Medicinal agents and metabolic syndrome.

The definition of the Metabolic Syndrome (MS) has encountered difficulty in reaching a universal consensus although there exists an agreement of its main pathologies which are hypertension, obesity, dyslipidemia, insulin resistance, inflammation and renal damage. The prevalent opinion is that three of those alterations may define the syndrome. The incidence of the MS has increased globally, particularly in the last few years, to the point of being regarded as an epidemic. The treatment of the MS can be approached from different angles, since it may be a multifaceted health problem. A healthy lifestyle, which means the practice of regular exercise is suggested to MS patients. Increasing physical activity has anti-inflammatory effects since there is an inverse association of physical activity and inflammatory biomarker concentrations. An adequate diet is recommended, such as the Mediterranean, which contains fish, tomatoes, garlic, red peppers, olive oil and includes red wine, that is, antioxidants and non-saturated oils. There are also the traditional herbal preparations, used in the alternative medicine. Several therapeutic tools can be used; the most common are the pharmaceutical products to deal with obesity, hypertension, dyslipidemias, diabetes and inflammation. In addition several pharmacological therapies such as non steroidal anti-inflammatory drugs are recommended. Recently new mechanisms of action of statins, fibrates, metformin and thiazolidinediones have demonstrated their anti-inflammatory effect and potential use to treat MS.

Sex steroid hormones, cardiovascular diseases and the metabolic syndrome.

The metabolic syndrome (MS) has become the new epidemic of this century. Although its associated pathologies may vary, the most common are hypertension, central obesity, dyslipidemia, low High Density Lipoproteins (HDL), high Low Density Lipoproteins (LDL), and type-2 diabetes. Several others can be present, such as hypertriglyceridemia, cardiopathies, atherosclerosis, altered levels of sex hormones, hypogonadism in men and nephropathy. Several factors such as gender, age, race, lifestyle and diet may contribute to modify its prevalence: men develop cardiovascular diseases at an earlier age than pre-menopausal women, who seem to be protected by the antioxidant properties of estrogens. The present review offers information, mostly from 2008 to the present, as well as our own work on a rat model of MS, which was developed by the administration of sucrose in drinking water. Sex steroid hormones play an important role in the appearance and development of the MS and of cardiovascular diseases. Variations in the levels of sex hormones, whether normal or pathological, may have significant influence in the onset of several diseases, metabolic syndrome components included, as well as in the behavior of tissues and organs. These are just some of the non-reproductive actions of sex hormones.

Sex hormones, metabolic syndrome and kidney.

In the metabolic syndrome (MS), a condition that associates three or more pathologies such as hypertension, central obesity, type II diabetes, insulin resistance and dyslipidemias, the kidneys are severely affected. The pathological alterations in the kidneys, associated with MS, may be modified by sex hormone levels. In general, estrogens are a protection against the development of cardiovascular and renal diseases in humans and experimental models, but androgens may have an opposite effect. Among the metabolic systems that can be modulated by sex hormones in the kidney, the more important are: renin-angiotensin-aldosterone system, arachidonic acid metabolism, nitric oxide system and renal extra-cellular matrix proteins. These are metabolic pathways normally associated, in order to maintain the most efficient functioning of renal hemodynamics. There is a close interrelationship between sex hormones and some pathways involved in the metabolic syndrome; also pathways can modulate each other. The circulating concentrations of hormones may determine the degree of overall pathological alterations in the syndrome.

[The uncertain future of general surgery. A specialty in the process of extinction]. / El futuro incierto de la cirugía general. Una especialidad en proceso de extinción.

General surgery was the first specialty of medicine. Nowadays, it is fragmented a progressive number of specialties, and has lost many of its fields. What will be the future of general surgery? What will be its repercussion on teaching surgery? From the point of view of a professor of surgery, our specialty today has nothing like what it was in the middle of the past century. Every day, its field of action becomes more and more reduced. Probably in the future, training in surgery will be limited to 2 years of basic knowledge, before the resident goes into the specialty of his/her choice.

[Unnecessary operations in the exercise of surgery. A topic of our times with serious implications in medical ethics]. / Las operaciones innecesarias en el ejercicio de la cirugía. Un tema de nuestro tiempo con graves implicaciones en la ética médica.

