Cytokine expression and anti-microbial effectiveness of different calcium hydroxide dilutions: An In Vitro study

Aims: To determine the cytokine expression by human gingival fibroblasts in response to different calcium hydroxide (Ca(OH)2) dilutions and test the effectiveness of these dilutions in root canal dentin infected with Enterococcus faecalis (E. faecalis). Methods: UltraCal XS Ca(OH)2 dilutions were prepared (60, 10, and 1 mg\mL) and co?cultured with gingival fibroblasts for 24 and 48 hours. Untreated cells were used as controls. Expressions of interleukin (IL?1?), tumour necrosis factor alpha (TNF??), transforming growth factor beta (TGF??), and IL?10 were analysed with real?time polymerase chain reaction (PCR). Root canals of extracted human teeth were inoculated with E. faecalis. After 21 days, canals were medicated with Ca(OH)2 dilutions for 7 days. Samples were taken to determine bacterial reduction using quantitative PCR. Analysis of variance, Tukey post?test, and Wilcoxon matched pair test were used for statistics. Results: IL?1? and TNF?? expressions of all Ca(OH)2 dilutions were higher at 24 and 48 hours compared to the control. Similarly, all Ca(OH)2 dilutions induced TGF?? expression at 24 hours compared to the control and continued to be higher in 60 mg/mL groups at 48 hours. In contrast, IL?10 was constitutively expressed by untreated cells in the control group and was down?regulated significantly by all Ca(OH)2 dilutions at 24 and 48 hours. All dilutions demonstrated a significant E. faecalis reduction (P < 0.001) with no significant difference between dilution groups (P > 0.05). Conclusions: All Ca(OH)2 dilutions had a differential inflammatory effect on fibroblasts and had a down?regulation effect to IL?10. All dilutions tested were effective against E. faecalis, with 60 mg/mL having the highest bacterial reduction

In vitro and in vivo antimalarial activity and cytotoxicity of extracts, fractions and a substance isolated from the Amazonian plant Tachia grandiflora (Gentianaceae)

Tachia sp. are used as antimalarials in the Amazon Region and in vivo antimalarial activity of a Tachia sp. has been previously reported. Tachia grandiflora Maguire and Weaver is an Amazonian antimalarial plant and herein its cytotoxicity and antimalarial activity were investigated. Spectral analysis of the tetraoxygenated xanthone decussatin and the iridoid aglyone amplexine isolated, respectively, from the chloroform fractions of root methanol and leaf ethanol extracts was performed. In vitro inhibition of the growth of Plasmodium falciparum Welch was evaluated using optical microscopy on blood smears. Crude extracts of leaves and roots were inactive in vitro. However, chloroform fractions of the root and leaf extracts [half-maximal inhibitory concentration (IC50) = 10.5 and 35.8 µg/mL, respectively] and amplexine (IC50= 7.1 µg/mL) were active in vitro. Extracts and fractions were not toxic to type MRC-5 human fibroblasts (IC50> 50 µg/mL). Water extracts of the roots of T. grandiflora administered by mouth were the most active extracts in the Peters 4-day suppression test in Plasmodium berghei-infected mice. At 500 mg/kg/day, these extracts exhibited 45-59% inhibition five to seven days after infection. T. grandiflora infusions, fractions and isolated substance have potential as antimalarials.

Bothrops pirajai snake venom L-amino acid oxidase: in vitro effects on infection of Toxoplasma gondii in human foreskin fibroblasts

