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Biomedical subjects

C R Woods

Publications and source records attributed to C R Woods.

At least 19 recordsLinked to original sources
PubMed2001

Vertical transmission of multidrug-resistant human immunodeficiency virus type 1 (HIV-1) and continued evolution of drug resistance in an HIV-1-infected infant.

To confirm the vertical transmission of multidrug-resistant (MDR) human immunodeficiency virus type 1 (HIV-1) and to assess its impact on further evolution of drug-resistant virus in an infant, proviral DNA amplified from infected peripheral blood mononuclear cell cultures was sequenced to identify reverse transcriptase (RT) and protease (PR) mutations. The infant had proviral DNA with evidence of RT mutations (M41L, L74V, and T215Y) and 3 PR substitutions (K20R, M36I, and V82A). After delivery, the mother's proviral DNA had the same substitutions. Phylogenetic analyses of these HIV-1 RT and PR sequences indicated epidemiological linkage. Plasma drug susceptibility was determined by using a recombinant virus assay. Plasma HIV-1 obtained after the infant's birth demonstrated reduced susceptibility to zidovudine and ritonavir. Thus, vertical transmission of MDR HIV-1 was demonstrated in the setting of detectable maternal plasma viremia. Further accumulation of broad MDR in the infant's virus to 3 antiretroviral classes occurred, despite postnatal therapy.

Anti-HIV Agents↗
PubMed2001

Synthesis of oligopyridines and their metal complexes as precursors to topological stereoisomers.

[structure: see text]. Palladium-based carbon-carbon coupling reactions in sequence with halogen-exchange chemistry on a series of heterocycles lead to an efficient synthetic strategy for oligopyridines that bind metal ions such as ruthenium to form coordination racks. The particular structures are designed to form terpyridine subunits for octahedral binding. Reaction of 4,6-diiodopyrimidine produces a "double-bay" terpyridine from which binuclear coordination complexes have been formed.

Journal Article↗
PubMed2001

Impact of different definitions on estimates of accuracy of the diagnosis data in a clinical database.

Computerized medical databases are increasingly used for research. The influence of different definitions of the accuracy of matching on the estimated accuracy of diagnosis data was assessed in a database of visits to a public pediatric clinic. Differences between definitions involved 1) unit of analysis, 2) number of diagnoses required to match per visit, and/or 3) whether database contents are required to match the medical record or medical record contents are required to be matched in the database. Overall, 90% of diagnoses in the database (391/435) were accurately coded relative to the medical record. Alternatively, 77% of diagnoses listed in the medical record (391/506) were accurately coded in the database. When individual visits were used as the unit of analysis, estimates of accuracy using six definitions ranged from 65% to 92%. The most appropriate definition to use for estimating accuracy of diagnosis data likely depends on the purpose of the study. Use of two or more such definitions may enhance portrayal of the accuracy of diagnosis data.

Algorithms↗
PubMed1999

Weapon carrying on school property among middle school students.

