Displaying publications 41 - 60 of 131 in total

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  1. Subramaniam S, Raman J, Sabaratnam V, Heng CK, Kuppusamy UR
    Int J Med Mushrooms, 2017;19(10):849-859.
    PMID: 29256840 DOI: 10.1615/IntJMedMushrooms.2017024355
    This study was conducted to evaluate the mycochemical composition and antiglycemic and antioxidant activities of Ganoderma neo-japonicum hot aqueous extracts, prepared at different boiling durations, and polysaccharides isolated from them. Ground basidiocarps of G. neo-japonicum were double-boiled at 100°C for 0.5, 3, or 4 hours, and the antiglycemic activity was assessed by α-amylase and α-glucosidase enzyme inhibition assays. The antioxidant capacity of the crude hot aqueous extracts (AE-1, AE-2, AE-3) was assessed by DPPH and ABTS radical scavenging and ferric-reducing antioxidant power assays. The total phenolics, protein, and sugar in the crude extracts were also determined. The hot aqueous extract (AE-3) containing a significant amount of total sugar and having enhanced antiglycemic and antioxidant activities was selected for polysaccharide isolation. The isolated crude polysaccharide was separated and purified using diethylaminoethyl-cellulose-52 and Sepharose 6B column chromatography. Fourier transform infrared spectroscopy studies of the purified polysaccharide fraction (PF) showed the presence of typical bands corresponding to polysaccharides. The estimated β-glucan concentration in the PF was 39.26%. In general, the PF exhibited significantly lower antioxidant activity than AE-3. Nevertheless, its potency in inhibiting carbohydratehydrolyzing enzymes may have potential in the management of diabetes mellitus.
  2. Subramaniam S, Sabran MR, Stanslas J, Kirby BP
    Front Nutr, 2022;9:1032810.
    PMID: 36466381 DOI: 10.3389/fnut.2022.1032810
    While it is well documented that aflatoxin B1 (AFB1); one of the most toxic food contaminants is linked to the development of depression. However, the mechanism on how it affects the gut and brain health leading to depressive-like behavior remains unclear. This study was conducted to determine the effect of AFB1 on the progression of depressive-like behavior. Thirty-two (n = 32) male Sprague Dawley rats were randomly allocated into four groups: control, low-dose (5 μg AFB1/kg), high-dose (25 μg AFB1/kg) and positive control group; exposed on chronic unpredictable mild stress (CUMS). After 4 weeks of exposure, sucrose preference test (SPT) and force swim test (FST) were used to measure behavioral despair. Fecal samples were selectively cultured to profile the bacteria. Body weight and relative organs weights were compared among groups. AFB1 and CUMS caused reduction in body weight and food intake as well as increased relative weight of adrenal glands, liver, and brain. Rats in AFB1 and CUMS groups had suppressed sucrose preference and prolonged immobility time in FST, wherein this could indicate anhedonia. Besides, fecal count of Lactobacillus spp. was significantly low following AFB1 exposure, with increasing count of Bifidobacterium spp, in comparison to the control. Indeed, further biochemical analysis and metagenomic approach are warranted to explore the underlying mechanisms on the role of gut microbiota dysbiosis and dysregulation of gut-brain axis due to AFB1 neurotoxicity on the progression of depressive-like behavior.
  3. Subramaniam S, Chan CY, Soelaiman IN, Mohamed N, Muhammad N, Ahmad F, et al.
    PMID: 32272697 DOI: 10.3390/ijerph17072526
    Background: The current osteoporosis screening instruments are not optimized to be used among the Malaysian population. This study aimed to develop an osteoporosis screening algorithm based on risk factors for Malaysians. Methods: Malaysians aged ≥50 years (n = 607) from Klang Valley, Malaysia were interviewed and their bone health status was assessed using a dual-energy X-ray absorptiometry device. The algorithm was constructed based on osteoporosis risk factors using multivariate logistic regression and its performance was assessed using receiver operating characteristics analysis. Results: Increased age, reduced body weight and being less physically active significantly predicted osteoporosis in men, while in women, increased age, lower body weight and low-income status significantly predicted osteoporosis. These factors were included in the final algorithm and the optimal cut-offs to identify subjects with osteoporosis was 0.00120 for men [sensitivity 73.3% (95% confidence interval (CI) = 54.1%-87.7%), specificity 67.8% (95% CI = 62.7%-85.5%), area under curve (AUC) 0.705 (95% CI = 0.608-0.803), p < 0.001] and 0.161 for women [sensitivity 75.4% (95% CI = 61.9%-73.3%), specificity 74.5% (95% CI = 68.5%-79.8%), AUC 0.749 (95% CI = 0.679-0.820), p < 0.001]. Conclusion: The new algorithm performed satisfactorily in identifying the risk of osteoporosis among the Malaysian population ≥50 years. Further validation studies are required before applying this algorithm for screening of osteoporosis in public.
  4. Subramaniam S, Chan CY, Soelaiman IN, Mohamed N, Muhammad N, Ahmad F, et al.
    Diagnostics (Basel), 2020 Mar 25;10(4).
    PMID: 32218298 DOI: 10.3390/diagnostics10040178
    BACKGROUND: Calcaneal quantitative ultrasound (QUS) is widely used in osteoporosis screening, but the cut-off values for risk stratification remain unclear. This study validates the performance of a calcaneal QUS device (CM-200) using dual-energy X-ray absorptiometry (DXA) as the reference and establishes a new set of cut-off values for CM-200 in identifying subjects with osteoporosis.

