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Biomedical subjects

M Harris

Publications and source records attributed to M Harris.

At least 19 recordsLinked to original sources
PubMed2006

Postpartum psychosis: two cohorts compared, 1875-1924 and 1994-2005.

BACKGROUND: There has been a long-standing debate as to whether postpartum psychoses are distinct from other psychoses. While the outcomes of postpartum psychosis are in general thought to be good, the disorder is linked to a high rate of suicide. METHOD: We have utilized a database of 3872 admissions to the North Wales Asylum during the period 1875-1924 to extract data on the prevalence, course and clinical features of postpartum psychoses during this period. We have collected first admissions for postpartum psychosis between 1994 and 2005 in North West Wales to establish a current incidence rate for the disorder. RESULTS: The incidence of psychoses with a first onset in the postpartum period in North West Wales has fallen in the modern period, while the incidence of postpartum psychoses in women with a pre-existing mental illness remains the same. Some features of the clinical picture and course of postpartum psychoses differ from other psychoses, but may be gender rather than disorder linked. CONCLUSIONS: These findings suggest that psychoses with their first onset in the postpartum period may be vanishing. If replicated, this would support claims that these disorders are distinct from other disorders. Alternately, if regarded as affective disorders, establishing the basis for the apparent decline in frequency of these disorders may have implications for other affective disorders.

Adult↗
PubMed2006

Salmonella spp., Vibrio spp., Clostridium perfringens, and Plesiomonas shigelloides in marine and freshwater invertebrates from coastal California ecosystems.

The coastal ecosystems of California are highly utilized by humans and animals, but the ecology of fecal bacteria at the land-sea interface is not well understood. This study evaluated the distribution of potentially pathogenic bacteria in invertebrates from linked marine, estuarine, and freshwater ecosystems in central California. A variety of filter-feeding clams, mussels, worms, and crab tissues were selectively cultured for Salmonella spp., Campylobacter spp., Escherichia coli-O157, Clostridium perfringens, Plesiomonas shigelloides, and Vibrio spp. A longitudinal study assessed environmental risk factors for detecting these bacterial species in sentinel mussel batches. Putative risk factors included mussel collection near higher risk areas for livestock or human sewage exposure, adjacent human population density, season, recent precipitation, water temperature, water type, bivalve type, and freshwater outflow exposure. Bacteria detected in invertebrates included Salmonella spp., C. perfringens, P. shigelloides, Vibrio cholerae, Vibrio parahaemolyticus, and Vibrio alginolyticus. Overall, 80% of mussel batches were culture positive for at least one of the bacterial species, although the pathogens Campylobacter, E. coli-O157, and Salmonella were not detected. Many of the same bacterial species were also cultured from upstream estuarine and riverine invertebrates. Exposure to human sewage sources, recent precipitation, and water temperature were significant risk factors for bacterial detection in sentinel mussel batches. These findings are consistent with the hypothesis that filter-feeding invertebrates along the coast concentrate fecal bacteria flowing from land to sea and show that the relationships between anthropogenic effects on coastal ecosystems and the environmental niches of fecal bacteria are complex and dynamic.

Animals↗
PubMed2006

Psychosocial factors and treatment adherence in paediatric HIV/AIDS.

A social ecological model provides a promising framework for understanding the individual, family, and societal factors contributing to non-adherence to treatment of paediatric HIV. This study explored which factors relevant to this model are associated with caregivers' adherence and child health outcomes. A cross-sectional design was utilized to assess relationships among current individual, familial, extra-familial factors, caregiver adherence, and viral load. Data were collected from 43 caregivers, and viral load data were obtained from the medical records of their HIV+ children. Caregiver drug and alcohol use and HIV+ status were associated with non-adherence and elevated viral load. Negative outcome expectancy was associated with lower adherence but was not significant in the multivariate analyses. Family factors were not significant, but these measures had low reliability in this sample. Extra-familial factors such as dissatisfaction with medical specialty care and more stressful life events were not directly associated with adherence but were related to increased caregiver substance use. Results of this first study to explore multiple predictors of adherence and health outcomes in paediatric HIV require replication with larger samples, but findings suggest caregiver characteristics that place children at risk for disease progression due to poor adherence to treatment.

Adolescent↗
PubMed2006

Regimen-dependent variations in adherence to therapy and virological suppression in patients initiating protease inhibitor-based highly active antiretroviral therapy.

