Browse publications by year: 2012

  1. Sia KJ, Tang IP, Kong CK, Nasriah A
    J Laryngol Otol, 2012 May;126(5):529-31.
    PMID: 22361094 DOI: 10.1017/S0022215112000175
    To discuss the pathophysiology of atlanto-axial subluxation as a rare complication of tonsillectomy, and to discuss the important radiological findings for diagnosis and treatment planning.
    MeSH terms: Atlanto-Axial Joint*; Child; Dislocations/etiology; Dislocations/radiography*; Dislocations/therapy; Humans; Male; Neck/radiography; Orthotic Devices; Postoperative Complications/diagnosis; Syndrome; Tomography, X-Ray Computed; Tonsillectomy/adverse effects*; Torticollis/etiology*; Torticollis/radiography; Torticollis/therapy; Traction; Neck Pain/etiology; Neck Pain/radiography; Neck Pain/therapy
  2. Balasubramaniam VR, Wai TH, Omar AR, Othman I, Hassan SS
    Virol J, 2012;9:53.
    PMID: 22361110 DOI: 10.1186/1743-422X-9-53
    Highly-pathogenic avian influenza (HPAI) H5N1 and Newcastle disease (ND) viruses are the two most important poultry viruses in the world, with the ability to cause classic central nervous system dysfunction in poultry and migratory birds. To elucidate the mechanisms of neurovirulence caused by these viruses, a preliminary study was design to analyze host's cellular responses during infections of these viruses.
    MeSH terms: Animals; Brain/pathology*; Chickens; Newcastle disease virus/pathogenicity*; Gene Expression Profiling/methods; Influenza A Virus, H5N1 Subtype/pathogenicity*; Host-Pathogen Interactions*; Transcriptome*
  3. Arockiaraj J, Easwvaran S, Vanaraja P, Singh A, Othman RY, Bhassu S
    Fish Shellfish Immunol, 2012 May;32(5):929-33.
    PMID: 22361112 DOI: 10.1016/j.fsi.2012.02.011
    This study reports the first full length gene of interferon related developmental regulator-1 (designated as MrIRDR-1), identified from the transcriptome of Macrobrachium rosenbergii. The complete gene sequence of the MrIRDR-1 is 2459 base pair long with an open reading frame of 1308 base pairs and encoding a predicted protein of 436 amino acids with a calculated molecular mass of 48 kDa. The MrIRDR-1 protein contains a long interferon related developmental regulator super family domain between 30 and 330. The mRNA expressions of MrIRDR-1 in healthy and the infectious hypodermal and hematopoietic necrosis virus (IHHNV) infected M. rosenbergii were examined using qRT-PCR. The MrIRDR-1 is highly expressed in hepatopancreas along with all other tissues (walking leg, gills, muscle, haemocyte, pleopods, brain, stomach, intestine and eye stalk). After IHHNV infection, the expression is highly upregulated in hepatopancreas. This result indicates an important role of MrIRDR-1 in prawn defense system.
    MeSH terms: Amino Acid Sequence; Animals; Gene Expression Regulation; Molecular Sequence Data; Phylogeny; Tissue Distribution; Open Reading Frames; Sequence Alignment/veterinary; Sequence Homology; Immediate-Early Proteins/genetics*; Immediate-Early Proteins/immunology*; Immediate-Early Proteins/chemistry; DNA, Complementary/genetics; DNA, Complementary/immunology; Densovirinae/immunology*; Computational Biology; Sequence Analysis, Protein/veterinary; Gene Expression Profiling/veterinary; Palaemonidae/genetics*; Palaemonidae/immunology*; Real-Time Polymerase Chain Reaction/veterinary
  4. Idris Z, Muzaimi M, Hussin S, Mahmood WH, Abdullah WZ
    Acta Neurochir (Wien), 2012 May;154(5):887-93; discussion 893-4.
