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Biomedical subjects

J Kendall

Publications and source records attributed to J Kendall.

At least 19 recordsLinked to original sources
PubMed2007

The optimum reperfusion pathway for ST elevation acute myocardial infarction: development of a decision framework.

There is currently much debate about the relative roles of pharmacological reperfusion (ie, thrombolysis) and mechanical reperfusion (ie, primary percutaneous coronary intervention (PPCI) in the management of patients with acute ST segment elevation acute myocardial infarction (STEMI). Whilst the scientific debate is reaching some resolution in terms of appropriate interpretation of the evidence base, there are still significant resource issues within the UK that limit our ability to implement gold standard reperfusion therapy. Current evidence supports the use of one or other strategy in certain situations depending on various patient-related and logistical factors. This paper reviews the literature and builds the case for developing a strategic approach which includes both mechanical and pharmacological interventions, proposing that these are not mutually exclusive-indeed, that an approach which excludes one of these interventions will not be to the benefit of all patients. There is also a discussion of the role of rescue PPCI, facilitated PPCI and early post thrombolysis angiography in the management of STEMI. Cardiac networks throughout the UK are developing strategies to improve access to these interventions and this paper offers advice on the logical selection of interventions for reperfusion in the context of a clinical decision framework that is evidence-based, pragmatic and develops through a series of scenarios with increasing availability of resources. Four sequential scenarios are presented: the first to set the scene is largely consigned to history; the last, as of yet, is not robustly achievable within the UK, but represents the "optimum reperfusion pathway", to which most cardiac networks are striving. Most of us currently find ourselves in a period of change between the two and will relate to either scenario two or three.

Angioplasty, Balloon, Coronary↗
PubMed2006

Randomized clinical trial to determine the effect of nasogastric drainage on tracheal acid aspiration following oesophagectomy.

BACKGROUND: The aim of this study was to investigate tracheal acid aspiration after oesophagectomy and to determine whether it is influenced by nasogastric (NG) drainage. METHODS: Thirty-four patients undergoing oesophagectomy were randomized to one of three methods of NG drainage: a single-lumen tube with free drainage and 4-hourly aspiration, a sump-type tube on continuous suction drainage, or no NG tube. A tracheal pH probe was used to collect information on acid aspiration for 48 h after surgery. A pH < 5.5 was considered abnormal (normal pH 6.8-7.2). Total time with tracheal pH < 5.5, number of reflux episodes and longest reflux time were compared between groups. RESULTS: There was significant and persistent tracheal acid aspiration in all patients. Patients with a sump-type tube had a significantly shorter total time with tracheal pH < 5.5 than those in the other groups (sump-type tube versus single-lumen tube, P = 0.0069; sump-type tube versus no tube, P = 0.0071). Patients randomized to no NG tube experienced more respiratory complications after surgery than those who had either single-lumen or sump-type tubes (seven of 12 versus four of 22 patients; P = 0.023). Insertion of a NG tube was necessary in the first week after surgery in seven of 12 patients in this group. CONCLUSION: Routine NG drainage after oesophagectomy is necessary. A sump-type NG tube is better at preventing tracheal acid aspiration and may reduce the incidence of respiratory complications.

Acids↗
PubMed2006

The PRIMA study: presentation ischaemia-modified albumin in the emergency department.

OBJECTIVES: To investigate the diagnostic accuracy of presentation ischaemia-modified albumin (IMA), in addition to cardiac troponin I (TnI), as a strategy to rapidly ascribe low risk to patients with chest pain attending an emergency department, and to determine whether IMA has the potential to reduce transit time in emergency departments. METHODS: A prospective observational study was carried out in two emergency departments (belonging to the John Radcliffe Hospital, Oxford, UK; and the Frenchay Hospital, Bristol, UK) of similar size. Consecutive adult patients presenting with features of possible ischaemic cardiac chest pain and a normal electrocardiogram were eligible. The index test (measurement of IMA and TnI at presentation) and reference standard (delayed TnI measurement, taken at least 8 h after pain onset) were applied to all recruited patients. All clinicians were blinded to the results of the index test. Assays were carried out in a single laboratory using standard techniques. RESULTS: 399 patients were recruited; 277 patients had a result for both the index test and reference standard. The sensitivity was 97.6% (95% confidence interval (CI) 87.4 to 99.9), negative predictive value 97% (95% CI 84.2 to 99.9) and specificity 13.6% (95% CI 9.5 to 18.7). Sensitivity analysis showed similar findings in three alternative scenarios. Receiver operating characteristic analysis indicated that a different "cut-off" value for IMA would not improve the properties of the test. The median potential time saved (n = 268) was 6 h and 10 min. CONCLUSION: The diagnostic accuracy of presentation IMA in this study does not support its use as an effective risk stratification tool for patients with chest pain in the emergency department. The sensitivity is insufficiently high, with a small number of false negatives undermining the safety of the test. Frequent false positives produce a low specificity that limits the practical value of the test.

