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Biomedical subjects

C Williams

Publications and source records attributed to C Williams.

At least 217 records · Page 12Linked to original sources
PubMed1998

Algorithms for resource allocation of substance abuse prevention funds based on composite risk-factor index score: a case study on state of Florida--Part 2.

The purpose of Part 2 is to develop a model for resource allocation of state prevention funds to be distributed to its substate jurisdictions based on the relative need for prevention services measured in terms of composite risk-factor index (COMRISK) scores computed for each county. The risk factors are extracted from an extensive review of risk and protective factors addressed in the prevention literature. Based on twenty-two risk and protective factors identified, we were able to explain 71.3 percent of the total variation in student drug using behavior observed at the individual level. By aggregating individual COMRISK scores to the county level, we were able to determine aggregated COMRISK index scores at the county level. By determining the proportion of each county's share of the total statewide COMRISK and by weighting the latter proportion by the population size of each county, we have devised Prevention Needs Index (PNI) score based on the risks for each county. Finally, the county's share of PNI score as a proportion of the total statewide PNI score is computed. The latter proportion is then multiplied by the total amount of prevention resources available at the state. In this way, we were able to develop an alternative resource allocation model solely based on risk and protective factors for determining prevention needs of each county, independent of composite index score of drug use (COMDRUG) presented in Part 1. A comparison of three models for resource allocation has shown a significant amount of similarity of the total funds computed for each county. Accordingly, no preference is made among the resource allocation models suggested, although it is emphasized that the final decision concerning the level of funding must be made on the selection of the resource allocation algorithms rather than the suggested amount of funding computed for each county.

Adolescent↗
PubMed1998

Toward a new paradigm in substance abuse and other problem behavior prevention for youth: youth development and empowerment approach.

The purpose of this article is to 1) address a paradigm shift taking place in the field of substance abuse prevention directed for youth and 2) to introduce an innovative approach to substance abuse and other problem behavior prevention that reflects this shift in prevention paradigm. The new path introduced is youth development and empowerment (YD&E) approach. In order to establish a conceptual foundation for this approach, this article 3) reviews the theoretical advances made in the field of substance abuse prevention during the last three decades. This is followed by a conceptualization of the processes of implementing the YD&E program by 4) specifying the mechanism used for the empowering processes and by 5) identifying the structural components of the youth empowerment model that serve the empowering processes. It is hoped that this article serves as a conduit for an improved approach to adolescent substance abuse prevention and youth development that goes beyond, rather than against, the traditional risk-factor approach. In this new approach, youths are viewed as assets and resources to our community rather than social problems or community liabilities. The organizing concept of this new paradigm is: social, economic, and public opportunity denied to youth is equal to social problems imposed on youth by adults.

Adolescent↗
PubMed1998

Algorithms for resource allocation of substance abuse prevention funds based on social indicators: a case study on state of Florida--Part 3.

