Incidence of surgical procedures for gastrointestinal complications after abdominal wall closure in patients with gastroschisis and omphalocele.

PURPOSE: This study aims to define the extent of additional surgical procedures after abdominal wall closure (AWC) in patients with gastroschisis (GS) and omphalocele (OC) with special focus on gastrointestinal related operations. METHODS: A retrospective chart review was performed including all operations in GS and OC patients in the first year after AWC (2010-2019). The risk for surgery was calculated using the one-year cumulative incidence (CI). RESULTS: 33 GS patients (18 simple GS, 15 complex) and 24 OC patients (12 without (= OCL), 12 OC patients with liver protrusion (= OCL +)) were eligible for analysis. 43 secondary operations (23 in GS, 20 in OC patients) occurred after a median time of 84 days (16-824) in GS and 114.5 days (12-4368) in OC. Patients with complex versus simple GS had a significantly higher risk of undergoing a secondary operation (one-year CI 64.3% vs. 24.4%; p = 0.05). 86.5% of surgical procedures in complex GS and 36.3% in OCL + were related to gastrointestinal complications. Complex GS had a significantly higher risk for GI-related surgery than simple GS. Bowel obstruction was a risk factor for surgery in complex GS (one-year CI 35.7%). CONCLUSION: Complex GS and OCL + patients had the highest risk of undergoing secondary operations, especially those with gastrointestinal complications.

Association of PDCD1 gene markers with susceptibility to thyroid cancer.

PURPOSE: PD-1 receptor is a co-signaling molecule with an important role in regulation of T-lymphocyte activity. Correlation between PD-1 gene (PDCD1) polymorphisms and some immune-related diseases has been reported before. In current study, we aimed to investigate the association of PD-1 polymorphisms at positions +7146 G/A (PD-1.3) and +7785 C/T (PD-1.5), as well as the emerged haplotypes with susceptibility to thyroid carcinoma. METHODS: One hundred five patients with confirmed thyroid cancer and 160 healthy individuals as control group were enrolled. Genotypes were identified using PCR-RFLP and nested PCR-RFLP methods. Results were analyzed by Arlequin and SPSS software packages. RESULTS: Analysis revealed a significant increase in the frequency of PD-1.5 mutant T allele and heterozygous CT genotype in patients with thyroid cancer in comparison with controls [79 (37.7%) vs. 71 (22.2%), and 51 (48.6%) vs. 51 (31.9%), p = 0.0001 and p = 0.009, receptively]. CC genotype at this position observed to be significantly higher among controls than the patients [99 (61.9%) vs. 40 (38.1%), p = 0.0002]. There were no significant differences in the frequencies of genotypes and alleles at locus PD-1.3 between patients and control group. Despite this, GT haplotype emerged from both positions (PD-1.3 G and PD-1.5 T) has also been observed with significant increased frequency between patients and controls [70 (36.8%) vs. 71 (22.2%), p = 0.0005]. CONCLUSION: As the first study to investigate two mentioned polymorphisms in thyroid cancer, current study confirmed the association of PD-1.5 C/T polymorphism and a haplotype resulted from both loci, PD-1.3 and PD-1.5, with susceptibility of Iranians to thyroid cancer.

Helper and cytotoxic T-cell subsets (Th1, Th2, Tc1, and Tc2) in benign and malignant salivary gland tumors.

OBJECTIVE: The objective of this study was to explore the prevalence of T helper type 1 (Th1; CD4(+) IFN-γ (+) ) and Th2 (CD4(+) IL-4(+) ) cells, as well as cytotoxic T cell type 1 (Tc1; CD8(+) IFN-γ(+) ) and Tc2 cells (CD8(+) IL-4(+) ) in peripheral blood of the patients with salivary gland tumors (SGTs). SUBJECTS AND METHODS: Thirty new patients with SGTs and 15 healthy controls were recruited. After intracellular cytokine staining, data acquisition and analysis were performed by flow cytometry. RESULTS: The mean percentages of Th1 and Tc1 cells, as well as the ratios of Th1/Th2 and Tc1/Tc2, were observed to be significantly lower in patients with malignant SGTs in comparison with controls. Furthermore, the geometric mean fluorescent intensity (geometric MFI, representing the cytokine expression intensity) for IL-4 production by Th2 and Tc2 lymphocytes was significantly higher in patients with malignant tumors than controls. Positive correlations were observed between the mean percentage of Tc2 cells with Th2 cells, and with the tumor size in patients with benign and malignant tumors, respectively. CONCLUSION: The findings suggest that the imbalance of Th1/Th2 and Tc1/Tc2 ratios, as well as the increase in the expression of IL-4 by Th2 and Tc2 lymphocytes, may contribute to the pathogenesis of SGTs, especially in malignant cases.

