Optimal linear filter design for process state and packet loss estimation in networked control systems

Considering the effect of packet losses on the behavior of networked systems, this work is concerned with estimation of the packet loss occurrences in the input channels possibly together with the system state. For this purpose, the commonly used Markov chain model of the successive packet loss occurrences is transformed to a linear recursive model in which the packet loss occurrence variables appear as new state variables. Two methods are proposed for combining the recursive packet loss model with the plant model to obtain an overall model for the whole networked control system (NCS). In the first method, a state space model of the plant is used which allows for simultaneous estimation of the packet loss occurrences and the plant state. In the second method, an input-output model of the plant is employed which allows for estimating only the packet loss occurrences. Both the zero and the hold packet loss handling strategies are considered and stability of the filters is analyzed. The proposed methods are compared with some existing results during an example to show their advantages.

Pregabalin-Tolperisone Combination to Treat Neuropathic Pain: Improved Analgesia and Reduced Side Effects in Rats

The current treatment of neuropathic pain (NP) is unsatisfactory; therefore, effective novel agents or combination-based analgesic therapies are needed. Herein, oral tolperisone, pregabalin, and duloxetine were tested for their antinociceptive effect against rat partial sciatic nerve ligation (pSNL)-induced tactile allodynia described by a decrease in the paw withdrawal threshold (PWT) measured by a dynamic plantar aesthesiometer. On day 7 after the operation, PWTs were assessed at 60, 120, and 180 min post-treatment. Chronic treatment was continued for 2 weeks, and again, PWTs were measured on day 14 and 21. None of the test compounds produced an acute antiallodynic effect. In contrast, after chronic treatment, tolperisone and pregabalin alleviated allodynia. In other experiments, on day 14, the acute antiallodynic effect of the tolperisone/pregabalin or duloxetine combination was measured. As a novel finding, a single dose of the tolperisone/pregabalin combination could remarkably alleviate allodynia acutely. It also restored the neuropathy-induced elevated CSF glutamate content. Furthermore, the combination is devoid of adverse effects related to motor and gastrointestinal transit functions. Tolperisone and pregabalin target voltage-gated sodium and calcium channels, respectively. The dual blockade effect of the combination might explain its advantageous acute analgesic effect in the present work.

Intravitreal Injections and Face Masks: Endophthalmitis Risk Before and During the COVID-19 Pandemic

Purpose

To assess the added risk of acute endophthalmitis after intravitreal injections associated with the widespread use of face masks during the COVID-19 pandemic.

Methods

In this retrospective, single-center study, records of patients with acute endophthalmitis following intravitreal bevacizumab (IVB) injections during the pre-COVID era-that is, March 1st , 2013 to October 31st , 2019 -and the COVID-19 era-that is, March 1st , 2020 to April 1st , 2021 -were reviewed and compared.

Results

A total of 28,085 IVB injections were performed during the pre-COVID era; nine eyes of nine patients developed acute post-IVB endophthalmitis in this era, giving an overall incidence of 0.032% (3.2 in 10,000 injections). In the COVID era, 10,717 IVB injections were performed; four eyes of four patients developed acute post-IVB endophthalmitis in this era, giving an overall incidence of 0.037% (3.7 in 10,000 injections). The incidences of post-IVB endophthalmitis during these two eras were not statistically significantly different (P = 0.779).

Conclusion

Face masking protocols seem unlikely to impose any additional risk of post-IVB endophthalmitis.

Does Gadolinium Deposition Lead to Metabolite Alteration in the Dentate Nucleus? An MRS Study in Patients with MS

BACKGROUND AND PURPOSE

Repeat contrast-enhanced MR imaging exposes patients with relapsing-remitting MS to frequent administration of gadolinium-based contrast agents. We aimed to investigate the potential metabolite and neurochemical alterations of visible gadolinium deposition on unenhanced T1WI in the dentate nucleus using MRS.

MATERIALS AND METHODS

This prospective study was conducted in a referral university hospital from January 2020 to July 2021. The inclusion criteria for case and control groups were as follows: 1) case: patients with relapsing-remitting MS, visible gadolinium deposition in the dentate nucleus (ribbon sign), >5 contrast-enhanced MR images obtained; 2) control 1: patients with relapsing-remitting MS without visible gadolinium deposition in the dentate nucleus, >5 contrast-enhanced MR images obtained; 3) control 2: patients with relapsing-remitting MS without visible gadolinium deposition in the dentate nucleus, <5 contrast-enhanced-MR images obtained; and 4) control 3: adult healthy individuals, with no contrast-enhanced MR imaging. Dentate nucleus and pontine single-voxel 12 × 12 × 12 MRS were analyzed using short TEs.

