Role of endoscopic ultrasound in the characterization of solid pseudopapillary neoplasm of the pancreas

BACKGROUND

Solid pseudopapillary neoplasm (SPN) is an uncommon pathology of the pancreas with unpredictable malignant potential. Endoscopic ultrasound (EUS) assessment plays a vital role in lesion characterization and confirmation of the tissue diagnosis. However, there is a paucity of data regarding the imaging assessment of these lesions.

AIM

To determine the characteristic EUS features of SPN and define its role in preoperative assessment.

METHODS

This was an international, multicenter, retrospective, observational study of prospective cohorts from 7 large hepatopancreaticobiliary centers. All cases with postoperative histology of SPN were included in the study. Data collected included clinical, biochemical, histological and EUS characteristics.

RESULTS

One hundred and six patients with the diagnosis of SPN were included. The mean age was 26 years (range 9 to 70 years), with female predominance (89.6%). The most frequent clinical presentation was abdominal pain (80/106; 75.5%). The mean diameter of the lesion was 53.7 mm (range 15 to 130 mm), with the slight predominant location in the head of the pancreas (44/106; 41.5%). The majority of lesions presented with solid imaging features (59/106; 55.7%) although 33.0% (35/106) had mixed solid/cystic characteristics and 11.3% (12/106) had cystic morphology. Calcification was observed in only 4 (3.8%) cases. Main pancreatic duct dilation was uncommon, evident in only 2 cases (1.9%), whilst common bile duct dilation was observed in 5 (11.3%) cases. One patient demonstrated a double duct sign at presentation. Elastography and Doppler evaluation demonstrated inconsistent appearances with no emergence of a predictable pattern. EUS guided biopsy was performed using three different types of needles: Fine needle aspiration (67/106; 63.2%), fine needle biopsy (37/106; 34.9%), and Sonar Trucut (2/106; 1.9%). The diagnosis was conclusive in 103 (97.2%) cases. Ninety-seven patients were treated surgically (91.5%) and the post-surgical SPN diagnosis was confirmed in all cases. During the 2-year follow-up period, no recurrence was observed.

CONCLUSION

SPN presented primarily as a solid lesion on endosonographic assessment. The lesion tended to be located in the head or body of the pancreas. There was no consistent characteristic pattern apparent on either elastography or Doppler assessment. Similarly SPN did not frequently cause stricture of the pancreatic duct or common bile duct. Importantly, we confirmed that EUS-guided biopsy was an efficient and safe diagnostic tool. The needle type used does not appear to have a significant impact on the diagnostic yield. Overall SPN remains a challenging diagnosis based on EUS imaging with no pathognomonic features. EUS guided biopsy remains the gold standard in establishing the diagnosis.

Endoscopic ultrasound guided gastrojejunostomy in the treatment of gastric outlet obstruction: multi-centre experience from the United Kingdom

BACKGROUND

Endoscopic ultrasound guided gastrojejunostomy (EUS-GJ) with lumen apposing metal stents has recently emerged as a viable option, as an alternative to surgical gastrojejunostomy and endoscopic enteral stenting, for managing gastric outlet obstruction (GOO). We aim to perform a retrospective analysis of the efficacy, safety and outcomes of EUS-GJ performed at three tertiary institutions in the United Kingdom.

METHODS

Consecutive patients who underwent EUS-GJ between August 2018 and March 2021 were identified from a prospectively maintained database. Data were obtained from interrogation of electronic health records.

RESULTS

Twenty five patients (15 males) with a median age of 63 years old (range 29-80) were included for analysis. 88% (22/25) of patients had GOO due to underlying malignant disease. All patients were deemed surgically inoperable or at high surgical risk. Both technical and clinical success were achieved in 92% (23/25) of patients. There was an improvement in the mean Gastric Outlet Obstruction Scoring System scores following a technically successful EUS-GJ (2.52 vs 0.68, p < 0.01). Adverse events occurred in 2/25 patients (8%), both due to stent maldeployment necessitating endoscopic closure of the gastric defect with clips. Long-term follow-up data were available for 21 of 23 patients and the re-intervention rate was 4.8% (1/21) over a median follow-up period of 162 (range 5-474) days.

CONCLUSION

EUS-GJ in carefully selected patients is an effective and safe procedure when performed by experienced endoscopists.

Initial United Kingdom experience of endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography

Backgrounds/Aims

Gallstone disease is a recognized complication of bariatric surgery. Subsequent management of choledocholithiasis may be challenging due to altered anatomy which may include Roux-en-Y gastric bypass (RYGB). We conducted a retrospective service evaluation study to assess the safety and efficacy of endoscopic ultrasound-directed transgastric endoscopic retrograde cholangiopancreatography (EDGE) in patients with RYGB anatomy.

Methods

All the patients who underwent EDGE for endoscopic retrograde cholangiopancreatography after RYGB at two tertiary care centers in the United Kingdom between January 2020 and October 2021 were included in the study. Clinical and demographic details were recorded for all patients. The primary outcome measures were technical and clinical success. Adverse events were recorded. Hot Axios lumen apposing metal stents measuring 20 mm in diameter and 10 mm in length were used in all the patients for creation of a gastro-gastric or gastro-jejunal fistula.

