Acute and chronic kidney injury during therapy for pediatric acute leukemia: A report from the Leukemia Electronic Abstraction of Records Network (LEARN).

Children with acute leukemia are at increased risk of kidney injury. Using electronic health record data from three centers between 2010 and 2018, this study retrospectively described acute kidney injury (AKI) and chronic kidney disease (CKD) prevalence in children with acute lymphoblastic or myeloid leukemia (ALL, AML) using Common Terminology Criteria for Adverse Events (CTCAE) and Kidney Disease Improving Global Outcomes (KDIGO) definitions. AKI during therapy was 25% (ALL) and 32% (AML) using CTCAE, versus 84% (ALL) and 74% (AML) using KDIGO. CKD prevalence was low and Grade 1/Stage 2. Further investigation is needed to optimally define kidney injury in acute leukemia.

Long-Term Kidney and Cardiovascular Complications in Pediatric Cancer Survivors.

OBJECTIVE: The objective of this study was to describe the burden of adverse kidney and hypertension outcomes in patients evaluated by pediatric nephrology in a multidisciplinary survivorship clinic. STUDY DESIGN: Retrospective chart review of all patients followed up by nephrology in our multidisciplinary survivorship clinic from August 2013 to June 2021. Data included clinic blood pressure, longitudinal ambulatory blood pressure monitoring (ABPM), echocardiography, serum creatinine, and first-morning urine protein/creatinine ratios. For patients with multiple ABPMs, results of initial and most recent ABPMs were compared. RESULTS: Of 422 patients followed in the multidisciplinary cancer survivorship clinic, 130 were seen by nephrology. The median time after therapy completion to first nephrology visit was 8 years. The most common diagnoses were leukemia/myelodysplastic syndrome (27%), neuroblastoma (24%), and Wilms tumor (15%). At the last follow-up, 68% had impaired kidney function, 38% had a clinical diagnosis of hypertension, and 12% had proteinuria. There were 91 ABPMs performed in 55 (42%) patients. Patients with multiple ABPMs (n = 21) had statistically significant reductions in overall median blood pressure loads: systolic initial load 37% vs most recent 10% (P = .005) and diastolic load 36% vs 14% (P = .017). Patients with impaired kidney function were more likely to have received ifosfamide. Patients with hypertension were more likely to have received total body irradiation or allogeneic stem cell transplant. CONCLUSIONS: History of leukemia/myelodysplastic syndrome, neuroblastoma, and Wilms tumor was frequent among survivors seen by nephrology. There was significant improvement in cardiovascular measures with increased recognition of hypertension and subsequent treatment.

Late renal allograft torsion in a pediatric transplant recipient.

BACKGROUND: Kidney allograft torsion is a rare complication of kidney transplant that can lead to allograft loss from prolonged ischemia if not quickly corrected with detorsion and nephropexy. We report a case of late intraperitoneal renal allograft torsion in a pediatric transplant recipient. CASE REPORT: The patient is a 7-year-old male with a history of end-stage renal disease secondary to renal dysplasia in the setting of bilateral high-grade vesicoureteral reflux. He underwent bilateral native nephrectomies for recurrent pyelonephritis and right ureteral kink with urinary tract obstruction. Torsion occurred 3 years after transplant in the setting of one day of emesis, loose stool, severe abdominal pain, and decreased urine output. Diagnosis of transplant torsion was suspected on non-contrast CT scan done after transplant Doppler ultrasound showed no flow to the allograft. The CT scan showed that the kidney had been medialized and renal hilum was flipped from the expected orientation. The patient required a transplant nephrectomy. CONCLUSIONS: Renal transplant torsion is a rare event but should be suspected in any renal transplant recipient with acute onset of abdominal pain, acute kidney injury, and decreased urine output, regardless of length of time from transplantation. Patients suspected to have renal torsion should be evaluated emergently with a transplant ultrasound Doppler.

Expanding the phenotypic spectrum of Mendelian connective tissue disorders to include prominent kidney phenotypes.

