Displaying publications 461 - 480 of 534 in total

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  1. Tan KM, Saw S, Sethi SK
    J Clin Lab Anal, 2013 Jul;27(4):301-4.
    PMID: 23852789 DOI: 10.1002/jcla.21602
    BACKGROUND: In this study, we aimed to determine the normal ranges of 25-hydroxy-vitamin D(3) (25-OHD(3)), parathyroid hormone (PTH), and the markers of bone turnover, procollagen type 1 N propeptide (P1NP) and C-terminal cross-linked telopeptide of type 1 collagen (CTX), in normal healthy women in Singapore, and to explore the relationship between vitamin D, PTH, and these markers of bone turnover in the women.

    METHODS: One hundred and ninety-seven healthy women, aged 25 to 60, were selected from a hospital staff health screening program; 68% were Chinese, 18% Malay, and 14% Indian. P1NP, CTX, and 25-OHD(3) were measured using the Roche Cobas® electrochemiluminescence immunoassay. Serum PTH was measured using the Siemens ADVIA Centaur® immunoassay.

    RESULTS: Sixty-five percent had 25-OHD(3) concentrations <50 nmol/l. Vitamin D insufficiency (25-OHD(3) < 50 nmol/l) was more prevalent in Malays (89%) and Indians (82%) compared to Chinese (56%). There was no correlation between vitamin D and age. PTH positively correlated with age, and Malays and Indians had higher PTH concentrations than Chinese. There was an inverse correlation between PTH and 25-OHD(3), but no threshold of 25-OHD(3) concentrations at which PTH plateaued. The bone turnover markers P1NP and CTX inversely correlated with age but were not different between ethnic groups. CTX and P1NP exhibited good correlation, however, there was no significant correlation between 25-OHD(3) or PTH concentrations and the bone turnover markers P1NP and CTX.

    CONCLUSIONS: Healthy women in Singapore have a high prevalence of vitamin D insufficiency. Vitamin D insufficiency was more prevalent in Malays and Indians compared to Chinese.

    Matched MeSH terms: Peptides/blood
  2. Yap MS, Tang YQ, Yeo Y, Lim WL, Lim LW, Tan KO, et al.
    Virol J, 2016 Jan 06;13:5.
    PMID: 26738773 DOI: 10.1186/s12985-015-0454-6
    The incidence of neurological complications and fatalities associated with Hand, Foot & Mouth disease has increased over recent years, due to emergence of newly-evolved strains of Enterovirus 71 (EV71). In the search for new antiviral therapeutics against EV71, accurate and sensitive in vitro cellular models for preliminary studies of EV71 pathogenesis is an essential prerequisite, before progressing to expensive and time-consuming live animal studies and clinical trials.
    Matched MeSH terms: Peptides/pharmacology
  3. Matsuzaki Tada A, Hamezah HS, Pahrudin Arrozi A, Abu Bakar ZH, Yanagisawa D, Tooyama I
    J Alzheimers Dis, 2022;89(3):835-848.
    PMID: 35964178 DOI: 10.3233/JAD-220192
    BACKGROUND: Tripeptide Met-Lys-Pro (MKP), a component of casein hydrolysates, has effective angiotensin-converting enzyme (ACE) inhibitory activity. Brain angiotensin II enzyme activates the NADPH oxidase complex via angiotensin II receptor type 1 (AT1) and enhances oxidative stress injury. ACE inhibitors improved cognitive function in Alzheimer's disease (AD) mouse models and previous clinical trials. Thus, although undetermined, MKP may be effective against pathological amyloid-β (Aβ) accumulation-induced cognitive impairment.

    OBJECTIVE: The current study aimed to investigate the potential of MKP as a pharmaceutical against AD by examining MKP's effect on cognitive function and molecular changes in the brain using double transgenic (APP/PS1) mice.

    METHODS: Experimental procedures were conducted in APP/PS1 mice (n = 38) with a C57BL/6 background. A novel object recognition test was used to evaluate recognition memory. ELISA was used to measure insoluble Aβ40, Aβ42, and TNF-α levels in brain tissue. Immunohistochemical analysis allowed the assessment of glial cell activation in MKP-treated APP/PS1 mice.

    RESULTS: The novel object recognition test revealed that MKP-treated APP/PS1 mice showed significant improvement in recognition memory. ELISA of brain tissue showed that MKP significantly reduced insoluble Aβ40, Aβ42, and TNF-α levels. Immunohistochemical analysis indicated the suppression of the marker for microglia and reactive astrocytes in MKP-treated APP/PS1 mice.

