How to assess nonresponsiveness to vasodilator stress.

Myocardial perfusion imaging (MPI) is a powerful tool for the functional assessment of ischemia in patients with suspected or known coronary artery disease (CAD). Given that the diagnostic accuracy and prognostic value of MPI and post-test management are highly dependent on achieving an adequate stress vasodilatory response, it is critical to identify those who may not have adequately responded to vasodilator pharmacological stress agents such as adenosine, dipyridamole, and regadenoson. Caffeine, a potent inhibitor of the adenosine receptor, is a compound that can affect vasodilatory hemodynamics, result in false negative studies, and potentially alter management in cases of inaccurate test results. Vasodilator non-responsiveness can be suspected by examining hemodynamics, quantitative positron emission tomography (PET) metrics such as myocardial flow reserve (MFR), and splenic response to stress. Quantitative MFR values of 1-1.2 should raise suspicion for nonresponsiveness in the setting of normal perfusion, along with the absence of a splenic switch off. Newer metrics, such as splenic response ratio, can be used to aid in the identification of potential nonresponders to pharmacologic vasodilators.

Effect of variable left ventricular ejection fraction assessed by equilibrium radionuclide angiocardiography using different software packages on the diagnosis of cardiotoxicity in patients with cancer.

BACKGROUND: The equilibrium radionuclide angiocardiography (ERNA) scan is an established imaging modality for assessing left ventricular ejection fraction (LVEF) in oncology patients. This study aimed to explore the interchangeability of two commercially available software packages (MIM and JS) for LVEF measurement for a cancer-therapy-related cardiac dysfunction (CTRCD) diagnosis. METHODS: This is a single-center retrospective study among 322 patients who underwent ERNA scans. A total of 582 scans were re-processed using MIM and JS for cross-sectional and longitudinal LVEF measurements. RESULTS: The median LVEF for MIM and JS were 56% and 66%, respectively (P < 0.001). LVEF processed by JS was 9.91% higher than by MIM. In 87 patients with longitudinal ERNA scans, serial studies processed by MIM were classified as having CTRCD in a higher proportion than serial studies processed by JS (26.4% vs 11.4%, P = 0.020). There were no significant differences in intra- or inter-observer LVEF measurement variability (R = 0.99, P < 0.001). CONCLUSIONS: Software packages for processing ERNA studies are not interchangeable; thus, reports of ERNA studies should include details on the post-processing software. Serial ERNA studies should be processed on the same software when feasible to avoid discrepancies in the diagnosis and management of CTRCD.

Revisiting cardiovascular risk reduction in type 2 diabetes and dyslipidemia.

Statin therapy has been a mainstay of cardiovascular disease (CVD) risk reduction for the past 20 years in type 2 diabetes management. Its application has been largely due to well-designed, randomized-control studies consistently showing 25-35% CVD risk reduction. However, the remaining 65-75% reduction potential for CVD risk has yet to be effectively addressed. With a push towards personalized medicine, the likelihood of a one-size-fits-all approach to CVD risk reduction in type 2 diabetes may not be as beneficial as anticipated. It is reasonable to suggest that we have aggregated separate CVD phenotypic groups under one treatment umbrella and consequently, dismissed further unaddressed CVD risk reduction potential. The hypothesis proposed in this review is that there are at least two phenotypic groups with distinct molecular mechanisms contributing to CVD risk requiring different treatment approaches that can be applied with present pharmacotherapy. The two phenotypes can be classified as the following: 1) high low-density lipoprotein (LDL) phenotype and 2) high triglyceride (TG) plus low high-density lipoprotein (HDL) phenotype. As both phenotypes are significantly represented in individuals with type 2 diabetes, a more precise understanding of molecular details can be merged with clinical CVD outcome studies to arrive at a new hypothesis for CVD treatment that can be substantiated with additional well-designed clinical trials. As we transition from 20th to 21st-century medicine, we should utilize new knowledge to adapt current CVD risk reduction measures for those with type 2 diabetes.

Cardiac AL amyloidosis presenting as recurrent dyspnoea in a patient with cancer: an important clinical clue to an early diagnosis.

Cardiac amyloidosis (CA) is challenging to diagnose due to its non-specific clinical manifestations early in the disease process. We report the case of a patient who presented with dyspnoea, abdominal distension and leg swelling. Medical history was notable for hypertension, recurrent vulvar squamous cell carcinoma and polysubstance abuse. Over 1 year before the official diagnosis of CA, the patient had multiple hospital readmissions for dyspnoea. Our case illustrates the importance of having a high index of clinical suspicion for an early diagnosis of CA. Furthermore, it highlights the need to re-evaluate a presumed diagnosis when a patient's symptoms recur or do not respond to appropriate treatment and to consider the influence of social factors on diagnostic processes.

Is Psychiatric Illness Associated With Worse Outcomes Following Pilon Fracture?

