In this study, porous hydroxyapatite (HA) samples were fabricated via sponge techniques with the aid of sago as part of the binder mixture. Development processes for the production of porous bone graft substitutes are studied using polyurethane sponge. To obtain the optimum amount of binder for successful fabrication of porous HA were done. Initially, porous HA powder was synthesized using calcium hydroxide and orthorphosphoric acid. Meanwhile, sago was mixed with PVA in a certain ratio to be used as binder for preparing the porous HA. After a series of investigative tests were conducted to characterize the sintered samples, the use of the sago and polymeric mixture was found to successfully aid the fabrication of porous HA samples. In this investigation, comparison of physical and mechanical characteristics between samples prepared using difference techniques was made.
MeSH terms: Biomechanical Phenomena; Bone and Bones/injuries; Bone and Bones/chemistry*; Calcium Hydroxide/chemistry; Humans; Phosphoric Acids/chemistry; Pilot Projects; Polymers; Bone Density; Bone Transplantation; Porosity; Durapatite/chemical synthesis; Durapatite/chemistry*; Bone Substitutes/chemical synthesis; Bone Substitutes/chemistry*; Tissue Engineering*; Tissue Scaffolds/chemistry*
Phenotypic variation in biofilm formation is common in clinical isolates of S. epidermidis. In the current study, nearly 5% of all clinical isolates analysed showed phenotypic variation in biofilm forming ability and electrophoretic mobility (EM). This is the first report of S. epidermidis strains irreversibly switching from biofilm-positive to biofilm-negative phenotype by spontaneous deletion of icaADBC genes which represents a new, possibly common mechanism of phenotypic variation.
MeSH terms: Bacterial Proteins/genetics; Bacterial Proteins/metabolism; Electrophoresis; Humans; Phenotype; Pilot Projects; Rec A Recombinases/genetics*; Rec A Recombinases/metabolism*; Rec A Recombinases/chemistry; Serine Endopeptidases/genetics; Serine Endopeptidases/metabolism; Staphylococcal Infections/genetics; Staphylococcal Infections/microbiology*; Staphylococcus epidermidis/genetics*; Staphylococcus epidermidis/metabolism; Time Factors; Gene Expression Regulation, Bacterial/genetics*; Gene Deletion*; Biofilms
In previous study, in vitro antiplasmodial activity fractions isolated from methanol extract of E. longifolia, Jack. have been evaluated. Among 5 isolates evaluated from the study, isolate 4 showed high in vitro antiplasmodial activity. However, which stage specificity of the isolates on P. falciparum cycles has not been evaluated. This study was intended to evaluate the stage specificity of the isolate on P. falciparum cycles. The study was conducted by observing the percentage of each stages of P. falciparum microscopically after 8, 16, 24, 32, 40, 48, 56, 64, and 72 hours incubation periods with 3 various concentration of isolate 4 compared with control. The result showed that isolate 4 of E. longifolia root methanol soluble fractions most potent at trophozoites stages of P. falciparum.
Cashew (Anacardium occindentale L) leaves extract (CLE) has potential as tyrosinase inhibitor that can be used for therapeutic in pigmentation problem. This study investigates the real potential of CLE to inhibit tyrosinase and melanin reduction using human epidermal melanocytes. The extracts were exposed to the human melanocytes for more than 24 hours. The CLE extract exhibited potential as tyrosinase inhibitor, reduced melanin and high in antioxidant activity relative to commercial extract of Emblica sp.
Lead (Pb) is a neurotoxic heavy metal and children in the developmental stage are particularly susceptible to toxic effects of lead exposure. The brain is the key organ involved in interpreting and responding to potential stressors. Epidemiological investigations have established the relationship between chronic lead exposure and cognitive impairments in young children. Excessive production of radical species plays an important role in neuronal pathology resulting from excitotoxic insults, therefore one plausible neuroprotective mechanism of bioflavonoids is partly relevant to their metal chelating and antioxidant properties. Centella asiatica (CA) is a tropical medicinal plant enriched with bioflavonoids and triterpenes and selenium, reported to rejuvenate the cells and promote physical and mental health. Bioflavonoids are claimed to be exert antimutagenic, neurotrophic and xenobiotics ameliorating and membrane molecular stabilizing effects. The objective of the present work is to study the protective antioxidant effect of pretreatment of CA extract (CAE) on lead acetate induced changes in oxidative biomarkers in the central nervous system (CNS) of mice.