    PMID: 22362049 DOI: 10.1007/s00701-012-1296-2
    Coagulation factor XIII and other haemostatic markers are known strengthen fibrin clot formation and, hence, may facilitate safer surgery. Currently however, factor XIII activity levels are not routinely screen. Therefore, the purpose of this study was to determine the association of perioperative factor XIII activity levels and other haemostatic markers with postoperative intracranial haematoma formation in neurosurgical patients.
    MeSH terms: Adolescent; Adult; Aged; Brain Neoplasms/surgery; Factor XIII/analysis; Factor XIII/metabolism*; Female; Hematoma/blood*; Humans; Male; Middle Aged; Platelet Count; Postoperative Complications/blood*; Cohort Studies; Biomarkers/blood; Treatment Outcome; Risk Assessment; Intracranial Hemorrhages/blood*; Young Adult
  5. Zulkifli MZ, Ho CC, Goh EH, Praveen S, Das S
    Clin Ter, 2012;163(1):23-5.
    PMID: 22362229
    Incidence of urolithiasis is on the rise due to climatic changes especially global warming.The pain due to presence of ureteric stone is a well known identity but many times it may be asymptomatic or even masked by concurrent presence of backache. In the present article, we describe the case of a 43-year-old male who came to the clinic for treatment of backache persisting for more than two years. The patient complained of backache two years back for which he was treated with analgesics and physiotherapy which relieved his pain. No X-ray was taken earlier because the attending clinician thought the backache to be musculo-skeletal in origin. Recently, one day a sudden episode of backache in the midst of night compelled him to seek medical treatment. However, this time a X-ray was performed and it showed the presence of calculi in the right upper pelvis of ureter which measured 1.9 cm vertically. An ultrasound confirmed the diagnosis. The patient was treated with two episodes of shock wave therapy which failed to crush the stone. A Double-J stent was inserted under general anaesthesia. The stone was crushed using a ureteroscope guided laser. The present case report describes how backache in professionals cannot be lightly attended. Even the characteristic groin to loin pain may be absent. All cases of backache should be properly investigated with an X-ray to rule out renal or ureteric calculi.
    MeSH terms: Analgesics/therapeutic use; Back Pain/complications; Back Pain/diagnosis*; Colic/diagnosis*; Colic/etiology; Diagnosis, Differential; Diagnostic Errors*; Humans; Lithotripsy; Male; Middle Aged; Ureteral Calculi/complications; Ureteral Calculi/diagnosis*; Ureteral Calculi/physiopathology; Ureteral Calculi/radiography; Ureteral Calculi/ultrasonography; Stents; Lithotripsy, Laser; Ureteroscopy; Physical Therapy Modalities; Delayed Diagnosis
  6. Zubaidah NH, Azim MI, Osama MH, Harunarashid H, Das S
    Clin Ter, 2012;163(1):27-9.
    PMID: 22362230
    The incidence of infection following TEVAR is low. To the best of our knowledge, this is the first case report of post thoracic endovascular aortic repair (TEVAR) with Streptococcus viridans graft infection. A 54-year-old male underwent TEVAR for dissecting thoracic aneurysm with spinal ischaemia. He had an eventful recovery with prolonged period of stay in intensive care unit. Three months later, he presented with persistent chest discomfort and fever. Computed tomography (CT) of the thorax revealed evidence of graft infection and the blood culture grew Streptococcus viridans. The rarity of TEVAR graft infection due to Streptococcus viridans and its management are being discussed.
