OBJECTIVESTo investigate the method of preparing porcine thoracic aortas acellular tissue matrix (ACTM) by trypsin, EDTA and Triton X-100 and to find the best concentration of X-100.

METHODSA total of 56 roots of fresh thoracic aortas (without adventitial tissue) from 80 kg-100 kg tame pigs were divided randomly into > groups, each containing 8 roots. Every vessel was put into a 50 ml centrifugal tube with a solution of 0.1% trypsin + 0.02EDTA in PBS for 24 h. After that, each group was separately immerged into a solution of 0.1%, 0.2%, 0.5%, 1.0%, 2.0%, 5.0%, 10.0% Triton X-100 for 144 h-240 h. Specimens were taken every 6 h. Specimens were stained with haematoxylin-eosin and observed grossly under the light and transmission electron microscopy.

RESULTSLight and transmission electron microscopy revealed that ACTM was composed of insoluble collagen, elastin, and some insoluble metamorphic organelles. The best concentration of Triton X-100 was 1% at the time of 176.25 h +/- 5.5 h.

CONCLUSIONSPorcine thoracic aortas ACTM can be obtained successfully through this procedure. Triton X-100 is a good reagent for preparing vessel ACTM.

Animals ; Aorta, Thoracic ; cytology ; surgery ; ultrastructure ; Blood Vessel Prosthesis ; Octoxynol ; pharmacology ; Swine ; Tissue Engineering ; methods

Phycoerythrocyanin(PEC) lyase-isomerase PecE/PecF from Mastigocladus laminosus is the specific enzyme for biosynthesis of PEC alpha-subunit(alpha-PEC). In this work, the specificity of PecE/PecF on substrate apoproteins was reported. PecE/PecF could catalyse the reconstitution of phycocyanobilin(PCB) with apoproteins of alpha-PEC from two different subspecies of Mastigocladus laminosus, as well the site-directed mutated apoprotein of alpha-PEC with Trp at 128 to Phe in vitro, but could not catalyse the reconstitution of PCB with apoprotein of phycocyanin alpha-subunit(alpha-CPC) from Mastigocladus laminosus. The surfactant Triton X-100 had no effect for the reconstitution of alpha-PEC, while it could improve the reconstitution of PCB with apoprotein of alpha-CPC.
Apoproteins ; metabolism ; Bacterial Proteins ; Catalysis ; Cyanobacteria ; enzymology ; Light-Harvesting Protein Complexes ; Lyases ; metabolism ; Octoxynol ; pharmacology ; Proteins ; metabolism ; Substrate Specificity

OBJECTIVETo develop a procedure by which Schwann cells and myelin in the peripheral nerve could be removed while the basal lamina tubes remained intact, and to obtain a thick and long acellular nerve allograft in humans.

METHODSFour ulnar nerves 10.0 cm long and 4.0 - 5.0 mm in diameter were excised from a donated male body and cleaned from external debris. The nerves were treated with a solution of Triton X-100 and a solution of sodium deoxycholate at room temperature. After a final wash in water, the nerves were stored in phosphate-buffered saline (PBS, pH 7.2) at 4 degrees C. HE, luxol fast blue and fibrin staining were performed to visualize cells, myelin and basal membranes respectively and immunohistochemical staining was performed to visualize the presence of laminin, a Schwann cell lamina component, both in fresh and acellular nerve segments. To reveal overall structure better, methylene blue-fuchsin staining was performed in semithin section. The ultrastructure of acellular and fresh nerves were observed and photographed in a transmission electron microscope.

RESULTSThe acellular human ulnar nerve was white long cylinder with well elasticity and ductility. HE, myelin and fibrin staining revealed that cells, axons and myelin sheath were removed and basal membrane was preserved after extraction procedure. Staining for the presence of laminin showed that the Schwann cell basal lamina component were present in the nerves after chemical treatment. Methylene blue-fuchsin staining and transmission electron microscopy showed that the myelin sheaths were absent in the extracted nerve segments and empty basal lamina tubes remained in the endoneurium.

CONCLUSIONSWe developed an extracted procedure with the detergents of Triton X-100 and deoxycholate, by which cells, axons and myelin sheaths could be removed from a human ulnar nerve while the basal lamina tubes remain intact and a thick long acellular nerve allograft is obtained. The laminin, a Schwann cell basal lamina component, can be preserved in the acellular nerve.

