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.

Multiple sclerosis and environmental risk factors: a case-control study in Iran

Studies have shown an increase in the incidence of MS in Iran. The aim of our study was to evaluate the relationship between environmental exposure and MS in Iran. This case-control study was conducted on 660 MS patients and 421 controls. Many environmental factors are compared between the two groups. Our findings demonstrated that prematurity ([OR = 4.99 (95% CI 1.34–18.68), P = 0.017]), history of measles and mumps ([OR = 1.60 (95% CI 1.05–2.45), P = 0.029; OR = 1.85 (95% CI 1.22–2.78), P = 0.003, respectively]), breast feeding [OR = 2.90 (95% CI 1.49–5.65), P = 0.002], head trauma in childhood ([OR = 8.21 (95% CI 1.56–43.06), P = 0.013]), vaccination in adulthood ([OR = 4.57 (95% CI 1.14–18.41), P = 0.032, respectively]), migraine ([OR = 3.50 (95% CI 1.61–7.59), P = 0.002]), family history of MS, IBD, migraine, and collagen vascular diseases ([OR = 2.73 (95% CI 1.56–4.78), P < 0.001], [OR = 3.14 (95% CI 1.460–6.78), P = 0.004; OR = 3.18 (95% CI 1.83–5.53), P < 0.001; OR = 1.81 (95% CI 1.03–3.20), P = 0.040, respectively]), stressful events ([OR = 32.57 (95% CI 17.21–61.64), P < 0.001]), and microwave exposure ([OR = 3.55 (95% CI 2.24–5.63), P ≤0.001]) were more in the MS group. Sun exposure ([OR = 0.09 (95% CI 0.02–0.38), P = 0.001]), dairy and calcium consumption ([OR = 0.44 (95% CI 0.27–0.71), P = 0.001]), diabetes mellitus ([OR = 0.11 (95% CI 0.01–00.99), P = 0.049], and complete vaccination during childhood appeared to decreased MS risk. Our results investigated many risk factors and protective factors in Iran.     

Stroke as a Neurological Complication of COVID-19: A Systematic Review and Meta-Analysis of Incidence,Outcomes and Predictors

IntroductionCOVID-19 is a multi-system infection which predominantly affects the respiratory system, but also causes systemic inflammation, endothelialitis and thrombosis. The consequences of this include renal dysfunction, hepatitis and stroke. In this systematic review, we aimed to evaluate the epidemiology, clinical course, and outcomes of patients who suffer from stroke as a complication of COVID-19.MethodsWe conducted a systematic review of all studies published between November 1, 2019 and July 8, 2020 which reported on patients who suffered from stroke as a complication of COVID-19.Results326 studies were screened, and 30 studies reporting findings from 55,176 patients including 899 with stroke were included. The average age of patients who suffered from stroke as a complication of COVID-19 was 65.5 (Range: 40.4–76.4 years). The average incidence of stroke as a complication of COVID-19 was 1.74% (95% CI: 1.09% to 2.51%). The average mortality of stroke in COVID-19 patients was 31.76% (95% CI: 17.77% to 47.31%). These patients also had deranged clinical parameters including deranged coagulation profiles, liver function tests, and full blood counts.ConclusionAlthough stroke is an uncommon complication of COVID-19, when present, it often results in significant morbidity and mortality. In COVID-19 patients, stroke was associated with older age, comorbidities, and severe illness.     

Respiratory cycle entrainment of septal neurons mediates the fast coupling of sniffing rate and hippocampal theta rhythm

Memory for odour information may result from temporal coupling between the olfactory and hippocampal systems. Respiration defines the frequency of olfactory perception, but how the respiratory rate affects hippocampal oscillations remains poorly understood. The afferent connectivity of the medial septum/diagonal band of Broca complex (MS/DB) proposes this region as a crossroads between respiratory and limbic pathways. Here we investigate if the firing rates of septal neurons integrate respiratory rate signals. We demonstrate that approximately 50% of MS/DB neurons are temporally correlated with sniffing frequency. Moreover, a group of slow‐spiking septal neurons are phase‐locked to the sniffing cycle. We show that inter‐burst intervals of MS/DB theta cells relate to the sniff rate. Intranasal odour infusion evokes sniff phase preference for the activity of fast‐spiking MS/DB neurons. Concurrently, the infusion augments the correlation between sniffing and limbic theta oscillations. During periods of sniffing–theta correlation, CA1 place cells fired preferentially during the inhalation phase, suggesting the theta cycle as a coherent time frame for central olfactory processing. Furthermore, injection of the GABAergic agonist muscimol into medial septum induces a parallel decrease of sniffing and theta frequencies. Our findings provide experimental evidence that MS/DB does not merely generate theta rhythm, but actively integrates sensorimotor stimuli that reflect sniffing rate. Such integration may provide temporal oscillatory synchronisation of MS/DB‐innervated limbic structures with the sniffing cycle.     

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.