La salud mundial contra la industria tabacalera: convenio marco para el control del tabaco / World health against tobacco industry: framework agreement for tobacco control

Este artículo editorial describe el impacto del tabaquismo sobre la mortalidad en el mundo subdesarrollado y los principales puntos del Convenio Marco para el Control del Tabaco acordados por 160 países en marzo de 2003 (legislación comercial e impositiva, medidas contra el tabaquismo pasivo, advertencias sanitarias, prohibición de la publicidad, fomento de las estrategias para el abandono del tabaco). Describe además las formas de presión implementadas por la industria tabacalera así como las claudicaciones de los gobiernos, particularmente en el tercer mundo y en Argentina

La salud mundial contra la industria tabacalera: convenio marco para el control del tabaco / World health against tobacco industry: framework agreement for tobacco control

Este artículo editorial describe el impacto del tabaquismo sobre la mortalidad en el mundo subdesarrollado y los principales puntos del Convenio Marco para el Control del Tabaco acordados por 160 países en marzo de 2003 (legislación comercial e impositiva, medidas contra el tabaquismo pasivo, advertencias sanitarias, prohibición de la publicidad, fomento de las estrategias para el abandono del tabaco). Describe además las formas de presión implementadas por la industria tabacalera así como las claudicaciones de los gobiernos, particularmente en el tercer mundo y en Argentina

Structural and ultrastructural characteristics of interrenal gland and chromaffin cell of matrinxã, Brycon cephalus Gunther 1869 (Teleostei-Characidae).

This work presents the structure and ultrastructure of the interrenal gland and chromaffin cells, as well as the morphology of the head kidney of Brycon cephalus. The head kidney is composed of fused bilateral lobes located anterior to the swim bladder and ventrolateral to the spinal column. The parenchyma revealed lympho-haematopoietic tissue, melano-macrophage centres, interrenal gland and chromaffin cells. The interrenal gland consisted of cords or strands of cells grouped around the posterior cardinal vein and their branches. Chromaffin cells are found in small groups, closely associated with the interrenal gland and/or under the endothelium of the posterior cardinal vein. So far, the ultrastructural analysis has revealed only one interrenal cell type which contained abundant smooth endoplasmic reticulum and numerous mitochondria with tubulo-vesicular cristae, characteristic of steroid-producing cells. Two types of chromaffin cells were observed. The first type was characterized by the presence of vesicles with round, strongly electron-dense granules, which were eccentrically located. Such cells were interpreted as noradrenaline cells. Meanwhile, cells which contained smaller vesicles and electron-lucent granules, with a small halo separating the granule from the vesicular limiting membrane, were identified as adrenaline cells.

[Nerve growth factor and diabetic neuropathy]. / Factor de crecimiento nervioso y neuropatía diabética.

INTRODUCTION: The progress made by contemporary neurobiology opens new horizons both for study and for treatment of disorders of the nervous system. At the present time we are in the age of growth factors. These are molecules which affect survival, development and the normal functioning of cell populations. DEVELOPMENT: One of the most widely studied growth factors is nervous growth factor (NGF) which is necessary for normal life of various types of neurones, including sensory nerves and nerves derived from the neural crests. Diabetic neuropathy, worldwide a major neurological disorder, is primarily characterized by involvement of the fine fibres for temperature and pain perception and also by a variety of autonomic disorders. The great dependence of sensory and sympathetic nerves on NGF, the quantity of results which show alterations in the levels of neurotrophic factors in diabetic neuropathy (DN), and the encouraging experimental and clinical results of using NGF as a new alternative to treatment with DN, were the basic reasons which led us to do this study. CONCLUSIONS: We started by considering neurotrophic factors, especially NGF and its connection with DN disorders and its clinical applications, we made a summary of the main findings in this field to date.

Synergism between toxin-gamma from Brazilian scorpion Tityus serrulatus and veratridine in chromaffin cells.

