Intra-articular remifentanil on postoperative pain in knee arthroscopic surgery; a double blind randomized clinical trial

BACKGROUND

We aimed to assess the efficacy of intra-articular remifentanil in relieving postoperative pain after knee arthroscopy.

METHODS

We conducted a double-blind randomized clinical trial study on 60 patients. Patients were divided into two equal groups. The control group received 25 ml of intra-articular normal saline, and the intervention group received 200 μg of remifentanil dissolved in 25 ml of saline. We evaluated at rest postoperative pain at 1, 3, 6, 12, 18, and 24 h after the surgery using the Visual Analog Scale (VAS). Patients with VAS scores of 4 or more received meperidine (pethidine). The first time meperidine was requested and the total amount of meperidine consumed was recorded.

RESULTS

Out of 60 patients, 49 were male (81.6%), and the mean age of participants was 32.71 (7.02) years. An hour after the surgery, the control group showed a mean VAS score of 8.66 (1.26), and decreased to 2.53 (1.67) at the end of 24 h. The intervention group started with a mean VAS score of 2.23 (1.81) and ended at 0.10 (0.305). All patients in the control group and 11 (36.7%) patients in the intervention group asked for analgesics during follow-up. The mean total meperidine dose in the control and intervention groups was 108.33 (23.97) mg and 13.33 (19.40) mg, respectively (P < 0.001; 95% confidence interval of the difference 83.72 to 106.27).

CONCLUSIONS

Intra-articular remifentanil may decrease postoperative pain and analgesic requirements in patients undergoing knee arthroscopy.

Efficacy of Granisetron versus Sufentanil on Reducing Myoclonic Movements Following Etomidate: Double-blind, randomised clinical trial

Objectives

This study aimed to reduce the intensity of myoclonus movements by comparing the effectiveness of granisetron and sufentanil in reducing the intensity of etomidate-induced myoclonic movements. Etomidate-induced myoclonus occurs in up to 85% of patients under general anaesthesia. This type of myoclonus can induce significant clinical and economic problems in patients with special conditions.

Methods

This double-blind randomised clinical trial study consisted of 96 adult patients recruited between January and July 2021 from Mashhad University of Medical Sciences, Mashhad, Iran. Using block randomisation, subjects were divided into three groups of 32 patients: the group receiving granisetron 40 μg/kg (group G), the group receiving sufentanil 0.2 μg/kg (group S) and the control group who did not receive the pretreatment (group C). Patients received these medications as pretreatments 120 seconds before induction with etomidate. After the injection of etomidate with a dose of 0.3 mg/kg, the incidence of myoclonus was evaluated. After evaluating the myoclonus, the full dose of narcotics (fentanyl 1 μg/kg) and muscle relaxants (atracurium 0.5 mg/kg) were administered to patients and a suitable airway was established for them.

Results

The findings indicated that granisetron reduced the intensity and incidence of myoclonic movements more than sufentanil. In addition, myoclonic movements were observed at a significantly higher intensity in the control group (P = 0.001).

Conclusion

The results obtained from the current study indicate that granisetron and sufentanil as pretreatments are effective for reducing myoclonus in patients.

Evaluation of Amino Acid Infusion preventive effect on Hypothermia during Spinal Anesthesia for Hip Arthroplasty

BACKGROUND

Hypothermia increases bleeding during surgery, risk of ischemic heart disease and postoperative wound infection. Intravenous amino acid increases cell synthesis and produces heat. Our goal was evaluating of the effect of amino acid on intraoperative hypothermia under spinal anesthesia.

METHODS

This is a randomized, double-blinded clinical trial that 36 adults undergoing Hip Arthroplasty were randomly assigned into two groups of 18 each. One group received Amino Acids solution (Aminoven 10%) 500ml (240ml/h) throughout spinal anesthesia, and control group received saline solution. We measured core body temperature, MAP and HR each 10 minutes, and also postoperative shivering, blood loss, operation time, postoperative BUN and Cr were compared in two groups.

RESULTS

Throughout surgery, the reduction in core temperature was more in the control group than the amino acids group (statistically not clinically). The decrease in core temperature was significantly larger in the controls (0.96°C ± 0.7°C) than in the amino acid patients (0.94°C ± 0.4°C), (P value= 0.02). Postoperative shivering was 73% in the controls regarding 11% in the amino acids patients. Overall, there were no significant statistical differences between other variables that we measured in two groups of patients.

CONCLUSION

Amino acids infusion during spinal anesthesia exerted a thermogenic effect. Our findings showed hypothermia was less in the aminoacid group, and also postoperative shivering was more in the control group.

