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Biomedical subjects

R Smith

Publications and source records attributed to R Smith.

At least 19 recordsLinked to original sources
PubMed2007

Selective use of older adults in right lobe living donor liver transplantation.

Many centers are reluctant to use older donors (>44 years) for adult right-lobe living donor liver transplantation (RLDLT) due to concerns about possible increased morbidity in donors and poorer outcomes in recipients. Since 2000, 130 adult RLDLTs have been performed at our institution. Recipients were divided into those who received a right lobe graft from a donor </=age 44 (n = 89, 68%; median age 30) and those who received a liver graft from a donor age >44 (n = 41, 32%; mean age 52). The two donor and recipient populations had similar demographic and operative profiles. With a median follow-up of 29 months, the severity and number of complications in older donors were similar to those in younger donors. No living donor died. Older donor allografts had initial allograft dysfunction compared to younger donors. Complication rates were similar among recipients in both groups but there was a higher bile duct stricture rate with older donor grafts (27% vs. 12%; p = 0.04). One-year recipient graft survival was 86% for older donors and 85% for younger donors (p = 0.95). Early experience with the use of selected older adults (>44 years) for RLDLT is encouraging, but may be associated with a higher rate of biliary complications in the recipient.

Adolescent↗
PubMed2006

Alcohol intake and incidence of coronary disease in Australian aborigines.

AIMS: To examine risk for coronary heart disease (CHD) and cardiovascular disease (CVD) in relation to alcohol in a cohort of Australian Aborigines. METHODS: In 1988-1989, alcohol intake, drinking pattern, and beverage preference were elicited by interviewer-administered questionnaire in Western Australian Aborigines (258 men, 256 women) and cardiovascular outcomes ascertained through linkage to mortality and hospital admission records to 2002. RESULTS: In proportional hazards models, risk for CHD, relative to lifetime abstainers, was significantly increased in ex-drinkers [Hazard ratio (HR) 2.29, 95% CL 1.23, 4.27], those drinking 41-60 g/day in men or 21-40 g/day in women (HR 2.80, 95% CL 1.04, 7.53), and those drinking >150 g/day for men or >100 g/day for women (HR 2.25, 95% CL 1.03, 4.90) with a J-shaped relationship. Low-to-moderate drinkers had lower waist girth, exercised more, and had a lower prevalence of overweight and smoking than at-risk drinkers. A preference for wine was associated with lower HR (0.28, 95% CL 0.10, 0.95). With CVD, only ex-drinkers showed significantly increased risk (HR 1.87, 95% CL 1.20, 2.91). CONCLUSIONS: More favourable health-related behaviours in low-to-moderate drinkers suggest that lower risk could be mediated by lifestyle, as proposed in other populations.

Adolescent↗
PubMed2006

Alcohol intake and incidence of coronary disease in Australian aborigines.

AIMS: To examine risk for coronary heart disease (CHD) and cardiovascular disease (CVD) in relation to alcohol in a cohort of Australian Aborigines. METHODS: In 1988-1989, alcohol intake, drinking pattern, and beverage preference were elicited by interviewer-administered questionnaire in Western Australian Aborigines (258 men and 256 women) and cardiovascular outcomes ascertained through linkage to mortality and hospital admission records to 2002. RESULTS: In proportional hazards models, risk for CHD, relative to lifetime abstainers, was significantly increased in ex-drinkers [Hazard ratio (HR), 2.29; 95% confidence intervals (CI), 1.23-4.27], those drinking 41-60 g/day in men or 21-40 g/day in women (HR 2.80; 95% CI, 1.04-7.53) and those drinking >150 g/day for men or >100 g/day for women (HR, 2.25; 95% CI, 1.03-4.90) with a J-shaped relationship. Low-to-moderate drinkers had lower waist girth, exercised more and had a lower prevalence of overweight and smoking than at-risk drinkers. A preference for wine was associated with lower HR (0.28; 95% CI, 0.10-0.95). With CVD, only ex-drinkers showed significantly increased risk (HR, 1.87; 95% CI, 1.20-2.91). CONCLUSIONS: More favourable health-related behaviours in low-to-moderate drinkers suggest that lower risk could be mediated by lifestyle, as proposed in other populations.

Adolescent↗
PubMed2006

Review of solutions for 3D hydrodynamic modeling applied to aquaculture in South Pacific atoll lagoons.

