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Biomedical subjects

D D Marshall

Publications and source records attributed to D D Marshall.

11 recordsLinked to original sources
PubMed2001

The clinical, morphologic, and molecular changes in the ileum associated with early postnatal dexamethasone administration: from the baby's bowel to the researcher's bench.

Focal small bowel perforation (FSBP) is a life-threatening event that predominantly affects extremely low birth weight (ELBW) infants. Histopathology from surgical specimens of ileum with FSBP shows a healthy mucosa overlying a thinned muscularis with segmental degeneration. Clinical data strongly support an association between early postnatal administration of dexamethasone (EPD) and FSBP. Additional risk factors, including gestational age, administration of prophylactic indomethacin, and severity of illness, may be synergistic with EPD for the pathogenesis of perforations. Animal models of dexamethasone administration show morphologic changes in the ileum, similar to those seen in ELBW infants, including increased mucosal maturation and thinning of the muscularis. These tissue-specific differences may be mediated by a perturbation in growth factor expression or accumulation. In support of this hypothesis, dexamethasone has been associated with increased IGF-I immunolocalization in the mucosa and decreased immunolocalization in the muscularis. The known growth-promoting functions of IGF-I are consistent with the observed dexamethasone-associated changes within both the mucosa and the muscularis. Ongoing studies in this animal model are exploring the potential mechanisms by which dexamethasone might affect IGF-I availability.

Animals↗
PubMed1999

Population-based study of chronic lung disease in very low birth weight infants in North Carolina in 1994 with comparisons with 1984. The North Carolina Neonatologists Association.

OBJECTIVE: To assess the pulmonary outcomes of very low birth weight (VLBW) infants in North Carolina in 1994 and to compare rates of survival and chronic lung disease (CLD) between 1994 and 1984 (see reference 2). METHODS: Data were collected prospectively by collaborators from all 13 neonatal intensive care units in North Carolina to determine survival and pulmonary outcomes of infants with birth weights of 500 to 1500 g. State vital statistics data were used to confirm completeness of the sample. CLD was defined as oxygen or ventilator therapy at 36 weeks' postmenstrual age (PMA). For comparisons with the 1984 cohort, survival and pulmonary outcomes of infants defined to be at risk for CLD (ventilated >48 hours and survived 30 days) were recorded at 30 days, 3 months, and 6 months of postnatal age. RESULTS: Outcome data were available for 1413 (92%) of the in-state VLBW live births. Of VLBW infants, 224 (15%) died before 48 hours of age. The overall rate of CLD in 1994 at 36 weeks' PMA was 25%. Rates by birth weight group were 57% for 500 to 750 g birth weight (BW), 41% for 751 to 1000 g BW, 19% for 1001 to 1250 g BW, and 8% for 1251 to 1500 g BW. Infants who received ventilator therapy for >48 hours accounted for 89% of the CLD cases. The CLD rate at 36 weeks' PMA in infants weighing 751 to 1500 g was 37% for those ventilated >48 hours versus 5% for those ventilated <48 hours (OR: 7.1; 95% CI: 4.4-11.3). Overall survival in 1994 was significantly higher for infants than in 1984 (78% vs 74%), most notably in infants 500 to 750 g BW (37% vs 24%), and 751 to 1000 g BW (82% vs 65%). When compared with 1984, the CLD rates in those infants defined to be at risk were significantly higher in 1994 at 30 days (68% vs 54%) and at 3 months (24% vs 15%) of postnatal age. For at-risk infants in 1994, there were fewer infants on the ventilator, but more infants on oxygen alone at all measured time points compared with 1984. CONCLUSION: Survival of VLBW infants has improved since 1984. Ventilator therapy for >48 hours remains a significant risk factor for CLD. The incidence of CLD has increased from 1984 to 1994 but has shifted from ventilator to oxygen therapy. bronchopulmonary dysplasia, epidemiology, infant, low birth weight, intensive care units, neonatal statistics, infant mortality, prospective studies.

Chronic Disease↗
PubMed1999

Risk factors for chronic lung disease in the surfactant era: a North Carolina population-based study of very low birth weight infants. North Carolina Neonatologists Association.