RESULTS

Forty participants (10 per group; 27 [67.5%] female; mean age, 35.6 [SD, 9.6] years) were enrolled. We did not detect any significant alteration in the levels of NAA and choline between the studied groups. The mean concentrations of mIns were 2.7 (SD, 0.73) (case), 1.5 (SD, 0.8) (control 1), 2.4 (SD, 1.2) (control 2), and 1.7 (SD, 1.2) (control 3) (P = .04). The mean concentration of Cr and mIns (P = .04) and the relative metabolic concentration (dentate nucleus/pons) of lipid 1.3/Cr (P = .04) were significantly higher in the case-group than in healthy individuals (controls 1-3). Further analyses compared the case group with cumulative control 1 and 2 groups and showed a significant increase in lactate (P = .02), lactate/Cr (P = .04), and Cr (dentate nucleus/pons) (P = .03) in the case group.

CONCLUSIONS

Although elevated concentrations of Cr, lactate, mIns, and lipid in the dentate nucleus of the case group indicate a metabolic disturbance, NAA and choline levels were normal, implying no definite neuronal damage.

Quality improvement intervention to reduce time to postoperative radiation in head and neck free flap patients

BACKGROUND

Best-practice guidelines for head and neck cancer patients advise postoperative radiation therapy (PORT) initiation within 6 weeks of surgery. We report our institutional experience improving timeliness of adjuvant radiation in free-flap patients.

METHODS

Thirty-nine patients met inclusion criteria in the 2017-2019 study period. We divided into "Early" (n = 19) and "Late" (n = 20) time-period groups to compare performance over time. The primary endpoint was time to PORT initiation, with success defined as <6 weeks.

RESULTS

The number of patients achieving timely PORT improved from 10.5% in the Early group to 50.0% in the Late group (p = 0.014). Patients undergoing concurrent adjuvant chemoradiation were more likely to meet the PORT target in the Late group (p = 0.012).

CONCLUSIONS

We ascribe this quality improvement in free-flap patients to increased communication among multidisciplinary care teams, proactive consultation referrals, and a targeted patient-navigator intervention. Though work is needed to further improve performance, insight gained from our experience may benefit other teams.

A comprehensive time course and correlation analysis of indomethacin-induced inflammation, bile acid alterations and dysbiosis in the rat small intestine

It has been proposed that changes in microbiota due to nonsteroidal anti-inflammatory drugs (NSAIDs) alter the composition of bile, and elevation of hydrophobic secondary bile acids contributes to small intestinal damage. However, little is known about the effect of NSAIDs on small intestinal bile acids, and whether bile alterations correlate with mucosal injury and dysbiosis. Here we determined the ileal bile acid metabolome and microbiota 24, 48 and 72 h after indomethacin treatment, and their correlation with each other and with tissue damage in rats. In parallel with the development of inflammation, indomethacin increased the ileal proportion of glycine and taurine conjugated bile acids, but not bile hydrophobicity. Firmicutes decreased with time, whereas Gammaproteobacteria increased first, but declined later and were partially replaced by Bilophila, Bacteroides and Fusobacterium. Mucosal injury correlated negatively with unconjugated bile acids and Gram-positive bacteria, and positively with taurine conjugates and some Gram-negative taxa. Strong positive correlation was found between Lactobacillaceae, Ruminococcaceae, Clostridiaceae and unconjugated bile acids. Indomethacin-induced dysbiosis was not likely due to direct antibacterial effects or alterations in luminal pH. Here we provide the first detailed characterization of indomethacin-induced time-dependent alterations in small intestinal bile acid composition, and their associations with mucosal injury and dysbiosis. Our results suggest that increased bile hydrophobicity is not likely to contribute to indomethacin-induced small intestinal damage.

Role of Immigration in Tuberculosis Transmission to Iran: A Systematic Review

Background:

Today, because of increasing immigration and the prevalence of drug-resistant tuberculosis in Iran, identifying intra-community cases is necessary in the country. It will be possible through the use of molecular epidemiologic methods. In this inquiry, in order to determine the role of immigrants in the transmission of specific strains to Iran, the studies have been examined which had been conducted based on molecular epidemiologic methods among Iranians and non-Iranians people.

