131 resultados para Creative Disposition


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Purpose of review To identify and discuss recent research studies that propose innovative psychosocial interventions in old age psychiatry. Recent findings Studies have shown that cognitive training research for healthy elderly has advanced in several ways, particularly in the refinement of study design and methodology. Studies have included larger samples and longer training protocols. Interestingly, new research has shown changes in biological markers associated with learning and memory after cognitive training. Among mild cognitive impairment patients, results have demonstrated that they benefit from interventions displaying cognitive plasticity. Rehabilitation studies involving dementia patients have suggested the efficacy of combined treatment approaches, and light and music therapies have shown promising effects. For psychiatric disorders, innovations have included improvements in well known techniques such as cognitive behavior therapy, studies in subpopulations with comorbidities, as well as the use of new computer-aided resources. Summary Research evidence on innovative interventions in old age psychiatry suggests that this exciting field is moving forward by means of methodological refinements and testing of creative new ideas.

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Objective: To develop a model to predict the bleeding source and identify the cohort amongst patients with acute gastrointestinal bleeding (GIB) who require urgent intervention, including endoscopy. Patients with acute GIB, an unpredictable event, are most commonly evaluated and managed by non-gastroenterologists. Rapid and consistently reliable risk stratification of patients with acute GIB for urgent endoscopy may potentially improve outcomes amongst such patients by targeting scarce health-care resources to those who need it the most. Design and methods: Using ICD-9 codes for acute GIB, 189 patients with acute GIB and all. available data variables required to develop and test models were identified from a hospital medical records database. Data on 122 patients was utilized for development of the model and on 67 patients utilized to perform comparative analysis of the models. Clinical data such as presenting signs and symptoms, demographic data, presence of co-morbidities, laboratory data and corresponding endoscopic diagnosis and outcomes were collected. Clinical data and endoscopic diagnosis collected for each patient was utilized to retrospectively ascertain optimal management for each patient. Clinical presentations and corresponding treatment was utilized as training examples. Eight mathematical models including artificial neural network (ANN), support vector machine (SVM), k-nearest neighbor, linear discriminant analysis (LDA), shrunken centroid (SC), random forest (RF), logistic regression, and boosting were trained and tested. The performance of these models was compared using standard statistical analysis and ROC curves. Results: Overall the random forest model best predicted the source, need for resuscitation, and disposition with accuracies of approximately 80% or higher (accuracy for endoscopy was greater than 75%). The area under ROC curve for RF was greater than 0.85, indicating excellent performance by the random forest model Conclusion: While most mathematical models are effective as a decision support system for evaluation and management of patients with acute GIB, in our testing, the RF model consistently demonstrated the best performance. Amongst patients presenting with acute GIB, mathematical models may facilitate the identification of the source of GIB, need for intervention and allow optimization of care and healthcare resource allocation; these however require further validation. (c) 2007 Elsevier B.V. All rights reserved.

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OBJECTIVE: To study the microanatomy of the brainstem related to the different safe entry zones used to approach intrinsic brainstem lesions. METHODS: Ten formalin-fixed and frozen brainstem specimens (20 sides) were analyzed. The white fiber dissection technique was used to study the intrinsic microsurgical anatomy as related to safe entry zones on the brainstem surface. Three anatomic landmarks on the anterolateral brainstem surface were selected: lateral mesencephalic sulcus, peritrigeminal area, and olivary body. Ten other specimens were used to study the axial sections of the inferior olivary nucleus. The clinical application of these anatomic nuances is presented. RESULTS: The lateral mesencephalic sulcus has a length of 7.4 to 13.3 mm (mean, 9.6 mm) and can be dissected safely in depths up to 4.9 to 11.7 mm (mean, 8.02 mm). In the peritrigeminal area, the distance of the fifth cranial nerve to the pyramidal tract is 3.1 to 5.7 mm (mean, 4.64 mm). The dissection may be performed 9.5 to 13.1 mm (mean, 11.2 mm) deeper, to the nucleus of the fifth cranial nerve. The inferior olivary nucleus provides safe access to lesions located up to 4.7 to 6.9 mm (mean, 5.52 mm) in the anterolateral aspect of the medulla. Clinical results confirm that these entry zones constitute surgical routes through which the brainstem may be safely approached. CONCLUSION: The white fiber dissection technique is a valuable tool for understanding the three-dimensional disposition of the anatomic structures. The lateral mesencephalic sulcus, the peritrigeminal area, and the inferior olivary nucleus provide surgical spaces and delineate the relatively safe alleys where the brainstem can be approached without injuring important neural structures.