    CONCLUSION: Based on these results, we consider that MKP could ameliorate pathological Aβ accumulation-induced cognitive impairment in APP/PS1 mice. Furthermore, our findings suggest that MKP potentially contributes to preventing cognitive decline in AD.

    Matched MeSH terms: Amyloid beta-Peptides/therapeutic use
  4. Khor TO, Gul YA, Ithnin H, Seow HF
    Int J Colorectal Dis, 2006 May;21(4):291-300.
    PMID: 16041507
    BACKGROUND AND AIMS: It is well accepted that activation of Wnt signalling occurs in colorectal carcinoma (CRC), but the correlation amongst the various proteins involved in primary tumours are still unclear. The expression of the inducer of this pathway, Wnt-1, and the downstream effectors, WISP-1, cyclin-D1 and survivin proteins, was compared in a series of CRC tissues with the apparently normal adjacent tissues to determine the relationship of these proteins.

    PATIENTS AND METHODS: Formalin-fixed, paraffin-embedded tissue samples of 47 CRCs surgically resected at the Kuala Lumpur Hospital (KLH) between 1999 and 2000 were used. Immunohistochemical staining with monoclonal antibodies against cyclin-D1 and survivin and polyclonal antibodies against Wnt-1 and WISP-1 was performed. Results of immunohistochemistry were analysed for correlation between biomolecules and histopathological data of the patients.

    RESULTS: Of the 47 CRCs, 26 (55.3%), 15 (31.9%), 5 (10.6%) and 28 (59.6%) of the tumours exhibited positivity for Wnt-1, WISP-1, cyclin D1 and survivin, respectively. A lower percentage of the 40 apparently normal adjacent tissues were found to be positive for Wnt-1 (7, 17.5%), WISP-1 (+/-5, 12.5%) and survivin (13, 32.5%), but cyclin D1 was not detected in any of them. Interestingly, the total scores of Wnt-1, WISP-1 and survivin were significantly higher in CRC tissues (p=0.001, 0.034 and 0.044, respectively). Using the Spearman rank correlation test, a positive linear relationship was found between total Wnt-1 score with total WISP-1 score (rho=0.319, p=0.003) and total survivin score (rho=0.609, p=or<0.001). The expression of WISP-1 in the CRC tissues was found to be positively correlated with patients older than 60 years old (p=0.011). In addition, nuclear cyclin-D1 expression was found to be associated with poorly differentiated CRC tissues (p<0.001, Table 5) and right-sided CRC tumour (p=0.019, Table 6). Total WISP-1 score was associated with well-differentiated CRC tissues (p=0.029).

    CONCLUSIONS: Overexpression and interplay between Wnt-1, WISP-1, survivin and cyclin-D1 may play a role in tumorigenesis, possibly by promoting cell cycle checkpoint progression, accelerating cell growth and inhibiting apoptosis. Our data may provide useful information towards the search for potent therapeutic targets towards the development of novel treatment strategies for CRC.

    Matched MeSH terms: Intracellular Signaling Peptides and Proteins/metabolism*
  5. Jindal HM, Zandi K, Ong KC, Velayuthan RD, Rasid SM, Samudi Raju C, et al.
    PeerJ, 2017;5:e3887.
    PMID: 29018620 DOI: 10.7717/peerj.3887
    BACKGROUND: Antimicrobial peptides (AMPs) are of great potential as novel antibiotics for the treatment of broad spectrum of pathogenic microorganisms including resistant bacteria. In this study, the mechanisms of action and the therapeutic efficacy of the hybrid peptides were examined.

    METHODS: TEM, SEM and ATP efflux assay were used to evaluate the effect of hybrid peptides on the integrity of the pneumococcal cell wall/membrane. DNA retardation assay was assessed to measure the impact of hybrid peptides on the migration of genomic DNA through the agarose gel. In vitro synergistic effect was checked using the chequerboard assay. ICR male mice were used to evaluate the in vivo toxicity and antibacterial activity of the hybrid peptides in a standalone form and in combination with ceftriaxone.

    RESULTS: The results obtained from TEM and SEM indicated that the hybrid peptides caused significant morphological alterations in Streptococcus pneumoniae and disrupting the integrity of the cell wall/membrane. The rapid release of ATP from pneumococcal cells after one hour of incubation proposing that the antibacterial action for the hybrid peptides is based on membrane permeabilization and damage. The DNA retardation assay revealed that at 62.5 µg/ml all the hybrid peptides were capable of binding and preventing the pneumococcal genomic DNA from migrating through the agarose gel. In vitro synergy was observed when pneumococcal cells treated with combinations of hybrid peptides with each other and with conventional drugs erythromycin and ceftriaxone. The in vivo therapeutic efficacy results revealed that the hybrid peptide RN7-IN8 at 20 mg/kg could improve the survival rate of pneumococcal bacteremia infected mice, as 50% of the infected mice survived up to seven days post-infection. In vivo antibacterial efficacy of the hybrid peptide RN7-IN8 was signficantly improved when combined with the standard antibiotic ceftriaxone at (20 mg/kg + 20 mg/kg) as 100% of the infected mice survived up to seven days post-infection.

