Biomedical subjects

C Roberts

Publications and source records attributed to C Roberts.

At least 91 records · Page 5Linked to original sources

PubMed2001

Evaluation of United States-licensed human immunodeficiency virus immunoassays for detection of group M viral variants.

Six Food and Drug Administration (FDA)-licensed human immunodeficiency virus type 1 (HIV-1) and HIV-1/2 immunoassays, including five enzyme immunoassays and one rapid test, were challenged with up to 250 serum samples collected from various global sites. The serum samples were from individuals known to be infected with variants of HIV-1 including group M subtypes A, B, B', C, D, E, F, and G and group O. All immunoassays detected the vast majority of samples tested. Three samples produced low signal over cutoff values in one or more tests: a clade B sample, an untypeable sample with a low antibody titer, and a group O sample. It is concluded that HIV-1 immunoassays used in the United States are capable of detecting most HIV-1 group M variants.

AIDS Serodiagnosis↗

PubMed2001

Transcriptional profiling shows that Gcn4p is a master regulator of gene expression during amino acid starvation in yeast.

Starvation for amino acids induces Gcn4p, a transcriptional activator of amino acid biosynthetic genes in Saccharomyces cerevisiae. In an effort to identify all genes regulated by Gcn4p during amino acid starvation, we performed cDNA microarray analysis. Data from 21 pairs of hybridization experiments using two different strains derived from S288c revealed that more than 1,000 genes were induced, and a similar number were repressed, by a factor of 2 or more in response to histidine starvation imposed by 3-aminotriazole (3AT). Profiling of a gcn4Delta strain and a constitutively induced mutant showed that Gcn4p is required for the full induction by 3AT of at least 539 genes, termed Gcn4p targets. Genes in every amino acid biosynthetic pathway except cysteine and genes encoding amino acid precursors, vitamin biosynthetic enzymes, peroxisomal components, mitochondrial carrier proteins, and autophagy proteins were all identified as Gcn4p targets. Unexpectedly, genes involved in amino acid biosynthesis represent only a quarter of the Gcn4p target genes. Gcn4p also activates genes involved in glycogen homeostasis, and mutant analysis showed that Gcn4p suppresses glycogen levels in amino acid-starved cells. Numerous genes encoding protein kinases and transcription factors were identified as targets, suggesting that Gcn4p is a master regulator of gene expression. Interestingly, expression profiles for 3AT and the alkylating agent methyl methanesulfonate (MMS) overlapped extensively, and MMS induced GCN4 translation. Thus, the broad transcriptional response evoked by Gcn4p is produced by diverse stress conditions. Finally, profiling of a gcn4Delta mutant uncovered an alternative induction pathway operating at many Gcn4p target genes in histidine-starved cells.

Amino Acids↗

PubMed2001

Unilateral versus bilateral acupuncture on knee function in advanced osteoarthritis of the knee--a prospective randomised trial.

We report a prospective randomised trial of acupuncture given to 44 patients with advanced osteoarthritis (OA) of the knee awaiting total knee joint replacement. Patients were randomly allocated into two groups, group A receiving acupuncture to the most affected knee only and group B receiving acupuncture to both knees. Acupuncture was given to four local points around the knee and one distal point. The local points were Spleen 9 (Yinlinquan, SP9), Spleen 10 (Xuehai, SP10), Stomach 34 (Liangqui, ST34), and Stomach 36 (Zusanli, ST36). The distal point was Large Intestine 4 (Hegu, LI4) on the first web space of the ipsilateral hand. A blinded observer assessed knee function before starting treatment, and at the end of two and six months. Analysis of the results showed a significant reduction in symptoms in both groups, and this improvement was sustained for six months. There was no statistically significant difference between the groups. In conclusion, unilateral acupuncture is as effective as bilateral acupuncture in increasing function and reducing the pain associated with OA of the knee. This trial is not able to distinguish the specific from the non-specific effects of the treatment.

Acupuncture Therapy↗

PubMed2001

Lymphadenopathy and lymph node infarction as a result of gold injections.

