Tehran University Medical Journal
Year:2009 | Volume:67 | Issue:9|Papers Count:18

Telomere, by which is a terminal structure of eukaryotic chromosomes was discovered at first in 1938 and has a vital role in chromosome protection. Telomere in human and other vertebrates consists of thousands of 5'-TTAGGG-3' tandem repeats at the end of the chromosome, has a main role in the chromosome stability. Telomere protects the end of the chromosome from degeneration, rearrangement and end to end fusion. There is a telomere loss at every cell division. Progressive loss in telomere length results in disassociation of telomere binding proteins and change in gene expression profiles.Adjacent genes are suppressed by the telomere effect so the telomere loss results in adjacent gene expressions. Apoptosis and replicative senescence are caused by progressive telomere loss. There are three mechanisms for increasing telomere length in eukaryotes and telomerase is the predominant mechanism. Telomerase can synthesize telomere, without the template. Telomerase is overexpressed in 90% of cancers. Therefore cancerous cells compensate the telomere loss in every cell division because of telomerase. In conclusion, telomerase is a proper target for cancer therapy and many methods including direct inhibition of telomerase and immunotherapy have been introduced.

Background: Increased rate of oxidative stress have important role in diabetic nephropathy. Oxidative stress induces the synthesis of antioxidant enzymes. One of them, Extracellular- SOD (EC–SOD) is a major anti-oxidative enzyme and the only one that neutralizes superoxide ion, a precursor of reactive oxygen species (ROS). The aim of this study was to evaluate the correlation between diabetes- associated oxidative stress and antioxidative defense in macroalbuminuric type II diabetic patients.Methods: One hundred and thirty three patients (74 women, 59 men) with type II diabetes were studied during 1385-86. According to level of urinary protein, two groups of patients; normoalbuminuric (urinary protein excertion below 30mg/24h) and macroalbuminuric (urinary protein excretion more than 300mg/24) were recognized. In each group serum level of oxidized- LDL and EC-SOD were measured.Results: The mean age of patients and the mean duration of diabetes was 59.09±8.26 years and 137.92±65.91 months, respectively. The plasma oxidized-LDL level and extracellular- superoxide dimutase level were significantly higher in macroalbuminuric than normoalbuminuric group (88.57±33.36 versus 78.24±27.59u/l, p=0.039 for oxidized-LDL and 87.60±21.18 versus 76.25±16.25mu/l, p<0.001 for EC-SOD). Oxidized- LDL was significantly correlated to EC-SOD in macroalbuminuric patients (r=0.425, p<0.0001).Oxidized-LDL and EC-SOD does not correlate to Fasting Plasma Glucose and HbA1c in each two groups.Conclusion: The significantly elevated plasma oxidized-LDL in patients with macroalbuminuria suggests that, oxidized-LDL may play an important role in the progression of diabetic nephropathy. Besides severity of oxidative stress in macroalbuminuic patients, increase level of EC-SOD enzyme could be a compensatory mechanism to prevent tissue damage.

Background: Dendritic Cell (DC) is an important antigen-presenting cell that present tumor antigen to CD8+ and CD4+ T- Lymphocytes and induce specific anti-tumor immunity. In order to induce effective anti-tumor response, an option is increasing the efficiency of antigen presentation of dendritic cells and T cell activation capacity. The aim of the present study was to investigate the effect of dendritic cell maturation with protein components of toxoplasma gondii on cytotoxic T lymphocyte activity and their infiltration in to the tumor.Methods: For DC generation, bone marrow cells were cultured in the presence of GMCSF and IL-4 for five days. After that, LPS, protein components and whole extract of toxoplasma gondii were added to the culture media and incubated for another two days for DC maturation. To generate tumor, mices were injected subcutaneously with WEHI-164 cell line. For immunotherapy 106 DCs matured with different compounds were injected around the tumor site. Infiltration of CD8+ T cells were determined by flow cytometry and cytotoxic activity was measured by LDH detection kit.Results: Immunotherapy with DCs treated with protein components of toxoplasma gondii led to a significant increase in the activity of cytotoxic T cells and infiltration of CD8+ T cells in to the tumor. Immunotherapy using protein components of toxoplasma gondii significantly improved the survival of the mice compared with other groups (p<0.0001).Conclusion: Protein components of toxoplasma are able to increase DC capability in induction of CTL-mediated anti-tumor response and increase infiltration of these cells in to the tumor.