Results

A total of 14 patients underwent EDGE during the study period. The majority of the patients were female (85.7%) and the mean age of patients was 65.8 ± 9.8 years. Technical success was achieved in all but one patient at the first attempt (92.8%) and clinical success was achieved in 100% of the patients. Complications arose in 3 patients with 1 patient experiencing persistent fistula and weight gain.

Conclusions

In patients with RYGB anatomy, EDGE facilitated biliary access has a high rate of clinical success with an acceptable safety profile. Adverse events are uncommon and can be managed endoscopically.

Increased ERCP volume improves cholangiogram interpretation: a new performance measure for ERCP training?

BACKGROUND/AIMS

Cholangiogram interpretation is not used as a key performance indicator (KPI) of endoscopic retrograde cholangiopancreatography (ERCP) training, and national societies recommend different minimum numbers per annum to maintain competence. This study aimed to determine the relationship between correct ERCP cholangiogram interpretation and experience.

METHODS

One hundred fifty ERCPists were surveyed to appropriately interpret ERCP cholangiographic findings. There were three groups of 50 participants each: "Trainees," "Consultants group 1" (performed >75 ERCPs per year), and "Consultants group 2" (performed >100 ERCPs per year).

RESULTS

Trainees was inferior to Consultants groups 1 and 2 in identifying all findings except choledocholithiasis outside the intrahepatic duct on the initial or completion/occlusion cholangiogram. Consultants group 1 was inferior to Consultants group 2 in identifying Strasberg type A bile leaks (odds ratio [OR], 0.86; 95% confidence interval [CI], 0.77-0.96), Strasberg type B (OR, 0.84; 95% CI, 0.74-0.95), and Bismuth type 2 hilar strictures (OR, 0.81; 95% CI, 0.69-0.95).

CONCLUSION

This investigation supports the notion that cholangiogram interpretation improves with increased annual ERCP case volumes. Thus, a higher annual volume of procedures performed may improve the ability to correctly interpret particularly difficult findings. Cholangiogram interpretation, in addition to bile duct cannulation, could be considered as another KPI of ERCP training.

10-year experience of Paediatric varicocele embolization in a tertiary centre with long-term follow-up

INTRODUCTION

Paediatric varicocele embolization has many benefits over surgical ligation, but lacks published long-term data. We investigated technical and clinical outcomes in this under reported patient group.

OBJECTIVE

To evaluate technical success, complications and recurrence rates following varicocele embolization in paediatric patients.

MATERIALS AND METHODS

A single-centre retrospective review of procedural data and electronic notes of consecutive patients referred for varicocele embolization over a 10-year period was performed (February 2010-March 2020). The primary outcomes were technical success and clinical efficacy (lack of symptom recurrence). Secondary outcomes included complications, testicular vein size reduction and procedural parameters including radiation exposure. Chi-square analysis was used to identify predictors of clinical success. Follow-up involved outpatient clinical assessment and telephone interview.

RESULTS

40 patients (median age 15) were referred for left-sided symptomatic varicocele. Technical embolization success was achieved in 36/40 patients (90%), with 4 procedures abandoned (inaccessible vein). Embolization technique was platinum-based coils ± sclerosant. There were no immediate or long-term procedural complications. 32/36 patients completed short term follow-up at a median interval of 2.8 months. 30/32 (93.78%) experienced early clinical success. We found a significant reduction in peritesticular vein size following embolization (pre-3.70 vs post-2.56 mm, p = 0.00017) and a significant relationship between varicocele grade and early clinical success (χ2 = 4.2, p = 0.04), but not pre-treatment peritesticular vein size (χ2 = 0.02, p = 0.88). 33/36 patients completed long-term follow-up (median 4.2 years, range 0.36-9.9 years) producing a late clinical success rate of 93.9% (31/33). No post procedural complications including hydroceles were identified.

DISCUSSION

This study demonstrates technical success, matching rates described in adult patients which is reassuring and in support of embolization in the younger patient cohort. More importantly, the overall clinical success rate is comparable with previous embolization studies. Reassuringly, all symptom recurrences occurred early in follow-up, and there is a cogent argument for a single follow-up appointment at this juncture. Our long-term average follow-up duration, primarily gained via telephone interview, exceeds other studies. Although our study has the longest follow-up for varicocele embolization in children, it is limited by a few patients being lost to early and long-term follow-up. This is a recognised issue faced by studies attempting to follow-up benign conditions with a high clinical success rate.

CONCLUSION

Paediatric varicocele embolization is a successful alternative to surgical ligation, with no complications and good clinical outcomes over a long-term follow-up.