Heritable connective tissue disorders are a group of diseases, each rare, characterized by various combinations of skin, joint, musculoskeletal, organ, and vascular involvement. Although kidney abnormalities have been reported in some connective tissue disorders, they are rarely a presenting feature. Here we present three patients with prominent kidney phenotypes who were found by whole exome sequencing to have variants in established connective tissue genes associated with Loeys-Dietz syndrome and congenital contractural arachnodactyly. These cases highlight the importance of considering connective tissue disease in children presenting with structural kidney disease and also serves to expand the phenotype of Loeys-Dietz syndrome and possibly congenital contractural arachnodactyly to include cystic kidney disease and cystic kidney dysplasia, respectively.

The incidence and risk factors for venous thromboembolism in adolescent and young adult oncology patients.

BACKGROUND: Venous thromboembolism (VTE) is a known complication among pediatric and adult cancer patients. Adolescent and young adult oncology (AYAO) patients have unique biological and physiological characteristics that make them distinct from other populations. Our objective was to study the VTE incidence, risk factors, and outcomes, which have been understudied in this population. PROCEDURE: A retrospective case-control study was conducted on AYAO participants with new or relapsed cancer and an imaging confirmed VTE from January 2011 to November 2016 at our institution. Eligible AYAO participants without a history of VTE were designated as controls and were randomly selected from our institution's tumor registry. Demographics, medical history, surgeries, central venous catheter (CVC) data, VTE diagnosis and treatment, relapses, and deaths were abstracted. RESULTS: Thirty-five VTE cases and 70 controls were included in this analysis. Eighty percent of cases had leukemia or lymphoma (vs. a solid tumor) compared to 58% of controls. The majority of VTEs (57%) were CVC associated, and more than 70% of cases had more than one CVC placed during their cancer treatment versus 34% of controls. Infection was associated with increased VTE risk (OR = 6.35, 95% CI = 2.30, 17.55, p < .0001). VTE cases had increased cancer relapse (23% vs. 10%) and mortality rates (29% vs. 16%) than controls. CONCLUSION: AYAO participants with a VTE were more likely to have leukemia or lymphoma, more than one CVC or infection. Further studies are needed to identify patients who would benefit from modifiable prevention measures, such as limiting to one CVC, preventing infections, or considering prophylactic anticoagulation for those with a liquid tumor.

Prognostic significance of tumor poliovirus receptor and CTLA4 expression in patients with surgically resected non-small-cell lung cancer.

INTRODUCTION: Poliovirus receptor (PVR) is a tumor promoter and a regulatory checkpoint that enhances immunosuppression. We investigated PVR expression by applying immunohistochemistry (IHC) staining. A positive association existed between PVR expression and cytotoxic T lymphocyte-associated antigen 4 (CTLA4) expression in patients with surgically resected non-small-cell lung cancer (NSCLC). PVR expression is a prognosis predictor of lung adenocarcinoma. PURPOSE: To investigate the prognostic significance of PVR expression and CTLA4 expression for surgically resected NSCLC. PATIENTS AND METHODS: The medical records of 108 Chinese patients with primary NSCLC who underwent surgery were retrospectively reviewed. The expression of PVR and CTLA4 were measured through IHC. Clinical characteristics, the association between PVR and CTLA4, and the prognostic significance of PVR were analyzed. RESULTS: A significant positive association was observed between PVR and CTLA4 expression in NSCLC (P = 0.016). PVR had a high positive rate among females, nonsmokers, and patients with adenocarcinoma and advanced lung cancer. The overall survival (OS) of patients with negative PVR expression was significantly longer than that of patients with positive PVR expression (P = 0.049), especially among females (P = 0.03) and nonsmokers (P = 0.025). Multivariate analysis results showed that advanced tumor stage and PVR expression were independent prognosis predictors of poor OS. CONCLUSION: PVR can potentially serve as a prognostic predictor and biomarker for NSCLC and cancer anti-CTLA4 immunotherapy response.

MicroRNA-421 confers paclitaxel resistance by binding to the KEAP1 3'UTR and predicts poor survival in non-small cell lung cancer.