The purpose of Part 3 is to develop an algorithm for an equitable distribution of state prevention funds to its substate jurisdictions based on the need for prevention services. In this series, the need for prevention services is measured in terms of the existing social indicators observed at the county level. In order to establish a conceptual link as well as the empirical relevance of the selected social indicators as proxy measurements of the estimated need for prevention at the county level, we have employed both concurrent and construct validity tests using the following three constructs as the criterion variables in a multiple regressing setting: 1) county-based composite drug use index score (COMDRUG) measured via the statewide drug survey; 2) county-based proportions of prevention target populations using the conceptual definition advanced by the Institute of Medicine (IOM); and 3) the composite risk factor score (COMRISK) assembled from a list of twenty-two risk and protective factors observed for each county. These constructs were identified previously in Parts 1 and 2. While employing eight social indicators to estimate the overall prevention needs observed at the county level, the social indicators thus selected were able to explain 69 percent of the variations in COMDRUG, 68 percent of the variation in the proportions of students in need of prevention services using IOM definition, and 60 percent of the variation in COMRISK. Following successful validations of the social indicators as viable media with which to estimate county-based prevention needs, the ensuing multiple regression equation is, then, used to build a resource allocation model by determining the proportion of each county's share of the total statewide COMDRUG-predicted from the social indicators and, then, by weighting the latter proportion by the population size of each county under age eighteen. In this way, we have devised county-based Prevention Needs Index (PNI) scores based solely on social indicators. Finally, the county's share of PNI score is computed as a proportion of to the total statewide PNI score. Following this line of algorithm for resource allocation, we were able to develop yet another resource allocation model solely based on social indicators without the benefits of survey data. Comparing the funding results originating from four resource allocation models (i.e., COMDRUG, IOM Definition, COMRISK, and Social Indicators), it has been learned that there is a remarkable similarity from one funding level to another. Since all four schedules of county-based prevention funding levels have shown very high intercorrelations with a range from .9862 to .9993, it has been determined that these schedules are measuring essentially either the same domain or latent domains that are functionally equivalent to one another. Accordingly, no preference is made among the resource allocation models suggested, although it is suggested that the final decision on the level of funding must be based on the selection of the schedule for resource allocation rather than the suggested amount or level of funding computed for each county.

Algorithms↗
PubMed1998

Algorithms for resource allocation of substance abuse prevention funds based on the estimated need: a case study on state of Florida--Part 1.

The purposes of Parts 1-3 of this article is to develop a framework for county-based prevention resource allocation algorithms based on the aggregated need for substance abuse prevention services estimated at the county level. The development of these algorithms is founded upon two databases: statewide student drug survey and a set of social indicators routinely collected and published by various agencies of the state of Florida. The resource allocation models are devised by developing several indices of prevention needs that are conceptualized in terms of: 1) county-based composite drug use index (COMDRUG), 2) the definitions of prevention target populations as envisioned by the Institute of Medicine (IOM), 3) composite risk-factor index score, and 4) a set of social indicators that are empirically related to COMDRUG observed at the county level. The first three models are based on the prevention needs estimated from the statewide student survey on substance abuse. The social indicator model, however, is presented as an alternative resource allocation model which may be used in lieu of or in the absence of statewide survey. The resource allocation algorithms found on these four conceptualizations are thought to be more equitable and appropriate to the prevention needs of various communities than may be contrived otherwise. Due to a significant amount of information leading to the development of these models, Part 1 of this series is devoted to the following three topics: 1) sampling method used, 2) poststratification weighting methods used to estimate county-based COMDRUG, and 3) the development of resource allocation models based on COMDRUG and the IOM definitions of prevention target populations.

Alcoholism↗
PubMed1998

Relation of tolerance of ambiguity to global and specific paranormal experience.

We examined the relationship of tolerance of ambiguity to severe global factors and specific types of anomalous or paranormal experience. 107 undergraduate students completed MacDonald's 1970 AT-20 and the Anomalous Experiences Inventory of Kumar, Pekala, and Gallagher. Scores on the five subscales of the Anomalous Experiences Inventory correlated differently with tolerance of ambiguity. Global paranormal beliefs, abilities, experiences, and drug use were positively associated with tolerance of ambiguity, whereas a fear of paranormal experience showed a negative relation. The specific types of anomalous experiences that correlated with tolerance of ambiguity often involved internal or physiological experience, e.g., precognitive dreams, memories of reincarnation, visual apparitions, and vestibular alterations. We generally found no effects of age of sex. These results are consistent with the idea that some paranormal experiences are misattributions of internal experience to external ('paranormal') sources, a process analogous to mechanisms underpinning delusions and hallucinations.

Adolescent↗
PubMed1998

Rapid and specific targeting of monoclonal antibody A33 to a colon cancer xenograft in nude mice.

