Effect of low-level laser therapy on mast cells in second-degree burns in rats

OBJECTIVE: This study sought to investigate whether low-level laser therapy (LLLT) with a helium-neon (He-Ne) laser would affect mast cell number and degranulation in second-degree burns in rats. Background Data: LLLT has been recently applied to stimulate the wound healing process. MATERIALS AND METHODS: Sixty-five rats were randomly allocated to one of five groups. A deep second-degree burn was inflicted on all rats except those in the control group. In the sham-exposed group burns remained untreated. In the two laser-treated groups, the burns were irradiated every day by LLLT, with energy densities of 1.2 and 2.4 J/cm(2). In the fifth group the burns were treated topically with 0.2% nitrofurazone cream every day. The unburned skin of the rats in the control group were used for baseline study. The effects on mast cell number and degranulation were assessed by counting the number of intact and degranulated mast cells in sections fixed in formalin and stained with toluidine blue. RESULTS: On the seventh and 16th days post-burn, the type 1 mast cell count in the 2.4-J/cm(2) laser-treated group was significantly higher than that of the control group. On the 30th day, the total numbers of mast cells in the laser-treated groups were lower than those in the control and sham-exposed groups. CONCLUSION: LLLT of deep second-degree cutaneous burns in rats significantly increased the number of intact mast cells during the inflammatory and proliferative phases of healing, and decreased the total number of mast cells during the remodeling phase.     

Crimean-Congo hemorrhagic fever among health care workers in Iran: a seroprevalence study in two endemic regions

Crimean-Congo hemorrhagic fever (CCHF) has repeatedly caused nosocomial outbreaks among hospital staff. In the summer of 2003, we studied the seroprevalence of anti-CCHF IgG among health care workers who had come in contact with Crimean-Congo hemorrhagic fever patients from three referral hospitals in endemic regions of Iran. A total of 223 eligible staff were examined. Whereas 5 of 129 (3.87%) exposed health care workers tested positive, none of the 94 in the unexposed group did (P=0.075). Seropositivity was more frequent among those whose intact skin had come in contact with nonsanguineous body fluids (9.52%) and those who had had percutaneous contacts (7.14%). Health care workers exposed to Crimean-Congo hemorrhagic fever patients, those who live in Systan-Baluchestan province, and older health care workers were more prone to seropositivity. Where introduction of high-risk modes of contact cannot be confined, we propose that health care workers take all the protective measures when handling Crimean-Congo hemorrhagic fever patients, particularly their blood and other body fluids.     

Heterotopic autotransplantation of vitrified mouse ovary

Purpose  

The aim of this study was to investigate the survival and development of premature follicles and oocytes from a vitrified-transplanted ovary in a murine experimental model.     

Pistachio Allergy-Prevalence and In vitro Cross-Reactivity with Other Nuts

BackgroundTree nut allergy is characterized by a high frequency of life-threatening reactions and is typically lifelong persistent. Some people with a pistachio nut allergy, which is common in the pistachio rich area of Iran, develop a hypersensitivity to other tree nuts as well. The aim of this study was to investigate the prevalence of pistachio nut allergy in Iran, the major pistachio cultivation region in the world. The study also addressed the presence of allergenic cross-reactivity between pistachio and other nuts, including almond, peanut, and cashew in pistachio allergic patients.MethodsA survey was conducted to determine whether the prevalence of pistachio allergy is affected by exposure to this nut in pistachio cultivation regions, as well as possible cross-reactivity between pistachio and other nuts including cashew, almond, and peanut. Inhibition Western blot and inhibition ELISA studies were conducted to assess the presence of allergenic cross-reactivity between pistachio and the other tree nuts.ResultsOur results revealed that the prevalence of pistachio allergy is twice as much in pistachio cultivation regions than other areas. Western blotting and inhibition ELISA presented high percentages of inhibition with pistachio and cashew, followed by almond and, to some degree, peanut which indicates different levels of aller- genic cross-reactivity.ConclusionsThe results indicate that exposure of people to pistachio significantly affects the prevalence of its allergic reactions. In addition, it was observed that, among pistachio allergic subjects, such exposure may affect the co-sensitivities with other nuts, including cashew and almond. The plant taxonomic classification of pistachio and other tree nuts does appear to predict allergenic cross-reactivity.     