P-P09 Salvage transgastric necrosectomy as a part of a step-up approach to managing acute necrotising pancreatitis

Background

The use of EUS (endoscopic ultrasound) guided drainage with endoscopic LAMS (lumen apposing metal stent) necrosectomy is an emerging treatment option for walled-off pancreatic necrosis (WOPN) secondary to acute severe pancreatitis. It can delay or remove the need for surgical necrosectomy, which can be associated with high morbidity and mortality. However, the endoscopic approach is not always successful due to a multitude of factors and salvage transgastric necrosectomy can be performed using the tract created by the LAMS to achieve internal drainage and remove necrotic pancreas. 

Methods

We describe our unit’s experience in managing WOPN in two patients. We suggest a treatment pathway of WOPN which includes a step-up approach including salvage transgastric necrosectomy in patients where multiple endoscopic necrosectomies and washouts have failed. 

Results

Two patients, aged 67 and 69, were admitted as intensive care transfers for gallstone and alcohol pancreatitis respectively. They underwent a step-up approach to treat their infected WOPN, starting with the deployment of LAMS and endoscopic necrosectomy. They both showed brief clinical improvement after repeated endoscopic necrosectomy but further imaging showed ongoing large collections that could not be treated endoscopically. Both patients underwent successful transgastric open necrosectomy where necrotic pancreatic tissue was accessed surgically through the already created cyst-gastrostomy. This had the advantage of internal drainage of the collection into the stomach without the need for external surgical drains.

Conclusions

The emphasis in the treatment of WOPN has shifted to minimally invasive percutaneous or endoscopic drainage modalities. Endoscopically inserted LAMS may not always achieve definitive drainage of the WOPN but should be employed in the first instance as they are associated with reduced morbidity and mortality compared to surgery. Ultimately, open necrosectomy with washout remains the definitive management strategy in the step-up approach. We believe that the trans-gastric open necrosectomy approach can be used successfully in patients where the minimally invasive approach has failed. 

Management of infected post-pancreatic resection fluid collections under endoscopic ultrasound guidance using lumen apposing metal stent: A case series and review of the literature

Backgrounds/Aims

Post-operative pancreatic fistulas (POPF) and fluid collections (POPFC) remain significant sources of morbidity and mortality after pancreatic resections. There remains a paucity of literature describing endoscopic ultrasound (EUS) guided drainage of POPFC using a Hot AXIOS™ lumen apposing metal stent (LAMS).

Methods

We conducted a retrospective study, encompassing all consecutive patients with POPFC managed using Hot AXIOS™ LAMS at our institution between January 2017 and December 2019. Primary outcome measures were technical and clinical success. Secondary outcome measures were adverse events and recurrence rates.

Results

Five patients underwent EUS guided drainage using Hot AXIOS™ LAMS during the study period. Mean age of patients was 67.8 &plusmn; 2.16 years. The majority (60.0%) of patients were males. Median duration of symptom onset after surgery was 9 days. All patients presented with abdominal pain. Median size of the collection measured on computed tomography was 91 mm. Median interval time between symptom onset and EUS drainage was 30 days. Two patients required percutaneous drainage prior to EUS guided drainage. Technical and clinical success were achieved for all patients. No adverse events were observed. Median duration of follow-up was 90 days. No recurrence of collection occurred during the follow-up period.

Conclusions

EUS guided drainage of POPFC using Hot AXIOS™ LAMS is a safe and effective treatment modality with technical and clinical success rates of 100% in our experience.

The epidemiology of Medical Emergency Team calls for orthopedic patients in a teaching hospital: A retrospective cohort study

BACKGROUND

Patients undergoing orthopedic surgery are at risk of post-operative complications and needing Medical Emergency Team (MET) review. We assessed the frequency of, and associations with MET calls in orthopedic patients, and whether this was associated with increased in-hospital morbidity and mortality.

METHODS

Retrospective cohort study of patients admitted over four years to a University teaching hospital using hospital administrative and MET call databases.

RESULTS

Amongst 6344 orthopedic patients, 55.8% were female, the median (IQR) age and Charlson comorbidity index were 66 years (47-79) and 3 (1-5), respectively. Overall, 54.5% of admissions were emergency admissions, 1130 (17.8%) were non-operative, and 605 (9.5%) patients received a MET call. The strongest independent associations with receiving a MET call was the operative procedure, especially hip and knee arthroplasty. Common MET triggers were hypotension (37.5%), tachycardia (25.0%) and tachypnoea (9.1%). Patients receiving a MET call were at increased risk of anemia, delirium, pressure injury, renal failure and wound infection. The mortality of patients who received a MET call was 9.8% compared with 0.8% for those who did not. After adjusting for pre-defined co-variates, requirement for a MET call was associated with an adjusted odd-ratio of 9.57 (95%CI 3.1-29.7) for risk of in-hospital death.

CONCLUSIONS

Approximately 10% of orthopedic patients received a MET call, which was most strongly associated with major hip and knee arthroplasty. Such patients are at increased risk of morbidity and in-hospital mortality. Further strategies are needed to more pro-actively manage at-risk orthopedic patients.

