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Biomedical subjects

R Bennett

Publications and source records attributed to R Bennett.

At least 19 recordsLinked to original sources

Evaluation of the live attenuated cpts 248/404 RSV vaccine in combination with a subunit RSV vaccine (PFP-2) in healthy young and older adults.

The safety and immunogenicity of the live attenuated cold-passaged, temperature-sensitive (cpts) 248/404 respiratory syncytial virus (RSV) A2 and the RSV A2 purified F glycoprotein (PFP-2) vaccine candidates were evaluated in a placebo-controlled trial in 60 healthy young adults and 60 healthy elderly subjects using simultaneous and sequential (cpts 248/404 followed by PFP-2) vaccination schedules. Both vaccines were well tolerated. The cpts 248/404 vaccine was moderately infectious in both young and old volunteers, but was highly restricted in replication in those who were infected. After both vaccines, RSV neutralizing antibody (neut Ab) titers increased fourfold in 22% of young subjects and in 16% of elderly subjects. Of those with low levels of RSV neut Ab (titer <9), 10/12 (83% of) young subjects and six/eight (75% of) elderly subjects had a >/=four fold rise in neut Ab titer. Young and elderly subjects immunized simultaneously had similar serum IgG and IgA postimmunization titers to RSV F (IgG, 16.4 vs 16.2, IgA 11.6 vs 12. 5, respectively) as did those who were immunized sequentially (IgG 17.4 vs 17.0, IgA 13.0 vs 13.5). In both age groups, sequential immunization elicited higher postimmunization RSV F IgG and IgA titers than simultaneous immunization. Further studies that combine the PFP-2 subunit vaccine with a less attenuated RSV vaccine should be performed.

Adolescent↗

Raman spectroscopic method for identification of clinically relevant microorganisms growing on solid culture medium.

Routine clinical microbiological identification of pathogenic microorganisms is largely based on nutritional and biochemical tests. In the case of severely ill patients, the unavoidable time delay associated with such identification procedures can be fatal. We present a novel identification method based on confocal Raman microspectroscopy. With this approach it is possible to obtain Raman spectra directly from microbial microcolonies on the solid culture medium, which have developed after only 6 h of culturing for the most commonly encountered organisms. Due to the limited thickness of microcolonies, some of the underlying culture medium is sampled together with the bacteria. Spectra measured at different depths in a microcolony contain different amounts of the medium signal. A mathematical routine, involving vector algebra, is described for the nonsubjective correction of spectra for variable signal contributions of the medium. To illustrate the possibilities of our approach for the identification of microorganisms, Raman spectra were collected from 6-h microcolonies of five bacterial strains on solid culture medium. The classification results show that confocal Raman microspectroscopy has great potential as a powerful new tool in clinical diagnostic microbiology.

Bacteriological Techniques↗

A history of dermatologic surgery in the United States.

BACKGROUND: Dermatologic surgery has a long and distinguished history in the United States. OBJECTIVE: To examine the specific contributions of American dermatologic surgeons. METHOD: The medical literature on cutaneous reconstructive and cosmetic surgery for the last century and a half was researched. RESULTS: Numerous American dermatologic surgeons have had a major impact on scientific and technological discoveries in cutaneous surgery. Dermatologic surgeons have been significantly involved in cutaneous surgery since the second half of the 19th century. Dermatologic surgeons have contributed many important advances to the fields of chemical peeling, cryosurgery, dermabrasion, electrosurgery, hair transplantation, soft tissue augmentation, tumescent liposuction, laser surgery, phlebology, Mohs chemosurgery, cutaneous reconstruction, wound healing, botulium toxin, blepharoplasty, and rhytidectomy. CONCLUSION: Dermatologic surgeons in the United States have contributed significantly to the history of reconstructive and cosmetic surgery. Dermatologic surgeons have been leaders in advancing this field and are poised to continue in the future.

Dermatology↗

Ignorance is bliss? HIV and moral duties and legal duties to forewarn.

