A Simple Admission Order-set Improves Adherence to Canadian Guidelines for Hospitalized Patients With Severe Ulcerative Colitis

Background

Individuals hospitalized with severe ulcerative colitis represent a complex group of patients. Variation exists in the quality of care of admitted patients with inflammatory bowel disease. We hypothesized that implementation of a standardized admission order set could result in improved adherence to current best practice guidelines (Toronto Consensus Statements) for the management of this patient population.

Methods

A retrospective cohort study of patients admitted with severe ulcerative colitis to a Montreal tertiary center was conducted. Two cohorts were defined based on pre- and post-implementation of a standardized order set. Adherence to 11 quality indicators was assessed before and after implementation of the intervention. These included: Clostridioides difficile and stool cultures testing, ordering an abdominal X-ray and CRP, organizing a flexible sigmoidoscopy, documenting latent tuberculosis, initiating thromboprophylaxis, use of intravenous steroids, prescribing infliximab if refractory to steroids, limiting narcotics, and surgical consultation if refractory to medical therapy.

Results

Adherence to 6 of the 11 quality indicators was improved in the post-intervention cohort. Significant increases were noted in adherence to C difficile testing (75.5% versus 91.9%, P < 0.05), CRP testing (71.4% versus 94.6%, P < 0.01), testing for latent tuberculosis (38.1% versus 84.6%, P < 0.01), thromboprophylaxis (28.6% versus 94.6%, P < 0.01), adequate corticosteroids prescription (72.9% versus 94.6%, P < 0.01), and limitation of narcotics prescribed (68.8% versus 38.9%, P < 0.01).

Conclusions

Implementation of a standardized order set, focused on pre-defined quality indicators for hospitalized patients with severe UC, was associated with meaningful improvements to most quality indicators defined by the Toronto Consensus Statements.

Muscle Mass and Direct Oral Anticoagulant Activity in Older Adults With Atrial Fibrillation

BACKGROUND

Direct oral anticoagulants (DOAC) are hydrophilic drugs with plasma levels inversely proportional to lean body mass. Sarcopenic patients with low muscle mass may be at risk for supra-therapeutic DOAC levels and bleeding complications. We therefore sought to examine the influence of lean body mass on DOAC levels in older adults with atrial fibrillation (AF).

METHODS

A prospective cohort study was conducted with patients 65 years of age or more receiving rivaroxaban or apixaban for AF. Appendicular lean mass (ALM) was measured using a bioimpedance device and a dual X-ray absorptiometry scanner. DOAC levels were measured using a standardized anti-Xa assay 4 hours after (peak) and 1 hour before (trough) ingestion.

RESULTS

The cohort consisted of 62 patients (47% female, 77.0 ± 6.1 years). The prescribed DOACs were apixaban 2.5 mg (21%), apixaban 5 mg (53%), and rivaroxaban 20 mg (26%). Overall, 16% had supra-therapeutic DOAC levels at trough and 25% at peak. In the multivariable logistic regression model, lower ALM was independently associated with supra-therapeutic DOAC levels at trough (odds ratio per ↓ 1-kg 1.23, 95% confidence interval 1.02 to 1.49) and peak (odds ratio per ↓ 1-kg 1.18, 95% confidence interval 1.02 to 1.37). Addition of ALM to a model consisting of age, total body weight, and renal function resulted in improved discrimination for supra-therapeutic DOAC levels.

CONCLUSION

Our proof-of-concept study has identified an association between ALM and DOAC levels in older adults with AF. Further research is needed to determine the impact of ALM on bleeding complications and the potential role of ALM-guided dosing for sarcopenic patients.

Adequacy Targets Can be Met in Anuric Patients by Automated Peritoneal Dialysis: Baseline Data from Eapos

♦ Objective

Conventional continuous ambulatory peritoneal dialysis (CAPD) in patients without residual renal function and with high solute transport is associated with worse clinical outcomes. Automated peritoneal dialysis (APD) has the potential to improve both solute clearance and ultrafiltration in these circumstances, but its efficacy as a treatment modality is unknown. The European Automated Peritoneal Dialysis Outcomes Study (EAPOS) is a 2-year, prospective, European multi-center study designed to determine APD feasibility and clinical outcomes in anuric patients. The present article describes the baseline data for patients recruited into the study.

