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Biomedical subjects

R Crosby

Publications and source records attributed to R Crosby.

At least 37 records · Page 2Linked to original sources

Longitudinal prediction of sexually transmitted diseases among adolescents: results from a national survey.

BACKGROUND: Although adolescent use of condoms has been increasing, incidence of sexually transmitted diseases (STDs) among young people remains high. To identify adolescent behavioral risk factors for acquiring STDs, this study assessed adolescent self-reports of acquired chlamydia, gonorrhea, syphilis, and trichomoniasis within 1 year after a baseline interview. METHODS: We used data from the National Longitudinal Survey of Adolescent Health for this study. Data were collected in the homes of survey respondents, using audio-computer-assisted self-interview (audio-CASI) technology and interviews. Participants were enrolled in grades 7-11 from 134 U.S. schools. A cohort of 4593 sexually experienced adolescents was followed for 1 year. We conducted separate analyses for both genders. RESULTS: About 3.1% of the male adolescents and nearly 4.7% of the female adolescents reported having had at least one STD after the baseline interview. For both genders, self-reported STD infection before baseline interview was the best predictor of self-reported STD infection 1 year after baseline interview. Female adolescents were more likely to report diagnosis with an STD after baseline if they self-identified as a minority race (other than Asian) and perceived that their mother did not disapprove of their having sex. Female adolescents were less likely to report STDs if they perceived that adults care about them. No additional variables predicted STD diagnosis after baseline for male adolescents. CONCLUSIONS: We conclude that past history of STD infection is the most important indicator of subsequent STD infection among adolescents. Thus, this study suggests the benefit of specific clinical efforts designed to promote preventive behavior among adolescents newly diagnosed with an STD.

Adolescent↗

Using quality function deployment to capture the voice of the customer and translate it into the voice of the provider.

BACKGROUND: Health care has a number of historical barriers to capturing the voice of the customer and to incorporating customer wants into health care services, whether the customer is a patient, an insurer, or a community. Quality function deployment (QFD) is a set of tools and practices that can help overcome these barriers to form a process for the planning and design or redesign of products and services. The goal of the project was to increase referral volume and to improve a rehabilitation hospital's capacity to provide comprehensive medical and/or legal evaluations for people with complex and catastrophic injuries or illnesses. HIGH-LEVEL VIEW OF QFD AS A PROCESS: The steps in QFD are as follows: capture of the voice of the customer, quality deployment, functions deployment, failure mode deployment, new process deployment, and task deployment. The output of each step becomes the input to a matrix tool or table of the next step of the process. CASE STUDY EXAMPLE: In 3 1/2 months a nine-person project team at Continental Rehabilitation Hospital (San Diego) used QFD tools to capture the voice of the customer, use these data as the basis for a questionnaire on important qualities of service from the customer's perspective, obtain competitive data on how the organization was perceived to be meeting the demanded qualities, identify measurable dimensions and targets of these qualities, and incorporate the functions and tasks into the delivery of service which are necessary to meet the demanded qualities. DISCUSSION: The future of providing health care services will belong to organizations that can adapt to a rapidly changing environment and to demands for new products and services that are produced and delivered in new ways.

Arizona↗

The formation of a covalent complex between a dipeptide ligand and the src SH2 domain.

The X-ray crystal structure of the src SH2 domain revealed the presence of a thiol residue (Cys 188) located proximal to the phosphotyrosine portion of a dipeptide ligand. An aldehyde bearing ligand (1) was designed to position an electrophilic carbonyl group in the vicinity of the thiol. X-ray crystallographic and NMR examination of the complex formed between (1) and the src SH2 domain revealed a hemithioacetal formed by addition of the thiol to the aldehyde group with an additional stabilizing hydrogen bond between the acetal hydroxyl and a backbone carbonyl.

Aldehydes↗

The Minnesota Substance Abuse Problems Scale. Psychometric analysis and validation in a clinical population.

The authors determined interrelationships among 61 items in a scale designed to assess the severity of substance-related disorder (SRD) and develop subscales that measure distinct substance-related areas of dysfunction. They evaluated 642 outpatients with items previously developed among patients with SRDs. Trained interviewers administered the Minnesota Substance Abuse Problem Scales (M-SAPS), which uses responses to yes/no (lifetime) questions. A factor analysis of items was compared with data from patients and addiction psychiatrists to measure the concurrent validity of the M-SAPS factors, yielding 37 items in three factors: Psychiatric-Behavioral Problems (14 items), Social-Interpersonal Problems (11 items), and Addiction-Dependence Symptoms (12 items). These three scales correlate with 10 scales/assessments concurrently collected independently of the M-SAPS, yielding a brief, valid, interviewer-administered, substance-related problem scale that assesses SRD severity in three distinct areas.

