A Cluster Analysis of Neuropsychological Impairment in Borderline Personality Disorder: Identifying a Neurocognitive Subtype Linked to Attention Deficit Hyperactivity Disorder.

INTRODUCTION: Cognitive impairment associated with borderline personality disorder (BPD) has been consistently demonstrated. However, a specific neuropsychological profile has not yet been established for this disorder, maybe due to the heterogeneity of BPD. The aim of this work is the search for distinct neuropsychological subtypes among patients with BPD and for the association of neuropsychological subgroups with specific clinical characteristics. METHODOLOGY: One hundred fifteen patients with BPD diagnosis received an extensive neuropsychological evaluation assessing attentional, memory and executive functions indexes. For subtyping strategies, a cluster analysis of neuropsychological BPD distribution was performed. Central clinical dimensions of BPD were measured and analysed in relation with the obtained neuropsychological clusters. RESULTS: Two clusters were found: Cluster 1 showed a significantly lower score on the working memory index, and Cluster 2 had significantly worse overall executive performance, response inhibition and planning abilities. Patients in the neurocognitive Cluster 2 showed significantly higher clinical deficits of attention as measured with subscales of the CAARS attention deficit hyperactivity disorder (ADHD) index (F = 2.549, p < 0.005, d = 11.49). CONCLUSIONS: Two neuropsychological clusters of patients were found in the BPD sample: Cluster 1 patients showed greater impairment in working memory, while Cluster 2 patients had greater deficits of executive functioning, particularly for response inhibition and planning. In addition, BPD patients with greater executive deficits presented greater levels of ADHD clinical features. These findings might also facilitate earlier diagnosis of severe BPD patient profiles and to establish more personalized treatment based on neurocognitive stimulation.

Transdiagnostic inflammatory and oxidative biomarkers with predictive capacity of self-injurious behavior in impulsive and unstable disorders.

INTRODUCTION: Alterations in inflammatory processes have previously been reported in impulsive and unstable disorders, as well as in other psychiatric conditions. In order to investigate transdiagnostic biomarkers associated with various phenotypic features of these disorders, this study is designed to identify biomarkers of inflammatory and oxidative endophenotypes related to autolytic behavior. METHODS: Peripheral blood mononuclear cells were collected from 35 patients with borderline personality disorder (BPD), 29 patients with restrictive eating disorder (rED), 21 patients with purging eating disorder (pED) and 23 control subjects. Plasma levels of different inflammatory and oxidative factors were measured by ELISA and the expression of selected proteins was by Western Blot. Principal component analysis (PCA) was performed to categorize the different inflammatory factors. Additionally, Ancova was performed to observe the differences in the principal components among the different groups and logistic regression analysis was conducted to assess the predictive capacity of these components for autolytic behaviors. RESULTS: We found two inflammatory/oxidative components were associated with BPD, characterized by high levels of JNK and ERK and low levels of GPx, SOD and Keap1; and two other inflammatory/oxidative components were linked to pED, associated with more JNK, TBARS and TNF-α and less GPx and SOD. Two components, with more JNK and ERK and less GPx, SOD and Keap1, predicted non-suicidal self-injury and three components, with higher JNK, TBARS and TNF-α levels and lower GPx, SOD and iNOS levels, predicted suicide attempts. CONCLUSIONS: These results strongly support the endophenotypic characterization of impulsivity and the identification of transdiagnostic inflammatory/oxidative biomarkers relevant to autolytic behavior in impulsive and unstable disorders. These dates lay the groundwork for developing of screening tests for these biomarker components to rapidly detect biological risk factors for specific impulse control disorders and future self-injurious behaviors.

Decreased oxytocin plasma levels and oxytocin receptor expression associated with aggressive behavior in aggressive-impulsive disorders.