In 1997, a court in Cyprus jailed Pavlos Georgiou for fifteen months for knowingly infecting a British woman, Janet Pink, with HIV-1 through unprotected sexual intercourse. Pink met Georgiou in January 1994 whilst on holiday. She discovered that she had contracted the virus from him in October 1994 but continued the relationship until July 1996 when she developed AIDS. She returned to the UK for treatment and reported Georgiou to the Cypriot authorities. There have been a number of legal cases involving deliberate transmission of HIV, but most have involved forced exposure to infected bodily fluids for example, rape or biting, and have been dealt with using the existing legislation for rape or assault. While it is often difficult to prove responsibility for transmission in cases of forced exposure to HIV, it is even more contentious in cases like those of Janet Pink where an individual has consented to sex but claims that he/she was not forewarned of his/her partner's HIV-positive status. At present there is no specific criminal offence of having unprotected sexual intercourse without disclosing one's HIV-positive status but a prosecution could possibly be brought under any one of a number of existing offences. Perhaps a change of policy needs to be considered. The Home Office has issued a consultation document which outlines a proposal that will allow the criminalization of intentional transmission of diseases, like HIV, that are likely to cause serious harm. This revised legislation would cover all other potentially fatal diseases (including salmonella and legionnaire's disease, for instance) but seems primarily to be targeted at HIV transmission. Should transmission of HIV through consensual sex, without the HIV-positive status of the individual being disclosed, be an offence? This question, and that of whether there is a moral obligation to disclose a positive HIV status prior to having a sexual relationship is the subject of this paper.

Crime↗

Preliminary estimates of the direct costs associated with endemic diseases of livestock in Great Britain.

Many 'economic' studies of livestock diseases in Great Britain have been carried out over time. Most studies have considered just one or two diseases and used a different methodology and valuation base from other studies, hampering any comparative assessment of the economic impact of diseases. A standardized methodology was applied to the estimation of the direct costs to livestock production of some 30 endemic diseases/conditions of farm animals in Great Britain. This involved identification of the livestock populations at risk, estimation of the annual incidence of each disease in these populations, identification of the range and incidence of physical effects of each disease on production, valuation of the physical effects of each disease and estimation of the financial value of output losses/resource wastage due to a disease and the costs of specific treatment and prevention measures. The wider economic impacts of disease (such as the implications for human health, animal welfare and markets) were not included in the assessments. Using this standardized methodology with common financial values, a simple spreadsheet model was constructed for each disease. Given the paucity of appropriate disease data for economic assessment, 'low' and 'high' values were used to reflect uncertainties surrounding key disease parameters. Preliminary estimates of the value of disease output losses/resource wastage, treatment and prevention costs are presented for each disease. Despite the limitations of the spreadsheet models and of the estimates derived from them, we conclude that the models represent a useful start in developing a system for the comparative economic assessment of livestock diseases in Great Britain.

Animals↗

Indole glucosinolate and auxin biosynthesis in Arabidopsis thaliana (L.) Heynh. glucosinolate mutants and the development of clubroot disease.

Mutants and wild type plants of Arabidopsis thaliana were analysed for differences in glucosinolate accumulation patterns, indole-3-acetic acid (IAA) biosynthesis and phenotype. A previously identified series of mutants, termed TU, with altered glucosinolate patterns was used in this study. Only the line TU8 was affected in shoot phenotype (shorter stems, altered branching pattern). Synthesis of IAA and metabolism were not much affected in the TU8 mutant during seedling development, although the content of free IAA peaked earlier in TU8 during plant development than in the wild type. Indole glucosinolates and IAA may, however, be involved in the development of clubroot disease caused by the obligate biotrophic fungus Plasmodiophora brassicae since the TU3 line had a lower infection rate than the wild type, and lines TU3 and TU8 showed decreased symptom development. The decline in clubroot formation was accompanied by a reduced number of fungal structures within the root cortex and slower development of the fungus. Indole glucosinolates were lower in infected roots of TU3 and TU8 than in control roots of these lines, whereas in wild-type plants the differences were not as prominent. Free IAA and indole-3-acetonitrile (IAN) were increased in infected roots of the wild type and mutants with normal clubroot symptoms, whereas they were reduced in infected roots of mutants TU3 and TU8. These results indicate a role for indole glucosinolates and IAN/IAA in relation to symptom development in clubroot disease.

Arabidopsis↗

A fluorescence energy transfer method for analyzing protein oligomeric structure: application to phospholamban.