Methods:

All studies from 1997 to the end of March 2017 were examined in three databases of PubMed, Scopus, and Google Scholar and finally, 16 studies were selected.

Results:

The common clustering rate between Iranians and non-Iranians was determined to be 19.8, and the intra-community recent transmission rate was from 0% to 49% with average of 18.1%. The rate of multidrug-resistant tuberculosis (MDR-TB) was 12.5%, which was higher among immigrants, especially Afghans, and a significant number of the strains were Beijing.

Conclusions:

The studies have shown that migrants, especially Afghans, are more effective in transmitting specific strains of tuberculosis to migratory areas. To control tuberculosis, it is necessary to register of immigrant's health information, while enter to the country, so that, by doing appropriate diagnostic tests, the curing the patients, the transmission of tuberculosis to the country would be prevented.

The role of bioresorbable intraluminal airway stents in pediatric tracheobronchial obstruction: A systematic review

INTRODUCTION

Tracheal stenosis and tracheobronchomalacia are complicated, patient-specific diseases that can be treated with intraluminal stenting. Most commonly, silicone and metal stents are utilized, however, they pose significant early and late morbidity and are further complicated by growth of the airway in the pediatric population. Given recent improvements in materials science, there is a growing body of evidence suggesting a strong role for bioresorbable intraluminal stents in treating pediatric tracheobronchial obstruction.

METHODS

A PubMed.gov literature search was performed on December 3, 2019 and May 15, 2020, and a 2-researcher systematic review was performed following the PRISMA criteria. The following search query was utilized: (((((((bioresorbable) OR bioabsorbable) OR resorbable) OR absorbable) OR biodegradable AND airway) OR trachea) AND stent. A pooled statistical analysis was performed on all reported pediatric patients using SPSS software.

RESULTS

1369 publications were screened and 26 articles with original data were identified. Materials used included polydioxanone (PDO), poly-l-lactic acid (PLLA), polyglycolic acid/poly-l-lactide co-polymer with Proglactin 910 (Vicryl®-PDS®), polycaprolactone (PCL), magnesium alloys, and co-polymers in varying proportions. Twelve articles presented data on human subjects, 8 of which were case series and case reports on pediatric populations using polydioxanone (PDO) stents. Pooled statistical analysis demonstrated an average age of 19 months (range 0.25-144), 56.5% associated with a cardiovascular anomaly, and overall complication rate of 21.7%, with a stent fragment foreign body being the most common (8.7%), followed by significant granulation tissue (4.3%), stent migration (4.3%), and local stenosis (4.3%). Comparative analysis demonstrated short-term improvement (up to 1 month) has a statistically significant association with tracheobronchomalacia versus tracheal stenosis on chi-squared test (p = 0.001). The remaining analyses did not yield statistical significance.

CONCLUSION

The reported application of bioresorbable materials as intraluminal airway stents is positive. All comparative animal studies report biocompatibility and fewer morbidities compared to metal and silicone stents, however, in human studies there are concerns over the short interval of degradation and the potential for obstructive foreign bodies in poorly seated stents. Overall, there are clear, reproducible advantages to bioresorbable intraluminal stents in pediatric airway obstruction, as well as common pitfalls, that warrant further research.

Simultaneous estimation of state and packet-loss occurrences in networked control systems

The information on data packet loss occurrences in a networked control system (NCS) is useful for improving the control performance and detecting communication failures or cyber-attacks. This study considers the simultaneous estimation of the plant state and packet loss occurrences at each time step. After formulation of the problem, two solutions are proposed. In the first one, an input-output representation of the NCS model is used to design a recursive filter for estimation of the packet loss occurrences. This estimation is then used for state estimation through Kalman filtering. In the second solution, a state-space model of NCS is used to design an estimator for both the plant state and the packet loss occurrences, which employs a Kalman filter. The effectiveness of the proposed solutions is shown during an example, and comparisons are made with another solution based on the interacting multiple model approach to estimation.