    MeSH terms: Aneurysm, Dissecting/complications; Aneurysm, Dissecting/surgery*; Anti-Bacterial Agents/therapeutic use; Esophageal Fistula/etiology; Esophageal Fistula/microbiology; Esophageal Fistula/radiography; Fever/etiology; Humans; Ischemia/etiology; Male; Middle Aged; Myocardial Infarction/complications; Paraplegia/etiology; Penicillins/therapeutic use; Postoperative Complications; Spinal Cord/blood supply; Streptococcal Infections/drug therapy; Streptococcal Infections/microbiology*; Streptococcal Infections/radiography; Vascular Fistula/etiology; Vascular Fistula/microbiology; Vascular Fistula/radiography; Prosthesis-Related Infections/drug therapy; Prosthesis-Related Infections/microbiology*; Prosthesis-Related Infections/radiography; Bacteremia/microbiology; Aortic Aneurysm, Thoracic/complications; Aortic Aneurysm, Thoracic/surgery*; Blood Vessel Prosthesis Implantation/adverse effects*; Amoxicillin-Potassium Clavulanate Combination/therapeutic use; Viridans Streptococci/isolation & purification*; Endovascular Procedures
  7. Muthupalaniappen L, Rosdinom R, Suguna M
    Clin Ter, 2012;163(1):31-2.
    PMID: 22362231
    Pisa syndrome or pleurothotonus is the persistent flexion of the body and head to one side giving the appearance of the leaning tower of Pisa. It is most commonly caused by typical and atypical antipsychotic drugs. We report a case of Pisa Syndrome caused by prolonged use of high dose cholinesterase inhibitor, rivastigmine. Symptoms subsided when rivastigmine was withdrawn and did not reappear when a different cholinesterase inhibitor, donepezil was introduced. Physicians should be aware of Pisa syndrome and should alert patient of this possibility when starting and stepping up medications. The purpose of reporting this case is to create awareness among general practitioners as it is a reversible condition which responds to removal of the offending drug.
    MeSH terms: Rivastigmine; Aged; Ambulatory Care Facilities; Benzodiazepines/adverse effects; Benzodiazepines/therapeutic use; Cholinesterase Inhibitors/adverse effects*; Delusions/drug therapy; Dementia/drug therapy; Humans; Indans/therapeutic use; Malaysia; Male; Movement Disorders/etiology*; Piperidines/therapeutic use; Posture; Syndrome; Phenylcarbamates/adverse effects*
  8. Noor Siah AA, Ho SE, Jafaar MZ, Choy YC, Das S, Ismail SM, et al.
    Clin Ter, 2012;163(1):63-7.
    PMID: 22362236
    BACKGROUND AND AIMS. The experience in intensive care unit (ICU) has created an intense emotional situation both to patients and their family members. The aim of this study was to determine the family members information needs of critically ill patients in ICU.

    MATERIALS AND METHODS:
    A descriptive cross-sectional study was conducted on 200 family members of patients admitted in ICU. A face to face interview was conducted and a self-report questionnaire of the Critical Care Family Needs Inventory (CCFNI) was used.

    RESULTS:
    Findings reported CCFNI five sub-attributes that ranked from highest to lowest included: support (mean 39.13 ± 6.189); proximity (mean 27.17 ± 3.384); information (mean 24.25 ± 3.093); assurance (mean 22.67 ± 1.862) and comfort (mean 16.24 ± 2.776). There were no significant differences in needs between family members with different gender (p >0.05). However, there were significant differences in support needs between family members with admission to ICU with (t=-2.111; p <0.05). There were significant differences in assurance needs (F=3.542; p <0.05) and information needs (F=3.681; p <0.05) between family members with age. There were no significant differences in needs between family members with different education level (p >0.05) whereas assurance needs were significant differences with education level of (F=3.542; p <0.05).

    CONCLUSION:
    The results suggest that family members perceived support and proximity as the most crucial need. Comfort need was viewed as least important. Although this study was conducted in a tertiary hospital, the findings could still provide insight for nurses to improve the delivery of care to patients and family members.
    MeSH terms: Adolescent; Adult; Emotions; Female; Health Services Needs and Demand*; Hospitals, University; Humans; Intensive Care Units; Malaysia; Male; Middle Aged; Professional-Family Relations*; Surveys and Questionnaires; Social Support; Truth Disclosure*; Comprehension; Young Adult; Self Report
  9. Yasin SM, Retneswari M, Moy FM, Darus A, Koh D
    Occup Med (Lond), 2012 Apr;62(3):174-81.
    PMID: 22362839 DOI: 10.1093/occmed/kqs005
    Job stressors may reduce the likelihood of quitting smoking.
