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Biomedical subjects

J Hill

Publications and source records attributed to J Hill.

At least 55 records · Page 3Linked to original sources
PubMed2003

The accumulation of potentially toxic elements in edible body tissues of lambs grazing after a single application of sewage sludge.

The application of sewage sludge to grassland can lead to the accumulation of potentially toxic elements (PTEs) at the soil surface that may be ingested, together with soil and herbage, by grazing ruminants. To investigate the extent to which the method of application of sludge to grassland might influence the accumulation of PTEs in body tissues of grazing sheep, two experiments were undertaken using grassland overlying two contrasting types of soil. At both sites, plots were either untreated or given liquid digested sludge in a single application in either autumn or spring by surface spreading or by injection. Weaned lambs were grazed on the experimental sites for 149 days (Experiment 1) or 160 days (Experiment 2). Muscle, kidney and liver tissues were assayed for concentrations of PTEs at each slaughter date. Applications of sludge were reflected in elevated concentrations of Pb and Cu in soil in Experiment 1 only (P < 0.05). Total loadings of PTEs for the treated grasslands did not exceed UK statutory limits to annual additions to soil. No significant differences were observed in the concentrations of PTEs in herbage between untreated and treated sites, with the exception of the concentration of Cu in herbage after surface application in the spring (Experiment 2). At the end of Experiment 1 the concentration of Cd tended to be higher in kidney tissues of lambs grazed on the pastures amended with sludge in the autumn compared to lambs grazed on untreated pastures. No other treatment effects were evident. Concentrations of PTEs in edible tissues of lambs grazed on grassland given a single dose of sludge were generally low and unlikely to pose a significant risk to the food chain. However, reduced food intake was observed in lambs grazed on grassland which had received sludge recently, indicating that the 21-day UK statutory no-grazing period should be reviewed in relation to grassland given sewage sludge in the spring.

Animals↗
PubMed2003

Yersinia pestis and plague.

Yersinia pestis is the aetiological agent of plague, a disease of humans that has potentially devastating consequences. Evidence indicates that Y. pestis evolved from Yersinia pseudotuberculosis, an enteric pathogen that normally causes a relatively mild disease. Although Y. pestis is considered to be an obligate pathogen, the lifestyle of this organism is surprisingly complex. The bacteria are normally transmitted to humans from a flea vector, and Y. pestis has a number of mechanisms which allow survival in the flea. Initially, the bacteria have an intracellular lifestyle in the mammalian host, surviving in macrophages. Later, the bacteria adopt an extracellular lifestyle. These different interactions with different host cell types are regulated by a number of systems, which are not well characterized. The availability of the genome sequence for this pathogen should now allow a systematic dissection of these regulatory systems.

Animals↗
PubMed2003

Survey of autologous blood transfusion activity in England (2001).

Better Blood Transfusion' (Department of Health (1998) HSC 1998/224) stressed the need for National Health Service Trusts to explore the feasibility of autologous blood transfusions and raise patient awareness of these techniques. The development of an appropriate strategy to promote autologous transfusion requires an understanding of current use, along with constraints to increasing practice. Past surveys have shown unchanging attitudes to autologous transfusion (Torrella et al. (2001) Transfusion Medicine, 11, 15-19), but detailed information regarding the extent of autologous transfusion in England and North Wales was not available. This survey, carried out in 2001, considered autologous transfusion under four headings: predeposit autologous donation, acute normovolaemic haemodilution, intra-operative cell salvage and postoperative cell salvage. Questionnaires were returned from 265/310 (85.4%) hospitals served by the National Blood Service. Sixty per cent of respondents performed at least one autologous technique, although practice was limited to a few clinicians within each hospital. Predeposit donation was the most widespread technique but involved very few patients. Intra- and postoperative cell salvage techniques were practised in fewer hospitals but on many more patients. The main constraints to increasing use of autologous techniques were perceived to be logistical, but removal of constraints may only result in small increases in individual practice. More clinicians need to be encouraged to utilize appropriate, evidence-based autologous techniques.

Blood Loss, Surgical↗
PubMed2003

Pathological staging of epidermoid anal carcinoma for the new era.

Chemoradiotherapy is the standard treatment for most patients with epidermoid anal cancer. Pre-treatment staging is based on size for T1-T3 lesions and clinical and radiological assessment of adjacent organ invasion for T4 lesions. For patients with residual or recurrent carcinoma, anorectal excision offers the best chance of oncological salvage. Pathological staging systems for anorectal excision specimens were validated at the time when surgical treatment was first line therapy. A validated staging system is necessary for salvage surgical excision specimens following an attempt to cure by radiotherapy and chemotherapy for the purpose of prognosis and further treatment planning.