Reproductive behaviour of mothers of children with beta-thalassaemia major.

Thalassaemia is the most common monogenic autosomal hereditary disease worldwide. This questionnaire-based cross-sectional study looked at the reproductive behaviour of 156 mothers of children affected with beta-thalassaemia major (Cooley anaemia) in Fars province, southern Islamic Republic of Iran. Regardless of the number of affected children, the parents of children with Cooley anaemia had an average of 3 unaffected children, the same as the average for the provincial population. The findings indicate that reproductive compensation occurs in families with a child with Cooley anaemia in this province. Genetic counselling, either before marriage or after the birth of the first affected child, had a significant effect on lowering the number of children born.

Ambient-temperature time-dependent deformation of cast and additive manufactured Al-Cu-Mg-Ag-TiB2 (A205).

A dual-stage indentation test at ambient temperature including a constant indentation load rate followed by a constant indentation load-hold segment was employed to assess the time-dependent plastic deformation of cast and additive manufactured Al-Cu-Mg-Ag-TiB2 alloys in as-fabricated and T7 conditions at room temperature. Optical microscopy, scanning electron microscopy, electron backscattered diffraction, and transmission electron microscopy techniques were used to study the microstructure of the samples and to correlate the microstructure with the creep properties. That is, the indentation load/displacement/time data from depth-sensing indentation creep were combined with the advanced microstructural assessments to analyze the controlling mechanisms of creep in as-cast, as-built, and T7 samples. Expectedly, the microstructure of samples manufactured by different methods was substantially different in terms of the grain size and the distribution of TiB2 particles. The θ'', θ' and Ω phase were formed in all heat-treated samples; however, the density of Ω phase was higher in the cast-T7 samples. Distinct microstructure and precipitation density resulted in different indentation-derived properties, both cast and AM samples at T7 condition showed enhanced creep resistance compared to their as-manufactured counterparts. The main controlling mechanism of creep deformation was found to be dislocation creep based on the indentation-derived creep stress exponent values.

Trace minerals source in calf starters interacts with birth weights to affect growth performance.

The present study was conducted to investigate the effects of partial replacement of inorganic minerals (IM) with trace minerals in advance chelate components form in starter diets for calves of different birth weights on performance, health, and behavior of Holstein calves. Fifty-two calves were assigned to 1 of 4 treatments in a 2 × 2 factorial arrangement with two mineral sources (IM or advanced chelated minerals (ACMS)) and two birth weights (low or normal birth weight; LBW or NBW). Calves were weaned on d 56 and remained until d 71 of the study. Results showed that NBW calves had higher feed intake, withers and hip height, larger heart girth and lower fecal score than LBW calves throughout the study. Calves receiving ACMS tended to have higher feed intake, larger hip width, lower eye and nose scores, and lower rectal temperature throughout the study than IM calves. In addition, ACMS calves had larger abdominal girths at d 56 of the study compared to IM calves. Interactions between birth weights and mineral sources for preweaning average daily gain (ADG) and weaning and final BW showed that ACMS supplementation improved ADG and BW in LBW calves. Non-nutritive oral behavior was lower in ACMS calves compared to IM calves during all periods. Overall, ACMS feeding decreased non-nutritive oral behavior and improved calf health status during the study. In addition, feeding ACMS to dairy calves with LBW increased their ADG to a similar extent as to NBW calves, suggesting an improvement in their efficiency.

Indentation-derived creep response of cast and laser powder bed fused AlSi10Mg alloy: Air temperature.