    DISCUSSION: Our results suggest that attacking and breaching the cell wall/membrane is most probably the principal mechanism for the hybrid peptides. In addition, the hybrid peptides could possess another mechanism of action by inhibiting intracellular functions such as DNA synthesis. AMPs could play a great role in combating antibiotic resistance as they can reduce the therapeutic concentrations of standard drugs.

    Matched MeSH terms: Peptides
  6. Mohd Lazaldin MA, Iezhitsa I, Agarwal R, Bakar NS, Agarwal P, Mohd Ismail N
    Int J Neurosci, 2018 Oct;128(10):952-965.
    PMID: 29488424 DOI: 10.1080/00207454.2018.1446953
    PURPOSE: Amyloid beta (Aβ) is known to contribute to the pathophysiology of retinal neurodegenerative diseases such as glaucoma. Effects of intravitreal Aβ(1-42) on retinal and optic nerve morphology in animal models have widely been studied but not those of Aβ(1-40). Hence, we evaluated the time- and dose-related effects of intravitreal Aβ(1-40) on retinal and optic nerve morphology. Since oxidative stress and brain derived neurotrophic factor (BDNF) are associated with Aβ-induced neuronal damage, we also studied dose and time-related effects of Aβ(1-40) on retinal oxidative stress and BDNF levels.

    MATERIALS AND METHODS: Five groups of rats were intravitreally administered with vehicle or Aβ(1-40) in doses of 1.0, 2.5, 5 and 10 nmol. Animals were sacrificed and eyes were enucleated at weeks 1, 2 and 4 post-injection. The retinae were subjected to morphometric analysis and TUNEL staining. Optic nerve sections were stained with toluidine blue and were graded for neurodegenerative effects. The estimation of BDNF and markers of oxidative stress in retina were done using ELISA technique.

    RESULTS AND CONCLUSIONS: It was observed that intravitreal Aβ(1-40) causes significant retinal and optic nerve damage up to day 14 post-injection and there was increasing damage with increase in dose. However, on day 30 post-injection both the retinal and optic nerve morphology showed a trend towards normalization. The observations made for retinal cell apoptosis, retinal glutathione, superoxide dismutase activity and BDNF were in accordance with those of morphological changes with deterioration till day 14 and recovery by day 30 post-injection. The findings of this study may provide a guide for selection of appropriate experimental conditions for future studies.

    Matched MeSH terms: Amyloid beta-Peptides
  7. Akbar, I., Jaswir, I., Jamal, P., Octavianti, F.
    MyJurnal
    Considerable attention has been directed to nanoparticles based on gelatin biopolymer due to its numerous available active group sites for attaching target molecules and acting as a drug or nutraceutical delivery system aiming to improve the therapeutic effects and also to reduce the side effects of formulated drugs as gelatin is a natural biodegradable biocompatible polymer, nontoxic, readily available, cheap and is used in parental formulations. With mammalian gelatin (pig and cow) as the major source of gelatin production, alternatives are required due to sociocultural and health concerns to maintain halal status. This paper aims at reviewing fish skin gelatin from warm water species which can provide a potential alternative source of gelatin with almost the same rheological properties as mammalian gelatin and is a beneficial way to use fish waste such as skin, bones and fin which is generally discarded. The study also entails a lot of research being done in the field of nanoencapsulation of gelatin with various nutraceuticals as well as drug and gene therapy. There is an especially increasing interest in encapsulating biopeptides within gelatin nanoparticles in the functional food industry due to their role in preventing or delaying the onset of various diseases, food fortification, improvement of food quality, increase in shelf life, targeted peptide delivery and hence can be used as additives in food products. This review also attempts to provide an overview of the application of gelatin nanoparticles in nanoencapsulation in the food industry.
    Matched MeSH terms: Peptides
  8. Kabir MF, Mohd Ali J, Haji Hashim O
    PeerJ, 2018;6:e5203.
    PMID: 30042885 DOI: 10.7717/peerj.5203
    Background: We have previously reported anticancer activities of Melicope ptelefolia (MP) leaf extracts on four different cancer cell lines. However, the underlying mechanisms of actions have yet to be deciphered. In the present study, the anticancer activity of MP hexane extract (MP-HX) on colorectal (HCT116) and hepatocellular carcinoma (HepG2) cell lines was characterized through microarray gene expression profiling.