Improved battery cycle life prediction using a hybrid data-driven model incorporating linear support vector regression and Gaussian process regression

The ability to accurately predict lithium‐ion battery life‐time already at an early stage of battery usage is critical for ensuring safe operation, accelerating technology development, and enabling battery second‐life applications. Many models are unable to effectively predict battery life‐time at early cycles due to the complex and nonlinear degrading behavior of lithium‐ion batteries. In this study, two hybrid data‐driven models, incorporating a traditional linear support vector regression (LSVR) and a Gaussian process regression (GPR), were developed to estimate battery life‐time at an early stage, before more severe capacity fading, utilizing a data set of 124 battery cells with lifetimes ranging from 150 to 2300 cycles. Two type of hybrid models, here denoted as A and B, were proposed. For each of the models, we achieved 1.1 % (A) and 1.4 % (B) training error, and similarly, 8.3 % (A) and 8.2 % (B) test error. The two key advantages are that the error percentage is kept below 10 % and that very low error values for the training and test sets were observed when utilizing data from only the first 100 cycles.The proposed method thus appears highly promising for predicting battery life during early cycles.

What Is the Effect of Pre-Emptive Oral Montelukast on Postoperative Pain Following Bimaxillary Orthognathic Surgery? A Triple-Blind Randomized Clinical Trial

PURPOSE

The aim of this study was to assess the effect of preoperative administration of oral montelukast on the amount of postoperative pain following bimaxillary orthognathic surgery.

METHODS AND MATERIALS

All healthy skeletal class III deformity candidates for bimaxillary orthognathic surgery were included in this triple-blind randomized clinical trial. The subjects were randomly divided into placebo and montelukast groups. One hour before the surgery, a 10 mL of apple juice was given to each and every patient; however, a 10 mg tablet of montelukast was dissolved in the juice for the intervention group. All operations were performed by the same surgical team, under the same general anesthesia protocols. The outcome variable was the amount of postoperative pain (1-, 3-, 6-, 12-, 18-, and 24-hour intervals) which was measured during the first 24 hours using a Visual Analog Scale. For statistical analysis, the significance level was set at 0.05 using SPSS 23.

RESULTS

A total of 60 consecutive patients, comprising 31 females (51.7%) and 29 males (48.3%) with an average age of 25.2 ± 2.2 were recruited. The average surgical duration was 193 ± 28.0 minutes. In general, pain intensity exhibited an increasing trend from the first hour postoperatively, reaching its peak in the 12th hour and decreasing thereafter. Nevertheless, the average amount of pain was significantly higher in the placebo group compared with the montelukast group, in all the studied time intervals (P < .05). The number of patients who required postoperative opioid analgesics was significantly higher in the placebo group compared to the montelukast group (P = .024). Moreover, the duration of surgery had a direct and significant effect on the postoperative pain intensity (P < .001).

CONCLUSIONS

It might be concluded that preoperative administration of montelukast is effective in reducing postoperative pain following bimaxillary orthognathic surgery. Further studies are necessary for more relevancy.

Histopathological study on neuroapoptotic alterations induced by etomidate in rat hippocampus

In human, there is substantial neurogenesis in the hippocampus that is implicated in memory formation and learning. These new-born neurons can be affected by neuropathological conditions. Anesthesia and surgical procedures are associated with postoperative cognitive changes particularly, impaired memory and learning. Therefore, the aim of this study was to evaluate the possible neurodegenerative effects of etomidate in rat hippocampus. Thirty male Wistar rats weighing 250 ± 30 g were randomly divided into 3 groups: 1) Etomidate group; four times 20 mg intraperitoneal injection with 1-h intervals, 2) Control group; the equal volume of normal saline, and 3) Normal group; without any intervention. 6 h after the last injection, the brains were removed and processed according to routine histological methods. TUNEL assay and toluidine blue staining were performed to evaluate neuro-histopathological changes in different regions of hippocampus. Our results showed that the number of TUNEL positive cells and dark neurons (DNs) in etomidate group were significantly higher in the CA1, CA2, CA3, and dentate gyrus (DG) of hippocampus compared with the control and normal groups (p < 0.05). While, there was no significant difference between the various regions of hippocampus in control and normal groups. Our findings showed that etomidate can increase apoptotic cells and dark neurons induction in different regions of hippocampus mainly in DG.

Mapping long-term coral reef ecosystems regime shifts: A small island developing state case study

Coral reefs are among the most fragile ecosystems that provide essential services to local Small Island Developing States (SIDS) communities. As such, exploring the characteristics and interactions shaping regime shifts of coral reefs is of paramount importance in managing system pressures; enhancing resilience; aiding their regeneration and recovery process; and restoring habitat complexity. However, understanding the dynamics of coral reef ecosystems regime shift requires employing an approach capable of dealing with systems being affected by multiple climatic and socio-economic non-climatic pressures as well as an effective treatment of systemic embedded uncertainties. This study applies Fuzzy Cognitive Mapping (FCM) in a participatory stepwise and systematic procedure to reflect dynamic casualties and temporal changes of coral reef ecosystem regime change over a long-time perspective. This mapping technique allows conceptualising dynamic models to represent causalities and modelling input values to simulate fluctuations within a complex temporal system. Port Resolution on Tanna Island in Vanuatu was selected as the case study region representative of Pacific-SIDS geography and human communities. As an initial outcome and an indicator of multidisciplinary of this study, twenty-seven principal influential factors and their corresponding causal relationships were identified. Subsequently, the coral reef regime shift was analysed under four main plausible scenarios representing major climatic and non-climatic trajectories. The results indicate that climate change factors play pivotal roles in the regime shift of the coral reef ecosystem globally. At the focal scale of this study, the tourism industry and coral fisheries are the most vulnerable services provided by coral reefs. As such, coupled local management interventions and global efforts in mitigating the adverse impacts of climate change is likely to yield better coral reef ecosystem services at a local community level.