OBJECTIVE: To examine differences among four protease inhibitor (PI)-based drug regimens in adherence to therapy and rate of achievement of virological suppression in a cohort of antiretroviral-naive patients initiating highly active antiretroviral therapy (HAART). METHODS: Participants were antiretroviral-naive and were first dispensed combination therapy containing two nucleosides and a ritonavir (RTV)-boosted PI, or unboosted nelfinavir, between 1 January 2000 and 30 September 2003. Logistic regression analysis was used to examine associations between the prescribed PI and other baseline factors associated with being >90% adherent to therapy and then to determine the associations of prescribed drug regimen, adherence to therapy and baseline variables with the odds of achieving two consecutive viral loads of <500 HIV-1 RNA copies/mL. RESULTS A total of 385 subjects were available for analysis. Lopinavir (LPV)/RTV was prescribed for 168 patients (42% of total); 86 (22%) received indinavir (IDV)/RTV; 91 (24%) received nelfinavir (NFV) and 40 (10%) received saquinavir (SQV)/RTV. SQV/RTV-based HAART was associated with reduced adherence to therapy [odds ratio (OR)=0.40; 95% confidence interval (CI) 0.19-0.83]. In multivariate models, IDV/RTV (OR=0.45; 95% CI 0.22-0.92), SQV/RTV (OR=0.18; 95% CI 0.07-0.43) and NFV were associated with reduced odds of achieving virological suppression within 1 year in comparison to LPV/RTV-based therapy. For patients receiving NFV, adjusting for adherence (OR=0.73; 95% CI 0.36-1.47) rendered this association nonsignificant. CONCLUSION: Patients prescribed IDV/RTV, NFV or SQV/RTV were less likely to achieve virological suppression on their first regimen compared with patients prescribed LPV/RTV. Reduced adherence to these therapies only partly explained these observed differences.

Adult↗
PubMed2006

Providing patients with reviews of evidence about COPD treatments: a controlled trial of outcomes.

Studies in many countries have identified gaps between what is known from research evidence and what is done in clinical practice. Merely making research evidence available to practitioners does not cause much change in their behaviour, and researchers are now looking for more effective ways to improve the implementation of evidence. We report outcomes at three months of a parallel group trial of an evidence based patient manual designed to improve implementation of evidence by the patient's doctors. The patient manual was produced with extensive patient and professional input. It contained summaries of the evidence for treatments used in COPD (chronic obstructive pulmonary disease) and prompted discussion of evidence with doctors. Participants in the intervention arm of the trial (n = 125) were supplied with the manual and participants in the control arm (n = 124) were supplied with a pamphlet about COPD produced by the Australian Lung Foundation. The primary outcome measure (rates of current influenza vaccination and bone density testing) was an indicator of evidence based management of COPD. Secondary outcomes were quality of life (mastery component), satisfaction with information, communication with usual doctor, and anxiety. At three months no pattern of benefit in outcome measures was found for either group. Process measures showed high levels of personal use of the manual but progression to conversations with doctors for fewer than half of participants, and little treatment change. The findings highlight the difficulties of promoting changes in health behaviour and show that even when all stakeholders are consulted success is not guaranteed. Further research is required to identify those patients most likely to use manuals such as the one reported here, and how to make patient mediated interventions more effective for a greater proportion of the target population.

Aged↗
PubMed2006

Lifetime suicide rates in treated schizophrenia: 1875-1924 and 1994-1998 cohorts compared.

BACKGROUND: Recent interest in suicide rates in schizophrenia has been considerable. AIMS: To establish the lifetime suicide rate from the pre-chlorpromazine era and to compare this with recent lifetime suicide rates for schizophrenia. METHOD: We have compared suicide and suicide attempt rates for 741 admissions for schizophrenia and 1303 admissions for psychoses to the North Wales Asylum between 1875 and 1924, with first admissions for psychosis in NorthWest Wales between 1994 and 1998. RESULTS: The suicide rate in schizophrenia between 1875 and 1924 was 20 per 100 000 hospital years, a lifetime rate of less than 0.5%. The suicide rate for all psychoses was 16 per 100 000 hospital years. Current rates of suicide for schizophrenia and other psychoses appear 20-fold higher. CONCLUSIONS: These findings point to an increase in suicide rates for patients with schizophrenia.