MeSH terms: Animals; Antioxidants/pharmacology*; Brain/drug effects*; Central Nervous System/drug effects; Flavonoids/pharmacology*; Organometallic Compounds/toxicity*; Pilot Projects; Triterpenes/pharmacology*; Biomarkers; Oxidative Stress/drug effects; Neuroprotective Agents/therapeutic use; Lead Poisoning, Nervous System/drug therapy*; Lead Poisoning, Nervous System/etiology; Lead Poisoning, Nervous System/prevention & control; Models, Animal; Mice
Aqueous extract of Ficus deltoidea var. agustifolia was examined for the subchronic toxicity effects in rats. Groups of 10 rats were given the extract daily by oral gavage for 90 days at 0 (control), 100 and 300mg/kg/body weight, respectively. Blood samples were collected upon sacrificed and analysed for haemogram and biochemistry. The results showed there were no significant changes of the blood parameters in all treated groups compared to the control.
Pollutants, especially heavy metals like cadmium, Chromium, lead and mercury, play a significant role in causing various water-borne diseases to humans. This study evaluates the sorption properties of bioactive constituents of Moringa oleifera seeds for decontamination of cadmium at laboratory scale. The performance of the bioactive constituent extracted by salt extraction method was enhanced by process optimization with various concentration of bioactive dosages, agitation speed, contact time, pH and heavy metal concentrations. Statistical optimization was carried out for evaluating the polynomial regression model through effect of linear, quadratic and interaction of the factors. The maximum removal of cadmium was 72% by using 0.2 g/l of bioactive dosage.
Large quantities of agro-based liquid wastes are produced every year and their disposal is often a problem for industries. In light of that, in this study prudent effort was done to screen the agro-industrial wastes - pineapple waste (PAW) and palm oil mill effluent (POME) for valuable biophenols product. Three different solvents; ethanol, acetone and distilled water were screened in order to enhance the process. All experiments were performed using fixed process conditions of solid to solvent ratio, temperatures, time and agitation speed. Effectiveness of extraction process to produce biophenol was based on high amount with more activity. POME was selected as potential source with biophenol content of 125.42 mg/L GAE.
The present work was to determine the development and re-epithelization of bilayered corneal construct (BCC) in vitro and in vivo using scanning electron microscopy (SEM). The in vitro BCC was transplanted to the rabbit's eye and after 90 days the BCC was harvested and analyzed. The corneas were processed for morphology studies. The result indicates that the BICC that was transplanted for 90 days showed good development and re-epithelization of epithelial layer similar to the normal cornea.
This study was conducted to explore the feasibility of culturing conjunctiva epithelial cells in serum-free and feeder layer-free culture system with regard to the cell morphology and immunocytochemistry of the rabbit bulbar, fornix and palpebral conjunctiva epithelia. The results showed that epithelium cells from all the three conjunctiva regions can be cultured in a serum-free and feeder layer-free environment. We obtained highest epithelial growth from fornix region with minimum invasion of fibroblast cells compared to other area. All cultured cells were stained positive for cytokeratin 19 and MUC5AC and negative for cytokeratin 3. These findings suggested that fornix was a better source of cells for the development of tissue engineered conjunctiva for future clinical application.
Spinal cord, sciatic nerve, olfactory ensheathing cell and bone marrow derived mesenchymal stem cells were evaluated as an alternative source for tissue engineering of nerve conduit. All cell sources were cultured in alpha-MEM medium. Olfactory Ensheathing Cell (OEC) showed the best result with higher growth kinetic compared to the others. Spinal cord and sciatic nerve were positive for GFAP, OEC were positive for GFAP, S100b and anti-cytokeratin 18 but negative for anti-Human Fibroblast.
