Human ABCA1 BAC transgenic mice show increased high density lipoprotein cholesterol and ApoAI-dependent efflux stimulated by an internal promoter containing liver X receptor response elements in intron 1

By using BAC transgenic mice, we have shown that increased human ABCA1 protein expression results in a significant increase in cholesterol efflux in different tissues and marked elevation in high density lipoprotein (HDL)-cholesterol levels associated with increases in apoAI and apoAII. Three novel ABCA1 transcripts containing three different transcription initiation sites that utilize sequences in intron 1 have been identified. In BAC transgenic mice there is an increased expression of ABCA1 protein, but the distribution of the ABCA1 product in different cells remains similar to wild type mice. An internal promoter in human intron 1 containing liver X response elements is functional in vivo and directly contributes to regulation of the human ABCA1 gene in multiple tissues and to raised HDL cholesterol, apoAI, and apoAII levels. A highly significant relationship between raised protein levels, increased efflux, and level of HDL elevation is evident. These data provide proof of the principle that increased human ABCA1 efflux activity is associated with an increase in HDL levels in vivo.

HIP1 functions in clathrin-mediated endocytosis through binding to clathrin and adaptor protein 2

Polyglutamine expansion in huntingtin is the underlying mutation leading to neurodegeneration in Huntington disease. This mutation influences the interaction of huntingtin with different proteins, including huntingtin-interacting protein 1 (HIP1), in which affinity to bind to mutant huntingtin is profoundly reduced. Here we demonstrate that HIP1 colocalizes with markers of clathrin-mediated endocytosis in neuronal cells and is highly enriched on clathrin-coated vesicles (CCVs) purified from brain homogenates. HIP1 binds to the clathrin adaptor protein 2 (AP2) and the terminal domain of the clathrin heavy chain, predominantly through a small fragment encompassing amino acids 276-335. This region, which contains consensus clathrin- and AP2-binding sites, functions in conjunction with the coiled-coil domain to target HIP1 to CCVs. Expression of various HIP1 fragments leads to a potent block of clathrin-mediated endocytosis. Our findings demonstrate that HIP1 is a novel component of the endocytic machinery.

Twenty-year audit of percutaneous liver biopsy in a major Australian teaching hospital

BACKGROUND

To examine the changes in indications, patient characteristics, safety and outcomes in consecutive patients undergoing percutaneous core liver biopsies in a major Australian teaching hospital over a period of two decades.

METHODS

A retrospective audit was carried out on all percutaneous core liver biopsies from a single institution between 1996 and 2005. This was combined with 10 years of data already reported on for the years 1986-1995 to detect trends in indications and outcomes.

RESULTS

Medical records from 1398 patients were included for analysis. Over a 20-year period, the most common indications for liver biopsy were hepatitis C (37.8%), hepatitis B (26.4%) and abnormal liver function tests (22.2%). Twelve major complications (1.0%) were seen; 10 episodes of haemorrhage, 1 bile leak and 1 visceral perforation. Seven of these patients had an abnormal baseline coagulation profile; a significant risk for major haemorrhage (P < 0.001), resulting in three deaths. All deaths occurred in inpatients with major comorbidities. Minor complications occurred in 13.6% of patients, with multiple passes a significant risk factor. Whereas the overall major and minor complication rates were independent of operator experience inadequate specimens were more frequently obtained by the registrar.

CONCLUSION

This large series extending over two decades shows that despite advances in biopsy techniques, the rates of both minor and major complications remain significant. Of particular concern are the procedure-related deaths. Identifying factors that may increase risk requires further scrutiny and careful patient selection needs to be undertaken.

Management of anticoagulation before and after gastrointestinal endoscopy

The management of anticoagulants and antiplatelet agents in patients undergoing gastrointestinal endoscopic procedures is a common clinical problem. Although guidelines have been published, they are supported by little prospective or randomized trial data, but are primarily based on observational studies, expert opinion, and best clinical practices. As a general principle, the risks of thromboembolism need to be balanced against the risks of bleeding during the endoscopic procedure. By understanding these risks, management plans for individual cases may be made. This article reviews the current data and guidelines on the management of anticoagulants, antiplatelet agents, use of reversal agents, and the role and risks of concomitant proton pump inhibitors.

