Displaying publications 61 - 80 of 143 in total

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  1. Khoo SC, Peng WX, Yang Y, Ge SB, Soon CF, Ma NL, et al.
    J Hazard Mater, 2020 12 05;400:123296.
    PMID: 32947701 DOI: 10.1016/j.jhazmat.2020.123296
    Synthetic adhesives in the plywood industry are usually volatile compounds such as formaldehyde-based chemical which are costly and hazardous to health and the environment. This phenomenon promotes an interest in developing bio-boards without synthetic adhesives. This study proposed a novel application of natural mycelium produced during mushroom cultivation as natural bio-adhesive material that convert spent mushroom substrate (SMS) into high-performance bio-board material. Different types of spent mushroom substrates were compressed with specific designed mould with optimal temperature at 160 °C and 10 mPa for 20 min. The bio-board made from Ganoderma lucidum SMS had the highest internal bonding strength up to 2.51 mPa. This is far above the 0.4-0.8 range of China and US national standards. In addition, the material had high water and fire resistance, high bonding and densified structures despite free of any adhesive chemicals. These properties and the low cost one step procedure show the potential as a zero-waste economy chain for sustainable agricultural practice for waste and remediation.
    Matched MeSH terms: Formaldehyde
  2. Kong PL, Looi LM, Lau TP, Cheah PL
    PLoS One, 2016;11(9):e0161720.
    PMID: 27598341 DOI: 10.1371/journal.pone.0161720
    Telomeres shorten with physiological aging but undergo substantial restoration during cancer immortalization. Increasingly, cancer studies utilize the archive of formalin-fixed, paraffin-embedded (FFPE) tissues in diagnostic pathology departments. Conceptually, such studies would be confounded by physiological telomere attrition and loss of DNA integrity from prolonged tissue storage. Our study aimed to investigate these two confounding factors. 145 FFPE tissues of surgically-resected, non-diseased appendixes were retrieved from our pathology archive, from years 2008 to 2014. Cases from 2013 to 2014 were categorized by patient chronological age (0-20 years, 21-40 years, 41-60 years, > 60 years). Telomere lengths of age categories were depicted by telomere/chromosome 2 centromere intensity ratio (TCR) revealed by quantitative fluorescence in situ hybridization. Material from individuals aged 0-20 years from years 2013/2014, 2011/2012, 2009/2010, and 2008 were compared for storage effect. Telomere integrity was assessed by telomere fluorescence intensity (TFI). Epithelial TCRs (mean ± SD) for the respective age groups were 4.84 ± 2.08, 3.64 ± 1.21, 2.03 ± 0.37, and 1.93 ± 0.45, whereas corresponding stromal TCRs were 5.16 ± 2.55, 3.84 ± 1.36, 2.49 ± 1.20, and 2.93 ± 1.24. A trend of inverse correlation with age in both epithelial and stromal tissues is supported by r = -0.69, p < 0.001 and r = -0.42, p < 0.001 respectively. Epithelial TFIs (mean ± SD) of years 2013/2014, 2011/2012, 2009/2010 and 2008 were 852.60 ± 432.46, 353.04 ± 127.12, 209.24 ± 55.57 and 429.22 ± 188.75 respectively. Generally, TFIs reduced with storage duration (r = -0.42, p < 0.001). Our findings agree that age-related telomere attrition occurs in normal somatic tissues, and suggest that an age-based reference can be established for telomere studies on FFPE tissues. We also showed that FFPE tissues archived beyond 2 years are suboptimal for telomere analysis.
    Matched MeSH terms: Formaldehyde
  3. Kuan YH, Bhat R, Senan C, Williams PA, Karim AA
    J Agric Food Chem, 2009 Oct 14;57(19):9154-9.
    PMID: 19757813 DOI: 10.1021/jf9015625
    The impact of ultraviolet (UV) irradiation on the physicochemical and functional properties of gum arabic was investigated. Gum arabic samples were exposed to UV irradiation for 30, 60, 90, and 120 min; gum arabic was also treated with formaldehyde for comparison. Molecular weight analysis using gel permeation chromatography indicated that no significant changes occurred on the molecular structure on the samples exposed to UV irradiation. Free amino group analysis indicated that mild UV irradiation (30 min) could induce cross-linking on gum arabic; this result was comparable with that of samples treated with formaldehyde. However, viscosity break down was observed for samples exposed to UV irradiation for longer times (90 and 120 min). All irradiated and formaldehyde-treated samples exhibited better emulsification properties than unirradiated samples. These results indicate that UV-irradiated gum arabic could be a better emulsifier than the native (unmodified) gum arabic and could be exploited commercially.
