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Biomedical subjects

M Lewis

Publications and source records attributed to M Lewis.

At least 73 records · Page 4Linked to original sources
PubMed2001

Subjective responses to caregiving for a spouse with dementia.

Family members, typically spouses, serve as the primary caregivers for individuals with dementia. While it is recognized that caregivers experience both positive and negative subjective responses to caregiving, relatively little research has been done on the relationship between these types of responses. The objectives of the study were to examine the relationships between and among spouse caregivers' positive and negative subjective responses to caregiving, and increase understanding of the experience of being a spouse caregiver for a person with dementia. Fifty spouse caregivers completed quantitative measures of positive subjective responses (Positive Aspects of Caregiving and Caregiver Competence) and negative subjective responses (Relational Deprivation, Role Captivity, and Loss of Self). Additionally, participants were interviewed concerning their caregiving experiences. Positive Aspects of Caregiving and Caregiving Competence were significantly related to each other (p < .01), as were the three measures of negative subjective responses (p < .01). No significant correlations were found between any measures of a positive and a negative subjective response, suggesting the two types of responses are independent. Duration of caregiving was significantly related to Positive Aspects of Caregiving (p < .05), Caregiver Competence (p < .05), and Relational Deprivation (p < .01). Qualitative interview data revealed that participants simultaneously experienced caregiving as self-affirming, while also enduring losses and difficulties resulting from their caregiving role. Integrating the positive and negative aspects of the whole of caregiving is important to understand the caregiving experience and to design interventions to support caregivers.

Aged↗
PubMed2001

Service use and costs of treating schizophrenia with atypical antipsychotics.

BACKGROUND: The high acquisition cost of the atypical antipsychotics has prompted their closer clinical and economic evaluation. This study aims to examine the financial implications of using atypical antipsychotics in a defined catchment area sample of patients with schizophrenia. METHOD: Service costs over a 10-month period were compared between groups of patients fulfilling DSM-IV criteria for schizophrenia who were taking different atypical antipsychotic agents. RESULTS: All patients studied were taking clozapine (N = 31). risperidone (N = 19), or olanzapine (N = 41). Clozapine was used in more chronic patients, while risperidone and olanzapine were prescribed in both chronic and recently diagnosed cases. After background group differences were controlled for, patients on risperidone treatment incurred the lowest costs. The monthly costs for the clozapine and olanzapine groups were higher than for risperidone by US $246 and US $566, respectively. CONCLUSION: Clozapine was reserved for more severe forms of schizophrenia, but its cost impact was relatively low. Risperidone, as prescribed in ordinary practice, may be more cost-effective than olanzapine.

Adult↗
PubMed2001

Infant temperament and the brainstem auditory evoked response in later childhood.

Brainstem auditory evoked responses (BAERs) were evaluated on 10-12-year-old children (N = 56) who had been classified as high or low reactive to unfamiliar stimuli at 4 months of age. BAER measurement was selected because high reactive infants tend to become inhibited or fearful young children, and adult introverts have a faster latency to wave V of the BAER than do extroverts. Children previously classified as high reactive at 4 months had larger wave V components than did low reactive children, a finding that possibly suggests greater excitability in projections to the inferior colliculus. The fact that a fundamental feature of brainstem activity differentiated preadolescent children belonging to two early temperamental groups supports the value of gathering physiological data in temperament research.

Age Factors↗
PubMed2001

Factors affecting over-the-counter use of aspirin in the secondary prophylaxis of cardiovascular disease.

Little is known about the contribution of over-the-counter (OTC) aspirin to cardiovascular prophylaxis. To investigate this, a two-phase cross-sectional study was carried out in nine general practices in North Staffordshire. In the first phase, all patients with cardiovascular disease (CVD) were identified from computer searches using morbidity registers and drug searches. The search also identfied the subgroup receiving prescribed prophylactic aspirin. In the second phase, a questionnaire was posted to all patients with CVD who were not on prescribed aspirin to establish their current use of OTC aspirin. Overall, 69% of the CVD group used aspirin, with 26% of aspirin being OTC. OTC aspirin use was more common in those aged under 65 years, men, and the more affluent. Also, there were significant differences in OTC aspirin use between the various practices. This study shows that a considerable amount of aspirin is used OTC in those with CVD. Its use is influenced by several factors that could be addressed when considering attempts to improve the overall uptake of aspirin.

Age Factors↗
PubMed2001

Six adoptees who murdered: neuropsychiatric vulnerabilities and characteristics of biological and adoptive parents.

