Bumblebee thermoregulation at increasing temperatures is affected by behavioral state.

Over the past decades, increasing environmental temperatures have been identified as one of the causes of major insect population declines and biodiversity loss. However, it is unclear how these rising temperatures affect endoheterothermic insects, like bumblebees, that have evolved thermoregulatory capacities to exploit cold and temperate habitats. To investigate this, we measured head, thoracic, and abdominal temperature of bumblebee (Bombus terrestris) workers across a range of temperatures (24 °C-32 °C) during three distinct behaviors. In resting bumblebees, the head, abdomen, and thorax conformed to the environmental temperature. In pre-flight bumblebees, the head and abdominal temperatures were elevated with respect to the environmental temperature, while the thoracic temperature was maintained, indicating a pre-flight muscle warming stage. In post-flight bumblebees, abdominal temperature increased at the same rate as environmental temperature, but the head and the thoracic temperature did not. By calculating the excess temperature ratio, we show that thermoregulation in bumblebees during flight is partially achieved by the active transfer of heat produced in the thorax to the abdomen, where it can more easily be dissipated. These results provide the first indication that the thermoregulatory abilities of bumblebees are plastic and behavior dependent. We also show that the flight speed and number of workers foraging increase with increasing temperature, suggesting that bees do not avoid flying at these temperatures despite its impact on behavioral performance.

Adaptation and implementation of body project as a universal body image program in Mexico and Latin America.

The Body Project (BP) intervention for body image issues is supported by extensive efficacy and effectiveness research, most of which has been conducted in the United States. The BP uses cognitive dissonance to help participants critique the ideal appearance through written, verbal, and behavioral exercises. This reduces the internalization of the appearance ideal, which in turn decreases body dissatisfaction symptoms and, in some individuals, the onset of eating disorders. To broadly implement this program in Mexico and Latin America, Comenzar de Nuevo (CdN), a non-profit organization for eating disorder treatment, partnered with the Body Project Collaborative in 2014. Together, they created a training and implementation infrastructure. This paper explores the adaptation of BP and its implementation in Mexico and Latin America. We used sustainable business, marketing, and educational models to fulfill CdN's mission to reduce eating disorder risk factors, including weight stigma, in the Latin American region. By integrating strategies to combat weight stigma within our program delivery, we strive to contribute to a more inclusive and supportive environment. We trained master trainers, regular trainers, and/or group facilitators from Argentina, Bolivia, Colombia, Costa Rica, Chile, Dominican Republic, El Salvador, Guatemala, Mexico, Panama, and Spain; and implemented the BP in 15 public schools supported by sponsorship programs. This paper provides crucial lessons learned, future directions, and implications for dissemination and implementation efforts in this region of the world.

Induced Relaxation Enhances the Cardiorespiratory Dynamics in COVID-19 Survivors.

Most COVID-19 survivors report experiencing at least one persistent symptom after recovery, including sympathovagal imbalance. Relaxation techniques based on slow-paced breathing have proven to be beneficial for cardiovascular and respiratory dynamics in healthy subjects and patients with various diseases. Therefore, the present study aimed to explore the cardiorespiratory dynamics by linear and nonlinear analysis of photoplethysmographic and respiratory time series on COVID-19 survivors under a psychophysiological assessment that includes slow-paced breathing. We analyzed photoplethysmographic and respiratory signals of 49 COVID-19 survivors to assess breathing rate variability (BRV), pulse rate variability (PRV), and pulse-respiration quotient (PRQ) during a psychophysiological assessment. Additionally, a comorbidity-based analysis was conducted to evaluate group changes. Our results indicate that all BRV indices significantly differed when performing slow-paced breathing. Nonlinear parameters of PRV were more appropriate for identifying changes in breathing patterns than linear indices. Furthermore, the mean and standard deviation of PRQ exhibited a significant increase while sample and fuzzy entropies decreased during diaphragmatic breathing. Thus, our findings suggest that slow-paced breathing may improve the cardiorespiratory dynamics of COVID-19 survivors in the short term by enhancing cardiorespiratory coupling via increased vagal activity.

Long-term taurine administration improves motor skills in a tubulinopathy rat model by decreasing oxidative stress and promoting myelination.

