Platelets circulate in an activated state in inflammatory bowel disease

BACKGROUND/AIMS

Platelets show proinflammatory as well as prothrombotic properties. Patients with inflammatory bowel disease are at increased risk of systemic thromboembolism, and multifocal microvascular infarction has been proposed as a pathogenetic mechanism in Crohn's disease. The aim of this study was to determine if inflammatory bowel disease is associated with abnormal platelet behavior.

METHODS

Platelet activation and aggregability were assessed using flow cytometry, Born aggregometry, and the modified method of Wu and Hoak. Serum beta-thromboglobulin was measured in patients with Crohn's disease and ulcerative colitis and, as controls, in healthy volunteers and patients with active rheumatoid arthritis.

RESULTS

Platelet surface expression of P-selectin and GP53 (markers of activation) were increased in Crohn's disease (13 of 30 patients abnormal for P-selectin; 9 of 28 abnormal for GP53) (P < 0.01) and ulcerative colitis (9 of 21 for P-selectin; 10 of 21 for GP53) (P < 0.01) compared with healthy controls. Increased circulating platelet aggregates (15 of 24 patients with Crohn's disease and 8 of 16 with ulcerative colitis) (P < 0.01), platelet aggregability in vitro, and serum beta-thromboglobulin were detected in active inflammatory bowel disease compared with healthy controls. Platelet behavior in active rheumatoid arthritis resembled that in healthy controls.

CONCLUSIONS

Increased platelet activation and aggregation are features of inflammatory bowel disease and may contribute to the risk of systemic thromboembolism and the pathogenesis of mucosal inflammation. Therefore, antiplatelet agents may be valuable in the management of inflammatory bowel disease.

Coats' disease of the retina (unilateral retinal telangiectasis) caused by somatic mutation in the NDP gene: a role for norrin in retinal angiogenesis

Coats' disease is characterized by abnormal retinal vascular development (so-called 'retinal telangiectasis') which results in massive intraretinal and subretinal lipid accumulation (exudative retinal detachment). The classical form of Coats' disease is almost invariably isolated, unilateral and seen in males. A female with a unilateral variant of Coats' disease gave birth to a son affected by Norrie disease. Both carried a missense mutation within the NDP gene on chromosome Xp11.2. Subsequently analysis of the retinas of nine enucleated eyes from males with Coats' disease demonstrated in one a somatic mutation in the NDP gene which was not present within non-retinal tissue. We suggest that Coats' telangiectasis is secondary to somatic mutation in the NDP gene which results in a deficiency of norrin (the protein product of the NDP gene) within the developing retina. This supports recent observations that the protein is critical for normal retinal vasculogenesis.

Chrysiogenes arsenatis gen. nov., sp. nov., a new arsenate-respiring bacterium isolated from gold mine wastewater

A new strictly anaerobic bacterium (strain BAL-1T) has been isolated from a reed bed at Ballarat Goldfields in Australia. The organism grew by reducing arsenate [As(V)] to arsenite [As(III)], using acetate as the electron donor and carbon source; acetate alone did not support growth. When BAL-1T was grown with arsenate as the terminal electron acceptor, acetate could be replaced by pyruvate, L- and D-lactate, succinate, malate, and fumarate but not by H2, formate, citrate, glutamate, other amino acids, sugars, or benzoate. When acetate was the electron donor, arsenate could be replaced by nitrate or nitrite but not by sulfate, thiosulfate, or iron oxide. Nitrate was reduced to ammonia via nitrite. The doubling time for growth on acetate (5 mM) plus arsenate (5 mM) or nitrate (5 mM) was 4 h. The G+C content of the DNA is 49 mol%. The 16S rRNA sequence data for the organism support the hypothesis that this organism is phylogenetically unique and at present is the first representative of a new deeply branching lineage of the Bacteria. This organism is described as Chrysiogenes arsenatis gen. nov., sp. nov.