Attitudes to radiation safety and cholangiogram interpretation in endoscopic retrograde cholangiopancreatography (ERCP): a UK survey

BACKGROUND

Fluoroscopy during endoscopic retrograde cholangiopancreatography (ERCP) exposes staff and patients to potentially harmful ionizing radiation. We performed a UK survey to explore trainee and trainer attitudes to radiation protection and cholangiogram interpretation in ERCP.

METHODS

An electronic 10-point survey was prospectively distributed to endoscopy unit leads, training programme directors between October and November 2019. Only UK-based ERCP trainees and trainers with hands-on procedural exposure were eligible for the survey.

RESULTS

The survey was completed by 107 respondents (58 trainees and 49 trainers), with an estimated overall response rate of 46%. Overall, 49% of respondents were up to date with their radiation protection course, 38% were aware of European Basic safety standards directive (BSSD), 38% wore radiation protection goggles, and 40% were aware of the average radiation screening dose per ERCP procedure. Compared with trainers, trainees were less likely to routinely wear thyroid protection shields (76% vs 92%; p=0.028), have awareness of the BSSD (20% vs 49%; p=0.037) or know their average procedural radiation dosages (21% vs 63%; p<0.001). With regard to cholangiogram interpretation, only 26% had received formal training, with 97% of trainees expressing a desire for further training.

CONCLUSION

This survey highlights a relative complacency in safety attitudes to radiation protection during ERCP. These data provide impetus to improve training and quality assurance in radiation protection, which should be regarded as a mandatory safety aspect prior to commencing hands-on ERCP training.

Current assessment and management of endoleaks after advanced EVAR: new devices, new endoleaks?

INTRODUCTION

In recent years there has been an increasing application of advanced EVAR techniques to tackle complex clinical and anatomical scenarios. In a bid to overcome the limitations of the traditional stent-grafts, newer EVAR endografts and techniques have been developed and introduced into clinical practice, permitting endovascular management of difficult infrarenal, juxta-renal and thoracoabdominal aneurysms for which previously there was no endovascular solution. As a consequence, we are now confronted with unique patterns of endoleak requiring customized clinical-radiological assessment and treatment. Despite the increasing body of evidence regarding new EVAR techniques and related endoleaks, current guidelines do not specifically address these issues.

OBJECTIVES

Our review aims to assess risk factors, development, and management strategies of these endoleaks, in the most recent infrarenal EVAR devices and in more complex fenestrated EVAR (FEVAR) and Chimney EVAR (Ch-EVAR).

EXPERT OPINION

Most new devices have demonstrated types of endoleaks that need specific imaging and treatment, as in EVAS, FEVAR, and ChEVAR. Knowledge of specific stent-graft characteristics and the nature of endoleaks associated with the various procedures facilitates the application of relevant useful imaging. In addition, it should aid development of a customized and practically relevant approach to patient management during intervention and follow-up.

Endoscopic ultrasound-guided pancreatic fluid collections' transmural drainage outcomes in 100 consecutive cases of pseudocysts and walled off necrosis: a single-centre experience from the United Kingdom

BACKGROUND AND AIM

Endoscopic ultrasound-guided drainage is a minimally invasive first-line modality for the drainage of pancreatic fluid collection (PFC) resulting in a shorter hospital stay and less morbidity compared with surgical cystogastrostomy. Our aim is to evaluate potential differences in the outcomes of endoscopic ultrasound (EUS) guided transmural drainage (EUS-TD) drainage of pancreatic pseudocyst (PP) and walled-off necrosis (WON).

METHOD

We retrospectively reviewed 100 consecutive EUS-guided drainages of PFC utilising EUS reports; clinical notes and imaging with follow-up (FU) to 12 months. All procedures were undertaken under conscious sedation with EUS guidance alone (without fluoroscopy) and placement of plastic double pigtail stents.

RESULTS

In these 100 sequential cases, there were 78 cases of PP and 22 cases of WON. All 22/22(100%) cases of WON had successful EUS-guided stent placement. In 2/22(9%), there was little or no clinical improvement. These two patients required further computed tomography (CT)-guided drainage and one of these patients (1/22) (4.5%) developed recurrence within 12 months FU after removal of stents. In case of PP, overall stent placement was successful in 76/78 (97%) patients, but 6/78(8%) required 2nd EUS procedure after failure to show clinical improvement; 3/78(2.5%) required further CT-guided drainage. The overall complication rate was 9%(9/100) with 4%(4/100) requiring endoscopic or CT-guided intervention with no overall 30-day mortality.

CONCLUSION

This is the largest series from a single UK centre demonstrating that EUS-guided cystogastrostomy of PFC drainage using plastic double pigtail stents is sufficient in majority of cases with PFC including that of WON, with or without infection.

Prostate artery embolization: a new, minimally invasive treatment for lower urinary tract symptoms secondary to prostate enlargement

Prostate artery embolization (PAE) is emerging as a safe and efficacious treatment which approaches benign prostatic obstruction (BPO) from a unique perspective. This brings with it distinct advantages and solutions, which we discuss along with cost, evidence, complications and disadvantages.

