Displaying publications 101 - 120 of 1705 in total

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  1. Damodaran T, Hassan Z, Navaratnam V, Muzaimi M, Ng G, Müller CP, et al.
    Behav Brain Res, 2014 Dec 15;275:252-8.
    PMID: 25239606 DOI: 10.1016/j.bbr.2014.09.014
    Cerebral ischemia is one of the leading causes of death and long-term disability in aging populations, due to the frequent occurrence of irreversible brain damage and subsequent loss of neuronal function which lead to cognitive impairment and some motor dysfunction. In the present study, the real time course of motor and cognitive functions were evaluated following the chronic cerebral ischemia induced by permanent, bilateral occlusion of the common carotid arteries (PBOCCA). Male Sprague Dawley rats (200-300g) were subjected to PBOCCA or sham-operated surgery and tested 1, 2, 3 and 4 weeks following the ischemic insult. The results showed that PBOCCA significantly reduced step-through latency in a passive avoidance task at all time points when compared to the sham-operated group. PBOCCA rats also showed significant increase in escape latencies during training in the Morris water maze, as well as a reduction of the percentage of times spend in target quadrant of the maze at all time points following the occlusion. Importantly, there were no significant changes in locomotor activity between PBOCCA and sham-operated groups. The BDNF expression in the hippocampus was 29.3±3.1% and 40.1±2.6% on day 14 and 28 post PBOCCA, respectively compared to sham-operated group. Present data suggest that the PBOCCA procedure effectively induces behavioral, cognitive symptoms associated with cerebral ischemia and, consequently, provides a valuable model to study ischemia and related neurodegenerative disorder such as Alzheimer's disease and vascular dementia.
    Matched MeSH terms: Time Factors
  2. Norsa'adah B, Rampal KG, Mohd Amin R
    Asian Pac J Cancer Prev, 2021 Nov 01;22(11):3623-3631.
    PMID: 34837921 DOI: 10.31557/APJCP.2021.22.11.3623
    BACKGROUND: Breast cancer patients in Malaysia often present late, delaying diagnosis and treatment. Decisions on health-seeking behaviour are influenced by a complex interplay of several factors. Early detection and subsequent successful treatment are the main goal in order to reduce breast cancer mortality. The aims of this study were to identify the time taken by women with breast cancer for consultation, diagnosis and first definitive treatment and the factors associated with the initiation of definitive treatment.

    METHODS: In this cohort study, we interviewed 328 women with histologically confirmed breast cancer at five medical centres in Malaysia. Times were measured from recognition of symptoms to first consultation to diagnosis and to the first definitive treatment. The event was initiation of definitive treatment. Data was analysed using multivariable Cox proportional hazards regression.

    RESULTS: The mean age was 47.9 (standard deviation 9.4) years and 79.9% were ethnic Malays. The median follow-up time was 6.9 months. The median times for first doctor consultation, diagnosis and initiation of treatment were 2 months, 5.5 months and 2.4 weeks, respectively. The percentage of consultation delay more than a month was 66.8%, diagnosis delay more than three months was 73.2% and treatment delay more than one month was 11.6%. Factors associated with not initiating the definitive treatment were pregnancy (adjusted hazard ratio (AHR) 1.75; 95% Confidence Interval (CI): 1.07, 2.88), taking complementary alternative medicine (AHR 1.45; 95% CI: 1.15, 1.83), initial refusal of mastectomy (AHR 3.49; 95% CI: 2.38, 5.13) and undergoing lumpectomy prior to definitive treatment (AHR 1.62; 95% CI: 1.16, 2.28).

    CONCLUSIONS: Delays in diagnosis and consultation were more serious than treatment delays. Most respondents would accept treatment immediately after diagnosis. Respondents themselves were responsible for a large proportion of the delays. This study was successful in understanding the process of breast cancer patients' experience, from symptoms recognition to consultation, diagnosis and treatment.