♦ Design

All PD patients treated in the participating centers were screened for inclusion criteria [urinary output < 100 mL/24 h, or residual renal function (RRF) < 1 mL/min, or both]. After enrollment, changes were made to the dialysis prescription to achieve a weekly creatinine clearance above 60 L per 1.73 m2 and an ultrafiltration rate above 750 mL in 24 hours.

♦ Setting

The study is being conducted in 26 dialysis centers in 13 European countries.

♦ Baseline Data Collection

The information collected includes patient demographics, dialysis prescription, achieved weekly creatinine clearance, and 24-hour ultra-filtration (UF).

♦ Results

The study enrolled 177 anuric patients. Median dialysis duration before enrollment was 22.5 months (range: 0 – 285 months). Mean solute transport measured as the dialysate-to-plasma ratio of creatinine (D/PCr) was 0.74 ± 0.12. Patients received APD for a median of 9.0 hours overnight (range: 7 – 12 hours) using a median of 11.0 L of fluid (range: 6 – 28.75 L). Median daytime volume was 4.0 L (range: 0.0 – 9.0 L). Tidal dialysis was used in 26 patients, and icodextrin in 86 patients. At baseline, before treatment optimization, the weekly mean total creatinine clearance was 65.2 ± 14.4 L/1.73 m2, with 105 patients (60%) achieving the target of more than 60 L/1.73 m2. At baseline, 81% of patients with high transport, 69% with high-average transport, and 40% with low-average transport met the target. At baseline, 70% of patients with a body surface area (BSA) below 1.7 m2, 60% with a BSA of 1.7 – 2.0 m2, and 56% with a BSA above 2.0 m2 achieved 60 L/1.73 m2 weekly. Median UF was 1090 mL/24 h, and 75% of patients achieved the UF target of more than 750 mL/24 h.

♦ Conclusion

This baseline analysis of anuric patients recruited into the EAPOS study demonstrates that a high proportion of anuric patients on APD can achieve dialysis and ultrafiltration targets using a variety of regimes. This 2-year follow-up study aims to optimize APD prescription to reach predefined clearance and ultrafiltration targets, and to observe the resulting clinical outcomes.

Hypersensitivity reactions to high osmolality Total Parenteral Nutrition: a case report

Background

The full range of allergic reactions to Total Parenteral Nutrition (TPN) remains unknown. Additionally, beyond individual allergens, there may be other factors contributing to TPN hypersensitivity reactions.

Case presentation

We present a case of a patient with negative skin testing to common TPN allergens who had recurrent urticarial reactions to TPN. Her skin reactions resolved once TPN was stopped. Following a literature review, we postulated that the reactions could be due to the high osmolality of her TPN. Consequently, lowering her TPN from 2785 to 1928 mOsm/kg and premedicating with cetirizine resulted in resolution of her urticaria.

Conclusions

When looking at patients who have hypersensitivity reactions to TPN, one must consider that their reactions may be due to factors other than allergens. More studies are needed to clarify the relationship between high osmolality TPN infusions and non-IgE mediated hypersensitivity reactions.

Variation of High-Sensitivity Troponin T Results in Patients Undergoing Continuous Renal Replacement Therapy

Background:

Cardiac troponins are the preferred biomarker to diagnose myocardial injury. Complicating the interpretation of serial troponins in patients with end-stage renal disease, it has been shown that the hemodialysis procedure results in a small but significant decline in high-sensitivity cardiac troponins (hs-cTnT). This raises the possibility that continuous renal replacement therapy (CRRT) might similarly alter cardiac troponin levels and affect their interpretation when cardiac ischemia is being considered.

Objective:

We sought to determine the effect of CRRT on hs-cTnT levels over time in a group of patients without active myocardial injury.

