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Mohammed A Al-Abri,1 Ibtisam Al lawati,2 Fahad Zadjali,3 Shyam Ganguly4 1Department of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman; 2Department of Physiology, Oman College of Health Sciences, Muscat, Sultanate of Oman; 3Department of Biochemistry, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Sultanate of Oman; 4Department of Family Medicine and Public Health, College of Medicine and Health Sciences, Sultan Qaboos University, Muscat, Sultanate of OmanCorrespondence: Mohammed A Al-AbriDepartment of Physiology, College of Medicine and Health Sciences, Sultan Qaboos University Hospital, Al-Khoud 123, P.O. Box 38, Muscat, Sultanate of OmanTel +968 24144702Email malabri@squ.edu.omBackground: Sleep patterns have changed continuously worldwide and it can be influenced by social, cultural, and environmental factors. These patterns may be associated with poor sleep quality and daytime sleepiness. The aim of the study was to investigate sleep patterns and quality in Omani adults using actigraphy.Subjects and Methods: This was a cross-sectional study conducted between June 2015 and February 2017. Four hundred subjects agreed to participate in the study (52% male, 48% female). Subjects were randomly selected and enrolled in the study among young adults and middle aged individuals living in the City of Muscat. Subjects were asked to fill-in Epworth sleepiness scale (ESS) and Pittsburgh sleep quality index (PSQI). Actigraphy was used to measure their sleep patterns for one week.Results: The mean age of participants was 32.80± 11.50 years. Four sleep patterns were identified: monophasic, bi-phasic (post-dawn), bi-phasic (afternoon siesta), and polyphasic (three sleep periods/24 hours). The study revealed that 35% of participants had biphasic-siesta sleep pattern, 28% polyphasic, 26% monophasic, and 11% biphasic-dawn. The biphasic siesta pattern was found to be associated with younger age group (25– 34 years) (P=0.001). Polyphasic sleep was associated with higher ESS score (P=0.001) but not with poor sleep quality (P=0.24). There was no significant difference in night sleep duration among all the sleep patterns (P=0.07) but the polyphasic sleep pattern had higher total 24-hour day sleep duration (P=0.03). Nearly 90% of participants practiced afternoon siestas with mean duration of 45± 43 minutes.Conclusion: The predominant sleep pattern among Omanis was biphasic-siesta and majority of people practiced afternoon siesta. Polyphasic sleep pattern is associated with daytime sleepiness.Keywords: sleep patterns, sleepiness, siesta, polyphasic, fragmented sleep

To investigate lisinopril effect on the contribution of nitric oxide (NO) and Kca channels to acetylcholine (ACh)-induced relaxation in isolated mesenteric arteries of spontaneously hypertensive rats (SHRs). Third branch mesenteric arteries isolated from lisinopril treated SHR rats (20 mg/kg/day for ten weeks, SHR-T) or untreated (SHR-UT) or normotensive WKY rats were mounted on tension myograph and ACh concentration-response curves were obtained. Westernblotting of eNOS and KCa channels was performed. ACh-induced relaxations were similar in all groups while L-NMMA and indomethacin caused significant rightward shift only in SHR-T group. Apamin and TRAM-34 (SKCa and IKCa channels blockers, respectively) significantly attenuated ACh-induced maximal relaxation by similar magnitude in vessels from all three groups. In the presence of L-NMMA, indomethacin, apamin and TRAM-34 further attenuated ACh-induced relaxation only in SHR-T. Furthermore, lisinopril treatment increased expression of eNOS, SKCa and BKCa proteins. Lisinopril treatment increased expression of eNOS, SKCa, BKCa channel proteins and increased the contribution of NO to ACh-mediated relaxation. This increased role of NO was apparent only when EDHF component was blocked by inhibiting SKCa and IKCa channels. Such may suggest that in mesenteric arteries, non-EDHF component functions act as a reserve system to provide compensatory vasodilatation if (and when) hyperpolarization that is mediated by SKCa and IKCa channels is reduced. [ABSTRACT FROM AUTHOR]

