Displaying publications 1 - 20 of 1515 in total

Abstract:
Sort:
  1. A non-parametric survival estimate after elimination of a cause of failure
    Fang YY, Suraiya Kassim
    Sains Malaysiana, 2013;42:673-683.
    In competing risks analysis, the primary interest of researchers is the estimation of the net survival probability (NSP) if a cause of failure could be eliminated from a population. The Kaplan-Meier product-limit estimator under the assumption that the eliminated risk is non-informative to the other remaining risks, has been widely used in the estimation of the NSP. The assumption implies that the hazard of the remaining risks before and after the elimination are equal and it could be biased. This paper addressed this possible bias by proposing a non-parametric multistate approach that accounts for an informative eliminated risk in the estimation procedure, whereby the hazard probabilities of the remaining risks before and after the elimination of a risk are not assumed to be equal. When a non-informative eliminated risk was assumed, it was shown that the proposed multistate estimator reduces to the Kaplan-Meier estimator. For illustration purposes, the proposed procedure was implemented on a published dataset and the change in hazard after elimination of a cause is investigated. Comparing the results to those obtained from using the Kaplan-Meier method, it was found that in the presence of (both constant and non-constant) informative eliminated risk, the proposed multistate approach was more sensitive and flexible.
    Matched MeSH terms: Survival Analysis
  2. Fulltext Non-Mixture Cure Model Estimation in Bladder Cancer Patients: A Novel Approach with Exponentiated Weibull Exponential Distribution
    Omer ME, Mustafa M, Ali N, Abd Rahman NH
    Asian Pac J Cancer Prev, 2023 Dec 01;24(12):4167-4177.
    PMID: 38156852 DOI: 10.31557/APJCP.2023.24.12.4167
    OBJECTIVE: Cure models are frequently used in survival analysis to account for a cured fraction in the data. When there is a cure rate present, researchers often prefer cure models over parametric models to analyse the survival data. These models enable the ability to define the probability distribution of survival durations for patients who are at risk. Various distributions can be considered for the survival times, such as Exponentiated Weibull Exponential (EWE), Exponential Exponential (EE), Weibull and lognormal distribution. The objective of this research is to choose the most appropriate distribution that accurately represents the survival times of patients who have not been cured. This will be accomplished by comparing various non-mixture cure models that are based on the EWE distribution with its sub-distributions, and distributions distinct from those belonging to the EWE distribution family.

    MATERIAL AND METHODS: A sample of 85 patients diagnosed with superficial bladder tumours was selected to be used in fitting the non-mixture cure model. In order to estimate the parameters of the suggested model, which takes into account the presence of a cure rate, censored data, and covariates, we utilized the maximum likelihood estimation technique using R software version 3.5.7.

    RESULT: Upon conducting a comparison of various parametric models fitted to the data, both with and without considering the cure fraction and without incorporating any predictors, the EE distribution yields the lowest AIC, BIC, and HQIC values among all the distributions considered in this study, (1191.921/1198.502, 1201.692/1203.387, 1195.851/1200.467). Furthermore, when considering a non-mixture cure model utilizing the EE distribution along with covariates, an estimated ratio was obtained between the probabilities of being cured for placebo and thiotepa groups (and its 95% confidence intervals) were 0.76130 (0.13914, 6.81863).

    CONCLUSION: The findings of this study indicate that EE distribution is the optimal selection for determining the duration of survival in individuals diagnosed with bladder cancer.

    Matched MeSH terms: Survival Analysis
  3. Survival at extreme altitude - The misery and miracle of aircraft stowaways
    Flaherty GT, Long IJ
    Travel Med Infect Dis, 2016 Jul-Aug;14(4):417-8.
    PMID: 27262631 DOI: 10.1016/j.tmaid.2016.05.016
    Matched MeSH terms: Survival*
  4. Fulltext Counselling changes in sexual functioning for women with breast cancer
    Loh, S.Y.
    JUMMEC, 2010;13(1):33-37.