This report describes a case of lymphadenopathy and lymph node infarction as a consequence of intramuscular gold administered to a patient suffering from rheumatoid arthritis, to highlight this rare association. A 34 year old woman with a four year history of rheumatoid arthritis affecting multiple joints was started on intramuscular gold injections after little response to anti-inflammatory medication. After her sixth injection the patient developed enlarged neck and axillary lymph nodes. Biopsy showed subtotal infarction of a reactive node, confirmed by histochemical, immunohistochemical, and molecular techniques. The patient continued to suffer from rheumatoid arthritis with no evidence of malignant lymphoma after three years. This case provides strong evidence that lymphadenopathy with infarction is a rare complication of gold injections. In such a situation, it is particularly important to exclude a diagnosis of lymphoma, because this is the most common cause of spontaneous lymph node infarction. This can be achieved through awareness of the association, and by the use of ancillary histochemical, immunohistochemical, and molecular techniques on the biopsy material.

Adult↗

PubMed2001

Patient satisfaction with out of hours primary medical care.

OBJECTIVES: To describe the relationship between patient satisfaction with out of hours care provided by deputising and practice doctors in four urban areas in England and characteristics of the service provided and patients, the care given, and health outcomes. SETTING: -Fourteen general practices in four urban areas in England. PARTICIPANTS: People who requested out of hours care. DESIGN: Analysis of data from a study of out of hours care. Patients were interviewed within 5 days of their request for out of hours care. Data on the service provided were obtained from medical records and all other data were collected at interview. Satisfaction was measured using a valid reliable instrument. RESULTS: 2152 patients were recruited to the study and 1466 were interviewed. Satisfaction data were available on 1402 patients. "Overall satisfaction" was associated with age, doctor type, lack of access to a car at the time of the request, and health outcome. The relationships between satisfaction subscales and patient characteristics (age, sex, ethnicity, and access to a car at the time of the request), service characteristics (doctor type and delay between the request and visit), whether a prescription was given, and health outcome were variable. If an expected home visit was not received, "overall satisfaction" and satisfaction with "communication and management", "doctor's attitude", and "initial contact person" were reduced. CONCLUSION: Patient satisfaction is dependent on many factors. Mismatch between patient expectation and the service received is related to decreased satisfaction. This may increase as general practitioners delegate more out of hours care to cooperatives and deputising services.

Adolescent↗

PubMed2001

School smoking policies and smoking prevalence among adolescents: multilevel analysis of cross-sectional data from Wales.

OBJECTIVE: To examine the association between school smoking policies and smoking prevalence among pupils. DESIGN: Multilevel analysis of cross-sectional data from surveys of schools and pupils. SETTING: 55 secondary schools in Wales. SUBJECTS: 55 teachers and 1375 pupils in year 11 (aged 15-16). MAIN OUTCOME MEASURES: Self-reported smoking behaviour. RESULTS: The prevalence of daily smoking in schools with a written policy on smoking for pupils, teachers, and other adults, with no pupils or teachers allowed to smoke anywhere on the school premises, was 9.5% (95% confidence interval (CI) 6.1% to 12.9%). In schools with no policy on pupils' or teachers' smoking, 30.1% (95% CI 23.6% to 36.6%) of pupils reported daily smoking. In schools with an intermediate level of smoking policy, 21.0% (95% CI 17.8% to 24.2%) smoked every day. School smoking policy was associated with school level variation in daily smoking (p = 0.002). In multilevel analysis, after adjusting for pupils' sex, parents' and best friends' smoking status, parental expectations, and alienation from school, there was less unexplained school level variation, but school smoking policy remained significant (p = 0.041). The association of smoking policy with weekly smoking was weaker than for daily smoking, and not significant after adjustment for pupil level variables. Both daily and weekly smoking prevalence were lower in schools where pupils' smoking restrictions were always enforced. Enforcement of teacher smoking restrictions was not significantly associated with pupils' smoking. CONCLUSIONS: This study demonstrates an association between policy strength, policy enforcement, and the prevalence of smoking among pupils, after having adjusted for pupil level characteristics. These findings suggest that the wider introduction of comprehensive school smoking policies may help reduce teenage smoking.

