High-throughput assays to assess variant effects on disease.

Interpreting the wealth of rare genetic variants discovered in population-scale sequencing efforts and deciphering their associations with human health and disease present a critical challenge due to the lack of sufficient clinical case reports. One promising avenue to overcome this problem is deep mutational scanning (DMS), a method of introducing and evaluating large-scale genetic variants in model cell lines. DMS allows unbiased investigation of variants, including those that are not found in clinical reports, thus improving rare disease diagnostics. Currently, the main obstacle limiting the full potential of DMS is the availability of functional assays that are specific to disease mechanisms. Thus, we explore high-throughput functional methodologies suitable to examine broad disease mechanisms. We specifically focus on methods that do not require robotics or automation but instead use well-designed molecular tools to transform biological mechanisms into easily detectable signals, such as cell survival rate, fluorescence or drug resistance. Here, we aim to bridge the gap between disease-relevant assays and their integration into the DMS framework.

Lower dorsal putamen D2/3 receptor availability and amphetamine-induced dopamine release are related to poorer cognitive function in recently abstinent people who smoke and healthy controls.

INTRODUCTION: In the dopamine system, the mesolimbic pathway, including the dorsal striatum, underlies the reinforcing properties of tobacco smoking, and the mesocortical pathway, including the dorsolateral prefrontal cortex (dlPFC), is critical for cognitive functioning. Dysregulated dopamine signaling has been linked to drug-seeking behaviors and cognitbie deficits. The dorsal striatum and dlPFC are structurally and functionally connected and are the key regions for cognitive functioning. We recently showed that people who smoke have lower dlPFC dopamine (D2/3R) receptor availability than people who do not, which is related to poorer cognitive function. The goal of this study was to examine the same brain-behavior relationship in the dorsal striatum. METHODS: Twenty-nine (18 males) recently abstinent people who smoke and twenty-nine sex-matched healthy controls participated in two same-day [11C]-(+)-PHNO positron emission tomography scans before and after amphetamine administration to provoke dopamine release. D2/3R availability (binding potential; BPND) and amphetamine-induced dopamine release (%ΔBPND) were calculated. Cognition (verbal learning and memory) was assessed with the CogState computerized battery. RESULTS: There were no group differences in baseline BPND. People who smoke have a smaller magnitude %ΔBPND in dorsal putamen than healthy controls (p=0.022). People who smoke perform worse on immediate (p=0.035) and delayed (p=0.011) recall than healthy controls. In all people, lower dorsal putamen BPND was associated with worse immediate (p=0.006) and delayed recall (p=0.049), and lower %ΔBPND was related to worse delayed recall (p=0.022). CONCLUSION: Lower dorsal putamen D2/3R availability and function are associated with disruptions in cognitive function that may underlie difficulty with resisting smoking. IMPLICATIONS: This study directly relates dopamine imaging outcomes in the dorsal striatum to cognitive function in recently abstinent people who smoke cigarettes and healthy controls. The current work included a well-characterized subject sample in terms of demographics, smoking characteristics, and a validated neurocognitive test of verbal learning and memory. The findings of this study extend previous literature relating dopamine imaging outcomes to cognition in recently abstinent people who smoke and people who do not smoke, expanding our understanding of brain-behavior relationships.

Remnant cystic duct adenocarcinoma presenting as gastric outlet obstruction.

Only a few case reports of remnant cystic duct carcinoma exist. The presented case of remnant cystic duct carcinoma with invasion to pylorus and bulbus of duodenum leading to gastric outlet obstruction was the first of its kind. We reviewed all cases of remnant cystic duct carcinoma that we found in the literature and summarized its definition, presentation, extent of invasion and clinical outcome after operation. The diagnosis can be difficult due to the rarity of disease, locally advanced nature of disease and distorted postoperative anatomy. A high index of suspicion can increase the likelihood of a preoperative diagnosis.

Hospital Authority audit of the outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong.