Adult↗
PubMed2006

Effects of storage at -20 degrees C on ischaemia-modified albumin results.

BACKGROUND: Ischaemia-modified albumin (IMA) is being studied as a new marker for reversible ischaemia in patients presenting with possible cardiac chest pain. The conditions under which samples are stored prior to analysis may be critical in influencing the analytical result and hence the cut-off used in any particular study. METHODS: Sixty-eight samples taken during a study assessing the performance of IMA for risk stratification in patients presenting with possible cardiac chest pain were analysed both within 2.5 h of collection and after periods of storage at -20 degrees C. RESULTS: Samples stored at -20 degrees C yielded IMA values on average 3 units higher than those analysed within 2.5 h (mean 90.5 vs. 87.5; P < 0.00001). A Bland-Altman plot showed that the difference was not concentration dependent. CONCLUSIONS: These results indicate that decision cut-offs will be influenced by conditions of sample storage prior to IMA analysis, and that these should be stated in detail for each study.

Freezing↗
PubMed2005

Self-administered subcutaneous fluid infusion at home in the management of fluid depletion and hypomagnesaemia in gastro-intestinal disease.

BACKGROUND AND AIMS: In short bowel fistula and some other gastrointestinal (GI) diseases, salt, water and magnesium (Mg) balance may continue negative despite oral treatment, even in patients with adequate nutritional status. This study describes the use of self-administered subcutaneous fluid infusions (HSCF) to treat this problem. PATIENTS & METHODS: HSCF was administered to patients with GI failure and adequate macro-nutrient status (BMI) when GI salt, water and magnesium balance continued negative despite optimal diet, drug and supplemental treatment. Mg depletion was confirmed using the Mg load test. Patients were taught to self-administer 0.5-1.0 l 0.9% saline +/-0.5 l 5% dextrose +/-2-4 mmol MgSO4 subcutaneously by gravity drip during 6-12 h overnight, 3-7 days/week. Water and Na balance were assessed (weight, serum creatinine, urea, Na) at baseline and at 1 and 3 months of treatment, but also monitored carefully during the first few days of treatment. Serum Mg was measured at baseline and at 2 and 4 weeks. RESULTS: In 10 patients (mean age 65.3+/-13.5 years) Na and water balance was rapidly restored. At baseline, 1 and 3 months, serum biochemical results were: Eight patients received 8-28 mmol MgSO4/week in the infused fluid. Serum Mg [0.7-1.0 mmol] at baseline, 2 and 4 weeks was 0.49+/-0.06, 0.79+/-0.18, 0.83+/-0.10 mmol/l (P=0.002). Tolerance was good; transient oedema developed in 2 patients, resolved by reducing infusion dose. No patient developed hypokalaemia. CONCLUSIONS: Subcutaneous self-administered fluid infusion at home (HSCF) is an easily managed, safe and effective method of restoring and maintaining water, salt and Mg balance in patients with large GI fluid losses but adequate macronutrient status, particularly in the frail or elderly in whom home parenteral nutrition may be difficult.

Aged↗
PubMed2001

Photosensitized (electron-transfer) deconjugation of 1-arylcyclohexenes.

[figure: see text] A series of 1-arylcyclohexenes have been deconjugated to the corresponding 3-arylcyclohexenes via a photosensitized electron-transfer reaction. The introduction of substituents on the aryl group has provided insight into the underlying mechanism and has defined the scope and limitations of the reaction.

Journal Article↗
PubMed2001

Movement and change: independent sector domiciliary care providers between 1995 and 1999.

Promoting the development of a flourishing independent sector alongside good quality public services was a key objective of the community care reforms of the last decade. This paper charts some of the ways the independent domiciliary care sector is changing, as local authorities shift the balance of their provision toward independent sector providers and away from a reliance on in-house services. Two surveys of independent domiciliary care providers were carried out in 1995 and 1999. The aims of the studies were to describe the main features of provider organisations, such as size of business, client group and funding sources; to examine the nature of provider motivations and their past and future plans; to consider how local authorities manage the supply side of social care markets; and to examine the effects on providers of the development of the mixed economy. The first survey in 1995 was conducted in eight local authority areas, which by 1999 had increased to 11 because of the creation of three new unitary authorities. The findings are based on 261 postal surveys together with 111 interviews between the two studies. The research illustrates a domiciliary care market that is still relatively young with many small but growing businesses. There are considerable differences in the split between in-house and independent sector services in individual authorities and a common perception among independent providers that in-house services receive favourable treatment and conditions. Spot or call-off contracts continue to be the most common form of contract although there are moves toward greater levels of guaranteed service and more sophisticated patterns of contracting arrangements. There remains an ongoing need to share information between local authorities and independent providers so that good working relationships can develop with proven and competent providers.

