesis blockade or potentiation (with N omega-nitro-L-arginine methyl ester [L-NAME] or N-acetylcysteine, respectively) can shift the relations between sodium excretion, papillary blood flow, and renal perfusion pressure. Papillary blood flow was measured by laser Doppler flowmetry. A low dose of L-NAME (3.7 nmol/kg per minute) reduced papillary blood flow only at high arterial pressure (140 mm Hg), but it had no effect on pressure natriuresis. Infusion of 37 nmol/kg per minute L-NAME reduced cortical blood flow by 9% at all perfusion pressures studied, lowered papillary blood flow by 8% and 19% at 120 and 140 mm Hg, respectively, and blunted the pressure-natriuresis response. The administration of 185 nmol/kg per minute L-NAME reduced cortical blood flow by 30% and decreased papillary blood flow by 25% in the range of 100 to 140 mm Hg of arterial pressure. Blockade of nitric oxide synthesis with L-NAME at all doses studied reduced papillary blood flow only at high renal perfusion pressures, but papillary blood flow remained essentially unchanged at low perfusion pressures, thus restoring papillary blood flow autoregulation. N-Acetyl-cysteine (1.8 mmol/kg) increased papillary blood flow by 9% and shifted the relations between papillary blood flow, sodium excretion, and renal perfusion pressure toward lower pressures. This effect of N-acetylcysteine on papillary blood flow was blocked by subsequent L-NAME administration.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of a kinin antagonist on mean blood pressure.

Administration of high doses of a kinin antagonist produces an increase in blood pressure. Thus, endogenous kinins may be involved in the regulation of blood pressure. Kinins can induce the release of vasoactive substances such as catecholamines, renin, vasopressin, histamine, and prostaglandins. To determine whether the blood pressure changes induced by high doses of kinin antagonist are due to agonistic activity mediated by these vasoactive substances, we studied the effect on blood pressure of a kinin antagonist (DArg0-Hyp3-Thi5,8-DPhe7-bradykinin) administered to control, nephrectomized, and adrenalectomized rats, and to rats treated with vasopressin V1-receptor antagonist, ganglionic and alpha- and beta-adrenergic receptor blockers (either separately or combined), histamine H1- and H2-receptor blockers, and indomethacin, a prostaglandin synthesis inhibitor. Blood pressure changes were monitored on awake, restrained rats. In the control rat, the kinin antagonist injected as a bolus (4 mg/kg) into the ascending aorta produced a transient biphasic blood pressure response, first a pressor effect (delta BP = 7 +/- 1 mm Hg; p less than 0.05), then a depressor effect (delta BP = -20 +/- 6 mm Hg; p less than 0.05). The pressor response to the kinin antagonist was not affected by any of the treatments; however, the depressor effect of the kinin antagonist appeared to be caused by the release of vasodilator prostanoids from the kidney, since it was not observed in the nephrectomized rats or in those treated with indomethacin. The pressor effect induced by the kinin antagonist suggests that kinins may contribute to the regulation of blood pressure.

Effect of a kinin antagonist on the acute antihypertensive activity of enalaprilat in severe hypertension.

The purpose of this study was to assess the role of kinins in the acute antihypertensive effect of the converting enzyme inhibitor (CEI) enalaprilat in rats with severe hypertension induced by aortic ligation between both renal arteries. For this study, we used a bradykinin analogue, D-Arg-Arg-Pro-Hyp-Gly-Thi-Ser-DPhe-Thi-Arg-TFA, with in vivo antagonistic properties. Hypertensive rats were infused intra-aortically for 15 minutes with either saline (30 microliters/min) or the kinin antagonist (40 micrograms/kg/min). Five minutes after the infusion was begun, a bolus injection of enalaprilat (60 micrograms/kg) was given. The blood pressure of the saline-infused animals decreased 48 +/- 6 mm Hg (from 180 +/- 7 to 132 +/- 7 mm Hg), while that of the rats treated with the antagonist decreased only 21 +/- 4 mm Hg (from 175 +/- 3 to 154 +/- 3 mm Hg). The difference between both decrements was significant (p less than 0.01). In another group of hypertensive animals (n = 9), we measured kinin concentration in plasma from arterial blood before and after administration of CEI (41 +/- 10 vs 68 +/- 20 pg/ml, respectively; NS). These results are consistent with the hypothesis that kinins play a role in the acute antihypertensive effect of CEIs in rats with severe hypertension. However, since arterial blood kinin concentrations were not increased significantly after CEI administration, the effect of the CEI may be due to an increase in tissue kinins, which could act as autacoids regulating vascular resistance.

