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K Davis

Publications and source records attributed to K Davis.

At least 199 records · Page 11Linked to original sources
PubMed1995

FM amplification for enhancement of conversational discourse skills: case study.

The purpose of this single-subject pilot study was to examine the efficacy of FM amplification for enhancing the discourse skills of a 4-year-old girl with a history of speech-language impairments, otitis media with effusion (OME), and motoric delays. Over a period of several weeks, language treatment sessions were conducted with and without FM amplification, in a classroom setting. Sessions were videotaped and analyzed for the appropriateness and effectiveness of the subject's conversational turns during sessions with amplification and with no amplification. Although the number of sessions was small, more appropriate and effective conversational turns occurred during sessions with amplification.

Amplifiers, Electronic↗
PubMed1994

Isolation and characterization of krp, a dibasic endopeptidase required for cell viability in the fission yeast Schizosaccharomyces pombe.

The activation of pro-hormones and many precursor proteins involves cleavage by endopeptidases belonging to the subtilisin-like family of enzymes. Here we describe the isolation and characterization of the first member of this family from the fission yeast Schizosaccharomyces pombe. The enzyme, which has been named krp for KEX2-related protease, is a type I membrane-bound endopeptidase that cleaves substrates after pairs of dibasic residues. It appears to be synthesized as a pre-pro-protein that is likely to undergo processing following translocation into the endoplasmic reticulum. Processing has been characterized in a cell-free translation/translocation system prepared from Xenopus eggs. Krp is N-glycosylated on all five of its potential sites and both the pre-sequence and the pro-sequence are quickly removed following translocation, the latter probably by autocatalytic cleavage. The inhibitor profile of krp broadly reflects the known properties of the eukaryotic subtilisin proteases, while its pH and Ca2+ dependence are consistent with it being active within the secretory pathway. One of its physiological substrates is likely to be the pheromone precursor pro-P-factor, which it is shown to process in an in vitro system, but identification of other substrates is complicated because, unlike other members of this family, krp is essential for cell viability.

Amino Acid Sequence↗
PubMed1994

Effect of coronary artery bypass graft surgery on survival: overview of 10-year results from randomised trials by the Coronary Artery Bypass Graft Surgery Trialists Collaboration.

We carried out a systematic overview using individual patient data from the seven randomised trials that have compared a strategy of initial coronary artery bypass graft (CABG) surgery with one of initial medical therapy to assess the effects on mortality in patients with stable coronary heart disease (stable angina not severe enough to necessitate surgery on grounds of symptoms alone, or myocardial infarction). 1324 patients were assigned CABG surgery and 1325 medical management between 1972 and 1984. The proportion of patients in the medical treatment group who had undergone CABG surgery was 25% at 5 years, 33% at 7 years, and 41% at 10 years: 93.7% of patients assigned to the surgery group underwent CABG surgery. The CABG group had significantly lower mortality than the medical treatment group at 5 years (10.2 vs 15.8%; odds ratio 0.61 [95% CI 0.48-0.77], p = 0.0001), 7 years (15.8 vs 21.7%; 0.68 [0.56-0.83], p < 0.001), and 10 years (26.4 vs 30.5%; 0.83 [0.70-0.98]; p = 0.03). The risk reduction was greater in patients with left main artery disease than in those with disease in three vessels or one or two vessels (odds ratios at 5 years 0.32, 0.58, and 0.77, respectively). Although relative risk reductions in subgroups defined by other baseline characteristics were similar, the absolute benefits of CABG surgery were most pronounced in patients in the highest risk categories. This effect was most evident when several prognostically important clinical and angiographic risk factors were integrated to stratify patients by risk levels and the extension of survival at 10 years was examined (change in survival -1.1 [SE 3.1] months in low-risk group, 5.0 [4.2] months in moderate-risk group, and 8.8 [5.4] months in high-risk group; p for trend < 0.003). A strategy of initial CABG surgery is associated with lower mortality than one of medical management with delayed surgery if necessary, especially in high-risk and medium-risk patients with stable coronary heart disease. In low-risk patients, the limited data show a non-significant trend towards greater mortality with CABG.

Adult↗
PubMed1994

Differences in stage at presentation of breast and gynecologic cancers among whites, blacks, and Hispanics.

