ABSTRACT
In survival studies when the event times are dependent, performing of the analy-sis by using of methods based on independent assumption, leads to biased. In this paper, using copula function and considering the dependence structure between the event times, a paramet-ric joint distribution has made fitting to the events, and the effective factors on each of these events would be determined. This retrospective cohort study was conducted from March 2003 to March 2007. The data collected from 256 patients with gastric cancer who underwent surgery and that the event time of the two outcomes of death and recurrence for them was recorded. Akaike Information Criterion [AIC] was used to determine of suitable parametric models. Moreover, applying copula function with regard to the relationships between the events, the effect of the risk factors of each of the two outcomes was determined. The data analysis was done using R2.12.1 software. According to the AIC criterion, the Weibull distribution had the best fitting in both of the event times. The median times for recurrence and survival of the patients were estimated 20.2 and 28.1 months respectively. Furthermore, with a fitting of Weibull distribution to the two event times using Clayton copula function, the variables of gender, tumor size and tumor pathological stage on survival, and tumor size and tumor pathological stage on recurrence were significant [P<0.001]. Applying copula function for determining specific risk factors of the semi-competing events produces suitable results opposite the common methods which are based on independent assumption of the events.
ABSTRACT
Currently, autologous and allogeneic adipose tissues represent a ubiquitous source of material for fat reconstructive therapies. However, these approaches are limited, and often accompanied by a 40-60% reduction in graft volume following transplantation, limited proliferative capacity of mature adipocytes for ex vivo expansion, and extensive adipocyte damage encountered when harvested with conventional liposuction techniques. Recently, cell-based approaches utilizing adipogenic progenitor cells for fat tissue engineering have been developed and were reported to promote both short-term in vivo adipogenesis and to repair defect sites. The aim of this study was to isolate stem cells from fat tissue than examine the growth of stem cells by invitro tests. For human adipose stem cell isolation [hASC], subcutaneous adipose tissue sites were obtained from female subjects undergoing elective procedures. Tissues were washed 3-4 times in phosphate buffered saline [PBS] and suspended in an equal volume of PBS supplemented with 1% FCS and 0.1% collagenase type I. The tissue was placed in an agitated water bath at 37 1C. The supernatant containing mature adipocytes, was aspirated. Portions of the SVF were suspended in DMEM medium. hASCs were selected based on their ability to adhere to tissue culture plastic and subsequently expanded to 75-90% confluence. Adipose stem cells were isolated and cultured on DMEM. To assess mesenchymal origin of stem cells we used flow-cytomery technique as well as differentiation to osteocyte and chondrocyte lines. The nature of the mesenchymal cells was confirmed by flow -cytometry techniques, based on the expression of CD90, CD105, CD166, and lack of expression of hematopoietic markers of CD34, CD31, and CD45. The successful differentiation of our stem cells to osteocyte, chondrocyte had been showed by specific Alizarin-Red and Toluidine-blue staining of cells. Although we have not the results of in vivo tests to support in vivo adipogenesis either alone or in combination with natural or synthetic matrix, the results showed that stem cells isolation from adipose tissue was successful, and we provided an environment for differentiation of stem cells
ABSTRACT
With the aim of regenerating healthy tissues, different tissue engineering strategies pointed to extracellular matrix [ECM]-based scaffolds in tissue engineering and regenerative medicine and wound healing. It is a multidisciplinary science works to create biocompatible scaffolds with perfect physical parameters, mechanical integrity and high porosity to promote cell growth, migration and angiogenesis. With the increased incidence of obesity, subcutaneous adipose tissue is abundant and readily accessible. Liposuction surgeries yield from 100 mL to 3 L of lipoaspirate tissue. We present our prepared acellular ECM powders derived from human adipose tissue obtained from lipoaspirate, which contains large amounts of collagen suitable for induction of adipogenesis. The study had been carried out from December 2012 to March 2013 in Tissue Bank and Research Center in Imam Khomeini Hospital Tehran, Iran. Fresh human adipose tissue was obtained by liposuction of abdominal fat pad in a private Day Clinic. By using wasted material of liposuction, we obtained 100 to 200 cc fat tissue from each patient. After physical [freeze-thaw-slicing-manual massage] and chemical [enzymaticdetergent-acid digestion] treatment, an acellularized matrix was created from fat tissue. The final material lyophilized and ground to powder. We analyzed ultra structure and biochemical properties of obtained ECM powder by using electron microscopy, immunohistochemistry [IHC] examination and proteomic studies. After mechanical and chemical process of decellularization, scanning electron micrographs of the samples showed smooth and contiguous collagenous components throughout the scaffold. INC showed strong positive labeling for collagen IV and no evidence of nuclear material in the specimen. Separation of protein complex by Blue Native Polyacrylamide gel electrophoresis [BNPAGE] has proven type I collagen triple helices associate to form banded fibrils. RNA preparation and Gene Expression Analysis [RT-PCR] by using specific primers for laminin, fibronectin, collagen type I and IV, desmin, and actin showed strong staining of our fat tissue scaffold with collagen type I, fibronectin, collagen IV and laminin. The results show that our decellularization method produced an adipose ECM scaffold rich of collagen fibers, suitable and effective substrate for use in soft tissue engineering and regenerative medicine
ABSTRACT
