فهرست مطالب samaneh hashemi

Since the outbreak of COVID-19 in December 2019, patients with End-Stage Kidney Disease (ESKD) have been deemed one of the most vulnerable populations due to their numerous comorbidities.

The study was a retrospective cohort study conducted between March 2nd, 2020, and September 21st, 2020. It included 240 patients who underwent MHD at Shahid Beheshti and Vali-Asr Hospitals affiliated with Abadan University of Medical Sciences. Out of these patients, 44 were diagnosed with COVID-19 based on their Reverse transcriptase polymerase chain reaction (rRT-PCR) test results or chest CT scan findings. Demographic, clinical, laboratory and radiologic findings of these patients were collected.

COVID-19 was diagnosed in 44 individuals, which accounts for 18.33%, and eight patients have died, which is 18.1% of the total COVID-19 cases. A total of 39 patients were tested through rRT-PCR, out of which 15 (34.09%) tested positive. Among the 44 patients, 26 were males (59.09%), and 18 were females (40.9%). The most common symptoms were fever (36.36%), shortness of breath (34.09%), cough (25%), and fatigue (13.63%). Additionally, 18.18% of patients were asymptomatic. Chest CT scans revealed ground glass opacity, consolidation, and pleural effusion in 54.83%, 48.38%, and 29.03% of cases, respectively. However, it was normal in 9.67% of patients. Peripheral and central pulmonary involvement was found in 70.96% and 19.35% of patients, respectively. The mean single pool KT/V (SpKT/V) was calculated as 1.10±0.39.

Based on our findings, the COVID-19 outbreak is a significant cause for concern for in-center hemodialysis patients. These individuals are particularly vulnerable due to their underlying health conditions. Furthermore, the limitations in maintaining social distancing, increased public exposure, and pre-existing lung involvement in these patients can further complicate their management and potentially impact their overall outcome.

Gestational diabetes (GDM) is one of the most important causes of complications during pregnancy and has a high prevalence, so it is essential to identify the factors affecting its physiopathology as a way to prevent and treat it. Therefore, the present study was performed with aim to investigate the serum level of vitamin D in healthy and diabetic pregnant women.

This case-control study was conducted in 2022-2023 on 198 pregnant women (99 with gestational diabetes and 99 without gestational diabetes in the control group) referred to the treatment centers of Abadan University of Medical Sciences. After obtaining consent from the subjects and recording demographic information, serum vitamin D levels were also recorded. Data were analyzed by SPSS software (version 24) and Independent T and Pearson correlation tests. P<0.05 was considered statistically significant.

The mean serum level of vitamin D in women with GDM was significantly lower than pregnant women in the control group (16.97 vs. 26.76 ng/ml). By grouping pregnant women based on age, gestational age, gravid and BMI, women with GDM had lower mean vitamin D levels than pregnant women in the control group (P<0.05). In the correlation analysis of women with GDM, vitamin D level had an inverse and significant relationship with 1-hour sugar (r=-0.212 and P=0.035) and 2-hour sugar (r=-0.223 and P=0.026), but no significant relationship with FBS level was observed. The sensitivity and specificity of vitamin D in the diagnosis of GDM at the cut-off point of 18.05 were 69.7% and 74.7%, and the positive and negative predictive value were 73.4% and 71.2%, and the overall accuracy was 72.2% and the level of agreement was moderate.

Women with GDM had significantly less vitamin D, which can be considered a risk factor for GDM during pregnancy.

Central venous catheter (CVC) infection is related to important morbidity and mortality in hemodialysis (HD) patients, even though they are routinely used as the primary vascular access for many HD patients. The goal of this study was to determine the prevalence and bacterial factors causing central venous catheter infections in hemodialysis patients in Abadan educational hospitals. In this study, from March 21, 2019, to March 19, 2020, information about patients with End-Stage Renal Disease (ESRD) who were referred to educational hospitals of Abadan University of Medical Sciences, including Frequency distribution of patients by gender and age, Duration of hemodialysis, embedded catheters, underlying disease, signs of clinical infection of the insertion site of the catheter in patients, antibiotics used in infectious patients were obtained through checklists and medical records. Seventy-six specimens of central venous catheter-related infections occurred in patients’ patients undergoing hemodialysis therapy. Among these cases, 40.8% (31) were male and 59.2% (45) were female. Forty-four (57.9%) patients with infection had femoral vein catheter placement. 82.9% of patients had more than twice-a-week hemodialysis sessions. Staphylococcus aureus was the most common bacterium isolated from bloodstream infections, accounting for 50% (45) of the cases. Prolonged central venous catheter use is a major risk factor for infection in hemodialysis patients. For empirical treatment, both Staphylococcus aureus and Gram-negative microorganisms must be considered. Compliance with hygienic measures and the careful use of antibiotics are suggested for lowering the risk of drug resistance.