MicroRNAs regulate post-transcriptional gene expression and play important roles in multiple cellular processes. In this study, we found that miR-421 suppresses kelch-like ECH-associated protein 1(KEAP1) expression by targeting its 3'-untranslated region (3'UTR). A Q-PCR assay demonstrated that miR-421 is overexpressed in non-small cell lung cancer (NSCLC), especially in A549 cells. Consistently, the level of miR-421 was higher in clinical blood samples from lung cancer patients than in those from normal healthy donors, suggesting that miR-421 is an important lung cancer biomarker. Interestingly, overexpression of miR-421 reduced the level of KEAP1 expression, which further promoted lung cancer cell migration and invasion, as well as inhibited cell apoptosis both in vivo and in vitro. Furthermore, knockdown of miR-421 expression with an antisense morpholino oligonucleotide (AMO) increased ROS levels and treatment sensitivity to paclitaxel in vitro and in vivo, indicating that high miR-421 expression may at least partly account for paclitaxel tolerance in lung cancer patients. To find the upstream regulator of miR-421, one of the candidates, ß-catenin, was knocked out via the CRISPR/Cas9 method in A549 cells. Our data showed that inhibiting ß-catenin reduced miR-421 levels in A549 cells. In addition, ß-catenin upregulation enhanced miR-421 expression, indicating that ß-catenin regulates the expression of miR-421 in lung cancer. Taken together, our findings reveal the critical role of miR-421 in paclitaxel drug resistance and its upstream and downstream regulatory mechanisms. Therefore, miR-421 may serve as a potential molecular therapeutic target in lung cancer, and AMOs may be a potential treatment strategy.

Real-world cardiovascular disease burden in patients with atherosclerotic cardiovascular disease: a comprehensive systematic literature review.

OBJECTIVE: Based on randomized controlled trials (RCTs), non-fatal myocardial infarction (MI) rates range between 9 and 15 events per 1000 person-years, ischemic stroke between 4 and 6 per 1000 person-years, CHD death rates between 5 and 7 events per 1000 person-years, and any major vascular event between 28 and 53 per 1000 person-years in patients with atherosclerotic cardiovascular disease (ASCVD). We reviewed global literature on the topic to determine whether the real-world burden of secondary major adverse cardiovascular events (MACEs) is higher among ASCVD patients. METHODS: We searched PubMed and Embase using MeSH/keywords including cardiovascular disease, secondary prevention and observational studies. Studies published in the last 5 years, in English, with ≥50 subjects with elevated low-density lipoprotein cholesterol (LDL-C) or on statins, and reporting secondary MACEs were included. The Newcastle-Ottawa Scale (NOS) was used to assess the quality of each included study. RESULTS: Of 4663 identified articles, 14 studies that reported MACE incidence rates per 1000 person-years were included in the review (NOS grades ranged from 8 to 9; 2 were prospective and 12 were retrospective studies). Reported incidence rates per 1000 person-years had a range (median) of 12.01-39.9 (26.8) for MI, 13.8-57.2 (41.5) for ischemic stroke, 1.0-94.5 (21.1) for CV-related mortality and 9.7-486 (52.6) for all-cause mortality. Rates were 25.8-211 (81.1) for composite of MACEs. Multiple event rates had a range (median) of 60-391 (183) events per 1000 person-years. CONCLUSIONS: Our review indicates that MACE rates observed in real-world studies are substantially higher than those reported in RCTs, suggesting that the secondary MACE burden and potential benefits of effective CVD management in ASCVD patients may be underestimated if real-world data are not taken into consideration.

Identification of mitoxantrone as a new inhibitor of ROS1 fusion protein in non-small cell lung cancer cells.

Mitoxantrone, an FDA-approved drug for multiple sclerosis and hormone refractory prostate cancer, is identified as a potent inhibitor of ROS1 fusion protein by in silico screening in non-small cell lung cancer cells. Mitoxantrone can suppress the phosphorylation of ROS1 and subsequently inhibit its downstream signaling pathway and thus induce cell apoptosis.

The Calcium-Induced Regulation in the Molecular and Transcriptional Circuitry of Human Inflammatory Response and Autoimmunity.

