Biomedical subjects

A Carroll

Publications and source records attributed to A Carroll.

At least 37 records · Page 2Linked to original sources

PubMed2001

Hand washing for health-care workers in domestic care settings.

Hand washing is recognized as the single most important practice in reducing the spread of infection. Infection problems, such as an increase in antibiotic resistant organisms, have now made apparent the need to return to such basic practice. Although optimum facilities and practices for hand washing in an inpatient setting have been described, these are rarely available for health-care workers providing increasingly more complex care to patients and clients in their own homes. Therefore community staff need to adopt a risk assessment approach and strategies to ensure that adequate decontamination of their hands is achieved in order that care can be given with the minimal risk of cross-infection between patients, clients and staff.

Community Health Nursing↗

PubMed2001

Structural biology of the cell adhesion protein CD2: alternatively folded states and structure-function relation.

Cluster of differentiation 2 (CD2) is a cell surface glycoprotein expressed on most human T cells and natural killer (NK) cells and plays an important role in mediating cell adhesion in both T-lymphocytes and in signal transduction. The understanding of the biochemical basis of molecular recognition by the cell adhesion molecule CD2 has been advanced greatly through the determination of structures and the dynamic properties of the complexes and their individual components and through site-directed mutagenesis. A number of general principles can be derived from the structural and functional studies of the extracellular domains of CD2 and CD58 and their complex. Significant electrostatic interactions within the protein-protein interfaces contribute directly to the formation of macromolecular complexes of CD2 and CD58. Also, residues located on the protein-protein interface demonstrate a certain degree of conformational change upon the formation of a complex. Structural analysis of CD2 has revealed that this adhesion molecule exhibits strong conformational flexibility with a partial non-native helical conformation at high temperatures and in the presence of an organic solvent. In addition, it can be converted into a domain swapped dimer, or trimer and tetramer through hinge deletion. Thus, the conformational status of the adhesive proteins contributes to the regulation of cell adhesion and the folding of CD2.

Animals↗

PubMed2000

Charged-particle multiplicity near midrapidity in central Au+Au collisions at sqrt[SNN]=56 and 130 GeV.

We present the first measurement of pseudorapidity densities of primary charged particles near midrapidity in Au+Au collisions at sqrt[s(NN)] = 56 and 130 GeV. For the most central collisions, we find the charged-particle pseudorapidity density to be dN/deta|(|eta|<1) = 408+/-12(stat)+/-30(syst) at 56 GeV and 555+/-12(stat)+/-35(syst) at 130 GeV, values that are higher than any previously observed in nuclear collisions. Compared to proton-antiproton collisions, our data show an increase in the pseudorapidity density per participant by more than 40% at the higher energy.

Journal Article↗

PubMed2000

Voices from the field: providers discuss HIV counseling and testing programs for drug users.

The use of illicit drugs plays a critical role in the spread of HIV, with approximately one-half of all new HIV infections in the United States attributed to this mode of transmission. There is a renewed emphasis on developing special HIV counseling and testing (C&T) programs for drug users. We conducted a qualitative study of C&T providers to identify client-centered and structural barriers to providing HIV C&T to high-risk drug users. Interviews focused on obtaining a detailed description of the services; successful and problematic forms of organization, financing, and service delivery; client access and barriers to C&T services; recommendations for increasing C&T accessibility and utilization by drug users; and linkages between C&T and other HIV-prevention and intervention services. The results of our interviews illustrate that it is tremendously complex and challenging work to provide C&T to populations with multiple and immediate needs within a context of layered constraints on individual behavior, provider resources, and service delivery. Providers clearly understand client-centered and structural barriers and have demonstrated a commitment to overcoming the barriers related to AIDS stigma, confidentiality, material needs, and fear when delivering HIV C&T services.

California↗

PubMed1999

Correlates of insight and insight change in schizophrenia.

Various theories have been proposed to account for poor insight in schizophrenia. This study examined the relationships between insight, mood, schizophrenic symptoms and cognitive functioning. The relationship between longitudinal changes in insight and changes in symptoms and mood was also investigated. One-hundred patients with DSM-III-R schizophrenia, recently recovered from a relapse of their illness, were rated on the Insight and Treatment Attitudes Questionnaire (ITAQ), the Positive and Negative Syndrome Scale (PANSS), the Montgomery Asberg Depression Rating Scale (MADRS), the Rivermead Behavioural Memory Test and tests of current and premorbid IQ. A random sample of 53 were then given an educational package (video and booklets) designed to improve their insight. Follow-up ratings on the ITAQ, PANSS and MADRS were subsequently obtained. At baseline, better insight was significantly correlated with lower mood and fewer positive symptoms. It was not related to cognitive functioning. Improvement in insight at follow up was related to worsening of mood, but not to change in positive symptoms. The results are consistent with the concept that poor insight, at least in part, results from the psychotic disease process itself. In addition, they suggest that poor insight may protect against depression in the early stages of recovery from schizophrenia.

