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Biomedical subjects

A Thornton

Publications and source records attributed to A Thornton.

At least 19 recordsLinked to original sources
PubMed2006

Ammonium removal from digested sludge liquors using ion exchange.

Liquors arising from the dewatering of digested sludge typically contain ammonium levels in the range 200-700mgl(-1) NH(4)(+)-N. These liquors are frequently recycled to the head of the wastewater treatment works (WwTW) untreated and can constitute >25% of the total nitrogen load entering the works at inlet. This paper investigates the use of a clay-based material, MesoLite, as an ion exchange medium for ammonium removal from recycle streams. Pilot-scale studies performed at Didcot WwTW, part of the Thames Water wastewater treatment network, indicate that MesoLite is highly selective for the ammonium ion. Results show that >95% of ammonium was removed from belt press liquors with an initial ammonium nitrogen concentration >600mgl(-1), with an overall ion exchange capacity >51g NH(4)(+)-Nkg(-1) medium and this resulted in an operating capacity in the range 27-36gNH(4)(+)-Nkg(-1).

Aluminum Silicates↗
PubMed2006

HER2 signaling modulates the equilibrium between pro- and antiangiogenic factors via distinct pathways: implications for HER2-targeted antibody therapy.

We determined the impact of HER2 signaling on two proangiogenic factors, vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8), and on an antiangiogenic factor, thrombospondin-1 (TSP-1). Re-expression of HER2 in MCF-7 and T-47D breast cancer cells that endogenously express low levels of HER2 resulted in elevated expression of VEGF and IL-8 and decreased expression of TSP-1. Inhibition of HER2 with a humanized anti-HER2 antibody (trastuzumab, or Herceptin) or a retrovirus-mediated small interfering RNA against HER2 (siHER2) decreased VEGF and IL-8 expression, but increased TSP-1 expression in BT474 breast cancer cells that express high levels of HER2. These in vitro results were further evaluated by treatment of BT474 xenografts in immunosuppressed mice with trastuzumab. Trastuzumab inhibited growth of BT474 xenografts and decreased microvascular density associated with downregulation of VEGF and IL-8 and with upregulation of TSP-1 expression. Inhibiting the PI3K-AKT pathway decreased VEGF and IL-8 expression. AKT1 overexpession increased VEGF and IL-8 expression, but did not increase TSP-1 expression. A p38 kinase inhibitor, SB203580, instead blocked TSP-1 expression and a p38 activator, MKK6, increased TSP-1 expression. Trastuzumab stimulated sustained p38 activation and SB203580 attenuated the TSP-1 upregulation induced by trastuzumab. HER2 signaling therefore influences the equilibrium between pro- and antiangiogenic factors via distinct signaling pathways. Trastuzumab inhibits angiogenesis and tumor growth, at least in part, through activation of the HER2-p38-TSP-1 pathway and inhibition of the HER2-PI3K-AKT-VEGF/IL-8 pathway.

Animals↗
PubMed2006

Safety of iron polymaltose given as a total dose iron infusion.

An audit of the in-hospital safety and tolerability of 401 infusions of iron polymaltose in 386 patients has shown no cases of anaphylaxis or other cardiorespiratory compromise. The infusion was terminated prematurely because of adverse events in six patients (1.6%). No adverse events occurred within the first 15 min of the infusion. Premedication (in 24%) was not associated with fewer adverse events. Fear of anaphylaxis should not inhibit the use of total dose iron infusion and the practices of premedication and of medical supervision during the first 15 min of the infusion should be abandoned.

Adolescent↗
PubMed2005

Sources of priority substances entering an urban wastewater catchment--trace organic chemicals.