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The pharmacokinetics of cyclophosphamide (CYC) enantiomers were evaluated in patients with lupus nephritis distributed in 2 groups according to creatinine clearance: group 1 (90.6-144.6 mL/min/1.73 m(2)) and group 2 (42.8-76.4 mL/min/ 1.73 m(2)). All patients were treated with 0.75 to 1.3 g of racemic CYC as a 2-hour infusion and with 1 mg intravenous midazolam as a drug-metabolizing marker. CYC enantiomers and midazolam concentrations in plasma were measured by liquid chromatography/tandem mass spectrometry (LC/MS/MS). The following differences (Wilcoxon test, P <= .05) were observed between the (S)-(-) and (R)-(+) enantiomers: AUC(0-infinity) 152.41 vs 129.25 mu g.h/mL, CL 3.28 vs 3.89 L/h, Vd 31.38 vs 29.74 L, and t(1/2) 6.79 vs 5.56 h for group 1 and AUC(0-infinity) 167.20 vs 139.08 mu g.h/mL, CL 2.99 vs 3.59 L/h, and t(1/2) 6.15 vs 4.99 h for group 2. No differences (Mann test, P <= .05) were observed between groups 1 and 2 in the pharmacokinetic parameters of both enantiomers. No significant relationship was observed between midazolam clearance (2.92-16.40 mL/min.kg) and clearance of each CYC enantiomer. In conclusion, CYC kinetic disposition is enantioselective, resulting in higher exposures of the (S)-(-) enantiomer in lupus nephritis patients, and the pharmacokinetic parameters of both enantiomers are not altered by the worsening of renal condition.

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Mexiletine (MEX), hydroxymethylmexiletine (HMM) and P-hydroxy-mexiletine (PHM) were analyzed in rat plasma by LC-MS/MS. The plasma samples were prepared by liquid-liquid extraction using methyl-tert-butyl ether as extracting solvent. MEX, HMM, and PHM enantiomers were resolved on a Chiralpak (R) AD column. Validation of the method showed a relative standard deviation (precision) and relative errors (accuracy) of less than 15% for all analytes studied. Quantification limits were 0.5 ng ml(-1) for the MEX and 0.2 ng ml(-1) for the HMM and PHM enantiomers. The validated method was successfully applied to quantify the enantiomers of MEX and its metabolites in plasma samples of rats (n = 6) treated with a single oral dose of racemic MEX. Chirality 21:648-656, 2009. (C) 2008 Wiley-Liss, Inc.

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Hypertension and dyslipidemia are independent risk factors for cardiovascular mortality and are frequently present in the same patient. Fluvastatin (FV), used to reduce cholesterol levels, and lercanidipine (LER), used to control blood pressured are marketed as racemic mixtures. Therapeutic activities are 30-fold higher for (+)-3R,5S-FV and 100- to 200-fold higher for S-LER compared with their respective antipodes. The present study describes the enantioselective pharmacokinetic interaction between LER and FV in healthy volunteers. A crossover randomized study was conducted in 3 phases on 8 volunteers treated with a single oral racemic dose of LER (20 mg) or FV (40 mg) or LER plus FV. Serial blood samples were collected from 0 to 24 hours. Plasma concentrations of the LER and FV enantiomers were determined by liquid chromatography/tandem mass spectrometry, and pharmacokinetic parameters were evaluated using the WinNonlin software. The Wilcoxon and Mann-Whitney tests (P < .05) were used to analyze enantiomer ratios and the pharmacokinetic drug interaction. Data are expressed as medians. In monotherapy, the kinetic disposition of both FV and LER was enantioselective. AUC values were significantly higher for (-)-3S,5R-FV than for (+)-3R,5S-FV (358.20 vs 279.68 ng.h/mL) and for S-LER compared with R-LER (13.90 vs 11.88 ng.h/mL). The pharmacokinetic parameters of FV were not enantioselective when combined with LER (AUC: (-)-3S,5R-FV: 325.21; (+)-3R,5S-FV: 316.44 ng.h/mL). There was a significant reduction in S-LER (8.06 vs 13.90 ng.h/mL) and R-LER (6.76 vs 11.88 ng.h/mL) AUC values when FV was coadministered. In conclusion, the interaction between FV-LER might be clinically relevant because AUC values of (+)-3R,5S-FV were increased when LER was coadministered, and AUC values of the 2 LER enantiomers were reduced when FV was coadministered.

