Comparative toxicity, phytochemistry, and use of 53 Philippine medicinal plants.

The study compares the toxicity of 53 selected medicinal plants commonly used in the Philippines to treat various diseases. It uses as a benchmark Vitex negundo L., which was approved by the Philippine Food and Drug Administration as an herbal drug for cough and asthma after passing clinical trials for safety and efficacy. The methods were chosen for their simplicity and accessibility even for resource-limited laboratories. Extracts (95 % ethanol) of the medicinal parts of the plants were (1) chemically profiled using qualitative phytochemical tests that detect the presence of key classes of bioactive compounds; and (2) evaluated for toxicity using the brine shrimp (Artemia sp.) lethality assay (BSLA). General phytochemical screening revealed the presence of tannins in 50 plant extracts, alkaloids in 43, glycosides in 33, flavonoids in 31, steroids in 21, triterpenoids in 20, anthraquinones in 10, and saponins in 8. Extracts from eight plants had LC50 values lower than the potassium dichromate control (approximately 12 µg/mL) and were considered highly toxic; extracts from 21 plants had LC50 values between 12 µg/mL and 100 µg/mL and were considered moderately toxic; extracts from 19 plant extracts, including Vitex negundo and some common vegetables, had LC50 values between 100 µg/mL and 500 µg/mL, and were considered mildly toxic and likely to have reasonable safety margins; five plant extracts, including common vegetables, had LC50 values above 500 µg/mL and were considered essentially nontoxic. No apparent correlation could be found between toxicity and chemical diversity or a specific class of phytochemicals present. Our findings may serve as a guide for herbal drug and nutraceutical development, especially in prioritizing plants for more detailed safety studies.

Excitable dynamics of Physarum polycephalum plasmodial nodes under chemotaxis.

Recent results show that the chemotactic response of uni-cellular decentralized systems such as amoeboid and mammalian cells, is excitable. The same observation has not yet been reported for multi-nucleated decentralized biological systems. Here we present experimental results that shows the Physarum polycephalum plasmodial nodes spatio-temporal chemotactic dynamics as an excitable response. We found a highly optimized signal synthesis method wherein the Physarum nodes employ two intensity thresholds to properly navigate the chemoattractant field and generate corresponding spike dynamics in the node count. The node spike dynamics was found to correspond to the polarized-depolarized transition in the Physarum polycephalum morphology. Validation of our experimental observations via Brownian lattice simulations yields the same quantitative results with our experiments.

Visualizing Phytochemical-Protein Interaction Networks: Momordica charantia and Cancer.

The in silico study of medicinal plants is a rapidly growing field. Techniques such as reverse screening and network pharmacology are used to study the complex cellular action of medicinal plants against disease. However, it is difficult to produce a meaningful visualization of phytochemical-protein interactions (PCPIs) in the cell. This study introduces a novel workflow combining various tools to visualize a PCPI network for a medicinal plant against a disease. The five steps are 1) phytochemical compilation, 2) reverse screening, 3) network building, 4) network visualization, and 5) evaluation. The output is a PCPI network that encodes multiple dimensions of information, including subcellular location, phytochemical class, pharmacokinetic data, and prediction probability. As a proof of concept, we built a PCPI network for bitter gourd (Momordica charantia L.) against colorectal cancer. The network and workflow are available at https://yumibriones.github.io/network/. The PCPI network highlights high-confidence interactions for further in vitro or in vivo study. The overall workflow is broadly transferable and can be used to visualize the action of other medicinal plants or small molecules against other diseases.

Vasoreactivity in CADASIL: Comparison to structural MRI and neuropsychology.

Impaired cerebrovascular reactivity precedes histological and clinical evidence of CADASIL in animal models. We aimed to more fully characterise peripheral and cerebral vascular function and reactivity in a cohort of adult CADASIL patients, and explore the associations of these with conventional clinical, imaging and neuropsychological measures. A total of 22 adults with CADASIL gave informed consent to participate in an exploratory study of vascular function in CADASIL. Clinical assessment, comprehensive vascular assessment, MRI and neuropsychological testing were conducted. We measured cerebral vasoreactivity with transcranial Doppler and arterial spin labelling MRI with hypercapnia challenge. Number and volume of lacunes, subcortical hyperintensity volume, microbleeds and normalised brain volume were assessed on MRI. Analysis was exploratory and examined the associations between different markers. Cerebrovascular reactivity measured by ASL correlated with peripheral vasoreactivity measured by flow mediated dilatation. Subjects with ≥5 lacunes were older, with higher carotid intima-media thickness and had impaired cerebral and peripheral vasoreactivity. Subjects with depressive symptoms, disability or delayed processing speed also showed a trend to impaired vasoreactivity. Impaired vasoreactivity and vascular dysfunction may play a significant role in the pathophysiology of CADASIL, and vascular assessments may be useful biomarkers of severity in both longitudinal and clinical trials.