Essentialism and Islamic Theology of Homosexuality: A Critical Reflection on an Essentialist Epistemology toward Same-Sex Desires and Acts in Islam

Although most traditional Muslim scholars condemn same-sex desires and acts, revisionist Muslim scholars have offered a more tolerant approach on this issue over the last two decades. Building on an essentialist approach to same-sex desires and acts, these scholars have argued that Islam accepts difference and diversity, including sexual diversity, as part of God's creation. Homosexuality, which in their view is an innate disposition to the same sex, is an alternative sexuality and, thus, accepted by the Qur'an and Islam. This article argues that an essentialist approach is not suitable to defend all manifestations of same-sex desires and acts, not only because it is narrow (as it excludes both bisexual Muslims and homosexual Muslims who believe that their sexual orientation is socially constructed), but also because it cannot even argue the case for the view of homosexuality as inborn. This article proposes to open up the debate beyond essentialism and constructivism, which both have their limitations, to accommodate a more inclusive and tolerant Islamic approach to same-sex desires and acts.

Nanogel-Integrated pH-Responsive Composite Hydrogels for Controlled Drug Delivery

A novel pH-sensitive hydrogel system consisting of poly(methacrylic acid-g-ethylene glycol) (P(MAA-g-EG)) and acryloyl group modified-cholesterol-bearing pullulan (CHPOA) nanogels was developed for the controlled delivery of an anticonvulsant drug, pregabalin (PGB). Here, the hydrophilic hydrogel network provides the pH-sensitive swelling behavior, whereas nanogel components form separate reservoirs for the delivery of drugs with different hydrophobicities. These nanocarrier-integrated hybrid gels were synthesized through both surface-initiated and bulk photopolymerization approaches. The swelling and drug release behavior of these pH-responsive hydrogels synthesized by different photopolymerization approaches at visible and UV light wavelenghts were studied at acidic and basic pH values. Nanogel-integrated hydrogels exhibited higher swelling behavior compared to plain hydrogels in reversible swelling experiments. Similarly, the presence of nanogels in hydrogel network enhanced the loading and release percentages of PGB and the release was analyzed to describe the mode of transport through the network. In vitro cytotoxicity assay suggests that hydrogels in altered groups are nontoxic. This is the first report about the visible light-induced synthesis of a pH-responsive network incorporated CHPOA nanogels. Responsive and multifunctional properties of this system could be used for pH-triggered release of therapeutic molecules for clinical applications.

Analgesia Following Arthroscopy - a Comparison of Intra-articular Bupivacaine and/or Midazolam and or Fentanyl

BACKGROUND

Arthroscopic intervention is very common for conducting orthopedic surgeries. After a knee arthroscopic surgery, different drugs are used through intra-articular administration to induce analgesia. The aim of this study was to evaluate analgesic effects of Bupivacaine (marcaine), Bupivacaine plus midazolam, and Bupivacaine plus fentanyl in reducing pain after knee arthroscopic surgery.

METHODS

Frothy five patients who were candidate for knee arthroscopy were divided into three groups. Group A, B and C received Bupivacaine (50 mg), Bupivacaine (50 mg) plus midazolam (50 µg/kg), and Bupivacaine (50 mg) plus fentanyl (3 µg/kg), respectively. The analgesic solutions were diluted with normal saline up to 20 ml. The analgesic effects were evaluated by VAS during first 24 hrs after surgery. With the VAS > 4, extra analgesic (pethidine) was administrated for patient.

RESULTS

The amount of induced analgesia and need for extra analgesic was different between groups; however, it was not statistically significant (p<0.109). The amount of administered analgesic (pethidine) in first 24 hours post-operatively was 275 mg for group A, while it was 150 mg for group B and 75 mg for group C. In group A, 46.67% of patients required further analgesic while this was 26.67% and 13.34% for groups B and C respectively (p<0.109).

CONCLUSION

Intra-articular administration of studied drugs in all three groups reduced post-operation pain. The amount of induced analgesia was the highest for group C, while group B drugs induced better analgesia compared to group C.

Effect of sub-chronic intraperitoneal administration of aminoguanidine on the memory and hippocampal apoptosis-related genes in diabetic rats

Memory impairment is a common disorder in diabetes mellitus which is associated with hippocampal neuronal apoptosis. The present study was conducted to examine the effect of one-week intraperitoneal (ip), administration of aminoguanidine (AG) on passive avoidance learning (PAL) and Bcl-2 family gene expression in the hippocampus of rats. Sixty male rats were divided into ten groups: non-diabetic/diabetic animals with/without AG (50, 100, 200 and 400 mg/kg, ip) treatment for one week. PAL and Bcl-2 family genes were examined. AG (100 and 200 mg/kg) improved both memory and Bax, Bak, Bcl-2 and Bcl-xl deficiency significantly in diabetic rats. AG treatment also ameliorated the diabetes-induced changes in (Bcl-2+Bcl-xl)/(Bak+Bax) ratios considerably. These results propose that one-week ip administration of AG may recover the deficit cognition in diabetic rats via enhancing (Bcl-2+Bcl-xl)/(Bak+Bax) proportions (Tab. 2, Fig. 4, Ref. 55).

