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L W Pickle

Publications and source records attributed to L W Pickle.

At least 19 recordsLinked to original sources
PubMed2000

Social context and geographic patterns of homicide among US black and white males.

OBJECTIVES: The recently published Atlas of United States Mortality depicted striking regional differences in homicide rates for Black and White males in the United States. This study examined these rates to gain an understanding of the contribution of social context to geographic variability in homicide. METHODS: Homicide rates were calculated by health service area for the years 1988 to 1992. The contributions of age, geographic location, urbanization, and sociostructural characteristics were evaluated by means of a weighted linear mixed effects model. RESULTS: Regional differences in urbanization explained much of the geographic variation in homicide rates, but sociostructural factors also had a significant impact. The results suggest that these effects operate similarly for White and Black males, although differences were found in the magnitudes of the effects for the 2 groups. CONCLUSIONS: Results point to a strong association between homicide and urbanization and socioeconomic conditions in all regions of the country for both Black and White males. These findings shed light on the potential correlates of high homicide rates in the United States in the near future.

Adolescent↗
PubMed1999

Application of a weighted head-banging algorithm to mortality data maps.

Smoothed data maps permit the reader to identify general spatial trends by removing the background noise of random variability often present in raw data. To smooth mortality data from 798 small areas comprising the contiguous United States, we extended the head-banging algorithm to allow for differential weighting of the values to be smoothed. Actual and simulated data sets were used to determine how head-banging smoothed spike and edge features in the data, and to observe the degree to which weighting affected the results. As expected, spikes were generally removed while edges and clusters of high rates near the U.S. borders were maintained by the unweighted head-banging algorithm. Incorporating weights inversely proportional to standard errors had a substantial effect on smoothed data, for example determining whether observed spikes were retained or removed. The process used to obtain the smoothed data, including the choice of head-banging parameters, is discussed. Results are considered in the context of general spatial trends. Published in 1999 by John Wiley & Sons, Ltd. This article is a U.S. Government work and is in the public domain in the United States.

Algorithms↗
PubMed1999

Exploring spatial patterns of mortality: the new atlas of United States mortality.

The National Center for Health Statistics, CDC, has produced an Atlas of United States Mortality which includes maps of rates for the leading causes of death in the United States for the period 1988-1992. As part of this project, many aspects of statistical mapping have been re-examined to maximize the atlas's effectiveness in conveying accurate mortality patterns to epidemiologists and public health practitioners. Because recent cognitive research demonstrated that no one map style is optimal for answering many different map questions, maps and graphs of several different mortality statistics are included for each cause of death. New mixed effects models were developed to provide predicted rates and improved variance estimates. Results from these models were smoothed using a weighted head-banging algorithm to produce maps of general spatial trends free of background noise. Maps of White female lung cancer rates from the new atlas are presented here to illustrate how this innovative combination of maps and graphs permits greater exploration of the underlying mortality data than is possible from previous single-map atlas designs. Published in 1999 by John Wiley & Sons, Ltd. This article is a U.S. Government work and is in the public domain in the United States.

Adult↗
PubMed1999

Geographic variation in cardiovascular disease mortality in US blacks and whites.

Cardiovascular disease mortality rates have dropped significantly over the past several decades, but a shift has occurred over time in the geographic patterns of both coronary heart disease (CHD) and stroke mortality. This article describes these patterns and discusses how they vary by sex, race, age, and over time. Death certificate information for Health Service Areas (HSAs) in 1988-1992 was used to analyze the geographic patterns of CHD and stroke death rates by race, sex, and age. Changes in these patterns from 1979-1993 also were examined. In 1988-1992, considerable geographic variation in both CHD and stroke mortality was demonstrated for each sex and race group. Coronary heart disease rates were particularly high in the lower Mississippi valley and Oklahoma for all four groups, in the Ohio River valley and New York for whites, and to a lesser extent for blacks. Areas of high rates among whites in the Carolinas resemble stroke mortality patterns. There were greater differences by racial group than by gender, by the definition of heart disease. Over time, rates have declined for both CHD and stroke, but regional differences in the rates of change give the appearance of a southwesternly movement of high heart disease rate clusters and a breakup of the "Stroke Belt." Further research is needed to elucidate the cause of regional variation in CHD and stroke mortality. Similar geographic patterns of high rates of CHD and stroke in the southeastern United States may reflect common risk factors. This knowledge can be used to help develop appropriate interventions to target these high-rate areas in the Mississippi and Ohio River valleys.

Adult↗
PubMed1997

Geographic variation in stroke mortality in blacks and whites in the United States.