Habilidades autorregulatorias e higiene bucal infantil con el apoyo de los padres / Self-regulatory skills and child oral hygiene with support from parents / Habilidades de auto-regulação e higiene bucal das crianças com o apoio dos pais

En este artículo se analizan diferentes variables que inciden en la conducta de auto-cuidado de los pacientes pediátricos que asisten a consulta médica, así como en la de sus padres, para una buena salud oral como son: las creencias de autoeficacia, la intención y el control del comportamiento. En el contexto mexicano, participaron 43 pacientes pediátricos, entre 6 y 13 años de edad, y 36 padres de familia, entre 21 y 47 años de edad, que acompañaban a sus hijos a recibir tratamiento dental. Los resultados muestran que los pacientes pediátricos presentan mayor autoeficacia que su progenitor encuestado; en cambio, los padres presentan mejores respuestas en intención de comportamiento y hábitos de higiene bucal. El control de la acción no presenta diferencias significativas entre los pacientes pediátricos y sus padres.

In this article the authors analyze different variables that influence the self-care behavior of pediatric patients attending medical consultations, as well as the behavior of their parents, in relation to achieving good oral health. These variables include: self-belief, behavioral intention and control. In this study conducted in Mexico, participants included 43 pediatric patients aged between 6 and 13 years old, and 36 parents aged between 21 and 47 years of age who accompanied their children to receive dental treatment. The results show that pediatric patients have higher self-belief than their parents. However, parents have better behavioral intentions and oral hygiene habits than their children. There were no significant differences between pediatric patients and their parents in action control.

Neste artigo se analisam diferentes variáveis que influenciam o comportamento de auto-atendimento de pacientes pediátricos que frequentam consultas médicas, bem como seus pais, para uma boa saúde bucal como são: as crenças de autoeficácia, a intenção e o controle comportamental. No contexto mexicano, participaram 43 pacientes pediátricos entre 6 e 13 anos de idade, e 36 pais entre 21 e 47 anos de idade, que acompanharam seus filhos para receber tratamento. Os resultados mostram que os pacientes pediátricos tem maior autoeficácia do que seu progenitor correspondente. Os pais têm melhores respostas na intenção comportamental e hábitos de higiene bucal. O controle da ação não apresenta diferenças significativas entre pacientes pediátricos e seus pais.

Investigation of AlGaN/GaN high electron mobility transistor structures on 200-mm silicon (111) substrates employing different buffer layer configurations.

AlGaN/GaN high electron mobility transistor (HEMT) structures are grown on 200-mm diameter Si(111) substrates by using three different buffer layer configurations: (a) Thick-GaN/3 × {AlxGa1-xN}/AlN, (b) Thin-GaN/3 × {AlxGa1-xN}/AlN, and (c) Thin-GaN/AlN, so as to have crack-free and low-bow (<50 µm) wafer. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, high resolution-cross section transmission electron microscopy, optical microscopy, atomic-force microscopy, cathodoluminescence, Raman spectroscopy, X-ray diffraction (ω/2θ scan and symmetric/asymmetric ω scan (rocking curve scan), reciprocal space mapping) and Hall effect measurements are employed to study the structural, optical, and electrical properties of these AlGaN/GaN HEMT structures. The effects of buffer layer stacks (i.e. thickness and content) on defectivity, stress, and two-dimensional electron gas (2DEG) mobility and 2DEG concentration are reported. It is shown that 2DEG characteristics are heavily affected by the employed buffer layers between AlGaN/GaN HEMT structures and Si(111) substrates. Particularly, we report that in-plane stress in the GaN layer affects the 2DEG mobility and 2DEG carrier concentration significantly. Buffer layer engineering is shown to be essential for achieving high 2DEG mobility (>1800 cm2/V∙s) and 2DEG carrier concentration (>1.0 × 1013 cm-2) on Si(111) substrates.