OBJECTIVES: To review the short-term outcome of endoscopic resection of superficial upper gastro-intestinal lesions in Hong Kong. DESIGN: Historical cohort study. SETTING: All Hospital Authority hospitals in Hong Kong. PATIENTS: This was a multicentre retrospective study of all patients who underwent endoscopic resection of superficial upper gastro-intestinal lesions between January 2010 and June 2013 in all government-funded hospitals in Hong Kong. MAIN OUTCOME MEASURES: Indication of the procedures, peri-procedural and procedural parameters, oncological outcomes, morbidity, and mortality. RESULTS: During the study period, 187 lesions in 168 patients were resected. Endoscopic mucosal resection was performed in 34 (18.2%) lesions and endoscopic submucosal dissection in 153 (81.8%) lesions. The mean size of the lesions was 2.6 (standard deviation, 1.8) cm. The 30-day morbidity rate was 14.4%, and perforations and severe bleeding occurred in 4.3% and 3.2% of the patients, respectively. Among patients who had dysplasia or carcinoma, R0 resection was achieved in 78% and the piecemeal resection rate was 11.8%. Lateral margin involvement was 14% and vertical margin involvement was 8%. Local recurrence occurred in 9% of patients and 15% had residual disease. The 2-year overall survival rate and disease-specific survival rate was 90.6% and 100%, respectively. CONCLUSION: Endoscopic mucosal resection and endoscopic submucosal dissection were introduced in low-to-moderate-volume hospitals with acceptable morbidity rates. The short-term survival was excellent. However, other oncological outcomes were higher than those observed in high-volume centres and more secondary procedures were required.

Randomized trial of endoscopic sphincterotomy with balloon dilation versus endoscopic sphincterotomy alone for removal of bile duct stones.

BACKGROUND & AIMS: Limited endoscopic sphincterotomy with large balloon dilation (ESBD) is an alternative to endoscopic sphincterotomy (ES) for removing bile duct stones, but it is not clear which procedure is most effective. We compared the 2 techniques in removal of bile duct stones. METHODS: Between September 2005 and September 2011, 156 consecutive patients with suspected of having, or known to have, common bile duct stones were randomly assigned to groups that underwent ES or ESBD. Patients in the ESBD group underwent limited sphincterotomy (up to half of the sphincter) followed by balloon dilation to the size of the common bile duct or 15 mm, and patients in the ES group underwent complete sphincterotomy alone. Stones were then removed using standard techniques. The primary outcome was percentage of stones cleared, and secondary outcomes included procedural time, method of stone extraction, number of procedures required for stone clearance, morbidities and mortality within 30 days, and direct cost. RESULTS: There was no significant difference between groups in percentage of stones cleared (ES vs ESBD: 88.5% vs 89.0%). More patients in the ES group (46.2%) than the ESBD group (28.8%) required mechanical lithotripsy (P = .028), particularly for stones ≥15 mm (90.9% vs 58.1%; P = .002). Morbidities developed in 10.3% of patients in the ES group and 6.8% of patients in the ESBD group (P = .46). The cost of the hospitalization was also significantly lower in the ESBD group (P = .034). CONCLUSIONS: ESBD and ES clear bile stones with equal efficacy. However, ESBD reduces the need for mechanical lithotripsy and is less expensive; ClinicalTrials.gov number, NCT00164853.

Blue rubber bleb nevus syndrome: treatment of multiple gastrointestinal hemangiomas with argon plasma coagulator.

Blue rubber bleb nevus syndrome is a rare clinical entity characterized by the formation of multiple blue or purplish rubbery cavernous hemangiomas on the skin and other epithelial surfaces. Involvement of the gastrointestinal tract is common and often presents with crippling anemia as a result of chronic occult blood loss. While surgical extirpation is an option for symptomatic hemangiomas in the intestine, endoscopic therapy is more appealing for lesions found in the stomach and colon. Here we report the successful use of argon plasma coagulation in the management of an adult with multiple hemangiomas in her colon and terminal ileum.

