Evaluating the Effect of Jammer Radiation on Learning and Memory in Male Rats.

Background: Previous studies shown that mobile phone can impairment of working memory in humans. Objective: In this study, the effect of radiofrequency radiation emitted from common mobile jammers have been studied on the learning and memory of rats. Material and Methods: In this prospective study, 90 Sprague-Dawley rats, were divided into 9 groups (N=10): Control, Sham1st (exposed to a switched-off mobile jammer device at a distance of 50 or 100 cm/1 day, 2 hours), Sham2nd (similar to Sham1st, but for 14 days, 2 h/day), Experimental1st -50 cm/1 day &100 cm/1 day (exposed to a switched-on device at a distance of 50 or 100 cm for 2 hours), Experimental2nd (similar to experimental1st, but for 14 days, 2 h/day). The animals were tested for learning and memory the next day, by the shuttle box. The time that a rat took to enter the dark part was considered as memory. Results: Mean short-term memory was shorter in the experimental- 50 cm/1 day than control and sham- 50 cm/1 day (P=0.034), long-term memory was similar. Mean short- and long-term memory were similar in the experimental- 100 cm/1 day, control and sham- 100 cm/1 day (P>0.05). Mean short-term memory was similar in experimental- 50 cm/14 days, control, and sham- 50 cm/14 days (P=0.087), but long-term learning memory was shorter in the radiated group (P=0.038). Mean short- and long-term were similar among experimental-100 cm/14 days, control or sham 100 cm/14 days (P>0.05). Conclusion: Rats exposed to jammer device showed dysfunction in short- and long-term memory, which shown the unfavorable effect of jammer on memory and learning. Our results indicated that the distance from radiation source was more important than the duration.

The pre- and postoperative neutrophil-to-lymphocyte and platelet-to-lymphocyte ratios: The comparison of laparoscopy and laparotomy in colorectal cancer patients.

INTRODUCTION: The management of inflammation after colorectal surgery is important to decrease the susceptibility to postoperative complications. Platelet-to-lymphocyte ratio (PLR) and neutrophil-to-lymphocyte ratio (NLR) in the peripheral blood are known as two important inflammatory markers. In this study we evaluated and compared colorectal laparoscopy and laparotomy based on the PLR and NLR. METHODS: Totally, 76 patients were divided into two groups including patients who underwent laparoscopy (45 cases) or laparotomy (31 cases). The PLR and NLR were calculated based on cell blood count analysis of preoperative and postoperative day (POD) one and three in both groups. Statistical analysis was performed using SPSS software version 22. RESULTS: The PLR and NLR have no significant association with age, gender and tumor site (p > 0.05). However, both ratios were significantly increased in laparotomy patients at POD1 compared with the laparoscopy patients (p < 0.05). According to the two by two comparisons, the preoperative and postoperative PLR were significantly different in the laparotomy group (p < 0.05) but not in the laparoscopy group (p > 0.05). However, the preoperative and postoperative NLR were significantly different in both laparoscopy and laparotomy groups (p < 0.05). CONCLUSION: The NLR and PLR markers indicated that laparoscopy can be a better choice for colorectal surgery due to lower induction of inflammation compared with laparotomy.

Safflower (Carthamus tinctorius L.) oil could improve abdominal obesity, blood pressure, and insulin resistance in patients with metabolic syndrome: A randomized, double-blind, placebo-controlled clinical trial.