Modelling zinc changes at the hippocampal mossy fiber synaptic cleft.

Zinc, a transition metal existing in very high concentrations in the hippocampal mossy fibers from CA3 area, is assumed to be co-released with glutamate and to have a neuromodulatory role at the corresponding synapses. The synaptic action of zinc is determined both by the spatiotemporal characteristics of the zinc release process and by the kinetics of zinc binding to sites located in the cleft area, as well as by their concentrations. This work addresses total, free and complexed zinc concentration changes, in an individual synaptic cleft, following single, short and long periods of evoked zinc release. The results estimate the magnitude and time course of the concentrations of zinc complexes, assuming that the dynamics of the release processes are similar to those of glutamate. It is also considered that, for the cleft zinc concentrations used in the model (≤ 1 µM), there is no postsynaptic zinc entry. For this reason, all released zinc ends up being reuptaken in a process that is several orders of magnitude slower than that of release and has thus a much smaller amplitude. The time derivative of the total zinc concentration in the cleft is represented by the difference between two alpha functions, corresponding to the released and uptaken components. These include specific parameters that were chosen assuming zinc and glutamate co-release, with similar time courses. The peak amplitudes of free zinc in the cleft were selected based on previously reported experimental cleft zinc concentration changes evoked by single and multiple stimulation protocols. The results suggest that following a low amount of zinc release, similar to that associated with one or a few stimuli, zinc clearance is mainly mediated by zinc binding to the high-affinity sites on the NMDA receptors and to the low-affinity sites on the highly abundant GLAST glutamate transporters. In the case of higher zinc release brought about by a larger group of stimuli, most zinc binding occurs essentially to the GLAST transporters, having the corresponding zinc complex a maximum concentration that is more than one order of magnitude larger than that for the high and low affinity NMDA sites. The other zinc complexes considered in the model, namely those formed with sites on the AMPA receptors, calcium and KATP channels and with ATP molecules, have much smaller contributions to the synaptic zinc clearance.

Total Mucosal Irradiation with Intensity-modulated Radiotherapy in Patients with Head and Neck Carcinoma of Unknown Primary: A Pooled Analysis of Two Prospective Studies.

AIMS: To determine the clinical outcomes of an intensity-modulated radiotherapy technique for total mucosal irradiation (TM-IMRT) in patients with head and neck carcinoma of unknown primary (HNCUP). MATERIALS AND METHODS: A single-centre prospective phase II trial design was used in two sequential studies to evaluate TM-IMRT for HNCUP. Patients were investigated for primary tumour site using examination under anaesthetic and biopsies, computed tomography ± magnetic resonance imaging (MRI) or 18-fluorodeoxyglucose positron emission tomography-computed tomography (PET-CT). Patients received IMRT to the potential primary tumour sites and elective cervical nodes. Concomitant chemotherapy was used in patients who received primary radiotherapy or those with nodal extracapsular extension. RESULTS: Thirty-six patients with HNCUP were recruited; 72% male. Twenty-five patients (69.4%) had p16-positive disease. Two year mucosal and local nodal control rates were 97.1% (95% confidence interval 91.4-100) and 89.8% (78.4-100), respectively. One mucosal primary was detected 7.3 months after TM-IMRT and three patients died from recurrent/metastatic squamous cell carcinoma of the head and neck. Twelve patients (33%) developed grade 3 (Late Effects in Normal Tissue-Subjective, Objective, Management and Analytical; LENT-SOMA) dysphagia with a 1 year enteric tube feeding rate of 2.7%. The high-grade subjective xerostomia rate (LENT-SOMA) at 24 months after IMRT was 15%. CONCLUSIONS: At a median follow-up of 36.1 months, the use of TM-IMRT was associated with good local control. Toxicity was comparable with previously reported TM-IMRT regimens encompassing similar mucosal volumes.

Induction Chemotherapy Followed by Chemo-intensity-modulated Radiotherapy for Locally Advanced Nasopharyngeal Cancer.