Design:

Prospective, observational study

Setting:

Single tertiary care hospital, Montreal, Quebec

Patients:

Ten critically ill patients with acute kidney injury (AKI) undergoing CRRT. Cardiac ICU (intensive care unit) patients and acute coronary syndrome patients were excluded from the study. The CRRT prescription was at the discretion of the treating intensivist and relatively high doses were used in this study.

Measurements:

The hs-cTnT levels were drawn pre-CRRT, within 6 hours of initiation, and approximately every 6 hours thereafter along with routine CRRT blood work.

Methods:

Changes in hs-cTnT, creatinine, and albumin levels were recorded over the course of CRRT. Mean change in serum analyte concentration and 95% confidence interval was determined for specified time intervals relative to baseline, with paired t tests used to determine statistical significance.

Results:

Among the 10 patients included in the study, the cause of AKI was primarily acute tubular necrosis from septic shock or hemorrhagic shock. Compared with baseline hs-cTnT levels prior to CRRT initiation, mean hs-cTnT level fell by 42% at 5 to 10 hours post-CRRT initiation, followed by a plateauing of levels for the duration of time on CRRT.

Limitations:

Single-center study only applicable to hs-cTnT assay.

Conclusions:

This study demonstrates a significant decrease in hs-cTnT within 5 to 10 hours of CRRT initiation. This suggests that interpretation of cardiac troponin changes during CRRT must take into consideration the timing of dialysis initiation relative to the time of sample collection.

Effect of Hemodialysis on Levels of High-Sensitivity Cardiac Troponin T

Cardiac troponin (cTn) is essential for the diagnosis of an acute coronary syndrome (ACS). However, in end-stage renal disease (ESRD) baseline cTn levels are often elevated, and it is unknown whether the hemodialysis (HD) procedure affects cTn levels. This leaves clinicians unsure of how to interpret cTn in HD patients with cardiac ischemia. We therefore sought to determine if plasma levels of high-sensitivity cardiac troponin T (hs-cTnT) vary during or after HD treatment. We prospectively enrolled 10 chronic HD patients who were admitted to our institution. All participants were receiving thrice weekly HD before admission and were medically stable. Those admitted for ACS or to critical care units were excluded. Baseline hs-cTnT was measured immediately before HD. For the subsequent 6 hours, hs-cTnT was measured every 2 hours and every 3 hours thereafter for a total collection period of 24 hours. A significant decline in mean hs-cTnT was noted with HD. During HD (2 hours after HD initiation), hs-cTnT decreased by 10.7% (confidence interval 5% to 17%). Immediately after HD (4 hours after HD initiation), a decline of 12% (confidence interval 5% to 19%) was observed. Thereafter hs-cTnT began to rise. Hs-cTnT levels returned to baseline by 11 hours after HD completion and remained stable for the reminder of the study. In conclusion, HD induces a short-lived negative bias in hs-cTnT. When measured for investigation of ACS, hs-cTnT concentration should be interpreted with respect to time of dialysis and specimen collection.

Dynamics of vitamin D in patients with mild or inactive inflammatory bowel disease and their families

BACKGROUND

25(OH) vitamin D levels may be low in patients with moderately or severely active inflammatory bowel diseases (IBD: Crohn's disease and Idiopathic Ulcerative Colitis) but this is less clear in patients with mild or inactive IBD. Furthermore there is limited information of any family influence on 25(OH) vitamin D levels in IBD. As a possible risk factor we hypothesize that vitamin D levels may also be low in families of IBD patients.

OBJECTIVES

To evaluate 25[OH] vitamin D levels in patients with IBD in remission or with mild activity. A second objective is to evaluate whether there are relationships within IBD family units of 25[OH] vitamin D and what are the influences associated with these levels.

METHODS

Participants underwent medical history, physical examination and a 114 item diet questionnaire. Serum 25[OH] vitamin D was measured, using a radioimmunoassay kit, (replete ≥ 75, insufficient 50-74, deficient < 25-50, or severely deficient < 25 nmol/L). Associations between 25[OH] vitamin D and twenty variables were evaluated using univariate regression. Multivariable analysis was also applied and intrafamilial dynamics were assessed.