Compared with time-consuming conventional uniaxial tensile/compressive creep experiments, depth-sensing indentation testing is considered a reliable, and convenient testing technique to assess the time-dependent plastic deformation of materials in a reasonable time scale. In the present study, we report the ambient (room) temperature indentation creep properties of additively manufactured (i.e., laser-powder bed fused) and cast AlSi10Mg alloy at as-fabricated and different post-fabrication heat treatment states. The indentation creep testing parameters (i.e., dwell time, peak indentation load, and indenter shape) were optimized to adequately represent the creep response (time-displacement) variations for different material conditions. To this end, dual-stage, constant loading rate followed by constant-load holding, pyramidal indentation experiments were performed at a loading rate of 10 mN/s, a peak load of 200 mN, and a dwell time of 400 s. Besides, electron backscattered diffraction was performed to evaluate the manufacturing process (selective laser melted versus cast)/ post-fabrication heat treatment/ texture/ creep properties relationships for the studied AlSi10Mg alloy. Also, the indentation hardness, indentation strain rate sensitivity, indentation creep exponent, and activation volume were analyzed to study and confirm the mechanism of indentation creep. The calculated high values of creep stress exponents (i.e., >10) are attributed to dislocation-reinforcing particle interaction as the controlling mechanism of the creep which agrees with this assumption that AlSi10Mg is indeed an in-situ metal matrix composite with eutectic silicon as the reinforcing particles.

An overview of microscale indentation fatigue: Composites, thin films, coatings, and ceramics.

There are many applications from computer hardware and sensors to thin films and coatings in which parts are fabricated in small sizes and low thicknesses. Most of these applications could undergo cyclic loading and unloading conditions during their operation. Therefore, cyclic and fatigue evaluations of these components are an essential topic and should be fully understood. In these cases, due to the dimensional limitations, conventional methods of the fatigue experiments encounter challenges and mostly are not accurate or applicable. Nano- and micro-indentation fatigue tests are considered non- or semi-destructive experiments that have opened a new approach to study the cyclic response of these small-sized specimens and thin films. The objective of the present review paper is to evaluate a convenient, reliable, and non-destructive testing approach in the assessment of fatigue (cyclic) response of materials on a small scale. Along with conventional bulk scale fatigue testing methods (i.e. reverse bending, pull-push, multi-axial bending), the depth-sensing indentation testing technique can be employed to study the cyclic behavior of metallic and non-metallic materials especially when a limited volume of the material is available. In this paper, we tried to cover most of the previous studies performed on indentation fatigue of composites, thin films, coatings, and ceramics along with associated discussions and main findings. We covered the physics behind the indentation and the difference between the indentation and conventional fatigue analyses. Followed by that, microstructural evaluations of some of the studies are provided to give readers more insights into this approach. In most applications, the indentation fatigue technique could be a reliable solution due to its accuracy, simplicity, and nondestructive approach in finding out the fatigue and cyclic behavior of materials having a small size or volume. It is worth noting that the loading mode in the indentation fatigue is completely different than the traditional (bulk-scale) fatigue as the tensile segment of the load cycle is not produced in the indentation fatigue (it is a compression-compression loading cycle). Therefore, the controlling mechanisms of failure between small-scale fatigue and bulk-scale fatigue may not be the same.

Th e eff ects of Nigella Sativa extract on renal tissue oxidative damage during neonatal and juvenile growth in propylthiouracil-induced hypothyroid rats.

OBJECTIVE: We investigated the effects of hydroalcoholic extract of Nigella sativa (NS) on renal tissue oxidative damage associated with propylthiouracil (PTU)-induced hypothyroidism during neonatal and juvenile growth in rats. METHODS: Pregnant rats were divided into five groups designated as: 1) control; 2) propylthiouracil (PTU); 3) PTU-NS100; 4) PTU-NS200, and 5) PTU-NS400. All mothers except the control group received 0.005% PTU in their drinking water during lactation. Besides PTU, mothers in groups 3-5 received 100, 200, and 400 mg/kg of NS extract. After lactation period, the off spring continued to receive the same experimental treatment for the first 8 weeks of their life. Ten male off springs of each group were randomly selected, blood samples collected, and the kidney tissues removed. RESULTS: The serum thyroxin concentration in PTU group was lower than control group and improved by extract. PTU increased the renal malondialdehyde (MDA), while reduced the total thiols concentrations and catalase (CAT) and superoxide dismutase (SOD) activity compared to control group. Administration of 200 and 400 mg/kg of NS extract decreased MDA level, while it increased the total thiols and 400 mg/kg increased CAT and SOD activity in renal tissues compared to PTU group. Serum creatinine and blood urea nitrogen (BUN) in PTU group was higher than in comparison with the control group. 400 mg/kg decreased creatinine, but both 200 and 400 mg/kg improved BUN concentration compared to PTU group. CONCLUSION: The results of this study demonstrate that the hydroalcoholic extract of NS has a protective effect on the renal tissue oxidative damage associated with PTU-induced hypothyroidism during neonatal and juvenile growth in rats.