The opioid receptor binding of dezocine, morphine, fentanyl, butorphanol and nalbuphine

The ability of morphine, fentanyl, butorphanol, nalbuphine, and dezocine to compete with radiolabeled ligands for binding at the mu1, mu2, kappa1, and delta opioid receptors and the sigma receptor was characterized. In the absence of sodium, the potency of opioid receptor competition at each receptor site was found to be: mu1-fentanyl > butorphanol > morphine > or = dezocine = nalbuphine; mu2-butorphanol > fentanyl > nalbuphine > morphine = dezocine; kappa1-butorphanol > nalbuphine >> morphine > or = dezocine > fentanyl; and delta-butorphanol > nalbuphine > or = dezocine > morphine > fentanyl. For all five compounds, competition at the sigma receptor was weak, with nalbuphine and dezocine having Kis of approximately 0.5 microM and the other opioids having Kis of greater than 1 microM. Since the presence of 100 mM NaCl during the competitive binding decreased the K(i), to varying degrees, of all five opioids at the mu1 and delta receptors and of some of the opioids at the mu2 and kappa1 receptors, the five compounds studied appear to differ in efficacy at the five receptor sites.

Raised plasma homocysteine as a risk factor for retinal vascular occlusive disease

BACKGROUND/AIMS

A moderately elevated plasma concentration of the sulphur amino acid homocysteine is an independent risk factor for atherosclerotic vascular disease. Many of the risk factors associated with coronary, cerebral, and peripheral atherosclerotic vascular disease are common to retinal vascular occlusive disease but it is unclear whether elevated plasma concentrations of homocysteine are also associated with such disease. This study assessed the relation between retinal vascular occlusive disease and elevated levels of plasma total homocysteine (tHcy).

METHODS

A retrospective case-control study involving hospital based controls and cases with retinal artery, central retinal vein (including hemiretinal vein), and branch retinal vein occlusions was performed. The relation between elevated tHcy, defined as a level greater than or equal to 12 micromol/l and risk of retinal vascular occlusive disease was examined.

RESULTS

87 cases of retinal vascular occlusive disease including 26 cases of retinal artery occlusion, 40 cases with central retinal vein occlusion, and 21 cases of branch retinal vein occlusion were compared with 87 age matched controls. Mean tHcy levels were higher in all disease groups and this difference was significant in patients with retinal artery occlusions (p= 0.032) and patients with central retinal vein occlusion (p=0.0001). When adjusted for known cardiovascular risk factors, tHcy was an independent risk factor for retinal vascular occlusive disease (OR 2.85 (95% CI 1.43-5.68)).

CONCLUSIONS

Elevated tHcy is an independent risk factor for retinal vascular occlusive disease. Assessment of tHcy may be important in the investigation and management of patients with retinal vascular occlusive disease.

Ocular adnexal lymphoma-comparison of MALT lymphoma with other histological types

AIMS

To correlate histological features of ocular adnexal lymphoma using the revised European American lymphoma classification (REAL), with stage of disease at presentation, treatment modalities, and patient outcome. MALT lymphoma defines an extranodal marginal zone B cell lymphoma as outlined in the REAL classification. Comparison groups of patients included those with primary ocular adnexal MALT lymphoma versus primary ocular adnexal lymphomas of other types, MALT lymphoma versus non-MALT lymphomas (primary and secondary), and primary ocular adnexal lymphoma (MALT lymphomas and other types) versus secondary ocular adnexal lymphomas.

METHODS

A retrospective review of the National Ophthalmic Pathology Laboratory records identified 20 cases of ocular adnexal lymphoma over a 10 year period which were reclassified using appropriate immunohistochemical stains. Patients' medical records were examined for data including stage of the disease at presentation, mode of treatment, and patient outcome.

RESULTS

Among the 20 cases identified 14 had primary ocular adnexal lymphomas. 10 of the primary lymphomas had histological features of MALT lymphoma. One case was a primary ocular adnexal T cell lymphoma, one a follicular centre, follicular B cell lymphoma, and two were large cell B cell lymphomas. Six cases had systemic disease, four large B cell, one follicular centre, follicular B cell, and one mantle cell. A significantly higher proportion of patients with MALT lymphomas had early disease (p = 0.005), initially required local treatment (p = 0.005) and were alive at last follow up (p = 0.001) than those without. Two patients with MALT lymphoma had recurrence of lymphoma which responded to further treatment.

CONCLUSIONS

Patients with primary ocular adnexal MALT lymphomas present with localised disease requiring local treatment and have a better outcome compared with patients with other types. As a small percentage of these tumours recur, patients should be followed up indefinitely.