RESULTS

55 patients and 48 controls with their respective families participated (N206). 25[OH] vitamin D levels between patients and controls were similar (71.2 ± 32.8 vs. 68.3 ±26.2 nmol/L). Vitamin D supplements significantly increased intake but correlation with serum 25[OH] vitamin D was significant only during non sunny months among patients. Within family units, patients' families had mean replete levels (82.3 ± 34.2 nmol/L) and a modest correlation emerged during sunny months between patients and family (r2 =0.209 p = 0.032). These relationships were less robust and non significant in controls and their families.

CONCLUSIONS

In patients with mild or inactive IBD 25[OH] vitamin D levels are less than ideal but are similar to controls. Taken together collectively, the results of this study suggest that patient family dynamics may be different in IBD units from that in control family units. However contrary to the hypothesis, intra familial vitamin D dynamics do not pose additional risks for development of IBD.

Effects of vitamin C and vitamin D administration on mood and distress in acutely hospitalized patients

BACKGROUND

Hypovitaminosis C and D are highly prevalent in acute-care hospitals. Malnutrition with regard to these vitamins has been linked to mood disturbance and cognitive dysfunction.

OBJECTIVE

The objective was to determine whether vitamin C or D supplementation improves mood state or reduces psychological distress in acutely hospitalized patients with a high prevalence of hypovitaminosis C and D.

DESIGN

A randomized, double-blind, active-control clinical trial compared the effects of vitamin C (500 mg twice daily) with those of high-dose vitamin D (5000 IU/d) on mood (Profile of Mood States) and psychological distress (Distress Thermometer).

RESULTS

Vitamin C provided for a mean of 8.2 d increased plasma vitamin C concentrations to normal (P < 0.0001) and was associated with a 71% reduction in mood disturbance (P = 0.0002) and a 51% reduction in psychological distress (P = 0.0002). High-dose vitamin D provided for a mean of 8.1 d increased plasma 25-hydroxyvitamin D [25(OH)D] concentrations (P < 0.0001), but not into the normal range, and had insignificant effects on mood (P = 0.067) and distress (P = 0.45). The changes in mood and distress in the vitamin C group were greater than those in the vitamin D group (P = 0.045 for mood; P = 0.009 for distress).

CONCLUSIONS

Short-term therapy with vitamin C improves mood and reduces psychological distress in acutely hospitalized patients with a high prevalence of hypovitaminosis C and D. No conclusion is possible regarding the effects of vitamin D because the dose and duration of therapy were insufficient to raise 25(OH)D concentrations into the normal range. This trial was registered at clinicaltrials.gov as NCT01630720.

Preoperative Parathyroid Hormone Levels as a Predictor of Postthyroidectomy Hypocalcemia

Objectives. The goal of the present study is to determine whether a decline in the 1-hour postoperative parathyroid hormone (PTH) level relative to the preoperative level is predictive of hypocalcemia.

Methods. This is a retrospective study involving 142 consecutive patients who underwent total thyroidectomy. Changes in preoperative PTH levels were then compared with the 1-hour levels.

Results. Thirty-four of 142 patients (23.9%) who underwent total thyroidectomy developed hypocalcemia. Thirty-one of the 34 patients who became hypocalcemic had a 1-hour postoperative PTH drop of 70% or more when compared with the preoperative value (sensitivity = 91%, specificity = 98%, positive predictive value = 94%, and negative predictive value = 97%).

Conclusion. A decline in the preoperative PTH level of 70% or greater at 1 hour following total thyroidectomy appears to be a reliable predictor of patients at risk of developing hypocalcemia. By allowing thyroid surgeons to identify these patients in the early postoperative period, calcium supplementation can be initiated sooner.

Comparison of a real-time polymerase chain reaction assay for lactase genetic polymorphism with standard indirect tests for lactose maldigestion

BACKGROUND & AIMS

There is a discrepancy in outcome between the lactose tolerance and breath hydrogen tests for lactose maldigestion. The availability of a validated genetic test for lactase polymorphism allows a reevaluation of these tests.

