Displaying publications 1 - 20 of 47 in total

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  1. Abdelhafez MMA, Ahmed KAM, Ahmed NAM, Ismail MH, Daud MNM, Eldiasty AME, et al.
    Afr J Reprod Health, 2024 Mar 31;28(3):122-129.
    PMID: 38583076 DOI: 10.29063/ajrh2024/v28i3.13
    Menopausal hormone therapy (MHT) is known to increase the risk of venous thromboembolism (VTE), which includes deep vein thrombosis, pulmonary embolism, and less frequently cerebral vein thrombosis, but the absolute risk for a given patient is very low. After starting MHT, the risk of VTE seems to be at its highest, declining to the non-HRT user baseline level of risk after stopping. Whether estrogen-only or estrogen-progestin HRT combination is linked to a similar risk of VTE is unclear from the available evidence. The aim of this study is to evaluate the risks of developing VTE in relation to different types as well as different modes of administration of MHT through a database search including PubMed, MEDLINE, Google Scholar, Cochrane Library, and others in order to provide the women carers with the up-to-date and evidence-based guidelines and recommendations while counseling the post-menopausal women enquiring on use of hormonal therapies either to alleviate the menopausal symptoms or to prevent the long-term sequelae of estrogen deficiency.
  2. Abdullah UYH, Ibrahim HM, Mahmud NB, Salleh MZ, Kek TL, Noorizhab MNFB, et al.
    Hemoglobin, 2019 May;43(3):182-187.
    PMID: 31298599 DOI: 10.1080/03630269.2019.1632893
    This is the first report of quadrupole time-of-flight (Q-TOF) mass spectrometric identification of the hemoglobin (Hb) subunits, α, β, δ and γ peptides, derived from enzymatic-digestion of proteins in the early unknown peaks of the cation exchange chromatography of Hb. The objectives were to identify the unknown high performance liquid chromatography (HPLC) peaks in healthy subjects and in patients with β-thalassemia (β-thal). The results demonstrate the existence of pools of free globin chains in red blood cells (RBCs). The α-, β-, δ- and γ-globin peptides were identified in the unknown HPLC peaks. The quantification and role of the free globin pool in patients with β-thal requires further investigation. Identification of all types of Hb subunits in the retention time (RT) before 1 min. suggests that altered Hbs is the nature of these fast-eluting peaks. Relevancy of thalassemias to the protein-aggregation disorders will require review of the role of free globin in the pathology of the disease.
  3. Acosta ML, Mat Nor MN, Guo CX, Mugisho OO, Coutinho FP, Rupenthal ID, et al.
    Neural Regen Res, 2021 Mar;16(3):482-488.
    PMID: 32985469 DOI: 10.4103/1673-5374.290097
    Compounds that block the function of connexin and pannexin protein channels have been suggested to be valuable therapeutics for a range of diseases. Some of these compounds are now in clinical trials, but for many of them, the literature is inconclusive about the molecular effect on the tissue, despite evidence of functional recovery. Blocking the different channel types has distinct physiological and pathological implications and this review describes current knowledge of connexin and pannexin protein channels, their function as channels and possible mechanisms of the channel block effect for the latest therapeutic compounds. We summarize the evidence implicating pannexins and connexins in disease, considering their homeostatic versus pathological roles, their contribution to excesive ATP release linked to disease onset and progression.
  4. Adam FA, Mohd N, Rani H, Baharin B, Mohd Yusof MYP
    J Ethnopharmacol, 2021 Jun 28;274:113882.
    PMID: 33513418 DOI: 10.1016/j.jep.2021.113882
    ETHNOPHARMACOLOGICAL RELEVANCE: Salvadora persica L. chewing stick, commonly known as miswak is still being used as an oral hygiene tool for plaque control and prevention against gingivitis. Various studies have reported on the therapeutics and prophylactic effects particularly on periodontal disease. This review aimed to evaluate the effectiveness of S. persica chewing stick compared to the standard toothbrush for anti-plaque and anti-gingivitis.