INTRODUCTION: This study aims to enhance the understanding of the association between the phenotypic and endophenotypic characteristics of impulsive-aggressive disorders, through the study of plasma oxytocin (OXT) and oxytocin receptor (OXTR) levels in patients with borderline personality disorder (BPD) and patients with eating disorders (ED), as well as to examine the relationship of OXT system with aggressive behavior in these disorders. METHODS: 68 patients with BPD, 67 patients with ED and 57 healthy control subjects were examined for plasma oxytocin levels and protein expression of OXTR in blood mononuclear cells. Aggressive behavior was assessed using the State-Trait Anger Expression Inventory (STAXI-2). Other self and hetero-aggressive behaviors were also evaluated through interviews. RESULTS: BPD and ED patients exhibited significantly lower plasma oxytocin levels than control subjects. Furthermore, BPD patients demonstrated significantly reduced expression of OXTR compared to controls. Plasma oxytocin levels negatively correlated with verbal aggression, while OXTR expression was inversely associated with the STAXI trait subscale. CONCLUSIONS: The findings validate the existence of oxytocin system dysfunction in impulsive-aggressive disorders. They also support the link between low OXT levels in plasma and OXTR expression and the impulsive-aggressive behavior that characterizes these patients in both state and trait situations.

Inflammatory and oxidative endophenotypes in borderline personality disorder: A biomarker cluster analysis.

OBJECTIVES: This study is designed to search for aggrupation of inflammatory/oxidative biomarker alterations in borderline personality disorder (BPD) and their association with phenotypic features. METHODOLOGY: Inflammatory/nitrosative proteins were measures in plasma and peripheral blood mononuclear cells obtained from BPD patients. Patients were assessed on different clinical dimensions of BPD. Oxidative damage was tested by measuring TBARS, nitrites, catalase, GPx and SOD. Protein expression of IκBα, NFκB, iNOS, COX-2, PPARγ, Keap1, NQO1, Nrf2 and α7nAChR was also determined. Western blot and ELISA were used for measurements and a cluster analysis of inflammatory/oxidative biomarkers alterations was performed to investigate subgroups of patients with similar alterations and its relationship with clinical features of BPD. RESULTS: 69 patients were included in the study. Two inflammatory/nitrosative clusters of patients were found: Cluster 1 patients showed significantly higher levels of GPx, IκBα, keap1, NQO1, PPARγ, α7nAChR and Nrf2 than cluster 2 patients. These patients had significantly longer duration of illness, milder anxiety symptoms and lower prescription of antipsychotic drugs than cluster 2. CONCLUSIONS: Two clusters of BPD patients according to the inflammatory/nitrosative profiles were identified. Cluster 1 had increased antioxidant and anti-inflammatory biomarkers and was characterised by greater chronicity of illness but less acute symptomatic severity.

Liquid phase IR-MALDI and differential mobility analysis of nano- and sub-micron particles.

Infrared matrix-assisted desorption and ionization (IR-MALDI) enables the transfer of sub-micron particles (sMP) directly from suspensions into the gas phase and their characterization with differential mobility (DM) analysis. A nanosecond laser pulse at 2940 nm induces a phase explosion of the aqueous phase, dispersing the sample into nano- and microdroplets. The particles are ejected from the aqueous phase and become charged. Using IR-MALDI on sMP of up to 500 nm in diameter made it possible to surpass the 100 nm size barrier often encountered when using nano-electrospray for ionizing supramolecular structures. Thus, the charge distribution produced by IR-MALDI could be characterized systematically in the 50-500 nm size range. Well-resolved signals for up to octuply charged particles were obtained in both polarities for different particle sizes, materials, and surface modifications spanning over four orders of magnitude in concentrations. The physicochemical characterization of the IR-MALDI process was done via a detailed analysis of the charge distribution of the emerging particles, qualitatively as well as quantitatively. The Wiedensohler charge distribution, which describes the evolution of particle charging events in the gas phase, and a Poisson-derived charge distribution, which describes the evolution of charging events in the liquid phase, were compared with one another with respect to how well they describe the experimental data. Although deviations were found in both models, the IR-MALDI charging process seems to resemble a Poisson-like charge distribution mechanism, rather than a bipolar gas phase charging one.

Decreased oxytocin plasma levels and oxytocin receptor expression in borderline personality disorder.