Monoclonal antibody (mAb) A33 detects a glycoprotein homogeneously expressed by > 95% of human colon cancers and by normal colon cells. The A33 antigen is not secreted or shed and after mAb A33 binds to antigen on the cell membrane, a fraction of membrane-bound mAb A33 is internalized into endosomes. Phase I 131I-mAb A33 biodistribution studies have shown consistent, specific tumor-targeting, and phase I radioimmunotherapy trials with 131I- or 125I-mAb A33 have demonstrated antitumor effects. Here we describe a nude mouse model that was established using a human colon cancer cell line, SW1222, which grows as a relatively hypovascular, invasive heterotransplant when injected i.m. Peak uptake of 131I-labeled or 111In-chelated mAb A33 was observed at 48-96 h, with a mean of 34% (SE +/- 5.0) and 46.7% (SE +/- 1.7) injected dose per gram of tumor tissue, respectively. 111In-mAb A33 was retained in tumor tissue longer than halide radioimmunoconjugates. The specificity of antibody localization was assessed using a control antibody (tumor uptake and pharmacokinetics), a control tumor, corrections for vascular antibody blood-pooling in tumor tissue, and blocking of radiolabeled mAb A33 localization by pretreating mice with excess unlabeled mAb A33. These experiments demonstrate that mAb A33 localization in tumor was specific, and they emphasize the unexpected rapidity with which the antibody localizes. Our conclusions were confirmed by immunohistochemical techniques which allowed direct visualization of localization and distribution of the humanized version of mAb A33 in tumor tissue. Furthermore, antibody doses approximating tumor-saturating doses demonstrated that a homogeneous distribution of antibody in tumor is possible. This model will be valuable for studies focusing on general physiologic aspects of antibody-to-tumor cell localization and critical as a guide to the evaluation of various A33 antibody constructs and combinations with other therapies for the treatment of colon cancer.

Animals↗
PubMed1998

Corynebacterial pneumonia in an African hedgehog.

A 3-mo-old, male African hedgehog (Atelerix albiventris) was anorectic and lethargic for a period of 3 days prior to death. Necropys revealed lungs that were diffusely firm, dark red, and dorsally adhered by fibrinous tags to the pericardial sac. Histopathology revealed necrosuppurative bronchopneumonia with pulmonary abscesses and suppurative pericarditis and myocarditis. A Corynebacterium sp. was isolated from the lungs. We believe this is the first reported case of corynebacterial pneumonia in an African hedgehog.

Animals↗
PubMed1998

Efficacy of a dentifrice containing zinc citrate for the control of plaque and gingivitis: a 6-month clinical study in adults.

The objective of this 6-month, double-blind, clinical study, conducted in harmony with American Dental Association (ADA) guidelines, was to evaluate the efficacy of a dentifrice containing 2% zinc citrate and 0.76% sodium monofluorophosphate in a silica base (zinc citrate dentifrice) for the control of supragingival plaque and gingivitis, compared to a control dentifrice containing 0.76% sodium monofluorophosphate in a silica base (control dentifrice). Adult men and women from the Atlanta, Georgia, area were entered in the study and stratified into two treatment groups, which were balanced for baseline Quigley-Hein Plaque Index scores and baseline Löe-Silness Gingival Index scores. Participants received an oral prophylaxis and were instructed to brush their teeth twice daily (morning and evening) for 1 minute with their assigned dentifrice, using a soft-bristled toothbrush. Examinations for supragingival plaque and gingivitis were conducted after 3 months and again after 6 months' use of the study dentifrices. Ninety-nine participants complied with the protocol and completed the entire 6-month clinical study. At both the 3- and 6-month study examinations, the zinc citrate dentifrice group exhibited statistically significant reductions in both plaque and gingivitis compared to the control dentifrice group, based on whole-mouth data. At the 6-month examination, the magnitude of these reductions met or exceeded 18% for both plaque and gingivitis (25.3% for plaque; 18.8% for gingivitis). The effect of the zinc citrate dentifrice was most pronounced on the more severe manifestations of plaque and gingivitis, indicating a statistically significant (50.2%) reduction in severe plaque and a statistically significant (66.7%) reduction in severe gingivitis over the control dentifrice after 6 months of use. Similar findings were observed for data obtained from proximal, lingual, and posterior sites. Among the sites that indicated a tendency toward high levels of plaque or gingivitis based on the baseline scores, substantially fewer sites tended to continue to present such high levels at follow-up exams in the zinc citrate dentifrice group than in the control dentifrice group. Thus, in accordance with the 1986 guidelines published by the ADA and the 1994 revision published by the Task Force on Design and Analysis in Dental and Oral Research, the results of this study support the conclusion that a dentifrice containing 2% zinc citrate and 0.76% sodium monofluorophosphate in a silica base is clinically efficacious for the control of supragingival plaque and gingivitis.

