47 research outputs found
Determining Overall Survival and Risk Factors in Esophageal Cancer Using Censored Quantile Regression
BACKGROUND:
Esophageal cancer is one of the leading causes of death worldwide. The global increasing rate of this type of cancer requires more attention. The purpose of this study was to determine the overall survival probability of esophageal cancer after diagnosis and to assess the potential risk factors in a population of Iranian patients.
MATERIALS AND METHODS:
This retrospective cohort study was conducted on 127 cases with esophageal cancer in the Azarbaijan province, East of Iran. Participants in the study were diagnosed during 2009-2010 and were followed up for 5 years. The event was considered death due to esophageal cancer and those who survived until the end of the study were assumed as right censored. Censored quntile regression was fitted to find the overall survival of the patients using adjusted effects of variables and was compared with Cox regression model.
RESULTS:
Patients’ mean and median survival time were 16.99 and 10.06 months respectively and 89% off cases died by the end of the study. The 1, 3, 6, 12 and 36-month survival probabilities were 0.95, 0.76, 0.60, 0.43, and 0.18. The median survival time for females and males without surgery were 21.79 and 14.76 month respectively. The accuracy of predictions were 0.99 and 0.74 for the censored quantile regression and Cox, respectively.
CONCLUSION:
We concluded that being male, not having surgery, longer wait time between having symptoms and being diagnosed, low socioeconomic status and old age to be significant risk factors in reducing the probability of survival from esophageal cancer
Epidemiological Aspects of Visceral Leishmaniasis in Baft District, Kerman Province, Southeast of Iran
Background: Visceral leishmaniasis (kala-azar) is an endemic disease in some areas of Iran. A cross- sectional study was conducted for sero-epidemiological survey of visceral leishmaniasis (VL) in Baft district from Kerman Province, southeast of Iran.Methods: Blood samples were collected from children up to 12 years old and 10% of adult population from Baft villages with a multi-stage randomized cluster sampling. In addition, blood samples were collected from 30 domestic dogs from the same areas. All the collected blood samÂples were tested by direct agglutination test (DAT) for the detection of anti-Leishmania antibodÂies in both human and dog using the cut-off value of ≥1:3200 and ≥ 1:320, respectively. ParasitologiÂcal, molecular, and pathological were performed on infected dogs. Chi-square and Fisher exact tests were used to compare sero-prevalence values.Results: From 1476 collected human serum samples, 23 (1.55%) showed anti-Leishmania antibodÂies at titers of 1:800 and 1:1600 whereas 14 (0.95%) showed anti-Leishmania infantum antibodies at titers of ≤ 1:3200. No statistically significant difference was found between male (1.18 %) and female (0.69%) sero-prevalence (P=0.330). Children of 5-8 years showed the highÂest sero-prevalence rate (3.22%). Seven out of 30 domestic dogs (23%) showed anti-Leishmania antibodies at titers ≤1:320. Leishmania infantum was identified in five infected dogs by nested - PCR assay.Conclusion: It seems that visceral leishmaniasis is being endemic in southern villages of Baft district, southeast of Iran
Determining risk factors for gastric and esophageal cancers between 2009-2015 in East-Azarbayjan, Iran using parametric survival models
Background: Esophageal cancer (EC) and Gastric cancer (GC) have been identified as two of the most common cancers in the northeastern regions of Iran. The increasing rates of these types of cancers requires attention. This study aims to assess the potential risk factors for these two cancers and then determine shared risk factors between them in a population of Iranian patients using parametric survival models. Methods: This retrospective cohort study was conducted using 127 patients with EC and 184 patients with GC in East Azarbaijan, Iran who were diagnosed and registered during the years 2009-2010 in Iran's National Cancer Control Registration Program and were followed for five years. Parametric survival models were used to find the risk factors of the patients. Akaike Information Criteria was used to identify the best parametric model in this study. Interaction analysis was used to determine shared risk factors between EC and GC. Results: The mean (±standard deviation) age of diagnoses for EC and GC were 66.92(±11.95) and 66.5(±11.5) respectively. The survival time ranges of GC patients was (0.07-70.33) and the survival time ranges were from 0.10 to 69.03 months for EC patients. Multivariable Log- logistic model showed that being married (OR=2.25, 95% CI: 1.33 - 3.81) for EC patients and Esophagectomy surgery for EC (OR: 1.62, 95% CI: 1.04 - 2.55) and GC (OR: 1.60, 95% CI: 1.02 - 2.53) had significant effects on survival. Age at the time of diagnosis, job status, and Esophagectomy surgery were statistically comparable regarding their magnitude of effect on survival of two cancers (all Ps > 0.05). Conclusion: Esophagectomy surgery and being married were important risk factors in EC and GC. The log-logistic model was the most appropriate statistical approach to identify significant risk factors on survival of both cancer
Hybrid Vapor-Solution Sequentially Deposited Mixed-Halide Perovskite Solar Cells
