Effect of Glucose on the Uricase Formation by Streptomyces sp

The effect of glucose on the formation of uricase by a strain of Streptomyces sp. incubated under conditions of nitrogen limitation was investigated. Glucose stimulated uricase formation in the presence of potassium ion and inhibited it in the absence of the ion. Glucose metabolism by the organism was altered in the absence of the ion, and this appeared to cause the inhibition of the enzyme formation. The stimulatory effect of glucose in the presence of potassium ion was to shorten the lag period. Comparisons of the enzyme formation with and without urate in the presence and absence of glucose revealed that glucose promoted the utilization of exogenous urate as the inducer. The effect of glucose appeared to require protein synthesis, since it was prevented by chloramphenicol. Cyclic adenosine 3′,5′-mono-phosphate showed apparently no effect on uricase formation of this organism.     

Energy metabolism and ATP free-energy change of the intertidal wormSipunculus nudus below a critical temperature

The intertidal wormSipunculus nudus was exposed to various temperatures for an analysis of the integrated changes in energy and acid-base status. Animals were incubated in sea water or maintained for up to 8 days at 4 and 0°C while dwelling in the sediment. Cannulation of the animals prior to experimentation allowed the analysis of blood gas parameters ( , and pH). fell to 0 torr within 8 days at 0°C. A simultaneous reduction of ventilatory activity was derived from measurements of the pattern of coelomic fluid pressure changes associated with ventilatory movements. The increase in and an onset of anaerobic metabolism, indicated by the accumulation of end products like acetate and propionate both in the coelomic fluid and the body wall musculature, led to the development of a progressive acidosis and a deviation from the alphastat regulation of intracellular pH seen in unburied animals. The drop in intracellular pH together with the depletion of the adenylates and the phosphagen, phospho-l-arginine, reflect a significant decrease in the Gibb's free-energy change of ATP hydrolysis. These changes are interpreted to indicate lethal cold injuries, because recovery was not possible when the animals were returned to 12°C after more than 2 days of exposure to 0°C. A low critical temperature indicating the onset of cold-induced anaerobiosis is concluded to exist below 4°C owing to the insufficient response of the ventilatory system to the developing hypoxia.     

Urinary and serum electrolyte changes in athletes during periodic and continuous hypokinetic and ambulatory conditions

Hypokinesia (HK) (diminished movement) induces significant electrolyte changes, but little is known about the effect of periodic hypokinesia (PHK) on minerals. The aim of this study was to measure the effect of PHK and continuous hypokinesia (CHK) on urinary and serum electrolytes. Studies were done during a 30-d period of prehypokinesia (HK) and during 364 d of PHK and CHK periods. Thirty male athletes aged 24.6±7.7 yr were chosen as subjects. They were equally divided into three groups: unrestricted ambulatory control subjects (UACS), continuously hypokinetic subjects (CHKS), and periodically hypokinetic subjects (PHKS). The UACS group experienced no changes in the daily activities and regular training and they were maintained under an average running distance of 11.7 km/d. The CHKS group was limited to an average walking distance of 0.7 km/d; and the PHKS group was limited to an average walking distance of 0.7 and running distance of 11.7 km/d for 5 d and 2 d/wk, respectively, for a period of 364 d. Urinary and serum phosphate (P), calcium (Ca), sodium (Na) and potassium (K), serum intact parathyroid hormone (iPTH), calcitonin (CT), plasma renin activity (PRA) and aldosterone (PA) levels, food and water intakes, and physical characteristics were measured. Urinary P, Ca, Na, and K loss, serum Ca, P, Na, and K, and PRA and PA values increased significantly (p≤0.01), whereas serum iPTH and CT levels decreased significantly (p≤0.01) in the PHKS and CHKS groups when compared with the UACS group. However, significant (p≤0.01) differences were observed between PHKS and CHKS groups regarding urinary and serum electrolytes, serum and plasma hormones. Food and water intakes, body weight, body fat, and peak oxygen uptake decreased significantly (p ≤ 0.01) in the CHKS group when compared with PHKS and UACS groups. Food and fluid intakes, body fat, and body weight increased significantly (p≤0.01), whereas peak oxygen uptake remained significantly (p≤0.01) higher in the PHKS group when compared with the CHKS group. Serum and urinary minerals, serum hormones, food and fluid intakes, and physical characteristics did not change significantly (p>0.01) in the UACS group when compared with their baseline control values. It was shown that both PHK and CHK induce significant serum and urinary electrolyte changes. However, urinary and serum electrolyte changes were significantly (p≤0.01) greater during PHK than CHK. It was concluded that the greater the stability of muscular activity, the smaller the serum and urinary electrolyte changes during prolonged HK.     

