A149 COMPARING THE REAL-WORLD EFFECTIVENESS OF 4L VERSUS 2L SPLIT COLONOSCOPY PREPARATIONS: PRELIMINARY DATA OF A SINGLE CENTRE EXPERIENCE THROUGH THE BRITISH COLUMBIA COLONOSCOPY SCREENING PROGRAM

Background

The British Columbia Colon Screening Program (CSP) is a population-based program offering biennial fecal immunochemical test (FIT) to individuals age 50–74 years with follow-up colonoscopy for a positive FIT as well as individuals with a personal history of neoplastic polyps or a high risk family history of colorectal cancer. Over 20,000 colonoscopies are performed annually. In December 2018, program colonoscopists in Vancouver, Canada agreed to switch from a 2L polyethylene glycol (PEG) preparation to a 4L PEG preparation after studies suggested superiority of the higher volume preparation in achieving adequate bowel cleansing and improving adenoma detection rates (ADR). High quality bowel cleansing is critical to minimize repeat procedures and maximize neoplasia detection.

Aims

To compare the quality of bowel preparation and neoplasia detection rates using the 4L high volume split preparation (HVSP) versus the 2L low volume split preparation (LVSP) in patients undergoing colonoscopy in the BC CSP.

Methods

A retrospective review of consecutive patients undergoing colonoscopy through the CSP at St. Paul’s Hospital from Dec 2017-Apr 2018 and Dec 2018-Apr 2019 was conducted. Inclusion criteria included: age 50–74, patients undergoing colonoscopy for any reason through the BC CSP. Variables collected included: patient demographics, bowel preparation qualty and pathologic findings. ADR and sessile serrated polyp detection rate (SSDR) were analyzed.

Results

462 colonoscopies were included, 280 in the LVSP group and 182 in the HVSP group. 8/280 (2.9%) had poor bowel preparation in the LVSP group, while 10/182 (5.5%) had poor bowel preparation in the HVSP group. The ADR and SSDR were 53.6% in LVSP vs. 50.0% in HVSP and 8.2% in LVSP vs. 8.8% in HVSP, respectively.

Conclusions

In this preliminary evaluation, the high volume PEG-based split preparation did not reduce the proportion of inadequate bowel preparations. Further evaluation of a larger number of colonoscopies is planned.

Funding Agencies

None

A168 IS ROUTINE SCREENING FOR HEREDITARY COLORECTAL CANCER FEASIBLE IN AN OUTPATIENT GASTROENTEROLOGY PRACTICE?

Background

Lynch syndrome (LS) is the most common cause of hereditary colorectal cancer (CRC), with a reported prevalence of 2–5% of all CRC cases. A study by Kastrinos et al. found that a simple 3 item survey identified 77% of individuals at high risk for hereditary CRC. Implementation of this questionnaire at a gastroenterology office may help identify patients at risk for LS and other hereditary CRC.

Aims

To assess whether implementation of a validated questionnaire to screen for hereditary CRC is feasible in an outpatient gastroenterology clinic.

Methods

Adult gastroenterology outpatients who consented to participate in the study completed the screening questionnaire. Those who had previously been assessed by the Hereditary Cancer Program were excluded. Each subject was asked the following three questions: (1) Do you have a first-degree relative with CRC or LS-related cancer diagnosed before age 50? (2) Have you had CRC or polyps diagnosed before age 50? (3) Do you have ≥3 relatives with CRC?. Answering yes to any question was considered a positive screen.

Results

A total of 288 patients were screened, with 12 (4.2%) screening positive for question 1, 28 (9.7%) screening positive for question 2, and 8 (2.8%) screening positive for question 3. In total, 14.2% of individuals surveyed screened positive.

Conclusions

Utilization of a simple 3-question survey as part of regular patient intake in a gastroenterology office resulted in 14.2% of individuals screening high-risk for hereditary CRC. This is similar to the 15% screen positive rate in the original study of individuals with CRC. Further research is needed to determine whether a physician’s knowledge of the questionnaire results will change management and whether a positive screen leads to a confirmed diagnosis of LS and other hereditary colorectal cancers.

Funding Agencies

None

A165 ASSESSING ATTENDANCE OF SUBSTANCE USER ENDOSCOPIES (A.S.U.R.E)

Background

In Canada, British Columbia (BC) is the leading province in opioid deaths with 30.6 per 100,000 population. Since substance users are stigmatized in health care, patient care requires specific, individualized management strategies, which often creates a gap between the patient and health care service. Diagnostic studies remain a challenge due to lack of funding and the unique requirements necessary to treat this patient population efficiently. Thus, new methods of prevention must be cultivated to ensure ideal patient care.

Aims

To investigate the proportion of patients on restricted narcotics that failed to attend scheduled gastroenterology and hepatology appointments at our center.

Methods

A retrospective chart review from 01/05 – 07/19 and data analysis of patients (≥ 19 yrs.) referred to a Downtown Gastroenterology office was performed. Data was collected from an electronic medical record system and filtered through a keyword search for ‘Methadone’, ‘Suboxone’, ‘Dilaudid’, and ‘Morphine’ to create a sample size of patients with recent/ongoing use of narcotic agents. Patients with chronic pain, or terminal illness prescribed these drugs were not included. Demographic information, type of appointment scheduled and failure to attend were recorded.

