Chronic effects of environmentally-relevant concentrations of lead in Pelophylax nigromaculata tadpoles: Threshold dose and adverse effects

2014 ◽  
Vol 104 ◽  
pp. 310-316 ◽  
Author(s):  
Min-Yi Huang ◽  
Ren-Yan Duan ◽  
Xiang Ji
Keyword(s):  
Adverse Effects ◽  
Threshold Dose ◽  
Chronic Effects ◽  
Pelophylax Nigromaculata

Acute and chronic effects of glucose and carbachol on insulin secretion and phospholipase C activation: studies with diazoxide and atropine

2006 ◽  
Vol 290 (1) ◽  
pp. E26-E33 ◽  
Author(s):  
Hanae Yamazaki ◽  
William Philbrick ◽  
Kathleen C. Zawalich ◽  
Walter S. Zawalich
Keyword(s):  
Insulin Secretion ◽  
Adverse Effects ◽  
Phospholipase C ◽  
Inositol Phosphate ◽  
Inhibitory Effect ◽  
Early Event ◽  
Β Cell ◽  
Simultaneous Exposure ◽  
Chronic Effects ◽  
Acute And Chronic Effects

The acute and chronic effects of 20 mM glucose and 10 μM carbachol on β-cell responses were investigated. Acute exposure of rat islets to 20 mM glucose increased glucose usage rates and resulted in a large insulin-secretory response during a dynamic perifusion. The secretory, but not the metabolic, effect of 20 mM glucose was abolished by simultaneous exposure to 100 μM diazoxide. Glucose (20 mM) significantly increased inositol phosphate (IP) accumulation, an index of phospholipase C (PLC) activation, from [3H]inositol-prelabeled islets. Diazoxide, but not atropine, abolished this effect as well. Unlike 20 mM glucose, 10 μM carbachol (in the presence of 5 mM glucose) increased IP accumulation but had no effect on insulin secretion or glucose (5 mM) metabolism. The IP effect was abolished by 50 μM atropine but not by diazoxide. Chronic 3-h exposure of islets to 20 mM glucose or 10 μM carbachol profoundly reduced both the insulin-secretory and PLC responses to a subsequent 20 mM glucose stimulus. The adverse effects of chronic glucose exposure were abolished by diazoxide but not by atropine. In contrast, the adverse effects of carbachol were abolished by atropine but not by diazoxide. Prior 3 h of exposure to 20 mM glucose or carbachol had no inhibitory effect on glucose metabolism. Significant secretory responses could be evoked from 20 mM glucose- or carbachol-pretreated islets by the inclusion of forskolin. These findings support the concept that an early event in the evolution of β-cell desensitization is the impaired activation of islet PLC.

Effects of hemodilution on skin microcirculation

1988 ◽  
Vol 254 (3) ◽  
pp. H411-H416 ◽  
Author(s):  
S. Mirhashemi ◽  
G. A. Breit ◽  
R. H. Chavez Chavez ◽  
M. Intaglietta
Keyword(s):  
Heart Rate ◽  
Connective Tissue ◽  
Adverse Effects ◽  
Systemic Arterial Pressure ◽  
Direct Proportion ◽  
Skin Microcirculation ◽  
Chronic Effects ◽  
Dextran 70 ◽  
Subcutaneous Connective Tissue ◽  
Arteriolar Diameter

Red blood cell (RBC) velocity, capillary hematocrit (Hctcap), RBC flux, and arteriolar diameter were studied in the subcutaneous connective tissue of the Syrian hamster skinfold window preparation during successive normovolemic hemodilutions with 6% solutions of Dextran 70. The experiments were carried out in the unanesthetized animal. Heart rate (HR), mean systemic arterial pressure (Psys), and systemic hematocrit (Hctsys) were monitored throughout the procedure to ensure that normovolemia was maintained and hemodilution caused no adverse effects. The changes of RBC flux in the hemodiluted state, up to 50% hemodilution (Hctsys = 25% +/- 4), were not statistically significant when compared with control (t test, P less than 0.5). At this Hctsys, capillary RBC velocity increased by 60% and Hctcap decreased by 30%. Both of these changes were statistically significant relative to control. The arteriolar diameter did not change significantly during the reduction of Hctsys. The animals were studied during subsequent days to determine the chronic effects of hemodilution. Hctsys increased by approximately 12% per day after the experiment, and the systemic parameters returned to the prehemodiluted state in direct proportion to the reestablishment of the Hctsys.