Assessing the value of a new pharmaceutical. A feasibility study of contingent valuation in managed care

OBJECTIVES

The authors assessed the feasibility and construct validity of the contingent valuation method for measuring the monetary value to healthy enrollees in a health maintenance organization of a new drug, filgrastim, as prophylaxis against febrile neutropenia after chemotherapy treatment for cancer.

METHODS

A random sample of 220 enrollees from a closed-panel staff-model health maintenance organization who did not have cancer were interviewed. Chemotherapy, febrile neutropenia and filgrastim were described by video and decision board. Questions were asked in two different scenarios: (1) User-based: Assuming they were at the point of consumption and about to receive chemotherapy, what is the maximum they would be willing to pay to receive filgrastim? and (2) Insurance-based: Given they were at risk of cancer in the future, what is the maximum they would be willing to pay in additional monthly insurance premiums to add filgrastim to the plan? In a second insurance scenario where respondents were told that filgrastim was covered, what is the minimum reduction in premium that persons were willing to accept to relinquish coverage of the drug? A 2 x 2 factorial design was used to contrast two bidding algorithms to test for starting point bias and two 5-yearly prior risks of cancer, 1/200 versus 1/100. Main effects were tested by ANCOVA controlling for age, sex, health, and income.

RESULTS

Demographics of experimental cells were similar. No evidence was found of significant starting point bias. For user-based questions, as expected, willingness-to-pay increases with febrile neutropenia risk reduction, but at a declining marginal rate. Despite careful presentation of information to respondents, willingness-to-pay for insurance was higher in the lower prior risk group. Consistent with previous contingent valuation studies, the authors of the present study found evidence that willingness-to-accept exceeds willingness-to-pay for coverage of the same benefit.

CONCLUSIONS

An insurance-based contingent valuation study is feasible in a health maintenance organization. Construct validation evidence was encouraging, with the exception of the test for prior risk of cancer; however, this was a between-person contrast and may have been confounded by other factors.

Aortoduodenal fistula after endovascular stent-graft of an abdominal aortic aneurysm

Despite satisfying short- and middle-term effectiveness and feasibility, endovascular stent-grafting for abdominal aortic aneurysm is still under evaluation. We report a case of an aortoduodenal fistula after the use of this technique. Enlargement of the upper aneurysmal neck was followed by caudal migration of the major portion of the stent-graft, which resulted in kinking of the device in the aneurysmal sac. Ulcerations were found on adjacent portions of both the aneurysmal sac and the adjacent duodenum. Only the textile portion of the prosthetic contralateral limb separated the aortic lumen from the corresponding duodenal lumen. Early detection of complications after stent-grafting is essential to allow successful treatment, either surgical or endoluminal.

Pupillary autonomic denervation with increasing duration of diabetes mellitus

BACKGROUND/AIMS

The autonomic pupillary changes in type I and II diabetic patients without clinical evidence of diabetic autonomic neuropathy (DAN) were compared with age matched controls. The relation between pupillary and cardiovascular autonomic function was assessed in the diabetic patients.

METHODS

A case-control study was performed with diabetics grouped according to type and duration of diabetes. Static infrared pupillography was used to compare mean dark adapted pupil size and mean percentage changes in pupil size with pilocarpine 0.1% and cocaine 4% in the diabetic and control groups. All diabetic patients underwent cardiovascular autonomic function assessment using the Valsalva ratio, the 30:15 ratio, and testing for orthostatic hypotension.

RESULTS

In total, 72 type I and 69 type II diabetic patients were compared with 120 controls. Mean dark adapted pupil size was significantly smaller in diabetic groups than controls. Except for type I diabetics with disease for less than 5 years, all patient groups had significantly greater mean percentage constriction in pupil size in response to dilute pilocarpine than controls. There was no significant difference between the mean percentage dilatation in response to cocaine 4% in diabetics and controls. A high proportion of patients had normal cardiovascular autonomic function particularly when this was assessed with the Valsalva ratio.

CONCLUSIONS

Denervation hypersensitivity to dilute pilocarpine is a result of damage to the pupillary parasympathetic supply of diabetic patients. This occurs before the pupillary sympathetic pathway is affected, it can be detected early in the disease, and it may be a possible explanation for the small pupil size seen in diabetic patients. Pupillary autonomic dysfunction occurs before cardiovascular autonomic changes and detection of pupil denervation hypersensitivity to dilute pilocarpine is an inexpensive way to detect early DAN.

