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Biomedical subjects

M Lawrence

Publications and source records attributed to M Lawrence.

At least 37 records · Page 2Linked to original sources
PubMed1996

A herpes simplex virus vector overexpressing the glucose transporter gene protects the rat dentate gyrus from an antimetabolite toxin.

The use of herpes simplex virus vectors offers an attractive means for the in vitro and in vivo transfer of novel genes into postmitotic neurons. Such an approach allows for the introduction of genes with the potential to protect neurons from necrotic insults. Toward that end, we have previously constructed a bicistronic herpes viral vector expressing the gene for the Glut-1 rat brain glucose transporter (GT), along with the Escherichia coli lacZ reporter gene. We observed that this vector enhances glucose uptake both in primary hippocampal cultures and in the hippocampus itself. Moreover, we have found that this vector will protect a variety of types of cultured neurons from necrotic insults and protect hippocampal neurons in vivo from seizure-induced damage. In the present report, we further demonstrate the neuroprotective potential of this GT-expressing vector. 3-Acetylpyridine, an electron transport uncoupler which is preferentially toxic to the dentate gyrus, was microinfused into the dorsal hippocampus of rats. Infection of dentate neurons with GT vectors at the time of exposure to the toxin significantly decreased damage, whereas infection with a physiologically neutral control vector did not. Moreover, there was a window of opportunity for this intervention, as microinfusion of the GT-expressing vector up to 1 h, but not 4 h, after the insult was still neuroprotective.

Animals↗
PubMed1996

Double-strength beclomethasone dipropionate (84 micrograms/spray) aqueous nasal spray in the treatment of seasonal allergic rhinitis.

BACKGROUND: The use of intranasally administered corticosteroid sprays is an established treatment option for seasonal allergic rhinitis. METHODS: In this double-blind, placebo-controlled, multicenter study, 438 patients with moderate to severe symptoms of seasonal allergic rhinitis were treated for 4 weeks with double-strength beclomethasone dipropionate (BDP) aqueous nasal spray (84 micrograms/spray: BDP-ds), once daily; regular-strength BDP (42 micrograms/spray: BDP-rs), twice daily; high-strength BDP (336 micrograms/spray: BDP-hs), once daily; or placebo. BDP-hs was included as a safety comparison group. All treatments were given as two sprays per nostril. RESULTS: Physician-rated nasal symptom scores were significantly improved in all three active treatment groups compared with those of the placebo group within the initial 3 days of treatment. Improvement was maintained throughout the 4-week treatment period. BDP-ds and BDP-rs were equivalent at all time points. The BDP-ds, BDP-rs, and BDP-hs groups had greater numbers of patients with a good or excellent therapeutic response at end point than the placebo group. All treatments were well-tolerated, and no unexpected adverse events were reported. No effects on laboratory evaluations or vital signs were evident for any treatment group. CONCLUSIONS: The results of this study show that BDP-ds given once a day and BDP-rs given twice a day in the same total daily dose are comparably safe and effective in the treatment of patients with seasonal allergic rhinitis.

Administration, Intranasal↗
PubMed1996

Fluticasone propionate compared with theophylline for mild-to-moderate asthma.

BACKGROUND: The inhaled corticosteroid, fluticasone propionate, was compared with the oral bronchodilator theophylline in the maintenance treatment of asthma. OBJECTIVE: The objective of the present study was to compare the efficacy and safety of twice-daily inhaled fluticasone propionate, 50 micrograms, and fluticasone propionate, 100 micrograms, with that of theophylline in the maintenance treatment of mild-to-moderate asthma. METHODS: In this randomized, double-blind, placebo-controlled, parallel-group study, 353 adult and adolescent patients with asthma inadequately controlled with inhaled beta-agonist therapy alone received fluticasone propionate, 50 micrograms, or fluticasone propionate, 100 micrograms, by metered-dose inhaler; theophylline capsules; or placebo twice daily for 12 weeks. Only inhaled albuterol was permitted as needed for acute symptoms. RESULTS: Both fluticasone propionate groups had a significantly greater probability of remaining in the study (ie, meeting asthma stability criteria) than did either the theophylline or placebo group (P < or = .008); 39% and 51% in the theophylline and placebo groups, respectively, were withdrawn due to lack of treatment efficacy compared with 14% and 21% in the fluticasone propionate, 50 micrograms, and fluticasone propionate, 100 micrograms, groups. Both fluticasone propionate groups experienced significantly greater improvement in FEV1 and PEF compared with patients in the theophylline or placebo group (P < or = .004). The incidence of potentially drug-related adverse events was significantly greater in the theophylline group (25%) than in the placebo group (11%) (P = .031), while there were no differences between placebo and fluticasone propionate, 50 micrograms, (18%) or fluticasone propionate 100 micrograms, (22%). CONCLUSION: Twice daily treatment with inhaled fluticasone propionate 50 micrograms or 100 micrograms was significantly more effective than theophylline in the treatment of mild-to-moderate asthma.

