Displaying publications 61 - 80 of 125 in total

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  1. Halim AS, Alwi AA
    Ann Plast Surg, 2014 Aug;73(2):170-3.
    PMID: 23528630 DOI: 10.1097/SAP.0b013e318270704b
    The use of internal mammary perforators (IMPs) as recipient vessels in autologous free flap breast reconstruction has many additional benefits compared with the internal mammary or thoracodorsal vessels. Our goals were to analyze the characteristics of these vessels and to evaluate the reliability of using them in an Asian population.
  2. Keong LC, Halim AS
    Int J Mol Sci, 2009 Mar;10(3):1300-1313.
    PMID: 19399250 DOI: 10.3390/ijms10031300
    One of the ultimate goals of wound healing research is to find effective healing techniques that utilize the regeneration of similar tissues. This involves the modification of various wound dressing biomaterials for proper wound management. The biopolymer chitosan (beta-1,4-D-glucosamine) has natural biocompatibility and biodegradability that render it suitable for wound management. By definition, a biocompatible biomaterial does not have toxic or injurious effects on biological systems. Chemical and physical modifications of chitosan influence its biocompatibility and biodegradability to an uncertain degree. Hence, the modified biomedical-grade of chitosan derivatives should be pre-examined in vitro in order to produce high-quality, biocompatible dressings. In vitro toxicity examinations are more favorable than those performed in vivo, as the results are more reproducible and predictive. In this paper, basic in vitro tools were used to evaluate cellular and molecular responses with regard to the biocompatibility of biomedical-grade chitosan. Three paramount experimental parameters of biocompatibility in vitro namely cytocompatibility, genotoxicity and skin pro-inflammatory cytokine expression, were generally reviewed for biomedical-grade chitosan as wound dressing.
  3. Lim CK, Halim AS, Lau HY, Ujang Z, Hazri A
    J Appl Biomater Biomech, 2007 May-Aug;5(2):82-7.
    PMID: 20799177
    Chitosan (beta-1, 4-D-glucosamine) is a deacetylated form of chitin with excellent biological properties in wound management. The natural properties of chitosan have the physical and chemical limitations to be widely used in biomedical fields. The improvement of the physical and chemical properties of chitosan with some additional chemicals will alter its biocompatibility. Therefore, the biological attribute of the modified chitosan must be evaluated. In this study, the cytotoxicity of oligo-chitosan (OC) and N, O- carboxymethyl-chitosan (NO-CMC) derivatives (O-C 1%, O-C 5%, NO-CMC 1% and NO-CMC 5%) was evaluated using primary normal human epidermal keratinocyte (pNHEK) cultures as an in vitro toxicology model at standardized cell passages (fourth passages). 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl tetrazolium bromide (MTT) was used as a cell viability assay. The O-C 1% is one of the most compatible chitosan derivatives because it steadily sustained >70% of viable cells until 72 hr post-treatment. This was followed by O-C 5%, NO-CMC 5% and NO-CMC 1%. Therefore, oligo-chitosan had the ideal properties of a biocompatible material compared to N, O- carboxymethyl-chitosan in this study.
  4. Hilmi AB, Halim AS, Hassan A, Lim CK, Noorsal K, Zainol I
    Springerplus, 2013 Dec;2(1):79.
    PMID: 23503998 DOI: 10.1186/2193-1801-2-79