Adolescent↗

PubMed2001

Paraoxonase status in coronary heart disease: are activity and concentration more important than genotype?

Human serum paraoxonase (PON1) hydrolyzes oxidized lipids in low density lipoprotein (LDL) and could therefore retard the development of atherosclerosis. In keeping with this hypothesis, several case-control studies have shown a relationship between the presence of coronary heart disease (CHD) and polymorphisms at amino acid positions 55 and 192 of PON1, which we associated with a decreased capacity of PON1 to protect LDL against the accumulation of lipid peroxides, but some other studies have not. However, the PON1 polymorphisms are only 1 factor in determining the activity and concentration of the enzyme. Only 3 of the previous 18 studies directly determined PON1 activity and concentration. Therefore, we studied PON1 activity, concentration, and gene distribution in 417 subjects with angiographically proven CHD and in 282 control subjects. We found that PON1 activity and concentration were significantly lower in subjects with CHD than in control subjects (activity to paraoxon 122.8 [3.3 to 802.8] versus 214.6 [26.3 to 620.8] nmol. min(-1). mL(-1), P<0.001; concentration 71.6 [11.4 to 489.3] versus 89.1 [16.8 to 527.4] microg/mL, P<0.001). There were no differences in the PON1-55 and -192 polymorphisms or clusterin concentration between patients with CHD and control subjects. These results indicate that lower PON1 activity and concentration and, therefore, the reduced ability to prevent LDL lipid peroxidation may be more important in determining the presence of CHD than paraoxonase genetic polymorphisms.

Adult↗

PubMed2001

Expression of the protein tyrosine phosphatase-like protein IA-2 during pancreatic islet development.

A tyrosine phosphatase-like protein, IA-2, is a major autoantigen in Type 1 diabetes but its role in islet function is unclear. Tyrosine phosphorylation mediates regulation of cellular processes such as exocytosis, cell growth, and cell differentiation. To investigate the potential involvement of IA-2 in islet differentiation and insulin secretion, we analyzed by immunohistochemistry expression of IA-2 during islet development in fetal rats and during the maturation of insulin secretory responses after birth. In the fetus, IA-2 immunoreactivity was detected in primitive islets positive for insulin and glucagon at 12 days' gestation. Subsequently, IA-2 was only weakly detectable in the fetal pancreas. In neonatal rat, a progressive increase in IA-2 immunoreactivity was observed in islets from very low levels at 1 day of age to moderate labeling at 10 days. In the adult, relatively high levels of IA-2 were detected in islets, with heterogeneous expression in individual cells within each islet. IA-2 marks a population of endocrine cells that transiently appear early in pancreatic ontogeny. Islet IA-2 expression reappears after birth concomitant with the development of mature insulin secretory responses, consistent with a role for this protein in regulated hormone secretion.

Animals↗

PubMed2001

Inflammatory endobronchial polyposis with bronchiectasis in cystic fibrosis.

An unusual case of endobronchial polyposis associated with extensive bronchiectasis in the context of cystic fibrosis (CF) has been described. A 15-yr-old female patient with CF underwent partial pneumonectomy for extensive bronchiectasis and frequent infective pulmonary exacerbations. Cylindrical bronchiectasis with associated purulent bronchitis and bronchiolitis, together with inflammatory polyposis, was noted in the resected lung. To the best of the authors' knowledge, this is the first report of multiple endobronchial polyposis and may represent a rare complication of bronchiectasis in a patient with cystic fibrosis. On-going infection and the cellular composition of the polyps are discussed in relation to their possible aetiological relevance and relationship to upper respiratory tract polyps.

Adolescent↗

PubMed2001

Systemic antibiotics fail to clear multidrug-resistant Klebsiella from a pediatric ICU.

