Chest radiography: optimization of X-ray spectrum for cesium iodide-amorphous silicon flat-panel detector

PURPOSE: To ascertain the optimum x-ray spectrum for chest radiography with a cesium iodide-amorphous silicon flat-panel detector. MATERIALS AND METHODS: End points for optimization included the ratio of tissue contrast to bone contrast and a figure of merit (FOM) equal to the square of the signal-to-noise ratio of tissue divided by incident exposure to the patient. Studies were conducted with both computer spectrum modeling and experimental measurement in narrow-beam and full-field exposure conditions for four tissue thicknesses (8-32 cm). Three parameters that affect spectra were considered: the atomic number (Z) of filter material (Z = 13, 26, 29, 42, 50, 56, 64, 74, and 82), kilovoltage (from 50 to 150 kVp), and filter thickness (from 0.25 to 2.00 half-value layer [HVL]). RESULTS: Computer modeling and narrow-beam experimental data showed similar trends for the full range of parameters evaluated. Spectrum model results showed that copper filtration at 120 kVp or more was optimum for FOM. The ratio of contrasts showed a trend to be higher with higher kilovoltage and only a minor variation with filter material. Full-field experimental results, which reflect the added contribution of x-ray scatter, differed in magnitude but not trends from the narrow-beam data in all cases except the ratio of contrasts in the mediastinum. CONCLUSION: The best performance overall, including both FOM and ratio of contrasts, was at 120 kVp with 1-HVL copper filtration (0.2 mm). With this beam spectrum and an increase in tube output (ie, milliampere seconds) of about 50%, a chest radiograph can be obtained with image quality approximately equal to that with a conventional spectrum but with about 25% less patient exposure.     

Long-term results of endovascular repair for descending thoracic aortic aneurysms

Objective

Since thoracic endovascular aortic repair (TEVAR) received U.S. Food and Drug Administration approval for the treatment of descending thoracic aneurysms in March 2005, excellent 30-day and midterm outcomes have been described. However, data on long-term outcomes are lacking with Medicare data suggesting that TEVAR has worse late survival compared with open descending repair. As such, the purpose of this study was to examine the long-term outcomes for on-label use of TEVAR for repair of descending thoracic aneurysms.

Intracerebral migration of stray bullet leading to sudden and fatal worsening

Gunshot wounds to the cranium are one of the leading cause of death and disability in young adults. Stray bullets are also being increasingly seen in clinical setting. We report a case of a 14-year-old boy who sustained a stray bullet to the cranium during election festivities. He arrived at the health care facility institution nearly 24 hours after the event in good neurological condition. He remained neurologically stable for about 8 hours after his presentation and later on deteriorated due to intracranial bullet migration. This required immediate bifrontal decompressive craniotomy along with right frontal lobectomy. However, the patient could not survive.     

Association of left ventricular hypertrophy with high-sensitive C-reactive protein in hemodialysis patients

Background

Micro inflammation and cardiovascular disease such as left ventricular hypertrophy (LVH) are common in hemodialysis (HD) patients. Hence, we have evaluated the relationship between high-sensitive C-reactive protein (hs-CRP), as an inflammation marker, and left ventricular mass index (LVMi) and left ventricular mass (LVM) in HD patients.

Methods

An analytical cross-sectional study was performed in 104 HD patients. Serum hs-CRP, LVMi, LVM, and blood pressure were evaluated; demographic data and duration of HD were also recorded. Finally, results were analyzed by using Student’s t test, Pearson’s correlation coefficient, one-way ANOVA and multiple regression to determine the relationship between LVMi and other variables.

Results

A total of 66 male patients (63.46 %) and 38 female patients, with a mean age of 51.75 ± 15.98 years-old, participated in this study. Hypertension was the most common underlying disease (65.4 %). The mean LVMi was 366.98 ± 120.89 g/m² and the mean hs-CRP was 8.55 mg/l. Eighty-nine percent of patients had LVH. The hs-CRP level was significantly associated with age and with LVM (P = 0.0001, P = 0.039, respectively). On multivariate analysis, hs-CRP and systolic blood pressure were found to be independent predictors of LVM and LVMi.

Conclusions

This study shows that hs-CRP and systolic BP are independent predictors of LVH in HD patients.     