Revisiting the dioecy-polyploidy association: alternate pathways and research opportunities

The evolutionary transition from hermaphroditism (combined sexes) to dioecy (separate sexes) is associated with whole genome duplication (polyploidy) in several flowering plant genera. Moreover, there is evidence for transitions in the opposite direction, i.e. a loss of dioecy with an increase in ploidy. Here, we review evidence for these associations, synthesize previous ideas on the mechanism underlying the patterns and explore alternative pathways. Specifically, we examine potential ecological and genetic mechanisms, differentiated by whether ploidy or gender (functional sex expression of the plant) changes are the primary cause and whether the effect is direct or indirect. An analysis of 22 genera variable for both ploidy and gender indicates that gender monomorphism (hermaphroditism, monoecy) is more common among diploid than polyploid species, whereas gender dimorphism (dioecy, gynodioecy, subdioecy) is more frequent among polyploid species. The transition from diploid hermaphroditic to polyploid gender-dimorphic taxa may arise directly through changes in gender as a result of genome duplication through genomic rearrangements or homeologous recombination, or changes in gender may result in increased unreduced gamete production leading to polyploid formation. Alternatively, the transition may occur through the indirect effects of genome duplication on mating system and inbreeding depression, which favor selection for unisexuality, or habitat shifts associated with unisexuality may simultaneously cause increased unreduced gamete production. Novel mechanisms for transitions in the opposite direction (from dioecy to hermaphroditism with increase in ploidy) include disruption of genetic sex determination and the benefits of reproductive assurance. We highlight key questions requiring further attention and promising approaches for answering them and better clarifying the genesis of sexual system polyploidy associations. See also the sister article focusing on animals by Wertheim et al. in this themed issue.

Predictive values of calcaneal quantitative ultrasound and dual energy X ray absorptiometry for non-vertebral fracture in older men: results from the MrOS study (Hong Kong)

Calcaneal QUS is comparable to DXA in predicting non-vertebral fractures in older Chinese men.

INTRODUCTION

The predictive values of calcaneal quantitative ultrasound (QUS) and dual-energy X-ray absorptiometry (DXA) for non-vertebral fractures in older Chinese men were examined.

METHODS

One thousand nine hundred twenty-one Chinese men aged 65-92 years had calcaneal QUS and axial DXA bone mineral density (BMD) measurements. The incidence of non-vertebral fractures was documented. Cox regression and receiver operating curve (ROC) analysis were used to examine the associations of QUS parameters and BMD with the incidence of non-vertebral fractures.

RESULTS

The duration of follow-up was (mean ± SD) 6.5 ± 1.7 years. One hundred thirty-one non-vertebral fractures were recorded, 71 of which were major fragility fractures. Broadband ultrasound attenuation (BUA) and quantitative ultrasound index (QUI) were significantly associated with non-vertebral fractures and major fragility fractures, with age and fracture history-adjusted hazard ratio (95% CI) of 1.23 (1.03, 1.47) and 1.32 (1.10, 1.59) per standard deviation reduction, respectively, for non-vertebral fractures; 1.32 (1.04, 1.68) and 1.43 (1.11, 1.84), respectively, for major fragility fractures. Age and fracture history-adjusted areas under ROC curves of hip or spine BMDs were significantly greater than that of BUA or QUI in predicting major fragility fractures, but not in predicting all non-vertebral fractures. The addition of BUA or QUI had no effect on AUCs of total hip BMD alone.

CONCLUSIONS

The ability of calcaneal QUS to predict non-vertebral fractures was comparable to that of axial BMD by DXA, but was inferior to BMD in predicting major fragility fractures in older Chinese men.

Helicobacter pylori eradication therapy: indications, efficacy and safety

BACKGROUND

Helicobacter pylori infects up to half of the world's population. It remains the major cause of peptic ulcer disease and is recognised as a carcinogen for its role in gastric carcinogenesis. Successful eradication of the bacteria is associated with improved health outcomes including fewer dyspeptic symptoms, reduced peptic ulcer recurrence and rebleeding, reduced peptic ulcer risk with NSAIDs and as a cure for low-grade gastric MALT lymphoma. The risk of gastric cancer is reduced in those without premalignant mucosal abnormalities at the time of eradication.

OBJECTIVE

This review outlines the current indications and options for therapy of H. pylori with particular reference to drug-induced adverse events associated with treatment.

METHODS

The indications for H. pylori eradication are evidence-based and in accordance with recent consensus statements and recommendations. The eradication treatment is based on numerous clinical trials and meta-analyses.

RESULTS/CONCLUSION

Eradication therapy, in general, is safe and well tolerated. Antibiotic therapy may be associated with significant drug adverse reactions, especially gastrointestinal symptoms.

Symptomatic age-related macular degeneration in Asian patients

PURPOSE

To characterize retinal and fluorescein angiographic findings of Asian patients with symptoms secondary to age-related macular degeneration (ARMD).

METHODS

We retrospectively reviewed 453 consecutive medical records corresponding to fluorescein angiograms performed between November 1992 and November 1995 to identify Asian patients with symptomatic ARMD. Presenting visual symptoms, best-corrected Snellen visual acuities, and retinal examination findings were determined from the medical records. Fundus photos and fluorescein angiograms were reviewed.