BACKGROUND: The anticancer-drug cisplatin (CP) causes nephrotoxicity through different mechanisms, including generation of free radicals. Ellagic acid (EA) is a polyphenolic antioxidant found in fruits and nuts. AIM: This study aimed to investigate the ability of different doses of EA to ameliorate CP nephrotoxicity in rats. MATERIALS AND METHODS: Animals were randomly divided into six groups and treated with saline; CP alone (6 mg/kg); two doses of EA, both alone (10 and 30 mg/kg) or with CP. RESULTS: Treatment with CP alone reduced body weight, water intake, urine output, and renal total antioxidant and reduced glutathione (GSH) concentrations (p < 0.01). In addition, it increased relative kidney weight, plasma creatinine, and blood urea nitrogen (BUN) concentrations (p < 0.01). However, a dose of 30 mg/kg EA mitigated most of the CP-induced actions, but no effect was seen for the 10 mg/kg dose. Histopathologically, rats given CP+EA30 showed < 25% necrotic lesions in the renal cortical area compared with > 60% in rats treated with CP alone. Molecular analysis showed that clusterin (Clu) mRNA and protein were expressed in all treated groups, meanwhile kidney injury molecule-1 (Kim-1) mRNA and protein were only expressed in the CP and CP+EA treated rats. CONCLUSIONS: EA (30 mg/kg) ameliorated most of the physiological, histological, and biochemical markers of CP nephrotoxicity. The molecular findings in this work did not completely tally with the conventional method used. The overexpression of the molecular markers may be related to the EA induced repair mechanism. [ABSTRACT FROM AUTHOR]

Plate-like structures had been thoroughly studied in literature over years to reduce the computational space from 3D to 2D. Many of these theories suffer either from satisfying the free traction condition or thickness extensibility in addition to the consistency of transverse shear strain energy. This work presents a higher order shear deformation thickness-extensible plate theory (eHSDT) for the analysis of plates. The proposed eHSDT satisfies the condition of free traction as other theories do but it also satisfies the condition of consistency of transverse shear strain energy which is neglected by many theories in the area of plates and shells. The implementation of the proposed theory in displacement-based finite element procedure requires continuity of derivatives across elements. This necessary condition was achieved using the penalty enforcement method for derivative-based nodal degrees of freedom across the standard 9-nodes Lagrange element. The theory was tested for elastic bending deformation of Polyether-ether-ketone (PEEK) which is one of the basic materials for medical implants. The theory showed good accuracy compared to experimental data of the three-points bending test. The present eHSDT was also tested for different conditions with a wide range of aspects ratios (thin to thick plates) and different boundary conditions. The accuracy of the proposed eHSDT was verified against exact solutions for these conditions which showed the advantage over other approaches and commercial finite element packages., (Creative Commons Attribution license.)

Study Objectives: We investigated the association between different sleep patterns and inflammatory and oxidative stress biomarkers in adults., Methods: A total of 321 consented adults who fulfilled the inclusion criteria were recruited in this cross-sectional study. The inclusion criteria were mainly based on apparently healthy adults aged 18-59 years. To identify sleep patterns, participants were requested to wear the actigraph for 1 week for 24 hours a day. Fasting blood was collected from each participant at day 8. The blood serum was analyzed for inflammatory and oxidative stress biomarkers. Sleep patterns were defined as monophasic (1 episode of night sleep) biphasic (2 episodes of sleep; night and aternoon siesta), and polyphasic sleep pattern (3 or more sleep episodes)., Results: There was no correlation between night sleep duration, total sleep in 24 hours, and napping among inflammatory and oxidative stress biomarkers: high-sensitivity C-reactive protein, malondialdehyde, total glutathione, and basal oxidizability status. Actigraphy reports showed 3 sleep patterns in this cohort, monophasic (24.3%), biphasic-napping (45.2%) and polyphasic (30.5%). Individuals with segmented sleep patterns were significantly associated with oxidative stress biomarkers. A polyphasic sleep pattern was significantly associated with higher basal oxidizability status ( P = .023), whereas a biphasic sleep pattern showed higher malondialdehyde ( P = .036) as compared to a monophasic sleep pattern. Total glutathione was significantly higher in monophasic sleepers ( P = .046). There was no difference in serum high-sensitivity C-reactive protein among all sleep patterns., Conclusions: Segmented sleep in polyphasic and biphasic sleep patterns is associated with higher serum malondialdehyde and basal oxidizability status in particular. Further studies are recommended on the cardiometabolic impact of oxidative stress biomarkers in individuals with segmented sleep., Citation: Al Lawati I, Zadjali F, Al-Abri MA. Elevated oxidative stress biomarkers in adults with segmented sleep patterns. J Clin Sleep Med. 2024;20(6):959-966., (© 2024 American Academy of Sleep Medicine.)