    Matched MeSH terms: Formaldehyde/pharmacology
  4. Lee SH, H'ng PS, Peng TL, Lum WC
    Pak J Biol Sci, 2013 Nov 01;16(21):1415-8.
    PMID: 24511759
    The objective of this study is to investigate the feasibility of formaldehyde catcher as termites repellent. Single-layered UF-bonded particleboard was post-treated with formaldehyde catcher and heat respectively. Besides that, some boards were also produced with the formaldehyde catcher was added into the resin during the blending process, called add-in method. Particleboard post-treated with formaldehyde catcher reported the most severe attack. Heat-treated particleboard showed slightly better durability than the control blocks while the add-in catcher showed the best durability among three methods. A valid test was obtained as the termites survived the first week of the test. However, all the termites were found dead at the end of the test.
    Matched MeSH terms: Formaldehyde*
  5. Lian, C.B., Ngeow, W.C.
    Ann Dent, 2000;7(1):-.
    MyJurnal
    Formalin is a clear solution of 37% formaldehyde in water. It is used in dentistry as a disinfectant, antiseptic and mainly as tissue fixative for preserving biologic specimens for histopathologic examination. The human knowledge on systemic formaldehyde intoxication is inadequate as only few cases of formalin ingestion have been reported. This paper presents a brief communication of the adverse effect of formalin to the human tissue.
    Matched MeSH terms: Formaldehyde
  6. Lim YC, Phang KS, Cheong SK
    Malays J Pathol, 1992 Dec;14(2):85-9.
    PMID: 1304629
    With the advent of new monoclonal antibodies that are applicable to formalin-fixed, paraffin embedded sections, immunophenotyping is becoming increasingly important in the diagnosis and classification of lymphomas. However, multiple factors such as fixation, trypsinization and even type of antibodies used have certain effects on the final outcome of the staining procedure. In this paper we report our experience and the problems encountered in our laboratory when we first tried to establish a workable immunostaining protocol for formalin-fixed, paraffin embedded tissue sections using the immunoalkaline phosphatase technique.
    Matched MeSH terms: Formaldehyde*
  7. Liu W, Zhang J, Hashim JH, Jalaludin J, Hashim Z, Goldstein BD
    Environ Health Perspect, 2003 Sep;111(12):1454-60.
    PMID: 12948883
    Burning mosquito coils indoors generates smoke that can control mosquitoes effectively. This practice is currently used in numerous households in Asia, Africa, and South America. However, the smoke may contain pollutants of health concern. We conducted the present study to characterize the emissions from four common brands of mosquito coils from China and two common brands from Malaysia. We used mass balance equations to determine emission rates of fine particles (particulate matter < 2.5 microm in diameter; PM(2.5)), polycyclic aromatic hydrocarbons (PAHs), aldehydes, and ketones. Having applied these measured emission rates to predict indoor concentrations under realistic room conditions, we found that pollutant concentrations resulting from burning mosquito coils could substantially exceed health-based air quality standards or guidelines. Under the same combustion conditions, the tested Malaysian mosquito coils generated more measured pollutants than did the tested Chinese mosquito coils. We also identified a large suite of volatile organic compounds, including carcinogens and suspected carcinogens, in the coil smoke. In a set of experiments conducted in a room, we examined the size distribution of particulate matter contained in the coil smoke and found that the particles were ultrafine and fine. The findings from the present study suggest that exposure to the smoke of mosquito coils similar to the tested ones can pose significant acute and chronic health risks. For example, burning one mosquito coil would release the same amount of PM(2.5) mass as burning 75-137 cigarettes. The emission of formaldehyde from burning one coil can be as high as that released from burning 51 cigarettes.
    Matched MeSH terms: Formaldehyde/analysis
  8. Long I, Suppian R, Ismail Z
    Korean J Pain, 2013 Jul;26(3):255-64.