    Methods: HCT116 and HepG2 cells were treated with MP-HX for 24 hr. Total RNA was extracted from the cells and used for transcriptome profiling using Applied Biosystem GeneChip™ Human Gene 2.0 ST Array. Gene expression data was analysed using an Applied Biosystems Expression Console and Transcriptome Analysis Console software. Pathway enrichment analyses was performed using Ingenuity Pathway Analysis (IPA) software. The microarray data was validated by profiling the expression of 17 genes through quantitative reverse transcription PCR (RT-qPCR).

    Results: MP-HX induced differential expression of 1,290 and 1,325 genes in HCT116 and HepG2 cells, respectively (microarray data fold change, MA_FC ≥ ±2.0). The direction of gene expression change for the 17 genes assayed through RT-qPCR agree with the microarray data. In both cell lines, MP-HX modulated the expression of many genes in directions that support antiproliferative activity. IPA software analyses revealed MP-HX modulated canonical pathways, networks and biological processes that are associated with cell cycle, DNA replication, cellular growth and cell proliferation. In both cell lines, upregulation of genes which promote apoptosis, cell cycle arrest and growth inhibition were observed, while genes that are typically overexpressed in diverse human cancers or those that promoted cell cycle progression, DNA replication and cellular proliferation were downregulated. Some of the genes upregulated by MP-HX include pro-apoptotic genes (DDIT3, BBC3, JUN), cell cycle arresting (CDKN1A, CDKN2B), growth arrest/repair (TP53, GADD45A) and metastasis suppression (NDRG1). MP-HX downregulated the expression of genes that could promote anti-apoptotic effect, cell cycle progression, tumor development and progression, which include BIRC5, CCNA2, CCNB1, CCNB2, CCNE2, CDK1/2/6, GINS2, HELLS, MCM2/10 PLK1, RRM2 and SKP2. It is interesting to note that all six top-ranked genes proposed to be cancer-associated (PLK1, MCM2, MCM3, MCM7, MCM10 and SKP2) were downregulated by MP-HX in both cell lines.

    Discussion: The present study showed that the anticancer activities of MP-HX are exerted through its actions on genes regulating apoptosis, cell proliferation, DNA replication and cell cycle progression. These findings further project the potential use of MP as a nutraceutical agent for cancer therapeutics.

