Percutaneous renal mass biopsy: historical perspective,current status,and future considerations

Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.     

A modality-specific somatosensory evoked potential test protocol for clinical evaluation: A feasibility study

ObjectiveWe aimed to establish an objective neurophysiological test protocol that can be used to assess the somatosensory nervous system.MethodsIn order to assess most fiber subtypes of the somatosensory nervous system, repetitive stimuli of seven different modalities (touch, vibration, pinprick, cold, contact heat, laser, and warmth) were synchronized with the electroencephalogram (EEG) and applied on the cheek and dorsum of the hand and dorsum of the foot in 21 healthy subjects and three polyneuropathy (PNP) patients. Latencies and amplitudes of the modalities were assessed and compared. Patients received quantitative sensory testing (QST) as reference.ResultsWe found reproducible evoked potentials recordings for touch, vibration, pinprick, contact-heat, and laser stimuli. The recording of warm-evoked potentials was challenging in young healthy subjects and not applicable in patients. Latencies were shortest within Aβ-fiber-mediated signals and longest within C-fibers. The test protocol detected function loss within the Aβ-fiber and Aδ-fiber-range in PNP patients. This function loss corresponded with QST findings.ConclusionIn this pilot study, we developed a neurophysiological test protocol that can specifically assess most of the somatosensory modalities. Despite technical challenges, initial patient data appear promising regarding a possible future clinical application.SignificanceEstablished and custom-made stimulators were combined to assess different fiber subtypes of the somatosensory nervous system using modality-specific evoked potentials.     

Temperature-controlled power modulation compensates for heterogeneous nanoparticle distributions: a computational optimization analysis for magnetic hyperthermia

Purpose: To study, with computational models, the utility of power modulation to reduce tissue temperature heterogeneity for variable nanoparticle distributions in magnetic nanoparticle hyperthermia.

Methods: Tumour and surrounding tissue were modeled by elliptical two- and three-dimensional computational phantoms having six different nanoparticle distributions. Nanoparticles were modeled as point heat sources having amplitude-dependent loss power. The total number of nanoparticles was fixed, and their spatial distribution and heat output were varied. Heat transfer was computed by solving the Pennes’ bioheat equation using finite element methods (FEM) with temperature-dependent blood perfusion. Local temperature was regulated using a proportional-integral-derivative (PID) controller. Tissue temperature, thermal dose and tissue damage were calculated. The required minimum thermal dose delivered to the tumor was kept constant, and heating power was adjusted for comparison of both the heating methods.

Results: Modulated power heating produced lower and more homogeneous temperature distributions than did constant power heating for all studied nanoparticle distributions. For a concentrated nanoparticle distribution, located off-center within the tumor, the maximum temperatures inside the tumor were 16% lower for modulated power heating when compared to constant power heating. This resulted in less damage to surrounding normal tissue. Modulated power heating reached target thermal doses up to nine-fold more rapidly when compared to constant power heating.

Conclusions: Controlling the temperature at the tumor-healthy tissue boundary by modulating the heating power of magnetic nanoparticles demonstrably compensates for a variable nanoparticle distribution to deliver effective treatment.     

有关医院空调水系统若干问题的探讨

主要阐述空调水系统利用平衡阀调节系统阻力,保持系统水力稳定;利用软启动器实施水泵的平滑软启动;压差旁通阀的作用及选型安装;系统管道热膨胀等问题。     

Intradiscal Thermal Annuloplasty for Discogenic Pain: An Outcome Study

Objectives: Published studies of intradiscal thermal annuloplasty (IDTA) have shown at most 50% pain relief as an improved outcome with little focus on functional improvement in the treatment of discogenic pain. Previous studies have used a number of criteria for patient selection including low back pain unresponsive to conservative care, no compressive radiculopathy, positive provocative discography and absence of previous surgery at the same symptomatic level. The purpose of present study is to examine the hypothesis that additional inclusion criteria for patient selection such as disc height, absence of degenerative disc disease (DDD) in untreated discs, absence of herniated nucleus pulposus or lumbar canal stenosis may improve the outcome of treatment. Methods: In this prospective case‐series study additional criteria of patient selection were introduced, namely disc height of at least 50%, no lumbar canal stenosis, one or two levels of DDD, no evidence of nucleus pulposus herniation on magnetic resonance image. Thirty‐four patients were enrolled in the study and 32 of them were followed over a period of 12 months. The visual analog scale (VAS) pain score and seven activities of daily living (ADLs) were followed and reported on a scale from 0 to 10. Results: Sustained decrease of the VAS pain scores was observed from 3 to 12 months following IDTA. ADLs improved in all patients between 3 and 12 months post‐treatment. Patients in the Bureau of Workers Compensation (BWC) group had a higher VAS score but showed the same level of improvement in ADLs as compared to commercial insurance or self‐pay patients. In the non‐BWC patient group an average VAS pain score decrease of more than 6 points on a 10‐point scale was reported at 6 to 12 months following IDTA. Conclusions: We found dramatic improvement of pain scores and ADLs following IDTA when strict patient selection was applied. We believe that IDTA is an effective, minimally invasive treatment for discogenic pain in properly selected patients.     

替硝唑葡萄糖注射液的稳定性研究

采用反相ＨＰＬＣ法测定替硝唑葡萄糖注射液中替硝唑的含量，用加温加速实验研究该制剂的热稳定动力学。结果表明，替硝唑的热降解反应为一级动力学过程，在５０、６５、８０、９５℃时的降解速度常数分别为５．５８×１０－４、２．６６×１０－３、８．１０×１０－３、２．８２×１０－２ｄ－１，为８．３年，半衰期为３９．５年。     

热分析中系列相关反应的补偿效应研究

根据热分析谱图峰顶的数学特征与Ｃｏａｔｓ－Ｒｅｄｆｅｒｎ方程，推得在一定实验条件下，在系列相关反应中，若峰顶温度相接近，则各反应的表观活化能Ｅ与指前因子Ａ之间存在着有动力学意义的补偿效应，即ｌｎＡ＝ａＥ＋ｂ。并经系列含水硫酸盐脱水反应实验验证。     

Comfort of fenestrated hydrogel lenses

A controlled, double-masked, randomized study was conducted on ten subjects to determine the effect of fenestration size on the initial comfort of hydrogel contact lenses. Four fenestrated lenses were tested, each lens containing four mid-peripheral fenestrations of the same size. The diameter of the fenestrations used in the four lenses ranged from 0.39 to 0.96 mm. An unfenestrated lens was also tested. All lenses were made of HEMA and were ordered with the following specifications: -3.00 D, 14.0 mm diameter, 8.4 mm back central optic radius and 0.06 mm centre thickness. There was a significant negative correlation between comfort and fenestration size, indicating that larger fenestrations are less comfortable. Even the lens with the smallest fenestrations (0.39 mm) was significantly less comfortable than the unfenestrated lens. The implication of this finding is that fenestrations may not be clinically efficacious in view of the poor comfort (and presumably increased mechanical effect of the fenestration edges on the tarsal conjunctiva) of fenestrated lenses.     

生理影像信息技术及其临床应用

生理影像是功能性医学影像的一个重要分支,也是临床医学工程的一个极其重要的研究和应用领域。多年来,作者及其研究生与临床医务人员相结合,在电生理影像和热生理影像的信息获取和数字化处理技术方面进行了大量及深入的研究,提出了一种体内热估计(ITE)新技术。本文重点介绍热生理影像信息在妇女乳腺癌诊断中的应用。通过对约五千例妇女乳腺病筛选的结果,表明了生理影像信息处理及ITE技术在临床医学上的应用价值。