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Alterations in mucin type: an indicator for suspicion of malignant gastric transformation

Cheah PL, Ramachandran K

Malays J Pathol, 1994 Jun;16(1):39-42.
PMID: 16329574

Mucins are produced by both benign and malignant gastric epithelium. In general, mucins can be classified into neutral and acidic mucins. The latter are of 2 major types, sulphated (sulphomucins) and carboxylated (sialomucins). A retrospective study was initiated at the Department of Pathology, University Hospital, Kuala Lumpur to histochemically study the mucin profiles of cases of intestinal (IGC) and diffuse (DGC) types of gastric carcinoma in Malaysian patients to determine whether a significant change of mucin type occurs in the event of malignant transformation. 42 IGC and 37 DGC were subjected to alcian blue-periodic acid Schiff and high iron diamine-alcian blue histochemical staining. In addition, 18 cases of gastrectomies performed for benign lesions in the stomach served as normal controls. The number of cases of IGC and DGC which exhibited sulphomucin production was significantly increased (p < 0.001) compared to normal controls. Also, the number of cases of DGC which produced neutral mucin were significantly less (p < 0.05) than the control group. However, there was no significant difference between the number of IGC and DGC cases which demonstrated sialomucin production and normal controls. It appears that while not pathognomonic, a lack of neutral mucin production should alert the pathologist to the possibility of a gastric malignancy, in particular DGC. The likelihood of a malignant lesion would be further supported if there is an increased sulphomucin production.
Amplifying the manganese scavenging potential of Streptococcus zooepidemicus to reactive oxygen species during production of hyaluronic acid

Mashitah MD, Masitah H, Ramachandran KB

Med J Malaysia, 2004 May;59 Suppl B:59-60.
PMID: 15468818

Streptococcus zooepidemicus (SZ) is an aerotolerant bacteria and its ability to survive under reactive oxidant challenge raises the question of the existence of a defense system. Thus growth, hyaluronic acid (HA) and hydrogen peroxide (H2O2) production by SZ in the presence of increasing concentration of Mn2+ were studied. The results suggested that the tested strain supported growth and HA production in cultures treated with 1 and 10 mM of Mn2+ regardless of H2O2 presence in the medium. This showed that SZ have acquired elaborate defense mechanisms to scavenge oxygen toxicity and thus protect cells from direct and indirect effect of this radical. In contrast, cells treated with 25 mM Mn2+ were sensitive, in which, the HA production was reduced considerably. Thus showing that the oxygen scavenger systems of the cells may be fully saturated at this concentration.
Studies on the kinetics of Isopropyl Palmitate synthesis in packed bed bioreactor using immobilized lipase

Kee CY, Hassan M, Ramachandran KB

Artif Cells Blood Substit Immobil Biotechnol, 1999 Sep-Nov;27(5-6):393-8.
PMID: 10595438

The objective of this research was to study the kinetics of synthesis of a commercially important ester - Isopropyl Palmitate (IPP) using immobilized lipase (Lipozyme IM). It was studied in a packed bed differential reactor. In order to establish the kinetics of the reaction, parameters such as linear velocity of the fluid through the reactor, particle size, substrate concentration, substrate molar ratio, temperature and water activity were studied. Operational and storage stability of the enzyme were also assessed. The reaction followed Michaelis-Menton kinetics as observed from the relationship of initial rate of the reaction as a function of substrate concentration. It was found that the optimum substrate concentration was 0.15M palmitic acid and isopropyl alcohol in 1:1 stoichiometric ratio. Inhibition by excess of isopropyl alcohol has been identified. The optimum temperature for the esterification reaction was found to be around 50 degrees C. The activation energy of this process was determined to be 43.67 kJ/mol. The optimum water content was 0.50%. The reaction rates were measured in the absence of any significant external diffusional limitations. Since internal diffusional limitations could not be eliminated, the kinetics observed is only apparent.
Fulltext Motivators and barriers to the acceptability of a human milk bank among Malaysians