    Matched MeSH terms: Time Factors
  3. Abdullah EA, Abdullah AH, Zainal Z, Hussein MZ, Ban TK
    J Environ Sci (China), 2012;24(10):1876-84.
    PMID: 23520859
    A modified hydrophilic penta-bismuth hepta-oxide nitrate (Bi5O7NO3) surface was synthesized via a precipitation method using TiO2 and Ag as modified agents. The synthesized product was characterized by different analytical techniques. The removal efficiency was evaluated using mono- and di-sulphonated azo dyes as model pollutants. Different kinetic, isotherm and diffusion models were chosen to describe the adsorption process. X-ray photoelectron spectroscopy (XPS) results revealed no noticeable differences in the chemical states of modified adsorbent when compared to pure Bi5O7NO3; however, the presence of hydrophilic centres such as TiO2 and Ag developed positively charged surface groups and improved its adsorption performance to a wide range of azo dyes. Dyes removal was found to be a function of adsorbent dosage, initial dye concentration, solution pH and temperature. The reduction of Langmuir 1,2-mixed order kinetics to the second or first-order kinetics could be successfully used to describe the adsorption of dyes onto the modified adsorbent. Mass transfer can be described by intra-particle diffusion at a certain stage, but it was not the rate limiting step that controlled the adsorption process. Homogenous behavior of adsorbent surface can be explored by applying Langmuir isotherm to fit the adsorption data.
    Matched MeSH terms: Time Factors
  4. Lam SK, Harvey S
    PMID: 1970531
    1. Anaesthesia caused marked decreases in the plasma concentrations of triiodothyronine (T3) and thyroxine (T4) and in the body temperature of young fowl. 2. Exogenous T4 or a thyroid hormone secretagogue (somatostatin antiserum), increased endogenous T3 and T4 concentrations and body temperature in conscious birds and prevented the body temperature decline in anaesthetized fowl. 3. These results provide further evidence for a role of T3 and T4 in temperature regulation in birds, particularly during anaesthesia.
    Matched MeSH terms: Time Factors
  5. Lee YY, Tee MH, Zurkurnai Y, Than W, Sapawi M, Suhairi I
    Singapore Med J, 2008 Apr;49(4):304-10.
    PMID: 18418522
    This study was primarily aimed to determine the failure rate of thrombolysis with streptokinase in acute myocardial infarction using electrocardiogram criteria and its association between various independent variables and outcome parameters.
    Matched MeSH terms: Time Factors
  6. Chua S, Viegas OA, Ratnam SS
    Asia Pac Popul J, 1990 Mar;5(1):125-34.
    PMID: 12283342
    Matched MeSH terms: Time Factors*
  7. Leschke M, Waliszewski M, Pons M, Champin S, Nait Saidi L, Mok Heang T, et al.
    Catheter Cardiovasc Interv, 2016 Sep;88(3):358-66.
    PMID: 26650913 DOI: 10.1002/ccd.26261
    OBJECTIVES: This observational study assessed the 9-month clinical outcomes in an « all comers » population with a focus on patients with atrial fibrillation (AF) after thin strut bare metal stenting.

    BACKGROUND: Drug eluting stent (DES) implantation is the treatment of choice for coronary artery disease (CAD) leaving only marginal indications for the use of bare metal stents (BMS). However, selected treatment populations with DES contraindications such as patients who cannot sustain 6-12 months of dual antiplatelet therapy (DAPT) remain candidates for BMS implantations.

    METHODS: Thin strut bare metal stenting in a priori defined subgroups were investigated in a non-randomized, international, multicenter «all comers» observational study. Primary endpoint was the 9-month TLR rate whereas secondary endpoints included the 9-month MACE and procedural success rates.

    RESULTS: A total of 783 patients of whom 98 patients had AF underwent BMS implantation. Patient age was 70.4 ± 12.8 years. Cardiovascular risk factors in the overall population were male gender (78.2%, 612/783), diabetes (25.2%, 197/783), hypertension (64.1%, 502/783), cardiogenic shock (4.9%, 38/783) and end stage renal disease (4.9%, 38/783). In-hospital MACE was 4.1% (30/783) in the overall population. The 9-month TLR rate was 4.5% (29/645) in the non-AF group and 3.3% (3/90) in the AF group (P = 0.613). At 9 months, the MACE rate in the AF-group and non-AF group was not significantly different either (10.7%, 69/645 vs. 6.7%, 6/90; P = 0.237). Accumulated stroke rates were 0.3% (2/645) in the non-AF subgroup at baseline and 1.1% (1/90) in the AF subgroup (P = 0.264).

    CONCLUSION: Bare metal stenting in AF patients delivered acceptably low TLR and MACE rates while having the benefit of a significantly shorter DAPT duration in a DES dominated clinical practice. © 2015 Wiley Periodicals, Inc.