Glycine transporter inhibitors: A new avenue for managing neuropathic pain

Interneurons operating with glycine neurotransmitter are involved in the regulation of pain transmission in the dorsal horn of the spinal cord. In addition to interneurons, glycine release also occurs from glial cells neighboring glutamatergic synapses in the spinal cord. Neuronal and glial release of glycine is controlled by glycine transporters (GlyTs). Inhibitors of the two isoforms of GlyTs, the astrocytic type-1 (GlyT-1) and the neuronal type-2 (GlyT-2), decrease pain sensation evoked by injuries of peripheral sensory neurons or inflammation. The function of dorsal horn glycinergic interneurons has been suggested to be reduced in neuropathic pain, which can be reversed by GlyT-2 inhibitors (Org-25543, ALX1393). Several lines of evidence also support that peripheral nerve damage or inflammation may shift glutamatergic neurochemical transmission from N-methyl-D aspartate (NMDA) NR1/NR2A receptor- to NR1/NR2B receptor-mediated events (subunit switch). This pathological overactivation of NR1/NR2B receptors can be reduced by GlyT-1 inhibitors (NFPS, Org-25935), which decrease excessive glycine release from astroglial cells or by selective antagonists of NR2B subunits (ifenprodil, Ro 25-6981). Although several experiments suggest that GlyT inhibitors may represent a novel strategy in the control of neuropathic pain, proving this concept in human beings is hampered by lack of clinically applicable GlyT inhibitors. We also suggest that drugs inhibiting both GlyT-1 and GlyT-2 non-selectively and reversibly, may favorably target neuropathic pain. In this paper we overview inhibitors of the two isoforms of GlyTs as well as the effects of these drugs in experimental models of neuropathic pain. In addition, the possible mechanisms of action of the GlyT inhibitors, i.e. how they affect the neurochemical and pain transmission in the spinal cord, are also discussed. The growing evidence for the possible therapeutic intervention of neuropathic pain by GlyT inhibitors further urges development of drugable compounds, which may beneficially restore impaired pain transmission in various neuropathic conditions.

Melatonin: An important anticancer agent in colorectal cancer

Colorectal cancer is one of the most common cancers among the elderly, which is also seen in the forms of hereditary syndromes occurring in younger individuals. Numerous studies have been conducted to understand the molecular and cellular pathobiology underlying colorectal cancer. These studies have found that cellular signaling pathways are at the core of colorectal cancer pathology. Because of this, new agents have been proposed as possible candidates to accompany routine therapy regimens. One of these agents is melatonin, a neuro-hormone known best for its essential role in upholding the circadian rhythm and orchestrating the many physiologic changes it accompanies. Melatonin is shown to be able to modulate many signaling pathways involved in many essential cell functions, which if deregulated cause an accelerated pace towards cancer. More so, melatonin is involved in the regulation of immune function, tumor microenvironment, and acts as an antioxidant agent. Many studies have focused on the beneficial effects of melatonin in colorectal cancers, such as induction of apoptosis, increased sensitivity to chemotherapy agents and radiotherapy, limiting cellular proliferation, migration, and invasion. The present review aims to illustrate the known significance of melatonin in colorectal cancer and to address possible clinical use.

Efficacy-Based Perspective to Overcome Reduced Opioid Analgesia of Advanced Painful Diabetic Neuropathy in Rats

Reduction of the opioid analgesia in diabetic neuropathic pain (DNP) results from μ-opioid receptor (MOR) reserve reduction. Herein, we examined the antinociceptive and antiallodynic actions of a novel opioid agonist 14-O-methymorphine-6-O-sulfate (14-O-MeM6SU), fentanyl and morphine in rats with streptozocin-evoked DNP of 9–12 weeks following their systemic administration. The antinociceptive dose-response curve of morphine but not of 14-O-MeM6SU or fentanyl showed a significant right-shift in diabetic compared to non-diabetic rats. Only 14-O-MeM6SU produced antiallodynic effects in doses matching antinociceptive doses obtained in non-diabetic rats. Co-administered naloxone methiodide (NAL-M), a peripherally acting opioid receptor antagonist failed to alter the antiallodynic effect of test compounds, indicating the contribution of central opioid receptors. Reduction in spinal MOR binding sites and loss in MOR immunoreactivity of nerve terminals in the spinal cord and dorsal root ganglia in diabetic rats were observed. G-protein coupling assay revealed low efficacy character for morphine and high efficacy character for 14-O-MeM6SU or fentanyl at spinal or supraspinal levels (E_max values). Furthermore, at the spinal level only 14-O-MeM6SU showed equal efficacy in G-protein activation in tissues of diabetic- and non-diabetic animals. Altogether, the reduction of spinal opioid receptors concomitant with reduced analgesic effect of morphine may be circumvented by using high efficacy opioids, which provide superior analgesia over morphine. In conclusion, the reduction in the analgesic action of opioids in DNP might be a consequence of MOR reduction, particularly in the spinal cord. Therefore, developing opioids of high efficacy might provide analgesia exceeding that of currently available opioids.