AIMS: To determine the toxicity and tumour control rates after chemo-intensity-modulated radiotherapy (chemo-IMRT) for locally advanced nasopharyngeal cancers (LA-NPC). MATERIALS AND METHODS: Patients with LA-NPC were enrolled in a trial to receive induction chemotherapy followed by parotid-sparing chemo-IMRT. The primary site and involved nodal levels received 65 Gy in 30 fractions and at risk nodal levels received 54 Gy in 30 fractions. Incidence of ≥grade 2 subjective xerostomia was the primary end point. Secondary end points included incidences of acute and late toxicities and survival outcomes. RESULTS: Forty-two patients with American Joint Committee on Cancer stages II (12%), III (26%) and IV (62%) (World Health Organization subtype: I [5%]; II [40%]; III [55%]) completed treatment between January 2006 and April 2010 with a median follow-up of 32 months. Incidences of ≥grade 2 acute toxicities were: dysphagia 83%; xerostomia 76%; mucositis 97%; pain 76%; fatigue 99% and ototoxicity 12%. At 12 months, ≥grade 2 subjective xerostomia was observed in 31%, ototoxicitiy in 13% and dysphagia in 4%. Two year locoregional control was 86.2% (95% confidence interval: 70.0-94.0) with 2 year progression-free survival at 78.4% (61.4-88.6) and 2 year overall survival at 85.9% (69.3-93.9). CONCLUSIONS: Chemo-IMRT for LA-NPC is feasible with good survival outcomes. At 1 year, 31% experience ≥grade 2 subjective xerostomia.

Molecular epidemiology of Bordetella pertussis in the Philippines in 2012-2014.

OBJECTIVES: The present study was designed to determine the genotypes of circulating Bordetella pertussis in the Philippines by direct molecular typing of clinical specimens. METHODS: Nasopharyngeal swabs (NPSs) were collected from 50 children hospitalized with pertussis in three hospitals during 2012-2014. Multilocus variable-number tandem repeat analysis (MLVA) was performed on the DNA extracts from NPSs. B. pertussis virulence-associated allelic genes (ptxA, prn, and fim3) and the pertussis toxin promoter, ptxP, were also investigated by DNA sequence-based typing. RESULTS: Twenty-six DNA extracts yielded a complete MLVA profile, which were sorted into 10 MLVA types. MLVA type 34 (MT34), which is rare in Australia, Europe, Japan, and the USA, was the predominant strain (50%). Seven MTs (MT29, MT32, MT33, and MT283-286, total 42%) were single-locus variants of MT34, while two (MT141 and MT287, total 8%) were double-locus variants of MT34. All MTs had the combination of virulence-associated allelic genes, ptxP1-ptxA1-prn1-fim3A. CONCLUSIONS: The B. pertussis population in the Philippines comprises genetically related strains. These strains are markedly different from those found in patients from other countries where acellular pertussis vaccines are used. The differences in vaccine types between these other countries and the Philippines, where the whole-cell vaccine is still used, may select for distinct populations of B. pertussis.

A phase II trial of induction chemotherapy and chemo-IMRT for head and neck squamous cell cancers at risk of bilateral nodal spread: the application of a bilateral superficial lobe parotid-sparing IMRT technique and treatment outcomes.

PURPOSE: To determine the feasibility of induction chemotherapy and chemo-IMRT in head and neck squamous cell cancers at risk of bilateral nodal spread (midline tumours) and to evaluate whether bilateral superficial lobe parotid-sparing IMRT can reduce the incidence of ⩾G2 subjective xerostomia. METHODS: Patients with midline tumours were enrolled to a phase II trial to receive induction platinum/5-fluorouracil and concomitant platinum with combined superficial lobe parotid-sparing IMRT. The primary site and involved nodal levels received 65 Gy in 30 fractions (f) and at risk nodal levels, 54 Gy/30f. Incidence of ⩾G2 subjective xerostomia was defined as the primary endpoint. Secondary endpoints included incidences of acute and late toxicities and survival outcomes dependent on human papilloma virus (HPV) status. RESULTS: One hundred and twenty patients with midline cancers completed treatment between December 2005 and May 2010 with median follow-up of 50 months. Incidences of ⩾G2 acute toxicities were: dysphagia 75%; xerostomia 65%; mucositis 86%; pain 83%; and fatigue 64%. At 12 months, ⩾G2 subjective xerostomia was observed in 21% (17% in HPV +ve). Two-year loco-regional progression-free survival (PFS) was 90.7% (95% CI: 85.2-96.2). According to HPV status, there was a significant difference for 2-year loco-regional PFS, 76.8% (HPV-negative) vs 98.6% (HPV-positive), P=0.001. 2-year overall survival was 93% for HPV-positive compared with 52% for HPV-negative cases, P<0.001. CONCLUSIONS: Sequential chemotherapy/chemo-IMRT for midline tumours is feasible, with excellent survival outcomes. At 1 year, 21% experience ⩾G2 subjective xerostomia. Two-year survival outcomes differ significantly between HPV-positive and HPV-negative disease, suggesting development of different treatment schedules for the different disease entities.