The concurrence of chronic obstructive pulmonary disease (COPD) and obstructive sleep apnea (OSA) is known as overlap syndrome (OS). The obstruction of the upper airway leads to OSA and the obstruction of the lower airway leads to COPD. The aim of this study was to compare polysomnographic findings of patients with OS according to severity of lower airway obstruction.

Seventy‑two patients were included in this cross‑sectional study. Patients with COPD referred to a sleep clinic with suspicion of OSA were evaluated by polysomnography (PSG). PSG findings were interpreted based on the American Academy of Sleep Association criteria (2012). COPD severity was categorized into four groups based on GOLD criteria using forced expiratory volume in the first second (FEV1 ). PSG findings also were compared between patients regarding severity of lower airway obstruction (FEV1 ≥50% and FEV1 <50%).

Sixty‑eight of the patients had OS. Twenty‑nine (42.6%) were male. The mean age was 62.3 ± 6.88 years. Thirty‑two (54.4%) of the patients were in GOLD 2. The mean apnea/hypopnea index was 57.41 ± 36.16. Seventy‑two percent of patients had severe OSA. Severe OSA was more prevalent in patients of GOLD 2 and 3 groups compared to the other groups. Among PSG findings, only N2 sleep stage was significantly longer in patients with FEV1 < 50% than in patients with FEV1 ≥50% (61.5 ± 11.2, 55.3 ± 13.4, P = 0.039).

Polysomnographic findings (except N2 stage) are not different in patients with OS with respect to severity of lower airway obstruction.

Despite significant improvement in End Stage Kidney Disease (ESKD) patient’s management, and better availability of dialysis for caregivers, mortality among these patients is unacceptably high.

We collected the data of 751 incident hemodialysis patients from March 2004 to November 2018. Survival curves was created by using the Kaplan-Meier method. Comorbidities, as well as time-dependent values of laboratory findings, were examined as independent factors by three models of Cox regression analysis.

The median follow-up period was 31.7 months (1.08 to 169.28). Patient survival rates were 88%, 77%, 56%, 32%, 26% ,16% and 12%, at 1, 2, 4,6, 8, 10, 12 and 14 years of follow-up, respectively. The most common cause of mortality was cardiovascular disease. We observed lower survival rates in patients ≥ 65 years (HR = 2.684, 95% CI: 1.133 to 3.377; P < .001), diabetes mellitus (HR = 1.729, 95% CI: 1.484 to 2.014; P < .001) and walking disability (HR = 2.505; 95% CI: 2.104 to 2.983; P < .001). Low hemoglobin level (HR = 1.496; 95% CI: 1.257 to 1.779; P < .001), hyperphosphatemia (HR = 1.305, 95% CI: 1.104 to 1.542; P = 0.002) and high low-density lipoprotein cholesterol level (HR = 1.933; 95% CI: 1.431 to 2.611; P < .001) were predictors of mortality. A single pool Kt/V > 1.2 (HR = 0.743, 95% CI: 0.635 to 0.870; P < .001) and high serum creatinine level (HR = 0.842, 95% CI: 0.811 to 0.874; P < .001) showed protective effects.

Our study showed a high survival rate in a single center cohort of hemodialysis patients in Iran. Traditional risk factors of mortality in general population, as well as indices of dialysis efficacy and general health status were the main predictors of mortality. Nationwide registries are necessary to investigate the dialysis survival rates and their predictors in our country.

