Biomedical subjects

Richard E Kennedy

Publications and source records attributed to Richard E Kennedy.

7 recordsLinked to original sources

PubMed2006

SScore: an R package for detecting differential gene expression without gene expression summaries.

SUMMARY: SScore is an R package that facilitates the comparison of gene expression between Affymetrix GeneChips using the S-score algorithm. The S-score algorithm uses probe level data directly to assess differences in gene expression, without requiring a preliminary separate step of probe set expression summary estimation. Therefore, the algorithm avoids introduction of error associated with the expression summary estimation process and has been demonstrated to improve the accuracy of identifying differentially expressed genes. The S-score produces accurate results even when few or no replicates are available. AVAILABILITY: The R package SScore is available from Bioconductor at http://www.bioconductor.org

Algorithms↗

PubMed2006

Empirical validation of the S-Score algorithm in the analysis of gene expression data.

BACKGROUND: Current methods of analyzing Affymetrix GeneChip microarray data require the estimation of probe set expression summaries, followed by application of statistical tests to determine which genes are differentially expressed. The S-Score algorithm described by Zhang and colleagues is an alternative method that allows tests of hypotheses directly from probe level data. It is based on an error model in which the detected signal is proportional to the probe pair signal for highly expressed genes, but approaches a background level (rather than 0) for genes with low levels of expression. This model is used to calculate relative change in probe pair intensities that converts probe signals into multiple measurements with equalized errors, which are summed over a probe set to form the S-Score. Assuming no expression differences between chips, the S-Score follows a standard normal distribution, allowing direct tests of hypotheses to be made. Using spike-in and dilution datasets, we validated the S-Score method against comparisons of gene expression utilizing the more recently developed methods RMA, dChip, and MAS5. RESULTS: The S-score showed excellent sensitivity and specificity in detecting low-level gene expression changes. Rank ordering of S-Score values more accurately reflected known fold-change values compared to other algorithms. CONCLUSION: The S-score method, utilizing probe level data directly, offers significant advantages over comparisons using only probe set expression summaries.

Algorithms↗

PubMed2004

Risperidone in the treatment of delirium: results from a prospective open-label trial.

BACKGROUND: Effective treatment is necessary to reverse delirium and prevent potentially serious consequences. METHOD: Patients were identified for screening by initial chart review of all consecutive admissions to the general medical or surgical wards at the Department of Veterans Affairs hospital and the University of Mississippi Medical Center in Jackson, Mississippi, between November 2000 and April 2002. Medically ill patients with delirium defined by DSM-IV criteria and a Delirium Rating Scale (DRS) score of >or= 13 were given risperidone, 0.5 mg, twice daily, with additional doses permitted on day 1 for target symptoms. Total day 1 dosage was given daily until the DRS score was <or= 12; dosage was then decreased by 50% (maintenance dose) and continued until day 6. Daily assessment included DRS, Cognitive Test for Delirium (CTD), and modified Extrapy-ramidal Symptom Rating Scale. Functional status (Karnofsky Scale of Performance Status; KSPS) and medical burden (Cumulative Illness Rating Scale) were assessed at baseline and day 6. RESULTS: Ten patients (mean age = 64.7 years) were enrolled. Mean daily maintenance risperidone dosage was 0.75 mg. Mean CTD scores improved from day 1 to the day maintenance dose was initiated (p <.0005) and remained improved at day 6 (7.1 +/- 2.0 and 16.9 +/- 3.0, days 1 and 6, respectively; p =.0078). Mean DRS scores improved from day 1 to the day maintenance dose was initiated (p <.0001) and remained improved at day 6 (25.2 +/- 0.9 and 11.3 +/- 1.5, days 1 and 6, respectively; p <.0001). Mean KSPS scores improved from 32.0 on day 1 to 45.5 on day 6 (p =.044). No patient developed movement disorders. One patient each discontinued because of sedation and hypotension. CONCLUSION: Low-dose risperidone can improve cognitive and behavioral symptoms of delirium in medically ill patients.

Adolescent↗

PubMed2002

Stereotypic movement disorder after acquired brain injury.

Stereotypic movement disorder (SMD) consists of repetitive, non-functional motor behaviour that interferes with daily living or causes injury to the person. It is most often described in patients with mental retardation. However, recent evidence indicates that this condition is common among otherwise normal individuals. This case study describes a patient with new-onset SMD occurring after subdural haematoma and brain injury. SMD has rarely been reported after acquired brain injury, and none have documented successful treatment. The current psychiatric literature regarding neurochemistry, neuroanatomy, and treatment of SMD are reviewed with particular application to one patient. Treatment options include serotonin re-uptake inhibitors, opioid antagonists and dopamine antagonists. SMD has been under-appreciated in intellectually normal individuals, and may also be unrecognized after brain injury. Further investigation is needed in this area, which may benefit other individuals with SMD as well.