STUDY OBJECTIVES: To determine the magnitude of infection rate and antimicrobial resistance in a pediatric ICU (PICU), and to evaluate the efficacy of using broad-spectrum antibiotics. DESIGN: A 3-month, prospective, observational cohort audit. SETTING: A 12-bed tertiary, referral PICU. PATIENTS OR PARTICIPANTS: All children admitted to the PICU for > 72 h. INTERVENTIONS: Surveillance cultures of throat and rectum on admission and once weekly thereafter. MEASUREMENTS AND RESULTS: Of the 150 admissions during the 3-month period, a total of 52 patients (24 girls and 28 boys) requiring mechanical ventilation for a minimum of 3 days were enrolled in the audit. The median age and interquartile range (IQR) was 17 months (IQR, 5.8 to 63); length of stay, 6.5 days (IQR, 4 to 13); ventilation days, 5 (IQR, 3 to 11); pediatric risk of mortality score, 14 (IQR, 9 to 19); and risk of mortality, 0.03 (IQR, 0.014 to 0.087). Fifteen patients (29%) developed 21 infections, mainly lower-airway infections and septicemias. Of the 52 children, 7 children carried multidrug-resistant bacteria and 3 patients progressed to develop four infections with those resistant bacteria. Of the seven carriers, six patients carried gentamicin-resistant Klebsiella. Methicillin-resistant Staphylococcus aureus, penicillin-resistant Streptococcus pneumoniae and gentamicin-resistant Pseudomonas aeruginosa each were carried by one child. Six of those nine resistant isolates were present in the admission flora. Despite the potent combination of piperacillin/tazobactam and amikacin, three children acquired the multidrug-resistant Klebsiella while in the PICU and became nosocomial carriers. CONCLUSIONS: Only surveillance cultures allow the distinction between import of multidrug-resistance and resistant bacteria acquired while in PICU. In this study, two thirds of the resistant isolates were imported. The introduction of newer potent systemic antibiotic combinations failed to control the endemic reservoir of multidrug-resistant Klebsiella and suggests that such policies have little impact.

Amikacin↗

PubMed2001

Sex, ethnicity, age and education effects on the Trail Making test in a sample of cocaine abusers.

Sex, ethnicity, age and education effects on the Trail Making test (TMT), a test often used to for screen for cognitive impairment, were examined in a sample of cocaine abusers in drug abuse treatment programs. A mixed race sample of 5116 males and 2614 females was drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 programs in 11 cities in the United States. The number of cocaine/crack abuser scores available for analysis was 4306. Data were analyzed to determine the effects of sex, ethnicity, age and education variables on the two parts of the TMT in this large treatment sample of cocaine abusers. The variables of sex age, ethnicity and education were statistically significant for both parts A and B of the TMT. In addition, R-Square values for overall models were quite weak (A = .08, B = .11) suggesting that sex, ethnicity, age and education effects on the TMT, while clearly present, account for relatively little overall variance in terms of cocaine users TMT performance. These results are consistent with earlier research using a more heterogenous drug abuse treatment sample.

Adolescent↗

PubMed2001

Using the Trail Making test to screen for cognitive impairment in a drug abuse treatment sample.

The Trail Making test (TMT) is a brief paper and pencil neuropsychological test often used for screening for cognitive impairment. The value of the TMT is examined in a sample of 5619 males and 2902 females was drawn from electronic files of data from the Drug Abuse Treatment outcome Study (DATOS), a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 programs in 11 cities in the United States. Data were analyzed to determine the effects of specific drugs of abuse on parts A and B of the TMT in this large sample of patients in drug abuse treatment programs. Most subjects, regardless of type of drug abused, on TMT parts A and B appeared to fall within normal limits relative to commonly accepted cutoff scores. These results suggest that the TMT parts A and B would have great value as screening measures for cognitive impairment in a drug abuse treatment population.

Adult↗

PubMed2001

Demographic effects on the Trail Making test in alcohol abusers.

Demographic effects on the Trail Making Test (TMT), a test often used for screening for cognitive impairment, are examined in a sample of alcohol abusers in drug abuse treatment programs. A sample was drawn from electronic files of data from the Drug Abuse Treatment outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 programs in 11 cities in the United States. The number of alcohol abuser's scores available for analysis was 1000. Data were analyzed to determine the effects of gender, ethnicity, age and education variables on the two parts of the TMT in this large treatment sample of alcohol abusers. The variables of age, ethnicity and education were statistically significant for both parts A and B of the TMT. R-Square values for overall models were quite weak (A = .12, B = .14) suggesting that demographic effects on the TMT, while clearly present, account for relatively little overall variance in terms of alcohol abuser's TMT performance. These results are consistent with earlier research using a more heterogenous drug abuse treatment sample.