METHODS

Thirty healthy adults participated in a 50-g lactose challenge test at a university clinic. Blood was drawn for genetic and timed blood glucose testing (2 hours), and breath hydrogen was measured (4.5 hours). Lactase genetic polymorphism was assessed by a real-time polymerase chain reaction assay. Participants completed a diet questionnaire, and symptoms were recorded during the lactose challenge. Sensitivity and specificity were calculated for each indirect test. The 2-way kappa coefficient between these tests was evaluated. Student t test and Wilcoxon rank sum test were used to compare variables.

RESULTS

The lactose tolerance test as a standard had an 87.5% sensitivity and 92.7% specificity for genetic status. Only a moderate agreement between lactose tolerance test and breath hydrogen test was observed (2-way kappa coefficient, .53; 95% confidence interval, .22-.83). When genetic status was used as standard, symptoms had a moderate sensitivity and specificity. Lactose tolerance test had very good sensitivity, and the breath test had excellent specificity.

CONCLUSIONS

Both indirect tests independently have good to very good sensitivities and specificities for genetic lactase status. The noted disagreement likely reflects variables that affect the tests independently of intestinal lactase status. The value of these tests in the light of the availability of genetic testing is discussed.

Putative common origin of two MLH1 mutations in Italian-Quebec hereditary non-polyposis colorectal cancer families

Hereditary non-polyposis colorectal cancer (HNPCC) is one of the most common inherited cancer syndromes, accounting for 3-5% of all cases of colorectal cancer. In most HNPCC families, the disease is caused by a germline mutation in MLH1 or MSH2. In some populations, founder mutations appear to explain a substantial fraction of HNPCC. We report here the identification and preliminary characterization of two putative MLH1 founder mutations. The mutation MLH1c.1831delAT was shown to segregate in two Quebec families of Italian origin who fulfilled the Amsterdam criteria for HNPCC. Haplotype analysis using five intragenic microsatellite/single nucleotide polymorphism markers spanning MLH1 on chromosome 3 showed that these two unrelated families share an identical haplotype. In addition, two other Italian kindred whose affected members carry MLH1g.IVS6 + 3A>G also share a common haplotype, suggesting that, similarly, the latter mutation has a common origin. These mutations are the first putative founder MLH1 mutations to be identified in HNPCC kindred of Italian origin.

Postoperative Parathyroid Hormone Levels in Conjunction with Corrected Calcium Values as a Predictor of Post-Thyroidectomy Hypocalcemia: Review of Outcomes 1 Year after the Implementation of a New Protocol

OBJECTIVES

To determine the effectiveness of post-thyroidectomy parathyroid hormone (PTH) levels in conjunction with corrected calcium values as predictors of patients at risk of developing hypocalcemia.

METHODS

This is a follow-up study reviewing the results of a newly implemented post-thyroidectomy algorithm. The changes in management from the previous protocol involve decision making based on the 12-hour corrected calcium and PTH levels, as well as the 1-hour PTH value. The study involved 120 patients separated into two groups: 60 prior to implementation of the protocol and 60 following the implementation of the protocol. Patients having completion thyroidectomy, neck dissections, or parathyroidectomy were excluded.

RESULTS

Since the implementation of the new protocol, there has been a reduction in the rate of transient hypocalcemia (25% to 12%; p = .059), fewer blood tests (23 to 15 per patient), and earlier patient discharges.

CONCLUSIONS

The new algorithm is effective in detecting patients who are not at risk of developing hypocalcemia at 12 hours. This has led to significant cost savings at our institution. Moreover, calcium supplementation based on the 1-hour PTH level has coincided with a reduction in cases of transient hypocalcemia.