    Chitosan is a marine-derived product that has been widely used in clinical applications, especially in skin reconstruction. The mammalian scaffolds derived from bovine and porcine material have many limitations, for example, prion transmission and religious concerns. Therefore, we created a chitosan skin regenerating template (SRT) and investigated the behavior of fibroblast cell-scaffold constructs. Primary human dermal fibroblasts (HDF) were isolated and then characterized using vimentin and versican. HDF were seeded into chitosan SRT at a density of 3×10(6) cells/cm(2) for fourteen days. Histological analysis and live cells imaging revealed that the cell-chitosan constructs within interconnected porous chitosan showed significant interaction between the cells as well as between the cells and the chitosan. Scanning electron microscopy (SEM) analysis revealed cells spreading and covering the pores. As the pore sizes of the chitosan SRT range between 40-140 μm, an average porosity is about 93 ± 12.57% and water uptake ratio of chitosan SRT is 536.02 ± 14.29%, it is a supportive template for fibroblast attachment and has potential in applications as a dermal substitute.
  5. Periayah MH, Halim AS, Hussein AR, Saad AZ, Rashid AH, Noorsal K
    Int J Biol Macromol, 2013 Jan;52:244-9.
    PMID: 23063426 DOI: 10.1016/j.ijbiomac.2012.10.001
    Chitosan-derived hemostatic agents with various formulations may have distinct potential in hemostasis. This study assessed the ability of different grades and forms of chitosan derivatives as hemostatic agents to enhance platelet adhesion and aggregation in vitro. The chitosan derivatives utilized were 2% NO-CMC, 7% NO-CMC (with 0.45 mL collagen), 8% NO-CMC, O-C 52, 5% O-CMC-47, NO-CMC-35, and O-C 53. Samples of chitosan derivatives weighing 5mg were incubated at 37°C with 50 μL of phosphate buffer saline (PBS) (pH 7.4) for 60 min. The morphological features of the platelets upon adherence to the chitosan were viewed using scanning electron microscope (SEM), and the platelet count was analyzed with an Automated Hematology Analyzer. For platelet aggregation, we added an adenosine diphosphate (ADP) agonist to induce the chitosan-adhered platelets. O-C 52 bound with platelets exhibited platelet aggregates and clumps on the surface of the membrane layer with approximately 70-80% coverage. A statistically significant correlation (p<0.01) for the platelet count was identified between the baseline value and the values at 10 min and 20 min. The results indicate that O-C 53 and O-C 52 were able to promote clotting have the potential to induce the release of platelets engaged in the process of hemostasis.
  6. Lim CK, Yaacob NS, Ismail Z, Halim AS
    Toxicol In Vitro, 2010 Apr;24(3):721-7.
    PMID: 20079826 DOI: 10.1016/j.tiv.2010.01.006
    Biopolymer chitosan (beta-1,4-d-glucosamine) comprises the copolymer mixture of N-acetylglucosamine and glucosamine. The natural biocompatibility and biodegradability of chitosan have recently highlighted its potential use for applications in wound management. Chemical and physical modifications of chitosan influence its biocompatibility and biodegradability, but it is unknown as to what degree. Hence, the biocompatibility of the chitosan porous skin regenerating templates (PSRT 82, 87 and 108) was determined using an in vitro toxicology model at the cellular and molecular level on primary normal human epidermal keratinocytes (pNHEK). Cytocompatibility was accessed by using a 3-[4,5-dimethyl-2-thiazolyl]-2,5-diphenyl tetrazolium bromide (MTT) assay from 24 to 72h. To assess the genotoxicity of the PSRTs, DNA damage to the pNHEK was evaluated by using the Comet assay following direct contact with the various PSRTs. Furthermore, the skin pro-inflammatory cytokines TNF-alpha and IL-8 were examined to evaluate the tendency of the PSRTs to provoke inflammatory responses. All PSRTs were found to be cytocompatible, but only PSRT 108 was capable of stimulating cell proliferation. While all of the PSRTs showed some DNA damage, PSRT 108 showed the least DNA damage followed by PSRT 87 and 82. PSRT 87 and 82 induced a higher secretion of TNF-alpha and IL-8 in the pNHEK cultures than did PSRT 108. Hence, based on our experiments, PSRT 108 is the most biocompatible wound dressing of the three tested.
  7. Halim AS, Ramasenderan N
