Partial sequences of the gene that codifies for the transcription factor VPHSFB1 in Vasconcellea pubescens: First report / Secuencias parciales del gen que codifica para el factor de transcripción VPHSFB1 en Vasconcellea pubescens: Primer reporte

Plant heat stress transcription factors (HSFs) are involved in the response to heat. In Arabidopsis thaliana the HSFs genes are completely identified, however there was no information available about these genes in Vasconcellea pubescens (Chamburo) until now. In this preliminary work we describe the VPHSFB1 gene of V. pubescens (gene expression evaluated by RT-PCR and the partial sequence) that was induced by the increment of temperature. From our results, VPHSFB1 could be used as a heat response marker gene in tropical species.

Los factores de transcripción del estrés por calor en plantas (HSFs) están involucrados en la respuesta al calor. En Arabidopsis thaliana los genes HSFs están completamente identificados, sin embargo no había información disponible sobre estos genes en Vasconcellea pubescens (Chamburo) hasta ahora. En este trabajo preliminar describimos el gen VPHSFB1 de V. pubescens (expresión génica evaluada por RT-PCR y la secuencia parcial) que fue inducido por el incremento de temperatura. A partir de nuestros resultados, se podría usar a VPHSFB1 como un gen marcador de respuesta a calor en especies tropicales.

Changes in the response to excitatory antagonists, agonists, and spasmolytic agents in circular colonic smooth muscle strips from patients with diverticulosis.

BACKGROUND: Colonic samples from asymptomatic diverticulosis (DS) patients presented enhanced electrical field stimulation (EFS)-contractions, in an earlier study of ours, suggesting increased endogenous responses. The aim of this study was to explore changes in excitatory neuromuscular transmission and to assess the pharmacodynamics of spasmolytic agents in DS. METHODS: Circular muscle strips from sigmoid colon of DS patients (n = 30; 69.5 ± 14.8 years) and controls (n = 32; 64.7 ± 16.2 years) were studied using organ baths to evaluate the direct effect of excitatory agonists (carbachol, neurokinin A [NKA] and substance P [SP]), and the effect of antagonists (atropine and NK2 antagonist GR94800) and spasmolytic drugs (otilonium bromide [OB] and N-butyl-hyoscine) on the contractions induced by EFS-stimulation of excitatory motorneurons. qRT-PCR was also performed to compare mRNA expression of M2 , M3 , NK2 receptors and L-type calcium channels. KEY RESULTS: Contractions to carbachol (Emax : 663.7 ± 305.6% control vs 2698.0 ± 439.5% DS; p < 0.0005) and NKA (Emax : 387.8 ± 35.6% vs 1102.0 ± 190.1%; p < 0.0005) were higher in DS group, without differences for SP. Higher potency for DS patients was observed in the concentration-response curves for atropine (pIC50  = 8.56 ± 0.15 control vs pIC50  = 9.95 ± 0.18 DS group; p < 0.005) and slightly higher for GR94800 (pIC50  = 7.21 ± 0.18 control vs pIC50  = 7.97 ± 0.32 group; p < 0.0001). Lower efficacy (Emax ) and potency (pIC50 ) was observed for spasmolytic drugs in DS, whereas no differences were found regarding the relative expression of the receptors evaluated between groups. CONCLUSIONS & INFERENCES: The greater response to cholinergic and tachykinergic agonists and greater potency for muscarinic and NK2 antagonists observed in DS might play a role in the spasticity found in diverticular disease.

Mast cell degranulation inhibits motor patterns of human ileum and sigmoid colon in vitro: relevance for postoperative ileus.

BACKGROUND: Local release of mast cell proteases during gastrointestinal surgery is associated with the inhibition of motility and postoperative ileus (POI). We determined whether activation of intramuscular mast cell affects the motor patterns of the human ileum and colon and whether proteases are involved. METHODS: Motor response of ileal and colonic circular muscle strips was measured in organ bath. Mast cell degranulation was induced by compound 48/80 (c48/80; 25-675 µg/mL). Motor response was quantified as tone, rhythmic phasic contractions (RPCs) and contractions to electric field stimulation (EFS; 40 Hz), and bethanechol-evoked contractions. Ketotifen (10(-6) mol/L) and a protease inhibitor cocktail (P8340) were used to evaluate the role of mast cell mediators. KEY RESULTS: (a) c48/80 impaired the spontaneous and the electrically evoked motor response in small bowel and colonic strips (sigmoid colon EC50 : 460.0 µg/mL for RPCs and 8.9 µg/mL for electrically evoked contraction amplitudes) and bethanechol-evoked contractions. (b) Preincubation with ketotifen (10(-6) mol/L, 1 h) prevented the impairment of RPCs and EFS-evoked contractions in the sigmoid colon and ileum but not in the right colon. (c) Preincubation with P8340 also prevented the impairment of contractions in the sigmoid colon but not in the ileum or the right colon. CONCLUSIONS & INFERENCES: Mast cell degranulation by c48/80 inhibits the spontaneous and the nerve-mediated motor response in the human ileum and colon. The effect is partially mediated by mast cell proteases and could be relevant in the pathophysiology of POI.