Toxin-gamma (Tgamma) from the Brazilian scorpion Tityus serrulatus venom caused a concentration- and time-dependent increase in the release of norepinephrine and epinephrine from bovine adrenal medullary chromaffin cells. Tgamma was approximately 200-fold more potent than veratridine judged from EC50 values, although the maximal secretory efficacy of veratridine was 10-fold greater than that of Tgamma (1.2 vs. 12 microg/ml of catecholamine release). The combination of both toxins produced a synergistic effect that was particularly drastic at 5 mM extracellular Ca2+ concentration ([Ca2+]o), when 30 microM veratridine plus 0.45 microM Tgamma were used. Tgamma (0.45 microM) doubled the basal uptake of 45Ca2+, whereas veratridine (100 microM) tripled it. Again, a drastic synergism in enhancing Ca2+ entry was seen when Tgamma and veratridine were combined; this was particularly pronounced at 5 mM [Ca2+]o. Veratridine induced oscillations of cytosolic Ca2+ concentration ([Ca2+]i) in single fura 2-loaded cells without elevation of basal levels. In contrast, Tgamma elevated basal [Ca2+]i levels, causing only small oscillations. When added together, Tgamma and veratridine elevated the basal levels of [Ca2+]i without causing large oscillations. Tgamma shifted the current-voltage (I-V) curve for Na+ channel current to the left. The combination of Tgamma with veratridine increased the shift of the I-V curve to the left, resulting in a greater recruitment of Na+ channels at more hyperpolarizing potentials. This led to enhanced and more rapid accumulation of Na+ in the cell, causing cell depolarization, the opening of voltage-dependent Ca2+ channels, and Ca2+ entry and secretion.

Hormonal and metabolic adjustments during exercise in hypoxia or normoxia in highland natives.

In sea-level natives, exposure to hypoxia for a few weeks is characterized by an increased dependence on blood glucose and a decreased reliance on lactate for energy metabolism during exercise. These metabolic adjustments have been attributed to behavioral changes in the sympathoadrenergic and pancreatic systems. The aim of this study was to test the hypothesis of a reduced sympathoadrenergic activation and subsequent metabolic changes when high-altitude natives are acutely exposed to normoxia. Young Andean natives performed incremental exercise to exhaustion during hypoxia (arterial PO2 55.1 +/- 1.1 Torr) or during acute normoxia (arterial PO2 78.7 +/- 1.7 Torr). As a whole, oxygen uptake was increased in normoxia compared with hypoxia during graded exercise. This finding is not related to a decrease in anaerobic metabolism but rather is interpreted as a consequence of a shift in substrate utilization during exercise (increased contribution of fat as assessed by a reduction in the respiratory exchange ratio). These metabolic changes are not accompanied by modifications of glucoregulatory hormones (catecholamines, insulin, and glucagon). In particular, the exercise-induced catecholamine secretion was similar in chronic hypoxia and acute normoxia. As a consequence, blood lactate accumulation during incremental exercise was similar in both conditions. It is concluded that high-altitude natives do not display any sign of a greater sympathoadrenergic activation during chronic hypoxia and that the exercise-induced hormonal changes remained unaffected by acute inhalation of a normoxic gas mixture.

Immunohistochemical localization of neurotensin in a subpopulation of noradrenergic chromaffin cells of the adrenal gland of the flat snake (Waglerophis merremii).

The distribution of neurotensin (NT)-like immunoreactivity (LI) in the adrenal gland of the snake Waglerophis merremii has been examined immunohistochemically. Double staining, combining NT with tyrosine hydroxylase (TH) or calcitonin gene-related peptide (CGRP) antibodies and TH with CGRP antibodies, was also carried out. Results were analyzed by conventional and by confocal fluorescence microscopy. Immunostaining revealed a subpopulation of chromaffin cells containing NT-LI within the dorsal noradrenergic ribbon. In addition, there were some NT-immunoreactive (IR) fibers in this region. NT immunoreactivity was not present within adrenergic chromaffin cells or in cortical tissue. Double staining revealed CGRP-IR fibers innervating most of the chromaffin adrenergic cells. Within the dorsal noradrenergic ribbon, two groups of chromaffin TH-IR cells were present, one receiving a dense CGRP-IR innervation and another without contact with CGRP-IR terminals. The latter chromaffin cells displayed NT-LI. These results show, for the first time, the presence of a neuropeptide in chromaffin noradrenergic cells of a reptilian adrenal gland and open up the possibility that other peptides may also be present in these cells.

