Split-skin grafting (SSG) is the gold standard treatment for full-thickness skin defects. For certain patients, however, an extensive skin lesion resulted in inadequacies of the donor site. Tissue engineering offers an alternative approach by using a very small portion of an individual's skin to harvest cells for propagation and biomaterials to support the cells for implantation. The objective of this study was to determine the effectiveness of autologous bilayered tissue-engineered skin (BTES) and single-layer tissue-engineered skin composed of only keratinocytes (SLTES-K) or fibroblasts (SLTES-F) as alternatives for full-thickness wound healing in a sheep model. Full-thickness skin biopsies were harvested from adult sheep. Isolated fibroblasts were cultured using medium Ham's F12: Dulbecco modified Eagle medium supplemented with 10% fetal bovine serum, whereas the keratinocytes were cultured using Define Keratinocytes Serum Free Medium. The BTES, SLTES-K, and SLTES-F were constructed using autologous fibrin as a biomaterial. Eight full-thickness wounds were created on the dorsum of the body of the sheep. On 4 wounds, polyvinyl chloride rings were used as chambers to prevent cell migration at the edge. The wounds were observed at days 7, 14, and 21. After 3 weeks of implantation, the sheep were euthanized and the skins were harvested. The excised tissues were fixed in formalin for histological examination via hematoxylin-eosin, Masson trichrome, and elastin van Gieson staining. The results showed that BTES, SLTES-K, and SLTES-F promote wound healing in nonchambered and chambered wounds, and BTES demonstrated the best healing potential. In conclusion, BTES proved to be an effective tissue-engineered construct that can promote the healing of full-thickness skin lesions. With the support of further clinical trials, this procedure could be an alternative to SSG for patients with partial- and full-thickness burns.
Various methods, such as vascularized bone transfers, Illizarov bone transport, allogenic bone grafts, bone graft substitutes, are available in treating traumatic bone loss. Free non-vascularised fibular graft is an autografting method that only requires minimal facilities or expertise. However, this method is not popularized due to its avascular property and there is not many reports regarding its use in treating a large traumatic bone loss. We reported a case in our center to demonstrate its possibility of successfully treating the traumatic radial bone loss in pediatric patient. Patient had good recovery with the regain of good range of movement of forearm and there is no harvest site morbidity after two years of follow up.
Matched MeSH terms: Transplantation, Autologous; Bone Transplantation
Mesenchymal stem cells (MSC) are multipotent, self-renewing cells that can be found mainly in the bone marrow, and other post-natal organs and tissues. The ease of isolation and expansion, together with the immunomodulatory properties and their capability to migrate to sites of inflammation and tumours make them a suitable candidate for therapeutic use in the clinical settings. We review here the cellular mechanisms underlying the emerging applications of MSC in various fields.
Four hundred (400) students studying first year Medicine, Dentistry, Laboratory Technology, Pharmacy, Biomedicine and Bioengineering degree courses in the University of Malaya were assessed on their awareness and knowledge on eye donation using an open ended questionnaire. The majority of the students (344, 86%) in this study were aware about eye donation; the awareness was higher in biomedical (77.1%) and medical students (76.7%) compared to the others (55.9%-70.7%). One hundred and eight students (27%) were willing to donate their eyes. Most of the students (376, 94%) did not know about any eye bank in Malaysia. One hundred and sixty (40%) students were aware that whole eye can be removed from the donor and 101 (25.25%) were aware that the cornea can be removed separately. However, only 121 (30.25%) knew that donated eyes were used for corneal grafting. More than half of the students (231, 57.7%) did not know that the donor eye could be stored before transplantation. The results of this study indicate that there is a need to educate the young adults in our society about corneal transplantation so that they can in turn motivate other members of society and their own family members to become eye donors, thus facilitating the availability of donor corneas for corneal transplantation in Malaysia.
Repair of an abdominal aortic aneurysm in a renal transplant recipient poses many different problems due to warm ischaemia to the grafted kidney. This is a case of 50-year-old gentleman who had a pervious renal transplant with abdominal aortic aneurysm. To reduce the effects of warm ischaemia on the transplanted kidney, an axillo unifemoral bypass was done prior to aneurysm repair. This ensured continued perfusion to the transplanted kidney. The post operative period was complicated by Methicillin Resistant Staphyloccus Aureus infection of the graft.