Unnecessary operations represent between 20 and 25% of total surgical practice. This article analyses causes, history, enormous economic effects and their consequences as an iatrogenic harm. Looking for a solution to the problem of unnecessary operations is urgent because these surgeries have a direct effect on the field of ethics and morality in the practice of surgery.

Insulin-induced endothelin release and vasoreactivity in hypertriglyceridemic and hypertensive rats.

Insulin-elicited endothelin release in hypertriglyceridemic, hypertensive, hyperinsulinemic (HTG) rats was shown. Weanling male Wistar rats were given 30% sucrose in their drinking water for 20-24 wk. In vitro contractions of aorta and femoral arteries were elicited with 40 mM KCl. Endothelin release induced with KCl plus 50 microU/ml insulin resulted in increases in contractile responses: 41 +/- 5.9 and 57 +/- 6% for control and 65.5 +/- 6 and 95 +/- 9% for HTG aortas and femoral arteries, respectively. The endothelin ET(B)-receptor blocker BQ-788 decreased responses to KCl + insulin by 39 +/- 8 and 53 +/- 5% in control and 48 +/- 13 and 79 +/- 3.5% in HTG aortas and femoral arteries, respectively. The ET(A)-receptor antagonist PD-151242 inhibited these responses by 12 +/- 10 and 1 +/- 9% in control and by 51.5 +/- 9 and 58.5 +/- 1% in HTG aortas and femoral arteries, respectively. These results suggest that endothelin may contribute to the hypertension in this model.

[History of surgical treatment of gastroesophageal reflux]. / La historia de las operaciones para el tratamiento del reflujo gastroesofágico.

There exists, in our times, a great confusion concording the different techniques for the treatment of gastroesophageal reflux. Today, for instance, we use the name "fundoplication" for different operations that, in many occasions, have nothing to do with the original description of the technique. It can be said that there exists a great lack of knowledge of the historical origins and of the evolution of all of these operations. The authors of this article have done a large-scale review of the original publications, as they appeared, for the first time, in medical literature.

An approach to the historical evolution of surgical operations for the treatment of gastroesophageal reflux.

There exists great confusion concerning the different techniques for the treatment of gastroesophageal reflux. For instance, we apply the term fundoplication to different operations that often have nothing to do with the original description, and there is a serious lack of knowledge of the historical origins of many of these operations. This analysis is the result of a large review of the operations, and of the original papers as they were published.

Endothelin mediation of insulin and glucose-induced changes in vascular contractility.

Although the prevalence of hypertension in diabetic patients is high and many factors participate, hyperinsulinemia cannot be discarded as a contributing factor. Insulin could act directly on smooth muscle altering intracellular calcium levels that mediate contraction and glucose transport or could induce the secretion of endothelin by the endothelial cells lining the vessels. The aim of the present report was to study the effect of different glucose and insulin concentrations on rat vascular smooth-muscle contractile characteristics and to determine whether insulin effects are mediated by endothelin. Femoral arteries obtained from Wistar rats were placed in an in vitro chamber and superfused with different glucose and/or insulin solutions. The contractile response to KCl 80 mmol/L, measured by the force generated, showed a significant decrease with high extracellular glucose concentrations (11 mmol/L). Insulin caused a dose-dependent increase in arterial contraction induced by KCl. This increase was significant when arteries were stimulated with 80 mmol/L KCl in the presence of 5.5 mmol/L glucose, but when 40 mmol/L KCl was used, an increase was observed with both 5.5 and 11 mmol/L glucose. The insulin-induced contraction was significantly reduced in the presence of hyperimmune anti-endothelin serum and in the presence of endothelin receptor ET(A) and ET(B) antagonists PD 151,242 and BQ-788, respectively. These results suggest that hyperinsulinemia and hyperglycemia may contribute to hypertension in diabetes and that responses to insulin are mediated partially by endothelin, thus explaining why non-insulin-dependent diabetes mellitus patients show an increase in arterial pressure before the onset of nephropathy.