This article is the first to document the perinatal trauma and neuropsychiatric impairment of a sequential sample of male adoptees who committed murder. It also is the first to report objectively verifiable psychopathology and violence in their biological and adoptive parents. It explores the interaction of these variables in the genesis of violence. Subjects were six adopted murderers on whom data regarding biological and adoptive parents could be obtained. In all six cases, central nervous system (CNS) development was compromised in utero or perinatally. In adolescence and/or young adulthood, three met DSM-IV criteria for Bipolar Mood Disorder, one for Schizophrenia, and two for Schizoaffective Disorder. All subjects had at least one psychotic biological parent. In five cases, subjects were adopted into psychotic or violent households. There was no evidence of a specific "bad seed" for violence. Adoptees' intrinsic vulnerabilities to psychoses and to the impulsiveness and emotional lability often associated with early brain trauma, coupled with maltreatment, predisposed them to homicidal violence. As such, these subjects were similar to other extraordinarily violent, nonadopted, offenders. Conscious feelings regarding adoption did not contribute to the subjects' homicidal rages, so much as did conscious rage toward abusive, rejecting adoptive families.

Adolescent↗
PubMed2000

Crystal structure of the lambda repressor C-terminal domain provides a model for cooperative operator binding.

Interactions between transcription factors bound to separate operator sites commonly play an important role in gene regulation by mediating cooperative binding to the DNA. However, few detailed structural models for understanding the molecular basis of such cooperativity are available. The c1 repressor of bacteriophage lambda is a classic example of a protein that binds to its operator sites cooperatively. The C-terminal domain of the repressor mediates dimerization as well as a dimer-dimer interaction that results in the cooperative binding of two repressor dimers to adjacent operator sites. Here, we present the x-ray crystal structure of the lambda repressor C-terminal domain determined by multiwavelength anomalous diffraction. Remarkably, the interactions that mediate cooperativity are captured in the crystal, where two dimers associate about a 2-fold axis of symmetry. Based on the structure and previous genetic and biochemical data, we present a model for the cooperative binding of two lambda repressor dimers at adjacent operator sites.

Amino Acid Sequence↗
PubMed2000

Lingual tonsillectomy for refractory paroxysmal cough.

Historically, the lingual tonsils are the most neglected members of Waldeyer's ring. They are often overlooked even in a thorough head and neck exam because of their anatomic location and the ambiguous constellation of symptoms which they produce when they are diseased or enlarged. The lingual tonsils have been reported to be associated with a variety of upper aerodigestive tract symptoms including odynophagia, dysphagia, otalgia, globus, halitosis, chronic cough, and dyspnea. Many patients with lingual tonsillar pathology may undergo extensive work-up for some of these non-specific upper airway complaints by their primary physician before referral to an otolaryngologist. Consequently, the diagnosis of lingual tonsillar disease requires a high index of suspicion and a thorough physical exam including evaluation of the tongue base and hypophaynx with indirect mirror or fiberoptic exam. In order to draw attention to this frequently unrecognized entity, we present a case report of a child with chronic cough resulting from lingual tonsillar hypertrophy.

Airway Obstruction↗
PubMed2000

Passive infusion of immune serum into simian immunodeficiency virus-infected rhesus macaques undergoing a rapid disease course has minimal effect on plasma viremia.

Antibody responses are often considered to play only a limited role in controlling viremia during chronic infections with human or simian immunodeficiency virus (SIV). We investigated this by determining the effect of passively infused antibody on plasma viremia in infected rhesus macaques. The emphasis of the study was to understand the mechanism(s) underlying any observed effects. We infused serum immunoglobulins (SIVIG) purified from SIV(mac)251-infected macaques into other SIV(mac)251-infected macaques. The rapid progressor recipients had high viral loads but negligible titers of antibodies to SIV. Thus, we could significantly increase antibody titers with exogenous SIVIG. Despite restoring anti-SIV titers to levels typical of macaques with a normal disease course, SIVIG had only a modest effect on plasma SIV RNA and cell-associated viral load; the maximum, transient, reduction was threefold. The decrease in plasma RNA commenced within 1-2 h of SIVIG infusion, the nadir was at 12 h, and then a rebound occurred. A two- to threefold drop in cell-associated viral RNA was simultaneous with the decrease in plasma RNA. The kinetics of the viremia changes are inconsistent with neutralization of new cycles of infection. More likely, perhaps unexpectedly, is that infused antibodies killed SIV-infected cells, via an effector mechanism such as antibody-dependent cellular cytotoxicity.

Animals↗
PubMed2000

Carpal tunnel syndrome: a nested case-control study of risk factors in women.