A workshop organized in French Polynesia in November 2004 allowed reviewing the current methods to model the three-dimensional hydrodynamic circulation in semi-enclosed atoll lagoons for aquaculture applications. Mollusk (e.g. pearl oyster, clam) aquaculture is a major source of income for South Pacific countries such as French Polynesia or Cook Islands. This aquaculture now requires a better understanding of circulation patterns to improve the spatial use of the lagoons, especially to define the best area to set larvae collectors. The pelagic larval duration of the relevant species (<20 days) and the size of the semi-closed lagoons (few hundreds of km2) drive the specifications of the model in terms of the spatial and temporal scale. It is considered that, in contrast with fish, mollusk larvae movements are limited and that their cycle occurs completely in the lagoon, without an oceanic stage. Atolls where aquaculture is productive are generally well-bounded, or semi-closed, without significant large and deep openings to the ocean. Nevertheless part of the lagoon circulation is driven by oceanic water inputs through the rim, ocean swells, tides and winds. Therefore, boundary conditions of the lagoon system are defined by the spatial structure of a very shallow rim (exposition and number of hoas), the deep ocean swell climate, tides and wind regimes. To obtain a realistic 3D numerical model of lagoon circulation with adequate forcing, it is thus necessary to connect in an interdisciplinary way a variety of methods (models, remote sensing and in situ data collection) to accurately represent the different components of the lagoon system and its specific boundary conditions. We review here the current methods and tools used to address these different components for a hypothetical atoll of the Tuamotu Archipelago (French Polynesia), representative of the semi-closed lagoons of the South Pacific Ocean. We hope this paper will serve as a guide for similar studies elsewhere and we provide guidelines in terms of costs for all the different stages involved.

Animals↗
PubMed2006

Systematic review: the lower gastrointestinal adverse effects of non-steroidal anti-inflammatory drugs.

BACKGROUND: Lower gastrointestinal effects of non-steroidal anti-inflammatory drugs (NSAIDs) are much more poorly characterized than upper gastrointestinal effects. AIM: To determine if NSAIDs increase lower gastrointestinal adverse effects and if the risk with non-selective NSAIDs is greater than with cyclooxygenase-2-selective inhibitors (coxibs). METHODS: Computerized databases were searched to identify studies of NSAID use reporting on lower gastrointestinal integrity (e.g. permeability), visualization (e.g. erosions, ulcers) and clinical events. RESULTS: Designs in 47 studies were randomized (18), case-control (14), cohort (eight) and before-after (seven). Non-selective-NSAIDs had significantly more adverse effects vs. no NSAIDs in 20 of 22 lower gastrointestinal integrity studies, five of seven visualization studies, seven of 11 bleeding studies (OR: 1.9-18.4 in case-control studies), two of two perforation studies (OR: 2.5-8.1) and five of seven diverticular disease studies (OR: 1.5-11.2). Coxibs had significantly less effect vs. non-selective-NSAIDs in three of four integrity studies, one endoscopic study (RR mucosal breaks: 0.3), and two randomized studies (RR lower gastrointestinal clinical events: 0.5; haematochezia: 0.4). CONCLUSIONS: An increase in lower gastrointestinal injury and clinical events with non-selective-NSAIDs appears relatively consistent across the heterogeneous collection of trials. Coxibs are associated with lower rates of lower gastrointestinal injury than non-selective-NSAIDs. More high-quality trials are warranted to more precisely estimate the effects of non-selective-NSAIDs and coxibs on the lower gastrointestinal tract.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed2006

Recent developments in the application of risk analysis to waste technologies.

The European waste sector is undergoing a period of unprecedented change driven by business consolidation, new legislation and heightened public and government scrutiny. One feature is the transition of the sector towards a process industry with increased pre-treatment of wastes prior to the disposal of residues and the co-location of technologies at single sites, often also for resource recovery and residuals management. Waste technologies such as in-vessel composting, the thermal treatment of clinical waste, the stabilisation of hazardous wastes, biomass gasification, sludge combustion and the use of wastes as fuel, present operators and regulators with new challenges as to their safe and environmentally responsible operation. A second feature of recent change is an increased regulatory emphasis on public and ecosystem health and the need for assessments of risk to and from waste installations. Public confidence in waste management, secured in part through enforcement of the planning and permitting regimes and sound operational performance, is central to establishing the infrastructure of new waste technologies. Well-informed risk management plays a critical role. We discuss recent developments in risk analysis within the sector and the future needs of risk analysis that are required to respond to the new waste and resource management agenda.