Aged↗
PubMed2001

The effect of resolution, compression, colour depth and display modality on the accuracy of accident and emergency telemedicine.

There are no current recommendations regarding the minimum technical specification for realtime telemedicine consultation in accident and emergency (A and E) practice. We assessed the effect of image resolution, compression, colour depth and display modality on perceived image quality and telediagnosis. Test sets of digitized radiographs and clinical images were subjected to a series of standardized manipulations and the resulting output files were evaluated by an expert panel using image scoring and receiver operating characteristic (ROC) analysis. For telemedicine in A and E work, the minimum technical specification should be regarded as images containing at least 250,000 pixels, compressed at up to JPEG 50 (or GIF for colour images) and displayed on a high-resolution computer monitor. These specifications resulted in average file sizes of 17 kByte for digital images and 9 kByte for radiographs.

Emergency Medicine↗
PubMed2001

Adaptation of a strain of Plasmodium vivax from India to New World monkeys, chimpanzees, and anopheline mosquitoes.

A strain of Plasmodium vivax from India was adapted to develop in splenectomized Saimiri boliviensis, Aotus lemurinus griseimembra, A vociferans, A. nancymai, A. azarae boliviensis, hybrid Aotus monkeys, and splenectomized chimpanzees. Infections were induced via the inoculation of sporozoites dissected from the salivary glands of Anopheles stephensi and An. dirus mosquitoes to 12 Aotus and 8 Saimiri monkeys; transmission via the bites of infected An. stephensi was made to 1 Aotus monkey and 1 chimpanzee. The intravenous passage of infected erythrocytes was made to 9 Aotus monkeys and 4 chimpanzees. Gametocytes in 13 Aotus monkeys and 4 chimpanzees were infectious to mosquitoes. Infection rates were markedly higher in mosquitoes fed on chimpanzees. PCR studies on 10 monkeys injected with sporozoites revealed the presence of parasites before their detection by microscopic examination. The India VII strain of P. vivax develops in Aotus and Saimiri monkeys and chimpanzees following the injection of parasitized erythrocytes, or sporozoites, or both. The transmission rate via sporozoites to New World monkeys of approximately 50% may be too low for the testing of sporozoite vaccines or drugs directed against the exoerythrocytic stages. However, the strain is highly infectious to commonly available laboratory-maintained anopheline mosquitoes. Mosquito infection is especially high when feedings are made with gametocytes from splenectomized chimpanzees.

Adaptation, Biological↗
PubMed2000

Efficacy of vaccines containing rhoptry-associated proteins RAP1 and RAP2 of Plasmodium falciparum in Saimiri boliviensis monkeys.

A vaccine trial was conducted with rhoptry-associated proteins 1 and 2 (RAP1 and RAP2) of Plasmodium falciparum in Saimiri boliviensis monkeys to compare the ability of parasite-derived (PfRAP1 and 2) and recombinant proteins (rRAP1 and 2) to induce protective immune responses and to find adjuvants suitable for use in humans. Eight groups of 6 monkeys each were immunized with parasite-derived or recombinant RAP1 and 2 with Freund's complete adjuvant (FCA) followed by Freund's incomplete adjuvant (FIA), Montanide ISA720 adjuvant, or CRL1005 adjuvant. Recombinant RAP1 and RAP2 were also administered separately, with Montanide ISA720. After 3 immunizations, monkeys were challenged by iv inoculation of 50,000 parasites of the Uganda Palo Alto strain of P. falciparum. Of the animals vaccinated using FCA/FIA, 1 of 6 control monkeys, 3 of 6 immunized with PfRAP1 and 2, and 2 of 6 with rRAP1 and 2 did not require drug treatment. Of the monkeys vaccinated with Montanide ISA720 adjuvant, 0 of the 6 control monkeys, 2 of 6 immunized with RAP1 and 2, 1 of 6 immunized with rRAP1, and 4 of 6 immunized with RAP2 did not require drug treatment. Two of 6 monkeys immunized with PfRAP1 and 2 with CRL1005 did not require treatment. All groups receiving RAP1, RAP2, or both had a significant decrease in initial parasite multiplication rates and there was a significant negative correlation between anti-RAP2 antibody and multiplication rates. Animals were rechallenged with the homologous parasite 126 days after the first challenge. Of the monkeys that did not require drug treatment after the first challenge, none developed detectable parasitemia following rechallenge.

