Premature responding

Baunez C, Nieoullon A, Amalric M (1995) In a rat model of parkinsonism, lesions of the subthalamic nucleus reverse increases of reaction time but induce a dramatic prematur responding deficit. J Neurosci 15(10) 6531-41... 

Although in most applications no assessment is made unless a component fails prematurely, many respondents to the survey mentioned above reported that they examine and analyse polymer components taken out of service at the end of their service lives. In this way they could establish directly whether the components were still fit for use, and could feed this back to validate the process of life prediction at the design stage. Such information is generally retained within a company, but it was gratifying to learn that this practice is more common than was thought. 

In the colon, semifluid material entering from the small bowel is thickened by absorption of water and salts (from about 1000 to 150 mL/d). If, due to the action of an irritant purgative, the colon empties prematurely, an enteral loss of NaCl, KCl and water will be incurred. To forestall depletion of NaCl and water, the body responds with an increased release of aldosterone (p. Ltillmann, Color Atlas of Pharmacology... 

Vitamin E may be indicated in some rare forms of anemia such as macrocytic, megaloblastic anemia observed in children with severe malnutrition and the hemolytic anemia seen in premature infants on a diet rich in polyunsaturated fatty acids. Also anemia s in malabsorption syndromes have shown to be responsive to vitamin E treatment. Finally, hemolysis in patients with the acanthocytosis syndrome, a rare genetic disorder where there is a lack of plasma jS-lipoprotein and consequently no circulating alpha tocopherol, responds to vitamin E treatment. In neonates requiring oxygen therapy vitamin E has been used for its antioxidant properties to prevent the development retrolental fibroplasia. It should be noted that high dose vitamin E supplements are associated with an increased risk in allcause mortality. 

Hypoprothrombinemia may occur in malabsorption syndromes and also the use of broad-spectrum antibiotics may produce a hypoprothrombinemia that responds readily to small doses of vitamin K. In premature infants and in infants with hemorrhagic disease of the newborn the use of vitamin K may be indicated. However, the main indication for the use of vitamin K is to antagonize the anticoagulant activity of coumarins. Oral absorption of phytonadione and the menaquinones is by the lymph while menadione and its water-soluble derivatives are absorbed directly. The absorption of phytonadione is energy-dependent and saturable. Intravenous administration of phytonadione has produced flushing, dyspnea, chest pains, and cardiovascular collapse. 

Procainamide can decrease the occurrence of all types of active ventricular dysrhythmias in patients with acute myocardial infarction who are free from A-V dissociation, serious ventricular failure, and cardiogenic shock. About 90% of patients with ventricular premature contractions and 80% of patients with ventricular tachycardia respond to procainamide administration. 

Lithium preparations include lithium carbonate, sustained-release preparations, and the liquid form, lithium citrate. The sustained-release preparations allow for a more gradual absorption of the drug, leading to blunted peak plasma levels. Because lithium has a slow onset of action, it can take weeks, and occasionally longer, to obtain an optimal clinical response. Thus, it is important to avoid a premature abandonment in those who are simply slower to respond. 

Most patients with cystic acne respond to 1-2 mg/kg, given in two divided doses daily for 4-5 months. If severe cystic acne persists following this initial treatment, after a period of 2 months, a second course of therapy may be initiated. Common adverse effects resemble hypervitaminosis A and include dryness and itching of the skin and mucous membranes. Less common side effects are headache, corneal opacities, pseudotumor cerebri, inflammatory bowel disease, anorexia, alopecia, and muscle and joint pains. These effects are all reversible on discontinuance of therapy. Skeletal hyperostosis has been observed in patients receiving isotretinoin with premature closure of epiphyses noted in children... 

While it seems clear that the cell types that respond to SA using the PR-la promoter are the mesophyll cells of the leaf, it may be premature to generalise this response to all of the SAR genes. However, it is interesting that the observed expression pattern is consistent with the observation that SAR protects best against foliar pathogens. 

Impaired milk ejection may respond to nasal oxytocin. Synthetic peptide and nonpeptide oxytocin antagonists that can prevent premature labor are being investigated. 

The outcomes in 100 chronic opiate-dependent pregnant women who received levomethadone substitution treatment have been reported (42). The average gestational age at delivery was 38 weeks and the mean birth weight was 2869 g. The rate of premature labor was 19% and the risk of premature delivery 11%. There were withdrawal symptoms in 74% of the neonates at a mean of 39 hours and all responded well to levomethadone. 

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