Environmental Health↗
PubMed2006

Clinical and functional characteristics of the human Arg59Ter insulin-like growth factor i receptor (IGF1R) mutation: implications for a gene dosage effect of the human IGF1R.

CONTEXT: Signaling via the IGF-I receptor (IGF-IR) is crucial for normal prenatal and postnatal growth. The heterozygous IGF-IR mutation Arg59Ter resulted in reduced IGF-IR expression and represents haploinsufficiency of the human IGF1R gene. OBJECTIVE: We studied clinical and in vitro aspects of a human IGF1R gene dosage effect. We provide detailed clinical data on the two half-brothers and their mother with the Arg59Ter mutation. Arg59Ter and control fibroblasts were examined for functionality of IGF-I and insulin-stimulated receptor phosphorylation and signal transduction. RESULTS: The two brothers presented with primary microcephaly, mild mental retardation, and intrauterine as well as postnatal growth deficits. After GH therapy (30 microg/kg.d) for 24 months, the growth deficit in the propositus decreased by +1.0 sd. There was no clinical evidence for impaired glucose tolerance or hypoglycemia in all Arg59Ter subjects. In vitro, IGF-IR-deficient Arg59Ter cells expressed less IGF-IR and unchanged insulin receptor (IR) protein. Receptor autophosphorylation and phosphorylation of downstream protein kinase B/Akt exhibited resistance to IGF-I but showed an augmented response to insulin in Arg59Ter cells. Decreased IGF-IR content was accompanied by a reduction of IGF-IR/IR receptor hybrids, and therefore, increased levels of IR/IR homodimers probably explain increased insulin-stimulated receptor autophosphorylation and Akt phosphorylation. CONCLUSIONS: In vivo and in vitro IGF-I resistance in Arg59Ter subjects and fibroblasts indicates a human IGF1R gene dosage effect involving not only the IGF-IR, but also IGF-IR/IR hybrids. The abundance of both the IGF-IR protein and IGF-IR/IR hybrid receptors may have an impact on human growth, organ function, and glucose metabolism.

Body Weight↗
PubMed2006

Metabolism of synthetic steroids by the human placenta.

Pregnant women with asthma are frequently exposed to synthetic glucocorticoids and glucocorticoids are known to reduce fetal growth. The fetus is normally protected from the harmful effects of maternally derived glucocorticoids by the placental enzyme 11beta-hydroxysteroid dehydrogenase type 2 (11beta-HSD2). Whether 11beta-HSD2 inactivates the synthetic glucocorticoids used for asthma treatment during pregnancy (budesonide, beclomethasone dipropionate and fluticasone propionate) remains unknown. To investigate the relationship between steroid use during pregnancy and fetal growth and development, pregnant women with (n=119) and without asthma (n=84) were followed throughout pregnancy. Data on asthma medication use, neonatal size at birth, placental weight and cord blood cortisol and estriol were collected. Placental tissue samples were collected from non-asthmatic women (n=8) for metabolism studies. Placental 11beta-HSD2 activity was determined using beclomethasone dipropionate, budesonide, fluticasone propionate, prednisolone, dexamethasone and betamethasone as steroid substrates. Steroids and their oxidised metabolites were examined using thin layer chromatography and densitometry. Placental 11beta-HSD2 metabolised beclomethasone, prednisolone, dexamethasone and betamethasone, but not budesonide or fluticasone. No association between the use of inhaled steroids for asthma treatment during pregnancy and alterations in neonatal size, placental weight, gestational age at delivery, or umbilical vein estriol concentrations was demonstrated compared to non-asthmatic women. In conclusion, the use of inhaled steroids for asthma treatment does not affect fetal growth, despite differences in placental metabolism by 11beta-HSD2.

Administration, Inhalation↗
PubMed2006

Predicting Autism Spectrum Quotient (AQ) from the Systemizing Quotient-Revised (SQ-R) and Empathy Quotient (EQ).