Anticancer properties of green-synthesised zinc oxide nanoparticles using Hyssopus officinalis extract on prostate carcinoma cells and its effects on testicular damage and spermatogenesis in Balb/C mice

The unclear bio-safety issue and potential risk of nanoparticles (NPs) on various organelles can be considered as a major challenge. In the present study, we have assessed the green synthesis of ZnO nanoparticles using Hyssop (Hyssopus officinalis) extract and their effects on PC3 cell line and BALB/c mice model. The cytotoxicity of the ZnO-NPs was assessed on PC3 cell line by MTT test after characterisation. Apoptotic effect of ZnO-NPs was determined by in vitro AO/PI staining. The histopathological assessments and determination of LH and FSH levels carried out as in vivo analysis in BALB/c adult male mice. The expression of major genes involved in spermatogenesis and sperm maturation (Adam3, Prm1, Spata19, Tnp2, Gpx5) were also analysed. The obtained result demonstrated that the IC₅₀ for PC3 cell line treated with green-synthesised ZnO-NPs during 24 and 48 hr was reported 8.07 and 5 µg/ml respectively. Meanwhile, the induced apoptosis was recorded 26.6% ± 0.05, 44% ± 0.12 and 80% ± 0.07 of PC3 cells. The results of gene expression analysis revealed that the increase in the concentration of ZnO-NPs significantly (p < .05) down-regulated the Adam3, Prm1, Spata-19, Tnp2 and Gpx5 genes. The overall results of this research elucidated that ZnO-NPs impaired spermatogenesis, sperm maturation process and sperm motility.     

No effect of risedronate on femoral periprosthetic bone loss following total hip arthroplasty: A 4-year follow-up of 61 patients in a double-blind,randomized placebo-controlled trial

Background and purpose

We have previously shown that during the first 2 years after total hip arthroplasty (THA), periprosthetic bone resorption can be prevented by 6 months of risedronate therapy. This follow-up study investigated this effect at 4 years.

Patients and methods

A single-center, double-blind, randomized placebo-controlled trial was carried out from 2006 to 2010 in 73 patients with osteoarthritis of the hip who were scheduled to undergo THA. The patients were randomly assigned to receive either 35 mg risedronate or placebo orally, once a week, for 6 months postoperatively. The primary outcome was the percentage change in bone mineral density (BMD) in Gruen zones 1 and 7 in the proximal part of the femur at follow-up. Secondary outcomes included migration of the femoral stem and clinical outcome scores.

Results

61 of the 73 patients participated in this 4-year (3.9- to 4.1-year) follow-up study. BMD was similar in the risedronate group (n = 30) and the placebo group (n = 31). The mean difference was −1.8% in zone 1 and 0.5% in zone 7. Migration of the femoral stem, the clinical outcome, and the frequency of adverse events were similar in the 2 groups.

Interpretation

Although risedronate prevents periprosthetic bone loss postoperatively, a decrease in periprosthetic BMD accelerates when therapy is discontinued, and no effect is seen at 4 years. We do not recommend the use of risedronate following THA for osteoarthritis of the hip.Adaptive bone remodeling around the femoral stem following total hip arthroplasty (THA) results in regional loss of bone mass, especially in proximal parts of the femur—most of which takes place within the first postoperative year (Bodén et al. 2006, Sköldenberg et al. 2006). Periprosthetic bone loss may predispose to periprosthetic fracture, aseptic loosening, and difficulties at revision surgery (Lindahl 2007, Streit et al. 2011, Sköldenberg et al. 2014).The bisphosphonate (BP) risedronate has been used successfully to prevent osteoporotic fractures, mainly in the hip and vertebrae, by inhibiting osteoclast activity (McClung et al. 2001). In recent years, the possible use of BPs to prevent or ameliorate periprosthetic adaptive bone resorption, osteolysis, and implant migration has been investigated thoroughly in animal models and humans. The short-term results of several studies showing the effects of postoperative BP treatment in reducing periprosthetic bone loss up to a year after the arthroplasty have already been published (Venesmaa et al. 2001, Wilkinson et al. 2001, Hennigs et al. 2002, Wilkinson et al. 2005, Arabmotlagh et al. 2006).We have previously found that risedronate given once a week for 6 months after THA reduces periprosthetic bone resorption around an uncemented femoral stem in the first and second postoperative year (Sköldenberg et al. 2011). We now report the 4-year outcome in the same cohort.     

The effects of diode laser (660 nm) on the rate of tooth movements: an animal study

Lasers in Medical Science - Low-level laser has been indicated to have the capability to facilitate the differentiation of the osteoclastic and osteoblastic cells which are responsible for the bone...