    PMID: 23861999 DOI: 10.3344/kjp.2013.26.3.255
    We investigated the effects of pre-emptive administration of ketamine and norBNI on pain behavior and the expression of DREAM, c-Fos, and prodynorphin proteins on the ipsilateral side of the rat spinal cord at 2 and 4 hours after formalin injection.
    Matched MeSH terms: Formaldehyde
  9. Long I, Suppian R, Ismail Z
    Neurochem Res, 2011 Mar;36(3):533-9.
    PMID: 21188515 DOI: 10.1007/s11064-010-0375-0
    Downstream Regulatory Element Antagonist Modulator (DREAM) protein modulates pain by regulating prodynorphin gene transcription. Therefore, we investigate the changes of mRNA and DREAM protein in relation to the mRNA and prodynorphin protein expression on the ipsilateral side of the rat spinal cord after formalin injection (acute pain model). DREAM like immunoreactivity (DLI) was not significantly different between C and F groups. However, we detected the upregulation of mean relative DREAM protein level in the nuclear but not in the cytoplasmic extract in the F group. These effects were consistent with the upregulation of the relative DREAM mRNA level. Prodynorphin like immunoreactivity (PLI) expression increased but the relative prodynorphin mRNA level remained unchanged. In conclusion, we suggest that upregulation of DREAM mRNA and protein expression in the nuclear compartment probably has functional consequences other than just the repression of prodynorphin gene. It is likely that these mechanisms are important in the modulation of pain.
    Matched MeSH terms: Formaldehyde/pharmacology*
  10. Looi LM, Loh KC
    Malays J Pathol, 2005 Jun;27(1):23-7.
    PMID: 16676689
    Although microwave irradiation has been used in the histopathology laboratory for several years, there has been minimal published experimental data on its effects on the technical and staining quality of histological sections. Furthermore, it has not been clear whether the advantages gained in reduction of fixation and staining duration has been at the expense of increasing architectural distortion to the tissues. We report here our experience with computerised morphometric analysis to investigate glomerular artifacts caused by microwave-stimulated fixation of renal tissues. 39 rat and 33 human autopsy kidney samples were subjected to (1) fixation in neutral buffered formaldehyde (control), (2) microwave-stimulated fixation followed by neutral buffered formaldehyde, and (3) neutral buffered formaldehyde followed by microwave irradiation. In addition, the effect of post-fixation in 70% ethanol was also investigated. Microwave irradiation was delivered through a dedicated laboratory microwave oven at 80% power and at 55 degrees C for 3 minutes. The different fixation methods were compared with regards to shrinkage (distortion) to glomerular structures (glomeruli and Bowman's spaces) on H and E sections, as determined by morphometric image analysis using a temporary assembled-system consisting of a trinocular microscope, a digital video camera and personal computer. A FlashPoint VGA 3.3 film-grabber card was used to capture images for morphometric analysis by using a Scion Image program. Morphometric analysis of glomerular structures showed that microwaves caused more shrinkage to the area bounded by the Bowman's capsule than the glomerulus proper, but post-fixation with ethanol reduced this shrinkage. These findings have implications on the logistics of tissue preparation of renal biopsies in clinical practice.
    Matched MeSH terms: Formaldehyde
  11. Mabruk MJ
    Expert Rev Mol Diagn, 2004 Sep;4(5):653-61.
    PMID: 15347259
    In situ hybridization is a method for detecting specific nucleic acid sequences within individual cells. This technique permits visualization of viral nucleic acid or gene expression in individual cells within their histologic context. In situ hybridization is based on the complementary binding of a labeled nucleic acid probe to complementary sequences in cells or tissue sections, followed by visualization of target sequences within the cells. It has been used widely for the detection of viral nucleic acid sequences within individual cells. This review will define the technical approaches of in situ hybridization and its current application to detect viral nucleic acids within formalin-fixed, paraffin-embedded tissue samples, with special reference to the Epstein-Barr virus.
    Matched MeSH terms: Formaldehyde/chemistry*
  12. Mahmoudian MR, Basirun WJ, Woi PM, Hazarkhani H, Alias YB
    Mikrochim Acta, 2019 05 22;186(6):369.
