似鲇高原鳅皮肤与鳍的组织学观察

采用石蜡切片技术及H.E和AB-PAS染色方法,对似鲇高原鳅(Triplophysa siluroides)头部、腹部、背部、侧线部和尾部皮肤结构及胸鳍、腹鳍、背鳍、臀鳍和尾鳍的组织结构进行观察。各部位皮肤均由表皮和真皮构成,真皮包括疏松层和致密层,不同部位皮肤厚度不同。表皮层腹部最厚,为(84.62±10.82)μm,侧线部最薄,为(14.97±3.95)μm,各部位表皮厚度差异显著。表皮层分布着黏液细胞、棒状细胞及味蕾。疏松层头部最厚,为(282.71±70.56)μm,尾部最薄,为(29.07±4.88)μm,该层分布有黑色素细胞、空泡状细胞和颗粒腺,而黏液腺分布于致密层。各部位的鳍均由表皮层、胶原纤维层、胶原下层及鳍条构成,表皮层与皮肤表皮层组成相似,鳍条是矿化的结缔组织。     

帕米尔漠蟾蜍皮肤、肾和肝的组织结构

为探究帕米尔漠蟾蜍(Bufotes taxkorensis)对高原环境的适应特征,观察了其皮肤、肾和肝的组织结构,并对躯干和胫部的皮肤总厚度、表皮层厚度、真皮层厚度和相对腺体数量,肾的肾小球密度、肾相对总滤过面积、远端小管和近端小管的相对管径在SPSS 25.0中做了独立样本t检验分析.结果显示:(1)帕米尔漠蟾蜍皮肤...     

双斑东方鲀皮肤溃烂症病原菌鉴定及药敏分析

【背景】2016年6月福建省海水鱼类苗种繁育科研中试基地养殖的双斑东方鲀出现皮肤溃烂症,病鱼特征为:游动缓慢,停止摄食,口角、表皮、鳍条溃烂,肾脏、脾脏充血严重。【目的】对发生皮肤溃烂症双斑东方鲀病原进行鉴定,以期为该疾病有效防治提供技术支撑。【方法】从濒死病鱼肾脏、脾脏和病灶部位肌肉组织分离出优势菌株,经人工肌肉注射感染证实其为致病菌。经菌株形态学、生理生化特征分析、16Sr RNA基因序列分析和系统发育树构建等手段综合鉴定并进行药敏分析。【结果】从患病鱼体脾脏分离得到一株优势菌株SBDFT-1#,人工感染实验证实为致病菌。结合形态、生理生化和分子生物学鉴定确定该菌为哈维氏弧菌(Vibrioharveyi),该菌为革兰氏阴性菌,极生单鞭毛,呈短杆状,菌体大小0.9×2.0μm。该菌株在2216E平板培养基菌落呈乳白色,边缘透明,中间凸起;在TCBS培养基菌落呈黄色,边缘整齐,中央隆起。该菌对苯唑西林、头孢噻肟、氧氟沙星、链霉素、复方新诺明、多粘菌素B等14种抗生素敏感,对氨苄西林、青霉素、四环素、麦迪霉素等9种抗生素耐药。【结论】哈维氏弧菌是海水养殖经济鱼类的常见致病菌,但从患病双斑...     

The location of silver in frog epidermis after treatment by ranvier's method,and possible implication of the flask cells in transport

Summary Frog skin, bladder wall, and sciatic nerve were treated by Ranvier's silver nitrate method and subsequently fixed and sectioned for electron microscopy. In the epidermis of the skin, more silver is found deposited in the flask cells than elsewhere, especially as a sub-apical plaque in the neck of the flask, which appears after the skin has been flooded with silver nitrate for 5 minutes. Mitochondria rich cells in the bladder also accumulate more silver than the surrounding epithelial cells, but do not show such a distinct sub-apical plaque. In myelinated nerve fibres treated similarly, silver accumulates in the paranodal regions of the axon, and outside the axon at the node. It is suggested that silver may accumulate near a site of ion transport, due to structural specialisations not visible by standard electron microscope techniques, and that the flask cells may therefore be implicated in transport in the frog skin.     

Counterpoint to “Infrared cameras overestimate skin temperature during rewarming from cold exposure”

We evaluated the paper by Maley et al. (2020) in this journal “Infrared cameras overestimate skin temperature during rewarming from cold Exposure” for the evidence provided in support of its title and conclusions. Several methodological issues were identified as well as issues with the data interpretation: 1: Only one camera was used but a conclusion was made for ‘cameras’ in general; 2: The camera accuracy (±2 °C) is too low to do a meaningful comparison without using local reference values or an on-site calibrator with higher accuracy; 3: Thermistor measurements are taken as a gold standard while issues such as temperature gradients and taping are known; 4: Both methods are not compared at the same location and a natural, physiological, gradient may be present between their locations; 5. The impact of the sensor and tape on delays in the change of the underlying tissue temperature is not considered; 6: Only a single pixel was used for the analysis, which has been shown to be problematic.We concluded that the paper by Maley et al. does not provide conclusive evidence that infrared cameras overestimate skin temperature during rewarming from cold exposure.     

