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  1. Lim SH, Lee HB, Ho AS
    Photochem Photobiol, 2011 Sep-Oct;87(5):1152-8.
    PMID: 21534974 DOI: 10.1111/j.1751-1097.2011.00939.x
    In our screening for photosensitizers from natural resources, 15(1)-hydroxypurpurin-7-lactone ethyl methyl diester (compound 1) was isolated for the first time from an Araceae plant. To evaluate the efficacy of compound 1 as a photosensitizer for head and neck cancers, compound 1 was studied in reference to a known photosensitizer pheophorbide-a (Pha), in terms of photophysical properties, singlet oxygen generation and in in vitro experiments (intracellular uptake and phototoxicity assays) in two oral (HSC2 and HSC3) and two nasopharyngeal (HK1 and C666-1) cancer cell lines. In this study, compound 1 exhibited higher intracellular uptake over 24 h compared with Pha in both HSC3 and HK1 cells. When activated by ≥4.8 J cm(-2) of light, compound 1 was slightly more potent as a photosensitizer than Pha by consistently having marginally lower IC(50) values across different cell lines. In flow cytometry experiments to study the mechanism of photoactivated cell death in HSC3, compound 1 was observed to induce more pronounced apoptosis compared with Pha, which may have been driven by the transient G(2)/M cell cycle block which was also observed. These promising results on compound 1 warrant its further investigation as a clinically useful photodynamic therapy agent for head and neck cancer.
    Matched MeSH terms: Dose-Response Relationship, Drug
  2. Shekhar KC, Achike FI, Kaur G, Kumar P, Hashim R
    J Altern Complement Med, 2002 Aug;8(4):445-57.
    PMID: 12230905
    A nonrandomized, non-placebo-controlled clinical trial to evaluate the efficacy of Cogent db (an herbal preparation; Cybele Herbal Laboratories [PVT] Ltd. Kochi, Kerala State, India) as an adjuvant in the treatment of patients with type 2 diabetes was carried out during a 3-month period.
    Matched MeSH terms: Dose-Response Relationship, Drug
  3. Ponto T, Ismail NI, Abdul Majeed AB, Marmaya NH, Zakaria ZA
    Methods Find Exp Clin Pharmacol, 2010 Jul-Aug;32(6):427-32.
    PMID: 20852752 DOI: 10.1358/mf.2010.32.6.1477907
    Schizophrenia is a chronic psychiatric disorder and pharmacotherapy plays a major role in its management. The 1950s and early 1960s saw milestones in the introduction of psychotropic drugs in clinical practice. A review of drug prescriptions in different settings provides an insight into the pattern of drug use, identifies drug-related problems and may be used to compare recommended guidelines with actual practice. This effort led to the evaluation of the drug prescribing pattern of antipsychotics in patients attending the psychiatric clinic at a government hospital. The data from 371 antipsychotic medication prescriptions that included 200 prescriptions for schizophrenia were collected during one month (1rst-31rst August 2008) at the outpatient pharmacy department. The mean age of patients was 35.0 years (SD = 1.131), with a male to female ratio of 2:1. The most widely used oral antipsychotic was haloperidol (16.3%) while the most common depot preparation prescribed was zuclopenthixol decanoate (8.8%). The daily dose of the average antipsychotic prescribed in this clinic was 342.06 mg equivalent of chlorpromazine. There was no relation between the doses received and ethnicity of the patient (Malay, Chinese or Indian). However, there was a significant relationship between the prescribed dose and patient age (P < 0.042). Nearly 32% of the schizophrenia patients were prescribed with atypical antipsychotics such as olanzapine (10.8%), risperidone (10.0%), quetiapine (7.6%) and clozapine (3.2%). Monotherapy was given to 73.0% of the schizophrenia patients. The majority of patients also received antidepressants. To conclude, this study gave evidence that physicians had a strong preference for monotherapy with conventional antipsychotic drugs while the use of atypical drugs was less prevalent.
    Matched MeSH terms: Dose-Response Relationship, Drug
  4. Kar SK, Dwibedi B, Kerketa AS, Maharana A, Panda SS, Mohanty PC, et al.
    PLoS Negl Trop Dis, 2015 Mar;9(3):e0003583.
