PubMed Health⌕ Search

Biomedical subjects

A Sullivan

Publications and source records attributed to A Sullivan.

At least 55 records · Page 3Linked to original sources
PubMed1998

Feasibility of multidrug resistance (MDR-1) gene transfer in patients undergoing high-dose therapy and peripheral blood stem cell transplantation for lymphoma.

We have performed a pilot study of MDR-1 gene transfer in patients receiving CD34-selected peripheral blood stem cell (PBSC) transplant for lymphoma. To ensure minimum engraftment thresholds and facilitate CD34 purification, mobilisation of > 2 x 10(6) CD34 cells/kg was a condition for recruitment. Of 11 patients counselled for study entry, only five achieved this target in a single apheresis. In three consenting patients, purified CD34 cells were exposed to A12M1 MDR-1 retroviral supernatant for 6 h, cryopreserved then thawed and readministered following ablative chemotherapy. No delay in engraftment was observed, although one patient received additional back-up cells. Gene transfer was demonstrated by polymerase chain reaction (PCR) for vector-derived MDR-1 cDNA sequence in all cases. Analysis of peripheral blood and bone marrow cells after transplant has, however, shown no evidence of in vivo gene transfer with a follow-up of 12, 15 and 18 months. The effect of MDR-1 substrate drugs has not yet been tested as all patients remain in clinical and radiological remission of their lymphoma. These results confirm the difficulty of achieving in vivo gene transfer in human haemopoietic cells and indicate major logistical constraints in PBSC mobilisation in patients with relapsed and resistant disease in whom initial studies are appropriate.

Adolescent↗
PubMed1998

Use of transfer impedance measurements for clinical assessment of lung mechanics.

Respiratory transfer impedance (Ztr) measured using the forced oscillation technique requires virtually no patient cooperation and provides a noninvasive approach for acquiring data reflective of lung mechanics. Also, model analysis of Ztr provides reliable estimates of separate airway and tissue properties (1), but only if data out to 64 Hz are acquired. The current study evaluated the clinical utility of Ztr from 1-80 Hz for assessing the degree and type of impaired lung function. Spirometry and Ztr measurements were made on 37 individuals: 11 healthy subjects and 26 patients with lung disease including chronic obstructive pulmonary disease (COPD), asthma, lung cancer, and sarcoidosis. Over the entire patient group, 12 were also smokers. We first established normal ranges for several Ztr features and model estimated mechanical properties. The COPD and smokers groups showed significant differences in portions of their Ztr spectra from that of the healthy group. Key Ztr spectral features included R0, the frequency at which the real part of impedance is zero; and Re4, the real part of impedance at 4 Hz. The key model parameter was airway resistance, Raw. We found Raw, Re4, and R0 to be significantly elevated during disease (p < 0.0005) and to significantly decrease with bronchodilator therapy (p < 0.025). Moreover, we found moderate to strong correlations between R0, Raw, and Re4 versus FVC and R0 versus FEV1. After bronchodilator, changes in R0, Re4, and Raw were correlated with changes in several spirometric indices. The R0 feature has not been previously evaluated since it is typically above 32 Hz (well above 32 Hz in diseased individuals) and not encompassed in previous clinical studies.

Adolescent↗
PubMed1998

A five-year evaluation of fissure sealants applied by dental assistants.

The aim of this study was to evaluate if sealings of fissures is a preventive method appropriate for delegation to auxiliary personnel. After a two-day course, giving theoretical as well as practical knowledge, 77 dental assistants working at twelve dental clinics, sealed 3218 first and second permanent molars in children. The material used was the light-cured resin Delton Opaque. The sealings were examined once a year by the childrens ordinary dentists, using internationally accepted criteria. The result showed a total retention rate of 91% after one year and 69% after five. There were differences in success rate between the clinics, the majority demonstrating a five-year total retention rate between 70 and 94%. It was evident that the retention of sealings was influenced by the age of the children but not by the position of teeth in the mouth. The main part of failures appeared during the first year (35%) and failures were essentially due to fractures (64%). Eight percent of all teeth present at the end of the five-year period had become carious. The dental assistants sealed the fissures without any assistance and none of them had any previous experience of fissure sealings. In our opinion, sealing of fissures is a method well suited for delegation to dental assistants after proper education but should be followed up, as the success rate showed a great variation.

Child↗
PubMed1997

Histochemical staining following LacZ gene transfer underestimates transfection efficiency.