    PMID: 31119482 DOI: 10.1007/s00604-019-3481-y
    The study presents the synthesis of polypyrrole-coated palladium platinum/nitrogen-doped reduced graphene oxide nanocomposites (PdPt-PPy/N-rGO NC) via direct the reduction of Pd(II) and Pt(II) in the presence of pyrrole monomer, N-rGO and L-cysteine as the reducing agent. X-ray diffraction confirmed the presence of metallic Pd and Pt from the reduction of Pd and Pt cations. Transmission electron microscopy images revealed the presence of Pd, Pt and PPy deposition on N-rGO. Impedance spectroscopy results gave a decreased charge transfer resistance due to the presence of N-rGO. The nanocomposites were synthesized with different Pd/Pt ratios (2:1, 1:1 and 1:2). A glassy carbon electrode (GCE) modified with the nanocomposite showed enhanced electrochemical sensing capability for formaldehyde in 0.1 M sulfuric acid solution. Cyclic voltammetry showed an increase in the formaldehyde oxidation peak current at the GCE modified with Pd2Pt1 PPy N-rGO. At a typical potential of 0.45 V (vs. SCE), the sensitivity in the linear segment was 345.8 μA.mM -1. cm-2. The voltammetric response was linear between 0.01 and 0.9 mM formaldehyde concentration range, with a 27 µM detection limit (at S/N = 3). Graphical abstract Schematic presentation of formaldehyde detection by Pd2Pt1-PPy/nitrogen-doped reduced Graphene Oxide Nanocomposite (Pd2Pt1-PPy /N-Gr NC). The decrease of charge transfer resistance and the agglomeration of deposited metals in the presence of N-rGO enhance the current response of the electrochemical sensor.
    Matched MeSH terms: Formaldehyde
  13. Mariam Ahmad Zawawi, Mohamed Kamel Abd Ghani, Gopal G, Hidayatulfathi Othman, Hartini Yusof, Norhisham Haron
    Sains Malaysiana, 2012;41:1095-1098.
    entamoeba histolytica dan/atau entamoeba dispar merupakan protozoa usus yang mempunyai prevalens infeksi yang tinggi dalam kalangan masyarakat pedalaman terutamanya masyarakat Orang Asli. Ia tersebar secara meluas di kawasan tropika dan subtropika serta di negara membangun berbanding negara maju. Sebanyak 111 sampel feses kanak-kanak Orang Asli daripada suku kaum Jahai telah diterima dan disaring untuk entamoeba histolytica dan/atau entamoeba dispar menggunakan kaedah apusan langsung yang memberi hasil positif terhadap 43 sampel atau 38.7%. Oleh sebab amaun sampel yang diterima adalah sedikit, hanya 66 sampel feses sahaja yang dapat diperiksa menggunakan tiga jenis teknik diagnostik berbeza iaitu apusan langsung, kepekatan formalin-eter dan pewarnaan trikrom. Hasil kajian mendapati, prevalens yang tinggi bagi infeksi entamoeba histolytica dan/atau entamoeba dispar iaitu 50% menggunakan
    ketiga-tiga teknik diagnosis. Prevalens infeksi yang tinggi juga turut ditunjukkan pada kanak-kanak perempuan iaitu 62.5% berbanding kanak-kanak lelaki 30.8% (p<0.05). Selain itu, daripada segi umur, kanak-kanak yang berumur 7-9 tahun adalah lebih terdedah kepada infeksi entamoeba histolytica dan/atau entamoeba dispar dengan prevalens 60.7% (p>0.05). Teknik pewarnaan trikrom menunjukkan pengesanan 100% ke atas infeksi entamoeba histolytica dan/atau entamoeba dispar, diikuti teknik kepekatan formalin-eter 78.8% dan apusan langsung 72.7%. Prevalens infeksi entamoeba histolytica dan/atau entamoeba dispar yang tinggi dalam kalangan kanak-kanak Orang Asli di Pos Sungai Rual ini berhubungkait dengan pelbagai faktor iaitu status sosioekonomi yang rendah, kekurangan pengetahuan tentang penjagaan kesihatan serta kebersihan diri yang rendah. Peningkatan prevalens infeksi dalam kajian ini juga menunjukkan pentingnya penggunaan teknik diagnostik yang lebih berkesan dalam pemeriksaan rutin bagi mendapatkan hasil diagnosis yang lebih tepat.
    Matched MeSH terms: Formaldehyde
  14. Marpani F, Sárossy Z, Pinelo M, Meyer AS
    Biotechnol Bioeng, 2017 12;114(12):2762-2770.