Survey of Irish general practitioners' preferences for continuing professional development

BACKGROUND

Doctors' continuing professional development (CPD) training needs are known to be strongly influenced by national and local contextual characteristics. Given the changing national demographic profile and government-mandated changes to primary care health care provision, this study aimed to investigate Irish General Practitioners' (GPs) perceptions of, and preferences for, current and future CPD programmes.

METHODS

A cross-sectional questionnaire, using closed- and open-ended questions, was administered to Irish GPs, focusing on training needs analysis; CPD course content; preferred format and the learning environment.

RESULTS

The response rate was 719/1000 (71.9%). GPs identified doctor-patient communication as the most important and best-performed GP skill. Discrepancies between perceived importance (high) and current performance (low) emerged for time/workload management, practice finance and business skills. GPs identified clinically-relevant primary care topics and non-clinical topics (stress management, business skills, practice management) as preferences for future CPD. Flexible methods for CPD delivery were important. Gender and practice location (urban or rural) significantly influenced CPD participation and future course preference.

CONCLUSION

The increasing diversity of services offered in the Irish primary care setting, in both clinical and non-clinical areas, should be tailored based to include GP practice location and structure.

Comparison of outcomes for cancer patients discussed and not discussed at a multidisciplinary meeting

OBJECTIVES

Comparison of outcomes for cancer patients discussed and not discussed at a multidisciplinary meeting (MDM).

STUDY DESIGN

Retrospective analysis of the association of MDM discussion with survival.

METHODS

All newly diagnosed cancer patients from 2009 to 2012, presenting to a large regional cancer service in South West Victoria, Australia (620 colorectal, 657 breast, 593 lung and 511 haematological) were recorded and followed up to 5 years after diagnosis. Treatment patterns and survival of patients whose treatment was discussed at an MDM compared to those who were not, were explored.

RESULTS

The proportion of patients presented to an MDM within 60 days after diagnosis was 56% (n = 366) for breast cancer, 59% (n = 363) for colorectal cancer, 27% (n = 137) for haematological malignancies and 60% (n = 355) for lung cancer. Seventy-three percent (n = 886) of patients discussed at an MDM had their tumour stage recorded in their medical records while only 52% (n = 604) of patients not discussed had their tumour stage recorded (P < 0.01). We found for haematological and lung cancer patients that those presented to an MDM prior to treatment had a significant reduction in mortality (lung cancer hazard ratio [HR] 0.62, 95% confidence interval [CI] 0.50-0.76, P < 0.01) (haematological cancer HR 0.58, 95% CI 0.35-0.96, P = 0.03) compared to patients whose cases were not discussed at an MDM after adjusting for the potential cofounders of age, stage, comorbidities and treatment. This was not the case for colorectal and breast cancer patients where there was no significant difference.

CONCLUSION

MDM discussion has been recommended as best practice in the management of cancer patients, however, from a public health perspective this creates potential issues around access and resources. It is likely that MDM presentation patterns and outcomes across tumour streams are linked in complex ways. We believe that our data would demonstrate that these patterns differ across tumour streams and that more detailed work is required to better allocate relatively scarce and potentially costly MDM resources to tumour streams and patient groups that may get the most benefit.

PATI: Patient accessed tailored information: A pilot study to evaluate the effect on preoperative breast cancer patients of information delivered via a mobile application

OBJECTIVES

The information needs of cancer patients are highly variable. Literature suggests an improved ability to modulate personalised stress, increased patient involvement with decision making, greater satisfaction with treatment choices and reduced anxiety levels in cancer patients who have access to information. The aim of this project was to evaluate the effects of a mobile information application on anxiety levels of patients undergoing surgery for breast cancer.

MATERIALS AND METHODS

An application was developed for use with Apple iPad containing information on basic breast cancer biology, different treatments used and surgical techniques. Content and face validity studies were performed. A randomized control trial was designed, with a 1:2 allocation. Data collected include basic demographics and type of surgery. Questionnaires used included: the HADS, Mini-MAC, information technology familiarity and information satisfaction.

RESULTS

A total of 39 women participated. 13 women had access to an iPad containing additional information and 26 women acted as controls. The mean age was 54 and technology familiarity was similar among both groups. Anxiety and depression scores at seven days were significantly lower in control patients without access to the additional information provided by the mobile application (p = 0.022 and 0.029 respectively).

CONCLUSION

Anxiety and depression in breast cancer patients is both multifactorial and significant, with anxiety levels directly correlating with reduced quality of life. Intuitively, information should improve anxiety levels, however, we have demonstrated that surgical patients with less information reported significantly lower anxiety. We advise the thorough testing and auditing of information initiatives before deployment.