OBJECTIVE: To identify risk factors for chronic lung disease (CLD) in a population-based cohort of very low birth weight infants, born in an era of surfactant usage. We specifically investigated the effects of antenatal steroids, nosocomial infection, patent ductus arteriosus (PDA), fluid management, and ventilator support strategies. METHODS: Data were prospectively collected on 1244 infants born in North Carolina in 1994 with birth weights 500 to 1500 g, and treated at 1 of the 13 intensive care nurseries across the state. The outcome of interest was CLD, defined as dependency on supplemental oxygen at 36 weeks' postmenstrual age. Multivariate odds ratios (OR) and 95% confidence intervals (CI) were estimated with logistic regression models. RESULTS: Among 865 survivors to 36 weeks' postmenstrual age, 224 (26%) had CLD. Nosocomial infection (OR: 2.0; 95% CI: 1.4-3.3), fluid intake on day 2 (OR: 1.06 per 10 mL increase; 95% CI: 1.01-1.11), and the need for ventilation at 48 hours of life (OR: 2.2; 95% CI: 1.3-3.7) were associated with an increased risk of CLD. Among infants ventilated at 48 hours, nosocomial infection (OR: 1.64; 95% CI: 1.02-2.62) and PDA (OR: 1.9; 95% CI: 1.2-3.1) were associated with an increased risk. No association was found with antenatal steroid receipt or increased levels of ventilator support. CONCLUSION: This analysis suggests that with widespread use of surfactant, nosocomial infection, PDA, and water balance persist as risk factors for CLD.

Chronic Disease↗
PubMed1998

Predictors of aggression in hospitalized adolescents.

Client records spanning a 14-month period were examined for an adolescent unit of a large state psychiatric hospital to identify client variables predictive of acts of physical aggression in hospitalized adolescents. Forty-two percent of the 43 girls and 55% of the 57 boys were classified as aggressive because they had committed at least one act of physical aggression during the data collection period. In logistic regression analyses, client characteristics were used to predict aggression classification and 79%, 81%, and 92% of the total sample, girls, and boys, respectively, were correctly classified. Aggression in the girls was associated with having a history of family violence, being of a minority race, and being on medication; for the boys, aggression was associated with a diagnosis of a conduct disorder, being on medication, and being previously hospitalized.

Adolescent↗
PubMed1998

Overexpression of scatter factor and its receptor (c-met) in oral squamous cell carcinoma.

HYPOTHESIS: Scatter factor (SF) is a pleiotropic growth factor that recently has been shown to induce epithelial cell proliferation, random motility, and invasion via interaction with its receptor, a tyrosine kinase encoded by the c-met proto-oncogene. Studies involving a variety of solid tumors have suggested that overexpression of the SF/c-met ligand-receptor pair is associated with the acquisition of a malignant phenotype. We hypothesize that SF and c-met are overexpressed in epithelial malignancies of the head and neck including squamous cell carcinoma (SCC) of the oral cavity. STUDY DESIGN: Immunohistochemical staining of randomly selected normal, dysplastic, and malignant oral tissues. METHODS: Formalin-fixed, paraffin-embedded tissues were obtained from the Department of Oral Pathology at Shands Hospital (University of Florida), Gainesville, Florida. Examples of mild dysplasia, severe dysplasia, well-differentiated SCC, moderately differentiated SCC, and poorly differentiated SCC were randomly selected from the dictated reports of one of two staff oral pathologists. Histologically normal margins of each specimen served as normal controls. The tissues were immunohistochemically stained using commercially available antibodies against SF and c-met. Appropriate negative controls were run with each batch to ensure staining specificity. Evaluation of staining intensity was carried out using a computerized image analysis system. A one-way analysis of variance (ANOVA) with pairwise multiple-comparison procedures (Fisher method) was used to analyze the data. RESULTS: Statistically significant differences (P < .0001) in the intensity of staining were noted between the malignant and normal and the malignant and dysplastic tissues for both SF and c-met. No differences were appreciated when staining of normal and dysplastic sections of the SF-stained tissue were compared. CONCLUSIONS: The results suggest that the SF/c-met ligand-receptor pair is overexpressed in SCC of the oral cavity.

Adult↗
PubMed1997

Mobilization of peripheral-blood progenitor cells with high-dose etoposide and granulocyte colony-stimulating factor in patients with breast cancer, non-Hodgkin's lymphoma, and Hodgkin's disease.

PURPOSE: We analyzed the safety and effectiveness of high-dose etoposide (2 g/m2) followed by granulocyte colony-stimulating factor (G-CSF) as a peripheral-blood progenitor cell (PBPC) mobilization regimen and assessed extent of tumor reduction in patients with breast cancer, non-Hodgkin's lymphoma (NHL), and Hodgkin's disease (HD). PATIENTS AND METHODS: One hundred sixty-nine consecutive patients who eventually underwent PBPC transplantation received treatment with high-dose etoposide (2 g/m2) followed by daily G-CSF (5 microg/kg). RESULTS: This mobilization method was effective in nearly all patients. No patients died of mobilization-related complications. A 50% reduction in tumor size was seen in 19% of assessable patients with breast cancer, 44% of those with NHL, and 38% of those with HD. Hematopoietic recovery (HR) following transplantation occurred in all patients. Patients with > or = 4 x 10(6) CD34+ cells/kg engrafted with neutrophils at a median of 9 days after transplant and patients with at least 1.2 x 10(6) CD34+/CD33- cells/kg achieved platelet recovery at a median of 15 days. CONCLUSION: Etoposide plus G-CSF is an effective and safe method for mobilization of PBPCs. Etoposide is an effective agent in tumor reduction in NHL and HD and is less effective in breast cancer. The substantially lower incidence of prior exposure to this agent compared with cyclophosphamide favors its use.