Ramachandran K, Dahlui M, Nik Farid ND

PLoS One, 2024;19(3):e0299308.
PMID: 38437241 DOI: 10.1371/journal.pone.0299308

The World Health Organisation (WHO) recommends that all babies be exclusively breastfed, stating that donor milk is the next best alternative in the absence of the mother's own milk. Milk sharing takes many forms, namely wet nursing, co-feeding, cross-feeding, and a human milk bank (HMB). However, the establishment of a human milk bank is still not widely accepted and is a debatable topic because of religious concerns in Malaysia. The aim of this study is to determine the facilitators and barriers among Malaysians towards the acceptance of an HMB. A cross-sectional study with 367 participants was conducted; the participants answered an online-validated, self-administered questionnaire. Data on sociodemographic, knowledge on breastfeeding benefits, knowledge and attitude on HMB-specific issues were analysed in terms of frequency before proceeded with multiple logistic regression. The majority of the respondents were Muslim (73.3%), had completed their tertiary education (82.8%), and were employed (70.8%). Only 55.9% of respondents had heard of HMB, stating the internet as their main source of information, but many respondents were agreeable to its establishment (67.8%). Most respondents had a good score on knowledge of breastfeeding benefits and on HMB-specific issues (70% and 54.2%, respectively), while 63.8% had a positive attitude towards HMB. In the multivariate analysis, mothers with a good score on general knowledge of breastfeeding (AOR: 1.715; 95% CI 1.047-2.808) were more likely to accept the establishment of HMB, while being a Muslim was negatively associated with its establishment (AOR = 0.113, 95% CI 0.050-0.253). The study found a high prevalence of mothers who were willing to accept the establishment of HMB. By educating mothers on the benefits of breastfeeding, as well as addressing their religious concerns, the establishment of a religiously abiding HMB in Malaysia may be accepted without compromising their beliefs or the health benefit of donor milk.
Rhodovulum sulfidophilum in the treatment and utilization of sardine processing wastewater

Azad SA, Vikineswary S, Chong VC, Ramachandran KB

Lett Appl Microbiol, 2004;38(1):13-8.
PMID: 14687209

Rhodovulum sulfidophilum was grown in settled undiluted and nonsterilized sardine processing wastewater (SPW). The aims were to evaluate the effects of inoculum size and media on the biomass production with simultaneous reduction of chemical oxygen demand (COD).
Growth and production of biomass of Rhodovulum sulfidophilum in sardine processing wastewater

Azad SA, Vikineswary S, Ramachandran KB, Chong VC

Lett Appl Microbiol, 2001 Oct;33(4):264-8.
PMID: 11559398

AIMS: Rhodovulum sulfidophilum was grown in sardine processing wastewater to assess growth characteristics for the production of bacterial biomass with simultaneous reduction of chemical oxygen demand.
METHODS AND RESULTS: Growth characteristics were compared in diluted and undiluted, settled and non-settled wastewater growing in anaerobic light and aerobic dark conditions; and also at different agitation speeds. The highest biomass (8.75 g l(-1)) and a reduction in chemical oxygen demand of 71% were obtained in unsettled, undiluted wastewater after 120 h culture with 15% inoculum. In settled wastewater, highest biomass (7.64 g l(-1)) and a COD reduction of 77% was also obtained after 120 h. Total biomass was higher (4.34 g l(-1)) after 120 h culture in anaerobic light compared to (3.23 g l(-1)) in aerobic dark growth.
CONCLUSIONS, SIGNIFICANCE AND IMPACT OF THE STUDY: Better performance, mean of total biomass (6.97 g l(-1) after 96 h), total carotenoids (4.24 mg g(-1) dry cell from 24 h) and soluble protein (431 microg ml(-1) after 96 h) were obtained from aerobic dark culture at 300 rev min(-1). The COD reduction, however, was lower (69%) after 96 h culture. Thus, the benefits in the production of bacterial biomass in non-sterilized sardine processing wastewater with the reduction of chemical oxygen demand could be achieved.
Fluorescence-based immunoassay for the detection of Xanthomonas oryzae pv. oryzae in rice leaf