    MyJurnal
    As women with breast cancer are living longer, issues beyond survivorship like the much neglected sexual functioning and issue of quality of life have become increasingly important. Experiences of significant alterations in sexual functioning need to be addressed. However, these sexual issues are often not acknowledged in our traditional medical model of health care delivery. This paper briefly reviews the changes in sexual functioning after a diagnosis of breast cancer, with implication for clinical practice and medical curicula.
    Matched MeSH terms: Survival; Survival Rate
  5. Fulltext In vitro cytotoxicity of superheated steam hydrolyzed oligo((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) and characteristics of its blend with poly(L-lactic acid) for biomaterial applications
    Rajaratanam DD, Ariffin H, Hassan MA, Nik Abd Rahman NMA, Nishida H
    PLoS One, 2018;13(6):e0199742.
    PMID: 29944726 DOI: 10.1371/journal.pone.0199742
    In order to clarify the in vitro cytotoxicity effect of superheated steam (SHS) treated poly((R)-3-hydroxybutyrate-co-(R)-3-hydroxyhexanoate) (PHBHHx) for biomaterial applications, SHS-treated PHBHHx oligoester samples: P(HB-co-6%-HHx) and P(HB-co-11%-HHx) with low and high percentages of unsaturated chain ends were evaluated for their cytotoxicity effects toward the growth of mouse fibroblast cell line NIH 3T3. From the results obtained after 24 and 48 h of the growth test, the SHS-treated PHBHHx oligoesters were found to be nontoxic to the growth of mouse fibroblast NIH 3T3 cell line with cell viability percentages of more than 95%. In order to serve as a potential resorbable medical suture, PHBHHx oligoesters were blended with poly(L-lactic acid) (PLLA) with a weight ratio of PHBHHx oligoester/PLLA = 20:80 (wt/wt) to improve mechanical properties of PHBHHx oligoesters. The PHBHHx oligoesters/PLLA blend films were evaluated for their thermal, mechanical, and surface wetting properties. Thermal properties of the blend films suggested a good compatibility between PHBHHx oligoesters and PLLA components. Mechanical properties of the blend films were determined to be close enough to a desirable strength range of medical sutures. Moreover, contact angle range of 65 < θ < 70° for the blend samples could provide desirable cell adhesion when used as biomaterials. Therefore, the blend of SHS-treated PHBHHx oligoesters and PLLA would be an ideal choice to be used as biomedical materials.
    Matched MeSH terms: Cell Survival/drug effects
  6. Fulltext Evaluation of MicroRNAs Regulating Anoikis Pathways and Its Therapeutic Potential
    Malagobadan S, Nagoor NH
    Biomed Res Int, 2015;2015:716816.
    PMID: 26587543 DOI: 10.1155/2015/716816
    Dysregulation of microRNAs (miRNAs) has been implicated in almost every known survival mechanisms utilized by cancer cells. One of such mechanisms, anoikis resistance, plays a pivotal role in enabling metastasis by allowing cancer cells to circumvent cell death induced by lack of attachment. Understanding how miRNAs regulate the various anoikis pathways has become the research question of increasing number of studies published in the past years. Through these studies, a growing list of miRNAs has been identified to be important players in promoting either anoikis or resistance to anoikis. In this review, we will be focusing on these miRNAs and how the findings from those studies can contribute to novel therapeutic strategies against cancer progression. We will be examining miRNAs that have been found to promote anoikis sensitivity in numerous cancer types followed by miRNAs that inhibit anoikis. In addition, we will also be taking a look at major signaling pathways involved in the action of the each of these miRNAs to gain a better understanding on how miRNAs regulate anoikis.
    Matched MeSH terms: Cell Survival
  7. Fulltext Corticosteroid Plus Tocilizumab in COVID-19: When Two Is Better Than One
    Kow CS, Hasan SS
    Chest, 2021 05;159(5):2108-2109.