INTRODUCTION: Borderline personality disorder (BPD) is characterized by intense affective reactions with underlying social and interpersonal cognitive deficits. Oxytocin has largely been associated with both stress regulation and social cognition in psychiatric patients and in non-clinical populations in previous studies. Finally, abnormal oxytocin levels have been preliminary reported in BPD patients. METHODS: 53 patients with moderate-severe BPD and 31 healthy control subjects were investigated for plasma levels of oxytocin and protein expression of oxytocin receptor in blood mononuclear cells. Clinical assessments were made for severity, functionality, and comorbidity with axis I and II conditions. RESULTS: Oxytocin plasma levels were significantly lower in BPD patients compared with controls. In addition, protein expression of oxytocin receptor was significantly reduced in the BPD group. A positive correlation was found between plasma oxytocin levels and the activity index score of the Zuckerman-Kuhlman Personality Questionnaire (ZKPQ). Oxytocin receptor protein expression, on the contrary, had a negative correlation with the ZKPQ sociability index score. CONCLUSIONS: Results support the evidence of a dysfunction of the oxytocin system in borderline personality disorder, which could be involved in emotional dysregulation and interpersonal disturbances in these patients.

Outcome of drug-induced sleep endoscopy-directed surgery for persistent obstructive sleep apnea after adenotonsillar surgery.

PURPOSE: Drug-induced sleep endoscopy (DISE) is suitable for evaluating persistent obstructive sleep apnea syndrome (OSAS) after adenotonsillar surgery as a means to guide surgical intervention, yet few studies demonstrate its usefulness in resolving the syndrome. We describe our experience of DISE-directed surgery in children with persistent OSAS by analysing objective and subjective outcomes of this treatment. METHODS: Prospective study of 20 otherwise healthy 2-12 year-old children with OSAS persisting after adenotonsillar surgery. All patients underwent DISE-directed surgery and were followed up clinically and with a polysomnogram at 12 ±â€¯3 months. RESULTS: All 20 children had an apnea-hypopnea index (AHI) score ≥1 (mean: 6.1 ±â€¯4.9) and 75% had AHI>3 before surgery. We performed a total of 14 total tonsillectomies (70%), 7 with associated pharyngoplasties; 5 radiofrequency turbinate reductions (25%); 7 radiofrequency lingual tonsil reductions (35%); and 10 revision adenoidectomies (50%). No surgery-related complications were observed. AHI scores at follow-up were significantly lower than AHI scores before surgery (1.895 ±â€¯1.11 vs 6.143 ±â€¯4.88; p < 0.05) and, in 85% (n = 17) of patients, AHI was below 3. There was a significant reduction in the number of children with AHI>3 in follow-up at 12 ±â€¯3 months (15%; n = 3) compared to before surgery (75%; n = 15) (p < 0.005). CONCLUSION: DISE-directed surgery for otherwise healthy children with persistent OSAS is a useful and safe technique to decide a therapeutic strategy and to obtain good objective and subjective results regarding resolution of the syndrome.

Elective neck dissection during salvage surgery after radiotherapy in patients with head and neck squamous cell carcinoma.

SUMMARY: Elective neck dissection in patients with recurrent head and neck squamous cell carcinoma (HNSCC) without evidence of neck disease (crN0) is poorly defined. A retrospective review was carried out on 165 crN0 patients treated with salvage surgery and elective neck dissection. Multivariate Cox analysis and recursive partitioning analysis were used to evaluate prognostic factors. The frequency of occult neck node metastases in the neck dissection (rpN+) was 16.4%. The risk of occult metastases for glottic rpT1-T2 recurrences was 5.9%, for glottic rpT3-T4 recurrences 13.2%, for non-glottic rpT1-T2 recurrences 16.1% and for locally advanced (rpT3-T4) non-glottic recurrences 31.1%. Patients with occult neck node metastases (rpN+) had a 5-year adjusted survival rate of 38.1%, while patients without nodal disease (rpN0) had a 5-year adjusted survival rate of 71.1% (p = 0.0001). Elective neck dissection can be omitted in crN0 patients with rT1-T2 glottic recurrence. We consider it advisable to perform elective neck dissection in all other situations.

Obstructive sleep apnea syndrome and growth failure.