Intradermal implants of histotypic adrenal gland rotary cultures.

The implantation of histotypic adrenal gland cultures is described in the present study. The cultures were prepared from mice at birth and were rotary incubated for 10 days. When the cells reached phenotypic maturation, they were implanted in the dermal bed of the auricular pavilion of young adult mice. This location was ideal for implantation because transillumination enabled daily inspection of the progress of implant survival. Twenty days after implantation, the implants and associated tissues were removed to study the degree of maturation and the viability of the implants. Some cultures showed a moderate percentage of steroidal cells, while others demonstrated a high predominance of the chromaffin cells. All the implanted cultures successfully survived a postoperative period of 20 days. Both adrenergic and noradrenergic cells reached their maximum grade of cytological differentiation and neither inflammatory reactions nor adverse immunological effects were observed. On the contrary, the implants were profusely vascularized by the host tissue, particularly in those implants with a higher content of chromaffin cells.

Histochemical study of chromaffin cells and nerve fibers in the adrenal gland of the flat snake (Waglerophis merremii).

The distributions of tyrosine hydroxylase (TH), protein gene product (PGP) 9.5, calcitonin gene-related peptide (CGRP), and peptide histidine isoleucine (PHI) have been examined immunohistochemically in the adrenal gland of the snake Waglerophis merremii. The morphology of chromaffin cells and the presence of ganglionic neurons in the gland revealed by means of the glutaraldehyde-silver technique and electron microscopy are also described. Two distinct types of TH-immunoreactive (-IR) cells are present in the dorsal noradrenergic ribbon: small chromaffin cells and a larger type identified as ganglionic neurons. Small, mostly round or fusiform cells often displayed long processes. Ganglionic cells, arranged in patches, had long processes entering the cortex of the gland. Chromaffin adrenergic cells, forming small groups of 4-7 cells, were scattered within the interrenal tissue and had a wide variety of shapes with processes that appeared to contact other chromaffin cells. Bundles of PGP 9.5-IR fibers occurred in the subcapsular zone of the adrenal gland with fibers entering the cortex and dorsal noradrenergic ribbon of the gland. Thick and thin TH-IR fibers were seen. Thick TH-IR fibers were nonvaricose and appeared to originate mainly in ganglionic neurons. Thin TH-IR fibers with small varicosities were numerous in the interrenal tissue and were frequently seen between clusters of adrenergic cells in close apposition to cortical cells and vessels. CGRP-IR fibers were present throughout the entire adrenal gland, whereas PHI-IR fibers had a preferential distribution in the interrenal tissue. Both CGRP- and PHI-IR fibers were closely associated with vessels and cortical cells.

Effect of scorpion toxin on the enterochromaffin-like cells in normal and Trypanosoma cruzi-infected rats: a morphological study.

Intravenous injection of scorpion toxin (Tityus serrulatus) in normal and Trypanosoma cruzi infected rats did not cause ultrastructural morphologic changes on enterochromaffin-like (ECL) cells of the stomach, although it induced a significant increase of the gastric secretion. Our data seem to indicate that gastric ECL cells structure is not affected by stimulation with scorpion toxin or by acute infection with T. cruzi in the rat.

G-cells and gastrinaemia in chronic nonspecific bulbitis.

Chronic nonspecific bulbitis (CNB), the number of G-cells in the antrum and the level of serum gastrin were unrelated in a group of 24 patients. Gastrin may be produced by cells outside the antrum or by a few but hyperactive antral G-cells.

