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Environmental radionuclides (40K, 137Cs, 210Pb, 226Ra) were determined in soils under semi-arid stands, a transition area from thorn to deciduous forest in El Angolo, and heath stands in the Alto Mayo in Northern Peru in order to elucidate their activity level in soil, and to trace underground environment in remote areas of little anthropogenic intervention. Anthropogenic 137Cs was only found in the uppermost portion of the soils in small amount, whereas the 210Pb activity was exceptionally high at the soil surfaces in a tropical stand of Alto Mayo. The results suggest a fallout nuclide, 210Pb, having been transported from local source(s) not to be specified yet. [ABSTRACT FROM AUTHOR]

Traditional AOAC colorimetric procedures for carotenoid analysis are known to lack specificity and accuracy. Newer HPLC methods provide the investigator with a more precise tool for carotenoid quantification in foods and tissues. In the present studies, reverse phase HPLC was utilized to evaluate the alpha- and beta-carotene content in raw and cooked leaves of lettuce, spinach and winged bean as well as in the carrot root. The vegetables were boiled or steamed and the true retention of alpha- and beta-carotene in the cooked products was determined. Boiling for 30 minutes resulted in a 53 and 40% loss of beta-carotene from lettuce and carrots, respectively. Full retention or even an increase in beta-carotene content in boiled winged bean leaves and spinach was noted. Steaming resulted in very good retention of alpha- and beta-carotene in all vegetables (83-139% retention). Thus, although cooking procedures (especially boiling) may result in oxidative loss of carotenoids in some vegetables, heat treatment increases the chemical extractability of alpha- and beta-carotene in others. The presence of carotenoproteins in some vegetables may affect the heat stability of extractability of alpha- and beta-carotene. [ABSTRACT FROM AUTHOR]

Observer variability in the pulmonary examination was assessed by having four blindfolded observers (two medical students and two pulmonary physicians) twice examine 31 patients with abnormal pulmonary findings. Examiners were consistent in the repetitive detection of pulmonary abnormalities in 74-89% of the examinations; conversely, 11-26% of the time they disagreed with themselves. Although pulmonary specialists recorded fewer (55% of observations) abnormal findings than did medical students (74%), they were significantly (p = 0.008) less self-consistent than were the students. There was no clear trend in agreement between examiners (kappa = 0.20-0.49). Each examiner's findings were compared with those of physicians specially trained in pulmonary examination. Dichotomous variables (wheezes, crackles, rubs) were more reliably detected (kappa = 0.30-0.70) than graded variables (tympany, dullness, breath sound intensity), where kappa = 0.16-0.43. The authors suggest that dichotomous variables deserve greatest clinical reliance; that time in training, alone, does not improve clinical performance; and that there is a disconcertingly large amount of inter- and intraobserver disagreement in this fundamental clinical task. [ABSTRACT FROM AUTHOR]

Copyright of Virchows Archiv A Pathological Anatomy & Histology is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Blut: Zeitschrift für die Gesamte Blutforschung is the property of Springer Nature and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In reticulocyte-rich suspensions of red blood cells from rats extrusion of cAMP as a regulatory mechanism of intracellular cAMP was investigated. In response to isoprenaline and/or the phosphodiesterase inhibitors Ro 20-1724 and rolipram extrusion of cAMP increases dependent on the concentration of the drugs and time of exposure. However, these drugs exert their effects on the extrusion of cAMP only indirectly, i.e. via increased intracellular levels of cAMP, since the respective EC-values of the drugs for intracellular accumulation and extrusion of cAMP are identical (isoprenaline: ∼50 nM; rolipram: ∼1 μM; Ro 20-1724: 15 μM). The dependence of the rate of extrusion on intracellular levels of cAMP is characterized by a typical concentration-effect relationship from which a maximal capacity of cAMP extrusion of 3-6 nmol/10 min/10 cells and a half maximal effective intracellular cAMP concentration of 40-50 nmol/10 cells can be derived. This relationship has been inferred from either kinetic or steady-state approaches. At rapidly changing intracellular levels of cAMP an apparent time lag of extracellular cAMP accumulation is obligatorily conditioned by this relationship. Vasodilating drugs which lower the ATP content of the cells as well as the uncoupler of oxidative phosphorylation, FCCP, inhibit the extrusive process (papaverine > FCCP > dipyridamole > dilazep ≫ hexobendine ≥ carbocromene) leading to a 3-5-fold increase of the intrato extracellular concentration gradient of cAMP. It is concluded that extrusion of cAMP is a saturable and energy-dependent process which regulates the intracellular cAMP concentration independent of the activities of adenylate cyclase and phosphodiesterase. [ABSTRACT FROM AUTHOR]

Rats pretreated with 1-acetyl-2-phenylhydrazide, to induce reticulocytosis, were treated with (±)isoprenaline (4×30 mg/kg in 6 h intervals within 24 h before blood sampling) in order to desensitize the β-adrenoceptor-adenylate cyclase-system of circulating red cells. [ABSTRACT FROM AUTHOR]

For the direct characterization of β-adrenoceptors in membrane preparations from the reticulocyte rich blood of rats treated with acetyl phenylhydrazide the β-adrenergic antagonist ligand (H)(−)dihydroalprenolol (DHAP) was used. [ABSTRACT FROM AUTHOR]

The degree of stimulation of adenylcyclase activity, in membranes from immature red blood cells from rats, brought about by isoprenaline, guanylyl-imidodiphosphate and sodium fluoride is strongly dependent on the basal activity of the enzyme. The inversal relationship between basal activity and the maximal degree of stimulation by (−) isoprenaline, shows an apparent seasonal dependence. [ABSTRACT FROM AUTHOR]

During the maturation of red blood cells from rats after stress erythropoiesis, adenyl cyclase activity and β-adrenoceptor density (pmoles/mg protein) decrease at distinctly different rates suggesting a different turnover of these membrane units. [ABSTRACT FROM AUTHOR]

Hematocrit (HCT) measurements were made in intact and splenectomized conscious dogs to determine if observed decreases in HCT were produced by plasma volume expansion or splenic sequestration of erythrocytes. We found that in conscious dogs HCT is a poor indicator of changes in plasma volume. [ABSTRACT FROM AUTHOR]