Post-spike hyperpolarization participates in the formation of auditory behavior-related response patterns of inferior collicular neurons in Hipposideros pratti.

To probe the mechanism underlying the auditory behavior-related response patterns of inferior collicular neurons to constant frequency-frequency modulation (CF-FM) stimulus in Hipposideros pratti, we studied the role of post-spike hyperpolarization (PSH) in the formation of response patterns. Neurons obtained by in vivo extracellular (N=145) and intracellular (N=171) recordings could be consistently classified into single-on (SO) and double-on (DO) neurons. Using intracellular recording, we found that both SO and DO neurons have a PSH with different durations. Statistical analysis showed that most SO neurons had a longer PSH duration than DO neurons (p<0.01). These data suggested that the PSH directly participated in the formation of SO and DO neurons, and the PSH elicited by the CF component was the main synaptic mechanism underlying the SO and DO response patterns. The possible biological significance of these findings relevant to bat echolocation is discussed.

Acute respiratory distress syndrome in a pregnant woman with systemic lupus erythematosus: a case report.

When the disease activity of systemic lupus erythematosus (SLE) is controlled appropriately, a pregnant woman who has lupus is able to carry safely to term and deliver a healthy infant. While the physiology of a healthy pregnancy itself influences ventilatory function, acute pulmonary distress may decrease oxygenation and influence both mother and fetus. Though respiratory failure in pregnancy is relatively rare, it remains one of the leading conditions requiring intensive care unit admission in pregnancy and carries a high risk of maternal and fetal morbidity and mortality, not to mention the complexity caused by lupus flare. We report a case of SLE complicated with lupus pneumonitis and followed by acute respiratory distress during pregnancy. Though there is a high risk of maternal and fetal morbidity and mortality, maternal respiratory function improved after cesarean section and treatment of the underlying causes. The newborn had an extremely low birth weight but was well at discharge.

Low prevalence of major depressive disorder in Taiwanese adults: possible explanations and implications.

BACKGROUND: This study examined the prevalence of major depressive disorder (MDD), and the correlations and co-morbid conditions associated with MDD, in the adult Taiwanese population, which a previous estimate in the 1980s had found to be at the lower end of the spectrum worldwide. Possible explanations for the reported low prevalence of MDD were evaluated. METHOD: As part of a survey of common psychiatric disorders in a nationally representative sample of individuals aged ≥ 18 years who were non-institutionalized civilians in Taiwan, a face-to-face interview using the paper version of the World Mental Health Survey of the World Health Organization (WHO) Composite International Diagnostic Interview (WMH-CIDI) was conducted between 2003 and 2005. Functional impairment and help-seeking behaviors were compared between Taiwanese subjects with MDD and their counterparts in the USA. RESULTS: Among the 10 135 respondents, the lifetime prevalence of MDD was 1.20% [standard error (S.E.)=0.2%]. Individuals who were divorced or widowed, aged ≤ 40 years, and female were at increased risk, whereas rural residents were at lower risk for MDD. The proportion of MDD cases co-morbid with other psychiatric disorders in this study was much lower than in the US study. Only one-third of Taiwanese individuals with MDD sought help despite having twice the number of lost workdays compared with the US sample. CONCLUSIONS: Despite the low prevalence of MDD in Taiwanese adults, the pattern of low help-seeking behavior and profound functional impairment indicates much room for improvement in the early detection of and intervention in major depression in this population.

Leptin regulated calcium channels of neuropeptide Y and proopiomelanocortin neurons by activation of different signal pathways.

The fat-derived hormone leptin regulates food intake and body weight in part by modulating the activity of neuropeptide Y (NPY) and proopiomelanocortin (POMC) neurons in the hypothalamic arcuate nucleus (ARC). To investigate the electrophysiological activity of these neurons and their responses to leptin, we recorded whole-cell calcium currents on NPY and POMC neurons in the ARC of rats, which we identified by morphologic features and immunocytochemical identification at the end of recording. Leptin decreased the peak amplitude of high voltage-activated calcium currents (I(HVA)) in the isolated neurons from ARC, which were subsequently shown to be immunoreactive for NPY. The inhibition was prevented by pretreatment with inhibitors of Janus kinase 2 (JAK2) and mitogen-activated protein kinases (MAPK). In contrast, leptin increased the amplitude of I(HVA) in POMC-containing neurons. The stimulations of I(HVA) were inhibited by blockers of JAK2 and phosphatidylino 3-kinase (PI3-k). Both of these effects were counteracted by the L-type calcium channel antagonist nifedipine, suggesting that L-type calcium channels were involved in the regulation induced by leptin. These data indicated that leptin exerted opposite effects on these two classes of neurons. Leptin directly inhibited I(HVA) in NPY neurons via leptin receptor (LEPR) -JAK2-MAPK pathways, whereas evoked I(HVA) in POMC neurons by LEPR-JAK2-PI3-k pathways. These neural pathways and intracellular signaling mechanisms may play key roles in regulating NPY and POMC neuron activity, anorectic action of leptin and, thereby, feeding.

A model of polyelectrolyte conductance in moist solvents as a basis of water sensors.

The conductance of interpenetrated polymer networks (IPNs) containing quaternary amino groups was studied in cyclohexane, toluene, ethyl ether, ethyl acetate, and tetrahydrofurane as a function of water content by electrochemical impedance spectroscopy. IPNs were then used as sensitive materials to detect water traces in organic solvents with promising results for the construction of a moisture sensor. The detection onset for water concentration increased with the dielectric constant of the solvent. Different IPN-based sensors in the same solvent showed a detection limit at lower water concentration if their characteristic plot [conductance/relative humidity (RH%) in air] was shifted toward lower RH%. This suggests that the composition of this class of polymers can be tuned to achieve the best performance for each solvent.

Development and validation of an instrument to measure perceived neighbourhood quality in Taiwan.

STUDY OBJECTIVE: s: Social epidemiologists have hypothesised that neighbourhood quality may exert an important contextual influence on mental and physical health. However, validated instruments do not exist for measuring neighbourhood quality in Taiwan. A self reported instrument to measure perceived neighbourhood quality in Taiwan was developed and tested. DESIGN: Community survey. SETTING: Southern Taiwan, including the metropolitan Kaohsiung area and eight surrounding communities, representing urban, suburban, and rural districts. PARTICIPANTS: A total of 1084 residents, aged 18 to 75, were surveyed during 1999 to 2000. MAIN RESULTS: Using factor analysis with varimax rotation, three subscales explained 54.8% of the variance in our 15 item Neighbourhood Quality Index: perceived social capital (Cronbach alpha=0.84), perceived security (alpha=0.78), and adequacy of services and facilities (alpha=0.67). Lower perceived neighbourhood social capital (odds ratio, OR, 1.26; 95% CI: 1.21 to 1.32), lower neighbourhood security (OR 1.37; 95% CI: 1.26 to 1.48), and inadequate neighbourhood services and facilities (OR 1.17; 95% CI: 1.06 to 1.28) were all related to higher residential dissatisfaction. CONCLUSIONS: A Neighbourhood Quality Index was developed for use in Taiwan with good internal consistency and test-retest reliability, as well as convergent validity. Future studies will examine the association between this index and measures of individual mental and physical health.