ETHNOPHARMACOLOGICAL RELEVANCE: Carthamus tinctorius L. (Safflower) has been widely recommended to treat metabolic disorders in traditional herbal medicine in Persia, China, Korea, Japan, and other East-Asian countries. The anti-hypercholesterolemic and antioxidant effects of this plant have been well documented, but its protective effects against Metabolic Syndrome (MetS) have not been fully illustrated. AIM OF THE STUDY: The present study aimed to evaluate the effects of safflower oil on MetS risk factors. MATERIALS AND METHODS: In this randomized, double-blind, placebo-controlled clinical trial, 67 patients with MetS were administered either divided 8 g safflower oil or placebo daily for 12 weeks. All patients were advised to follow their previous diets and physical activities. RESULTS: Safflower oil resulted in a significant reduction in waist circumference (-2.42 ± 3.24 vs. 0.97 ± 2.53, p<0.001), systolic blood pressure (-8.80 ± 9.77 vs. -2.26 ± 8.56, p = 0.021), diastolic blood pressure (-3.53 ± 7.52 vs. -0.70 ± 6.21, p = 0.041), fasting blood sugar (-5.03 ± 10.62 vs. 2.94 ± 7.57, p = 0.003), and insulin resistance (-0.59 ± 1.43 vs. 0.50 ± 1, p = 0.012), but an increase in adiponectin level (0.38 ± 0.99 vs. -0.09 ± 0.81, p = 0.042) in the treatment group in comparison to the placebo group. The results revealed a direct relationship between leptin level and Body Mass Index (BMI) in both groups (p<0.001). In addition, increase in BMI resulted in a non-significant decrease in adiponectin level in both groups. Moreover, no significant difference was observed between the two groups regarding lipid profiles, leptin serum level, serum creatinine concentration, and other outcomes. CONCLUSION: Safflower oil without lifestyle modification improved abdominal obesity, blood pressure, and insulin resistance in patients with MetS.

Evaluation of Twenty Genes in Prognosis of Patients with Ovarian Cancer Using Four Different Clustering Methods.

BACKGROUND: Comparison of gene expression algorithms may be beneficial for obtaining disease pattern or grouping patients based on the gene expression profile. The current study aimed to investigate whether the knowledge within these data is able to group the ovarian cancer patients with similar disease pattern. METHODS: Four different clustering methods were applied on 20 genes expression data of 37 women with ovarian cancer. All selected genes in this study had prominent roles in the control of the activity of the immune system, as well as the chemotaxis, angiogenesis, apoptosis, and etc. Comparison of different clustering methods such as K-means, Hierarchical, Density-Based Spatial Clustering of Applications with Noise (DBSCAN) and Expectation-Maximization (EM) algorithm was the other aim of the present study. In addition, the percentage of correct prediction, Robustness-Performance Trade-off (RPT), and Silhouette criteria were used to evaluate the performance of clustering methods. RESULTS: Six out of 20 genes (IFN-γ, Foxp3, IL-4, BCL-2, Oct4 and survivin) selected by the Laplacian score showed key roles in the development of ovarian cancer and their prognostic values were clinically and statistically confirmed. The results indicated proper capability of the expression pattern of these genes in grouping the patients with similar prognosis, i.e. patients alive after 5 years or dead (62.12%). CONCLUSION: The results revealed the better performance for k-means and hierarchical clustering methods, and confirmed the fact that by using the expression profile of these genes, patients with similar behavior can be grouped in the same cluster with acceptable accuracy level. Certainly, the useful information from these data may contribute to the prediction of prognosis in ovarian cancer patients along with other features of patients.
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Evaluation of the efficacy of Zataria multiflora essential oil versus albendazole in patients infected with liver cystic echinococcosis: A nonrandomized clinical trial.