Anus Neoplasms↗
PubMed2003

Fat distribution is altered in HIV-infected men without clinical evidence of the HIV lipodystrophy syndrome.

OBJECTIVE: To determine if fat distribution is altered in HIV-infected men without clinical evidence of lipodystrophy. METHODS: In a cross-sectional design, 14 protease inhibitor (PI)-treated men with lipodystrophy and 12 PI-treated and five PI-naive men without clinical evidence of lipodystrophy underwent body composition and fat distribution analysis by dual-energy X-ray absorptiometry and computed tomography. Their fat distribution was compared to 43 uninfected male controls matched for age and BMI. RESULTS: The percent of body fat in the trunk of men with HIV lipodystrophy was significantly greater compared to both HIV-infected and healthy controls. The percentage of body fat in the extremities was significantly lower in men with HIV lipodystrophy compared to both HIV-infected and healthy controls. HIV-infected men without clinical evidence of lipodystrophy also had a significantly greater percentage of total body fat in the trunk and a significantly lower percent of body fat in the extremities compared to healthy controls. Among the HIV-infected men, age was an independent predictor of truncal and extremity adiposity. CONCLUSION: This study suggests that a continuum of change is present in the adipose organ of HIV-infected men on antiretroviral therapy. Physical examination alone can miss significant changes in body fat distribution in HIV-infected patients.

Abdomen↗
PubMed2003

Validation of the stages of change with mild, moderate, and strenuous physical activity behavior, intentions, and self-efficacy.

The stages of change construct of the Transtheoretical Model (TTM) has been proposed for examining exercise adoption. Studies investigating the construct validity of the stages of change for exercise have used physical activity of moderate or higher intensity as operationalization criterion. Since it has been shown that physical activity of lower intensity also provides health benefits, we investigated whether the stages of change appropriately address lower intensity physical activity. Data with respect to the stages of change as well as behavior, intention and self-efficacy associated with mild, moderate, and strenuous exercise were collected in a sample of 467 males and females aged 20 - 85. Results show that the stages of change can be distinguished by moderate and strenuous but are not consistent with mild exercise. Implications for future research utilizing the stage of change conceptualization are discussed and development of new stage assessment instruments for mild exercise is recommended.

Adult↗
PubMed2003

The accumulation of potentially-toxic metals by grazing ruminants.

The main factors affecting the accumulation of potentially-toxic metals (PTM) by grazing animals are the presence of the metal, its concentration in herbage and at the soil surface, and the duration of exposure to the contaminated pasture and soil. In addition, the elapsed time between the contamination of the pasture and grazing, the quantity of soil ingested together with herbage, the mechanism of absorption of the metal into blood and the presence or absence of antagonistic metals can interact to influence the rate and extent of accumulation of heavy metals in edible body tissues. Models of the accumulation of metals by grazing animals may be used to determine the statutory limits of radionuclides and PTM in soils under grazed pastures. Meta-analysis of existing data, using a random-effects model, is a useful approach to understanding the factors affecting the accumulation of some metals, e.g. Cd. The target edible body tissues for the accumulation of most PTM are the liver and kidneys, with the exception of radiocaesium, which accumulates in muscle to a greater extent than in other tissues. The livers and kidneys of mature livestock that have been grazed on areas of pasture at the legal limit of contamination by Cd for more than one grazing season should be removed from the human food chain in order to reduce the risk of intake of Cd by the human population.

Animal Feed↗
PubMed2003

The development and evaluation of a drug information leaflet for patients with rheumatoid arthritis.

OBJECTIVES: To develop and assess the effectiveness of a drug information leaflet (DIL) for D-penicillamine (DPA) and determine whether additional verbal information provides enhanced benefit. METHODS: Three preliminary studies were undertaken: a reading age study; the development of a DIL for DPA; and a DPA knowledge questionnaire. The primary study assessed the effect of the DIL on the knowledge of 30 patients at weeks 0 and 24 after commencing DPA. A follow-up study of 100 patients randomly assigned to receive the DIL alone (control group) or with additional verbal backup (experimental group) determined the effects of additional verbal information by comparison of DPA knowledge questionnaire scores at weeks 0 and 24. RESULTS: The reading study showed that 12% of the sample had difficulty reading and so the DPA DIL was designed to be easy to read using the Flesch Reading Index. An assessment of knowledge of DPA prior to reading the DIL resulted in scores ranging from 0 to 13 with a median of 2 (maximum possible 14). By week 24 the median score was 10 (range 6-14), which was significant at P < 0.0001. The assessment of additional verbal backup showed that both the control group and the experimental group knew little about DPA on study entry, with a median score 2 in each group. On study exit, both groups knew significantly more (P < 0.001) about the drug; the control group scored 9 and the experimental group 11 (not significantly different; P=0.109). CONCLUSIONS: A large minority of patients have poor reading skills, but when a DIL is designed to be easy to read patients gain significant amounts of knowledge from it. Providing additional verbal explanations did bring about increases in knowledge but these were not significant.

