Effects of laser irradiation (670-nm InGaP and 830-nm GaAlAs) on burn of second-degree in rats

This study investigated the effects of 670-nm indium gallium phosphide (InGaP) and 830-nm gallium aluminum arsenide (GaAlAs) laser therapy on second-degree burns induced on the back of Wistar rats. Sixty-three male Wistar rats were anesthetized, and second-degree burns were made on their back. The animals were then divided randomly into three groups: control (C), animals treated with 670-nm InGaP laser (LIn), and animals treated with 830-nm GaAlAs laser (LGa). The wound areas were removed after 2, 6, 10, 14, and 18 days of treatment and submitted to structural and morphometric analysis. The following parameters were studied: total number of granulocytes and fibroblasts, number of newly formed blood vessels, and percentage of birefringent collagen fibers in the repair area. Morphometric analysis showed that different lasers 670-nm InGaP and 830-nm GaAlAs reduced the number of granulocytes and an increase of newly formed vessels in radiated lesions. The 670-nm InGaP laser therapy was more effective in increasing the number of fibroblasts. The different treatments modified the expression of VEGF and TGF-β1, when compared with lesions not irradiated. The different types of light sources showed similar effects, improved the healing of second-degree burns and can help for treating this type of injury. Despite the large number of studies with LLTI application in second-degree burns, there is still divergence about the best irradiation parameters to be used. Further studies are needed for developing a protocol effective in treating this type of injury.     

Clinical and Cost Effectiveness of Hexaminolevulinate-guided Blue-light Cystoscopy: Evidence Review and Updated Expert Recommendations

Context

Non–muscle-invasive bladder cancer (NMIBC) is associated with a high recurrence risk, partly because of the persistence of lesions following transurethral resection of bladder tumour (TURBT) due to the presence of multiple lesions and the difficulty in identifying the exact extent and location of tumours using standard white-light cystoscopy (WLC). Hexaminolevulinate (HAL) is an optical-imaging agent used with blue-light cystoscopy (BLC) in NMIBC diagnosis. Increasing evidence from long-term follow-up confirms the benefits of BLC over WLC in terms of increased detection and reduced recurrence rates.

Objective

To provide updated expert guidance on the optimal use of HAL-guided cystoscopy in clinical practice to improve management of patients with NMIBC, based on a review of the most recent data on clinical and cost effectiveness and expert input.

Evidence acquisition

PubMed and conference searches, supplemented by personal experience.

Evidence synthesis

Based on published data, it is recommended that BLC be used for all patients at initial TURBT to increase lesion detection and improve resection quality, thereby reducing recurrence and improving outcomes for patients. BLC is particularly useful in patients with abnormal urine cytology but no evidence of lesions on WLC, as it can detect carcinoma in situ that is difficult to visualise on WLC. In addition, personal experience of the authors indicates that HAL-guided BLC can be used as part of routine inpatient cystoscopic assessment following initial TURBT to confirm the efficacy of treatment and to identify any previously missed or recurrent tumours. Health economic modelling indicates that the use of HAL to assist primary TURBT is no more expensive than WLC alone and will result in improved quality-adjusted life-years and reduced costs over time.

Conclusions

HAL-guided BLC is a clinically effective and cost-effective tool for improving NMIBC detection and management, thereby reducing the burden of disease for patients and the health care system.

Patient summary

Blue-light cystoscopy (BLC) helps the urologist identify bladder tumours that may be difficult to see using standard white-light cystoscopy (WLC). As a result, the amount of tumour that is surgically removed is increased, and the risk of tumour recurrence is reduced. Although use of BLC means that the initial operation costs more than it would if only WLC were used, over time the total costs of managing bladder cancer are reduced because patients do not need as many additional operations for recurrent tumours.     

7 tesla magnetic resonance imaging: A closer look at substantia nigra anatomy in Parkinson's disease

A hallmark of Parkinson's disease (PD) is the progressive neurodegeneration of dopaminergic neurons in the substantia nigra pars compacta (SNc). Dopaminergic denervation is commonly imaged using radiotracer imaging in target structures such as the striatum. Until recently, imaging made only a modest contribution to detecting neurodegenerative changes in the substantia nigra (SN) directly. Histologically, the SN is subdivided into the ventral pars reticulata and the dorsal pars compacta, which is composed of dopaminergic neurons. In humans, dopaminergic neurons, which are known to accumulate neuromelanin, form clusters of cells (nigrosomes) that penetrate deep into the SN pars reticulata (SNr). The SNr contains higher levels of iron than the SNc in normal subjects. Neuromelanin and T2*‐weighted imaging therefore better detect the SNc and the SNr, respectively. The development of ultra‐high field 7 Tesla (7T) magnetic resonance imaging (MRI) provided the increase in spatial resolution and in contrast that was needed to detect changes in SN morphology. 7T MRI allows visualization of nigrosome‐1 as a hyperintense signal area on T2*‐weighted images in the SNc of healthy subjects and its absence in PD patients, probably because of the loss of melanized neurons and the increase of iron deposition. This review is designed to provide a better understanding of the correspondence between the outlines and subdivisions of the SN detected using different MRI contrasts and the histological organization of the SN. The recent findings obtained at 7T will then be presented in relation to histological knowledge. © 2014 International Parkinson and Movement Disorder Society     

Micro- and Nano-CT for the Study of Bone Ultrastructure

Micro-computed tomography (micro-CT)—a version of X-ray CT operating at high spatial resolution—has had a considerable success for the investigation of trabecular bone micro-architecture. Currently, there is a lot of interest in exploiting CT techniques at even higher spatial resolutions to assess bone tissue at the cellular scale. After recalling the basic principles of micro-CT, we review the different existing system, based on either standard X-ray tubes or synchrotron sources. Then, we present recent applications of micro- and nano-CT for the analysis of osteocyte lacunae and the lacunar-canalicular network. We also address the question of the quantification of bone ultrastructure to go beyond the sole visualization.