    MATERIAL AND METHODS: A PRISMA-compliant systematic search of literature was done from the MEDLINE, CENTRAL, Science Direct, PubMed and Google Scholar. Literature that fulfilled eligibility criteria was identified. Data measuring plaque score and bleeding score were extracted. Qualitative and random-effects meta-analyses were conducted.

    RESULTS: From 1736 titles and abstracts screened, eight articles were utilized for qualitative analysis, while five were selected for meta-analysis. The pooled effect estimates of SMD and 95% CI were -0.07 [-0.60 to 0.45] with an χ2 statistic of 0.32 (p = 0.0001), I2 = 80% as anti-plaque function and 95% CI were -2.07 [-4.05 to -0.10] with an χ2 statistic of 1.67 (p = 0.02), I2 = 82%.

    CONCLUSION: S. persica chewing stick is a tool that could control plaque, comparable to a standard toothbrush. Further, it has a better anti-gingivitis effect and can be used as an alternative.

  5. Adam FA, Mohd N, Rani H, Mohd Yusof MYP, Baharin B
    J Ethnopharmacol, 2023 Feb 10;302(Pt A):115863.
    PMID: 36283639 DOI: 10.1016/j.jep.2022.115863
    ETHNOPHARMACOLOGICAL RELEVANCE: Salvadora persica L., also known as miswak, is an indigenous plant most prevalent in the Middle Eastern, some Asian, and African countries. It has medicinal and prophylactics function for numerous illnesses, including periodontal disease. Various trials, apart from World Health Organization encouragement have contributed to the production and use of S. persica in extract form in the formulation of mouthwash. This systematic review and meta-analysis aimed to compare the clinical effect of Salvadora persica-extract mouthwash and chlorhexidine gluconate mouthwash for anti-plaque and anti-gingivitis functions.

    METHODS: Using the PRISMA 2020 Protocol, a systematic search of the publications was undertaken from the MEDLINE, CENTRAL, Science Direct, PubMed, and Google Scholars for randomized control trials published through 31st January 2022 to determine the effectiveness of Salvadora persica-extract mouthwash relative to chlorhexidine gluconate as anti-plaque and anti-gingivitis properties.

    RESULTS: A total of 1809 titles and abstracts were screened. Of these, twenty-two studies met the inclusion criteria for the systematic review while only sixteen were selected for meta-analysis. The overall effects of standardized mean difference and 95% CI were 0.89 [95% CI 0.09 to 1.69] with a χ2 statistic of 2.54, 15 degrees of freedom (p 