Results

Acquired data yielded 2630 patients of which 350 patient were included. Mean age was 47 years (61% male). 35% of the patients were current narcotics users, the rest being previous users of these agents. Scheduled appointments and non-attendance are shown in Tables 2 and 3. Most patients (70%) were referred for various general GI complaints with HCV accounting for 23% of the consults. Despite the use of confirmation lines, 20% of HCV referred patients and 29% of non-HCV referred patients did not attend their first appointment.

Conclusions

Current and prior narcotic users failed to attend more than one quarter of scheduled gastroenterology/hepatology appointments. Ideal management of care for GI disease can’t be obtained without contact with those that provide the service. Creative, innovative management strategies are required to ensure ideal care for this unique group of patients.

Funding Agencies

None

Mapping interactions with the chaperone network reveals factors that protect against tau aggregation

A network of molecular chaperones is known to bind proteins ('clients') and balance their folding, function and turnover. However, it is often unclear which chaperones are critical for selective recognition of individual clients. It is also not clear why these key chaperones might fail in protein-aggregation diseases. Here, we utilized human microtubule-associated protein tau (MAPT or tau) as a model client to survey interactions between ~30 purified chaperones and ~20 disease-associated tau variants (~600 combinations). From this large-scale analysis, we identified human DnaJA2 as an unexpected, but potent, inhibitor of tau aggregation. DnaJA2 levels were correlated with tau pathology in human brains, supporting the idea that it is an important regulator of tau homeostasis. Of note, we found that some disease-associated tau variants were relatively immune to interactions with chaperones, suggesting a model in which avoiding physical recognition by chaperone networks may contribute to disease.

Assessing and Improving the Quality of Information for Health Evaluation and Promotion

Studies by the author based upon a sample of over 1.1 million patients in the North West of England have shown that the introduction of computers cannot be demonstrated to produce significant improvements in health promotion activity. Other studies have revealed error rates in health-care information systems in excess of 50%. This paper considers the reasons for these findings and demonstrate that there is a level of maturity of information management required before information systems can make a significant contribution to health promotion and evaluation. With the advent of locality commissioning and a re-affirmation of the emphasis upon health promotion activity set out in Health of the Nation and Our Healthier Nation [8], the role of information management has become even more significant. The paper presents a maturity model developed by the author, known as General Practice Information Maturity Model (GPIMM) that provides a strategic framework to improve the use of information by practices and to improve practice to enable viable sharing of accurate information. The paper will show the model can be used as a basis for the development of training and information strategies. The model identifies computerised practices as being in one of five stages of maturity: (1) Computerised, (2) Computerised PHC Team, (3) Coded, (4) Bespoke, (5) Paperless. The model specifically leads practices to a point in their development where they are able to carry out health evaluation, promotion and audit activities as a routine activity. Once these activities form part of practice activity they are then extended to encompass a group of practices such as a Primary Care Group. Finally, a case study is presented to show how the model was used to enable two very different but geographically neighbouring practices to work together towards the establishment of a common dataset. This dataset will be used to enable health promotion and evaluation activity to be provided for a total population of over 20,000 patients.

Can computers improve the health of the nation?

In this paper the authors consider whether the use of computers can be demonstrated to have a positive impact upon the effectiveness of health screening, in accordance with the Health of the Nationdocument. The paper is based on a study of 1.1 million patients registered with 283 general practices in the north-west region of the UK.

Epitope analysis following active immunization with tau proteins reveals immunogens implicated in tau pathogenesis

BACKGROUND

Abnormal tau hyperphosphorylation and its accumulation into intra-neuronal neurofibrillary tangles are linked to neurodegeneration in Alzheimer's disease and similar tauopathies. One strategy to reduce accumulation is through immunization, but the most immunogenic tau epitopes have so far remained unknown. To fill this gap, we immunized mice with recombinant tau to build a map of the most immunogenic tau epitopes.

METHODS

Non-transgenic and rTg4510 tau transgenic mice aged 5 months were immunized with either human wild-type tau (Wt, 4R0N) or P301L tau (4R0N). Each protein was formulated in Quil A adjuvant. Sera and splenocytes of vaccinated mice were collected to assess the humoral and cellular immune responses to tau. We employed a peptide array assay to identify the most effective epitopes. Brain histology was utilized to measure the effects of vaccination on tau pathology and inflammation.

RESULTS

Humoral immune responses following immunization demonstrated robust antibody titers (up to 1:80,000 endpoint titers) to each tau species in both mice models. The number of IFN-γ producing T cells and their proliferation were also increased in splenocytes from immunized mice, indicating an increased cellular immune response, and tau levels and neuroinflammation were both reduced. We identified five immunogenic motifs within either the N-terminal (9-15 and 21-27 amino acids), proline rich (168-174 and 220-228 amino acids), or the C-terminal regions (427-438 amino acids) of the wild-type and P301L tau protein sequence.

CONCLUSIONS

Our study identifies five previously unknown immunogenic motifs of wild-type and mutated (P301L) tau protein. Immunization with both proteins resulted in reduced tau pathology and neuroinflammation in a tau transgenic model, supporting the efficacy of tau immunotherapy in tauopathy.

Patient recollections of perioperative anaesthesia risks

There is widespread variation as to the method of presentation of informed anaesthetic consent with little empirical data on the nature of communication and how much information is retained. At a dedicated anaesthesia pre-admission clinic, 149 patients undergoing elective surgery under general anaesthesia were both verbally informed and shown written information about four major and three minor anaesthesia risks. The major risks were death, pneumonia, heart attack and stroke. The minor risks were dental damage, nausea and vomiting. On the day of scheduled surgery, retention of information about these anaesthetic risks was examined. Thirty-eight patients (26%) could not recall any anaesthesia risks, 55 patients (37%) could not recall any major risks and 126 patients (84%) could not recall any minor risks. Our findings indicate that patients should receive a second explanation on the day of surgery, even if informed consent was provided only two weeks earlier.

