Changes in cytosolic calcium during cholinergic and adrenergic stimulation of the parotid salivary gland

Ca-selective microelectrodes were used to examine calcium transport during acetylcholine (ACh) and Epinephrine (Ep) stimulation of amylase secretion in the parotid gland. The cytosolic concentration of free ionized Ca2+ ( [Ca]i) determined in unstimulated cells was 0.44 +/- 0.04 microM. By measuring the induced changes in intracellular electrode potentials (ECa, EM) we were able to demonstrate that ACh at 10(-9), 10(-8), 10(-7), 10(-6), and 10(-5) M increased [Ca]i by 0.20 +/- 0.02, 0.61 +/- 0.04, 0.53 +/- 0.02, 0.30 +/- 0.05, and 0.14 +/- 0.03 microM. Similarly, Ep increased [Ca]i by 0.14 +/- 0.01, 0.42 +/- 0.06, 0.31 +/- 0.04, 0.15 +/- 0.03, and 0.05 +/- 0.04, respectively. Removal of extracellular Ca2+ significantly (P less than 0.001) altered the changes in ECa in response to ACh and Ep stimulation, thereby demonstrating that the induced increases in [Ca]i must be due to a transmembrane movement of Ca2+. Enzyme secretion was found to vary with the concentration of the stimulus used. Maximal secretion occurred during stimulation using 10(-7) M and 10(-8) M Ep with a suppression of release at supramaximal concentrations. The dose-response curve for ACh differed in that there were two concentrations of stimulus (2 X 10(-9) and 1 X 10(-6) M ACh) in which the greatest rate of secretion occurred. Concentrations of stimulus which increase [Ca]i between 0.86 +/- 0.06 microM and 0.74 +/- 0.05 appeared to produce optimal amylase secretion, indicating that salivary secretion in the mouse parotid is regulated within a narrow concentration range of cytosolic Ca2+.     

Sensitivity to binaural intensity and phase difference cues in kitten inferior colliculus.

1. Responses of single neurons to monaural or binaural CF tones delivered through a closed and calibrated sound delivery system were studied in the central nucleus of the inferior colliculus (ICC) in ketamine and barbiturate-anesthetized kittens 4-105 days old. 2. Neurons from young kittens had elevated thresholds, some greater than 100 dB in the youngest kittens tested. Average thresholds in the ICC matched those previously measured in the auditory nerve (AN), cochlear nuclei (CN), and auditory cortex (CTX), suggesting that the drop in threshold as a function of age is primarily determined by development at the periphery. 3. Minimal first-spike latencies were relatively long in the youngest kittens, approaching adult values by the end of the third postnatal week. Latencies were distributed between values previously determined for the CN and auditory cortex and can be attributed to the centripetal development of the auditory system. 4. The range of frequencies that were effective in exciting ICC neurons was restricted in young kittens. Neurons having characteristic frequencies (CFs) greater than 7 kHz were not recorded before postnatal day 10. CF distribution matched that obtained in previous experiments from AN, CN, and CTX, reflecting the development of the cochlea. 5. Both monotonic and nonomonotonic spike count-versus-intensity functions were found in the youngest kittens. There was a tendency for monotonic functions from the youngest kittens to be steeper than those from older kittens. No age-related changes in the shapes of non-monotonic functions were found. 6. Sensitivity to interaural intensity difference (IID), tested by holding the intensity to the excitatory ear at a suprathreshold level and increasing the intensity of the stimulus to the inhibitory ear, was exhibited as early as 8 days after birth. The majority of the cells exhibiting sensitivity to IID (89.5%) were classified as EI cells, and almost all IID sensitive cells had CFs between 3 and 25 kHz. Within our sample the shapes of IID functions, as well as the operating range of the IID functions, closely resembled those obtained from the adult cat. Thresholds of excitation and of inhibition were highly correlated, suggesting that the ipsilateral and contralateral inputs to the ICC develop as a matched set. 7. Sensitivity to interaural phase difference (IPD), tested either by shifting the onset phase of a CF tone to one ear relative to the other or by presenting tones of slightly different frequency to the two ears, was present as early as 12 days after birth.(ABSTRACT TRUNCATED AT 400 WORDS)     

四川省自贡市儿童1型糖尿病发病率研究

为摸清我省儿童１型糖尿病的发病情况,按ＷＨＯ儿童糖尿病多国研究计划方案,我们在自贡市（四区,两县）对１９８９～１９９６年儿童１型糖尿病发病率进行了调查研究。１　材料与方法１．１　病例来源　第一来源：自贡市３０个县区级有１型糖尿病诊断能力的医院。第二来...     

Cholera in India: an analysis of reports, 1997�C2006

Objective

To more accurately define the annual incidence of cholera in India, believed to be higher than reported to the World Health Organization (WHO).

Methods

We searched the biomedical literature to extract data on the cases of cholera reported in India from 1997 to 2006 and compared the numbers found to those reported annually to WHO over the same period. The latter were obtained from WHO’s annual summaries of reported cholera cases and National health profile 2006, published by India’s Central Bureau of Health Intelligence.