    METHODS: The bone health status of Malaysians aged ≥40 years was assessed using CM-200 and DXA. Sensitivity, specificity, area under the curve (AUC) and the optimal cut-off values for risk stratification of CM-200 were determined using receiver operating characteristic (ROC) curves and Youden's index (J). Results: From the data of 786 subjects, CM-200 (QUS T-score 0.05). Modified cut-off values for the QUS T-score improved the performance of CM-200 in identifying subjects with osteopenia (sensitivity 67.7% (95% CI: 62.8-72.3%); specificity 72.8% (95% CI: 68.1-77.2%); J = 0.405; AUC 0.702 (95% CI: 0.666-0.739); p < 0.001) and osteoporosis (sensitivity 79.4% (95% CI: 70.0-86.9%); specificity 61.8% (95% CI: 58.1-65.5%); J = 0.412; AUC 0.706 (95% CI: 0.654-0.758); p < 0.001). Conclusion: The modified cut-off values significantly improved the performance of CM-200 in identifying individuals with osteoporosis. Since these values are device-specific, optimization is necessary for accurate detection of individuals at risk for osteoporosis using QUS.

  5. Subramaniam S, Ong KC, Sabaratnam V, Chua KH, Kuppusamy UR
    Int J Med Mushrooms, 2023;25(4):27-42.
    PMID: 37075082 DOI: 10.1615/IntJMedMushrooms.2023047595
    Ganoderma neo-japonicum Imazeki is a medicinal mushroom consumed by the indigenous people in Malaysia as a remedy for diabetes. This study aims to validate the efficacy of G. neo-japonicum polysaccharides (GNJP) on obesity-induced type 2 diabetes mellitus (T2DM) in C57BL/6J mice. Mice were divided into seven groups; normal diet (ND)-control, high-fat-diet (HFD)-control, HFDGNJP-treated (50, 100, 200 mg/kg b.w.), HFDMET (metformin 50 mg/kg; positive-control) and ND-GNJP (200 mg/kg b.w.). Mice were administered GNJP or metformin orally for 10 weeks (thrice/week) and sacrificed after an oral glucose tolerance test. Body weight, serum biochemicals, liver histology, adipocyte gene expressions, glucose and insulin levels were measured. HFD caused obesity, dyslipidemia, and diabetes in the untreated groups. GNJP (50 mg/kg b.w.) supplementation prevented weight gain and liver steatosis, improved serum lipid profile and glucose tolerance and attenuated hyperglycemia and hyperinsulinemia more effectively when compared with the other treatment groups. The prevention of obesity and lipid dysregulation is plausibly attributed to the increased hormone-sensitive lipase and reduced Akt-1 and Ppary gene expressions while the up-regulation of AdipoQ (adiponectin), Prkag2 and Slc2a4 genes served to sensitize insulin and improve glucose uptake. Thus, supplementation with an appropriate dose of GNJP has promising efficacies in preventing HFD aka obesity-induced T2DM and associated metabolic abnormalities.
  6. Subramaniam S, Ima-Nirwana S, Chin KY
    PMID: 29987247 DOI: 10.3390/ijerph15071445
    Bone health screening plays a vital role in the early diagnosis and treatment of osteoporosis to prevent fragility fractures among the elderly and high-risk individuals. Dual-energy X-ray absorptiometry (DXA), which detects bone mineral density, is the gold standard in diagnosing osteoporosis but is not suitable for screening. Therefore, many screening tools have been developed to identify individuals at risk for osteoporosis and prioritize them for DXA scanning. The Osteoporosis Self-assessment Tool (OST) is among the first tools established to predict osteoporosis in postmenopausal women. It can identify the population at risk for osteoporosis, but its performance varies according to ethnicity, gender, and age. Thus, these factors should be considered to ensure the optimal use of OST worldwide. Overall, OST is a simple and economical screening tool to predict osteoporosis and it can help to optimize the use of DXA.
  7. Subramaniam S, Min Tet C, Hazabbah Wan Hitam W, Hussein A, Ahmed Khan S, Kanti Pal H, et al.
    Int J Ophthalmol, 2011;4(1):112-4.
    PMID: 22553623 DOI: 10.3980/j.issn.2222-3959.2011.01.26
    A 60 year-old man presented with acute on set of left eye proptosis and ptosis. It was associated with poor vision, eye pain and restriction of eye movement of the same eye after 5 hours post left upper molar tooth extraction. The visual acuity in the left eye was hand movement. There was severe ptosis and proptosis of the left eye. The conjunctiva was chemotic with quite anterior chamber. The pupil was mid dilated and sluggished to light. The ocular movement was restricted in all directions. Fundoscopy of the left eye revealed features of central retinal artery occlusion with hyperaemic disc and subretinal exudates at posterior pole. The right eye appeared normal. Urgent MRI brain and orbit revealed severe left paranasal sinusitis with anterior displacement of the left globe and presence orbital abscess. Patient was managed with Otorhinolaryngology and Neurosurgery teams. He underwent emergency transnasal drainage of abscess. Histopathological examination of unhealthy sinus mucosa showed evidence of fungal infection. However, the culture and sensitivity result was inconclusive. Patient was treated with amphotericin B, ceftriaxone, amoxicillin clavulanate and metronidazole. Patient was detected to have high blood sugar level and was managed accordingly. The proptosis improved with treatment. However, his vision, ptosis and ophthalmoplegia remained static. Assessing the immunocompromised status is important for the management of patient presented as acute orbital apex syndrome to avoid fatal outcome.