Germline truncating mutations in both MSH2 and BRCA2 in a single kindred

There has been interest in the literature in the possible existence of a gene that predisposes to both breast cancer (BC) and colorectal cancer (CRC). We describe the detailed characterisation of one kindred, MON1080, with 10 cases of BC or CRC invasive cancer among 26 first-, second- or third-degree relatives. Linkage analysis suggested that a mutation was present in BRCA2. DNA sequencing from III: 22 (diagnosed with lobular BC) identified a BRCA2 exon 3 542G>T (L105X) mutation. Her sister (III: 25) had BC and endometrial cancer and carries the same mutation. Following immunohistochemical and microsatellite instability studies, mutation analysis by protein truncation test, cDNA sequencing and quantitative real-time PCR revealed a deletion of MSH2 exon 8 in III: 25, confirming her as a double heterozygote for truncating mutations in both BRCA2 and MSH2. The exon 8 deletion was identified as a 14.9 kb deletion occurring between two Alu sequences. The breakpoint lies within a sequence of 45 bp that is identical in both Alu sequences. In this large BC/CRC kindred, MON1080, disease-causing truncating mutations are present in both MSH2 and BRCA2. There appeared to be no increased susceptibility to the development of colorectal tumours in BRCA2 mutation carriers or to the development of breast tumours in MSH2 mutation carriers. Additionally, two double heterozygotes did not appear to have a different phenotype than would be expected from the presence of a mutation in each gene alone.

Impact of ambulance transportation on resource use in the emergency department

OBJECTIVE

To determine how ambulance transportation is associated with resource use in the emergency department (ED).

METHODS

A retrospective administrative database review of patient visits to a Montreal tertiary care hospital ED in one year (April 2000-March 2001). Measures of resource use included ED length of stay, admission to the hospital, and whether consultations and radiology/imaging tests (excluding plain-film x-rays) were ordered from the ED.

RESULTS

During the study period, 39,674 patients made 59,142 visits to the ED. Ambulance transportation was used for 15.6% of these ED visits. Compared with non-ambulance visits, ambulance visits were more likely to be made by older patients (mean age: 68 vs. 47 years), to be made by females (59% vs. 55%), to have a greater triage urgency score (mean on 1-5 scale, with 1 most urgent: 2.7 vs. 3.9), and to occur after office hours, 5 PM to 9 AM (47% vs. 43%). Ambulance visits were also more likely than non-ambulance visits to result in: a longer length of stay (mean: 13.3 hours [95% CI = 13.0 to 13.6] vs. 5.9 [95% CI = 5.8 to 6.0]), hospital admission (40% vs. 10%) (odds ratio [OR]: 5.94 [95% CI = 5.59 to 6.33]), consultations (56% vs. 20%) (OR: 5.15 [95% = 4.86 to 5.45]), and radiology/imaging tests (20% vs. 12%) (OR: 1.93 [95% CI = 1.81 to 2.07]). In multivariate models that adjusted for the effects of age, gender, triage urgency, and temporal factors, ambulance transportation maintained its association with greater resource use.

CONCLUSIONS

This preliminary study indicates that patients arriving at the ED by ambulance use significantly more resources than their walk-in counterparts.

Postoperative Parathyroid Hormone Level as a Predictor of Post-thyroidectomy Hypocalcemia

OBJECTIVES

To evaluate levels of parathyroid hormone following total thyroidectomy in order to ascertain its ability to predict postoperative hypocalcemia. To establish standardized criteria permitting the safe discharge of total thyroidectomy patients within 13 hours of surgery.

METHODS

This is a prospective study in which parathyroid hormone levels were tested in 54 consecutive patients who underwent total thyroidectomy. Levels were measured postoperatively at 6, 12, and 20 hours. Corrected calcium levels were also measured at 6, 12, and 20 hours in accordance with the preexisting protocol.

RESULTS

Statistical analysis demonstrates that patients with corrected calcium levels greater than or equal to 2.14 mmol/L and parathyroid hormone levels greater than or equal to 28 ng/L at 12 hours post-thyroidectomy can be discharged without further need for calcium monitoring. The analysis also demonstrates that patients with 12-hour parathyroid hormone levels less than or equal to 20 ng/L are at significant risk of developing hypocalcemia.