Adolescent↗

PubMed1999

An infectious molecular clone of a Japanese genotype 1b hepatitis C virus.

We describe an infectious molecular clone of a Japanese genotype 1b strain of hepatitis C virus (HCV-N). The molecularly cloned sequence of HCV-N was compared with alignments of other HCV sequences, leading to the identification of 15 unique, nonconservative amino acid substitutions within the HCV-N open reading frame (ORF). These were repaired to the consensus genotype 1b residue, and the infectivity of RNA transcribed from the repaired clone was assessed by intrahepatic inoculation of a chimpanzee. Viral RNA was first detected in the serum of this chimpanzee 3 weeks following inoculation, and was intermittently present over the next 14 weeks. A strong and persistent anti-HCV serological response developed 13 weeks following inoculation, with seroconversion in the recombinant immunoblot assay (RIBA). A weaker, transient serological response, characterized by seroconversion in a third-generation enzyme-linked immunosorbent assay (ELISA) but not RIBA, occurred between weeks 1 and 5. This may have represented an anamnestic response to HCV antigens translated directly from the intrahepatically inoculated RNA, because the animal previously had undergone 2 unsuccessful attempts at rescue of HCV by intrahepatic RNA inoculation. There was neither biochemical nor histological evidence of liver disease. Although this is within the range of expected outcomes in an HCV-naive chimpanzee, prior immunologic priming may have modified the infection in this animal. The HCV-N clone is the first infectious molecular clone of HCV that is comprised entirely of genotype 1b sequence, and it contains an ORF sequence that is significantly divergent from that of a previously described genotype 1a/1b chimera.

3' Untranslated Regions↗

PubMed1999

Tissue-specific alternative mRNA splicing of phenylethanolamine N-methyltransferase (PNMT) during development by intron retention.

The expression of phenylethanolamine N-methyl transferase (EC 2. 1.1.2.8, PNMT), the final enzyme in the cascade of catecholamine synthesis, is differentially regulated in adrenergic neurons in the brain and in adrenal chromaffin cells. Using reverse transcription-polymerase chain reaction-based techniques, we detected in the prenatal developing rat brainstem, two species of PNMT mRNA which were produced by a rare alternative splicing mechanism known as intron retention. The spliced, intronless message was downregulated postnatally, while the intron-retained mRNA species continued to be constitutively expressed through adulthood. By contrast in the adrenals, at all stages of development examined, only the intronless message was expressed. In line with previous reports on the failure of glucocorticoids to induce PNMT expression in the brain, the pattern of PNMT splicing in brainstem explants was not affected by the presence of the synthetic glucocorticoid dexamethasone. Undifferentiated sympathoadrenal PC12 pheochromocytoma cells expressed very low basal levels of both mRNA variants, accompanied by a very low basal PNMT enzymatic activity. Exposure of PC12 cells to dexamethasone resulted in the upregulation of only the spliced mRNA variant concomitant with a 3-fold increase in PNMT enzymatic activity. In contrast, treatment of PC 12 cells with nerve growth factor (NGF) enhanced the expression of both the intron-retained and the intronless mRNA species without changes in the basal enzyme activity. This latter result suggests that the translation of the intronless mRNA species may be regulated by the intron-retained mRNA species, which by itself may yield a truncated, yet enzymatically functional translational product. Our data suggest that the tissue-specific regulation of PNMT expression is based on a rare alternative splicing mechanism termed intron retention, and that in the adrenal, but not in the brain, this mechanism is sensitive to regulation by glucocorticoids. Thus, this system is uniquely suited for studying the hormonal control of tissue-specific splicing in the nervous system.

Adrenal Medulla↗

PubMed1999

Differential patterns of executive function in children with attention-deficit hyperactivity disorder according to gender and subtype.

