Effect of sodium ortho-iodobenzoate on oxygen transport and erythropoiesis in hypoxemic dogs with a right-to-left cardiac shunt

Eight dogs were made hypoxemic by surgical construction of a right-to-left cardiac shunt; and they were given sodium ortho-iodobenzoate (OISB) before and for 3 months after operation. The P(50) at 50% saturation) rose from 27.2 +/- 0.7 to 31.2 +/- 0.6 mm Hg (p less than 0.001) during OLSB treatment before operation and increased further to 32.2 +/- 0.8 mm Hg 3 months after creation of hypoxemia. The P(50) remained elevated for an additional 3 months after OISB was stopped. Administration of OISB before operation did not alter the red blood cell 2,3-diphosphoglycreate concentration. Hypoxemia caused an increase of this metabolite from 0.91 +/- 0.21 to 1.50 +/- 0.28 moles/moles of hemoglobin (p less than 0.05); the rise was not as great as that observed in hypoxemic dogs without OISB treatment. In spite of significant hypoxemia, hematocrit rose only slightly during the period of OISB infusion. OISB increased P50 and prevented the compensatory polycythemia regularly seen when dogs are made hypoxemic. Altering oxygen transport in this fashion may increase tissue oxygen delivery in patients with conditions which result in tissue hypoxia.     

A difference in the composition of bronchial mucus between smokers and non-smokers

The effects of the duration of the overall compression cycle and of the duration of the maximum compressive force on tablet strength were studied using an instrumented rotary tablet press. Various direct compression fillers were evaluated. Increasing the overall compression cycle duration to 10 sec resulted in significantly greater tablet tensile strengths with microcrystalline cellulose and compressible starch fillers but not with lactose or compressible sugar. Increasing the duration of the maximum compressive force to 20 sec significantly increased the tensile strength in all cases, but microcrystalline cellulose and compressible starch tablets were affected more than lactose or sugar tablets. The maximum compressive force decayed with time for all fillers but at a greater rate with microcrystalline cellulose and compressible starch. This behavior was attributed to differences in the extent of plastic flow. The decay curves were analyzed using the Maxwell model.     

Effect of variations in adrenocortical function on dopamine beta-hydroxylase and norepinephrine in the brain of the rat

The effect of adrenalectomy and corticosterone treatment on dopamine beta-hydroxylase (DBH) activity, catecholamine content and norepinephrine formation and metabolism were studied in the hypothalamus and other parts of the brain of male rats. Two days after adrenalectomy, there was a decrease in DBH activity in the hypothalamus and the brain stem but no change in norepinephrine or dopamine content. Conversion of intraventricularly administered tritiated dopamine to tritiated norepinephrine was slightly increased and norepinephrine was metabolized at a more rapid rate than normal. Corticosterone in a dose of 100 mg/kg increased DBH activity but decreased hypothalamic norepinephrine and copamine content. In adrenalectomized rats, smaller, more physiological doses of corticosterone did not change DBH activity or catecholamine content. The fact that norepinephrine formation and metabolism were increased at the same time that DBH activity in vitro was decreased suggests that DBH is not rate-limiting in adrenergic neurons in the hypothalamus, or that a change in the in vitro activity of the enzyme was not accompanied by a parallel change in its activity in vivo.     

Amino acid supplementation of low protein turkey starting rations

Turkey poults fed rations containing 22.1% protein had a much slower rate of growth when compared with poults receiving a ration containing 29.8% protein. Methionine supplementation had no effect on body weight and mortality to 18 days of age. Supplementation of the 22.1% protein diet with lysine (0.2%) significantly improved growth rate over the unsupplemented 22.1% protein diet. The addition of methionine to the 22.1% protein diet supplemented with lysine (0.2%) produced slight additional response in body weight; however the drop in mortality was much more dramatic as increments of methionine were added to the 22.1% protein diet supplemented with lysine (0.2%).     