Adolescent↗
PubMed1998

Assessment of sequence-based p53 gene analysis in human breast cancer: messenger RNA in comparison with genomic DNA targets.

The high prevalence of p53 mutations in human cancers and the suggestion from several groups that the presence or absence of p53 mutations might have both prognostic and therapeutic consequences point to the importance of optimal methods for p53 determination. Several strategies exploring this have been described, based either on mRNA or genomic DNA as a template. However, no comparative study on the reliability of the two templates has been performed. The principal aim of this study was to study the concordance of RNA- and DNA-based direct sequencing methods in detecting p53 mutations in breast tumors. In 100 tumors, 22 mutations were detected by both methods. Furthermore, one stop mutation, two splice-site mutations, and one intron alteration were found only by genomic sequencing. In addition, the comparative study suggests that cells with missense mutations have increased steady-state concentrations of p53-specific mRNA, in contrast to cells with a gene encoding a truncated protein.

Aneuploidy↗
PubMed1998

Acucise endopyelotomy: a successful therapeutic intervention in the treatment of ureteropelvic junction obstruction.

Ureteropelvic junction obstruction is a well-recognized cause of pain and eventual renal failure. This condition may be congenital or it can develop secondary to renal calculi, infection, and instrumentation. Surgical intervention is the definitive therapy, and a number of surgical options are available to treat ureteropelvic junction obstruction. We describe an approach using the Acucise cutting balloon to perform retrograde endopyelotomy. In 12 patients making up 13 renal units, our success rate was 92.3%, at a mean follow-up of 8.4 months (range 2 to 21 months). Complications were minimal. Based on our experience, Acucise endopyelotomy is a successful therapeutic intervention in treating ureteropelvic junction obstruction.

Adolescent↗
PubMed1998

The gastrointestinal bacteria of mink (Mustela vison L): influence of age and diet.

Total numbers of aerotolerant and anaerobic bacteria, and densities of Enterobacteriaceae, lactobacilli, staphylococci, salmonella and shigella, and campylobacteria were enumerated in the contents of the stomach, small intestine (and the associated mucosa), and colon of mink beginning at 2 weeks of age to adulthood, and in adults that were fed diets with different levels and types of fiber or food deprived. Highest densities of all bacterial groups were found in the colon at all ages (up to 10(8) cfu per g for total anaerobes), but were 2-4 orders of magnitude lower than those of other mammals. When all regions were pooled, significant age-related increases (p < 0.05) were detected for anaerobes, aerobes, and staphylococci, and these coincided with the dietary shift at weaning. Enterobacteriaceae did not vary with age. Lactobacilli were never common isolates, but were detected more often after weaning, particularly in adults fed diets containing the 2 sources of fiber. Campylobacteria were detected only at 2 weeks of age, and salmonella and shigella were not isolated from any of the experimental mink. Total bacterial densities, the relative proportions of the bacterial groups, and age- and diet-related effects differ from those known for other mammals, which may be related to the carnivorous diet and rapid movement of digesta through the GIT.

Age Factors↗