Risk factors for the development of carpal tunnel syndrome in women were studied by means of a nested case-control analysis of a prospective cohort study of the health effects of oral contraception in British women. A total of 1,264 women who had a diagnosis of carpal tunnel syndrome reported by their general practitioner between 1968 and 1993 were compared with 1,264 age-matched control women who did not have this diagnosis. The syndrome was associated in older women with some hormonal factors, notably past use of oral contraception (adjusted odds ratio in women aged 40 years and over = 1.38, 95 percent confidence interval: 1.08, 1.76) and more generally with obesity (adjusted odds ratio = 1.68, 95 percent confidence interval: 1.29, 2.18). However, the strongest link was with a previous history of another musculoskeletal complaint for which consultation had been sought (adjusted odds ratio = 1.98, 95 percent confidence interval: 1.61, 2.42). Previous findings of a higher risk in women with diabetes and myxoedema were confirmed, but these contribute only a small proportion of all cases in women. There was no link with psychologic problems or nonmusculoskeletal pain complaints. The previously described increased incidence of carpal tunnel syndrome in women may be partly due to hormonal factors, but is also related to an underlying propensity to musculoskeletal problems and their higher overall frequency in women.

Adult↗
PubMed2000

Gemcitabine and vinorelbine in advanced nonsmall cell lung carcinoma: a phase II study.

BACKGROUND: The authors conducted a Phase II study to evaluate the activity of the combination of gemcitabine and vinorelbine in patients with advanced nonsmall cell lung carcinoma (NSCLC). METHODS: Patients were eligible if they had Stage IIIB (malignant pleural effusion) or Stage IV NSCLC, no prior chemotherapy, and Cancer and Leukemia Group B performance status (PS) 0-2. Patients with brain metastases were eligible if they were neurologically stable after brain irradiation. Thirty-three patients from participating institutions were enrolled. One patient was ineligible due to untreated brain metastases. Patients were treated with gemcitabine 1250 mg/m(2) over 30 minutes (1000 mg/m(2) for the first 6 patients) and vinorelbine 25 mg/m(2) over 6 minutes, both administered intravenously on Days 1 and 8 every 21 days. Treatment was planned for a total of six cycles or more if the patient had persistent benefit. Growth factors were not allowed. RESULTS: Among all 32 eligible patients, there were 8 partial responses, for an overall response rate of 25% (95% confidence interval [CI], 11.5-43. 4%). The median survival time was 8.3 months and the 1-year survival rate was 38% (95% CI, 24-59%). Patients with PS 0-1 had a median survival of 11.7 months and a 1-year survival rate of 48%. Grade 3 and 4 neutropenia was observed in 13% and 25% of the 148 treatment cycles, respectively. One patient died of neutropenic sepsis. Only 2 episodes of Grade 3 and 4 thrombocytopenia were observed. Nonhematologic toxicity was minimal. CONCLUSIONS: Gemcitabine and vinorelbine is an active and well-tolerated regimen in patients with advanced NSCLC, with response and survival rates at least comparable to those achieved with standard platinum-based regimens. This combination may be particularly suitable for the elderly or for patients who cannot tolerate more toxic platinum-based regimens.

Aged↗
PubMed2000

Atypical antipsychotics in ordinary clinical practice: a pharmaco-epidemiologic survey in a south London service.

The introduction of atypical antipsychotics has triggered a reevaluation of treatment strategies in schizophrenia. Although research findings inform about the efficacy and safety of drugs, it is the decisions made daily in ordinary practice that affect the vast majority of patients. The aim of this paper was to examine the use of atypical antipsychotics in clinical care, by means of a survey of prescribing practices for clozapine, risperidone, olanzapine, sertindole and quetiapine for all patients treated for DSM-IV schizophrenia within a psychiatric service. Seventy-five (26%) of the 286 patients identified were on atypical antipsychotics. Patients on clozapine were mostly male, had more than 15 years of contact with psychiatric services and were poor responders. Patients prescribed other atypicals had responded to prior treatment with typical neuroleptics and had less than five years of contact with psychiatric services. Gender distribution was equal in this group. The use of research criteria for treatment resistance identified only one patient, as prolonged use of high-dose neuroleptics was uncommon. The new atypical antipsychotics appear to be replacing older neuroleptics as the first-line treatment of schizophrenia while clozapine is mostly reserved for poor responders. Clinicians' definition of treatment resistance was variable and below the threshold used in research.

Adult↗
PubMed2000

A closer view of the conformation of the Lac repressor bound to operator.

