Diminished bronchial reactivity to cold air in diabetic patients with autonomic neuropathy.

To investigate the role of neural pathways in the nonasthmatic response to eucapnic hyperventilation with below freezing air five diabetic patients with severe symptomatic autonomic neuropathy were studied. Their responses were compared with those shown by five diabetic patients without autonomic neuropathy and five non-diabetic controls. After bronchial provocation testing with cold air the diabetic patients with autonomic neuropathy did not show a significant fall in specific airways conductance (mean (SE) maximum percentage fall 2.0 (3)%), whereas conductance fell in the diabetic patients without neuropathy by 30.8 (2.0)% (p less than 0.001) and in the non-diabetic controls by 22.7 (4.6)% (p less than 0.02). In subjects who do not have asthma the bronchial response to cold air is mediated largely via neural mechanisms.     

Circadian variation in renal function of the obese rat.

The influence of food and water intake on renal function was assessed by comparisons between the hyperphagic Zucker obese rat and its lean littermate, which demonstrates nocturnal dominance in activity. Serum creatinine and cortisol levels, creatine kinase activities, creatinine and urine clearances, and sodium and potassium excretion rates were measured over a 24-hour period in both lean and obese rats (n = 24 each). Six rats in each group were studied every 8 h to permit characterization over a 12-hour light/dark cycle at 2-hour intervals. Urine and creatinine clearances were increased in lean rats during the dark phase coincident with onset of eating. Similarly, renal sodium and potassium excretion rates were markedly increased during the dark cycle, despite relatively constant serum potassium and sodium levels over the 24-hour period. In contrast, no circadian patterns in urine and creatinine clearances were found in the obese rat, which exhibits continuous feeding habits throughout the 24-hour period. Moreover, renal electrolyte excretion in the obese rat was modestly increased during the dark cycle, unlike the significant differences over time observed in lean rats. Serum creatinine levels were increased during the dark cycle in both rat groups. Creatine kinase activity, a measure of ambulatory activity, was constant in lean rats during the study period. Although creatine kinase activity was increased in obese rats during the dark cycle, no correlations with renal functional parameters were found. These results indicate that differences in food and water intake are significant determinants in diurnal cyclic changes in renal function.     

Inhibitory effects of orotate on precursor incorporation into nucleic acids.

The influence of orotic acid on the incorporation of precursors into nucleic acids was studied in mice and rats and in isolated cells. In vivo, orotate levels were modified by two diets which are known to increase the rate of pyrimidine nucleotide synthesis in rat liver. Of these diets, a 1% orotate diet had greater inhibitory effects than an arginine-deficient diet on the incorporation of [3H]orotate into RNA of mouse kidney than mouse liver. This contrasted with the situation in the rat where there was a greater effect in the liver than the kidney. The situation in the rat was more readily interpreted than in the mouse in terms of previously established effects of these diets on ribonucleotide pool sizes. However, studies using [3H]adenosine as a precursor for incorporation into RNA suggested that even in the mouse the effects of orotate were on pool sizes rather than an inhibitory effect on RNA synthesis. The incorporation of [3H]thymidine into DNA was inhibited by orotate to a similar degree in cultured HTC hepatoma cells and a line of rat liver epithelial cells. An effect on DNA synthesis rather than solely on pool sizes was suggested by the observation that the pool size of dTTP was not increased by 5 mM orotate under conditions in which there was a four-fold increase in the level of UTP in HTC cells. An inhibitory effect of orotate on DNA synthesis was further supported by an observation of decreased incorporation of [3H]deoxyadenosine into DNA and a lower rate of cellular proliferation.     

The response of cultured trigeminal and spinal cord motoneurons to nerve growth factor

Dissociated neurons from the trigeminal (V) region of the metencephalic basal plate or the ventral spinal cord from chick embryos of Day 4 (V basal plate) or Day 5 (spinal cord) were cultured on a laminin substratum either in the presence of nerve growth factor (NGF) or in control medium. Assessment was made of neuronal survival, the amount of neurite elaborated, and the percentage of neurons initiating neurites. The presence of motoneurons was verified by retrograde labeling with the fluorescent dye diI. NGF was found to significantly increase the quantity of neuritic processes produced by the spinal cord dissociates at both 24 and 48 hr in vitro. The percentage of neurons initiating neuritic processes was significantly increased by NGF in the trigeminal population at 48 hr in vitro. Neuronal survival was not enhanced by NGF in either group. Both trigeminal and spinal cord neurons were also found to specifically bind 125I-NGF in culture. These results provide direct evidence for an influence of NGF on process formation of early embryonic motoneurons in culture.     