    Matched MeSH terms: Intracellular Signaling Peptides and Proteins
  9. Roshani Othman, Sharr Azni Harmin, Ina-Salwany Md Yasin
    MyJurnal
    Mass production of fish broodstock with high quality eggs requires the knowledge on the chemical composition and physiochemical properties of vitellogenin (Vtg) during ovulation. Vtg is an egg yolk precursor phospholipoglycoprotein, and has been analysed to evaluate the reproductive conditions and determine the spawning period in captive and wild fish. In this study, Vtg was induced in male H. nemurus through three intramuscular injections of 17-estradiol (E2). The Vtg was purified from the serum using gel filtration chromatography and the purified protein was reduced via SDS-PAGE. One major polypeptide corresponding to 130 kDa was observed. Vtg identification was done using peptide mass fingerprint (PMF) from the trypsin digestion of male H. nemurus Vtg induced with E2. The sequence homology of H. nemurus AYLAGAAADVLEVGVR matched the Vtg of other fish species when analysed using MALDI-TOF. Vtg was confirmed by MASCOT at 95% significant level. The potential protein that controls the reproductive process and oocyte development isolated from this study was discussed to understand the structure and function of Vtg.
    Matched MeSH terms: Peptides
  10. Khoo HE, Azlan A, Abd Kadir NAA
    Front Chem, 2019;7:5.
    PMID: 30766864 DOI: 10.3389/fchem.2019.00005
    This study aims to identify potential phenolic compounds, terpenoids, and other phytochemicals, as well as fatty acid profile and peptides in Canarium odontophyllum (CO) oil and oleoresin, extracted using supercritical carbon dioxide. LC-ESI-MS was applied in separation and tentative identification of phytochemicals in CO oil and oleoresin. Based on the results, 11 common fatty acids and their isomers, monoglycerides, diglycerides, as well as other types of lipid, were tentatively identified in the CO oil and oleoresin. The identified fatty acids consisted of saturated fatty acids (C8-C16), monounsaturated fatty acids (C16:1 and C18:1), polyunsaturated fatty acids (C18:2, C18:3, C18:4, and C20:3), and other unclassified fatty acids. The tentatively identified phenolic compounds were phenolic acids, flavonoids, lignans, and a phenolic monoester. Triterpenes, sesquiterpenes, and apocarotenoids were the terpenoids found in CO oil and oleoresin. Besides these typical bioactives, some volatiles, aromatic compounds, peptides, and other known and unknown phytochemicals were also tentatively identified in the oil and oleoresin of CO. Some of these compounds are new compounds identified in CO oil and oleoresin, which are not found in many other fruit oils. Although CO oil and oleoresin contain a small number of phytochemicals, their contribution as antioxidants may prevent several diseases. In this study, we hypothesized that CO oleoresin contains certain types of fatty acids that render its semi-solid together with other chemical components which are not found in CO oil. This is the first study that tentatively identified fatty acids, peptides, and potential phytochemicals in CO oil and oleoresin using LC-ESI-MS.
    Matched MeSH terms: Peptides
  11. Low, Qin Jian, Lim, Tzyy Hue, Teoh, Kuo Zhau, Siow, Garry Peir Woeei, Go, Zher Lin, Tee, Vern Jun, et al.
    MyJurnal
    Purple urine bag syndrome (PUBS) is a rare presentation of urinary tract infections (UTIs). It is commonly seen in constipated patients. There is a deep purple discoloration of contents of urine bag due to presence of indigo and indirubin pigments which are metabolites of tryptophan. We would like to describe an interesting case of purple urine bag syndrome of 88-year-old woman who presented with catheter-related urinary tract infection. She had low-grade fever and suprapubic discomfort for three days duration. She had increased white cell count and C-reactive peptide (CRP). Urinalysis showed protein 2+, nitrite and leucocyte esterase positive. Urine culture grew Escherichia coli and Klebsiella pneumoniae. She was treated with oral cefuroxime and recovered. This case report may be the first case of PUBS reported in this region.
    Matched MeSH terms: Peptides
  12. Quah Y, Mohd Ismail NI, Ooi JLS, Affendi YA, Abd Manan F, Teh LK, et al.
    J Zhejiang Univ Sci B, 2019 1 8;20(1):59-70.
    PMID: 30614230 DOI: 10.1631/jzus.B1700586
    Globally, peptide-based anticancer therapies have drawn much attention. Marine organisms are a reservoir of anticancer peptides that await discovery. In this study, we aimed to identify cytotoxic oligopeptides from Sarcophyton glaucum. Peptides were purified from among the S. glaucum hydrolysates produced by alcalase, chymotrypsin, papain, and trypsin, guided by a methylthiazolyldiphenyl-tetrazolium bromide (MTT) assay on the human cervical cancer (HeLa) cell line for cytotoxicity evaluation. Purification techniques adopted were membrane ultrafiltration, gel filtration chromatography, solid phase extraction (SPE), and reversed-phase high-performance liquid chromatography (RP-HPLC). Purified peptides were identified by de novo peptide sequencing. From papain hydrolysate, three peptide sequences were identified: AGAPGG, AERQ, and RDTQ (428.45, 502.53, and 518.53 Da, respectively). Peptides synthesized from these sequences exhibited cytotoxicity on HeLa cells with median effect concentration (EC50) values of 8.6, 4.9, and 5.6 mmol/L, respectively, up to 5.8-fold stronger than the anticancer drug 5-fluorouracil. When tested at their respective EC50, AGAPGG, AERQ, and RDTQ showed only 16%, 25%, and 11% cytotoxicity to non-cancerous Hek293 cells, respectively. In conclusion, AERQ, AGAPGG, and RDTQ are promising candidates for future development as peptide-based anticancer drugs.
    Matched MeSH terms: Oligopeptides; Peptides
  13. Ramli SR, Moreira GMSG, Zantow J, Goris MGA, Nguyen VK, Novoselova N, et al.
    PLoS Negl Trop Dis, 2019 01;13(1):e0007131.
    PMID: 30677033 DOI: 10.1371/journal.pntd.0007131
    BACKGROUND: Leptospirosis is the most common zoonotic disease worldwide. The diagnostic performance of a serological test for human leptospirosis is mainly influenced by the antigen used in the test assay. An ideal serological test should cover all serovars of pathogenic leptospires with high sensitivity and specificity and use reagents that are relatively inexpensive to produce and can be used in tropical climates. Peptide-based tests fulfil at least the latter two requirements, and ORFeome phage display has been successfully used to identify immunogenic peptides from other pathogens.

