616 research outputs found
Bilateral SMAS rhytidectomy in parotid recurrent pleomorphic adenoma
A case is presented of a young female with parotid recurrent pleomorphic adenoma and skin infiltration treated with subtotal parotidectomy combined with a bilateral superficial muscular aponeurotic system rhytidectomy
The morphology and application of stem cells in digestive system surgery
Background: Stem cells constitute a group of cells which possess the ability to self-renew as well as the capacity to differentiate into a vast number of different cells within the human organism. Moreover, stem cells are able to undergo a potentially unlimited number of divisions and this characteristic is clinically essential. Specific fields of its application include treatment of diseases mainly in the field of haematology, orthopaedics, surgery, dentistry, and neurology.
Materials and methods: In the following work, the current knowledge concerning mechanisms of stem cell treatment in different parts of the digestive system with its diseases as well as adjacent therapy for surgery has been revised.
Results: Stem cells therapy may be used in the treatment of various diseases of different parts of the digestive system. This also applies to the end part of the digestive tract (proctological diseases) because stem cells can be used to treat fistulas. Liposuction allows more recovery of mesenchymal stem cells, compared to previous bone marrow harvesting methods. Despite the application of stem cells in the treatment of different diseases used for many years so far, the therapeutic use for the regeneration of the gastrointestinal tract is still rare and unfamiliar.
Conclusions: Regenerative medicine seems to be a promising tool in medical research, especially when insulated cells and designed biomaterials are taken into consideration. Major points of discussion include types of stem cells, their origin or differentiation for the treatment of many diseases
Hydrostatic pressure study of paramagnetic-ferromagnetic phase transition in (Ga,Mn)As
The effect of hydrostatic pressure on the paramagnetic - ferromagnetic phase
transition has been studied in (Ga,Mn)As. The variation of the Curie
temperature (TC) with pressure was monitored by two transport methods: (1) -
measurement of zero field resistivity versus temperature {\rho}(T), (2) -
dependence on temperature of the Hall voltage hysteresis loop. Two specimens of
different resistivity characteristics were examined. The measured
pressure-induced changes of TC were relatively small (of the order of 1K/GPa)
for both samples, however they were opposite for the two.Comment: 8 pages, 7 figure
Phytochemical and comparative antidiabetic studies of leaf extracts of Viscum album from different plant hosts
Phytochemical screening and evaluation of antidiabetic activity of leaf extracts of Viscum album from four different plant hosts were carried out using standard procedures. The results of the phytochemical screening revealed that the different leaf extracts vary in their phytochemical constituents depending on the plant host. Moreso, all the leaf extracts of Viscum album demonstrated significant (p<0.001) lowering of blood glucose level (BGL) in alloxan-induced diabetic rats. The leaf extract of V. album from Dennettia tripetala exhibited the highest antidiabetic activity than the other extracts followed by Citrus sinensis and Pisium guajava and their activities were more pronounced than that of standard drug, glibenclamide during acute study. On prolonged treatment, Viscum album leaf extracts from C. sinensis (VAC ) and P. guajava (VAP) had comparably higher antidiabetic effects than the other extracts and glibenclamide. These were followed by that from Dacroydes edulis (VAD) while Dennettia tripetala (VADT) had the lowest antidiabetic effect. Although V. album possesses antidiabetic property, its antidiabetic efficacy depends on its phytochemical constituents which in turn depends on the plant host.Keywords: Mistletoe, Hyperglycemia, Alloxan, Glibenclamid
Drug-induced gingival hyperplasia : an in vitro study using amlodipine and human gingival fibroblasts
Gingival overgrowth is a serious side effect that accompanies the use of amlodipine. Several conflicting theories have been proposed to explain the fibroblast\u2019s function in gingival overgrowth. To determine whether amlodipine alters the inflammatory responses, we investigated its effects on gingival fibroblast gene expression as compared with untreated cells. Fragments of gingival tissue of healthy volunteers (11 years old boy, 68 years old woman, and 20 years old men) were collected during operation. Gene expression of 29 genes was investigated in gingival fibroblast cell culture treated with amlodipine, compared with untreated cells. Among the studied genes, only 15 (CCL1, CCL2D, CCL5, CCL8, CXCL5, CXCL10, CCR1, CCR10, IL1A, IL1B, IL5, IL7, IL8, SPP1, and TNFSF10) were significantly deregulated. In particular, the most evident overexpressed genes in treated cells were CCR10 and IL1A. These results seem to indicate a possible role of amlodipine in the inflammatory response of treated human gingival fibroblasts
Experimental observation of defect pair separation triggering phase transitions
First-order phase transitions typically exhibit a significant hysteresis resulting for instance in boiling retardation and supercooling. The hysteresis arises, because nucleation of the new phase is activated. The free-energy change is positive until the nucleus reaches a critical size beyond which further growth is downhill. In practice, the barrier is often circumvented by the presence of heterogeneous nucleation centres, e. g. at vessel walls or seed crystals. Recently, it has been proposed that the homogeneous melting of ice proceeds via separation of defect pairs with a substantially smaller barrier as compared to the mere aggregation of defects. Here we report the observation of an analogous mechanism catalysing a two-dimensional homogeneous phase transition. A similar process is believed to occur in spin systems. This suggests that separation of defect pairs is a common trigger for phase transitions. Partially circumventing the activation barrier it reduces the hysteresis and may promote fluctuations within a temperature range increasing with decreasing dimensionality
Phenytoin and gingival mucosa: A molecular investigation.