CONCLUSION

Parathyroid hormone levels in conjunction with corrected calcium values are accurate predictors of the calcium trends of post-thyroidectomy patients. Implementation of this protocol can result in shorter hospital stays for the majority of post-thyroidectomy patients, which can translate into substantial cost savings for the health care system.

The founder mutation MSH2*1906G-->C is an important cause of hereditary nonpolyposis colorectal cancer in the Ashkenazi Jewish population

Hereditary nonpolyposis colorectal cancer (HNPCC) is caused by mutations in the mismatch-repair genes. We report here the identification and characterization of a founder mutation in MSH2 in the Ashkenazi Jewish population. We identified a nucleotide substitution, MSH2*1906G-->C, which results in a substitution of proline for alanine at codon 636 in the MSH2 protein. This allele was identified in 15 unrelated Ashkenazi Jewish families with HNPCC, most of which meet the Amsterdam criteria. Genotype analysis of 18 polymorphic loci within and flanking MSH2 suggested a single origin for the mutation. All colorectal cancers tested showed microsatellite instability and absence of MSH2 protein, by immunohistochemical analysis. In an analysis of a population-based incident series of 686 Ashkenazi Jews from Israel who have colorectal cancer, we identified 3 (0.44%) mutation carriers. Persons with a family history of colorectal or endometrial cancer were more likely to carry the mutation than were those without such a family history (P=.042), and those with colorectal cancer who carried the mutation were, on average, younger than affected individuals who did not carry it (P=.033). The mutation was not detected in either 566 unaffected Ashkenazi Jews from Israel or 1,022 control individuals from New York. In hospital-based series, the 1906C allele was identified in 5/463 Ashkenazi Jews with colorectal cancer, in 2/197 with endometrial cancer, and in 0/83 with ovarian cancer. When families identified by family history and in case series are included, 25 apparently unrelated Ashkenazi Jewish families have been found to harbor this mutation. Although this pathogenic mutation is not frequent in the Ashkenazi Jewish population (accounting for 2%-3% of colorectal cancer in those whose age at diagnosis is <60 years), it is highly penetrant and accounts for approximately one-third of HNPCC in Ashkenazi Jewish families that fulfill the Amsterdam criteria.

An MLH1 haplotype is over-represented on chromosomes carrying an HNPCC predisposing mutation in MLH1

BACKGROUND

The mismatch repair gene, MLH1, appears to occur as two main haplotypes at least in white populations. These are referred to as A and G types with reference to the A/G polymorphism at IVS14-19. On the basis of preliminary experimental data, we hypothesised that deviations from the expected frequency of these two haplotypes could exist in carriers of disease associated MLH1 germline mutations.

METHODS

We assembled a series (n=119) of germline MLH1 mutation carriers in whom phase between the haplotype and the mutation had been conclusively established. Controls, without cancer, were obtained from each contributing centre. Cases and controls were genotyped for the polymorphism in IVS14.

RESULTS

Overall, 66 of 119 MLH1 mutations occurred on a G haplotype (55.5%), compared with 315 G haplotypes on 804 control chromosomes (39.2%, p=0.001). The odds ratio (OR) of a mutation occurring on a G rather than an A haplotype was 1.93 (95% CI 1.29 to 2.91). When we compared the haplotype frequencies in mutation bearing chromosomes carried by people of different nationalities with those seen in pooled controls, all groups showed a ratio of A/G haplotypes that was skewed towards G, except the Dutch group. On further analysis of the type of each mutation, it was notable that, compared with control frequencies, deletion and substitution mutations were preferentially represented on the G haplotype (p=0.003 and 0.005, respectively).

CONCLUSION

We have found that disease associated mutations in MLH1 appear to occur more often on one of only two known ancient haplotypes. The underlying reason for this observation is obscure, but it is tempting to suggest a possible role of either distant regulatory sequences or of chromatin structure influencing access to DNA sequence. Alternatively, differential behaviour of otherwise similar haplotypes should be considered as prime areas for further study.