BACKGROUND AND PURPOSE: We sought to determine whether the "Stroke Belt" has continued to shift and to assess variation in geographic patterns by age, sex, and race. METHODS: Mortality data for Health Service Areas for 1988 to 1992 were used for analyses of geographic mortality patterns for stroke by race, sex, and age (50, 70, and 90 years). RESULTS: In 1988 to 1992, considerable geographic variation in stroke mortality was demonstrated for each sex/race group. In black and white women and men, previously described high mortality in the southeastern United States persisted. Mortality rates were generally higher in the South than in the North and in the East than in the West. Compared with data from 1962 to 1988, there was a continuation of the previously described westward shift of high-rate areas to the Mississippi River valley, a trend more marked at age 50 years than at 70 or 90 years. Although rates in the Pacific region were low overall, a surprising area of high rates was seen in southern California among women at all three ages examined. CONCLUSIONS: In whites, rapid declines in stroke mortality in the Southeast have left West South Central states with relatively high mortality rates; this trend may continue as younger cohorts age. However, rates in the Southeast also remain high, especially for blacks.

Black or African American↗
PubMed1996

Determination of dextromethorphan metabolic phenotype by salivary analysis with a reference to genotype in Chinese patients receiving renal hemodialysis.

BACKGROUND: The polymorphic metabolism of debrisoquin and sparteine by cytochrome P450IID6 (CYP2D6) is genetically determined. Determination of the CYP2D6 metabolic phenotype with conventional urine analytic methods is not feasible in anuric patients with renal failure. The possibility of using salivary analysis, with dextromethorphan as a probe drug, to determine the CYP2D6 metabolic phenotype in patients with renal failure was evaluated. METHODS AND RESULTS: One hundred four Chinese patients with renal failure were recruited. All 104 patients were receiving hemodialysis. Saliva was collected before and at 3 hours after each patient took a capsule of dextromethorphan hydrobromide (30 mg). Four patients were excluded because of insufficient samples of saliva. The distribution of logarithms of the metabolic ratios (log[MR]) in the 100 patients appeared to be normal. Administration of quinidine sulfate (200 mg twice daily) to nine of the patients significantly and markedly increased the dextromethorphan metabolic ratios. The metabolic ratios of nine patients pretreated with quinidine were higher than any of the 100 patients with renal failure who did not receive quinidine pretreatment. A metabolic ratio of 33 separated these two groups. Genomic deoxyribonucleic acid was extracted from whole blood in a subset of patients. Polymerase chain reaction (PCR)-based methods were used to detect the CYP2D6 and B mutant genes. Mutant B alleles (which are common in white poor metabolizers) of CYP2D6 genes were not detected in any of the 47 subjects tested. A PCR-based test of cytosine (C188) to thymine (T188) polymorphism at 188 base pairs in exon 1 of CYP2D6 genes was performed in 61 patients. Subjects who were homozygous for C188 had significantly (p = 0.0067) lower log[MR] values than those who were homozygous for T188. CONCLUSIONS: Determination of dextromethorphan metabolic ratios in saliva is feasible in patients with renal failure requiring hemodialysis. All subjects in this study appeared to be "extensive metabolizer" phenotype for CYP2D6, and no poor metabolizer was identified. From the results with quinidine pretreatment, a metabolic ratio of 33 is suggested to be a tentative antimode for identification of poor metabolizers in patients with renal failure.

Adult↗
PubMed1992

The logistic modeling of interobserver agreement.

An approach to the logistic modeling of interobserver agreement is described that allows for the estimation of a commonly employed measure of agreement. The dependent variable is defined to be 1 if the two raters agree, and 0 otherwise. Covariates may be included in the regression equation in order to obtain adjusted or subgroup-specific estimates of percent agreement. As an empirical example, logistic models were fitted to data from a validation study of the agreement between interview information and physician records on the history of post-menopausal estrogen use, from a case-control study of breast cancer conducted on Oahu, Hawaii. Variables found to be related to agreement in previous univariate analyses were examined as covariates in the logistic model. The directly calculated estimates of percent agreement agreed well with the modeled estimates derived from the regression coefficients. Thus, the logistic model may provide a useful alternative to existing methods for the description of interobserver agreement.

Breast Neoplasms↗
PubMed1992

The logistic modeling of sensitivity, specificity, and predictive value of a diagnostic test.