Findings

Of India’s 35 states or union territories, 21 reported cholera cases during at least one year between 1997 and 2006. The state of West Bengal reported cases during all 10 years, while the state of Maharashtra and the union territory of Delhi reported cases during nine, and Orissa during seven. There were 68 outbreaks in 18 states, and 222 038 cases were detected overall. This figure is about six times higher than the number reported to WHO (37 783) over the same period. The states of Orissa, West Bengal, Andaman and Nicobar Islands, Assam and Chhattisgarh accounted for 91% of all outbreak-related cases.

Conclusion

The reporting of cholera cases in India is incomplete and the methods used to keep statistics on cholera incidence are inadequate. Although the data are sparse and heterogeneous, cholera notification in India is highly deficient.     

Residential Traffic Exposure,Pulse Pressure,and C-reactive Protein: Consistency and Contrast among Exposure Characterization Methods

Background

Traffic exposure may increase cardiovascular disease (CVD) risk via systemic inflammation and elevated blood pressure, two important clinical markers for managing disease progression.

Objectives

We assessed degree and consistency of association between traffic exposure indicators as predictors of C-reactive protein (CRP) and pulse pressure (PP) in an adult U.S. Puerto Rican population (n = 1,017).

Methods

Cross-sectional information on health and demographics and blood data was collected. Using multiple linear regression, we tested for associations between CRP, PP, and six traffic exposure indicators including residential proximity to roads with > 20,000 vehicles/day and traffic density [vehicle miles traveled per square mile (VMT/mi²)]. Diabetes and obesity [body mass index (BMI) ≥ 30 kg/m²] were tested as effect modifiers.

Results

CRP was positively associated with traffic density in the total population [36% CRP difference with 95% confidence interval (CI) 2.5–81%] for residence within the highest versus lowest VMT/mi² level. With BMI ≥ 30, CRP showed significant positive associations with five of six traffic indices including residence ≤ 200 m versus > 200 m of a roadway [22.7% CRP difference (95% CI, 3.15–46.1)] and traffic density in the third highest versus lowest VMT/mi² level [28.1% difference (95% CI, 1.0–62.6)]. PP was positively associated with residence within ≤ 100 m of a roadway for the total population [2.2 mmHg (95% CI, 0.13–4.3 mmHg)] and persons with BMI ≥ 30 [3.8 mmHg (95% CI, 0.88–6.8)]. Effect estimates approximately doubled for residence within ≤ 200 m of two or more roadways, particularly in persons with diabetes [8.1 mmHg (95% CI, 2.2–14.1)].

Conclusions

Traffic exposure at roadway volumes as low as 20,000–40,000 vehicles/day may increase CVD risk through adverse effects on blood pressure and inflammation. Individuals with elevated inflammation profiles, that is, BMI ≥ 30, may be more susceptible to the effects of traffic exposure.     

Potentiated 5-hydroxytryptophan induced response suppression in rats following chronic reserpine

Since reserpine precipitates depression in some hypertensive patients, we tested this drug on our animal model of depression. The present experiment was designed to measure the effects of chronic reserpine treatment on 5-hydroxytryptophan (5-HTP) induced behavioral depression in rats trained on a food reinforcement operant schedule. Based on the Aprison et al. model of depression involving the serotonergic system, we predicted the development of receptor supersensitivity of postsynaptic serotonin (5-HT) receptors due to the decreased release of this neurotransmitter as a consequence of chronic reserpine treatment. Rats were trained on a VI 1 reinforcement schedule and then divided into 3 chronic treatment groups. One received daily injections of a placebo, another 0.025 mg/kg reserpine and the third 0.05 mg/kg reserpine. We found that 5-HTP induced behavioral depression was potentiated in rats chronically treated with reserpine, thus suggesting the development of supersensitive 5-HT receptors. These results support the hypothesis that in some types of human depression a decreased release of 5-HT occurs of sufficient duration to permit the subsequent development of supersensitive 5-HT receptors.     

Radium in the environment: exposure pathways and health effects

Radium is a naturally occurring radioactive element in the environment that can exist as several isotopes. Little information is available on the acute (short-term) non-cancer effects in humans. Radium exposure has resulted in acute leukopenia, anemia, necrosis of the jaw, and other effects. Cancer is the major effect of concern. Radium, via oral exposure, is known to cause bone, head, and nasal passage tumors in humans. The US Environmental Protection Agency has not classified radium for carcinogenicity.     

牛奶和钙盐在胃肠道内的钙吸收

目的和方法目前尚不清楚，摄入非水溶性钙盐的钙吸收是否比摄入水溶性差的钙盐钙吸收更好；另外也不清楚，牛奶制品的钙吸收是否比钙盐钙吸收更好。作者采用一种单次服用就能精确测定钙的净吸收率的方法，给８例健康空腹受试者服用含５００mg钙的５种不同水溶性的钙盐和牛奶，服用顺序是随机的。结果按钙盐的水溶性递减次序排列，以平均钙的净吸收率±标准误表示：醋酸钙（３２±４）％，乳酸钙（３２±４）％，葡萄糖酸钙（２７±３）％，柠檬酸钙（３０±３）％；碳酸钙（３９±３）％。按方差分析，钙盐和牛奶的钙吸收率差异无统计学意义…