  8. Soo Yean CY, Selva Raju K, Xavier R, Subramaniam S, Gopinath SC, Chinni SV
    PLoS One, 2016;11(7):e0158736.
    PMID: 27367909 DOI: 10.1371/journal.pone.0158736
    Non-protein coding RNA (npcRNA) is a functional RNA molecule that is not translated into a protein. Bacterial npcRNAs are structurally diversified molecules, typically 50-200 nucleotides in length. They play a crucial physiological role in cellular networking, including stress responses, replication and bacterial virulence. In this study, by using an identified npcRNA gene (Sau-02) in Methicillin-resistant Staphylococcus aureus (MRSA), we identified the Gram-positive bacteria S. aureus. A Sau-02-mediated monoplex Polymerase Chain Reaction (PCR) assay was designed that displayed high sensitivity and specificity. Fourteen different bacteria and 18 S. aureus strains were tested, and the results showed that the Sau-02 gene is specific to S. aureus. The detection limit was tested against genomic DNA from MRSA and was found to be ~10 genome copies. Further, the detection was extended to whole-cell MRSA detection, and we reached the detection limit with two bacteria. The monoplex PCR assay demonstrated in this study is a novel detection method that can replicate other npcRNA-mediated detection assays.
  9. Salman OH, Rasid MF, Saripan MI, Subramaniam SK
    J Med Syst, 2014 Sep;38(9):103.
    PMID: 25047520 DOI: 10.1007/s10916-014-0103-4
    The healthcare industry is streamlining processes to offer more timely and effective services to all patients. Computerized software algorithm and smart devices can streamline the relation between users and doctors by providing more services inside the healthcare telemonitoring systems. This paper proposes a multi-sources framework to support advanced healthcare applications. The proposed framework named Multi Sources Healthcare Architecture (MSHA) considers multi-sources: sensors (ECG, SpO2 and Blood Pressure) and text-based inputs from wireless and pervasive devices of Wireless Body Area Network. The proposed framework is used to improve the healthcare scalability efficiency by enhancing the remote triaging and remote prioritization processes for the patients. The proposed framework is also used to provide intelligent services over telemonitoring healthcare services systems by using data fusion method and prioritization technique. As telemonitoring system consists of three tiers (Sensors/ sources, Base station and Server), the simulation of the MSHA algorithm in the base station is demonstrated in this paper. The achievement of a high level of accuracy in the prioritization and triaging patients remotely, is set to be our main goal. Meanwhile, the role of multi sources data fusion in the telemonitoring healthcare services systems has been demonstrated. In addition to that, we discuss how the proposed framework can be applied in a healthcare telemonitoring scenario. Simulation results, for different symptoms relate to different emergency levels of heart chronic diseases, demonstrate the superiority of our algorithm compared with conventional algorithms in terms of classify and prioritize the patients remotely.
  10. Rohaizam J, Subramaniam SK, Vikneswaran T, Tan VE, Tan TY
    Med J Malaysia, 2009 Sep;64(3):213-5.
    PMID: 20527270 MyJurnal
    Shifting the paradigm of treatment of a locally recurrent nasopharyngeal carcinoma (NPC) from the non-surgical management to a surgical modality has always been a challenge. However, many studies on endoscopic nasopharyngectomy have proven it to be a reliable form of treatment with an excellent outcome. Since 2007, in Sarawak General Hospital, six cases of endoscopic nasopharyngectomy for locally recurrent NPC have been performed with encouraging results.
  11. Repici A, Khalaf K, Troncone E, Subramaniam S, Hassan C, Bhandari P, et al.
    Dig Liver Dis, 2024 Feb;56(2):322-329.
    PMID: 37558571 DOI: 10.1016/j.dld.2023.07.026
    BACKGROUND/OBJECTIVE: Increasing infectious rate estimates and low microbiological surveillance affect safety of gastrointestinal endoscopy globally. Single use endoscopes and accessories have been claimed to improve safety, but there is lack of data on their indication and sustainability. We aimed to identify a series of best practice recommendations for the use of single use endoscopes and accessories using a modified Delphi.