Organ transplantation has become increasingly routine as a means of saving and improving the quality of lives of thousands of people each year. However, transplant activity is increasingly constrained by the shortage of organs. The major impediment in procuring organs for transplant in Malaysia is the lack of cadaveric donors. The lack of cadaveric donors has encouraged patients to go to countries like India and China to purchase organs especially kidneys for transplantation. The inadequacies of the existing Malaysian Human Tissues Act 1974 has also contributed to this problem. For instance, the word 'tissue" is not defined under the Act. This raises complex and ethical questions as to the scope of the definition for "tissue". There is also no definition of "the person lawfully in possession of the body." This is significant as he is the person who is empowered by the Act to authorise removal of tissue. Further, there is also no articulation of a hierarchy of relatives who are deemed the next of kin. In a situation involving a large number of relatives, asserting different opinions, this may pose a problem. The articulation of a priority list is particularly difficult in Malaysia as it is a multi-cultural society where the hierarchy of relatives with the right to claim decision-making powers may vary in different cultures. Furthermore, there is also a pressing need for a legislation to ensure that the rights of potential live donors are protected. At the moment, the Human Tissues Act 1974 only relates to cadaveric donors whereas live donors fall within the purview of the common law. The system of "opting out" should be considered in Malaysia whereby every individual is presumed to be a donor unless he or she registers an objection. But this system can only be fair if every person in the community is given notice of the law and understands its implications. For the system to work, there must also exist a simple and effective way of registering objections. There is a need for continuous intensive public education and counselling. A nationally co-ordinated mechanism must be in place to ensure effectiveness of identifying potential donors and recipients.
Matched MeSH terms: Organ Transplantation/legislation & jurisprudence*
A review was carried out in 21 cases of bone transport in the tibia done between May 1995 and December 1997. These were done for the treatment of compound (Grade IIIB) fractures with extensive bone and soft tissue loss and in infective non-unions of the tibia using the Ilizarov technique and ring fixator. In 5 cases, 2 or 3 additional procedures were needed such as tendo achilles (TA) lengthening, bone grafting, revision of construct or revision of scar at the docking site. Average resection of infected bone was 5.2 cms in the infective non-union group and average bone and soft tissue loss was 8 cms in the compound Grade IIIB fracture group. The defect was bridged and regenerate bone occurred in all the cases except one. Union was achieved in all the cases although 10 needed bone grafting. Infection was eradicated in all the cases. Limb length discrepancy was corrected in all the cases except three. Mean duration of treatment was 12 months.
The MtC tests performed prospectively was correlated with graft survival in 73 living, related grafts. The MLC was expressed as the relative response (RR), and graft survival assessed at six months, one year and two years. The l-haplotype matched grafts with high RR had poorer graft survival at one and two years than those with low RR, but this difference was not statistically significant.
This paper presents four cases of Fournier's gangrene, including one involving a reconstructive procedure using a preputial rotation flap to cover the raw area, to reduce the period of wound healing. Since Fournier's description of Idiopathic scrotal gangrene in 1884, there have been a number of reports on this relatively rare disease but the problem of achieving early healing and epithelialisation remains.
Tacrolimus, which bonds to an immunophilin, FK506 binding protein (FKBP) has emerged as one of the most widely used immunosuppressant post solid organ transplantation. It offers excellent patient survival rates post-transplantation and a lesser number of acute rejections as compared to cyclosporine. Tacrolimus has a narrow therapeutic window with overexposure leading to acute and chronic forms of nephrotoxicity. Remarkably few data have been published on the overexposure to tacrolimus following mild diarrhoea in post-transplant patients who received treatment with tacrolimus. We observed a post-liver transplant patient with increased trough level of tacrolimus during severe diarrhoea with no complications following a timely adjustment on the dose of tacrolimus.
Matched MeSH terms: Liver Transplantation; Organ Transplantation
Mature T and natural killer (NK) cell non-Hodgkin lymphoma (T-NHL) has a poor prognosis. Data from existing retrospective and prospective studies have suggested that high-dose chemotherapy followed by autologous hematopoietic cell transplantation (auto-HCT) may improve the survival in patients with chemosensitive disease, either in the upfront or salvage setting. Auto-HCT is currently recommended to be used as frontline consolidation in peripheral T cell lymphoma not otherwise specified, angioimmunoblastic T cell lymphoma, anaplastic large cell lymphoma-anaplastic lymphoma kinase negative, NK/T cell (disseminated), and enteropathy-associated T cell lymphoma. However, about one-third of patients never reach transplantation because of early relapse or refractory disease. Allogeneic hematopoietic cell transplantation (allo-HCT), via its immunologic graft-versus-lymphoma effect, has been used to salvage patients with relapsed or refractory disease, resulting in long-term disease-free survival in a fraction of patients. However, the higher risk of transplant-related mortality due to regimen-related toxicities, graft-versus-host disease, and post-transplant infectious complications continues to limit the mainstream adoption of allo-HCT for this disease. Despite that, allo-HCT has been incorporated as part of the frontline treatment for aggressive subtypes of T-NHL, such as γδ T cell lymphoma and aggressive NK cell leukemia. Recent attempts to incorporate novel targeted T cell directed therapies into the treatment pathway of T-NHL may enhance treatment response and enable more patients to reach transplant, offering an alternative means of treating this disease.