    PMID: 25781977 DOI: 10.1371/journal.pntd.0003583
    Although current programmes to eliminate lymphatic filariasis have made significant progress it may be necessary to use different approaches to achieve the global goal, especially where compliance has been poor and 'hot spots' of continued infection exist. In the absence of alternative drugs, the use of higher or more frequent dosing with the existing drugs needs to be explored. We examined the effect of higher and/or more frequent dosing with albendazole with a fixed 300 mg dose of diethylcarbamazine in a Wuchereria bancrofti endemic area in Odisha, India. Following screening, 104 consenting adults were randomly assigned to treatment with the standard regimen annually for 24 months (S1), or annually with increased dose (800 mg albendazole)(H1) or with increased frequency (6 monthly) with either standard (S2) or increased (H2) dose. Pre-treatment microfilaria counts (GM) ranged from 348 to 459 mf/ml. Subjects were followed using microfilaria counts, OG4C3 antigen levels and ultrasound scanning for adult worm nests. Microfilarial counts tended to decrease more rapidly with higher or more frequent dosing at all time points. At 12 months, Mf clearance was marginally greater with the high dose regimens, while by 24 months, there was a trend to higher Mf clearance in the arm with increased frequency and 800 mg of albendazole (76.9%) compared to other arms, (S1:64%, S2:69.2% & H1:73.1%). Although higher and/or more frequent dosing showed a trend towards a greater decline in antigenemia and clearance of "nests", all regimens demonstrated the potential macrofilaricidal effect of the combination. The higher doses of albendazole did not result in a greater number or more severe side effects. The alternative regimens could be useful in the later stages of existing elimination programmes or achieving elimination more rapidly in areas where programmes have yet to start.
    Matched MeSH terms: Dose-Response Relationship, Drug
  5. Ataie-Jafari A, Loke SC, Rahmat AB, Larijani B, Abbasi F, Leow MK, et al.
    Clin Nutr, 2013 Dec;32(6):911-7.
    PMID: 23395257 DOI: 10.1016/j.clnu.2013.01.012
    This participant-blinded parallel-group randomized placebo-controlled study demonstrated that alfacalcidol (vitamin D analogue) preserves beta cell function in newly diagnosed type 1 diabetes (T1DM) in children.
    Matched MeSH terms: Dose-Response Relationship, Drug
  6. Abdul-Majeed S, Mohamed N, Soelaiman IN
    Curr Drug Targets, 2013 Dec;14(13):1579-90.
    PMID: 23848479
    Skeletal tissue undergoes continuous remodeling which makes it unique among other body tissues. Osteoporosis is a common bone metabolic disorder affecting both men and women. Osteoporosis and its complications mainly osteoporotic fractures, have a high impact on health and economy. Current approved medications are associated with numerous side effects, which limit their use. Identification of a new and safe therapy is mandatory. Statins, also known as HMGCoA reductase inhibitors, are frequently used for the treatment of hypercholesterolemia and for the prevention of morbidity and mortality associated with cardiovascular disease. Statins improved bone health status in intact and ovariectomised rodents following high clinically intolerable oral doses. However, this beneficial effect of statins could not be significantly demonstrated in humans. The reason behind this discrepancy might be due to the safety and bioavailability of the currently used oral statins. Vitamin E, especially the tocotrienols at the dose 60 mg/kg/day provided significant antiosteoporotic effects in different animal models of osteoporosis. The use of the aforementioned dose of tocotrienols was shown to be safe in both humans and animals. Enhancement of bone formation and reduction of bone resorption were achieved more effectively by a combination of tocotrienols and statins than by either treatment when supplemented separately at clinically tolerable doses. Therefore, the adverse effects associated with high statin doses might be avoided with the coadministration of tocotrienols. Moreover, the combination therapy strategy might be useful for patients who are at high risk of osteoporosis, cardiovascular events and hypercholesterolaemia.