Obstructive sleep apnea syndrome is a common problem among children and is recognized as a cause of significant medical morbidity. Since the 1980s, it has been suggested that obstructive sleep apnea syndrome is a risk factor for growth failure in children. In many cases, it has been shown that growth failure is reversible once the obstructive sleep apnea syndrome is resolved. The objectives of this study were to analyze and compare growth failure prevalence in a Mediterranean population of children with obstructive sleep apnea syndrome and healthy children matched in age and sex, and to assess the effectiveness of tonsillectomy and adenoidectomy in resolving growth retardation. We compared 172 children with obstructive sleep apnea syndrome (apnea-hypopnea index ≥ 3) who had undergone tonsillectomy and adenoidectomy with 172 healthy controls in terms of key anthropometric parameters. Most of the criteria used for growth failure were higher to a statistically significant degree in the study group vs the control group: height-for-age ≤ 3rd percentile (7.56% vs 2.91%; p = 0.044), weight-for-age ≤ 5th percentile (9.30% vs 2.33%; p = 0.005), weight-for-age ≤ 3rd percentile (8.14% vs 2.33%; p = 0.013) and height and/or weight for-age ≤ 5th percentile (13.95% vs 5.81%; p = 0.009). The height-for-age ≤ 5th percentile was almost at the limit of statistical significance (8.72% for the study group vs 4.65% for the control group; p = 0.097). At one-year post-surgery follow-up, 10 of 15 children with height-for-age ≤ 5th percentile had achieved catch-up growth (66.6%), and 14 of 24 children with height- and/or weight-for-age ≤ 5th percentile had normalized growth (58.33%). For children with failure to thrive or who have growth failure, physicians should consider the possibility of obstructive sleep apnea. A significant number of children with obstructive sleep apnea concurrent with growth failure could benefit from tonsillectomy and adenoidectomy to recover and normalize their growth rate.

Optical microfiber mode interferometer for temperature-independent refractometric sensing.

We report on a functional optical microfiber mode interferometer and its applications for absolute, temperature-insensitive refractive index sensing. A standard optical fiber was tapered down to 10 µm. The central part of the taper, i.e., the microfiber, is connected to the untapered regions with two identical abrupt transitions. The transmission spectrum of our device exhibited a sinusoidal pattern due to the beating between modes. In our interferometer the period of the pattern-an absolute parameter-depends strongly on the surrounding refractive index but it is insensitive to temperature changes. The period, hence the external index, can be accurately measured by taking the fast Fourier transform (FFT) of the detected interference pattern. The measuring refractive index range of the device here proposed goes from 1.33 to 1.428 and the maximum resolution is on the order of 3.7×10(-6).

Spheroidal Fabry-Perot microcavities in optical fibers for high-sensitivity sensing.

All-optical-fiber Fabry-Perot interferometers (FPIs) with microcavities of different shapes were investigated. It was found that the size and shape of the cavity plays an important role on the performance of these interferometers. To corroborate the analysis, FPIs with spheroidal cavities were fabricated by splicing a photonic crystal fiber (PCF) with large voids and a conventional single mode fiber (SMF), using an ad hoc splicing program. It was found that the strain sensitivity of FPIs with spheroidal cavities can be controlled through the dimensions of the spheroid. For example, a FPI whose cavity had a size of ~10x60 µm exhibited strain sensitivity of ~10.3 pm/µÎµ and fringe contrast of ~38 dB. Such strain sensitivity is ~10 times larger than that of the popular fiber Bragg gratings (~1.2 pm/µÎµ) and higher than that of most low-finesse FPIs. The thermal sensitivity of our FPIs is extremely low (~1pm/°C) due to the air cavities. Thus, a number of temperature-independent ultra-sensitive microscopic sensors can be devised with the interferometers here proposed since many parameters can be converted to strain. To this end, simple vibration sensors are demonstrated.