The taiep rat undergoes hypomyelination and progressive demyelination caused by an abnormal microtubule accumulation in oligodendrocytes, which elicits neuroinflammation and motor behavior dysfunction. Based on taurine antioxidant and proliferative actions, this work explored whether its sustained administration from the embryonic age to adulthood could prevent neuroinflammation, stimulate cell proliferation, promote myelination, and relieve motor impairment. Taurine (50 mg/L of drinking water = 50 ppm) was given to taiep pregnant rats on gestational day 15 and afterward to the male offspring until eight months of age. We measured the levels of nitric oxide (NO), malondialdehyde + 4-hydroxyalkenals (MDA + 4-HDA), CXCL1, CXCR2 receptor, growth factors (BNDF and FGF2), cell proliferation, and myelin content over time. Integral motor behavior was also evaluated. Our results showed that taurine administration significantly decreased NO and MDA + 4-HDA levels, increased cell proliferation, and promoted myelination in an age- and brain region-dependent fashion compared with untreated taiep rats. Taurine effect on chemokines and growth factors was also variable. Taurine improved vestibular reflexes and limb muscular strength in perinatal rats and fine movements and immobility episodes in adult rats. These results show that chronic taurine administration partially alleviates the taiep neuropathology.

Prevalencias de estado de nutrición en recién nacidos mexicanos por peso y longitud al nacimiento: un análisis de los certificados de nacimiento del Sinac.

Objective: To describe the national by federal entity prevalence of the nutritional status of weight and length at birth. Materials and Methods: Cross-sectional descrip­tive study. Data from 1 907 341 alive newborns in 2017, registered in the Subsistema de Información sobre Nacimientos (Sinac), were analyzed. The percentiles for weight and length were estimated in the INTERGROWTH-21st platform. Results: The prevalence of small gestational age (SGA) and insufficient length (IL) was 7.4 and 4.8%, respectively. Differ­ences in the prevalence of IL, SGA and large for the gestational age (LGA) by sex were recorded (p <0.01). The entities with the highest prevalence of SGA were Estado de México and Yucatán (10.4%); Sonora (15.3%) and Baja California Sur (16.8%) of LGA. Conclusion: Sizing the nutritional status at birth allows the identification of entities that require targeted actions to reduce the risks associated with malnutrition.

Objetivo. Describir la prevalencia nacional por entidad federativa del estado de nutrición de peso y longitud al nacimiento. Material y métodos. Estudio transversal descriptivo. Se analizaron datos de 1 907 341 recién nacidos vivos en 2017, registrados en el Subsistema de Información sobre Nacimientos (Sinac). Los percentiles para peso y lon­gitud se estimaron en la plataforma INTERGROWTH-21st. Resultados. La prevalencia de pequeños para la edad ges­tacional (PEG) y longitud insuficiente (LI) fue de 7.4 y 4.8%, respectivamente. Se registraron diferencias por sexo en las prevalencias de LI, PEG y grandes para la edad gestacional (GEG) (p <0.01). Las entidades con mayores prevalencias de PEG (10.4%) fueron Estado de México y Yucatán. De GEG, fueron Sonora (16.8%) y Baja California Sur (15.3%). Conclu­sión. Dimensionar el estado de nutrición al nacer permite identificar entidades que requieren acciones focalizadas para disminuir los riesgos asociados con la malnutrición.

Slow gait speed is associated with dynapenic obesity in Mexican ambulatory older adults.

An increased risk of slow gait speed (GS) has been reported among older adults with decreased muscle strength, coupled with a concomitant increase in body fat known as dynapenic obesity (DO); however, these two conditions together have rarely been studied. The objective of this study was to determine the association between GS and DO in older Mexican ambulatory adults. A cross-sectional study was conducted; body fat percentage, and muscle strength and GS using EWGSOP criteria, were measured in 126 older ambulatory Mexican adults, with a mean age of 71 years old. The association was evaluated using controlled logistic regression models. Among ambulatory older adults with slow GS, the risk of DO was 3.4 times higher than among those without, controlling for age and sex (p<0.01). In conclusion, slow GS in ambulatory older adults can be a useful indicator for the early identification of DO.

Sex differences in CRF1, CRF, and CRFBP expression in C57BL/6J mouse brain across the lifespan and in response to acute stress.