BACKGROUND: Cystic echinococcosis (CE) is a life-threatening disease in many countries. Albendazole, as the drug of choice for medical treatment of CE, is accompanied by adverse effects and may be ineffective in 20%-40% of cases; hence, new and more effective compounds are urgently needed to optimize the management of the disease. This study was performed to evaluate the efficacy of Zataria multiflora essential oil (ZMEO) versus albendazole against human liver CE. MATERIALS AND METHODS: In this nonrandomized and single-blinded clinical trial, thirty patients who were infected with liver CE were divided into two groups (15 in each) and treated with albendazole (800 mg daily) and ZMEO (60 mg daily), respectively. Albendazole and ZMEO were administered orally for 180 consecutive days. The volume of hydatid cysts was measured by ultrasonography before and 2, 4 and 6 months after the start of treatment. Simultaneously, biochemical analysis was performed on the blood samples of patients to assess the possible side effects of the two treatment regimens. RESULTS: Two, 4 and 6 months after the start of treatment, ZMEO indicated a significantly higher ability in reduction of the volume of the hydatid cysts, compared to albendazole (P < 0.05). The mean values of aspartate aminotransferase, alanine transaminase and alkaline phosphatase were also significantly lower in the patients treated with ZMEO in comparison to those treated with albendazole (P < 0.05). No clinical adverse effects were observed in the patients treated by ZMEO. CONCLUSION: From the point of view of efficacy and safety, ZMEO indicated a significant superiority to albendazole. Hence, ZMEO may be considered as an alternative for albendazole in the medical treatment of liver CE.

Does Determination of Initial Cluster Centroids Improve the Performance of K-Means Clustering Algorithm? Comparison of Three Hybrid Methods by Genetic Algorithm, Minimum Spanning Tree, and Hierarchical Clustering in an Applied Study.

Random selection of initial centroids (centers) for clusters is a fundamental defect in K-means clustering algorithm as the algorithm's performance depends on initial centroids and may end up in local optimizations. Various hybrid methods have been introduced to resolve this defect in K-means clustering algorithm. As regards, there are no comparative studies comparing these methods in various aspects, the present paper compared three hybrid methods with K-means clustering algorithm using concepts of genetic algorithm, minimum spanning tree, and hierarchical clustering method. Although these three hybrid methods have received more attention in previous researches, fewer studies have compared their results. Hence, seven quantitative datasets with different characteristics in terms of sample size, number of features, and number of different classes are utilized in present study. Eleven indices of external and internal evaluating index were also considered for comparing the methods. Data indicated that the hybrid methods resulted in higher convergence rate in obtaining the final solution than the ordinary K-means method. Furthermore, the hybrid method with hierarchical clustering algorithm converges to the optimal solution with less iteration than the other two hybrid methods. However, hybrid methods with minimal spanning trees and genetic algorithms may not always or often be more effective than the ordinary K-means method. Therefore, despite the computational complexity, these three hybrid methods have not led to much improvement in the K-means method. However, a simulation study is required to compare the methods and complete the conclusion.

The Effect of Aromatherapy by Lavender Oil on Infant Vaccination Pain: a Double Blind Randomized Controlled Trial.

Introduction: Exposure to noxious stimuli can cause pain in infants. This study was conducted to evaluate the effects of the lavender oil inhalation on the pain resulting from the pentavalent vaccination. Methods: This clinical trial consisted of two groups: the lavender oil group with 42 infants and the placebo group with 57 infants. The healthy infants without congenital abnormalities in need of pentavalent vaccine also participated in our study. The infants started the lavender oil or placebo aromatherapy one minute before injection. The pain was assessed three times, using the Neonatal Infant pain Scale (NIPS): before vaccination, 15 s, and 5 min after vaccination. Also, the duration of crying was measured in both groups. Results: At baseline, the two groups were similar in relation to the NIPS scores. While, after 5 minutes, the NIPS score was significantly lower in the lavender group. Based on the repeated measures analysis, the NIPS score changed over time totally. However, the two groups were significantly different in relation to the NIPS score over time. The duration of crying was 75.47 (60.675) second in the lavender group and 105.22 (75.739) s in the control group. The statistical test showed a significant difference between the two groups. Conclusion: A low concentration of the lavender oil inhalation can reduce the pain and improve soothing in the infants with the pentavalent vaccine injection.

Effect of Lavender Oil Aroma in the Early Hours of Postpartum Period on Maternal Pains, Fatigue, and Mood: A Randomized Clinical Trial.