Adolescent↗
PubMed1995

The soft-tissue shaving procedure for removal of adipose tissue. A new, less traumatic approach than liposuction.

OBJECTIVE: To introduce the soft-tissue shaving cannula, a new, precise alternative to conventional liposuction that embodies an entirely different method of soft-tissue extraction and that appears to be less traumatic and more precise than methods currently used in liposuction. DESIGN: Nonrandomized, nonblinded comparison of the soft-tissue shaver and conventional liposuction devices in fresh cadavers, followed by clinical use of the liposhaver in selected patients undergoing cosmetic facial liposuction. INTERVENTIONS: Conventional liposuction devices and the soft-tissue shaving cannulas in fresh cadavers (< 8 hours old). A submental lipectomy and a melolabial fold liposhaving were performed in a clinical setting. OUTCOME MEASURES: Subjective evaluation by the operating surgeons. RESULTS: The fat was cleanly shaved and the contour result was even, without dimpling or asymmetry. CONCLUSIONS: Our early experiences suggest that this new liposhaving technique may offer a precise, less traumatic alternative to conventional liposuction. Fat can be shaved in an open fashion under direct vision. It does not rely on a vacuum seal. The soft-tissue shaving cannula shaves fat one layer at a time. The depth of each layer removed, the depth of soft-tissue injury, and the optimal settings and sizes for various procedures remain to be reported.

Adipose Tissue↗
PubMed1990

Comparative analysis of the plaque removal ability of .007 and .008 toothbrush bristles.

A two-phase study was conducted to compare the plaque-removal effectiveness of a .007 toothbrush and a .008 toothbrush when used in an unsupervised home-care program. In the first phase of the study, two children's toothbrushes, a .007 toothbrush (POH Junior #8) and a .008 toothbrush (Allie-Croc), were compared in a population of third through sixth grade children. The .007 group had a greater reduction of plaque from pretest to post-test than the .008 group in all grades, with statistically significant differences favoring the .007 toothbrush for fourth and sixth grades. In phase two a .007 adult toothbrush (POH #4) was compared to a .008 adult toothbrush (Oral B 40) in a population of nursing and dental hygiene students. Both toothbrushes performed equally well with a significant decrease in plaque and gingival inflammation observed from pretest to post-test regardless of toothbrush used. Any changes in soft-tissue abrasion were negligible and not statistically significant. Based on the results of this study, both brushes appear to be safe and effective and can be recommended with confidence.

Adult↗
PubMedDate not supplied

Focal small bowel perforation: an adverse effect of early postnatal dexamethasone therapy in extremely low birth weight infants.

OBJECTIVE: We tested the hypothesis that early postnatal dexamethasone (EPD) increases the risk of focal small bowel perforation (FSBP) in extremely low birth weight (ELBW) infants. STUDY DESIGN: The techniques of meta-analysis were applied to studies evaluating EPD, which we identified through a systematic literature search. Studies were included if they were randomized, placebo-controlled trials of EPD, enrolled infants with birth weights < or =1000 g, and reported FSBP as an outcome variable. The Breslow-Day test was used to assess for homogeneity and a summary odds ratio was calculated using the Mantel-Haenszel exact method. RESULTS: Four studies, with a pooled sample of 1383 infants, were included in the primary analysis. The Breslow-Day test showed a p-value of 0.61, indicating homogeneity among the studies. FSBP was significantly higher in EPD treated infants [odds ratio 1.91, 95% confidence interval (CI) 1.21, 3.07; p=0.004]. CONCLUSION: EPD increases the risk of FSBP in ELBW infants.

Anti-Inflammatory Agents↗
PubMedDate not supplied

Research methodology. Part IV: Understanding canonical correlation analysis.

Canonical correlation is presented as a technique to determine how sets of dependent variables are related with sets of independent variables. Canonical correlation reveals the strength of the relationship between the clusters using case data as illustration, three pairs of clusters (factors or profiles) emerged. Interpretation of the clusters are presented. As indicated in the case presentation, Canonical Correlation (CA) is the fourth in a series of methodologies selected for illustration as precursors to advanced statistics and modeling. In this paper, background will be given, a schematic example presented, sample size and CA, SPSS procedure to perform CA, and interpretation of CA and possible uses of CA in nursing research.

Analysis of Variance↗