    PMID: 33965134 DOI: 10.1016/j.chest.2020.11.073
    Matched MeSH terms: Survival Analysis
  8. Fulltext Turnbull versus Kaplan-Meier estimators of cure rate estimation using interval censored data
    Bader Ahmad Aljawadi, Mohd Rizam Abu Bakar, Noor Akma
    Pertanika Journal of Science & Technology, 2012;20(2):243-255.
    MyJurnal
    This study deals with the analysis of the cure rate estimation based on the Bounded Cumulative Hazard (BCH) model using interval censored data, given that the exact distribution of the data set is unknown. Thus, the non-parametric estimation methods are employed by means of the EM algorithm. The Turnbull and Kaplan Meier estimators were proposed to estimate the survival function, even though the Kaplan Meier estimator faces some restrictions in term of interval survival data. A comparison of the cure rate estimation based on the two estimators was done through a simulation study.
    Matched MeSH terms: Survival Analysis
  9. Fulltext The study on the survival of Escherichia coli in water at room temperature
    Aung TS, Masandid H, Oo KS, Lin Z, Rayaji SJ
    Borneo Journal of Medical Sciences, 2016;10(1):14-18.
    MyJurnal
    Escherichia coli (E. coli) is one of the most frequent causes of many bacterial infections especially
    gastroenteritis in developing countries. It is also used as an indicator for faecal pollution in the
    surveillance of bacteriological quality of drinking water. This study was conducted to determine the
    survival of E. coli in water at room temperature (27oC). E. coli which is cultured in Lactose Peptone Broth
    was inoculated into 8 bottles each containing 10 millilitres of distilled water. They were kept at 27oC.
    Starting from the day 1, ten-fold dilutions were made from each bottle number and E. coli count was
    done from each dilutions by using pour plate method. The colony forming unit/ millilitre (CFU/ml) was
    calculated. The same procedure was carried out from bottles number 2 to 8 from day 2 to day 8
    consecutively. CFU/ml of E. coli in dilution 10-5was markedly decreased from 3.9 x 106
    in day 1to 0 in
    day 8. The findings suggest that if the water is contaminated with low number of E. coli, it can be
    eliminated by keeping water at room temperature for only few days.
    Matched MeSH terms: Survival
  10. Total paralysis regime in severe tetanus
    Alhady SMA, Bowler DP, Reid HA, Scott LT
    Br Med J, 1960;1:540-545.
    Tetanus may be mild, moderate, severe, or inevitably fatal. Our clinical experience suggests it may be classified as severe (or, maybe, inevitably fatal) when a tetanic spasm stops respiration. Ten patients with severe tetanus were treated by the total paralysis regime (T.P.R.), consisting of tracheostomy, curarization, and intermittent positiveor positive/negative-pressure respiration. Two of the patients were saved by T.P.R. and therefore only limited effectiveness can be claimed for the regime. In inevitably fatal cases survival can be prolonged by T.P.R. so that further effects of tetanus toxin emerge. Of these, the most important appears to be direct damage to the myocardium.
    Matched MeSH terms: Survival
  11. Interval estimations for parameters of gompertz model with time-dependent covariate and right censored data
    Kiani K, Arasan J, Habshah Midi
    Sains Malaysiana, 2012;41:471-480.
    There are numerous parametric models for analyzing survival data such as exponential, Weibull, log-normal and gamma. One of such models is the Gompertz model which is widely used in biology and demography. Most of these models are extended to new forms for accommodating different types of censoring mechanisms and different types of covariates. In this paper the performance of the Gompertz model with time-dependent covariate in the presence of right censored data was studied. Moreover, the performance of the model was compared at different censoring proportions (CP) and sample sizes. Also, the model was compared with fixed covariate model. In addition, the effect of fitting a fixed covariate model wrongly to a data with time-dependent covariate was studied. Finally, two confidence interval estimation techniques, Wald and jackknife, were applied to the parameters of this model and the performance of the methods was compared.