BACKGROUND: Busy care providers focus on the serious complications of postpartum period. This issue causes the seemingly trivial complications, such as mother's pains, fatigue, and psychological status, to be less taken into account. The study aimed to determine the effect of lavender oil aroma in the early hours of postpartum period on maternal pains, fatigue, and mood in primiparous mothers. METHODS: This randomized clinical trial was conducted on 56 participants; 29 in intervention group and 27 in control group. The intervention group received lavender oil in three doses during the first 24 h after delivery. Sesame oil was used in the control group. Intensity of pain, fatigue, and distress level was measured by visual analog scale before and after the interventions. Besides, mood status was assessed through the positive and negative affect schedule. RESULTS: The mean age of all the participants was 23.88 ± 3.88 years. After the first intervention and also in the tomorrow morning assessment, significant differences were found between the two groups regarding perineal pain (P = 0.004, P < 0.001), physical pain (P < 0.001), fatigue (P = 0.02, P < 0.001), and distress scores (P < 0.001). In addition, significant differences were found concerning the mean scores of positive (P < 0.001) and negative (P = 0.007, P < 0.001) moods between the two groups after the interventions. Repeated measures analyses showed that the two groups were significantly different over time in all the evaluated variables. CONCLUSIONS: Lavender oil aromatherapy starting in the first hours of postpartum period resulted in better physical and mood status compared to nonaromatic group.

Identifying the Prognosis Factors in Death after Liver Transplantation via Adaptive LASSO in Iran.

Despite the widespread use of liver transplantation as a routine therapy in liver diseases, the effective factors on its outcomes are still controversial. This study attempted to identify the most effective factors on death after liver transplantation. For this purpose, modified least absolute shrinkage and selection operator (LASSO), called Adaptive LASSO, was utilized. One of the best advantages of this method is considering high number of factors. Therefore, in a historical cohort study from 2008 to 2013, the clinical findings of 680 patients undergoing liver transplant surgery were considered. Ridge and Adaptive LASSO regression methods were then implemented to identify the most effective factors on death. To compare the performance of these two models, receiver operating characteristic (ROC) curve was used. According to the results, 12 factors in Ridge regression and 9 ones in Adaptive LASSO regression were significant. The area under the ROC curve (AUC) of Adaptive LASSO was equal to 89% (95% CI: 86%-91%), which was significantly greater than Ridge regression (64%, 95% CI: 61%-68%) (p < 0.001). As a conclusion, the significant factors and the performance criteria revealed the superiority of Adaptive LASSO method as a penalized model versus traditional regression model in the present study.

Improving the Accuracy of Early Diagnosis of Thyroid Nodule Type Based on the SCAD Method.

Although early diagnosis of thyroid nodule type is very important, the diagnostic accuracy of standard tests is a challenging issue. We here aimed to find an optimal combination of factors to improve diagnostic accuracy for distinguishing malignant from benign thyroid nodules before surgery. In a prospective study from 2008 to 2012, 345 patients referred for thyroidectomy were enrolled. The sample size was split into a training set and testing set as a ratio of 7:3. The former was used for estimation and variable selection and obtaining a linear combination of factors. We utilized smoothly clipped absolute deviation (SCAD) logistic regression to achieve the sparse optimal combination of factors. To evaluate the performance of the estimated model in the testing set, a receiver operating characteristic (ROC) curve was utilized. The mean age of the examined patients (66 male and 279 female) was 40.9 ± 13.4 years (range 15- 90 years). Some 54.8% of the patients (24.3% male and 75.7% female) had benign and 45.2% (14% male and 86% female) malignant thyroid nodules. In addition to maximum diameters of nodules and lobes, their volumes were considered as related factors for malignancy prediction (a total of 16 factors). However, the SCAD method estimated the coefficients of 8 factors to be zero and eliminated them from the model. Hence a sparse model which combined the effects of 8 factors to distinguish malignant from benign thyroid nodules was generated. An optimal cut off point of the ROC curve for our estimated model was obtained (p=0.44) and the area under the curve (AUC) was equal to 77% (95% CI: 68%-85%). Sensitivity, specificity, positive predictive value and negative predictive values for this model were 70%, 72%, 71% and 76%, respectively. An increase of 10 percent and a greater accuracy rate in early diagnosis of thyroid nodule type by statistical methods (SCAD and ANN methods) compared with the results of FNA testing revealed that the statistical modeling methods are helpful in disease diagnosis. In addition, the factor ranking offered by these methods is valuable in the clinical context.