Synthetic lethal interactions in yeast reveal functional roles of J protein co-chaperones

J proteins are a diverse family of co-chaperones that cooperate with heat shock protein 70 (Hsp70) to coordinate protein quality control, especially in response to cellular stress. Current models suggest that individual J proteins might play roles in recruiting Hsp70s to specific functions, such as maintaining cell wall integrity or promoting ribosome biogenesis. However, relatively few stresses have been used to test this model and, as a result, only a few specific activities have been identified. To expand our understanding of the J protein network, we used a synthetic lethal approach in which 11 Saccharomyces cerevisiae deletion strains were treated with 12 well-characterized chemical inhibitors. The results defined new roles for specific J proteins in major signaling pathways. For example, an important role for Swa2 in cell wall integrity was identified and activities of the under-explored Jjj1, Apj1, Jjj3 and Caj1 proteins were suggested. More generally, these findings support a model in which some J proteins, such as Ydj1 and Zuo1, play "generalist" roles, while others, such as Apj1 and Jjj2, are "specialists", having roles in relatively few pathways. Together, these results provide new insight into the network of J proteins.

Molecular chaperones DnaK and DnaJ share predicted binding sites on most proteins in the E. coli proteome

In Escherichia coli, the molecular chaperones DnaK and DnaJ cooperate to assist the folding of newly synthesized or unfolded polypeptides. DnaK and DnaJ bind to hydrophobic motifs in these proteins and they also bind to each other. Together, this system is thought to be sufficiently versatile to act on the entire proteome, which creates interesting challenges in understanding the interactions between DnaK, DnaJ and their thousands of potential substrates. To address this question, we computationally predicted the number and frequency of DnaK- and DnaJ-binding motifs in the E. coli proteome, guided by free energy-based binding consensus motifs. This analysis revealed that nearly every protein is predicted to contain multiple DnaK- and DnaJ-binding sites, with the DnaJ sites occurring approximately twice as often. Further, we found that an overwhelming majority of the DnaK sites partially or completely overlapped with the DnaJ-binding motifs. It is well known that high concentrations of DnaJ inhibit DnaK-DnaJ-mediated refolding. The observed overlapping binding sites suggest that this phenomenon may be explained by an important balance in the relative stoichiometry of DnaK and DnaJ. To test this idea, we measured the chaperone-assisted folding of two denatured substrates and found that the distribution of predicted DnaK- and DnaJ-binding sites was indeed a good predictor of the optimal stoichiometry required for folding. These studies provide insight into how DnaK and DnaJ might cooperate to maintain global protein homeostasis.

The CHAT project: paediatricians and mental health clinicians: working together for the sake of the children

INTRODUCTION

The Shared Care model, originally developed to address the paucity of adult mental health resources, has potential applicability to the design and delivery of mental health services for children and youth. With a similar prevalence of mental illness and more difficulty accessing mental health care than adults, Canadian children and youth have been even less well served than their parents. As there is a significant overlap in the types of health concerns for which children and youth are seen by mental health clinicians and paediatricians, building improved collaboration between these groups is an obvious, though under-utilized, method of enhancing mental health care for this population. The CHAT project was a one year collaboration involving three different types of collaborative activities between mental health clinicians and paediatricians.

METHODS

Out-patient mental health clinicians and community paediatricians were surveyed about their educational needs and interests. A community paediatrician joined an outpatient mental health care team, continuing professional educational activities were provided by each group for the other and were evaluated.

RESULTS

The paediatrician's participation was evaluated positively by team members. Eighty-three percent of mental health clinicians (n=10) rated the educational sessions positively and 77.8% (n=7) noted increased knowledge. Paediatricians expressed strong interest in having more mental health-related educational activities.

CONCLUSION

This small project provided opportunities for useful exchanges between mental health clinicians and community paediatricians and preliminary evidence that shared care initiatives for children and youth should be further researched.

The use of ketamine as rescue analgesia in the recovery room following morphine administration--a double-blind randomised controlled trial in postoperative patients

In some patients, control of postoperative pain can be difficult with morphine alone. This double-blind randomised controlled trial was designed to evaluate whether a small bolus dose of ketamine could improve pain scores in those patients who had inadequate relief of their postoperative pain after two standard doses of morphine. Forty-one patients with uncontrolled postoperative pain were randomly assigned to receive either morphine (M) alone, or morphine plus 0.25 mg/kg ketamine (K) in the recovery room. No other analgesics were to be given. The study had adequate power to detect a 25% difference in pain scores. There was no statistically significant difference in verbal rating scale pain scores between the two groups either in the recovery room (K = 5.16, M = 6.28, P = 0.065), or at a later time on the ward. There was no apparent difference between groups in sedation, morphine consumption, postoperative nausea and vomiting, quality of recovery or need for rescue analgesia. We could not demonstrate an effective role for ketamine in the management of problematic postoperative pain at the dose studied.