    Matched MeSH terms: Survival Analysis
  12. Cell Viability Assessment of PEDOT Conducting Polymer-Coated Microneedles for Skin Sampling
    Mokhtar SMA, Derrick-Roberts ALK, Evans DR, Strudwick XL
    ACS Appl Bio Mater, 2023 Nov 20;6(11):4662-4671.
    PMID: 37902811 DOI: 10.1021/acsabm.3c00416
    Recently, transdermal monitoring and drug delivery have gained much interest, owing to the introduction of the minimally invasive microneedle (MN) device. The advancement of electroactive MNs electrically assisted in the capture of biomarkers or the triggering of drug release. Recent works have combined conducting polymers (CPs) onto MNs owing to the soft nature of the polymers and their tunable ionic and electronic conductivity. Though CPs are reported to work safely in the body, their biocompatibility in the skin has been insufficiently investigated. Furthermore, during electrical biasing of CPs, they undergo reduction or oxidation, which in practical terms leads to release/exchange of ions, which could pose biological risks. This work investigates the viability and proliferation of skin cells upon exposure to an electrochemically biased MN pair comprising two differently doped poly(3,4-ethylenedioxy-thiophene) (PEDOT) polymers that have been designed for skin sampling use. The impact of biasing on human keratinocytes and dermal fibroblasts was determined at different initial cell seeding densities and incubation periods. Indirect testing was employed, whereby the culture media was first exposed to PEDOTs prior to the addition of this extract to cells. In all conditions, both unbiased and biased PEDOT extracts showed no cytotoxicity, but the viability and proliferation of cells cultured at a low cell seeding density were lower than those of the control after 48 h of incubation.
    Matched MeSH terms: Cell Survival
  13. Allele-specific PCR for a cost-effective & time-efficient diagnostic screening of spinal muscular atrophy
    Marini M, Sasongko TH, Watihayati MS, Atif AB, Hayati F, Gunadi, et al.
    Indian J Med Res, 2012;135:31-5.
    PMID: 22382180
    Genetic diagnosis of spinal muscular atrophy (SMA) is complicated by the presence of SMN2 gene as majority of SMA patients show absence or deletion of SMN1 gene. PCR may amplify both the genes non selectively in presence of high amount of DNA. We evaluated whether allele-specific PCR for diagnostic screening of SMA is reliable in the presence of high amount of genomic DNA, which is commonly used when performing diagnostic screening using restriction enzymes.
    Matched MeSH terms: Survival of Motor Neuron 1 Protein/blood*; Survival of Motor Neuron 1 Protein/genetics; Survival of Motor Neuron 2 Protein/blood; Survival of Motor Neuron 2 Protein/genetics
  14. In vitro 3D colon tumor penetrability of SRJ09, a new anti-cancer andrographolide analog
    Wong CC, Periasamy N, Sagineedu SR, Sidik S, Sumon SH, Loadman P, et al.
    Invest New Drugs, 2014 Oct;32(5):806-14.
    PMID: 24875131 DOI: 10.1007/s10637-014-0105-6
    Limited tumor penetrability of anti-cancer drugs is recognized as one of the major factors that lead to poor anti-tumor activity. SRJ09 (3,19-(2-bromobenzylidene) andrographolide) has been identified as a lead anti-cancer agent for colon cancer. Recently, this compound was shown by us to be a mutant K-Ras binder. In this present study, the penetrability of SRJ09 through the DLD-1 colon cancer multicell layer (MCL) was evaluated. The amount of SRJ09 that penetrated through the MCL was quantitated by utilizing high performance liquid chromatography (HPLC). Histopathological staining was used to visualize the morphology of MCL. A chemosensitivity assay was performed to assess the anti-cancer activity of SRJ09 in DLD-1 cells. SRJ09 was able to penetrate through DLD-1 MCL and is inversely proportional with the MCL thickness. The flow rates for SRJ09 through MCL were 0.90 ± 0.20 μM/min/cm(2) and 0.56 ± 0.06 μM/min/cm(2) for days 1 and 5, respectively, which are better than doxorubicin. Histopathological examination revealed that the integrity of the DLD-1 MCL was retained and no visible damage was inflicted on the cell membrane, confirming the penetration of SRJ09 was by diffusion. Short term exposure (1 h) in DLD-1 cells demonstrated SRJ09 had IC50 of 41 μM which was approximately 4-folds lower than andrographolide, the parent compound of SRJ09. In conclusion, SRJ09 successfully penetrated through DLD-1 MCL by diffusion and emerged as a potential candidate to be developed as a clinically viable anti-colon cancer drug.
