Magnetic resonance imaging of renal abscess in an experimental animal model

The value of magnetic resonance imaging (MRI) in the diagnosis of renal abscess was investigated in an experimental animal model. MRI is capable of depicting the location and extent of the inflammatory process using T1 weighted scans because of relatively long T1 relaxation values which were significantly longer than T1 relaxation times of adjacent normal renal parenchyma.     

Age-dependent effects of acoustic deprivation on spherical cells of the rat anteroventral cochlear nucleus

The effects of monaural deprivation by ligation of the external auditory meatus on spherical cells in the anteroventral cochlear nucleus of the rat were examined. Sound deprivation from postnatal days 10, 16, 24, and 36 resulted in a reduction in spherical cell size, with the most dramatic reduction produced by deprivation at 10 and 16 days after birth. The anteroventral cochlear nucleus was subdivided into dorsal, middle, and ventral zones which generally correspond to different frequency representations, and the effects of deprivation on cells in these regions were examined. Cells in the dorsal zone of the anteroventral cochlear nucleus were significantly smaller than cells in the middle or ventral zones, thus indicating a position-dependent effect of acoustic deprivation. Our results suggest a sensitive period during which alterations in normal acoustic input can significantly and differentially affect the development of cells in the anteroventral cochlear nucleus.     

Generating an ex vivo vascular model

Realistic ex vivo anthropometric vascular environments are required for endovascular device optimization and for preclinical evaluation of interventional procedures. The objective of this research is to build an anthropomorphic model of the human carotid artery. The combination of magnetic resonance angiography image processing and computer-aided design and manufacturing techniques allowed fabrication of multicomponent morphologically precise casts of the carotid artery. The lost core technique was used to produce a hollow vessel prototype incorporating polyvinyl alcohol cryogel (PVA-C) as a tissue-mimicking vessel wall material. PVA-C was mechanically characterized by uniaxial tensile testing after different numbers of freeze/thaw cycles. The novel model construction approach outlined in this study accounts for the morphologic complexities of the human vasculature, and proved successful for the production of realistic compliant ex vivo arterial model.     

Gaucher mutation N188S is associated with myoclonic epilepsy

The recent article by Montfort et al. [2004] reported a functional analysis of 13 glucocerebrosidase alleles, including mutation N188S, which they considered to be a "very mild mutation" or "modifier variant." Our clinical experience with patients carrying this mutation and preliminary protein modeling data lead us to dispute this conclusion.     

Essential hypotension is accompanied by deficits in attention and working memory

In the present study, the authors investigated the relationship between low blood pressure (BP) and attentional performance through the application of a multidimensional diagnostic approach. The authors compared 40 subjects with essential hypotension (mean systolic BP = 97.6 mmHg) with 40 normotensive controls (mean systolic BP = 124.1 mmHg) using 6 computer-based tasks measuring tonic and phasic alertness; selective, divided, and sustained attention; and working memory. To control for possible confounders, the authors used a test battery examining motor performance and a mood questionnaire. BP was monitored continuously during the entire experiment. Hypotensives showed prolonged execution times in each of the attentional tasks (p < .001). Moderately decreased accuracy was found in the tests assessing sustained attention (p = .059) and working memory (p = .012). Moreover hypotensives showed smaller elevations in BP during the execution of the cognitive tasks. This study is the first to demonstrate the relationship between BP and cognitive performance while controlling for motor function and mood.     

Scoring method for early prediction of neonatal chronic lung disease using modified respiratory parameters

In our previous study, we have demonstrated that peak inspiratory pressure over birth weight (PIP/kg) and mean airway pressure over birth weight (MAP/kg) were more significant risk factors for the development of neonatal chronic lung disease (CLD) than PIP and MAP. We aimed to develop a scoring method using the modified respiratory variables (SMUMRV) to predict CLD at early postnatal period. From 1997 to 1999, a retrospective review was performed for 197 infants <1,500 g for the development of the SMUMRV based on statistical analysis. From 2000 to 2001, calculated scores on day 4, 7 and 10 of life were obtained prospectively for 107 infants <1,500 g. Predictive values and the area under the receiver operator characteristic curve (AUC) were determined and compared with the result of the previous regression model. Gestational age, birth weight, 5 min Apgar score, PIP/kg at 12 hr of age, fractional inspired oxygen (FiO2), MAP/kg, modified oxygenation index and ventilatory mode were selected as parameters of SMUMRV. No significant differences of AUCs were found between the SMUMRV and the Yoder model. It is likely that our scoring method provides reliable values for predicting the development of CLD in very low birth weight infants.     

Does provider adherence to a treatment guideline change clinical outcomes for patients with bipolar disorder? Results from the Texas Medication Algorithm Project

BACKGROUND: Despite increasing adoption of clinical practice guidelines in psychiatry, there is little measurement of provider implementation of these recommendations, and the resulting impact on clinical outcomes. The current study describes one effort to measure these relationships in a cohort of public sector out-patients with bipolar disorder.METHOD:Participants were enrolled in the algorithm intervention of the Texas Medication Algorithm Project (TMAP). Study methods and the adherence scoring algorithm have been described elsewhere. The current paper addresses the relationships between patient characteristics, provider experience with the algorithm, provider adherence, and clinical outcomes. Measurement of provider adherence includes evaluation of visit frequency, medication choice and dosing, and response to patient symptoms. An exploratory composite 'adherence by visit' score was developed for these analyses.RESULTS: A total of 1948 visits from 141 subjects were evaluated, and utilized a two-stage declining effects model. Providers with more experience using the algorithm tended to adhere less to treatment recommendations. Few patient factors significantly impacted provider adherence. Increased adherence to algorithm recommendations was associated with larger decreases in overall psychiatric symptoms and depressive symptoms over time, but did not impact either immediate or long-term reductions in manic symptoms.CONCLUSIONS: Greater provider adherence to treatment guideline recommendations was associated with greater reductions in depressive symptoms and overall psychiatric symptoms over time. Additional research is needed to refine measurement and to further clarify these relationships.