A method is described for modeling the sensitivity, specificity, and positive and negative predictive values of a diagnostic test. To model sensitivity and specificity, the dependent variable (Y) is defined to be the dichotomous results of the screening test, and the presence or absence of disease, as defined by the "gold standard", is included as a binary explanatory variable (X1), along with variables used to define the subgroups of interest. The sensitivity of the screening test may then be estimated using logistic regression procedures. Modeled estimates of the specificity and predictive values of the screening test may be similarly derived. Using data from a population-based study of peripheral arterial disease, the authors demonstrated empirically that this method may be useful for obtaining smoothed estimates of sensitivity, specificity, and predictive values. As an extension of this method, an approach to the modeling of the relative sensitivity of two screening tests is described, using data from a study of screening procedures for colorectal disease as an example.

Arterial Occlusive Diseases↗
PubMed1992

Sensitivity and specificity-like measures of the validity of a diagnostic test that are corrected for chance agreement.

Chance agreement may account for a sizeable proportion of the specificity of a screening test when the disease prevalence is low. Conversely, the observed sensitivity may be largely accounted for by chance agreement when the prevalence of disease is high. We derive descriptive statistics that are analogous to sensitivity and specificity and corrected for the agreement expected by chance. These coefficients of validity are shown to be dependent on the true prevalence of disease, as well as sensitivity and specificity.

Humans↗
PubMed1991

Regression methods for estimating attributable risk in population-based case-control studies: a comparison of additive and multiplicative models.

A regression method that utilizes an additive model is proposed for the estimation of attributable risk in case-control studies carried out in defined populations. In contrast to previous multivariate procedures for the estimation of attributable risk, which have utilized logistic regression techniques to adjust for confounding factors, the model assumes an additive relation between the covariates included in the regression equation. As an empirical example, additive and logistic models were fitted to matched case-control data from a population-based study of childhood astrocytoma brain tumors. Although both models fitted the data well, the additive model provided a more satisfactory estimate of the risk attributable to multiple exposures, in the absence of significant additive interaction. In contrast to the results from the logistic model, the adjusted estimates of the risk attributable to each factor included in the additive model summed to the overall estimate for all of the factors considered jointly. Thus, the additive approach provides a useful alternative to existing procedures for the multivariate estimation of attributable risk when the additive model is determined to be appropriate on the basis of goodness-of-fit.

Astrocytoma↗
PubMed1991

Lung cancer risk associated with cancer in relatives.

Family history data from an incident case-control study of lung cancer conducted in the Texas Gulf Coast region between 1976 and 1980 were analyzed to evaluate the contribution of cancer in first-degree relatives to lung cancer risk. Odds ratios (OR) increased slightly as the number of relatives with any cancer increased (reaching 1.5 with 4 or more relatives with cancer). Risks were higher for tobacco-related cancers (OR = 1.5 for 2 or more relatives with these tumors) and greatest for first-degree relatives with lung cancer (OR = 2.8 for lung cancer in 2 or more relatives). For cases of squamous cell carcinoma and adenocarcinoma of the lung, risks with 3 or more relatives with any cancer were increased 2-fold (OR = 1.8 and 1.9 respectively), and a significantly elevated risk was found for having a first-degree relative with lung cancer for each histologic type (ORs from 1.7-2.1). Having a spouse with lung cancer increased lung cancer risk (OR = 2.5), and cases with lung cancer reported in a first-degree relative were diagnosed at an earlier age, as were case siblings with lung cancer.

Adenocarcinoma↗
PubMed1991

Salivary analysis for determination of dextromethorphan metabolic phenotype.

Debrisoquin oxidative phenotype is a determinant of pharmacologic response for many drugs. Poor and extensive metabolizers can be identified by the dextromethorphan metabolic ratio (dextromethorphan/dextrorphan). We developed and tested a method to determine debrisoquin phenotype on the basis of the metabolic ratio in saliva. Each of 62 normal volunteers was given a 50 mg capsule of dextromethorphan hydrobromide and collected urine (0 to 8 hours) and saliva (at 3 hours). Dextromethorphan and dextrorphan in saliva and urine were assayed by HPLC. The distributions of paired urinary and 3-hour salivary metabolic ratios of samples from 61 subjects were compared. The urinary and salivary metabolic ratios were distributed trimodally and bimodally, respectively. The Spearman rank correlation coefficient for logarithm of urinary metabolic ratio vs that of salivary metabolic ratio was 0.704. All the poor metabolizers identified by urinary metabolic ratio were also identified by the metabolic ratio in saliva at 3 hours (100% concordance). This study demonstrates that salivary analysis for determination of dextromethorphan metabolic phenotype is feasible.

Administration, Oral↗
PubMed1991

Some but not all benefits of intravenous immunoglobulin therapy after marrow transplantation appear to correlate with IgG trough levels.