Pseudoexfoliation and sensorineural hearing loss

AIMS

There is increasing evidence that pseudoexfoliation (PXF) not only affects ocular anterior segment structures, but may also be a systemic disease. This study was undertaken to assess the relationship between PXF and sensorineural hearing loss.

METHODS

Patients with PXF were identified from hospital records and underwent complete ocular examination. The sum of pure-tone hearing thresholds measured at 1, 2 and 3 kHz (HTL1,2,3) in each ear was compared with the ISO 7029 standard sex-matched, median age-associated hearing loss summed over the same frequencies (AAHL1,2,3). The proportion of ears with thresholds higher than the ISO 7029 median AAHL1,2,3 on the same side as eyes without PXF was compared with the proportion of ears ipsilateral to eyes with PXF but without glaucoma and similarly the proportion of ears on the same side as eyes with PXF and glaucoma.

RESULTS

In total, 69 patients were studied, of whom 39 were male (56.5%). The mean age of the male patients was 75.8 years, while that of the female group was 75.1 years. All patients had PXF affecting at least one eye. Overall 101 ears (73.7%) had a higher HTL1,2,3 than the ISO 7029 median AAHL1,2,3 which included 56 ears of 78 in the male group (71.8%) and 45 ears of 59 in the female group (76.3%). There was no significant difference between the proportion of ears with HTL1,2,3 higher than the ISO 7029 median AAHL1,2,3 on the same side as eyes without PXF, with PXF but not glaucoma and with PXF and glaucoma, in either the male or female groups.

CONCLUSIONS

A large proportion of patients with PXF have sensorineural hearing loss in comparison to age-matched controls, regardless of whether or not there is associated glaucoma. This finding supports the theory that PXF may be a systemic condition.

Biochemical identification of interbreeding between B-type and non B-type strains of the tobacco whitefly Bemisia tabaci

Polyacrylamide gel electrophoresis and a kinetic microplate assay were used to detect heterozygotes resulting from a cross between B-type and non B-type strains of the whitefly Bemisia tabaci. Both strains were homozygous for different esterase and acetylcholinesterase (AChE) enzymes, and heterozygotes were produced in one of two crosses between B-type females (diploid) and non B-type males (haploid). In reciprocal crosses, however, no female offspring were produced, indicating that fertilization had not occurred. Despite the identification of individuals heterozygous for the esterase and AChE markers, there was clearly a significant degree of reproductive incompatibility between the two strains. The biochemical assays provided a vital component of this study and the advantages of their use are discussed.

Long-term outcomes of laparoscopic antireflux surgery for gastroesophageal reflux disease (GERD)-related airway disorder

A strong link exists between gastroesophageal reflux disease (GERD) and airway diseases. Surgical therapy has been recommended as it is more effective than medical therapy in the short-term, but there is little data on the effectiveness of surgery long-term. We analyzed the long-term response of GERD-related airway disease after laparoscopic anti-reflux surgery (LARS).

METHODS

In 2004, we contacted 128 patients with airway symptoms and GERD who underwent laparoscopic antireflux surgery (LARS) between 12/1993 and 12/ 2002. At median follow-up of 53 months (19-110 mo) we studied the effects on symptoms, esophageal acid exposure, and medication use and we analyzed the data to determine predictors of successful resolution of airway symptoms.

RESULTS

Cough, hoarseness, wheezing, sore throat, and dyspnea improved in 65-75% of patients. Heartburn improved in 91% (105/116) of patients and regurgitation in 92% (90/98). The response rate for airway symptoms was the same in patients with and without heartburn. Almost every patient took proton pump inhibitors (PPIs) preoperatively (99%, 127/128) and 61% (n = 78) were taking double or triple dose. Postoperatively, 33% (n = 45) of patients were using daily antiacid therapy but no one was on double dose. The only factor that predicted a successful surgical outcome was the presence of abnormal reflux in the pharynx as determined by 24-hour pharyngeal pH monitoring. One hundred eleven (87%) patients rated their results as excellent (n = 78, 57%) or good (n = 33, 24%).