Whole-genome association analysis of treatment response in obsessive-compulsive disorder

Up to 30% of patients with obsessive-compulsive disorder (OCD) exhibit an inadequate response to serotonin reuptake inhibitors (SRIs). To date, genetic predictors of OCD treatment response have not been systematically investigated using genome-wide association study (GWAS). To identify specific genetic variations potentially influencing SRI response, we conducted a GWAS study in 804 OCD patients with information on SRI response. SRI response was classified as 'response' (n=514) or 'non-response' (n=290), based on self-report. We used the more powerful Quasi-Likelihood Score Test (the MQLS test) to conduct a genome-wide association test correcting for relatedness, and then used an adjusted logistic model to evaluate the effect size of the variants in probands. The top single-nucleotide polymorphism (SNP) was rs17162912 (P=1.76 × 10(-8)), which is near the DISP1 gene on 1q41-q42, a microdeletion region implicated in neurological development. The other six SNPs showing suggestive evidence of association (P<10(-5)) were rs9303380, rs12437601, rs16988159, rs7676822, rs1911877 and rs723815. Among them, two SNPs in strong linkage disequilibrium, rs7676822 and rs1911877, located near the PCDH10 gene, gave P-values of 2.86 × 10(-6) and 8.41 × 10(-6), respectively. The other 35 variations with signals of potential significance (P<10(-4)) involve multiple genes expressed in the brain, including GRIN2B, PCDH10 and GPC6. Our enrichment analysis indicated suggestive roles of genes in the glutamatergic neurotransmission system (false discovery rate (FDR)=0.0097) and the serotonergic system (FDR=0.0213). Although the results presented may provide new insights into genetic mechanisms underlying treatment response in OCD, studies with larger sample sizes and detailed information on drug dosage and treatment duration are needed.

The at-risk medical student--what more can we do?

Securing a place in medical school is extremely difficult-students who are successful all have similar high levels of academic achievement. So why do some students, and not others, have difficulty with the course, and in some cases, leave the programme? Studies on medical school attrition offer valuable insight into why medical students under-perform. Identification of the 'at-risk' student can trigger additional support and early remediation, helping some students remain in their chosen profession.

Strategy to control type I error increases power to identify genetic variation using the full biological trajectory

Genome-wide association studies have been successful in identifying loci that underlie continuous traits measured at a single time point. To additionally consider continuous traits longitudinally, it is desirable to look at SNP effects at baseline and over time using linear-mixed effects models. Estimation and interpretation of two coefficients in the same model raises concern regarding the optimal control of type I error. To investigate this issue, we calculate type I error and power under an alternative for joint tests, including the two degree of freedom likelihood ratio test, and compare this to single degree of freedom tests for each effect separately at varying alpha levels. We show which joint tests are the optimal way to control the type I error and also illustrate that information can be gained by joint testing in situations where either or both SNP effects are underpowered. We also show that closed form power calculations can approximate simulated power for the case of balanced data, provide reasonable approximations for imbalanced data, but overestimate power for complicated residual error structures. We conclude that a two degree of freedom test is an attractive strategy in a hypothesis-free genome-wide setting and recommend its use for genome-wide studies employing linear-mixed effects models.

Homeobox genes in obsessive-compulsive disorder

BACKGROUND

Despite evidence that obsessive-compulsive disorder (OCD) is a familial neuropsychiatric condition, progress aimed at identifying genetic determinants of the disorder has been slow. The OCD Collaborative Genetics Study (OCGS) has identified several OCD susceptibility loci through linkage analysis.

METHODS

In this study we investigate two regions on chromosomes 15q and 1q by first refining the linkage region using additional short tandem repeat polymorphic (STRP) markers. We then performed association analysis on single nucleotide polymorphisms (SNP) genotyped (markers placed every 2-4 kb) in the linkage regions in the OCGS sample of 376 rigorously phenotyped affected families.

RESULTS

Three SNPs are most strongly associated with OCD: rs11854486 (P = 0.00005 [0.046 after adjustment for multiple tests]; genetic relative risk (GRR) = 11.1 homozygous and 1.6 heterozygous) and rs4625687 [P = 0.00007 (after adjustment = 0.06); GRR = 2.4] on 15q; and rs4387163 (P = 0.0002 (after adjustment = 0.08); GRR = 1.97) on 1q. The first SNP is adjacent to NANOGP8, the second SNP is in MEIS2, and the third is 150 kb between PBX1 and LMX1A.

CONCLUSIONS

All the genes implicated by association signals are homeobox genes and are intimately involved in neurodevelopment. PBX1 and MEIS2 exert their effects by the formation of a heterodimeric complex, which is involved in development of the striatum, a brain region involved in the pathophysiology of OCD. NANOGP8 is a retrogene of NANOG, a homeobox transcription factor known to be involved in regulation of neuronal development. These findings need replication; but support the hypothesis that genes involved in striatal development are implicated in the pathogenesis of OCD.

