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61.
Skin is a multilayered organ which covers and protects the surface of human body by providing a barrier function against exogenous
agents. Meanwhile, the efficacy of several topically applicated drugs is directly related to their penetration through the
skin barrier. Several techniques are commonly used to evaluate the rate, the speed and the depth of penetration of these drugs,
but few of them can provide real-time results. Therefore, the use of nondestructive and structurally informative techniques
permits a real breakthrough in the investigations on skin penetration at a microscopic scale. Confocal Raman microspectroscopy
is a nondestructive and rapid technique which allows information to be obtained from deep layers under the skin surface, giving
the possibility of a real-time tracking of the drug in the skin layers. The specific Raman signature of the drug enables its
identification in the skin. In this study, we try to follow the penetration of Metronidazole, a drug produced by Galderma
as a therapeutic agent for Rosacea treatment, through the skin. The first step was the spectral characterization of Metronidazole
in the skin. Then micro-axial profiles were conducted to follow the penetration of the drug in the superficial layers, on
excised human skin specimens. For more accurate information, transverse sections were cut from the skin and spectral images
were conducted, giving information down to several millimeters deep. Moreover, the collected spectra permit us to follow the
structural modifications, induced by the Metronidazole on the skin, by studying the changes in the spectral signature of the
skin constituents.
Presented at the joint biannual meeting of the SFB-GEIMM-GRIP, Anglet France, 14–19 October, 2006. 相似文献
62.
Peter Twumasi Elena T Iakimova Tian Qian Wim van Ieperen Jan HN Schel Anne MieC Emons Olaf van Kooten Ernst J Woltering 《BMC plant biology》2010,10(1):162
Background
The xylem vascular system is composed of fused dead, hollow cells called tracheary elements (TEs) that originate through trans-differentiation of root and shoot cambium cells. TEs undergo autolysis as they differentiate and mature. The final stage of the formation of TEs in plants is the death of the involved cells, a process showing some similarities to programmed cell death (PCD) in animal systems. Plant proteases with functional similarity to proteases involved in mammalian apoptotic cell death (caspases) are suggested as an integral part of the core mechanism of most PCD responses in plants, but participation of plant caspase-like proteases in TE PCD has not yet been documented. 相似文献63.
Maria D. Van Kerkhove Tommi Asikainen Niels G. Becker Steven Bjorge Jean-Claude Desenclos Thais dos Santos Christophe Fraser Gabriel M. Leung Marc Lipsitch Ira M. Longini Jr Emma S. McBryde Cathy E. Roth David K. Shay Derek J. Smith Jacco Wallinga Peter J. White Neil M. Ferguson Steven Riley for the WHO Informal Network for Mathematical Modelling for Pandemic Influenza HN 《PLoS medicine》2010,7(6)
64.
Pitre Nandan N. Moses J. B. Tzeng Edith Abramowitch Steven Velankar Sachin S. 《Biomechanics and modeling in mechanobiology》2023,22(3):1083-1094
Biomechanics and Modeling in Mechanobiology - Composites comprising crimped fibers of finite length embedded in a soft matrix have the potential to mimic the strain-hardening behavior of tissues... 相似文献
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Physicochemical, microbial and pharmacological studies on Fe (III)--Tamoxifen complex have been carried out in solid and aqueous phases. On the basis of elemental analysis, polarographic studies, amperometric titrations and IR spectral studies the probable formula for the complex has been worked out to be 1:1, Fe(III)--Tamoxifen. A tentative structure has been suggested to the complex. The metal ligand interaction has been studied using polarographic method at 27 degrees +/- 1 degree C and at ionic strength of mu = 1.0 (KCl). Microbial studies on the complex was carried out against various pathogenic bacteria and fungi using Raper's method. Mouse sarcoma cell line 180 and Balb/C mice were used for the anticancer screening of solid complex, in vitro and in vivo, respectively. The results of microbial and pharmacological studies with the M:Drug complex revealed that the complex is more potent as compared to the pure drug as regards to its anticancer activity. As such Fe (III) Tamoxifen complex may be recommended to the therapeutic experts for its possible use as more potent anticancer drug. 相似文献
68.