CONCLUSION

LARS provides an effective and durable barrier to reflux, and in so doing improves GERD-related airway symptoms in approximately 70% of patients and improves typical GERD symptoms in approximately 90% of patients. Pharyngeal pH monitoring identifies those patients more likely to benefit from LARS, but better diagnostic tools are needed to improve the response of airway symptoms to that of typical esophageal symptoms.

Medium- and long-term outcome of laparoscopic redo fundoplication

BACKGROUND

For a small subset of patients, laparoscopic fundoplication fails, typically resulting in recurrent reflux or severe dysphagia. Although redo fundoplications can be performed laparoscopically, few studies have examined their long-term efficacy.

METHODS

Using a prospectively maintained database, the authors identified and contacted 41 patients who had undergone redo laparoscopic fundoplications at the University of Washington between 1996 and 2001. The median follow-up period was 50 months (range, 20-95 months). Current symptoms were compared with those acquired and entered into the authors' database preoperatively. Patients also were asked to return for esophageal manometry and pH testing.

RESULTS

All redo fundoplications were performed laparoscopically. There were no conversions. The most common indication for redo fundoplication was recurrent reflux. The most common anatomic abnormality was a herniated wrap. Heartburn improved in 61%, regurgitation in 69%, and dysphagia in 74% of the patients. Complete resolution of these symptoms was achieved, respectively, in 45%, 41% and 38% of these same patients. Overall, 68% of the patients rated the success of the procedure as either "excellent" or "good," and 78% said they were happy they chose to have it. For those who underwent reoperation for gastroesophageal reflux disease, distal esophageal acid exposure according to 24-h pH monitoring decreased after redo fundoplication from 15.7% +/- 18.1% to 3.4% +/- 3.6% (p = 0.041).

CONCLUSION

Although not as successful as primary fundoplication, a majority of patients can expect durable improvement in their symptoms with a laparoscopic redo fundoplication.

The influence of gamma radiation on arachidonic acid release and prostacyclin synthesis

Cultured pulmonary artery endothelial cells produce PGI2 as their primary prostaglandin. Conditions which inhibit cell division have been shown to accelerate the synthesis of this compound. Exposure of endothelial cells to gamma radiation results in an irreversible cessation of growth and enhanced production of PGI2. The level of PGI2 measured after radiation exposure exceeds that observed in cultures rendered quiescent by serum reduction. This indicates a role for gamma radiation in the elevation of PGI2 levels which is distinct from its effect on cell division. Results presented indicate that exposure to gamma radiation does not, in and of itself, elevate PG levels but capacitates cells for enhanced production when presented with appropriate stimuli. Increased PGI2 synthesis appears to be a result of an observed increase in arachidonic acid release and an activation of cyclooxygenase.

Effect of fixation on quantification of the expression of leucocyte function-associated surface antigens

The surface expression of adhesion molecules and other function-associated antigens on peripheral blood leucocytes may be measured by flow cytometry. However, quantification of these antigens is difficult, because their expression can be rapidly and artefactually modulated if the cells are activated in vitro. Consequently, it is common, when analyzing these antigens either: (1) to label leucocytes in whole blood at 4 degrees C, to lyse erythrocytes and then fix the leucocytes, or (2) to fix the leucocytes in whole blood, to lyse the erythrocytes, and then label the leucocytes. We have compared the mean fluorescence intensity (MFI) values for CD11b, CD18, and L-selectin (Leu-8 and TQ1 epitopes) on human peripheral blood leucocytes, using these two approaches. In addition, we have simultaneously evaluated how anticoagulants (acid citrate, K3EDTA, and heparin) and the presence or absence of divalent metal ions (Ca2+ and Mg2+) affect the expression levels of these antigens. The results for all four epitopes varied markedly depending on the preparation procedure used but were less affected by the choice of anticoagulant and whether divalent cations were or were not present in the media used for cell preparation and labelling. Comparison of the results obtained using these procedures, which involve fixation with formaldehyde, with those obtained by a recently developed procedure in which unfixed leucocytes were labelled with the vital nuclear dye LDS-751 and antibodies together, then analysed in unlysed whole blood at 4 degrees C, showed that formaldehyde-based preparation techniques underestimated the expression (MFI) of CD18, Leu-8, and TQ1. It is recommended that, whenever practicable, measurements are made on unfixed cells stained using the newer procedure.