Administration, Inhalation↗
PubMed1996

The effect of a computer-generated patient-held medical record summary and/or a written personal health record on patients' attitudes, knowledge and behaviour concerning health promotion.

OBJECTIVE: The aim of the study was to examine the effect of a computer-generated patient-held medical record summary (CHR) and/or a written personal health record (PHR) on patients' attitudes, knowledge and behaviour concerning health promotion. METHOD: It was conducted in five general practices in Oxfordshire. Patients aged 25-65 years in each practice were randomly assigned to receive either a CHR plus PHR, CHR only, PHR only, or no personal record. Patients were recruited by mail (one practice) or opportunistically by nurses (four practices). Health checks were carried out using the randomly assigned record, which the patient retained. Attitudes to patient-held records, and pre- and post-intervention knowledge and behaviour concerning health promotion, were assessed using questionnaires. Only those who responded to 'before' and 'after' questionnaires were included in the analysis. RESULTS: A sample of 261 patients was obtained from mail recruitment and 103 from opportunistic nurse recruitment. Patients receiving a CHR as part of mail recruitment were significantly more likely to attend for a health check (P = 0.016). Those receiving both PHR and CHR were more likely to keep (P = 0.014) and use (P = 0.029) the record. Those receiving PHR as part of the package improved their knowledge of health promotion and became more aware of and more likely to change their life-style (P = 0.022). CONCLUSIONS: The effectiveness of a computer-generated patient-held health summary and an explanatory booklet together is greater than either separately in changing patients' knowledge attitudes and behaviour concerning health promotion.

Adult↗
PubMed1996

Adapting total quality management for general practice: evaluation of a programme.

OBJECTIVE: Assessment of the benefits and limitations of a quality improvement programme based on total quality management principles in general practice over a period of one year (October 1993-4). DESIGN: Questionnaires to practice team members before any intervention and after one year. Three progress reports completed by facilitators at four month intervals. Semistructured interviews with a sample of staff from each practice towards the end of the year. SETTING: 18 self selected practices from across the former Oxford Region. Three members of each practice received an initial residential course and three one day seminars during the year. Each practice was supported by a facilitator from their Medical Audit Advisory Group. MEASURES: Extent of understanding and implementation of quality improvement methodology. Number, completeness, and evaluation of quality improvement projects. Practice team members' attitudes to and involvement in team working and quality improvement. RESULTS: 16 of the 18 practices succeeded in implementing the quality improvement methods. 48 initiatives were considered and staff involvement was broad. Practice members showed increased involvement in, and appreciation of, strategic planning and team working, and satisfaction from improved patients services. 11 of the practices intend to continue with the methodology. The commonest barrier expressed was time. CONCLUSION: Quality improvement programmes based on total quality management principles produce beneficial changes in service delivery and team working in most general practices. It is incompatible with traditional doctor centred practice. The methodology needs to be adapted for primary care to avoid quality improvement being seen as separate from routine activity, and to save time.

England↗
PubMed1996

Influenza immunization rates for Louisiana Medicare beneficiaries (1993-1995): a need for interventions.

Influenza is a disease, especially in the elderly, with potentially serious health and fiscal consequences. Vaccines, even though available and proven to be efficacious for prevention, appear to be underutilized in the Medicare population. This paper highlights influenza immunization rates from 1993-1995 for Louisiana Medicare eligible beneficiaries served by Louisiana providers. The authors discuss some of the current efforts underway to increase the number of influenza vaccinations. This was a retrospective study of claims based data on Medicare beneficiaries in Louisiana. Rates were also compared to other states from published Health Care Financing Administration data over the study period. In Louisiana, from 1993-1995, approximately 31% of Medicare beneficiaries age 65 years or older received an influenza vaccination that was paid for by Health Care Financing Administration. This finding indicates an attainment of half of the Department of Health and Human Services Year 2000 goal of 60% influenza immunization rate. The rate for Medicare African-American beneficiaries was approximately one half that of Caucasian beneficiaries. Overall, the billing data indicated that female beneficiaries received influenza immunization slightly more often than male. Medicare beneficiaries aged 75 to 84 years were immunized proportionally more than other age groups. The age group with the smallest percentage of immunized beneficiaries was 85 years or older. These results and rates obtained from the National Health Information Survey and Behavioral Risk Factor Surveillance System for the state collectively indicate marked opportunity for improvement in immunization rates for the State of Louisiana. Health care providers can assist and play an integral role in interventions designed to impact on this vulnerable population in order to meet the Department of Health and Human Services Year 1996 overall goal of 56% influenza immunization rate for all persons age 65 years or older.