The recent sky-rocketing performance of perovskite solar cells has triggered a strong interest in further upgrading the fabrication techniques to meet the scalability requirements of the photovoltaic industry. The integration of vapor-deposition into the solution process in a sequential fashion can boost the uniformity and reproducibility of the perovskite solar cells. Besides, mixed-halide perovskites have exhibited outstanding crystallinity as well as higher stability compared with iodide-only perovskite. An extensive study was carried out to identify a reproducible process leading to highly crystalline perovskite films that when integrated into solar cells exhibited high power conversion efficiency (max. 19.8%). This was achieved by optimizing the deposition rate of the PbI2 layer as well as by inserting small amounts of methylammonium (MA) bromide and chloride salts to the primary MAI salt in the solution-based conversion step. The optimum MABr/MAI molar ratio leading to the most efficient and stable solar cells was found to be 0.4. Stabilities were in excess of 90 hours for p-i-n type solar cells. This reproducible approach towards the fabrication of triple halide perovskites using a hybrid vapor-solution method is a promising method towards scalable production techniques
Spatial Distribution and Molecular Identification of Leishmania Species from Endemic Foci of South-Eastern Iran
Background: Cutaneous leishmaniasis constitutes a major public health problem in many parts
of the world including Iran. The primary objective of this study was to identify Leishmania species in endemic districts of Kerman Province, south-eastern Iran.
Methods: This study was conducted by random sampling as cross- sectional descriptive between
2008 and 2010. Overall, 203 skin scraping smears were taken from the patients. Nested –PCR
was performed to amplify variable minicircle fragments of Leishmania kDNA.
Results: Bam was the most infected district (71.1%), followed by Kerman (14.7%), Jiroft (5.4%),
Baft (2.7%), Sirjan (1.6%), Shahr-e Babak (1.5%) and others (3.0%). L. tropica was the most
common species identified (194 cases, 95.6%), while L. major was found in only 9 cases (4.4%).
Of 203 identified patients, all species in Bam (l07 cases), Kerman (32 cases), Jiroft (l6 cases) and
Shahr-e- Babak (l1 cases) were detected as L. tropica, whereas infected subjects in Baft and Sirjan showed L. tropica or L. major. Characterization of Leishmania species resulted in generation
of 750 bp and 560 bp fragments, corresponding to those of L. tropica and L. major, respectively.
Conclusion: L. tropica is the main species (95.6%) caused ACL in endemic areas of Kerman
Province; however L. major is present in low level (4.4%)
Biallelic variants in the ectonucleotidase ENTPD1 cause a complex neurodevelopmental disorder with intellectual disability, distinct white matter abnormalities, and spastic paraplegia.
OBJECTIVE: Human genomics established that pathogenic variation in diverse genes can underlie a single disorder. For example, hereditary spastic paraplegia (HSP) is associated with over 80 genes with frequently only few affected individuals described for each gene. Herein, we characterize a large cohort of individuals with biallelic variation in ENTPD1, a gene previously linked to spastic paraplegia 64 (MIM# 615683). METHODS: Individuals with biallelic ENTPD1 variants were recruited worldwide. Deep phenotyping and molecular characterizations were performed. RESULTS: A total of 27 individuals from 17 unrelated families were studied; additional phenotypic information was collected from published cases. Twelve novel pathogenic ENTPD1 variants are described: c.398_399delinsAA; p.(Gly133Glu), c.540del; p.(Thr181Leufs* 18), c.640del; p.(Gly216Glufs* 75), c.185T>G; p.(Leu62*), c.1531T>C; p.(*511Glnext* 100), c.967C>T; p.(Gln323*), c.414-2_414-1del, and c.146 A>G; p.(Tyr49Cys) including four recurrent variants c.1109T>A; p.(Leu370* ), c.574-6_574-3del, c.770_771del; p.(Gly257Glufs*18), and c.1041del; p.(Ile348Phefs*19). Shared disease traits include: childhood-onset, progressive spastic paraplegia, intellectual disability (ID), dysarthria, and white matter abnormalities. In vitro assays demonstrate that ENTPD1 expression and function are impaired and that c.574-6_574-3del causes exon skipping. Global metabolomics demonstrates ENTPD1 deficiency leads to impaired nucleotide, lipid, and energy metabolism. INTERPRETATION: The ENTPD1 locus trait consists of childhood disease-onset, ID, progressive spastic paraparesis, dysarthria, dysmorphisms, and white matter abnormalities with some individuals showing neurocognitive regression. Investigation of an allelic series of ENTPD1: i) expands previously described features of ENTPD1-related neurological disease, ii) highlights the importance of genotype-driven deep phenotyping, iii) documents the need for global collaborative efforts to characterize rare AR disease traits, and iv) provides insights into the disease trait neurobiology. This article is protected by copyright. All rights reserved
The Prevalence of Cutaneous Leishmaniasis in the City and Suburb of Mohammadabad, Jiroft District and Identification of Parasite Species by Nested-PCR, 2008
Abstract:
Background & Aims: Cutaneous leishmaniasis (CL) is a health problem in the world, including Iran. The objective of this study was to assess the epidemiology of CL and determination of the causative parasite species in the city and suburb of Mohammadabad, Jiroft district.