Adaptation, Psychological↗

Effect of body weight and caloric restriction on serum complement proteins, including Factor D/adipsin: studies in anorexia nervosa and obesity.

Complement plays important roles in host immune defences, and recent studies suggest that adipose tissue is an important site of production for some complement proteins. Starvation has been associated with low complement levels, but studied populations have usually had concomitant opportunistic infections or other conditions which might affect complement levels. To determine the impact of body weight and changes in body weight on serum complement, we investigated levels of complement proteins in otherwise healthy patients with a wide range of body weights, including patients with anorexia nervosa before and after treatment, obese dieters before and after weight loss, and normal weight controls. We found that complement proteins of the alternative pathway (C3, B, and D), alternative pathway haemolytic activity (AP50) and the inhibitors H and I were low in starving anorectics and normalized with weight gain. C3a levels were comparable in anorectics at low weight and after weight gain, indicating that low serum complement levels were attributable to hypoproduction and not complement cascade activation with consumption. Further, levels of C3, B, AP50, H and I, but not D, were higher than controls in obese patients and decreased toward normal after weight loss. Overall, percentage of ideal body weight, changes in body weight, and serum transferrin were each highly correlated with serum levels of complement proteins. We conclude that levels of alternative pathway complement components are determined in part by factors that influence body weight and by weight changes, possibly due to changes in production in adipose tissue or at other sites.

Adult↗

T-lymphocyte subsets in patients with abnormal body weight: longitudinal studies. in anorexia nervosa and obesity.

OBJECTIVE: In contrast to other types of starvation which are characterized by low CD4+ counts and increased susceptibility to infection, anorexia nervosa is not associated with an increase in infectious complications. To determine why infection risk of anorectics differs from that of other starving populations, we studied T-lymphocytes, including CD4+ and CD8+ phenotypes, in patients with anorexia nervosa, and for comparison, in dieting obese subjects. METHODS: T-lymphocyte phenotypes were determined by flow cytometric analysis of monoclonal antibody-labeled cells obtained from patients with anorexia nervosa before and after successful therapy and weight gain, and in obese subjects before and after weight loss on a very-low-calorie diet. RESULTS: Weight loss in anorectics and obese dieters was associated with normal CD4+ counts. Unexpectedly, CD8+ counts were low in anorectics, both before and after weight gain, and in obese subjects after (but not before) dieting. DISCUSSION: Normal CD4+ counts in anorectics and obese dieters, despite marked weight loss, may explain the lack of increased infection risk in these eating-disordered patients, in contrast to other starving populations. The observation that CD8+ counts are low in anorectics with low and restored body weight and in obese patients after dieting has not been previously reported. The persistence of low CD8+ counts in anorectics even after weight gain suggests that some factors other than weight loss per se may be involved, possibly including effects due to stress, comorbid psychiatric conditions, or unidentified aspects of dysregulated pathophysiology secondary to disordered eating.

Adolescent↗

Prevalence of ADHD and comorbid disorders among elementary school children screened for disruptive behavior.

In the context of a school-based prevention of conduct disorder program, 7,231 first- through fourth-grade children were screened for cross-setting disruptive behavior. Frequencies of DSM-III-R psychiatric disorders and patterns of comorbidity were assessed. We also examined the association of psychiatric diagnosis with child and parent characteristics to determine differential risk based on diagnostic subgroups. Attention deficit hyperactivity disorder (ADHD) and oppositional-defiant disorder (ODD) were the most frequent diagnoses. Mood and anxiety disorders were infrequent as single diagnoses. Patterns of comorbidity demonstrated that both externalizing and internalizing disorders commonly cooccurred with ADHD. More severe degrees of psychopathology and psychosocial risk accrued to the subgroup of youths with ADHD plus a comorbid externalizing disorder.

Attention Deficit Disorder with Hyperactivity↗

Ten-year follow-up of anorexia nervosa: clinical course and outcome.

The clinical course and outcome of anorexia nervosa are presented in a 10-year follow-up study of 76 severely ill females with anorexia nervosa who met specific diagnostic criteria and had participated in a well-documented hospital treatment study. Information was obtained on 100% of the subjects. A comprehensive assessment was made in 93% of the living subjects in specific categories of weight, eating and weight control behaviours, menstrual function, anorexic attitudes, and psychological, sexual, social and vocational adjustment. Five subjects had died, which gives a crude mortality rate of 6.6%. Standardized mortality rates demonstrated an almost 13-fold increase in mortality in the anorexia nervosa subjects. Only eighteen (23.7%) were fully recovered. Sixty-four per cent developed binge-eating at some time during their illness, 57% at least weekly. Twenty-nine (41%) were still bulimic at follow-up. The high frequency and chronicity of the bulimic symptoms plus the high rate of weight relapse (42% during the first year after hospital treatment) suggest that intensive intervention is needed to help anorexics restore and maintain their weight within a normal range and to decrease abnormal eating and weight control behaviours.