A potential cure for hearing loss would be to regenerate hair cells by stimulating cells of the damaged inner ear sensory epithelia to proliferate and differentiate into hair cells. Here, we investigated the possibility to isolate, culture-expand and characterize the cells from the cochlea membrane of adult mice. Our results showed that the cultured cells isolated from mouse cochlea membrane were heterogenous in nature. Morphologically there were epithelial like cells, hair cell like, nerve cell like and fibroblastic cells observed in the culture. The cultured cells were immunopositive for specific hair cell markers including Myosin 7a, Calretinin and Espin.
Chondrocytes were isolated from normal and microtic human auricular cartilage after ear surgery carried out at Universiti Kebangsaan Malaysia Medical Centre. Chondrocytes were cultured and expanded until passage 4. After reached confluence, cultured chondrocytes at each passage (P1, P2, P3 and P4) were harvested and assigned for growth profile analysis. There was no significant difference in cell viability between both normal and microtic samples (p = 0.84). Both samples showed no significant differences for growth profile parameters in terms of growth rate, population doubling time and total number of cell doubling, except in passage 1, where there is significant difference in cell growth rate (p = 0.004). This preliminary data has indicated that chondrocytes from microtic cartilage has the potential to be used in the reconstruction of human pinna in the future.
This study aimed to compare the effects of three different media on the in vivo chondrogenesis of sheep bone marrow stem cells (BMSC). Sheep BMSC were cultured in F12:DMEM + 10% FBS, chondrogenic medium containing 5ng/ml TGF,3 + 50ng/ml IGF-1 and UKM-MECC for three weeks. The cultured cells were then harvested for construct formation with fibrin. Constructed tissues were implanted subcutaneously into nude mice for in vivo development. Cell aggregates were formed in both chondrogenic medium and UKM-MECC demonstrated the early chondrogenesis process. After five weeks of in vivo development, both chondrogenic medium and UKM-MECC promoted cartilage matrix synthesis confirmed by Safranin O staining.
Bone marrow derived progenitor cells have been widely studied for its multipotent property and have proofed to be an important resource in regenerative medicine. However, the propagation of murine bone marrow appeared to be a great challenge as compared to other mammalian species. In this study, various isolation techniques and the plasticity of the isolated cells were evaluated. Our result shows that magnetic sorting technique yielded the most viable cells and displayed wider differentiation capacity.
Although unsaturated fatty acids such as eicosapentaenoic acid (EPA, C20:5n-3), docosahexaenoic acid (DHA, C22:6n-3) and arachidonic acid (ARA, C20:4n-6), collectively known as the highly unsaturated fatty acids (HUFA), play pivotal roles in vertebrate reproduction, very little is known about their synthesis in the ovary. The zebrafish (Danio rerio) display capability to synthesize all three HUFA via pathways involving desaturation and elongation of two precursors, the linoleic acid (LA, C18:2n-6) and linolenic acid (LNA, C18:3n-3). As a prerequisite to gain full understanding on the importance and regulation of ovarian HUFA synthesis, we described here the mRNA expression pattern of two enzymes; desaturase (fadsd6) and elongase (elovl5), involved in HUFA biosynthesis pathway, in different zebrafish ovarian follicle stages. Concurrently, the fatty acid profile of each follicle stage was also analyzed.
