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Biomedical subjects

D Devine

Publications and source records attributed to D Devine.

At least 19 recordsLinked to original sources
PubMed2005

Chlorhexidine-modified glass ionomer for band cementation? An in vitro study.

OBJECTIVE: To compare the mean retentive strength, predominant site of band failure, amount of cement remaining on the tooth at deband and survival time of orthodontic micro-etched bands cemented with chlorhexidine-modified (CHXGIC) or conventional glass ionomer cement (GIC). DESIGN: In vitro study. SETTING: Dental Materials Laboratory. MATERIALS AND METHODS: One-hundred-and-twenty intact, caries-free third molars were collected from patients attending for third molar surgery. These were stored for 3 months in distilled water and decontaminated in 0.5% chloramine. To assess retentive strength, 80 teeth were randomly selected and 40 were banded with each cement. Testing was undertaken using a Nene M3000 testing machine at a cross-head speed of 1 mm/min. Following debanding, the predominant site of failure was recorded as cement-enamel or cement-band interface. The amount of cement remaining on the tooth surface following deband was assessed and coded. Survival time for another 40 banded specimens, 20 cemented with each cement, was assessed following application of mechanical stress in a ball mill. MAIN OUTCOME MEASURES: Retentive strength, predominant site of failure, amount of cement remaining on the tooth surface, survival time. RESULTS: Mean retentive strength for bands cemented with CHXGIC (0.32 MPa, SD 0.09) or GIC (0.28 MPa, SD 0.07) did not differ significantly (p=0.05). All bands failed at the enamel-cement interface. There was no significant difference in the amount of cement remaining on the tooth surface after deband for each cement type (p=0.23). The mean survival time of bands cemented with CHXGIC or GIC was 7.0 and 6.4 hours, respectively (p=0.23). CONCLUSIONS: There was no significant difference in mean retentive strength, amount of cement remaining on the tooth after deband or mean survival time of bands cemented with CHXGIC or GIC. Bands cemented with either cement failed predominantly at the enamel-cement interface. The results suggest that CHXGIC may have comparable clinical performance to GIC for band cementation.

Anti-Infective Agents, Local↗
PubMed2001

Investigation to evaluate and validate the Leeds in situ device for the study of enamel remineralisation in vivo.

OBJECTIVES: Recently, a novel device to generate dental plaque in situ on a removable human enamel surface was described. The device permitted the recovery of plaque intact and undisturbed on its enamel substrate. The aim of this investigation was to determine the utility and robustness of this model for analysis of the effects of therapeutics on both enamel remineralisation and on the overlying biofilm composition. METHODS: Enamel slices were taken from extracted sound human teeth, sterilised and a 'flat' area ground on each slice. An artificial lesion was formed within this area using acidified gel and the hardness of the enamel within the area of the lesion was determined at five sites using a 'Vickers' indenter. A nylon ring was then attached over the area of the lesion with cyanoacrylate and the excess enamel removed to form the completed device. Two devices were attached to the upper molars of 22 volunteers. Each volunteer was randomly assigned to receive either a fluoride containing (1500 ppm) or a fluoride free dentifrice. The devices were retained for a 4 week period whilst undertaking normal oral hygiene. All procedures were conducted according to GCP. After a 2 week break, the volunteers were fitted with two further devices, given dentifrice of the alternate type and the procedure repeated. Plaque from each device was harvested for microbiological analyses and the enamel subject to microhardness measurement. Then for each device the change in microhardness of the enamel within the lesion over the 4 week period was calculated. RESULTS: There were no significant differences in viable counts of total aerobic bacteria, mutans streptococci or lactobacilli, nor in acidic, aciduric or arginolytic populations in plaque from patients using the two different dentifrices. However, devices subjected to the fluoride containing dentifrice demonstrated a significantly greater increase in microhardness of the enamel (P<0.025). CONCLUSIONS: These results suggest that the novel in situ device is capable of measuring the effect of 1500 ppm fluoride on remineralisation of carious enamel over a 4 week period and is also well suited to determining concomitant effects on plaque ecology.

Adult↗
PubMed2000

Risk-resistance adaptation model for caregivers and their children with sickle cell syndromes.

