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Biomedical subjects

R Lewis

Publications and source records attributed to R Lewis.

At least 127 records · Page 7Linked to original sources
PubMed1996

Selected issues in premature rupture of the membranes: herpes, cerclage, twins, tocolysis, and hospitalization.

A number of issues related to premature rupture of the membranes (PROM) are less common or have not been thoroughly evaluated. Genital herpes simplex colonization carries the potential for significant perinatal morbidity, particularly with primary infection and membrane rupture. Cervical cerclage is both a risk factor for preterm PROM (pPROM) and confounds the management of women with PROM. Twin gestations carry an increased risk of pPROM and earlier membrane rupture. Membrane rupture can involve the presenting or nonpresenting sac. In each case, the fetus with intact membranes is at risk due to brief latency or intrauterine infection after membrane rupture of its sibling. Prophylactic and therapeutic tocolysis remains controversial because of the high risk of intrauterine infection after PROM, and the lack of data demonstrating long-term efficacy. With increased attention to health care costs, home management of pPROM has recently been suggested as an alternative to hospitalization after pPROM. This article reviews the clinical course and management options regarding these issues. Also discussed are those issues for which there is controversy but little available data. Each of these issues offers fruitful ground for discussion and further study.

Cervix Uteri↗
PubMed1996

An evaluation of community nursing services for HIV/AIDS patients in Lothian, Scotland.

This paper reports on a postal questionnaire survey of district nurses' work with HIV positive patients. Each nurse was asked to provide information about their contact with HIV positive patients and the level of training they had received in HIV/AIDS care. The nature of nursing activities carried out for these patients was established along with levels of confidence the nurses had in being able to provide a high standard of care. Where the nurses indicated less than full confidence they were asked to indicate what factors predisposed their response. Questionnaires were completed by 101 district nurses. On average, each nurse made 1.25 visits to HIV-infected patients in the two weeks preceding the study. The nursing activities most commonly carried out for these patients were providing advice/counselling, carer support, general nursing care and specialist treatments. The activities least commonly carried out were technical procedures, tests and assessments. Nurses were most confident in providing a high standard in relation to general nursing care and least confident that high standards were being achieved in providing specialist treatments. The most frequently encountered explanations offered by the district nurses for their lack of confidence in achieving a high standard were a lack of specialist training and a lack of experience with HIV-infected patients.

Attitude of Health Personnel↗
PubMed1996

Group and single-subject evaluation of a programme to promote self-care in elderly nursing home residents.

Residents and staff of a nursing home in a metropolitan area were randomly assigned to three conditions to: (a) test whether staff's use of operant behavioural management strategies (Condition 1) would cause a greater increase in residents' self-care behaviour than staff's use of mutual goal setting (Condition 2) or routine nursing care (Condition 3), and (b) examine how useful group scores were, compared to individual scores, in determining change in individual residents' behaviour due to treatment. In-service training was provided to staff in Conditions 1 and 2 but not in Condition 3. Over a period of 22 weeks, nursing staff encouraged subjects to perform targeted self-care tasks independently. Data analysis indicated significantly greater change in self-care behaviours for subjects in Condition 1 than for subjects in Conditions 2 and 3. However, visual inspection of data for each case revealed that individual scores were more useful than averages and differences between groups for determining the effectiveness of the clinical interventions.

Aged↗
PubMed1996

Initial single-center experience with an advanced third-generation investigational defibrillator.