Adjuvants, Immunologic↗
PubMed2000

Adaptation of a chloroquine-resistant strain of Plasmodium vivax from Indonesia to New World monkeys.

The spread of chloroquine-resistant Plasmodium vivax from Papua New Guinea and Indonesia poses a serious health threat to areas of Southeast Asia where this species of malaria parasite is endemic. A strain of P. vivax from Indonesia was adapted to develop in splenectomized Aotus lemurinus griseimembra, Aotus vociferans, Aotus nancymai, and Saimiri boliviensis monkeys. Transmission to splenectomized Saimiri monkeys was obtained via sporozoites. Chemotherapeutic studies indicated that the strain was resistant to chloroquine and amodiaquine while sensitive to mefloquine. Infections of chloroquine-resistant P.vivax in New World monkeys should be useful for the development of alternative treatments.

Adaptation, Physiological↗
PubMed2000

Differentiation of dorsal-spined elaphostrongyline larvae by polymerase chain reaction amplification of ITS-2 of rDNA.

Molecular genetics was used to devise the first reliable diagnostic tool for differentiating morphologically indistinguishable dorsal-spined, first-stage larvae (L1's) and other stages of the nematode protostrongylid subfamily Elaphostrongylinae. A polymerase chain reaction (PCR) assay employing specifically designed primers was developed to selectively amplify DNA of the ITS-2 region of the ribosomal gene. Amplification of the entire ITS-2 region differentiated between larvae of the genera Elaphostrongylus and Parelaphostrongylus, based on the lengths of fragments produced. Three sets of primers were designed and used successfully to distinguish larvae at the species level. Although it was demonstrated that one primer set in a single PCR assay was capable of distinguishing each of the three Parelaphostrongylus spp., a second primer set would be required for confirmation in routine diagnostic use. Two of the three primer sets were capable of amplifying DNA from all six elaphostrongyline species and of identifying Elaphostrongylus alces and Parelaphostrongylus odocoilei. Although two separate fragments were produced from each Elaphostrongylus cervi and Elaphostrongylus rangiferi, it was not possible to distinguish these two parasites from each other based on the fragment size. The use of various nematodes, hosts, and fecal controls demonstrated the reliability of the primers for all developmental stages including L1's, third-stage larvae, and adult worms. These primers also have potential for identifying other lungworms as was shown by the amplification of Umingmakstrongylus pallikuukensis, the muskox protostrongylid, and Dictyocaulus sp. from white-tailed deer. Although this assay may benefit from further refinement, its present design provides researchers, wildlife managers, clinicians, and animal health regulators with a practical tool for the control, management, and study of meningeal and tissue worms and their close relatives.

Animals↗
PubMed1999

Sibling accounts of attention deficit hyperactivity disorder (ADHD).

The goal of this research was to generate a description of how siblings in families with attention deficit hyperactivity disorder (ADHD) children experienced and lived with this chronic behavioral disorder. Interview and diary data from 11 families (N = 43) were analyzed using the constant comparative method. Data analysis revealed that siblings felt victimized by their ADHD sibling and that their experience of victimization was often minimized or overlooked in the family. Findings suggest that there is a need for increased social and mental health services for all members of the family over the course of the disorder, and that the effects on siblings, in particular, can be potentially quite deleterious to their health and well-being.

Attention Deficit Disorder with Hyperactivity↗
PubMed1999

The portable laboratory: an evaluation of the accuracy and reproducibility of i-STAT.

The i-STAT point-of-care testing analyser, which utilizes single-use multisensor cartridges, was evaluated. Two cartridges were assessed: the 6+ and the G3+, which provide results for urea, glucose, sodium, potassium, chloride, haematocrit, pH, PCO2, PO2 and various calculated parameters. The results for all analytes agreed well with the analysers in routine use in the laboratory. The reproducibility was comparable even when analysis was carried out by a nurse with only 5 min training. The system was found to be reliable, easy to use and required no maintenance (only a 2-min daily check of the electronics). These features, together with portability and the storage capacity for results, make the i-STAT suitable for point-of-care use, particularly in critical care units.

Clinical Chemistry Tests↗
PubMed1999

Axial coding and the grounded theory controversy.

The purpose of this article is to describe the similarities and differences between two approaches to grounded theory research: grounded theory as espoused by Glaser and grounded theory as espoused by Strauss and Corbin. The focus of the article is the controversy surrounding the use of axial coding. The author proposes a resolution to the controversy by suggesting that one does not need to view either approach as right or wrong; rather, the qualitative and grounded theory researcher can choose an approach, and that choice is based on the goal of the researcher's study. Examples of both approaches, from the author's research study on the experiences of living in a family with a child with attention deficit hyperactivity disorder (ADHD), are provided.

Adaptation, Psychological↗