BACKGROUND: Empathizing is a specific component of social cognition. Empathizing is also specifically impaired in autism spectrum condition (ASC). These are two dimensions, measurable using the Empathy Quotient (EQ) and the Autism Spectrum Quotient (AQ). ASC also involves strong systemizing, a dimension measured using the Systemizing Quotient (SQ). The present study examined the relationship between the EQ, AQ and SQ. The EQ and SQ have been used previously to test for sex differences in 5 'brain types' (Types S, E, B and extremes of Type S or E). Finally, people with ASC have been conceptualized as an extreme of the male brain. METHOD: We revised the SQ to avoid a traditionalist bias, thus producing the SQ-Revised (SQ-R). AQ and EQ were not modified. All 3 were administered online. SAMPLE: Students (723 males, 1038 females) were compared to a group of adults with ASC group (69 males, 56 females). AIMS: (1) To report scores from the SQ-R. (2) To test for SQ-R differences among students in the sciences vs. humanities. (3) To test if AQ can be predicted from EQ and SQ-R scores. (4) To test for sex differences on each of these in a typical sample, and for the absence of a sex difference in a sample with ASC if both males and females with ASC are hyper-masculinized. (5) To report percentages of males, females and people with an ASC who show each brain type. RESULTS: AQ score was successfully predicted from EQ and SQ-R scores. In the typical group, males scored significantly higher than females on the AQ and SQ-R, and lower on the EQ. The ASC group scored higher than sex-matched controls on the SQ-R, and showed no sex differences on any of the 3 measures. More than twice as many typical males as females were Type S, and more than twice as many typical females as males were Type E. The majority of adults with ASC were Extreme Type S, compared to 5% of typical males and 0.9% of typical females. The EQ had a weak negative correlation with the SQ-R. DISCUSSION: Empathizing is largely but not completely independent of systemizing. The weak but significant negative correlation may indicate a trade-off between them. ASC involves impaired empathizing alongside intact or superior systemizing. Future work should investigate the biological basis of these dimensions, and the small trade-off between them.

Adolescent↗
PubMed2006

Higher neutrophil infiltration mediated by osteopontin is a likely contributing factor to the increased susceptibility of females to alcoholic liver disease.

Alcoholic liver disease (ALD) is a major public health problem in the United States and women are known to be more susceptible to ALD. However, the precise mechanism for increased susceptibility of females to ALD is not completely understood. The present study is based on the hypothesis that induction of osteopontin (OPN), a matricellular protein, is the likely contributing factor for higher neutrophil recruitment in females during alcoholic steatohepatitis (ASH). ASH was induced in male and female Sprague-Dawley rats by feeding them a Lieber-DeCarli diet containing ethanol (EtOH) for 6 weeks, followed by a single injection of lipopolysaccharide (LPS, 10 mg/kg, ip). Liver injury, measured by plasma transaminase elevations and confirmed by haematoxylin and eosin-stained liver sections, revealed approximately 25-fold higher liver injury in the female ASH model compared with the males. Although steatosis, necrosis, and neutrophil infiltration were evident in both male and female rats, hepatic neutrophilic necrotic foci were noted as early as 2 h after LPS injection in the EtOH-treated female rats. Hepatic neutrophil infiltration correlated with higher expression of cleaved (cOPN) and uncleaved OPN in the EtOH + LPS-treated female rats compared with the males. OPN secretion was localized predominantly in the biliary epithelium and females had significantly higher OPN mRNA than their male counterparts in the ASH model. The ability of OPN to attract neutrophils was further confirmed in vivo, in a peritonitis rat model, and by neutralizing OPN (nOPN) antibody experiments. Hepatic neutrophil infiltration was largely inhibited ( approximately 50%) by nOPN antibody. Flow cytometry experiments revealed OPN-mediated up-regulation of the CD11b neutrophil adhesion molecule. In conclusion, these data suggest that higher hepatic expression of OPN is the likely reason for higher and early hepatic neutrophil infiltration making females more susceptible to ALD during ASH.

Animals↗
PubMed2006

Primary splenic marginal zone lymphoma with bladder metastases mimicking interstitial cystitis.