The use of Ketamine as Rescue Analgesia in the Recovery Room following Morphine Administration—A Double-Blind Randomised Controlled Trial in Postoperative Patients

In some patients, control of postoperative pain can be difficult with morphine alone. This double-blind randomised controlled trial was designed to evaluate whether a small bolus dose of ketamine could improve pain scores in those patients who had inadequate relief of their postoperative pain after two standard doses of morphine. Forty-one patients with uncontrolled postoperative pain were randomly assigned to receive either morphine (M) alone, or morphine plus 0.25 mg/kg ketamine (K) in the recovery room. No other analgesics were to be given. The study had adequate power to detect a 25% difference in pain scores. There was no statistically significant difference in verbal rating scale pain scores between the two groups either in the recovery room (K=5.16, M=6.28, P=0.065), or at a later time on the ward. There was no apparent difference between groups in sedation, morphine consumption, postoperative nausea and vomiting, quality of recovery or need for rescue analgesia. We could not demonstrate an effective role for ketamine in the management of problematic postoperative pain at the dose studied.

Models of the subthalamic nucleus. The importance of intranuclear connectivity

A coherent set of models is presented that provide novel and testable predictions about the functional role of the subthalamic nucleus (STN) in the basal ganglia. The STN is emerging as an important target for novel therapeutic strategies for the alleviation of Parkinsonian type symptoms [Lancet 345 (1995) 91; Science 249 (1990) 1436]. Computational and mathematical models based on the properties of the STN and its interactions are reviewed. These models focus on core anatomical and physiological data that span many levels. By assessing models of anatomy, dynamic network models, and a detailed model of a recent pharmacological experiment, we can expose the primary modes of STN function and highlight their underlying properties. We show that the presence of functional interactions between STN projection neurons is critical in defining its behaviour and how it interacts with other basal ganglia nuclei. Pulses or switch-like activity patterns emerge in the models as a consequence of these local interactions. Furthermore, the models demonstrate that this behaviour can break down under abnormal conditions resulting in low frequency bursting oscillations. Such oscillations may play a role in symptoms of Parkinson's disease.

Arm position and blood pressure: a risk factor for hypertension?

The objective of this study was to re-evaluate the effect of arm position on blood pressure (BP) measurement with auscultatory and oscillometric methods including ambulatory blood pressure monitoring (ABPM). The setting was the hospital outpatient department and the subjects chosen were normotensive and hypertensive. The effect of lowering the arm from heart level on indirect systolic BP (SBP) and diastolic BP (DBP) measurement as well as the importance of supporting the horizontal arm were measured. In the sitting position, lowering the supported horizontal arm to the dependent position increased BP measured by a mercury device from 103+/-10/60+/-7 to 111+/-14/67+/-10 mmHg in normotensive subjects, a mean increase of 8/7 mmHg (P<0.01). In hypertensive subjects, a similar manoeuvre increased BP from 143+/-21/78+/-17 to 166+/-29/88+/-20 mmHg, an increase of 23/10 mmHg (P<0.01). Combined results from normotensive and hypertensive subjects demonstrate a direct and proportional association between BP (SBP and DBP) and the increase produced by arm dependency. Similar changes and associations were noted with oscillometric devices in the clinic situation. However, supporting the horizontal arm did not alter BP. Of particular interest, analysis of 13 hypertensive subjects who underwent ABPM on two occasions, once with the arm in the 'usual' position and once with the arm held horizontally for BP measurement during waking hours, demonstrated changes comparable to the other devices. The mean 12-hour BP was 154+/-19/82+/-10 mmHg during the former period and significantly decreased to 141+/-18/74+/-9 mmHg during the latter period (P<0.01). Regression analysis of the change in SBP and DBP with arm position change again demonstrated a close correlation (r(2)=0.8113 and 0.7273; P<0.001) with the artefact being larger with higher systolic and diastolic pressures. In conclusion, arm movements lead to significant artefacts in BP measurement, which are greater, the higher the systolic or diastolic pressure. These systematic errors occur when using both auscultatory and oscillometric (clinic and ABPM) devices and might lead to an erroneous diagnosis of hypertension and unnecessary medication, particularly in individuals with high normal BP levels. Since clinical interpretations of heart level vary, the horizontal arm position should be the unambiguous standard for all sitting and standing BP auscultatory and oscillometric measurements.

Computational models of the basal ganglia

Computer simulation studies and mathematical analysis of models of the basal ganglia are being used increasingly to explore theories of basal ganglia function. We review the implications of these new models for a general understanding of basal ganglia function in normal as well as in diseased brains. The focus is on their functional similarities rather than on the details of mathematical methodologies and simulation techniques. Most of the models suggest a vital role for the basal ganglia in learning. Although this interest in learning is partly driven by experimental results associating the acute firing of dopamine cells with reward prediction in monkeys, some of the models have preceded the electrophysiological results. Another common theme of the models is selection. In this case, the striatum is seen as detecting and selecting cortical contexts for access to basal ganglia output. Although the behavioral consequences of this selection are hard to define, the models provide frameworks within which to explore these ideas empirically. This provides a means of refining our understanding of basal ganglia function and to consider dysfunction within the new logical frameworks.

Assessing and improving the quality of information for health evaluation and promotion

Studies by the author based upon a sample of over 1.1 million patients in the North West of England have shown that the introduction of computers cannot be demonstrated to produce significant improvements in health promotion activity. Other studies have revealed error rates in healthcare information systems in excess of 50%. This paper considers the reasons for these findings and demonstrate that there is a level of maturity of information management required before information systems can make a significant contribution to health promotion and evaluation. With the advent of locality commissioning and a re-affirmation of the emphasis upon health promotion activity set out in Health of the Nation and Our Healthier Nation [8], the role of information management has become even more significant. The paper presents a maturity model developed by the author, known as General Practice Information Maturity Model (GPIMM) that provides a strategic framework to improve the use of information by practices and to improve practice to enable viable sharing of accurate information. The paper will show the model can be used as a basis for the development of training and information strategies. The model identifies computerised practices as being in one of five stages of maturity: (1) Computerised, (2) Computerised PHC Team, (3) Coded, (4) Bespoke, (5) Paperless. The model specifically leads practices to a point in their development where they are able to carry out health evaluation, promotion and audit activities as a routine activity. Once these activities form part of practice activity they are then extended to encompass a group of practices such as a Primary Care Group. Finally, a case study is presented to show how the model was used to enable two very different but geographically neighbouring practices to work together towards the establishment of a common dataset. This dataset will be used to enable health promotion and evaluation activity to be provided for a total population of over 20,000 patients.