Gastrointestinal [GI] cancers are a significant source of morbidity and mortality in Iran, with stomach adenocarcinoma as the most common cancer in men and the second common cancer in women. Also, some parts of Northern Iran have one of the highest incidences of esophageal cancer in the world. Multi-disciplinary organ-based joint clinics and tumor boards are a well-recognized necessity for modern treatment of cancer and are routinely utilized in developed countries, especially in major academic centres. But this concept is relatively new in developing countries, where cancer treatment centres are burdened by huge loads of patients and have to cope with a suboptimum availability of resources and facilities. Cancer Institute of Tehran University of Medical Sciences is the oldest and the only comprehensive cancer treatment centre in Iran, with a long tradition of a general tumor board for all cancers. But with the requirements of modern oncology, there has been a very welcome attention to sub-specialized organ-based tumor boards and joint clinics here in the past few years. Considering this, we started a multi-disciplinary tumor board for GI cancers in our institute in early 2010 as the first such endeavor here. We hereby review this 2-year evolving experience. The process of establishment of a GI tumor board, participations from different oncology disciplines and related specialties, the cancers presented and discussed in the 2 years of this tumor board, the general intents of treatment for the decisions made and the development of interest in this tumor board among the Tehran oncology community will be reviewed. The GI tumor board of Tehran Cancer Institute started its work in January 2010, with routine weekly sessions. A core group of 2 physicians from each surgical, radiation and medical oncology departments plus one gastroenterologist, GI pathologist and radiologist was formed, but participation from all interested physicians was encouraged. An electronic database was kept from the beginning. The number of patients presented in the tumor board increased from 4 in January 2010 to 16 in December 2011. Most patients were presented by radiation oncology department [38%] and then surgical [36%] and medical oncology [20%] departments. Physicians' participation also grew from an average of 8 each session to 12 in the same months, with a number of cancer specialists taking part from other university hospitals in Tehran. A total number of 225 patients were presented with a treatment decision made in this 2-year period. The majority of cases were colorectal [32%], stomach [23%], and esophageal [17%] cancers. The number of pancreatic [7%] and hepatobiliary [6%] cancers were much smaller. Most decisions were for a primary treatment [surgery or radiochemotherapy] and then a neoadjuvant approach. Tehran Cancer Institute's GI tumor board is one of the first multi-disciplinary organ-based tumor boards in Iran, and as such has made a successful start, establishing itself as a recognized body for clinical decisions and consultations in GI oncology. This experience is growing and evolving, with newer presentation and discussion formats and adapted guidelines for treatment of GI cancers in Iran sought
ABSTRACT
McGill pain questionnaire is the most useful standard tools for assessing pain. McGill pain questionnaire contains 78-word descriptive of the 20 subclasses forming in three main sensory, affective and evaluative domains. Due to cultural differences, the questionnaire has been translated into several languages. This study aimed to translate MPQ into Persian language and assess its reliability, validity and acceptability in patients with cancer. The study performed in Medical Oncology Department of Cancer Institute in Imam Khomeini Hospital in the Spring 2012. After translation of MPQ by two experts fluent in English, Persian version was returned to English. Then that backward translation was compared with the original questionnaire and words that did not match were reviewed. Patients with different types of cancer who suffering from chronic pain were admitted in our study. They did not receive any kind of pain killer drugs during the previous 24 hours. There was no restriction of age, sex, education, type of cancer or treatment modality. The reliability and validity of Persian-McGill pain questionnaire after interviewing patients was assessed by test-retest reliability and internal consistency [Cronbach's alpha]. In total, 84 patients were interviewed and 30 patients who were available after 24 hour with the same condition recomplete the questionnaire. Cronbach's alpha of each domain was in 0.622-0.743 and total Crobach's alpha [n=84] was 0.85. Evaluative aspect has only one subgroup and because of this, it is not have Crobach's alpha. The stability coefficient [n=30] in all areas [sensory, emotional, and other domains] were 0.812-0.964. Stability coefficient among the 20 Persian McGill Pain Questionnaire [PMPQ] subclasses showed significant and reliable relationships over time for all groups. This study is the first study that assessed psychometric properties and usefulness of the MPQ in Iranian patients with cancer, showed that it is a potentially useful measure with a high validity and reliability standards
ABSTRACT
Gastric cancer [GC] is one of the most common cancers in the world. Despite of improvements in cancer treatment, survival rate of these patients is low. There are various factors that influence on the recurrence. The aim of this study was to assess the survival of the gastric cancer patients with relapse and determine the related risk factors. A total of 93 gastric cancer patients with relapse who entered from 21 March 2003 to 21 March 2007 to the cancer institute of Imam Khomeini Hospital [Tehran] were surveyed in this study. The survival time was considered monthly from the time of cancer diagnosis up to death or end of study. The effect of various risk factors such as gender, diagnosis age, tumor site, pathologic stage of disease, type of treatment, degree of differentiation on survival patients after relapse are considered in this study. From 93 patients with relapse, 79.6% were men. 48.4% of patients were died during their follow up. The mean age from diagnosis to relapse was 15.7 +/- 11.7 and half of the patients experienced relapse 11 months after the treatment. Survival mean and median were 14.5 and 9 months respectively. One, three and five year survival of the patients was 0.42, 0.19 and 0.13 respectively. Pathologic stage, age at diagnosis, degree of differentiation and using radiography were significantly related to the survival. Half of the patients experienced relapse in the first year following their treatment. Thus, monthly referral of patients is necessary for timely diagnosis