Adolescent↗

Peptide inhibitors of src SH3-SH2-phosphoprotein interactions.

Activated pp60c-src has been implicated in a number of human malignancies including colon carcinoma and breast adenocarcinoma. Association of the src SH2 domain with tyrosine-phosphorylated proteins plays a role in src-mediated signal transduction. Inhibitors of src SH2 domain-phosphoprotein interactions are, thus, of great interest in defining the role(s) of src in signal transduction pathways. To facilitate such studies, an enzyme-linked immunosorbent assay (ELISA) was developed to detect inhibitors of src SH2-phosphoprotein interactions. This assay measures inhibition of binding of a fusion construct (glutathione S-transferase src SH3-SH2) with autophosphorylated epidermal growth factor receptor tyrosine kinase domain. Activities of phosphopeptide segments derived from potential src SH2 cognate phosphoprotein partners were determined, with the focal adhesion kinase-derived segment VSETDDY*AEIIDE yielding the highest inhibitory activity. Structure activity studies starting from acetyl (Ac)-Y*EEIE have identified Ac-Y*Y*Y*IE as the most active compound screened in the ELISA. This compound is at least 20-fold more active than the parent peptide Ac-Y*EEIE. A high resolution (2 A) crystal structure of human src SH2 complexed with Ac-Y*EEIE was obtained and provided a useful framework for understanding the structure-activity relationships. Additionally, Ac-Y*EEIE was able to block interactions between src and its cellular phosphoprotein partners in vanadate-treated cell lysates from MDA-MB-468 breast carcinoma cells. However, it is unable to abrogate proliferation of MDA-MB-468 cells in culture, presumably because of poor cell penetration and/or lability of the phosphate group on tyrosine.

Amino Acid Sequence↗

Methodological issues in the administration of multiple doses of smoked cocaine-base in humans.

Many methodological issues exist in human laboratory research with smoked cocaine-base that include safety, precision of dose delivery of smoked cocaine, and the lack of an adequate placebo. All of these issues are particularly apparent with studies involving multiple doses of cocaine. Addressing these concerns is important in conducting parametric studies that require examining dose-response effects. The purposes of this study were to determine: 1) the safest interval between doses to deliver smoked cocaine; 2) the accuracy or reproducibility of administering precise and multiple doses of cocaine; 3) the potential for using a control dose of cocaine; and 4) the influence of multiple doses on these parameters. Six black males were given 10 doses of either 5 or 35 mg of cocaine-base at 15-, 30-, and 45-min intervals. The dependent measures included physiological, subjective, and performance responses. These measures were taken prior to dosing and at specific time intervals after each dose of smoked cocaine. The results showed: 1) dosing at 30-min intervals allowed sufficient time for recovery of blood pressure and heart rate to permit up to 10 doses to be safely administered; 2) reproducible blood cocaine levels were obtained with repeated dosing using a heated wire-coil device; 3) significant differences were observed between the 5- and 35-mg dose with 5 mg being a low enough dose to produce minimal effects; 4) acute tolerance was evidenced with multiple doses of cocaine for most of the measures; and 5) considerable between- and within-subject variability was observed in the pattern of responses to cocaine.

Administration, Inhalation↗

Violence in patients with narcissistic personality pathology: observations of a clinical series.

This paper presents clinical observations on a group of nine patients whose action consisted of either the commission of violent acts or of seriously threatening behaviors suggestive of precursors to violence. A cluster of common features was observed to be present to some degree in all patients: (1) significant narcissistic personality pathology, (2) recent narcissistic injury, (3) inability to acknowledge or express affect related to this injury, (4) some history of impulsiveness when stressed, and (5) the availability of a weapon. Discussion is presented that the clinician's ability to predict the potential for violence may be enhanced by special attention to these features.

Adult↗

Cognitive-behavioral group psychotherapy of bulimia nervosa: importance of logistical variables.