Fixation with formaldehyde induces expression of activation dependent platelet membrane glycoproteins, P selectin (CD62) and GP53 (CD63)

Platelet activation in vivo is important in the pathogenesis of thrombosis. Accurate measurement is difficult due to artefactual in vitro preparation related activation. This can be overcome by using whole blood techniques, such as flow cytometry. However, there is little consensus on methods of platelet preparation, procedures for use of fixation, or the optimal types/amounts of fixative. The use of unfixed platelets has received little attention. We describe a series of experiments comparing platelet activation antigen expression detected by flow cytometry in fixed and unfixed samples. Formaldehyde increased the expression of both CD62 and CD63. We recommend that fixation with formaldehyde should not be used when studying platelet activation.

Anatomy of the extraneural blood supply to the intracranial oculomotor nerve

AIMS

An anatomical study was undertaken to determine the extraneural blood supply to the intracranial oculomotor nerve.

METHODS

Human tissue blocks containing brainstem, cranial nerves II-VI, body of sphenoid, and associated cavernous sinuses were obtained, injected with contrast material, and dissected using a stereoscopic microscope.

RESULTS

Eleven oculomotor nerves were dissected, the intracranial part being divided into proximal, middle, and distal (intracavernous) parts. The proximal part of the intracranial oculomotor nerve received extraneural nutrient arterioles from thalamoperforating arteries in all specimens and in six nerves this blood supply was supplemented by branches from other brainstem vessels. Four nerves were seen to be penetrated by branches of brainstem vessels and these penetrating arteries also supplied nutrient arterioles. The middle part of the intracranial oculomotor nerve did not receive nutrient arterioles from adjacent arteries. The distal part of the intracranial oculomotor nerve received nutrient arterioles from the inferior cavernous sinus artery in all 11 nerves and in seven nerves this was supplemented by a tentorial artery arising from the meningohypophyseal trunk. The inferior hypophyseal artery arose from the meningohypophyseal trunk in all 11 cavernous sinuses dissected.

CONCLUSION

This study shows a constant pattern to the blood supply of the intracranial oculomotor nerve. It also highlights the close relation between the blood supplies to the intracavernous oculomotor nerve and the pituitary gland.

Effect of des arginine9-bradykinin and other bradykinin fragments on the synthesis of prostacyclin and the binding of bradykinin by vascular cells in culture

Bradykinin (BK) fragments, des arg1-BK, des arg1,pro2-BK, des phe8,arg9-BK and des pro7,phe8,arg9-BK were synthesized and along with des arginine9-BK (daBK), tested for their ability to induce prostacyclin synthesis in homogeneous cultures of cells from the calf pulmonary artery. Of the fragments daBK was the only peptide, in addition to bradykinin (BK), to activate the synthesis of prostacyclin (PGI2) and platelet activating factor (PAF) in endothelial cells and PGI2 in fibroblasts and smooth muscle cells. Half-maximal activation of PGI2 synthesis differed with the cell type. The other fragments tested did not directly affect PGI2 synthesis. These fragments also did not inhibit daBK or BK activation of PG synthesis. BK bound to endothelial cells with a dissociation constant (Kd) of 2.1 nM and a Bmax of 47.9 fmoles/10(6) cells. The Kd for the binding of BK to smooth muscle cells and fibroblasts was somewhat higher, 4.9 nM and 7.9 nM, respectively. None of the fragments tested, including daBK, altered the binding of BK. Des arg9[leu8]-BK, reported to be a competitive antagonist of the bradykinin B1 receptor, inhibited daBK induced PG of PAF synthesis in endothelial cells but had little effect of BK binding or BK induced PG synthesis. Finally, the BK antagonist [thi5,8, d-phe7]-BK blocked both BK binding and the ability of either BK or daBK to induce PG synthesis, thus substantiating that the binding of these kinins is a step in the activation of PG synthesis.