    Matched MeSH terms: Dose-Response Relationship, Drug
  7. Tham CL, Liew CY, Lam KW, Mohamad AS, Kim MK, Cheah YK, et al.
    Eur J Pharmacol, 2010 Feb 25;628(1-3):247-54.
    PMID: 19958764 DOI: 10.1016/j.ejphar.2009.11.053
    Curcumin is a highly pleiotropic molecule with significant regulatory effects upon inflammation and inflammatory related diseases. However curcumin has one major important limitation in which it has poor bioavailability. Design of synthetic structural derivatives of curcumin is but one approach that has been used to overcome its poor bioavailability while retaining, or further enhancing, its drug-like effects. We have synthesized a series of curcumin analogues and describe the effects of 2,6-bis-4-(hydroxyl-3-methoxy-benzylidine)-cyclohexanone or BHMC upon nitric oxide and cytokine synthesis in cellular models of inflammation. BHMC showed a significant dose-response inhibitory action upon the synthesis of NO and we have shown that this effect was due to suppression of both iNOS gene and enzyme expression without any effects upon scavenging of nitrite. We also demonstrated that BHMC has a very minimal effect upon iNOS activity with no effect at all upon the secretion of PGE(2) but has a strong inhibitory effect upon MCP-1 and IL-10 secretion and gene expression. Secretion and gene expression of TNF-alpha and IL-6 were moderately inhibited whereas IL-8 and IL-1beta were not altered. We conclude that BHMC selectively inhibits the synthesis of several inflammatory mediators. BHMC should be considered a promising drug lead for preclinical and further pharmacological studies.
    Matched MeSH terms: Dose-Response Relationship, Drug
  8. Rahim H, Sadiq A, Khan S, Khan MA, Shah SMH, Hussain Z, et al.
    Drug Des Devel Ther, 2017;11:2443-2452.
    PMID: 28860715 DOI: 10.2147/DDDT.S140626
    This study was aimed to enhance the dissolution rate, oral bioavailability and analgesic potential of the aceclofenac (AC) in the form of nanosuspension using cost-effective simple precipitation-ultrasonication approach. The nanocrystals were produced using the optimum conditions investigated for AC. The minimum particle size (PS) and polydispersity index was found to be 112±2.01 nm and 0.165, respectively, using hydroxypropyl methylcellulose (1%, w/w), polyvinylpyrrolidone K30 (1%, w/w) and sodium lauryl sulfate (0.12%, w/w). The characterization of AC was performed using zeta sizer, scanning electron microscopy, transmission electron microscopy, powder X-ray diffraction and differential scanning calorimetry. The saturation solubility of the AC nanocrystals was substantially increased 2.6- and 4.5-fold compared to its unprocessed active pharmaceutical ingredient in stabilizer solution and unprocessed drug. Similarly, the dissolution rate of the AC nanocrystals was substantially enhanced compared to its other counterpart. The results showed that >88% of AC nanocrystals were dissolved in first 10 min compared to unprocessed AC (8.38%), microsuspension (66.65%) and its marketed tablets (17.65%). The in vivo studies of the produced stabilized nanosuspension demonstrated that the Cmax were 4.98- and 2.80-fold while area under curve from time of administration to 24 h (AUC0→24 h) were found 3.88- and 2.10-fold greater when compared with unprocessed drug and its marketed formulation, respectively. The improved antinociceptive activity of AC nanocrystals was shown at much lower doses as compared to unprocessed drug, which is purely because of nanonization which may be attributed to improved solubility and dissolution rate of AC, ultimately resulting in its faster rate of absorption.
    Matched MeSH terms: Dose-Response Relationship, Drug
  9. Arulnathan SB, Leong KH, Ariffin A, Kareem HS, Cheah KKH
    Anticancer Agents Med Chem, 2020;20(9):1072-1086.
    PMID: 32188392 DOI: 10.2174/1871520620666200318100051
    BACKGROUND: Oxadiazoles, triazoles, and their respective precursors have been shown to exhibit various pharmacological properties, namely antitumour activities. Cytotoxic activity was reported for these compounds in various cancer cell lines.