Background: Vulvovaginal candidiasis is a fungal disease with itching, and vaginal thick white discharge. Most of non-albicans species have less sensitivity to azoles. So, definition of candida species which lead to vulvovaginal candidiasis is very important to perfect usage of drugs. In the present study 191 Candida isolates from 175 patients who admitted in Gynecology department of Mahdieh Hospital during the period 1385-1387 were identified by multiplex PCR.Methods: One hundred seventy five vaginal swab specimens from patients were cultured on Sabouraud Dextrose Agar (SDA). The internal transcribed spacer 1 (ITS1) region between the 18S and 5.8S rRNA genes and a specific DNA fragment within the ITS2 region of Candida albicans were amplified and the multiplex PCR products were separated by electrophoresis in 2% agarose gel (200 mA, 140V), visualized by staining with ethidium bromide, and photographed.Results: One hundred ninety one Candida isolates were identified in vaginal swab specimens from 175 patients. In 89.7% of cases, single candida species and in 10.3% cases, multiple candida species were isolated. C. albicans (65.1%), C. glabrata (13.1%), C. tropicalis (6.2%), C. krusei (4%), C. guilliermondii (0.6%), C. parapsilosis (0.6%), C. glabrata and C. albicans (5.7%), C. albicans and C. parapsilosis (1.1%), C. glabrata and C. tropicalis (0.6%), C. krusei and C. tropicalis (0.6%), C. albicans and C. tropicalis (0.6%), C. krusei and C. albicans (0.6%), C. glabrata and C. krusei (0.6%), and C. glabrata and C. krusei and C. albicans (0.6%) were the cause of disease.Conclusion: Our findings suggest that, the common cause of both recurrent and nonrecurrent vulvovaginal candidiasis was C. albicans, and then C. glabrata. Also the most common mixtures of Candida species were combination of them.

Background: Stress incontinence is the most common type of urinary incontinence which has been treated by different surgical techniques. The objectives of our study were to compare the laparoscopic Burch colposuspension with Trans- obturator Tape (TOT) procedure.Methods: This randomized clinical trial was conducted on 40 patients with stress incontinence referred to Arash hospital from 2007 to 2009. All patients were randomly divided in two groups (laparoscopic Burch and TOT). Patient information was using obtained demographic, I-QOL (Which contained 22 questions), UDI-6 (urinary symptoms), ISI (Severity of urinary incontinence) questionnaires and urodynamic test.Results: The data collected from 19 patients in TOT group and 16 patients in laparoscopic Burch groups. The objective cure rate which was determined by no urinary leakage during stress and were analyzed urodynamic evaluation was 75% in laparoscopic and 84.2% in TOT (p=0.53). Result of ISI questionnaire with showing the subjective cure rate following surgery had no significant difference between two groups (p=0.23). UDI-6 questionnaire was used to compare the result of both groups before and after surgery and showed that the improvement in Urgency was significant in TOT in compare to Burch (p=0.04). I-QOL score significantly increased in both groups after six months of operation (p<0.05). But the differences were not statistically significant.Conclusion: Based on our results subjective and objective cure rate were not significantly different between TOT and laparoscopic Burch colposuspension.

Background: It is a well known fact that language functions are primarily related to the left hemisphere in right handed individuals, there is still no agreement about hemispheric language dominance in left handers. The aim of this study is to evaluate the possibility of using functional Transcranial Doppler ultra sonography (TCD), as a non-invasive method for investigation of hemispheric language dominance and also to explore possible gender influence on hemispheric language representation.Methods: We performed functional TCD during a word generation task, in 62 healthy volunteers (30 right handers and 32 left handers, 50% male and 50% female). All subjects were medical students in the age range of 22-29 years. Right or left handedness was determined using Edinburgh questionnaire. Two subjects were excluded from the study because of poor temporal windows. Mean blood flow velocity was measured in both right and left middle cerebral arteries (MCA) at rest and during a word generation task, and changes in flow velocities were compared.Results: Increase of MCA blood flow velocity was observed in 55% (33 subjects) of the students in the left side, and in 45% (27 subjects) of them in the right side. Right hemispheric dominance was observed in 43.3% of right handers and 46.7% of left handers. Left hemispheric dominance was observed in 56.7% of right handers and 53.3% of left handers. Our results showed no significant right hemispheric language dominance in left handed subjects.Conclusion: This study does not show significant difference in hemispheric language dominance between right and left handers, using functional TCD.