BACKGROUND: One of the possible assumptions for the higher mortality from cancer of blacks versus whites is that blacks tend to be diagnosed relatively more often with later stage disease. This study examined the stages at diagnosis for female breast cancer and other gynecologic cancers among blacks, non-Hispanic whites, and Hispanic whites. METHODS: Data for Dade County were analyzed in this study, which was based on the tumor registry data from the Florida Cancer Data System from 1981-1989. The stages at diagnosis were classified as in situ, local, regional, and distant according to the International Classification of Diseases for Oncology coding rules. RESULTS: The percentage of early stage diagnoses (in situ and local stage) was significantly lower among blacks and Hispanic whites than among non-Hispanic whites, but only for breast and cervical cancer. There was a significant increase in the percentage of early stage diagnoses of breast cancer among all three groups during 1981-1989, whereas this increase was found only in Hispanic whites for cervical cancer. The percentage of in situ cervical cancers was much lower in women older than age 45, especially among women older than age 65, in all three groups. CONCLUSIONS: These data suggest that screening programs need to be targeted differently for specific age and ethnic groups.

Adult↗
PubMed1994

Cancer in south Florida Hispanic women. A 9-year assessment.

BACKGROUND: Cancer incidence varies among race and ethnic subgroups. Relatively little information exists on cancer among Hispanics, and none of it it stratified by race. METHODS: To explore and compare cancer incidence rates of each site of cancer among white Hispanic, white non-Hispanic, black Hispanic, and black non-Hispanic women in Dade County, South Florida, we accessed 9 years of cancer incidence data. Dade County's Hispanic population is the second largest of any US county. For each site, incidence rates, rate ratios, and 95% confidence intervals are presented. RESULTS: Among white Hispanics, there were statistically significant lower rates of cancers of the oral cavity, esophagus, colon, pancreas, lung, breast, ovary, bladder, kidney, melanoma, Kaposi's sarcoma, and non-Hodgkin's lymphoma than among white non-Hispanics. Black Hispanics had significantly lower rates of cancers of the oral cavity, stomach, rectum, lung, cervix, and bladder than black non-Hispanics. However, white Hispanic women had significantly higher rates of cancers of the liver, gallbladder, and uterine cervix than white non-Hispanic women. No in situ breast cancer cases among blacks of either ethnic subgroup was found. CONCLUSION: Both white Hispanic and black Hispanic women generally had lower rates of cancer than their race-specific non-Hispanic counterparts. However, incidence rates among Hispanics differ substantially by race; failure to distinguish them may lead to erroneous conclusions.

Adult↗
PubMed1994

Product-induced stabilization of tertiary and quaternary structure in Escherichia coli dehydroquinase.

The effects of irreversibly attaching product at the active site of type I dehydroquinase from Escherichia coli have been investigated at the level of the secondary, tertiary, and quaternary structure of the protein by spectroscopic and hydrodynamic techniques. The results agree with the previously identified stabilization of the enzyme but show for the first time that the protein dimer is also stabilized and suggest that the E. coli dehydroquinase subunit may be bilobal.

Circular Dichroism↗
PubMed1994

Cancer among Hispanic males in south Florida. Nine years of incidence data.

BACKGROUND: Dade County (Florida) is the largest county in the United States in which a majority of the population is Hispanic. To describe and compare cancer incidence among white and black Hispanic and non-Hispanic males in South Florida and to identify those sites showing important racial-ethnic differences between sub-groups, incidence rates were determined from 9 years of prospective population-based cancer surveillance data. METHODS: All incident cancer cases diagnosed among male residents of Dade County for the period January 1, 1981, through December 31, 1989, were obtained from the statewide tumor registry for Florida, the Florida Cancer Data System. Race- and ethnic-specific age-standardized incidence rates and standardized rate ratios to compare rates among racial-ethnic subgroups for each site are presented. RESULTS: Compared with white non-Hispanics, white Hispanic males had significantly higher rates of cancers of the liver, gallbladder, nasal cavity, penis, and thyroid; acute lymphocytic leukemia; and Kaposi's sarcoma. Significantly lower rates were found for cancers of the esophagus, stomach, colon, rectum, pancreas, lung, testes, bladder, and kidney, and for mesothelioma, melanoma, non-Hodgkin's lymphoma, and chronic lymphocytic leukemia. Black Hispanics had significantly lower rates only of cancers of the esophagus, lung, and prostate than did black non-Hispanics. CONCLUSION: Differences were found in incidence rates by race-ethnicity; while incidence rates for most sites among white Hispanic males were lower than among white non-Hispanics, higher rates for several sites are of particular concern and merit further investigation to determine differences in risk factors and exposures.

Black or African American↗
PubMed1994

Obesity in preschool and school-age children. Treatment early and often may be best.