This investigation examined the risk-resistance adaptation model for children with sickle cell disease and their primary caregivers. Participants were 55 children, ranging in age from 5 to 16 years with a mean age of 9 years 2 months, diagnosed with sickle cell disease and their primary caregivers, recruited from a university medical center. Measures included adjustment (i.e. primary caregiver and child adjustment), risk factors (i.e. disease and disability, functional independence, and psychosocial stressors), resistance factors (i.e. intrapersonal health locus of control, social-ecological), and stress processing (coping). Primary caregivers' adjustment was associated with developmental coping, changeR2 = .08, and child adaptation was associated with an internal health locus of control, changeR2 = .22. An indirect effect of primary caregivers' coping on child adjustment was found through influence on primary caregivers' adjustment, changeR2 = .11. The findings support research among other chronically ill populations that suggests an association between coping and disease adjustment. The results were interpreted to support the use of theoretically driven models in predicting the adaptation of children with chronic illness and adjustment in their caregivers.

Adaptation, Psychological↗
PubMed1999

The AtCAO gene, encoding chlorophyll a oxygenase, is required for chlorophyll b synthesis in Arabidopsis thaliana.

Chlorophyll b is synthesized from chlorophyll a and is found in the light-harvesting complexes of prochlorophytes, green algae, and both nonvascular and vascular plants. We have used conserved motifs from the chlorophyll a oxygenase (CAO) gene from Chlamydomonas reinhardtii to isolate a homologue from Arabidopsis thaliana. This gene, AtCAO, is mutated in both leaky and null chlorina1 alleles, and DNA sequence changes cosegregate with the mutant phenotype. AtCAO mRNA levels are higher in three different mutants that have reduced levels of chlorophyll b, suggesting that plants that do not have sufficient chlorophyll b up-regulate AtCAO gene expression. Additionally, AtCAO mRNA levels decrease in plants that are grown under dim-light conditions. We have also found that the six major Lhcb proteins do not accumulate in the null ch1-3 allele.

Amino Acid Sequence↗
PubMed1999

Women who are HIV infected: the role of religious activity in psychosocial adjustment.

The role of religious activity in the psychosocial adjustment of 205 inner-city African-American women, one-half of whom are HIV infected, was examined. Those who were HIV infected reported praying more but viewed prayer as less effective in coping with a chronic illness. Frequency of prayer predicted optimism about the future, whereas religious activity was not related to current depressive symptoms.

Acquired Immunodeficiency Syndrome↗
PubMed1998

Purification and functional analysis of the DnaK homologue from Prevotella intermedia OMZ 326.

This study examined heat shock proteins (hsps) of the periodontal pathogen Prevotella intermedia and the closely related species, Prevotella nigrescens and Prevotella corporis. After heat shock at 45 degrees C for 5 min, cell-free extracts were analysed by SDS-PAGE and Western blotting with polyclonal antibodies against Escherichia coli hsps. P. intermedia, P. nigrescens and P. corporis all expressed a DnaK homologue. The P. nigrescens DnaK was of a similar molecular mass to E. coli DnaK (70 kDa), whilst those of P. intermedia and P. corporis were approximately 69 kDa. DnaJ homologues were expressed in each species; however, no homologue of GrpE was detected. P. intermedia DnaK was purified to homogeneity by ion-exchange and affinity-chromatography, and was shown to restore activity of denatured luciferase. This molecular chaperone activity was enhanced by E. coli DnaJ and GrpE which are components of the Hsp70 molecular chaperone machine.

Antibodies, Bacterial↗
PubMed1997

Prospective evaluation of neutrophil autoantibodies in 500 consecutive patients with inflammatory bowel disease.