Effect of diuretics on sodium and chloride permeability in the rat papillary collecting duct

While in vivo data suggests that diuretics such as furosemide and hydrochlorothiazide alter inner medulla collecting duct (IMCD) cell electrolyte transport, this has not been confirmed by in vivo studies nor have the mechanisms been evaluated. This study evaluated the direct effect of these diuretics as well as amiloride on sodium and chloride unidirectional permeability in the isolated perfused rat IMCD. In the absence of diuretics, the permeability of sodium was lower than that of chloride (0.63 +/- 0.05 compared with 0.83 +/- 0.08 micrometer/s), although both were relatively impermeable when compared to water. Furosemide (10(-4)) and hydrochlorothiazide (10(-3)) both increased the diffusional permeability of chloride by approximately 30% (0.80 +/- 0.06 to 1.04 +/- 0.09 micrometer/s, p < 0.01, and 0.74 +/- 0.09 to 0.98 +/- 0.10 micrometer/s, p < 0.02, respectively). However, sodium permeability was unaltered. Inhibition of Na+, K+-ATPase by ouabain or cooling (4 degrees C) inhibited basal sodium but not chloride permeability while a maximal antidiuretic AVP concentration did not alter sodium or chloride permeability. However, increasing the lumen and bath sodium chloride concentration from 150 to 300 and 600 mM significantly increased both sodium and particularly chloride conductance. In contrast, amiloride (10(-4)) significantly reduced both sodium and chloride permeability. These studies support a direct effect of furosemide and hydrochlorothiazide on the IMCD and suggest that their in vivo effect is primarily mediated by facilitating the passive movement of chloride into the lumen via a favourable electrochemical gradient. These results also demonstrate that amiloride inhibits both sodium and chloride unidirectional permeability by mechanisms separate to that of the sulphonamide-related diuretics.

Pro-haemorrhagic effects of calcium antagonists: a comparison of isradipine and atenolol on ex vivo platelet function in hypertensive subjects

It has been suggested that long term treatment with calcium antagonist drugs might inhibit platelet function and lead to an anti-atheromatous effect. However recent data have also suggested that such an effect might increase mortality due to an increased incidence of gastrointestinal bleeding. We identified 43 subjects from general practice with uncomplicated mild to moderate hypertension to compare the effects of the calcium antagonist isradipine with that of the beta-blocker atenolol on platelet function, plasma beta-thromboglobulin levels, fibrinolysis, and serum lipids in a randomised double-blind parallel group study. After careful evaluation to exclude concomitant aspirin use, only 24 subjects were eligible to enter the study. While isradipine and atenolol produced comparable and clinically significant falls in blood pressure (167 +/- 2/102 +/- 1 to 153 +/- 3/91 +/- 2 mm Hg, and 165 +/- 2/101 +/- 1 to 156 +/- 4/91 +/- 2 mm Hg, respectively), neither drug produced a detectable effect on ex vivo platelet aggregation, platelet retention, or thromboxane generation with adrenaline, collagen, adenosine-di-phosphate, or platelet activating factor. However a decrease in plasma beta-thromboglobulin levels was observed which reached statistical significance (P < 0.05) after 12 weeks treatment in the isradipine but not the atenolol group. A 39% reduction with isradipine compared with 34% following atenolol treatment. Euglobulin clot lysis time was not altered by either drug. Serum cholesterol concentrations were also unaltered by drug treatment. Therapeutic doses of the calcium antagonist isradipine may produce a minor indirect effect on platelet function after several weeks of treatment. However, this is of doubtful clinical importance and may simply reflect an effect of lowered blood pressure on platelet function.

Numerical chromosomal aberrations in Hodgkin's disease detected by in situ hybridisation on routine paraffin sections

AIMS

To visualise directly numerical chromosomal aberrations and polyploidy in both Hodgkin and Reed Sternberg (HRS) cells and background cells from cases of Hodgkin's disease using in situ hybridisation.

METHODS

Non-isotopic DNA in situ hybridisation was applied to interphase cell nuclei of Hodgkin's disease within routine paraffin embedded tissue sections. Two a satellite DNA probes, specific for chromosomes 3 and 12, were used to evaluate the feasibility of this approach. Double labelling with immunocytochemical detection of the CD30 antigen was used to identify HRS cells. Cytogenetic normal diploid and triploid placental tissue served as controls.

RESULTS

The eight cases of Hodgkin's disease investigated displayed frequent polysomy, while the majority of background cells showed disomy signals.

CONCLUSIONS

Numerical chromosomal aberrations were detected in HRS cells from eight cases of Hodgkin's disease by in situ hybridisation. These data show that in Hodgkin's disease HRS cells frequently display polyploidy compared with background cells and are, therefore, probably the only neoplastic component in this disease. Correlations between polysomy and tumour type or grade could not be made from these data owing to the limited number of cases examined and to problems with interpreting data from truncated nuclei.