The surgical anatomy of the radial nerve and the triceps aponeurosis

The radial nerve passes around the posterior aspect of the humerus where it is prone to injury in both humeral fractures and surgical exploration of this region. We examined 55 cadaveric limbs to determine whether the exact position of the radial nerve could be reliably predicted on the basis of superficial anatomical markings. We found that when there is considerable variability in the position of the nerve in relation to the lateral epicondyle, the nerve consistently passed adjacent to the lateral border of the triceps aponeurosis at a distance of 22-27 (+/-2) mm. It was never found to be closer than 13 (+/-1) mm to the aponeurosis. The lateral border of the triceps aponeurosis is easy to identify and our findings may help avoid iatrogenic injury to the radial nerve during exploration.

Short-term exercise training improves body composition and hyperlipidaemia in HIV-positive individuals with lipodystrophy

Exercise/physical activity is increasingly being advocated as a positive addition to the treatment regimen of HIV-positive individuals. We investigated the effects of 10 weeks' aerobic and resistance training on individuals with HIV-related lipodystrophy. These individuals demonstrated an improvement in exercise tolerance, body composition and blood lipid profiles. Potentially, such changes may contribute to an amelioration of some of the adverse metabolic effects associated with highly active antiretroviral therapy.

Expression of P-glycoprotein and multidrug resistance-associated protein in healthy volunteers and HIV-infected patients

Increased expression of the multidrug efflux transporters P-glycoprotein (P-gp) and multidrug resistance-associated protein (MRP) has been suggested as a potential mechanism for decreased drug availability at certain intracellular sites that provide sanctuary for HIV. Here we investigate the expression of these transporters in peripheral blood mononuclear cells (PBMCs) of HIV-infected patients and healthy volunteers. Venous blood (30 ml) was taken from healthy volunteers (n = 21) and HIV-infected patients (n = 21; 4 antiretroviral drug naive, 17 antiretroviral drug experienced). PBMCs were isolated and fixed. To assess P-gp expression, PBMCs were incubated with an isotype control antibody or an antibody directed to an external epitope of P-gp (UIC2). To assess MRP expression, cells were permeabilized before incubation with either a control antibody or an antibody directed to an internal epitope of MRP (MRPm5). After washing, a secondary phycoerythrin-bound antibody was incubated. After additional wash steps, samples were fixed and analyzed by flow cytometry. The median fluorescence intensity of 5000 events was recorded. Results are expressed as fold increase between isotype control and UIC2/MRPm5 samples. Expression of P-gp in HIV-infected patients (1.42 +/- 0.36) was significantly lower (p = 0.0021; 95% CI, -0.633 to -0.164) than in healthy volunteers (1.82 +/- 0.55). However, MRP expression was similar in HIV-infected patients (1.37 +/- 0.34) and healthy volunteers (1.37 +/- 0.21; p = 0.91; 95% CI, -0.148941 to 0.165191). We conclude that in HIV infection, P-gp expression in total PBMCs is reduced whereas MRP expression appears to be unaltered.

Effect of alpha1-acid glycoprotein on the intracellular accumulation of the HIV protease inhibitors saquinavir, ritonavir and indinavir in vitro

AIMS

Since alpha1-acid glycoprotein (AGP) levels may be raised during HIV infection, we have examined in vitro the effect of increasing the concentration of AGP on the intracellular accumulation of the HIV protease inhibitors saquinavir (SQV), ritonavir (RTV) and indinavir (IDV).

METHODS

U937 cells (5 x 10(6) cells in 5 ml RPMI growth medium) were incubated at 37 degrees C for 18 h with [14C]-SQV (0.1 microCi), [3H]-RTV and [3H]-IDV (0.135 microCi) to a final concentration of 1 microM in the presence of 0, 0.5 and 2.0 mg x ml(-1) AGP. Following extraction in 60% methanol the intracellular drug concentration was determined by liquid scintillation counting.

RESULTS

Binding to AGP (2.0 mg x ml(-1)) reduced the mean intracellular concentration of SQV from 31.5 microM to 7.4 microM (P < 0.0001; 95% CI 19.4-28.8). RTV concentration was also reduced (8.8 microM to 1.6 microM; P < 0.0001; 95% CI 5.4-9.0) as was the concentration of IDV (3.0 microM to 1.5 microM; P < 0.0001; 95% CI 1.1-1.9).

CONCLUSIONS

Reduced intracellular protease inhibitor concentrations in the presence of increasing concentrations of AGP will certainly impact on the antiviral activity in vitro. However, since protease inhibitors are high clearance drugs, free drug concentration will likely remain unaffected in the presence of elevated AGP during chronic oral dosing although there will be an increase in total plasma drug concentration.

A simple sore throat?

Apreviously healthy 26-year-old man presented with a 3-day history of sore throat, fever, rigors, loin pain and vomiting. He was pyrexial (40°C) and tachycardic (104 beats/minute), but had a normal blood pressure. Clinical examination revealed erythematous fauces without any exudates, and bilateral submandibular Iymph node enlargement. There was no meningism or para-spinal tenderness. The platelet count was decreased (108 × 109/litre, normal range (NR) 150–400x109/litre) and white cell count was elevated (16.1×109/litre, NR 4–11x109/litre) with a neutrophilia. Markers of inflammation (erythrocyte sedimentation rate 61mm/h and C-reactive protein 226mg/litre) and urea (11.1 mmol/litre, NR 3–7 mmol/litre) were also elevated.