Aged↗
PubMed1995

The effects of alloplastic implant onlays on bone in the rabbit mandible.

The relative importance of the factors that contribute to the bone erosion seen underlying alloplastic implants remains unknown. This study was designed to examine the effects of different alloplastic onlays on the mandible in a rabbit animal model. Three alloplastic materials (soft solid silicone, methyl methacrylate, and porous polyethylene) were examined to determine the importance of implant composition in bone resorption. Thin (1.5-mm) and thick (6-mm) onlays were used to determine the relative importance of implant thickness. Fluorescent markers were administered at different time intervals to evaluate the patterns of new bone formation. A total of 96 implants placed on the mandibles of 16 animals were examined grossly, histologically, and under fluorescent microscopy after 12 and 24 weeks. The frequency and degree of bone erosion were related both to the type of alloplast and to the thickness of the implant. Silicone implants were associated with the greatest amount of bone resorption (p < 0.01). Thicker silicone implants were associated with a greater degree of thinning (p < 0.05). Bone resorption beneath the implants was documented by the presence of osteoclasts actively eroding bone and by changes in the normal patterns of the fluorescent markers. Both the thin methyl methacrylate and the thin porous polyethylene implants had a low incidence of bone thinning. The thick methyl methacrylate implants caused more erosion than the thin implants of the same material, although this was less than the silicone groups. Increasing the thickness of porous polyethylene implants did not adversely affect the underlying bone.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1995

Hormone replacement therapy: characteristics of users and non-users in a British general practice cohort identified through computerised prescribing records.

STUDY OBJECTIVE: To assess the feasibility of recruiting a cohort of women, including long term users of postmenopausal hormone replacement therapy (HRT), through computerised general practice prescribing records, and to compare clinical and demographic characteristics of users and non-user controls. DESIGN: Cross sectional analysis of questionnaire data. SETTING: Subjects were recruited through 17 general practices in the Oxfordshire, south west Thames, and north west Thames regions that contributed to the VAMP Research Database. PARTICIPANTS: A total of 2964 women aged 45-64 years were identified. Altogether 1482 were long term (> 1 year) users of HRT and 1482 were non-user controls: 1037 (70%) of the users and 819 (55.3%) of the controls agreed to participate and provided questionnaire data. MAIN RESULTS: Users of HRT were more likely to have undergone hysterectomy than controls. Most women with a history of hysterectomy used unopposed oestrogen, while those with intact uteri generally used a combination of oestrogen and a progestagen. Among women who had undergone hysterectomy, HRT users did not differ significantly from controls over a range of demographic and clinical characteristics but they were more likely to be past users of oral contraceptives. Among women with intact uteri, users were similar to controls in terms of reported clinical characteristics, but were of higher social class and were more likely to be past users of oral contraceptives and to have had a mammogram after the age of 50. Compared with the general population, all categories of women recruited to the study were of higher social class and exhibited more health conscious behaviours. CONCLUSIONS: Electronic general practice prescribing records provide a feasible and efficient method for recruiting women to a cohort of HRT. Women who agreed to participate in this study were not representative of the general population, emphasising the importance of internal controls in such a study. Among participants, HRT users who had not undergone hysterectomy showed evidence of better health than non-users on some dimensions. In the whole sample, however, there were no appreciable differences in social class and self reported health indicators between users and controls.

Cohort Studies↗
PubMed1995

Continuing risk for hepatitis B virus transmission among Southeast Asian infants in Louisiana.