Signaling pathways mediated by corticotropin-releasing factor and its receptor 1 (CRF1) play a central role in stress responses. Dysfunction of the CRF system has been associated with neuropsychiatric disorders. However, dynamic changes in the CRF system during brain development and aging are not well investigated. In this study, we characterized CRF1, CRF, and corticotropin-releasing factor binding protein (CRFBP) expression in different brain regions in both male and female C57BL/6J mice from 1 to 18 months of age under basal conditions as well as after an acute 2-hr-restraint stress. We found that CRF and CRF1 levels tended to increase in the hippocampus and hypothalamus, and to decrease in the prefrontal cortex with aging, especially at 18 months of age, whereas CRFBP expression followed an opposite direction in these brain areas. We also observed area-specific sex differences in the expression of these three proteins. For example, CRF expression was lower in females than in males in all the brain regions examined except the prefrontal cortex. After acute stress, CRF and CRF1 were up-regulated at 1, 6, and 12 months of age, and down-regulated at 18 months of age. Females showed more robust changes compared to males of the same age. CRFBP expression either decreased or remained unchanged in most of the brain areas following acute stress. Our findings suggest that brain CRF1, CRF, and CRFBP expression changes dynamically across the lifespan and under stress condition in a sex- and regional-specific manner. Sex differences in the CRF system in response to stress may contribute to the etiology of stress-related neuropsychiatric disorders.

Comparisons of neuroinflammation, microglial activation, and degeneration of the locus coeruleus-norepinephrine system in APP/PS1 and aging mice.

BACKGROUND: The role of microglia in Alzheimer's disease (AD) pathogenesis is becoming increasingly important, as activation of these cell types likely contributes to both pathological and protective processes associated with all phases of the disease. During early AD pathogenesis, one of the first areas of degeneration is the locus coeruleus (LC), which provides broad innervation of the central nervous system and facilitates norepinephrine (NE) transmission. Though the LC-NE is likely to influence microglial dynamics, it is unclear how these systems change with AD compared to otherwise healthy aging. METHODS: In this study, we evaluated the dynamic changes of neuroinflammation and neurodegeneration in the LC-NE system in the brain and spinal cord of APP/PS1 mice and aged WT mice using immunofluorescence and ELISA. RESULTS: Our results demonstrated increased expression of inflammatory cytokines and microglial activation observed in the cortex, hippocampus, and spinal cord of APP/PS1 compared to WT mice. LC-NE neuron and fiber loss as well as reduced norepinephrine transporter (NET) expression was more evident in APP/PS1 mice, although NE levels were similar between 12-month-old APP/PS1 and WT mice. Notably, the degree of microglial activation, LC-NE nerve fiber loss, and NET reduction in the brain and spinal cord were more severe in 12-month-old APP/PS1 compared to 12- and 24-month-old WT mice. CONCLUSION: These results suggest that elevated neuroinflammation and microglial activation in the brain and spinal cord of APP/PS1 mice correlate with significant degeneration of the LC-NE system.

Clinical guidelines for the management of keratoconus patients with gas permeable contact lenses based on expert consensus and available evidence.

PURPOSE OF REVIEW: Fitting rigid gas permeable contact lenses (RGP CLs) in keratoconic patients is the most common visual rehabilitation option to improve patients' quality of life, but require long patient and practitioner chair time. The purpose of this review is to provide evidence-based clinical practice guidelines (CPG) in the management of patients with keratoconus with RGP CLs. RECENT FINDINGS: An extensive literature review from 1990 to 2017 identified 354 potentially relevant publications. Fifty-two articles were reviewed and included in the CPG. An international expert panel of eight contact lens practitioners, with vast experience in keratoconus management reviewed and appraised the CPG following the Appraisal of Guidelines for Research and Evaluation II consortium requirements. The developed CPG clearly outlines a strategy for the successful fitting of RGP CLs in patients with keratoconus. This includes how to calculate parameters of the first diagnostic lens, criteria for assessing good fit and a standardized schedule of wear time and follow-up appointments. SUMMARY: The current evidence and consensus-based CPG helps guide clinicians in a successful strategy for fitting RGP CLs in patients with keratoconus.

Comorbidities associated with maternal mortality from COVID-19 in Mexico.