Perfil antigénico celular de cepas aisladas de Leptospira en León y Chinandega, Nicaragua / No disponible

Objetivo. El siguiente trabajo se desarrollo con el objetivo de determinar los perfiles antigénicos celulares que sean reconocidos por el suero de personas vacunados con vax-SPIRAL® de cepas obtenidas de los departamentos de León y Chinandega.Métodos. Se analizaron cepas aisladas de hemocultivos tomadas de casos con sospecha clínica de leptospirosis, determinándose los perfiles antigénicos mediante electroforesis de células enteras y western blotting usando como anticuerpos, sueros provenientes de personas vacunadas con vax-SPIRAL®.Resultados y conclusiones. Se evidenció una gran homología antigénica entre todas las cepas estudiadas. Los resultados del presente estudio sugieren que en los departamentos de León y Chinandega circulan cepas de L. interrogans con un fuerte reconocimiento antigénico frente a sueros provenientes de personas vacunadas con vax-SPIRAL®(AU)

Objective.The following work was development with the objective of determining the profiles cellular antigenics that are recognized by the serum of people vaccinated with vax-SPIRAL® of obtained strains of the León and Chinandega departments. Methods. Blood cultures samples were analyzed taken in sharp phase to cases with suspicion leptospirosis clinic, being determined the profiles antigenics by means of electrophoresis of whole cells and western blotting using as antibodies, serums coming from people vaccinated with vax-SPIRAL®. Results and conclusions. A great antigenic homology was evidenced among all the studied strains. The present study results suggest that in León and Chinandega departments circulate L. interrogans strains with a strong antigenic recognition front of serums of people vaccinated with vax-SPIRAL®(AU)

Impacto de los cambios realizados en la etapa de multiplicación celular durante la obtención de la Sustancia Sensibilizante de Eritrocitos utilizada en el diagnóstico serológico de la Leptospirosis / No disponible

Introducción: En Cuba desde 1981 se tiene implementada la hemoaglutinación indirecta como técnica diagnostica de Leptospirosis de forma alternativa en ausencia de otras que pueden ser más costosas pero efectivas en los diferentes estadios de la enfermedad. Para el desarrollo de la técnica se hace necesaria la sustancia sensibilizante de eritrocitos (SSE), asumiendo su producción el Instituto Finlay en el año 2009, a partir de una tecnología obsoleta en la etapa de multiplicación celular.Objetivo. El objetivo de este trabajo fue realizar cambios en esta etapa para obtener la SSE con los medios de cultivos disponibles en la planta de producción para el óptimo rendimiento del producto, sin afectar la actividad biológica como parámetro fundamental de calidad.Métodos. Fueron formados 8 grupos experimentales teniendo en cuenta: cepa productora (cepa LABIOFAM y cepa Finlay) medio de cultivo (MK y EMJH) y condiciones de cultivos (estático o agitado).Resultados y conclusión. Se obtuvo como resultado que la mejor variante fue en la que se utilizó la cepa de LABIOFAM, crecimiento en medio MEJH y agitado, con una disminución considerable en el tiempo de obtención de la SSE mediante esta nueva tecnología, con un título consistente con las exigencias de calidad. Permitiendo así comenzar los diferentes diseños de estudios de estabilidad y registro del producto(AU)

Introduction: In Cuba since 1981 has implemented the indirect hemagglutination as an alternative technique of Leptospirosis diagnosed, in the absence of others that may be more costly but effective at different stages of the disease. For the development of the technique requires the Erythrocytes Sensitize Substance (ESS), assuming the production Finlay Institute in 2009, from obsolete technology in the process of cell multiplication.Objective: The aim of this study was to make changes at this stage to obtain the ESS with the culture media available at the plant for optimum product performance, without affecting the biological activity as the basic parameter of quality.Methods: Eight experimental groups were formed according to multifactorial design, taking into account: production strain (LABIOFAM or Finlay strain of L. biflexa Patoc I), culture medium (MK and MEJH) and culture conditions (static or agitated).Results and conclusion: We obtained as a result that the best variant was the combination (LABIOFAM strain, growth in MEJH and agitated), with a considerable decrease in the time of the ESS obtaining by means of this new technology, with a consistent title with the demands of quality. This work allowed to use the best variant to begin the different designs of stability studies of the product(AU)

The cholesterol-lowering effect of coconut flakes in humans with moderately raised serum cholesterol.

