Use of autofluorescence and fluorescent probes as a potential diagnostic tool for oral cancer: A systematic review

IntroductionThe prognosis of patients with Oral squamous cell carcinoma (OSCC) are directly related to the stage of development of the tumor at the time of diagnosis, but it is estimated an average delay in diagnosis of 2–5 months. New non-invasive techniques for the early diagnosis of OSCC are being developed, such as methodologies to detect spectral changes of tumor cells. We conducted a systematic review to analyze the potential use of autofluorescence and/or fluorescent probes for OSCC diagnosis.Material and MethodsFour databases (PubMed, Scopus, Embase and Web of Science) were used as research sources. Protocol was registered with PROSPERO. It was included studies that evaluated tissue autofluorescence and/or used fluorescent probes as a method of diagnosing and/or treatment of oral cancer in humans.ResultsForty-five studies were selected for this systematic review, of which 28 dealt only with autofluorescence, 18 on fluorescent probes and 1 evaluated both methods. The VELscope® was the most used device for autofluorescence, exhibiting sensitivity (33%–100%) and specificity (12%–88.6%). 5-Aminolevulinic acid (5-ALA) was the most used fluorescent probe, exhibiting high sensitivity (90%–100%) and specificity (51.3%–96%). Hypericin, rhodamine 6 G, rhodamine 610, porphyrin and γ-glutamyl hydroxymethyl rhodamine green have also been reported.ConclusionThus, the autofluorescence and fluorescent probes can provide an accurate diagnosis of oral cancer, assisting the dentist during daily clinical activity, but it is not yet possible to suggest that this method may replace histopathological examination.     

Priming with a very low dose of DNA complexed with cationic block copolymers followed by protein boost elicits broad and long-lasting antigen-specific humoral and cellular responses in mice

Cationic block copolymers spontaneously assemble via electrostatic interactions with DNA molecules in aqueous solution giving rise to micellar structures that protect the DNA from enzymatic degradation both in vitro and in vivo. In addition, we have previously shown that they are safe, not immunogenic and greatly increased antigen-specific CTL responses following six intramuscular inoculations of a very low dose (1 μg) of the vaccine DNA as compared to naked DNA. Nevertheless, they failed to elicit detectable humoral responses against the antigen. To gain further insight in the potential application of this technology, here we show that a shorter immunization protocol based on two DNA intramuscular inoculations of 1 μg of DNA delivered by these copolymers and a protein boost elicits in mice broad (both humoral and cellular) and long-lasting responses and increases the antigen-specific Th1-type T cell responses and CTLs as compared to priming with naked DNA. These results indicate that cationic block copolymers represent a promising adjuvant and delivery technology for DNA vaccination strategies aimed at combating intracellular pathogens.     

A semi-quantitative direct contact assay using fluorescein diacetate and L929 mouse fibroblasts in monolayer culture

Summary A semi-quantitative procedure is described for measuring cell viability after short-term exposure to a test substance using a monolayer culture. Test substances are placed in direct contact with cell monolayers for various time intervals. The substances are removed and the monolayers are incubated in the presence of fluorescein diacetate. Monolayers are viewed under a fluorescent microscope and the percentage of fluorescing (viable) cells is estimated. The method is suitable for examining cytotoxic effects at short times of exposure and for discriminating between test substances that give similar, low toxicity endpoints in standard 24-h assays.     

化学染发剂和冷烫精的毒性及对人体健康影响的调查研究

本文通过化学染发剂和冷烫精对大白鼠骨髓多染红细胞，毛囊细胞的微核实验及人群健康影响调查，结果表明化学染发剂，冷烫清具有较强致突变作用，两者同时使用致突变明显增强，并提出研制高效无毒染发剂和加强防护的重要性。     

表面活性剂在硝酸士的宁注射液酸性染料比色法中的应用

表面活性剂在光度分析中已经有了广泛的应用,不论是在水溶液中测定的胶束增溶光度法还是在有机溶剂中测定的胶束萃取光度法中,表面活性剂的加入都具有明显的增溶、增敏和增稳作用,它能直接影响显色反应的速度、平衡位置以及配合物的构型,能改变溶剂的     

AlEtCl_2／t－BuCl引发α－蒎烯阳离子聚合反应研究

考察了在ＡｌＥｔＣｌ２／ｔ－ＢｕＣｌ引发体系作用下的α－蒎烯阳离子聚合行为．结果表明，ｔ－ＢｕＣｌ与ＡｌＥｔＣｌ２复合后，由于生成（ＣＨ３）Ｃ正离子而使引发活性增大．但ｔ－ＢｕＣｌ的引人对产物分子量及其分布影响不大，产物主要由二、三聚体组成．聚合过程的动力学研究表明，α－蒎烯在进行阳离子聚合时容易发生链终止反应而导致单体转化率和产物分子量较低．α－蒎烯在聚合反应的同时伴随着异构化反应，用制备ＧＰＣ分离出异构化产物，然后经１ＨＮＭＲ测定其结构．     

环磷酰胺冲击与小剂量持续应用对大鼠性激素影响的比较研究

Wistar大鼠随机分3组，每天组予环磷酰胺组（CP）8mg／kg·d×4W，ip；冲击组予CP56mg／kg·d×4W，ip；对照组予生理盐水1ml／d×4W，ip。结果：①睾丸生精细胞损伤：每日组重于冲击组；②血睾酮（T）含量每日组显著低于冲击组（P＜0．05）；冲击组与对照组无显著差异（P＞0．05）。③对睾丸间质细胞的影响：冲击组轻于每日组；④血FSH、LH含量与垂体重量：每日组与冲击组皆正常；⑤血BUN、Cr水平：3组皆正常．说明CP冲击疗法对睾丸间质细胞损伤较轻；CP除直接损伤睾丸组织外，可能还对下丘脑—垂体—睾丸轴有抑制作用．     