    Matched MeSH terms: Time Factors
  8. Venkata Srikanth M, Songa AS, Nali SR, Battu JR, Kolapalli VR
    Drug Dev Ind Pharm, 2014 Jan;40(1):33-45.
    PMID: 23317339 DOI: 10.3109/03639045.2012.744416
    The objective of the present investigation was to study the applicability of thermal sintering technique for the development of gastric floating tablets of propranolol HCl. Formulations were prepared using four independent variables, namely (i) polymer quantity, (ii) sodium bicarbonate concentration, (iii) sintering temperature and (iv) sintering time. Floating lag time and t95 were taken as dependent variables. Tablets were prepared by the direct compression method and were evaluated for physicochemical properties, in vitro buoyancy and dissolution studies. From the drug release studies, it was observed that drug retarding property mainly depends upon the sintering temperature and time of exposure. The statistically optimized formulation (PTSso) was characterized by Fourier transform infrared spectroscopy and differential scanning calorimetry studies, and no significant chemical interaction between drug and polymer was observed. Optimized formulation was stable at accelerated conditions for a period of six months. PTSso was evaluated for in vivo buoyancy studies in humans for both fed and fasted states and found that gastric residence time of the floating tablets were enhanced by fed stage but not in fasted state. Optimized formulation PTSso and commercial formulation Ciplar LA 80 were subjected to bioavailability studies in healthy human volunteers by estimating pharmacokinetic parameters such as Cmax, Tmax, area under curve (AUC), elimination rate constant (Kel), biological half-life (t1/2) and mean residence time (MRT). There was a significant increase in the bioavailability of the propranolol HCl from PTSso formulation, which was evident from increased AUC levels and larger MRT values than Ciplar LA 80.
    Matched MeSH terms: Time Factors
  9. Armstrong JW, Tang J, Wang S
    J Econ Entomol, 2009 Apr;102(2):522-32.
    PMID: 19449631
    The late-aged egg and third-instar life stages of laboratory-reared Malaysian fruit fly, Bactrocera latifrons (Hendel); Mediterranean fruit fly, Ceratitis capitata (Wiedemann); melon fly, B. cucurbitae Coquillett; and oriental fruit fly, B. dorsalis (Hendel), (Diptera: Tephritidae); and the third instars of wild Mediterranean fruit fly were exposed to thermal treatments. A heating block system was used to determine the thermal death kinetics of the four fruit fly species. Treatments consisted of heating the fruit fly life stages to 44, 46, 48, and 50 degrees C and holding for different times ranging from 0 to 120 min depending on the thermal mortality response and time required to obtain 100% mortality for each species and life stage. The 0.5-order kinetic model had the best fit to the survival ratio for all the treatment temperatures and was used to predict lethal times. The thermal death time (TDT) curves showed a tolerance order of Mediterranean fruit fly eggs < or = third instars at 44, 46, and 50 degrees C, third instars < or = eggs at 48 degrees C, and wild third instars < the laboratory-reared third instars. Comparison between Mediterranean fruit fly third instar thermotolerance from Hawaii and Israel showed that Israel Mediterranean fruit fly was more thermotolerant. A comparison of minimum treatment times at a given temperature required to obtain 100% mortality of laboratory-reared Malaysian, Mediterranean (Hawaii and Israel strains), melon, Mexican, and oriental fruit fly eggs or third instars and wild Mediterranean fruit fly (Hawaii strain) eggs or third instars showed that oriental fruit fly was the most thermotolerant among the third instars, and the difference in heat tolerance between third instars and eggs was negligible at 50 degrees C.
    Matched MeSH terms: Time Factors
  10. Aziz NA, Leonardi-Bee J, Phillips M, Gladman JR, Legg L, Walker MF
    PMID: 18425928 DOI: 10.1002/14651858.CD005952.pub2
    BACKGROUND: Current practice of rehabilitation intervention mainly concentrates on the first six months of stroke. At present, there is no agreed consensus about the benefits of such a service more than one year after stroke.

    OBJECTIVES: To ascertain whether therapy-based rehabilitation services can influence outcome one year or more after stroke.

    SEARCH STRATEGY: We searched the trials registers of the following Cochrane Review Groups: Stroke Group (last searched September 2007), Effective Practice and Organisation of Care Group (last searched October 2006) and Dementia and Cognitive Improvement Group (last searched October 2006). We also searched the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library Issue 4, 2006), MEDLINE (1966 to October 2006), EMBASE (1980 to October 2006), CINAHL (1982 to October 2006), AMED (1985 to October 2006), PEDro (1952 to October 2006), British Nursing Index (1993 to October 2006), DARE (1994 to October 2006), HMIC (1979 to October 2006) and NHS EED (1991 to October 2006). We also searched dissertation databases and ongoing trials and research registers, scanned reference lists and contacted researchers and experts in the field.