Can computers improve the Health of the Nation?

In this paper the author considers whether the use of computers can be demonstrated to have a positive impact upon the effectiveness of health screening, in accordance with the Health of the Nation document. It is based upon a study of 1.1 million patients registered with 283 general practices in the North West region of the UK.

Improving patient care in the UK: clinical audit in the Oxford Region

This paper is concerned with the effectiveness of clinical audit as the principal quality control and improvement process in the UK National Health Service (NHS). The paper starts by tracing the historical development of clinical audit in the UK within the context of the major management reforms introduced within the NHS in the last ten years. The paper presents the findings of a major study of published audits within the Oxford, Four Counties and Anglia region. This study provides a snapshot of current audit practice and provides the opportunity to test the hypothesis that current practice does not reflect the stated aim of a structured investigation into the quality of patient care leading to a direct improvement in patient care. The paper considers the reasons for the discrepancy between theory and practice. It argues for the need for a structured approach to address some of these issues. The paper outlines a systematic and structured approach to clinical audit which is part of an overall programme of trying to harmonize and improve practice in audit within the Region. It concludes with plans for the future including the development of a dedicated audit tool based around a structured method.

The effect of adrenalectomy on water permeability in rat papillary collecting duct

1. Chronic adrenal insufficiency impairs maximal urine concentration, probably in part due to reduced medullary tonicity but also possibly by inhibition of distal nephron water transport. This latter defect has been demonstrated in rabbit but not in rat. 2. Since the time between adrenalectomy and experiment was different in rabbit and rat studies, diffusional water permeability was evaluated in the papillary collecting duct in the absence and presence of submaximal (20 microU/mL) and supramaximal (200 microU/mL) arginine vasopressin (AVP) in adrenalectomized rats at 7, 14 and 21 days. 3. Experimentation 7 days after adrenalectomy failed to demonstrate significantly altered basal or AVP-induced water permeability which increased by 23 and 78% with submaximal and supramaximal concentrations, respectively. Submaximal AVP concentrations also induced a comparable change in water permeability in adrenalectomized rats at 14 days; however, 21 days after adrenalectomy, diffusional water permeability was not increased by 20 microU/mL AVP (3.31 +/- 0.22 to 3.31 +/- 0.24 microns/s). Nevertheless, the effect of a supramaximal AVP concentration (200 microU/mL) was not altered by adrenalectomy (4.54 +/- 0.39 to 8.08 +/- 0.96; P < 0.01). Incubation of collecting ducts in aldosterone for 2 h did not reverse the inhibitory effect of chronic adrenalectomy on AVP-stimulated water transport. 4. These studies suggest that mineralocorticoid withdrawal does impair the hydro-osmotic action of AVP in the rat papillary collecting duct but that this effect takes between 14 and 21 days to occur.

Expression of J chain mRNA in duodenal IgA plasma cells in IgA nephropathy

Glomerular IgA in IgA nephropathy (IgAN) is at least in part polymeric, and is thought to derive from the mucosal IgA system in view of the association between mucosal infection and haematuria in this condition. To investigate this hypothesis, an in situ hybridization (ISH) technique was developed for the detection of J chain mRNA, the expression of which has been correlated with the secretion of high level polymeric immunoglobulin (pIg). Endoscopic duodenal biopsies from ten patients and matched controls were examined by: (i) two color immunofluorescence (IF); (ii) ISH; and (iii) combined ISH and IF, to permit simultaneous identification of plasma cell type. IF revealed a reduction in the percentage of IgA plasma cells (P < 0.02) and increased absolute numbers of IgG cells (P < 0.02) in patient biopsies. ISH demonstrated fewer J chain mRNA expressing plasma cells (P < 0.005) with lower signal intensity (P < 0.002) in patients' biopsies compared with controls. Combined ISH and IF confirmed a reduction in J chain mRNA-positive IgA plasma cells in the patient biopsies (P < 0.02). The reduction in J chain mRNA expression in duodenal IgA plasma cells in IgAN argues against the gastrointestinal lamina propria as the source of glomerular pIgA.

Hypertension education: patient knowledge and satisfaction

Education of patients with various diseases, including hypertension, usually occurs at an individual level through a patient's doctor as well as via various media campaigns which also includes general community education. To evaluate their effects, the knowledge of 84 patients with hypertension was evaluated by a simple 13 question true/false questionnaire and the results compared with 58 normotensive subjects matched for sex, age and educational status. A significant difference in knowledge about hypertension could not be elicited between the two groups even when compared for sex or educational status. However, subjects > 70 years of age (hypertensives and controls) demonstrated a lower level of knowledge (P < 0.05). Further questioning of the hypertensive group elicited a high level of satisfaction with their doctor's educational skills (68%) and 57% were satisfied with their own knowledge. Nevertheless, 70% requested more information about their disease. These results suggest a reasonable level of knowledge within the general community presumably reflecting community education programmes. While hypertensive patients were not more knowledgeable under the test conditions, they were reasonably satisfied with their knowledge which they stated came primarily from their doctor. Nevertheless, these findings question the effectiveness of some current patient education initiatives.