Previous studies have shown antineutrophil cytoplasmic autoantibodies (ANCA) in patients with inflammatory bowel disease (IBD). A particular subclass, the so-called 'atypical' (perinuclear) p-ANCA type, occurs in the majority of patients with ulcerative colitis. The purpose of this prospective study was to assess, in a blinded fashion, this 'subclinical' serological marker in a consecutive series of IBD patients. Five hundred patients were evaluated, including 247 patients with ulcerative colitis and 253 with Crohn's disease involving the small and/or large intestine. Overall, 194 (38.8%) of all patients with IBD were positive, including 164 (66.3%) with ulcerative colitis and 30 (11.9%) with Crohn's disease. Except for coexistent sclerosing cholangitis, no other clinical or laboratory variable had an effect on the rate of ANCA detection. This is the largest single study of ANCA in patients with IBD and the only study to provide data solely from a single Canadian centre. Results emphasize the immunopathological differences between ulcerative colitis and Crohn's disease, and indicate that both disorders are heterogeneous inflammatory disease processes.

Adult↗
PubMed1996

Cascading toward divorce: the roles of marital and child factors.

This longitudinal study examined the role of marital and child factors in predicting divorce potential and actual divorce occurrence. Participants included 140 young adolescents (73 girls, 67 boys; mean age = 13 years 2 months) and their parents. Child-related (number of children in the family, the presence of a male child in the family, and the adolescent's level of anxiety-withdrawal and conduct disorder problems) and intramarital (marital satisfaction and, for some analyses, divorce potential) factors served as predictors. For both wife and husband data, lower levels of marital satisfaction predicted higher current levels of divorce potential, and, in turn, divorce potential predicted greater likelihood for divorce up to 7 years later. No child-related variables predicted divorce potential or divorce occurrence.

Adolescent↗
PubMed1995

Quartz inactivates alpha 1-antiproteinase: possible role in mineral dust-induced emphysema.

Occupational exposure to some types of mineral particles has been shown to be associated with the development of emphysema, but the mechanism of this process is unknown. Because many mineral particles are known to catalyze the formation of active oxygen species in aqueous solution, we hypothesized that mineral particles could oxidatively inactive antiproteinases, leading to an imbalance between protease and antiprotease activities, events similar to those believed to occur with cigarette smoke. To test this hypothesis, human alpha 1-antiproteinase (alpha 1-AP) was incubated with suspensions of freshly ground or aged quartz, and antiproteolytic activity was determined by using porcine pancreatic elastase. Increasing concentrations of quartz were associated with increasing losses of antiproteolytic activity; this effect could be prevented by catalase. Freshly ground quartz was more active than aged quartz. Western blot analysis for alpha 1-AP showed abnormal banding, suggesting that porcine pancreatic elastase-alpha 1-AP complex formation was impaired by silica exposure. Chemical assay of aqueous quartz suspensions demonstrated production of hydrogen peroxide; incubation of alpha 1-AP with hydrogen peroxide caused a dose-dependent loss of antiproteolytic activity, and this also could be prevented by catalase. We conclude that, at least in vitro, quartz can inactivate alpha 1-AP through a hydrogen peroxide-mediated mechanism and that oxidative loss of antiproteinase activity could play a role in mineral dust-induced emphysema.

Animals↗
PubMed1994

Adolescent depressed mood and young adult functioning: a longitudinal study.

The present study examined two aspects of depressed mood in adolescence: (1) stability across the adolescent years and (2) ability to predict functioning in young adulthood. Participants included 82 Caucasian individuals (46 females and 36 males) who were assessed one time per year for 4 consecutive years during adolescence (mean age at initial assessment = 13.5 years) and again during young adulthood (mean age = 19). The results indicated that depressed mood, as measured by the Children's Depression Inventory (CDI), remained relatively stable across at least 3 consecutive years of data collection during adolescence. In addition, adolescent CDI scores predicted young adult functioning in each of four areas: prosocial competence, self-esteem, externalizing problems, and internalizing problems.

Adaptation, Psychological↗
PubMed1994

Analysis of immunoglobulin class, IgG subclass and titre of HPA-1a antibodies in alloimmunized mothers giving birth to babies with or without neonatal alloimmune thrombocytopenia.