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Citalopram (CITA) is available as a racemic mixture or as (+)-(S)-CITA. In humans, CITA is metabolized to demethylcitalopram (DCITA) by CYP2C19, CYP2D6, and CYP3A and to didemethylcitalopram by CYP2D6. There are no data regarding the enzymes involved in CITA and DCITA metabolism in rats. The present study investigated the influence of CYP inhibitors on the enantioselective metabolism of CITA in rats. Male Wistar rats (n = 6) received a single dose of 20 mg.kg(-1) CITA after pretreatment with 80 mg.kg(-1) quinidine, 10 mg.kg(-1) fluvoxamine, 50 mg.kg(-1) ketoconazole, or vehicle (control). Blood samples were collected up to 20 h after CITA administration. The CITA and DCITA enantiomers were analyzed by LC-MS/MS using a Chiralcel OD-R column. The kinetic disposition of CITA was enantioselective in rats (AUC(S/R) ratio = 0.4). Coadministration with quinidine resulted in non-enantioselective inhibition of the metabolism of CITA. Coadministration with fluvoxamine or ketoconazole, however, inhibited only the metabolism of (+)-(S)-CITA, but not of (-)-(R)-CITA when the racemic drug was administered to rats.

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center dot Citalopram (CITA) pharmacokinetics are enantioselective in healthy volunteers and the metabolism of (+)-(S)-CITA to (+)-(S)-DCITA is dependent on CYP2C19. Omeprazole is a potent CYP2C19 inhibitor. WHAT THIS STUDY ADDS center dot This study indicates that omeprazole induces a loss of enantioselectivity in the CITA pharmacokinetics because of the selective inhibition of (+)-(S)-CITA metabolism. AIM The study assessed the influence of omeprazole on the kinetic disposition of the (+)-(S)-citalopram (CITA) and (-)-(R)-CITA enantiomers in healthy volunteers. METHODS In a cross-over study, healthy volunteers (n = 9) phenotyped as extensive metabolizers of CYP2C19 and CYP2D6 and with an oral midazolam clearance ranging from 10.9 to 149.3 ml min-1 kg-1 received a single dose of racemic CITA (20 mg orally) in combination or not with omeprazole (20 mg day-1 for 18 days). Serial blood samples were collected up to 240 h after CITA administration. CITA and demethylcitalopram (DCITA) enantiomers were analyzed by LC-MS/MS using a Chiralcel (R) OD-R column. RESULTS The kinetic disposition of CITA was enantioselective in the absence of treatment with omeprazole, with the observation of a greater proportion of plasma (-)-(R)-CITA [AUC S : R ratio of 0.53 (95% CI 0.41, 0.66) for CITA and 1.08 (95% CI 0.80, 1.76) for DCITA] than (+)-(S)-CITA. Racemic CITA administration to healthy volunteers in combination with omeprazole showed a loss of enantioselectivity in CITA pharmacokinetics with an increase of approximately 120% in plasma (+)-(S)-CITA concentrations [AUC S : R ratio of 0.95 (95% CI 0.72, 1.10) for CITA and 0.95 (95% CI 0.44, 1.72) for DCITA]. CONCLUSIONS The administration of multiple doses of omeprazole preferentially inhibited (+)-(S)-CITA metabolism in healthy volunteers. Although omeprazole increased plasma concentrations of (+)-(S)-CITA by approximately 120%, it is difficult to evaluate the clinical outcome because the range of plasma CITA concentrations related to maximum efficacy and minimum risk of adverse effects has not been established.