    PMID: 28832942 DOI: 10.1002/bit.26405
    Enzymatic reduction of carbon dioxide (CO2 ) to methanol (CH3 OH) can be accomplished using a designed set-up of three oxidoreductases utilizing reduced pyridine nucleotide (NADH) as cofactor for the reducing equivalents electron supply. For this enzyme system to function efficiently a balanced regeneration of the reducing equivalents during reaction is required. Herein, we report the optimization of the enzymatic conversion of formaldehyde (CHOH) to CH3 OH by alcohol dehydrogenase, the final step of the enzymatic redox reaction of CO2 to CH3 OH, with kinetically synchronous enzymatic cofactor regeneration using either glucose dehydrogenase (System I) or xylose dehydrogenase (System II). A mathematical model of the enzyme kinetics was employed to identify the best reaction set-up for attaining optimal cofactor recycling rate and enzyme utilization efficiency. Targeted process optimization experiments were conducted to verify the kinetically modeled results. Repetitive reaction cycles were shown to enhance the yield of CH3 OH, increase the total turnover number (TTN) and the biocatalytic productivity rate (BPR) value for both system I and II whilst minimizing the exposure of the enzymes to high concentrations of CHOH. System II was found to be superior to System I with a yield of 8 mM CH3 OH, a TTN of 160 and BPR of 24 μmol CH3 OH/U · h during 6 hr of reaction. The study demonstrates that an optimal reaction set-up could be designed from rational kinetics modeling to maximize the yield of CH3 OH, whilst simultaneously optimizing cofactor recycling and enzyme utilization efficiency.
    Matched MeSH terms: Formaldehyde/chemistry*
  15. Marzuki, A.F., Masudi, S.M.
    MyJurnal
    Dentin morphology and the lesion found in dental caries have been studied for many years. It was first observed under optical microscopy, and later using electron microscopy. Confocal laser scanning microscopy (CLSM) applied with several fluorescent dyes such as alizarin red to see normal dentinal tubules. However, as far as authors aware, the CLSM studies of dentinal tubules in human caries using alizarin red is rare. The aim of this study is to examine histopathological and morphological changes in dentinal tubules of dentin caries stained with alizarin red using CLSM. Fifteen extracted carious teeth (premolar or molar) was collected and fixed in neutral formalin solution buffered with phosphate buffer, rinsed and stored in calcium free phosphate buffer saline (PBS) at 4°C. The specimens were dehydrated and embedded in resin. Longitudinal or cross sections were cut and polished and then stained with alizarin red S (100 μg/ml) in 0.5 M HCl solution for 24-48 hour at 37°C. After dehydration specimens were mounted on glass slide and examined under CLSM using epi-flourescent mode or transmission light mode with wave length of 512 nm. The images of dentinal tubules were taken serially and optimum images of three-dimensional structures were reconstructed using software of CLSM. Histopathological changes of dentinal tubules in human caries showed area of demineralized dentin, translucent zone, and normal area. The dentinal tubules were thin and had numerous branches. In conclusion, confocal microscopy revealed Study shows that confocal microscopy revealed histopathological changes in dentinal tubules affected by carious lesions.
    Matched MeSH terms: Formaldehyde
  16. Masir N, Ghoddoosi M, Mansor S, Abdul-Rahman F, Florence CS, Mohamed-Ismail NA, et al.
    Histopathology, 2012 Apr;60(5):804-15.
    PMID: 22320393 DOI: 10.1111/j.1365-2559.2011.04127.x
    To investigate RCL2 as a fixative for tissue fixation in routine histopathological examination and to assess tissue suitability for ancillary investigations.
    Matched MeSH terms: Formaldehyde*
  17. Menicagli R, Bolla G, Menicagli L, Esseiridou A
    Gulf J Oncolog, 2017 May;1(24):70-74.
    PMID: 28798007
    INTRODUCTION AND OBJECTIVES: Nasopharyngeal Carcinoma represents 0.7% of the total cancer cases in the world with an ASR index of 1.7 and is widely associated with Epstein-Barr virus. It is not common in Italy (ASR index of 0.5) while in China (ASR 1.9), one third of the clinical cases are observed in Guangdong (ASR index 11.3). It is also quite common in Malaysia and Indonesia. The activation of the cancerogenesis process happens after the exposure to some environmental parameters that epidemiological studies have indicated with various dietary habits, mainly for salted fish consumption. The purpose of this work is to highlight such as exposure to compounds, such as formaldehyde, which is present in the different working conditions of these countries and may lead to the real cause to establish the carcinogenic process.