Colorectal Cancer Staging Using Three Clustering Methods Based on Preoperative Clinical Findings.

Determination of the colorectal cancer stage is possible only after surgery based on pathology results. However, sometimes this may prove impossible. The aim of the present study was to determine colorectal cancer stage using three clustering methods based on preoperative clinical findings. All patients referred to the Colorectal Research Center of Shiraz University of Medical Sciences for colorectal cancer surgery during 2006 to 2014 were enrolled in the study. Accordingly, 117 cases participated. Three clustering algorithms were utilized including k-means, hierarchical and fuzzy c-means clustering methods. External validity measures such as sensitivity, specificity and accuracy were used for evaluation of the methods. The results revealed maximum accuracy and sensitivity values for the hierarchical and a maximum specificity value for the fuzzy c-means clustering methods. Furthermore, according to the internal validity measures for the present data set, the optimal number of clusters was two (silhouette coefficient) and the fuzzy c-means algorithm was more appropriate than the k-means clustering approach by increasing the number of clusters.

Prediction and Diagnosis of Non-Alcoholic Fatty Liver Disease (NAFLD) and Identification of Its Associated Factors Using the Classification Tree Method.

BACKGROUND: Non-alcoholic fatty liver disease (NAFLD) is the most common form of liver disease in many parts of the world. OBJECTIVES: The aim of the present study was to identify the most important factors influencing NAFLD using a classification tree (CT) to predict the probability of NAFLD. PATIENTS AND METHODS: This cross-sectional study was conducted in Kavar, a town in the south of Fars province, Iran. A total of 1,600 individuals were selected for the study via the stratified method and multiple-stage cluster random sampling. A total of 30 demographic and clinical variables were measured for each individual. Participants were divided into two datasets: testing and training. We used the training dataset (1,120 individuals) to build the CT and the testing dataset (480 individuals) to assess the CT. The CT was also used to estimate class and to predict fatty liver occurrence. RESULTS: NAFLD was diagnosed in 22% of the individuals in the sample. Our findings revealed that the following variables, based on univariate analysis, had a significant association with NAFLD: marital status, history of hepatitis B vaccine, history of surgery, body mass index (BMI), waist-hip ratio (WHR), systolic blood pressure (SBP), diastolic blood pressure (DBP), high-density lipoprotein (HDL), triglycerides (TG), alanine aminotransferase (ALT), cholesterol (CHO0, aspartate aminotransferase (AST), glucose (GLU), albumin (AL), and age (P < 0.05). The main affecting variables for predicting NAFLD based on the CT and in order of importance were as follows: BMI, WHR, triglycerides, glucose, SBP, and alanine aminotransferase. The goodness of fit model based on the training and testing datasets were as follows: prediction accuracy (80%, 75%), sensitivity (74%, 73%), specificity (83%, 77%), and the area under the receiver operating characteristic (ROC) curve (78%, 75%), respectively. CONCLUSIONS: The CT is a suitable and easy-to-interpret approach for decision-making and predicting NAFLD.

The early outcome of single-incision versus multi-port laparoscopic cholecystectomy.