Background: Patients with psychiatric comorbidities represent a significant subset of those sustaining pilon fractures. The purpose of this study is to examine the association of psychiatric comorbidities (PC) in patients with pilon fractures and clinical outcomes. Methods: A multi-institution, retrospective review was conducted. Inclusion/exclusion criteria were skeletally mature patients with a tibia pilon fracture (OTA Type 43B/C) who underwent definitive fracture fixation utilizing open reduction internal fixation (ORIF) with a minimum of 24 weeks of follow-up. Patients were stratified into two groups for comparison: PC group and no PC group. Results: There were 103 patients with pilon fractures that met the inclusion/exclusion criteria of this study. Of these patients, 22 (21.4%) had at least one psychiatric comorbidity (PC) and 81 (78.6%) did not have psychiatric comorbidities (no PC). There was a higher percentage of female patients (PC: 59.1% vs no PC: 25.9%, p=0.0.005), smokers (PC: 40.9% vs no PC: 16.0%, p=0.02), and drug users (PC: 22.7% vs no PC: 8.6%, p=0.08) amongst PC patients. Fracture comminution (PC: 54.5% vs no PC: 32.1%, p=0.05) occurred more frequently in PC patients. The PC group had a higher incidence of weightbearing noncompliance (22.7% vs 7.5%, p=0.04) and reoperation (PC: 54.5% vs no PC: 29.6%, p=0.03). Conclusion: Patients with psychiatric comorbidities represent a significant percentage of pilon fracture patients and appear to be at higher risk for postoperative complication. Risk factors that may predispose patients in the PC group include smoking/substance use, weightbearing noncompliance, and fracture comminution. Level of Evidence: III.

A post-market, randomized, controlled, prospective study evaluating intrathecal pain medication versus conventional medical management in the non-cancer, refractory, chronic pain population (PROSPER).

INTRODUCTION: Intrathecal therapy has been limited by non-randomized prospective studies, particularly for those suffering from non-cancer. Further, no prospective, randomized studies investigating the efficacy, safety, and utilization of intrathecal polyanalgesic consensus guidelines exist. METHODS: After IRB approval, patients were enrolled in a 1:1 fashion for intrathecal drug delivery (IDD) or conventional management (CMM), employing standard of care, excluding intrathecal drug delivery, based on the principal investigator's discretion. They were followed 3, 6, 9, and 12 months. Assessments included PROMIS 29, NPRS, and PriceMonkey. RESULTS: Seventy-nine patients were screened, 54 patients were enrolled: 26 to IDD and 28 to CMM. At 3 months, there was no measurable difference in pain improvement in either subgroups within the CMM for chronic pain-related syndromes (CPRS) or failed back and related spine disorders (FBRS). For the IDD, early and maintained benefit from the baseline was statistically achieved. Cost analysis of pump to CMM breakeven was 4.5 months. There were no adverse events related to compounded intrathecal medications. CONCLUSION: This is the first randomized prospective, multicenter study investigating the safety, cost, and efficacy of off-label medications for intrathecal therapy, as compared to conventional management, and suggests early detection of improvement, cost savings, safety of intrathecal compounded medication use, and safety and efficacy of employing the PACC guidance.

KRAS2 mutations in human pancreatic acinar-ductal metaplastic lesions are limited to those with PanIN: implications for the human pancreatic cancer cell of origin.

Pancreatic intraepithelial neoplasia (PanIN) is a precursor to invasive ductal adenocarcinoma of the pancreas. Observations made in genetically engineered mouse models suggest that the acinar/centroacinar compartment can give rise to ductal neoplasia. To integrate findings in mice and men, we examined human acinar cells, acinar-ductal metaplasia (ADM) lesions, and PanINs for KRAS2 gene mutations. Surgically resected pancreata were screened for foci of ADM with or without an associated PanIN lesion. Stromal cells, acinar cells, ADMs, and PanINs were separately isolated using laser capture microdissection. KRAS2 status was analyzed using genomic DNA isolated from the microdissected tissue. Twelve of these 31 foci of ADM occurred in isolation, whereas 19 were in the same lobules as a PanIN lesion. All 31 microdissected foci of acinar cells were KRAS2 gene wild-type, as were all 12 isolated ADM lesions lacking an associated PanIN. KRAS2 gene mutations were present in 14 of 19 (74%) PanIN lesions and in 12 of the 19 (63%) foci of ADM associated with these PanINs. All ADM lesions with a KRAS2 gene mutation harbored the identical KRAS2 gene mutation found in their associated PanIN lesions. Ductal neoplasms of the human pancreas, as defined by KRAS2 gene mutations, do not appear to arise from acinar cells. Isolated AMD lesions are genetically distinct from those associated with PanINs, and the latter may represent retrograde extension of the neoplastic PanIN cells or less likely are precursors to PanIN.

Local Zinc Chloride Release From a Calcium Sulfate Carrier Enhances Fracture Healing.