Although much of the psychotherapy for psychiatric disorders is conducted on a weekly basis, several researchers in the field of bulimia nervosa have utilized a more intensive approach as a means to strengthen treatment effects. A second issue concerns the amount of emphasis that should be placed on encouraging the interruption of bulimic symptoms early in treatment. In the current study we systematically studied these two issues. Subjects were randomly assigned to one of four forms of cognitive-behavioral group psychotherapy, the four cells differing on the variables of intensity and emphasis on abstinence. The results indicate that a high intensity approach, an early abstinence approach, or a combination of these two approaches are all significantly more effective in inducing remission in patients with bulimia nervosa compared with a weekly psychotherapy that uses the same manual-based cognitive-behavioral therapy approach.

Adolescent↗

Treatment of crack cocaine use with carbamazepine.

Crack is a rock crystalline alkaloid form of cocaine which can be smoked. At the University of Minnesota, we have developed an experimental pharmacologic treatment for cocaine abusers. Of 26 patients treated to date, 16 have been crack cocaine users. During the hundred days preceding treatment, the 16 crack subjects used cocaine by all routes an average of 71 days each. Improvement was based on a self-reported decrease in cocaine frequency of use. Using carbamazepine, seven highly successful and six partially successful patients reduced their use to 0.7 days and 26 days per 100 days, respectively. These results, though hopeful, must be viewed with caution and considered preliminary and tentative.

Adult↗

Precise localization of the autonomic nerves from the pelvic plexus to the corpora cavernosa: a detailed anatomical study of the adult male pelvis.

The anatomical location of the branches of the pelvic plexus that innervate the corpora cavernosa has been identified previously in stillborn male neonates and fetuses. Based upon these observations, the techniques of radical retropubic prostatectomy and cystectomy have been modified to avoid injury to the autonomic innervation of the corpora cavernosa. However, the exact anatomical relationships of these nerves to the prostate, urethra and other pelvic structures in adults are unclear, since the initial anatomical studies of the pelvic plexus were performed in stillborn neonates in whom the accompanying vessels and fascia had been removed. Because these nerves are microscopic in size and can only be identified by their association with other pelvic structures, it was believed that a more refined understanding of the anatomy was necessary. In an effort to identify precisely the relationship of the cavernous branches of the pelvic plexus to the lateral pelvic fascia and the branches of the prostatovesicular arteries and veins, the following study was performed. Shortly after death a 60-year-old man was perfused completely with Bouin's fixative solution. The entire bladder, prostate, urethra, penis, corpora cavernosa, rectum, and pelvic sidewall fascia and musculature were removed en bloc. The specimen was serially sectioned transversely at 10 mu thickness, and every tenth section was stained with hematoxylin and eosin. An anatomical reconstruction in 3 dimensions was performed and illustrated. Thus, the specific location of the nerves that innervate the corpora cavernosa and their important relationships to the urethra, prostatic capsule, Denonvilliers' fascia and pelvic floor vasculature have been identified.

Autonomic Nervous System↗

Modular approach to CPR training.

Basic and advanced cardiopulmonary resuscitation training is worthwhile yet time consuming. Anesthesiologists should be among the most qualified leaders in CPR teaching programs. Using a modular self-teaching presentation for basic and advanced cardiac life support courses, minimal instructor time is required to accomplish proficiency in both didactic and mannequin performance for participants. This method can be adapted to various educational levels and time constraints without compromising quality of teaching.

Anesthesiology↗

Antimalarial activities of various 4-quinolonemethanols with special attention to WR-142,490 (mefloquine).

Pilot appraisals of the activities of a selected group of 4-quinolinemethanols against acute Plasmodium falciparum infections in owl monkeys indicated that compounds of this class are equally active against infections with chloroquine-resistant and chloroquine-susceptible strains and that this efficacy is not compromised by concomitant resistance to pyrimethamine, and in addition, identified three derivatives with outstanding activity (WR-226,253; WR-142,490; and WR-184,806). WR-142,490, the second 4-quinolinemethanol evaluated in the above model, was five times as active as chloroquine against infections with the chloroquine-susceptible, pyrimethamine-resistant strain and had a much larger therapeutic index. Expanded evaluations designed to support projected studies in human volunteers provided full confirmation of the pilot appraisals and in addition showed: (i) that the activity of WR-142,490 was a function of the total dose delivered, single doses being as effective as three or seven fractional doses administered over as many days; (ii) that intravenous administration of this agent was feasible and effective; and (iii) that the compound was at least as active against infections with P. vivax as against infections with P. falciparum. Companion studies in rhesus monkeys infected with P. cynomolgi showed that WR-142,490 lacked prophylactic or radical curative activity, but that it was as effective as chloroquine as a companion to primaquine in a combination curative drug regimen. The results of human volunteer and field trials agree well with comparable segments of these experimental evaluations.

Administration, Oral↗