BACKGROUND: Single-incision laparoscopic cholecystectomy (SILC) is a newly developed method of performing cholecystectomy and has been increasingly used. The aim of this study is to see if SILC has any advantages over conventional (three-port) laparoscopic cholecystectomy (CLC). MATERIALS AND METHODS: In this cross-sectional study, 52 patients who underwent SILC (group A) during the period from May 2011 to March 2013 were compared with 62 patients who underwent CLC (group B) at two centers affiliated to Shiraz University of Medical Sciences in Shiraz, Iran. Data were gathered on operation time, pre- and postoperative complications, patients' postoperative pain, pain reliever use, duration of hospital stay, and return to work, and these data were compared using SPSS software version 16. RESULTS: The mean age of patients was 38.01 ± 13.24 in group A and 44.82 ± 15.11 in group B. Mean body mass index (BMI) was 23.97 ± 4.78 and 26.22 ± 4.67 in groups A and B, respectively. The mean operation time was 76.4 ± 29.0 min in group A and 72.9 ± 24.1 min in group B (P = 0.496). Preoperative complications were 3.8% in group A and 0 in group B (P = 0.206). Postoperative complications were 17.3% in group A and 11.3% in group B (P = 0.423). The mean for early postoperative pain revealed no significant difference (P = 0.814), but the mean pain on discharge was significantly higher in group A patients (P = 0.034). Regarding the mean admission time and return to normal activity, we found no significant differences. CONCLUSION: SILC does not have any special advantages over CLC with regard to surgical outcomes, but it can be a safe alternative to CLC, especially in patients concerned about cosmoses.

Five Years Survival of Patients After Liver Transplantation and Its Effective Factors by Neural Network and Cox Poroportional Hazard Regression Models.

BACKGROUND: Transplantation is the only treatment for patients with liver failure. Since the therapy imposes high expenses to the patients and community, identification of effective factors on survival of such patients after transplantation is valuable. OBJECTIVES: The current study attempted to model the survival of patients (two years old and above) after liver transplantation using neural network and Cox Proportional Hazards (Cox PH) regression models. The event is defined as death due to complications of liver transplantation. PATIENTS AND METHODS: In a historical cohort study, the clinical findings of 1168 patients who underwent liver transplant surgery (from March 2008 to march 2013) at Shiraz Namazee Hospital Organ Transplantation Center, Shiraz, Southern Iran, were used. To model the one to five years survival of such patients, Cox PH regression model accompanied by three layers feed forward artificial neural network (ANN) method were applied on data separately and their prediction accuracy was compared using the area under the receiver operating characteristic curve (ROC). Furthermore, Kaplan-Meier method was used to estimate the survival probabilities in different years. RESULTS: The estimated survival probability of one to five years for the patients were 91%, 89%, 85%, 84%, and 83%, respectively. The areas under the ROC were 86.4% and 80.7% for ANN and Cox PH models, respectively. In addition, the accuracy of prediction rate for ANN and Cox PH methods was equally 92.73%. CONCLUSIONS: The present study detected more accurate results for ANN method compared to those of Cox PH model to analyze the survival of patients with liver transplantation. Furthermore, the order of effective factors in patients' survival after transplantation was clinically more acceptable. The large dataset with a few missing data was the advantage of this study, the fact which makes the results more reliable.

Efficacy and Safety of Low-Dose-Rate Endorectal Brachytherapy as a Boost to Neoadjuvant Chemoradiation in the Treatment of Locally Advanced Distal Rectal Cancer: A Phase-II Clinical Trial.