This study investigated the effect of coconut flakes on serum cholesterol levels of humans with moderately raised serum cholesterol in 21 subjects. The serum total cholesterol of subjects differed and ranged from 259 to 283 mg/dL. The study was conducted in a double-blind randomized crossover design on a 14-week period, consisting of four 2-week experimental periods, with each experimental period separated by a 2-week washout period. The test foods were as follows: corn flakes as the control food, oat bran flakes as the reference food, and corn flakes with 15% and 25% dietary fiber from coconut flakes (made from coconut flour production). Results showed a significant percent reduction in serum total and low-density lipoprotein (LDL) cholesterol (in mg/dL) for all test foods, except for corn flakes, as follows: oat bran flakes, 8.4 +/- 1.4 and 8.8 +/- 6.0, respectively; 15% coconut flakes, 6.9 +/- 1.1 and 11.0 +/- 4.0, respectively; and 25% coconut flakes, 10.8 +/- 1.3 and 9.2 +/- 5.4, respectively. Serum triglycerides were significantly reduced for all test foods: corn flakes, 14.5 +/- 6.3%; oat bran flakes, 22.7 +/- 2.9%; 15% coconut flakes, 19.3 +/- 5.7%; and 25% coconut flakes, 21.8 +/- 6.0%. Only 60% of the subjects were considered for serum triglycerides reduction (serum triglycerides >170 mg/dL). In conclusion, both 15% and 25% coconut flakes reduced serum total and LDL cholesterol and serum triglycerides of humans with moderately raised serum cholesterol levels. Coconut flour is a good source of both soluble and insoluble dietary fiber, and both types of fiber may have significant role in the reduction of the above lipid biomarker. To our knowledge, this is the first study conducted to show a relationship between dietary fiber from a coconut by-product and a lipid biomarker. Results from this study serves as a good basis in the development of coconut flakes/flour as a functional food, justifying the increased production of coconut and coconut by-products.

Effect of losartan microinjections into the NTS on the cardiovascular components of chemically evoked reflexes in a rabbit model of acute heart ischemia.

In the acute phase of myocardial infarction (MI) there are modifications of the autonomic outflow with an increase in the sympathetic tone and changes in cardiovascular reflexes. Activation of angiotensin AT1 receptors in the nucleus tractus solitarii (NTS) inhibits the baroreceptor and enhances the carotid chemoreflex. In this study, we investigated the role of NTS-AT1 receptors on the cardiovascular reflex responses evoked on stimulation of carotid chemoreflex and cardiac chemosensitive fibres in the acute phase of MI. We also test the hypothesis that changes in cardiovascular responses to activation of carotid chemo and cardiac chemosensitive reflexes are secondary to changes in haemodynamic conditions due to infarction or to the activation of nociceptors of the heart. Rabbits were anaesthetised, paralysed and artificially ventilated. Carotid chemoreceptors and cardiac chemosensitive fibres were stimulated with lobeline and ATP, respectively. Arterial blood pressure, electrocardiogram and heart rate were monitored. A craniotomy was made to expose the caudal portions of the medulla and a multibarreled glass microelectrode was inserted in order to allow the identification of NTS and the microinjection of losartan (an angiotensin AT1 receptor antagonist). The heart was exposed by a midline thoracotomy and cardiac ischemia was produced by ligating the left descending coronary artery. The carotid chemoreflex and cardiac chemosensitive reflexes were evoked before and following the coronary ligation. The effect of losartan injection into the NTS on these reflexes was also assessed. In control experiments reflexes were assessed before and after the administration of capsaicin and procainamide. Results show that the activation of carotid chemoreflex elicited a greater increase of blood pressure and bradycardia after MI and that this was partially reversed by losartan microinjection after MI. Also the stimulation of cardiac chemosensitive fibres evoked a larger decrease on blood pressure and heart rate after MI and these were also partially reversed by losartan. The same enhancement of cardiovascular carotid chemo and cardiac chemosensitive receptors was observed after administration of capsaicin on the ventricular surface but not after procainamide. In conclusion, this study strongly suggests that, at NTS level, angiotensin AT1 receptors are involved in the modifications of autonomic outflow observed in the acute phase of MI.

