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Biomedical subjects

J B Ellis

Publications and source records attributed to J B Ellis.

At least 19 recordsLinked to original sources
PubMed2006

Pharmaceutical and personal care products (PPCPs) in urban receiving waters.

The transport pathways of pharmaceutical and personal care products (PPCP) discharges within the urban water cycle include both combined and separate sewer systems with only the former receiving treatment. The dry-weather flow dilution patterns for selected PPCPs following discharge from a sewage treatment works (STW) to a North London stream indicate a persistent downstream increase in concentration. The dilution ratio analysis also indicates that the STW's final effluent only contributes a dilution of the endogenous concentrations already present in the river flow which reflects a progressive PPCP load with increasing urbanization; "worst-case" scenarios being probably related to wet-weather conditions. Maximum PPCP concentrations fall above the reported PEC levels and the analysis highlights the deficiencies of conventional acute toxicity for the evaluation of long-term effects of episodic urban discharges. Groundwater analysis points to sewer exfiltration which is limited in terms of PPCP impact to 25-50 cm depths.

Cities↗
PubMed2005

Factors influencing exfiltration processes in sewers.

Exfiltration from sewers is widespread and emerging legislation may require water service providers to identify, and rectify, its sources in sewerage systems. This paper describes exfiltration test apparatus and a series of experiments undertaken using sewage to gain a better understanding of the influence of sewage solids and sediments on leakage rates. An overview of the results obtained is given, which demonstrates that most previous estimates of exfiltration leakage rates were too high due to a lack of appreciation of the "self-repairing" action of sewage and sewage associated solids. Exfiltration rates of 0.1% of the sewer flow or 0.001 I/s have been recorded for defects up to 6 mm wide.

Equipment Failure↗
PubMed2005

Constructed wetlands in UK urban surface drainage systems.

This paper presents the outcome of an inventory of planted wetland systems in the UK which are classified according to land use type and are all examples of sustainable drainage systems. The introduction of constructed wetlands to treat surface runoff essentially followed a 1997 Environment Agency for England and Wales report advocating the use of "soft engineered" facilities including wetlands in the context of sustainable development and Agenda 21. Subsequently published reports by the UK Construction Industry Research and Information Association (CIRIA) have promoted the potential benefits to both developer and the community of adopting constructed wetlands and other vegetated systems as a sustainable drainage approach. In addition, the UK Environment Agency and Highways Agency (HA) have recently published their own design criteria and requirements for vegetative control and treatment of road runoff. A case study of the design and performance of a constructed wetland system for the treatment of road runoff is discussed. The performance of these systems will be assessed in terms of their design criteria, runoff loadings as well as vegetation and structure maintenance procedures. The differing design approaches in guidance documents published in the UK by the Environment Agency, CIRIA and HA will also be evaluated.

Data Collection↗
PubMed2004

Multicriteria decision approaches to support sustainable drainage options for the treatment of highway and urban runoff.

The control and treatment of urban and highway runoff involves a variety of stakeholders in the selection of sustainable drainage systems (SUDS) as the design process needs to consider not only water quantity but also water quality and amenity. Thus, technical, environmental/ecological, social/community and economic cost factors become prime potential sustainability criteria in terms of assessing long-term, cost-effective drainage options. The paper develops a multicriteria analysis methodology for the evaluation and accreditation of SUDS structures within the context of an overall decision-support framework. Approaches independently developed in the UK and France are outlined with the common multicriteria structures defining generic performance criteria together with supporting benchmark standards and exclusion thresholds. A French case study is presented to illustrate the approach and to highlight the inherent constraints and subjectivity embedded in the decision-making process.

Benchmarking↗
PubMed2003

Experimental studies of sewer exfiltration.

The effects of joint openings and in-pipe sediment on exfiltration losses in an experimental sewer are reported and the influence of flow and head on loss rates are also evaluated. Exfiltration rates tend to be exponential with changes in head for clean-water tests but exhibit power functions when the pipe is subject to sedimentation. In-pipe sediment leads to an effective sealing of joints especially if the invert deposits are both organic in nature and contain saturated adhesive material such as shredded toilet tissue. Simple tracer techniques are described to quantify exfiltration losses and the potential effects of tracer adsorption by pipe solids are evaluated.

Adsorption↗
PubMed2002

Sewer losses and interactions with groundwater quality.

Inflow/infiltration (I/I) and infiltration/exfiltration (I/E) are interactive processes which dynamically affect sewer and groundwater performance. The incidence and condition of "critical" sewers in the UK are identified together with chemical and bacterial methods of quantifying I/E and its potential impact on sewer performance and on urban groundwater pollution. Whilst the impacts of I/E do not appear to be substantial on the basis of existing evidence, some caution is advocated in respect of long term sewer sustainability.