Self-reported knowledge, attitudes and behaviour towards evidence-based practice of occupational therapy students in Ireland

It is widely accepted that the occupational therapy profession needs to incorporate research findings into clinical practice so as to improve client outcomes. The purpose of this study was to investigate the knowledge and attitudes toward evidence-based practice (EBP) of occupational therapy students in the Republic of Ireland. A validated questionnaire was used to survey the population of final-year students from the four universities in Ireland in 2008. There was a response rate of 77% (n = 86) to the Knowledge, Attitude and Behaviour Questionnaire. All students reported that they had a clear understanding of EBP and were willing to practice EBP in the future. The majority (85%, n = 73) reported accessing evidence weekly or more often. Lack of time and fieldwork educators not practising EBP were important barriers for 31% (n = 27) and 27% (n = 23), respectively. Over half (55%, n = 47) reported difficulty in finding evidence. The internet (28%, n = 24) and textbooks (27%, n = 23) were the most popular sources of evidence. Limitations include the self-report, cross-sectional design. Future research could include longitudinal studies to understand the transfer of learning into clinical practice.

Classification of the spectrum of Coats' disease as subtypes of idiopathic retinal telangiectasis with exudation

PURPOSE

An increasing variety of eponymous terms have been used to describe atypical cases of Coats' disease. A group of typical cases of Coats' disease and other cases of differing severity were classified as one of four subtypes of idiopathic retinal telangiectasis with exudation and compared with regard to clinical outcome.

METHODS

In a retrospective clinical review patients with typical and atypical Coats' disease were classified as severe, focal, juxtafoveal or associated (with another disease) forms of idiopathic retinal telangiectasis with exudation.

RESULTS

53 eyes in 50 patients were examined of which 62% (n=31) were male. 12 eyes were classified as severe (group 1), 22 focal (group 2), 12 juxtafoveal (group 3) and 7 associated (group 4). The mean age at diagnosis was lowest in group 1 eyes (6.8 years). The best visual acuity at presentation was 6/60 in group 1 whereas high proportions of eyes in the other groups had initial visual acuities of 6/24 or better. In group 1 only one eye was treated, the majority of eyes were blind or had been enucleated whereas 34 (79%) of eyes in the other groups were suitable for treatment and 29 eyes (67%) retained pre-treatment visual acuity or better at last follow-up.

CONCLUSIONS

Idiopathic retinal telangiectasis with exudation is a spectrum of disease, which is synonymous with Coats' disease. In this retrospective study eyes with severe idiopathic retinal telangiectasis with exudation corresponding to typical Coats' disease, have poorer vision at presentation, are less suitable for treatment and have worse outcomes than eyes with other subtypes. The spectrum of disease severity seen in idiopathic retinal telangiectasis with exudation may be due to second somatic mutations in genes with an existing germline mutation (the two hit theory) and a mosaic phenotype.

The use of clinical logs to improve nursing students' metacognition: a pilot study

The purpose of this study was to examine the effectiveness of the use of a reflective clinical log to improve students' thinking strategies and metacognition (cognitive awareness). Rather than prepare a written nursing care plan prior to entering the clinical setting, students instead were asked to write in a clinical log at the completion of their clinical day, reflecting upon client problems that they had identified, the data that were used to identify these problems, the nursing interventions that were used, and the results of these interventions. The students reported that they preferred the use of a reflective log over writing nursing care plans and they felt that the logs improved their ability to think about their thinking (i.e. their metacognition). The results of this pilot study indicate that reflection in clinical logs assists students to become more active learners, to manage their own thinking, and to improve their metacognition. Additional research in this area is needed to confirm study findings and to provide further understanding regarding the effectiveness of clinical logs as a teaching strategy to improve students' metacognition.

Protein A immunoadsorption in chronic refractory ITP reverses increased platelet activation but fails to achieve sustained clinical benefit

Adults with chronic relapsing ITP present a difficult therapeutic challenge. The ongoing antibody-mediated platelet destruction in this group might be expected to be associated with increased expression of platelet surface membrane activation antigens. We have studied a group of 10 patients with refractory ITP and 35 healthy controls. Using an immediate, sensitive, unfixed, whole blood, flow cytometric method to detect platelet surface P-selectin and GP53, we have detected markedly increased platelet activation in the ITP group compared with the controls (P-selectin; patient median 24.5% v control median 2.0%. GP53 median 6.5% v 2.1%, P < 0.01 for both). Five patients underwent protein A immunoadsorption therapy. The effect of protein A immunoadsorption on platelet activation before, during and after 18 treatments in these patients was studied and patients were followed-up to assess clinical outcome. Platelet-associated immunoglobulin measurements were made before and at the end of six treatments. Platelet activation decreased after immunoadsorption. P-selectin expression fell significantly; pre- and post-treatment median values differed by 15.5%, P < 0.01, for GP53 the difference was 2.5%, P = NS. A reduction in both platelet-associated IgG (median reduction of 11.8 ng/10(6) platelets, P = 0.08) and IgM (7.6 ng/10(6) platelets, P = 0.06) was recorded.

