مجله دانشکده پزشکی دانشگاه علوم پزشکی تهران
سال هفتادم شماره 3 (پیاپی 135، خرداد 1391)

Human embryonic stem cells (hESCs) are capable of self-renewal and large-scale expansion. They also have the capacity to differentiate into a variety of cell types including liver, cardiac and neuron cells. However, it is not yet clear whether hESCs can differentiate to hemangioblasts under in-vitro conditions. Hemangioblasts are bipotential progenitors that can generate hematopoietic lineages and endothelial cells. The aim of this study was to identify the potential of human Royan H5 embryonic stem cells in differentiating into hemangioblast cells. HESCs were cultured at suspension system in DMEM/F12 supplemented with bFGF. 7-day old cells differentiated into blast cells under defined condition consisting of hematopoietic cytokines including BMP4, VEGF, etc. Blast cell markers kinase insert domain receptor (KDR), CD31, and CD34 were evaluated by flow cytometry and blast gene expressions (TAL-1, Runx-1 and CD34) were detected by qRT-PCR. Clonogenic assays were performed in semisolid medium by colony forming unit-assays. The hESCs (Royan H5) had the capacity of differentiating into hemangioblast cells. We could detect colonies that expressed 79%±12.5 KDR+, 5.6%±2.8 CD31+-CD34+ and 6%±2.12 KDR+-CD31+ on day 8 in the hESCs. Up-regulation of TAL-1, Runx-1 and CD34 occurred during hemangioblast commitment (P≤0.05 and P≤0.01, respectively). Moreover, hemangioblast cells generated mixed-type and endothelial-like colonies in semi-solid media. Our results showed that hESCs (Royan H5) were able to differentiate into hemangioblasts under in-vitro conditions. The hemangioblasts had the potential to generate two non-adherent (Mixed-type) and adherent (endothelial-like) cell populations.

Microangiopathy and macroangiopathy frequently coexist in type 2 diabetes mellitus (T2DM). Both types of the vascular complications share traditional risk factors but it is not clear whether the presence of microangiopathy, such as diabetic retinopathy, constitutes a predictor of atherosclerosis in carotid arteries in patients with the disease. In this study we looked for the association between diabetic retinopathy and intima-media thickness in carotid arteries of patients with T2DM. In this case-control study we examined 100 consecutive patients with T2DM in Rasoul Akram Hospital in Tehran, Iran during 2009-2010. We assessed intima-media thickness of carotid arteries by ultrasonography. All patients underwent ophthalmo-logic examination. Diabetic retinopathy was found in 50 (50%) patients. Intima-media thickness was higher in patients with diabetic retinopathy than those without it (0.77±0.17 mm vs. 0.71±0.2 mm, respectively, P=0.041). Moreover, intima-media thickness was more prevalent in patients with proliferative diabetic retinopathy than patients with non-proliferative form of the disease (0.87±0.16 mm vs. 0.68±0.1 mm, respectively, P<0.001). Diabetic retinopathy seems to be associated with increased intima-media thickness of carotid arteries in T2DM. It may be a common denominator of pathogene-sis of microvascular complications and atherosclerosis in T2DM. Evaluations of carotid arteries are to be done by non-invasive methods such as color Doppler sonography for screening and preventing prospective cereberovascular accidents in patients with diabetic retinopathy, especially proliferative retinopathy, in routine ophthalmological examination of patients with T2DM.

Endometrial carcinoma (EC) is the most common gynecologic malignancy; however, mechanisms underlying its pathogenesis remain obscure. Endometrial carcinoma has been classified into two major categories: type I (related to estrogen or endometrioid adenocarcinoma) and type II (unrelated to estrogen). Estrogen is the main trigger for the abnormal proliferation in the endometrial epithelium but progesterone can inhibit this process. The aim of this study was to analyze the expression of estrogen and progesterone receptors in all types of endometrial hyperplasia in comparison to endometrioid adenocarcinoma of endometrium.

Forty-seven specimens including 23 cases of histopathologically confirmed hyperplastic endometrium (12 simple hyperplasia, 5 complex hyperplasia without atypia, and 6 complex hyperplasia with atypia) and 24 cases of endometrial carcinoma were studied. Immunohistochemical staining of estrogen and progesterone receptors was performed in paraffin-embedded blocks and expression of estrogen and progesterone receptors were scored according to the proportion of positive staining cells.