Role of a conserved amino-terminal sequence in the ecotropic MLV receptor mCAT1

The amino-terminus of mCAT1 and homologous proteins is predicted to form a positively charged, amphipathic alpha helix on the cytoplasmic side of the plasma membrane. Peptides with similar sequence motifs often provide membrane anchors, protein-protein interaction domains, or intracellular transport-targeting signals. Deleting most of the cytoplasmic N-terminal sequence of mCAT1 led to reduced expression on the cell surface and accumulation in the endoplasmic reticulum but did not abrogate receptor function. Surprisingly, when the N-terminal 36 or 18 amino acids of mCAT1 were fused to green fluorescent protein (gfp), gfp accumulated almost exclusively in mitochondria. Mitochondrial targeting depended on arginines at positions 15 and 16 and was inhibitable by downstream transmembrane sequences. Although the full-length mCAT1 was not detected in mitochondria, the mitochondrial-targeting property of the N-terminal sequence fused to gfp is conserved in orthologous and paralogous proteins that diverged approximately 80 million years ago, suggesting a conserved biological function. We propose that the conserved N-terminal motif of CAT proteins provides a regulatable signal for transport to, or retention in, different cell membrane compartments.     

Selective planting of cationized,haptenized ovalbumin on the rat tubular basement membrane

We developed an experimental protocol for planting exogenous antigens with different molecular weights and charges on the constituents of the renal tubulointerstitium. The cationized antigens were injected selectively into the left renal arteries of Wistar rats. Antigen localization was documented by immunohistochemistry on frozen sections. Cationized bovine serum albumin (BSA; 68 kDa, isoelectric point =9.5) localized almost exclusively along the glomerular capillary wall. After application of highly cationic polyethyleneimine, cationized BSA given subsequently was found in a linear distribution along the glomerular capillary wall and along the peritubular capillaries. The fate of highly cationized ovalbumin conjugated with trinitrophenol (TNP-OA), subjected to gel filtration to obtain monomers (42 kDa, isoelectric point >10) differed; it was deposited in a linear pattern on the tubular basement membrane (TBM) and Bowman's capsule, and remained up to 36 h after injection. Noncationized, monomeric TNP-OA (42 kDa, isolectnic point =4.6) showed fine granular deposition in the tubular epithelium exclusively. These findings indicate that the barrier of the glomerular BM acts selectively on antigens with different molecular weights. They either settle on the peritubular capillaries, after passing the glomerular, or reach the urinary space, after which they are reabsorbed by the tubular epithelial cells to reach the TBM.     

Substrate specificity of the luminal Na+-dependent sulphate transport system in the proximal renal tubule as compared to the contraluminal sulphate exchange system

The efflux of [³⁵S]sulphate from the lumen of the proximal renal tubule into tubular cells of rats was measured by the stop-flow tubular-lumen microperfusion technique. The transport parameters obtained and the apparent K _i values of competing substrates were compared with those of the contraluminal influx of [³⁵-S]sulphate from the interstitium into tubular cells. For the luminal sulphate efflux a K _m(l, SO ₄ ^2– ) of 0.8 mmol/l and a J _max(l, SO ₄ ^2– ) of 0.2 pmol s^–1 cm^–1 were found. The corresponding contraluminal values were K _m(cl,SO ₄ ^2– ) 1.4 mmol/l and J _max(cl, SO ₄ ^2– ) 1.2 pmol s^–1 cm^–1. Omission of Na⁺ from the perfusates reduced the luminal efflux of sulphate by 83%, while the contraluminal influx of sulphate was not changed. Increase in HCO ₃ ^– concentration inhibited both luminal efflux and contraluminal influx of sulphate, while a change of pH from 6.0 to 8.0 was without effect. Comparing the apparent K _i(SO ₄ ^2– ) values for luminal and contraluminal sulphate transport, a relationship close to 11 was seen for some inorganic substrates with tetrahedral molecular structure (thio-sulphate, sulphate, molybdate and selenate). The same holds for phosphate, while for oxalate the contraluminal K _i(SO ₄ ^2– ) value was lower than the luminal one (1.2 and 4.5 mmol/l). Some of the dicarboxylates and disulphonates tested show the same affinity to the luminal Na⁺-dependent sulphate transporter and the contraluminal sulphate exchange system, whereas most of the benzene carboxylate and benzenesulphonate derivatives tested exhibit higher luminal than contraluminal k _i values. The inhibitory potency increased with rising numbers of substituents on the benzene ring. This effect was more pronounced for the contraluminal sulphate transporter. In general, only disulphonates and analogues as well as similarly structured compounds (5-sulphosalicylate, 2-hydroxy-5-nitrobenzenesulphonate, eosine-5-isothiocyanate) have a good inhibitory potency toward the luminal sulphate transporter [apparent K _i 0.9–3.1 mmol/l]. All the tested sulphamoyl and phenoxy diuretics, and fluorescein and phenolphthalein dyes showed no or a smaller inhibitory potency to the luminal sulphate transport system than to the contraluminal. The most effective inhibitors of both sulphate transport systems are 8-anilino-1-naphthalenesulphonate, orange G, and H₂-DIDS. The data indicate that the Na⁺-dependent luminal and the Na⁺-independent contraluminal sulphate transport systems accommodate a similar spectrum of anionic substrates, whereby the inhibitory potency against the luminal Na⁺-dependent sulphate transport system is identical or smaller than against the contraluminal transporter.