The implementation of new legislation such as the Water Framework Directive (WFD) requires Member States to gain a better understanding of priority substances entering surface waters. This will include inputs from wastewater treatment works as well as from other urban, industrial and agricultural sources. There is currently a lack of available data regarding the magnitude and sources of organic priority substances entering treatment works. As a consequence the concentrations of organic priority substances including PAHs, surfactants, polybrominated diphenylethers (PBDEs), diethylhexyl phthalate (DEHP), pesticides and solvents were determined in the wastewater from an urban catchment located in the UK, as part of a project undertaken for UK Water Industry Research (UKWIR). Most organic priority substances were detected in the microg/l range. Significant variations in the concentration of linear alkylbenzene sulphonate (LAS), DEHP, PBDEs and nonylphenol ethoxylates (NPEOs), in particular, were observed for the different sources. The greatest differences were evident between new and older domestic discharges. Solvent levels varied considerably reflecting use and production within the catchment. Chloroform levels were highest in domestic effluent, while trichloroethene and tetrachloroethene were detected only in commercial samples.

Organic Chemicals↗
PubMed2005

Diffuse sources of heavy metals entering an urban wastewater catchment.

New legislation such as the Water Framework Directive (WFD) will require Member States to better understand the concentrations and loads of contaminants entering surface waters. This will include inputs from wastewater treatment plants (WWTP) as well as from other urban, industrial and agricultural sources. A review of available literature revealed a shortage of data on the levels and sources of heavy metals entering WWTP from urban sources. As a consequence, the concentrations of heavy metals (cadmium, chromium, copper, mercury, nickel, lead and zinc) were determined in the wastewater from an urban catchment located in the UK, as part of a project undertaken for UK Water Industry Research (UKWIR). Both foul and surface water samples were taken. Metal concentrations varied considerably in the foul water samples, both between sources and over the course of the week. Concentrations of most metals were higher in the Monday town centre samples, attributed to leaching from stagnant water remaining in the pipework of office buildings over the weekend. Runoff concentrations were higher in the light industrial estate samples than in the domestic samples for all the metals, and exhibited highest levels in the 'first flush' samples, coincident with the initial flow of runoff containing the highest concentrations of suspended solids.

Agriculture↗
PubMed2004

Dementia Care Mapping reconsidered: exploring the reliability and validity of the observational tool.

BACKGROUND: Dementia Care Mapping (DCM) is a widely used observational method for evaluating the service quality provided to people with dementia. However, there is little evidence concerning its reliability and validity when used by routine care staff for whom it was designed. METHOD: The study evaluated levels of inter-observer agreement; The ability of the five-minute time frame to reflect the 'actual passing of time'; And the nature of the relationship between individual Well/Ill-Being values (WIB) and dependency levels. Data collected using DCM and continuous time sampling (CTS) were compared. The methods were used in parallel where the CTS coder and the DCM mapper(s) observed the same participants. Observations were carried out with 64 people with dementia within a day hospital and a continuing care ward. Inter-observer agreement was calculated across 20 participants. Dependency levels were measured using the Clifton Assessment Procedure for the Elderly (CAPE) (Pattie and Gilleard, 1979). RESULTS: Low levels of inter-observer agreement were found where 11 of the 25 Behaviour Category codes and all six Well/Ill-being Codes produced unacceptable kappas (<0.6). The Behaviour coding frame provided a meaningful picture of activities participants engaged in, but significantly underestimated participant levels of inactivity.A strong relationship was demonstrated between participants' WIB score and levels of dependency, thus DCM was unable to measure well-/ill-being as a separate construct from participants' levels of dependency. CONCLUSIONS: Questions were raised regarding the reliability and validity of DCM as used by routine care staff. Possible reasons for this, and suggestions for amendments are made.

Aged↗
PubMed2004

Music interventions for people with dementia: a review of the literature.

This paper provides a qualitative review of 21 published articles of clinical empirical studies looking at the effects of a variety of music activities on the emotional and behavioural responses in people with dementia. General information is reviewed such as the setting and context of studies, research findings and explanatory variables. Methodological issues are also discussed, particularly in relation to observational methods, and theoretical frameworks such as the progressively lowered stress threshold model are evaluated. Music appears to have a range of applications in dementia care but previous reviews have highlighted methodological weaknesses of studies. Recommendations for future research include the use of continuous time sampling methodology and to record the duration of observed behaviours. This review paper also argues for the use of Kitwood's theory of personhood as a framework to inform and guide future research.