The aim of this study was to determine the effectiveness of demineralized freeze-dried bone xenograft (DFDBBX) in minimizing post-surgical recession in moderate to advanced adult periodontitis in patients. Nine patients with a total of eighteen intrabony defects were matched for the tooth type, location of defects and periodontal pocket depth (5 to 7mm). Following an initial nonsurgical treatment, recession at defects indicated for surgery was measured pre-operatively. Surgical treatment was carried out by split mouth design, where the test sites were assigned DFDBBX and the control sites were subjected to debridement without the use of DFDBBX. Recessions were measured at 3 months, 6 months and 9 months post-operatively. The results showed no statistically significant difference in mean recession at 3, 6 and 9 months post-operatively compared to baseline for both test and control groups. Thus, DFDBBX was ineffective in minimizing recession on patients with moderate to severe periodontitis, as compared to surgical debridement alone.
Matched MeSH terms: Transplantation, Heterologous; Bone Transplantation
The concept of regenerative endodontics wherein one can replace damaged pulp structures and recuperate the functionality in erstwhile necrotic and infected root canal systems has been a cutting-edge technology. Though the notion started as early as the 1960s, even before the discovery of stem cells and regenerative medicine, it was in the 2000s that this procedure gained momentum. Ever since then, researchers continue to discover its essential benefit to immature teeth and its ability to overcome the caveats of endodontic therapy, which is commonly known as root canal treatment. Further, through this therapy, one can redevelop root even in immature teeth with necrotic pulps, which overall helps in maintaining skeletal and dental development. Past literature indicates that regenerative endodontic procedures seem to be successful, especially when compared with other conventional techniques such as Mineral Trioxide Aggregate apexification. Besides, many clinicians have begun to apply regenerative endodontic procedures to mature teeth in adult patients, with several clinical case reports that have shown complete resolution of signs and symptoms of pulp necrosis. Generally, the three most desirable outcomes anticipated by clinicians from this procedure include resolution of clinical signs and symptoms, root maturation and redevelopment of the neurogenesis process. Despite this, whether these objectives and true regeneration of the pulp/dentin complex are achieved is still a question mark. Following the discovery that regenerative endodontics indeed is a stem cell-based treatment, addressing the fundamental issue surrounding stem cells might assist in achieving all identified clinical outcomes while favoring tissue formation that closely resembles the pulp-dentin complex.
Sarcopenia is a common condition in the geriatric population. It refers to age-related and progressive decline in muscle mass and function, which has a great impact on one's mobility and quality of life. Patients with sarcopenia are mainly treated with nutritional therapy, exercise therapy, or a combination of both. Since the identification of mesenchymal stem cells (MSCs) several decades ago, many studies have explored the application of MSCs in the field of regenerative medicine. MSCs are popular candidates for cell-based therapy owing to their multipotent nature and immunomodulatory properties. Even though MSCs do not naturally differentiate into myogenic cells, they are important players in skeletal muscle health, as MSCs support myogenic differentiation of other cells and promote recovery of injured skeletal muscle. Recent studies have found that MSCs may be of benefits in the treatment of sarcopenia. This article gives an overview of sarcopenia and the role of MSCs in skeletal muscle homeostasis. It also discusses the therapeutic potential of MSCs and their derivatives, as well as the underlying mechanisms of the therapeutic effects of MSCs and MSC-based products in sarcopenia.
Bone processing and radiation were reported to influence mechanical properties of cortical bones due in part to structural changes and denaturation of collagen composition. This comparative study was to determine effects of bone processing on mechanical properties and organic composition, and to what extent the radiation damaging after each processing. Human femur cortical bones were processed by freezing, freeze-drying and demineralisation and then gamma irradiated at 5, 15, 20, 25 and 50 kGy. In the compression test, freeze drying significantly decreased the Young's Modulus by 15%, while demineralisation reduced further by 90% (P
Children with Down syndrome (DS) are at a significantly higher risk of developing acute myeloid leukemia, also termed myeloid leukemia associated with DS (ML-DS). In contrast to the highly favorable prognosis of primary ML-DS, the limited data that are available for children who relapse or who have refractory ML-DS (r/r ML-DS) suggest a dismal prognosis. There are few clinical trials and no standardized treatment approach for this population. We conducted a retrospective analysis of international study groups and pediatric oncology centers and identified 62 patients who received treatment with curative intent for r/r ML-DS between year 2000 to 2021. Median time from diagnosis to relapse was 6.8 (range, 1.1-45.5) months. Three-year event-free survival (EFS) and overall survival (OS) were 20.9 ± 5.3% and 22.1 ± 5.4%, respectively. Survival was associated with receipt of hematopoietic stem cell transplantation (HSCT) (hazard ratio [HR], 0.28), duration of first complete remission (CR1) (HR, 0.31 for > 12 months) and attainment of remission after relapse (HR, 4.03). Patients who achieved complete remission (CR) before HSCT, had an improved OS and EFS of 56.0 ± 11.8% and 50.5 ± 11.9%, respectively compared to those who underwent HSCT without CR (3-year OS and EFS of 10.0 ± 9.5%). Treatment failure after HSCT was predominantly because of disease recurrence (52%) followed by treatment-related mortality (10%). The prognosis of r/r ML-DS remains dismal even in the current treatment period and serve as a reference point for current prognostication and future interventional studies. Clinical trials aimed at improving the survival of patients with r/r ML-DS are needed.