Nitrergic neuro-muscular transmission is up-regulated in patients with diverticulosis.

BACKGROUND: Neuro-transmission impairment could be associated to motility changes observed in patients with diverticular disease. Therefore, the objective was to characterize the inhibitory neuro-muscular transmission and gene expression changes of the enteric inhibitory pathways in patients with diverticulosis (DS). METHODS: Circular muscle strips from sigmoid colon of patients with DS and controls were studied using the organ bath technique to evaluate spontaneous contractility and enteric motor neurons stimulated by electrical field and qRT-PCR to assess the expression of nNOS, iNOS, P2Y1 R and PGP9.5. KEY RESULTS: Patients with DS presented decreased spontaneous rhythmic contractions (SRC) that were significantly enhanced after incubation with L-NNA (1 mM) and TTX (1 µM), and unaffected by the P2Y1 antagonist MRS2500 (1 µM). Stimulation on enteric motor neurons caused an increased duration of the latency of OFF-contractions in DS group (p < 0.001), antagonized by L-NNA and slightly affected by MRS2500 (1 µM). No differences in the IC50 between controls and DS patients were observed on inhibition of SRC for the NO-donor sodium nitroprusside (SNP) and the preferential P2Y agonist ADPßS. Moreover, nNOS relative expression was also up-regulated 2.3-fold in the DS group (p < 0.05) whereas there was no significant difference in relative expression of iNOS, P2Y1 R and the neuronal marker PGP9.5 between groups. CONCLUSIONS & INFERENCES: Patients with DS presented an over-expression of nNOS with increased endogenously NO-mediated responses suggesting enhanced NO-release. Up-regulation in the nitrergic pathway in early stages of the disease might play a role in colonic motor disorders associated to diverticular disease.

Metastatic lymph node ratio versus number of metastatic lymph nodes as a prognostic factor in gastric cancer.

OBJECTIVE: Knowledge of prognostic factors in gastric cancer is essential to decide on single patient management. We aim to establish the value of lymph node ratio compared to lymph node involvement in the prediction of gastric cancer survival and treatment approach. METHODS: Charts of ninety-six consecutive patients undergoing gastrectomy for resectable gastric cancer were reviewed between January 1996 and December 2005. Receiver operating characteristic (ROC) curves were plotted to verify the accuracy of metastatic lymph node ratio (MLNR) and number of metastatic lymph node (NMLN) cut-off values for survival prediction. Patients were divided into two groups according to ROC curve cut-offs and accuracy in prognosis was reviewed. RESULTS: ROC curves showed that 5 metastatic nodes and a node ratio value of 20% had the best survival prognostic correlation. The median survival of patients with MLNR and NMLN were similar according to cut-off determinations (≤ 5/> 5 metastatic nodes and ≤20/>20% lymph node ratio). Five-year survival rates were 70.9% vs 17.1% and 72.4% vs 15.6%, respectively (p < 0.001). Positive correlation coefficient was found between the number of excised nodes and the number of metastatic nodes. CONCLUSION: Number of metastatic lymph nodes showed greater accuracy than lymph node ratio for survival prediction in gastric cancer.

¿Es el diámetro ganglionar mayor un factor pronóstico en cáncer gástrico? / Large lymph node size harvested as prognostic factor in gastric cancer?