Vitamin D deficiency is highly prevalent worldwide, especially with limited sun exposure and sun avoidance. Thus, reliable monitoring of vitamin D levels in food and biological samples is vital for medicinal diagnosis. Herein, a potent method for the extraction and determination of vitamin D 3 is presented using a microchip-based solid-phase extraction (SPE) device followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) detection. A new magnetic adsorbent based on Fe 3 O 4 magnetic nanoparticles (MNPs) modified ZnFe layered double hydroxide (LDH)/2-aminoterephthalic acid-Zn 2+ metal-organic framework (IRMOF-3) composite (IRMOF-3@MLDH) was successfully synthesized and fixed inside a rectangular micro-column (4 × 2 × 12 mm). The porous structure and high surface area of IRMOF-3@MLDH provide abundant adsorbing sites and make it a potent SPE adsorbent, with an exceptional ability to retain vitamin D 3 . The adsorption isotherm showed that the composite was highly efficient at extracting vitamin D 3 with an extraction capacity of 126 mg g -1 . The designed extraction microchip simplified the SPE process, paving the way for automated SPE systems. The developed method presented a broad linear range of 5-2000 ng mL -1 , with a detection limit of 1.4 ng mL -1 . In comparison to conventional silica-based adsorbents, a higher sensitivity was obtained in the determination of vitamin D 3 using the IRMOF-3@MLDH adsorbent. The selectivity of the method was also satisfactory, enabling the measurement of vitamin D 3 in food and blood samples with high recovery values in the range from 95.2 to 101%. Thus, the newly developed adsorbent and method offer an efficient alternative to the commonly used C18-based approach., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Purpose: To describe the effect of seasonal variations on sleep patterns in a hot climate Arab region., Methods: This is a cross-sectional study that included healthy Omani subjects of both genders between ages 18 and 59 years. Data for sleep pattern identification in summer and winter were collected from participants using an actigraphy wristband., Results: Among 321 participants, in summer seasons, a polyphasic sleep pattern (40%) prevailed over other sleep patterns (P < 0.001). While in the winter season, monophasic sleep (31%) was the dominant pattern (P < 0.001). Subjects slept longer during the winter seasons with total hours of sleep during the day 48 min longer than in the summer, though the difference was not statistically significant (P > 0.05), while siesta duration in the summer was significantly longer (13 min, P < 0.01). In summer, the sleep quality was good (PSQI ≤ 5); however, it was poor (PSQI > 5) in winter (P < 0.05). Night sleep duration, daytime sleepiness, and sleep latency were not statistically different between the summer and winter seasons., Conclusion: Sleep patterns may be influenced by seasonal changes. A polyphasic sleep pattern prevailed in summer while a monophasic pattern was the predominant sleep pattern in winter. In summer, the sleep quality was good and the siesta duration was longer compared to the winter., (© 2022. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Introduction: Sleep has different patterns followed worldwide and can be influenced by social, cultural, and environmental factors. Daytime napping is commonly practiced in different parts of the world with controversial results of its effect on glucose metabolism. The current study aims to examine the association of afternoon napping and night sleep duration with metabolic derangements., Methods: This is a cross-sectional study involving young adults and middle-aged subjects. Anthropometric measurements were taken for height and weight and hip and waist ratio. Consented subjects were asked to wear actigraphy for 1 week and run their usual daily activities. Home sleep apnea testing was performed to exclude obstructive sleep apnea. Subjects had been asked to come fasting on day seven for blood collection to test for fasting glucose, glycated hemoglobin, lipid profile, and insulin., Results: A total of 405 subjects were involved to complete the study (52% male, 48% female). The mean age of participants was 32.8 ± 11.5 years. The study indicated that the duration of afternoon napping was significantly associated with abnormal glycated hemoglobin (HbA1c > 5.7%) ( p = 0.01) and body mass index ( p = 0.046) independent of age, gender, and nocturnal sleep duration. Nocturnal sleep duration was associated with increased insulin level ( p = 0.04)., Conclusion: Afternoon napping is associated with an increased level of glycated hemoglobin and obesity and that may predispose to the development of type 2 diabetes mellitus., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2022 Al-Abri, Al Lawati and Al Zadjali.)

Objectives: Stroke is a significant public health problem and one of the most important preventable non-communicable diseases. Preventive stroke programmes with a better focus on increasing awareness among those who are currently at risk are yet to be properly established in Oman. This study was conducted to describe the characteristics of stroke patients presenting to a tertiary care hospital in Oman., Methods: This cross-sectional hospital-based study included 193 stroke cases which were prospectively recruited from the Emergency Department of Khoula Hospital, Muscat, Oman. Data were collected from November 2017 to April 2018., Results: The total number of patients was 193 with 82.9% of strokes being ischaemic strokes. Of this, 58% were male. The mean age of stroke patients was 61.05 years. Risk factors included hypertension (72.5%) and diabetes mellitus (54.4%). Dyslipidaemia, atrial fibrillation and ischaemic heart diseases were not particularly prevalent in the studied population and 24.4% of ischaemic strokes had large artery atherosclerosis while 21.9% had small vessel occlusion. Significantly more patients had lower Glasgow Coma Scale scores, required intensive care unit admission and experienced in-hospital deaths due to haemorrhagic stroke compared to ischaemic stroke., Conclusion: This study provides essential data regarding stroke characteristics specific to Oman's population. Most of the information obtained appears to be in-line with what has been described internationally and, hence, preventive strategies similar to those indicated in extant literature can be implemented. This information can be utilised by health administrators in planning resource allocation. Further research is needed to explore rehabilitation aspects and long-term outcomes., Competing Interests: CONFLICT OF INTEREST The authors declare no conflicts of interest., (© Copyright 2022, Sultan Qaboos University Medical Journal, All Rights Reserved.)