INTRODUCTION: In Mexico, there is a syndemic in pregnant women, where the epidemic of obesity and chronic diseases coexists with that of coronavirus disease 2019 (COVID-19), which has been associated with a higher risk of maternal mortality. OBJECTIVE: To evaluate the association of comorbidities during pregnancy with maternal mortality from COVID-19 in Mexico. MATERIAL AND METHODS: SISVER COVID-19 databases and epidemiological surveillance reports on maternal mortality were used. Multivariate logistic regression models were used to evaluate the association of comorbidities with maternal deaths from COVID-19. RESULTS: A total of 29,416 pregnant women were evaluated, out of which 39% were positive for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2); the risk of maternal mortality was 3.24 times higher (p < 0.01) for positive in comparison with negative women. COVID-19 is the leading cause of maternal death since July 2020 and explains more than 50% of total deaths in 2021. Chronic kidney disease (odds ratio [OR]: 4.11; p < 0.01) and diabetes (OR: 2.53; p < 0.01) were the two main comorbidities that were positively associated with maternal death from COVID-19. CONCLUSION: Comorbidities during pregnancy that are possibly associated with an increase in the inflammatory response and an alteration of the immune response increase the risk of maternal death from COVID-19 in Mexican pregnant women.

INTRODUCCIÓN: En México existe una sindemia en las mujeres gestantes, donde coexiste la epidemia de obesidad y enfermedades crónicas con la de enfermedad por coronavirus 2019 (COVID-19), lo que se ha asociado con un mayor riesgo de mortalidad. OBJETIVO: Evaluar la asociación de las comorbilidades en la mortalidad materna por COVID-19 en México. MATERIAL Y MÉTODOS: Se utilizaron las bases de datos de COVID-19 del SISVER y los reportes de vigilancia epidemiológica de muertes maternas. Se utilizaron modelos de regresión logística multivariante para evaluar la asociación de las comorbilidades durante la gestación con mortalidad materna por COVID-19. RESULTADOS: Se evaluaron 29,416 mujeres embarazadas, el 39% fueron positivas para coronavirus 2 del síndrome respiratorio agudo grave, el riesgo de mortalidad materna fue 3.24 veces mayor (p < 0.01) para las mujeres positivas en comparación con las negativas. La COVID-19 es la primera causa de muerte materna desde julio del 2020 y explica más del 50% del total de muertes en el 2021. La enfermedad renal crónica (razón de momios [RM]: 4.11; p < 0.01) y la diabetes (RM: 2.53; p < 0.01) fueron las dos principales comorbilidades asociadas positivamente a la mortalidad materna por COVID-19. CONCLUSIÓN: Las comorbilidades durante el embarazo posiblemente asociadas con un incremento de la respuesta inflamatoria y alteración de la respuesta inmunitaria incrementan el riesgo de muerte materna por COVID-19 en mujeres gestantes mexicanas.

Reduced accumulation of defective viral genomes contributes to severe outcome in influenza virus infected patients.

Influenza A virus (IAV) infection can be severe or even lethal in toddlers, the elderly and patients with certain medical conditions. Infection of apparently healthy individuals nonetheless accounts for many severe disease cases and deaths, suggesting that viruses with increased pathogenicity co-circulate with pandemic or epidemic viruses. Looking for potential virulence factors, we have identified a polymerase PA D529N mutation detected in a fatal IAV case, whose introduction into two different recombinant virus backbones, led to reduced defective viral genomes (DVGs) production. This mutation conferred low induction of antiviral response in infected cells and increased pathogenesis in mice. To analyze the association between low DVGs production and pathogenesis in humans, we performed a genomic analysis of viruses isolated from a cohort of previously healthy individuals who suffered highly severe IAV infection requiring admission to Intensive Care Unit and patients with fatal outcome who additionally showed underlying medical conditions. These viruses were compared with those isolated from a cohort of mild IAV patients. Viruses with fewer DVGs accumulation were observed in patients with highly severe/fatal outcome than in those with mild disease, suggesting that low DVGs abundance constitutes a new virulence pathogenic marker in humans.

ErbB4 Receptors in the Medial Habenula Regulate Contextual Fear Memory.

The Medial Habenular (MHb) and the Lateral Habenular nuclei are 2 main parts of the habenular complex (Hb). Recent studies showed that MHb plays an important role in memory, and in the expression of ErbB4. However, the expression of MHb ErbB4 receptor and its role in fear memory is not well understood. In this study, western blotting and quantitative real-time polymerase chain reaction were used to assess the protein and mRNA levels of ErbB4 in the process of contextual fear conditioning. A pharmacological approach was used to block and stimulate the ErbB4 receptor. Contextual fear conditioning tests induced a significant increase on the expression of ErbB4 at various times in the Hb and the MHb. Moreover, the blockade and stimulation of MHb ErbB4 receptors did not affect the fear formation but impaired and improved the contextual-dependent fear expression. Furthermore, in vitro electrophysiological recordings showed that the blockade of the MHb ErbB4 receptor reduced the presynaptic gamma-amino butyric acid release. ErbB4 is a susceptible gene for schizophrenia and the above findings may provide new insights into the mechanisms of fear-related responses.