  6. Ahmad R, Ali WN, Nor ZM, Ismail Z, Hadi AA, Ibrahim MN, et al.
    Malar J, 2011;10:361.
    PMID: 22166101 DOI: 10.1186/1475-2875-10-361
    The application of the Geographic Information Systems (GIS) to the study of vector transmitted diseases considerably improves the management of the information obtained from the field survey and facilitates the study of the distribution patterns of the vector species.
  7. Akram W, Hussein MS, Ahmad S, Mamat MN, Ismail NE
    Saudi Pharm J, 2015 Oct;23(5):499-503.
    PMID: 26594115 DOI: 10.1016/j.jsps.2015.01.011
    There is no instrument which collectively assesses the knowledge, attitude and perceived practice of asthma among community pharmacists. Therefore, this study aimed to validate the instrument which measured the knowledge, attitude and perceived practice of asthma among community pharmacists by producing empirical evidence of validity and reliability of the items using Rasch model (Bond & Fox software®) for dichotomous and polytomous data. This baseline study recruited 33 community pharmacists from Penang, Malaysia. The results showed that all PTMEA Corr were in positive values, where an item was able to distinguish between the ability of respondents. Based on the MNSQ infit and outfit range (0.60-1.40), out of 55 items, 2 items from the instrument were suggested to be removed. The findings indicated that the instrument fitted with Rasch measurement model and showed the acceptable reliability values of 0.88 and 0.83 and 0.79 for knowledge, attitude and perceived practice respectively.
  8. Al-Hinai KH, Benkara Mohd N, Rozullyah Zulkepely N, Md Nor R, Mohd Amin Y, Bradley DA
    Appl Radiat Isot, 2013 Dec;82:126-9.
    PMID: 23978507 DOI: 10.1016/j.apradiso.2013.07.013
    We describe two example pilot efforts to help define new thermoluminescent dosimeter media. The first concerns ZnS:Mn nanophosphors, prepared by chemical precipitation using zinc and sodium sulfate, doped with manganese sulfate at concentrations varying from 1 to 3mol. The second concerns chemical vapor deposited diamond, produced as a thin film or as amorphous carbon on a single-crystal silicon substrate, each deposited under the same conditions, use being made of the hot filament-chemical vapor deposition (HFCVD) technique. The gas concentrations used were 1% CH4 in 99% H2 and 25% CH4 in 75% H2. Characterization of formations used FESEM, XRD and EDX. The nanophosphors consisted of particles of sizes in the range 85-150nm, the thermoluminescence (TL)-based radiation detection medium giving rise to a single peaked glow curve of maximum yield at a temperature of 250°C at a heating rate of 5°C/s. The TL response increased linearly with radiation dose, ZnS doped to 2mol of Mn being found the most sensitive. Regarding chemical vapor deposited (CVD) carbon, inappreciable TL was found for the resultant ball-like amorphous carbon films, graphite, and the silicon substrate, whereas CVD diamond films showed a promising degree of linearity with dose. For both the ZnS and diamond samples, TL signal fading was appreciable, being some 40% per day for ZnS and>50% per day for CVD films even under storage in the dark at room temperature, making it apparent that there is need to adjust parameters such as the size of nanoparticles.
  9. Asghar MT, Yusof YA, Mokhtar MN, Yaacob ME, Ghazali HM, Varith J, et al.
    J Sci Food Agric, 2020 Aug;100(10):4012-4019.
    PMID: 32337729 DOI: 10.1002/jsfa.10446
    BACKGROUND: Coconut sugar has a caramel color with a taste like brown sugar. It is commonly used as natural sweetener. However, coconut sugar has been produced from coconut sap using a traditional method that involves heating the sap at high temperature (>100 °C) in an open pan for a long period (3-5 h). This conventional method results in an over-cooked sugar, which leads to quality deterioration in terms of both its physical and chemical properties. The current study aimed to investigate the processing of coconut sap into sugar syrup using alternative processing techniques such as rotary vacuum evaporation (RE) and microwave evaporation (ME), comparing them with open-heat evaporation (OHE) technique.

    RESULTS: Coconut sugar syrup produced by rotary evaporation at 60 °C and 250 mbar vacuum (RE-60) required the shortest production time (12.2 min) and the lowest processing temperature (54.8 °C) when compared with ME (13 min and 103.2 °C) and OHE (46.8 min and 101.6 °C). It also had a light brownish color with a higher L* value (35.17) than the ME (29.84) and OHE (23.84) methods. It was found to contain higher amounts of monosaccharides (fructose and glucose) and lower amounts of disaccharides (sucrose). Furthermore, the amount of energy required for RE-60 (0.35 kWh) was much less than for OHE (0.83 kWh).

    CONCLUSION: This study provided an alternative processing method for the sugar processing industry to produce coconut sugar using the rotary evaporation method at 60 °C under 250 mbar vacuum with better physicochemical qualities, shorter processing time, and minimum input energy. © 2020 Society of Chemical Industry.