    MeSH terms: Adult; Humans; Malaysia; Male; Middle Aged; Occupations; Surveys and Questionnaires; Smoking/epidemiology; Smoking/prevention & control; Social Support; Stress, Psychological*; Universities; Cohort Studies; Cognitive Therapy; Smoking Cessation/methods; Smoking Cessation/psychology*; Workplace/psychology*
  10. Saifur RG, Dieng H, Hassan AA, Salmah MR, Satho T, Miake F, et al.
    PLoS One, 2012;7(2):e30919.
    PMID: 22363516 DOI: 10.1371/journal.pone.0030919
    BACKGROUND: The domestic dengue vector Aedes aegypti mosquitoes breed in indoor containers. However, in northern peninsular Malaysia, they show equal preference for breeding in both indoor and outdoor habitats. To evaluate the epidemiological implications of this peridomestic adaptation, we examined whether Ae. aegypti exhibits decreased survival, gonotrophic activity, and fecundity due to lack of host availability and the changing breeding behavior.

    METHODOLOGY/PRINCIPAL FINDINGS: This yearlong field surveillance identified Ae. aegypti breeding in outdoor containers on an enormous scale. Through a sequence of experiments incorporating outdoors and indoors adapting as well as adapted populations, we observed that indoors provided better environment for the survival of Ae. aegypti and the observed death patterns could be explained on the basis of a difference in body size. The duration of gonotrophic period was much shorter in large-bodied females. Fecundity tended to be greater in indoor acclimated females. We also found increased tendency to multiple feeding in outdoors adapted females, which were smaller in size compared to their outdoors breeding counterparts.

    CONCLUSION/SIGNIFICANCE: The data presented here suggest that acclimatization of Ae. aegypti to the outdoor environment may not decrease its lifespan or gonotrophic activity but rather increase breeding opportunities (increased number of discarded containers outdoors), the rate of larval development, but small body sizes at emergence. Size is likely to be correlated with disease transmission. In general, small size in Aedes females will favor increased blood-feeding frequency resulting in higher population sizes and disease occurrence.

    MeSH terms: Aedes/anatomy & histology; Aedes/growth & development*; Analysis of Variance; Animals; Data Collection; Dengue/epidemiology*; Dengue/parasitology*; Feeding Behavior/physiology; Female; Fertility/physiology; Geography; Housing; Larva/growth & development; Life Cycle Stages/physiology; Malaysia; Oviposition/physiology; Ovum/cytology; Reproduction/physiology; Wings, Animal/anatomy & histology; Survival Analysis; Body Size
  11. Bhoo-Pathy N, Hartman M, Yip CH, Saxena N, Taib NA, Lim SE, et al.
    PLoS One, 2012;7(2):e30995.
    PMID: 22363531 DOI: 10.1371/journal.pone.0030995
    The burden of breast cancer in Asia is escalating. We evaluated the impact of ethnicity on survival after breast cancer in the multi-ethnic region of South East Asia.
    MeSH terms: Asia, Southeastern/epidemiology; Breast Neoplasms/diagnosis; Breast Neoplasms/ethnology*; Breast Neoplasms/mortality*; Breast Neoplasms/pathology; Ethnic Groups/ethnology*; Ethnic Groups/statistics & numerical data*; Female; Humans; Lymph Nodes/pathology; Middle Aged; Neoplasm Metastasis; Survival Analysis
  12. Ibraheem ZO, Sattar MA, Abdullah NA, Rathore HA, Johns EJ
    Bosn J Basic Med Sci, 2012 Feb;12(1):26-32.