Rheumatoid arthritis synovial fibroblasts (RASFs) are fundamental effector cells in RA driving the joint inflammation and deformities. Celastrol is a natural compound that exhibits a potent anti-arthritic effect promoting endoplasmic reticulum (ER) stress mediated by intracellular calcium (Ca2+) mobilization. Ca2+ is a second messenger regulating a variety of cellular processes. We hypothesized that the compound, celastrol, affecting cytosolic Ca2+ mobilization could serve as a novel strategy to combat RA. To address this issue, celastrol was used as a molecular tool to assay the inflammatory gene expression profile regulated by Ca2+. We confirmed that celastrol treatment mobilized cytosolic Ca2+ in patient-derived RASFs. It was found that 23 genes out of 370 were manipulated by Ca2+ mobilization using an inflammatory and autoimmunity PCR array following independent quantitative PCR validation. Most of the identified genes were downregulated and categorized into five groups corresponding to their cellular responses participating in RA pathogenesis. Accordingly, a signaling network map demonstrating the possible molecular circuitry connecting the functions of the products of these genes was generated based on literature review. In addition, a bioinformatics analysis revealed that celastrol-induced Ca2+ mobilization gene expression profile showed a novel mode of action compared with three FDA-approved rheumatic drugs (methotrexate, rituximab and tocilizumab). To the best of our knowledge, this is a pioneer work charting the Ca2+ signaling network on the regulation of RA-associated inflammatory gene expression.

Rh2E2, a novel metabolic suppressor, specifically inhibits energy-based metabolism of tumor cells.

Energy metabolism in cancer cells is often increased to meet their higher proliferative rate and biosynthesis demands. Suppressing cancer cell metabolism using agents like metformin has become an attractive strategy for treating cancer patients. We showed that a novel ginsenoside derivative, Rh2E2, is as effective as aspirin in preventing the development of AOM/DSS-induced colorectal cancer and suppresses tumor growth and metastasis in a LLC-1 xenograft. A sub-chronic and acute toxicity LD50 test of Rh2E2 showed no harmful reactions at the maximum oral dosage of 5000 mg/kg body weight in mice. Proteomic profiling revealed that Rh2E2 specifically inhibited ATP production in cancer cells via down-regulation of metabolic enzymes involving glycolysis, fatty acid ß-oxidation and the tricarboxylic acid cycle, leading to specific cytotoxicity and S-phase cell cycle arrest in cancer cells. Those findings suggest that Rh2E2 possesses a novel and safe anti-metabolic agent for cancer patients by specific reduction of energy-based metabolism in cancer cells.

Assessment of algorithms to identify patients with thrombophilia following venous thromboembolism.

INTRODUCTION: Routine testing for thrombophilia following venous thromboembolism (VTE) is controversial. The use of large datasets to study the clinical impact of thrombophilia testing on patterns of care and patient outcomes may enable more efficient analysis of this practice in a wide range of settings. We set out to examine how accurately algorithms using International Classification of Diseases 9th Revision (ICD-9) codes and/or pharmacy data reflect laboratory-confirmed thrombophilia diagnoses. MATERIALS AND METHODS: A random sample of adult Kaiser Permanente Colorado patients diagnosed with unprovoked VTE between 1/2004 and 12/2010 underwent medical record abstraction of thrombophilia test results. Algorithms using "ICD-9" (positive if a thrombophilia ICD-9 code was present), "Extended anticoagulation (AC)" (positive if AC therapy duration was >6 months), and "ICD-9 & Extended AC" (positive for both) criteria to identify possible thrombophilia cases were tested. Using positive thrombophilia laboratory results as the gold standard, the sensitivity, specificity, positive predictive value (PPV), and negative predictive value of each algorithm were calculated, along with 95% confidence intervals (CIs). RESULTS: In our cohort of 636 patients, sensitivities were low (<50%) for each algorithm. "ICD-9" yielded the highest PPV (41.5%, 95% CI 26.3-57.9%) and a high specificity (95.9%, 95% CI 94.0-97.4%). "Extended AC" had the highest sensitivity but lowest specificity, and "ICD-9 & Extended AC" had the highest specificity but lowest sensitivity. CONCLUSIONS: ICD-9 codes for thrombophilia are highly specific for laboratory-confirmed cases, but all algorithms had low sensitivities. Further development of methods to identify thrombophilia patients in large datasets is warranted.