A simple technique for estimation ofDrechslera nodulosa (Berk. & Curt.) Subram. and Jain propagules in soil

Summary A baiting technique was developed to estimate the population ofDrechslera nodulosa (Berk. and Curt.) Subram. and Jain in soil by using susceptible ragi (Eleusine coracana Gaertn.) culms. The number of lesions developed on baited culms were reduced with the reduction in concentration ofD. nodulosa propagules in both sterilized and unsterilized soils. Based on this a standard correlation (concentrationvs infection probability) was established which was found to be quite efficient method to estimate the population in soil and to bait even when the inoculum level was 4 propagules per g of soil.     

Changes in cellular composition during magnesium deficiency.

1. Concentrations and compositions of liver, serum and milk lipids of cows were measured during 6 days' starvation and serum lipids during 60 days' re-feeding. 2. The concentration of free fatty acid in serum increased fivefold during starvation. 3. The content of total lipid in liver (g/100g of liver dry matter) doubled owing to a 20-fold increase in triglyceride, an eightfold increase in cholesterol ester, a three fold increase in free fatty acid and a 20% increase in cholesterol. There were no changes in the content or composition of liver phospholipids. 4. Starvation lowered the concentrations of total lipid, phospholipid and cholesterol ester of dextran sulphate-precipitable serum lipoproteins. Total lipid and cholesterol ester concentrations in lipoproteins of d greater than 1.055 and in lipoproteins not precipitable by dextran sulphate decreased from day 4 of the starvation period and during the first 20 days' re-feeding. 5. During starvation there were decreases in percentages of stearic acid and increases in oleic acid in serum free fatty acids and triglycerides and in liver neutral lipid. 6. Throughout starvation total milk lipid yield decreased, yields and percentages of C4-14 fatty acids decreased and percentages of C18 fatty acids increased. 7. It is suggested that accumulation of triglyceride in liver may be caused by increased uptake of plasma free fatty acids without corresponding increase in lipoprotein secretion.     

Intersexual variation in the foraging ecology of sexually monochromatic Western Wood‐Pewees

ABSTRACT Investigators generally pool observations of males and females in studies of the foraging behavior of sexually monochromatic songbirds. However, such pooling can obscure possible intersexual differences. We compared the foraging behavior of male and female Western Wood‐Pewees (Contopus sordidulus), a sexually monochromatic species, in the Sierra Nevada Mountains of California during the breeding seasons of 2007 and 2008. We recorded 143 foraging observations (male N= 74, female N= 69). Overall, mean foraging rates of females (2.8 attacks/min) were higher (P < 0.001) than those of males (1.1 attacks/min). In addition, female foraging rates were significantly higher during incubation than during the nest building, nestling, and fledgling periods. When foraging, males perched higher above ground than females (means = 17.1 and 6.7 m, respectively). Differences between male and female Western Wood‐Pewees in foraging rates and perch heights suggest that males may spend more time on vigilance while females focus on foraging quickly during incubation and when feeding nestlings. Because metrics such as foraging attack rates are sometimes used as indicators of habitat quality and we found that rates can differ between the sexes and among nesting stages, investigators should consider the possibility of such differences when assessing habitat quality, especially for sexually monochromatic species of birds.     

Effects of chemical and botanical insecticides used for locust control on Metarhizium anisopliae var. acridum conidia after short- to medium-term storage at 30°C

The short- to medium-term viability and growth of Metarhizium anisopliae var. acridum conidia were investigated when combined with six insecticides, at three different concentrations. All of the insecticides used in this study were suitable for immediate spraying with M. anisopliae var. acridum conidia except for fenitrothion. Fipronil, teflubenzuron, and fenitrothion formulations significantly reduced conidial viability over time. The 10% teflubenzuron treatment caused loss of viability relatively quickly with 9.9% germination after 28 days. Mycelial growth was affected by all the treatments except fenitrothion.