    Asian J Surg, 2023 Jan;46(1):47-51.
    PMID: 35545474 DOI: 10.1016/j.asjsur.2022.04.079
    Cutaneous squamous cell carcinoma (CSCC) is a common type of skin malignancy that affects people who have been exposed to sunlight for a long time. It has been associated to a high mutational load, making treatment problematic, especially for individuals with high-risk CSCC characteristics. Patients with high-risk CSCC are difficult to define since definitions are still imprecise. Firstly, we review the evidence to see how relevant locoregional involvement is in terms of patient survival and recurrence risk. Second, we go through the difficulties and obstacles that come with sentinel lymph node biopsy (SLNB) and their importance in the management of locally progressed CSCC. Methods and findings from a variety of lymph node investigations are described. There is yet no empirical evidence for the involvement of SLNB in CSCC. Finally, we discussed the most recent developments in the treatment of CSCC. The mainstays of treatment are surgery and radiation. To slow the disease progression, cancer medicines have switched to disrupting particular signaling pathways. Advanced nations have more easily accessible drugs like Cetuximab (epidermal growth factor receptor inhibitor) and Cemiplimab (anti-programme receptor-1 antibodies), which are utilized in advanced CSCC. The response rate varies based on the patient, although there is still a lack of proof. This article discusses the misconception that CSCC is a tumor with a favorable prognosis, as well as the difficulties in treating high-risk CSCC.
  8. Periayah MH, Halim AS, Yaacob NS, Saad AZ, Hussein AR, Rashid AH, et al.
    Biomed Res Int, 2014;2014:653149.
    PMID: 25247182 DOI: 10.1155/2014/653149
    Platelet membrane receptor glycoprotein IIb/IIIa (gpiibiiia) is a receptor detected on platelets. Adenosine diphosphate (ADP) activates gpiibiiia and P2Y12, causing platelet aggregation and thrombus stabilization during blood loss. Chitosan biomaterials were found to promote surface induced hemostasis and were capable of activating blood coagulation cascades by enhancing platelet aggregation. Our current findings show that the activation of the gpiibiiia complex and the major ADP receptor P2Y12 is required for platelet aggregation to reach hemostasis following the adherence of various concentrations of chitosan biomaterials [7% N,O-carboxymethylchitosan (NO-CMC) with 0.45 mL collagen, 8% NO-CMC, oligochitosan (O-C), and oligochitosan 53 (O-C 53)]. We studied gpiibiiia and P2Y12 through flow cytometric analysis and western blotting techniques. The highest expression of gpiibiiia was observed with Lyostypt (74.3 ± 7.82%), followed by O-C (65.5 ± 7.17%). Lyostypt and O-C resulted in gpiibiiia expression increases of 29.2% and 13.9%, respectively, compared with blood alone. Western blot analysis revealed that only O-C 53 upregulated the expression of P2Y12 (1.12 ± 0.03-fold) compared with blood alone. Our findings suggest that the regulation of gpiibiiia and P2Y12 levels could be clinically useful to activate platelets to reach hemostasis. Further, we show that the novel oligochitosan is able to induce the increased expression of gpiibiiia and P2Y12, thus accelerating platelet aggregation in vitro.
  9. Rosli MA, Sulaiman WAW, Ismail WFW, Yahaya S, Saad AZM, Wan Z, et al.
    PMID: 34756555 DOI: 10.1016/j.bjps.2021.09.032
    BACKGROUND: With the advent of new techniques, foot salvage is feasible following talus oncological resection. As the reconstruction aims to achieve a pain-free, stable ankle for ambulation, biological limb reconstruction is the best option. This case series will evaluate the primary indications, complications, and functional outcomes of the reconstructed talus and highlighting the technical aspects of the surgery with a novel technique of triangular double-barrel free fibula flap.