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Labetalol is clinically available as a mixture of two racemates (four stereoisomers). The stereoisomer (R,R) has as main activity the beta(1)-antagonism and the stereoisomer (S,R) is highly selective for the alpha(1) adrenoceptor and is responsible for most of the alpha-blocker activity. In the present investigation, a method for the analysis of labetalol stereoisomers in human plasma was developed and applied to pharmacokinetic studies. Plasma samples (0.5 ml) were extracted with methyl tert-butyl ether at pH 9.5. The four labetalol stereoisomers were analyzed by LC-MS/MS on a Chirobiotic (R) V column using a mobile phase consisting of methanol, acetic acid, and diethylamine, with a recovery of more than 90% for all four. The quantitation limit was 0.5 ng/ml and linearity was observed at 250 ng/ml plasma for each stereoisomer. Studies of precision and accuracy presented coefficients of variation and percentage inaccuracy of less than 15%, indicating that the method is precise and accurate. The method was applied to the study of the kinetic disposition of labetalol over a period of 12 h after oral administration of a single 100 mg dose to a hypertensive pregnant woman. The clinical study revealed stereoselectivity in the pharmacokinetics of labetalol, with a lower plasma proportion for the active stereoisomers (R,R)-labetalol and (S,R)-labetalol. The stereoselectivity observed after oral administration is due to the hepatic metabolism and the first pass effect, with an AUC((R,R))/AUC((S,S)) ratio of 0.5. Chirality 21:738-744, 2009. (C) 2008 Wiley-Liss, Inc.

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The study of lingual surfaces and the surface of interface epithelium-connective tissue of the tongue of Bradypus torquatus was performed by employing the light and scanning electron microscopy (SEM) techniques. The results revealed that the rostral part of the tongue presents a round apex and covered by filiform and fungiform lingual papillae and a ventral smooth surface. It was observed that the epithelial layer of the dorsal surface possesses the basal, spinosum, granular and cornified epithelial cells. The lamina propria is characterized by a dense connective tissue forming the long, short and round papillae. Numerous typical filiform papillae are located especially in the rostral part intermingled for few fungiform papillae, which were revealed in three-dimensional SEM images. Usually, the fungiform papillae are located in the border of rostral apex of the tongue exhibiting the rounded form. They are covered by keratinized epithelial cells. In the fungiform papillae, several taste pores were observed on the surface. The vallate papillae presented numerous taste buds in the wall of epithelial cells, being that the major number of taste buds is located on the superior half of vallate papilla. The taste pores are surrounded by several laminae of keratinized epithelial cells. The samples treated with NaOH solution and examined by SEM revealed, after removal of the epithelial layer, the dense connective core in original disposition, presenting different sizes and shapes. The specimens stained with Picrosirius and examined by polarized light microscopy revealed the connective tissue, indicating the collagen fibres type I and type III.

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In the present paper were analysed the three-dimensional characteristics of the interface epithelium-connective tissue surface of finger prints of Cebus apella monkey employing the scanning electron microscopic methods. The connective tissue core (CTC) and epithelial papillae were examined verifying the three-dimensional configuration of the tissue projections. The samples were fixed in Bouin solsution for histologic preparations and in modified Karnovsky for examine to observe in scanning electron microscopy. After treatment in the 10% NaOH solution during 3 to 5 days, the surface of finger prints revealed a distribution of CTC of lamina propria in situ showing original three-dimensional SEM images. The linear and circular dispositions CTC, and the furrows were clearly identified. Each pointed papilla presented a large base and longitudinal disposition of thick collagen fiber bundles and in some areas with a complex reticular formations. The longitudinal furrows between the pointed papillae exhibited a dense layer of connective tissue and showed only low CTC or laminar in shape. The presence of numerous foramina of sweat gland were noted in three-dimensional SEM images.