Substance use among school-based youths in Puerto Rico: differences between gender and grade levels.

The present study examined substance use rates among adolescents in Grades 7-12 in Puerto Rico. Nine hundred eighty-nine students completed the Spanish version of the International Survey of Adolescent Health. More than 50% of middle school youths and 75% of high-school youths reported lifetime alcohol use.

The influence of sulfur and iron on dissolved arsenic concentrations in the shallow subsurface under changing redox conditions.

The chemical speciation of arsenic in sediments and porewaters of aquifers is the critical factor that determines whether dissolved arsenic accumulates to potentially toxic levels. Sequestration of arsenic in solid phases, which may occur by adsorption or precipitation processes, controls dissolved concentrations. We present synchrotron x-ray absorption spectra of arsenic in shallow aquifer sediments that indicate the local structure of realgar (AsS) as the primary arsenic-bearing phase in sulfate-reducing conditions at concentrations of 1-3 mmol.

Tegumental surface changes in adult Fasciola hepatica following treatment in vitro and in vivo with an experimental fasciolicide.

Our objective was to determine by scanning electron microscopy the structural changes in the tegument of adult Fasciola hepatica after treatment with 5-chloro-2-methylthio-6-(1-naphtyloxy)-1 H-benzimidazole, called compound alpha, and its active metabolite sulphoxide, under in vitro and in vivo conditions. For the in vitro studies, flukes from sheep were exposed to 40 mg/l of compound alpha-sulphoxide over different incubation times. Flukes for the in vivo studies were raised in sheep treated orally with compound alpha and killed at different times post-treatment.

An efficient synthesis of an alphavbeta3 antagonist.

A practical preparation of an alpha(v)beta(3) antagonist is reported. The antagonist consists of three key components, a tetrahydronaphthyridine moiety, a beta-alanine moiety, and a central imidazolidone moiety. The tetrahydronaphthyridine component was prepared using two different methods, both of which relied on variations of the Friedländer reaction to establish the desired regiochemistry.

Highly diastereoselective heterogeneously catalyzed hydrogenation of enamines for the synthesis of chiral beta-amino acid derivatives.

Pure (Z)-enamines readily prepared from beta-ketoesters and amides using (S)-phenylglycine amide were hydrogenated with very high diastereoselectivities (up to 200:1) using heterogeneous catalysis. Hydrogenolytic cleavage of the (S)-phenylglycine amide afforded the corresponding chiral beta-aminoesters and amides. The high geometrical purity of the (Z)-enamine and a simple activation procedure for the PtO2 catalyst are essential in achieving high selectivity.

Oral morphine and respiratory function amongst hospice inpatients with advanced cancer.

Background: Respiratory depression is the opioid adverse effect feared most by physicians. This may hinder adequate dosing in cancer pain. The study was conducted to examine the respiratory function of patients with advanced cancer receiving significant doses (>100 mg/24 h) of oral morphine.

Mutational mechanisms of Williams-Beuren syndrome deletions.

Williams-Beuren syndrome (WBS) is a segmental aneusomy syndrome that results from a heterozygous deletion of contiguous genes at 7q11.23. Three large region-specific low-copy repeat elements (LCRs), composed of different blocks (A, B, and C), flank the WBS deletion interval and are thought to predispose to misalignment and unequal crossing-over, causing the deletions.

Pulpal therapy for primary teeth: formocresol vs electrosurgery: a clinical study.

Post-operative clinical and x-ray findings on 80 primary molars were evaluated. These molars had undergone pulpal therapy by 2 techniques: pulpotomy with formocresol and with electrosurgery. The sample was selected from children between the ages of 4 and 7.

Opioids in cancer pain: common dosing errors.

Many individuals with advanced malignancy continue to suffer from pain and, consequently, impaired quality of life. The clinical scenarios in advanced cancer pain are complex, and successful management may require a more sophisticated and individualized approach than suggested by the World Health Organization guidelines. In patients referred to the Harry R.

Opioids, respiratory function, and dyspnea.

Dyspnea, the sensation of difficult breathing, is a common debilitating symptom in advanced cancer and chronic progressive cardiopulmonary disease. Primary treatment is correction of the underlying etiology. In incurable illness wherein the cause is irreversible and the goal is palliation, opioids are the drugs of choice for symptomatic relief.

Pseudoscopic imaging in a double diffraction process with a slit.

Pseudoscopic images that keep a continuous parallax are shown to be possible due to a double diffraction process intermediated by a slit. One diffraction grating acts as a wavelength encoder of views while a second diffraction grating decodes the projected image. The process results in the enlargement of the image under common white light illumination.

Vitiligo: complex segregation and linkage disequilibrium analyses with respect to microsatellite loci spanning the HLA.

Familial clustering and linkage disequilibrium studies suggest that genetic factors predispose to vitiligo, although a clear transmission pattern and cosegregation of vitiligo with specific mutations have not been demonstrated. We collected pedigree data on vitiligo from a set of 56 multigeneration families belonging to the Paisa community from Antioquia, Colombia, with the goal of applying the unified model of complex segregation and linkage disequilibrium analyses to test the hypotheses of the existence of a major gene predisposing to vitiligo and that allelic or haplotype polymorphisms of microsatellite loci at 6p21.3-21.