    AIM AND OBJECTIVES: In this study, we aim at investigating the mechanism of apoptosis by N-(4-chlorophenyl)-2-(4- (3,4,5-trimethoxybenzyloxy)benzoyl)-hydrazinecarbothioamide, a triazole precursor, henceforth termed compound P7a, in breast cancer cell line, MCF-7. We first screen a series of analogues containing (3,4,5-trimethoxybenzyloxy) phenyl moiety in breast cancer cell lines (MCF-7 and MDA-MB-231) to select the most cytotoxic compound and demonstrate a dose- and time-dependent cytotoxicity. Then, we unravel the mechanism of apoptosis of P7a in MCF-7 as well as its ability to cause cell cycle arrest.

    METHODS: Synthesis was performed as previously described by Kareem and co-workers. Cytotoxicity of analogues containing (3,4,5-trimethoxybenzyloxy)phenyl moiety against MCF-7 and MDA-MB-231 cell lines was evaluated using the MTS assay. Flow cytometric analyses was done using Annexin V/PI staining, JC-1 staining and ROS assay. The activity of caspases using a chemoluminescence assay and western blot analysis was conducted to study the apoptotic pathway induced by the compound in MCF-7 cells. Lastly, cell cycle analysis was conducted using flow cytometry.

    RESULTS: Upon 48 hours of treatment, compound P7a inhibited the proliferation of human breast cancer cells with IC50 values of 178.92 ± 12.51μM and 33.75 ± 1.20μM for MDA-MB-231 and MCF-7, respectively. Additionally, compound P7a showed selectivity towards the cancer cell line, MCF-7 compared to the normal breast cell line, hTERT-HME1, an advantage against current anticancer drugs (tamoxifen and vinblastine). Flow cytometric analyses using different assays indicated that compound P7a significantly increased the proportion of apoptotic cells, increased mitochondria membrane permeabilisation and caused generation of ROS in MCF-7. In addition, cell cycle analysis showed that cell proliferation was arrested at the G1 phase in the MCF-7 cell line. Furthermore, upon treatment, the MCF-7 cell line showed increased activity of caspase-3/7, and caspase-9. Lastly, the western blot analysis showed the up-regulation of pro-apoptotic proteins along with up-regulation of caspase-7 and caspase-9, indicating that an intrinsic pathway of apoptosis was induced.

    CONCLUSION: The results suggest that compound P7a could be a potential chemotherapeutic agent for breast cancer.