Analysis of multiple samples using multiplex sample NMR: selective excitation and chemical shift imaging approaches

Two improved approaches for the rapid analysis of multiple samples using multiplex sample NMR are described. In the first approach, frequency-selective 90 degrees radio frequency pulses and large pulsed field gradients are applied to excite and detect multiple samples in rapid succession. This method is advantageous for samples with relatively long longitudinal (T1) relaxation times. In the second approach, chemical shift imaging is applied to acquire both the spectral and spatial information of multiple samples simultaneously. Chemical shift imaging is more time-consuming than selective excitation; however, it is advantageous for detecting samples with short T1's and for signal averaging. Both approaches demonstrate the potential of multiplex sample NMR for carrying out high-throughput NMR detection.

Role of molecular diagnostic testing in familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer families

PURPOSE

Genetic tests are available for familial adenomatous polyposis and hereditary nonpolyposis colorectal cancer. The goal of this review was to develop an algorithm for application of molecular diagnostic techniques to the management of hereditary colorectal carcinoma and to familiarize the clinician with the vocabulary of molecular genetic testing for hereditary colorectal carcinoma.

METHODS

Studies examining the clinical use of genetic testing for hereditary colorectal carcinoma syndromes are evaluated. Recent advances in molecular genetic technology are reviewed, and clinical management as practiced here and elsewhere is outlined.

RESULTS

This review is a guide to the most reliable molecular diagnostic techniques. Three key questions are answered: who, when, and how to test.

CONCLUSIONS

When integrated with existing testing protocols for colorectal carcinoma and when applied with appropriate caveats, particularly regarding interpretation of negative results, genetic testing can result in improved management of patients and families.

NMR probe for the simultaneous acquisition of multiple samples

A dual channel probe for the simultaneous acquisition of NMR data from multiple samples has been developed. This multiplex probe consists of two noninteracting sample coils that are each capable of detecting NMR signals at the same resonant frequency with good sensitivity and resolution. 13C free induction decays for the two samples, methanol (13C, 99%) and carbon tetrachloride (13C, 99%), were acquired simultaneously at 75.44 MHz using a single transmitter pulse and separate NMR receivers. S/N measurements are comparable to those observed using single coils. No evidence of cross talk is evident in the spectra even after considerable signal averaging. The probe demonstrates the feasibility of significant parallelism in NMR, which will be of interest in situations where high throughput analysis is desired.

Using participatory action research to understand the meanings aboriginal Canadians attribute to the rising incidence of diabetes

This paper discusses the advantages of adopting forms of participatory action research with aboriginal Canadians. Using a recent qualitative study of non-insulin-dependent diabetes mellitus among the James Bay Cree, it outlines and discusses the methodology used to construct a form of action research that focused on what meaning the Cree gave to the rising incidence and prevalence of diabetes. In order to understand this perspective, the researchers recruited members of the Cree community as co-researchers in the study. This facilitated the development of a Cree perspective on diabetes and also allowed the Cree members of the study to acquire a grounding in the knowledge and skills necessary for forms of qualitative research that can inform both policy and practice in health care and related areas. In particular, the paper discusses how the study was constructed and what lessons can be drawn from this form of collaborative inquiry.

Provision of leucocyte poor blood at the bedside

The Imugard IG 500 cotton wool filter and the Cellselect cellulose acetate filter were adapted for filtration of leucocytes from packed cell transfusions at the bedside. Sixty five transfusions were given via the Imugard IG 500 filter and 54 transfusions were given via the Cellselect filter. Packed red cell concentrates from the National Blood Transfusion Service provided for routine blood transfusions were used in all cases. No patient in either group of multitransfused patients experienced a febrile blood transfusion reaction during the study. The Imugard IG 500 removed 91% +/- 9 (SEM) leucocytes; the Cellselect removed 96% +/- 7 (SEM) leucocytes. In the Imugard IG 500 group one patient received greater than 0.5 X 10(9) leucocytes. In the Imugard IG 500 group one patient received greater than 0.5 X 10(9) leucocytes, but no patient in the Cellselect group received greater than 0.5 X 10(9) leucocytes in any single transfusion. This is a safe method of providing leucocyte poor blood at the bedside.