Surgical salvage of bleeding peptic ulcers after failed therapeutic endoscopy.

BACKGROUND: The approach to salvage surgery after failed endoscopic therapy for a bleeding peptic ulcer is controversial. We aimed to compare the outcomes of salvage surgery after failed endoscopic therapy for bleeding peptic ulcers over a 10-year period. METHODS: Patients receiving salvage surgery for bleeding peptic ulcers were divided into 2 cohorts, the 1st from 1993 to 1998 and the 2nd from 1999 to 2004. The type of salvage surgery was defined as minimal if ulcer plication or an ulcerectomy was performed, and definitive if the patient received a vagotomy or gastrectomy. RESULTS: One hundred and twenty-three patients received salvage surgery in the 1st cohort, while 42 patients received surgical hemostasis for the bleeding peptic ulcer in the 2nd cohort. Patients in the 2nd cohort consisted of a larger proportion of in-hospital bleeders (cohort 1: 12.2%, cohort 2: 42.9%; p < 0.005) and had a significantly higher proportion of comorbidities. A larger number of patients received minimal surgery in cohort 2 (cohort 1: 42.3%, cohort 2: 73.8%; p < 0.005). CONCLUSIONS: With advances in therapeutic endoscopy, patients who developed failed endoscopic hemostasis are likely to be poor surgical candidates with multiple comorbidities. The approach to salvage surgery has inclined towards minimal surgery to hasten surgical hemostasis among these fragile patients.

Management of massive peptic ulcer bleeding.

Massive bleeding from a peptic ulcer remains a challenge. A multidisciplinary team of skilled endoscopists, intensive care specialists, experienced upper gastrointestinal surgeons, and intervention radiologists all have a role to play. Endoscopy is the first-line treatment. Even with larger ulcers, endoscopic hemostasis can be achieved in the majority of cases. Surgery is clearly indicated in patients in whom arterial bleeding cannot be controlled at endoscopy. Angiographic embolization is an alternate option, particularly in those unfit for surgery. In selected patients judged to belong to the high-risk group--ulcers 2 cm or greater in size located at the lesser curve and posterior bulbar duodenal, shock on presentation, and elderly with comorbid illnesses--a more aggressive postendoscopy management is warranted. The optimal course of action is unclear. Most would be expectant and offer medical therapy in the form of acid suppression. Surgical series suggest that early elective surgery may improve outcome. Angiography allows the bleeding artery to be characterized, and coil embolization of larger arteries may further add to endoscopic hemostasis. The role of early elective surgery or angiographic embolization in selected high-risk patients to forestall recurrent bleeding remains controversial. Prospective studies are needed to compare different management strategies in these high-risk ulcers.

Predicting mortality in patients with bleeding peptic ulcers after therapeutic endoscopy.

BACKGROUND & AIMS: Despite advances in management of patients with bleeding peptic ulcers, mortality is still 10%. This study aimed to identify predictive factors and to develop a prediction model for mortality among patients with bleeding peptic ulcers. METHODS: Consecutive patients with endoscopic stigmata of active bleeding, visible vessels, or adherent clots were recruited, and risk factors for mortality were identified in this deprivation cohort by using multiple stepwise logistic regression. A prediction model was then built on the basis of these factors and validated in the evaluation cohort. RESULTS: From 1993 to 2003, 3220 patients with bleeding peptic ulcers were treated. Two hundred eighty-four of the patients developed rebleeding (8.8%); emergency surgery was performed on 47 of these patients, whereas others were managed with endoscopic retreatment. Two hundred twenty-nine of these sustained in-hospital death (7.1%). In patients older than 70 years, presence of comorbidity, more than 1 listed comorbidity, hematemesis on presentation, systolic blood pressure below 100 mm Hg, in-hospital bleeding, rebleeding, and need for surgery were significant predictors for mortality. Helicobacter pylori-related ulcers had lower risk of mortality. The receiver operating characteristic curve comparing the prediction of mortality with actual mortality showed an area under the curve of 0.842. From 2004 to 2006, data were collected prospectively from a second cohort of patients with bleeding peptic ulcers, and mortality was predicted by using the model developed. The receiver operating characteristic curve showed an area under the curve of 0.729. CONCLUSIONS: Among patients with bleeding peptic ulcers after endoscopic hemostasis, advanced age, presence of listed comorbidity, multiple comorbidities, hypovolemic shock, in-hospital bleeding, rebleeding, and need for surgery successfully predicted in-hospital mortality.