  10. Aziz HA, Adlan MN, Ariffin KS
    Bioresour Technol, 2008 Apr;99(6):1578-83.
    PMID: 17540556
    This paper presents the results of research on heavy metals removal from water by filtration using low cost coarse media which could be used as an alternative approach to remove heavy metals from water or selected wastewater. A series of batch studies were conducted using different particle media (particle size 2.36-4.75 mm) shaken with different heavy metal solutions at various pH values to see the removal behaviour for each metal. Each solution of cadmium (Cd), lead (Pb), zinc (Zn), nickel (Ni), copper (Cu) and chromium (Cr(III)) with a concentration of 2 mg/L was shaken with the media. At a final pH of 8.5, limestone has significantly removed more than 90% of most metals followed by 80% and 65% removals using crushed bricks and gravel, respectively. The removal by aeration and settlement methods without solid media was less than 30%. Results indicated that the removal of heavy metals was influenced by the media and not directly by the pH. Investigations on the removal behaviour of these metals indicated that rough solid media with the presence of carbonate were beneficial for the removal process. Adsorption and precipitation as metals oxide and probably as metals carbonate were among the two mechanisms that contributed to the removal of metals from solution.
  11. Christelle K, Norhayati MN, Jaafar SH
    Cochrane Database Syst Rev, 2022 Aug 26;8(8):CD006034.
    PMID: 36017945 DOI: 10.1002/14651858.CD006034.pub3
    BACKGROUND: Heavy menstrual bleeding and pain are common reasons women discontinue intrauterine device (IUD) use. Copper IUD (Cu IUD) users tend to experience increased menstrual bleeding, whereas levonorgestrel IUD (LNG IUD) users tend to have irregular menstruation. Medical therapies used to reduce heavy menstrual bleeding or pain associated with Cu and LNG IUD use include non-steroidal anti-inflammatory drugs (NSAIDs), anti-fibrinolytics and paracetamol. We analysed treatment and prevention interventions separately because the expected outcomes for treatment and prevention interventions differ. We did not combine different drug classes in the analysis as they have different mechanisms of action. This is an update of a review originally on NSAIDs. The review scope has been widened to include all interventions for treatment or prevention of heavy menstrual bleeding or pain associated with IUD use.

    OBJECTIVES: To evaluate all randomized controlled trials (RCTs) that have assessed strategies for treatment and prevention of heavy menstrual bleeding or pain associated with IUD use, for example, pharmacotherapy and alternative therapies.

    SEARCH METHODS: We searched CENTRAL, MEDLINE, Embase and CINAHL to January 2021.

    SELECTION CRITERIA: We included RCTs in any language that tested strategies for treatment or prevention of heavy menstrual bleeding or pain associated with IUD (Cu IUD, LNG IUD or other IUD) use. The comparison could be no intervention, placebo or another active intervention.

    DATA COLLECTION AND ANALYSIS: Two review authors independently assessed trials for inclusion and risk of bias, and extracted data. Primary outcomes were volume of menstrual blood loss, duration of menstruation and painful menstruation. We used a random-effects model in all meta-analyses. Review authors assessed the certainty of evidence using GRADE.