Bone marrow transplantation in thalassemia major patients using "short" anti-thymocyte globulin therapy in Shiraz, Southern Iran.

Allogeneic bone marrow transplantation (BMT) was performed on 113 Iranian transfusion-dependent thalassemia major patients from May 1993 through September 2003. To have at least 2 years follow-up, we report BMT on 90 patients transplanted up to December 2001. The donors were human leukocyte antigen (HLA)-identical, mixed lymphocyte culture (MLC)-nonreactive siblings (n = 74) on parents (n = 6); HLA-identical MLC-reactive siblings (n = 5) or parents (n = 1); and one HLA antigen-mismatched sibling (n = 4). The induction regimen in 11 patients was oral busulfan (BU) (14 mg/kg) and IV cyclophosphamide (CY; 200 mg/kg); in fifteen patients it was BU (15 mg/kg) and cyclophosphamide (CY; 200 mg/kg); in 47 patients, BU (15 mg/kg), CY (200 mg/kg), and short course of anti-thymocyte globulin (ATG, horse; 40 mg/kg including 10 mg/kg on days -2, -1, +1, +2); and in 15 patients, BU (15 mg/kg) CY (200 mg/kg), and ATG (60 to 100 mg/kg; 10 mg/kg at 3 to 5 days before and after BMT). Graft-versus-host disease (GVHD) prophylaxis consisted of cyclosporine and prednisolone. The group who received BU (14 mg/kg) and CY (200 mg/kg), as compared to the group receiving BU (15 mg/kg) and CY (200 mg/kg), was of younger age and lower risk; median age 7 versus 10 years, and 46% versus 7% in Lucarelli's risk group class I (the best prognostic group), respectively. These patients showed a lower disease-free survival (DFS), namely 64% versus 73%, with a follow up of 2 to 10.5 years. Thus from 9.5 years ago, our standard protocol for BU has been 15 mg/kg. The group who received "short" ATG (40 mg/kg), BU (15 mg/kg), and CY (200 mg/kg) showed almost the same outcome as the group who received a higher dose of ATG (60 to 100 mg/kg), namely DFS 72% versus 73%, respectively, despite the fact that half of both groups were included in the Lucarelli's risk group class III (the worst prognostic group) 49% versus 53%. We showed the same DFS for the patients who received BU (15 mg/kg), CY (200 mg/kg), and no ATG compared with the ATG group (73% vs 72%), but 27% of the group without ATG developed grade IV acute GVHD and 54% developed chronic GVHD. In the group with short ATG, 15% and 17% of patients developed grade IV acute and chronic GVHD, respectively. There was no significant difference for falls in platelets and white blood cell or engraftment days and the number of packed red blood cell transfusions among the groups. The median hospital stay was longer for the group with BU (15 mg/kg), CY (200 mg/kg) namely 81 versus 61 to 65 days. Second bone marrow infusions were needed in 6% and 20% of patients who received ATG doses of (40 versus 60 to 100 mg/kg; respectively (1 to 2 month post-BMT). BU at a dose of 15 mg/kg was more effective than 14 mg/kg BU for its myeloablative properties. By adding "short" ATG course to the conditioning regimen, the incidence of grade IV acute and chronic GVHD was reduced in thalassemic patients, especially when an HLA disparity was present.

Visual failure caused by suprasellar extramedullary hematopoiesis in beta thalassemia: case report.