[30 years' experience with posterior fundoplasty in the treatment of gastroesophageal reflux (analysis of 1499 cases)]. / Trente ans d'expérience avec la fundoplastie postérieure dans le traitement du reflux gastro-oesophagien (analyse de 1,499 cas).

Posterior fundoplasty, is an antireflux procedure we introduced in 1966 after experimental laboratory trials and published in 1969. To data, we have operated more than 2,000 cas. Although we now also use laparoscopic procedures, the present study reports our experience with 1499 patients who underwent the conventional procedure and who have been followed for 4 to 30 years. Mortality has been nil and mean failure rate was 9.6%. One important feature of this technique is the low incidence of undesirable effects: 3.66% dysphagia (none required dilatation), 3.94% impossibility to vomit, and 4.94% difficulties in belching. This study establishes comparisons between this group of 1499 patients and another group of 68 patients who underwent the original Nissen procedure performed under laparoscopy by the same surgeon and followed for a similar period. Such a larger personal series followed for 30 years is rare in the medical literature.

Esophageal fibrovascular polyp protruding from the mouth.

A case of a 66-year-old woman with a giant fibrovascular polyp protruding from the mouth is presented. The polyp was successfully removed by a cervical esophagotomy.

[An operative primary health care services model including physicians and technicians]. / Un modelo operativo de servicios de atención primaria a la salud con médicos y técnicos.

The operative Model of Primary Health Care, was developed to offer health services to a population living under conditions of extreme poverty in the municipality of Chimalhuacán, State of México. This article describes the theorical framework, organization and operationalization of an innovative model, changing the current paradigm of clinical practice to include allied health personnel with and especial training. At the core of the model is the Basic Unit of Primary Care that includes one physician and five allied health technicians for each 15,000 habitants. This model offer an alternative to improve the utilization of available personnel and infrastructure. Finally this paper emphasizes the importance of the permanece, surveillance and evaluation of the model.

Effects of alpha adrenergic stimulation on time independent potassium current of isolated ventricular myocytes.

The role of alpha adrenergic receptor stimulation on ventricular electrical activity is controversial. The aim of the present paper was to study a wide range of concentrations of alpha adrenergic agonists on the electrical properties of guinea pig's heart isolated ventricular myocytes. The experiments were performed according to the single electrode voltage clamp technique. Phenylephrine and epinephrine (in the presence of propranolol) were used at concentrations from 1 x 10(-9) to 10(-5) M. It was observed that both agonists induce an increase in the time independent inward rectifying potassium current (IK1), that could explain the shortening of the action potential. All the observed effects were dose-dependent and disappeared during washout. These results could explain, at least partially, some of the electrical changes observed during ischemia.

Different mechanism for insulin induced and contraction induced increases in skeletal muscle glucose uptake.

Glucose facilitated diffusion into cells depends on concentration gradients between intracellular and extracellular spaces and can be modified by several factors such as insulin and contractions. Calmodulin participates in the insulin induced recruitment of vesicles containing glucose transporter molecules and its inhibition by trifluoperazine blocks insulin increases in glucose uptake. In the present study we tested if calmodulin inhibition with trifluoperazine blocks hindlimb muscle glucose uptake increase induced by contractions. Trifluoperazine does not inhibit exercise induced increases in glucose uptake; therefore, the mechanisms by which insulin and functional activity increase glucose uptake are different.

Regulation by glucose availability of tension development and electrical activity in fetal and neonatal rat hearts.

The aim of the present article was to study if changes in glucose availability modify the functional activity of the glucose-dependent developing heart. Our data indicate that a decrease in glucose availability increases tension development and action potential duration at early fetal stages. This fact could probably be explained by the enhancement of Ca2+ movements that regulate the number and turnover rate of membrane glucose transporters in muscle cells. The sensitivity to glucose availability decreases postnatally as the heart becomes fatty acid-dependent.

[The development of cardiac function and its relation to metabolism during the perinatal period]. / Desarrollo de la función cardíaca y su relación con el metabolismo durante el periodo perinatal.

Several aspects of heart development are reviewed such as development of excitability and electrical and mechanical activity of the heart. Special emphasis is made upon metabolic changes during heart development and its possible consequences on electrical and mechanical activity.