Awaludin N, Abdullah J, Salam F, Ramachandran K, Yusof NA, Wasoh H

Anal Biochem, 2020 12 01;610:113876.
PMID: 32750357 DOI: 10.1016/j.ab.2020.113876

The identification of rice bacterial leaf blight disease requires a simple, rapid, highly sensitive, and quantitative approach that can be applied as an early detection monitoring tool in rice health. This paper highlights the development of a turn-off fluorescence-based immunoassay for the early detection of Xanthomonas oryzae pv. oryzae (Xoo), a gram-negative bacterium that causes rice bacterial leaf blight disease. Antibodies against Xoo bacterial cells were produced as specific bio-recognition molecules and the conjugation of these antibodies with graphene quantum dots and gold nanoparticles was performed and characterized, respectively. The combination of both these bio-probes as a fluorescent donor and metal quencher led to changes in the fluorescence signal. The immunoreaction between AntiXoo-GQDs, Xoo cells, and AntiXoo-AuNPs in the immuno-aggregation complex led to the energy transfer in the turn-off fluorescence-based quenching system. The change in fluorescence intensity was proportional to the logarithm of Xoo cells in the range of 100-105 CFU mL-1. The limit of detection was achieved at 22 CFU mL-1 and the specificity test against other plant disease pathogens showed high specificity towards Xoo. The detection of Xoo in real plant samples was also performed in this study and demonstrated satisfactory results.
Fulltext Introgression of bacterial leaf blight (BLB) resistant gene, Xa7 into MARDI elite variety, MR219 by marker assisted backcrossing (MABC) approach

Yazid SN, Ahmad K, Razak MSFA, Rahman ZA, Ramachandran K, Mohamad SNA, et al.

Braz J Biol, 2021;84:e248359.
PMID: 34730685 DOI: 10.1590/1519-6984.248359

Bacterial leaf blight (BLB) is one of the major rice diseases in Malaysia. This disease causes substantial yield loss as high as 70%. Development of rice varieties which inherited BLB resistant traits is a crucial approach to promote and sustain rice industry in Malaysia. Hence, this study aims were to enhance BLB disease resistant characters of high yielding commercial variety MR219 through backcross breeding approach with supporting tool of marker-assisted selection (MAS). Broad spectrum BLB resistance gene, Xa7 from donor parent IRBB7 were introgressed into the susceptible MR219 (recurrent parent) using two flanking markers ID7 and ID15. At BC3F4, we managed to generate 19 introgressed lines with homozygous Xa7 gene and showed resistant characteristics as donor parent when it was challenged with Xanthomonas oryzae pv. oryzae through artificial inoculation. Recurrent parent MR219 and control variety, MR263 were found to be severely infected by the disease. The improved lines exhibited similar morphological and yield performance characters as to the elite variety, MR219. Two lines, PB-2-107 and PB-2-34 were chosen to be potential lines because of their outstanding performances compared to parent, MR219. This study demonstrates a success story of MAS application in development of improved disease resistance lines of rice against BLB disease.
Fulltext Microstructural and mechanical behaviours of Y-TZP prepared via slip-casting and fused deposition modelling (FDM)

Gnanasagaran CL, Ramachandran K, Jamadon NH, Kumar VH, Muchtar A, Pazhani A, et al.

Heliyon, 2023 Nov;9(11):e21705.
PMID: 37954343 DOI: 10.1016/j.heliyon.2023.e21705