    METHODS/DESIGN: Consensus statements for the use of single use endoscopy and accessories were developed using a modified Delphi process, utilizing an international endoscopist expert panel of 62 experts from 33 nations. The main steps in the process were selecting the consensus group, conducting systematic literature reviews, developing statements, and anonymous voting on the statements until consensus was reached. High-risk patients were defined as those with multi-drug-resistant infections, immunosuppressive medication or chemotherapy, post-transplantation, or with severe neutropenia.

    RESULTS: Of the 26 statements that were voted upon through two rounds, 17 statements reached consensus. Category 1: single use accessories (8 statements), related to defining recommendations for the use of single use accessories in all patient populations or high-risk patients. Category 2: clinical indication for single use endoscopes (9 statements), including indications to high-risk patients, protecting the endoscope apparatus and contamination measures in endoscopy units. Category 3: technical factors (4 statements), related to superior performance and technical specifications with the new innovation. Category 4: environmental issues (2 statements), concerning mechanisms that reduce the detrimental burden to the environment. Category 5: financial implications (3 statements), related to healthcare policies, cost neutrality and other financial associations of single use endoscopy.

    CONCLUSIONS: This is the first international initiative in determining clinical indications for single use endoscopy and accessories. The study's findings should serve as a framework for future physicians to guide future research and aid the proper evidence-based indications for the implementation of single use endoscopes in clinical practice.