The present investigation examined differential patterns in executive functions of children with attention-deficit hyperactivity disorder (ADHD; no diagnosed comorbid disorders) according to subtype and gender, and identified instrumentation sensitive to executive function in children aged 6 to 12 years with ADHD. Data were obtained from 94 children diagnosed with ADHD (predominantly inattentive, n = 32, ADHD combined, n = 62), and from 28 controls. Participants with ADHD, who were unmedicated at the time of testing, were administered five tests of executive function (the Wisconsin Card Sorting Test, the Stroop Color-Word Test, the Matching Familiar Figures Test, the Trail Making Test, and the Tower of London). A two-way multivariate analysis of covariance with age as the covariate and subtype and gender as the independent variables was conducted on all of the tests administered. While children with ADHD predominantly inattentive and those with ADHD combined differed from controls, it was only the latter subtype that differed significantly in perseveration and response inhibition. The absence of diagnosed comorbidity in the children with ADHD at the time of test administration demonstrates that the impairments in executive function are clearly located in ADHD, particularly in the ADHD combined subtype, thus providing support for Barkley's proposed unifying theory of ADHD.

Attention Deficit Disorder with Hyperactivity↗

PubMed1999

Patients with t(8;21)(q22;q22) and acute myeloid leukemia have superior failure-free and overall survival when repetitive cycles of high-dose cytarabine are administered.

PURPOSE: To examine the effect of single compared with repetitive (at least three) cycles of high-dose cytarabine after induction therapy for patients with acute myeloid leukemia (AML) who have the t(8;21)(q22;q22) karyotype. PATIENTS AND METHODS: Patients entered onto the study had AML and t(8;21) and attained a complete remission on four successive Cancer and Leukemia Group B studies. In these studies, either > or = three cycles of high-dose cytarabine or one cycle of high-dose cytarabine was administered, followed by sequential cyclophosphamide/etoposide and mitoxantrone/diaziquone with or without filgrastim support. Outcomes of these two groups of t(8;21) patients were compared. RESULTS: A total of 50 patients with centrally reviewed AML and t(8;21) were assigned to receive one (n = 29) or > or = three cycles (n = 21) of high-dose cytarabine as postinduction therapy. The clinical features of these two groups of patients were similar. Initial remission duration for t(8;21) patients assigned to one cycle of high-dose cytarabine was significantly inferior (P =.03), with 62% of patients experiencing relapse with a median failure-free survival of 10.5 months, compared with the group of patients who received > or = three cycles, in which only 19% experienced relapse and failure-free survival is estimated to be greater than 35 months. Furthermore, overall survival was also significantly compromised (P =.04) in patients assigned to one cycle of high-dose cytarabine, with 59% having died as a consequence of AML, compared with 24% of those who received > or = three cycles of high-dose cytarabine. CONCLUSION: These data demonstrate that failure-free survival and overall survival of patients with t(8;21)(q22;q22) may be compromised by treatment approaches that do not include sequential high-dose cytarabine therapy.

Adolescent↗

PubMed1999

At-risk and not at-risk primary school children: an examination of goal orientations and social reputations.

AIMS: The purpose of the present research was to examine whether at-risk and not at-risk primary school aged students differ in two social and psychological domains (future goal orientations and social reputation). SAMPLE: A total of 886 years 5, 6 and 7 students from five primary schools in the Brisbane metropolitan area of Queensland, Australia, participated in the study. METHOD: The Children's Activity Questionnaire which constitutes three parts (demographic information, the Importance of Goals Scale, and the Reputation Enhancement Scale) was administered under standardised conditions. RESULTS: A series of multivariate analyses of variance (MANOVA) and univariate F-tests performed on each of the sets of dependent variables (goal orientations and reputation enhancement) revealed significant differences between the at-risk and not at-risk participants on both goals and reputation. CONCLUSIONS: Not at-risk children sought to attain an Academic Image through education and interpersonal goals, whereas at-risk children sought a Social Image and attached greater importance to physical goals. In line with this, children in the not at-risk group perceived themselves and ideally wished to be perceived as a conforming person, while at-risk children perceived themselves and ideally wished to be perceived as non-conforming. Significant gender differences were also found on both sets of dependent variables. COMMENT: The findings are compared to recent research conducted with high school adolescents.

Antisocial Personality Disorder↗

PubMed1999

Adolescent reputation enhancement: differentiating delinquent, nondelinquent, and at-risk youths.

This research reports the findings of two studies conducted to measure and then investigate differences between delinquent, nondelinquent, and at-risk youths' orientations towards reputation enhancement. In the first study, concerning item selection and scale development, the factor structure and content validity of a potential Reputation Enhancement Scale were tested by examining the item responses of the scale completed by 230 high-school students. In the second study, the scale was validated by comparing the item responses of 80 delinquent, 90 at-risk, and 90 nondelinquent adolescents with the responses of the original students. The instrument was found to be reliable (alphas from .64 to .92), indicating that the factors are dependable across different samples, and the coefficients of congruence were sufficiently high to investigate meaningful group differences. Three second-order factors (Conforming Reputation, Nonconforming Reputation, Self-presentation) were derived from the 15 first-order factors. Although multivariate analyses revealed significant differences between the reputational orientations of delinquent, at-risk, and nondelinquent participants, the self-presentation second-order factor did not differentiate the three groups.