Purpose: To investigate the agreement in sleep pattern recording by self-reported sleep questionnaires and actigraphy in adults., Methods: This is a cross-sectional study. Men and women who met inclusion criteria were recruited for this study. The inclusion criteria were apparently healthy Omani nationals ages 19 to 50 years. Sleep questionnaires were randomly distributed in Muscat either directly or via electronic and paper announcements. Data were collected from the participants using the self-reported questionnaires with four piloted questions for sleep pattern identification and through the actigraphy wristband given to subjects to wear for a week. Cohen's kappa test was performed for agreement analysis., Results: A total of 964 Omani subjects between ages 18 and 59 years of both genders were recruited and completed the questionnaires successfully. Out of these, only 321 subjects wore the actigraphy wristband for 1 week (response rate = 33%). Agreement analysis reported a mild level of agreement for the monophasic (41%), moderate level for biphasic (59%), and good level for polyphasic (70%) sleep patterns. The overall agreement level of sleep patterns between the two methods was 57%. There is a low specificity of self-reported assessment in reporting sleep pattern., Conclusion: The average agreement level of subjective versus objective assessments of sleep patterns was moderate at 57% and self-reported sleep pattern is not specific. The study recommends the use of actigraphy along with sleep questionnaires for accurate assessment of sleep patterns in cohort studies., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG part of Springer Nature.)

Herein, a novel paper-based chemiluminescence (CL) assay is reported using a smartphone readout for on-site and reliable analytical applications. The CL system was based on the high-performance improving effect of cobalt-imidazole metal-organic framework (CoMOF) on luminol-hydrogen peroxide (H 2 O 2 ) CL emission. The CoMOF was grown on paper and used as a support for the CL reaction, which led to an intense CL emission and good reproducibility. More importantly, the stability of luminol, as the CL reagent, was greatly improved in the presence of CoMOF. This high stability, along with the high-yield CL emission, makes the device highly suitable for commercialization. Furthermore, using a smartphone as the detector for the developed device made the process easier and more accessible for public usage. In this work, the new paper-based CL smartphone device was used for the detection of the total phenolic content of food samples. Phenolic compounds (PC) are hydroxyl radical scavengers that can effectively quench the CL emission of the luminol-H 2 O 2 -CoMOF system. After optimizing the reaction conditions, the system could detect PC at the μg mL -1 level. Detection limits of 0.12, 0.28, 0.46, 0.85, and 1.23 μg mL -1 were obtained for gallic acid, quercetin, catechin, kaempferol, and caffeic acid, respectively. This work is the first report on the practical application of smartphone CL assays for the estimation of PC. The proposed assay is an easy-to-use, low-cost, portable, and suitable assay for on-site screening purposes., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Objectives: This study aimed to identify the relationship between antenatal depression and pregnancy outcomes, including the risk of developing postpartum depression in Oman., Methods: This follow-up prospective longitudinal cohort study included pregnant women attending primary healthcare institutions in Muscat, Oman from January to November 2014. The Edinburgh Postnatal Depression Scale (EPDS) was used to screen for antenatal and postnatal depression. Pregnant Omani women with a gestational age ≥32 weeks attending 12 local health centres for antenatal care in Muscat were invited to participate. Recruited women were followed-up at 6-8 weeks after delivery. The following pregnancy outcomes were assessed: mode of delivery (normal or Caesarean section [CS]), gestational age at delivery (preterm or full-term), baby's birth weight and development of postnatal depression., Results: A total of 959 women participated in this study (response rate: 97.3%). In total, 233 women (24.4%) had antenatal depression with a score of ≥13 on the EPDS. Of the 592 participants (61.7%) who attended postnatal clinics at 6-8 weeks post-delivery, 126 (21.3%) were positive for postnatal depression. Logistic multivariate regression analysis showed that antenatal depression was associated with increased risk of CS (odds ratio [OR] = 1.79; 95% confidence interval [CI]: 1.20-2.66) and postnatal depression (OR = 8.63; 95% CI: 5.56-13.39)., Conclusion: Screening women for antenatal depression and providing appropriate management may reduce adverse pregnancy outcomes and the risk of developing postnatal depression., Competing Interests: CONFLICT OF INTEREST The authors declare no conflicts of interest., (© Copyright 2020, Sultan Qaboos University Medical Journal, All Rights Reserved.)

