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Biomedical subjects

C Davis

Publications and source records attributed to C Davis.

At least 127 records · Page 7Linked to original sources
PubMed1998

Submandibular salivary proteases: lack of a role in anti-HIV activity.

Whole human saliva contains a number of proteolytic enzymes, mostly derived from white blood cells and bacteria in the oral cavity. However, less information is available regarding proteases produced by salivary glands and present in salivary secretions. In the present study, we have analyzed submandibular saliva, collected without contaminating cells, and identified multiple proteolytic activities. These have been characterized in terms of their susceptibility to a series of protease inhibitors. The submandibular saliva proteases were shown to be sensitive to both serine and acidic protease inhibitors. We also used protease inhibitors to determine if salivary proteolytic activity was involved in the inhibition of HIV infectivity seen when the virus is incubated with human saliva. This anti-HIV activity has been reported to occur in whole saliva and in ductal saliva obtained from both the parotid and submandibular glands, with highest levels of activity present in the latter fluid. Protease inhibitors, at concentrations sufficient to block salivary proteolytic activity in an in vitro infectivity assay, did not block the anti-HIV effects of saliva, suggesting that the salivary proteases are not responsible for the inhibition of HIV-1 infectivity.

Anti-HIV Agents↗
PubMed1998

The mouth is a gateway to the body: gene therapy in 21st-century dental practice.

Gene therapy may become an integral tool in dental practice early in the 21st century. It and other biological therapies are expected to be applied to oral diseases and disorders during the midpractice lifetime of today's dental students. If the applications of oral gene transfer are expanded to systemic diseases, oral health care providers in the future could routinely be "gene therapists" with therapeutic targets well outside the oral cavity.

Animals↗
PubMed1998

Simultaneous kidney pancreas transplantation: patient issues and nursing interventions.

Nursing care across the service delivery continuum is essential for patients undergoing simultaneous kidney pancreas transplantation. The self-management of complicated treatment choices and care regimens requires education and support, which are the domain of transplant nursing coordinators. Even successful transplantation is associated with complications in the first 6 months. Continuous posttransplant nursing interventions to monitor patients, teach and reinforce self-care, and support adjustment is crucial to patient well-being. This article describes nursing strategies used at one transplant center to address these patient needs.

Family↗
PubMed1997

Two new S-phase-specific genes from Saccharomyces cerevisiae.

Two new yeast genes, ASF1 (Anti-Silencing Function) and ASF2, as well as a C-terminal fragment of SIR3, were identified as genes that derepressed the silent mating type loci when overexpressed. ASF2 overexpression caused a greater derepression than did ASF1. ASF1 overexpression also weakened repression of genes near telomeres, but, interestingly, ASF2 had no effect on telomeric silencing. Sequences of these two genes revealed open reading frames of 279 and 525 amino acids for ASF1 and ASF2, respectively. The ASF1 protein was evolutionarily conserved, MCB motifs, sequences commonly present upstream of genes transcribed specifically in S phase, were found in front of both genes, and, indeed, both genes were transcribed specifically in the S phase of the cell cycle. While an asf2 mutant was viable and had no obvious phenotypes, an asf1 mutant grew poorly. Neither mutant exhibited derepression of the silent mating type loci. The asf1 mutant was sensitive to methyl methane sulfonate, slightly UV-sensitive and somewhat deficient in minichromosome maintenance. It also lowered the restrictive temperature of a cdc13ts mutant. These phenotypes suggested a role for ASF1 in DNA repair and chromosome maintenance.

Amino Acid Sequence↗
PubMed1997

Neutropenia in allogeneic marrow transplant recipients receiving ganciclovir for prevention of cytomegalovirus disease: risk factors and outcome.

To determine risk factors, frequency, time patterns, and outcome of ganciclovir-related neutropenia in allogeneic marrow transplant recipients, 278 consecutive patients receiving ganciclovir from engraftment until day 100 were studied. In this cohort, 159 patients (57%) had absolute neutrophil counts (ANC) less than 1,500/microL, 112 (41%) had an ANC less than 1,000/microL, 87 (31%) less than 750/microL, and 56 (21%) less than 500/microL for at least 2 consecutive days. Statistically significant risk factors for neutropenia in a Cox model were low marrow cellularity between day 21 and 28 (relative risk [RR] 2.4, P = .0002), hyperbilirubinemia > or =6 mg/dL during the first 20 days (RR 2.5, P = .0001), and elevation of serum creatinine > or =2 mg/dL after day 21 after transplant (RR 2.1, P = .001). Restriction to factors present at engraftment resulted in a similar model with low marrow cellularity, hyperbilirubinemia > or =6 mg/dL, and elevated serum creatinine as significant risk factors. Patients with no risk factor had an incidence of neutropenia of 21%, an incidence of 31% for one risk factor, and of 57% for two or more risk factors (RR 3.8, P = .001). Neutropenia was a negative predictor of overall (RR 2.0, P = .0001) and event-free survival (RR 2.1, P < .0001), and a predictor of relapse (RR 1.7, P = .03) and nonrelapse mortality (RR 2.1, P = .003). Thus, early liver dysfunction, elevated serum creatinine, and low marrow cellularity are risk factors for ganciclovir-related neutropenia. Neutropenia in ganciclovir recipients after marrow transplantation is an independent risk factor for mortality.

