Screening Tests in 1957 with Synthetic Compounds for Toxicity to House Flies When Applied Spce Sprays

1959 ◽  
Vol 52 (5) ◽  
pp. 954-955
Author(s):  
P. G. Piquett ◽  
W. A. Gersdorff
1960 ◽  
Vol 53 (2) ◽  
pp. 299-301
Author(s):  
P. G. Piquett ◽  
W. A. Gersdorff ◽  
B. H. Alexander

Author(s):  
F. G. Zaki ◽  
E. Detzi ◽  
C. H. Keysser

This study represents the first in a series of investigations carried out to elucidate the mechanism(s) of early hepatocellular damage induced by drugs and other related compounds. During screening tests of CNS-active compounds in rats, it has been found that daily oral administration of one of these compounds at a dose level of 40 mg. per kg. of body weight induced diffuse massive hepatic necrosis within 7 weeks in Charles River Sprague Dawley rats of both sexes. Partial hepatectomy enhanced the development of this peculiar type of necrosis (3 weeks instead of 7) while treatment with phenobarbital prior to the administration of the drug delayed the appearance of necrosis but did not reduce its severity.Electron microscopic studies revealed that early development of this liver injury (2 days after the administration of the drug) appeared in the form of small dark osmiophilic vesicles located around the bile canaliculi of all hepatocytes (Fig. 1). These structures differed from the regular microbodies or the pericanalicular multivesicular bodies. They first appeared regularly rounded with electron dense matrix bound with a single membrane. After one week on the drug, these vesicles appeared vacuolated and resembled autophagosomes which soon developed whorls of concentric lamellae or cisterns characteristic of lysosomes (Fig. 2). These lysosomes were found, later on, scattered all over the hepatocytes.


Author(s):  
M.T. Otten ◽  
P.R. Buseck

ALCHEMI (Atom Location by CHannelling-Enhanced Microanalysis) is a TEM technique for determining site occupancies in single crystals. The method uses the channelling of incident electrons along specific crystallographic planes. This channelling results in enhanced x-ray emission from the atoms on those planes, thereby providing the required site-occupancy information. ALCHEMI has been applied with success to spinel, olivine and feldspar. For the garnets, which form a large group of important minerals and synthetic compounds, the channelling effect is weaker, and significant results are more difficult to obtain. It was found, however, that the channelling effect is pronounced for low-index zone-axis orientations, yielding a method for assessing site occupancies that is rapid and easy to perform.


2015 ◽  
Vol 72 (4) ◽  
pp. 219-224 ◽  
Author(s):  
Stephanie A. Bridenbaugh

Es gibt eine starke Assoziation zwischen Kognition und Mobilität. Ältere Erwachsene mit Gangdefiziten haben ein erhöhtes Risiko, kognitive Defizite, sogar eine Demenz, zu entwickeln. Kognitive Defizite wiederum sind mit einer Verschlechterung des Gehens assoziiert. Sowohl kognitive als auch Mobilitätsdefizite sind mit einem erhöhten Sturzrisiko verbunden. Untersuchungen der Kognition, vor allem der Exekutivfunktionen, und die funktionale Mobilität sollen daher ein wesentlicher Bestandteil jedes umfassenden geriatrischen Assessments sein. Einige schnelle Screening-Tests können in der Hausarztpraxis durchgeführt werden, um Mobilitätsprobleme zu erfassen. Falls diese pathologisch ausfallen, sollten genauere Ganguntersuchungen veranlasst werden. Bei Untersuchungen des Ganges sind Dual-Task Paradigmen (Gehen und gleichzeitig eine andere Aufgaben ausführen) besonders aussagekräftig in der Früherkennung von Mobilitäts- und auch Hirnleistungsdefiziten. Die Früherkennung erlaubt eine frühzeitige Implementierung von gezielten Interventionen, um die Gangsicherheit und möglicherweise auch gewisse Hirnleistungen zu verbessern.


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