Comparative study evaluating efficacy of sufentanil versus midazolam in preventing myoclonic movements following etomidate

Background and Aims:

Myoclonus is a major side-effect following etomidate injection requiring use of medical intervention.

Material and Methods:

In this double-blinded clinical trial, 50 consecutive patients, randomly received sufentanil 0.2 μg/kg or midazolam 0.015 mg/kg, 90 s before induction of anesthesia with etomidate (0.3 mg/kg). Then, the patients were monitored for any myoclonic movements during anesthesia.

Results:

The incidence of myoclonus was 28% in the sufentanil group and 84% in the midazolam group. The frequency and intensity of myoclonus were significantly higher in the midazolam group, compared to the sufentanil group (P < 0.001). Myoclonus duration in the sufentanil and midazolam groups were 5.8 ± 13.2 and 69 ± 47.8 s, respectively (P < 0.0010).

Conclusion:

The frequency, intensity and duration of myoclonus in the midazolam group, were significantly more prevalent than the sufentanil group.

A Survey of Blood Request Versus Blood Utilization at a University Hospital in Iran

BACKGROUND

Reservation of blood leads to blood wastage if the blood is not transfused. Therefore, in some centers only blood type and screen are evaluated. In this study, the efficacy of a blood crossmatch-to-transfusion ratio was measured and then compared with the standard levels.

METHODS

This prospective study was conducted during one year in a university hospital. During this period, 398 patients for whom blood had been requested were studied. In these patients, at the first surgical type, the laboratory tests (hematocrit, hemoglobin, platelet count, and prothrombin time) and the number of preoperative crossmatched and intraoperative transfused blood units were recorded. Then the crossmatch-to-transfusion ratio, transfusion probability, transfusion index, and correlation between related factors, and the transfusion ratio were evaluated.

RESULTS

In this cross-sectional study, blood was requested for 398 patients. According to available blood unit deficiency, from 961 blood unit requisitions, only 456 units were crossmatched and 123 units were transfused. The crossmatch-to-transfusion ratio, transfusion probability, and transfusion index were 3.71 (7.81 if all requisitions were crossmatched), 16.83%, and 0.31, respectively. The most unfavorable indexes were observed in patients who had ear, nose, and throat surgeries (0 transfused from 19 crossmatched blood units) and obstetric and gynecologic surgery (crossmatch-to-transfusion ratio was 18.6). The best indexes were related to thoracic surgery and neurosurgery (crossmatch-to-transfusion ratio was 1.53 and 1.54, respectively). There were no significant correlations between hemoglobin, hematocrit, platelet count, and prothrombin time with the number of transfused blood units (P = 0.2, 0.14, 0.26, and 0.06, respectively).

CONCLUSION

The data for the crossmatch-to-transfusion ratio, transfusion probability, and transfusion index were suboptimal at this center, especially for ear, nose, and throat and obstetric and gynecologic surgeries. Further multidimensional studies and determination of a new model for blood requests and to decrease blood wastage are needed.

EFFECTS OF EXERCISE ON MIR-29 AND IGF-1 EXPRESSION AND LIPID PROFILE IN THE HEART OF OVARIECTOMIZED RAT

Introduction

Menopause increases the risk of cardiovascular disease in women. The aims of the present study were to evaluate the effects of swimming training on cardiac histology and expression of miR-29 and IGF-1 in the ovariectomized rats.

Materials and methods

Thirty female Wistar rats were divided into sham and ovariectomized groups: sedentary control (OVX) and trained with 8 weeks exercise (OVX.E). On 57^th day, blood was collected and used for lipid profile measurement. In addition, heart tissue was analyzed by reverse transcription-polymerase chain reaction for IGF-1 mRNA and miR-29, and studied for histopathological changes.

Results

Ovariectomy significantly decreased miR-29 and IGF-1 expression in the heart compared to sham animals group (p<0.05). Exercise training increased miR-29 and IGF-1 expression in the trained rats and improved histology and lipid profile compared with OVX group (p<0.05).

Conclusion

Estrogen deficiency could lead to cardiac fibrosis through deregulation miR-29 and IGF-1 expression. The findings of the current study suggests a protective effect of exercise on heart against fibrotic changes in ovariectomized rats and support a potential preventive value of exercise in improving cardiac function after menopause.

Protective effects of Iranian Achillea wilhelmsii essential oil on acetaminophen-induced oxidative stress in rat liver

CONTEXT

Achillea wilhelmsii C. Koch (Asteraceae) is widely used in Iranian traditional medicine.

OBJECTIVE

This in vivo study evaluates the hepatoprotective role of Iranian A. wilhelmsii oils against acetaminophen-induced oxidative damages in rats.