[Evaluation of physical and psychological dependence in Mexican adult smokers, Encodat 2016.] / Evaluación de la dependencia física y psicológica al tabaco en fumadores mexicanos adultos, Encodat 2016.

OBJECTIVE: To evaluate the physical and psychological dependence to tobacco of Mexican smokers and its association with physical, psychological and social factors. MATERIALS AND METHODS: The 2016 National Alcohol and Tobacco Drug Consumption Survey (n=7 331) was analyzed using the Fagerström nicotine physical dependence scale (FTND) and the short scale of psychological dependence on tobacco (TAPDSc). Bivariate analyzes and generalized ordinal logistic regressions were performed to evaluate the associated factors. RESULTS: 82.3% of daily smokers and 98.8% of occasional smokers reported mild physical dependence, while 47.9 and 37.9% respectively reported moderate psychological dependence. The age of initiation of tobacco use, drug use, high alcohol consumption and high emotional distress were associated with high levels of psychological dependence in all smokers. CONCLUSIONS: The exclusive use of FTND does not allow to adequately evaluate Mexican smokers. The physical and psychological dependence on tobacco should be assessed with independent and validated scales in this population.

OBJETIVO: Evaluar la dependencia física y psicológica de los fumadores mexicanos y su asociación con factores físicos, psicológicos y sociales. MATERIAL Y MÉTODOS: . A partir de la Encuesta Nacional de Consumo de Drogas, Alcohol y Tabaco 2016 (n=7 331), se analizó la escala de dependencia física a la nicotina de Fagerström (FTND) y la escala corta de dependencia psicológica al tabaco (TAPDSc). Se realizaron análisis bivariados y regresiones logísticas ordinales generalizadas para evaluar los factores asociados. RESULTADOS: 82.3% de fumadores diarios y 98.8% de ocasionales reportaron dependencia física leve, mientras que 47.9 y 37.9%, respectivamente, presentaron dependencia psicológica moderada. La edad de inicio temprana de consumo de tabaco, uso de drogas, consumo alto de alcohol y malestar emocional se asociaron con niveles altos de dependencia psicológica en todos los fumadores. CONCLUSIONES: El uso exclusivo de FNTD no permite evaluar adecuadamente a los fumadores mexicanos. La dependencia física y psicológica al tabaco debe ser diagnosticada con escalas independientes y validadas en esta población.

"Vive Sin Tabaco ¡Decídete!" Feasibility and Acceptability of an e-Health Smoking Cessation Informed Decision-Making Tool Integrated in Primary Healthcare in Mexico.

Introduction:While smoking remains one of the leading causes of death in Mexico, uptake of evidence-based cessation therapy remains low. Widespread use of mobile devices and internet in Mexico has created new avenues for providing access to cessation treatment.Methods:We assessed the feasibility and acceptability of "Vive Sin Tabaco… ¡Decídete!" (English: Live without Tobacco…. Decide!), a web-based, informed decision-making tool designed to help Mexican smokers develop a quit plan and take advantage of cessation resources. We invited 164 smokers in two primary care clinics. Measures included physical, situational, and psychological nicotine dependence, interest in using pharmacotherapy and counseling, smoking status at 3 months, and satisfaction with the program.Results:Most participants were light smokers and reported low-to-moderate nicotine dependence. Immediately after using ¡Vive Sin Tabaco… ¡Decídete!, the majority were interested in quitting, set a quit date, and reported interest in using pharmacotherapy and cessation counseling. Follow-up rate at 3 months was 81.5%; seven-day point prevalence abstinence was 19.1% using intention-to-treat analysis.Conclusion:Integration of e-Health tools in primary healthcare settings has the potential to improve knowledge about cessation treatments among smokers and integrate smoking cessation into routine of care.

More Evidence for the Genetic Susceptibility of Mexican Population to Nonalcoholic Fatty Liver Disease through PNPLA3.