The impact of genomic testing on the recommendation for radiation therapy in patients with ductal carcinoma in situ: A prospective clinical utility assessment of the 12-gene DCIS score™ result.

BACKGROUND AND OBJECTIVES: Twenty percent of breast cancers are ductal carcinoma in situ (DCIS), with 15-60% having a local recurrence (LR) after surgery. Radiotherapy reduces LR by 50% but has not impacted survival. The validated Oncotype DX(®) 12-gene assay (DCIS Score) provides individualized 10-year LR estimates. This is the first study to assess whether DCIS Score impacts physicians' recommendations for radiation. METHODS: Ten sites enrolled women (9/2012-2/2014) with DCIS eligible for breast-conserving therapy, excluding patients with invasive carcinoma and planned mastectomy. Prospective data collected included clinicopathologic factors, DCIS Score assay, and treatment recommendation before and after the assay result was known. RESULTS: In 115 patients (median age: 61 years; 74.8% postmenopausal), median DCIS size was 8 mm; 20% were nuclear grade 1, 46.1% grade 2; 64.4% reported necrosis. 86.1% were ER+, 79.1% PR+ (immunohistochemistry assay). Median DCIS Score: 29 (range: 0-85). Pre-assay, 73% (95%CI: 64.0-80.9%) had radiotherapy recommendations vs. 59.1% (95%CI: 49.6-68.2%) post-assay (P= 0.008). Physicians rated DCIS Score as the most impactful factor in planning treatment. CONCLUSIONS: The radiotherapy recommendation changed from pre-assay to post-assay 31.3% (95%CI: 23.0-40.6%) of the time--a clinically significant change. This study supports the clinical utility of the DCIS Score and indicates that the test provides additional, individualized information on LR risk.

Fractional photothermolysis treatment of digital cutis laxa reverses hand disability.

In this case study, we present a safe and novel treatment for a patient with soft tissue hand disability caused by severe and chronic lupus and cutis laxa (CL). This patient was a woman in her 50s with a 20-year history of systemic lupus erythematous (SLE) and multiple sclerosis who developed hand disability because of the drastic loss of firmness in her soft tissue, extending from the dermis down to the ligaments. The likely cause was CL with SLE synovitis, exacerbated by corticosteroid tapering. Fractional photothermolysis (FP) LASER (Fraxel DUAL 1550/1927; Solta Medical) therapy profoundly alleviated her joint locking in addition to improving the firmness of the overlying skin to reverse her hand disability. This case illustrates a novel approach to CL hand treatment and the profound impact the treatment had on the patient's disabled hand. FP therapy is quick and safe, and its medical application to skin and joints should be further explored.

A retrospective study of the impact of 21-gene recurrence score assay on treatment choice in node positive micrometastatic breast cancer.

To assess clinical utility of the 21-gene assay (Oncotype DX® Recurrence Score®), we determined whether women with HER2(-)/ER+ pN1mi breast cancer with low (<18) Recurrence Scores results are given adjuvant chemotherapy in a lower proportion than those with high scores (≥31). This was a multicenter chart review of ≥18 year old women with pN1mi breast cancer, HER2(-)/ER+ tumors, ductal/lobular/mixed histology, with the assay ordered on or after 1 January 2007. One hundred and eighty one patients had a mean age of 60.7 years; 82.9% had ECOG performance status 0; 33.7% had hypertension, 22.7% had osteoporosis, 18.8% had osteoarthritis, and 8.8% had type-2 diabetes. Mean Recurrence Score was 17.8 (range: 0-50). 48.6% had a mastectomy; 55.8% had a lumpectomy. 19.8% of low-risk group patients were recommended chemotherapy vs. 57.9% in the intermediate-risk group and 100% in the high-risk group (p < 0.001). A total of 80.2% of the low-risk group were recommended endocrine therapy alone, while 77.8% of the high-risk group were recommended both endocrine and chemotherapy (p < 0.001). The Oncotype DX Recurrence Score result provides actionable information that can be incorporated into treatment planning for women with HER2(-)/ER+ pN1mi breast cancer. The Recurrence Score result has clinical utility in treatment planning for HER2(-)/ER+ pN1mi breast cancer patients.