Adolescent↗
PubMed2003

Effects of rheumatoid arthritis on sexual activity and relationships.

OBJECTIVES: The primary aim of this research was to assess patients' perceptions of the effects of rheumatoid arthritis (RA) on their sexual relationship and sexual activity, the causes of any difficulties and who they would turn to for help. METHODS: A self-report questionnaire was distributed to 74 patients attending a regional rheumatology clinic and returned by prepaid post. Fifty-nine questionnaires were returned (response rate 80%) and 57 of them were usable. RESULTS: Thirty-five per cent of the cohort thought that their disease strained their relationship with their partner, and reasons for this included curtailment of daily and social activities, changes in the balance of the relationship, emotional changes and changed financial circumstances. Over half (56%) of the patients found that their arthritis placed limitations on sexual intercourse and the principal reasons cited were fatigue and pain. Sexual ability was important to 58% of the sample and ageing had a negative impact on its importance (P<0.005). Poor communication was a major problem, patients being reluctant to approach health professionals and vice versa. The topic of sexual relationships was broached with patients attending one nurse practitioner's clinic, but only one other patient had ever been offered any discussion. Thirty-nine per cent of the cohort would consider talking to someone if they had a problem and the nurse and the doctor were the professionals most often chosen. CONCLUSION: RA impacts on the sexual lives of a large minority of patients and this is a problem that patients and health professionals are reluctant to discuss face to face. However, patients do appear to be willing to complete questionnaires and this may be an acceptable format for assessment. Further training and support is needed by nurses and other health professionals in this sadly neglected area.

Adult↗
PubMed2003

Expression of heterologous O-antigen in Yersinia pestis KIM does not affect virulence by the intravenous route.

All strains of Yersinia pestis examined have been found to lack an O-antigen. In other members of the Enterobacteriaceae, the rough phenotype often results in attenuation. However, Y. pestis is the aetiological agent of bubonic plague. In evolving from the ancestral enteropathogenic Yersinia pseudotuberculosis, and with the development of an arthropod-vectored systemic pathogenesis, smooth LPS production is not necessary for Y. pestis virulence and the metabolic burden has been alleviated by inactivation of the O-antigen biosynthetic operon. To investigate this, Y. pestis strain KIM D27 was transformed with a plasmid carrying the operon encoding the O-antigen of Yersinia enterocolitica O : 3. Expression of the O-antigen could be detected in silver-stained gels. The receptor for bacteriophage phiYeO3-12 has been shown to be O-antigen, and infection by this bacteriophage results in lysis of Y. enterocolitica O : 3. Expression of the O-antigen in Y. pestis conferred sensitivity to lysis by phiYeO3-12. The O-antigen-expressing clone was shown to be as virulent in mice by the intravenous route of challenge as the rough wild-type. Assays showed no alteration in the ability of Y. pestis to resist lysis by cationic antimicrobial peptides, serum or polymyxin.

Animals↗
PubMed2003

Specialist vaccination advice and pockets of resistance to MMR vaccination: lessons from an outbreak of measles.

An outbreak of measles was associated with a private nursery school in north west London. Sixteen cases were identified of whom 13 were laboratory confirmed. The majority of cases were aged three years or younger. Older cases were siblings of younger cases. None of the cases had been vaccinated against measles. In the nursery school 33% of the children had not received MMR vaccination. Based on specialist advice from the Health Protection Agency the outbreak control team recommended that children with no history of MMR vaccination should have a first MMR dose as soon as possible and that children with one MMR dose should receive the second dose as soon as possible (minimum of one month between doses). Some parents had strong negative views about MMR and represented 'pockets of resistance' to vaccination advice. The specialist vaccination advice, which was different to national immunisation guidelines, also caused some confusion amongst other health professionals. With a decrease in MMR vaccination uptake and resulting increased potential for future measles outbreaks, clinicians should be aware of and understand specialist vaccination advice intended to deal with outbreaks.