Adolescent↗

PubMed1999

Forms management for the health care supervisor.

The creation of necessary, efficient forms at the lowest possible cost is possible. However, it requires a willingness to diligently perform forms analysis, design, and control. Untrained forms designers may know what items they need on a form, but they do not necessarily know how to arrange items on a form or how to select the physical properties of the form. This article addresses the salient points of forms analysis, design, and control.

Communication↗

PubMed1998

Frequency of prolonged remission duration after high-dose cytarabine intensification in acute myeloid leukemia varies by cytogenetic subtype.

Advances in the treatment of acute myeloid leukemia (AML) have occurred with the introduction of new therapies including high-dose cytarabine and the identification of powerful prognostic factors such as cytogenetics that predict for long-term outcome. To date, the prognostic impact of cytarabine dose escalation within various cytogenetic groups of AML has not been assessed. We describe 285 newly diagnosed patients with primary AML who had adequate karyotypes and were enrolled on a prospective Cancer and Leukemia Group B cytogenetic study. All patients were randomly assigned to postremission treatment with standard-, intermediate-, or high-dose cytarabine intensification. Patients were categorized to one of three cytogenetic groups: (a) core binding factor type [(CBF); ie., t(8;21) inv(16), t(16;16), and del(16)]; (b) normal; and (c) other abnormality karyotype. An evaluation of these patients after a median follow-up time of over 7 years was performed to determine the relationship of intensification to outcome by cytogenetic group. Patients included 57 patients with CBF AML, 140 patients with normal karyotype AML, and 88 patients with other cytogenetic abnormalities. The treatment outcome of CBF AML patients was superior, with an estimated 50% still in complete remission (CR) after 5 years as compared with 32 and 15% for patients with normal karyotype AML and other abnormality AML, respectively (P < 0.001). Univariate analysis showed the following nonkaryotype factors to predict a prolonged CR duration: (a) younger age (P < 0.008); (b) lower leukocyte count (P=0.01); (c) the presence of Auer rods (P=0.004); (d) a lower percentage of bone marrow blasts (P=0.001) at the time of diagnosis, (e) and a higher postremission cytarabine dose (P < 0.001). The impact of cytarabine dose on long-term remission was most marked (P < 0.001) in the CBF AML group (after 5 years, 78% of those with a dose of 3 g/m2 were still in CR, 57% of those with a dose of 400 mg/m2 were still in CR, and 16% of those with a dose of 100 mg/m2 were still in CR) followed by normal karyotype AML (P=0.01; after 5 years, 40% of those with a dose of 3 g/m2 were still in CR, 37% of those with a dose of 400 mg/m2 were still in CR, and 20% of those with a dose of 100 mg/m2 were still in CR). In contrast, cytarabine at all doses produced only a 21% or less chance of long-term continuous CR for patients with other cytogenetic abnormalities. A multivariate analysis of CR duration assessed the independent impact of each of these variables on cure. Significant factors entering this model in descending order of importance were cytogenetic group (CBF > normal > other abnormality; P=0.00001), cytarabine dose (3 g/m2 > 400 mg/m2 > 100 mg/m2; P=0.00001), logarithm of leukocyte count at the time of diagnosis (P=0.0005), and histological subtype of AML (P=0.005). This study demonstrates that the curative impact of cytarabine intensification varies significantly among cytogenetic groups and results in a substantial prolongation of CR among patients with CBF and normal karyotypes, but not in those with other karyotypic abnormalities. These findings support the use of pretreatment cytogenetics in risk stratification of postremission AML therapy.

Acute Disease↗

PubMed1998

Health-related quality of life in Australian children with asthma: lessons for the cross-cultural use of quality of life instruments.

The development of Australian forms of the Childhood Asthma Questionnaires (CAQs) is reported. Focus group methods and psychometric analyses were used to establish the conceptual, semantic and technical equivalence of these forms with the UK versions. Both versions also provide for data collection from non-asthmatic youngsters. The internal consistency was found to be acceptable (Cronbach's alpha 0.52-0.90) and the health-related quality of life (HRQoL) scores were found to vary with asthma severity (p < 0.05). Comparison with the UK data revealed that the non-asthmatic scores were higher for Australian than British children (p < 0.001) but that the scores for children with asthma did not differ between the two countries. It was only in the Australian sample that the group with asthma reported impaired HRQoL when compared to their healthy peers. These findings were interpreted in the context of cultural expectations of life quality and conclusions are presented regarding the importance of the gap between experience and expectations. The difficulties raised by the developmental and cultural issues inherent in paediatric HRQoL research were discussed.