Analysis of LacZ gene expression is conventionally inferred from blue staining that results from exposure of the transfected cells or tissue to the substrate 5-bromo-4-chloro-3-indolyl-beta-D-galactopyranoside (X-Gal). Such histochemical staining reports not whether the gene product is present or absent, but where it is active. We investigated the hypothesis that identification of activity, as opposed to presence, of the enzyme underestimates gene expression following LacZ gene transfer. Under conditions optimized for in vitro histochemistry, up to 20% of cells stably transfected with nls-LacZ remained unstained by X-Gal. In contrast, immunostaining with a monoclonal or a polyclonal anti-beta-galactosidase (beta-Gal) antibody positively stained 99% of the cell nuclei. Following in vivo transfection of naked DNA encoding for nls-LacZ, X-Gal staining disclosed 2.7 +/- 1.7 positive nuclei per LacZ-transfected animal, or a transfection efficiency of 0.015%. In contrast, immunohistochemical staining disclosed 118 +/- 32.7 positive nuclei per transfected animal, yielding a transfection efficiency of 0.64% (p < 0.0001 versus X-Gal staining). Thus, 42.9 times more positive cells were detected by antibody than X-Gal staining. Finally, LacZ gene expression following intramuscular gene transfer with an adenoviral vector was observed in 7.6% of skeletal muscle cells assessed with X-Gal; anti-beta-Gal antibody identified 21.8% of cells as being successfully transfected (p < 0.0001). Thus, X-Gal histochemistry following gene transfer of constructs encoding LacZ may underestimate the anatomic extent of gene expression. The superior sensitivity of immunostaining suggests that anti-beta-Gal antibody represents the preferred analytical tool for light microscopic evaluation of LacZ gene transfer.

Adenoviridae↗
PubMed1997

Isolation of putative progenitor endothelial cells for angiogenesis.

Putative endothelial cell (EC) progenitors or angioblasts were isolated from human peripheral blood by magnetic bead selection on the basis of cell surface antigen expression. In vitro, these cells differentiated into ECs. In animal models of ischemia, heterologous, homologous, and autologous EC progenitors incorporated into sites of active angiogenesis. These findings suggest that EC progenitors may be useful for augmenting collateral vessel growth to ischemic tissues (therapeutic angiogenesis) and for delivering anti- or pro-angiogenic agents, respectively, to sites of pathologic or utilitarian angiogenesis.

Animals↗
PubMed1997

On the pH-lowering potential of lactobacilli and mutans streptococci from dental plaque related to the prevalence of caries.

The common method used today to identify persons at risk of dental caries is to estimate the numbers of cariogenic bacteria such as lactobacilli and mutans streptococci in saliva or plaque samples taken from the patient. However, the value of these bacterial counts for explaining and predicting individuals at risk of caries has not been powerful enough. Evaluating one virulence factor such as the acidogenicity of these bacteria might increase their explanatory values for caries. Sixty children aged 14-15 yrs participated in this study. Smooth surface caries and restorations were registered and total plaque samples collected. Counts of lactobacilli and mutans streptococci were estimated, and the pH-lowering potential of both bacteria was measured in an adapted glucose broth. The results showed a weak association between dental caries and lactobacilli, but in the subgroup with this bacterium the explanatory value increased to 14% and in the subgroup with a strong pH-lowering potential it was as high as 27%. For mutans streptococci the associations were weak in all groups.

Adolescent↗
PubMed1997

The psychological repercussions of the sociocultural oppression of Alaska Native peoples.

Issues of the mental health of arctic and subarctic Alaska Natives are explored. Their sociopolitical history is described to familiarize psychologists with the special circumstances of several groups of peoples in Alaska that have been ignored in psychological literature. This history demonstrates how intervention by European Americans in Alaska has prompted a self-alienation of Native peoples that has contributed to exorbitant suicide rates, increasing levels of addiction, high rates of interpersonal violence, and high teenage pregnancy. These developments are contrasted with traditional lifestyles. Recommendations are made about the role of psychology in the facilitation of the recovery process of Alaska Native peoples.

Acculturation↗
PubMed1996

Psychotherapy for delinquents?

The results of a psychotherapy consultation service for delinquents are presented. Based on the clinical material obtained from this programme, and a review of relevant delinquency and psychotherapy literature, a working model of individual psychotherapy related to attachment theory as it applies to this population is discussed. Developmental and existential difficulties that warrant resolution are included, as are issues with resistance and counter transference.

Journal Article↗
PubMed1996

Comprehensive interdisciplinary care: making a difference in pregnancy outcomes for Hispanic women.

Hispanic women constitute one of the fastest growing and most diverse groups in the United States, representing many countries of origin and cultural practices. The purpose of this evaluation study, using an ex post facto design, was to examine well-being during pregnancy and pregnancy outcomes for a cohort of 113 Hispanic women receiving perinatal care at the clinic of a community hospital in an old industrial city in the Northeast. The received adequacy of prenatal care for the study sample women was very high. The low-birthweight rate was lower than for the study hospital, the study city, the state, and the entire United States. The results of this study demonstrate the favorable effects of a comprehensive, interdisciplinary, and culturally sensitive model of prenatal care on these women's well-being and birth outcomes. Findings also support the need for an outreach program targeted at hard-to-reach women in the inadequate, received-care group and women with later initiation of care.