BACKGROUND: The gene for patatin-like phospholipase domain containing 3 (PNPLA3) is associated with nonalcoholic fatty liver disease (NAFLD) development. We previously found that Mexican indigenous population had the highest frequency reported of the PNPLA3 148M risk allele. Further, we observed a relationship between M148M genotype with elevated ALT levels in individuals with normal weight, overweight and obese. We sought to investigate whether PNPLA3 polymorphism is associated with NAFLD development in Mexicans. MATERIAL AND METHODS: We enrolled 189 Mexican patients with NAFLD and 201 healthy controls. Anthropometric, metabolic, and biochemical variables were measured, and rs738409 (Ile148Met substitution) polymorphism was genotyped by sequencing. RESULTS: Logistic regression analysis, using a recessive model, suggested that PNPLA3 polymorphism in Mexican population is significantly associated (OR = 1.711, 95% CI: 1.014-2.886; P = 0.044) with NAFLD. CONCLUSIONS: The PNPLA3 gene is associated with NAFLD in Mexican population. More studies are required to explain the high prevalence of PNPLA3 polymorphism in Mexican-Americans, Mexican-Indians, and Mexican-Mestizos.

Thrombosis of the Portal Venous System in Cirrhotic vs. Non-Cirrhotic Patients.

INTRODUCTION AND AIM: Thrombosis is a vascular disorder of the liver often associated with significant morbidity and mortality. Cirrhosis is a predisposing factor for portal venous system thrombosis. The aim of this study is to determine differences between cirrhotics and non-cirrhotics that develop thrombosis in portal venous system and to evaluate if cirrhosis severity is related to the development of portal venous system thrombosis. MATERIAL AND METHODS: We studied patients diagnosed with portal venous system thrombosis using contrast-enhanced computed tomography scan and doppler ultrasound at Medica Sur Hospital from 2012 to 2017. They were categorized into two groups; cirrhotics and non-cirrhotics. We assessed the hepatic function by Child-Pugh score and model for end-stage liver disease. RESULTS: 67 patients with portal venous system thrombosis (25 with non-cirrhotic liver and 42 with cirrhosis) were included. The mean age (± SD) was 65 ± 9.5 years in cirrhotic group and 57 ± 13.2 years (p = 0.009) in non-cirrhotic group. Comparing non-cirrhotics and cirrhotics, 8 non-cirrhotic patients showed evidence of extra-hepatic inflammatory conditions, while in the cirrhotic group no inflammatory conditions were found (p < 0.001). 27 (64.29%) cirrhotic patients had thrombosis in the portal vein, while only 9 cases (36%) were found in non-cirrhotics (p = 0.02). CONCLUSIONS: In cirrhotic patients, hepatocellular carcinoma and cirrhosis were the strongest risk factors to develop portal venous system thrombosis. In contrast, extrahepatic inflammatory conditions were main risk factors associated in non-cirrhotics. Moreover, the portal vein was the most frequent site of thrombosis in both groups.

Enhancing smoking cessation in Mexico using an e-Health tool in primary healthcare.

OBJECTIVE: To evaluate an e-Health tool designed to enhance smoking cessation in Mexico in primary healthcare. MATERIALS AND METHODS: Smokers 18 years of age and older were recruited in the waiting room of two primary healthcare clinics in Mexico City. Participants used an eHealth smoking cessation tool that included smoking-related assessments, education on pharmacotherapy, and motivational videos. A follow-up assessment was conducted at 12 weeks week on smoking status. Logistic regression models were performed to identify factors associated with smoking cessation or consumption reduction. RESULTS: A total of 132 smokers were enrolled in the study. At follow-up, 23.5% of participants self-reported smoking cessation. Among those who did not quit smoking, 65.0% decreased the number of cigarettes. Factors associated significantly with smoking cessation were: being a non-daily smoker, being interested in quitting smoking, having low level of physical dependence, and participating in cessation treatment. CONCLUSIONS: The e-Health tool produced a high rate of smoking cessation. Better outcomes are obtained when this tool is used with conventional cessation programs.

Effect of exposure to p,p´-DDE during the first half of pregnancy in the maternal thyroid profile of female residents in a Mexican floriculture area.