    PMID: 22364300
    The current study evaluates the impact of high saturated fat feeding in rat model of experimental nephrotoxicity induced by gentamicin. Sprague-Dawley rats weighing 200 g were randomized into four groups; the first one received the standard rodents chow for 8 weeks and was treated as control, the second group (HFD)received an experimental high fat diet rich in palm kernel oil (40% of Calories as fat) for the same period. The third group (HFDG) was given 80 mg/kg (body weight)/day gentamicin sulphate intraperitoneally during the last 24 days of the feeding period while the fourth group was given gentamicin as above along with the standard rodents chow. Renal function was assessed through measuring serum creatinine, creatinine clearance and absolute and fractional excretion of both sodium and potassium. At the end, rats underwent a surgical procedure for blood pressure measurement. Renal function study showed a stronger nephrotoxicity for HFDG group. Hypertension was observed in HFD group while the pressure declined after gentamicin co-administration. Overall, changing the feeding behavior toward using more SAFFAs for rats injected with gentamicin promotes the progression of renal failure.
    MeSH terms: Animals; Anti-Bacterial Agents/toxicity*; Disease Models, Animal; Fatty Acids/administration & dosage*; Fatty Acids, Nonesterified/administration & dosage*; Gentamicins/toxicity*; Kidney/pathology; Male; Rats, Sprague-Dawley; Disease Progression; Rats; Renal Insufficiency/chemically induced*; Renal Insufficiency/pathology
  13. Malik AS, Malik RH
    Med Teach, 2012;34(3):198-204.
    PMID: 22364451 DOI: 10.3109/0142159X.2011.588741
    Retaining lectures in problem-based learning (PBL) curriculum places new demands on lecturers. In addition to subject knowledge, the lecturers must know the overall aims of the lectures, their context in the course, their relation to the subsequent examinations and the underlying educational philosophy.
    MeSH terms: Consumer Participation; Curriculum/standards; Education, Medical/methods*; Education, Medical/trends; Humans; Students, Medical/psychology*; Teaching/methods; Teaching/organization & administration; Program Evaluation/methods; Program Development/methods; Problem-Based Learning/methods*; Problem-Based Learning/trends
  14. Zahid NI, Abou-Zied OK, Hashim R, Heidelberg T
    Langmuir, 2012 Mar 20;28(11):4989-95.
    PMID: 22364590 DOI: 10.1021/la3001976
    Water-driven self-assembly of lipids displays a variety of liquid crystalline phases that are crucial for membrane functions. Herein, we characterize the temperature-induced phase transitions in two compositions of an aqueous self-assembly system of the octyl β-D-glucoside (βGlcOC(8)) system, using steady-state and time-resolved fluorescence measurements. The phase transitions hexagonal ↔ micellar and cubic ↔ lamellar were investigated using tryptophan (Trp) and two of its ester derivatives (Trp-C(4) and Trp-C(8)) to probe the polar headgroup region and pyrene to probe the hydrophobic tail region. The polarity of the headgroup region was estimated to be close to that of simple alcohols (methanol and ethanol) for all phases. The pyrene fluorescence indicates that the pyrene molecules are dispersed among the tails of the hydrophobic region, yet remain in close proximity to the polar head groups. Comparing the present results with our previously reported one for βMaltoOC(12), increasing the tail length of the hexagonal phase from C(8) to C(12) leads to less interaction with pyrene, which is attributed to the more random and wobbling motion of the longer alkyl tail. We measured a reduction (more hydrophobic) in the ratio of the vibronic peak intensities of pyrene (I(1)/I(3)) for the lamellar phase compared to that of the cubic phase. The higher polarity in the cubic phase can be correlated to the nature of its interface, which curves toward the bulk water. This geometry also explains the slight reduction in polarity of the headgroup region compared to the other phases. Upon the addition of Trp-C(8), the fluorescence lifetime of pyrene is reduced by 28% in the lamellar and cubic phases, whereas the I(1)/I(3) value is only slightly reduced. The results reflect the dominant role of dynamic interaction mechanism between the C(8) chain of Trp-C(8) and pyrene. This mechanism may be important for these two phases since they participate in the process of membrane fusion. Both lipid compositions show completely reversible temperature-induced phase transitions, reflecting the thermodynamic equilibrium structures of their mesophases. Probing both regions of the different lipid phases reveals a large degree of heterogeneity and flexibility of the lipid self-assembly. These properties are crucial for carrying out different biological functions such as the ability to accommodate various molecular sizes.