Somatostatin as a modulator of distal nephron water permeability

1. Experiments in vivo and in vitro were performed in the rat to define the role of somatostatin in modulating the hydro-osmotic action of arginine vasopressin. 2. Somatostatin had a biphasic effect on basal collecting duct diffusional water permeability with 10(-9) mol/l somatostatin producing a 14% reduction in permeability, whereas concentrations of 10(-6) and 10(-5) mol/l significantly increased basal water permeability by 13% and 22%, respectively. Somatostatin (10(-9) mol/l) also inhibited the increase in water permeability produced by arginine vasopressin, although this inhibitory effect was reduced by a 10-fold increase in arginine vasopressin concentration (5 ng/ml). 3. In the anaesthetized water-diuretic rat, low dose somatostatin (60 micrograms/h) increased free water clearance by 23% (P < 0.01), whereas increasing the somatostatin concentration (600 micrograms/h) produced a transitory 40% fall in free water clearance (P < 0.01). As in the experiment in vitro, somatostatin inhibited the action of arginine vasopressin, although a very high concentration of arginine vasopressin (250 ng/h) partly overcame this effect. 4. Glomerular filtration rate and renal electrolyte excretion (sodium, potassium, calcium, magnesium) were not altered by somatostatin, although renal inorganic phosphate excretion was increased. The papillary solute gradient was unaltered by somatostatin. 5. These results suggest that circulating somatostatin may have a physiological role in modulating distal nephron water transport with a low concentration directly inhibiting and a high concentration facilitating water transport. There is also evidence of competitive binding between somatostatin and arginine vasopressin which antagonizes the hydro-osmotic action of arginine vasopressin.

Simultaneous in situ hybridisation of native mRNA and immunoglobulin detection by conventional immunofluorescence in paraffin wax embedded sections

AIMS

The development of a technique for simultaneous in situ hybridisation for native mRNA and conventional immunofluorescence for cytoplasmic antigens in routine pathology specimens.

METHODS

Cocktails of synthetic deoxyoligonucleotides coding for immunoglobulin J chain and kappa light chain were 3' end labelled enzymatically with digoxigenin using terminal deoxynucleotidyl transferase. Native mRNA sequences were "unmasked" using proteolytic digestion with proteinase K and hybrid detection was achieved with an alkaline phosphatase labelled anti-digoxigenin antibody. Alkaline phosphatase was visualised with Fast red/naphthol AS-MX phosphate. Fluorescein isothiocyanate (FITC) conjugated anti-isotype antibodies were used simultaneously at the detection stage to identify the isotype production by individual plasma cells in endoscopic duodenal biopsy specimens.

RESULTS

The IgA plasma cells of the lamina propria were identified by immunofluorescence and hybrids were detected in the anticipated plasma cell population by Fast red visualisation. The reaction product was visible in bright field or ultraviolet illumination which allowed FITC and Fast red labels to be visualised together under ultraviolet light at 490 nm. Dual labelled cells were clearly visible. Morphology was well preserved throughout.

CONCLUSIONS

This technique permits the demonstration of specific mRNA species in cells expressing immunoglobulin. It combines all the advantages of non-radioactive synthetic oligonucleotide probes and conventional immunofluorescence techniques in routine formol-saline fixed and paraffin wax embedded sections with good retention of morphology.

Intracatheter streptokinase for recurrent peritonitis in CAPD

Intracatheter streptokinase (SK) is advocated as effective treatment with minimal adverse effects in both recurrent bacterial peritonitis and catheter fibrin blockage in continuous ambulatory peritoneal dialysis (CAPD) patients. We reviewed 35 instillations in 20 patients noting a high (86%) side effect profile consisting of fever, onset of turbid dialysis effluent and/or abdominal pain. SK probably releases fibrin clot containing bacteria, leukocytes and debris from the colonized catheter into the peritoneal cavity causing a "peritonitis-like syndrome" of 1 to 3 days duration. Fungal peritonitis occurred after SK in 2 patients. Failure of SK therapy was encountered in Staphylococcus epidermidis infection (p less than 0.05 versus other organisms), which may be related to its protective capsular polysaccharide slime and ability to adhere to plastic prosthetic devices. SK, in this study, was useful treatment in relapsing bacterial peritonitis (50% overall cure) but failed to correct catheter malfunction.

Hypertension and asthma: psychological aspects

Essential hypertensive and asthmatic patients, plus normal non-clinical controls, were compared on a number of psychological measures in order to identify the relationship between psychological distress, coping strategies and compliance behaviour. The hypothesised relationship between chronic clinical ailments and psychological distress was confirmed. The association between the presence of physical symptoms in the symptomatic condition, asthma, and greater psychological distress was also confirmed. The coping strategies adopted by the patients did not discriminate between the two clinical groups. Compliance with medication was negatively correlated with measures of psychological distress. Compliance with an appropriate healthy lifestyle was not correlated with medication compliance, although it too was negatively correlated with other measures of psychological distress.

Absorption of retinal and subretinal hemorrhages

Patients with intra- and subretinal hemorrhages who recovered useful vision from an initially poor visual acuity are described. Three patients with intraretinal hemorrhages all cleared without adverse visual sequelae within four to eight weeks; three patients with subretinal or subpigmental hemorrhages cleared with minimal loss of visual acuity, within three to six months. It seems that the amount of damage done to the retina by an intraretinal or subretinal hemorrhage is related to its size and the ability of ocular tissue to clear the blood. Small amount of hemorrhage in or under the retina is capable of clearing with minimal damage. Subretinal hemorrhage seem to be associated more often with damage to the retina for few possible reasons: (a) direct iron toxicity on the photoreceptors; (b) iron toxicity or mechanical damage to the RPE; (c) cellular migration and proliferation in the subretinal space; (d) proliferation of fibrovascular membrane which may further damage the external retina.