Adult ; Axons ; drug effects ; Cell Separation ; methods ; Deoxycholic Acid ; pharmacology ; Humans ; Male ; Myelin Sheath ; drug effects ; Octoxynol ; pharmacology ; Transplantation, Homologous ; Ulnar Nerve ; cytology ; transplantation ; ultrastructure

The detergent Triton X-100 was used to establish a model for apoptosis in hepatoma cell lines. The electrophoresis of DNA extracted from 0.01% Triton X-100 treated hepatoma cell lines showed DNA ladder formation, a hallmark of apoptosis. The DNA fragmentation appeared within less than 60 min of the Triton X-100 treatment. Chromatin condensation and apoptotic bodies were observed by hematoxylin and eosin (H & E) stain, and fragmented nucleosome was detected by terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labelling (TUNEL) test. Apoptosis was semi-quantitated by measuring the lactate dehydrogenase (LDH) level for cytotoxity. It was found that apoptosis had been induced in more than 90% of the cells treated with Triton X-100 for 150 min. These data show that Triton X-100 efficiently induces the apoptotic cell death in hepatoma cell lines.
Apoptosis* ; Carcinoma, Hepatocellular/pathology* ; Carcinoma, Hepatocellular/genetics ; DNA Fragmentation ; Detergents/pharmacology* ; Human ; Liver Neoplasms/pathology* ; Liver Neoplasms/genetics ; Octoxynol/pharmacology* ; Tumor Cells, Cultured/drug effects

OBJECTIVETo study the possibility of removal melanin granules from autogenic acellular dermal matrix of giant nevus tissue by H2O2 bleaching technique.

METHODSA total of 32 skin specimens (0.5 cm x 0.5 cm) from giant nevus tissue and 1 piece (0.5 cm x 0.5 cm) of normal skin were obtained from the surgical removal. One giant nevus tissue was chosen as control. The others and the normal skin tissue were treated with solution of 0.25% Dispase II for digestion for 24 hours under normal temperature to remove epidermis. Then each piece was immerged into solution of 0.5% Triton X-100 for digestion for 48 hours in normal temperature. One giant nevus tissue and the normal skin tissue were chosen as control. The others were immerged into solution of different concentrations of H2O2, treated under different temperature and lasting for different period. Lastly, all specimens were treated with HE staining, immunohistochemical staining, light microscopy and so on.

RESULTSAfter giant nevus tissues were treated with solution of 0.25% Dispase II and immerged into solution of 0.5% Triton X-100 in normal temperature, nevus cells and all other cellular components of pigmented nevus tissues can be effectively removed, there were the cavities left by removal of cells without any residual cell debris, but still remaining part of pigment. Then each specimen were immerged into solution of different concentrations of H2O2, under different temperature and lasting for different period which can remove residual melanin granules. In solution of 3% H2O2 for 36 h under 37 degrees C, can remove all the melanin particles, the content of collagen type I in the obtained specimen was not changed. Collagen fibers were uniform in thickness, regular in arrangement with no obvious degeneration.

CONCLUSIONSWith solution of 0.25% Dispase II and solution of 0.5% Triton X-100 in normal temperature, all cells in nevus tissue can be removed effectively. Further treatment with 3% H2O2 at 37 degrees C for 36 h can remove all the melanin particles, while collagen type I has no obvious change. The preparation of acellular dermal matrix of the giant nevus may possibly be applied as autologous tissue implant to repair tissue defects.

Acellular Dermis ; Endopeptidases ; pharmacology ; Epidermis ; Humans ; Hydrogen Peroxide ; pharmacology ; Melanins ; Nevus ; pathology ; Nevus, Pigmented ; pathology ; Octoxynol ; pharmacology ; Skin Lightening Preparations ; pharmacology ; Skin Neoplasms ; pathology ; Skin Pigmentation ; drug effects ; Skin Transplantation ; Surface-Active Agents ; pharmacology