    MeSH terms: Fluorescent Dyes/chemistry*; Glycolipids/chemistry*; Micelles*; Spectrometry, Fluorescence
  15. Ngai SC, Rosli R, Nordin N, Veerakumarasivam A, Abdullah S
    Gene, 2012 May 1;498(2):231-6.
    PMID: 22366305 DOI: 10.1016/j.gene.2012.01.071
    Lentivirus (LV) encoding woodchuck posttranscriptional regulatory element (WPRE) and central polypurine tract (cPPT) driven by CMV promoter have been proven to act synergistically to increase both transduction efficiency and gene expression. However, the inclusion of WPRE and cPPT in a lentiviral construct may pose safety risks when administered to human. A simple lentiviral construct driven by an alternative promoter with proven extended duration of gene expression without the two regulatory elements would be free from the risks. In a non-viral gene delivery context, gene expression driven by human polybiquitin C (UbC) promoter resulted in higher and more persistent expression in mouse as compared to cytomegalovirus (CMV) promoter. In this study, we measured the efficiency and persistency of green fluorescent protein (GFP) reporter gene expression in cells transduced with LV driven by UbC (LV/UbC/GFP) devoid of the WPRE and cPPT in comparison to the established LV construct encoding WPRE and cPPT, driven by CMV promoter (LV/CMV/GFP). However, we found that LV/UbC/GFP was inferior to LV/CMV/GFP in many aspects: (i) the titer of virus produced; (ii) the levels of reporter gene expression when MOI value was standardized; and (iii) the transduction efficiency in different cell types. The duration of reporter gene expression in selected cell lines was also determined. While the GFP expression in cells transduced with LV/CMV/GFP persisted throughout the experimental period of 14 days, expression in cells transduced with LV/UbC/GFP declined by day 2 post-transduction. In summary, the LV driven by the UbC promoter without the WPRE and cPPT does not exhibit enhanced or durable transgene expression.
    MeSH terms: Animals; Cell Line/virology; Cytomegalovirus/genetics; Genetic Vectors*; Humans; Promoter Regions, Genetic; Regulatory Sequences, Nucleic Acid*; Time Factors; Transduction, Genetic/methods*; Gene Expression; Lentivirus/genetics*; Genes, Reporter; Gene Transfer Techniques; Transgenes; Polyubiquitin/genetics; Green Fluorescent Proteins/genetics; Green Fluorescent Proteins/metabolism; Mice
  16. Saidin S, Abdul Kadir MR, Sulaiman E, Abu Kasim NH
    J Dent, 2012 Jun;40(6):467-74.
    PMID: 22366313 DOI: 10.1016/j.jdent.2012.02.009
    The aim of this study was to analyse micromotion and stress distribution at the connections of implants and four types of abutments: internal hexagonal, internal octagonal, internal conical and trilobe.
    MeSH terms: Dental Abutments; Algorithms; Biomechanical Phenomena; Computer Simulation; Crowns; Humans; Mandible/anatomy & histology; Materials Testing; Models, Biological; Motion; Rotation; Stress, Mechanical; Surface Properties; User-Computer Interface; Computer-Aided Design; Dental Prosthesis Design*; Finite Element Analysis; Imaging, Three-Dimensional/methods; Dental Implant-Abutment Design*
  17. Shuit SH, Ong YT, Lee KT, Subhash B, Tan SH
    Biotechnol Adv, 2012 Nov-Dec;30(6):1364-80.