    MAIN RESULTS: This review includes 21 trials involving 3689 participants from middle- and high-income countries. Women were 18 to 45 years old and either already using an IUD or had just had one placed for contraception. The included trials examined NSAIDs and other interventions. Eleven were treatment trials, of these seven were on users of the Cu IUD, one on LNG IUD and three on an unknown type. Ten were prevention trials, six focused on Cu IUD users, and four on LNG IUD users. Sixteen trials had high risk of detection bias due to subjective assessment of pain and bleeding. Treatment of heavy menstrual bleeding Cu IUD Vitamin B1 resulted in fewer pads used per day (mean difference (MD) -7.00, 95% confidence interval (CI) -8.50 to -5.50) and fewer bleeding days (MD -2.00, 95% CI -2.38 to -1.62; 1 trial; 110 women; low-certainty evidence) compared to placebo. The evidence is very uncertain about the effect of naproxen on the volume of menstruation compared to placebo (odds ratio (OR) 0.09, 95% CI 0.00 to 1.78; 1 trial, 40 women; very low-certainty evidence). Treatment with mefenamic acid resulted in less volume of blood loss compared to tranexamic acid (MD -64.26, 95% CI -105.65 to -22.87; 1 trial, 94 women; low-certainty evidence). However, there was no difference in duration of bleeding with treatment of mefenamic acid or tranexamic acid (MD 0.08 days, 95% CI -0.27 to 0.42, 2 trials, 152 women; low-certainty evidence). LNG IUD The use of ulipristal acetate in LNG IUD may not reduce the number of bleeding days in 90 days in comparison to placebo (MD -9.30 days, 95% CI -26.76 to 8.16; 1 trial, 24 women; low-certainty evidence). Unknown IUD type Mefenamic acid may not reduce volume of bleeding compared to Vitex agnus measured by pictorial blood assessment chart (MD -2.40, 95% CI -13.77 to 8.97; 1 trial; 84 women; low-certainty evidence). Treatment of pain Cu IUD Treatment with tranexamic acid and sodium diclofenac may result in little or no difference in the occurrence of pain (OR 1.00, 95% CI 0.06 to 17.25; 1 trial, 38 women; very low-certainty evidence). Unknown IUD type Naproxen may reduce pain (MD 4.10, 95% CI 0.91 to 7.29; 1 trial, 33 women; low-certainty evidence). Prevention of heavy menstrual bleeding Cu IUD We found very low-certainty evidence that tolfenamic acid may prevent heavy bleeding compared to placebo (OR 0.54, 95% CI 0.34 to 0.85; 1 trial, 310 women). There was no difference between ibuprofen and placebo in blood volume reduction (MD -14.11, 95% CI -36.04 to 7.82) and duration of bleeding (MD -0.2 days, 95% CI -1.40 to 1.0; 1 trial, 28 women, low-certainty evidence). Aspirin may not prevent heavy bleeding in comparison to paracetamol (MD -0.30, 95% CI -26.16 to 25.56; 1 trial, 20 women; very low-certainty evidence). LNG IUD Ulipristal acetate may increase the percentage of bleeding days compared to placebo (MD 9.50, 95% CI 1.48 to 17.52; 1 trial, 118 women; low-certainty evidence). There were insufficient data for analysis in a single trial comparing mifepristone and vitamin B. There were insufficient data for analysis in the single trial comparing tranexamic acid and mefenamic acid and in another trial comparing naproxen with estradiol. Prevention of pain Cu IUD There was low-certainty evidence that tolfenamic acid may not be effective to prevent painful menstruation compared to placebo (OR 0.71, 95% CI 0.44 to 1.14; 1 trial, 310 women). Ibuprofen may not reduce menstrual cramps compared to placebo (OR 1.00, 95% CI 0.11 to 8.95; 1 trial, 20 women, low-certainty evidence).