Melatonin-mediated regulation of autophagy: Making sense of double-edged sword in cancer

Much research has been conducted to discover novel techniques to reverse the process of tumorigenesis and, cure already stablished malignancies. One well-stablished approach has been the use of organic compounds and naturally found agents such as melatonin whose anticancer effects have been shown in multiple studies, signaling a unique opportunity regarding cancer prevention and treatment. Various agents use a variety of methods to exert their anticancer effects. Two of the most important of these methods are interfering with cell signaling pathways and changing cellular functions, such as autophagy, which is essential in maintaining cellular stability against multiple exogenous and endogenous sources of stress, and is a major tool to evade early cell death. In this study, the importance of melatonin and autophagy are discussed, and the effects of melatonin on autophagy, and its contribution in the process of tumorigenesis are then noted.

Antibacterial, antibiofilm and antiquorum sensing effects of Thymus daenensis and Satureja hortensis essential oils against Staphylococcus aureus isolates

AIMS

The present study was conducted to investigate the effects of Thymus daenensis and Satureja hortensis essential oils (EOs) on the planktonic growth, biofilm formation and quorum sensing (QS) of some Staphylococcus aureus isolates (strong biofilm producers).

METHODS AND RESULTS

Minimum inhibitory concentration (MIC) of the EOs, inhibition of biofilm formation as well as disruption of preformed Staph. aureus biofilms were assessed. The antibiofilm activity of the EOs was determined using microtitre plate test (MtP) and scanning electron microscope (SEM). The QS inhibitory activity was also examined on the pregrown biofilms by gene expression analysis using quantitative real-time RT-polymerase chain reaction (PCR) of hld gene (RNAIII transcript). Moreover, tetrazolium-based colorimetric assay (MTT) was performed to detect cytotoxic effects of these EOs on the Vero cell line. Finally, the major components of the tested EOs were determined using Gas Chromatography-Mass Spectrometry (GC-MS). The MICs of T. daenensis and S. hortensis EOs against planktonic cells of the isolates were 0·0625 and 0·125 μl ml^-1 respectively. The minimum bactericidal concentrations for both of the EOs was 0·125 μl ml^-1 . The MtP test showed a significant inhibitory effect of the EOs on the biofilm formation and disruption at sub-MIC concentrations. These results were confirmed by SEM. Real-time PCR revealed a significant down-regulation of hld gene following treatment with MIC/2 concentration of S. hortensis EO. GC-MS analysis showed that carvacrol, terpinene and thymol were the major components of the applied EOs.

CONCLUSIONS

As selected EOs did not show significant cytotoxic effects even up to tenfold of MIC concentration, the applied EOs seem to be good candidates for preventing of biofilm formation of Staph. aureus cells.

SIGNIFICANCE AND IMPACT OF THE STUDY

The present study introduced T. daenensis and S. hortensis EOs as new antibiofilm, and S. hortensis EO as anti-QS herbal agents with natural origin against Staph. aureus.

Molecular analysis of the bacille Calmette-Guérin vaccine strain currently being used in Iran

BACKGROUND

In developing countries, tuberculosis (TB) infection control remains a challenge. The bacille Calmette-Guérin (BCG) vaccine is the only effective vaccine available for TB control. Iran uses a local BCG vaccine strain with an unknown substrain.

OBJECTIVE

To investigate the molecular characteristics of the current BCG strain being used in Iran using comparative genomics of the evolutionarily late strains, including BCG vaccines Pasteur, BCG-Danish, BCG-Glaxo, BCG-Prague, BCG-Frappier, BCG-Connaught and BCG-Moreau.

METHODS

A total of 67 different vials of BCG vaccine were cultured. DNA was extracted using the modified cetrimonium bromide (CTAB) method, and multiplex polymerase chain reaction (PCR) was performed to determine four target genomic regions of difference (RD) 1, RD8, RD16 and SenX3-RegX3, and to see whether RD2 and RD14 were present.

RESULTS

Our results showed that all studied batches were Mycobacterium bovis; molecular analysis revealed that the Iranian vaccine strains possess RD8, RD16 and SenX3-RegX3 regions but not RD1, RD2 and RD14. All of the vaccine batches analysed were compatible with BCG-Pasteur 1173p2, the original strain.