    Matched MeSH terms: Cell Survival/drug effects
  15. The in vitro efficacy of antimicrobial agents against the pathogenic free-living amoeba Balamuthia mandrillaris
    Ahmad AF, Heaselgrave W, Andrew PW, Kilvington S
    J. Eukaryot. Microbiol., 2013 Sep-Oct;60(5):539-43.
    PMID: 23869955 DOI: 10.1111/jeu.12062
    The free-living amoeba Balamuthia mandrillaris causes usually fatal encephalitis in humans and animals. Only limited studies have investigated the efficacy of antimicrobial agents against the organism. Assay methods were developed to assess antimicrobial efficacy against both the trophozoite and cyst stage of B. mandrillaris (ATCC 50209). Amphotericin B, ciclopirox olamine, miltefosine, natamycin, paromomycin, pentamidine isethionate, protriptyline, spiramycin, sulconazole and telithromycin had limited activity with amoebacidal levels of > 135-500 μM. However, diminazene aceturate (Berenil(®) ) was amoebacidal at 7.8 μM and 31.3-61.5 μM for trophozoites and cysts, respectively. Assays for antimicrobial testing may improve the prognosis for infection and aid in the development of primary selective culture isolation media.
    Matched MeSH terms: Cell Survival/drug effects
  16. Phenylethanoid glycosides isolated from Paraboea paniculata
    Yue TH, Hock AH, Kiang LC, Mooi LY
    Nat Prod Commun, 2012 Jun;7(6):775-8.
    PMID: 22816305
    Phytochemical studies of the leaves and rhizomes of Paraboea pa niculata (Gesneriaceae) are reported for the first time. Three phenylethanoid glycosides were isolated and characterized as 3,4-dihydroxyphenethyl-(3"-O-beta-D-apiofuranosyl)-beta-D-glucopyranoside, calceoralarioside E, and acteoside. These isolates exhibited weak cytotoxic activity against the K-562 cell line with a 50% of cell killing rate of 40.18 microM, 27.05 microM, and 27.24 microM, respectively. In the DPPH free radical scavenging assay, their IC50 values were determined as 75.89 microM, 25.00 microM, and 26.04 microM, respectively.
    Matched MeSH terms: Cell Survival/drug effects
  17. Fulltext Antioxidant, total phenolic content and cytotoxicity evaluation of selected Malaysian plants
    Qader SW, Abdulla MA, Chua LS, Najim N, Zain MM, Hamdan S
    Molecules, 2011 Apr 21;16(4):3433-43.
    PMID: 21512451 DOI: 10.3390/molecules16043433
    Aqueous and ethanol extracts of different traditional Malaysian plants (Polygonum minus, Andrographis paniculata, Curcuma xanthorrhiza, Momordica charantia and Strobilanthes crispus) were evaluated for their antioxidant properties, total phenolic content and cytotoxic activity. Antioxidant activity was evaluated by using 1,1-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays. The results showed that ethanol extracts contain high antioxidant activities compared to aqueous extracts. The findings exhibited a strong correlation between antioxidant activity and the total phenol contents. In addition, all the plant extracts showed non-toxic effects against a normal human lung fibroblast cell line (Hs888Lu). Although traditionally aqueous extracts are used, we determined that ethanol extracts usually achieved better activity in the assays.
    Matched MeSH terms: Cell Survival/drug effects
  18. Cytotoxic caged-polyprenylated xanthonoids and a xanthone from Garcinia cantleyana
    Shadid KA, Shaari K, Abas F, Israf DA, Hamzah AS, Syakroni N, et al.