    SELECTION CRITERIA: All randomised controlled trials of community-based stroke patients, in which at least 75% were recruited one year after stroke and received a therapy-based rehabilitation intervention that was compared with conventional care.

    DATA COLLECTION AND ANALYSIS: Two review authors independently selected trials and extracted data on a number of pre-specified outcomes. The primary outcomes were the proportion of participants who had deteriorated or were dependent in personal activities of daily living at the end of scheduled follow up.

    MAIN RESULTS: We identified five trials of 487 participants that were eligible for the review. Overall, there was inconclusive evidence as to whether therapy-based rehabilitation intervention one year after stroke was able to influence any relevant patient or carer outcome. Trials varied in design, type of interventions provided, quality, and outcomes assessed.

    AUTHORS' CONCLUSIONS: This review highlights the dearth of evidence investigating long-term therapy-based rehabilitation interventions for patients with stroke.

    Matched MeSH terms: Time Factors
  11. Hattori R, Matsubara H
    Mol Cell Biochem, 2004 Sep;264(1-2):151-5.
    PMID: 15544044
    Conventional therapies for severe ischemic heart disease are limited in applicability. While several angiogenesis researches have shown novel efficacy, safety and feasibility for clinical use, recently we have started the clinical trial of a sole cell therapy using autologous bone marrow mononuclear cells transplantation targeted into ischemic hibernating myocardium. Here, we review the background of bone marrow cell research and introduce therapeutic angiogenesis for severe ischemic heart disease by autologous bone marrow cells transplantation.
    Matched MeSH terms: Time Factors
  12. Holland B
    Hum Biol, 1987 Jun;59(3):477-87.
    PMID: 3610122
    The effects of breast-feeding on infant health and mortality, particularly in the developing nations, are a matter of controversy and importance. The Malaysian Family Life Survey (MFLS) of over 1200 women has recently been the source of a great deal of valuable information on the influence of breast-feeding and interacting social variables on the incidence of infant mortality. Accuracy of reporting of breast-feeding duration is a key issue in the validity of studies of breast-feeding and infant mortality. This paper presents an illustrative analysis of the quality of breast-feeding data from the Malaysian Family Life Survey, using logit model schedules. Lesthaeghe and Page derived a logit model schedule of breast-feeding, summarizing empirical experience. This family of model breast-feeding duration curves is similar to the logit model life tables developed by Brass, and was intended for similar applications. To verify the MFLS retrospective breast-feeding reports, the observed median duration and variability were calculated for ethnic group/cohort subsets, and expected duration distribution curves were generated from the model using these observed parameter values. The expected curve generated from the model fit the observed curve of breast-feeding discontinuation extremely closely. Thus it is unlikely that any significant distortion of the pattern of discontinuation of breast-feeding occurred in data collection. Extensions of this method of data quality checking to other duration distributions are suggested.
    Matched MeSH terms: Time Factors
  13. Prakash KM, Raymond AA
    Med J Malaysia, 2003 Mar;58(1):69-78.
    PMID: 14556328
    Bell's palsy is a common neurological problem causing considerable loss of self-esteem among patients. A prospective observational study was conducted to determine the short-term outcome of Bell's palsy at 1 month and 2 months after the onset and the relationship between these outcomes with facial nerve degeneration. We also determined if gender, age, diabetes, systolic and diastolic blood pressure influence the severity of facial nerve degeneration and the clinical outcome at 2 months after the onset. After clinically grading the newly diagnosed unilateral Bell's palsy patients using the House-Brackmann facial nerve grading system, nerve conduction studies of the facial nerve were done to determine the severity of facial nerve degeneration. The recovery of the facial paralysis was clinically graded again at the end of 1 month and 2 months from the onset. A total of 37 patients were recruited. There was a strong positive correlation between facial nerve degeneration and the clinical outcome of Bell's palsy at 1 month (r = 0.794; p < 0.0005) and 2 months (r = 0.732; p < 0.0005) after the onset. There was no significant correlation between either the facial nerve degeneration or the clinical outcome at 2 months with the patients' age (p = 0.288 and p = 0.799 respectively), systolic blood pressure (p = 0.425 and p = 0.933 respectively) or diastolic blood pressure (p = 0.243 and p = 0.579 respectively). Neither the severity of facial nerve degeneration nor the clinical outcome at 2 months were significantly different between male and female patients (p = 0.460 and p = 0.725 respectively) or diabetic and non-diabetic patients (p = 0.655 and p = 0.655 respectively).
    Matched MeSH terms: Time Factors
  14. Saad AZ, Halim AS, Khoo TL
    J Reconstr Microsurg, 2011 Feb;27(2):103-8.
    PMID: 20976667 DOI: 10.1055/s-0030-1268208
    Major reconstructive surgery may be extensive and prolonged, and it may cause edema and compromise the flap pedicle if closed under tension. Glycerol-preserved skin allograft (GPA) can provide a means for tension-free closure and temporary cover of the wound. Seven years of analysis on GPA used in conjunction with major reconstruction was undertaken to highlight its indications, results, and outcomes. Forty-seven patients were included, aged between 9 and 73 years. Majority of patients had reconstruction following tumor resection and trauma. The main indication for use of GPA was temporary, loose cover of the wound in 44% of cases; flap pedicle protection in 31% of cases; donor site wound cover in 10%; flap monitoring in one case; and management of flap-related complications in 6% of cases. Free flap reconstruction was performed in 72% of cases. In conclusion, GPA is a useful adjunct in reconstructive surgery. It can be used temporarily to allow tension-free wound closure, as well as to protect the flap pedicle until edema subsides and the pedicle becomes stable. This latter approach allows secondary wound closure and good esthetic outcome.
    Matched MeSH terms: Time Factors
  15. Nandrajog P, Idris Z, Azlen WN, Liyana A, Abdullah JM
    Asian J Neurosurg, 2017 Jul-Sep;12(3):447-453.
    PMID: 28761523 DOI: 10.4103/1793-5482.180921
    BACKGROUND: The aim of the study is to compare the amplitude and latency of the P300 event-related potential (ERP) component between a control group and patients after mild traumatic brain injury (mTBI) during 1-7 days (short duration) and 2-3 months (long duration), and to compare the outcome of neuropsychological tests between the long duration postinjury and control study groups.