    AUTHORS' CONCLUSIONS: Findings from this review should be interpreted with caution due to low- and very low-certainty evidence. Included trials were limited; the majority of the evidence was derived from single trials with few participants. Further research requires larger trials and improved trial reporting. The use of vitamin B1 and mefenamic acid to treat heavy menstruation and tolfenamic acid to prevent heavy menstruation associated with Cu IUD should be investigated. More trials are needed to generate evidence for the treatment and prevention of heavy and painful menstruation associated with LNG IUD.

  12. Dehzangi A, Abdullah AM, Larki F, Hutagalung SD, Saion EB, Hamidon MN, et al.
    Nanoscale Res Lett, 2012;7(1):381.
    PMID: 22781031 DOI: 10.1186/1556-276X-7-381
    The junctionless nanowire transistor is a promising alternative for a new generation of nanotransistors. In this letter the atomic force microscopy nanolithography with two wet etching processes was implemented to fabricate simple structures as double gate and single gate junctionless silicon nanowire transistor on low doped p-type silicon-on-insulator wafer. The etching process was developed and optimized in the present work compared to our previous works. The output, transfer characteristics and drain conductance of both structures were compared. The trend for both devices found to be the same but differences in subthreshold swing, 'on/off' ratio, and threshold voltage were observed. The devices are 'on' state when performing as the pinch off devices. The positive gate voltage shows pinch off effect, while the negative gate voltage was unable to make a significant effect on drain current. The charge transmission in devices is also investigated in simple model according to a junctionless transistor principal.
  13. Fazilah A, Azemi MN, Karim AA, Norakma MN
    J Agric Food Chem, 2009 Feb 25;57(4):1527-31.
    PMID: 19166335 DOI: 10.1021/jf8028013
    Hemicelluloses from oil palm frond (OPF) were extracted using 3 M potassium hydroxide (KOH) for 4 h at 40 degrees C with stirring at 400 rpm to obtain hemicelluloses A and B. The total yield of the hemicellulose isolated from OPF was 33% (dry weight). Both hemicelluloses A and B were then subjected to hydrothermal treatment at 121 degrees C and 1.03 x 10(5) Pa for 10, 30, and 50 min. Physicochemical characterizations of hydrothermally treated hemicelluloses, such as Klason lignin content and reducing sugar content, were performed to study the effect of autohydrolysis processing on OPF-derived hemicelluloses. It was shown that Klason lignin content in hemicellulose A was higher than that in hemicellulose B and decreased after hydrothermal treatment. Hydrothermal treatment enhanced the solubility of hemicelluloses, which reflects their higher reducing sugar content. Monosaccharide analysis using HPLC showed that xylose was the predominant monosaccharide for both hemicelluloses A and B.
  14. Halim SA, Razali N, Mohd N
    Data Brief, 2020 Dec;33:106535.
    PMID: 34026955 DOI: 10.1016/j.dib.2020.106535
    Pellet mixed with 5 wt% and 10 wt% of binders was tested. The pelleting process was performed using a pellet mill operated at 100 °C and at 50 MPa. The physical and chemical characteristics including hardness, high heating value and proximate analysis of pellet produces were obtained using durometer and through thermographic analysis and the results were reported in this paper. Bulk and unit density were determined according to ASABE standard. The dataset presented here are the data of palm kernel shell pellet prepared using two types of binder; (1) sago starch and (2) sodium acetate. The pelletization of palm kernel shell aimed to increase the density and strength of the palm kernel shell pellet and consequently provide better thermal degradation characteristics.
  15. Hassan FW, Mohd N
    Spec Care Dentist, 2021 Jan;41(1):92-97.
    PMID: 33125720 DOI: 10.1111/scd.12537
    BACKGROUND/AIM: Polycythemia rubra vera (PRV) is a myeloproliferative disease, which is characterized by the proliferation of all three major hematopoietic groups (erythrocytes, leucocytes and platelets). This hematological condition presented with different clinical manifestations depending on the thrombohemorrhagic status of the patient. It is suggested patient with preexisting PRV may suffer complication during periodontal treatment. Thus, this case would therefore demonstrate periodontal management outcome in PRV patient.

    CASE PRESENTATION: A 60-year-old Malay gentleman presented to the Periodontic Clinic, Universiti Kebangsaan Malaysia. He was a known case of primary PRV for the past 5 years. Intraoral examination showed generalized periodontal deep pockets ranging from 5 to 10 mm. He was diagnosed as Stage III Grade C periodontitis. Nonsurgical periodontal therapy was provided, followed by surgical correction of residual periodontal deep pockets on teeth 17, 11, and 23. He was reviewed at 4-month intervals for supportive periodontal therapy after stabilization of his periodontal condition.

    CONCLUSION: Polycythemia rubra vera (PRV) patients should have preoperative therapeutic control for more than 4 months and have been treated with myelosuppressive agents prior to periodontal surgery. Good oral hygiene and periodical supportive periodontal therapy are the key factors for successful periodontal treatment outcomes in well-controlled PRV patients.