Multiple benefits of intravenous immunoglobulin (IVIG) therapy after marrow transplantation have been reported, including decreased incidence of acute graft-versus-host disease (GVHD), infection, sepsis, cytomegalovirus (CMV) pneumonitis and platelet use. To test the hypothesis that the observed beneficial effects of IVIG are related to the serum IgG levels achieved, we followed IgG levels (pre-infusion, 1 h and 24 h post-infusion) in 45 consecutive marrow transplant recipients. IVIG 500 mg/kg was given weekly for six doses starting day -8 pre-transplant, then every other week for a total of 11 doses. Forty-one patients (22 allogeneic, 17 autologous, two syngeneic) were evaluable. Patients with acute GVHD had significantly lower serum IgG trough levels (less than 1200 mg/dl) noted at day +20 post-transplant and afterwards than patients without GVHD (greater than or equal to 1200 mg/dl). Pharmacokinetic modeling of the data indicates that IgG half-life between day -8 and day +6 may predict which recipients are at increased risk of acute GVHD. Allogeneic recipients in the group with trough levels less than 1200 mg/dl required more platelet transfusions. Although there was no significant difference in fungal infection rates or bacteremia, sepsis was noted in only two recipients (one allogeneic, one autologous), both with serum IgG trough levels less than 1200 mg/dl. In addition, three allogeneic recipients had cytomegalovirus pneumonitis, all in the group with lower IgG trough levels. Thus, while serum IgG trough levels less than 1200 mg/dl appear to be strongly associated with acute GVHD, low levels may also be associated with increased platelet utilization, with cytomegalovirus pneumonitis, and sepsis, but not with the overall incidence of infection.

Adolescent↗
PubMed1991

Conditioning-related toxicity and acute graft-versus-host disease in patients given methotrexate/cyclosporine prophylaxis.

Intensive chemoradiotherapy conditioning regimens and acute graft-versus-host disease (GVHD) are both associated with significant morbidity and mortality after bone marrow transplantation. In this study, we investigated whether the conditioning regimen affected the development of acute GVHD. Thirty-four patients, four with severe aplastic anemia and 30 with a lymphohemopoietic malignancy, were prepared for transplantation either with cyclophosphamide (CY) alone, with CY combined with total body irradiation (TBI) or CY combined with etoposide and either TBI or busulfan. GVHD prophylaxis included methotrexate (MTX 10 mg/m2) given on days 1, 3 and 6, and daily cyclosporine (CSP) on days--1 through 180. The overall incidence of acute GVHD was 36% (15% for HLA identical, 87% for HLA non-identical recipients). However, when assessed by the severity of conditioning regimen-related toxicity, the incidence of GVHD grades II-IV (HLA identical; HLA non-identical) was 0% (0%; 0%), 37% (20%; 67%) and 50% (22%; 100%) for patients with mild, moderate and severe toxicity, respectively. Compliance with GVHD prophylaxis declined with increasing intensity and toxicity of the conditioning regimen. These data suggest that a regimen of three doses of MTX and daily CSP is as effective as four doses of MTX/CSP for GVHD prophylaxis in patients given HLA identical marrow grafts. However, GVHD regimen compliance and efficacy of GVHD prevention are inversely related to the intensity of the conditioning regimen.

Acute Disease↗
PubMed1990

Lung cancer and the debrisoquine metabolic phenotype.

In a case-control study, we tested the hypothesis that the genetically determined ability to metabolize debrisoquine is related to risk of lung cancer. Overall, individuals who were extensive metabolizers of debrisoquine were at significantly greater risk of lung cancer than those who were poor or intermediate metabolizers (odds ratio = 6.1; 95% confidence interval = 2.2-17.1). In this study, case patients had lung cancer, and control subjects had either chronic obstructive pulmonary disease or cancers other than lung cancer. Results were adjusted for age, race, asbestos exposure, and smoking. Both black and white individuals who were extensive metabolizers of debrisoquine were at significantly increased risk after similar adjustment (for blacks, odds ratio = 4.5, 95% confidence interval = 1.1-18.1; for whites, odds ratio = 10.2, 95% confidence interval = 2.0-51.4). Significantly increased risk of lung cancer was also present for individuals who were extensive metabolizers when subjects with chronic obstructive pulmonary disease or other cancers were considered separately. These data confirm that the ability to metabolize debrisoquine is a major determinant of susceptibility to lung cancer. Evaluation of the marker in other case-control settings, further exploration of racial differences, and the prospective evaluation of this marker in subgroups at high risk of lung cancer are areas worthy of further study.

Adenocarcinoma↗