Quantitative Modeling of Cerenkov Light Production Efficiency from Medical Radionuclides

There has been recent and growing interest in applying Cerenkov radiation (CR) for biological applications. Knowledge of the production efficiency and other characteristics of the CR produced by various radionuclides would help in accessing the feasibility of proposed applications and guide the choice of radionuclides. To generate this information we developed models of CR production efficiency based on the Frank-Tamm equation and models of CR distribution based on Monte-Carlo simulations of photon and β particle transport. All models were validated against direct measurements using multiple radionuclides and then applied to a number of radionuclides commonly used in biomedical applications. We show that two radionuclides, Ac-225 and In-111, which have been reported to produce CR in water, do not in fact produce CR directly. We also propose a simple means of using this information to calibrate high sensitivity luminescence imaging systems and show evidence suggesting that this calibration may be more accurate than methods in routine current use

f(R) theories

Over the past decade, f(R) theories have been extensively studied as one of the simplest modifications to General Relativity. In this article we review various applications of f(R) theories to cosmology and gravity - such as inflation, dark energy, local gravity constraints, cosmological perturbations, and spherically symmetric solutions in weak and strong gravitational backgrounds. We present a number of ways to distinguish those theories from General Relativity observationally and experimentally. We also discuss the extension to other modified gravity theories such as Brans-Dicke theory and Gauss-Bonnet gravity, and address models that can satisfy both cosmological and local gravity constraints.Comment: 156 pages, 14 figures, Invited review article in Living Reviews in Relativity, Published version, Comments are welcom

Rapid Internalization of the Oncogenic K+ Channel KV10.1

KV10.1 is a mammalian brain voltage-gated potassium channel whose ectopic expression outside of the brain has been proven relevant for tumor biology. Promotion of cancer cell proliferation by KV10.1 depends largely on ion flow, but some oncogenic properties remain in the absence of ion permeation. Additionally, KV10.1 surface populations are small compared to large intracellular pools. Control of protein turnover within cells is key to both cellular plasticity and homeostasis, and therefore we set out to analyze how endocytic trafficking participates in controlling KV10.1 intracellular distribution and life cycle. To follow plasma membrane KV10.1 selectively, we generated a modified channel of displaying an extracellular affinity tag for surface labeling by α-bungarotoxin. This modification only minimally affected KV10.1 electrophysiological properties. Using a combination of microscopy and biochemistry techniques, we show that KV10.1 is constitutively internalized involving at least two distinct pathways of endocytosis and mainly sorted to lysosomes. This occurs at a relatively fast rate. Simultaneously, recycling seems to contribute to maintain basal KV10.1 surface levels. Brief KV10.1 surface half-life and rapid lysosomal targeting is a relevant factor to be taken into account for potential drug delivery and targeting strategies directed against KV10.1 on tumor cells

Identification of sixteen novel candidate genes for late onset Parkinson’s disease

Background Parkinson’s disease (PD) is a neurodegenerative movement disorder affecting 1–5% of the general population for which neither effective cure nor early diagnostic tools are available that could tackle the pathology in the early phase. Here we report a multi-stage procedure to identify candidate genes likely involved in the etiopathogenesis of PD. Methods The study includes a discovery stage based on the analysis of whole exome data from 26 dominant late onset PD families, a validation analysis performed on 1542 independent PD patients and 706 controls from different cohorts and the assessment of polygenic variants load in the Italian cohort (394 unrelated patients and 203 controls). Results Family-based approach identified 28 disrupting variants in 26 candidate genes for PD including PARK2, PINK1, DJ-1(PARK7), LRRK2, HTRA2, FBXO7, EIF4G1, DNAJC6, DNAJC13, SNCAIP, AIMP2, CHMP1A, GIPC1, HMOX2, HSPA8, IMMT, KIF21B, KIF24, MAN2C1, RHOT2, SLC25A39, SPTBN1, TMEM175, TOMM22, TVP23A and ZSCAN21. Sixteen of them have not been associated to PD before, were expressed in mesencephalon and were involved in pathways potentially deregulated in PD. Mutation analysis in independent cohorts disclosed a significant excess of highly deleterious variants in cases (p = 0.0001), supporting their role in PD. Moreover, we demonstrated that the co-inheritance of multiple rare variants (≥ 2) in the 26 genes may predict PD occurrence in about 20% of patients, both familial and sporadic cases, with high specificity (> 93%; p = 4.4 × 10− 5). Moreover, our data highlight the fact that the genetic landmarks of late onset PD does not systematically differ between sporadic and familial forms, especially in the case of small nuclear families and underline the importance of rare variants in the genetics of sporadic PD. Furthermore, patients carrying multiple rare variants showed higher risk of manifesting dyskinesia induced by levodopa treatment. Conclusions Besides confirming the extreme genetic heterogeneity of PD, these data provide novel insights into the genetic of the disease and may be relevant for its prediction, diagnosis and treatment