We have developed a method using fluorescence energy transfer (FET) to analyze protein oligomeric structure. Two populations of a protein are labeled with fluorescent donor and acceptor, respectively, then mixed at a defined donor/acceptor ratio. A theoretical simulation, assuming random mixing and association among protein subunits in a ring-shaped homo-oligomer, was used to determine the dependence of FET on the number of subunits, the distance between labeled sites on different subunits, and the fraction of subunits remaining monomeric. By measuring FET as a function of the donor/acceptor ratio, the above parameters of the oligomeric structure can be resolved over a substantial range of their values. We used this approach to investigate the oligomeric structure of phospholamban (PLB), a 52-amino acid protein in cardiac sarcoplasmic reticulum (SR). Phosphorylation of PLB regulates the SR Ca-ATPase. Because PLB exists primarily as a homopentamer on sodium dodecyl sulfate polyacrylamide gel electrophoresis, it has been proposed that the pentameric structure of PLB is important for its regulatory function. However, this hypothesis must be tested by determining directly the oligomeric structure of PLB in the lipid membrane. To accomplish this goal, PLB was labeled at Lys-3 in the cytoplasmic domain, with two different amine-reactive donor/acceptor pairs, which gave very similar FET results. In detergent solutions, FET was not observed unless the sample was first boiled to facilitate subunit mixing. In lipid bilayers, FET was observed at 25 degrees C without boiling, indicating a dynamic equilibrium among PLB subunits in the membrane. Analysis of the FET data indicated that the dye-labeled PLB is predominantly in oligomers having at least 8 subunits, that 7-23% of the PLB subunits are monomeric, and that the distance between dyes on adjacent PLB subunits is about 10 A. A point mutation of PLB (L37A) that runs as monomer on SDS-PAGE showed no energy transfer, confirming its monomeric state in the membrane. We conclude that FET is a powerful approach for analyzing the oligomeric structure of PLB, and this method is applicable to other oligomeric proteins.

Animals↗

Effects of female relative support in labor: a randomized controlled trial.

BACKGROUND: This study was a randomized controlled trial of primigravidas in Botswana to determine the effectiveness of the presence of a female relative as a labor companion on labor outcomes. METHODS: One hundred and nine primigravidas in uncomplicated spontaneous labor were randomly distributed into a control group who labored without family members present, and an experimental group who had a female relative with them during labor. RESULTS: Significantly more mothers in the experimental group had a spontaneous vaginal delivery (91% vs 71%), less intrapartum analgesia (53% vs 73%), less oxytocin (13% vs 30%), fewer amniotomies to augment labor (30% vs 54%), fewer vacuum extractions (4% vs 16%), and fewer cesarean sections (6% vs 13%) than in the control group. These differences were all significant at p < 0.05. Epidural analgesia was not used in the hospital at the time of the study. The only analgesics used were intramuscular pethidine or hyoscine N-butylbromide (Buscopan). CONCLUSIONS: The presence in labor of a female relative was shown to be associated with fewer interventions and a higher frequency of normal delivery compared with the outcomes of those without family member support. The presence of a female relative as a labor companion is a low-cost, preventative intervention that is consistent with the traditional cultural practices in Botswana. In the light of this and previous studies, all women giving birth in a hospital should be offered the choice of a female relative as a companion to give support during labor.

Adult↗

Fibromyalgia, chronic fatigue syndrome, and myofascial pain.

Epidemiologic studies continue to provide evidence that fibromyalgia is part of a spectrum of chronic widespread pain. The prevalence of chronic widespread pain is several times higher than fibromyalgia as defined by the 1990 American College of Rheumatology guidelines. There is now compelling evidence of a familial clustering of fibromyalgia cases in female sufferers; whether this clustering results from nature or nature remains to be elucidated. A wide spectrum of fibromyalgia-associated symptomatology and syndromes continues to be described. During the past year the association with interstitial cystitis has been explored, and neurally mediated hypotension has been documented in both fibromyalgia and chronic fatigue syndrome. Abnormalities of the growth hormone-insulin-like growth factor-1 axis have been also documented in both fibromyalgia and chronic fatigue syndrome. The commonly reported but anecdotal association of fibromyalgia with whiplash-type neck trauma was validated in a report from Israel. However, unlike North America, 100% of Israeli patients with posttraumatic fibromyalgia returned to work. Basic research in fibromyalgia continues to pinpoint abnormal sensory processing as being integral to understanding fibromyalgia pain. Drugs such as ketamine, which block N-methyl-D-aspartate receptors (which are often upregulated in central pain states) were shown to benefit fibromyalgia pain in an experimental setting. The combination of fluoxetine and amitriptyline was reported to be more beneficial than either drug alone in patients with fibromyalgia. A high prevalence of autoantibodies to cytoskeletal and nuclear envelope proteins was found in chronic fatigue syndrome, and an increased prevalence of antipolymer antibodies was found in symptomatic silicone breast implant recipients who often have fibromyalgia.