Adaptation, Psychological↗
PubMed2004

Emotional and behavioural responses to music in people with dementia: an observational study.

Using continuous time sampling and direct observation methodology, this study examined the impact of social interaction in music listening on behavioural responses of people with moderate-to-severe dementia (n = 24). Using Kitwood's theory of personhood as a framework, it was hypothesized that levels of well-being and engagement would be greatest during a live music condition compared with recorded and no music conditions and that levels of challenging behaviour would decrease most in the live music conditions compared with the other music conditions. The relationship between severity of cognitive impairment and well-being, engagement and challenging behaviours across conditions was also examined. The findings suggest that live music was significantly more effective in increasing levels of engagement and well-being regardless of level of cognitive impairment. No significant differences across conditions were found for challenging behaviours, but the correlation between these and cognitive impairment revealed mixed results. Clinical implications regarding the use of live music in dementia care settings are highlighted and recommendations for future research of interventions aimed at reducing challenging behaviours are discussed.

Aged↗
PubMed2003

The effects of right ventricular apical pacing on left ventricular function. Stimulation of the right ventricular apex: should it still be the gold standard?

Current pacing practice is undergoing continuous and substantial changes. Initially pacing had an exclusively palliative role, since it was reserved for patients developing complete heart block or severe symptomatic bradycardia. With the appearance of novel pacing indications such as pacing for heart failure and atrial fibrillation, the effect of pacing site on cardiac function has become a critically important issue and a subject for consideration. It seems that the classical pacing site in the right ventricular apex is no longer the gold standard because of possible disadvantageous effects on cardiac function. The aim of this review article is to discuss the effect of right ventricular apical pacing on cardiac function including cellular and hemodynamic changes. We also aim to discuss the role of alternative pacing sites in the light of cardiac function.

Journal Article↗
PubMed2001

Potentiation of simian immunodeficiency virus (SIV)-specific CD4(+) and CD8(+) T cell responses by a DNA-SIV and NYVAC-SIV prime/boost regimen.

T cell-mediated immune responses play an important role in the containment of HIV-1 replication. Therefore, an effective vaccine against HIV-1 should be able to elicit high frequencies of virus-specific CD8(+) and CD4(+) T cells. The highly attenuated poxvirus-based vaccine candidate, NYVAC-SIV-gag-pol-env (NYVAC-SIV-gpe), has been shown to induce and/or expand SIV-specific CD4(+) and CD8(+) T cell responses in both naive and infected macaques. In this study, the immunogenicity of NYVAC-SIV-gpe alone was compared with a combination regimen where priming with an optimized DNA-SIV-gag-env vaccine candidate was followed by a NYVAC-SIV-gpe boost. In macaques immunized with the prime-boost regimen, the extent and durability of CD8(+) T cell response to an immunodominant SIV gag epitope was increased and these animals recognized a broader array of subdominant SIV epitopes in the cytolytic assay. In addition, the prime-boost regimen significantly enhanced the proliferative responses to both SIV gag and env proteins. Thus, the combination of these vaccine modalities may represent a valuable strategy in the development of a vaccine for HIV.

Animals↗
PubMed2001

Hypothalamic/pituitary function following high-dose conformal radiotherapy to the base of skull: demonstration of a dose-effect relationship using dose-volume histogram analysis.