OBJECTIVE: To determine if timing and frequency of interventions affect the outcome of treatment of obesity in pediatric patients. DESIGN: Retrospective chart review; comparison of subgroups defined by age and frequency of visits. SETTING: A nutrition evaluation clinic, an outpatient referred care clinic at a metropolitan hospital. PARTICIPANTS: All 93 obese children, aged 1 to 10 years, seen within 1 year and with one or more subsequent visits in the next year. Obesity was defined as greater than 120% ideal body weight for height age (IBWH). Mean percent IBWH was 171% (median, 199%; range, 127% to 251%). INTERVENTIONS: (1) Initial visit. Comprehensive history and physical examination, by physician, registered dietician, and licensed clinical social worker; design of individualized care plan, including prescribed frequency and size of meals and snacks; and type, frequency, and duration of exercise. (2) Subsequent visits (after 1 month, then with frequency tailored to need). Review of progress, adjustment of energy intake and expenditure; management of biopsychosocial obstacles to needed changes. MEASUREMENTS/MAIN RESULTS: Four patient groups were defined by two variables: age (preschool vs school-age children) and frequency of visits in 1 year (two to three vs four or more). Groups were compared on change in mean percent IBWH and on mean change in percent IBWH. All groups showed significant change in percent IBWH (P < or = .040 for school-age children, P < or = .012 for preschool children). For all visits, the mean change was more than twice as great for preschool as for school-age children (4.7 +/- 5.4 vs 1.9 +/- 4.8, P = .027). CONCLUSIONS: (1) The most successful treatment of pre-adolescent obesity may be in preschool children with frequent visits. (2) A randomized trial is warranted to test this possibility. (3) Many of the techniques used to treat early obesity can be adapted for prevention and intervention in early obesity during the preschool years, and this is the preferred approach.

Body Height↗
PubMed1994

Quantitative assessment of groundwater quality using a biological indicator: some preliminary observations.

The genotoxicity of groundwater was evaluated, using a novel application of the SOS microplate assay (SOSMA). Organic residues were extracted from groundwater samples from Maryland, Pennsylvania, and Delaware by using C-18 bonded silica solid phase extraction tubes. Total organic carbon content (TOC) of water samples was also determined. The genotoxicity of the extracts was determined by the SOSMA. Relative activity (RA) as determined by the SOSMA is a quantitative measure of genotoxicity based on a comparison to the activity of the mutagen, 4-nitroquinoline oxide. Low levels of RA (about 2x background) were detected in waters from sites within these states. There was considerable temporal and spatial variation in the observed RA, but no definite patterns were observed in the variation. Between sampling sites there was a positive correlation between RA and TOC; however, this relationship appeared to be reversed occasionally within a sampling site. The extraction and bioassay methods provide an easy and relatively inexpensive means of determining water quality.

Delaware↗
PubMed1994

Preclinical studies of monoclonal antibodies for intravesical radioimmunotherapy of human bladder cancer.

Eighty percent of bladder cancers present as superficial disease. Many are multifocal, and apparently successful treatment is frequently followed by recurrence. The use of monoclonal antibodies (MAbs) to target radiotherapy to these tumors offers great potential, especially since they can be administered directly into the bladder (intravesically) bypassing many of the side effects encountered to date with systemic MAb-based therapy. Implantation of human bladder cancer cell lines in the bladder wall of nude rats results in tumor formation, providing an excellent model to test this. Tumor size can be monitored by X-ray analysis after administration of urograffin. Comparative studies of two murine MAbs, BLCA-8, IgG3, and C1-137, IgG1, against malignant human bladder cancer cells have been performed. Radioimmunoconjugates produced with 125Iodine (125I) have been used for biodistribution studies following administration directly into rat bladder. Radioiodinated intact MAbs or Fabs administered intravesically into nontumor bearing rats did not leak into the systemic circulation and were stable in urine for up to 100 h. Biodistribution studies carried out following intravesical administration of radioimmunoconjugates to tumor-bearing nude rats indicate better tumor uptake of C1-137 than BLCA-8. Further studies to test two-step intravesical administration of biotinylated MAb followed by radioiodinated streptavidin are in progress. Our studies indicate that the C1-137 MAb may have considerable potential for intravesical radioimmunotherapy of patients with superficial bladder tumors.

Administration, Intravesical↗
PubMed1994

Measures of salivary secretory immunoglobulin A and state anxiety after a nursing back rub.