Persons with Disabilities↗

A randomized trial comparing peak expiratory flow and symptom self-management plans for patients with asthma attending a primary care clinic.

Great emphasis is placed on educating asthmatics to use action plans to achieve better control of symptoms. The use of peak flow meters (PFM) has been recommended as an important part of self-management plans. We studied 92 (47 F) adult patients with asthma in a primary care setting to compare the effectiveness of action plans using either peak flow monitoring or symptoms to guide self-management. Each patient was instructed in the use of the action plan in the context of a 6-mo asthma education program taught by a nurse. Patients were already using inhaled corticosteroids or were newly prescribed corticosteroids by their family physician. Forty-four patients were randomized to the PFM group and 48 to the symptoms group. Spirometry, symptom scores, quality of life, medication use, and measures of health care utilization and morbidity (emergency department visits, hospitalizations, unscheduled doctor visits, and days lost from work or school) were recorded at baseline and throughout the study period. PC20 methacholine was measured at the first and at the final visits. There were significant improvements within groups for FEV1, symptoms score, PC20 methacholine, and quality of life, but no between-group differences. A significant shift from higher to lower daily use of beta-agonists (p < 0.008 for both groups) and significant shifts to higher daily doses of inhaled steroids (p < 0.001) occurred in each group. Adherence to the self-management plans was only 65% in the PFM group and 52% in the symptoms group. Outcomes for health care utilization were similar except for fewer patients making unscheduled doctor visits within the PFM group. Our findings show that education, regular follow-up, and an action plan are effective in improving asthma control and quality of life, but the routine use of PFM to guide interventions is not the only way to accomplish these objectives.

Adult↗

Demonstrating minimal invasive therapy over the Internet.

Use of the Internet for multimedia conferencing began in the early 1990s. Multimedia conferencing allows people at multiple, distributed locations to communicate using audio, video and shared workspace programs; the Multicast Backbone of the Internet (MBONE) provides the technical solution to make the most efficient use of the limited Internet bandwidth for such interactions. The scope for using this technology in medical applications was recognised by the MICE project which, in November 1994, used Sun SPARC workstations connected to the MBONE to send video and commentary of live operations from Sweden and San Francisco to a workshop held in London. These sessions were marred by severe congestion experienced on the networks on the day, but the consensus of those organising and attending the workshop was that the exercise was worthwhile. The main lessons learnt from this first transmission were the need to provide better quality links and to ensure confidentiality. In December 1995, the MERCI project, funded by the European Union under the TELEMATICS for Research programme, began work to refine and further propagate the use of the multimedia conferencing software. Part of this work is to provide these improved facilities to transmit operations to two more workshops scheduled for 1997. MERCI will offer confidentiality through encryption facilities built into the conferencing programs, improved programs which cope better with adverse network conditions, use of the new high-speed JAMES network and access to a multimedia server from which recordings of operations and medical instrumentation can be delivered to the workshop participants.

Computer Communication Networks↗

U.S. hospital care for HIV-infected persons and the role of public, private, and Veterans Administration hospitals.

Hospitals are a major provider of medical care for human immunodeficiency virus (HIV)-infected persons. Although utilization and patterns of care profiles in public and private hospitals have been evaluated for acquired immunodeficiency syndrome (AIDS)-related Pneumocystis carinii pneumonia (PCP), one of the most costly and common severe complications of AIDS, information from Veterans Administration (VA) hospitals has not been reported previously. This article reports on inpatient care for PCP patients by obtaining data from VA, private, and public hospitals. Cost and resource utilization data were obtained from reviews of medical records, claims, and provider bills from 26 non-VA hospitals and 18 VA hospitals in 10 cities in the United States. Data on severity of illness, patterns of care, and outcomes for PCP were obtained from medical record reviews from 2,174 PCP cases treated in 82 non-VA and 14 VA hospitals in five U.S. cities. Estimates were made of the average costs and the rates of use of diagnostic tests, anti-PCP medications, and intensive care units for samples of public hospital, private hospital, and VA patients with PCP. With mean charges for a single PCP episode of $14,500 to $16,060, PCP remains one of thea most costly complications of AIDS. Although the severity of PCP illness at admission was greatest at public hospitals, the intensity of care was lowest: for frequency of cytologic diagnosis (48% at public, 62% at VA, and 66% at private hospitals), bronchoscopy (45% at public, 60% at VA, and 66% at private hospitals), and intensive care unit use (11% at public, 22% at VA, and 19% at private hospitals). In-hospital mortality rates for PCP also differed in the three types of hospitals (20% at public, 24% at VA, and 18% at private hospitals). Patterns of PCP care differ among VA, public, and private hospitals. Future studies on the HIV epidemic should include data collected from uniform data sources from VA hospitals, in addition to public and private hospitals, to provide insight on the processes of care and outcomes for HIV-infected persons.