Adolescent↗
PubMed1997

A randomized trial of a consultation service to reduce falls in nursing homes.

CONTEXT: Falls are a major health problem in nursing homes, but no interventions have been shown to prevent falls in nursing home residents. OBJECTIVE: To evaluate an intervention program designed to prevent falls and associated injuries in high-risk nursing home residents. DESIGN: Randomized controlled trial. SETTING AND PARTICIPANTS: Seven pairs of middle Tennessee nursing homes with 1 facility in each pair randomly assigned to the intervention. Facilities had 482 (261 control, 221 intervention) residents who qualified for the study because they had high risk of falls and a potential safety problem that could be addressed by the intervention. INTERVENTION: Comprehensive structured individual assessment with specific safety recommendations that targeted suboptimal practices for environmental and personal safety, wheelchair use, psychotropic drug use, and transferring and ambulation. Facility staff were encouraged to implement the individual recommendations and to improve overall facility safety. MAIN OUTCOME MEASURES: The mean proportion of recurrent fallers and incidence rate of injurious falls in the facility in the year following the intervention. RESULTS: The mean proportion of recurrent fallers in intervention facilities (43.8%) was 19.1% (95% confidence interval, 2.4%-35.8%) lower than that in control facilities (54.1%, P=.03). Intervention facilities had a nonsignificant trend toward a lower mean rate of injurious falls (13.7 vs 19.9 per 100 person-years, reduction of 31.2%, P=.22). Subgroup analyses suggested greatest benefits for residents for whom the recommended interventions were carried out or who had 3 or more falls in the preceding year. CONCLUSION: The high rate of falls and related injuries in nursing homes should not be viewed as inevitable, but as outcomes that can be substantially improved through structured safety programs.

Accident Prevention↗
PubMed1997

Human submandibular saliva specifically inhibits HIV type 1.

Studies from a number of laboratories have shown the presence of factor(s) in whole, parotid, and submandibular human saliva capable of inhibiting HIV-1 infectivity in vitro. Data from our laboratory suggested that the level of anti-HIV-1 activity is higher in submandibular than parotid or whole saliva. Previous results obtained with pooled submandibular saliva from seronegative individuals included a filtration step following saliva-virus interaction. In this article, we present data on the HIV-1 inhibitory activity of individual submandibular saliva samples collected from 15 donors. We show that although anti-HIV activity is quantitatively similar in most individuals (9 of 15), some (4 of 15) are much less active than others and some (2 of 15) lack inhibitory activity. We also show that for most individuals the level of anti-HIV inhibitor is similar with or without a filtration step. However, 2 of the 15 samples demonstrated activity only after filtration. The quantitative and qualitative anti-HIV activity of individual saliva samples appeared to reflect differences in the individual donors. We further show that the anti-HIV activity of submandibular saliva is demonstrated not only against laboratory strains of HIV-1 but is similarly active against three clinical HIV-1 isolates. In contrast, submandibular saliva had little effect on the infectivity of HIV-2 or SIV.

Antiviral Agents↗
PubMed1997

Normal and neurotic perfectionism in eating disorders: an interactive model.

OBJECTIVE: Previous nonclinical research found that both normal (or adaptive) and neurotic (or maladaptive) perfectionism were related, in the positive direction, to attitudes and behaviors associated with eating disorders. However, based on a related body of research, it was hypothesized that these two aspects of perfectionism would relate to body esteem in an interactive rather than an additive fashion. METHOD: Anorexic and bulimic patients (n = 123) were assessed on multidimensional aspects of perfectionism, neuroticism, and body esteem. RESULTS: Predictions were confirmed. Normal perfectionism was positively associated with body esteem, but only when levels of neurotic perfectionism were low. Conversely, body-image disparagement was most pronounced when normal and neurotic perfectionism were both elevated. DISCUSSION: These findings demonstrate that the interpretation of simple relationships among personality variables--at least in the area of body image and eating disorder research--may provide a misleading picture.

Adult↗
PubMed1997

A qualitative study of breast cancer self-help groups.

This study reports on the experience of women in four community breast cancer self-help groups in Ontario, Canada. Semi-structured interviews were conducted with 24 women, asking them about benefits and limitations of their group involvement, and about their perspectives on group processes and structures. Overall, participants reported their group involvement to be extremely helpful for navigating the short and long-term impact of breast cancer. Emotional support benefits included connecting with other breast cancer survivors, feeling understood and sharing experiences, providing hope, and sharing healing laughter. Informational and practical support benefits included sharing of important information and learning how to get what you want. Even where there were concerns about limitations or tensions of group experience, these occurred against a backdrop of appreciation and commitment. From the discussion of group processes and structures, a number of issues were identified as problematic. Most notable were how to deal with deaths of group members and how to balance the group's primary purpose of providing mutual support with secondary goals of dealing with group business and engaging in meaningful advocacy.