CONCLUSION

All of the BCG strains studied were recognised as the BCG-Pasteur 1173p2 strain. No genetic diversity among stocks and ready-for-use vaccine vials were detected.

Identification and determination of the fatty acid composition of Quercus brantii growing in southwestern Iran by GC-MS

This article reports the fatty acid composition of the oil extracts from Quercus brantii fruits growing in Kohgiloye va Boyer Ahmad province in southwestern Iran. The oil from Q. brantii fruits was extracted with hexane in Soxhlet apparatus and subsequently identified and determined by using gas chromatography-mass spectroscopy. The results revealed that the major fatty acids were oleic acid (52.99-66.14%), linoleic acid (10.80-11.11%), palmitic acid (8.08-10.06%), stearic acid (0.74-1.57%), α-linolenic acid (0.19-0.35%), erucic acid (0.12-0.15%) and arachidic acid (0.12-0.13%). The total proportion of unsaturated and saturated oil was 64.60-77.27% and 9.17-11.75%, respectively. Results indicate that the fruits of Q. brantii contained 0.19-0.35% omega-3, 10.92-14.77% omega-6 and 53.14-66.26% omega-9. Therefore, Q. brantii can be introduced as rich sources of fatty acid in food dietary and medical health.

Determination of trace elements in soil, leaves and fruits of Quercus brantii grown in southwestern Iran by atomic spectroscopy

Quercus brantii acorn is rich of some useful mineral elements such as K, Fe and Zn. The content of these mineral elements in Quercus are dependent on their region and environmental conditions. Q. brantii grown naturally in different regions of Iran especially in Kohgiloye va Boyer Ahmad province (southwestern of Iran). In this study total concentration of Fe, Zn and K elements were determined using atomic absorption and emission spectroscopy in fruits, leaves of Q. brantii and also in the soils where this plant was grown. Statistical evaluation (ANOVA test) was employed for all measurements. Results confirmed that the concentration of elements in fruit and leave depended on area which the plant is growth. The transport factor of elements was also considered.

Experimental simulation of personal dosimetry in production of medical radioisotopes by research reactor

Due to their work conditions, research reactor personnel are exposed to ionising nuclear radiations. Because the absorbed dose values are different for different tissues due to variations in sensitivity, in this work personal dosimetry has been performed under normal working conditions at anatomical locations relevant to more sensitive tissues as well as for the whole body by employing a Rando phantom and thermoluminescent dosemeters (TLDs). Fifty-two TLDs-100H were positioned at high-risk organ locations such as the thyroid, eyes as well as the left breast, which was used to assess the whole-body dose in order to study the absorbed doses originating from selected locations in the vicinity of the reactor. The results have employed the tissue weighting factors based on International Commission on Radiological Protection ICRP 103 and ICRP 60 and the measured results were below the dose limits recommended by ICRP. The mean effective dose rates calculated from ICRP 103 were the following: whole body, 30.64-6.44 µSv h(-1); thyroid, 1.22-0.23 µSv h(-1); prostate, 0.085-0.045 µSv h(-1); gonads, 1.00-0.51 µSv h(-1); breast, 3.68-0.77 µSv h(-1); and eyes, 33.74-7.01 µSv h(-1).

Evaluation of apoptosis-related genes: Fas (CD94), FasL (CD178) and TRAIL polymorphisms in Iranian multiple sclerosis patients

Multiple sclerosis (MS) is a central nervous system (CNS) demyelinating disease characterized by a relapsing-remitting course leading to progressive disability. Given the critical role of apoptosis-related genes in the maintenance of homeostasis in the immune privilege sites, mutations in these genes have a profound effect on occurring autoimmune diseases such as multiple sclerosis. In the current study, polymorphisms in the apoptosis-related genes: Fas _-670 A>G, FasL _-844C>T, FasLIVS2nt _124 A>G and TRAIL_1595C>T were analyzed in 107 Iranian patients suffering from MS and 112 unrelated healthy controls using PCR-RFLP method. Our results demonstrated that among Iranian patients with MS and controls being homozygous in Fas_670A/A, G/G and FasL_-844C/C, TT in the promoter region and homozygocity in the minor allele for FasLIVS2nt_124G/G and TRAIL_1595C/C, polymorphisms were not associated with the MS risk in Iranian patients when compared with normal controls. However, the Fas _-670G/G genotype had a borderline significantly increased frequency with secondary progressive MS type (X(2)=5.8, P=0.05). In conclusion, no statistical association was found between the Fas, FasL and TRAIL polymorphisms and the risk of MS in Iranian patients.