Antiproliferative Effect of H2O2 against Human Acute Myelogenous Leukemia KG1 Cell Line

It has clearly been established that oxidative stress leads to perturbation of various cellular processes resulting in either inhibition of cell proliferation or cell death. In addition, there is a growing body of evidence indicating that reactive oxygen species (ROS) are required as signal molecules that regulate different physiological processes including survival or death. Free radicals, particularly ROS, have been proposed as general mediators for apoptosis and recent studies have established that the mode of cell death depends on the severity of the oxidative damage. In this study, we determined the effect of oxidative stress on cell proliferation and characterization of cell death in human KG1 cells treated with H₂O₂. Our results indicated that oxidative stress leads to a significant decrease in cell proliferation and induction of apoptosis. Moreover, our study suggests that antiproliferative and apoptotic cell death effects of H₂O₂ took place via activation of caspase-3, affecting the expression of Bcl-2 and Bax (an antiapoptotic and a proapoptotic factor, respectively), and through deactivation of catalase enzyme, leading to accumulation of intracellular ROS and depletion of intracellular ATP level.     

Effect of Nano Silica on Setting Time and Physical Properties of Mineral Trioxide Aggregate

IntroductionMineral trioxide aggregate (MTA) has been widely used in all fields of endodontics. One of the major drawbacks of this material is the long setting time. MTA is primarily composed of type 1 Portland cement and bismuth oxide. In cement, nanoscale SiO₂ behaves as a filler to improve microstructure and to accelerate hydration process. The aforementioned reaction is also expected in MTA because of the same structure. Thus, the aim of this study was to evaluate the effect of addition of nano-SiO₂ to MTA on the setting time and its physical properties.MethodsTwo concentrations (8% and 10%) of nano-SiO₂ were added to the white MTA powder. After mixing with water, the setting time, compressive strength, and flexural strength were investigated and compared with pure MTA.ResultsWith the addition of 8% and 10% of nano-SiO₂ to the MTA, the setting time of both mixtures decreased significantly (P < .05). However, the compressive strength (after 1 day and 1 week) and flexural strength increased; this was not significant (P > .05). There was no significant difference between MTA mixed with 8% and 10% nano-SiO₂ in setting time, compressive strength, and flexural strength (P > .05).ConclusionsThe addition of 8% and 10% of nano-SiO₂ to MTA accelerated the hydration process, reduced the setting time, and had no adverse effect on the compressive and flexural strength of MTA.     

Co-stimulation with 4-1BB ligand allows extended T-cell proliferation, synergizes with CD80/CD86 and can reactivate anergic T cells

Activation of T cells requires co-stimulation, in addition to signals through the antigen-receptor complex. Antigen encounter without adequate co-stimulation results in T-cell desensitization or anergy, a mechanism of peripheral tolerance and an apparent obstacle to cancer immunotherapy. One important co-stimulatory pathway involves CD28 engagement by CD80 or CD86. However, other ligand-receptor pairs can also provide co-stimulation and may have important functions modulating the immune response. Previous reports indicated that co-stimulation using 4-1BB ligand (4-1BBL) or agonistic anti-4-1BB antibodies could prolong T-cell responses, avoid activation-induced cell death and promote anti-tumour responses in mice. To further investigate the potential for cancer immunotherapy, we studied the effects of CD80/CD86 and 4-1BBL in repeated stimulation of human T cells and asked whether 4-1BBL might be capable of reversing anergy. We expressed CD80, CD86 and 4-1BBL in A549 lung carcinoma cells using adenovirus vectors and co-cultured these with human T cells stimulated with anti-CD3 antibody. Proliferation co-stimulated by CD80 or CD86 was transient; however, 4-1BBL-co-stimulated cultures continued to proliferate for up to 5 weeks, with repeated stimulation. Combined co-stimulation with CD80/CD86 and 4-1BBL also allowed continuous proliferation at a faster rate than either signal alone. Co-stimulation with 4-1BBL did not suppress expression of the inducible, inhibitory CD80/CD86R, CTLA-4. Significantly, we show that T cells that had become non-responsive to anti-CD3, either alone or together with CD80/CD86 co-stimulation, and thus were anergic, could be reactivated to proliferate when costimulated with 4-1BBL, either alone or combined with CD80/CD86.