    MATERIALS AND METHODS: The most recent publications regarding the impact of various external factors on Pub Med, Google, TOXLINE, Chem Abstract, were analyzed with the radiological data that were found in Milan hospitals database.

    RESULTS: The relationship between food consumption and nasopharyngeal cancer are not clear and statistically insignificant in Indonesia. In Malaysia, the preparation of natural rubber for the use of formaldehyde is a dangerous environmental factor. The same exposure is a risk factor in Guangdong, where many workers are employed in the wood panel industry. Incidence of cancer in these Chinese ethnic groups decreases when they migrate to other countries. In the last 5 years, few cases were recorded in Italy, without any apparent change in ethnic environmental factors or HBV infection Discussion: In the production of natural rubber, a lot of people are exposed to formaldehyde during the various steps of preparation and production such as stripping, drying and coagulation without observing proper environmental hygiene precautions. The same working conditions are present in industrial production of wood panels in Guangdong, China. The relationship between exposure to formaldehyde and nasopharyngeal cancer is demonstrated by the fact that epidemiological studies on the population of this Chinese district whose immigrant populations were not exposed to these pollutants, the appearance of these tumors decreases. Also an examination of our radiological data in Italy shows that in about one hundred sixty cases of nasopharyngeal cancer none of the patients were Indonesian or Chinese Conclusion: The preliminary results of our study suggest that EPST-BARR virus could be a risk factor if associated with exposure to compounds such as formaldehyde which is present in industrial productions of countries like Indonesia, Malaysia, and China.

    Matched MeSH terms: Formaldehyde
  18. Mittal P, Briggs M, Klingler-Hoffmann M, Kaur G, Packer NH, Oehler MK, et al.
    Anal Bioanal Chem, 2021 Apr;413(10):2721-2733.
    PMID: 33222001 DOI: 10.1007/s00216-020-03039-z
    It is well established that cell surface glycans play a vital role in biological processes and their altered form can lead to carcinogenesis. Mass spectrometry-based techniques have become prominent for analysing N-linked glycans, for example using matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). Additionally, MALDI MS can be used to spatially map N-linked glycans directly from cancer tissue using a technique termed MALDI MS imaging (MALDI MSI). This powerful technique combines mass spectrometry and histology to visualise the spatial distribution of N-linked glycans on a single tissue section. Here, we performed N-glycan MALDI MSI on six endometrial cancer (EC) formalin-fixed paraffin-embedded (FFPE) tissue sections and tissue microarrays (TMA) consisting of eight EC patients with lymph node metastasis (LNM) and twenty without LNM. By doing so, several putative N-linked glycan compositions were detected that could significantly distinguish normal from cancerous endometrium. Furthermore, a complex core-fucosylated N-linked glycan was detected that could discriminate a primary tumour with and without LNM. Structural identification of these putative N-linked glycans was performed using porous graphitized carbon liquid chromatography tandem mass spectrometry (PGC-LC-MS/MS). Overall, we observed higher abundance of oligomannose glycans in tumour compared to normal regions with AUC ranging from 0.85-0.99, and lower abundance of complex N-linked glycans with AUC ranges from 0.03-0.28. A comparison of N-linked glycans between primary tumours with and without LNM indicated a reduced abundance of a complex core-fucosylated N-glycan (Hex)2(HexNAc)2(Deoxyhexose)1+(Man)3(GlcNAc)2, in primary tumour with associated lymph node metastasis. In summary, N-linked glycan MALDI MSI can be used to differentiate cancerous endometrium from normal, and endometrial cancer with LNM from endometrial cancer without.
    Matched MeSH terms: Formaldehyde
  19. Mohamad A, Zamri-Saad M, Amal MNA, Al-Saari N, Monir MS, Chin YK, et al.
    Vaccines (Basel), 2021 Apr 10;9(4).