    METHODOLOGY/PRINCIPAL FINDINGS: Two ORFeome phage display libraries of the entire Leptospira spp. genomes from five local strains isolated in Malaysia and seven WHO reference strains were constructed. Subsequently, 18 unique Leptospira peptides were identified in a screen using a pool of sera from patients with acute leptospirosis. Five of these were validated by titration ELISA using different pools of patient or control sera. The diagnostic performance of these five peptides was then assessed against 16 individual sera from patients with acute leptospirosis and 16 healthy donors and was compared to that of two recombinant reference proteins from L. interrogans. This analysis revealed two peptides (SIR16-D1 and SIR16-H1) from the local isolates with good accuracy for the detection of acute leptospirosis (area under the ROC curve: 0.86 and 0.78, respectively; sensitivity: 0.88 and 0.94; specificity: 0.81 and 0.69), which was close to that of the reference proteins LipL32 and Loa22 (area under the ROC curve: 0.91 and 0.80; sensitivity: 0.94 and 0.81; specificity: 0.75 and 0.75).

    CONCLUSIONS/SIGNIFICANCE: This analysis lends further support for using ORFeome phage display to identify pathogen-associated immunogenic peptides, and it suggests that this technique holds promise for the development of peptide-based diagnostics for leptospirosis and, possibly, of vaccines against this pathogen.