This study examined the effects of a 10-minute nursing back rub on salivary secretory immunoglobulin A (s-IgA) and state anxiety in well older adult subjects. A control group (n = 14) received no intervention, and an experimental group (n = 18) received a slow stroke effleurage back rub. All subjects initially completed the state portion of the Spielberger State/Trait Anxiety Inventory (STAI) and provided a timed, nonstimulated saliva sample. Control subjects lay positioned in bed for 10 minutes, and experimental subjects received the back rub. Both groups then provided a second saliva sample and completed the STAI again. Anxiety scores decreased for both groups, but not significantly, and s-IgA concentration increased in the experimental group. This study provides rationale for further research into the holistic benefits of the nursing back rub and should encourage nurses to continue to provide caring touch interventions to patients.

Adult↗
PubMed1994

Comparison of pressure and flow triggering systems during continuous positive airway pressure.

STUDY OBJECTIVE: Compare the inspiratory work of breathing (WOBI) during pressure triggering (PT), and flow triggering (FT) using two microprocessor ventilators. DESIGN: A randomized, crossover comparison of triggering strategies and ventilators used. SETTING: Surgical intensive care unit. PATIENTS: Ten patients recovering from acute respiratory failure (eight men, two women; mean age, 48 +/- 12 years) breathing on continuous positive airway pressure (CPAP) of 5 cm H2O were studied. INTERVENTIONS: Patients were randomly assigned to either receive 5 cm H2O CPAP via one of two units (Hamilton Veolar or Puritan Bennett 7200ae) using either PT or FT. Each patient had 30-min trials using the following: (1) Veolar FT; (2) Veolar PT; (3) 7200ae FT; and (4) 7200ae FT. MEASUREMENTS AND RESULTS: During each trial period, work of breathing (WOB) and pressure time product (PTP) were measured using a respiratory monitor (Bi-core CP-100). All patients were placed in semi-Fowler position and esophageal balloons were inserted and their position confirmed using the occlusion technique. Continuous measurements of peak negative pressure during inspiration, tidal volume (VT), minute ventilation (VE), respiratory frequency (f) were accomplished with a flow transducer at the proximal airway. FT with the 7200ae was superior to PT as measured by both the WOB (0.58 +/- 0.3 vs 0.84 +/- 0.2 J/L, p < 0.01) and PTP (148 +/- 50 vs 206 +/- 41 cm H2O/s/min, p, 0.05). FT with the Veolar was also superior to PT with respect to the WOB (0.53 +/- 0.2 vs 0.93 +/- 0.2 J/L, p < 0.01) and PTP (140 +/- 39 vs 229 +/- 46 cm H2O/s/min, p < 0.05). CONCLUSION: FT reduces the WOB compared with PT, regardless of the ventilator used. The reduction in WOB during FT is related to improved responsiveness and changes in the posttrigger phase.

Cross-Over Studies↗
PubMed1994

Pharmacological properties of a novel ACAT inhibitor (CP-113,818) in cholesterol-fed rats, hamsters, rabbits, and monkeys.

The novel acyl-CoA:cholesterol acyltransferase (ACAT) inhibitor CP-113,818 has been characterized in vitro against ACAT isolated from liver and intestine from a variety of species including human subjects, and in vivo in cholesterol-fed rats, hamsters, rabbits, and two species of nonhuman primates. CP-113,818 is a potent and specific inhibitor of liver and intestinal ACAT with IC50s ranging from 17 to 75 nM. This ACAT inhibitor also prevented the absorption of exogenous radiolabeled cholesterol in hamsters (ED50 = 6 micrograms/kg), rabbits (ED50 1/2 10 micrograms/kg), and cynomolgus and African green monkeys (40 and 26% inhibition at 10 mg/kg, respectively). CP-113,818 effectively prevented the increase in liver cholesterol levels in cholesterol-fed rats, hamsters, and rabbits. In lipoprotein characterization studies in rabbits, CP-113,818 selectively decreased apoB-containing lipoproteins (beta-VLDL, IDL, and LDL) and shifted the distribution of cholesterol from beta-VLDL, IDL, and LDL (96% before treatment to 81% after treatment) to HDL (4% before treatment to 19% after treatment). Finally, in monkeys, CP-113,818 significantly decreased LDL cholesterol by approximately 30% while either increasing HDL cholesterol (cynomolgus monkeys) or not affecting HDL cholesterol (African green monkeys), thereby improving the total plasma cholesterol/HDL ratios. In summary, CP-113,818 significantly inhibited cholesterol absorption, prevented the increase in liver cholesterol, and improved the lipoprotein profiles by selectively decreasing the cholesterol concentrations of the atherogenic lipoproteins (VLDL, IDL, and LDL) in a variety of cholesterol-fed animals. These data suggest that ACAT inhibition may be a useful therapeutic approach for lowering LDL cholesterol and thereby reducing the risk of developing coronary heart disease.

Animals↗