Food in low-income families

This descriptive study used both quantitative and qualitative research methods to examine the food and nutrient intake, food purchasing patterns and budgeting strategies of 29 sole-parent low-income families with dependent children living in Corio Shire, Victoria, in 1989-90. Expenditure on food and nonalcoholic beverages when compared with the average for all Australian households showed that the study families allocated a greater proportion, but similar amounts of money to cereals, dairy products, fruit and vegetables and miscellaneous foods, and less to meat, nonalcoholic beverages and food eaten away from home. Despite large differences in the amount of money spent in the first and second weeks of a social security payment period, the nutrient density of the parents' diets was maintained at a similar level in both weeks. The only exception was vitamin C, for which the median intake was significantly lower in the second week, consistent with reduced purchases of fruit and vegetables in the same period. In interviews with 13 of the parents a variety of purchasing and budgeting strategies were described, indicating common concerns with making the most of their limited resources. The data from this study support the notion that low-income families give priority to food purchases above other expenses such as recreation. They also support the view that low-income families are concerned about health and nutrition and manage to consume nutritionally sound diets under difficult circumstances. Nutrition education programs could support them in this endeavour.

Isolation, characterization, and biological activity of naphthoquinones from Calceolaria andina L

Two compounds recognized as responsible for the insecticidal activity of extracts of Calceolaria andina L. (Scrophulariaceae) have been isolated and characterized as 2-(1, 1-dimethylprop-2-enyl)-3-hydroxy-1,4-naphthoquinone and the corresponding acetate, 2-acetoxy-3-(1,1-dimethylprop-2-enyl)-1, 4-naphthoquinone. Their activities against 29 pest species and 9 beneficial species of arthropod from a total of 11 orders have been determined. Activities against homopteran and acarine species are of the same order as those of established pesticides, and, significantly, no cross-resistance is observed for strains resistant to established classes of insecticide. Mammalian toxicities are low.

Thermolabile MTHFR genotype and retinal vascular occlusive disease

BACKGROUND

Raised levels of total plasma homocysteine (tHcy) are associated with an increased risk of retinal vascular occlusive disease. A thermolabile form of a pivotal enzyme in homocysteine metabolism, methylenetetrahydrofolate reductase (MTHFR), has been associated with vascular occlusive disease and raised tHcy levels. The relation between thermolabile MTHFR genotype, tHcy, and retinal vascular occlusive disease has not been determined.

METHODS

A retrospective case-control study involving hospital based controls and cases with retinal vascular occlusions in whom tHcy levels had been determined was undertaken. Genotyping for the MTHFR 677 C-T mutation that specifies the thermolabile form of the enzyme was performed by established methods in all subjects. The relation between homozygosity for thermolabile MTHFR genotype (TT), raised tHcy levels, and risk of retinal vascular occlusive disease was examined.

RESULTS

87 cases of retinal vascular occlusive disease (mean age 68.7 years) comprising 26 cases of retinal artery occlusion and 61 of retinal vein occlusion were compared with 87 controls (mean age 70.2 years). The TT genotype did not confer a significantly increased risk of retinal vascular occlusive disease. The mean tHcy level was significantly higher in the cases than in the controls (p<0.0001). Overall, and in both the cases and controls, the frequency of the TT genotype was higher in those with normal tHcy levels than in those with increased levels of tHcy. However, the TT genotype did not significantly alter the risk of increased tHcy levels in these patients.

CONCLUSIONS

The TT genotype is not associated with an increased risk of retinal vascular occlusive disease or increased tHcy levels in this group of elderly patients. In older patients, nutritional rather than genetic factors may be more important in increasing tHcy levels, a known risk factor for retinal vascular occlusive disease.