  12. Ramlal A, Bhat I, Nautiyal A, Baweja P, Mehta S, Kumar V, et al.
    Front Physiol, 2023;14:1172684.
    PMID: 37324400 DOI: 10.3389/fphys.2023.1172684
    Cardiovascular diseases (CVDs) are one of the major reasons for deaths globally. The renin-angiotensin-aldosterone system (RAAS) regulates body hypertension and fluid balance which causes CVD. Angiotensin-converting enzyme I (ACE I) is the central Zn-metallopeptidase component of the RAAS playing a crucial role in maintaining homeostasis of the cardiovascular system. The available drugs to treat CVD have many side effects, and thus, there is a need to explore phytocompounds and peptides to be utilized as alternative therapies. Soybean is a unique legume cum oilseed crop with an enriched source of proteins. Soybean extracts serve as a primary ingredient in many drug formulations against diabetes, obesity, and spinal cord-related disorders. Soy proteins and their products act against ACE I which may provide a new scope for the identification of potential scaffolds that can help in the design of safer and natural cardiovascular therapies. In this study, the molecular basis for selective inhibition of 34 soy phytomolecules (especially of beta-sitosterol, soyasaponin I, soyasaponin II, soyasaponin II methyl ester, dehydrosoyasaponin I, and phytic acid) was evaluated using in silico molecular docking approaches and dynamic simulations. Our results indicate that amongst the compounds, beta-sitosterol exhibited a potential inhibitory action against ACE I.
  13. Rahmah S, Ahmad Mubbarakh S, Soo Ping K, Subramaniam S
    ScientificWorldJournal, 2015;2015:961793.
    PMID: 25861687 DOI: 10.1155/2015/961793
    Protocorm-like bodies (PLBs) of Brassidium Shooting Star orchid were successfully cryopreserved using droplet-vitrification method. Vitrification based cryopreservation protocol is comprised of preculture, osmoprotection, cryoprotection, cooling, rewarming, and growth recovery and each and every step contributes to the achievement of successful cryopreservation. In order to reveal the lethal and nonlethal damage produced by cryopreservation, histological observation, scanning electron microscopy (SEM), and biochemical analysis were carried out in both cryopreserved and noncryopreserved PLBs of Brassidium Shooting Star orchid comparing with the control PLBs stock culture. Histological and scanning electron microscopy analyses displayed structural changes in cryopreserved PLBs due to the impact of cryoinjury during exposure to liquid nitrogen. Total soluble protein significantly increased throughout the dehydration process and the highest value was achieved when PLBs were stored in liquid nitrogen. Ascorbate peroxidase (APX) and catalase (CAT) showed the highest enzyme activities in both dehydration and cryostorage treatments indicating that stress level of PLBs was high during these stages.
  14. Qadori HQ, Zulkarnain ZA, Hanapi ZM, Subramaniam S
    Sensors (Basel), 2017 Jun 03;17(6).
    PMID: 28587187 DOI: 10.3390/s17061280
    Mobile agent (MA), a part of the mobile computing paradigm, was recently proposed for data gathering in Wireless Sensor Networks (WSNs). The MA-based approach employs two algorithms: Single-agent Itinerary Planning (SIP) and Multi-mobile agent Itinerary Planning (MIP) for energy-efficient data gathering. The MIP was proposed to outperform the weakness of SIP by introducing distributed multi MAs to perform the data gathering task. Despite the advantages of MIP, finding the optimal number of distributed MAs and their itineraries are still regarded as critical issues. The existing MIP algorithms assume that the itinerary of the MA has to start and return back to the sink node. Moreover, each distributed MA has to carry the processing code (data aggregation code) to collect the sensory data and return back to the sink with the accumulated data. However, these assumptions have resulted in an increase in the number of MA's migration hops, which subsequently leads to an increase in energy and time consumption. In this paper, a spawn multi-mobile agent itinerary planning (SMIP) approach is proposed to mitigate the substantial increase in cost of energy and time used in the data gathering processes. The proposed approach is based on the agent spawning such that the main MA is able to spawn other MAs with different tasks assigned from the main MA. Extensive simulation experiments have been conducted to test the performance of the proposed approach against some selected MIP algorithms. The results show that the proposed SMIP outperforms the counterpart algorithms in terms of energy consumption and task delay (time), and improves the integrated energy-delay performance.
  15. Purayil FT, Robert GA, Gothandam KM, Kurup SS, Subramaniam S, Cheruth AJ
    3 Biotech, 2018 Feb;8(2):109.
    PMID: 29430370 DOI: 10.1007/s13205-018-1108-3