Chest X-ray and glandular fever slide test were both normal. The patient was started on intravenous ceftriaxone after blood, urine and throat swabs were sent off for culture.

The patient's temperature settled over the next 4 days, and he was converted to oral antibiotics. Gram-negative anaerobes were cultured from the blood; these were identified as Fusobacterium nucleatum, suggesting that the patient had necrobacillosis. Throat swabs failed to grow the organism. In order to exclude an abdominal source for the organism, the patient also had an abdominal ultrasound and a radiolabelled white cell scan, both of which were normal. The patient's inflammatory markers and renal function returned to normal with antibiotic treatment, and he remains well 1 year after his illness.

Isometric muscle strength in alcoholic and nonalcoholic liver-transplantation candidates

Intensity of isometric muscle contractions was measured in alcoholic subjects with cirrhosis (N = 42), nonalcoholic subjects with cirrhosis (N = 33), and normal controls (N = 31). Muscle strength and endurance were comparable in the alcoholic and nonalcoholic cirrhotic subjects for all variables. Both cirrhotic groups were inferior to normal controls for all variables. The quantity x frequency (Q x F) index reported for the period during peak alcohol consumption correlated with 6 muscle-force variables, accounting for 9-20% of the variance. Alcoholic and nonalcoholic cirrhotic subjects did not differ in Quality of Life Inventory (QOLI) scales. Significant correlations, however, were found for the alcoholic cirrhotic subjects but not for the nonalcoholic cirrhotic subjects between quality-of-life indices and muscle strength and endurance. Muscle weakness is thus differentially associated with quality of life in alcoholic cirrhotic subjects as compared with nonalcoholic subjects with cirrhosis even though level of strength and endurance in the two groups is comparable.

The environmental contaminant DDE fails to influence the outcome of sexual differentiation in the marine turtle Chelonia mydas

In many turtles, the temperature experienced during the middle of egg incubation determines the sex of the offspring. The implication of steroid sex hormones as the proximate trigger for sex determination opens the possibility that endocrine-disrupting contaminants may also influence the outcome of sexual differentiation. In this study we investigate the potential effects of DDE (a common DDT metabolite) on sexual differentiation of Chelonia mydas (green sea turtle). Four clutches of eggs collected from Heron Island, Queensland, Australia, were treated with DDE at the beginning of the thermosensitive period for sexual determination. An incubation temperature of 28 degrees C or less produces male hatchlings in this species, whereas 30 degrees C or more produces female hatchlings. Dosed eggs were consequently incubated at two temperatures (27.6 degrees C and 30.4 degrees C) on the upper and lower boundaries of the sex determination threshold for this species. DDE, ranging from 3.3 to 66.5 microg, was dissolved in 5, 10, and 25 microl ethanol and applied to eggshells above the embryo. Less than 2.5 ng/g DDE was present in eggs prior to dosing. Approximately 34% of the applied DDE was absorbed in the eggs, but only approximately 8% of applied DDE was found in embryos. Thus, treated eggs, corrected for background DDE, had up to 543 ng/g DDE. The sex ratio at these doses did not differ from what would be expected on consideration of temperature alone. Incubation time, hatching success, incidence of body deformities, hatching size, and weight were also within the limits of healthy developed hatchlings. This indicates that the eggs of C. mydas in the wild with concentrations of DDE less than 543 ng/g should produce hatchlings with relatively high hatching success, survival rate, and normally differentiated gonads.

Firearm injury in Orleans parish: a 24-month perspective

This study is a retrospective review of all gunshot wounds treated at Charity Hospital, the Orleans Parish designated trauma center, for the 24-month period from November 1993 to November 1995. Its purpose was to define the magnitude of firearm injury in the parish and the impact on the health care system. One-thousand-six-hundred-sixty-nine gunshot wounds were analyzed. Most involved African-American males. Twenty percent were fatal. Two-thousand-forty-three emergent operations were performed. Ten percent of surviving patients had some permanent disability, 6% required institutional care. In 760 patients, initial hospital charges totaled $5,153,516. Extrapolation of these figures to the entire group yields an initial hospital cost of $11,317,392. Transport by the "911" system and in-house trauma team activation were required in most patients. In summary, firearm injury poses a serious economic problem and is a substantial drain on health care providers and their resources.

Object chaining and thought disorder in schizophrenic speech

The phenomenon of object chaining was investigated to determine its relationship to thought disorder in schizophrenia. Samples from thought-disordered schizophrenics (N = 12) and controls (10 non-thought-disordered schizophrenics and 10 normals) were analysed. Using the object subject ratio (OSR) to measure object chaining, we found higher OSRs in the speech of thought-disordered subjects than in that of subjects free of thought disorder. Object chaining correlated with low predictability of speech. We conclude that object chaining is associated with reduced speech comprehensibility and probably contributes to the judgement that thought disorder is present.