    Matched MeSH terms: Dose-Response Relationship, Drug
  10. Chan ZCK, Leong KH, Kareem HS, Norazit A, Noor SM, Ariffin A
    Naunyn Schmiedebergs Arch Pharmacol, 2020 03;393(3):405-417.
    PMID: 31641820 DOI: 10.1007/s00210-019-01730-2
    The rationale of designing compounds containing a (3,4,5-trimethoxybenzyloxy) phenyl moiety is largely due to its potential antioxidant and cytotoxic activities. A previous study focused on its antioxidant mechanism, whereas in this study, we investigated the cytotoxicity of a series of 28 analogues and the mechanism of apoptosis of the most cytotoxic compound against wild-type (HCT-116) and p53 mutant (HT-29) colorectal cancer cell lines. The series of analogues comprise of different families, namely hydrazone, oxadiazole, thiosemicarbazides and triazoles. In the initial cytotoxicity screening, N-(3,4,5-trimethoxybenzylidene)-4-(3,4,5-trimethoxybenzyloxy) benzohydrazide, henceforth known as, P5H, was found to be most cytotoxic against human colorectal cancer cell lines (IC50 for HCT-116 = 11.79 μM and HT-29 = 18.52 μM). Additionally, P5H was found to have some degree of selectivity towards cancer cells compared to normal human colon cells (CCD-112 CoN). Subsequent investigation had brought insight on P5H ability to induce apoptosis in both HCT-116 and HT-29 cell lines. Cell cycle analysis showed both cell lines were arrested at the G2/M phase upon treatment. Our study concluded that P5H induced the death receptor, DR5 in HCT-116 and mitochondria-mediated apoptosis pathway in HT-29. Therefore, P5H may be a promising candidate as a chemotherapy agent against colon cancer. Graphical abstract The apoptotic pathways induced in HT-29 and HCT-116 cells upon P5H treatment.
    Matched MeSH terms: Dose-Response Relationship, Drug
  11. Chuah TS, Loh JY, Hii YS
    Bull Environ Contam Toxicol, 2007 Nov;79(5):557-61.
    PMID: 17639329
    Acute and chronic effects of insecticide-endosulfan on the survival and reproduction performance of Moina macrocopa were determined in a laboratory study. Endosulfan concentrations that cause 50% mortality (LC50) after exposure for 24 and 48 h were 3.34 and 0.16 mg L(-1), respectively. Average longevity, initial age of reproduction and intrinsic rate of natural increase were reduced at 0.002 mg L(-1). Fecundity was greatly reduced by about 70% at 0.0004 mg L(-1) and approximately 97% at 0.002 mg L(-1) as compared to control organisms throughout the whole life span of 15 days. If environmental concentration of endosulfan do not exceed 0.0004 mg L(-1), application of this insecticide is unlikely to induce detrimental effects on these cladoceran populations in agro-ecosystem.
    Matched MeSH terms: Dose-Response Relationship, Drug
  12. Budin SB, Siti Nor Ain SM, Omar B, Taib IS, Hidayatulfathi O
    J Zhejiang Univ Sci B, 2012 Oct;13(10):783-90.
    PMID: 23024045
    Litsea elliptica Blume has been traditionally used to treat headache, fever, and stomach ulcer, and has also been used as an insect repellent. The acute and subacute toxicities of L. elliptica essential oil were evaluated orally by gavage in female Sprague-Dawley rats. For the acute toxicity study, L. elliptica essential oil was administered in doses from 500 to 4000 mg/kg (single dose), and in the subacute toxicity test, the following doses were used: 125, 250, and 500 mg/kg, for 28 consecutive days. In the acute toxicity study, L. elliptica essential oil caused dose-dependent adverse behaviours and mortality. The median lethal dose value was 3488.86 mg/kg and the acute non-observed-adversed-effect level value was found to be 500 mg/kg. The subacute toxicity study of L. elliptica essential oil did not reveal alterations in body weight, and food and water consumptions. The haematological and biochemical analyses did not show significant differences between control and treated groups in most of the parameters examined, except for the hemoglobin, mean cell hemoglobin concentration, mean cell volume, mean cell hemoglobin, serum albumin, and serum sodium. However, these differences were still within the normal range. No abnormalities or histopathological changes were observed in the liver, pancreatic islet of Langerhans, and renal glomerulous and tubular cells of all treated groups. In conclusion, L. elliptica essential oil can be classified in the U group, which is defined as a group unlikely to present an acute hazard according to World Health Organization (WHO) classification.