MATERIALS AND METHODS

The animals were divided into five groups: in negative control and control groups, the DMSO and 500 mg/kg acetaminophen were i.p. injected, respectively. In treatment groups, 100 and 200 mg/kg oils and 10 mg/kg BHT were given i.p. immediately after acetaminophen administration. Then, the hepatic oxidative/antioxidant parameters such as lipid peroxidation (LP), glutathione (GSH), superoxide dismutase (SOD), catalase (CAT), and ferric reducing ability of plasma (FRAP) were measured in time intervals (2, 4, 8, 16, and 24 h) after administrations confirmed by histophatological consideration at 24 h.

RESULTS

The results indicated that acetaminophen caused a significant elevation in SOD activity (8-24 h) and LP and FRAP levels (4 h) paralleled with significant decline in GSH level (4 and 8 h). The apparent oxidative injury was associated with evident hepatic necrosis confirmed in histological examination. The presences of A. wilhelmsii oils (100 and 200 mg/kg) with acetaminophen mitigated significantly the rise in SOD, LP, and FRAP levels and restored the GSH compared with the group treated with acetaminophen. These were confirmed by histological examination indicating the hepatic necrosis reversal by the oils.

DISCUSSION AND CONCLUSION

It can be concluded that concomitant administration of A. wilhelmsii oils with acetaminophen may be useful in reversing the drug hepatotoxicity.

Differentiation between CSF Otorrhea and Rhinorrhea in an Obscure Case of Recurrent Meningitis

INTRODUCTION

Leakage of cerebrospinal fluid in the skull base may be accompanied with recurrent meningitis. The site of leakage may either be anterior (in the nose and paranasal sinuses) or posterior (in the temporal bone). Various imaging techniques can be used to precisely locate the point of leakage but despite all the advances in imaging techniques there are still some rare cases in which the surgeon can't be sure on the management approach before the beginning of surgery.

CASE REPORT

In this article we present one of these cases; we used intrathecal fluorescein to locate the source of the leak and made the final decision on the operating table.

CONCLUSION

Intrathecal fluorescein is helpful in locating the leakage in the ear or the nose in ambiguous cases.

Paracetamol, ondansetron, granisetron, magnesium sulfate and lidocaine and reduced propofol injection pain

Background:

Propofol is a most widely used intravenous anesthetic drug. One of its most common complications is the pain upon injection; therefore, different methods, with various effects, have been proposed in order to alleviate the pain.

Objectives:

This study investigates the effects of paracetamol, ondansetron, granisetron, magnesium sulfate and lidocaine drugs on reducing the pain of propofol injection during anesthetic induction. Also, the hemodynamic changes will be analyzed.

Patients and Methods:

This is an interventional study containing 336 patients underwent elective orthopedic surgeries in Educational Hospitals of Mashhad University, using systematic sampling, the patients were divided into six groups. A 20-gauge needle was inserted into a venous vessel in the back of the hand and 100 cc of Ringer serum was injected into the vein, which was applied proximal to the injection site. Afterwards, paracetamol 2 mg/kg (group p), magnesium sulfate 2 mmol (group M), ondansetron 4 mg (group O), granisetron 2 mg (group G), lidocaine 40 mg (group L) and 5 cc saline (group S) were injected into the vessel, after 60 seconds, the tourniquet was opened. One quarter of the total dose of propofol (2.5 mg/kg) was injected with a flow rate of 4 mg/sec and then the injection pain was measured. Finally, the fentanyl (2 µg/kg), atracurium 0.5 mg/kg, and the remaining dose of propofol were injected and the vital signs were recorded before the administration of propofol and 1, 3, 5 and 10 minutes after the propofol injection.

Results:

The six groups did not significantly differ, regarding their gender, weight or age. Propofol injection pain was less in L and G groups, in comparison with the others (P ≤ 0.001). By analyzing the hemodynamic changes, it was observed that the least amount of change in mean arterial pressure was observed in the paracetamol group.

Conclusions:

The reduction of propofol injection pain was observed by using medications (in comparison with normal saline), but it was more significant in groups G and L. Moreover, Hypotension was higher in groups S and G and it was lessened in group P.

Effect of dexmedetomidine on postoperative pain in knee arthroscopic surgery; a randomized controlled clinical trial

BACKGROUND

Various drugs are administered intra-articularly to provide postoperative analgesia after arthroscopic knee surgery. The purpose of this study was to assess the analgesic effects of intra-articular injection of a dexmedetomidine following knee arthroscopy.

METHODS

Forty six patients scheduled for arthroscopic knee surgery under general anaesthesia, were randomly devided into two groups. Intervention group received 1µg/kg dexmedetomidine (D) and isotonic saline. Control group received 25ml isotonic saline (P). Analgesic effects were evaluated by measuring pain intensity (VAS scores) and duration of analgesia.

RESULTS

There was no significant difference between the two groups in terms of age, sex and weight. The mean of post-operation pain severity in 1, 3, 6,12, and 24 h was significantly lower in the intervention group (D) in comparison with the control group (P). the mean of the total dose of tramadol consumption was significantly lower in the intervention group in comparison with the control group (P<0.001).

CONCLUSIONS

Intra-articular injection of dexmedetomidine at the end of arthroscopic knee surgery, alleviates the patients' pain, reducing the postoperative need for narcotics as analgesics, and increase the first analgesic request after operation.