The effect of an L-amino acid oxidase isolated from Bothrops pirajai snake venom (BpirLAAO-I) was investigated on infection of Toxoplasma gondii in human foreskin fibroblasts (HFF). The cytotoxic activity of BpirLAAO-I on HFF cells showed a dose-dependent toxicity with median cytotoxic dose (TD50) of 11.8 µg/mL. BpirLAAO-I induced considerable dose-dependent decrease in the T. gondii infection index under two different conditions, treatment of tachyzoites before infection or treatment of HFF cells after infection. A maximal inhibition of infection (56 percent) was found for treatment before infection, with a median inhibitory dose (ID50) at 1.83 µg/mL and selectivity index (SI) at 6.45. For treatment after infection, it was observed a maximal inhibition of infection at 65 percent, ID50 of 1.20 µg/mL and SI of 9.83. The treatment before infection was also effective to reduce intracellular parasitism up to 62 percent, although presenting higher values of ID50 (3.14 µg/mL) and lower values of SI (3.76). However, treatment after infection was not effective, suggesting that the enzyme seems to have no effect on the parasite intracellular replication for this condition. In conclusion, BpirLAAO-I was more effective to inhibit the infection of neighboring cells and consequently parasite dissemination than primary infection and parasite replication. Thus, the effect of BpirLAAO-I described herein could be taken into account for the development of new synthetic anti-parasite therapeutic agents.

Reprogramming the human skin fibroblast cell into stem cell / 基础医学与临床

In recent years, researchers have made some breakthroughs on human embryonic stem cells, in particular, on reprogramming differentiated cell (such as human skin fibroblast) into human embryonic stem cell. Induced pluripotent stem cells could be generated from human skin fibroblasts by inducting into four transcription factors known as OCT3/4, SOX2, C-MYC and KLF4. This approach enables better understanding the pathogenesis of diseases from the perspective of genetic component and promising in the treatment of related diseases. This article introduces the latest advancement of those researches.

Human Dermal Fibroblast Viability Against Time and Calcium Alginate Density in Vitro

One approach for soft tissue augmentation is tissue engineering technique which uses autogenous fibroblasts localized within a biocompatible polymer. Many reports of chondrocytes within calcium alginate for cartilage transplantation in vitro have been presented, but no report of fibroblasts within calcium alginate has been presented. This study is related to the conditions of polymerization depending on alginate density and culture time in the viability of human fibroblasts encapsulated in calcium alginate matrix. Human dermal fibroblasts were obtained from STSG patients, enzymatically dissociated, and cultured in DMEM/ Ham's F-12, then the fibroblasts were collected by centrifugation. Alginate discs containig fibroblasts were made from 1 or 2% sodium alginate mixed in 150 mM CaCl2 solution. Viability of fibroblasts was measured by quantification of the DNA content per alginate disc at six different time intervals from 1 to 8 weeks. Significant initial cell loss was observed in the first two weeks after which the survival rate remained stationary. According to the alginate density, fibroblasts seeded at 1% alginate showed higher survival rate than at 2% alginate in early periods(by 6 weeks), then inversed in late periods(p<0.05). Our study provides a significant information in manufacturing alginate-fibroblast induced soft tissue by tissue engineering.

Human Dermal Fibroblast Viability Against Time and Calcium Alginate Density in Vitro

One approach for soft tissue augmentation is tissue engineering technique which uses autogenous fibroblasts localized within a biocompatible polymer. Many reports of chondrocytes within calcium alginate for cartilage transplantation in vitro have been presented, but no report of fibroblasts within calcium alginate has been presented. This study is related to the conditions of polymerization depending on alginate density and culture time in the viability of human fibroblasts encapsulated in calcium alginate matrix. Human dermal fibroblasts were obtained from STSG patients, enzymatically dissociated, and cultured in DMEM/ Ham's F-12, then the fibroblasts were collected by centrifugation. Alginate discs containig fibroblasts were made from 1 or 2% sodium alginate mixed in 150 mM CaCl2 solution. Viability of fibroblasts was measured by quantification of the DNA content per alginate disc at six different time intervals from 1 to 8 weeks. Significant initial cell loss was observed in the first two weeks after which the survival rate remained stationary. According to the alginate density, fibroblasts seeded at 1% alginate showed higher survival rate than at 2% alginate in early periods(by 6 weeks), then inversed in late periods(p<0.05). Our study provides a significant information in manufacturing alginate-fibroblast induced soft tissue by tissue engineering.