Appearance of B and H blood group antigens in the developing cochlear hair cells

Summary The presence of human blood-group antigens was analyzed in the rat cochlea during its postnatal development, using anti-A, anti-B and anti-H antibodies. At no stage was reactivity with anti-A antibody observed. With the anti-H antibody, a strong reactivity was observed from 1 to 9 days after birth within hair cells and some other surface epithelial cells of the cochlear duct. After postnatal day 9, only a faint reactivity persisted in a few non-sensory cells. With the anti-B antibody, only hair cells were selectively labeled. At early stages (postnatal day 1 and 3), the reactivity was intense and observed both around the cell surface and within the supranuclear region of cytoplasm. Later on, the reactivity decreased; it was limited at postnatal day 9 to a reactive spot below the cuticular plate. Results are compared with a preliminary finding describing the first appearance of B and H antigens in the organ of Corti at a prenatal stage, and with data concerning other sensory and neural structures. The appearance and progressive disappearance of B and H antigens on sensory and non-sensory cells can be correlated with significant events in the development of the cochlea. The transient expression of B and H antigens in cochlear sensory cells may correspond to developmental changes in their surface glycoconjugates.     

Adrenergic nerves and 5-hydroxytryptamine-containing cells in the pulmonary vasculature of the aquatic file snake Acrochordus granulatus

Summary The adrenergic innervation of the pulmonary vasculature of the file snake Acrochordus granulatus was examined by use of glyoxylic acid-induced fluorescence. Perivascular plexuses of blue-green fluorescent nerves are observed around the common pulmonary artery, the anterior and posterior pulmonary arteries, the arterioles leading to the gas exchange capillaries of the lung, the venules draining the lung, and the anterior and posterior pulmonary veins. Adrenergic nerves are also associated with the visceral smooth muscle of the lung septa and other tissues. Thus, adrenergic control of pulmonary blood flow may occur either at the common pulmonary artery or more regionally within the lung. Regional control of blood flow in the elongate lung of this snake may be important in matching pulmonary perfusion with the distribution of respiratory gas. Glyoxylic acid-histochemistry and immunohistochemistry revealed that populations of cells located in the common pulmonary artery contain the indoleamine 5-hydroxy-tryptamine. Many of the cells are intimately associated with varicose blue-green fluorescent nerves. It is proposed that the 5-hydroxytryptamine-containing cells may be involved in intravascular chemoreception.     

Red white and blue – bright light effects in a diurnal rodent model for seasonal affective disorder

Despite the common use of bright light exposure for treatment of seasonal affective disorder (SAD), the underlying biology of the therapeutic effect is not clear. Moreover, there is a debate regarding the most efficacious wavelength of light for treatment. Whereas according to the traditional approach full-spectrum light is used, recent studies suggest that the critical wavelengths are within the range of blue light (460 and 484 nm). Our previous work shows that when diurnal rodents are maintained under short photoperiod they develop depression- and anxiety-like behavioral phenotype that is ameliorated by treatment with wide-spectrum bright light exposure (2500 lux at the cage, 5000 K). Our current study compares the effect of bright wide-spectrum (3,000 lux, wavelength 420- 780 nm, 5487 K), blue (1,300 lux, wavelength 420-530 nm) and red light (1,300 lux, wavelength range 600-780 nm) exposure in the fat sand rat (Psammomys Obesus) model of SAD. We report results of experiments with six groups of sand rats that were kept under various photoperiods and light treatments, and subjected to behavioral tests related to emotions: forced swim test, elevated plus maze and social interactions. Exposure to either intense wide-spectrum white light or to blue light equally ameliorated depression-like behavior whereas red light had no effect. Bright wide-spectrum white light treatment had no effect on animals maintained under neutral photoperiod, meaning that light exposure was only effective in the pathological-like state. The resemblance between the effects of bright white light and blue light suggests that intrinsically photosensitive retinal ganglion cells (ipRGCs) are involved in the underlying biology of SAD and light therapy.     