Enhancement of carotid chemoreceptor reflex and cardiac chemosensitive reflex in the acute phase of myocardial infarction of the anesthetized rabbit.

In the acute phase of cardiac ischemia there is an imbalance of the autonomic outflow with a depression of the baroreceptor reflex. Carotid chemoreceptor stimulation evokes an increase on arterial blood pressure and bradycardia in the anesthetized and paralyzed animal. The activation of cardiac chemosensitive fibers elicit the Bezold-Jarisch reflex comprising a decrease of arterial blood pressure and bradycardia. In the present study, we studied the modifications of the carotid chemoreceptor reflex and the Bezold-Jarisch reflex elicited during the acute phase of myocardial infarction (MI) in the anesthetized and paralyzed rabbit. Rabbits were anesthetized with pentobarbitone, paralyzed and artificially ventilated. The carotid sinus region was exposed and a cannula was inserted retrogradely through the external carotid artery into the carotid bifurcation; the carotid body was stimulated by a lobeline injection. A catheter was advanced, via the right carotid artery, to the origin of the aorta and the Bezold-Jarisch reflex was evoked by an injection of ATP. The baroreflex was provoked by an increase in after-load or by clamping the common carotid artery. Heart ischemia was provoked by ligation of the descending coronary artery. Arterial blood pressure, carotid artery pressure, heart rate and electrocardiogram were monitored. Stimulation of cardiovascular and cardiac receptors was performed before and after coronary ligation. Results show an overall increase in the cardiovascular reflex responses elicited by stimulation of chemically activated receptors and an overall decrease of the baroreceptor responses after MI. In conclusion, these data show the existence of an enhancement of the reflex cardiovascular responses to carotid chemoreceptor and cardiac chemosensitive receptors stimulation and confirmed the depression of baroreceptor reflexes following heart ischemia that could account for the imbalance of the autonomic output observed in the acute phase of myocardial infarction.

Early and medium term results of tailored therapy for heart failure.

UNLABELLED: Patients (pts) with advanced chronic heart failure, in NYHA functional class IV, refractory to conventional medical therapy, show a poor short-term survival prognosis. Heart transplant remains the therapy of choice but it can currently be performed in only a minority of pts. Therapy tailored to hemodynamic goals has been suggested as a potential alternative for patients with advanced congestive heart failure. Intravenous and, subsequently, oral vasodilators (v) and diuretics (d) are titrated, in order to achieve specific hemodynamic parameters: systolic arterial pressure (SAP) > 80 mmHg, pulmonary wedge pressure (PWP) < 15 mmHg, right atrial pressure (RAP) < 8 mmHg, and systemic vascular resistance (SVR) < 1200 dynes.sec.cm-5. AIM: To assess short and medium term (two years) results of a tailored therapy management program for treatment of patients with advanced heart failure. METHODS: 27 pts (19 males, 61 +/- 10 years), NYHA functional class IV, with dilated cardiomyopathy (13 idiopathic, 10 ischemic, 4 hypertensive), 17 with exclusion criteria for heart transplantation, were included. Echocardiographic left ventricular end-diastolic dimension and ejection fraction were 68 +/- 8 mm and 20 +/- 9%, respectively. Initial (i) serum sodium (Na+) was 136 +/- 5 mEq/l and i serum creatinine (Cr) was 1.4 +/- 0.8 mg/dl. Baseline, at referral, hemodynamics: SAP = 125 +/- 23, PWP = 23 +/- 6, RAP = 12 +/- 6, cardiac index (CI) = 1.9 +/- 0.5 l/min/m2, SVR = 2193 +/- 670. Using bedside right heart catheterization (Swan-Ganz catheter) we set out to achieve the above hemodynamic goals. RESULTS: 1) v and d used: sodium nitroprusside--cumulative dose = 196 +/- 121 mg, captopril--daily dose (dd) = 157 +/- 95 mg, isosorbide dinitrate--dd = 91 +/- 57 mg, hydralazine--dd = 95 +/- 67 mg, and furosemide--dd = 105 +/- 70 mg; 2) final (f) hemodynamic parameters on tailored therapy: SAP = 109 +/- 20*, PWP = 12 +/- 3*, RAP = 4 +/- 3*, CI = 2.5 +/- 0.6*, SVR = 1317 +/- 340* (*: p < 0.001 vs baseline); 3) duration of invasive monitoring was 3.0 +/- 1.9 days; 4) f Na+ = 134 +/- 5, and f Cr = 1.5 +/- 0.8 (NS vs i); 5) there was one (4%) in-hospital death; functional class of discharged pts: III--4 pts, II--18 pts, I--4 pts; 6) nine pts (35%) died after discharge--three due to refractory heart failure and six (including two potential heart transplant candidates) had sudden death; 7) actuarial survival (Kaplan-Meyer method): at 6 months (m)--80%, 12 m--71%, 18 m--64%, 24 m--55%; 8) after a mean follow-up of 18 +/- 8 m, functional class in survivors was: NYHA IV--2 pts, III--4 pts, II--8 pts, and I--3 pts. CONCLUSIONS: Therapy tailored to hemodynamic goals is a valid approach for pts with advanced heart failure, showing good hemodynamic and functional short-term results, and reasonable survival at two years. The significant incidence of sudden death demands strategies for risk stratification and a search for prophylactic measures in this population.