This paper reports the microstructural characteristics and mechanical properties of yttria-stabilized zirconia prepared via fused deposition modelling and slip casting. X-Ray Diffraction peaks indicated that yttria-stabilized zirconia crystallized in tetragonal structure for both slip casted(SC) and fused deposition modelled(FDM) samples. Further, scanning electron microscopy of slip casted sample showcased closely packed structure with fine grains and an average grain size of ∼65 nm whilst fused deposition modelled samples showcased non-homogeneous pores with ∼20 nm grain size. Average relative density of slip casted samples was ∼99.4 % while that of fused deposition modelled sample exhibited ∼96.2 %. The Vickers Hardness of slip casted (∼15.26 ± 0.4 GPa) was ∼10 % higher than the fused deposition modelled samples (∼13.79 ± 0.3 GPa). Likewise, indentation fracture toughness of slip casted (5.78 ± 0.5 MPa m1/2) was 14 % higher than fused deposition modelled samples which could have been due to the change in grain size as well as porosity of the ceramics. Compressive strength of the fused deposition modelled samples was 32 % less than slip casted samples (∼510 ± 10 MPa) due to its non-homogenous pores which led to weakening van der Waals force of attraction.
Fulltext A Rare Case of Cerebrospinal Fluid Rhinorrhea from Canal of Stenberg

Ngu CYV, Lee TH, Ramachandran K, Liew DNS, Tang IP

Indian J Otolaryngol Head Neck Surg, 2023 Apr;75(Suppl 1):764-767.
PMID: 37206705 DOI: 10.1007/s12070-022-03347-z

Background: A spontaneous cerebrospinal leak from Sternberg's canal with meningoencephalocele is a very rare clinical entity. Endoscopic repair of the defect is challenging and crucial in identifying the defect. The aim of this case report is to highlight the presence and management with endoscopic surgery in repairing Sternberg canal. Case: 40-year-old woman presents with spontaneous CSF rhinorrhea with no predisposing factors. CT imaging and MRI showed osteodural defect in the lateral recess of sphenoid with meningoencephalocoele lateral to the foramen rotundum. Endoscopic transethmoidal - transphenoidal - transpterygoid approach was used to repair the defect, and patient is well post-operative with least complication from the intervention surgery. Conclusion: Endoscopic approach proved to be the best and safest method in localizing the defect and closure of the leak. Angled scopes and image guided system were used to identify the precise location of the leak.
SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s12070-022-03347-z.
A 4-year review of surgical and oncological outcomes of endoscopic endonasal transpterygoid nasopharyngectomy in salvaging locally recurrent nasopharyngeal carcinoma

Tang IP, Ngui LX, Ramachandran K, Lim LY, Voon PJ, Yu KL, et al.

Eur Arch Otorhinolaryngol, 2019 Sep;276(9):2475-2482.
PMID: 31227870 DOI: 10.1007/s00405-019-05522-5

PURPOSE: To study the surgical and oncological outcomes of endoscopic endonasal transpterygoid nasopharyngectomy (EETN) in salvaging locally recurrent nasopharyngeal carcinoma (NPC).
METHOD: This was a retrospective clinical record review study carried out at a tertiary centre from June 2013 until May 2017. A total of 55 locally recurrent NPC patients (rT1-rT4) underwent EETN performed by single skull base surgeon with curative intention with postoperative adjuvant chemotherapy but without postoperative radiotherapy.
RESULTS: There were 44 (80.0%) males and 11 (20.0%) females, with mean age of 52.5 years. The mean operating time was 180 min (range 150-280 min). 85% (47/55) of patients achieved en bloc tumour resection. 93% (51/55) of patients obtained negative microscopic margin based on postoperative histopathological evaluation. Intraoperatively, one (1.8%) patient had internal carotid artery injury which was successfully stented and had recovered fully without neurological deficit. There were no major postoperative complications reported. During a mean follow-up period of 18-month (range 12-48 months) postsurgery, five patients (9.1%) had residual or recurrence at the primary site. All five patients underwent re-surgery. One patient at rT3 passed away 6 months after re-surgery due to distant metastasis complicated with septicaemia. The 1-year local disease-free rate was 93% and the 1-year overall survival rate was 98%.
CONCLUSIONS: EETN is emerging treatment options for locally recurrent NPC, with relatively low morbidity and encouraging short-term outcome. Long-term outcome is yet to be determined with longer follow-up and bigger cohort study. However, a successful surgical outcome required a very experienced team and highly specialised equipment.

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