Transient receptor potential vanilloid 4 (TRPV4) channel responds to temperature, as well as various mechanical and chemical stimuli. This non-selective cation channel is expressed in several organs, including the blood vessels, kidneys, oesophagus and skin. In the skin, TRPV4 channel is present in various cell types such as keratinocytes, melanocytes and sensory neurons, as well as immune and inflammatory cells, and engages in several physiological actions, from skin homeostasis to sensation. In addition, there is substantial evidence implicating dysfunctional TRPV4 channel-in the form of either deficient or excessive channel activity-in pathological cutaneous conditions such as skin barrier compromise, pruritus, pain, skin inflammation and carcinogenesis. These varied functions, combined with the fact that TRPV4 channel owns pharmacologically-accessible sites, make this channel an attractive therapeutic target for skin disorders. In this review, we summarize the different physiological and pathophysiological effects of TRPV4 in the skin., (© Copyright 2020, Sultan Qaboos University Medical Journal, All Rights Reserved.)

Oxidative stress plays a pivotal role in the pathogenesis of cardiovascular diseases (CVD). Postmenopausal women have an increased risk of developing CVD due to decreased estrogen availability, which is accompanied by increased oxidative stress. Serum free thiols (R-SH) provide a robust and powerful read-out of systemic oxidative stress. In this study, we aimed to establish serum levels of free thiols and explore associations between free thiols and demographic, clinical, and biochemical parameters related to obesity and the risk for developing CVD in both pre- and postmenopausal women. Serum free thiols were measured in a cohort consisting of healthy pre- ( n = 223) and postmenopausal ( n = 118) Omani women. Postmenopausal women had significantly lower levels of serum free thiols as compared to premenopausal women (762.9 ± 85.3 vs. 780 ± 80.9 μM, age-adjusted p < 0.001). Women's age was positively associated with serum free thiol levels in premenopausal women (β = 0.36, p = 0.002), whereas an inverse association was observed in postmenopausal women (β = -0.29, p = 0.002). Homocysteine levels were significantly inversely associated with serum free thiol levels in both pre- (β = -0.19, p = 0.005) and postmenopausal (β = -0.20, p = 0.032) women, independent from known cardiovascular risk factors. In this study, we show that postmenopausal women are affected by increased systemic oxidative stress, which independently associates with homocysteine levels.

Herein, a novel paper-based chemiluminescence (CL) device has been reported for the estimation of total phenolic content of food samples. The CL system implemented on the paper was based on a hydrogen peroxide (H 2 O 2 )-rhodamine b (RhoB)-cobalt metal organic framework (CoMOF) reaction. It was found that the reaction of H 2 O 2 with RhoB molecules, loaded into the nanopores of CoMOF (R@CoMOF), can produce an intensive CL emission. The experiments on the paper indicated that in the presence of CoMOF, the CL emission was greatly increased. In addition to this strong catalyzing effect, application of CoMOF on the paper improved the stability of the CL system for several days. As a useful analytical application for the obtained paper-based CL device (PCD), it was examined for the detection of phenolic antioxidants. It was observed that the addition of 5 μL of phenolic compounds (PC) on the paper containing the CL reagents can remarkably decrease the CL intensity. This effect was applied to design a simple analytical assay for PC. After the optimization process, the best sensitivity was obtained for gallic acid, quercetin, catechin, kaempferol, and caffeic acid with detection limits of 0.98, 1.36, 1.48, 1.81, and 2.55 ng mL -1 , respectively. The relative standard deviations (RSD%) were also less than 5%. This study is the first report on the practical application of PCD using a nanomaterial assisted CL reaction. It is simple, portable, and low-cost and consumes a very low amount of reagents and sample solution. The device was successfully applied in the investigation of total antioxidant capacity of molasses and honey samples.