Equipment Failure↗
PubMed2000

Risk assessment approaches for ecosystem responses to transient pollution events in urban receiving waters.

Alternative risk assessment approaches are reviewed for the evaluation of the ecological status and health of urban receiving waters subject to intermittent pollution events. Performance-based criteria founded on exceedance probabilities and related to the end-of-pipe discharge of chemical-specific substances comprise the conventional basis for setting regulatory standards in both North America and Europe. The difficulties and limitations of this approach, particularly in identifying realistic chronic, sub-lethal toxic risks arising from complex effluents are discussed. The potential role of Toxicity Based Criteria (TBC) for setting ecological consent limits for stormwater effluents is considered and the capabilities and limitations of Direct Toxicity Assessment (DTA) are identified. The inability of DTA procedures to satisfactorily evaluate chronic, sub-lethal risks has led to increasing interest in the potential use of in-situ biomarker techniques for the fingerprinting of stress-response properties as a means of diagnosing risk assessment for integrated urban runoff management.

Ecosystem↗
PubMed1997

The treatment of systemic candidiasis in neonates with oral fluconazole.

Fungal septicaemia has become a frequent problem in neonatal intensive care units. The usual treatment for this condition, amphotericin B alone or in combination with 5-fluorocytosine, is sometimes unsatisfactory, especially in neonates. We report our experience of fluconazole in neonates. Neonates who developed Candida septicaemia in the neonatal unit of Ga-Rankuwa Hospital (MEDUNSA) over a 1-year period were treated with oral fluconazole. The diagnosis was based on fungal cultures obtained from sites which are normally sterile. Blood cultures and renal, haematological and liver functions were monitored regularly. Therapy was continued for at least 1 week after the first negative culture was obtained. Twenty-one neonates were treated; the clinical and microbiological cure rate was 90.5%. No serious renal, haematological or hepatic complications were detected; mild hepatotoxicity was evidenced by elevated enzymes in a third of the children. Relapse occurred in one baby who received inadequate doses of fluconazole. Two babies died of causes unrelated to a systemic fungal infection. We conclude that fluconazole may be a safe and effective alternative for the management of systemic candidiasis in neonates. A comparative trial is necessary.

Antifungal Agents↗
PubMed1996

Fluconazole vs. amphotericin B for the treatment of neonatal fungal septicemia: a prospective randomized trial.

OBJECTIVE: Fungal septicemia is a devastating disease in the neonate, especially in the low birth weight preterm infant who is especially vulnerable to disseminated fungal sepsis. The objective of this study was to compare the efficacy, safety and overall convenience of fluconazole vs. amphotericin B for the treatment of disseminated fungal sepsis in neonates. DESIGN: A prospective, randomized, collaborative study conducted at two South African neonatal units. SUBJECTS: Twenty-four infants with proven fungal septicemia were treated from June, 1992, to June, 1993. Twelve received fluconazole, 11 received amphotericin B and 1 was excluded. Assessment of hepatic, renal and hematologic functions were performed before, during and after treatment. The two groups were comparable at the time of enrollment into the study. RESULTS: Infants receiving amphotericin B had significantly higher values of total and direct bilirubin and alkaline phosphatase values at the end of treatment, while the fluconazole group showed a significant increase in the platelet count. The cumulative total numbers of days receiving intravenous therapy for the administration of antifungal drugs were 57 for the fluconazole group and 162 for the amphotericin group; no central lines were needed in the fluconazole group, whereas 3 babies given amphotericin B had central catheters for a cumulative total of 27 days. The case fatality rate was 33% in the fluconazole group and 45% in the amphotericin B group; there was still proof of fungal septicemia at the time of death in 1 patient given amphotericin B and 2 given fluconazole. CONCLUSION: Fluconazole showed fewer side effects than amphotericin B and was more convenient to use.

Administration, Oral↗
PubMed1995

Family support and other social factors precipitating suicidal ideation.

To examine the effects of family support and demographics on suicidal behavior, 385 subjects completed a demographic questionnaire and a Suicidal Ideation Questionnaire (SIQ). Sixteen percent described themselves as "serious" ideators, while 59% were seen as ideators, numbers consistent with past suicide research. Multiple regression analyses revealed that the type of caregiver a person reported having while growing up accounted for a significant amount of the variance on ideator status. Serious ideators were more common among single parent households. Although many demographic variables were assessed, only the primary caregiver a person had as a child impacted their status as a suicidal ideator. This suggests that suicidal behaviors may occur due to a complex interaction between social factors and childhood care. The influence of living in a single-parent home may contribute to whether or not a person considers suicide.