PURPOSE: Despite advances in rectal cancer treatment over the last decade, local control and risk of late side effects due to external beam radiation therapy (EBRT) remain as concerns. The present study aimed to investigate the efficacy and the safety of low-dose-rate endorectal brachytherapy (LDRBT) as a boost to neoadjuvant chemoradiation for use in treating locally advanced distal rectal adenocarcinomas. METHODS: This phase-II clinical trial included 34 patients (as the study arm) with newly diagnosed, locally advanced (clinical T3-T4 and/or N1/N2, M0) lower rectal cancer. For comparative analysis, 102 matched patients (as the historical control arm) with rectal cancer were also selected. All the patients were treated with LDRBT (15 Gy in 3 fractions) and concurrent chemoradiation (45-50.4 Gy). Concurrent chemotherapy consisted of oxaliplatin 130 mg/m(2) intravenously on day 1 plus oral capecitabine 825 mg/m(2) twice daily during LDRBT and EBRT. RESULTS: The study results revealed a significant differences between the study arm and the control arm in terms in the pathologic tumor size (2.1 cm vs. 3.6 cm, P = 0.001), the pathologic tumor stage (35% T3-4 vs. 65% T3-4, P = 0.003), and the pathologic complete response (29.4% vs. 11.7%, P < 0.028). Moreover, a significantly higher dose of EBRT (P = 0.041) was found in the control arm, and a longer time to surgery was observed in the study arm (P < 0.001). The higher rate of treatment-related toxicities, such as mild proctitis and anemia, in the study arm was tolerable and easily manageable. CONCLUSION: A boost of LDRBT can optimize the pathologic complete response, with acceptable toxicities, in patients with distal rectal cancer.

Diagnosis of Malignancy in Thyroid Tumors by Multi-Layer Perceptron Neural Networks With Different Batch Learning Algorithms.

To diagnose the malignancy in thyroid tumor, neural network approach is applied and the performances of thirteen batch learning algorithms are investigated on accuracy of the prediction. Therefore, a back propagation feed forward neural networks (BP FNNs) is designed and three different numbers of neuron in hidden layer are compared (5, 10 and 20 neurons). The pathology result after the surgery and clinical findings before surgery of the patients are used as the target outputs and the inputs, respectively. The best algorithm(s) is/are chosen based on mean or maximum accuracy values in the prediction and also area under Receiver Operating Characteristic Curve (ROC curve). The results show superiority of the network with 5 neurons in the hidden layer. In addition, the better performances are occurred for Polak-Ribiere conjugate gradient, BFGS quasi-newton and one step secant algorithms according to their accuracy percentage in prediction (83%) and for Scaled Conjugate Gradient and BFGS quasi-Newton based on their area under the ROC curve (0.905).

The comparison between drainage, delayed excision and primary closure with excision and secondary healing in management of pilonidal abscess.

OBJECTIVE: There are numerous methods of treatment for pilonidal abscess; however the best method in acute pilonidal abscess has remained controversial. The present study was designed to compare drainage, delayed excision and primary closure with excision and secondary healing in this relation. METHODS: In a randomized clinical trial study among 102 patients with definite diagnosis of pilonidal abscess referred to the Colorectal Clinic of Nemazee Hospital, 80 patients who fulfilled the criteria of entering the study were selected and divided into two groups of A and B. The exclusion criteria were any history of pilonidal abscess operation, diabetes mellitus, renal failure and immunosuppression. In group A, drainage and delayed excision (3weeks afterwards) and primary closure were performed while in group B, excision and secondary healing was performed. Patients were followed twice a week for 1month and then 2, 6 and 12months after the operation. The two methods were compared in terms of time period for wound healing, postoperative complications and any sign of recurrence. RESULTS: Symptoms were relieved in all patients. All patients returned to work 7-9days after the operation. After 6months, there was no signs of recurrence in both groups. After 12months in group B, the same results were observed as previous months while in group A, 14% developed recurrence of pilonidal abscess. Wound infection was noticed in 5.6% of patients in group A and 2.5% in group B and the difference was not significant (p>0.05). All patients in group B developed wound healing during 6weeks except two of them who had a delay in this finding up to 8weeks. CONCLUSION: The results of drainage and primary wound closure were comparable to the excision and secondary wound healing except in the rate of recurrence which was more frequent in the primary wound closure. As a result, in spite of much property and comfort of primary wound closure, this method would not be recommended for all cases with acute pilonidal abscess.