20 research outputs found
Assessment of AFT and Cox Models in Analysis of Factors Influencing the survival of Women with Breast Cancer in Yazd city
BACKGROUND AND OBJECTIVE: Breast cancer is one of the most common cancers in women. The statistical methods in the survival analysis of these patients are accelerated time models and Cox model. The purpose of this study is to evaluate two models in determining the effective factors in the survival of breast cancer.
METHODS: The study was an analytical and cohort study of survival analysis. The 538 of the patients referred to Ramezanzade Radiotherapy Center who had breast cancer and recorded survival status as a census from the April 2005 until March 2012 in Yazd. and survived by phone call. The Kaplan-Meier estimate was used to describe the survival of the patients. The research variables included clinical and demographic factors. The choice of final variables in the model was done by the methods of diminishing the dimension and all possible Cox regressions by the acaian criterion. Then, the best accelerated time model was considered Getting different distributions was also determined by the Akayake criteria.
FINDINGS: The most effective Cox model among all Cox models was variables including Age, Her2 and Ki67 variables (AIC = 30270). The generalized gamma model was the most optimal accelerated time model (AIC 463.966). Her2 was significant in both accelerated and cox models(p0.05).
CONCLUSION: In both accelerated time- Generalized Gamma- models and Cox Models, the Her2 variable was identified as a risk factor for breast cancer and There is a positive impact on the risk of death and reduced survival
The study of the stability, toxicity and antimicrobial effect of allicin solution
Abstract
Introduction: Allicin is extracted from Garlic, and can attach to the tiol groups of proteins by tiosulfanate group. This attachment leads to damage of various proteins and enzymes of microbes, and can affect wide spectrum of viruses, bacteria, fungi, and parasites. The aim of this study was to investigate the stability, toxicity and antimicrobial effect of allicin solution.
Methods: First, serial concentrations of allicin solution were prepared, and exposed to suspension of standard isolates of bacteria (Escherichia coli, Staphylococcus aureus, andPsodomonasaerogina) and fungi (Aspergillusnige rand Candida albicans).The minimum inhibitory concentration(MIC50 and MIC90) of this compound against each isolate was determined. To evaluate the toxicity of allicin solution, the suspension of skin cells of Balb/C mice was prepared, and incubated with serial concentrations of allicin for 6, 12 and 24 h. Then, cell viability was calculated by MTT assay, based on control. To evaluate stability of allicin solution,some pieces of sterilized marble were prepared, and their surfaces were treated with the solution of allicin. After 6, 12 and 24 h,marbles were sampled, inoculated on the nutrient agar, and incubated for 48 h at 37 °C. Finally, the number of colonies grown on each plate was counted.
Results: The micro-dilution test showed that allicin solution had antimicrobial effecton the all bacterial and fungal isolates which studied. This study also showed that the toxicity of allicin solution slightly dependent on the time and concentration, but increase the time until 24 h had nota significant impact on the reducing of stability.
Conclusions: The allicin solution has antimicrobial activity and its toxicity is negligible. Also, this material has high stability in the environmental conditions.
Keywords: Antimicrobial activity, Nanoparticles, Allicin, Toxicity, Stabilit
"Comparison of AgNORs count in exfoliative cytology of normal oral mucosa in smokers and non- smokers"
Background and Aim: A strong causal relationship exists between cigarette smoking and development of oral squamous cell carcinoma, so oral screening using exfoliative cytology has been recommended to facilitate the early diagnosis of cellular alterations in oral mucosa and silver staining (AgNOR technique) has been proven to be of value in the detection of incipient cellular alterations. The purpose of this study was to compare the argyrophilic nucleolar regions (AgNORs) count of cells collected from normal mucosa of cigarette smokers with that obtained from non- smokers. Materials and Methods: In this cross-sectional study, cytologic smears of normal tongue, buccal mucosa and floor of the mouth from 19 smokers and 19 non- smokers were stained for AgNORs. The AgNORs count was established on 100 cells. The count value of groups were compared and analyzed using the Levens, Paired T, Student and Factorial tests. Using P<0.05 as the limit of significance. Results: The AgNORs were round and had a clustered distribution in both groups. The mean AgNORs count was statistically higher in cells of smokers than non- smokers (P<0.05). There was a significant difference between smears from the floor of the mouth and other anatomical sites in both groups. In this study, no correlation was found between AgNORs count and gender. Conclusion: Analysis of AgNORs suggests that there might be a correlation between the smoking habit and an increased rate of cellular proliferation in the oral mucosal cells
An Investigation of Hydraulic Fracturing Initiation and Near-Wellbore Propagation from Perforated Boreholes in Tight Formations
In this study, hydraulic fracturing tests were conducted on 10 and 15 cm synthetically manufactured cubic tight mortar samples. The use of cube samples allowed application of three independent stresses to mimic real far field stress conditions. A true triaxial stress cell was used for this purpose. The lab test parameters were scaled to simulate the operations at field scale. The hole and perforations were made into the sample after casting and curing were completed. Various scenarios of vertical and horizontal wells and in situ stress regimes were modeled. These factors are believed to play a significant role in fracture initiation and near-wellbore propagation behavior; however, they are not independent parameters, hence should be analyzed simultaneously. In addition to experimental studies, analytical solutions were developed to simulate the mechanism of fracture initiation in perforated boreholes in tight formations. Good agreements were observed between the experimental and analytical results. The results of this study showed that a lower initiation pressure is observed when the minimum stress component is perpendicular to the axis of the perforations. It was also seen that, even when the cement sheath behind the casing fails, the orientation of the perforations may affect the initiation of the induced fracture noticeably. Furthermore, it was found that stress anisotropy influences the fracturing mechanism in a perforated borehole, and affects the geometry of the initiated near-wellbore fracture
Detection of Unauthorized Tissues in Trade Frozen Minced Meat Marketed in Yazd with Histological Method
Introduction: Nowadays the consumption of meat and animal carcasses in most countries is increasing. Regarding to economic values of meat, usage of unauthorized tissues in minced meat by jobbers is probable. Therefore; the present study was performed in order to detect unauthorized tissues in minced meat.
Methods: In this study, a total of 20 samples of trade frozen minced meat was purchased from various stores in Yazd city.Then each sample was divided into three parts and then one piece was taken from each part. The tissues were fixed in 10 % neutral-buffered formalin and were routinely processed for light microscopy and embedded in paraffin. The paraffin-embedded blocks were cut into 6 µm sections and stained using hematoxylin and eosin (H&E) for histological study.
Results: The skeletal muscle tissues were visible clearly in all samples. Although, connective tissue, adipose tissue and smooth muscle were seen but unauthorized tissues were not detected in any sample. Just in one sample, the residuals of the skin tissue was showed and in another sample , possessed bone tissue and in half of the samples the residuals of visceral organs were seen. In addition, some sections of the ligament were found.
Conclusion: The present study showed that the meat which has been used in preparation of this product had not premium quality. Due to importance of health and quality of meat, detection of unauthorized tissues in this product with histological technique is suggeste