    PMID: 33920311 DOI: 10.3390/vaccines9040368
    Multiple infections of several bacterial species are often observed under natural farm conditions. The infections would cause a much more significant loss compared to a single infectious agent. Vaccination is an essential strategy to prevent diseases in aquaculture, and oral vaccination has been proposed as a promising technique since it requires no handling of the fish and is easy to perform. This research attempts to develop and evaluate a potential feed-based polyvalent vaccine that can be used to treat multiple infections by Vibrios spp., Streptococcus agalactiae, and Aeromonas hydrophila, simultaneously. The oral polyvalent vaccine was prepared by mixing formalin-killed vaccine of V. harveyi, S. agalactiae, and A. hydrophila strains with commercial feed pellet, and palm oil as an adjuvant was added to improve their antigenicity. Thereafter, a vaccinated feed pellet was tested for feed quality analysis in terms of feed stability in water, proximate nutrient analysis, and palatability, safety, and growth performance using Asian seabass, Lates calcarifer as a fish host model. For immune response analysis, a total of 300 Asian seabass juveniles (15.8 ± 2.6 g) were divided into two groups in triplicate. Fish of group 1 were not vaccinated, while group 2 was vaccinated with the feed-based polyvalent vaccine. Vaccinations were carried out on days 0 and 14 with oral administration of the feed containing the bacterin at 5% body weight. Samples of serum for antibody and lysozyme study and the spleen and gut for gene expression analysis were collected at 7-day intervals for 6 weeks. Its efficacy in protecting fish was evaluated in aquarium challenge. Following vaccination by the polyvalent feed-based vaccine, IgM antibody levels showed a significant (p < 0.05) increase in serum against Vibrio harveyi, Aeromonas hydrophila, and Streptococcus agalactiae and reached the peak at week 3, 5, and 6, respectively. The high-stimulated antibody in the serum remained significantly higher than the control (p < 0.05) at the end of the 6 weeks vaccination trial. Not only that, but the serum lysozyme level was also increased significantly at week 4 (p < 0.05) as compared to the control treatment. The immune-related gene, dendritic cells, C3, Chemokine ligand 4 (CCL4), and major histocompatibility complex class I (MHC I) showed significantly higher expression (p < 0.05) after the fish were vaccinated with the oral vaccine. In the aquarium challenge, the vaccine provided a relative percentage survival of 75 ± 7.1%, 80 ± 0.0%, and 80 ± 0.0% after challenge with V. harveyi, A. hydrophila, and S. agalactiae, respectively. Combining our results demonstrate that the feed-based polyvalent vaccine could elicit significant innate and adaptive immunological responses, and this offers an opportunity for a comprehensive immunization against vibriosis, streptococcosis, and motile aeromonad septicemia in Asian seabass, Lates calcarifer. Nevertheless, this newly developed feed-based polyvalent vaccination can be a promising technique for effective and large-scale fish immunization in the aquaculture industry shortly.
    Matched MeSH terms: Formaldehyde
  20. Mohamed Kamel Abd. Ghani, Anisah Hj. Musa
    Jurnal Sains Kesihatan Malaysia, 2018;16(101):89-93.
    MyJurnal
    Giardia intestinalis is among the protozoa that is commonly found in the human fecal samples throughout the world. The prevalence of infection is higher among people living in developing countries than developed countries. One hundred and eleven Orang Asli children at Pos Titom, Pahang participated in this study. The prevalence study was conducted in accordance to gender, age groups and the diagnostic techniques employed. Fecal samples were collected and examined for the presence of G. intestinalis using three diagnostic techniques ie; the direct fecal smear, formalin-ether concentration and the trichrome staining technique. The overall prevalence of G. intestinalis infection among Orang Asli children at Pos Titom was 23.42%. The infection was higher among females (25%) as compared to males (21.57%) eventhough it was not statistically significant (p > 0.05). In terms of age groups, no positive case was observed among preschoolers whose age were below seven-years while the school aged children (7 to 12-years old) showed 24.53% infection. The trichrome staining technique was the most sensitive with a detection rate of 22.52% followed by the formalin-ether concentration technique with a detection of 19.82% whilst the direct smear technique only detected 12.61% of cases. The prevalence of giardiasis amongst the Orang Asli children at Pos Titom, Pahang was still high despite various efforts made and improvements in basic infrastructural facilities undertaken for their community. The health care status and personal hygiene of Orang Asli children remains poor and needs to be further improved.
    Matched MeSH terms: Formaldehyde
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