The Influence of Specimen Thickness in Quantitative Electron Energy Loss Spectroscopy

1980 ◽  
Vol 38 ◽  
pp. 112-113
Author(s):  
Nestor J. Zaluzec
Keyword(s):  
Quantitative Analysis ◽  
Adverse Effects ◽  
Energy Loss ◽  
Electron Energy ◽  
Electron Energy Loss Spectroscopy ◽  
Materials Science ◽  
Light Element ◽  
Specimen Thickness ◽  
Element Analysis ◽  
Electron Energy Loss

The application of electron energy loss spectroscopy (EELS) to light element analysis is rapidly becoming an important aspect of the microcharacterization of solids in materials science, however relatively stringent requirements exist on the specimen thickness under which one can obtain EELS data due to the adverse effects of multiple inelastic scattering.1,2 This study was initiated to determine the limitations on quantitative analysis of EELS data due to specimen thickness.

Abhängigkeitspotenzial und andere Risiken von Opioidanalgetika im Alter

2017 ◽  
Vol 63 (2) ◽  
pp. 99-114 ◽  
Author(s):  
Dirk K. Wolter
Keyword(s):  
Adverse Effects ◽  
Psychische Störungen ◽  
Opioid Analgesics ◽  
Alte Menschen ◽  
Dsm 5 ◽  
Icd 10

Zusammenfassung. Zielsetzung: Übersicht über Suchtpotenzial und andere Risiken von Opioidanalgetika im höheren Lebensalter. Methodik: Narrativ review. Literaturrecherche in PubMed (Suchbegriffe: opioid analgesics UND abuse; opioid analgesics UND dependence; opioid analgesics UND addiction; opioid analgesics UND adverse effects; jeweils UND elderly) sowie aktuellen einschlägigen Standardwerken; Auswahl nach altersmedizinischer Relevanz und Aktualität. Ergebnisse: Die Verordnung von Opioidanalgetika (OA) hat in den letzten 25 Jahren massiv zugenommen, die weitaus meisten Verordnungen entfallen auf alte Menschen und Menschen mit chronischen Nicht-Tumorschmerzen (CNTS). Die diagnostischen Kriterien für die Opiatabhängigkeit in ICD-10 und DSM-5 sind für die OA-Behandlung von CNTS ungeeignet. Bei langfristiger OA-Behandlung bei CNTS kann eine spezifische Form von Abhängigkeit entstehen, die nicht mit der illegalen Opiat-(Heroin-)Sucht gleichzusetzen ist. Vorbestehende Suchterkrankungen und andere psychische Störungen sind die wesentlichsten Risikofaktoren. Weitere Nebenwirkungen sind zu beachten. Schmerztherapie bei Suchtkranken stellt eine besondere Herausforderung dar. Schlussfolgerungen: Die Anwendung von OA bei CNTS verlangt eine sorgfältige Indikationsstellung. Die besondere Form der Abhängigkeit von OA ist nicht ausreichend erforscht und wird zu wenig beachtet.

Inter-Method Reliability of Pulse Volume Related Measures Derived Using Finger-Photoplethysmography

2018 ◽  
Vol 32 (4) ◽  
pp. 182-190 ◽  
Author(s):  
Kenta Matsumura ◽  
Koichi Shimizu ◽  
Peter Rolfe ◽  
Masanori Kakimoto ◽  
Takehiro Yamakoshi
Keyword(s):  
Light Intensity ◽  
Adverse Effects ◽  
Light Source ◽  
Direct Current ◽  
Resting State ◽  
Current Component ◽  
Psychophysiological Measures ◽  
Pulse Volume ◽  
Optical Paths ◽  
Sensor Positions

Abstract. Pulse volume (PV) and its related measures, such as modified normalized pulse volume (mNPV), direct-current component (DC), and pulse rate (PR), derived from the finger-photoplethysmogram (FPPG), are useful psychophysiological measures. Although considerable uncertainties exist in finger-photoplethysmography, little is known about the extent of the adverse effects on the measures. In this study, we therefore examined the inter-method reliability of each index across sensor positions and light intensities, which are major disturbance factors of FPPG. From the tips of the index fingers of 12 participants in a resting state, three simultaneous FPPGs having overlapping optical paths were recorded, with their light intensity being changed in three steps. The analysis revealed that the minimum values of three coefficients of Cronbach’s α for ln PV, ln mNPV, ln DC, and PR across positions were .948, .850, .922, and 1.000, respectively, and that those across intensities were .774, .985, .485, and .998, respectively. These findings suggest that ln mNPV and PR can be used for psychophysiological studies irrespective of minor differences in sensor attachment positions and light source intensity, whereas and ln DC can also be used for such studies but under the condition of light intensity being fixed.

Sign in / Sign up

Export Citation Format

Share Document