    Matched MeSH terms: Peptides
  14. Hermizi Hapidin, Hawa Mahmood, Sakinah Harith
    Sains Malaysiana, 2013;42:1191-1200.
    Menopause is the most prevalent cause of accelerated bone loss in women. Biochemical markers of bone resorption can be used clinically to predict future bone loss. This study aimed to determine the level of bone resorption markers in healthy pre and postmenopausal Malay women and determine their association with the risk. A total of 150 healthy women were recruited for this study (51 pre and 99 postmenopausal subjects). Data on socioeconomic, lifestyle habit and clinical were gained by personal interview. Fasting serum was collected to measure both C-telopeptide (CTx) and N-telopeptide (NTx) of type 1 collagen. Both markers were highly correlated with each other (r=0.568, p<0.001). Both intra- and inter-assay coefficient of variations (CV) of NTx were higher than those of CTx (8% and 12% vs 6% and 5%). The mean CTx values of pre and postmenopausal subjects were comparable with the expected values (0.2833 (0.1769) ng/mL and 0.4323 (1.851) ng/mL compared with 0.287 and 0.438 ng/mL, respectively). The NTx value for premenopausal subjects were higher than the expected values (15.2 (8.10) compared to 12.6 (3.20) nM BCE). The median was 19.929 nM BCE. The mean CTx and NTx levels of postmenopausal subjects were significantly lower than premenopausal subjects (p<0.05). The risk factors for bone resorption in this population were duration of menopause, marital status, body mass index (BMI), physical activity and education level. In conclusion, postmenopausal women showed a higher bone resorption, indicating higher bone loss. Increasing education and physical activity intervention might be effective to ensure better health in Malaysian older population.
    Matched MeSH terms: Peptides
  15. Jumardi Roslan, Siti Mazlina Mustapa Kamal, Khairul Faezah Md. Yunos, Norhafizah Abdullah
    Sains Malaysiana, 2014;43:1715-1723.
    Fish protein hydrolysate was prepared from tilapia muscle using commercial Alcalase enzyme. Optimization of enzymatic hydrolysis process for preparing tilapia muscle protein hydrolysates (TMPH) was performed by employing central composite design (CCD) method of response surface methodology (RSM). O-phtaldialdehyde (OPA) method was employed to calculate the degree of hydrolysis (DH), which is the key parameter for monitoring the reaction of protein hydrolysis. The suggested model equation was proposed based on the effects of pH, temperature, substrate concentration and enzyme concentration on the DH. Optimum enzymatic hydrolysis conditions using Alcalase enzyme were obtained at pH7.5, temperature of 50oC, substrate concentration of 2.5% and enzyme concentration of 4.0%. Under these conditions, the highest value of the DH was achieved at 25.16% after hydrolysing at 120 min. The TMPH was further assessed for their nutritional value with respect to chemical and amino acid compositions. Molecular weight distributions of TMPH were characterized by SDS-PAGE. TMPH contains moderate amount of protein (28.14%) and good nutritive value with respect to the higher total amino acid composition (267.57 mg/g). Glutamic acid, aspartic acid and lysine were the most abundant amino acids present in TMPH with values 42.68, 29.16 and 26.21 mg/g, respectively. Protein hydrolysates from tilapia muscle containing a desirable peptide with low molecular weight which may potentially to be used as functional food products.
    Matched MeSH terms: Peptides
  16. Hempolchom C, Reamtong O, Sookrung N, Srisuka W, Sakolvaree Y, Chaicumpa W, et al.
    Acta Trop, 2019 Jun;194:82-88.
    PMID: 30922801 DOI: 10.1016/j.actatropica.2019.03.026
    Although several studies have reported pharmacological and immunological activity, as well as the role of black flies in transmitting pathogens to vertebrate hosts through salivary glands (SG) during blood feeding, SG proteomes of the anthropophilic black flies in Thailand have never been reported. Therefore, this study determined the SG proteomes of female S. nigrogilvum and S. nodosum. Sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE) and two-dimensional (2-DE) gels containing separated SG proteins of individual species were subjected to liquid chromatography-tandem mass spectrometry (LCMS/MS) and an orthologous protein search from eukaryotic organism, nematocera and simuliidae databases for total protein identification. SDS-PAGE and protein staining revealed at least 13 and 9 major protein bands in the SGs of female S. nigrogilvum and S. nodosum, respectively, as well as several minor ones. The 2-DE demonstrated a total of 56 and 41 protein spots for S. nigrogilvum and S. nodosum, respectively. Most of the proteins obtained in both species were enzymes involved in blood feeding, including proteases, apyrases, hyaluronidases, aminopeptidase and elastase. The results obtained in this study provided a new body of knowledge for a better understanding on the role of salivary gland proteins in these black fly species in Thailand.
    Matched MeSH terms: Salivary Proteins and Peptides
  17. Seyedi SS, Tan SG, Namasivayam P, Yong CSY
    Sains Malaysiana, 2016;45:717-727.
    The Hibiscus sabdariffa var. UMKL (Roselle) investigated here may potentially be used as an alternative fibre source. To
    the best of our knowledge, there was no study focusing on the genetics underlying the cellulose biosynthesis machinery
    in Roselle thus far. This paper presents the results of the first isolation of the cellulose synthase gene, HsCesA1 from this
    plant, which is fundamental for working towards understanding the functions of CesA genes in the cellulose biosynthesis
    of Roselle. A full-length HsCesA1 cDNA of 3528 bp in length (accession no: KJ608192) encoding a polypeptide of 974
    amino acid was isolated. The full-length HsCesA1 gene of 5489 bp length (accession no: KJ661223) with 11-introns
    and a promoter region of 737 bp was further isolated. Important and conserved characteristics of a CesA protein were
    identified in the HsCesA1 deduced amino acid sequence, which strengthened the prediction that the isolated gene being
    a cellulose synthase belonging to the processive class of the 2-glycosyltransferase family 2A. Relative gene expression
    analysis by semi-quantitative reverse transcription polymerase chain reaction (RT-PCR) on young leaf and stem tissues
    found that HsCesA1 had similar levels of gene expression in both tissues. Phylogenetic and Blast analyses also supported
    the prediction that the isolated HsCesA1 may play roles in the cell wall depositions in both leaf and stem tissues.
    Matched MeSH terms: Peptides
  18. Mohamed Nasir N, Hiji J, Jayapalan JJ, Hashim OH
    PeerJ, 2020;8:e8248.
    PMID: 32030317 DOI: 10.7717/peerj.8248
    Background: Most human hairs collected at old crime scenes do not contain nuclear DNA and are therefore of less value for forensic investigations. In the present study, hair shaft proteins were extracted from 40 healthy subjects between the ages of 21 to 40 years and profiled using gel electrophoresis-based proteomics to determine if they can be used to distinguish gender and ethnicity.

    Methods: Extraction of the human hair shaft proteins was performed using a newly developed alkaline solubilisation method. The extracts were profiled by 2-dimensional electrophoresis and resolved protein spots were identified by mass spectrometry and queried against the human hair database. The study was then followed-up by immunoblotting of the identified hair shaft keratin of interest using commercially available antibodies.

    Results: Separation of the human hair shaft proteins by 2-dimensional electrophoresis generated improved and highly resolved profiles. Comparing the hair shaft protein profiles of 10 female with 10 male subjects and their identification by mass spectrometry and query of the human hair database showed significant altered abundance of truncated/processed type-II keratin peptides K81 (two spots), K83 (one spot) and K86 (three spots). The 2-dimensional electrophoresis profiling of 30 hair shaft samples taken from women of similar age range but from three distinctive ethnic subpopulations in Malaysia further showed significant altered abundance of one type-I and four type-II truncated/processed keratin peptides including K33b, K81, K83 and K86 (2 spots) between at least two of the ethnic groups. When a followed-up immunoblotting experiment was performed to detect the relative expression of the K86 peptides using commercialised antibodies, similar trends of expression were obtained. The present data, when taken together, demonstrated the potential use of keratin peptide signatures of the human hair shaft to distinguish gender and ethnicity although this needs to be further substantiated in a larger scale study.