Growth of Visceral Fat,Subcutaneous Abdominal Fat,and Total Body Fat in Children

Objective: To examine the patterns of growth of visceral fat, subcutaneous abdominal fat, and total body fat over a 3‐ to 5‐year period in white and African American children. Research Methods and Procedures: Children (mean age: 8.1 ± 1.6 years at baseline) were recruited from Birmingham, Alabama, and those with three or more repeated annual measurements were included in the analysis (N = 138 children and 601 observations). Abdominal adipose tissue (visceral and subcutaneous) was measured using computed tomography. Total body fat and lean tissue mass were measured by DXA. Random growth curve modeling was performed to estimate growth rates of the different body fat compartments. Results: Visceral fat and total body fat both exhibited significant growth effects before and after adjusting for subcutaneous abdominal fat and lean tissue mass, respectively, and for gender, race, and baseline age (5.2 ± 2.2 cm²/yr and 1.9 ± 0.8 kg/yr, respectively). After adjusting for total body fat, the growth of subcutaneous abdominal fat was not significant. Whites showed a higher visceral fat growth than did African Americans (difference: 1.9 ± 0.8 cm²/yr), but there was no ethnic difference for growth of subcutaneous abdominal fat or total body fat. There were no gender differences found for any of the growth rates. Discussion: Growth of visceral fat remained significant after adjusting for growth of subcutaneous abdominal fat, implying that the acquisition of the two abdominal fat compartments may involve different physiologic mechanisms. In contrast, growth of subcutaneous abdominal fat was explained by growth in total body fat, suggesting that subcutaneous fat may not be preferentially deposited in the abdominal area during this phase of growth. Finally, significantly higher growth of visceral fat in white compared with African American children is consistent with cross‐sectional findings.     

Isolation and characterization of plasma membrane from lactating bovine mammary gland

Plasma membranes were isolated from lactating bovine mammary gland. Two crude membrane fractions; medium/d 1.033 (light membrane) and 1.033/1.053 interfaces (heavy membrane), were obtained by Ficoll density gradient centrifugation of osmotically washed microsomal fraction. Two crude membranes were further purified separately by sucrose density gradient centrifugation. Both light and heavy membranes banded at a sucrose density of 1.14. The purified membranes appeared as heterogeneous smooth membrane vesicles on electron microscopy. The contaminating suborganelles were not detected. The yield of the purified membranes relative to the homogenate was 1.2%. The degree of purity of the membranes was shown by a great increase in the specific activity of 5′-nucleotidase over the homogenate of 20-fold for light membrane and of 16-fold for heavy membrane. The relative activities of Mg²⁺-ATPase, (Na⁺ + K⁺)-ATPase, γ-glutamyl transpeptidase, phosphodiesterase I, akaline phosphatase and xanthine oxidase were also high (12–18-times) and nearly 20% of these enzymes was recovered. The activity of marker enzyme for mitochondria, endoplasmic reticulum and Golgi apparatus was very low, while that of acid phosphatase for lysosome was relatively high (5-times). DNA and RNA contents were very low. The major polypeptides rich in other suborganelles were not detected profoundly in the membrane fraction and the polypeptide compositions in both light and heavy membranes were similar upon SDS-polyacrylamide gel electrophoresis.     

丹参酮ⅡA 磺酸钠注射液对原发性高血压患者血脂水平及内皮功能的影响

目的:研究丹参酮ⅡA磺酸钠注射液对原发性高血压患者血脂水平及内皮功能的影响。方法:选择2013年5月-2015年10月在我院首次诊断为原发性高血压的80例患者作为研究对象,根据治疗方法不同将入组患者随机分为实验组和对照组。实验组患者接受丹参酮ⅡA磺酸钠注射液联合口服降压药物治疗,对照组患者仅接受口服降压药物治疗,比较两者患者治疗前后的血压、肝肾功能、血脂水平以及内皮功能指标的变化。结果:治疗后,两组患者的收缩压、舒张压水平均低于治疗前,且实验组患者的收缩压、舒张压水平与对照组比较均无统计学差异。治疗后,两组患者的ALT、AST、Scr水平均与治疗前比较均无显著差异,且实验组患者的ALT、AST、Scr水平与对照组比较无统计学差异。治疗后,实验组患者的TC、TG、LDL水平明显低于治疗前(P0.05),对照组患者的TC、TG、LDL与治疗前比较无统计学差异(P0.05),实验组患者的TC、TG、LDL水平显著低于对照组(P0.05)。结论:丹参酮ⅡA磺酸钠注射液有助于改善原发性高血压患者的血脂代谢以及内皮功能,且对患者的肝肾功能无明显影响。     

Origin of the Koreans: a population genetic study.

A population genetic study was undertaken to investigate the origin of Koreans. Thirteen polymorphic and 7 monomorphic blood genetic markers (serum proteins and red cell enzymes) were studied in a group of 437 Koreans. Genetic distance analyses by both cluster and principal components models were performed between Koreans and eight other populations (Koreans in China, Japanese, Han Chinese, Mongolians, Zhuangs, Malays, Javanese, and Soviet Asians) on the basis of 47 alleles controlled by 15 polymorphic loci. A more detailed analysis using 65 alleles at 19 polymorphic loci was performed on six populations. Both analyses demonstrated genetic evidence of the origin of Koreans from the central Asian Mongolians. Further, the Koreans are more closely related to the Japanese and quite distant from the Chinese. The above evidence of the origin of Koreans fits well with the ethnohistoric account of the origin of Koreans and the Korean language. The minority Koreans in China also maintained their genetic identity.