Effect of chronic glucagon-administration on the digestive and absorptive function of rat small intestine in vivo

Mitomycin C-induced sister chromatic exchange and quadriradial formation were studied in chromosomes from Muntiacus muntjac fibroblasts and A9, a transformed mouse cell line. We present the first direct cytological evidence for the induction of true somatic recombination involving homologous chromosomes. Analysis of the quadriradials from Muntjac cells indicates a non-random distribution with respect to the chromosomes involved and with respect to the points of conjunction. Sister chromatid exchange and quadriradial formation may reflect the outcome of repair processes involving a high frequency of homologous exchanges in the interphase nucleus.     

Screening for dementia with the memory impairment screen

OBJECTIVES: To validate a sensitive and specific screening test for AD and other dementias, assess its reliability and discriminative validity, and present normative data for its use in various applied settings. BACKGROUND: To improve discrimination in screening for AD and dementia, we developed the Memory Impairment Screen (MIS), a 4-minute, four-item, delayed free- and cued-recall test of memory impairment. The MIS uses controlled learning to ensure attention, induce specific semantic processing, and optimize encoding specificity to improve detection of dementia. METHODS: Equivalent forms of the MIS were given at the beginning and end of the testing session to assess alternate forms reliability. Discriminative validity was assessed in a criterion sample of 483 aged individuals, 50 of whom had dementia according to Diagnostic and Statistical Manual of Mental Disorders (3rd ed., revised) criteria. RESULTS: The MIS had good alternate forms reliability, high construct validity for memory impairment, and good discriminative validity in terms of sensitivity, specificity, and positive predictive value. We present normative data for use in settings with different base rates (prevalences) of AD and dementia. CONCLUSION: The MIS provides efficient, reliable, and valid screening for AD and other dementias.     

Ex vivo transduction of corneal epithelial progenitor cells using a retroviral vector

An in vivo model was used to determine whether bone hyperemia precedes increased intracortical porosity induced by disuse. Twenty-four adult male roosters (age 1 yr) were randomly assigned to intact-control, 7-days-sham-surgery, 7-days-disuse, and 14-days-disuse groups. Disuse was achieved by isolating the left ulna diaphysis from physical loading via parallel metaphyseal osteotomies. The right ulna served as an intact contralateral control. Colored microspheres were used to assess middiaphyseal bone blood flow. Bone blood flow was symmetric between the left and right ulnae of the intact-control and sham-surgery groups. After 7 days of disuse, median (+/-95% confidence interval) standardized blood flow was significantly elevated compared with the contralateral bone (6.5 +/- 5.2 vs. 1.0 +/- 0.8 ml x min-1 x 100 g-1; P = 0.03). After 14 days of disuse, blood flow was also elevated but to a lesser extent. Intracortical porosity in the sham-surgery and 7-days-disuse bones was not elevated compared with intact-control bones. At 14 days of disuse, the area of intracortical porosity was significantly elevated compared with intact control bones (0.015 +/- 0.02 vs. 0. 002 +/- 0.002 mm2; P = 0.03). We conclude that disuse induces bone hyperemia before an increase in intracortical porosity. The potential interaction between bone vasoregulation and bone cell dynamics remains to be studied.     

Stage distributions for five health behaviors in the United States and Australia

BACKGROUND: A key variable for the design of individual and public health interventions is the Stage of Change. The five stages of readiness to change are Precontemplation, Contemplation, Preparation, Action, and Maintenance. The distribution of individuals across the stages of change can provide a valuable tool for designing health interventions. METHODS: The pattern of distribution across the stages of change for five behavioral risk factors is presented from five independent surveys, two from the United States and three from Australia. The five risk factors are smoking, low fat diet, regular exercise, reducing stress, and losing weight. Identical single-item questionnaire items for staging health behaviors were used in all surveys. RESULTS: The stage distributions for the five risk factors were similar across the five independent samples. In general, the pattern of stage distributions was stable across health risk factors, gender, country, and sample. CONCLUSIONS: Single-item survey measures of stage of change that are readily applicable to population studies appear to provide important information about the population characteristics of readiness to change behavioral risk factors. The stability of these distributions suggests that interventions matched by stage may have broad applicability.