    Matched MeSH terms: Dose-Response Relationship, Drug
  13. Hor SY, Ahmad M, Farsi E, Lim CP, Asmawi MZ, Yam MF
    J Ethnopharmacol, 2011 Oct 11;137(3):1067-76.
    PMID: 21767625 DOI: 10.1016/j.jep.2011.07.007
    Coriolus versicolor, which is known as Yun Zhi, is one of the commonly used Chinese medicinal herbs. Recent studies have demonstrated its antitumor activities on cancer cells which led to its widespread use in cancer patient. However, little toxicological information is available regarding its safety. The present study evaluated the potential toxicity of Coriolus versicolor standardized water extract after acute and subchronic administration in rats.
    Matched MeSH terms: Dose-Response Relationship, Drug
  14. Salga MS, Ali HM, Abdulla MA, Abdelwahab SI
    Int J Mol Sci, 2012;13(2):1393-404.
    PMID: 22408397 DOI: 10.3390/ijms13021393
    The current study described the synthesis and the in vivo acute oral toxicity evaluations in Sprague Dawley rats. The compounds were characterized by elemental analyses, LC-MS, FTIR, (1)H NMR, (13)C NMR and UV-visible spectroscopy. In the acute toxicity study, a single administration of the compounds was performed orally to the rats at the single doses of 2000 mg/kg and they were then monitored for possible side effects, mortality or behavioral changes up to 14 days. The serum level of aspartate (AST), alanine aminotransferases (ALT), alkaline phosphate (ALP), triglyceride, high density lipoprotein (HDL), immunoglobulins (GAM) and the C-reactive proteins did not significantly change. The hematological indices white blood cells (WBC), haematocrit (HCT), red blood cells (RBC), mean corpuscular volume (MCV), mean corpuscular haemoglobin concentration (MCHC), and mean corpuscular hemoglobin (MCH) were within the normal range. The renal function indices examined were also within the reference range. Generally, the compounds exhibited low toxic effects as required for further in vivo therapeutic studies.
    Matched MeSH terms: Dose-Response Relationship, Drug
  15. Mohamat-Yusuff F, Sarah-Nabila AG, Zulkifli SZ, Azmai MNA, Ibrahim WNW, Yusof S, et al.
    Mar Pollut Bull, 2018 Feb;127:150-153.
    PMID: 29475647 DOI: 10.1016/j.marpolbul.2017.11.046
    This study was conducted to investigate the median lethal concentration (LC50) of copper pyrithione (CuPT) at 96-hr exposure on adult Javanese medaka (Oryzias javanicus) in revealing toxicological effects of CuPT contamination in the tropical area. Wild stock fishes were acclimatized for 14-days prior analysis. Triplicate of test tanks for seven test concentrations were placed with ten fishes each, this includes two control tanks. The behaviour of the tested fishes was manually observed through a camera. The LC50 of CuPT at 96-h was found to be 16.58mg/L. Tested fishes swam slowly in vertical movement and swam fast towards food during feeding time as the sign of stress behaviour. Meanwhile, fishes in the two control groups swam actively in a horizontal manner and no excitement during feeding time. No mortality in control groups. Results indicate CuPT to be toxic to Javanese medaka at low concentration and caused behavioural stress.
    Matched MeSH terms: Dose-Response Relationship, Drug
  16. Bebakar WM, Chow CC, Kadir KA, Suwanwalaikorn S, Vaz JA, Bech OM, et al.
    Diabetes Obes Metab, 2007 Sep;9(5):724-32.
    PMID: 17593237 DOI: 10.1111/j.1463-1326.2007.00743.x
    Aim: To evaluate the efficacy and safety of adding biphasic insulin aspart 30 (BIAsp30; NovoMix 30) to existing oral antidiabetic agents (OADs) vs. optimizing OADs in a subgroup of Western Pacific patients with type 2 diabetes inadequately controlled on oral monotherapy or oral combination therapy.