Adolescent↗
PubMed2005

Neonatal leptin treatment reverses developmental programming.

An adverse prenatal environment may induce long-term metabolic consequences, in particular obesity and insulin resistance. Although the mechanisms are unclear, this programming has generally been considered an irreversible change in developmental trajectory. Adult offspring of rats subjected to undernutrition during pregnancy develop obesity, hyperinsulinemia, and hyperleptinemia, especially in the presence of a high-fat diet. Reduced locomotor activity and hyperphagia contribute to the increased fat mass. Using this model of maternal undernutrition, we investigated the effects of neonatal leptin treatment on the metabolic phenotype of adult female offspring. Leptin treatment (rec-rat leptin, 2.5 microg/g.d, sc) from postnatal d 3-13 resulted in a transient slowing of neonatal weight gain, particularly in programmed offspring, and normalized caloric intake, locomotor activity, body weight, fat mass, and fasting plasma glucose, insulin, and leptin concentrations in programmed offspring in adult life in contrast to saline-treated offspring of undernourished mothers who developed all these features on a high-fat diet. Neonatal leptin had no demonstrable effects on the adult offspring of normally fed mothers. This study suggests that developmental metabolic programming is potentially reversible by an intervention late in the phase of developmental plasticity. The complete normalization of the programmed phenotype by neonatal leptin treatment implies that leptin has effects that reverse the prenatal adaptations resulting from relative fetal undernutrition.

Absorptiometry, Photon↗
PubMed2005

Fasting ghrelin levels are not elevated in children with hypothalamic obesity.

Morbid obesity is a common problem after damage to the hypothalamus. Hypothalamic dysfunction is also thought to underlie the obesity that is typical of Prader-Willi syndrome. Elevated fasting levels of the appetite-stimulating hormone ghrelin have been reported in Prader-Willi syndrome. The aim of this study was to determine whether fasting ghrelin levels are increased in children with hypothalamic obesity. Fasting total ghrelin levels were compared in three groups: normal-weight controls (n = 16), obese controls (n = 16), and patients with hypothalamic obesity (n = 16). Obese children had lower fasting total ghrelin levels than normal controls, but there was no difference between the fasting total ghrelin level in obese controls and children with hypothalamic obesity (P = 0.88). These data suggest that it is unlikely that an elevation in fasting total ghrelin is responsible for the obesity that occurs after hypothalamic damage. Therapeutic interventions aimed at reducing fasting total ghrelin may prove ineffective in controlling weight gain in this group.

Adolescent↗
PubMed2005

New genotypes and factors associated with Cryptosporidium detection in mussels (Mytilus spp.) along the California coast.

A 3 year study was conducted to evaluate mussels as bioindicators of faecal contamination in coastal ecosystems of California. Haemolymph samples from 4680 mussels (Mytilus spp.) were tested for Cryptosporidium genotypes using PCR amplification and DNA sequence analysis. Our hypotheses were that mussels collected from sites near livestock runoff or human sewage outflow would be more likely to contain the faecal pathogen Cryptosporidium than mussels collected distant to these sites, and that the prevalence would be greatest during the wet season when runoff into the nearshore marine environment was highest. To test these hypotheses, 156 batches of sentinel mussels were collected quarterly at nearshore marine sites considered at higher risk for exposure to livestock runoff, higher risk for exposure to human sewage, or lower risk for exposure to both faecal sources. Cryptosporidium genotypes detected in Haemolymph samples from individual mussels included Cryptosporidium parvum, Cryptosporidium felis, Cryptosporidium andersoni, and two novel Cryptosporidium spp. Factors significantly associated with detection of Cryptosporidium spp. in mussel batches were exposure to freshwater outflow and mussel collection within a week following a precipitation event. Detection of Cryptosporidium spp. was not associated with higher or lower risk status for exposure to livestock faeces or human sewage sources. This study showed that mussels can be used to monitor water quality in California and suggests that humans and animals ingesting faecal-contaminated water and shellfish may be exposed to both host-specific and anthropozoonotic Cryptosporidium genotypes of public health significance.

Animals↗
PubMed2005

Summer outbreak of respiratory disease in an Australian prison due to an influenza A/Fujian/411/2002(H3N2)-like virus.