Omeprazole before endoscopy in patients with gastrointestinal bleeding.

BACKGROUND: A neutral gastric pH is critical for the stability of clots over bleeding arteries. We investigated the effect of preemptive infusion of omeprazole before endoscopy on the need for endoscopic therapy. METHODS: Consecutive patients admitted with upper gastrointestinal bleeding underwent stabilization and were then randomly assigned to receive either omeprazole or placebo (each as an 80-mg intravenous bolus followed by an 8-mg infusion per hour) before endoscopy the next morning. RESULTS: Over a 17-month period, 638 patients were enrolled and randomly assigned to omeprazole or placebo (319 in each group). The need for endoscopic treatment was lower in the omeprazole group than in the placebo group (60 of the 314 patients included in the analysis [19.1%] vs. 90 of 317 patients [28.4%], P=0.007). There were no significant differences between the omeprazole group and the placebo group in the mean amount of blood transfused (1.54 and 1.88 units, respectively; P=0.12) or the number of patients who had recurrent bleeding (11 and 8, P=0.49), who underwent emergency surgery (3 and 4, P=1.00), or who died within 30 days (8 and 7, P=0.78). The hospital stay was less than 3 days in 60.5% of patients in the omeprazole group, as compared with 49.2% in the placebo group (P=0.005). On endoscopy, fewer patients in the omeprazole group had actively bleeding ulcers (12 of 187, vs. 28 of 190 in the placebo group; P=0.01) and more omeprazole-treated patients had ulcers with clean bases (120 vs. 90, P=0.001). CONCLUSIONS: Infusion of high-dose omeprazole before endoscopy accelerated the resolution of signs of bleeding in ulcers and reduced the need for endoscopic therapy. (ClinicalTrials.gov number, NCT00164866 [ClinicalTrials.gov] .).

Prophylactic ilioinguinal neurectomy in open inguinal hernia repair: a double-blind randomized controlled trial.

OBJECTIVE: We conducted a double-blinded randomized controlled trial to investigate the short- to mid-term neurosensory effect of prophylactic ilioinguinal neurectomy during Lichtenstein repair of inguinal hernia. METHOD: One hundred male patients between the age of 18 and 80 years with unilateral inguinal hernia undergoing Lichtenstein hernia repair were randomized to receive either prophylactic ilioinguinal neurectomy (group A) or ilioinguinal nerve preservation (group B) during operation. All operations were performed by surgeons specialized in hernia repair under local anesthesia or general anesthesia. The primary outcome was the incidence of chronic groin pain at 6 months. Secondary outcomes included incidence of groin numbness, postoperative sensory loss or change at the groin region, and quality of life measurement assessed by SF-36 questionnaire at 6 months. All follow-up and outcome measures were carried out by a designated occupational therapist at 1 and 6 months following surgery in a double-blinded manner. RESULTS: The incidence of chronic groin pain at 6 months was significantly lower in group A than group B (8% vs. 28.6%; P = 0.008). No significant intergroup differences were found regarding the incidence of groin numbness, postoperative sensory loss or changes at the groin region, and quality of life measurement at 6 months after the operation. CONCLUSIONS: Prophylactic ilioinguinal neurectomy significantly decreases the incidence of chronic groin pain after Lichtenstein hernia repair without added morbidities. It should be considered as a routine surgical step during the operation.