Can nitroxides evoke the Keap1–Nrf2–ARE pathway in skin?

Nitroxides are stable cyclic radicals of diverse size, charge, and lipophilicity. They are cell-permeative, which effectively protects cells, tissues, isolated organs, and laboratory animals from radical-induced damage. The mechanisms of activity through which nitroxides operate are diverse, including superoxide dismutase-mimetic activity, oxidation of semiquinone radicals, oxidation of reduced metal ions, procatalase-mimetic activity, interruption of radical chain reactions, and indirect modulation of NO levels. Nitroxides possess both a nucleophilic (reducing properties) and an electrophilic (oxidizing properties) nature and, therefore, they may affect different cellular pathways. In the current study, a novel mechanism of action by which nitroxides provide skin protection based on their electrophilic nature is suggested. This study shows that nitroxides may act as electrophiles, directly or indirectly, capable of activating the Keap1–Nrf2–ARE pathway in human keratinocytes (HaCaT) and in human skin (human organ culture model). The high potency of oxoammonium cations versus hydroxylamines in activating the system is demonstrated. The mechanism of action by which nitroxides activate the Keap1–Nrf2–ARE pathway is discussed. Understanding the mechanism of activity may expand the usage of nitroxides as a skin protection strategy against oxidative stress-related conditions.     

Ectoine disperses keratin and alters hydration kinetics in stratum corneum

Moisturizing compounds are commonly applied topically to human stratum corneum (SC). Many types of molecular species are employed, most commonly including humectants and occlusives. We find new evidence of keratin dispersion caused by the moisturizing compound ectoine (1,4,5,6-tetrahydro-2-methyl-4-pyrimidinecarboxylic acid), and provide the first characterization of its impacts on the hydration kinetics and biomechanics of SC. A second compound, 2-(2-hydroxyethoxy)ethylguanidine succinate (HEG) was investigated for comparison. A suite of biomechanical and biochemical assays including FTIR, drying stress, and cellular cohesion were used. Studies were conducted on normal, lipid-extracted, and lipid plus natural moisturizing factor extracted SC. Ectoine was found to improve the dispersity and hydration of keratin bundles in corneocytes. It also decreased rates of stress development in lipid extracted SC when exposed to a dry environment by ～30% while improving stress reduction during rehydration by ～20%. Peak stresses were increased in harsh drying environments of <5% RH, but SC swelling measurements suggest that water retention was improved in ambient conditions. Further, changes up to ～4 J/m² were seen in cohesion after ectoine treatments, suggesting corneodesmosome interactions. HEG was tested and found to disperse keratin without impacting corneodesmosomes. These results indicate that keratin dispersants produce beneficial effects on SC hydration kinetics, ultimately resulting in higher SC hydration under ambient conditions.     

Giant locally advanced and metastatic squamous cell skin carcinoma of head and neck region: case report

IntroductionAt the present time, the skin tumors are among the most common cancers. Optimal therapy is based on the extent of the disease and the age of the patient. The need for radiotherapy occurs for inoperable locally advanced tumors and in the event of failure, salvage surgery is applied.Materials and methodsWe provided a case report of an older patient with giant squamous cell skin carcinoma and a review of published articles.ResultsWe present a rare case of giant squamous cell skin carcinoma with metastatic satellite tumors that was primarily treated with curative radiotherapy. Five months after radiotherapy, a recurrent tumor was detected at the site of origin and the treatment was completed by salvage surgery. Full remission was achieved for four years.ConclusionDespite the seemingly incurable finding it is always necessary to consider radical treatment regardless of the patient´s age. Curative treatment could achieve long term remission in the group of older patients.     

Modelling hand skin temperature in relation to body composition

Skin temperature is a challenging parameter to predict due to the complex interaction of physical and physiological variations. Previous studies concerning the correlation of regional physiological characteristics and body composition showed that obese people have higher hand skin temperature compared to the normal weight people. To predict hand skin temperature in a different environment, a two-node hand thermophysiological model was developed and validated with published experimental data. In addition, a sensitivity analysis was performed which showed that the variations in skin blood flow and blood temperature are most influential on hand skin temperature. The hand model was applied to simulate the hand skin temperature of the obese and normal weight subgroup in different ambient conditions. Higher skin blood flow and blood temperature were used in the simulation of obese people. The results showed a good agreement with experimental data from the literature, with the maximum difference of 0.31 °C. If the difference between blood flow and blood temperature of obese and normal weight people was not taken into account, the hand skin temperature of obese people was predicted with an average deviation of 1.42 °C. In conclusion, when modelling hand skin temperatures, it should be considered that regional skin temperature distribution differs in obese and normal weight people.