Speech impairment in primary hypothyroidism

OBJECTIVE

Thyroid hormone deficiency may affect human speech and voice. The aim of this study was to evaluate speech variables in patients with hypothyroidism.

DESIGN

A case control study.

PATIENTS

One hundred and twenty patients, 106 women and 14 men with symptoms and signs of thyroid failure; the diagnosis was confirmed by serum T4<4.5 μg/dl and serum TSH>10 mU/l. Eighty-eight normal subjects, 78 women and 10 men, age-, sex-, and smoking status- matched, served as controls.

MEASUREMENTS

All symptoms and signs of hypothyroidism were recorded. Serum T4, T3, and TSH concentrations were measured. Speech parameters were analyzed by the Visipitch III system model 3900 and multidimensional voice program software and compared to a group of normal subjects with no thyroid disease.

RESULTS

Mean age was 35.9±11.4 yr. Dryness in larynx and pharynx, dyspnea, and sensation of lump in the throat were reported by 53.49 and 43% of patients, respectively. Fundamental frequency, voice turbulence index, and soft phonation index were significantly different from control values. There was positive correlation between TSH concentration and variation in fundamental frequency and prevalence of voice disorders (37.2±31.2 vs 23.9±25.8 mU/l, p<0.003).

CONCLUSION

Frequent speech disturbances occur in patients with primary hypothyroidism.

Effect of adding ketamine to pethidine on postoperative pain in patients undergoing major abdominal operations: a double blind randomized controlled trial

To determine the effect of adding ketamine to pethidine in reducing post-operative pain in patients undergoing major abdominal operations, in a double blind randomized controlled trial, 100 patients aged 15-60 years who were candidate for elective major abdominal surgery allocated into two groups of pethidine + ketamine group (5 mg pethidine and 0.25 mg kg(-1) ketamine) or pethidine and placebo group (10 mg pethidine and NS) according to the regimen prescribed in postanesthesia care unit. Severity of pain (using visual analogue scale), prescribed dose of pethidine and side effects were recorded until 24 h after operation. Regarding post-operative pain, pethidine + ketamine group showed significant lower scores in all the times except 0 min, 2, 6 and 16 h. Nausea was significantly less frequent amongst pethidine + placebo group at times of 0, 15, 30 and 45 min (p < 0.05). Comparison of two groups did not show significant differences in prescribed pethedine dose in 0, 9, 12, 16, 20 and 24 h (p > 0.05). Yet, the mean dose of administered pethidine as rescue analgesic was significant lower in pethidine + ketamine group compared to pethidine + placebo group (112 +/- 31.5 mg vs. 133.5 +/- 24.5 mg, p < 0.001). In conclusion, our results showed that co-administration of ketamine and pethidine in postanesthesia care unit will improve postoperative pain and reduce narcotic consumption. It may, however, increase rate of postoperative nausea in the first hour after operation.

Effects of oral clonidine premedication on haemodynamic response to laryngoscopy and tracheal intubation: a clinical trial

The objective of this study was to evaluate the efficacy of pre-anesthetic orally administration of clonidine on pulse rate and blood stress response to laryngoscopy and tracheal intubation. In a double-blinded, randomized study, 274 ASA I and II subjects with age of 18 to 45 years scheduled for elective surgery under general anesthesia were enrolled. They were randomly allocated to receive oral clonidine (0.2 mg) or placebo as premedication 90-120 min before surgery. All the patients received Succinylcholine (1.5 mg kg(-1)) after induction of anesthesia with Fentanyl (50 microg) and Thiopentone (5 mg kg(-1)). The anesthesia was maintained with halothane (1.5 Mac) in 50% mixture of N2O/O2. Heart rate and systolic blood pressure were recorded before, immediately after and then every 5 min after intubation until 20 min. The Clonidine group showed a significant superiority over placebo in the prevention of increase in systolic blood pressure as well as heart rate over the intubation. A significant difference was observed in both heart rate and systolic blood pressures were significantly higher in Control group at three subsequent measurements following intubation. The results of this study suggest that orally administered clonidine in preanesthetic period, provides more haemodynamic stability and attenuates the stress response to laryngoscopy and intubation.