OBJECTIVE: Implementation and evaluation of a hepatitis B vaccination program for Southeast Asian infants in Louisiana. METHODS: A baseline seroprevalence survey of hepatitis B virus (HBV) infection in US-born Southeast Asian children was conducted in 1991 before the implementation of a vaccination program. Hepatitis B vaccination and postvaccination serologic testing of survey participants 10 years of age and younger was performed. Eighteen months after the hepatitis B vaccine was integrated into infant immunization schedules in July 1993, a vaccination coverage survey was performed. RESULTS: Baseline serologic testing was conducted on 96% of persons from 225 randomly selected households in a Southeast Asian community in Louisiana. Of 676 US-born children, 28 (4.1%) had chronic HBV infection; 61% of children with chronic HBV infection were born to hepatitis B surface antigen (HBsAg)-negative women. Among children born to HBsAg-negative women, the prevalence of chronic HBV infection increased with age, reaching 7.3% for children 13 to 16 years of age. Children born to HBsAg-negative women and living with carriers were 5.4 times more likely to have evidence of HBV infection than were children who did not live with carriers. Before the survey, only one child had received three doses of hepatitis B vaccine. In July 1993, 43% of Southeast Asian infants 9 to 18 months of age born in Louisiana had received three doses of hepatitis B vaccine. Infants who received immunizations from private providers were more likely to be fully vaccinated than were infants who received services from public sector clinics (prevalence ratio, 2.1; 95% confidence interval, 1.4, 3.1). CONCLUSIONS: HBV transmission occurs throughout childhood in US-born Southeast Asian children, and the prevalence of chronic HBV infection approaches that of the country of origin. Few US-born Southeast Asian children have received hepatitis B vaccine. Because of the high rates of early childhood HBV transmission and the high risk of chronic infection in Asian and Pacific Islander communities, prevention efforts should be enhanced to ensure that all Asian and Pacific Islander infants receive hepatitis B vaccine in the first 12 months of life and that older children are vaccinated.

Adolescent↗
PubMed1995

The unconscious experience.

BACKGROUND: Although considerable research has been done on pathophysiology, metabolic and physical causes, and prognostic indicators, little is known about unconsciousness or coma from the perspective of the patient. OBJECTIVE: To describe the experiences of patients who were once documented as being unconscious. METHODS: Phenomenologic interviews were conducted with 100 patients whose records indicated that they had been unconscious during hospitalization. Interviews were also attempted with primary family members, significant others, or other external observers. Chart audits documenting the unconscious episode, medications, and diagnoses were also carried out. Data were compared, using van Kaam's method, and contrasted. RESULTS: Patients experienced one or more of five states: unconsciousness, inner consciousness, perceived unconsciousness, distorted consciousness, and paranormal experiences. They described hearing, understanding, and responding emotionally to what was being said when it was assumed they were not aware. In addition, 23 subjects reported near-death experiences or visits, out-of-body experiences, or some other paranormal experience. CONCLUSION: Patients' unconscious experiences can cause long-term effects. Patients often need reassurance that other patients subjected to similar conditions also have these experiences.

Auditory Perception↗
PubMed1994

Percutaneous nephrolithotomy in the elderly.

OBJECTIVES: To evaluate the success and morbidity of percutaneous nephrolithotomy (PNL) performed in patients aged 65 years and older. METHODS: A retrospective review of 42 PNLs performed on 33 patients aged 65 years and older was compared with a cohort of 160 PNLs performed on younger patients over the same time period. RESULTS: The presence of complete staghorn calculi (17 of 36 renal units [47%] versus 88 of 160 renal units [55%], p = 0.46) and average stone size (3.8 cm versus 4.3 cm, p = 0.2) were similar for the 2 groups. Eighty-two percent of patients (27 of 33) were stone-free or left with fragments < 5 mm at 3 months after surgery. Elderly patients had a higher transfusion rate after PNL despite similar preoperative hemoglobin levels (11 of 42 PNLs [26%] versus 22 of 160 PNLs [14%], p < 0.01). Serious complications were infrequent and there were no deaths. CONCLUSIONS: Percutaneous nephrolithotomy is a safe and effective therapy for elderly patients with complex stone disease; however, awareness of an apparent increased requirement for blood transfusion is warranted.

Age Factors↗
PubMed1994

Complications of laparoscopic hysterectomy.

Although laparoscopic hysterectomy is now being performed worldwide, few reported data are available on the associated morbidity and mortality. Between December 1990 and September 1993, 220 women underwent laparoscopic hysterectomy at the Melbourne Gynoscopy Centre. Complications occurred in 35 (15.9%). Among these were anterior abdominal wall vessel injury in 5 patients, bladder injury in 5, febrile illness in 13, secondary hemorrhage in 4, temporary ureteral obstruction in 4, and Richter hernia in 1.

Abdominal Muscles↗