Background: Left-handedness is the preferential use of the left hand in single-handed activities such as writing. There are many studies in the literature on left-handedness in relation to professional sports, medicine and surgery. Although dentistry largely depends on manual dexterity and hand skills, there has been little research to investigate the effect of left-handedness on clinical dentistry, particularly in Australasia., Aim: To gain an insight into the clinical learning experience of left-handed undergraduate dental students at the Faculty of Dentistry, University of Otago, New Zealand., Methods: Purposive sampling of left-handed students was done within the final-year class of undergraduate dental students, and they were invited to participate in a semi-structured group interview to discuss their clinical learning experience at the Faculty. Six participants agreed to participate, and the interview was recorded and transcribed verbatim. Collected data were analysed using a thematic inductive/interpretive analysis approach according to the constructivist grounded theory., Results: All participants reported having clinical difficulties being left-handed students learning using right-handed equipment. There was a common theme of experiencing hand and wrist musculoskeletal problems as well as feeling of guilt causing patient discomfort during treatment. The majority of participants reported incidents where they were told by their supervisors to learn practising dentistry with their right hand and they felt that little guidance was given on how to operate as a left-handed clinician. All participants perceived that being a left-handed operator affected their efficiency and confidence level in their early clinical years., Conclusion: Left-handed students have a strong sense of adaptability. However, in order to improve the learning experience regardless of the difference in the operator's preference of dominant hand, students should be provided with appropriate equipment such as ambidextrous dental chairs and professional guidance, especially during their early career., (© 2019 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

A novel mixing approach was utilized with a highly sensitive chemiluminescence (CL) method to determine the total phenolic content (TPC) in honey samples using an acidic potassium permanganate-formaldehyde system. The mixing approach was based on exploiting the mixing efficiency of nanodroplets generated in a microfluidic platform. Careful optimization of the instrument setup and various experimental conditions were employed to obtain excellent sensitivity. The mixing efficiency of the droplets was compared with the CL signal intensity obtained using the common serpentine chip design, with both approaches using at a total flow rate of 15 μl min -1 ; the results showed that the nanodroplets provided 600% higher CL signal intensity at this low flow rate. Using the optimum conditions, calibration equations, limits of detection (LOD) and limits of quantification (LOQ) for gallic acid (GA), caffeic acid (CA), kaempferol (KAM), quercetin (QRC) and catechin (CAT) were obtained. The LOD ranged from 6.2 ppb for CA to 11.0 ppb for QRC. Finally, the method was applied for the determination of TPC in several local and commercial honey samples., (Copyright © 2018 John Wiley & Sons, Ltd.)

Calcium channel blockers (CCBs) are widely used to treat cardiovascular disease (CVD) including hypertension. As aging is an independent risk factor for CVD, the use of CCBs increases with increasing age. Hence, this study was designed to evaluate the effect of aging on the sensitivity of small mesenteric arteries to L-type voltage-gated calcium channel (LTCC) blockers and also to investigate whether there was a concomitant change in calcium current density. Third order mesenteric arteries from male F344 rats, aged 2.5-3 months (young) and 22-26 months (old) were mounted on wire myograph to measure the tension during isometric contraction. Arteries were contracted with 100 mM KCl and were then relaxed in a cumulative concentration-response dependent manner with nifedipine (0.1 nM-1 μM), verapamil (0.1 nM-10 μM), or diltiazem (0.1 nM-10 μM). Relaxation-concentration response curves produced by cumulative concentrations of three different CCBs in arteries of old rats were shifted to the right with statistically significant IC50s. pIC50 ± s.e.m: (8.37 ± 0.06 vs. 8.04 ± 0.05, 7.40 ± 0.07 vs. 6.81 ± 0.04, and 6.58 ± 0.07 vs. 6.34 ± 0.06) in young vs. old. It was observed that the maximal contractions induced by phenylephrine and reversed by sodium nitroprusside were not different between young and old groups. However, Bay K 8644 (1 μM) increased resting tension by 23 ± 4.8% in young arteries and 4.7 ± 1.6% in old arteries. LTCC current density were also significantly lower in old arteries (-2.77 ± 0.45 pA/pF) compared to young arteries (-4.5 ± 0.40 pA/pF); with similar steady-state activation and inactivation curves. Parallel to this reduction, the expression of Cav1.2 protein was reduced by 57 ± 5% in arteries from old rats compared to those from young rats. In conclusion, our results suggest that aging reduces the response of small mesenteric arteries to the vasodilatory effect of the CCBs and this may be due to, at least in part, reduced current density of LTCC.

Objectives: This study aimed to identify the prevalence of antenatal depression and the risk factors associated with its development among Omani women. No previous studies on antenatal depression have been conducted in Oman., Methods: This descriptive cross-sectional study was carried out between January and November 2014 in Muscat, Oman. Pregnant Omani women ≥32 gestational weeks who were attending one of 12 local primary care health centres in Muscat for routine antenatal care were invited to participate in the study (n = 986). An Arabic version of the validated self-administered Edinburgh Postnatal Depression Scale questionnaire was used to measure antenatal depression. A cut-off score of ≥13 was considered to indicate probable depression., Results: A total of 959 women participated in the study (response rate: 97.3%). Of these, 233 were found to have antenatal depression (24.3%). A bivariate analysis showed that antenatal depression was associated with unplanned pregnancies (P = 0.010), marital conflict (P = 0.001) and a family history of depression (P = 0.019). The adjusted odds ratio (OR) after logistic multivariate regression analysis showed that antenatal depression was significantly associated with unplanned pregnancies (OR: 1.37; 95% confidence interval [CI]: 1.02-1.86) and marital conflict (OR: 13.83; 95% CI: 2.99-63.93)., Conclusion: The prevalence of antenatal depression among the studied Omani women was high, particularly in comparison to findings from other Arab countries. Thus, antenatal screening for depression should be considered in routine primary antenatal care. Couples should also be encouraged to seek psychological support should marital conflicts develop during pregnancy.