An outbreak of influenza A occurred in a prison system in New South Wales, Australia in January 2003 during the southern hemisphere summer. This report documents only the third confirmed outbreak of influenza in a prison environment. The outbreak investigation included case ascertainment, state-wide surveillance, a case-control study and interventions to limit the outbreak such as infection control, quarantine, cohorting of cases, and the use of antiviral medication for prophylaxis. A total of 37 clinical cases were identified. Influenza A virus was detected in 11 of the 22 respiratory tract specimens collected. The virus was typed as an influenza A/Fujian/411/2002 (H3N2)-like virus. This strain subsequently became the predominant virus strain during the northern hemisphere winter and the following 2003 Australian southern hemisphere winter influenza season.

Case-Control Studies↗
PubMed2005

Measuring adherence to treatment of paediatric HIV/AIDS.

Parent, child, physician report and pill counts were used to measure adherence in paediatric HIV. Relationships to viral load were assessed. Pill counts were considered invalid. Adherence measures did not correlate with one another. Physicians reported lower adherence than parents, but parent and physician report correlated with viral load. The clinical and research utility of the various measures are discussed.

Adolescent↗
PubMed2005

Printed patient education interventions to facilitate shared management of chronic disease: a literature review.

BACKGROUND: Printed materials for patient self-education are a comparatively low cost, flexible and potentially useful aid for dealing with the growing burden of chronic disease in our society. A comprehensive review of existing trials is required. AIMS: We conducted a comprehensive review which aimed to (i) evaluate the evidence for effectiveness of print-only interventions in increasing patient participation in chronic disease management and (ii) identify disease or intervention characteristics associated with success. METHODS: Medline, the Cochrane Central Register of Controlled Trials, EMBASE and CINAHL were searched for the period 1992 to January 2005 for reports of controlled trials of printed patient materials in chronic disease. The quality of both studies and interventions was assessed. RESULTS: Seven studies were found. They focussed on inflammatory bowel disease, arthritis, asthma and diabetes. Few studies named primary outcomes, continued beyond 6 months or included process evaluations. Few reports gave the behaviour-change rationale of the intervention. Few interventions were reported as having been designed using testing and improvement, psychosocial theory, checks of patient understanding or other patient input. A variety of outcomes was measured. Statistically significant change was found for few. Knowledge improved in three studies, adherence improved in two and quality of life declined in one. CONCLUSIONS: We found that printed interventions as currently designed appear to produce, at best, modest benefits. The design of interventions, studies and study reports all need improvement before decisions can be made about effectiveness and characteristics associated with success.

Arthritis↗
PubMed2005

Frame semantics and the domain of functioning, disability and health.

We explore the use of FrameNet (FN) frames and their frame elements to represent content from the International Classification of Functioning, Disability and Health (ICF) Self-Care chapter. Terms were extracted from the ICF and mapped to FN frames. The mappings were validated by an expert. FN provided relevant and nearly complete coverage of ICF terms, suggesting FN may be an important resource to leverage for semantic language processing and knowledge representation in this domain.

Activities of Daily Living↗
PubMed2004

Antiapoptotic effects of leptin in human neuroblastoma cells.

Many factors regulate nervous system development, including complex cross-talk between local neuroendocrine systems. The adipocyte-secreted hormone leptin, mainly known for its key roles in nutrition and reproductive balance, may also be involved in neuroanatomical organization, myelination processes, and neuronal/glia maturation. SK-N-SH-SY5Y neuroblastoma cells were employed as an in vitro model of human neuronal cells to determine whether leptin exerts neuroprotective activities. We show that SH-SY5Y cells express leptin, the long and short isoforms of the leptin receptor (ObRl, ObRs). In SH-SY5Y cells, leptin induced signal transducer and activator of transcription (STAT)-3 phosphorylation and suppressor of cytokine signaling-3 mRNA expression. Leptin dose-dependently increased cell number (up to 200% at 1 microm by 48 h, P < 0.01), and at 24-48 h, leptin at 100 nm increased SH-SY5Y cell number by 30-50%, respectively. SH-SY5Y cell viability was reduced in serum-free conditions at 24 h, and addition of leptin at 100 nm significantly reduced apoptosis by approximately 20% (P < 0.001). Leptin's antiapoptotic activity required Janus kinase/STAT, MAPK, and phosphatidylinositol-3-kinase activation because the antiapoptotic effects of leptin were abolished, and caspase-3 immunoreactivity increased in the presence of the specific blockers AG490, U0126, or LY294002. Gene array demonstrated that leptin inhibits apoptosis via potent down-regulation of caspase-10 and TNF-related apoptosis-inducing ligand. Our data thus demonstrate, for the first time, that leptin stimulates, in a time- and dose-dependent manner, neuroblastoma cell proliferation and that the underlying mechanisms involve suppression of apoptosis via the Janus kinase-STAT, phosphatidylinositol-3 kinase, and MAPK pathways that culminate altogether in the down-regulation of the apoptotic factors caspase-10 and TNF-related apoptosis-inducing ligand.