Somatic mutations of phosphoinositide-3-kinase, catalytic, alpha; PIK3CA gene have been reported in several types of human cancers. The majority of the PIK3CA mutations map to the three "hot spots" - E542 K and E545 K in the helical (exon 9) and H1047R in the kinase (exon 20) domains of the p110alpha. These hot spot mutations lead to a gain of function in PI3 K signaling. We aimed to determine the frequency of PIK3CA mutations in the three most common Malaysian cancers. In this study, we assessed the genetic alterations in the PIK3CA gene in a series of 20 breast carcinomas, 24 colorectal carcinomas, 27 nasopharyngeal carcinomas (NPC), and 5 NPC cell lines. We performed mutation analysis of the PIK3CA gene by genomic polymerase chain reaction (PCR) and followed by DNA direct sequencing in exons 9 and 20. No mutations were detected in any of the 24 colorectal and 27 NPC samples, but one hot spot mutation located at exon 20 was found in a NPC cell line, SUNE1. Interestingly, PIK3CA somatic mutations were present in 6/20 (30%) breast carcinomas. Two of the six mutations, H1047R, have been reported previously as a hot spot mutation. Only one out of three hot spot mutations were identified in breast tumor samples. The remaining four mutations were novel. Our data showed that a higher incidence rate of PIK3CA mutations was present in Malaysian breast cancers as compared to colorectal and nasopharyngeal tumor tissues. Our findings also indicate that PIK3CA mutations play a pivotal role in activation of the PI3 K signaling pathway in breast cancer, and specific inhibitors of PIK3CA could be useful for breast cancer treatment in Malaysia.
MeSH terms: Breast Neoplasms/genetics*; Breast Neoplasms/metabolism; DNA Mutational Analysis; Humans; Malaysia; Mutation*; Nasopharyngeal Neoplasms/genetics; Nasopharyngeal Neoplasms/metabolism; Colorectal Neoplasms/genetics; Colorectal Neoplasms/metabolism; Signal Transduction; Phosphatidylinositol 3-Kinases/genetics; Phosphatidylinositol 3-Kinases/metabolism*; Cell Line, Tumor
First discovered in the early 1950s, reoviruses (respiratory enteric orphan viruses) were not associated with any known disease, and hence named orphan viruses. Recently, our group reported the isolation of the Melaka virus from a patient with acute respiratory disease and provided data suggesting that this new orthoreovirus is capable of human-to-human transmission and is probably of bat origin. Here we report yet another Melaka-like reovirus (named Kampar virus) isolated from the throat swab of a 54 year old male patient in Kampar, Perak, Malaysia who was suffering from high fever, acute respiratory disease and vomiting at the time of virus isolation. Serological studies indicated that Kampar virus was transmitted from the index case to at least one other individual and caused respiratory disease in the contact case. Sequence analysis of the four small class genome segments indicated that Kampar and Melaka viruses are closely related. This was confirmed by virus neutralization assay, showing an effective two-way cross neutralization, i.e., the serum against one virus was able to neutralize the other. Although the exact origin of Kampar virus is unknown, epidemiological tracing revealed that the house of the index case is surrounded by fruit trees frequently visited by fruit bats. There is a high probability that Kampar virus originated from bats and was transmitted to humans via bat droppings or contaminated fruits. The discovery of Kampar virus highlights the increasing trend of emergence of bat zoonotic viruses and the need to expand our understanding of bats as a source of many unknown viruses.
Primary corneal myxoma is extremely rare. It has only been reported on 2 previous occasions. Secondary corneal myxomas are more common, arising from corneal diseases such as infective keratitis, keratoconus, and bullous keratopathy. Myxomas occur commonly in other soft tissues such as the heart, paranasal sinuses, and muscles but can rarely present in periocular structures including the conjunctiva, orbit, and eyelid. Ours is only the third case of primary corneal myxoma reported in the literature and illustrates several unusual features. These include an inferonasal location between the corneal epithelium and Bowman layer and with no relationship to the corneal stroma, rapid tumor growth over a 3-month period, and no previous ocular trauma or conjunctival pathology. The histology of this lesion has an important part to play in the management of this condition as it determines the cellular origin, establishes a benign or malignant state, and helps with treatment and prognosis. One reported case of primary corneal myxoma recurred within 2 months after local resection. This was treated with bandage soft contact lens, and no recurrence had been reported since. Our case is now 12 months post op and has had no recurrence.