Adolescent↗
PubMed1994

Paraffin ingestion--the problem.

Paraffin ingestion is the commonest cause of accidental childhood poisoning in South Africa. Children from the lower socio-economic group are affected most. They drink paraffin in the summer months from bottles or intermediate containers, mistaking it for water or cold-drink. The children are predominantly male with a mean age of 24 months. The clinical picture is one of respiratory distress with a hospital case fatality rate of 0.74%. The use of paraffin as a source of household energy in South Africa is on the increase. Based on a modernisation index it would seem that this trend will continue into the next century. It can therefore be expected that the number of cases of paraffin ingestion will steadily increase if no active steps are taken to address the problem. Prevention should entail a wide spectrum of measures, the basis of which should be a child-resistant container. An effective durable, low-cost child-resistant container which is easy to pour from should be made available by petroleum companies and/or entrepreneurs and distributed through their network. This should be combined with health education on the danger of paraffin. Health care workers and administrators should be made more aware of the problem and become involved in health education and prevention. Further research should be undertaken on the effect a change in the colour of paraffin and the use of child-resistant caps would have on the incidence of paraffin ingestion in South Africa.

Accidents, Home↗
PubMed1994

The impact of child-resistant containers on the incidence of paraffin (kerosene) ingestion in children.

The commonest cause of accidental poisoning in the South African black paediatric population is paraffin ingestion. In this intervention study a specifically designed child-resistant container (CRC) was introduced to evaluate whether its use would decrease the incidence of paraffin ingestion. CRCs were distributed to 20,000 households in the study area (Gelukspan district). No CRCs were distributed in the control area (Lehurutshe district). Health education about paraffin poisoning prevention was given in both the control and the study areas. The monthly incidence rates of paraffin ingestion were monitored during the 14-month intervention period after the distribution and were compared with the pre-intervention incidence rates in the study and control areas. The main finding was that the incidence of paraffin ingestion dropped by 47% in the study area during the intervention period. The circumstances surrounding the cases of paraffin ingestion that still occurred in the study and control areas were investigated by means of a questionnaire. We recommend that paraffin be sold in CRCs, and suggestions are made for improving health education to prevent paraffin poisoning.

Accidents, Home↗
PubMed1992

Mood influences on reasons for living in older adolescents.

Suicide is a major public health problem of the current period, particularly among young people, and is the second leading cause of death among the 15- to 24-year-old age group (Rudd 1989). Moreover, the suicide rate among the nation's youth has increased dramatically in the last two decades, an increase that amounts to having tripled in the years 1956 to 1975 (Holinger 1982).

Adaptation, Psychological↗
PubMed1992

The proposed death certificate for South Africa. Part I. Death certificate description.

An altered 'Cause of Death' certificate is proposed. The major changes involve the use of the international format for certification of death and provision for collection of extra data, i.e. estimated age at death, sex, population group and, where relevant, the mass of an infant at birth. The new format will facilitate improved data collection and the certificate will stand international comparison.

Data Collection↗
PubMed1992

The proposed death certificate for South Africa. Part II. Feasibility study.

The proposed new death certificate was tested in urban and rural hospitals and among general practitioners. Of the 471 death certificates returned, 70% were correctly completed. The underlying cause of death was identifiable in 86.6% of cases. The accuracy of cause of death statements was analysed in greater detail. Some items on the proposed form were not clear and needed improvement, i.e. instructions to mark an applicable answer and refer to instructions on the reverse page. The participants completed a questionnaire to assess and comment on the new form. A refined version thereof was prepared as a result of this study.

Cause of Death↗
PubMed1991

Diagnosis-related groups--application in a paediatric department.

The Diagnosis-Related Groups (DRG) system is used in the USA to classify patients on the basis of diagnosis into medically meaningful groups. The system was developed for evaluation of resource utilisation for peer review purposes. It has become better known through being utilised by Medicare, the medical insurance system for the poor in the USA, for prospective determination and payment of patient's hospitalisation costs. A pilot study to compare the costs of hospital care in a sample of the paediatric patient population at Ga-Rankuwa Hospital with the DRG weightings was undertaken to assess its application locally. A poor correlation was found. The costing studies conducted for this purpose were also used to compare resource use between units in the Department of Paediatrics, and substantial unexplained variations were found. It is concluded that the weightings used in the US DRG system cannot be directly applied to the patients at Ga-Rankuwa Hospital for billing purposes. The DRG principle, however, is feasible and has important management benefits; it is recommended that locally determined DRG weightings be developed, and that other hospitals explore their use in peer review of resource management, costing and pricing.

Diagnosis-Related Groups↗