Overexpression of progesterone receptors was seen in 18 (75%) out of 24 cases of endometrial carcinoma and 23 (100%) of all types of endometrial hyperplasia. The aforesaid differences were statistically significant (P=0.023). 70.8% of cases with endometrial carcinoma were 3+ for immunohistochemical staining of progesterone receptors as were 85.7% of the cases with endometrial hyperplasia; the difference being also statistically significant (P=0.02).

Considering the increased proportion of progesterone receptor expression in all types of hyperplastic endometrium in comparison to endometrial carcinoma, hormonal therapy by progestinal agents is recommended as a treatment of choice.

Carotid endarterectomy (CEA) is a standard method for patient with significant carotid stenosis but direct surgical repair via carotid endarterectomy may not be a good option in some patients because of the overall health status that may make the surgery too risky. Carotid angioplasty and stenting (CAS), is a relatively new procedure for the treatment of carotid artery disease in patients who may not be fit enough to undergo surgery. In this investigation, we determined short- and long-term outcomes of stent angioplasty in high-risk patients for whom the risk of perioperative morbidity and mortality is high.

We have followed 82 consecutive symptomatic patients with a ≥50% and asymptomatic patients with a ≥70%- 80% carotid stenosis within 15.9 months of angioplasty and stenting in Baqiyatallah and Jamaran hospitals from 2008-2010. All the patients were considered poor surgical candidates by experienced surgeons and anesthesiologists upon pre-surgical consultation.

This descriptive cross-sectional study was performed on 28 women and 54 men with a mean age of 69.7±9.2 years. The procedure was technically successful in 79 (96.3%) cases. There were 6 (7.3%) deaths, 5 (6.1%) strokes, 4 (4.9%) MIs and 4 (4.9%) TIAs during the follow-up period.

The clinical results during the short available follow-up period suggested stent angioplasty to be useful, effective, reliable and safe in the treatment of significant cervical carotid stenosis in high-risk patients. Further analytical investigations with longer follow-up periods for predicting risk factors are recommended.

Since non-contrast spiral CT (NCCT) is an imaging method of choice performed before extracorporeal shockwave lithotripsy (ESWL), we aimed to find the association between renal stone characteristics including stone density, location, volume, and skin-to-stone distance (SSD) on NCCT and ESWL success for a more efficient selection of patients for the procedure.

We retrospectively studied 100 patients having undergone initial ESWL for a solitary renal calculus of 0.5-2.5 cm. Stone size, location, density, and SSD were determined on pretreatment NNCT. The outcome was categorized as stone free, complete fragmentation (<5 mm), incomplete fragmentation (>5 mm) and unchanged, based on KUB radiography 2 weeks after ESWL.

Of 100 patients, 32 were female and 68 were male with a mean age of 46.7 years. ESWL was successful in 55 and failure occurred in 45 patients. Sex (P=0.301), age (P=0.895) and SSD (P=4.06) were not associated with treatment success. Mean stone volume in ESWL success and failure groups, respectively were 531.4 and 930.5 mm3 and stone volume was statistically associated with treatment success (P=0.01). Mean stone density in ESWL success and failure groups were 545.7 and 962.3 HU, respectively and stone density was also associated with ESWL success (P<0.01). ESWL failure likelihood was 5 times greater in stones with a density >740 HU than smaller stones.

We strongly suggest performing densitometry in bone window for renal stones on pre-ESWL NCCT scanning and using an alternative treatment other than ESWL for stone densities greater than 740 HU.

Perioperative administration of tranexamic acid (TA), decreases bleeding and the need for transfusion after cardiac procedures. Hence, the results may vary in different clinical settings and the most appropriate timing to get the best results is unclear. The primary objectives of the present study were to determine the efficacy of TA in decreasing chest tube drainage, the need for perioperative allogeneic transfusions and the best timing for TA administration following primary, elective, coronary artery bypass grafting (CABG) in patients with a low baseline risk of postoperative bleeding. In this double-blind, prospective, placebo-controlled clinical trial in Seiedoshohada Hospital during 2011-2012, we evaluated 150 patients scheduled for elective, primary coronary revascularization. They were randomly divided into three groups. Group B received tranexamic 10 mg/kg prior to, Group A received tranexamic acid 10 mg/kg after cardiopulmonary bypass and group C received an equivalent volume of saline solution. Blood requirement and postoperative chest tube drainage were recorded. The placebo group (group C) had a greater postoperative blood loss 12 h after surgery (501±288 vs. 395±184 in group B and 353±181 mL in group A, P=0.004). The placebo group also had greater postoperative total blood loss (800±347 vs. 614±276 in group B and 577±228 mL in group A, P=0.001). There was a significant increase in allogeneic blood requirement in the placebo group (P=0.001). For elective, first time coronary artery bypass surgery, a single dose of tranexamic acid before or after cardiopulmonary bypass is equally effective.

