Landscape of MicroRNA Regulatory Network Architecture and Functional Rerouting in Cancer

Somatic mutations are a major source of cancer development, and many driver mutations have been identified in protein coding regions. However, the function of mutations located in miRNA and their target binding sites throughout the human genome remains largely unknown. Here, we built detailed cancer-specific miRNA regulatory networks across 30 cancer types to systematically analyze the effect of mutations in miRNAs and their target sites in 3' untranslated region (3' UTR), coding sequence (CDS), and 5' UTR regions. A total of 3,518,261 mutations from 9,819 samples were mapped to miRNA-gene interactions (mGI). Mutations in miRNAs showed a mutually exclusive pattern with mutations in their target genes in almost all cancer types. A linear regression method identified 148 candidate driver mutations that can significantly perturb miRNA regulatory networks. Driver mutations in 3'UTRs played their roles by altering RNA binding energy and the expression of target genes. Finally, mutated driver gene targets in 3' UTRs were significantly downregulated in cancer and functioned as tumor suppressors during cancer progression, suggesting potential miRNA candidates with significant clinical implications. A user-friendly, open-access web portal (mGI-map) was developed to facilitate further use of this data resource. Together, these results will facilitate novel noncoding biomarker identification and therapeutic drug design targeting the miRNA regulatory networks.

SIGNIFICANCE

A detailed miRNA-gene interaction map reveals extensive miRNA-mediated gene regulatory networks with mutation-induced perturbations across multiple cancers, serving as a resource for noncoding biomarker discovery and drug development.

The Management of Hydrothorax in Continuous Ambulatory Peritoneal Dialysis (CAPD)

Four patients on continuous ambulatory peritoneal dialysis (CAPD) developed large, symptomatic pleural effusions after commencing peritoneal dialysis. Pleuroperitoneal fistula in each case was diagnosed by the presence of a high glucose content in pleural fluid, with a normal corresponding blood sugar, and was confirmed by isotope or contrast peritoneography. Two patients had their effusions drained percutaneously, and then underwent pleural sclerosis with intracavitary tetracycline. Two patients had a thoracotomy performed, of which no fistula was identified in one case, and the other patient underwent pleurectomy. All four patients successfully recommenced CAPD several weeks after therapy, without recurrence of effusions. We conclude that pleuroperitoneal connections associated with CAPD do not mandate cessation of peritoneal dialysis and conversion to maintenance haemodialysis. Definitive diagnosis requires aspiration of pleural effusions for glucose estimation. Contrast or isotopic peritoneography is helpful in localising the fistula, but in our experience did not alter management. Simple sclerotherapy is effective and avoids the need for a formal thoracotomy.

Percutaneous antegrade ureteric stent removal using a rigid alligator forceps

To evaluate the safety and efficacy of percutaneous antegrade ureteric stent removal using a rigid alligator forceps. Twenty patients were included in our study. Indications for ureteric stent insertion included stone disease (n = 7), malignancy (n = 8) and transplant anastomotic strictures (n = 5). Stent retrieval was carried out for proximal stent placement/migration in seven patients and encrustation in the remaining 13. Twenty-two stents were successfully retrieved in 20 patients. There was one technical failure (5%). There were no major complications. We had four minor complications, which included nephrostomy site pain (n = 2), periprocedural sepsis (n = 1) and a small urinoma (n = 1). All patients settled with conservative management. Percutaneous radiologically guided antegrade ureteric stent removal with an alligator forceps is safe and effective, particularly when initial surgical removal has failed.

Huntington disease in indigenous Australians

Huntington disease (HD) in indigenous Australians is a poorly analysed and difficult problem. This study addresses the issue of HD in remote indigenous Australian populations in the north-west of Western Australia. Proband identification, clinical assessment, neurogenetic studies and pedigree analysis led to the discovery of HD in the 63-year-old male proband and his family. HD in remote indigenous Australian communities is a challenging diagnostic and management problem compounded by the complexity of distance.

A Prospective Comparison of Two Types of Tunneled Hemodialysis Catheters: The Ash Split Versus the PermCath

PURPOSE

In a prospective randomized study a standard dual-tip hemodialysis catheter (PermCath, Sherwood Medical, St. Louis, MO, USA) was compared with a newer split-lumen catheter (Ash Split, Medcomp, Harleysville, PA, USA).

METHODS

Sixty-nine patients (42 men, 27 women; mean age 62 years) were randomized to receive either the Ash Split (AS) or the PermCath (PC) catheter. The catheters were inserted into the internal jugular vein. The primary outcome evaluated was blood flow measurements during the first six hemodialysis sessions. Secondary outcomes included: technical difficulties encountered at insertion, early complications and late complications requiring catheter removal or exchange.