The CPI PRxII is a recently approved, multitiered implantable cardioverter defibrillator (ICD) that delivers high and low energy biphasic shocks, antitachycardia (ATP) and bradycardia pacing, and stores 2.5 minutes of electrograms from the widely spaced shocking electrodes. The PRxII was implanted in 58 patients at Yale-New Haven Hospital between December 1993 and January 1995. At implant, mean biphasic defibrillation threshold (DFT) in patients with testing to failure was 10 J (1-20). All 36 patients who were candidates for a new transvenous system underwent successful nonthoracotomy implantation. Based on noninvasive predischarge EPS results, 30 patients had > or = 1 VT zone: 21 patients had ATP, 9 others had first shock < or = 5 J. During follow-up, 13 patients had been treated for 379 events (range, 1-127). Of 340 events in a zone with ATP, 97% responded to ATP, 3% required shock. First programmed shock converted all events in a VF zone. Details, including RR intervals, were available for all events in 15 of 17 patients receiving appropriate or inappropriate therapy or diverted shocks. One hundred eleven of 148 available electrograms confirmed VT by morphology, rate, and/or presence of AV dissociation. In nine patients, electrogram data altered therapy through diagnosis of inappropriate or diverted therapy, guidance of detection enhancements, or diagnosis of previously unrecognized VTs. We conclude the PRxII achieves low DFTs that obviate the need for thoracotomy and effectively treats ventricular arrhythmias with ATP and shock, with programming guided by noninvasive electrophysiology. Multiple stored electrograms from widely spaced shocking electrodes greatly enhance diagnostic capabilities, facilitating effective treatment.

Aged↗
PubMed1996

Chronic proliferative hepatitis in A/JCr mice associated with persistent Helicobacter hepaticus infection: a model of helicobacter-induced carcinogenesis.

Helicobacter hepaticus causes hepatitis in selected strains of mice and in A/JCr mice is linked to liver cancer. To analyze whether H. hepaticus persists in specified ecological niches, to determine whether biomarkers of infection exist, and to analyze the influence of H. hepaticus on hepatocyte proliferation, a longitudinal study of H. hepaticus-infected A/JCr mice was undertaken. A/JCr mice were serially euthanatized from 3 through 18 months and surveyed by enzyme-linked immunosorbent assay; bacterial culture of liver, colon, and cecum; histology; electron microscopy; hepatocyte proliferation indices determined by using 5-bromo-2'-deoxyuridine; and measurement of the liver enzyme alanine aminotransferase. In infected animals throughout the 18-month study, H. hepaticus was consistently isolated from the lower bowel but only sporadically from the liver. By electron microscopy, H. hepaticus was noted infrequently and only in bile canaliculi. Infected mice, particularly males, showed chronic inflammation; oval cell, Kupffer cell, and Ito cell hyperplasia; hepatocytomegaly; and bile duct proliferation. The inflammatory and necrotizing lesion was progressive and involved the hepatic parenchyma, portal triads, and intralobular venules. Hepatic adenomas were noted only in male mice, whereas 5-bromo-2'-deoxyuridine proliferation indices were markedly increased in both sexes, but especially in males, compared to control A/J mice. Infected mice also developed sustained anti-H. hepaticus serum immunoglobulin G antibody responses and elevated alanine aminotransferase levels. H. hepaticus, which persists in the lower bowels and livers of A/JCr mice, is associated with a chronic proliferative hepatitis, and hepatomas in selected male mice indicate that this novel bacterium may cause an increased risk of hepatic cancer induction in susceptible strains of mice. This murine model should prove useful in dissecting the molecular events operable in the development of neoplasms induced by bacteria belonging to this expanding genera of pathogenic Helicobacter species.

Alanine Transaminase↗
PubMed1996

The use of calcium-channel blockers in pregnancy.

Over the past 10 yrs, calcium-channel blockers have been used in obstetrics and gynecology for the treatment of patients with both gestational hypertension and preterm labor. Several randomized trials have been performed which demonstrated that calcium-channel blockers are at least as efficacious as other, better-known antihypertensive agents. Despite animal studies which have shown unfavorable outcomes with the use of some of these agents, the use of calcium-channel blockers in pregnancy has been increasing. As we gain further information on the correlation between calcium homeostasis and several additional disease states, the role of calcium-channel blockers will become further elucidated.

Animals↗
PubMed1995

Persistent genital human papillomavirus infection as a risk factor for persistent cervical dysplasia.