Objetivo: valorar el interés del diámetro del ganglio mayor extirpadocomo factor pronóstico en los pacientes intervenidos porcáncer gástrico, para determinar si su detección puede ser un factorde interés en el periodo preoperatorio, para indicar tratamientoneoadyuvante.Material y métodos: se analiza un registro de 128 casos consecutivosde pacientes afectos de adenocarcinoma gástrico resecable,durante un periodo de 10 años en los que en el estudio anatomopatológicose determinó el diámetro del ganglio mayor aislado.Se estudia la relación del mismo con factores pronósticos universalmenteaceptados, el grado de penetración, la presencia y extensiónde metástasis ganglionares y el estadio TNM, y con la supervivenciaa 5 años, estudiándose dos grupos, el grupo I compuesto por aquellosenfermos con diámetro menor o igual a 10 mm, y el grupo IIcon diámetros superiores a 10 mm.Resultados: no se han detectado diferencias estadísticas respectoa edad y sexo (67,4 vs. 64; p = 0,34 y 66,1 vs. 68,1%; p =0,27, respectivamente). Existen diferencias significativas entreambos grupos en el grado de penetración tumoral, T1-T2,(78,1% por 39,1%, p < 0,001), en el porcentaje de pacientes sinmetástasis ganglionares (62,7 vs. 30,5%; p < 0,001), así comoen el porcentaje de estadios precoces (Ia y Ib, 57,6% por 17,4, p< 0,001). La supervivencia global acumulada a los 60 meses fuesignificativa entre ambos grupos (p log-rank = 0,0003), aunquesin alcanzar significación estadística en los pacientes N+ (p <0,006).Conclusiones: la relación del diámetro ganglionar mayorpuede ser un factor pronóstico útil y junto con otros factores pronósticosfacilitaría la valoración de quimioterapia neoadyuvante.Su detección mediante exploraciones complementarias adquiriríapor consiguiente un mayor interés(AU)

Objective: knowledge regarding prognostic factors in gastriccancer is essential to decide on single patient management. Weaim to establish the value of large lymph node size in order to improveperioperative approach.Material and methods: charts of one hundred and twentyeightconsecutive patients undergoing gastrectomy for resectablegastric cancer were reviewed between January 1996 and December2005. Patients were split in two groups according to largelymph node size harvested, group I, lymph node size <= 10 mmand group II, lymph node size > 10 mm. Overall five-year survivalrelated to cancer were analyzed as a main endpoint. Prognosticfactors as TNM classification and degree of differentiation havebeen considered.Results: there were no differences regarding age and gender(67.4 vs. 64; p = 0.34 and 66,1 vs. 68,1%; p = 0.27, respectively).Nevertheless, a significant difference has been found accordingto T1-T2 of TNM stage (78.1 vs. 39.1% p = < 0.001), for Ngrade staging, has statistical signification for grade N0 (62.7 vs.30.5%; p < 0.001), and for Ia and Ib stages (57.6 vs. 17.4%).Five years overall survival has a great statistical signification (p logrank= 0.0003), however, overall survival between groups withpositive lymph nodes according to lymph node size was close tosignification, (p log-rank = 0.0636).Conclusions: our data indicates that large lymph node sizecould be a powerful predictor for overall survival in gastric cancer,when it could be evaluated in preoperative period. In our opinionlymph node size should be considered for perioperativechemotherapy schemas. Detection and staging techniques forlymph node affection acquire much more importance(AU)

Effects of excitatory and inhibitory neurotransmission on motor patterns of human sigmoid colon in vitro.

BACKGROUND AND PURPOSE: To characterize the in vitro motor patterns and the neurotransmitters released by enteric motor neurons (EMNs) in the human sigmoid colon. EXPERIMENTAL APPROACH: Sigmoid circular strips were studied in organ baths. EMNs were stimulated by electrical field stimulation (EFS) and through nicotinic ACh receptors. KEY RESULTS: Strips developed weak spontaneous rhythmic contractions (3.67+/-0.49 g, 2.54+/-0.15 min) unaffected by the neurotoxin tetrodotoxin (TTX; 1 microM). EFS induced strong contractions during (on, 56%) or after electrical stimulus (off, 44%), both abolished by TTX. Nicotine (1-100 microM) inhibited spontaneous contractions. Latency of off-contractions and nicotine responses were reduced by N(G)-nitro-L-arginine (1 mM) and blocked after further addition of apamin (1 microM) or the P2Y(1) receptor antagonist MRS 2179 (10 microM) and were unaffected by the P2X antagonist NF279 (10 microM) or alpha-chymotrypsin (10 U mL(-1)). Amplitude of on- and off-contractions was reduced by atropine (1 microM) and the selective NK(2) receptor antagonist Bz-Ala-Ala-D-Trp-Phe-D-Pro-Pro-Nle-NH(2) (1 microM). MRS 2179 reduced the amplitude of EFS on- and off-contractions without altering direct muscular contractions induced by ACh (1 nM-1 mM) or substance P (1 nM-10 microM). CONCLUSIONS AND IMPLICATIONS: Latency of EFS-induced off-contractions and inhibition of spontaneous motility by nicotine are caused by stimulation of inhibitory EMNs coreleasing NO and a purine acting at muscular P2Y(1) receptors through apamin-sensitive K(+) channels. EFS-induced on- and off-contractions are caused by stimulation of excitatory EMNs coreleasing ACh and tachykinins acting on muscular muscarinic and NK(2) receptors. Prejunctional P2Y(1) receptors might modulate the activity of excitatory EMNs. P2Y(1) and NK(2) receptors might be therapeutic targets for colonic motor disorders.