Activated charcoal (AC) is a sorbent that has been shown to remove urinary toxins like urea and indoxyl sulfate. Here, the influence of AC on kidney function of rats with experimental chronic renal failure (CRF) is investigated. CRF was induced in rats by feeding adenine (0.75%) for four weeks. As an intervention, AC was added to the feed at concentrations of 10%, 15% or 20%. Adenine treatment impaired kidney function: it lowered creatinine clearance and increased plasma concentrations of creatinine, urea, neutrophil gelatinase-associated lipocalin and vanin-1. Furthermore, it raised plasma concentrations of the uremic toxins indoxyl sulfate, phosphate and uric acid. Renal morphology was severely damaged and histopathological markers of inflammation and fibrosis were especially increased. In renal homogenates, antioxidant indices, including superoxide dismutase and catalase activity, total antioxidant capacity and reduced glutathione were adversely affected. Most of these changes were significantly ameliorated by dietary administration of AC at a concentration of 20%, while effects induced by lower doses of dietary AC on adenine nephrotoxicity were not statistically significant. The results suggest that charcoal is a useful sorbent agent in dietary adenine-induced CRF in rats and that its usability as a nephroprotective agent in human kidney disease should be studied., (Copyright © 2014 Elsevier Ltd. All rights reserved.)

Introduction: This study aimed at comparing the effects of feeding mice and rats with adenine to induce a state of chronic renal failure (CRF), and to assess the effect of treatment with gum acacia (GA) thereon., Methods: We compared the outcome, in mice, of feeding adenine at three different doses (0.75%, 0.3%, and 0.2%, w/w). Biochemical and histopathological studies were conducted in plasma, urine and renal homogenates from both species., Results: When mice and rats were fed adenine (0.75%, w/w), all treated rats survived the treatment, but all treated mice died within 1-2 days. The dosage in mice was reduced to 0.3%, w/w, for 4 weeks, but again all treated mice died within 3-4 days. A further reduction in the dosage in mice to 0.2%, w/w, for 4 weeks resulted in no mortality, and produced alterations similar to those observed in rats fed adenine at a dose of 0.75%,w/w, for 4 weeks. Plasma creatinine, urea and urinary protein were significantly increased (P<0.001) in adenine-treated mice and rats, and this action was incompletely, but significantly (P<0.05), reversed by GA. Adenine significantly (P<0.001) reduced superoxide dismutase (SOD) activity and reduced glutathione (GSH) concentration in renal homogenates from both species, and these reductions were significantly (P<0.05) ameliorated by GA., Discussion: Our data suggest that mice are more sensitive to adenine than rats, and that a dose of adenine of 0.2%, w/w, for 4 weeks in mice is suggested as a model for CRF. In both models, GA (15%, w/v, in the drinking water for 4 weeks) given concomitantly with adenine ameliorated the severity of CRF to a similar extent., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Emodin (a rhubarb anthraquinone) has strong antioxidant and anticancer actions, and recent studies indicated that it reduces cellular oxidative stress induced by various insults and drugs. Cisplatin is an anticancer drug that is associated with nephrotoxicity and induces oxidative stress in cultured human kidney (HEK 293) cells. This study aimed to assess the in-vitro antioxidant properties of the emodin against cisplatin-induced oxidative stress in HEK 293 cells. Our study revealed that emodin acted as a potent free radical scavenger and provided nephroprotection against cisplatin-induced oxidative stress. Emodin as low as 0.5 µm did not decrease cell viability and restored the cisplatin-induced glutathione depletion and total antioxidant capacity in a dose-dependent manner. Emodin augmented the cisplatin-induced inhibition of antioxidant enzymes (catalase, glutathione peroxidase, glutathione S-transferase, glutathione reductase and superoxide dismutase). These results suggest that emodin has the potential to be used as an adjunct therapeutic agent in patients receiving cisplatin treatment., (Copyright © 2012 John Wiley & Sons, Ltd.)