Synthesis of a gene coding for an insect-specific scorpion neurotoxin and attempts to express it using baculovirus vectors.

We have explored the possibility of improving baculovirus pesticides by incorporating an insect-specific neurotoxin gene into a baculovirus genome. A 112-bp gene (BeIt) encoding insectotoxin-1 of the scorpion Buthus eupeus was synthesized and cloned in Escherichia coli. For expression, BeIt was transferred to the DNA genome of Autographa californica nuclear polyhedrosis virus (AcMNPV). Three different recombinant AcMNPVs, carrying BeIt under the control of the strong AcMNPV polyhedrin promoter, were constructed and expression of BeIt was monitored upon infection of Spodoptera frugiperda (Sf) cells. Toxin expression was low using a recombinant virus in which BeIt was inserted 6 nucleotides (nt) downstream from the intact polyhedrin mRNA leader. More expression was observed when a signal-peptide was attached in-frame to the N terminus of BeIt. The highest level of expression was observed with a fusion gene comprised of the 58 N-terminal codons of polyhedrin fused to BeIt; however, the level of expression was ten- to twenty-fold below that for polyhedrin. Polyhedrin promoter-directed transcripts of all three recombinants accumulated to levels similar to those of wild-type polyhedrin transcripts, indicating that the limitation to expression of unfused BeIt was not at the level of transcription but rather at the posttranscriptional level including translation or protein stability. Paralytic activity of the toxin products was not detected.

Protective effect of N-acetyl-L-cysteine on the renal failure induced by inferior vena cava occlusion.

BACKGROUND: Renal ischemia is produced during orthotopic liver transplantation when the inferior vena cava is clamped above the renal veins (inferior vena cava occlusion [IVCO]), and it often leads to postoperative renal failure. Although free radicals and nitric oxide (NO) have been implicated in the pathogenesis of ischemic renal failure, the effect of free radical scavengers in this model is unknown. METHODS: The effects of N-acetyl-L-cysteine (NAC), a free radical scavenger, on the acute renal failure that follows IVCO were evaluated in pentobarbital-anesthetized dogs. The effect of NO synthesis inhibition with NG-nitro-L-arginine methyl ester (NAME) was also studied. Renal vascular endothelial function was tested by infusing acetylcholine (Ach) into the renal artery before the ischemia and during reperfusion. RESULTS: Renal failure developed during IVCO and persisted during reperfusion in all groups. However, in NAC-pretreated dogs, the glomerular filtration rate recovered progressively, reaching 31% of basal preischemic values 150 min after reperfusion. During reperfusion, fractional excretion of sodium increased above preischemic values only in the control group, which indicates a beneficial effect of NAC and NAME on the tubular dysfunction observed during reperfusion. The renal response to Ach was abolished in control dogs and in animals given NAME during reperfusion, which indicates endothelial dysfunction. However, in NAC-pretreated dogs, the renal response to Ach was preserved during reperfusion. CONCLUSIONS: These results demonstrate that NAC ameliorates the renal failure and renal endothelial dysfunction induced by IVCO. This protective effect was abolished by NAME, which suggests that NO is involved in the beneficial effects of NAC. These data also suggest that the use of NAC could be beneficial in ameliorating the acute renal failure observed after orthotopic liver transplantation.