Confrontation naming and semantic relatedness judgements in Spanish/English bilinguals

Background: The results of many current studies on naming in bilingualism have provided converging evidence for a semantic representation common to both languages within a bilingual individual. However, the interaction between lexical access and semantic representation in bilinguals is relatively unclear. Aims: To further understand this relationship in normal bilingual individuals, we asked the following questions: (1) Is there homogeneity in naming accuracy for both languages across subjects? We predicted that naming accuracy would differ across subjects based on their proficiency levels in each language. (2) After separating subjects into groups based on their proficiency levels (balanced, Spanish dominant, English dominant), is there a difference in their mean ratings of the semantic similarity of word pairs across proficiency groups? According to the mixed model (De Groot, Dannenburg, & van Hell, 1994), it was predicted that similar mean ratings would be observed across all groups. Methods & Procedures: A total of 23 Spanish/English bilinguals (average age = 35.5 years) completed a confrontation naming task and a semantic relatedness questionnaire in both languages. The same set of stimuli, controlled for various factors, was used for each task in both languages and counterbalanced by language across two sessions. Based on naming performances, participants were assigned to the balanced bilingual (N = 10), English dominant (N = 10), or Spanish dominant (N = 3) group (Kohnert, Hernandez, & Bates, 1998). Outcomes & Results: Overall English mean correct was 94.29%; Spanish was 88.19%. Significant differences in naming were seen between groups, F(2, 85) = 4.3, p =. 01, and within the language dominant groups across subjects (p <. 05) and items (p <. 05). On the semantic relatedness task, no significant difference was observed between the ratings of word pairs in each language across participants or items in any group. Conclusions: Despite differences in lexical access, participants in all proficiency groups rated word pairs similarly, indicating a shared semantic representation for both languages. The mixed model (de Groot et al., 1994) can explain the findings for all groups. Results of this study have clinical implications for bilingual aphasic patients. It is imperative to ascertain a patient's pre‐morbid language use prior to brain damage in order to gauge pre‐morbid proficiencies. Treatment should consider proficiency levels in both languages, with consideration that the strength of connections between each lexicon and from each lexicon to semantic memory may differ.     

Microphonic versus end-tidal carbon dioxide nasal airflow detection in neonates with apnea

Impedance pneumography in combination with expired CO2 monitoring are commonly used techniques for detecting central and obstructive apnea in infants. In this investigation an American Telephone and Telegraph StarSet-1 3000-ohm self-actuating microphone connected to the end of an infant cannula was used to monitor neonatal nasal airflow to detect breaths and apnea. The microphone was placed in a soundproof container to eliminate environmental sound artifacts. Analyses of 100 breaths from five patient samples during active and quiet sleep showed that there was no significant difference between microphone and expired CO2 recording of respiration. The techniques were 98% and 96% sensitive, respectively. Microphonic detection of nasal airflow identified 27 of the 32 episodes of upper airway obstruction (84.2%) registered by end-tidal CO2 recording. Inspiratory and expiratory events could also be well documented. Microphonic recording of nasal airflow is a reliable and inexpensive technique to detect apnea.     

Application of modeling and simulation to integrate clinical pharmacology knowledge across a new drug application

Typical drug development includes few studies to find the right dose/dosing regimen and several other bridging studies evaluating various prognostic factors (e.g.: co-administration of other drugs, organ failure). The drug sponsors and the regulators use this information to formulate labeling instructions for safe and effective use of the drug. In the current article, modeling and simulation are proposed as tools to integrate the knowledge from the effectiveness/safety studies and the bridging studies. Simulations allow exploring the impact of various prognostic factors on the effectiveness and safety. The concept is exemplified using the new drug application of an anti-migraine drug. The exercise aids in integrating all the knowledge across the drug development to suggest rationale dosing strategies; effectively communicating the impact of the prognostic factors to the clinicians/regulators; and protect against any intellectual losses due to development team changes.     