Paragangliomatosis multiple: el problema de su localización; informe del primer caso estudiado con (131I) meta-iodobenzilguanidina en nuestro medio y revisión de la literatura / Multiple chromaffin tumors: report of a case studied with (131i) meta iodo-benzyl-guanidine and review of the literature

Los tumores de tejido cromafín, hormonalmente activos y capaces de producir daño a varios órganos e incluso la muerte, con frecuencia permanecen insospechados ejerciendo por períodos prolongados su efecto deletéreo. Con frecuencia son múltiples y al problema de su diagnóstico se agrega el de su localización. Describimos el caso de una mujer joven, con historia de episodios paroxísticos de palpitaciones, disnea, opresión precordial e hipertensión arterial de ocho años de evolución. El diagnóstico de tumor cromafín fue realizado a través de determinación de catecolaminas séricas y urinarias. Fué intervenida quirúrgicamente en tres ocasiones después de efectuar ultrasonografía de abdomen y pelvis, tomografía axial computada de torax, abdomen y pelvis, muestreo hormonal a través de cavografía; arteriografía selectiva y empleo de metaiodo-benzyl-guanidina 131. Enfatizamos la incapacidad de los métodos empleados, cruentos e incruentos y la ausencia del procedimiento ideal cuando se emplean aisladamente. Recomendamos también el estudio de la respuesta presora al ejercicio en banda sinfín para evaluar el comportamiento de las resistencias periféricas en sí, una vez conseguida la curación quirúrgica

Alteraçöes quantitativas das células neuroendócrinas no megacólon chagásico / Quantitative changes in the neuroendocrine cells of chagasic megacolon

Utilizando-se técnicas histoquímicas pela prata (Masson-Fontana e Sevier-Munger) estudaram-se a distribuiçäo e o número de células enterocromafins (EC) e do conjunto EC mais células argirófilas (ARG) em peças cirúrgicas de megassigmóide chagásico. Observou-se que tanto nos "megas" (n = 16) como nos controles (n = 8), a posiçäo das células EC e ARG na mucosa foi predominantemente basal, com distribuiçäo irregular, principalmente das EC. A análise histológica revelou aparente aumento numérico das EC e do conjunto EC mais ARG. Todavia, contagens sistematizadas mostraram que somente o conjunto dessas células apresentou aumento estatisticamente significativo (P<0,01). Realizou-se tambéjm o estudo morfométrico da mucosa e das musculares que revelou espessamento significativo (P<0,01) dessas camadas em relaçäo aos casos controles

[Histological analysis of the gastric mucosa, enterochromaffin cells and gastrin-producing cells in endoscopic biopsies of patients with achlorhydria]. / Análise histológica da mucosa gástrica, das células enterocromafins e das produtoras de gastrina em biopsias endoscópicas de pacientes com acloridria.

Twenty achlorhydric patients and five controls were submitted to gastric endoscopic biopsies in order to study the histological pattern of the gastric mucosa and the number of enterochromaffin (EC) and gastrin (G) cells of the antral mucosa. The histological changes of the oxyntic mucosa of achlorhydric patients were variable being the predominant pattern the severe chronic atrophic gastritis. The antral mucosa was normal in appearance or revealed mild degree of gastritis. In the most achlorhydric patients the antral EC cell number was decreased when compared to the controls and the G cell number were relatively numerous. The results of the present work are suggestive of an increased G:EC cell ratio in achlorhydric patients.

[Diagnosis and etiology of Barrett esophagus. Presence of gastrin secreting cells (G cells)]. / Diagnóstico y etiología del esofago de Barrett. Presencia de células secretoras de gastrina (G).

We present the patterns for the diagnosis, checking the clinical, radiological, endoscopical and histological data of 35 patients suffering from Barrett's Esophagus (BE) (columnar metaplasia lining the lower esophagus). The clinical characteristics are those of a severe esophagitis of long evolution, although metaplasia itself is asymptomatic, and its features depend on the inflammation degree. Radiology can bring out some data as GE reflux, hiatal hernia, ulcers or stricture, and perhaps double contrast may show any sign by means of which endobrachyesophagus (EBE) can be suspected. Endoscopy provides us with accurate data about EBE, ulcers, stricture and inflammation. Histology reveals the type of columnar metaplasia (junctional or cardial, gastric fundic, intestinal or specialized, or composite). Acquired or congenital etiology can be clarified by an immunohistochemical method, Peroxidase anti-Peroxidase (PAP), showing the presence of gastrin secretory cells (G cells) in the congenital cases.