Doxazosina asociada a la combinación bloqueante del eje-renina-angiotensina y calcioantagonista en pacientes con insuficiencia renal crónica / Doxazosine associated to renin-angiotensin blockers and calcioantagonists in chronic renal failure patients

Objetivo. El estudio ZAFRA se diseñó para evaluar la seguridad de un nuevo bloqueantede los canales del calcio, lercanidipino, en la insuficiencia renal crónica, ysu posible sobre la función renal en los pacientes tratados con fármacos que bloqueanel eje renina-angiotensina. Los pacientes que no controlaron su PA con estos fármacosfueron tratados con doxazosina.Diseño y métodos. El estudio reclutó 203 pacientes con insuficiencia renal (creatinina> 1,4 mg/dl en varones o > 1,2 mg/dl en mujeres, o aclaramiento de creatinina< 80 ml/min). Todos los pacientes estaban siendo tratados con IECA o antagonistasde receptores y la medicación se mantuvo a lo largo del estudio, sin quepudieran recibir diuréticos a lo largo del seguimiento. Los pacientes eran evaluadosclínica y analíticamente 1, 3 y 6 meses después de iniciar tratamiento con lercanidipino.Aquellos pacientes que en la segunda visita no estaban controlados añadierondoxazosina GITS (4 mg en dosis única) al tratamiento.Resultados: 57 pacientes que iniciaron el estudio fueron tratados con doxazosina(edad media 64,8 ± 12,7 años, 47,4 varones y 52,6 mujeres). La PA se redujo significativamentedesde 164 ± 17/92 ± 9 hasta 135 ± 13/78 ± 8 mmHg (p < 0,001). Seprodujeron reducciones significativas de la PA en el 67,6% de los enfermos y el32,4% de los pacientes redujeron su PA hasta los límites recomendados (<130/85mmHg). Únicamente 2 (3,6) pacientes han presentado reacciones adversas. No sedetectó aumento de la incidencia de edema. La creatinina plasmática (1,9 ± 0,6mg/dl) no se había modificado al final del estudio (2,0 ± 0,8 mg/dl) ni el aclaramientode creatinina (38,7 ± 15,7 vs 38,5 ± 14,5). También se detectó un descensosignificativo del urato plasmático (7,0 ± 1,9 vs 6,7 ± 1,6 mg/dl, p < 0,05).Conclusiones: La doxazosina ha presentado un excelente perfil de seguridad enlos pacientes renales, destacando la ausencia de edemas a pesar de la insuficienciarenal de los pacientes

Objective. To evaluate the safety and effectiveness of the alfa-blocker doxazosinGITS in CRF patients.Design and methods. The study recruited 203 CRF patients (creatinine > 1,4mg/dl for males, creatinine > 1,2 mg/dl for females, or creatinine clearance < 80ml/min). All patients were receiving ACE inhibitores (63.4%) or angiotensin II antagonist(36.6%) therapy but they had higher blood pressure than recommended forCRF (130/85 mmHg). Patients were clinically evaluated 1, 3 and 6 moths after startingtreatment with lercanidipine (10 mg once daily). Patients with high blood pressurein spite of combined therapy with two drugs added doxazosin GITS 4-8 mgonce daily to treatment.Result: 57 patients rendered evaluable for the study (age 64.8 ± 12.7 years,47.4% males and 52.6 females). BP significantly decrease from 164 ± 17/92 ± 9mmHg to 135 ± 13/78 ± 8 mmHg. 67.6% patients showed a significant BP reductionand 32.4% gets optimal BP control (< 130/85 mmHg). Two patients (3.6%)showed untoward effects. No biochemical changes were detected.Conclusions: Doxazosin showed a good antihypertensive effect in CRF patientswhen used as third drug in resistant severe hypertension. It has a good tolerabilityprofile and showed a neutral profile on biochemical parameters

Lercanidipine in patients with chronic renal failure: the ZAFRA study.