    Nine (9) different date palm (Phoenix dactylifera L.) cultivars from UAE, which differ in their flower timings were selected to determine the polymorphism and genetic relationship between these cultivars. Hereditary differences and interrelationships were assessed utilizing inter-simple sequence repeat (ISSR) and directed amplification of minisatellite DNA region (DAMD) primers. Analysis on eight DAMD and five ISSR markers produced total of 113 amplicon including 99 polymorphic and 14 monomorphic alleles with a polymorphic percentage of 85.45. The average polymorphic information content for the two-marker system was almost similar (DAMD, 0.445 and ISSR, 0.459). UPGMA based clustering of DAMD and ISSR revealed that mid-season cultivars, Mkh (Khlas) and MB (Barhee) grouped together to form a subcluster in both the marker systems. The genetic similarity analysis followed by clustering of the cumulative data from the DAMD and ISSR resulted in two major clusters with two early-season cultivars (ENg and Ekn), two mid-season cultivars (MKh and MB) and one late-season cultivar (Lkhs) in cluster 1, cluster 2 includes two late-season cultivars, one early-season cultivar and one mid-season cultivar. The cluster analysis of both DAMD and ISSR marker revealed that, the patterns of variation between some of the tested cultivars were similar in both DNA marker systems. Hence, the present study signifies the applicability of DAMD and ISSR marker system in detecting genetic diversity of date palm cultivars flowering at different seasons. This may facilitate the conservation and improvement of date palm cultivars in the future.
  16. Pua KC, Khoo AS, Yap YY, Subramaniam SK, Ong CA, Gopala Krishnan G, et al.
    Med J Malaysia, 2008 Sep;63 Suppl C:59-62.
    PMID: 19230249
    Nasopharyngeal carcinoma (NPC) is a cancer which is common in Asia. We report the establishment and early results of a multi-institutional prospective study of nasopharyngeal carcinoma, which seeks to systematically collect data as well as blood and tumour tissue samples from patients diagnosed with nasopharyngeal cancer at six centres in Malaysia. A total of 484 confirmed NPC cases were reported from the six participating centres between 1st July 2007 and 29th February 2008. Of these, 225 were newly diagnosed cases, 53 were recurrent cases and 206 were in remission at the time of reporting. Amongst the newly diagnosed cases, the most common presenting symptom was the presence of neck lumps (42%). Ophthalmo-neurologic symptoms were the presenting symptoms of 11% of the new cases. The majority of cases (75%) presented at stage III/IV.
  17. Poobathy R, Sinniah UR, Xavier R, Subramaniam S
    Appl Biochem Biotechnol, 2013 Jul;170(5):1066-79.
    PMID: 23640259 DOI: 10.1007/s12010-013-0241-z
    Dendrobium sonia-28 is an important ornamental orchid in the Malaysian flower industry. However, the genus faces both low germination rates and the risk of producing heterozygous progenies. Cryopreservation is currently the favoured long-term storage method for orchids with propagation problems. Vitrification, a frequently used cryopreservation technique, involves the application of pretreatments and cryoprotectants to protect and recover explants during and after storage in liquid nitrogen. However, cryopreservation may cause osmotic injuries and toxicity to cryopreserved explants from the use of highly concentrated additives, and cellular injuries from thawing, devitrification and ice formation. Reactive oxygen species (ROS), occurring during dehydration and cryopreservation, may also cause membrane damage. Plants possess efficient antioxidant systems such as the superoxide dismutase (SOD) and catalase (CAT) enzymes to scavenge ROS during low temperature stress. In this study, protocorm-like bodies (PLBs) of Dendrobium sonia-28 were assayed for the total protein content, and both SOD and CAT activities, at each stage of a vitrification exercise to observe for deleterious stages in the protocol. The results indicated that cryopreserved PLBs of Dendrobium sonia-28 underwent excessive post-thawing oxidative stress due to decreased levels of the CAT enzyme at the post-thawing recovery stage, which contributed to the poor survival rates of the cryopreserved PLBs.
  18. Poobathy R, Zakaria R, Murugaiyah V, Subramaniam S
    PLoS One, 2018;13(4):e0195642.
    PMID: 29649288 DOI: 10.1371/journal.pone.0195642
    Anoectochilus sp. and Ludisia discolor are known as Jewel orchids. Both species are terrestrial wild orchids that grow in shaded areas of forests. The Jewel orchids are renowned for the beauty of their leaves, which are dark-green laced with silvery or golden veins. The orchids are used as a cure in various parts of Asia. Overharvesting and anthropogenic disturbances threaten the existence of the Jewel orchids in the wild, necessitating human intervention in their survival. An understanding of the structure and adaptations of a plant may assist in its survival when propagated outside of its habitat. In this study, ex vitro leaves of Anoectochilus sp. and L. discolor were subjected to freehand sectioning, and then inspected through brightfield and fluorescence microscopy. The study indicated that all parts of both plants presented typical monocotyledonous characteristics except the leaves. The leaves displayed dorsiventrality with distinct palisade and spongy mesophyll layers. The spongy mesophyll layer contained cells which fluoresced a bright red when exposed to ultraviolet, blue, and green light wavelengths, hinting at the presence of anthocyanins for photoprotection. Cyanidin was detected in the leaves of L. discolor, as enumerated through high performance liquid chromatography (HPLC). The observations indicated that Anoectochilus sp. and L. discolor are well-adapted to live under shaded conditions with minimal exposure to light.
  19. Ping KS, Poobathy RR, Zakaria R, Subramaniam S
    Cryo Letters, 2018 5 8;38(4):290-298.
    PMID: 29734430
      BACKGROUND: Conservation of commercially important ornamental plants is important to maintain its unique beauty to cater the market demands.