We report the case of a 76-year-old patient with a past medical history of low-grade chronic lymphocytic leukaemia who presented with severe chronic bladder symptoms attributed to interstitial cystitis. She underwent cystectomy and ileal conduit formation after the failure of all conventional treatment. Bladder histopathology revealed primary splenic marginal zone lymphoma. Literature review shows the rarity of such non-hematopoietic visceral metastases. This may represent the first reported splenic marginal zone lymphoma with bladder involvement and highlights the clinical and histological similarities with interstitial cystitis.

Aged↗
PubMed2006

Diabetes prevention: is there more to it than lifestyle changes?

Over the past years, there has been an explosive increase in the prevalence of type 2 diabetes (T2DM) and this is expected to continue, entailing associated morbidity and mortality. An increasing number of studies explore the different ways T2DM could be prevented. On-going lifestyle modifications need to be addressed. High-risk patients should be given counselling on weight loss, possibly using a low glycaemic index diet, with a target of around 7-10% over 6-12 months, as well as instruction for increasing physical activity to around 150 min of physical exercise weekly (NNT = 4-8). Moderate alcohol consumption and coffee consumption may also be of benefit (NNT = 89 and 66, respectively). Metformin (NNT = 14), acarbose (NNT = 11) and troglitazone (NNT = 6) have been shown to prevent/delay T2DM and angiotensin-converting enzyme (ACE) inhibitors and statins appear to have an adjunctive role (NNT = 42 and 112, respectively). Trials with orlistat and bariatric surgery have also prevented T2DM (NNT = 36 and 6, respectively), and forthcoming treatment with GLP1 mimetics appears promising. Diabetes prevention studies should help create well-defined strategies for screening and treating high-risk populations in the real world, as prevention is our only chance to alleviate the ever growing burden of diabetes mellitus in the world.

Diabetes Mellitus, Type 2↗
PubMed2005

Increased sperm DNA damage in patients with varicocele: relationship with seminal oxidative stress.

BACKGROUND: The pathophysiology of the testicular damage in varicocele has not been completely understood. Oxidative stress and related sperm DNA damage have been identified as significant causes of male infertility. The current study was designed to determine the extent of sperm nuclear DNA damage in patients with varicocele and to examine its relationship with oxidative stress. METHODS: Semen samples from 55 patients with clinical varicocele and 25 normozoospermic donors were examined. Varicocele sperm samples were classified as normal or abnormal according to World Health Organization guidelines. Sperm DNA damage was evaluated by the sperm chromatin structure assay/flow cytometry and by the terminal deoxyribonucleotidyl transferase-mediated dUTP nick-end labelling (TUNEL) assay. Levels of reactive oxygen species (ROS) and total antioxidant capacity were assessed by a chemiluminescence assay. RESULTS: DNA fragmentation index (DFI) (percentage of sperm with denatured DNA) values and the percentage of TUNEL-positive cells were significantly greater in patients with varicocele, either with normal (DFI, 20.7 +/- 4.0; TUNEL positive, 26.1 +/- 3.2) or with abnormal (DFI, 35.5 +/- 9.0; TUNEL positive, 32.2 +/- 4.1) semen profile, compared with controls (DFI, 7.1 +/- 0.9; TUNEL positive, 14.2 +/- 1.2). Similarly, ROS levels were significantly higher (P < 0.01) in both groups of patients with varicocele. CONCLUSIONS: The presence of a varicocele is associated with high levels of DNA-damage spermatozoa even in the presence of normal semen profile. The results also indicate that oxidative damage is associated with sperm DNA damage in these patients.

Biomarkers↗
PubMed2005

Ecological consequences of dredged material disposal in the marine environment: a holistic assessment of activities around the England and Wales coastline.

This study provides a holistic perspective on the ecological effects of dredged material disposal, both intertidally and subtidally. A number of numerical techniques (univariate, distributional, multivariate and meta-analysis) were used to assess impacts at 18 different disposal sites. The analyses revealed that ecological effects associated with dredged material disposal were dependent on the numerical techniques used, and that impacts were disposal-site specific. Disposal-site communities were generally faunistically impoverished to varying degrees, and impacts following intertidal placement were comparable to those of subtidal placement. We conclude that any assessment of the consequences of dredged material disposal to the coastal environment must take account of site-specific variation in prevailing hydrographic regimes and in ecological status, along with information on the disposal activity itself (mode, timing, quantity, frequency and type of material). As would be expected, variability in the latter presents a significant challenge in attempts to generalise about environmental and ecological impacts.

Animals↗