    Methods: This 26-week, multi-centre, open-labelled, randomized, two-arm parallel trial consisted of a 2-week screening period, followed by 24 weeks of treatment. Subjects randomized to BIAsp30 treatment (n = 129) received BIAsp30 once daily (o.d.) at dinnertime between Week 2 and Week 14, and those not reaching treatment targets were switched to twice daily (b.i.d.) BIAsp30 at Week 14 (n = 50). Subjects randomized to the OAD-only arm (n = 63) continued with their previous OAD treatment and, in an attempt to reach treatment goals, the dose was optimized (but OAD unchanged) in accordance to local treatment practice and labelling.

    Results: Significantly greater reductions in HbA(1c) over Weeks 0-13 with BIAsp30 (o.d.) vs. OAD-only treatment (1.16 vs. 0.58%; p < 0.001), and over Weeks 0-26, with BIAsp30 (o.d.) and BIAsp30 (b.i.d.) treatments vs. OAD-only treatment (1.24 vs. 1.34 vs. 0.67%; p < 0.01). Hypoglycaemic episodes were reported in 54% of the patients in BIAsp30 (o.d. and b.i.d. pooled) and 30% of the patients in OAD-only group. All episodes were minor or symptomatic, except for one in each treatment group, which was major.

    Conclusions: Initiating BIAsp30 treatment is a safe and more effective way to improve glycaemic control in Western Pacific patients with type 2 diabetes inadequately controlled with oral monotherapy or oral combination therapy compared with optimizing oral combination therapy alone. In patients not reaching treatment target on BIAsp30 (o.d.), treatment with BIAsp30 (b.i.d.) should be considered.
    Matched MeSH terms: Dose-Response Relationship, Drug
  17. Khan S, Khan SU
    J Clin Pharm Ther, 2020 Oct;45(5):927-936.
    PMID: 32672366 DOI: 10.1111/jcpt.13204
    WHAT IS KNOWN AND OBJECTIVE: The imbalance in serum potassium caused by laxatives can negatively affect the cardiovascular system, leading to life-threatening consequences. Our objective was to evaluate the reported evidence of adverse events related to the cardiac system due to laxative-induced hypokalaemia from case reports.

    METHODS: A systematic electronic literature search of PubMed, Embase, the Cochrane Library and Science Direct was conducted for the period 1995-2019. In these databases, search terms describing hypokalaemia and cardiotoxicity were combined with the term laxative use.

    RESULTS AND DISCUSSION: Over the 23 years, 27 incidents were identified in 12 countries. There were 19 female and eight male patients, with ages ranging from 1 month to 93 years. The frequency of reported cases according to severity was the following: severe hypokalaemia 48%, moderate hypokalaemia 44.4% and mild hypokalaemia 7.4%. In 70% of patients, the effect of laxative on the heart was typical hypokalaemic electrographic changes, 7.4% showed abnormal changes in cardiac rhythm, whereas in 18.5%, the cardiotoxicity observed was a very serious kind. Two patients died due to severe cardiac effects.

    WHAT IS NEW AND CONCLUSION: The laxatives-along with the involvement of some other contributing factors-caused mild-to-severe hypokalaemic cardiotoxicity. These factors were non-adherence of the patient to the recommended dosage, laxative abuse, drug-drug and drug-disease interactions, non-potassium electrolyte imbalances and the use of herbal laxatives. We recommend that laxatives and aggravating factors should be taken into account in the assessment of patients with suspected hypokalaemic cardiotoxicity.

    Matched MeSH terms: Dose-Response Relationship, Drug
  18. Tatit NS, Kevin P
    Med J Malaysia, 2019 12;74(6):504-508.
    PMID: 31929476
    INTRODUCTION: Choriocarcinoma is malignant cancer originating from placental trophoblast. The incidence of this cancer is estimated at 0.57-1.1 per 1000 births in the United States of America, Australia, Europe, and New Zealand. The rate is much higher in South East Asia and Japan with two occurrences per a thousand births. Telomerase activity is an important part of the apoptotic process. Increased telomerase activity will result in cellular immortality and poor prognosis in cancer. Vitamin A possess an essential role in cell proliferation and differentiation. One of the active metabolites of vitamin A is All-Trans Retinoic Acid (ATRA).

    METHODS: In this study, we examined the role of ATRA against telomerase activity in choriocarcinoma cell. This cell was derived from BeWo cell line (ATCC CCL-98) and were given different doses of ATRA.