AIDS-Related Opportunistic Infections↗

Dental health of aboriginal pre-school children in Brisbane, Australia.

This investigation studied the dental health status of a group of 184 Australian Aboriginal children with a mean age of 4.4 +/- 0.8 years, who were attending pre-schools in metropolitan Brisbane, a non-fluoridated state capital city. The DDE (Developmental Defects of Enamel) Index was used to chart enamel hypoplasia and enamel opacities. WHO criteria was used to diagnose dental caries. The results showed that 98% of children had at least one tooth showing developmental enamel defects. Each child had a mean of 3.8 +/- 1.7 teeth affected by enamel hypoplasia and another 1.1 +/- 0.8 teeth affected by enamel opacity. Seventy-eight percent of the children had dental caries. The mean number of decayed, missing, filled teeth (dmft) per child was 3.8 +/- 3.7. The decayed component constituted 3.5 (95%) of the mean dmft, indicating a high unmet restorative need in this group. The mean dmfs (decayed, missing, filled, surfaces) was 5.9 +/- 7.3. Maxillary anterior labial decay of at least one tooth affected 43 (23%) of the children. In this sub-group, the dmft and dmfs was 9.1 +/- 2.8 and 15.4 +/- 7.7 respectively. Oral debris was found in 98% of the children. It is hypothesized that the high levels of underlying developmental enamel defects, compounded by low fluoride exposure, poor oral hygiene and a diet high in refined sugars pose an important caries risk factor in this group of children.

Child, Preschool↗

Maternal risks for very low birth weight infant mortality.

OBJECTIVE: To determine whether known maternal risk factors for low birth weight directly contribute to infant mortality among very low birth weight infants. DESIGN: Retrospective population-based, case-control study. SETTING: Four hospitals in the Oakland, California, area: one community, two private, one health maintenance organization. PARTICIPANTS: All live-born singleton very low birth weight ( < 1500 g) infants born to Oakland residents over a 3-year period. Cases were infants who died before their first birthday, identified by computerized linkage of birth and death certificates. For each case, a surviving control was selected to match for birth weight, sex, and race. Forty matched pairs were identified in total. OUTCOME MEASURES: Prevalence of maternal risk factors among cases versus controls. RESULTS: After controlling for other factors known to influence either birth weight or infant mortality, maternal cocaine use (odds ratio [OR] = 5.43), prior infant death (OR = 27.14), and planned pregnancy (OR = 6.33) were significantly associated with the survival of very low birth weight infants. CONCLUSIONS: Some maternal risk factors for low birth weight confer a survival advantage to very low birth weight infants. Our data reveal that maternal cocaine use is independently associated with survival among this subset of infants. Prior research supports the observed relationship as well as the scientific plausibility of a cocaine-mediated survival advantage among premature infants. Our study also showed both planned pregnancy and prior infant death to be independently associated with infant survival among this subset of infants, suggesting that maternal behaviors may play a role in determining birth weight-specific mortality. These data should be systematically evaluated to better define their relationship to infant mortality.

Adolescent↗

The association of systemic lupus erythematosus and Lambert-Eaton myasthenic syndrome.

The association of systemic lupus erythematosus (SLE) and myasthenia gravis is well known. However, the association between SLE and Lambert-Eaton myasthenic syndrome (LEMS) is described in only 2 cases. We describe the case of a 31-year-old woman with SLE who presented with severe, predominantly proximal muscle weakness of subacute onset. The diagnosis of LEMS was based on her distinctive clinical and electrophysiological findings. She was treated successfully with plasmapheresis and oral prednisone. She remains in remission 6 months after this episode.

Action Potentials↗