BACKGROUND: Cervical dysplasia, also referred to as squamous intraepithelial lesion (SIL) in cytology or cervical intraepithelial neoplasia in histopathology, is thought to have the potential to advance in progressive stages to cervical cancer. However, not all cases of SIL progress, and most of the mild lesions spontaneously regress. Factors that govern regression, persistence, and progression of SIL are poorly understood. PURPOSE: Our analysis sought to identify factors that determined persistence or regression of SIL. METHODS: Seventy subjects with histopathologically confirmed cervical dysplasia were followed at 3-month intervals for 15 months. At each visit, the cervix was evaluated by Pap smear and colposcopy, and exfoliated cervicovaginal cells were analyzed for human papillomavirus (HPV) DNA. For each subject, data from every two consecutive visits were grouped as a pair. Persistent SIL was considered present if a lesion was detected at a visit (t) as well as at the next visit (t + 1) and absent if a lesion was detected at visit t but not at visit t + 1. A statistical model for time-dependent data correlated persistent SIL with various risk factors. RESULTS: Age, ethnicity, education, sexual behavior, smoking, and the use of oral contraceptives did not correlate with persistent SIL. The risk of persistent SIL was associated with continual HPV infection in visits t and t + 1 (HPV positive by Southern blot analysis: odds ratio [OR] = 3.91, and 95% confidence interval [CI] = 1.58-9.65; HPV positive by polymerase chain reaction [PCR]: OR = 2.42, and 95% CI = 1.03-5.67) and a persistent high viral load (OR = 4.07, and 95% CI = 1.35-12.30). When typed by PCR, individuals with type-specific persistent infection in visits t and t + 1, and particularly those with a continual high viral load (OR = 4.97; 95% CI = 1.45-17.02), had the highest risk for persistent SIL compared with those with a low level of type-specific persistent infection or non-type-specific persistent infection. The presence of persistent HPV infection in visits t-1 (the preceding time interval) was also predictive of persistent SIL in visits t and t + 1, although the strength of association was weaker, suggesting that persistent HPV and SIL occur synchronously. CONCLUSION: HPV infection and its associated cervical lesions tend to occur concurrently, and type-specific persistent HPV infection, particularly with a high viral load, produces chronic cervical dysplasia. IMPLICATIONS: The natural history of genital HPV infection directly influences the prognosis of cervical dysplasia as measured by persistence of the lesion. Testing for HPV infection may be valuable in the clinical management of women with cervical dysplasia.

Adult↗
PubMed1995

Phosphorylation and DNA binding of the octamer binding transcription factor Oct-3.

Phosphorylation influences DNA binding and transactivator capabilities of multiple transcription factors. In this study, we demonstrate that the POU-domain transcription factor, Oct-3, can be phosphorylated in vivo. In addition, we show that in COS-1 cells Oct-3 is phosphorylated exclusively on serine residues. Lastly, we provide evidence that phosphorylation is not required for Oct-3 binding to DNA and treatment of Oct-3 with calf intestinal alkaline phosphatase does not influence its ability to bind DNA.

Alkaline Phosphatase↗
PubMed1995

MDM2 and CDK4 gene amplification in Ewing's sarcoma.

Amplification of the MDM2 gene, which maps to chromosome band 12q13 and encodes a p53-binding protein, may result in functional inactivation of p53 and has been observed in various bone and soft tissue sarcomas. Published studies have included few cases of Ewing's sarcoma (ES) or peripheral neuroectodermal tumour (PNET), a tumour group in which alterations of the p53 pathway have so far not been extensively studied. We examined two ES cell lines, RD-ES and SK-ES-1, and 30 specimens from 27 patients (24 ES, 6 PNET; 19 primary, 4 local recurrence, 7 metastasis) for MDM2 gene amplification by Southern blot analysis. All 30 clinical specimens had been confirmed to contain sufficient ES/PNET DNA by the demonstration of a rearrangement of the t(11;22)-associated EWS gene using an EWS cDNA probe on the same blots. MDM2 gene amplification was detected in 3 of 30 specimens (10 per cent), including two ES and one PNET, but in neither of the cell lines. The three cases with amplification were morphologically typical primary tumours. Two of the three cases also showed co-amplification of the CDK4 gene, which encodes a cyclin-dependent kinase and also maps to band 12q13. Clinically, all three cases had metastatic disease at diagnosis, compared with only 1 of 15 MDM2-negative cases where the primary tumour was studied. The difference was statistically significant (P = 0.005), suggesting an association of MDM2 amplification with advanced stage.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

The impact of initiating a human immunodeficiency virus screening program in an urban obstetric population.