Background: Pelvic Organ Prolapse (POP) and related urinary symptoms are frequent disorders in elderly women and their management improves life expectancy and quality of life. Urodynamic tests applied in pathophysiologic diagnosis and treatment of urinary disorders are not always cost effective. This study aims to evaluate the results of Urodynamic tests in patients with pelvic organ prolaps.Methods: This case- control study was done using UDI-6 questionnaire during 18 months in vali-e-asr clinic of Imam Khomeini Hospital, Iran with 105 cases of POP; the cases were divided into two groups: group one (66 cases with urinary incontinency) and group two (39 without incontinency) and assessed with urodynamic tests.Results: Based on UDI-6, the patients of group one had more clinical symptoms (frequency, urine leakage, urge incontinence and stress incontinence). (p<0.001).Except for first desire to voide and normal voided volume indices, there were no significant differences in the other urodynamic parameters in two groups. Sensitivity and specificity of urgency leak in group one was 22 and 68.8% and in group two was 30 and 65.5% respectively. Stress leak sensitivity and specificity in group one were 25.4% and 100% and in group two were 57.1% and 71.9% respectively.Conclusion: In this study, considering sensitivity and specificity of symptoms and urodynamic test for urinary incontinency assessment is advised in patients with POP who need surgery.

Background: Measuring end tidal carbon dioxide (ETCo2) is one of the methods used for estimating arterial carbon dioxide (PaCo2) during general anesthesia. ETCo2 measurements maybe obviate the need for repeating arterial puncture for determination of arterial PaCo2. This study performed to determine the accuracy of ETCo2 levels as a measure of PaCo2 levels in patients undergoing coronary artery bypass graft and also to evaluate variation of the gradient between PaCo2 and ETCo2, peri- cardiopulmonary bypass operation.Methods: In a prospective, cross-sectional study, a total of 40 patients with age 57±11 (35-73) years old undergoing coronary artery bypass graft were enrolled. ETCo2 levels (mmHg) were recorded using side stream capnography at the time of arterial blood gas sampling, before (T0) and after (T1) cardiopulmonary bypass.Results: Mean P(a-ET)Co2 at T0 was 4.3±4.4mmHg, with the mean PaCo2, 33±6mmHg and mean ETCo2, 29±5mmHg and these values at T1 were 4.5±4.1mmHg, 33±5mmHg and 29±2mmHg respectively. There was no variation of the mean gradient (PaCo2-PETCo2) during, before and after cardiopulmonary bypass (p>0.870). Significant correlation was found between ETCo2 and PaCo2 at T0 and T1 (r=0.754 and 0.685 respectively and p=0.001).Conclusion: Capnography is a non- invasive and a safe technique for determining arterial PCo2 and for measurements of ETCo2 that correlate well with PaCo2 values in healthy patients undergoing coronary artery bypass graft. ETCo2 measurements maybe sufficient measures of PaCo2 in selected patients and obviate the need for repeating arterial blood gas determination. Further study is warranted.

Background: Asthma prevalence has increased in developed and developing countries in several last decades. Although cigarette smoking is an identified risk factor for many diseases such as coronary Heart disease and chronic obstructive lung disease, its effect on asthma is controversial. The aim of this study was to determine the odds ratio and its confidence interval for asthma morbidity among children referred to the Immunology and Allergy department of children medical center according to their parents' smoking and daily cigarette consumption.Methods: A case-control study was conducted during two years period on the asthmatic patients who referred to Immunology and Allergy department of children medical center. Demographic information and parents' smoking and daily cigarette consumption assessed by a questionnaire. Healthy children with same age and sex were entered to the study as the control group. Statistical analysis was performed to calculate odds ratio.Results: Among 215 patients who entered the study 63 patients were exposed the cigarette smoke. Odds ratio for asthma morbidity among children whose parents smoke more than five cigarettes per day in comparison with whose smoke less than five or do not smoke was 2.38 (p<0.01).Conclusion: Parent’s cigarette smoking is a risk factor for childhood asthma and could increase the risk of asthma to 2.38 folds in children whose parents smoke more than five cigarettes. Increasing in parents' knowledge level that probably relate to their education results in cigarette consumption decline.