Method: This descriptive and cross-sectional study was performed in census manner. Diagnosis was based on direct smear microscopy and Nested-PCR technique was applied for the identification of species.
Results: Overall, 3516 individuals consisting of 1743 females (49.6%) and 1773 males (50.4%) were physically examined for the presence of active lesion or scar. The prevalence rate was 6.2% in female and 4.5% in male subjects with a significant difference (P<0.05). Most of the infection was in the age group of 11-20 years (10.5%) and the lowest was in the age group of 21-30 year (3%). Most of the lesions were on the face (47%) and the majority (64%) had one lesion. Based on Nested-PCR technique all examined cases were Leishmania tropica.
Conclusion: This study has been conducted for the first time in north of Jiroft district in proximity of Bam district. Increasing rate of this disease after the earthquake and in accordance with the epidemic condition in the city of Bam is due to the frequent traveling of people to this rural area.
Keywords: Cutaneous Leishmaniasis, Epidemiology, Leishmania Species, Nested-PCR, Jirof
Identification of Nonresponsive Isolates to Glucantime in Patients with Cutaneous Leishmanaisis in Bam
abstract:
Background & Aims: Cutaneous leishmaniasis (CL) is a prevalent disease worldwide including Iran. In Iran Leishmania tropica and Leishmania major are two causing factors of cutaneous leishmaniasis and Bam is one of the old and well-known focuses of CL. The objective of the present study was to identify the resistant isolates to meglumine antimoniate (MA) for implementation of future control measures in Bam.
Methods: This work has been conducted during 2009-2010 in the city of Bam and Kerman School of Medicine. From a total of 2126 patients with CL, 235 patients (11.1%) were resistant against MA (Glucantime) of whom 51 ones were randomly selected. Skin scrapings were taken for direct smear preparations and culture media and Nested-polymerase chain reaction (PCR) were used for species identification.
Findings: In this study, 122 males (51.9%) and 113 females (48.1%), resistant to MA were identified that shows no significant difference between the two sexes. With a significant difference most of the resistant patients were in the age group 11-21 years (29.4%), followed by ≤ 10 years (21.6%) and the lowest were in the age group≥ 55 years (5.9%). Most of the lesions were on face (55.5%), the majority had one lesion (64.5%) and 33.3% received MA intra -lesionally. According to the results of PCR, all 51 isolates were Leishmania tropica.
Conclusion: To our knowledge this is the first study that is carried out on the resistant patients to MA in Bam. Since the incidence of this disease and drug resistance have been increased after the earth quake of 2003, further studies to identify genetic variants of resistant isolates in order to use new alternative drugs are required.
Keywords: Cutaneous leishmaniasis, Leishmania tropica, Drug resistance, Nested PCR, Ba
Effect of Printing Parameters on Mechanical Performance of Material-Extrusion 3D-Printed PEEK Specimens at the Point-of-Care
Additive manufacturing (AM) of polyetheretherketone (PEEK) biomaterials using the material-extrusion (MEX) method has been studied for years. Because of the challenging manufacturing process, precisely controlling printing parameters is crucial. This study aimed to investigate the effects of printing parameters such as orientation and position of printing on mechanical properties. Thus, 34 samples were printed using PEEK filament and the MEX process. Samples were divided into two main groups (A,B) according to their printing orientations (A: groups 1–3) and positions on the build plate (B: groups 4–8). Mechanical tensile tests were performed to evaluate the effects of different printing orientations and positions on mechanical properties. The means of the tensile modulus in samples 3D-printed in XY (group 1), XZ (group 2), and ZX (group 3) orientations were not significantly different (p-value = 0.063). Groups 1 and 2 had smaller distributions than group 3 in the means of tensile strength. The t-test showed that the overall means of the measurements in groups 4–8 did not differ significantly (p-value = 0.315). The tensile tests indicated that printing in vertical and horizontal orientations had no significant influence on mechanical properties. There were no significant differences in mechanical strength between top/bottom printed samples in five different lateral positions. Reliability of printing with good mechanical properties could be a step forward to manufacturing patient-specific implants