An investigation of the association between ownership structure and corporate performance

Purpose

– The main purpose of the present research is to study the relationship between ownership concentration and the type of ownership, i.e. state, firm (legal persons), individual, family, institutional – on the value of the companies listed in Tehran Stock Exchange (TSE).

Design/methodology/approach

– The study applies panel data regression analysis to a sample of companies listed in TSE during the period 2005-2009. Two-stage least-squares analysis is conducted.

Findings

– The paper finds that ownership concentration is positively related to ROE, and that ownership concentration is negatively related to ROA. Moreover, state, family, and individual ownership are negatively related to performance, and firm (legal person) and institutional ownership are positively related to performance. The paper also finds that higher firm profitability requires a more diffused ownership structure.

Research limitations/implications

– The results of the present research support agency theory and efficient monitoring hypothesis. The results strongly suggest the failure of state ownership in increasing companies' value and underline the importance of accelerating privatization in Iran.

Practical implications

– To improve the performance and consequently the value of companies, the process of privatization in Iran must be accelerated and public ownership must be transferred to the private sector. Further, investors must pay special attention to the type of ownership and ownership concentration of companies when deciding to buy their shares.

Originality/value

– The study builds on prior research in several ways. First, the paper offers new insights into the relationship between corporate governance and economic performance by using data from Iranians listed firms, this new evidence from an emerging market enhances the understanding of corporate governance in Asian countries. Second, the study focuses on five dimensions: ownership concentration, state, firm, individual, family, and institutional ownership which allow one to get a more accurate picture of the ownership structure-firm value relationship.

Comparison of the effects and complications of unilateral spinal anesthesia versus standard spinal anesthesia in lower-limb orthopedic surgery

INTRODUCTION

A restricted sympathetic block during spinal anesthesia may minimize hemodynamic changes. This prospective randomized study compared unilateral and bilateral spinal anesthesia with respect to the intra- and postoperative advantages and complications of each technique.

MATERIAL AND METHODS

Spinal anesthesia was induced with 0.5% hyperbaric bupivacaine and a 25-G Quincke needle (Dr. J) in two groups of patients with physical status ASA I-II who had been admitted for orthopedic surgeries. In group A, dural puncture was performed with the patient in a seated position using 2.5 cm(3) of hyperbaric bupivacaine. Each patient was then placed in the supine position. In group B, dural puncture was performed with the patient in the lateral decubitus position with 1.5 cm(3) of hyperbaric bupivacaine. The lower limb was the target limb. The speed of injection was 1 mL/30s, and the duration of time spent in the lateral decubitus position was 20 min.

RESULTS

The demographic data were similar in both groups. The time to the onset of the sensory and motor block was significantly shorter in group A (p=0.00). The duration of motor and sensory block was shorter in group B (p<0.05). The success rate for unilateral spinal anesthesia in group B was 94.45%. In two patients, the spinal block spread to the non-dependent side. The incidence of complications (nausea, headache, and hypotension) was lower in group B (p=0.02).

CONCLUSION

When unilateral spinal anesthesia was performed using a low-dose, low-volume and low-flow injection technique, it provides adequate sensory-motor block and helps to achieve stable hemodynamic parameters during orthopedic surgery on a lower limb. Patients were more satisfied with this technique as opposed to the conventional approach. Furthermore, this technique avoids unnecessary paralysis on the non-operated side.

Comparison of Effectiveness of Betamethasone gel Applied to the Tracheal Tube and IV Dexamethasone on Postoperative Sore Throat: A Randomized Controlled Trial

INTRODUCTION

Postoperative sore throat is a common complaint in patients with endotracheal intubation and has potentially dangerous complications. This randomized controlled trial study investigated the incidence of postoperative sore throat after general anesthesia when betamethasone gel is applied to a tracheal tube compared with when IV dexamethasone is prescribed.

MATERIALS AND METHODS

Two hundred and twenty five American Society of Anesthesiologist (ASA)-class I and II patients undergoing elective abdominal surgery with tracheal intubation were randomly divided into three groups: betamethasone gel, intravenous (IV) dexamethasone, and control groups. In the post-anesthesia care unit, a blinded anesthesiologist interviewed all patients regarding postoperative sore throat at 1,6, and 24 hours after surgery.

RESULTS

The incidence of sore throat was significantly lower in the betamethasone gel group compared with the IV dexamethasone and control groups, 1, 6, and 24 hours after surgery. In the first day after surgery 10.7% of the betamethasone group had sore throat whereas 26.7% of the IV dexamethasone group and 30.7% of the control group had sore throat. Bucking before extubation was observed in 14(18.4%), 8(10.4%), and 9(12.2%) patients, in the IV dexamethasone, betamethasone gel, and control group, respectively.

CONCLUSION

We concluded that wide spread application of betamethasone gel over tracheal tubes effectively mitigates postoperative sore throat, compared with IV dexamethasone application.

Evaluation of Oral Tiazinidine Effects on [intraoperative] Hemodynamic Responses During Direct Laryngoscopy Under General Anesthesia

Background

Direct laryngoscopy and tracheal intubation can result in blood pressure and heart rate increase which in turn may lead to myocardial ischemia, cerebral hemorrhage, and even death in susceptible patients. Tizanidine is α₂-receptor agonists that suppresses central sympathetic system.