The role of C-reactive protein as a prognostic indicator in advanced cancer.

C-reactive protein (CRP) is a nonspecific but sensitive marker of inflammation. Interleukin-6 (IL-6), IL-1, and tumor necrosis factor alpha induce the synthesis of CRP in hepatocytes. Increased CRP level is considered to be an important risk factor for atherosclerosis, myocardial infarction, peripheral vascular disease, and ischemic stroke.

[In vitro antimicrobial susceptibility of Helicobacter pylori strains: isolation of strains resistant to clarithromycin].

Background: Our laboratory has carried out an epidemiological surveillance of Helicobacter pylori antimicrobial susceptibility since 1997.

Aim: To report the antimicrobial susceptibility of H pylori strains, isolated in Chile from August 1997 to August 2000.

Material And Methods: Ninety one H pylori strains, obtained from antral gastric biopsies during upper gastrointestinal endoscopies were studied.

Highly regioselective Friedländer reaction.

[reaction: see text]. A highly regioselective Friedländer reaction is described. By introduction of a phosphonate group at one of the alpha-carbons of a ketone, regioselectivity can be perfectly controlled.

[Analysis of complex segregation in a large family with hereditary cerebrovascular disease in Antioquia, Colombia].

Introduction: Among different kinds of cerebrovascular diseases, few of them are caused by genetic disturbances, such as CADASIL (caused by Notch3 mutations), CARASIL, mitochondrial encephalopathy, MELAS and dementia typed Binswanger. However, to describe these type of cerebrovascular diseases related with genetic mutations could permit to determinate the causes of both hereditary and sporadic cerebrovascular diseases and then lead solutions.

Objective: To describe the genetic, environmental and cohort factors that determinate the presence of many affected people by a several cerebrovascular diseases in the pedigree of a large family from Antioquia (Colombia).

Promoting cancer prevention and screening: the impact of the Cancer Information Service. Part 7.

Cancer Information Service (CIS) inquiries about cancer prevention and screening are an important opportunity to educate callers about primary or secondary cancer prevention, facilitate their decision-making, and, where appropriate, encourage action. An evaluation was conducted to assess whether these callers' information needs are being satisfied and to determine if the information provided facilitates decisionmaking and subsequent risk reduction actions. A random sample of 2,489 callers was surveyed during a 5-week period, 3 to 6 weeks after their initial call to CIS; prevention or screening was stated as the main reason for calling by 331 respondents.

Synthesis of an anti-methicillin-resistant Staphylococcus aureus (MRSA) carbapenem via stannatrane-mediated Stille coupling.

[formula: see text] A short synthesis of carbapenem 1 is described. They key step involves the cross-coupling of an enol triflate with an amino-substituted sp3 carbon. This cross-couping, which allows the introduction of the complete side chain in one step, utilizes a stannatrane as the heteroalkyl transfer reagent.

Infection and atherosclerosis--focus on cytomegalovirus and Chlamydia pneumoniae.

Background And Objective: Numerous studies have reported an association of coronary atherosclerosis and restenosis with certain bacterial and viral infections. This article reviews the pathophysiology of atherosclerosis, the role of infectious agents (i.e, cytomegalovirus and Chlamydia pneumoniae) in atherogenesis, and studies supporting the potential beneficial effects of antibiotics or antiviral agents in the management of atherosclerotic disease.

[Cyclosporosis. Report of a clinical case in Concepción, Chile].

Cyclospora cayetanensis is a newly recognized parasite widely distributed throughout the world, and isolated from children, immunocompetent adults and HIV infected individuals. The clinical manifestations of the infection are watery prolonged diarrhea, anorexia, fatigue, nausea, bloating and weight loss. In immunocompetent individuals, diarrhea is usually self limited but may last several weeks.

Four retinal ganglion cell types that project to the superior colliculus in the thirteen-lined ground squirrel (Spermophilus tridecemlineatus).

The morphology of retinal ganglion cells projecting to the superior colliculus (SC) of the thirteen-lined ground squirrel (Spermophilus tridecemlineatus) was studied after retrogradely labeling the cells with cholera toxin subunit B. On the basis of previous reports, labeled cells were classified as small (6-10 microm in soma diameter), medium (11-14 microm), or large (>14 microm). A total of 3,427 cells were studied.

Temporary and permanent restorations for fractured permanent teeth with immature apices: a clinical study.

Clinical and radiological studies of the fractured teeth of patients between seven and eleven years old were conducted to assess the use of permanent and immediate (emergency) techniques for reconstructing anterior permanent teeth with immature apices. The general hypothesis states that, given the physical and biocompatible properties of the materials used in the immediate (emergency) technique, there are no significant differences between the two techniques as far as pulp vitality and apical growth are concerned. A sample of fifty-six patients was selected.