PURPOSE: To evaluate the incidence and pattern of hypopituitarism from hypothalamic (HT) and pituitary gland (PG) damage following high-dose conformal fractionated proton-photon beam radiotherapy (PPRT) to the base of skull (BOS) region in adults. The relationship between dose, volume, and PG function is explored. METHODS AND MATERIALS: Between May 1982 to October 1997, 107 adults with non-PG and non-HT neoplasms (predominantly chordoma and chondrosarcomas) of the BOS were treated with PPRT after subtotal resection(s). The median age was 41.2 years (range, 17-75) with 58 males and 49 females. Median prescribed target dose was 68.4 cobalt gray equivalent (CGE) (range, 55.8-79 CGE) at 1.80-1.92 CGE per fraction per day (where CGE = proton Gy x 1.1). The HT and PG were outlined on planning CT scans to allow dose-volume histograms (DVH) analysis. All patients had baseline and follow-up clinical testing of anterior and posterior pituitary function including biochemical assessment of thyroid, adrenal, and gonadal function, and prolactin secretion. RESULTS: The 10-year actuarial overall survival rate was 87%, with median endocrine follow-up time of 5.5 years, thus the majority of patients were available for long-term follow-up. Five-year actuarial rates of endocrinopathy were as follows: 72% for hyperprolactinemia, 30% for hypothyroidism, 29% for hypogonadism, and 19% for hypoadrenalism. The respective 10-year endocrinopathy rates were 84%, 63%, 36%, and 28%. No patient developed diabetes insipidus (vasopressin deficiency). Growth hormone deficiency was not routinely followed in this study. Minimum target dose (Dmin) to the PG was found to be predictive of endocrinopathy: patients receiving 50 CGE or greater at Dmin to the PG experiencing a higher incidence and severity (defined as the number of endocrinopathies occurring per patient) of endocrine dysfunction. Dmax of 70 CGE or greater to the PG and Dmax of 50 CGE or greater to the HT were also predictive of higher rates of endocrine dysfunction. CONCLUSION: Radiation-induced damage to the HT & PG occurs frequently after high-dose PPRT to the BOS and is manifested by anterior pituitary gland dysfunction. Hyperprolactinemia was detected in the majority of patients. Posterior pituitary dysfunction, represented by vasopressin activity with diabetes insipidus, was not observed in this dose range. Limiting the dose to the HT and PG when feasible should reduce the risk of developing clinical hypopituitarism.

Adolescent↗
PubMed2001

Selective inner hair cell loss in premature infants and cochlea pathological patterns from neonatal intensive care unit autopsies.

BACKGROUND: Deafness and handicapping sensorineural hearing impairment occur frequently in neonatal intensive care unit survivors for unknown reasons. PATIENTS AND METHODS: Hearing was tested early and repeatedly in neonatal intensive care unit patients with an auditory brainstem response (ABR) screener. The temporal bones of 15 nonsurvivors (30 ears) were fixed promptly (average, 5 hours) after death for histological evaluation. RESULTS: Among these patients, 12 failed the ABR screen bilaterally, 1 passed unilaterally, and 2 passed bilaterally. Cochlear histopathologic conditions that could contribute to hearing loss included bilateral selective outer hair cell loss in 2 patients, bilateral selective inner hair cell loss in 3 (all premature), and a combination of both outer and inner hair cell loss in 2. Other hair cell abnormalities were noted; the 2 infants who had passed the ABR screen demonstrated normal histological features. Neuronal counts were normal. CONCLUSIONS: Auditory brainstem response failure among these neonatal intensive care unit infants who died was extremely common in part owing to an unexpected histological alteration, selective inner hair cell loss among premature newborns, that should be detectable uniquely by the ABR testing method. Additional histological patterns suggest more than one cause for neonatal intensive care unit hearing loss. Hair cell loss patterns seem frequently compatible with in utero damage.

Cochlea↗
PubMed2001

Profile of first-line nurse managers in New South Wales, Australia, in the 1990s.

AIMS: To determine a demographic profile, employment history and career plans of a sample of nursing unit managers (first-line managers) in New South Wales (NSW), Australia in 1999. To compare the profile of first-line nurse managers in 1999 with those in 1989. BACKGROUND: This study replicates another undertaken a decade earlier (see Duffield 1992). Tracking the changes to nurse manager positions is important, given changes to the educational preparation of nurses and restructuring within hospitals which have occurred in the past decade. METHOD: The same questionnaire was used in both studies, with minor amendments and the addition of two items to reflect changes to organizational structures, whereby nurse managers are now responsible for non-nursing staff. In 1999 all first-line nurse managers in the largest health service in NSW were invited to participate in the study. RESULTS: A response rate of 77% was achieved. There were few differences of note in the demographic profile from 1989 to 1999. However educationally, first-line nurse managers in 1999 were more highly qualified. A greater proportion had higher degrees and increasingly, in the management discipline. CONCLUSION: Perhaps reflecting these qualifications, more managers in 1999 indicated their intention to move to more senior management positions in the next decade. The mode for experience in this role of 1 year in both 1989 and 1999 reflects a worrying trend of high turnover and inexperience amongst this group of managers. While maternity relief might account for this result, further research needs to determine more precise reasons. The ad hoc bases on which expert clinicians (clinical nurse specialists) act as the manager in his/her absence need to be critically examined. Alternative strategies such as introducing a formal second- in-charge position may ensure more successful recruitment and retention of staff to these critical management positions.