Protective role of vitamin E on the oxidative stress in Hansen's disease (Leprosy) patients

BACKGROUND: A constellation of reactive oxygen species (ROS) capable of damaging cellular constituents generated in excess during the chronic, inflammatory, neurodegenerative disease process of leprosy. The consequences of this leads to enhanced oxidative stress and lower antioxidant status. Enzymatic antioxidants provide first line defense against ROS. We have measured the levels of oxidative stress indices like lipid peroxidation (LPO), protein carbonyls together with enzymatic antioxidants in the blood samples of control and leprosy patients. Nutritional rehabilitation by way of exogenous supplementation of functionally efficient antioxidants like vitamin E reactivates the enzymatic antioxidant system and guards against the insult caused by ROS during the pathogenesis of the disease and antileprosy chemotherapy. DESIGN: Untreated leprosy patients were selected on the basis of clinical examination and skin smear. All diagnosed untreated leprosy patients received multi drug therapy (MDT) consisting of rifampicin, dapsone and clofazimine as recommended by World Health Organization. A small number of untreated cases were selected for co-supplementation of vitamin E along with MDT. Oxidative stress indices, enzymatic and nonenzymatic antioxidant status were assayed in untreated, MDT treated and those supplemented vitamin E along with MDT. STATISTICAL METHODS: We have compared the significance in the mean+/-s.d. values of the oxidative stress indices and the levels of antioxidants using one way analysis of variance (ANOVA) between control, untreated, MDT treated and those supplemented vitamin E with MDT and the results were significant at P < 0.05. Statistical analysis of the results suggests that oral administration of vitamin E lowers oxidative stress and augments antioxidant status in affected individuals.Results:Enhanced oxidative stress as evidenced by increased LPO and protein carbonyl in leprosy cases lowers the antioxidant status. Treatment with MDT has a limited impact on increased oxidative stress and decreased antioxidant status. Coadministration of vitamin E along with MDT decreases oxidative stress and activate the antioxidant status. DISCUSSION: The excess production of ROS as seen in leprosy cases could lead to degeneration of tissues and derangement of internal organs. The possible reason for the decreased antioxidant status in leprosy cases may be increased production of ROS, deranged liver function, and the free radical producing ability of drugs used in MDT of leprosy. Intervention with antioxidant supplementation like vitamin E prevents oxidative stress mediated through ROS and activates the net antioxidant status during the chronic course of the disease and antileprosy chemotherapy.     

A randomized, multicenter masked comparison trial of poractant alfa (Curosurf) versus beractant (Survanta) in the treatment of respiratory distress syndrome in preterm infants

We compared the onset of clinical response and safety of two surfactants, poractant alfa (Curosurf, Chiesi Pharmaceuticals, Parma, Italy) and beractant (Survanta, Ross Laboratories, Columbus, OH), for treatment of respiratory distress syndrome (RDS) in preterm infants weighing 750 to 1750 g at birth and <35 weeks gestation. The study was performed as a 20-center prospective, randomized, masked comparison trial. Preterm infants (n = 293) with RDS were randomized to receive an initial dose of either 100 (n = 96) or 200 (n = 99) mg/kg of poractant alfa or 100 ( n = 98) mg/kg of beractant. All repeat dosing was given at 100 mg/kg. The onset of clinical response after the first dose was studied by comparing changes in the fraction of inspired oxygen (F IO(2)) between 0 and 6 hours measured using the area under the curve (F IO(2) AUC (0-6)); other outcomes were assessed for the entire cohort at 28 days and for infants born at < or = 32 weeks gestation at 36 weeks postconceptional age. We found that the mean F IO(2) AUC (0-6) values for the 100 and 200 mg/kg poractant alfa groups were both significantly lower than the mean F IO(2) AUC (0-6) values for the beractant group ( p < 0.005) but were not different from each other. Other outcomes were not different among the three groups for the entire cohort, but in infants born at < or = 32 weeks gestation, mortality up to 36 weeks postconceptional age was significantly less in the 200 mg/kg poractant alfa group than in either the beractant group (3% versus 11%; p = 0.034) or in the 100 mg/kg poractant alfa group (3% versus 11%; p = 0.046). Need for more than one dose of surfactant was significantly lower in infants treated with an initial dose of 200 mg/kg poractant alfa in comparison to the beractant-treated group ( p < 0.002). Treatment with poractant alfa (200 mg/kg initial dose) resulted in rapid reduction in supplemental oxygen with fewer additional doses of surfactant versus treatment with beractant in infants <35 weeks gestation with RDS, and significantly reduced mortality ( p <0.05) than either beractant or poractant alfa (100 mg/kg dosing) in infants < or =32 weeks gestation with RDS.