    Phytochemistry, 2007 Oct;68(20):2537-44.
    PMID: 17602714
    Phytochemical studies on the leaves and trunk bark of Garcinia cantleyana yielded five caged-xanthonoids including one tetra- and four tri-prenylated xanthones, cantleyanone A (1), 7-hydroxyforbesione (2) and cantleyanones B-D (4-6), as well as a simple xanthone, 4-(1,1-dimethylprop-2-enyl)-1,3,5,8-tetrahydroxyxanthone (3). Eight other known compounds, deoxygaudichaudione A, gaudichaudione H, friedelin, garbogiol, macranthol, glutin-5-en-3beta-ol, and a mixture of sitosterol and stigmasterol were also isolated. Their structures were elucidated by means of spectroscopic data and comparison of their NMR data with literature values. Significant cytotoxicity against MDA-MB-231, CaOV-3, MCF-7 and HeLa cancer cell-lines was demonstrated by cantleyanones B-D, 7-hydroxyforbesione, deoxygaudichaudione A and macranthol, with IC(50) values ranging from 0.22 to 17.17 microg/ml.
    Matched MeSH terms: Cell Survival/drug effects
  19. Biocompatibility test of polyhydroxybutyrate on human cell line
    Raouf AA, Samsudin AR, Al-Joudi FS, Shamsuria O
    Med J Malaysia, 2004 May;59 Suppl B:101-2.
    PMID: 15468838
    The human fibroblast MRC-5 cells incubated with PHB granules (TM) added at a final concentration of 4 mg/ml showed a time-course pattern of survival. The percentages of dead cells obtained were at the rate of 3.8% after 7 days, respectively. When the MRC-5 cells grown in different material, using the test concentration of 4 mg/ml PCM, they were found to show a similar time-course increasing pattern of death as that obtained with PHB. However, the death was noted in the cells incubated for 7 days, the death rates obtained was 40.54% respectively.
    Matched MeSH terms: Cell Survival/drug effects*
  20. Fulltext Intestinal obstruction: predictor of poor prognosis in colorectal carcinoma?
    Mohd Suan MA, Tan WL, Soelar SA, Ismail I, Abu Hassan MR
    Epidemiol Health, 2015;37:e2015017.
    PMID: 25868638 DOI: 10.4178/epih/e2015017
    OBJECTIVES: The goal of this study was to assess the relationship between intestinal obstruction and the prognosis of colorectal carcinoma.

    METHODS: Data pertaining to 4,501 colorectal carcinoma patients were extracted from the national colorectal registry and analysed. Survival analysis was performed using the Kaplan-Meier method. The log-rank test was used to compare the survival rate between patients with intestinal obstruction and those without intestinal obstruction. The p-values<0.05 were considered to indicate statistical significance. Simple Cox proportional hazards regression analysis was used to estimate the crude hazard ratio of mortality from colorectal cancer.

    RESULTS: Intestinal obstruction was reported in more than 13% of patients. The 3-year survival rate after treatment was 48.3% (95% confidence interval [CI], 43.9 to 52.8) for patients with intestinal obstruction (n=593) and 54.9% (95% CI, 53.1 to 56.6) for patients without intestinal obstruction (n=3,908). The 5-year survival rate for patients with intestinal obstruction was 37.3% (95% CI, 31.9 to 42.8), which was lower than that of patients without intestinal obstruction (45.6%; 95% CI, 43.5 to 47.7). After adjusting the hazard ratio for other prognostic variables, intestinal obstruction had a statistically significant negative correlation with the survival rate of colorectal cancer patients, with an adjusted hazard ratio of 1.22 (p=0.008).

    CONCLUSIONS: The presence of intestinal obstruction is associated with a lower survival rate among colorectal cancer patients.

    Matched MeSH terms: Survival Rate; Survival Analysis
Related Terms
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links