RESULTS

A total of 69 hemodialysis catheters, 33 AS and 36 PC, were successfully inserted in the internal jugular vein (right 60, left 9) of 69 patients. Mean blood flow during dialysis (Qb) was 270.75 ml/min and 261.86 ml/hr for the AS and PC groups respectively (p = 0.27). Mean duration of catheter use was 111.7 days (range 5.4-548.9 days) and 141.2 days (range 7.0-560.9 days) in the AS and PC groups respectively (p = 0.307). Catheter failures leading to removal or exchange occurred in 20 patients: 14 in the AS group and six in the PC group. Survival curves with censored endpoints (i.e., recovery, arteriovenous fistula formation, peritoneal dialysis and transplantation) showed significantly better outcome with PermCath catheters (p = 0.024). There was no significant difference in ease of insertion or early complication rates.

CONCLUSION

The Ash Split catheter allows increased rates of blood flow during hemodialysis but this increase was not significant at the beginning (p = 0.21) or end (p = 0.27) of the first six hemodialysis sessions. The Ash Split catheter is more prone to minor complications, particularly dislodgment, than the PermCath catheter.

Endoluminal graft stenting of peripheral aneurysms: questionable results compared with conventional surgery

Popliteal and femoral aneurysms can be treated by endoluminal graft stenting, instead of conventional surgery. Results in four cases suggest, however, that long-term results do not justify an endovascular approach.

Prospective comparison of MRA with catheter angiography in the assessment of patients with aortoiliac occlusion before surgery or endovascular therapy

AIM

The purpose of this study was to evaluate the usefulness of gadolinium enhanced 3D magnetic resonance (MR) angiography (CE MRA) as an alternative to translumbar or brachial angiography in the pre-operative work-up of patients with aortoiliac occlusion.

MATERIALS AND METHODS

Nineteen patients (14 men and five women; age range 45-77 years; mean 62 years), not suitable for perfemoral angiography (aortoiliac occlusion, n = 18; infected femoro-femoral graft with femoral artery pseudoaneurysm, n = 1), underwent pre-operative CE MRA and catheter angiography (translumbar, n = 5; brachial, n = 14). CE MRA was performed using a 3D fast spoiled gradient-recalled pulse sequence during the intravenous injection of 40 ml of gadolinium DTPA and a 32-s breath-hold. All patients subsequently underwent surgical (n = 13) or percutaneous transluminal (n = 6) treatment for their vascular disease. The accuracy of CE MRA was determined compared with the findings at catheter angiography taken as the gold standard.

RESULTS

CE MRA gave accurate information about the occlusion, inflow and distal run-off in the majority of patients. CE MRA revealed occlusions with an accuracy of 94.7% in the aortic segment, 98.7% in the iliac segment, and 100% in the common femoral segment. The arterial segments distal to the common femoral artery were not completely visualized in four patients but CE MRA provided sufficient information to plan either surgical or percutaneous transluminal therapy in all but one patient.

CONCLUSION

CE MRA is highly accurate in showing the presence and extent of aortoiliac occlusions. In our study group, CE MRA gave sufficient information in the pre-operative evaluation of aortoiliac occlusion.

Rebuilding a clinical workstation with spider's silk of the Web

The Yale-New Haven Hospital (YNHH) clinical workstation came into existence in 1993 to provide a simple menu-driven interface to high use information systems that would be easily accessible on the wards and in the intensive care units. Direct Internet access, advances in Web-based software, and greater cooperation between Yale-New Haven Hospital and Yale School of Medicine network technology groups have enabled the clinical workstations to become an integral tool for providing clinical care. The workstation provides bedside access to an expanding array of internal and external resources to support patient care and has the potential to become the basis for an interface that will be utilized throughout the multi-location Yale-New Haven Healthcare System.

Radiologic evaluation of simultaneous pancreas-kidney transplantation

We describe the radiographic imaging modalities that were used in the first twelve consecutive patients who have undergone simultaneous pancreas and kidney transplantation (SPK) at our institution. The total number of examinations undertaken in this study included ultrasound (n = 22), radionucleide scanning (n = 19), cystography (n = 14), computed tomography (n = 2) and magnetic resonance imaging (n = 1). Eighteen percent (5/22) ultrasound examinations were abnormal (perirenal collection [n = 4], peri-pancreatic collection [n = 1]. Two collections required aspiration and were confirmed as lymphocoeles. Cystography showed ureteric reflux in two patients and radionucleide DTPA scanning revealed a delay in the excretory phase in 20% of patients. CT was used in two patients with SPK and demonstrated large peri-pancreatic collections. No episodes of rejection or late graft pancreatitis were noted in this series. We discuss the role of radiographic imaging in detecting early graft failure and also in defining the surgical complications that may arise following transplantation. We also outline the merits and disadvantages of each imaging modality. We conclude that the most useful initial imaging techniques in the evaluation of patients following SPK are ultrasound including Doppler and nuclear medicine.