OBJECTIVE: To examine the association between carrying a weapon at school and the age of onset of substance use, other indicators of violence, and other health risk behaviors among middle school students. DESIGN: In 1995, a modified version of the Centers for Disease Control and Prevention Youth Risk Behavior Survey was administered to 2227 students (49% were female) attending 53 (of 463) randomly selected middle schools in North Carolina. Weapon carrying on school property during school hours was measured with 2 questions assessing carrying a gun and carrying other weapons such as knives or clubs. The Youth Risk Behavior Survey also assessed other indicators of violence, drug use, suicide plans and attempts, and being threatened with a weapon at school. Variables significantly (P< or =.001) associated with gun and other weapon carrying by chi2 tests were analyzed with stepwise logistic regression using the likelihood ratio approach. Odds ratios (ORs) were adjusted for all other variables in the model and 95% confidence intervals (CIs) were computed. RESULTS: Our study showed that 3% of students had carried a gun and 14.1% had carried a knife or club to school. Gun carrying was associated with increased age (OR, 1.57 [95% CI, 1.15-2.14]); male sex (OR, 5.62 [95% CI, 2.42-13.03]); minority ethnicity (OR, 3.30 [95% CI, 1.55-5.05]); and earlier age of onset of cigarette (OR, 0.85 [95% CI, 0.74-0.97]), alcohol (OR, 0.81 [95% CI, 0.71-0.94]), marijuana (OR, 0.81 [95% CI, 0.71-0.92]), and cocaine use (OR, 0.73 [95% CI, 0.62-0.86]). Knife or club carrying was associated with age (OR, 1.32 [95% CI, 1.14-1.53]); male sex (OR, 2.39 [95% CI, 1.77-2.32]); and ear-lier age of onset of cigarette (OR, 0.88 [95% CI, 0.84-0.94]), alcohol (OR, 0.81 [95% CI, 0.76-0.86]), and marijuana use (OR, 0.77 [95% CI, 0.72-0.83]). Gun carrying was also associated with frequency of cigarette (OR, 1.34 [95% CI, 1.14-1.57]), alcohol (OR, 4.59 [95% CI, 1.27-16.58]), cocaine (OR, 2.96 [95% CI, 1.29-6.82]), and marijuana use (OR, 3.66 [95% CI, 1.67-8.06]) after adjusting for male sex and minority ethnicity. Carrying a knife or club was associated with carrying a gun (OR, 1.83 [95% CI, 1.31-2.55]); being threatened with a weapon at school (OR, 1.65 [95% CI, 1.10-2.49]); fighting (OR, 4.62 [95% CI, 2.56-8.37]); frequency of alcohol (OR, 2.91 [95% CI, 1.88-4.50]) and cigarette use (OR, 1.20 [95% CI, 1.10-1.31]); and a suicide plan (OR, 1.54 [95% CI, 1.07-2.20]). CONCLUSIONS: Middle school students are more likely to carry a knife or club (14.1%) than a gun (3%) to school. Young adolescents who initiate substance use early and engage in it frequently are more likely to carry guns and other weapons to school, after adjusting for age, sex, and ethnicity. Being threatened with a weapon at school and fighting were only associated with knife or club carrying at school. These findings suggest that school-based prevention programs targeting both violence prevention and substance use should be introduced in elementary school.

Adolescent↗
PubMed1999

Gender differences in risk behaviors among adolescents who experience date fighting.

OBJECTIVE: Although dating violence frequently begins during adolescence, few studies have focused on date fighting in middle and high school students. Fewer studies have studied gender differences in date violence. This study examines whether gender-specific patterns of risk behaviors exist among adolescents who report date fighting. DESIGN: The study was conducted on data collected from 21 297 students in grades 8 through 12 participating in the Vermont 1995 Youth Risk Behavior Survey. Data were analyzed on 20 724 students (females = 50.1%) who reported: 1) never having been involved in a physical fight (n = 8737); 2) that their last physical fight was with a girlfriend, boyfriend, or other dating partner (n = 432); and 3) that their last fight was with someone other than a dating partner (n = 11 555). Indicators of violence (weapon carrying, being threatened, and fighting), suicide attempts, substance use, sexual behavior, and pregnancy were analyzed with chi(2) tests. Significant variables were analyzed with stepwise logistic regression. RESULTS: Of the males, 1.8% and of the females, 4.2% reported that their last fight was with a boyfriend, girlfriend, or dating partner. Risk behaviors significantly associated among females who only experienced date fighting included the number of male sexual partners in the past 3 months (adjusted odds ratio: 1. 48; 95% confidence interval: 1.26-1.74), number of suicide attempts in the past 12 months (1.55; 1.30-1.85), riding in a car with a drinking driver (1.23; 1.10-1.37), injection of illegal drugs (2.87; 1.10-7.50), use of alcohol before last sexual encounter (1.53; 1. 27-1.86), number of pregnancies (1.66; 1.26-2.21), forced sex (2.92; 2.18-3.91), and inhalant use (1.19; 1.06-1.34). Risk behaviors significantly associated among males who experienced only date fighting were sexual activity (4.11; 2.24-7.53), number of male partners in the past 3 months (1.40; 1.12-1.75), number of times of getting someone pregnant (1.68; 1.17-2.40), experiencing forced sex (2.38; 1.11-5.13), and the number of times threatened with physical violence in past 12 months (1.82; 1.53-2.17). When compared with adolescents who reported fighting with someone other than a date, risk factors significantly associated with date fighting among females were the number of male sexual partners in the past 3 months (1.21; 1.10-1.34), older age (1.21; 1.10-1.34), carrying a weapon in the past 30 days (.77;.66-.90), experiencing forced sex (1.70; 1. 30-2.22), condom non-use (1.96; 1.60-2.41), and number of times of being threatened with physical violence in past 12 months (1.11; 1. 01-1.22). The risk factors among males were the number of male sexual partners in the past 3 months (1.43; 1.28-1.60), experiencing forced sex (1.91; 1.02-3.60), and older age (1.34; 1.14-1.57). CONCLUSIONS: The patterns of risk behaviors differed among male and female adolescents reporting dating violence. Females who reported date fighting were more likely than were nonfighters to have attempted suicide, to engage in sexual and human immunodeficiency virus risk behaviors (use of injectable drugs), to have been pregnant, experienced forced sex, and to have ridden in a car with a drinking driver. Sexual behaviors, including same-gender sexual partners, forced sex, and having been threatened with physical violence, were associated with date fighting among males. These findings are important in screening adolescents at risk for date violence.date fighting, adolescence, risk behaviors, gender.