Changes in "active" and "inactive" renin in the juxtaglomerular apparatuses of rat nephrons and plasma induced by different salt intake

The juxtaglomerular apparatuses (JGA) of deep and superficial nephrons were isolated by microbiopsy or by microdissection. Inactive renin content was determined by acidification of JGA or plasma to pH 3.0. In rats with low salt intake the renin content of superficial JGA was 13.4 +/- 3.0 ng AI/JGA/h before and 20.4 +/- 3.4 ng AI/JGA/h (n = 9), P less than 0.05) after acidification. The corresponding values for deep JGA were 9.1 +/- 1.2 ng AI/JGA/h and 12.7 +/- 2.7 ng AI/JGA/h (n = 9, P less than 0.01). The plasma renin concentration was 54.1 +/- 15.0 ng AI/ml/h before and 56.0 +/- 10.6 ng AI/JGA/h (n = 7, N.S.) after acidification. In rats with a normal salt intake the superficial renin JGA renin content was 11.6 +/- 2.3 ng AI/JGA/h before and 11.0 +/- 2.7 ng AI/JGA/h (n = 9, N.S.) after acidification. The renin content of deep JGA was 4.6 +/- 0.6 ng AI/JGA/h before and 8.6 +/- 3.1 ng AI/JGA/h (n = 9, P less than 0.005) after acidification. Plasma renin concentration was 34.5 +/- 4.7 ng AI/ml/h and did not change after acidification. In rats with a high salt intake superficial JGA content was 6.8 +/- 1.7 ng AI/JGA/h before and 8.4 +/- 2.1 ng AI/JGA/h (n = 9, N.S.) after acidification. The corresponding values for deep JGA were 5.7 +/- 1.6 ng AI/JGA/h and 6.9 +/- 1.6 ng AI/JGA/h (n = 9, N.S.) respectively. Plasma renin concentration was 13.1 +/- 1.1 ng AI/ml/h and this to 21.8 +/- 2.9 ng AI/ml/h (n = 8, P less than 0.01) after acidification. These results suggest that although the synthesis of active and inactive renin is linked, the secretion of the two forms may be independent.

Formation and activation of renin in vivo

Active and acid activated renin was measured in glomeruli of rats obtained by microbiopsy and in rat plasma. Sodium depletion increased total and active renin in the juxtaglomerular apparatus and approximately one third of the renin was in an inactive form in sodium depletion. Sodium loading decreased active and total renin and there was no inactive renin present. In plasma changes in a similar direction occurred for active and total renin but in sodium depletion there was no inactive renin present while with sodium loading approximately 40% was in the inactive form. Haemorrhage caused a release of active renin in both sodium states and did not alter the renin content of the J.G.A. Increased delivery of sodium chloride to the macula densa increased the active renin content of J.G.A. but did not alter the total renin content. These results are compatible with two different roles of the renin angiotensin system. One being concerned with intrarenal regulation of glomerular filtration and renal blood flow and the other with maintenance of vascular tone. The conversion of inactive renin to active renin being of particular importance in the regulation of G.F.R.

Active and inactive renin in individual juxtaglomerular apparatuses

1. Renin was measured in individual juxtaglomerular apparatuses before and after acidification in vitro. 2. Active renin increased with delivery of extra sodium by microperfusion to the macula densa and this increase was similar to that achieved with acidification. 3. In rats pretreated with an inhibitor of protein synthesis active renin increased when extra sodium was delivered to the macula densa. 4. Salt intake changed the amount of renin present in the juxtaglomerular apparatus. In rats on a high salt intake the total renin was low and was all in an active form.

Effect of tienilic acid and amiloride in healthy volunteers and in hypertensives with normal renal function

1 A double-blind comparison of the effect of tienilic acid (250 mg) and amiloride (5 mg) on renal function in healthy volunteers and of tienilic acid plus amiloride compared to hydrochlorothiazide (50 mg) plus amiloride in patients with mild to moderate essential hypertension for safety and hypotensive efficacy was made.

2 Renal plasma flow ([I¹²⁵] iodohippurate clearance) and glomerular filtration rate ([I¹³¹] iothalamate clearance and 24 h creatinine clearance) were not affected by tienilic acid or amiloride alone or in combination despite a rise in plasma urea and plasma creatinine (within the normal range) in healthy volunteers.

3 In hypertensive patients tienilic acid and tienilic acid plus amiloride treatments caused a rise in plasma urea and plasma creatinine similar to hydrochlorothiazide and hydrochlorothiazide plus amiloride but no significant change in creatinine clearance occurred with any of the treatments.

4 Tienilic acid and hydrochlorothiazide caused hypokalaemia in the patients which was normalized by addition of amiloride. Fewer subjects became hypokalaemic when amiloride was added to tienilic acid than when tienilic acid was given alone.

5 The antihypertensive effect of tienilic acid and tienilic acid plus amiloride was similar to hydrochlorothiazide and hydrochlorothiazide plus amiloride in patients with hypertension. No effect on blood pressure was observed in the healthy volunteers.

6 Plasma uric acid was significantly reduced by tienilic acid alone and in combination in patients and subjects whereas a significant elevation occurred with hydrochlorothiazide.

7 Side effects were increased when amiloride was added to either tienilic acid or hydrochlorothiazide, but side effects were less common after treatment with tienilic acid than following hydrochlorothiazide.

8 The combination of tienilic acid plus amiloride significantly reduces blood pressure and appears to be well tolerated with no adverse effects on renal function or plasma potassium in patients with mild to moderate hypertension and normal renal function. Addition of amiloride may be useful if hypokalaemia occurs following tienilic acid therapy in such patients.