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Dana Oliver

Publications and source records attributed to Dana Oliver.

7 recordsLinked to original sources
PubMed2006

Reading a research article part III: the data collection instrument.

Parts I through III of this series of articles gave an introduction to some of the issues requiring attention when performing clinical studies and summarizing the results statistically as well as clinically. Statistical methods have been described for the identification of statistically significant differences and associations between an experimental group and a control group or over the course of time after an intervention. The next article will address the methods used for the determination of the strength or magnitude of these identified statistically significant differences.

Biomedical Research↗
PubMed2005

Effect of testosterone on functional recovery in a castrate male rat stroke model.

Both increased and decreased testosterone levels have been reported to correlate with poor outcome after acute ischemic stroke. The present study focused on the role of testosterone during recovery from neurological deficits in a rat focal ischemia model. Castrate male rats were subjected to behavioral tests after 90 min of middle cerebral artery occlusion (MCAO). On day 7 post-MCAO, neurological deficit-matched rats were assigned to a treatment group implanted with subcutaneous testosterone pellets or a control group implanted with sham cholesterol pellets. After 4 weeks post-MCAO, the average infarct volume was not significantly different between the two groups. Rats in the testosterone group demonstrated significantly earlier improvement in neurological deficits and shortened latency of adhesive tape removal compared with the control group as analyzed by Wilcoxon signed ranks test. Walking on parallel bars improved in both groups with a trend towards early recovery observed in the testosterone group. Biased left body swings persisted during the test period in both groups post-MCAO. Serum testosterone was within physiological levels in the treatment group but was not detectable in the control group by radioimmunoassay. GAP-43 and synaptophysin expression did not differ between groups. Less GFAP expression and reactive astrocyte hypertrophy were found around the infarct area in testosterone-treated rats compared with control rats. In conclusion, testosterone replacement post-MCAO accelerated functional recovery in castrate rats, suggesting a potential therapeutic role for testosterone replacement in stroke recovery.

Androgens↗
PubMed2005

Reading a research article part II: parametric and nonparametric statistics.

Researchers often try to use a randomization technique in an attempt to reduce bias and ensure that treatment and control groups are as similar as possible. This article has provided an overview of how researchers might use parametric and nonparametric statistics when analyzing data and looking for differences between groups. Researchers must consider the types of data and choose the tests that are appropriate for the variable types to draw appropriate conclusions. The next article in this series will address comparison of more than two groups and repeated measures and other design issues.

Age Distribution↗
PubMed2004

Nonalcoholic steatohepatitis: histologic features and clinical correlations with 30 blinded biopsy specimens.

Thirty overweight patients with clinically characterized and biopsy proven nonalcoholic steatohepatitis (NASH) were enrolled in a 48-week treatment trial with rosiglitazone, a peroxisome proliferator-activator receptor (PPAR)-gamma agonist that enhances insulin sensitivity. Improvement in laboratory liver tests, insulin resistance and liver fat content were documented; blinded biopsy review demonstrated decreases in necroinflammatory activity or grade and in individual components of grade, and changes in the relationship of lobular and portal inflammation as well as in the nature of perisinusoidal fibrosis. The current study identified correlations of histological features of the protocol entry biopsy specimens with contemporaneous laboratory and imaging tests. Significant correlations with histologically assessed steatosis were liver fat, evaluated by computed tomography (P = 0.001); mean HbA1C, a measure of glycemic control (P = 0.004); and QUICKI, a measure of insulin sensitivity (P = 0.05). Histologically determined grades of steatohepatitis (SH) correlated with HbA1C (P = 0.01), and a trend toward elevated fasting glucose levels was seen. No subject in the study was cirrhotic at entry; fibrosis scores of the 30 subjects did not significantly correlate with age, gender, body mass index, or clinical tests. All subjects underwent 3 biopsies (prior, entry, and posttreatment), and all had undergone a prior biopsy with diagnostic SH. By blinded analysis, 7 study entry biopsy specimens did not fulfill published strict criteria for SH. Laboratory results from these subjects included normal fasting glucose level and, compared with the 23 subjects with criteria for SH, lower mean alanine aminotransferase and aspartate aminotransferase levels (P = 0.02 for both), less insulin resistance (P = 0.03), and lower mean HbA1C (P = 0.001). We conclude that biopsy findings determined by blinded analysis correlated with image-detected steatosis, laboratory markers of hepatic inflammation, insulin resistance, and long-term glycemia; the findings confirm the usefulness of strict histological criteria in the evaluation of NASH.