To evaluate the effects of p-octyl polyethylene glycol phenyl ether (Triton X-100), polyoxyl 35 caster oil (EL35) and polyoxyl 40 hydrogenated caster oil (RH40) on the activity of Cytochrome P450 3A (CYP3 As) in vivo. Rats were administered with saline, ketoconazole (75 mg x kg(-1) x d(-1)), Triton X-100 (30 mg x kg(-1) x d(-1)), EL35 (150 mg x kg(-1) x d(-1)) and RH40 (150 mg x kg(-1) x d(-1)) intragastrically for 5 consecutive days, and then given midazolam 10 mg x kg(-1) 20 min after the last treatment of ketoconazole or three surfactants with the same dose through duodenal administration. Pharmacokinetics parameters for midazolam and its metabolite 1'-hydroxymidazolam were estimated from the plasma concentration-time data by a noncompartmental approach. The results showed that multiple dose administration of Triton X-100, EL35 and RH40 decreased the ratios of 1'-hydroxymidazolam and midazolam AUC0-infinity from 1.14 to 0.90, 1.03 and 0.64, respectively. In contrast, multiple dose administration of ketoconazole caused the ratios of 1'-hydroxymidazolam and midazolam a significant decrease to 0.50. This study indicated that Triton X-100 and EL35 would have no inhibition on CYP3A, while RH40 had significant inhibition on CYP3A. Therefore, RH40 might be used to prepare drug formulations in pharmaceutical industry and would increase the bioavailability of some drugs transformed by CYP3As and further lead to significant clinical pharmacologic effects.
Animals ; Area Under Curve ; Biological Availability ; Biotransformation ; Cytochrome P-450 CYP3A ; metabolism ; Ketoconazole ; pharmacology ; Male ; Midazolam ; analogs & derivatives ; pharmacokinetics ; Octoxynol ; pharmacology ; Polyethylene Glycols ; pharmacology ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Surface-Active Agents ; pharmacology

OBJECTIVETo study the effect of extremely low frequency magnetic fields on intracellular calcium concentration ([Ca(2+)]i).

METHODSFura-2 loaded HepG2 cells were exposed to 1.55 mT (average value), 16 Hz pulsed magnetic fields for 60 min and to 300 mT, 2 Hz rotating magnetic fields for 5 min, and then [Ca(2+)]i was measured by fluorescence spectrophotometer. [Ca(2+)]i of HepG2 cells was also measured when they were exposed to 0.9 mT [root mean square (rms)], 16 Hz sinusoidal magnetic fields in real time.

RESULTSThe R values (F(340) nm/F(380) nm) of the control and the exposed group were 2.4519 +/- 0.2378 and 2.5266 +/- 0.2915 respectively after HepG2 cells were exposed to 1.55 mT, 16 Hz magnetic fields, 1.365 0 +/- 0.0626 and 1.3602 +/- 0.0771 respectively to 300 mT, 2 Hz rotating magnetic fields. The ratios of the trendline slope [r((501 - 1,000)) / r((0 - 500))] from the data of R values were 1.1213 +/- 0.4559 and 1.0727 +/- 0.1971 respectively (P > 0.05), and the ratios of the intercept [b((501 - 1,000)) / b((0 - 500))] from the trendline were 0.9912 +/- 0.0098 and 0.9979 +/- 0.0060 (P > 0.05) when HepG2 cells were exposed to the 0.9 mT, 16 Hz sinusoidal magnetic fields.

CONCLUSIONThe effect of extremely low frequency magnetic fields on [Ca(2+)]i of HepG2 cells under the experimental condition has not been found.

Calcium ; metabolism ; Cell Line, Tumor ; drug effects ; metabolism ; radiation effects ; Chelating Agents ; pharmacology ; Egtazic Acid ; pharmacology ; Electromagnetic Fields ; Humans ; Ion Transport ; drug effects ; radiation effects ; Octoxynol ; pharmacology ; Spectrometry, Fluorescence ; Time Factors