Adolescent↗
PubMed1998

Problem dieting behaviors among young adolescents.

OBJECTIVE: To examine dieting, eating and exercise behaviors, use of diet pills, and vomiting or use of laxatives to lose weight among younger adolescents. DESIGN: Analysis of data from a modified version of the Youth Risk Behavior Survey administered to middle school students in North Carolina in 1995. SETTING: Fifty-three randomly selected middle schools in North Carolina. SUBJECTS: Two thousand three hundred thirty-one students in the sixth, seventh, and eighth grades. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Responses to questions regarding weight control practices, including vomiting or laxative use, dieting, exercise, or diet pill use. RESULTS: Of the students surveyed, 110 (9.7%) of the girls and 46 (4.0%) of the boys reported vomiting or using laxatives to lose weight. Among the girls, vomiting or laxative use was associated with feeling overweight, other weight loss practices, older age, being a poor student, smoking, eating more salads or vegetables, and eating more candy or other sweets (P< or =.01). A logistic regression model consisting of diet pill use, dieting to lose weight, lower academic achievement, and currently trying to lose weight correctly classified 92% of female students who had or had not vomited or used laxatives. Among boys, vomiting or laxative use was associated with feeling overweight, other weight loss practices, minority racial status, smoking, frequency of eating hamburgers or other high-fat meats, and frequency of eating french fries or potato chips (P< or =.01). A model consisting of diet pill use, minority race, dieting to lose weight, smoking, feeling overweight, and number of servings of hamburgers, hot dogs, or barbecue correctly classified 97% of the boys who had or had not vomited or used laxatives. CONCLUSION: Younger adolescents trying to lose weight engage in a variety of problem dieting and weight loss behaviors that can compromise health and may be associated with eating disorders.

Adolescent↗
PubMed1996

Rapid determination of outbreak-related strains of Neisseria meningitidis by repetitive element-based polymerase chain reaction genotyping.

Outbreaks of invasive disease caused by Neisseria meningitidis have increased in the United States in the 1990s. Repetitive element-based polymerase chain reaction (rep-PCR), a recently developed genotyping method, was used to evaluate a group of 8 outbreak-related and 35 other meningococcal isolates previously typed by multilocus enzyme electrophoresis (MLEE). All were serogroup B or C. Sets of genotypes were generated using primers based on either of two different repetitive sequences. Genotype sets were analyzed in a blinded fashion. Each set correctly identified outbreak-related isolates. Among the other 35 isolates, rep-PCR delineated 14 and 13 strains, respectively, in the two sets of genotypes. Seventeen electrophoretic types had been delineated by MLEE. Rep-PCR holds promise as a rapid, genome-based typing method for delineation of apparent outbreaks of meningococcal disease.

Disease Outbreaks↗
PubMed1995

Vertical transmission of Citrobacter diversus documented by DNA fingerprinting.