    MATERIALS AND METHODS: We studied responses to auditory stimulation in two main and one subgroups, namely the control healthy group (19 patients, both ERP and neuropsychology test done), the mTBI 1 group (17 patients, only ERP done within 7 days after injury), and the mTBI 2 subgroup (the 17 mTBI 1 patients in whom a repeated ERP together with neuropsychological testing was done at 2-3 months postinjury). Auditory evoked responses were studied with two different stimuli (standard and target stimuli), where the P300 amplitude and latency were recorded from three midline sites and results were compared between the groups, as were the neuropsychological test results.

    RESULTS: There was a significant prolongation of the target P300 latency values shown by the MBI 1 group measured at the central electrode when compared to the control group, which was also seen when the mTBI 1 and mTBI 2 groups were compared. The results of the P300 amplitude values measured at the frontal electrode showed the control group to have higher readings during the presentation of standard tones when compared to the mTBI 1 group. The mTBI 2 group performed better on some neuropsychological tests.

    CONCLUSION: The latency of P300 was significantly prolonged in early mTBI patients who improved over time, and the neuropsychological testing on mTBI 2 patients showed them to be comparable to the control group. The study indicates that ERP should be used as an additional modality of investigation in mTBI patients.
    Matched MeSH terms: Time Factors
  16. Rogayah J, Zulkifli A
    Med J Malaysia, 2001 Sep;56(3):324-30.
    PMID: 11732078
    A total of 356 doctors responded to a survey on the timing and stability of choice of medical specialty. The majority of doctors made their final decision while working as a medical officer. One hundred (48.5%) of the doctors had made an earlier choice as medical students, 63 (30.6%) during their internship and 43 (20.9%) made their final choice while they were medical officers. Working experience in the specialty was the most important factor in determining final choice of specialty. Advice from consultants/seniors, better financial prospects and parental influence were more important for the male doctors while marriage and family considerations were more important for the female doctors in making their final choice.
    Matched MeSH terms: Time Factors
  17. Oxford J, Berezin EN, Courvalin P, Dwyer DE, Exner M, Jana LA, et al.
    Am J Infect Control, 2014 Apr;42(4):423-5.
    PMID: 24679569 DOI: 10.1016/j.ajic.2013.10.016
    We investigated the survival of a pandemic strain of influenza A H1N1 on a variety of common household surfaces where multiple samples were taken from 4 types of common household fomite at 7 time points. Results showed that influenza A H1N1sw virus particles remained infectious for 48 hours on a wooden surface, for 24 hours on stainless steel and plastic surfaces, and for 8 hours on a cloth surface, although virus recovery from the cloth may have been suboptimal. Our results suggest that pandemic influenza A H1N1 can survive on common household fomites for extended periods of time, and that good hand hygiene and regular disinfection of commonly touched surfaces should be practiced during the influenza season to help reduce transmission.
    Matched MeSH terms: Time Factors
  18. Ismail NM, Mustapha MS, Megat R
    Ann Acad Med Singap, 1997 Nov;26(6):754-7.
    PMID: 9522974
