Radiotherapy for breast cancer induced long-term diminished accumulation of radiotracer on bone scan of the irradiated ribs

Radiotherapy may result in long term effects and composition alterations in bones. Bone scintigraphy after radiotherapy may demonstrate decreased skeletal uptake; however, this is a transient effect with bone scan normalized after a few years. We describe a case of a 31-year-old female patient treated for left breast cancer with chemotherapy and radiotherapy, exhibiting reduced and diffuse diphosphonate uptake in the heavily irradiated sections of left ribs, even twelve years post-treatment. Similarly, quantitative computed tomography indicated altered bone composition. To our knowledge this is the first case describing such a long radiation side effect in breast cancer treatment

Gender specific association of decreased bone mineral density in patients with epilepsy

Objective To evaluate whether epilepsy or certain antiepileptic drugs render patients prone to develop low bone mineral density (BMD) and osteoporosis risk. Methods Thirty-eight (27 males, 11 females) consecutive adult epileptic patients receiving antiepileptic drugs (AEDs) and 71 control individuals matched for race, gender, age and body mass index (BMI) were subjected to dual energy X-ray absorptiometry (DXA). Results The mean lumbar spine and total hip BMD values were lower in the patients compared to control group (0.90±0.24g/cm2 vs 1.04±0.14g/cm2, p<0.001 and 0.92±0.14g/cm2 vs 0.99±0.13g/cm2, p=0.02, respectively). At the same skeletal sites, male patients had significantly reduced BMD compared to control males (0.90±0.21g/cm2 vs 1.03±0.15g/cm2, p=0.004 and 0.93±0.14g/cm2 vs 1.02±0.13g/cm2, p=0.009, respectively) while there was a trend but no significant differences in females. This BMD reduction was independent of AED type. Conclusion Adult epileptic, predominantly male patients have lower BMD and could be screened with densitometry for early diagnosis and prevention of osteoporosis

A new FRDA mouse model [Fxnnull:YG8s(GAA) > 800] with more than 800 GAA repeats

Introduction: Friedreich’s ataxia (FRDA) is an inherited recessive neurodegenerative disorder caused by a homozygous guanine-adenine-adenine (GAA) repeat expansion within intron 1 of the FXN gene, which encodes the essential mitochondrial protein frataxin. There is still no effective therapy for FRDA, therefore the development of optimal cell and animal models of the disease is one of the priorities for preclinical therapeutic testing. Methods: We obtained the latest FRDA humanized mouse model that was generated on the basis of our previous YG8sR, by Jackson laboratory [YG8JR, Fxnnull:YG8s(GAA) > 800]. We characterized the behavioral, cellular, molecular and epigenetics properties of the YG8JR model, which has the largest GAA repeat sizes compared to all the current FRDA mouse models. Results: We found statistically significant behavioral deficits, together with reduced levels of frataxin mRNA and protein, and aconitase activity in YG8JR mice compared with control Y47JR mice. YG8JR mice exhibit intergenerational GAA repeat instability by the analysis of parent and offspring tissue samples. Somatic GAA repeat instability was also detected in individual brain and cerebellum tissue samples. In addition, increased DNA methylation of CpG U13 was identified in FXN GAA repeat region in the brain, cerebellum, and heart tissues. Furthermore, we show decreased histone H3K9 acetylation and increased H3K9 methylation of YG8JR cerebellum tissues within the FXN gene, upstream and downstream of the GAA repeat region compared to Y47JR controls. Discussion: These studies provide a detailed characterization of the GAA repeat expansion-based YG8JR transgenic mouse models that will help investigations of FRDA disease mechanisms and therapy.Friedreich’s Ataxia Research Alliance (FARA) (2018) and Brunel University London (BRIEF Award; 2019)

Dose measurements and calculations in the epithermal neutron beam at the Brookhaven Medical Research Reactor (BMRR)

The characteristics of the epithermal neutron beam at BMRR were measured, calculated, and reported. This beam has already been used for animal irradiations. We anticipate that it will be used for clinical trials. Thermal and epithermal neutron flux densities distributions, and dose rate distributions, as a function of depth were measured in a lucite dog-head phantom. Monte Carlo calculations were performed and compared with the measured values. 2 refs., 4 figs., 1 tab

Risk factors in spinal bone mineral densitometry

Absorptiometric methods have gained widespread use in quantification of bone mineral density, particularly for the assessment of fracture risk in osteoporosis. The aim of the present study was to determine the radiation burden to patients and operators related to the assessment of bone mineral status in the spine using either dual X ray absorptiometry (DXA), or single energy spectrum quantitative computed tomography (SE-QCT). Effective dose to adult patients from spinal bone mineral density measurement was found to be in the order of 1 μSv in DXA and 100 μSv in SE-QCT. The radiation burden to the operators was found to be low