The role of the concentration and distribution of water in the complex permittivity of breast fat tissue

The structure of breast tissue is complicated and highly variable and presents a great challenge in the development of physical models that may be used to obtain its effective complex permittivity. Empirical models are commonly used by researchers to fit measured data and extrapolated to higher frequencies. However, these models have not been verified experimentally at higher frequencies. Theoretical models of tissue permittivity to explain the role of water are not available today. This communication is a systematic study of several models to estimate the complex permittivity of breast fat tissue based on volume content and distribution of water in the tissue. These models are implemented in (i) long wavelength, sparse concentration limit; (ii) full wave finite element simulation; and (iii) numerical implementation of dynamic multiple scattering theory. A comparison of the proposed models with experimental data is done at 3.2 GHz. Some of the measurement values are in fair agreement with the modeling. The results of the present study are useful for interpreting the large variability in experimentally measured values of the permittivity of breast fat tissue by taking the distribution of water into account. Bioelectromagnetics 30:669–677, 2009. © 2009 Wiley‐Liss, Inc.     

下丘脑腹内侧核损毁对大鼠nesfatin-1/NUCB2表达的影响

目的:观察下丘脑腹内侧核(VMH)损毁对大鼠脂肪组织nesfatin-1/NUCB2表达的影响及其机制。方法:电损毁VMH,观察大鼠体重和脂肪组织变化,采用Western blot检测脂肪组织中nesfatin-1/NUCB2表达改变。腹腔注射6-羟多巴胺(50 mg/kg)以阻断交感神经;持续外周注射卡巴胆碱(180μg/kg)用以模拟VMH损毁,观察其对大鼠皮下脂肪nesfatin-1/NUCB2表达的影响。结果:与对照组和假手术组比较,VMH损毁后大鼠体重明显增加(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)也显著增多;Western blot分析结果显示,nesfatin-1/NUCB2在胰腺和肝脏中表达较多,但皮下、肠系膜脂肪和肩胛间棕色脂肪组织(i BAT)中表达较少,骨骼肌(腓肠肌)中鲜有表达;与对照组和假手术组比较,VMH损毁组大鼠nesfatin-1/NUCB2在肝脏、胰腺、骨骼肌和i BAT中表达无显著差异(P0.05),皮下脂肪(P0.05)和肠系膜脂肪(P0.05)nesfatin-1/NUCB2表达显著增多与对照组相比,6-羟多巴胺组nesfatin-1/NUCB2表达显著升高(t=3.43,P0.05),而卡巴胆碱组nesfatin-1/NUCB2表达无显著差异(t=0.37,P=0.72)。结论:VMH损毁后大鼠脂肪组织nesfatin-1/NUCB2表达改变可能通过抑制交感神经活动介导。     

Optical quantitative pathology of cervical intraepithelial neoplasia in human tissues using spatial frequency analysis

An optical quantitative histological method in human tissues using spatial frequencies is demonstrated. Optical spatial frequency spectra from different stages of human Cervical Intraepithelial Neoplasia (CIN) tissue are evaluated as a potential quantitative pathological tool. The degree of randomness of tissue structures from normal to different stages of CIN tissue can be recognized by spatial frequency analysis. The standard deviation, σ of human normal and CIN tissue, is obtained by assuming the spatial frequency spectra as a Gaussian distribution. A support vector machine classifier (SVM) is trained in the subspace of σ. Twenty‐eight normal and CIN samples of varying grades are examined and compared with current diagnostic outcomes. Our results suggest that an excellent accuracy for diagnostic purposes can be achieved. This approach offers a simple, efficient and objective way to supplement histopathology in recognizing alterations from normal to different stages of cervical pre‐cancer, which are reflected by spatial information contained within the aperiodic and random structures of the different types of tissue. (© 2015 WILEY‐VCH Verlag GmbH &Co. KGaA, Weinheim)     

A proteomic profile of synoviocyte lesions microdissected from formalin-fixed paraffin-embedded synovial tissues of rheumatoid arthritis

Background

Rheumatoid arthritis (RA) is a systemic autoimmune disease characterized by chronic inflammation of the synovial joints. Early intervention followed by early diagnosis can result in disease remission; however, both early stage diagnosis and provision of effective treatment have been impeded by the heterogeneity of RA, which details of pathological mechanism are unclear. Regardless of numerous investigations of RA by means of genomic and proteomic approaches, proteins interplaying in RA synovial tissues that contain various types of synoviocytes, are not yet sufficiently understood. Hence we have conducted an HPLC/mass spectrometry-based exploratory proteomic analysis focusing on synoviocyte lesions laser-microdissected (LMD) from formalin-fixed paraffin-embedded (FFPE) synovial tissues (RA, n = 15; OA, n = 5), where those of Osteoarthritis (OA) were used as the control.

Results

A total of 508 proteins were identified from the RA and OA groups. With the semi-quantitative comparisons, the spectral index (SpI), log2 protein ratio (R_SC) based on spectral counting, and statistical G-test, 98 proteins were found to be significant (pair-wise p < 0.05) to the RA synovial tissues. These include stromelysin-1 (MMP3), proteins S100-A8 and S100-A9, plastin-2, galectin-3, calreticulin, cathepsin Z, HLA-A, HLA-DRB1, ferritin, neutrophil defensin 1, CD14, MMP9 etc.

Conclusions

Our results confirmed the involvement of known RA biomarkers such as stromelysin-1 (MMP3) and proteins S100-A8 and S100-A9, and also that of leukocyte antigens such as HLA-DRB1. Network analyses of protein–protein interaction for those proteins significant to RA revealed a dominant participation of ribosome pathway (p = 5.91 × 10⁻⁴⁵), and, interestingly, the associations of the p53 signaling (p = 2.34 × 10⁻⁵). An involvement of proteins including CD14, S100-A8/S100-A9 seems to suggest an activation of the NF-kB/MAPK signaling pathway. Our strategy of laser-microdissected FFPE-tissue proteomic analysis in Rheumatoid Arthritis thus demonstrated its technical feasibility in profiling proteins expressed in synovial tissues, which may play important roles in the RA pathogenesis.