Child↗
PubMed2002

Genome sequencing of a 239-kb region of rice chromosome 10L reveals a high frequency of gene duplication and a large chloroplast DNA insertion.

In this study we describe a 239-kb region on the long arm of rice chromosome 10 that contains a high density (71%) of locally duplicated genes, including 24 copies of a glutathione S-transferase gene. Intriguingly, embedded within this cluster is a large insertion (approximately 33 kb) of rice (Oryza sativa) chloroplast DNA that is derived from two separate regions of the chloroplast genome. We used DNA fiber-based fluorescence in situ hybridization (fiber-FISH) analyses of O. sativa spp. japonica nuclei to confirm that the insertion of organellar DNA was not a cloning artifact. The sequence of the chloroplast insertion is nearly identical (99.7% identity) to the corresponding regions in the published rice chloroplast genome sequence, suggesting that the transfer event occurred recently. PCR amplification and sequence analysis in two subspecies of rice, O. sativa spp. japonica and spp. indica, indicates that the transfer event predated the divergence of these two subspecies. The chloroplast insertion is flanked by a 2.1-kb perfect direct repeat that is unique to this location in the rice genome.

Base Sequence↗
PubMed2002

Anti-V antigen antibody protects macrophages from Yersinia pestis -induced cell death and promotes phagocytosis.

The pathogenic Yersinia spp. harbor a common plasmid (pYV) essential for virulence. The plasmid encodes a type III secretion system that functions to translocate Yersinia outer proteins (Yops) into the host cytosol. Within the host cell, the Yops act to inhibit phagocytosis and induce apoptosis. One of the plasmid-encoded proteins, virulence antigen (V), is a major protective immunogen that is involved in Yop translocation. Yersinia pestis, like the enteric Yersinia spp., was both resistant to phagocytosis by and cytotoxic for J774.A1, a murine macrophage cell line. Both of these activities were dependent on culture of the bacteria at 37 degrees C for 1.5-2 h before infection. However, extending the preculture period at 37 degrees C to 24 h, which induced formation of a capsule, completely blocked cytotoxicity. Treating the bacteria with either rabbit polyclonal anti-V antibodies (R anti-V) or monoclonal antibody (MAb) 7.3, antibodies specific for V and protective against plague in vivo, protected J774.A1 cells from Y. pestis -induced cell death and also reversed the inhibition of phagocytosis. Whereas protection against cell cytotoxicity was afforded by the F(ab')(2) portion of R anti-V, the ability of anti-V to induce uptake of Y. pestis appeared to be dependent on the Fc portion of the Ab. The protective epitope(s) recognized by R anti-V was contained in the central region of Y. pestis V (aa 135-275) and were partially cross reactive with Y. pseudotuberculosis and Y. enterocolitica serotype 08 V antigens.

Animals↗
PubMed2002

Ammonia emission, deposition and impact assessment at the field scale: a case study of sub-grid spatial variability.

A local ammonia (NH3) inventory for a 5x5 km area in central England was developed, to investigate the variability of emissions, deposition and impacts of NH3 at a field scale, as well as to assess the validity of the UK 5-km grid inventory. Input data were available for the study area for 1993 and 1996 on a field by field basis, allowing NH3 emissions to be calculated for each individual field, separately for livestock grazing, livestock housing and manure storage, landspreading of manures and fertiliser N application to crops and grassland. An existing atmospheric transport model was modified and applied to model air concentrations and deposition of NH3 at a fine spatial resolution (50 m grid). From the mapped deposition estimates and land cover information, critical loads and exceedances were derived. to study the implications of local variability for regional NH3 impacts assessments. The results show that the most extreme local variability in NH3 emissions, deposition and impacts is linked to housing and storage losses. However, landspreading of manures and intensive cattle grazing are other important area sources, which vary substantially in the landscape. Overall, the range of predicted emissions from agricultural land within the study area is 0-2000 kg N ha(-1) year(-1) in 1993 and 0-8000 kg N ha(-1) year(-1) in 1996, respectively, with the peak at a poultry farm located in the study area. On average, the estimated field level NH3 emissions over the study area closely match the emission for the equivalent 5-km grid square in the national inventory for 1996. Deposition and expected impacts are highly spatially variable, with the edges of woodland and small "islands" of semi-natural vegetation in intensive agricultural areas being most at risk from enhanced deposition. Conversely the centres of larger nature reserves receive less deposition than average. As a consequence of this local variability it is concluded that national assessments at the 5 km grid level underestimate the occurrence of critical loads exceedances due to NH3 in agricultural landscapes.