Several distinct classes of drugs, such as anticonvulsants, immunosuppressants, and calcium channel blockers, caused gingival overgrowth. One of the main drugs associated with the gingival overgrowth is the anti-epileptic such as phenytoin, which affects gingival tissues by altering extracellular matrix metabolism. In our study, we evaluate the effect of phenytoin, a drug whose active substance is phenytoin, on gingival fibroblasts of healthy volunteers. Gene expression of 29 genes was investigated in gingival fibroblasts' cell culture treated with phenytoin compared with untreated cells. Among the studied genes, only 13 genes (CXCL5, CXCL10, CCR1, CCR3, CCR5, CCR6, IL-1A, IL-1B, IL-5, IL-7, IL-6R, BMP-2, and TNFSF-10) were statistically significant. All but one gene resulted downregulated after 24\u2009h of treatment with phenytoin. BPM2 was the only, although weakly, up-expressed gene. Probably, we have not highlighted overexpression of the other inflammatory molecules because the study was performed on healthy people. Many studies show that phenytoin induces the overexpression of these cytokines but, probably, in our study, the drug does not have the same effect because we used gingival fibroblasts of healthy people
Mechanisms of the Epithelial-Mesenchymal Transition and Tumor Microenvironment in Helicobacter pylori-Induced Gastric Cancer
Helicobacter pylori (H. pylori) is one of the most common human pathogens, affecting half of the world's population. Approximately 20% of the infected patients develop gastric ulcers or neoplastic changes in the gastric stroma. An infection also leads to the progression of epithelial-mesenchymal transition within gastric tissue, increasing the probability of gastric cancer development. This paper aims to review the role of H. pylori and its virulence factors in epithelial-mesenchymal transition associated with malignant transformation within the gastric stroma. The reviewed factors included: CagA (cytotoxin-associated gene A) along with induction of cancer stem-cell properties and interaction with YAP (Yes-associated protein pathway), tumor necrosis factor α-inducing protein, Lpp20 lipoprotein, Afadin protein, penicillin-binding protein 1A, microRNA-29a-3p, programmed cell death protein 4, lysosomal-associated protein transmembrane 4β, cancer-associated fibroblasts, heparin-binding epidermal growth factor (HB-EGF), matrix metalloproteinase-7 (MMP-7), and cancer stem cells (CSCs). The review summarizes the most recent findings, providing insight into potential molecular targets and new treatment strategies for gastric cancer
Cell Activities on Viscoelastic Substrates Show an Elastic Energy Threshold and Correlate with the Linear Elastic Energy Loss in the Strain-Softening Region
Energy-sensing in viscoelastic substrates has recently been shown to be an important regulator of cellular activities, modulating mechanical transmission and transduction processes. Here, this study fine-tunes the elastic energy of viscoelastic hydrogels with different physical and chemical compositions and shows that this has an impact on cell response in 2D cell cultures. This study shows that there is a threshold value for elastic energy (≈0.15 J m−3) above which cell adhesion is impaired. When hydrogels leave the linear stress–strain range, they show softening (plastic) behavior typical of soft tissues. This study identifies a correlation between the theoretical linear elastic energy loss in the strain-softening region and the number of cells adhering to the substrate. This also has implications for the formation of vinculin-rich anchorage points and the ability of cells to remodel the substrate through traction forces. Overall, the results reported in this study support that the relationship between cell activities and energy-sensing in viscoelastic substrates is an important aspect to consider in the development of reliable ex vivo models of human tissues that mimic both normal and pathological conditions
Acoustic Phonon-Assisted Resonant Tunneling via Single Impurities
We perform the investigations of the resonant tunneling via impurities
embedded in the AlAs barrier of a single GaAs/AlGaAs heterostructure. In the
characteristics measured at 30mK, the contribution of individual donors
is resolved and the fingerprints of phonon assistance in the tunneling process
are seen. The latter is confirmed by detailed analysis of the tunneling rates
and the modeling of the resonant tunneling contribution to the current.
Moreover, fluctuations of the local structure of the DOS (LDOS) and Fermi edge
singularities are observed.Comment: accepted in Phys. Rev.
- …