Objectives

This study evaluates the effects of oral Tizanidine on hemodynamic responses during operations and aims to determine the appropriate Propofol dosage to maintain anesthesia under BIS monitoring.

Materials and Methods

A double-blind clinical trial has been performed on 70 candidates for elective abdominal surgery undergoing general anesthesia in Educational Hospital of Ghaem, Mashhad, Iran. 35 randomly selected patients (the case group) were given 4 mg of oral Tizanidine 90 minutes before the induction of anesthesia whereas the remaining subjects (the control group) were given placebo. Blood pressure and heart rate before and after induction of anesthesia, and after intubation and extubation, existence of postoperative shivering, and the needed Propofol dosage were measured and recorded. Data analysis was done with T-test and Chi-squared test, using SPSS software version 16.

Results

Variations of blood pressure and heart rate after anesthesia induction, intubation and extubation were less in Tizanidine group generally. Postoperative shivering was reported in 28.6% and 11.4% of patients in control and case group respectively. Average propofol needed dose for anesthesia maintenance in case group was 25% less than the needed amount in the control group.

Conclusions

Using oral Tizanidine as a premedication, yielded stability in blood pressure and heart rate during surgery and decreased required Propofol. Considering its short duration of action, Tizanidine use as a premedication is recommended for sedation and stabilization of hemodynamic responses during the operations.

Co-encapsulation of gallium with gentamicin in liposomes enhances antimicrobial activity of gentamicin against Pseudomonas aeruginosa

OBJECTIVES

The aim of this study was to enhance the antimicrobial efficacy of a liposomal gentamicin formulation with gallium metal (Lipo-Ga-GEN) against clinical isolates of Pseudomonas aeruginosa.

METHODS

Sputum isolates of P. aeruginosa from cystic fibrosis patients were used to determine the MIC and MBC of Lipo-Ga-GEN. P. aeruginosa biofilms were formed and used to compare the minimum biofilm eradication concentration of the conventional drugs with that of Lipo-Ga-GEN. Quorum sensing (QS) molecule reduction of P. aeruginosa was determined by monitoring N-acyl homoserine lactone production using Agrobacterium tumefaciens reporter strain (A136). Viability of the cultured human lung epithelial cells (A549) was determined by Trypan Blue assay in order to assess Ga toxicity.

RESULTS

MIC and MBC values indicated that gentamicin was more effective against a highly resistant strain of P. aeruginosa (PA-48913) when delivered as a Lipo-Ga-GEN formulation (256 mg/L free gentamicin versus 2 mg/L Lipo-Ga-GEN). Lipo-Ga-GEN was the only formulation that completely eradicated biofilms and blocked QS molecules at a very low concentration (0.94 mg/L gentamicin). The decrease in cell viability was less in A549 cells exposed to Lipo-Ga, suggesting that encapsulated Ga is safer.

CONCLUSIONS

The results clearly indicate that the Lipo-Ga-GEN formulation is more effective than gentamicin alone in eradicating antibiotic-resistant P. aeruginosa isolates growing in a planktonic or biofilm community.

The effects of insulin on glucose and fluid transport in the isolated small intestine of normal rats

Chronically administered insulin returns enhanced maximal glucose transport capacity induced by diabetes to its normal state. In this study, the direct and acute effects of insulin on glucose transport in different parts of isolated small intestine were investigated. Mucosal Fluid Transport (MFT), Mucosal Glucose Transport (MGT) and Serosal Glucose Transport (SGT) were measured in the presence and absence of insulin in averted sacs, prepared from female Wistar rats. This study shows that the presence of insulin in vitro (40 and 80 microU/mL) can reduce MGT and SGT in different segments of the small intestine (duodenum, jejunum and ileum) after 30 min whereas it had no effect on MFT. Mucosal glucose transfer rates in the duodenum, jejunum and ileum of the controls were 6.07+/-0.4, 6.34+/-0.62 and 6.43+/-0.47 mg/g tissue respectively which were significantly reduced to 3.82+/-0.93, 3.60+/-0.50 and 1.17+/-0.45 in the presence of 80 microU/mL of insulin. Serosal glucose transfer too was decreased significantly from 0.3+/-0.05, 0.57+/-0.07 and 0.43+/-.07 in the duodenum, jejunum and ileum to 0.16+/-0.03, 0.16+/-0.04 and .07+/-.02 respectively. Mucosal fluid transfer was not affected by insulin. Insulin was as effective whether it was added on the mucosal or the serosal side. The results of this study show that insulin can directly affect glucose transport in the small intestine; its physiological role must be examined. Direct effect of insulin deficiency on glucose absorption in diabetic patients may play a role in the pathophysiology of the disease.

Efficacy of sacral neuromodulation for symptomatic treatment of refractory urinary urge incontinence

OBJECTIVES

To determine the efficacy and complications of sacral neuromodulation as therapy for refractory urinary urge incontinence.