Pharmacologic or genetic manipulation of glutathione S-transferase P1-1 (GSTpi) influences cell proliferation pathways.

Glutathione S-transferase P1-1 (GSTpi) is an abundant and ubiquitously expressed protein in normal and malignant mammalian tissues and possesses catalytic and ligand binding properties. Our present data suggest that the protein contributes to the regulation of cell proliferation. Mouse embryo fibroblasts (MEFs) isolated from mice with a GSTP1-1 [glutathione S-transferase P1-1 (isozyme in nonhepatic tissue)] null genotype (GSTpi(-/-)) doubled their population in 26.2 h versus 33.6 h for the wild type (GSTpi(+/+)). Retroviral transfection of GSTP1-1 into GSTpi(-/-) MEF cells slowed the doubling time to 30.4 h. Both early passage and immortalized MEF cells from GSTpi(-/-) animals expressed significantly elevated activity of extracellular signal-regulated kinases ERK1/ERK2, kinases linked to cell proliferation pathways. In vivo, GSTpi(-/-) mice had higher basal levels of circulating white blood cells compared with GSTpi(+/+). Administration of a peptidomimetic inhibitor of GSTP1-1, TLK199, (gamma-glutamyl-S-(benzyl)cysteinyl-R-phenyl glycine diethyl ester), stimulated both lymphocyte production and bone marrow progenitor (colony-forming unit-granulocyte macrophage) proliferation, but only in GSTpi(+/+) and not in GSTpi(-/-) animals. Selection of a resistant clone of an HL60 tumor cell line through chronic exposure to TLK199 resulted in cells with elevated activities of c-Jun NH2 terminal kinase (JNK1) and ERK1/ERK2, and allowed the cells to proliferate under stress conditions that induced high levels of apoptosis in the wild type cells. The in vitro and in vivo data are consistent with the principle that GSTP1-1 influences cell proliferation.

Naloxone inhibits nicotine-induced receptor current and catecholamine secretion in bovine chromaffin cells.

Nicotine-induced catecholamine (CA) secretion and inward ionic currents were inhibited by the opioid antagonist naloxone in cultured bovine chromaffin cells. Naloxone inhibited nicotine-induced CA secretion, as detected by an on-line real-time electrochemical technique, in a dose-dependent manner (IC(50)=29 microM). In voltage-clamped chromaffin cells, nicotine (10 microM) evoked an average peak inward current of -146 pA that was inhibited by low concentrations of naloxone (42% at 0.1 microM). The antagonist also inhibited total charge influx associated with nicotinic receptor activation (53% at 0.1 microM). This provides strong evidence that naloxone modulation of nicotine-induced CA secretion does not involve opioid receptors but results from the direct interaction with the nicotinic receptor itself, which might also be the case for other related opioid compounds.