Biopsy↗
PubMed2003

Improved nonalcoholic steatohepatitis after 48 weeks of treatment with the PPAR-gamma ligand rosiglitazone.

Insulin resistance (IR) commonly is associated with nonalcoholic steatohepatitis (NASH). To establish whether IR causes NASH, this study was undertaken to determine if improving IR would improve the histologic features that define NASH. Thirty adults with prior biopsy evidence of NASH were enrolled to receive rosiglitazone, 4 mg twice daily for 48 weeks. All patients were overweight (body mass index [BMI] > 25 kg/m(2)) and 23% were severely obese (BMI > 35 kg/m(2)); 50% had impaired glucose tolerance or diabetes. Liver biopsy specimens were obtained before beginning treatment and at treatment completion. Twenty-six patients had posttreatment biopsies; of these, 22 had initial protocol liver biopsies that met published criteria for NASH on subsequent blinded evaluation. Within this initial NASH group, the mean global necroinflammatory score significantly improved with treatment and biopsies of 10 patients (45%) no longer met published criteria for NASH after treatment. Significant improvement in hepatocellular ballooning and zone 3 perisinusoidal fibrosis also occurred. Five patients withdrew early; the 25 patients completing 48 weeks of treatment had significantly improved insulin sensitivity and mean serum alanine aminotransferase (ALT) levels (104 initially, 42 U/L at the end of treatment). Adverse effects led to withdrawal of 3 patients (10%). Weight gain occurred in 67% of patients and the median weight increase was 7.3%. Within 6 months of completing treatment, liver enzyme levels had increased to near pretreatment levels. In conclusion, improving insulin sensitivity with rosiglitazone resulted in improved histologic markers of NASH, an observation suggesting that insulin resistance contributes to its development and that improving insulin sensitivity may be important in treating this liver disease.

Adult↗
PubMedDate not supplied

Effect of feeding-tube properties on residual volume measurements in tube-fed patients.

BACKGROUND: The effect of feeding tube size and port configuration on the ability to measure gastric residual volume (GRV) is poorly understood. In addition, there is confusion about the need to measure GRVs during feedings into the small bowel. This study sought to (1) compare the volume of gastric contents obtained from small-diameter feeding tubes and large-diameter sump tubes concurrently positioned in the stomach and (2) describe the distribution of GRVs during small-bowel feedings. METHODS: For the first objective, GRV measurements were made from 10-Fr tubes (n = 645) and 14-Fr or 18-Fr sump tubes (n = 645) concurrently present in 62 critically ill patients. Sixty-milliliter syringes were used to measure GRVs from the 10-Fr tubes; the fluid was returned to the stomach and measurements were repeated from the large-diameter sump tubes. To address the second research objective, 890 GRV measurements were made from 14-Fr or 18-Fr gastric sump tubes (not connected to suction) in 75 critically ill patients who were receiving small-bowel feedings. RESULTS: When GRVs were >50 mL, a linear regression equation indicated that volumes obtained from the large-diameter sump tubes were about 1.5 times greater than those obtained from the small-diameter tubes concurrently present in the stomach, p < .001. Gastric volumes > or =100 mL were found in 11.6% of the 890 measurements made in patients receiving small-bowel feedings; volumes > or =150 mL were found in 5.4% of the measurements. CONCLUSIONS: The findings suggest that GRVs obtained from large-diameter sump tubes are about 1.5 times greater than those obtained from 10-Fr tubes. Large GRVs occur in at least 5% of patients receiving postpyloric feedings.

Adolescent↗