On the development of pituitary responsiveness to LRH and the characteristics of pre-ovulatory LH-surges in the rat. Effect of oestradiol benzoate

1980 ◽  
Vol 93 (2) ◽  
pp. 162-167
Author(s):  
G. A. Schuiling ◽  
A. F. Zürcher ◽  
N. Pols-Valkhof ◽  
T. R. Koiter
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Effective Dose ◽  
Threshold Dose ◽  
Oestradiol Benzoate ◽  
System 2 ◽  
The Central Nervous System ◽  
Moderate Effect ◽  
Time Of Administration

Abstract. Administration of oestradiol benzoate (OeB) on the second day of dioestrus of 5-day cyclic rats may advance ovulation by 24 h. The threshold dose of OeB necessary to achieve this effect varies with the time of administration. At 09.00 h, the 50% effective dose (ED-50) of OeB for advancing ovulation was 3.1 μg; at 17.00 h it was 31 μg. In the present study OeB was injected at either 09.00 or 17.00 h at doses about 3 times the corresponding ED-50's: 10 and 100 μg, respectively. Though both regimens of OeB administration resulted in advancement of ovulation, neither had more than a moderate effect on the development of pituitary responsiveness to LRH. In neither group could OeB-induced LH-surges be distinguished from "normal" 4-day rat-LH-surges and both differ from 5-day rat-LH-surges. It is concluded that (1) in the "Everett-model" OeB acts almost exclusively on the central nervous system; (2) the oestrogen-induced surge of LH is an all-or-none effect; and (3) there exists no relationship between the blood oestrogen concentrations and the characteristics of the induced LH-surges.

Compounds affecting the central nervous system. 2. Aromatic acetals of tropanediols

1972 ◽  
Vol 15 (5) ◽  
pp. 509-514 ◽  
Author(s):  
Sol. J. Daum ◽  
Anthony J. Gambino ◽  
Mario D. Aceto ◽  
Robert L. Clarke
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
System 2 ◽  
The Central Nervous System

scholarly journals Primary angiitis of the central nervous system: 2 atypical cases

2012 ◽  
Vol 3 ◽  
pp. 293-299 ◽  
Author(s):  
Fabio Pagni ◽  
Giuseppe Isimbaldi ◽  
Francesco Vergani ◽  
Paolo Casiraghi ◽  
Laura Marzorati ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Primary Angiitis ◽  
System 2 ◽  
The Central Nervous System

scholarly journals Experimental encephalitis following peripheral inoculation of West Nile virus in mice of different ages

1970 ◽  
Vol 68 (3) ◽  
pp. 435-446 ◽  
Author(s):  
Leslie P. Weiner ◽  
Gerald A. Cole ◽  
Neal Nathanson
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
West Nile ◽  
Neurotropic Viruses ◽  
System 2 ◽  
The Central Nervous System ◽  
Individual Variables ◽  
Central Nervous System Invasion ◽  
The Brain ◽  
Convenient Model

SUMMARYExperimental arbovirus infections of mice provide a convenient model to study factors which determine the occurrence or severity of encephalitis following ex-traneural infection with certain neurotropic viruses. Varying doses of West Nile or Powassan viruses were inoculated by intraperitoneal or intramuscular routes into mice of varing ages; individual variables were manipulated to influence the outcome of infection. Three patterns of pathogenesis were delineated: (1) Fatal encephalitis, preceded by early viraemia, and invasion of the central nervous system. (2) In-apparent infection, with no detectable viraemia and no evidence of central nervous system invasion. (3) Subclinical encephalitis, usually preceded by trace viraemia, with minimal transient levels of virus in the brain. In this latter type of subclinical infection with a potentially lethal virus, the immune response probably plays an important role in recovery.

Effects of Hyperoxia on Lung Utrastructure

1970 ◽  
Vol 28 ◽  
pp. 26-27
Author(s):  
Gladys Harrison
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Light Microscopy ◽  
Oxygen Effects ◽  
Age Dependent ◽  
The Central Nervous System ◽  
The Subject ◽  
Space Age ◽  
Alveolar Septa ◽  
Extensive Damage

With the advent of the space age and the need to determine the requirements for a space cabin atmosphere, oxygen effects came into increased importance, even though these effects have been the subject of continuous research for many years. In fact, Priestly initiated oxygen research when in 1775 he published his results of isolating oxygen and described the effects of breathing it on himself and two mice, the only creatures to have had the “privilege” of breathing this “pure air”.Early studies had demonstrated the central nervous system effects at pressures above one atmosphere. Light microscopy revealed extensive damage to the lungs at one atmosphere. These changes which included perivascular and peribronchial edema, focal hemorrhage, rupture of the alveolar septa, and widespread edema, resulted in death of the animal in less than one week. The severity of the symptoms differed between species and was age dependent, with young animals being more resistant.

Emigration of neutrophils in the central nervous system

1983 ◽  
Vol 41 ◽  
pp. 788-789
Author(s):  
John L.Beggs ◽  
John D. Waggener ◽  
Wanda Miller ◽  
Jane Watkins
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Osmium Tetroxide ◽  
White Blood Cells ◽  
Arterial Perfusion ◽  
E Coli ◽  
Intracisternal Injection ◽  
The Central Nervous System ◽  
Brain And Spinal Cord ◽  
Interendothelial Junctions

Studies using mesenteric and ear chamber preparations have shown that interendothelial junctions provide the route for neutrophil emigration during inflammation. The term emigration refers to the passage of white blood cells across the endothelium from the vascular lumen. Although the precise pathway of transendo- thelial emigration in the central nervous system (CNS) has not been resolved, the presence of different physiological and morphological (tight junctions) properties of CNS endothelium may dictate alternate emigration pathways.To study neutrophil emigration in the CNS, we induced meningitis in guinea pigs by intracisternal injection of E. coli bacteria.In this model, leptomeningeal inflammation is well developed by 3 hr. After 3 1/2 hr, animals were sacrificed by arterial perfusion with 3% phosphate buffered glutaraldehyde. Tissues from brain and spinal cord were post-fixed in 1% osmium tetroxide, dehydrated in alcohols and propylene oxide, and embedded in Epon. Thin serial sections were cut with diamond knives and examined in a Philips 300 electron microscope.

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