RESULTS

There were 26 symptomatic eyes in 19 Asian patients with a median age of 73 years. Presenting visual symptoms included decreased visual acuity (19 eyes), metamorphopsia (5 eyes), or scotoma (2 eyes). Retinal findings included occult choroidal neovascularization (CNV) in 5 (19%) eyes, serous pigment epithelial detachment (PED) in 8 (31%) eyes, PED with CNV in 5 (19%) eyes, drusen in 5 (19%) eyes, retinal pigment epithelial atrophy in 1 (4%) eye, vitreous hemorrhage in 1 (4%) eye, and a disciform scar in 1 (4%) eye.

CONCLUSION

In this cohort of Asian patients with ARMD, the majority of symptomatic eyes had either CNV (46%) or serous PED (31%).

Outcomes of single-dose peri-procedural antibiotic prophylaxis for endoscopic ultrasound-guided fine-needle aspiration of pancreatic cystic lesions

BACKGROUND

Endoscopic ultrasound (EUS)-guided fine-needle aspiration (FNA) is a technique frequently used to diagnose solid and cystic lesions of the pancreas. Antibiotic prophylaxis has been recommended for EUS-FNA of pancreatic cystic lesions but is not universally observed. The most effective antibiotic and the most efficacious route and regimen of administration are also unknown.

OBJECTIVE

This cohort study was undertaken to evaluate whether single-dose piperacillin/tazobactam or ciprofloxacin given at the time of the procedure effectively prevents major adverse events and to audit the adherence to this protocol in the setting of EUS-FNA of pancreatic cystic lesions.

DESIGN

Consecutive EUS-FNA procedures of pancreatic cystic lesions were performed at Concord Hospital and significant variables regarding the procedure and adverse events were recorded. Patients were also contacted by telephone to follow-up any subacute adverse events they may have experienced.

PATIENTS

Over a 30 month period (January 2010-July 2012), a total of 85 EUS-FNAs of pancreatic cysts were performed on 80 different patients. The mean age was 63.2 years (range 17-89 years; 58% females).

INTERVENTIONS

Single-dose piperacillin/tazobactam IVs was administered to 87% of patients, while 12% of patients received ciprofloxacin IVs.

RESULTS

No patients developed cyst infection, fever, or sepsis (0%) and one patient (1.2%) was hospitalised for self-limited nausea without adverse sequelae.

CONCLUSIONS

Single-dose piperacillin/tazobactam at the time of EUS-FNA of pancreatic cysts is an effective prophylaxis of cyst infection or sepsis and can be conveniently given as a single-dose peri-procedurally without further oral antibiotics.

Comparison of tissue injury between laparosonic coagulating shears and electrosurgical scissors in the sheep model

STUDY OBJECTIVE

To compare laparosonic coagulating shears (LCS), which use ultrasonic energy, and unipolar diathermy scissors with respect to depth of tissue injury.

DESIGN

Prospective observational study (Canadian Task Force classification I).

SETTING

A reproduced surgical setting.

SUBJECTS

An anesthetized sheep.

INTERVENTION

We laparoscopically harvested uterine horn and bowel tissue.

MEASUREMENTS AND MAIN RESULTS

Tissue was transected while hemostasis was maintained. Two pathologists examined tissue independently, and each was blinded as to the instrument used for harvesting. Clinical characteristics and tissue injury created by the instruments were compared.

CONCLUSION

Subjectively, LCS appeared to produce less smoke plume than diathermy scissors. It also produced greater tissue damage than unipolar electrosurgery on settings of 35 W cut and 30 W coagulate.

Deeply infiltrating endometriosis: implications, diagnosis, and management

Deeply infiltrating endometriosis was described in the early part of the last century. Only recently, has there become a greater awareness and understanding of this form of endometriosis aided in part by advances in laparoscopic surgical technology in techniques. The clinical implications of the disease as well as diagnosis and current management are reviewed.