    METHODS: We performed a retrospective case note review of patients undergoing foot salvage surgeries and primary talus reconstruction with double-barrel free fibula flaps between 2009 and 2019. Patient demographics, aetiologies, operative details, complications, and outcomes were analysed. All patients underwent the same talar reconstruction technique whereby a wide-based triangular framework was created from two bony struts of the osteotomized fibula. The Musculoskeletal Tumour Society (MSTS) scoring system was used to analyse the short- to mid-term functional outcomes.

    RESULTS: Four consecutive patients with aggressive benign and malignant tumours were identified. They consist of three males and one female, with a median age of 32 (range 27-39). Patients were followed up for a median duration of 60 months (range 24-132). Two flaps were complicated with venous thromboses; however, all were salvageable following re-explorations. All patients achieved solid bony fusion with good functional and aesthetic outcomes. The median MSTS score was 74.5% (range 66-76). No donor site morbidity and local recurrence were reported.

    CONCLUSION: The triangular double-barrel free fibular flap is a good option for limb salvage following total talus resection, with good short- to mid-term functional and aesthetic outcomes.

  10. Sulaiman AR, Sallehudin AY, Shahidan Y, Iskandar MA, Halim AS
    Med J Malaysia, 2005 Jul;60 Suppl C:119-21.
    PMID: 16381298
    The use of 'spare part' tissue from an amputated segment to cover a stump with soft tissue deficiency is a viable option for augmenting the shape of the stump and preserving functional length of the stump without additional donor morbidity. The procedure requires no microsurgical skill if the tissues are used as pedicle fillet flaps transfer. This concept of fillet flap makes the amputation distal to an unfavourable definitive amputation site such as in congenital constriction band possible. We report herein a case of amputation distal to constriction ring to illustrate the application of fillet flap in reconstruction surgery.
  11. Zreaqat M, Hassan R, Halim AS
    Int J Oral Maxillofac Surg, 2012 Jun;41(6):783-8.
    PMID: 22424709 DOI: 10.1016/j.ijom.2012.02.003
    This comparative cross-sectional study assessed the facial surface dimensions of a group of Malay children with unilateral cleft lip and palate (UCLP) and compared them with a control group. 30 Malay children with UCLP aged 8-10 years and 30 unaffected age-matched children were voluntarily recruited from the Orthodontic Specialist Clinic in Hospital Universiti Sains Malaysia (HUSM). For the cleft group, lip and palate were repaired and assessment was performed prior to alveolar bone grafting and orthodontic treatment. The investigation was carried out using 3D digital stereophotogrammetry. 23 variables and two ratios were compared three-dimensionally between both groups. Statistically significant dimensional differences (P<0.05) were found between the UCLP Malay group and the control group mainly in the nasolabial region. These include increased alar base and alar base root width, shorter upper lip length, and increased nose base/mouth width ratio in the UCLP group. There were significant differences between the facial surface morphology of UCLP Malay children and control subjects. Particular surgical procedures performed during primary surgeries may contribute to these differences and negatively affect the surgical outcome.
  12. Halim AS, Zulmi W
    Med J Malaysia, 2005 Mar;60(1):109-11.
    PMID: 16250294
    A rectus abdominis myocutaneous flap can provide a large amount of tissue for defect coverage. Rarely a flabby and redundant abdominal tissue was used as a huge extended flap. We report a case of recurrence malignant fibrous histiocytoma of the thigh which was radically resected. The resultant massive defect was success reconstructed with an extended pedicle inferiorly based rectus abdominis myocutaneous flap.
  13. Dorai AA, Halim AS
    Singapore Med J, 2007 May;48(5):e141-5.
    PMID: 17453087
    Extensive full thickness anterior abdominal wall defects pose a difficult challenge to the reconstructive surgeon. The objectives of reconstruction are the support of the intra-abdominal structures in order to preserve the functional integrity and achieve an aesthetically-acceptable appearance. Autologous tissues are versatile and provide the best reconstructive option in this type of defects. The tensor fascia latae myocutaneous flap provides identical abdominal wall musculofascial cover for full thickness defects. In extensive defects, the extended tensor fascia latae flap is a versatile option with a second microvascular anastomosis at the distal end of the flap. A total anterior abdominal wall soft tissue tumour resection defect was reconstructed with the use of the double pedicle extended free tensor fascia latae myocutaneous flap in a 60-year-old man. The patient however succumbed to the disease process six months post-reconstruction. During the follow-up period, there was no evidence of hernia at the anterior abdominal wall.
  14. Sukur SM, Halim AS, Singh KK
    Indian J Plast Surg, 2011 Jan;44(1):112-7.
    PMID: 21713196 DOI: 10.4103/0970-0358.81459
    AIM: The effect of Tualang honey on wound healing in bacterial contaminated full-thickness burn wounds was evaluated in 36 male Sprague Dawley rats.