Plasma antidiuretic hormone levels in children with spina bifida

Purpose: Urological management of spina bifida patients is controversial. The goals of therapy of neurogenic bladder are continence, prevention of infections and preservation of urinary tract. Desmopressin has been recently used in a spina bifida population that is dry during the day (daytime continence was achieved with clean intermittent catheterization and anticholinergics) but wet at night. The aim of this study was to assess plasma antidiuretic hormone (ADH) levels in these children. Materials and Methods: The study included 24 patients, 11 males and 13 females (mean age 6.4 years) referred to the Spina Bifida Centre of the Catholic University of Rome, and 57 normal age-matched controls. Morning (07.30-08.00 h) plasma ADH levels were measured using a specific radioimmunoassay. Results: Plasma ADH levels (normal range 5-11 mug/l) did not differ between spina bifida population and healthy controls. Serum ADH had a mean of 6.8 mug/l in affected children and a mean of 7.4 mug/l in the controls. Conclusion:We conclude that the use of desmopressin in children with spina bifida should be reserved only in patients with decreased secretion of ADH, or may be useful in patients with persistent nocturnal incontinence to reduce night wetting. Therefore, research with a larger population is needed. Copyright (C) 2002 S. Karger AG, Basel

Efficacy of one-year maintenance in early adjuvant chemotherapy for intermediate risk non-muscle-invasive bladder cancer. Preliminary results of a randomized cooperative trial.

Introduction and Objective: The clinical value of early intravesical adjuvant chemotherapy after TUR of intermediate risk non-muscle-invasive bladder cancer (NMI TCCB) is well established. On the other hand, the optimal schedule regimen and the role of maintenance are still debated. The aim of the present study was to evaluate the effectiveness of one-year maintenance schedule in patients submitted to TUR plus adjuvant early intravesical chemotherapy. Methods: Between May 2002 and August 2003, 577 patients, were recruited. All patients underwent TUR and early (within 6 hours) intravesical chemotherapy with epirubicin at the dose of 80 mg diluted in 60 ml of saline solution. When histology was available, 95 patients were excluded from the study since they were harbouring T1G3, Tis or single and primary Ta G1-G2 tumors. Four hundred eighty-two patients with intermediate risk NMI TCCB were randomized according 2 different intravesical instillation schedules: Arm A, 5 more weekly instillations; arm B, 5 more weekly instillations followed by monthly instillations for a total of 16 instillations. All patients were submitted 3-monthly for the first 2-years and then 6-monthly to cytology, cystoscopy and biopsy of every suspicious bladder lesion. Results: Out of 482 randomized patients, 396 are evaluable for toxicity and 392 for efficacy. The tumours were multiple in 318 patients (66.0%) and recurrent in 192 (39.8%). No difference emerged between the 2 arms in relation to tumors’ characteristics. The median follow-up time was 22 months (range: 3-56). Eighty-two (20.9%) patients recurred at a median time of 9 months from TUR. Four patients progressed (1%). The recurrence rate was 24.5% (47/192) in arm A and 17.5% (35/200) in arm B (p=0.05). No difference was evident between the two arms for recurrence rate at 3 months (p=0.06). However, an advantage in favour of maintenance emerged in terms of recurrence rate at 6 (p=0.01), 9 (p=0.04) and 12 months (p=0.03) and in terms of recurrence-free interval (p=0.03). No difference for toxicity was evident according to treatment schedule. Conclusions: A preliminary analysis at 2-year mean follow-up, in patients with intermediate risk NMI TCCB treated with early epirubicin intravesical chemotherapy followed by 5 weekly instillation, the risk of tumour recurrence is significantly reduced without enhanced toxicity by one-year maintenance