OBJECTIVE AND IMPORTANCE: Small deposits of extramedullary hematopoiesis, acting as epileptogenic foci, have been observed near convexity dura and adjacent to falx cerebri. These foci could potentially grow and act as space-occupying lesions, producing focal neurological deficits. This condition was observed in a unique case of thalassemia major, with progressive visual loss caused by extramedullary hematopoiesis originating from the base of the cranium and extending up to the inferior third ventricle. The patient had been operated on 4 years earlier to relieve the compressive effects of ectopic marrow in the thoracolumbar epidural space. CLINICAL PRESENTATION: A 21-year-old man is reported with progressive visual loss caused by compressive optic neuropathy as a result of extramedullary hematopoiesis. Computed tomography of the head revealed a suprasellar and parasellar enhancing mass originating from the pre-sphenoid cranial base and approaching the lower third ventricle. INTERVENTION: Partial resection of the tumor was accomplished by a transsphenoidal approach. Monthly blood transfusions and low-dose radiotherapy of the appropriate anatomic structures were then performed. The patient's visual acuity improved only modestly. CONCLUSION: Extramedullary hematopoiesis, although extremely rare, could arise from the base of the cranium and act as a parasellar tumor. When any patient with thalassemia major requiring multiple transfusions develops visual failure, appropriate studies should be performed to rule out compression of visual pathways by ectopic marrow, especially if the patient is receiving deferoxamine.

Bone marrow transplantation for hematological disorders--Shiraz experience.

OBJECTIVE: In the past 8 years, 120 cases of hematological disorders were transplanted from the HLA identical donors. METHOD: Using chemotherapy based conditioning regimen with cyclophosphamide 200 mg/kg and busulfan 15-16 mg/kg, 80 cases of beta-thalassemia major and 35 cases of leukemia and five patients with aplastic anemia had received bone marrow transplantation. RESULT: The five-year-survival in thalassemic group was 72%, for leukemic group (acute and chronic) was 58%, and also for aplastic anemia 65%. Transplantation related mortality was the cause of death in 29 cases. The two major causes of death were acute graft versus host disease and poor medical condition of patients before marrow transplantation. CONCLUSION: At the present time, allogenic marrow transplantation is curative mode of treatment for many hematological diseases.

Bone marrow transplantation in thalassaemia patients in Shiraz, Islamic Republic of Iran.

We report the results of allogeneic bone marrow transplantation in 26 female and 37 male patients with beta-thalassaemia major (age range: 2-17 years), performed at Namazi Hospital over the period 1992-99. In all cases, standard conditioning and immunosuppressive regimens were employed. Currently, 50 patients remain thalassaemia-free, 9 of whom have developed chronic graft-versus-host disease. There were 8 deaths among the 13 unsuccessful transplant cases: 4 due to acute uncontrollable graft-versus-host disease, and 4 to non-transplant-related causes such as hypoglycaemia, hypersensitivity reactions and advanced disease. We conclude that allogeneic bone marrow transplantation is an effective therapy for the treatment of beta-thalassaemia major, particularly for patients classified as classes I and II.

Acute graft-versus-host disease in thalassaemic marrow transplantation with low-dose antithymocyte globulin.

Our unit performed transplantations on 21 classes II and III thalassaemic patients (class II patients had either hepatomegaly or portal fibrosis and class III patients had both). We used busulfan (15 mg/kg) and cyclophosphamide (200 mg/kg). Graft-versus-host disease (GVHD) prophylaxis was cyclosporin, prednisolone and low-dose antithymocyte globulin. Our patient data showed a low incidence of acute GVHD following transplantation. We offer this regimen as an acceptable therapy for thalassaemic patients undergoing allogeneic marrow transplantation as a safe clinical procedure, irrespective of the class of patient.

Auditory screening in infants for early detection of permanent hearing loss in northern iran.

BACKGROUND: Undiagnosed hearing loss can cause disorders in speech and language and delay in social and emotional development. AIM: This study aimed to screen for hearing loss in all newborns born in Babol city during 2009-2011. SUBJECTS AND METHODS: Fifteen thousand one hundred and sixty-five newborns (49% [7430/15165] male and 51% [7735/15165] female) born during a 30-month period in Babol, underwent hearing screening by the otoacoustic emission (OAE) test at the age of 15 days. In infants referred at this stage, an auditory brainstem response (ABR) test was the next investigation. Data analyzed using Statistical Package for the Social Sciences software Version 16 (Chicago, IL, USA, 16) through descriptive statistic method. RESULTS: In the first screening stage, 10.8% (1648/15165) cases were referred to the second stage for further investigation. 9.4% (154/1648) were lost to follow-up from among the referred cases despite continuous contact and education about the importance of the problem. Among the participants in the second stage, 6.2% (92/1494) were referred to the third stage and underwent ABR and OAE testing. 14.1% (13/92) were lost at this stage. Of the remaining participants, 34.2% (27/79) were diagnosed with a hearing loss. Therefore, the incidence of hearing loss in this study was 1.8/1,000 newborns. CONCLUSION: Given the prevalence of hearing loss in this study, implementation of a universal newborn hearing screening program is recommended.

