Analysis Study (analysis + study)

Distribution by Scientific Domains

Selected Abstracts

Atypical Response of Xeroderma Pigmentosum to 5-Fluorouracil: A Histopathological Image Analysis Study Reveals New Insight into Etiopathogenesis

S.A. Centurion
Xeroderma pigmentosum (XP) is a recessively inherited genodermatosis associated with extreme sun sensitivity, defective repair of several types of sunlight induced adducts in cellular DNA, and numerous, early-onset skin cancers. The dry, rough skin corresponds to progressive cytologic atypia and loss of polarity in the underlying epidermis. Associated with these changes are immune deficiencies against ultraviolet radiation-induced skin cancer. 5-Fluorouracil (5-FU) is a DNA synthesis antimetabolite used against several types of cancers. Applied topically in normal subjects it is associated with moderate to severe inflammation in areas where actinic keratoses have arisen followed by ablation of the actinic keratoses which is dependent on the inflammation. We applied 5-FU to the sun-exposed skin of two patients with XP, a 14 year-old light complected black male and a 14 year-old Caucasian female. No inflammation was observed, but marked improvement in the clinical presentation of the skin was seen, as well as an absence of new malignancies. This change was confirmed histopathologically and correlated with normalization of polarity and cytologic changes in the epidermal cells. These histologic findings were quantitated using computerized image analysis. These results may be due to activation of alternative DNA repair pathways in these nucleotide excision repair deficient cells. [source]

Synthesis, Herbicidal Activities and Comparative Molecular Field Analysis Study of Some Novel Triazolinone Derivatives

Lei Wang
A series of novel triazolinones were synthesized and their structures were characterized by 1H NMR, elemental analysis and single-crystal X-ray diffraction analysis. The herbicidal activities were evaluated against Echinochloa crusgalli (L.) Beauv., Digitaria adscendens, Brassica napus and Amaranthus retroflexus. The herbicidal activity data indicated that the title compounds had higher activities with substituted benzyl group moieties than with other groups such as sulfonyl, alkyl, etc. To further investigate the structure,activity relationship, comparative molecular field analysis was performed on the basis of herbicidal activity data. Both the steric and electronic field distributions of comparative molecular field analysis are in good agreement in this work. The results showed that a bulky and electronegative group around the ortho- or para -positions of the benzene ring would possibly lead to higher activity. Based on the comparative molecular field analysis, compound I-23 was designed and synthesized, which display as good herbicidal activities as the commercial herbicide, carfentrazone-ethyl. The activity against Digitaria adscendens is 66.1% under pre-emergence at 300 g of a.i./ha. [source]

Autosomal Dominant Inheritance of Centrotemporal Sharp Waves in Rolandic Epilepsy Families

EPILEPSIA, Issue 12 2007
Bhavna Bali
Summary Purpose: Centrotemporal sharp (CTS) waves, the electroencephalogram (EEG) hallmark of rolandic epilepsy, are found in approximately 4% of the childhood population. The inheritance of CTS is presumed autosomal dominant but this is controversial. Previous studies have varied considerably in methodology, especially in the control of bias and confounding. We aimed to test the hypothesis of autosomal dominant inheritance of CTS in a well-designed family segregation analysis study. Methods: Probands with rolandic epilepsy were collected through unambiguous single ascertainment. Siblings in the age range 4,16 years underwent sleep-deprived EEG; observations from those who remained awake were omitted. CTS were rated as present or absent by two independent observers blinded to the study hypothesis and subject identities. We computed the segregation ratio of CTS, corrected for ascertainment. We tested the segregation ratio estimate for consistency with dominant and recessive modes of inheritance, and compared the observed sex ratio of those affected with CTS for consistency with sex linkage. Results: Thirty siblings from 23 families underwent EEG examination. Twenty-three showed evidence of sleep in their EEG recordings. Eleven of 23 recordings demonstrated CTS, yielding a corrected segregation ratio of 0.48 (95% CI: 0.27,0.69). The male to female ratio of CTS affectedness was approximately equal. Conclusions: The segregation ratio of CTS in rolandic epilepsy families is consistent with a highly penetrant autosomal dominant inheritance, with equal sex ratio. Autosomal recessive and X-linked inheritance are rejected. The CTS locus might act in combination with one or more loci to produce the phenotype of rolandic epilepsy. [source]

Assessing patients' preferences for characteristics associated with homoeopathic and conventional treatment of asthma: a conjoint analysis study

J Ratcliffe

Second law analysis of two-stage compression transcritical CO2 heat pump cycle

Arif Emre Özgür
Abstract Because of the global warming impact of hydro fluorocarbons, the uses of natural refrigerants in automotive and HVAC industries have received worldwide attention. CO2 is the most promising refrigerant in these industries, especially the transcritical CO2 refrigeration cycle. The objective of this work is to identify the main factors that affect two-stage compression transcritical CO2 system efficiency. A second law of thermodynamic analysis on the entire two-stage CO2 cycle is conducted so that the exergy destruction of each system component can be deduced and ranked, allowing future efforts to focus on improving the components that have the highest potential for advancement. The inter-stage pressure is used as a variable parameter in the analysis study. The second law efficiency, coefficient of cooling performance and total exergy destruction of the system variations with the inter-stage pressure are presented graphically. It was concluded that there is an optimum inter-stage pressure that maximizes both first law and second law efficiencies. Copyright © 2008 John Wiley & Sons, Ltd. [source]

Factors associated with delirium severity among older patients

Philippe Voyer PhD
Aim., The goal of this study was to determine whether the factors associated with delirium varied according to the severity of the delirium experienced by the older patients. Background., Delirium among older patients is prevalent and leads to numerous detrimental effects. The negative consequences of delirium are worse among older adults with severe delirium compared with patients with mild delirium. There has been no study identifying those factors associated with delirium severity among long-term care older patients newly admitted to an acute care hospital. Design., This is a descriptive study. Methods., This is a secondary analysis study of institutionalized older patients newly admitted to an acute care hospital (n = 104). Upon admission, patients were screened for delirium with the Confusion Assessment Method and severity of delirium symptoms were determined by using the Delirium Index. Results., Of the 71 delirious older patients, 32 (45·1%) had moderate-severe delirium while 39 (54·9%) presented mild delirium. In univariate analyses, a significant positive relationship was observed between the level of prior cognitive impairment and the severity of delirium (p = 0·0058). Low mini-mental state examination (MMSE) scores (p < 0·0001), the presence of severe illness at the time of hospitalization (p = 0·0016) and low functional autonomy (BI: p = 0·0017; instrumental activities of daily living: p = 0·0003) were significantly associated with moderate-severe delirium. Older patients suffering from mild delirium used significantly more drugs (p = 0·0056), notably narcotics (p = 0·0017), than those with moderate-severe delirium. Results from the stepwise regression indicated that MMSE score at admission and narcotic medication use are the factors most strongly associated with the severity of delirium symptoms. Conclusions., This present study indicates that factors associated with moderate-severe delirium are different from those associated with mild delirium. Given the result concerning the role of narcotics, future studies should evaluate the role of pain management in the context of delirium severity. Relevance to Clinical Practice., As moderate-severe delirium is associated with poorer outcomes than is mild delirium, early risk factor identification for moderate-severe delirium by nurses may prove to be of value in preventing further deterioration of those older patients afflicted with delirium. [source]