Cost effectiveness of a 92-gene assay for the diagnosis of metastatic cancer.

OBJECTIVES: To estimate the clinical and economic trade-offs involved in using a molecular assay (92-gene assay, CancerTYPE ID) to aid in identifying the primary site of difficult-to-diagnose metastatic cancers and to explore whether the 92-gene assay can be used to standardize the diagnostic process and costs for clinicians, patients, and payers. METHODS: Four decision-analytic models were developed to project the lifetime clinical and economic impact of incorporating the 92-gene assay compared with standard care alone. For each model, total and incremental costs, life-years, quality-adjusted life-years (QALYs), incremental cost-effectiveness ratios (ICERs), and the proportion of patients treated correctly versus incorrectly were projected from the payer perspective. Model inputs were based on published literature, analyses of SEER (Surveillance Epidemiology and End RESULTS) data, publicly available data, and interviews with clinical experts. RESULTS: In all four models, the 92-gene assay increased the proportion of patients treated correctly, decreased the proportion of patients treated with empiric therapy, and increased quality-adjusted survival. In the primary model, the ICER was $50,273/QALY; thus, the 92-gene assay is therefore cost effective when considering a societal willingness-to-pay threshold of $100,000/QALY. These findings were robust across sensitivity analyses. CONCLUSIONS: Use of the 92-gene assay for diagnosing metastatic tumors of uncertain origin is associated with reduced misdiagnoses, increased survival, and improved quality of life. Incorporating the assay into current practice is a cost-effective approach to standardizing diagnostic methods while improving patient care. Limitations of this analysis are the lack of data availability and resulting modeling simplifications, although sensitivity analyses showed these to not be key drivers of results.

Ginsenoside compound K induces apoptosis in nasopharyngeal carcinoma cells via activation of apoptosis-inducing factor.

BACKGROUND: Nasopharyngeal carcinoma (NPC) has a high incidence rate in Southern China. Although there are conventional therapies, the side effects and toxicities are not always tolerable for patients. Recently, the tumoricidal effect of ginsenosides on different cancer cells has been studied. This study aims to investigate the anti-cancer effect of ginsenosides on NPC cells and their underlying mechanism. METHODS: The cytotoxicity of ginsenosides on NPC cell line HK-1 was measured by MTT assay. Apoptosis was detected by propidium iodide staining followed by flow cytometry. A xenograft tumor model was established by injecting nude mice with HK-1 cells. The activation of caspases and apoptosis-inducing factor (AIF) were evaluated by Western blot analysis. Nuclear translocation of AIF was also studied by immunofluorescence staining. Mitochondrial membrane potential was measured by JC-1 dye using flow cytometry. RESULTS: Four ginsenosides, 20 (S)-Rh2, compound K (CK), panaxadiol (PD) and protopanaxadiol (PPD), induced apoptotic cell death in HK-1 cells in a concentration-dependent manner. CK inhibited HK-1 xenograft tumor growth most extensively and depleted mitochondrial membrane potential depolarization and induced translocation of AIF from cytoplasm to nucleus in HK-1 cells. In addition, depletion of AIF by siRNA abolished CK-induced HK-1 cell death. CONCLUSION: Ginsenoside CK-induced apoptosis of HK-1 cells was mediated by the mitochondrial pathway and could significantly inhibit tumor growth in vivo.

Proteome profiling of spinal cord and dorsal root ganglia in rats with trinitrobenzene sulfonic acid-induced colitis.

AIM: To investigate proteomic changes in spinal cord and dorsal root ganglia (DRG) of rats with trinitrobenzene sulfonic acid (TNBS)-induced colitis. METHODS: The colonic myeloperoxidase (MPO) activity and tumor necrosis factor-α (TNF-α) level were determined. A two-dimensional electrophoresis (2-DE)-based proteomic technique was used to profile the global protein expression changes in the DRG and spinal cord of the rats with acute colitis induced by intra-colonic injection of TNBS. RESULTS: TNBS group showed significantly elevated colonic MPO activity and increased TNF-α level. The proteins derived from lumbosacral enlargement of the spinal cord and DRG were resolved by 2-DE; and 26 and 19 proteins that displayed significantly different expression levels in the DRG and spinal cord were identified respectively. Altered proteins were found to be involved in a number of biological functions, such as inflammation/immunity, cell signaling, redox regulation, sulfate transport and cellular metabolism. The overexpression of the protein similar to potassium channel tetramerisation domain containing protein 12 (Kctd 12) and low expression of proteasome subunit α type-1 (psma) were validated by Western blotting analysis. CONCLUSION: TNBS-induced colitis has a profound impact on protein profiling in the nervous system. This result helps understand the neurological pathogenesis of inflammatory bowel disease.