    OBJECTIVE: The main objective is to develop an efficient cryopreservation technique for Aranda Broga Blue orchid PLBs using droplet-vitrification method.

    MATERIALS AND METHODS: Several critical factors in cryopreservation were accessed such as preculture concentrations and durations, choice of vitrification solutions, two-step or three-step vitrification, growth recovery medium and PVS2 exposure duration.

    RESULTS: The best growth regeneration percentage (5%) was obtained when 3-4mm PLBs were precultured in 0.2M sucrose for 3 days, followed by osmoprotection for 20 minutes, dehydration in PVS2 for 20 minutes at 0 degree C, LN storage, thawed and unloading for 20 minutes, and growth regeneration in VW10 medium. PLBs were found to be very sensitive to osmotic stress imposed by high molecular weight cryoprotectant such as sucrose and glycerol. Osmotic potential of growth recovery medium is one of the main factors that affect growth recovery in cryopreserved PLBs.

    CONCLUSION: Current report showed possibilities in cryopreserving Aranda Broga Blue PLBs using droplet-vitrification technique. However, further improvement of growth recovery can be done by focussing on approaches that facilitate sufficient water removal from PLBs without causing severe osmotic injuries to the plant cells.

  20. Parab AR, Lynn CB, Subramaniam S
    Mol Biol Rep, 2021 Nov;48(11):7223-7231.
    PMID: 34586562 DOI: 10.1007/s11033-021-06714-1
    BACKGROUND: Clonal propagation is one of the attributes of plant tissue culture. Therefore, analysis of genetic stability among the in vitro cultured plants is a crucial step. It helps to signify the clonal propagation of the micropropagated plants. Regenerated Ficus carica var. Black Jack plantlets were established using woody plant medium supplemented with 20 μM 6-Benzylaminopurine and 8 μM Indole-3-acetic acid under different light treatments such as normal fluorescent white light (60 μmol m-2 s-1), and four different LED spectra, white (400-700 nm), blue (440 nm), red (660 nm) and blue + red (440 nm + 660 nm). Genetic stability analysis was performed on the in vitro and ex vitro plants of Ficus carica var. Black Jack.

    METHODS AND RESULTS: Ten primers of each, ISSR and DAMD molecular markers, were used to assess the genetic stability of the eight samples of Ficus carica var. Black Jack. ISSR markers showed 97.87% of monomorphism whereas DAMD markers showed 100% monomorphism. Polymorphism of 2.13% was observed for the UBC840 ISSR-DNA primer which was negated under the genetic similarity index analysis for the eight samples. The findings of this study revealed that ISSR and DAMD markers are efficient in determining the polymorphism and monomorphism percentage among the in vitro and ex vitro samples of Ficus carica var. Black Jack.

    CONCLUSION: Monomorphism of 100% obtained using DAMD markers and more than 95% of monomorphism obtained using ISSR markers indicate that the regenerated plants are significantly genetically stable. These molecular markers can be used to test the genetic stability of in vitro regenerated plants. It is recommended that genetic stability analysis should be performed for long-term maintenance of such micropropagated plants.

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