Agriculture↗
PubMed2002

A prospective study of the incidence and open-label treatment of interferon-induced major depressive disorder in patients with hepatitis C.

Interferon (IFN) therapy has been associated with the development of Major Depressive Disorder (MDD) when given to patients with hepatitis C (HCV). The incidence, time course, risk factors, and treatment of IFN-induced MDD are poorly understood. The objectives of the present study were to determine the incidence of IFN-induced MDD, as well as to determine the efficacy of open-label antidepressant treatment, in particular selective serotonin reuptake inhibitors (SSRIs) for IFN-induced MDD. Thirty-nine HCV patients on IFN therapy were monitored weekly using the Beck Depression Inventory (BDI). Those who became depressed were treated with citalopram, a SSRI antidepressant. Main outcome measures included the incidence of IFN-induced MDD, as well as response rates to antidepressants in those patients who developed IFN-induced MDD. Our results showed that 13 of 39 patients (33%) developed IFN-induced MDD. There were no differences in age, gender, past history of MDD, or substance use between those who became depressed and those who did not. However, there were significantly fewer African American patients in the depressed group. Patients who developed IFN-induced MDD were on IFN therapy for an average of 12.1 weeks prior to the development of MDD. Eleven of 13 patients (85%) were responsive to antidepressant treatment. We conclude that IFN-induced MDD is common in HCV patients. Health care providers should follow IFN-treated HCV patients for the development of MDD, particularly between the 2nd and 5th months of IFN therapy. SSRIs, in particular citalopram, are an effective treatment for IFN-induced depression in HCV patients.

Adult↗
PubMed2002

Two cases of immune haemolytic anaemia, associated with anti-piperacillin, detected by the 'immune complex' method.

BACKGROUND AND OBJECTIVES: Sera containing antibodies to penicillin and penicillin-related drugs are typically thought to react with drug-coated red blood cells (RBCs) (drug adsorption method), but not when the sera are added to drug and RBCs in the same tube ('immune complex' method). Two cases of immune haemolytic anaemia caused by anti-piperacillin have been previously described. Serological details were given in only one patient. In that subject, the antibody was immunoglobulin (Ig)M + IgG and reacted by both the drug adsorption and 'immune complex' methods. MATERIALS AND METHODS: Two patients with cystic fibrosis developed positive direct antiglobulin tests (DATs) and haemolytic anaemia after 11-12 days of piperacillin therapy. Serological studies were performed with piperacillin, Zosyn (piperacillin + tazobactam) and penicillin by using the drug adsorption and 'immune complex' methods. RESULTS: The first patient's serum contained an IgG, complement-activating anti-piperacillin that reacted by the 'immune complex' method only. The second patient's IgM + IgG, complement-activating anti-piperacillin reacted by the 'immune complex' method and agglutinated piperacillin-treated RBCs. An eluate from the patient's RBCs reacted weakly with all RBCs tested without the presence of drug. This patient had evidence of intravascular haemolysis and died. CONCLUSIONS: We describe the third and fourth examples of immune haemolytic anaemia caused by anti-piperacillin; one was associated with fatal haemolytic anaemia. As piperacillin is commonly used in the treatment of cystic fibrosis, anti-piperacillin should be considered whenever patients with cystic fibrosis develop haemolytic anaemia and/or positive DATs.

Adult↗
PubMed2002

Preperitoneal approach to parastomal hernia with coexistent large incisional hernia.

OBJECTIVE: To assess the outcome of preperitoneal mesh repair of complex incisional herniae incorporating a stoma and large parastomal hernia. METHODS: From 1994 to 1998, symptomatic patients who had repair of combined incisional hernia and parastomal hernia were reviewed. Body mass index, co-morbidity, length of hospital stay, patient satisfaction and outcomes were recorded. RESULTS: Ten patients (seven females and three males), mean age 62 (range 48-80) years underwent primary repair. All had significant comorbidities (ASA grade 3) and mean body mass index was 31.1 (range 20-49). Median hospital stay was 15 (range 8-150) days. Complications were of varying clinical significance (seroma, superficial infection, major respiratory tract infection and stomal necrosis). There were no recurrences after a mean follow up of 54 (range 22-69) months. CONCLUSION: The combination of a parastomal hernia and generalised wound dehiscence is an uncommon but difficult problem. The application of the principles of low-tension mesh repair can provide a satisfactory outcome and low recurrence rate. This must be tempered by recognition of the potential for significant major postoperative complication.

Journal Article↗