OBJECTIVE: The objective was primary to evaluate the safe use of a new calcium channel blocker, lercanidipine, in patients with chronic renal failure (CRF). The secondary objective was to study the protective effect of calcium channel blocker on renal function in CRF patients previously treated with ACE inhibitors or angiotensin receptor blockers. DESIGN AND METHODS: The study recruited 203 CRF patients (creatinine >1.4 mg/dL for males, creatinine > 1.2 mg/dL for females, or creatinine clearance <70 mL/min). All patients were receiving ACE inhibitors (63.4%) or angiotensin II antagonist (36.6%) therapy, but they had higher blood pressure than recommended for CRF (130/85 mmHg). No patients were under diuretic treatment. Patients were clinically evaluated 1, 3, and 6 months after starting treatment with lercanidipine. Samples for urine and blood examination were taken during the examination. When needed, a third drug was added to the treatment, excluding diuretics. Creatinine clearance was measured using 24 h urine collection. RESULTS: 175 patients rendered valuable for the study (age 63.9+/-11.9 years, 52.9% males and 47.1% females). Blood pressure (BP) significantly decreased from 162+/-17/93+/-8.3 mmHg to 132+/-12/78+/-6 mmHg. 89.2% of patients showed a significant BP reduction, and 58.1% achieved optimal BP control (<130/85 mmHg). Seven patients (3.4%) showed untoward effects. Not one case of edema was detected, and the prevalence of adverse effects related to vasodilatation was extremely low (three patients, 1.48%). Plasmatic creatinine did not change (1.9+/-0.5 baseline versus 1.9+/-0.6 mg/dL), but creatinine clearance increased at the end visit (41.8+/-16.0 baseline versus 45.8+/-18.0 mL/min, p=0.019). Plasmatic cholesterol also decreased from 221+/-46 to 211+/-35 mg/dL (p=0.001). CONCLUSIONS: Lercanidipine showed a high antihypertensive effect in CRF patients. It has a good tolerability profile and showed an interesting effect on plasmatic lipids. An improvement in renal function, measured through creatine clearance, was detected.

[Doxazosine associated to renin-angiotensin blockers and calcioantagonists in chronic renal failure patients]. / Doxazosina asociada a la combinación bloqueante del eje-renina-angiotensina y calcioantagonista en pacientes con insuficiencia renal crónica.

OBJECTIVE: To evaluate the safety and effectiveness of the alfa-blocker doxazosin GITS in CRF patients. DESIGN AND METHODS: The study recruited 203 CRF patients (creatinine > 1,4 mg/dl for males, creatinine > 1,2 mg/dl for females, or creatinine clearance < 80 ml/min). All patients were receiving ACE inhibitores (63.4%) or angiotensin II antagonist (36.6%) therapy but they had higher blood pressure than recommended for CRF (130/85 mmHg). Patients were clinically evaluated 1, 3 and 6 moths after starting treatment with lercanidipine (10 mg once daily). Patients with high blood pressure in spite of combined therapy with two drugs added doxazosin GITS 4-8 mg once daily to treatment. RESULT: 57 patients rendered evaluable for the study (age 64.8 +/- 12.7 years, 47.4% males and 52.6 females). BP significantly decrease from 164 +/- 17/92 +/- 9 mmHg to 135 +/- 13/78 +/- 8 mmHg. 67.6% patients showed a significant BP reduction and 32.4% gets optimal BP control (< 130/85 mmHg). Two patients (3.6%) showed untoward effects. No biochemical changes were detected. CONCLUSIONS: Doxazosin showed a good antihypertensive effect in CRF patients when used as third drug in resistant severe hypertension. It has a good tolerability profile and showed a neutral profile on biochemical parameters.

[Lercanidipine in diabetic patients with renal failure]. / Lercanidipino en pacientes diabéticos it con insuficiencia renal.