Adolescent↗
PubMed1996

Number of mutans streptococci or lactobacilli in a total dental plaque sample does not explain the variation in caries better than the numbers in stimulated whole saliva.

For practical reasons the numbers of mutans streptococci (MS) and lactobacilli (LB) in plaque are commonly estimated from saliva samples. The saliva counts are considered to be a reasonable indicator of the entire dentition's total microbial load. However, the value of salivary counts for explaining and predicting caries have been found to be low. There was therefore reason to compare the relationships between caries on the one hand and, on the other, the number of MS or LB in plaque and in saliva, respectively, in order to assess their relative merits for explaining the variation in caries, both in a total material and in subgroups with less favourable oral hygiene. Sixty children aged 14-15 years participated in the study. Caries and plaque were registered and the number of MS and LB was estimated in total plaque and in stimulated saliva samples. The results showed that the number of MS or LB in plaque did not explain the variation in caries to a greater degree than did the salivary counts. For both bacteria the explanatory values increased, as expected, in subgroups with less favourable oral hygiene, but not even at this higher level of explanation was there any difference between plaque and saliva. The LB count was a stronger explanatory variable than the MS count. It was concluded that the number of MS and LB, estimated in total plaque as well as in saliva samples, is not a useful tool in prediction.

Adolescent↗
PubMed1996

Women with chest pain: is exercise testing worthwhile?

OBJECTIVE: To determine the diagnostic value of the exercise tolerance test (ETT) in women presenting with chest pain. DESIGN: Prospective study of all women presenting to a centre with chest pain between 1987 and 1993 who were assessed by an ETT and coronary angiography. SETTING: The outpatient clinic of one consultant cardiologist in a tertiary referral centre. PATIENTS: All women referred to this outpatient clinic with chest pain were screened. For inclusion, patients had to perform ETT and undergo coronary angiography. Of the 347 referred during this period, 142 were excluded because they were unable to perform ETT or because of Q waves or other abnormalities on their resting electrocardiogram. RESULTS: Overall the sensitivity of the ETT was 68% and the specificity was 61%, with a positive predictive value of 0.61 and a negative predictive value of 0.68. There were 42 false positive and 31 false negative ETT results (36% of the study group). The predictive value of a negative test was higher in younger women (< 52 years) than in the older group (> or = 52 years) (P = 0.004), but the positive predictive value in the two groups was not significantly different. The predictive value of a negative test was also higher in those with two or fewer risk factors than in those with three or more risk factors (P = 0.001). The negative predictive value for those women above 52 years with three or more risk factors (24% of the study group) was only 0.25. Lack of chest pain during ETT was associated with a higher negative predictive value in the younger group than in the older women (P = 0.006). CONCLUSIONS: In women with chest pain use of the ETT was a misleading predictor of the presence or absence of coronary disease in 36% of these patients. In particular, a negative test in older women with three or more risk factors had a very low predictive value. The inclusion of risk factors and division by age can, however, be used to identify a population at intermediate risk for coronary artery disease in whom the ETT result has the highest diagnostic utility.

Adult↗
PubMed1995

Inconsistent levels of mutans streptococci and lactobacilli measured in stimulated whole saliva.

The counts of mutans streptococci (MS) and lactobacilli (LB) in saliva have been used for prediction of dental caries. The results have not justified putting the methods into clinical practice as the explanatory values of the bacteria for caries are low. There is therefore reason to question how representative the methods for sampling and estimation of those bacteria are. The aims of this study were to investigate if the variation in caries is better explained by the bacteria, estimated as means of numbers in double saliva samples, than by numbers in single samples, and to determine whether chewing on either the preferred or the non-preferred side influences the bacterial counts. Twenty-five healthy subjects were included in the study. Two saliva samples were collected with a 1-wk interval by chewing on a piece of sterile paraffin wax on the preferred side only. One month later this was repeated on the opposite side. In order to test if there were variations in the numbers of bacteria due to the laboratory methods, a paired cultivation of 20 samples was carried out. The results showed that the coefficients of variation (c.v.) for the differences between the individual double samples varied between 110 and 276% of the total mean of the double samples. The paired cultivation gave r values for MS of 0.93 and for LB of 0.99. Using double samples did not increase the explanatory values for caries. There were higher explanatory values for caries on the preferred side than on the non-preferred side, this being much more pronounced for lactobacilli than for mutans streptococci.

Adult↗