METHODS

Forty-one patients (mean age 54.3 +/- 15.8 years) with urge incontinence refractory to conservative therapy (ie, pharmacologic, behavioral, biofeedback therapy) were retrospectively evaluated. The patients included those who received permanent one-staged or two-staged InterStim implants. Surgical implantation of the InterStim was performed in patients who experienced a greater than 50% reduction in urge incontinence symptoms, as documented by voiding diaries during a 3 to 7-day test stimulation period.

RESULTS

Ninety percent of patients had 50% or greater improvement in presenting symptoms and quality-of-life parameters after InterStim implantation, with a median follow-up of 12 months (interquartile range 12 to 26.5) for single-stage and 4.5 months (interquartile range 1.5 to 12) for staged implants (P = 0.0003 Wilcoxon rank-sum test). Patients with urge incontinence had a significant reduction in mean leaking episodes (from 8.8 to 2.3 per day, P = 0.0001), with a significant decrease in the mean number of pads used (from 4.7 to 0.82 per day, P < 0.0001). No patient experienced operative complications, and postoperative complications were encountered in 29% of patients.

CONCLUSIONS

Our results have demonstrated that sacral neuromodulation is a safe and effective approach for the treatment of urinary urge incontinence that is refractory to other more conservative forms of treatment.

A comparative study on the cortico-hypoglossal connections in primates, using biotin dextranamine

The anterograde projections of the motorcortical tongue area to the hypoglossal nucleus and neighbouring structures were studied in the rhesus monkey, squirrel monkey, saddle-back tamarin and tree shrew. Biotin dextranamine served as tracer. Direct projections into the hypoglossal nucleus were only found in the rhesus monkey and squirrel monkey. All four species, however, showed a direct projection into the dorsal and parvocellular reticular formation which in turn projects into the hypoglossal nucleus. The findings suggest a phylogenetic trend in the projections of the motorcortical tongue area from non-primate mammals via non-human primates to man in the sense that the cortico-motoneuronal connection is strengthened towards man. This might be one reason for the superior role the tongue plays in human vocal behaviour in contrast to non-human vocalization.

Anterograde projections of the cortical tongue area of the tree shrew (Tupaia belangeri)

In altogether seven tree shrews, Tupaia belangeri, the anterograde projections of the motorcortical tongue area were investigated as part of a larger comparative study. Identification of the tongue area was carried out by electrical brain stimulation. Three different tracers were used: biotin-conjugated dextranamine (BDA), Phaseolus vulgaris leucoagglutinin (PHA-L) and 3H-leucine. Intracortical projections were found to the motor cortex around the injection site, the premotor cortex, supplementary motor area, the homologues of the primate frontoparietal operculum and insula, the anterior cingulate and agrannular retrosplenial cortex, the somatosensory and bordering inferior parietal cortex as well as to the perirhinal cortex. Except the very weak projections into the retrosplenial, posterior parietal and perirhinal region which were ipsilateral, all other projections were bilateral. Subcortically, there was a projection into the ventral putamen, rostrodorsal claustrum and, very sparsely, into the caudate nucleus. In the thalamus, terminal labeling was found in the nuclei reticularis, anteroventralis, anteromedialis, ventralis lateralis, ventralis posterior medialis, ventralis posterior inferior, medialis dorsalis, in the intralaminar nuclei paracentralis, centralis lateralis, centrum medianum and parafascicularis, in the midline thalamus and in the nuclei posterior and pulvinaris. Further diencephalic projections, however all of them wak, could be traced into the zona incerta, dorsolateral subthalamus, dorsomedial, lateral and supraoptic hypothalamus. In the midbrain, labeling was found in the deep layers of the lateral superior colliculus, in the bordering reticular formation and, very sparsely, in the periaqueductal grey. In the lower brain-stem, fibres ended in the griseum pontis, dorsolateral reticular formation, principal and spinal trigeminal nucleus and, sparsely, in the lateral parabrachial region, solitary tract nucleus, inferior olive and magnocellular reticular formation. No terminals were found in the hypoglossal nucleus. The projection system revealed with PHA-L was less extensive than that demonstrated with BDA and 3H-leucine, both of which were similar.

Human bioassays to assess environmental genotoxicity: development of a DNA break bioassay in HepG2 cells

OBJECTIVES

Increasing interest in environmental health issues has created a demand for improved methods for the assessment of pollutant effects on humans. Our laboratory has developed an in vitro assay for the quantification of genotoxicity, monitored as DNA single strand breaks (SSB), in the HepG2 human hepatoma cell line.

DESIGN AND METHODS

This assay procedure, which is based upon alkaline unwinding and hydroxylapatite DNA chromatography, is both rapid and simple to perform.

RESULTS

HepG2 cells responded to the standard mutagen, 4-nitroquinoline N-oxide, demonstrating SSB formation at concentrations above 0.1 mumol/L. Phenanthrene-9,10-quinone, a component of diesel exhaust, mediated SSB formation at concentrations above 250 nmol/L. Finally, an extract of contaminated sediment from the Great Lakes Basin mediated SSB formation in a dose-dependent manner.

CONCLUSIONS

These results illustrate the utility of this human genotoxicity assay for future use in screening of environmental pollutants.