OBJECTIVE: To evaluate the safe use of a new calcium channel blocker, lercanidipine, in diabetic chronic renal failure (CRF) patients. DESIGN AND METHODS: The study recruited 42 diabetic CRF patients (creatinine > 1.4 mg/dl for males, creatinine > 1.2 mg/dl for females, or creatinine clearance < 70 ml/min). Mean age was 68.2 +/- 9.1 years. 53.8% were males and 46.2% females. Three patients were type 1 diabetics and 39 ones were type II. All patients were receiving ACE inhibitors (67.4%) or angiotensin II antagonist (32.6%) therapy but they had higher blood pressure than recommended for CRF patients (130/85 mmHg). No patients were under diuretic treatment. Patients were clinically evaluated 1, 3 and 6 months after starting treatment with lercanidipine. Samples for urine and blood examination were taken during the examination. When needed, a third drug was added to treatment, excluding diuretics. Creatinine clearance was measured using 24 h urine collection. RESULTS: BP significantly decrease from 163 +/- 18/90 +/- 8 mmHg to 134 +/- 12/77 +/- 9 mmHg. One half of patients showed significant reduction of blood pressure, 26.7% reached the target blood pressure (< 130/85 mmHg) and 20.0% gets optimal BP control (< 130/85 mmHg). No one patient showed untoward effects. No edema was detected nor adverse effects related to vasodilatation were found. Plasmatic creatinine did not change (1.9 +/- 0.5 baseline vs 1.8 +/- 0.5 mg/dl) and creatinine clearance increased at the end visit (40.1 +/- 14.5 baseline vs 45.4 +/- 18.2 ml/min) but the difference was not significant. Proteinuria was unchanged. CONCLUSIONS: Lercanidipine showed a good antihypertensive effect in diabetics CRF patients. It has a good tolerability profile and showed neutral effect on plasmatic lipids. Neither impairment of renal function nor increment in proteinuria were detected.

The measurement of drinking patterns and consequences in Mexico.

The paper addresses the experiences of measuring and monitoring patterns of alcohol consumption and consequences in Mexico, provides an overview of alcohol use and problems, describes local cultural values that influence patterns of drinking, and discusses measurement implications.

Sensitivity of optical sensors based on laser-excited surface-plasmon waves.

We investigate the effect of the divergence of a Gaussian laser beam on the resonance curve and the sensitivity of optical sensors based on surface-plasmon resonance (SPR). For He-Ne laser beams it is found that, for beams with a waist radius of less than 300 microm, the SPR-curve characteristics differ appreciably from the case in which a plane wave is considered. Simple expressions for the sensitivity of (bio)chemical sensors are given. A simple Lorentzian model is used to estimate the maximum possible sensitivity when a multilayer system is used to enhance the resonance peak. It was found that the sensitivity can reach its highest value when the width of the SPR curve is equal to the laser-beam divergence. The results could be particularly important when a SPR curve is used to measure the absolute value of the refractive index of a sample or the dielectric constant and the thickness of a metal layer.

Antisocial behavior: its relation to selected sociodemographic variables and alcohol and drug use among Mexican students.

This study is part of the National School Survey on drug use by high school students in Mexico. The validity, reliability, and results of the Antisocial Acts Scale in Mexico City (n = 3,501) are discussed. Using factorial analyses of the Antisocial Acts Scale, two major sources of variability were observed. The first one is related to antisocial acts with severe social consequences, in which violence and drug selling are included, and the second one is related to thefts. Significant differences were found in the number of offenses among groups of different gender, age, and occupation during the previous year. More antisocial acts were perpetrated by alcohol and drug users than by nonusers. In a logistic regression model, it was found that the main risk factors for perpetrating antisocial acts were being male, using alcohol, and using other drugs.

Drug use pathways among high school students of Mexico.

OBJECTIVE: This study surveyed high school student drug users in urban areas of Mexico to describe use patterns and drug-related behaviors among adolescents and to develop predictor models of pathways to underage drug use. SUBJECT/DESIGN: A National School Survey was conducted among high school students where data are provided by the State. Only urban sites were considered for this study (n = 40,521). Stratified two-stage cluster sampling was used; schools and groups within the schools were the sampling units. CONCLUSIONS: Male adolescents who have worked the previous year, have high exposure within the family and are affiliated with drug using peers are at increased risk of becoming drug users and subject to depression and suicidal ideation as well as drug-related social problems.

Measuring optical power transmission near the critical angle for sensing beam deflection.

We investigate an internal-transmission method for measuring microdeflections of an optical beam as a potential tool for the development of new compact and stable optical sensors. We calculate the detection limits of the internal-transmission method when an ideal coherent optical source and an ideal quasi-monochromatic thermallike source are used. The proposed method is compared with an internal-reflection method previously studied. It is found theoretically and verified experimentally that the transmission method may have better resolution than the reflection method. We also compare the calculated sensitivity as a function of the angle of incidence with experimental results for both methods.