    The aim of this study was to investigate if colloidal bismuth subcitrate (CBS) can penetrate the gastric mucus barrier to reach the different sites of the antral mucosa and to estimate the time course for CBS to reach and remain in the mucosa. A single dose of CBS was administered orally to rats that were sacrificed at different time intervals post treatment. The control group received gum acacia without CBS. Colloidal bismuth subcitrate, visualised as electron dense precipitate (EDP), was seen in the gastric mucus layer, intercellular spaces and intracellularly after 30 minutes and disappeared after 6 hours. Scant amounts of EDP were observed in the gastric crypts, confined only to the upper parts of these structures. We concluded that CBS can penetrate the mucus and has a wide but uneven distribution in the gastric mucosa. Colloidal bismuth subcitrate, in the concentration given only penetrated the upper two-thirds of gastric pits and not the lower one-third. We also concluded that CBS has to be given 6 hourly to ensure its continuous presence in the gastric mucosa.
    Matched MeSH terms: Time Factors
  19. Kothare SN
    Singapore Med J, 1978 Jun;19(2):98-105.
    PMID: 751194
    This is an analysis of histologically proven neoplasms encountered in Sarawak in 1976 and 1977. There were 1447 benign and 1368 malignant tumours. The detailed breakdown of malignant neoplasms with their racial and sex distribution is reported, Lymph node involvement, with primary and metastatic lesions, constituted the largest single group with 22.3 per cent of all malignancies. The next in order of frequency was the Reproductive system with a marked preponderance of Cervical Carcinoma in females. The next in frequency were Skin cancers (8.85%) and Nasopharyngeal Carcinoma (8.4%). Primary liver cell cancer and Breast cancer constituted 5.85 per cent and 5.79 per cent respectively of all malignant tumours. The high prevalence of malignant neoplasms in Chinese is suggestive of racial predisposition.
    Matched MeSH terms: Time Factors
  20. Kadir NH, David R, Rossiter JT, Gooderham NJ
    Toxicology, 2015 Aug 6;334:59-71.
    PMID: 26066520 DOI: 10.1016/j.tox.2015.06.002
    Cruciferous vegetable consumption correlates with reduced risk of cancer. This chemopreventative activity may involve glucosinolates and their hydrolysis products. Glucosinolate-derived isothiocyanates have been studied for their toxicity and chemopreventative properties, but other hydrolysis products (epithionitriles and nitriles) have not been thoroughly examined. We report that these hydrolysis products differ in their cytotoxicity to human cells, with toxicity most strongly associated with isothiocyanates rather than epithionitriles and nitriles. We explored mechanisms of this differential cytotoxicity by examining the role of oxidative metabolism, oxidative stress, mitochondrial permeability, reduced glutathione levels, cell cycle arrest and apoptosis. 2-Propenylisothiocyanate and 3-butenylisothiocyanate both inhibited cytochome P450 1A (CYP1A) enzyme activity in CYP expressing MCL-5 cells at high cytotoxic doses. Incubation of MCL-5 cells with non-cytotoxic doses of 2-propenylisothiocyanate for 24h resulted in a dose-dependent inhibition of ethoxyresorufin O-deethylase, yet failed to affect CYP1A1 mRNA expression indicating interference with enzyme activity rather than inhibition of transcription. Increased reactive oxygen species (ROS) production was observed only for 2-propenylisothiocyanate treatment. 2-Propenylisothiocyanate treatment lowered reduced glutathione levels whereas no changes were noted with 3,4-epithiobutylnitrile. Cell cycle analysis showed that 2-propenylisothiocyanate induced a G2/M block whereas other hydrolysis products showed only marginal effects. We found that 2-propenylisothiocyanate and 3-butenylisothiocyanate induced cell death predominantly via necrosis whereas, 3,4-epithiobutylnitrile promoted both necrosis and apoptosis. Thus the activity of glucosinolate hydrolysis products includes cytotoxicity that is compound-class specific and may contribute to their putative chemoprotection properties.
    Matched MeSH terms: Time Factors
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