Adaptation, Psychological↗
PubMed1997

Microwave fixation of rabies specimens for fluorescent antibody testing.

An adaptation of the conventional procedure for fixation of brain impressions prior to rabies testing was developed using a microwave oven to fix slides in less than 1 min. A total of 2394 routine specimens were examined to evaluate the efficacy of microwave fixation of brain impressions as an aid to shortening the turnaround time for reporting. Slides were fixed for 55-60 s in a standard household microwave oven at 50%, power using phosphate buffered saline supplemented with 3% Tween 20 as a fixative medium. They were then stained using the standard rabies immunofluorescent staining procedure with minor modifications. This process potentially could allow results to be reported to submitters within 1.5 h after specimens arrive in the laboratory. Microwave fixation was in complete agreement with conventional acetone fixation for detection of positive rabies specimens.

Animals↗
PubMed1997

Use of the QSR.NUD.IST computer program to identify how clinical midwife mentors view their work.

This paper looks at the use of a computer program (QSR.NUD.IST) to analyse qualitative data. The data are derived from interviews with clinical midwife mentors as part of an evaluation of a midwifery educational programme. An account is given of the content analysis of the data with reference to the literature, and then the way the programme was used to analyse the data a second time. A description is given of the way this programme in particular functions using the textual data as an example. The use of computers in general for analysing qualitative data is discussed in terms of their advantages and disadvantages. The results of the study are described briefly showing how the mentors view their role and responsibilities.

Data Interpretation, Statistical↗
PubMed1997

Comparison of the morphological transforming activities of dibenzo[a,l]pyrene and benzo[a]pyrene in C3H10T1/2CL8 cells and characterization of the dibenzo[a,l]pyrene-DNA adducts.

C3H10T1/2CL8 (C3H10T1/2) mouse embryo fibroblasts were used to study the in vitro carcinogenic activities of dibenzo[a,l]pyrene (DB[a,l]P) and benzo[a]pyrene (B[a]P). The morphological transforming activities of these rodent carcinogens were compared using replicate concentration-response studies. In concentration ranges where both polycyclic aromatic hydrocarbons (PAHs) were active, DB[a,l]P proved to be four to 12 times as potent as B[a]P based on concentration. At lower concentrations DB[a,l]P was active at 0.10 and 0.20 microM, concentrations where B[a]P was inactive. This makes DB[a,l]P the most potent non-methylated PAH evaluated to date in C3H10T1/2 cells. DNA adducts of DB[a,l]P in C3H10T1/2 cells were analyzed by both TLC and TLC/HPLC 32P-postlabeling methods using mononucleotide 3'-phosphate adduct standards derived from the reactions of anti-DB[a,l]P-11,12-diol-13,14-epoxide (anti-DB[a,l]PDE) and syn-DB[a,l]P-11,12-diol-13,14-epoxide (syn-DB[a,l]PDE) with deoxyadenosine 3'-monophosphate and deoxyguanosine 3'-monophosphate. All of the DNA adducts observed in C3H10T1/2 cells treated with DB[a,l]P were identified as being derived from the metabolism of DB[a,l]P to its fjord region diol epoxides through DB[a,l]P-11,12-diol. The predominant adduct was identified as an anti-DB[a,l]PDE-deoxyadenosine adduct. Other major adducts were anti-DB[a,l]PDE-deoxyguanosine and syn-DB[a,l]PDE-deoxyadenosine adducts with minor amounts of syn-DB[a,l]PDE-deoxyguanosine adducts. These DNA adduct data are consistent with similar findings of DB[a,l]PDE-deoxyadenosine adducts in mouse skin studies and human mammary cells in culture.

Animals↗
PubMed1997

Inhibition of HIV infectivity by human saliva.

OBJECTIVE: Human saliva is known to decrease HIV infectivity in vitro. The purpose of this study was to extend these findings and to focus on the mechanism of action of these salivary factor(s). DESIGN: A number of viruses and several assay systems have been utilized to determine if the effect of submandibular saliva is directly on the virus, on the host cell, or on the virus-cell interaction. MATERIALS AND METHODS: Submandibular saliva from seronegative donors was incubated with HIV-1, other retroviruses, or unrelated viruses. Viral infectivity was monitored either by determining p24 antigen levels in peripheral blood mononuclear cells or Sup T1 cells, or using HeLa cells expressing CD4 and an HIV derived long terminal repeat linked to the beta-galactosidase gene. RESULTS: The inhibition of viral infectivity by submandibular saliva is specific for HIV-1. While inhibition increases with time of incubation of saliva with virus, pretreatment of cells with saliva does not inhibit HIV production, and saliva has only modest inhibitory effects when added to HIV-infected cells. CONCLUSIONS: It appears that the effect of submandibular saliva on decreasing the infectivity of HIV-1 is directly on the virus, rather than on the host cell.

Antiviral Agents↗