Design and preliminary testing of an active intramedullary nail.

Purpose: To enhance bone healing through controlled interfragmentary movements, numerous experiments have been conducted in animal models employing external fixation devices to apply mechanical stimulation to the fracture site. However, the efficacy of these fixators has been questioned. On the other hand, intramedullary nailing is a widely established clinical practice for reducing closed tibial fractures.

Would increased interstitial fluid flow through in situ mechanical stimulation enhance bone remodeling?

Bone accommodates to changes in its functional environment ensuring that sufficient skeletal mass is appropriately positioned to withstand the mechanical loads that result from functional activities. Increasing physical activity will result in increased bone mass, while the removal of functional loading would result in bone loss. Bone is a composite material made up of a collagen-hydroxyapatite matrix and a complex network of lacunae-canaliculi channels occupied by osteocyte and osteoblast processes, immersed in interstitial fluid.

The VYtorin on Carotid intima-media thickness and overall arterial rigidity (VYCTOR) study.

This study assessed the effect of 3 lipid-lowering therapies on the reduction of the carotid intima-media thickness (IMT) in high-risk coronary Mexican patients. The study was a randomized, comparative, and open clinical trial. Ninety high-risk coronary patients were allocated to 3 groups: pravastatin 40 mg, simvastatin 40 mg, and simvastatin 20 mg and ezetimibe 10 mg initially.

Metformin, arterial function, intima-media thickness and nitroxidation in metabolic syndrome: the mefisto study.

1. Metabolic syndrome (MS) is one of the greatest public health problems in Mexico, where more than 75% of adults in urban populations are overweight or obese. Metabolic syndrome has several comorbidities, which result in a high cardiometabolic risk.

Intraluminal-restricted 17 beta-estradiol exerts the same myocardial protection against ischemia/reperfusion injury in vivo as free 17 beta-estradiol.

Several in vitro studies show that in animals and isolated cells, 17 beta-estradiol induces cardiovascular protective effects and it has also been observed that it reduces coronary heart disease risk. However, the use of estrogens to improve or protect cardiovascular function in humans has been controversial, this might be explained by the wide variety of effects, because estrogen receptors (ER) are expressed ubiquitously. Therefore, a cell-specific targeting therapeutic approach might be necessary.

Cardiovascular risk factors in the urban Mexican population: the FRIMEX study.

Background: Atherosclerotic ischaemic heart disease is the second leading cause of general mortality in Mexico due to the growing prevalence of atherosclerotic risk factors in our society. The data of the FRIMEX study (Factores de Riesgo en México, Risk Factors in Mexico), considered together with those of other contemporary epidemiological surveys, will aid in our comprehension of the current state of cardiovascular epidemics in Mexico.

Methods: Frequencies of obesity, hypertension and smoking, and total cholesterol and glucose in capillary blood were estimated in a non-probabilistic sample comprised of 140017 individuals (aged 44+/-13 years; 42% men and 58% women), from six Mexican cities (Mexico City, Guadalajara, Monterrey, Puebla, Leon and Tijuana).

Differential expression of alpha1-adrenergic receptor subtypes in coronary microvascular endothelial cells in culture.

It has been postulated that in blood vessels under alpha(1)-related stimulation, the endothelial intracellular calcium concentration ([Ca(2+)](i)) increases, which is necessary to induce nitric oxide synthesis, is the result of an increase in vascular smooth muscle, which subsequently, flows into the endothelial cells through gap junctions and it is not the result of a direct adrenergic stimulation of endothelial receptors. Others, however, postulate that endothelial alpha(1D)-adrenoceptors, have a direct effect on nitric oxide synthesis. In order to clarify this phenomena, in this work we analyzed the presence of alpha(1)receptor subtypes and their functional association with nitric oxide synthesis in rat coronary microvascular endothelial cells in culture, with pharmacological, immunological and reverse transcriptase polymerase chain reaction approaches.

The pathogenesis of myocardial fibrosis in the setting of diabetic cardiomyopathy.

Diabetes has emerged as a major threat to worldwide health. The increasing incidence of diabetes in young individuals is particularly worrisome given that the disease is likely to evolve over a period of years. In 1972, the existence of a diabetic cardiomyopathy was proposed based on the experience with four adult diabetic patients who suffered from congestive heart failure in the absence of discernible coronary artery disease, valvular or congenital heart disease, hypertension, or alcoholism.

Caveolin scaffolding peptide-1 interferes with norepinephrine-induced PLC-beta activation in cultured rat vascular smooth muscle cells.

Caveolins are a family of integral membrane proteins implicated in various cell functions, including the organization and inactivation of signaling molecules of G protein-coupled receptors. We tested the ability of human caveolin scaffolding peptide-1 (CSP-1) to regulate norepinephrine- (NE) or histamine (HIS)-induced increases on intracellular calcium concentrations ([Ca(2+)]i). In cultured rat vascular smooth muscle cells (VSMC), CSP-1 inhibited in a concentration-dependent manner NE- and HIS-induced increases in [Ca(2+)]i.

Profibrotic influence of high glucose concentration on cardiac fibroblast functions: effects of losartan and vitamin E.

Long-standing diabetes can result in the development of cardiomyopathy, which can be accompanied by myocardial fibrosis. Although exposure of cultured kidney and skin fibroblasts to high glucose (HG) concentration is known to increase collagen synthesis, little is known about cardiac fibroblasts (CFs). Therefore, we determined the influence of HG conditions on CF functions and the effects of losartan and vitamin E in these responses.

Relationship between extra and intracellular sources of calcium and the contractile effect of thiopental in rat aorta.

To evaluate the relationship between the vasocontractile effect of thiopental and the extra and intracellular sources of Ca2+, we analyzed both the contractile effect of the barbiturate on rat aortic rings and its ability to modify the intracellular calcium concentration in cultured rat aorta smooth muscle cells. Thiopental (10-310 microg/mL) contracted aortic rings only in the presence of extracellular Ca2+, and this effect was not blocked by verapamil or diltiazem. On the contrary, Ca2+ (0.

Thiopental inhibits nitric oxide production in rat aorta.

We studied whether thiopental affects endothelial nitric oxide dependent vasodilator responses and nitrite production (an indicator of nitric oxide production) elicited by acetylcholine, histamine, and A23187 in rat aorta (artery in which nitric oxide is the main endothelial relaxant factor). In addition, we evaluated the barbiturate effect on nitric oxide synthase (NOS) activity in both rat aorta and kidney homogenates. Thiopental (10-100 microg/mL) reversibly inhibited the endothelium-dependent relaxation elicited by acetylcholine, histamine, and A23187.

Leiomyosarcoma of the rectum.

Leiomyosarcoma of the rectum is a rare entity. Approximately 150 cases have been described in the literature. Differentiation from its benign counterpart, leiomyoma, and other connective-tissue tumors is often difficult, but it is important because each tumor has an entirely different prognosis.

Sigmoid volvulus in the high altitude of the Andes. Review of 230 cases.

Sigmoid volvulus (SV) is uncommon in the United States. Little has been published in the English literature about the high incidence of SV among rural areas of the Bolivian and Peruvian Andes at 13,000 feet above sea level. A review of 230 cases of SV in a Bolivian hospital is presented.