Background: Leg cramp is the painful contraction of the muscles that often occurs at night. Pregnancy is the most common cause of muscle cramps that usually occur in the second trimester of pregnancy. Although the reasons of the spasms had not been determined, the imbalance between the absorption and elimination of serum electrolytes such as Ca, Mg and potassium and also insufficiency of some vitamins and probably the changes in activities of motor neurons of spinal cord, can be the source of these problems. The aim of this study was the evaluation of frequency and predisposing factors of leg cramps.Methods: In a cross sectional descriptive analytic study, a group of 400 women in the third trimester of pregnancy were asked to record the symptoms of leg cramp. Their education level and job recorded and their total serum level of Ca and Mg was measured in the first visit. Exclusion criteria included systemic medical conditions such as thyroid disease, diabetes, osteoporosis and prenatal disorders such as gestational diabetes mellitus and preeclampsia and patient cooperation.Results: In our study the prevalence of leg cramp was 54.75%. There was a statistically significant relationship between leg cramp and serum level of magnesium (p=0.04).There was no relation between calcium serum level and leg cramp (p=0.294). The women’s age, their nutritional habits and individual characteristics were not significantly related to occurrence of leg cramp.Conclusion: Leg cramp is a common symptom in pregnancy and in patients with low serum levels of magnesium, a magnesium supplement can be helpful.

Background: Routine oophorectomy in women with colorectal cancer is under debate, the aim of this study is to determine incidence, clinicopathologic features and prognostic factors of ovarian involvement in primary colorectal cancer (CRC) and to clear the role of prophylactic oophorectomy.Methods: Data from primary CRC women treated between years 1990 and 2004 were retrieved and clinical and pathologic features of those who had undergone oophorectomy during CRC surgery were reviewed.Results: One hundred eighty cases (mean age 47.5 years) were included. In 120(66.6%), ovaries were preserved and 60(33.3%) cases underwent bilateral oophorectomy in addition to primary CRC resection. Reasons for oophorectomy were prophylactic in 22(36.6%), abnormal morphology in 35(58.3%), and undetermined in 3(5%) cases. There were five metastatic carcinomas, eight primary ovarian tumors and 47 normal ovaries in pathologic evaluation. No complication directly related to oophorectomy was noted.Patients with ovarian metastases had higher stages of tumor. Ovarian metastases were not related to menstrual status, CRC location, size, differentiation, and mucin production, as well as abnormal morphology of ovary. The global prevalence of ovarian metastasis in CRC was 2.7%, and isolated ovarian metastases occurred in less than half of them. Of 120 women that underwent colectomy alone, eight (6.6%) developed ovarian metastasis during two years of follow-up. Only three cased had isolated ovarian metastases. No patient with synchronous or metachronous ovarian metastases from CRC survived five years.Conclusion: Isolated ovarian metastases from primary CRC occur with a low frequency and this may partially explain the debate regarding prophylactic oophorectomy at the time of curative resection for primary CRC.

Background: Nerve entrapment neuropathies are relatively frequent in the upper limb.Significant costs related to resultant disability and treatment, and also simultaneous occurrence of some of these syndromes can result in alteration in the treatment approach. The aim of this study was to evaluate the frequency of these syndromes, the rate of concurrence of carpal tunnel syndrome as the most prevalent syndrome with others, related risk factors, and accordance of clinical and electrophysiological findings.Methods: In a retrospective study, data of the 170 affected patients to these syndromes operated during a period of 10 years in a referral center were searched using recorded documents. Information about patient's gender, age, occupation and associated comorbidities, clinical and surgical findings and their accordance to the EMG-NCV findings, and also concurrence of these syndromes were assessed.Results: Patients' range of age was 10-91 year (mean: 48.09 year) and 74.5% of them were female. In this study carpal tunnel and cubital tunnel syndrome were the most frequent (81.7% and 15.8% respectively). In 23.5% of patients with carpal tunnel syndrome, electrophysiological findings were negative but there was no false positive result. Concurrent carpal tunnel syndrome with other syndromes were found in three cases of cubital tunnel syndrome, two cases of thoracic outlet syndrome and one case of Guyon's canal syndrome.Conclusion: Constellation of symptoms, physical examination and electrophysiological findings altogether should be considered for correct diagnosis of nerve entrapment syndromes in the upper extremity. Simultaneous entrapment in the other regions of the same nerve or other nerves in the same extremity is a probable condition.