    RESULTS: From this study, Choriocarcinoma cell that was given ATRA in dosage of 50μg/ml inhibit telomerase activity by extending the cycle time of 39.51±0.09, compared to the control group with a cycle time of 37.62±0.43. Cycle length change consistently with higher dose of ATRA.

    CONCLUSION: This study has proven that ATRA could inhibit telomerase activity by lengthening the cycle. Changes in the increase of ATRA doses in this experimental test need to be studied further on experimental animals, either administered as a single agent or as an addition to standard treatment of trophoblastic disease.

    Matched MeSH terms: Dose-Response Relationship, Drug
  19. Ibrahim MH, Jaafar HZ, Karimi E, Ghasemzadeh A
    ScientificWorldJournal, 2014;2014:360290.
    PMID: 24683336 DOI: 10.1155/2014/360290
    A split plot 3 by 4 experiment was designed to investigate and distinguish the relationships among production of secondary metabolites, soluble sugar, phenylalanine ammonia lyase (PAL; EC 4.3.1.5) activity, leaf gas exchange, chlorophyll content, antioxidant activity (DPPH), and lipid peroxidation under three levels of CO2 (400, 800, and 1200 μ mol/mol) and four levels of light intensity (225, 500, 625, and 900 μ mol/m(2)/s) over 15 weeks in Labisia pumila. The production of plant secondary metabolites, sugar, chlorophyll content, antioxidant activity, and malondialdehyde content was influenced by the interactions between CO2 and irradiance. The highest accumulation of secondary metabolites, sugar, maliondialdehyde, and DPPH activity was observed under CO2 at 1200 μ mol/mol + light intensity at 225 μ mol/m(2)/s. Meanwhile, at 400 μ mol/mol CO2 + 900 μ mol/m(2)/s light intensity the production of chlorophyll and maliondialdehyde content was the highest. As CO2 levels increased from 400 to 1200 μ mol/mol the photosynthesis, stomatal conductance, f v /f m (maximum efficiency of photosystem II), and PAL activity were enhanced. The production of secondary metabolites displayed a significant negative relationship with maliondialdehyde indicating lowered oxidative stress under high CO2 and low irradiance improved the production of plant secondary metabolites that simultaneously enhanced the antioxidant activity (DPPH), thus improving the medicinal value of Labisia pumila under this condition.
    Matched MeSH terms: Dose-Response Relationship, Drug
  20. Sizaret P, Tuyns A, Martel N, Jouvenceaux A, Levin A, Ong YW, et al.
    Ann N Y Acad Sci, 1975 Aug 22;259:136-55.
    PMID: 54017
    Alpha-Fetoprotein (AFP) levels of 1,335 males (15 years and older) of seven ethnic groups (Chinese, Indians, and Malays from Singapore, Caucasians from Lyon, and Blacks from Nairobi, forest, and the savanna region of the Ivory Coast) were determined by radioimmunoassay. A few elevated levels (up to 30 nanounits/ml) were detected in some normal individuals, especially in the older age-groups. In addition, there was a systematic age-dependency of AFP levels particularly evident in the groups from Singapore-Lyon, in which there was a 50% AFP increase between the ages of 20 and 40. Comparison between Africans on the one hand and people from Singapore-Lyon on the other hand revealed highly significant differences (p less than 0.001), especially in the younger groups, whereas Chinese, Malays, and Indians from Singapore had very similar AFP pattern; this suggests an important role for environmental factors in the regulation of AFP levels. The age dependency of the presumed effect of environmental factors is in keeping with experimental data showing that young animals respond more vigorously to AFP-stimulating factors. Although the incidence of hepatocellular carcinoma (HCC) differs in the three Singapore groups (the highest in Chinese and the lowest in Indians), no relationship was observed in this study between mean AFP level and HCC incidence in Singapore.
    Matched MeSH terms: Dose-Response Relationship, Drug
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