    PMID: 22366515 DOI: 10.1016/j.biotechadv.2012.02.009
    In recent years, environmental problems caused by the use of fossil fuels and the depletion of petroleum reserves have driven the world to adopt biodiesel as an alternative energy source to replace conventional petroleum-derived fuels because of biodiesel's clean and renewable nature. Biodiesel is conventionally produced in homogeneous, heterogeneous, and enzymatic catalysed processes, as well as by supercritical technology. All of these processes have their own limitations, such as wastewater generation and high energy consumption. In this context, the membrane reactor appears to be the perfect candidate to produce biodiesel because of its ability to overcome the limitations encountered by conventional production methods. Thus, the aim of this paper is to review the production of biodiesel with a membrane reactor by examining the fundamental concepts of the membrane reactor, its operating principles and the combination of membrane and catalyst in the catalytic membrane. In addition, the potential of functionalised carbon nanotubes to serve as catalysts while being incorporated into the membrane for transesterification is discussed. Furthermore, this paper will also discuss the effects of process parameters for transesterification in a membrane reactor and the advantages offered by membrane reactors for biodiesel production. This discussion is followed by some limitations faced in membrane technology. Nevertheless, based on the findings presented in this review, it is clear that the membrane reactor has the potential to be a breakthrough technology for the biodiesel industry.
    MeSH terms: Biotechnology/economics; Biotechnology/methods*; Biotechnology/standards; Catalysis; Membranes, Artificial*; Bioreactors/economics; Biofuels/analysis*; Biofuels/economics; Biofouling
  18. Bhoo-Pathy N, Yip CH, Hartman M, Saxena N, Taib NA, Ho GF, et al.
    Eur J Cancer, 2012 May;48(7):982-9.
    PMID: 22366561 DOI: 10.1016/j.ejca.2012.01.034
    Adjuvant! Online is a free web-based tool which predicts 10-year breast cancer outcomes and the efficacy of adjuvant therapy in patients with breast cancer. As its prognostic performance has only been validated in high income Caucasian populations, we validated the model in a middle income Asian setting.
    MeSH terms: Adult; Aged; Breast Neoplasms/ethnology*; Breast Neoplasms/mortality*; Breast Neoplasms/therapy; Female; Follow-Up Studies; Humans; Malaysia; Middle Aged; Prognosis*; Chemotherapy, Adjuvant*; Radiotherapy, Adjuvant; Internet; Asian Continental Ancestry Group
  19. Makita N, Kosugi Y, Dannoura M, Takanashi S, Niiyama K, Kassim AR, et al.
    Tree Physiol, 2012 Mar;32(3):303-12.
    PMID: 22367761 DOI: 10.1093/treephys/tps008
    The root systems of forest trees are composed of different diameters and heterogeneous physiological traits. However, the pattern of root respiration rates from finer and coarser roots across various tropical species remains unknown. To clarify how respiration is related to the morphological traits of roots, we evaluated specific root respiration and its relationships to mean root diameter (D) of various diameter and root tissue density (RTD; root mass per unit root volume; gcm(-3)) and specific root length (SRL; root length per unit root mass; mg(-1)) of the fine roots among and within 14 trees of 13 species from a primary tropical rainforest in the Pasoh Forest Reserve in Peninsular Malaysia. Coarse root (2-269mm) respiration rates increased with decreasing D, resulting in significant relationships between root respiration and diameter across species. A model based on a radial gradient of respiration rates of coarse roots simulated the exponential decrease in respiration with diameter. The respiration rate of fine roots (<2mm) was much higher and more variable than those of larger diameter roots. For fine roots, the mean respiration rates for each species increased with decreasing D. The respiration rates of fine roots declined markedly with increasing RTD and increased with increasing SRL, which explained a significant portion of the variation in the respiration among the 14 trees from 13 species examined. Our results indicate that coarse root respiration in tree species follows a basic relationship with D across species and that most of the variation in fine root respiration among species is explained by D, RTD and SRL. We found that the relationship between root respiration and morphological traits provides a quantitative basis for separating fine roots from coarse roots and that the pattern holds across different species.
    MeSH terms: Malaysia; Models, Biological; Phenotype; Rain; Temperature; Trees/anatomy & histology*; Trees/metabolism; Trees/physiology*; Tropical Climate; Plant Roots/anatomy & histology; Plant Roots/metabolism; Plant Roots/physiology*; Cell Respiration/physiology
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