  16. Henry CJ, Webster-Gandy JD, Koon PB, Ismail MN
    Am J Hum Biol, 2005 Nov-Dec;17(6):818-20.
    PMID: 16254909
    This cross-sectional study of age matched (10-11 years), pre-menarcheal girls in England and Malaysia investigated the effect of ethnicity on resting metabolic rate (RMR). The children were recruited from schools in Oxford, England, and Kuala Lumpur, Malaysia, and all measurements were conducted in the schools. The Malaysian girls were shorter (143.7 +/- 6.5 cm and 140.1 +/- 5.3 cm (mean +/- SD) for the English and Malaysian girls respectively) and lighter (32.5 +/- 5.3 kg compared with 38.0 +/- 8.7 kg for the English girls) with a smaller fat mass and fat free mass (FFM) than the English girls. Energy expenditure was lower in the Malaysian girls (4555 +/- 531 kJ/day compared with 5178 +/- 688 kJ/day for the English girls). Although a difference in RMR was observed between the two groups, when corrected for body composition the difference was no longer significant. No effect of ethnicity on the relationship of FFM and RMR was shown when the data were analyzed using analysis of covariance.
  17. Ismail MNB, Rahim SMA
    Clin Med (Lond), 2021 Jan;21(1):e108-e109.
    PMID: 33479090 DOI: 10.7861/clinmed.2020-0882
    Tuberculosis is an airborne multisystemic disease which primarily infects the lungs. Isolated tuberculous arthritis is rare. We present a case of a 41-year-old woman with a known case of lupus nephritis class IV who complained of pain and swelling over her left ankle joint for several months. She was treated for rheumatoid arthritis and was started with immunosuppressive agents. However, she did not improve with treatment and was later diagnosed with tuberculous arthritis based on a molecular study from joint aspiration. She was started on antituberculosis medication and showed improvement. We highlight the challenges in reaching the diagnosis and the importance of including tuberculous arthritis in differential diagnoses in cases with persistent ankle swelling.
  18. Kim Y, Griffin JM, Nor MNM, Zhang J, Freestone PS, Danesh-Meyer HV, et al.
    Neurotherapeutics, 2017 Oct;14(4):1148-1165.
    PMID: 28560708 DOI: 10.1007/s13311-017-0536-9
    The cis benzopyran compound tonabersat (SB-220453) has previously been reported to inhibit connexin26 expression in the brain by attenuating the p38-mitogen-activated protein kinase pathway. We show here that tonabersat directly inhibits connexin43 hemichannel opening. Connexin43 hemichannels have been called "pathological pores" based upon their role in secondary lesion spread, edema, inflammation, and neuronal loss following central nervous system injuries, as well as in chronic inflammatory disease. Both connexin43 hemichannels and pannexin channels released adenosine triphosphate (ATP) during ischemia in an in vitro ischemia model, but only connexin43 hemichannels contributed to ATP release during reperfusion. Tonabersat inhibited connexin43 hemichannel-mediated ATP release during both ischemia and reperfusion phases, with direct channel block confirmed using electrophysiology. Tonabersat also reduced connexin43 gap junction coupling in vitro, but only at higher concentrations, with junctional plaques internalized and degraded via the lysosomal pathway. Systemic delivery of tonabersat in a rat bright-light retinal damage model (a model for dry age-related macular degeneration) resulted in significantly improved functional outcomes assessed using electroretinography. Tonabersat also prevented thinning of the retina, especially the outer nuclear layer and choroid, assessed using optical coherence tomography. We conclude that tonabersat, already given orally to over 1000 humans in clinical trials (as a potential treatment for, and prophylactic treatment of, migraine because it was thought to inhibit cortical spreading depression), is a connexin hemichannel inhibitor and may have the potential to be a novel treatment of central nervous system injury and chronic neuroinflammatory disease.
  19. Larki F, Dehzangi A, Abedini A, Abdullah AM, Saion E, Hutagalung SD, et al.
    Beilstein J Nanotechnol, 2012;3:817-23.
    PMID: 23365794 DOI: 10.3762/bjnano.3.91
    A double-lateral-gate p-type junctionless transistor is fabricated on a low-doped (10(15)) silicon-on-insulator wafer by a lithography technique based on scanning probe microscopy and two steps of wet chemical etching. The experimental transfer characteristics are obtained and compared with the numerical characteristics of the device. The simulation results are used to investigate the pinch-off mechanism, from the flat band to the off state. The study is based on the variation of the carrier density and the electric-field components. The device is a pinch-off transistor, which is normally in the on state and is driven into the off state by the application of a positive gate voltage. We demonstrate that the depletion starts from the bottom corner of the channel facing the gates and expands toward the center and top of the channel. Redistribution of the carriers due to the electric field emanating from the gates creates an electric field perpendicular to the current, toward the bottom of the channel, which provides the electrostatic squeezing of the current.
  20. Manaf SM, NurWaliyuddin HZ, Panneerchelvam S, Zafarina Z, Norazmi MN, Chambers GK, et al.
    Blood Transfus, 2015 Oct;13(4):610-5.
    PMID: 26057487 DOI: 10.2450/2015.0278-14
    Human neutrophil antigens (HNA) are polymorphic and immunogenic proteins involved in the pathogenesis of neonatal alloimmune neutropenia, transfusion-related acute lung injury (TRALI) and transfusion-related alloimmune neutropenia. The characterisation of HNA at a population level is important for predicting the risk of alloimmunisation associated with blood transfusion and gestation and for anthropological studies.
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