Genetic diversity of HCV among various high risk populations (IDAs, thalassemia, hemophilia, HD patients) in Iran.

OBJECTIVE: To determine the patterns of distribution of HCV genotypes among high risk population in north of Iran. METHODS: A cross-sectional study was conducted on 135 HCV RNA-positive high risk individuals including thalassemia, hemophilia, patients under hemodialysis and intravenous drug addicts. HCV genotypes were determined based on amplification with type-specific primers methods. RESULTS: Among the 187 anti-HCV positive samples, only 135 (72.2%) gave HCV-RNA positvity. Over all, the most identified HCV type was genotype 3a (51.1%) followed by 1a (27.4%), 1b (8.2%). Sixteen (11.9%) out of 135 HCV RNA-positive participants have infected with more than one genotype or subtypes as follow; 1a/1b in 11 (8.2%), 2/3a in 3 (2.2%), and 1a/1b/3a in 2 (1.5%). Stratification of participants revealed that HCV subtype 3a was more prominent in thalassemia, hemophilia and HD patients but 1a and 1b were frequent in intravenous drug addicts. CONCLUSIONS: This study is the first report on HCV genotypes among Iranian subjects with different exposure categories resided in Mazandaran, where genotype 3a was found to be the most frequent genotype in thalassemia, hemophilia, and hemodialysis patients but not in IDAs. Since the addiction age is decreasing in Iran and a lot of addicts are IDAs, it might change the subtype pattern of HCV in general population.

Interferon-gamma low producer genotype +5644 over presented in patients with focal brucellosis.

Genetic polymorphisms that affect production levels of certain cytokines may determine the risk, severity or protection in some infectious diseases like brucellosis. IFN-gamma plays a key role in the defense mechanism against brucella infection. This study aimed to determine the influence of the polymorphism within the +5644 position of IFN-gamma gene on the susceptibility to brucellosis. We investigated the allelic and genotypes distribution of A5644G polymorphism in IFN-gamma gene in an Iranian population comprising 259 patients with brucellosis and 238 healthy controls. The single nucleotide polymorphism was determined using the polymerase chain reaction in association with sequence-specific primers (PCR-SSP) incorporating mismatches at the 3'-end. Allelic and genotype frequencies of G5644A polymorphism of IFN-gamma gene were not significantly differed between patients with brucellosis and controls (p > 0.05). Stratification of patients to focal and non focal diseases revealed a significant increased of 5644A allele in patients with focal brucellosis (79.31% vs. 61.94%, p = 0.0005). Moreover, multivariate logistic regression models showed patients harboring the INF-y G5644A genotype were significantly more likely to develop focal infectious complications (OR = 3.45, p = 0.0004, 95% CI = 1.26-7.94). The present study suggests that the variant genotypes of G6544A of IFN-gamma might be associated with focal form of brucellosis and play as a genetic risk factor in brucellosis.

p 53 codon 72 polymorphism in stomach and colorectal adenocarcinomas in Iranian patients.

BACKGROUND: The association of a functional single nucleotide polymorphism at codon 72 of the p53 gene (Arg72Pro) with malignancy is a subject of controversy. We analyzed this polymorphism in 224 patients with gastrointestinal cancers (92 with stomach cancer and 132 with colorectal cancer) and in 163 healthy controls. MATERIAL AND METHODS: DNA was extracted from peripheral blood mononuclear cells and amplified with an allele-specific polymerase chain reaction. RESULTS: There was no significant association between p53 alleles and gastrointestinal cancers. The frequency of the Arg allele was 59.7, 58.8, and 59.2% in the stomach cancer patients, colorectal cancer patients, and controls, respectively. Frequencies of the Pro allele were 40.3% in patients with stomach cancer, 41.2% in patients with colorectal cancer, and 40.8% in controls. Likewise, genotype frequencies did not differ significantly between the two patient groups and controls. There were no differences in genotype or allele frequencies by gender, age, or histological grade. CONCLUSIONS: The data do not support the association of the p53 codon 72 polymorphism with stomach or colorectal cancers in Iranian patients.