Adult↗

PubMed2001

Demographic effects on the Trail Making Test in marijuana abusers.

Demographic effects on the Trail Making Test (TMT), a test often used for screening for cognitive impairment, were examined in a sample of marijuana abusers in drug abuse treatment programs. A sample was drawn from electronic files of data from the Drug Abuse Treatment outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 programs in 11 cities in the United States. The number of marijuana abusers' scores available for analysis were 259. Data were analyzed to determine the effects of sex, ethnicity, age, and education variables on the two parts of the TMT in this large treatment sample of marijuana abusers. The variables of age and education level were statistically significantly related to TMT parts A and B, and ethnicity was statistically significant for part B of the TMT. R-Square values for overall models were moderate (A = .15, B = .18) suggesting that demographic effects on the TMT are weak.

Adolescent↗

PubMed2001

Demographic effects on the Trail Making Test in amphetamine abusers.

Demographic effects on the Trail Making Test (TMT), a test often used for screening for cognitive impairment, were examined in a sample of amphetamine abusers in drug abuse treatment programs. A sample was drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991-1993, in 96 programs in 11 cities in the United States. The number of amphetamine abusers scores available for analysis were 185. Data were analyzed to determine the effects of sex, ethnicity, age, and education variables on the two parts of the TMT in this large treatment sample of amphetamine abusers. No variables were statistically significant for either parts A and B of the TMT. R-square values for overall models were also negligible (A = .03, B = .08) suggesting that demographic effects on the TMT account for a minuscule amount of overall variance in terms of amphetamine abusers' TMT performance.

Adolescent↗

PubMed2001

Demographic effects on the Trail Making Test in sedatives abusers.

Demographic effects on the Trail Making test (TMT), a test often used to screen for cognitive impairment, were examined in a sample of sedatives abusers in drug abuse treatment programs. A sample was drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991-1993 in 96 programs in 11 cities in the United States. The number of sedatives abusers' scores available for analysis were 72. Data were analyzed to determine the effects of sex, ethnicity, age, and education variables on the two parts of the TMT in this large treatment sample of sedatives abusers. None of the demographic variables were statistically significantly related to TMT parts A and B, when considered as single variables. In addition, R-Square values for overall models were low (A = .15, B = .18), suggesting that demographic effects on the TMT in a sample of sedative abusers are very weak.

Adolescent↗

PubMed2001

Demographic effects on the Trail Making Test in narcotic/other opiate abusers.

Demographic effects on the Trail Making Test (TMT), a test often used to screen for cognitive impairments, were examined in a sample of narcotic/other opiate abusers in drug abuse treatment programs. A sample was drawn from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991 through 1993 in 96 programs within 11 cities in the United States. The number of narcotic/other opiate abusers' scores available for analysis was 191. Data were analyzed to determine the effects of sex, ethnicity, age, and education on the two parts of the TMT in this sample of narcotic/other opiate abusers. The variables of age and education level were statistically significantly related to TMT parts A and B, and ethnicity was statistically significant for part B of the TMT. R-square values for overall models were moderate (A = .34, B = .24), suggesting that demographic effects on the TMT are moderate.

Adult↗

PubMed2001

Derived trail making test indices in a sample of substance abusers: demographic effects.

Derived indices on the Trail Making Test (TMT), a test often used to screen for cognitive impairments, were examined in a sample of substance abusers in drug abuse treatment programs. A mixed race sample was drawn from electronic files of data from the Drug Abuse Treatment Outcome Study (DATOS). The DATOS was a naturalistic, prospective cohort study that collected data from 1991 through 1993 within 96 programs in 11 cities in the United States. Data were analyzed to determine the effects of demographic variables on derived indices created by adding, subtracting, multiplying, and dividing parts A and B of the TMT in this large treatment sample of substance abusers. The variables of sex, age, ethnicity, and education were statistically significant for selected derived indices of the TMT.

Adult↗