Adult↗

PubMedDate not supplied

Evaluation of the Neurobehavioral Functioning Inventory as a depression screening tool after traumatic brain injury.

OBJECTIVE: To examine the utility of the Neurobehavioral Functioning Inventory (NFI) for diagnosing depression in a rehabilitation setting. DESIGN: In a prospective study, a structured clinical interview (Structured Clinical Interview for DSM-IV-TR) was used to identify DSM-IV-defined major depressive disorder (MDD) symptoms among patients with traumatic brain injury (TBI). NFI Depression scale items were compared with DSM-IV diagnosis obtained by the Structured Clinical Interview for DSM-IV Axis I Disorders. SETTING: Outpatient neuropsychology clinic at a university hospital, private outpatient physical medicine and rehabilitation clinic, and a long-term specialized living assistance program. PARTICIPANTS: Participants consisted of 78 patients with TBI who were at least 3 months postinjury and 18 years of age or older. MAIN OUTCOME MEASURES: Structured Clinical Interview for DSM-IV Axis I Disorders and the NFI. RESULTS: Psychiatric diagnostic interview with the Structured Clinical Interview for DSM-IV Axis I Disorders indicated that 50% of patients with TBI in our sample had at least one of the following in their lifetime: MDD, MDD due to general medical condition, dysthymia, or adjustment disorder with depressed mood. Thirty percent met diagnostic criteria for current MDD with or without general medical condition. Analyses of the NFI items revealed that individuals with depression endorsed greater levels of problems than did those without depression on 14 of the 32 items related to the DSM-IV symptom domains for depression (P < .00156 with Bonferroni correction). In predicting the diagnosis of depression using individual NFI items, the classification rate based on the Random Forests estimate was 83%. CONCLUSION: Findings indicate that the NFI items differentiated between depressed and nondepressed patients with TBI. Imposing minimal burden on patients and staff, the NFI appears to have good predictive value in diagnosing major depression. In clinical practice and research, the NFI is a potentially valuable screening tool for identifying major depression in persons with TBI.

Adolescent↗

PubMedDate not supplied

Complicated mild traumatic brain injury on the inpatient rehabilitation unit: a multicenter analysis.

OBJECTIVE: To determine characteristics of patients with complicated mild traumatic brain injury (CMTBI) on the inpatient rehabilitation unit and to accentuate limits of current classification systems for patients with mild TBI. DESIGN: Multicenter analysis of individuals with a Glasgow Coma Scale (GCS) score of 13 to 15 (lowest score in 24 h) and positive computed tomography findings admitted to inpatient rehabilitation for TBI. SETTING: 16 TBI Model System centers funded by the National Institute on Disability and Rehabilitation Research. PARTICIPANTS: 373 adults with CMTBI. MAIN OUTCOME MEASURES: Functional Independence Measure (FIM) and Disability Rating Scale (DRS) scores, length of stay, and medical complications. RESULTS: 16% of the sample experienced serious cranial complications (eg, cerebrospinal fluid leak, intracranial hypertension), with seizures being the most common during the course of inpatient rehabilitation. Most patients demonstrated substantial improvements on functional outcome measures during rehabilitation (mean admission FIM 68.2, discharge FIM 100.6; admission DRS 9.1, discharge DRS 4.8). Age, acute length of stay, and FIM score on rehabilitation admission were significant predictors of rehabilitation length of stay. Factors not predictive of rehabilitation duration were GCS score, ethnicity, gender, incidence of fractures, and incidence of cranial/noncranial complications. CONCLUSION: Despite favorable GCS scores, some patients with CMTBI suffer a variety of serious cranial and noncranial complications. Such patients appear to benefit from additional brain injury services offered in inpatient rehabilitation. Further study of the unique treatment needs of these patients is warranted.

Activities of Daily Living↗

PubMedDate not supplied

Use of the cognitive test for delirium in patients with traumatic brain injury.

The sensitivity and specificity of the Cognitive Test for Delirium, which was originally developed for use in intensive care units, were tested in a group of patients with traumatic brain injury who were admitted to a neurorehabilitation center. Sixty-five consecutive patients were evaluated weekly by using the DSM-IV criteria for delirium and the Cognitive Test for Delirium. Complete ratings were available for 249 of 304 weekly observations. Analysis of the receiver operating characteristic curve suggested an optimum cutoff score of less than 22 for identification of delirium by using the Cognitive Test for Delirium, with a sensitivity of 72% and a specificity of 71% compared with the DSM-IV diagnosis. The results suggest that the Cognitive Test for Delirium provides an acceptable level of differentiation between delirious and nondelirious patients with traumatic brain injury.

Adolescent↗