BACKGROUND: Dichlorodiphenyldichloroethene (p,p´-DDE), the main metabolite of dichlorodiphenyltrichloroethane (DDT), has been associated with changes in human thyroid hormone levels. Maternal thyroid hormones are essential for adequate fetal neurodevelopment during the first half of pregnancy. OBJECTIVE: To evaluate the association between maternal p,p´-DDE concentration and the maternal thyroid profile during the first half of pregnancy. MATERIALS AND METHODS: We analyzed the information of 430 pregnant women from a Mexican floriculture area, with a gestational age ≤16 weeks. By questionnaire, we obtained sociodemographic, reproductive, and life-style, information. Serum concentrations of thyroid stimulating hormone (TSH), and total and free T3 and T4 were determined by means of Enzyme-Linked ImmunoSorbent Assay (ELISA). p,p´-DDE was analyzed by Gas Chromatography. The association between p,p´-DDE and thyroid profile was assessed through linear and logistic regression models. RESULTS: Thirty eight percent of women had p,p´-DDE levels below the Limit of Detection and 12.3% below the Limit of Quantification. Within the quantifiable range, median was 53.03ng/g. TSH >2.5 mIU/L was present in 9.3% of women; 47.7% had isolated hypothyroxinemia; 3.5% had subclinical hypothyroidism, and 5.8% had overt hypothyroidism. We observed a significant positive association between quantifiable p,p´-DDE and total T3 serum levels in comparison with those with concentrations below the Limit of Detection (ß=0.19; 95% CI=0.06, 0.34). There were no significant associations with other hormones of the thyroid profile or with clinical diagnosis. CONCLUSIONS: Our findings suggest that p,p´-DDE exposure, even at low concentrations, could disrupt thyroid homeostasis during pregnancy.

Regulation of human GDNF gene expression in nigral dopaminergic neurons using a new doxycycline-regulated NTS-polyplex nanoparticle system.

The human glial-cell derived neurotrophic factor (hGDNF) gene transfer by neurotensin (NTS)-polyplex nanoparticles functionally restores the dopamine nigrostriatal system in experimental Parkinson's disease models. However, high levels of sustained expression of GDNF eventually can cause harmful effects. Herein, we report an improved NTS-polyplex nanoparticle system that enables regulation of hGDNF expression within dopaminergic neurons. We constructed NTS-polyplex nanoparticles containing a single bifunctional plasmid that codes for the reverse tetracycline-controlled transactivator advanced (rtTA-Adv) under the control of NBRE3x promoter, and for hGDNF under the control of tetracycline-response element (TRE). Another bifunctional plasmid contained the enhanced green fluorescent protein (GFP) gene. Transient transfection experiments in N1E-115-Nurr1 cells showed that doxycycline (100 ng/mL) activates hGDNF and GFP expression. Doxycycline (5 mg/kg, i.p.) administration in rats activated hGDNF expression only in transfected dopaminergic neurons, whereas doxycycline withdrawal silenced transgene expression. Our results offer a specific doxycycline-regulated system suitable for nanomedicine-based treatment of Parkinson's disease.

Success of Rigid Gas Permeable Contact Lens Fitting.

OBJECTIVES: To assess the percentage of successful rigid gas permeable (GP) contact lenses (CLs) fit for both refractive and therapeutic reasons. METHODS: New CLs (soft or GP) fittings were retrospectively analyzed and divided into refractive and therapeutic prescriptions. A standardized fitting protocol that included complete CLs information after a first eye examination, a diagnostic fitting visit, a dispensing visit, and a prescribing visit was used in all fittings. A GP fitting was defined as successful if full-time wear and optimal ocular surface physiology were both achieved at the review assessment 2 to 3 weeks after lens dispensing. RESULTS: Of 232 new CLs fittings analyzed, 166 were refractive fittings (71.6%) and 66 were therapeutic (28.4%). Of the refractive fittings, 88 subjects (53%) were initially fitted with GP CLs and 61 (69.3%) of these met the criteria for successful GP fitting. Within this group, a different percentage of successful fits were found for neophyte (72%), previous soft lens wearers (62%), and previous GP wearers (92.3%). Of the therapeutic fittings, 61 subjects (92.4%) were initially fitted with GP CLs and 59 (96.7%) of these met the criteria for successful GP fitting. CONCLUSIONS: Following a standardized CLs fitting protocol, a relatively high percentage of successful GP fits was achieved for refractive (7/10 subjects) and therapeutic (9/10 subjects) prescriptions. These results will improve the information available to patients and aid in their CL choices by providing them with a realistic attitude. It will also help eye care practitioners in their clinical activities by providing evidence-based information.