The purpose of this study was to determine the appropriate locations of fuel supply stations (CNG) according to the existing criteria in the western areas of Tehran. In this regard, using the GIS, a map of effective parameters in locating gas refueling stations, such as: population density, passages and access, land slope, compatible and incompatible uses was prepared .. Using the Analytic Hierarchy Process (AHP) model Parallel comparisons between criteria were performed and the importance and weight of each criterion were determined using Expert Choice software. The results of weighing the criteria showed that the criteria of fire, access and population density had the greatest impact on creating suitable locations for gas refueling, respectively, and the development of gas stations in the western part of Tehran Municipality has not been done based on population needs of different areas. The output map obtained by spatial analysis and AHP showed that among the available stations, about 29% of them are located in areas with good potential and 71% of places are in places with medium potential and no places are located in places with unsuitable  potential. Also, 32.53% of the areas have suitable potential, 43.76% have medium potential and 23.7% have inappropriate potential for construction of refueling station.

One of the most effective and comprehensive ways to deal with security risks as well as smuggling of contraband including drugs is using Dual Energy X-ray inspection devices with the capability of materials classification. An important parameter in relation to the use of these devices in the vehicle inspection is the car driver and sensitive body organs dose which can lead to person’s diseases caused by radiation. The aim of this study is the risk assessment for car driver in each scan and also determination of maximum number passes through inspection device for a specified time based on individual doses per scan and the ANSI standard. By using a homespun and programmed car inspection dual-energy X-ray as well as using a Rando phantom of a man and TLD dosimeters, dosimetry was performed to assess the doses of overall and sensitive body organs at three energy situations of the X-ray tube, 155, 175 and 195 kVp. The results show that maximum dose is absorbed in the stomach and the mean total dose of car driver for 155, 175 and 195 kVp energy is 0.276. 0.315 and 0.338μSv respectively. With respect to the overall mean car driver dose (the 0.31μSv) and according to the ANSI standard, machine is known in the category of devices with limited utility. Anyone can pass through this machine in maximum for a year, a month and a week 806, 66 and 15 times respectively and more scan could lead to radiation biohazards according to ANSI standard.

Background and Dual-energy mammography is a technique which is used to enhance the accuracy of breast cancer diagnosis especially in dense breasts. This study was conducted based on the simultaneous use of two contrast agents for automatic separation and also to evaluate their accuracy using dual-energy digital mammography. A breast phantom was designed and built. Different thicknesses of aluminum sheets were imaged for micro-calcification simulation and Iodine and Bismuth contrast agents were placed at various density thicknesses inside the phantom. Also, an X-ray tube with Tungsten anode and a flat panel semiconductor detector Si/GadOx was used for imaging processes. To apply dual-energy imaging, appropriate filter for high-energy spectrum was designed by MCNP-4C Monte Carlo code and built. Matlab software was used for equations solving and image processing. The separation of Iodine images was prepared for thicknesses greater than 0.5 mg/cm2and Bismuth images greater than 0.53 mg/cm2. According to the results, simultaneous isolation of two contrast agent images, I and Bi, from breast tissue were accurately prepared by dual-energy digital mammography via choosing appropriate contrast agent materials and image processing technique. So, this method could help the physicians in making an easy and more accurate diagnosis.

Background and Concave eye applicators of Ru-106, a beta emitter source, have a lot of use in brachytherapy of intraocular tumors. This has led to the need of knowing the exact dose distribution caused by beta radiation to the tumor and its normal surrounding tissue. The purpose of this study was the 3D calculation of dose distribution for three Ru-106 plaques: CCA, CCB, and CGD in a human eye model using the MCNP-4C code in treatment of uveal melanoma with 5mm thickness from the sclera surface. In this regard, eye’s different parts including the sclera, choroid, retina, cornea, etc., and also Ru-106 plaques with their real properties were simulated by MCNP-4C code. Dose rate of three plaques in tumor and sensitive surrounding tissues were studied. According to this study and the ALARA principle (which aims to deliver the maximum dose to the tumor and minimizing the dose to healthy tissues), full knowledge of the shape and size of tumor is essential before treatment by aforementioned plaques. To minimize damage to adjacent healthy tissue using CCA plaques are recommended in treatment of small-sized tumors < 5mm depth. CCA plaque with a lowest absorbed dose in the healthy tissue around the tumor such as sclera and lens showed better results than other studied plaques, thus it is recommended for the treatment of small-sized melanoma tumors.