Toxicity and endocytosis of spinocerebellar ataxia type 6 polyglutamine domains: role of myosin IIb.

Spinocerebellar ataxia type 6 (SCA6) is a dominantly inherited neurodegenerative disease caused by a small expansion of CAG repeats in the sequence coding for the cytoplasmic C-terminal region of the Ca(v)2.1 subunit of P/Q-type calcium channels. We have tested the toxicity of mutated Ca(v)2.1 C-terminal domains expressed in the plasma membrane. In COS-7 cells, CD4-green fluorescent protein fused to Ca(v)2.1 C-terminal domains containing expanded 24 polyglutamine (Q) tracts displayed increased toxicity and stronger expression at the cell surface relative to 'normal' 12 Q tracts, partially because of reduced endocytosis. Glutathione S-transferase pull-down and proteomic analysis indicated that Ca(v)2.1 C-termini interact with the heavy and light chains of cerebellar myosin IIB, a molecular motor protein. This interaction was confirmed by coimmunoprecipitation from rat cerebellum and COS-7 cells and shown to be direct by binding of in vitro-translated (35)S-myosin IIB heavy chain. In COS-7 cells, incremented polyglutamine tract length increased the interaction with myosin IIB. Furthermore, the myosin II inhibitor blebbistatin reversed the effects of polyglutamine expansion on plasma membrane expression. Our findings suggest a key role of myosin IIB in promoting accumulation of mutant Ca(v)2.1Ct at the plasma membrane and suggest that this gain of function might contribute to the pathogenesis of SCA6.

The CT motion quantitation of lung lesions and its impact on PET-measured SUVs.

UNLABELLED: We previously reported that respiratory motion is a major source of error in quantitation of lesion activity using combined PET/CT units. CT acquisition of the lesion occurs in seconds, rather than the 4-6 min required for PET emission scans. Therefore, an incongruent lesion position during CT acquisition will bias activity estimates using PET. In this study, we systematically analyzed the range of activity concentration changes, hence SUV, for lung lesions. METHODS: Five lung cancer patients were scanned with PET/CT. In CT, data were acquired in correlation with the real-time positioning. CT images were acquired, in cine mode, at 0.45-s intervals for slightly longer (1 s) than a full respiratory cycle at each couch position. Other scanning parameters were a 0.5-s gantry rotation, 140 kVp, 175 mA, 10-mm couch increments, and a 2.5-mm slice thickness. PET data were acquired after intravenous injection of about 444-555 MBq of (18)F-FDG with a 1-h uptake period. The scanning time was 3 min per bed position for PET. Regularity in breathing was assisted by audio coaching. A commercial software program was then used to sort the acquired CT images into 10 phases, with 0% corresponding to end of inspiration (EI) and 50% corresponding to end of expiration (EE). Using the respiration-correlated CT data, images were rebinned to match the PET slice locations and thickness. RESULTS: We analyzed 8 lesions from 5 patients. Reconstructed PET emission data showed up to a 24% variation in the lesion maximum standardized uptake values (SUVs) between EI and EE phases. Examination of all the phases showed an SUV variation of up to 30%. Also, in some cases the lesion showed up to a 9-mm shift in location and up to a 21% reduction in size when measured from PET during the EI phase, compared with during the EE phase. CONCLUSION: Using respiration-correlated CT for attenuation correction, we were able to quantitate the fluctuations in PET SUVs. Because those changes may lead to estimates of lower SUVs, the respiratory phase during CT transmission scanning needs to be measured or lung motion has to be regulated for imaging lung cancer in routine clinical practice.