Adaptation, Psychological↗

PubMed1998

Reputations, self-concepts and coping strategies of volatile solvent users.

Data pertaining to the reputations, self-concepts and coping strategies of thirty-one secondary school Volatile Solvent Users (VSUs), forty-four ex-VSUs, and forty-eight non-VSUs in the Perth Metropolitan area of Western Australia were obtained using the High School Student Activity Questionnaire. Findings revealed that significant differences between current VSUs, ex-VSUs, and non-VSUs were more attributable to factors of reputation enhancement than to factors of either self-concept or coping strategies. Current VSUs identified themselves as both having and wanting to have a more non-confronting reputation, and as admiring drug-related activities significantly more than both ex-VSUs and non-VSUs. Two coping variables were also found to be significant indicating that females use more non-productive coping strategies and external coping strategies than males. No interaction effects were identified. The implications for drug education and further research are discussed.

Adaptation, Psychological↗

PubMed1998

Volatile solvent use among Western Australian adolescents.

Semistructured interviews were conducted with 40 adolescents who reported inhaling volatile solvents. Their average age was 14.2 years, and they used a range of substances. All were aware of the short-term health risks involved in volatile solvent use, and most reported experiencing ill effects, such as headaches and vomiting. Users were found to be organized into groups and peer networks, which often were involved in theft, prostitution, and other risk-taking behaviors. More chronic users had higher status within the group. Suggestions pertaining to intervention were obtained, and these are discussed in light of the findings.

Adolescent↗

PubMed1997

Western Australian primary school teachers' knowledge about childhood asthma and its management.

A total of 164 primary school teachers from Perth, Western Australia anonymously completed a survey of their knowledge and attitudes about asthma. These teachers were active in assisting children with asthma management but most (91.5%) felt that they did not know enough about asthma. Attitudes toward children with asthma were positive; 97% agreed that such children should be encouraged to participate in sporting activities. Specific knowledge about asthma management and medications was, however, poor. This large sample of Western Australian teachers knew more than their European counterparts but asthma training is needed and should be targeted at improving knowledge of both regular and emergency treatments for asthma.

Adult↗

PubMed1996

Autologous bone marrow transplantation versus intensive consolidation chemotherapy for acute myeloid leukemia in childhood. Pediatric Oncology Group.

BACKGROUND: The value of autologous bone marrow transplantation in the treatment of children with acute myeloid leukemia (AML) is unknown. We compared autologous bone marrow transplantation with intensive consolidation chemotherapy as treatments for children with AML in first remission. METHODS: We induced remission with one course of daunorubicin, cytarabine, and thioguanine, followed by one course of high-dose cytarabine (3 g per square meter of body-surface area for six doses). Patients in remission after the second course of induction therapy were eligible for randomization. Between June 1988 and March 1993, 552 of 649 enrolled patients who could be evaluated (85 percent) entered remission. A total of 209 patients were not eligible for randomization; of the remaining 343 patients, 232 were randomly assigned to receive six courses of intensive chemotherapy (117 patients) or autologous transplantation (115 patients). Of the original 649 patients, 189, including 21 with Down's syndrome, were nonrandomly assigned to receive intensive chemotherapy. RESULTS: The rates of event-free survival and overall survival for the entire group at three years were 34 +/- 2.5 percent and 42 +/- 2.6 percent, respectively. For patients who were randomly assigned to one of the two treatment groups, the mean (+/- SE) rates of event-free survival three years after randomization were not significantly different in the two groups when examined by intention-to-treat analysis: 36 +/- 5.8 percent for the intensive-chemotherapy group as compared with 38 +/- 6.4 percent for the autologous-transplantation group; and the relative risk of treatment failure for the chemotherapy group as compared with the autologous-transplantation group was 0.81 (P = 0.20 by the log rank test; 95 percent confidence interval, 0.58 to 1.12). Overall survival at three years followed a similar pattern. There was a lower relapse rate (31 percent vs. 58 percent, P < 0.001) but a higher rate of treatment-related mortality (15 percent vs. 2.7 percent, P = 0.005) in the group treated with autologous transplantation than in the intensive-chemotherapy group. The event-free survival at three years for the nonrandomized intensive-chemotherapy group was 39 +/- 5.1 percent, and for a contemporaneous group of patients each of whom received a histocompatible bone marrow transplant from a sibling, it was 52 +/- 8.0 percent. CONCLUSIONS: Treatment of children with AML in first remission with either autologous bone marrow transplantation or intensive chemotherapy prolongs event-free survival equally.

Acute Disease↗