Gastric Cancer Screening in Common Variable Immunodeficiency

Individuals with common variable immunodeficiency (CVID) have an increased risk of gastric cancer, and gastrointestinal lymphoma, yet screening for premalignant gastric lesions is rarely offered routinely to these patients. Proposed screening protocols are not widely accepted and are based on gastric cancer risk factors that are not applicable to all CVID patients. Fifty-two CVID patients were recruited for screening gastroscopy irrespective of symptoms or blood results and were compared to 40 controls presenting for gastroscopy for other clinical indications. Overall, 34% of CVID patients had intestinal metaplasia (IM), atrophic gastritis or moderate to severe non-atrophic gastritis, which can increase the risk of gastric cancer, compared to 7.5% of controls (p < 0.01). Focal nodular lymphoid hyperplasia, a precursor lesion for gastrointestinal lymphoma, was seen in eight CVID patients (16%), one of whom was diagnosed with gastrointestinal lymphoma on the same endoscopy. High-risk gastric pathology was associated with increased time since diagnosis of CVID, smoking, Helicobacter pylori, a low-serum pepsinogen I concentration, and diarrhea, but not pepsinogen I/II ratio, iron studies, vitamin B12 levels or upper gastrointestinal symptoms. There was a lower rate of detection of IM when fewer biopsies were taken, and IM and gastric atrophy were rarely predicted by the endoscopist macroscopically, highlighting the need for standardized biopsy protocols. The prevalence of premalignant gastric lesions in patients with CVID highlights the need for routine gastric screening. We propose a novel gastric screening protocol to detect early premalignant lesions and reduce the risk of gastric cancer and gastric lymphoma in these patients.

Laparoscopic presacral neurectomy: a review

Dysmenorrhea can be a severe and debilitating symptom in many women. Although most women may find adequate relief of symptoms from pharmacological approaches, there remain a few with resistant pain. Presacral neurectomy, although technically challenging, may be offered after other approaches are unsuccessful. The operation is now performed increasingly by the laparoscopic approach, which has revived this operation in some centers. The anatomy, technique, and indications as well as a review of the literature supporting this operation are reviewed. The potential complications of this operation are discussed also.

Incisional hernia in a 5 mm laparoscopic port site incision

Herniation of omentum or bowel through laparoscopic incision sites is uncommon. Herniations through 5 mm ports sites are very rare, with less than a handful described in the literature. Undoubtedly however, with the increasing interest.

Laparoscopic presacral neurectomy - retrospective series

A retrospective audit of medical records was conducted for one surgeon (AL). All patients who underwent laparoscopic presacral neurectomy for severe midline dysmenorrhoea were identified. Details of the preoperative symptoms, clinical findings and operative records were studied. Improvement of dysmenorrhoea was assessed according to a pain scale. Twelve patients who had a laparoscopic presacral neurectomy performed were identified. Eight patients reported significant improvement of symptoms, with a further two reporting mild improvement. Two patients failed to show any improvement of symptoms. We believe that the role of laparoscopic presacral neurectomy should be limited to patients with severe midline dysmenorrhoea not responding to the medical therapy. It may be a supplementary procedure to laparoscopic resection of endometriosis or adhesiolysis.

Is benchmarking possible in audit of early outcomes after operations for head and neck cancer?

There is a need for a validated means of adjusting for case mix in morbidity audits of patients with cancer of the head and neck. To address this, we did a multicentre audit of 3 U.K. NHS cancer networks that treat patients with head and neck cancer, to compare the incidence of early adverse postoperative outcomes and to develop a means of adjusting for case mix. We did a retrospective and prospective audit of the case notes of 901 consecutive patients who had 1034 operations for squamous cell carcinoma (SCC) of the head and neck under general anaesthesia at 3 NHS hospitals. Analysis of raw data showed postoperative 30-day mortality (n=17) to be consistent between sites (1.7%-1.9%) but 30-day complication rates varied more (34%-49%). Logistic regression models predicting morbidity discriminated well (area under the curve 0.74-0.76). Adjusted morbidity rates for the 3 units were compared on a funnel plot with 95% and 99% confidence intervals to account for random variation. It is possible to benchmark surgical performance by focusing on early postoperative outcomes in head and neck surgery. Morbidity is common and usually has a considerable impact on recovery, bed occupancy, cost, and the patient's perception of the quality of care.

A Thermodynamic Model for Interpreting Tryptophan Excitation-Energy-Dependent Fluorescence Spectra Provides Insight Into Protein Conformational Sampling and Stability

It is now over 30 years since Demchenko and Ladokhin first posited the potential of the tryptophan red edge excitation shift (REES) effect to capture information on protein molecular dynamics. While there have been many key efforts in the intervening years, a biophysical thermodynamic model to quantify the relationship between the REES effect and protein flexibility has been lacking. Without such a model the full potential of the REES effect cannot be realized. Here, we present a thermodynamic model of the tryptophan REES effect that captures information on protein conformational flexibility, even with proteins containing multiple tryptophan residues. Our study incorporates exemplars at every scale, from tryptophan in solution, single tryptophan peptides, to multitryptophan proteins, with examples including a structurally disordered peptide, de novo designed enzyme, human regulatory protein, therapeutic monoclonal antibodies in active commercial development, and a mesophilic and hyperthermophilic enzyme. Combined, our model and data suggest a route forward for the experimental measurement of the protein REES effect and point to the potential for integrating biomolecular simulation with experimental data to yield novel insights.