Apoptosis↗
PubMed2004

Tositumomab and iodine I 131 tositumomab for recurrent indolent and transformed B-cell non-Hodgkin's lymphoma.

PURPOSE: An open-label phase II study was conducted at two centers to establish the efficacy and safety of tositumomab and iodine I 131 tositumomab at first or second recurrence of indolent or transformed indolent B-cell lymphoma. PATIENTS AND METHODS: A single dosimetric dose was followed at 7 to 14 days by the patient-specific administered radioactivity required to deliver a total body dose of 0.75 Gy (reduced to 0.65 Gy for patients with platelets counts of 100 to 149 x 10(9)/L). Forty of 41 patients received both infusions. RESULTS: Thirty-one of 41 patients (76%) responded, with 20 patients (49%) achieving either a complete (CR) or unconfirmed complete remission [CR(u)] and 11 patients (27%) achieving a partial remission. Response rates were similar in both indolent (76%) and transformed disease (71%). The overall median duration of remission was 1.3 years. The median duration of remission has not yet been reached for those patients who achieved a CR or CR(u). Eleven patients continue in CR or CR(u) between 2.6+ and 5.2+ years after therapy. Therapy was well tolerated; hematologic toxicity was the principal adverse event. Grade 3 or 4 anemia, neutropenia, and thrombocytopenia were observed in 5%, 45%, and 32% of patients, respectively. Secondary myelodysplasia has occurred in one patient. Four patients developed human antimouse antibodies after therapy. Five of 38 assessable patients have developed an elevated thyroid-stimulating hormone; treatment with thyroxine has been initiated in one patient. CONCLUSION: High overall and CR rates were observed after a single dose of tositumomab and iodine I 131 tositumomab in this patient group. Toxicity was modest and easily managed.

Adult↗
PubMed2004

Motion artefact reduction of the photoplethysmographic signal in pulse transit time measurement.

Motion artefact is a common occurrence that contaminates photoplethysmographic (PPG) measurements. To extract timing information from signals during artefact is challenging. PPG signal is very sensitive to artefacts and can be used in applications like, pulse transit time (PTT) as part of the polysomnographic studies. A correlation cancellation or signal processing approach is implemented with the adaptive cancelling filter concept and a triaxial accelerometry. PPG signals obtained from a Masimo (Reference) pulse oximeter is used as reference to compare with the reconstructed PPG signals. Different hands are used for each PPG source, one stationary while the other involves typical movements during sleep. A second Masimo pulse oximeter is used to register intensity of timing errors on commercial PPG signals. 108 PTT measurements are recorded in three different movements with PTT estimates from unprocessed PPG signals showing 35.51+/-27.42%, Masimo 50.02+/-29.40% and reconstructed 4.32+/-3.59% difference against those from the Reference PPG. The triaxial accelerometry can be used to detect the presence of artefact on PPG signals. This is useful in PTT measurements when signal contaminated with artefacts are required for further analysis, especially after and during arousals in sleep. The suggested filtering model can then reconstruct these corrupted PPG signals.

Acceleration↗
PubMed2004

The metabolic consequences of prematurity.

An association between low birth weight, commonly a reflection of an adverse in utero environment, and the subsequent development of diseases such as type 2 diabetes and hypertension in later life is now generally accepted - as is an association between an adverse perinatal environment and a permanent reduction in insulin sensitivity. This and other metabolic abnormalities have been demonstrated from childhood through to adulthood in subjects who were born full-term but small for gestational age (SGA). Less is known about children born prematurely into an adverse neonatal environment. We present data demonstrating that premature infants also have metabolic abnormalities similar to those observed in full-term, SGA children, and that these occur irrespective of whether the premature infants are SGA or appropriate for gestational age (AGA).

Child↗