OBJECTIVE: To confirm the vertical transmission of Citrobacter diversus from a mother to her infant and to evaluate the epidemiologic usefulness of a new automated procedure for analysis of polymerase chain reaction (PCR)-generated DNA fingerprints. DESIGN: Repetitive element-based PCR (rep-PCR) analysis of C diversus isolates from the blood and amniotic fluid of a mother and the blood of her infant was performed. Unrelated C diversus isolates also were characterized and compared with the isolates from mother and infant. DNA fingerprints were generated by gel electrophoresis of PCR products derived from either unlabeled standard repetitive sequence-based oligonucleotide primers or fluorescent primers. The standard rep-PCR fingerprints were analyzed by visual inspection. The fluorescent primers were used in fluorophore-enhanced rep-PCR (FERP), and the FERP DNA fingerprints were analyzed by an Applied BioSystems (ABI) Model 373A laser scanning unit equipped with Genescan 672 software (Applied Biosystems, Inc, Foster City, CA). SETTING AND PATIENTS: A mother and her newborn infant, both with invasive disease due to C diversus, in an urban tertiary-care hospital. RESULTS: The DNA fingerprints of the maternal blood, amniotic fluid, and infant blood isolates of C diversus were identical by both visual inspection of ethidium bromide-stained agarose gels and computer-aided analysis of FERP patterns. These strains appeared to differ from all but one control isolate, which had been collected 7 years earlier in the same city in which the infant was born. CONCLUSIONS: Vertical transmission of C diversus from mother to infant can occur in utero. Automated analysis of rep-PCR-generated DNA fingerprints derived using fluorescent primers is an objective means for comparing isolates of C diversus and in all likelihood would be useful for other species of bacteria that possess repetitive elements.

Adult↗
PubMed1994

Invasive disease caused by Neisseria meningitidis relatively resistant to penicillin in North Carolina.

A case of sepsis and meningitis caused by Neisseria meningitidis with relative resistance to penicillin occurred in North Carolina in August 1992. This isolate was relatively resistant due to decreased affinity of its penicillin-binding protein 2 for penicillin. Such isolates have been reported in Spain, elsewhere in Europe, in South Africa, and in Canada, but invasive disease caused by meningococcal isolates relatively resistant to penicillin was not recognized in the United States before a preliminary report of this case in October 1992. The Centers for Disease Control and Prevention recently retrospectively identified 3 additional cases from 1991. A fifth case occurred in Kentucky in 1993. Surveillance studies of penicillin susceptibility of N. meningitidis isolates suggest such meningococci have existed sporadically in the past. Increases in prevalence and magnitude of penicillin resistance among strains of N. meningitidis would require reconsideration of current clinical practice with regard to treatment of meningococcal disease.

Amoxicillin↗
PubMed1993

Recurring ventriculitis due to Citrobacter diversus: clinical and bacteriologic analysis.

Neonatal meningitis due to Citrobacter diversus is usually accompanied by the development of brain abscesses and tends to have high rates of morbidity and mortality. We report a case of a newborn with C. diversus meningitis and brain abscesses who relapsed after initial antibiotic therapy and from whom C. diversus was recovered from cerebrospinal fluid 4 years later during a neurosurgical procedure. Genetic differences in the early and late isolates were discovered, and explanations for this phenomenon are suggested. Possible mechanisms for prolonged persistence in the central nervous system are explored. This unusual case and the analysis of the organisms illustrate the unique features of C. diversus as a pathogen and underscore the need for developing optimal therapeutic strategies.

Cerebrospinal Fluid↗
PubMed1993

Whole-cell repetitive element sequence-based polymerase chain reaction allows rapid assessment of clonal relationships of bacterial isolates.

Repetitive element sequence-based polymerase chain reaction (rep-PCR) enables the generation of DNA fingerprints which discriminate bacterial species and strains. We describe the application of whole-cell methods which allow specimens from broth cultures or colonies from agar plates to be utilized directly in the PCR mixture. The rep-PCR-generated DNA fingerprints obtained with whole-cell samples match results obtained with genomic DNA templates. Examples with different gram-negative bacteria (e.g., Citrobacter diversus, Escherichia coli, and Pseudomonas aeruginosa) and gram-positive bacteria (e.g., Staphylococcus aureus and Streptococcus pneumoniae) are demonstrated. Rapid specimen preparation methods enable rep-PCR-based fingerprinting to be completed in several hours and, therefore, allows the timely analysis of epidemiological relationships.

Bacteriological Techniques↗