OBJECTIVE: Our purpose was to describe the incidence of human immunodeficiency virus infection and to assess the cost/benefit ratio of universal antenatal human immunodeficiency virus screening. STUDY DESIGN: Medical records of women in this urban obstetrics population, from the years 1988 to 1993, were examined. The incidence of known human immunodeficiency virus seropositivity at delivery was determined. The costs of performing human immunodeficiency virus screening, evaluating the disease status, and administering therapy were calculated. These costs were compared with an averaged cost for care and follow-up of infants infected through vertical transmission. RESULTS: The incidence of known human immunodeficiency virus seropositivity at delivery approximately doubled since the initiation of a human immunodeficiency virus screening program (0.26% to 0.48%). Obstetric screening added an approximate $100,000 to medical costs. The calculated cost of pediatric follow-up of human immunodeficiency virus-seropositive infants for the first 18 months was estimated at $344,355. In our population, with universal screening and zidovudine therapy, the medical costs could be reduced by $175,500 per year. CONCLUSION: A program of voluntary human immunodeficiency virus screening increases the incidence of known human immunodeficiency virus infection. Offering screening and follow-up to all pregnant patients in an urban setting is both cost-effective and medically beneficial.

Adult↗
PubMed1995

HIV agencies: can they evaluate their own services?

This paper describes the development and implementation of self-evaluation methods and guidelines in non-statutory HIV agencies that have been funded by Lothian Health. Two researchers developed this work under the aegis of the Lothian Health Centre for HIV/AIDS and Drug Studies (CHADS). It was implemented in eight agencies providing a diverse range of services. The methodology used included seminars, interviews, and self-evaluation report booklets, which the agencies completed. This process was not designed to be a full evaluation on its own, but rather used in conjunction with independent health board evaluation and monitoring systems. It proved to be an effective system and is currently being used with drug services who have already received an independent evaluation.

Community Health Services↗
PubMed1995

Accuracy and interlaboratory reliability of human papillomavirus DNA testing by hybrid capture.

Epidemiologists and clinicians wishing to introduce human papillomavirus (HPV) testing into cervical cancer prevention programs need standardized, reliable, and accurate HPV DNA tests that can detect the full spectrum of pathogenic HPV types. The Hybrid Capture System assay from Digene (hybrid capture assay) is a nonradioactive kit designed to detect 14 HPV types in two groups: a mix of 9 high-risk types associated with anogenital cancer (HPV types 16, 18, 31, 33, 35, 45, 51, 52, and 56) and another group of 5 low-risk types associated with condyloma acuminatum (HPV types 6, 11, 42, 43, and 44). The assay yields quantitative data meant to reflect viral concentration. In a study of 199 cervical specimens from women with concurrent Pap smears, we assessed the reliability of the new assay by comparing the hybrid capture assay results from three laboratories. We assessed the accuracy of the hybrid capture assay in comparison with a reference standard of HPV DNA content (multiple testing by several methods in two reference laboratories). We also compared the hybrid capture assay results with the concurrent cytologic diagnoses on the basis of an independent review of each smear by five pathologists. Pairwise interlaboratory agreement rates on HPV positivity for either high-risk or low-risk types ranged from 87 to 94%, and kappa values ranged from 0.61 to 0.83. Among specimens positive for high-risk types (the most important clinical outcome), the interlaboratory correlations of the quantitative data ranged from 0.60 to 0.90. Test results from all three laboratories were strongly associated with those of the HPV DNA reference standard and with the concurrent cytopathologic diagnoses. The most common errors were sporadic, apparently false-positive results.

Cervix Uteri↗
PubMed1995

Experience with a novel selective medium for isolation of Actinomyces spp. from medical and dental specimens.

A selective medium containing mupirocin and metronidazole was evaluated for the isolation of Actinomyces spp. from clinical material. The study was a one-year prospective comparison of the method with existing methods, which use nonselective media, at a general hospital and a dental hospital. Significantly more Actinomyces spp. were isolated on the selective medium than on nonselective media from both dental specimens and intrauterine contraceptive devices. However, differentiating between Actinomyces spp. and related nonsporulating gram-positive rods remains a slow and sometimes uncertain process which can introduce lengthy delays in reporting.

Actinomyces↗