    MATERIALS AND METHODS: The rats were randomly divided into three groups (n = 12/group). Three full-thickness burn wounds were created on each rat. Each group of rats was inoculated with a different organism in the burn wounds: Group A was inoculated with Pseudomonas aeruginosa, Group B was inoculated with Klebsiella pneumoniae and Group C was inoculated with Acinetobacter baumannii. One wound on each rat was dressed with either Tualang honey, Chitosan gel or Hydrofibre silver. Each wound size was measured on day 3, 6, 9, 12, 15, 18 and 21 of the study.

    RESULTS: The mean wound size of the Tualang honey-treated wounds was not statistically different than that of the Chitosan gel or Hydrofibre silver-treated wounds when the wounds were compared throughout the entire experiment (P > 0.05). However, comparing the mean wound size on day 21 alone revealed that the Tualang honey-treated wounds were smaller in comparison to that of the Chitosan gel and Hydrofibre silver-treated groups.

    CONCLUSIONS: This study shows that topical application of Tualang honey on burn wounds contaminated with P. aeruginosa and A. baumannii gave the fastest rate of healing compared with other treatments.

  15. Ho HL, Halim AS, Sulaiman WAW, Fatimah MJ
    Ann Burns Fire Disasters, 2023 Mar;36(1):19-28.
    PMID: 38680901
    Accuracy of burn size estimation is critical in acute burn management because it directly affects the patient's outcome and prognosis. This study aims to quantify the discrepancies of total body surface area (TBSA) burned between the burn unit (TBSAb) and the referring facilities (TBSAr). Data of all referred adult and paediatric patients admitted to the Hospital Universiti Sains Malaysia Burn Unit within 24 hours post burn were retrospectively reviewed from 2015 to 2019. %TBSA discrepancies were calculated by the differences between TBSAb and TBSAr. A total of 208 patients (111 adults and 97 paediatric patients) were recruited in this study. Of these, the TBSA was overestimated in 60.58% cases, underestimated in 13.46% cases, accurate in 7.69% cases, and in 18.27% cases the referrals had no TBSAr stated. The %TBSA discrepancy was the highest in severe burns (mean 10.80% in adults and 7.59 in paediatric patients; P<0.001). The time interval between referral and reassessment and patients' body mass index (BMI) were not statistically significant for the magnitude of TBSA discrepancy. The number of burn areas involved correlated with the %TBSA discrepancies, with the highest recorded discrepancy being 21.50% in whole body involvement. There were significant discrepancies in TBSA estimations between the referring facilities and those of the Hospital Universiti Sains Malaysia (USM) burn unit, especially among the paediatric patients and those with severe burns. Implementation of educational programs by burn care experts and agreement on a universal method of TBSA assessment are necessary in reducing the discrepancies.
  16. Hanifi N, Halim AS, Aleas CF, Singh J, Marzuki M, Win TT, et al.
    Exp Clin Transplant, 2015 Jun;13(3):273-8.
    PMID: 26086837
    Skin grafting has been evolving as an important application in reconstructive surgery. Mixed reports about the survival of allogeneic and xenogeneic keratinocytes require further substantiation to determine the role of these cells in wound healing.
  17. Rasool AH, Ghazali DM, Abdullah H, Halim AS, Wong AR
    Microvasc Res, 2009 Sep;78(2):230-4.
    PMID: 19481100 DOI: 10.1016/j.mvr.2009.05.005