Electronic supplementary material

The online version of this article (doi:10.1186/s12014-015-9091-8) contains supplementary material, which is available to authorized users.     

Numerical simulation of the effect of superparamagnetic nanoparticles on microwave rewarming of cryopreserved tissues

In this study, the microwave rewarming process of cryopreserved samples with embedded superparamagnetic (SPM) nanoparticles was numerically simulated. The Finite Element Method (FEM) was used to calculate the coupling of the electromagnetic field and the temperature field in a microwave rewarming system composed of a cylindrical resonant cavity, an antenna source, and a frozen sample phantom with temperature-dependent properties. The heat generated by the sample and the nanoparticles inside the electromagnetic field of the microwave cavity was calculated. The dielectric properties of the biological tissues were approximated using the Debye model, which is applicable at different temperatures. The numerical results showed that, during the rewarming process of the sample phantom without nanoparticles, the rewarming rate was 29.45 °C/min and the maximum temperature gradient in the sample was 3.58 °C/mm. If nanoparticles were embedded in the sample, and the cavity power was unchanged, the rewarming rate was 47.76 °C/min and the maximum temperature gradient in the sample was 1.64 °C/mm. In the presence of SPM nanoparticles, the rewarming rate and the maximum temperature gradient were able to reach 20.73 °C/min and 0.68 °C/mm at the end of the rewarming under the optimized cavity power setting, respectively. The ability to change these temperature behaviors may prevent devitrification and would greatly diminish thermal stress during the rewarming process. The results indicate that the rewarming rate and the uniformity of temperature distribution are increased by nanoparticles. This could be because nanoparticles generated heat in the sample homogeneously and the time-dependent parameters of the sample improved after nanoparticles were homogeneously embedded within it. We were thus able to estimate the positive effect of SPM nanoparticles on microwave rewarming of cryopreserved samples.     

Analysis of humoral immune responses in rhesus macaques vaccinated with attenuated SIVmac239Δnef and challenged with pathogenic SIVmac251

Background To determine the correlation between protection and humoral immune response against simian immunodeficiency virus (SIVmac251), 11 macaques were immunized with live‐attenuated SIVmac239Δnef either intravenously or via the tonsils and exposed to SIVmac251 after either 6 or 15 months along with unvaccinated controls. Results Independent of the route of vaccine application, viremia was significantly reduced in vaccinees compared with controls 2 weeks post‐challenge. Concomitantly, viremia correlated inversely with SIV‐specific IgG, complement‐mediated lysis and neutralizing antibodies and these parameters seemed to contribute to reduced viremia. During chronic infection, six monkeys controlled viremia in the circulation (two or fewer infectious units per 10⁶ PBMCs) and showed no signs of trapping in lymphatic tissues (Appendix S1). Conclusions As no significant differences were observed throughout the study, with respect to the humoral immune response and viremia control, between the two vaccinated cohorts, mucosal immunization strategies are recommended due to more simplified application.     

火棘不同组织内生细菌群落多样性

为了解火棘不同组织内生细菌群落多样性,该研究采用高通量测序技术对火棘内生细菌16S rRNA V5～V7可变区进行测序,分析火棘不同组织部位内生细菌群落多样性。结果表明:(1)从火棘根、茎、叶组织中共获得内生细菌OTU 1 818个,其中根部754个,茎部 308 个,叶部756个,三者共有 OTU 152 个。(2)物种分类显示,不同火棘组织内生细菌具有丰富的群落多样性,火棘根部内生细菌种类隶属于23门53纲137目216科373属557种,其中异样根瘤菌属(Allorhizobium-Neorhizobium-Pararhizobium-Rhizobium)和链霉菌属(Streptomyces)为优势属,其相对丰度分别为 10.57%和 8.00%; 茎部内生细菌种类隶属于21门32纲76目126科204属270种,其中马赛菌属(Massilia)和未知分类的丛毛单胞菌科属(unclassified_f_Comamonadaceae)为优势属,其相对丰度分别为31.10%和12.82%; 叶部内生细菌种类隶属于21门52纲130目210科380属581种,其中土芽孢杆菌属(Geobacillus)和假单胞菌属(Pseudomonas)为优势属,其相对丰度分别为12.31%和9.84%。(3)PICRUSt功能预测表明,根部内生细菌物种最丰富,参与各种代谢调控的细菌丰度最高。该研究结果为进一步探讨植物内生细菌功能,挖掘新的有益微生物资源提供了参考。     

Effects of post-chilling temperature on growth and variegation in Solomon's Seal

Effects of temperature were studied on the current and following season's growth of shoots from chilled rhizomes of Variegated Solomon's Seal. The rate of progress to completed elongation of the aerial shoot in chilled plants increased linearly with increasing temperature up to 28°C (24 h mean). A post‐chilling thermal time of 658 ± 47°Cd (> ‐1.3°C) was required for aerial shoots to become fully extended. Temperatures of 28°C and 33°C accelerated aerial shoot senescence and decreased rhizome and root dry weights, as compared with 18°C and 23°C treatments. Leaf number and variegation were not affected by temperature treatments during current growth season and all plants produced 12–13 leaves with between 7% and 9% leaf area variegated. Leaf variegation, however, was significantly increased in plants that had been grown after chilling at 28°C during the preceding growing season. Proteins of approximately 26, 32 and 62 kDa were present in the green parts of leaves but not in the white parts.