Crystal structures of the Lac repressor, with and without isopropyithiogalactoside (IPTG), and the repressor bound to operator have provided a model for how the binding of the inducer reduces the affinity of the repressor for the operator. However, because of the low resolution of the operator-bound structure (4.8 A), the model for the allosteric transition was presented in terms of structural elements rather than in terms of side chain interactions. Here we have constructed a dimeric Lac repressor and determined its structure at 2.6 A resolution in complex with a symmetric operator and the anti-inducer orthonitrophenylfucoside (ONPF). The structure enables the induced (IPTG-bound) and repressed (operator-bound) conformations of the repressor to be compared in atomic detail. An extensive network of interactions between the DNA-binding and core domains of the repressor suggests a possible mechanism for the allosteric transition.

Allosteric Regulation↗
PubMed2000

Flogging the dead horse: the myth of nursing empowerment?

With the move towards a more 'open' National Health Service, a new deal for staff, and greater staff involvement the way ahead for nursing seems bright. The proposals in the governmental White Paper (1997) The New NHS: Modern, Dependable reflect the need for greater co-operation and for a greater empowerment of nurses. If the aims of such major change in the NHS are to be achieved we need to consider both the real effects of nursing empowerment from past history, and the problems involved in greater nursing involvement in the NHS as an organization. As such our discussion may throw some light on the possible ways to progress during such fundamental change. It is from such lessons that positive future progress may be made. Firstly a discussion of the concept and its relationship to health and effective self-image is considered. Opportunities in respect of changing environments, and a move to more transformational change within the NHS could allow greater empowerment and feelings of self-efficacy. Such large scale change is essentially cultural and attitudinal; central to governmental proposals for NHS reform. The authors consider the real effect of nursing empowerment; based in part on the work of Kanter (1993) in the USA and work on empowerment and the role of nursing; and of power relationships within the organization. The links with the nurse's role in primary care groups and clinical governance are strong, with subsequent lessons for the British nurse during these initial changes. The potential for positive benefit is high; but coupled with this is a discussion on the relationship of NHS management, and a brief analysis of managerial practice and attitude, which may mitigate against empowerment. The authors put the case that structural changes are not sufficient to allow greater empowerment; which in its present form may only be an ideal. A greater effort by all is required if the myth is to be made a true reality.

Attitude of Health Personnel↗
PubMed2000

An evaluation of hospital cleaning regimes and standards.

A four-part study assessing cleanliness in up to 113 environmental surfaces in an operating theatre and a hospital ward is reported. Surfaces were assessed visually, using microbiological methods and ATP bioluminescence. Results from a preliminary random survey indicated variability in cleanliness. These results were then used to select sites for monitoring before and after routine cleaning, over a 14-day period. Using published microbiological and ATP specifications 70 and 76% of these sites were unacceptable after cleaning. Visual assessment was a poor indicator of cleaning efficacy with only 18% considered unacceptable. Sites most likely to fail in the ward were in the toilet and kitchen, areas which are frequently implicated in the spread of infectious intestinal disease. Operating theatre sites had lower ATP results but 61% of sites would be considered unacceptable. There was no significant difference in general microbiological or ATP results overall before and after routine cleaning. Although some important hand contact sites showed no significant difference, overall there was a significant decrease in staphylococcal and enterobacteria counts in the ward but not in the operating theatre after cleaning. The routine cleaning programmes used did not include a biocide and cleaning using a hypochlorite based sanitizer gave much lower values. The results are discussed in relation to infection control, cleaning audits and cleaning schedules: an integrated cleaning monitoring programme using ATP bioluminescence in conjunction with visual and microbiological assessments is recommended.

Adenosine Triphosphate↗
PubMed2000

Recurrent use of newer oral contraceptives and the risk of venous thromboembolism.

The epidemiological studies that assessed the risk of venous thromboembolism (VTE) associated with newer oral contraceptives (OC) did not distinguish between patterns of OC use, namely first-time users, repeaters and switchers. Data from a Transnational case-control study were used to assess the risk of VTE for the latter patterns of use, while accounting for duration of use. Over the period 1993-1996, 551 cases of VTE were identified in Germany and the UK along with 2066 controls. Totals of 128 cases and 650 controls were analysed for repeat use and 135 cases and 622 controls for switching patterns. The adjusted rate ratio of VTE for repeat users of third generation OC was 0.6 (95% CI:0.3-1.2) relative to repeat users of second generation pills, whereas it was 1.3 (95% CI:0.7-2.4) for switchers from second to third generation pills relative to switchers from third to second generation pills. We conclude that second and third generation agents are associated with equivalent risks of VTE when the same agent is used repeatedly after interruption periods or when users are switched between the two generations of pills. These analyses suggest that the higher risk observed for the newer OC in other studies may be the result of inadequate comparisons of pill users with different patterns of pill use.

Adult↗