Adult↗
PubMed2001

Mutations induced by 2-amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP) in cecum and proximal and distal colon of lacI transgenic rats.

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a food-borne mutagen and carcinogen that induces tumors of the colon and the prostate gland in male rats and of the mammary gland in female rats. In this study we describe the frequency and specificity of PhIP-induced mutations in the cecum, proximal colon and distal colon of male and female lacI transgenic rats. This is the first report of mutational data from discrete regions of the colon. After 61 days of treatment with 200 p.p.m. PhIP mixed into the diet, PhIP-induced mutant frequencies were elevated 7-fold in the cecum and 14- to 21-fold in the colon of male and female rats compared with untreated controls. PhIP-induced mutant frequencies increased significantly (overall trend, P < 10(-4)) along the length of the colon of both males and females, with cecum < proximal colon < distal colon. A total of 754 PhIP mutants (363 male, 391 female) were sequenced to provide the mutational spectra for each of the three tissue sections from males and females. These mutational spectra consisted predominantly of G:C-->T:A and G:C-->C:G transversions and deletions of G:C base pairs. There were no significant differences between the mutational spectra with respect to sex or position in the colon. Therefore, we surmise that following induction of mutations by PhIP in male and female colons, non-mutagenic factors, possibly hormonal, preferentially influence the formation of tumors in the colon of male rats.

Animals↗
PubMed2001

The developmental paradigm, reading history sideways, and family change.

The developmental paradigm, reading history sideways, and cross-cultural data have converged to exert a profound influence on social scientists and ordinary people. Through the use of these tools, social scientists of the 1700s and 1800s concluded that family patterns in northwest Europe had undergone many substantial changes before the early 1800s. These conclusions were accepted until the last several decades of the 1900s, when almost all were seriously challenged; many were declared to be myths. Further, the developmental paradigm, reading history sideways, and the conclusions of generations of social scientists created a package of ideas--developmental idealism--that subsequently became a powerful influence for family change in many parts of the world during the past two centuries. This developmental idealism has been a substantial force for changing living arrangements, marriage, divorce, gender relations, intergenerational relationships, and fertility.

Cross-Cultural Comparison↗
PubMed2000

Development of a pharmacy residency program in home care.

A residency training program developed by a college of pharmacy in conjunction with a home care company is described. The 12-month program is based on the ASHP Residency Learning System and the goal statements and educational objectives of ASHP's accreditation standard for pharmacy practice residency training with emphasis in home care. Establishing the program involved identifying goals, objectives, and learning experiences consistent with the expected outcomes. Specific objectives for meeting goals in four categories--practice foundation skills, direct patient care, drug information and drug policy development, and practice management--were linked to expected program outcomes. Learning experiences that would lead to achievement of the program objectives and outcomes were selected and organized into one- to eight-week rotations (e.g., in acute care, care of pediatric patients, pain management, nutrition, patient education and counseling, and administration and practice management). Throughout the program, residents gain experience in pharmaceutical services and research. Skills in care planning and monitoring are emphasized, as is practicing pharmaceutical care in an interdisciplinary environment. Residents who have completed the program have found employment immediately as pharmacy managers of home infusion centers. Pharmacy residency training in home care provides the experience needed to function as a competent clinician and manager who can identify and solve problems to improve patient care.

Education, Pharmacy↗