The increasing use of β-lactam antibiotics in clinics for the treatment of different bacterial infections since early 1980s has led to increased rates of resistant bacteria isolated from patients. One of the problems in the treatment of nosocomial infections is related to resistant bacteria such as Enterobacter cloacae due to cross resistance through extended-spectrum beta-lactamase production. The aim of this study was to determine the prevalence of extended-spectrum beta-lactamase producing E. cloacae from different clinical specimens collected from hospitalized patients. In the present study, 101 E. cloacae confirmed by standard specific microbiologic tests were collected from different specimens in Milad and Motahri hospitals in Tehran, Iran during February 2010 and September 2011. Antibiotic susceptibility tests were conducted according to the process recommended by the Clinical and Laboratory Standards Institute for 13 antibiotics of choice. Extended-spectrum beta-lactamase producing strains were screened for by combined disk method as a phenotypic diagnostic test. From a total of 101 E. cloacae, 33 (33%) were shown to produce extended-spectrum beta-lactamase by phenotypic tests; 5% of the bacteria were resistant to imipenem too. This study clearly showed the high prevalence of resistance to broad-spectrum beta-lactam antibiotics in the isolated E. cloacae among which 5% were multi drug resistant. All the isolated E. cloacae were susceptible to Colistin. These results can be alarming for physicians treating resistant E. cloacae infections, especially extended-spectrum beta-lactamase producing species.

Currently, share of the scientific output, citation per paper, and co-authorship for articles indexed in databases such as ISI Web of Science, are very important criteria for the evaluation and ranking of countries, researchers, institutes, articles, disciplines and journals in the world. Therefore, the main objectives of the study were to determine co-authorship, the average citation per paper and the most prolific Iranian university or institution in the field of immunology. For performing this scientometric study, we employed survey methods and citation analysis of the indexed papers in the ISI Web of Science from 1974 to 2010. A total of 1775 articles by Iranian authors in the field of immunology had been indexed in the database for the aforesaid period. Most collaborations and co-authorship of Iranian authors was with their counterparts from the USA. The average citation per paper in the field was 6.26 per paper. Tehran University of Medical Sciences had the highest number of articles in the database. According to the results, Iranians collaborated with American peers more than any other nationality andthe average citation per paper in the field of immunology is higher than that of other fields in Iran but lower than the global average. Tehran University of Medical Sciences is the most prolific university in the field.

Musculoskeletal disorders (MSDs) are the most common reported occupational health problem which cause high financial burden and reduce efficiency of workers. MSDs are often multifactorial. This study was done to determine the frequency of MSDs and their relation to occupational stress among office workers. 332 office workers were recruited in descriptive-analytical study. To assess the frequency of MSDs, we used Nordic questionnaires and to assess the occupational stress, we used the general Nordic questionnaire for psychological and social factors at work (QPS Nordic+34 questionnaire). The collected data were processed and analyzed. Our study showed that the frequency of MSDs among office workers was higher than the general population and the stress index was higher (P=0.002) among the office workers with MSDs than employees without it. This study showed that occupational stress was a risk factor for MSDs, especially in the upper extremities.

Intracranial lipomas are rare benign neoplasms that comprise 1% of all primary brain tumors. Generally, occur in midline structure and usually identified incidentally on CT scans or in autopsies. The incidence of intracranial lipomas is about 0.08 to 0.46% on autopsies. These benign lesions are slow-growing, usually asymptomatic and rarely require surgery. We report a 20 years old male who complained of headache since two years ago. On CT examination, a quadrigeminal cistern lipoma without any pressure effect on neural structures demonstrated. His headache remitted with conservative measures. Here, we have a review on the literature and explain CT scan and MRI findings. According to the literature and present case, it seems that direct surgical excision of tumor is not justified in the majority of cases and symptoms of patients greatly respond to conservative measures and, at most, in cases of hydrocephalus, CSF shunting relieves their symptoms.