We analysed the titre and isotype composition of antibodies produced by mothers giving birth to babies with or without neonatal alloimmune thrombocytopenic purpura (NAITP) and patients with post-transfusion purpura (PTP). All these individuals produced an antibody specific for the HPA-1a allotype present on the platelet glycoprotein IIb-IIIa (GPIIb-IIIa). Sera from mothers who gave birth to thrombocytopenic babies (group 1, n = 36), non-thrombocytopenic babies (group 2, n = 4) or from PTP patients (group 3, n = 3) were tested by an indirect-ELISA. Results indicated no evident differences in the isotype composition or titre of the antibodies from the three groups of sera. The antibody titre ranged from 1:120 to 1:3500. Antibodies with the IgG1 subclass were present in all sera. Most sera contained IgG1 alone (24/43 sera tested) or in combination with IgG3 (10/43). IgG2 was never present and only three sera showed intermediate reactivity with anti-IgG4 MAb. Few sera (nine sera from groups 1 and 2) were weakly positive when tested with the anti-IgM antibodies. These results suggest that neither the titre nor the isotype composition can be used to predict the severity or the occurrence of thrombocytopenia in newborns.

Adult↗
PubMed1989

Pathophysiology of thrombocytopenia associated with HIV infection in homosexual men. A preliminary report.

The pathophysiology of HIV associated immune thrombocytopenia (HIV-ITP) and its response to AZT was investigated. Using autologous 111Indium-labelled platelets, platelet kinetic were analysed in two patient groups. Group 1 (untreated) was comprised of 13 patients with HIV-ITP. Group 2 (AZT) was comprised of 6 patients with a history of HIV-ITP prior to starting AZT. These patients were studied following a rise in their platelet count on AZT. Platelet survivals in both groups were shortened compared to controls, however there was no significant difference between the 2 groups. However platelet turnover rates were significantly depressed in Group 1 compared to Group 2 (P less than 0.05) and control values (P less than 0.05). The platelet count correlated with platelet turnover in Group 1 but not in AZT treated patients. Thus patients with HIV-ITP appear to have both shortened survivals and suppressed platelet production. The mechanism of the latter is unknown, but the increased turnover rate seen with AZT suggests it is a direct or indirect effect of the HIV virus.

Acquired Immunodeficiency Syndrome↗
PubMed1988

Molested as children: a hidden contribution to substance abuse?

A history of child sexual victimization may be much more prevalent among substance abusers than previously suspected and may be commonly missed if not assessed directly in every patient. The rates of reporting child sexual abuse among inpatient substance abusers were compared before and after the question was routinely asked in a treatment program. Before routine inquiry, 4% of men and 20% of women disclosed such abuse but after routine inquiries began the rates for adult men quadrupled, up to 42% of the teenaged boys reported such abuse, about 75% of adult women admitted such abuse, and 71 to 90% of teenaged girls disclosed histories of child sexual abuse. Unresolved issues from childhood sexual abuse may be a hidden factor underlying much substance abuse and if not treated may lead to rapid relapse.

Adolescent↗
PubMed1986

Aggressive combination therapy in the successful management of life-threatening intracranial hemorrhage in a patient with idiopathic thrombocytopenic purpura.

We describe acute therapy for a 13-year-old female from Panama with chronic idiopathic thrombocytopenia purpura (ITP) refractory to steroids, splenectomy, vinca alkaloids, and azathioprine. She presented with neurologic deterioration from a posterior fossa intracranial hemorrhage (ICH). This followed a 3-month history of severe dysfunctional uterine bleeding, progressive from menarche, which had required multiple red cell transfusions. Steroid and vinblastine therapy and transfusion of 40 U of platelets failed to increase the platelet count above 10,000/microliter. Development of a second larger ICH (frontal) produced morbid increase in intracranial pressure that necessitated neurosurgical decompression. Plasma exchange and colloid repletion with intravenous gamma globulin (1 g/kg) and an infusion of 20 U of platelets resulted in a transient rise in platelet count to 160,000/microliter, permitting surgery without bleeding. Danazol (800 mg/day) and conjugated estrogen (Premarin 25 mg/day) were begun to control the uterine bleeding. Intensive plasma exchange and i.v. IgG infusions were continued daily for 24 days, then twice weekly for several weeks. Platelet-bound IgG decreased almost 500% over the first 10 days of therapy, and platelets increased dramatically to 600,000/microliter after 3 weeks of therapy. The patient has remained amenorrheic with a normal platelet count for more than 24 months on daily danazol therapy and monthly infusions of i.v. IgG (0.4 g/kg/dose).

Adolescent↗