Objective: To explore the effects and mechanism of water-soluble chitosan hydrogel on infected full-thickness skin defect wounds in diabetic mice. Methods: The experimental research method was adopted. The control hydrogel composed of polyvinyl alcohol and gelatin, and the water-soluble chitosan hydrogel composed of the aforementioned two materials and water-soluble chitosan were prepared by the cyclic freeze-thaw method. The fluidity of the two dressings in test tube before and after the first freeze-thawing was generally observed, and the difference in appearance of the final state of two dressings in 12-well plates were compared. According to random number table (the same grouping method below), the cell strains of L929 and HaCaT were both divided into water-soluble chitosan hydrogel group and control hydrogel group, respectively. After adding corresponding dressings and culturing for 24 h, the cell proliferation activity was measured using cell counting kit 8. Rabbit blood erythrocyte suspensions were divided into normal saline group, polyethylene glycol octyl phenyl ether (Triton X-100) group, water-soluble chitosan hydrogel group, and control hydrogel group, which were treated accordingly and incubated for 1 hour, and then the hemolysis degree of erythrocyte was detected by a microplate reader. Twenty-four female db/db mice aged 11-14 weeks were selected, and full-thickness skin defect wounds on their backs were inflicted and inoculated with the methicillin-resistant Staphylococcus aureus (MRSA), 72 h later, the mice were divided into blank control group, sulfadiazine silver hydrogel group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. On post injury day (PID) 0 (immediately), 7, 14, and 21, the healing of the wound was observed. On PID 14 and 21, the wound healing rate was calculated. On PID 14, MRSA concentration in wounds was determined. On PID 21, the wounds were histologically analyzed by hematoxylin and eosin staining; the expression of CD31 in the wounds was detected by immunofluorescence method, and its positive percentage was calculated. Raw264.7 cells were taken and divided into interleukin-4 (IL-4) group, blank control group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. At 48 h of culture, the percentages of CD206 positive cells were detected by flow cytometry. The number of samples was all 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, least significant difference test, and Dunnett T3 test. Results: Two dressings in test tube had certain fluidity before freeze-thawing and formed semi-solid gels after freeze-thawing for once. The final forms of two dressings in 12-well plates were basically stable and translucent sheets, with little difference in transparency. At 24 h of culture, the cell proliferation activities of L929 and HaCaT in water-soluble chitosan hydrogel group were significantly higher than those in control hydrogel group (with t values of 6.37 and 7.50, respectively, P<0.01). At 1 h of incubation, the hemolysis degree of erythrocyte in water-soluble chitosan hydrogel group was significantly lower than that in Triton X-100 group (P<0.01), but similar to that in normal saline group and control hydrogel group (P>0.05). On PID 0, the traumatic conditions of mice in the 4 groups were similar. On PID 7, more yellowish exudates were observed inside the wound in blank control group and control hydrogel group, while a small amount of exudates were observed in the wound in sulfadiazine silver hydrogel group and water-soluble chitosan hydrogel group. On PID 14, the wounds in blank control group and control hydrogel group were dry and crusted without obvious epithelial coverage; in sulfadiazine silver hydrogel group, the scabs fell off and purulent exudate was visible on the wound; in water-soluble chitosan hydrogel group, the base of wound was light red and obvious epithelial coverage could be observed on the wound. On PID 14, the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 21, the wound in water-soluble chitosan hydrogel group was completely closed, while the wounds in the other 3 groups were not completely healed; the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 14, the concentration of MRSA in the wound in water-soluble chitosan hydrogel group was significantly lower than that in blank control group (P<0.01), but similar to that in control hydrogel group and sulfadiazine silver hydrogel group (P>0.05). On PID 21, the new epidermis was severely damaged in blank control group; the epidermis on the wound in control hydrogel group also had a large area of defect; complete new epidermis had not yet being formed on the wound in sulfadiazine silver hydrogel group; the wound in water-soluble chitosan hydrogel group was not only completely covered by the new epidermis, the basal cells of the new epidermis were also regularly aligned. On PID 21, the percentage of CD31 positivity in the wound in water-soluble chitosan hydrogel group was (2.19±0.35)%, which was significantly higher than (0.18±0.05)% in blank control group, (0.23±0.06)% in control hydrogel group, and (0.62±0.25)% in sulfadiazine silver hydrogel group, all P<0.01. At 48 h of culture, the percentage of CD206 positive Raw264.7 cells in water-soluble chitosan hydrogel group was lower than that in IL-4 group (P>0.01) but significantly higher than that in blank control group and control hydrogel group (P<0.05 or P<0.01). Conclusions: The water-soluble chitosan hydrogel has good biosafety and can induce higher level of macrophage M2 polarization than control hydrogel without water-soluble chitosan, so it can enhance the repair effect of MRSA-infected full-thickness skin defect wounds in diabetic mice and promote rapid wound healing.
Mice ; Female ; Animals ; Rabbits ; Interleukin-4 ; Hydrogels/pharmacology* ; Wound Healing ; Chitosan/pharmacology* ; Diabetes Mellitus, Experimental ; Water ; Methicillin-Resistant Staphylococcus aureus ; Gelatin ; Polyvinyl Alcohol ; Hemolysis ; Saline Solution ; Eosine Yellowish-(YS) ; Hematoxylin ; Octoxynol ; Silver ; Phenyl Ethers ; Sulfadiazine