    Post occlusive skin reactive hyperemia (PORH) is a tool used to assess microcirculation. Endothelial nitric oxide synthase (eNOS) mediates nitric oxide (NO) production; polymorphism of the eNOS gene may affect response to the PORH process. This study aims to determine whether eNOS G894T gene polymorphism affects response to skin PORH. 230 normotensive male and females between 18 and 40 years participated in this cross-sectional study. 170 subjects were of the homozygous GG genotype, whereas 60 were of the GT genotype. Skin PORH was performed by occlusion of the upper arm at 200 mm Hg for 3 min. Skin perfusion and temperature were monitored before, during and after occlusion release using the laser Doppler fluximetry. There were no significant differences between genotypes in their baseline blood pressure, serum cholesterol, BMI and age. Maximum change in perfusion after occlusion release (PORHmax) for the GG and GT genotypes were not significantly different at 50.15+/-1.29 vs. 47.92+/-2.17 AU; ANCOVA, p=0.351. Peak perfusion (PORHpeak) were also not significantly different between the two genotypes (61.23+/-1.36 vs. 57.72+/-2.32 AU; p=0.169). Minimum baseline perfusion were however higher in the GG compared to the GT genotype (10.83+/-0.29 vs. 9.61+/-0.50, p=0.029). We conclude that microvascular reactivity, assessed by change in perfusion after temporary ischemia was not significantly different between the GG and GT genotypes of the eNOS G894T gene. eNOS 894T allele carriers however, have lower baseline perfusion compared to the homozygous G894 allele carrier.
  18. Halim AS, Nor FM, Mat Saad AZ, Mohd Nasir NA, Norsa'adah B, Ujang Z
    J Taibah Univ Med Sci, 2018 Dec;13(6):512-520.
    PMID: 31435371 DOI: 10.1016/j.jtumed.2018.10.004
    Objectives: Chitosan, the N-deacetylated derivative of chitin, has useful biological properties that promote haemostasis, analgesia, wound healing, and scar reduction; chitosan is bacteriostatic, biocompatible, and biodegradable. This study determined the efficacy of chitosan derivative film as a superficial wound dressing.

    Methods: This multicentre randomised controlled trial included 244 patients, of whom 86 were treated with chitosan derivative film and 84 with hydrocolloid. The percentage of epithelisation, as well as patient comfort, clinical signs, and patient convenience in application and removal of the dressings were assessed.

    Results: The primary outcome of this study was the percentage of epithelisation. Except for race (p = 0.04), there were no significant differences between groups in sex, age, antibiotic usage, or initial wound size (p > 0.05). There was no significant difference in the mean epithelisation percentage between groups (p = 0.29). Patients using chitosan derivative film experienced more pain during removal of dressing than those in the hydrocolloid group (p = 0.007). The chitosan derivative film group showed less exudate (p = 0.036) and less odour (p = 0.024) than the control group. Furthermore, there were no significant differences between groups in terms of adherence, ease of removal, wound drainage, erythema, itchiness, pain, and tenderness. No oedema or localised warmth was observed during the study.

    Conclusion: This study concluded that chitosan derivative film is equivalent to hydrocolloid dressing and can be an option in the management of superficial and abrasion wounds.

    Clinical trial No: NMRR-11-948-10565.

  19. Halim AS, Wan Ahmad Kamal WS, Noor NM, Abdullah S
    Arch Plast Surg, 2013 Nov;40(6):687-96.
    PMID: 24286040 DOI: 10.5999/aps.2013.40.6.687
    Ischemic preconditioning has been shown to improve the outcomes of hypoxic tolerance of the heart, brain, lung, liver, jejunum, skin, and muscle tissues. However, to date, no report of ischemic preconditioning on vascularized bone grafts has been published.
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