    Matched MeSH terms: Peptides
  19. Ha ZY, Mathew S, Yeong KY
    Curr Protein Pept Sci, 2020;21(1):99-109.
    PMID: 31702488 DOI: 10.2174/1389203720666191107094949
    Butyrylcholinesterase is a serine hydrolase that catalyzes the hydrolysis of esters in the body. Unlike its sister enzyme acetylcholinesterase, butyrylcholinesterase has a broad substrate scope and lower acetylcholine catalytic efficiency. The difference in tissue distribution and inhibitor sensitivity also points to its involvement external to cholinergic neurotransmission. Initial studies on butyrylcholinesterase showed that the inhibition of the enzyme led to the increment of brain acetylcholine levels. Further gene knockout studies suggested its involvement in the regulation of amyloid-beta, a brain pathogenic protein. Thus, it is an interesting target for neurological disorders such as Alzheimer's disease. The substrate scope of butyrylcholinesterase was recently found to include cocaine, as well as ghrelin, the "hunger hormone". These findings led to the development of recombinant butyrylcholinesterase mutants and viral gene therapy to combat cocaine addiction, along with in-depth studies on the significance of butyrylcholinesterase in obesity. It is observed that the pharmacological impact of butyrylcholinesterase increased in tandem with each reported finding. Not only is the enzyme now considered an important pharmacological target, it is also becoming an important tool to study the biological pathways in various diseases. Here, we review and summarize the biochemical properties of butyrylcholinesterase and its roles, as a cholinergic neurotransmitter, in various diseases, particularly neurodegenerative disorders.
    Matched MeSH terms: Amyloid beta-Peptides/antagonists & inhibitors; Amyloid beta-Peptides/genetics; Amyloid beta-Peptides/metabolism
  20. Sarkar P, Lite C, Kumar P, Pasupuleti M, Saraswathi NT, Arasu MV, et al.
    Int J Biol Macromol, 2020 Oct 31.
    PMID: 33137391 DOI: 10.1016/j.ijbiomac.2020.10.222
    The antioxidant role of sulfite reductase (SiR) derived from Arthrospira platensis (Ap) was identified through a short peptide, TL15. The study showed that the expression of ApSiR was highly expressed on day ten due to sulfur deprived stress in Ap culture. TL15 peptide exhibited strong antioxidant activity when evaluated using antioxidant assays in a concentration ranging from 7.8 and 125 μM. Further, the cytotoxicity of TL15 peptide was investigated, even at the higher concentration (250 μM), TL15 did not exhibit any toxicity, when tested in vitro using human leucocytes. Moreover, a potential reduction in reactive oxygen species (ROS) production was observed due to the treatment of TL15 peptide (>15.6 μM) to H2O2 exposed leucocytes. For the in vivo assessment of TL15 toxicity and antioxidant ability, experiments were performed in zebrafish (Danio rerio) larvae to analyse the developmental toxicity of TL15 peptide. Results showed that, exposure to TL15 peptide in tested concentrations ranging from 10, 20, 40, and 80 μM, did not affect the development and physiological parameters of the zebrafish embryo/larvae such as morphology, survival, hatching and heart rate. Fluorescent assay was performed using DCFH-DA (2,7-dichlorodihydrofluorescein diacetate) to examine the production of intracellular reactive oxygen species (ROS) in zebrafish treated with TL15 peptide during the embryo-larval stages. Fluorescent images showed that pre-treatment with TL15 peptide to attenuate the H2O2 induced ROS levels in the zebrafish larvae in a dose-dependent manner. Further to uncover the underlying biochemical and antioxidant mechanism, the enzyme activity of superoxide dismutase (SOD), catalase (CAT) and lipid peroxidation (LPO) levels were studied in zebrafish larvae. TL15 pre-treated groups showed enhanced antioxidant enzyme activity, while the hydrogen peroxide (H2O2) exposed larvae showed significantly diminished activity. Overall results from the study revealed that, TL15 act as a potential antioxidant molecule with dose-specific antioxidant property. Thus, TL15 peptide could be an effective and promising source for biopharmaceutical applications.
    Matched MeSH terms: Peptides
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