BACKGROUND: This study examined the efficacy of calcium sulfate (CaSO4) as a carrier for intramedullary delivery of zinc chloride (ZnCl2) to treat fracture healing in a BB Wistar rat model. A non-carrier-mediated injection of 3.0 mg/kg of ZnCl2 has previously been shown to enhance fracture healing. METHODS: A heterogeneous mixture of ZnCl2 and CaSO4 was administered into the intramedullary femoral canal and a mid-diaphyseal femur fracture was created unilaterally. Early and late parameters of fracture healing were assessed using biomechanical testing, radiographic scoring, quantitative histomorphometry (for percentage of new cartilage and bone within the fracture callus), and long-term histologic evaluation. RESULTS: Fractures treated with 1.0 mg/kg of ZnCl2/CaSO4 demonstrated a significantly higher maximum torque to failure compared with both CaSO4 (P = 0.048) and saline (P = 0.005) controls at 4 weeks postfracture (396.4 versus 251.3 versus 178.7 N mm, respectively). Statistically significant increases in torsional rigidity, effective shear modulus, and effective shear stress were also found, as well as a 3.5 times increase in radiographic score (based on bone union). Histologic examination of the fracture callus indicated enhanced chondrogenesis at day 14 postfracture, with increased percent cartilage for the ZnCl2/CaSO4 group compared with saline (P = 0.0004) and CaSO4 (P = 0.0453) controls. Long-term radiographic and histologic evaluation revealed no abnormal bone formation or infection up to 12 weeks postoperatively. CONCLUSIONS: The effective dose of ZnCl2 augmentation for the enhancement of fracture healing in rats was reduced 3-fold in this study compared with previous findings. Furthermore, CaSO4 acted synergistically with ZnCl2 to increase the mechanical strength and stability at the fracture site.

Quantifying the relative amount of mouse and human DNA in cancer xenografts using species-specific variation in gene length.

Human cancer cell lines and xenografts are valuable samples for whole-genome sequencing of human cancer. Tumors can be maintained by serial xenografting in athymic (nude) or severe combined immunodeficient (SCID) mice. In the current study, we developed a molecular assay to quantify the relative contributions of human and mouse in mixed DNA samples. The assay was designed based on deletion/insertion variation between human and mouse genomes. The percentage of mouse DNA was calculated according to the relative peak heights of PCR products analyzed by capillary electrophoresis. Three markers from chromosomes 9 and 10 accurately predicted the mouse genome ratio and were combined into a multiplex PCR reaction. We used the assay to quantify the relative DNA amounts of 93 mouse xenografts used for a recently reported integrated genomic analysis of human pancreatic cancer. Of the 93 xenografts, the mean percentage of contaminating mouse DNA was 47%, ranging from 17% to 73%, with 43% of samples having >50% mouse DNA. We then comprehensively compared the human and mouse genomes to identify 370 additional candidate gene loci demonstrating human-mouse length variation. With increasing whole-genome sequencing of human cancers, this assay should be useful to monitor strategies to enrich human cancer cells from mixed human-mouse cell xenografts. Finally, we discuss how contaminating mouse DNA affects next-generation DNA sequencing.

Surgical strategy for cystic diseases of the liver in a western hepatobiliary center.

The aim of this study was to define the indications and evaluate the results of various management options in patients with cystic liver disease. Between 1992 and 1999 we managed 60 consecutive patients with cystic liver disease. Diagnoses included a simple cyst (solitary 12, multiple 10), adult polycystic liver disease (APLD 17), Caroli's disease (8), hydatid cysts (4), and neoplastic cysts (9). Half of the patients with simple cysts had mild or no symptoms and required no treatment. Percutaneous drainage in eight patients (simple cyst 4, APLD 4) was followed by symptomatic recurrence in three. Laparoscopic deroofing in three patients (multiple simple cysts 2, APLD 1) was followed by symptomatic enlargement of the remaining cysts that required further intervention (laparoscopic deroofing 2, transplantation 1). Laparoscopic hepatectomy was successful in three patients with solitary simple cysts. Of 18 patients who underwent open hepatic resection (neoplastic 8, Caroli's 4, simple cysts 3, hydatid cysts 2, APLD 1), 2 patients with Caroli's disease required liver transplantation for disease progression. Nine patients (Caroli's 5, APLD 4) underwent liver transplantation, and three had a concomitant renal transplant. Seven patients developed complications, and three died (5%). Cholangiocarcinoma developed in three patients with bilateral Caroli's disease, and all died. Radiologic treatment has a limited role in the management of patients with simple cysts or APLD. Laparoscopic deroofing of simple cysts may have to be repeated, whereas resection minimizes cyst recurrence. Unilobar Caroli's disease may be resected, whereas bilateral disease requires early liver transplantation owing to the high risk of malignancy. Transplantation is a reserved option in patients with extensive APLD.