Laryngeal chondroma: an unusual cause of upper airway obstruction

Cartilaginous tumours of the larynx should be considered in the differential diagnosis of upper airway obstruction. We report two cases of chondroma of the thyroid cartilage and discuss the radiological findings in each case.

Color Doppler imaging of the thyroid gland in a fetus with congenital goiter: a case report

Fetal goiter is a rare disorder, usually associated with maternal thyroid disease. Antenatal diagnosis of fetal goiter is crucial for the immediate postpartum management of these neonates. A case report is presented of an antenatally diagnosed fetal goiter induced by antithyroid medications. Color Doppler was used to demonstrate a high flow pattern that, unlike in the adult goiter, was associated with hypothyroidism in the neonate. A scan of fetal neck region is recommended in patients with current or previous history of thyroid disease, or if neck extension is noted on routine examination of fetal spine.

Practice locally, search globally

The National Library of Medicine introduced the Grateful Med software package for accessing its databases over six years ago. Many new features have been added to the program since its inception in 1986. These major improvements enable health professionals to gain a more user friendly access to the biomedical literature of the National Library of Medicine than ever before. The software enhancements aid the end-user in performing searches that will retrieve material with greater specificity and accuracy. Grateful Med provides a time-saving, cost-effective means of equal access to the medical literature regardless of the user's physical location or lack of access to other resources.

Safety and efficacy of high kV biliary lithotripsy: preliminary experience

Despite intense interest in laparoscopic cholecystectomy, biliary lithotripsy (BL), by avoiding the need for general anesthesia, could remain a useful alternative in approximately 10% of patients with symptomatic gallstones. The poor stone clearance rates reported by the Dornier National Biliary Lithotripsy Study has led to disenchantment with biliary lithotripsy. However, the results may reflect the relatively low kV (18.7 +/- 1.7) used. We have compared symptomatic gallbladder stone/cholecystolithiasis patients with one to five stones of aggregate diameter < 60 mm treated with one to three sessions on an MPLS 9000 (Dornier) lithotripter at moderate kV (22.7 +/- 1.7 kV; mean number of shocks 1473 +/- 356) with a similar group treated with high kV (26 kV, mean number of shocks 1357 +/- 507). Ultrasound stone diameter measurements were made pre- and post-BL; 12-wk results are reported. Treatment safety was assessed by recording adverse experiences and serum, urine, hematology, and chemistry. For patients with single stones, the high kV treatment took significantly (p < 0.05) less time (74 +/- 30 min) than moderate kV treatment (118 +/- 33 min). At 3 months, the moderate kV-treated single-stone group had a residual maximum fragment size of 3.2 +/- 3.3 mm versus 1.8 +/- 2.3 mm in the high kV-treated single-stone group. The 3-month stone-free rate for patients with single stones treated at high kV was 44% compared with 46% for the moderate kV-treated group (NS). At 1 wk, 11 patients had microscopic or macroscopic hematuria and six patients had mildly elevated liver function tests. At 6 wk, however, all urine and hematological measurements had returned to normal. Two patients suffered pancreatitis, one in each group. High kV BL appears to be safe and, for patients with single stones, gives better fragmentation and takes less time to administer than moderate kV. Whether a high kV treatment protocol can achieve improved long-term stone-free rates remains to be assessed.

Altered skin temperature and electromyographic activity in the irritable bowel syndrome

A prospective study to determine the presence or absence of any difference in skin temperature and electromyographic (EMG) activity in 20 patients with irritable bowel syndrome (IBS) compared with 20 age- and sex-matched controls was conducted. A representative digital temperature and EMG activity during 4 phases, baseline, mental activity (arithmetic), unpleasant thoughts and audio biofeedback relaxation, were recorded using standard biofeedback equipment. Results showed the IBS group to have a significantly lower digital temperature and significantly higher EMG activity during the baseline and arithmetic phases. No difference was found in EMG activity for the unpleasant thought or audio biofeedback relaxation phases. Indeed, the IBS group were able to achieve a level of EMG activity during the audio feedback relaxation phase that approximated very closely that of the control group. These results provide further evidence suggestive of altered autonomic nervous system function in IBS patients and indicate that further studies should be undertaken to determine whether the reduction achieved in EMG activity post-relaxation is sustained, and if so, if it is associated with a corresponding improvement in symptoms.