KARIN KUNZI‐RAPP PETER KASKEL RUDOLF STEINER RALF UWE PETER GERTRAUD KRHN 《Pigment cell & melanoma research》2001,14(1):9-13
The chorioallantoic membrane (CAM) of the fertilized egg allows grafting of human melanomas for short‐term investigations and offers the opportunity to investigate the behavior of metastasizing cells and the release of S100β into peripheral blood. Tissue from one primary melanoma as well as cutaneous and subcutaneous metastases of 10 melanoma patients with elevated levels of S100 in the peripheral blood before surgery were transplanted onto the CAM of chick embryos at day 5/6 of development. Grafts were nourished by the host blood supply 2 days after transplantation. Histologically, 3 days after grafting, metastasizing melanoma cells could be found near the vessels of the host membrane, penetrating the endothelial layer and entering the blood system. Growth conditions remained stable for 6 days after transplantation. Blood samples were taken from a larger CAM vessel before collecting the xenografts 5 days after grafting. Measurement of human S100 in peripheral blood was performed in a blinded manner. No negative control showed elevated levels of human S100 protein. Samples deriving from melanoma xenografts contained highly elevated levels of S100 protein in 80% of cases. The data strongly support the concept of graft–host interaction concerning adherence of tumors and extravasation of human melanoma cells. 相似文献
69.
Michael J. Ashenden Chirstopher J. Gore Caroline M. Burge Melissa L. Clough Pitre C. Bourdon Geoffrey P. Dobson Allan G. Hahn 《European journal of applied physiology and occupational physiology》1999,79(6):535-537
Investigation of the impact of environmental stimuli such as altitude exposure on hemoglobin mass currently rely on invasive techniques that require venous blood sampling. This study assessed the feasibility of lancet skin pricks as an alternative to venepuncture to estimate hemoglobin mass with the carbon monoxide (CO) dilution technique, with the intent of making the technique accessible to technicians without phlebotomy training. Sixteen healthy volunteers rebreathed CO via a small-volume rebreathing apparatus. Blood was sampled simultaneously with a glass syringe (VEN) from a superficial forearm vein and with a capillary tube from either a lanced fingertip or earlobe (CAP). As a control, VEN blood was then aliquoted into capillary tubes (CONTROL-CAP). Samples were assayed for carboxy-hemoglobin (HbCO) using a diode-array spectrophotometer. Mean %HbCO was higher in CAP than VEN (bias 0.3+/-0.2%HbCO, p < 0.01), but VEN and CONTROL-CAP were not different (p = 0.55). Compared to VEN, Hb mass derived from CAP samples was overestimated by 1.7% (15+/-22 g Hb, p = 0.01). CAP samples to estimate Hb mass demonstrated a technical error of measurement of 2.7%, which is comparable to the 1.9% reported previously with VEN samples. We conclude that using CAP samples gives a reliable measure of %HbCO, and will make the estimation of Hb mass with the CO-technique accessible to technicians without phlebotomy training. 相似文献
70.
GERTRAUD KRHN PETRA GOTTL
BER CHRISTIAN SANDER RALF U. PETER 《Pigment cell & melanoma research》1998,11(3):151-154
Dermatoscopy and high frequency sonography have recently been combined to increase diagnostic preoperative accuracy in the treatment of pigmented skin lesions. In this monocentric study 80 patients with pigmented skin lesions were evaluated clinically, by dermatoscopy, and 20 MHz-sonography followed by dermatohistopathological evaluation; 39 malignant melanomas, 37 common nevi, 3 dysplastic nevi, and 1 nevus Spitz were diagnosed histologically. In 72 of the 80 cases (91.3%) dermatoscopical diagnoses were confirmed by histopathology, compared to only 79% correct clinical diagnoses. For the mere clinical diagnosis of melanoma sensitivity was 79%, specificity was 78% and diagnostic accuracy was 65%. All diagnostic values increased by dermatoscopy: sensitivity reached 90%, specificity was 93%, and diagnostic accuracy was 83%. In order to determine tumor thickness preoperatively tumor thickness was measured by 20 MHz sonography. The correlation of tumor thickness between histometric and sonographic results was determined for nevi (r = 0.93) and melanoma (r = 0.95); 74.3% of melanomas were diagnosed correctly within an 0.2 mm range. Regarding the clinical important limit of 1 mm tumor thickness, 87.2% were diagnosed in accordance with histometric evaluation. An increase of 18% in diagnostic accuracy by dermatoscopy and 87.2% of correctly diagnosed cases of tumor thickness of malignant melanoma by high frequency sonography clearly demonstrate that these methods should be considered standard procedures in the diagnosis of pigmented skin lesions and will facilitate the decision on necessary surgical treatment. 相似文献