Nephrotoxicity of the anticancer drug cisplatin (CP) involves the generation of reactive oxygen species in renal cortex, and emodin (a rhubarb anthraquinone) has strong antioxidant and anticancer actions. Therefore, we tested here the possible ameliorative effect of emodin on CP nephrotoxicity in rats. Emodin was given orally (10 mg/kg/day for nine consecutive days), and on day 4, some of the treated rats were also injected intraperitoneally with either saline or CP (6 mg/kg). Five days after CP treatment, rats were killed, and blood and urine samples, and kidneys were collected for the assessment of histopathological renal damage and apoptosis, and for biochemical estimation of creatinine and urea concentrations in plasma and urine, several cytosolic antioxidant enzyme activities in kidneys, and urinalyses. CP significantly increased the concentrations of urea and creatinine, and decreased creatinine clearance. It also significantly reduced cortical glutathione concentration and the activity of superoxide dismutase. CP treatment significantly increased urine volume and N-acetyl-β-D-glucosaminidase activity and significantly decreased osmolarity and protein concentrations. Emodin treatment markedly and significantly mitigated all these effects. Sections from saline- and emodin-treated rats showed apparently normal proximal tubules. However, kidneys of CP-treated rats had a moderate degree of necrosis. This was markedly lessened when CP was given simultaneously with emodin. The concentration of CP in the cortical tissues was not significantly altered by emodin treatment. The results suggested that emodin had ameliorated CP nephrotoxicity in rats. Pending further pharmacological and toxicological studies emodin may be considered a potentially useful nephroprotective agent., (© 2011 The Authors Fundamental and Clinical Pharmacology © 2011 Société Française de Pharmacologie et de Thérapeutique.)

The effects of Hibiscus sabdariffa (HS) in lowering blood pressure in human and animal hypertension have been documented. This study investigated the effect of the water extract of the dried calyx of HS and Hibiscus anthocyanins (HAs) on left ventricular myocardial capillary length and surface area in spontaneously hypertensive rats (SHRs). Twelve-week-old male SHRs were divided into eight groups (six rats in each group). Three groups were given three doses; 10%, 15% and 20% of the water extract of HS in lieu of drinking water for 10 consecutive weeks (HS10, HS15 and HS20) with one group kept as control (C). Another three groups were given three doses of the HAs orally at doses of 50, 100 and 200 mg/kg for five consecutive days with one group kept as a control (C). Systolic (SBP) and diastolic (DBP) blood pressures, as well as heart rate (HR), were measured weekly. After the experimental protocols, the left ventricles (LV) of all rats were obtained. Capillary surface area density and length density were determined by unbiased sterological methods on 3 μm LV tissue samples from perfusion-fixed hearts. HS ingestion significantly reduced SBP, DBP and LV mass in a dose-dependent fashion but did not affect the HR. HS significantly increased surface area and length density of myocardial capillaries by 59%, 65% and 86%, and length density by 57%, 77% and 57%, respectively. Myocyte nuclear volume was significantly decreased in HS-treated rats. There was a decrease (although insignificant) in SBP and DBP with HA ingestion compared with controls. These changes suggest that the observed beneficial effect of HS on high BP in SHRs could be mediated through a reduction in the diffusion distance between capillaries and myocytes, as well as new vessel formation. It is proposed that these effects might be beneficial in restoring myocyte normal nutritional status compromised by the hypertrophic state of hypertension.

An aqueous extract of Hibiscus sabdariffa L. is a common beverage in many parts of the world. Reports on its effect on reproduction are conflicting, with anecdotal evidence that the plant is an aphrodisiac, while others report that it is estrogenic, and adversely affects spermatogenesis in rats. We have studied the effect of different concentrations of aqueous extracts of H. sabdariffa calyces (10%, 15% and 20%) used as drinking water for 10 consecutive weeks, and its anthocyanins (50, 100, 200 mg/kg for 5 days, orally) on the weight and histology of the testis, and on some biochemical constituents in testicular homogenates, in addition to the plasma concentrations of testosterone, luteinizing hormone and estradiol. The possible presence of an estrogenic effect of the extract and anthocyanins on the uteri of immature female rats was also tested. Neither the H. sabdariffa extract nor the anthocyanins significantly altered either testicular weight and histology, or uterus weight. Plasma concentrations of the three hormones studied, the testicular concentrations of protein, reduced glutathione and total cholesterol, and superoxide dismutase activity were all insignificantly affected by either the extract or the anthocyanins, except for a slight, but statistically significant, decrease in testicular protein concentration caused by the 15% aqueous extract when compared with controls. These results suggest that H. sabdariffa exerts no adverse effect on the male reproductive system. Consumption of H. sabdariffa aqueous extract inhibited the growth of the rats compared with the controls.