Effat Omar

Cellular events and biomarkers of wound healing

Researchers have identified several of the cellular events associated with wound healing. Platelets, neutrophils, macrophages, and fibroblasts primarily contribute to the process. They release cytokines including interleukins (ILs) and TNF-α, and growth factors, of which platelet-derived growth factor (PDGF) is perhaps the most important. The cytokines and growth factors manipulate the inflammatory phase of healing. Cytokines are chemotactic for white cells and fibroblasts, while the growth factors initiate fibroblast and keratinocyte proliferation. Inflammation is followed by the proliferation of fibroblasts, which lay down the extracellular matrix. Simultaneously, various white cells and other connective tissue cells release both the matrix metalloproteinases (MMPs) and the tissue inhibitors of these metalloproteinases (TIMPs). MMPs remove damaged structural proteins such as collagen, while the fibroblasts lay down fresh extracellular matrix proteins. Fluid collected from acute, healing wounds contains growth factors, and stimulates fibroblast proliferation, but fluid collected from chronic, nonhealing wounds does not. Fibroblasts from chronic wounds do not respond to chronic wound fluid, probably because the fibroblasts of these wounds have lost the receptors that respond to cytokines and growth factors. Nonhealing wounds contain high levels of IL1, IL6, and MMPs, and an abnormally high MMP/TIMP ratio. Clinical examination of wounds inconsistently predicts which wounds will heal when procedures like secondary closure are planned. Surgeons therefore hope that these chemicals can be used as biomarkers of wounds which have impaired ability to heal. There is also evidence that the application of growth factors like PDGF will help the healing of chronic, nonhealing wounds.

Human Pentastomiasis Caused by Armillifer moniliformis in Malaysian Borneo

We report a case of visceral pentastomiasis caused by Armillifer moniliformis in a 70-year-old aboriginal farmer from rural Malaysian Borneo. The patient complained of upper abdominal pain, jaundice, and loss of weight. Radiological investigations and subsequent histopathological examination revealed an adenocarcinoma of the pancreas with an adjacent liver nodule containing a nymph of A. moniliformis. This report constitutes the first documented human pentastomid infection in the whole of Malaysia after nearly 40 years, and it is the third description from Malaysian Borneo. Cases of human and animal pentastomiasis in Malaysia are discussed.

Sarcocystosis among Wild Captive and Zoo Animals in Malaysia

Sarcocystis sp. infection was investigated in 20 necropsied captive wild mammals and 20 birds in 2 petting zoos in Malaysia. The gross post-mortem lesions in mammals showed marbling of the liver with uniform congestion of the intestine, and for birds, there was atrophy of the sternal muscles with hemorrhage and edema of the lungs in 2 birds. Naked eye examination was used for detection of macroscopic sarcocysts, and muscle squash for microscopic type. Only microscopically visible cysts were detected in 8 animals and species identification was not possible. Histological examination of the sections of infected skeletal muscles showed more than 5 sarcocysts in each specimen. No leukocytic infiltration was seen in affected organs. The shape of the cysts was elongated or circular, and the mean size reached 254 x 24.5 µm and the thickness of the wall up to 2.5 µm. Two stages were recognized in the cysts, the peripheral metrocytes and large numbers of crescent shaped merozoites. Out of 40 animals examined, 3 mammals and 5 birds were positive (20%). The infection rate was 15% and 25% in mammals and birds, respectively. Regarding the organs, the infection rate was 50% in the skeletal muscles followed by tongue and heart (37.5%), diaphragm (25%), and esophagus (12.5%). Further ultrastructural studies are required to identify the species of Sarcocystis that infect captive wild animals and their possible role in zoonosis.

Leptin Increases Blood Pressure and Markers of Endothelial Activation during Pregnancy in Rats

Raised leptin levels have been reported in the placentae and serum of women with elevated blood pressure and proteinuria during pregnancy. The role of leptin in this however remains unknown. This study investigates the effect of leptin administration on systolic blood pressure (SBP) and proteinuria and serum markers of endothelial activation during pregnancy in Sprague Dawley rats. From day 1 of pregnancy, 24 rats were randomised into those given either saline (group 1) or leptin at 60 or 120 μg/kg/body weight/day (groups 2 and 3 resp.). SBP was measured every 5 days and 24-h urinary protein was measured at days 0 and 20 of pregnancy. Animals were euthanised on day 20 of pregnancy, and serum was collected for estimation of E-selectin and ICAM-1. Compared to group 1, SBP during the latter part of the pregnancy was significantly higher in the leptin-treated group (P < 0.01). Urinary protein excretion, serum E-selectin, and ICAM-1 were significantly higher in leptin-treated rats (P < 0.05). It seems that leptin administration to normotensive Sprague Dawley rats during pregnancy significantly increases SBP, urinary protein excretion, and markers of endothelial activation. However, further studies are required to examine the underlying mechanism responsible for this and its relevance to preeclampsia in humans.

ACE2 activation by xanthenone prevents leptin-induced increases in blood pressure and proteinuria during pregnancy in Sprague-Dawley rats

This study investigates the effect of ACE2 activation on leptin-induced changes in systolic blood pressure (SBP), proteinuria, endothelial activation and ACE2 expression during pregnancy in Sprague-Dawley rats. Pregnant rats were given subcutaneous injection of either saline, or leptin, or leptin plus xanthenone (ACE2 activator), or xanthenone (XTN) alone. SBP, serum ACE, ACE2, endothelin-1, E-selectin and ICAM-1 levels were estimated; also their gene expressions were determined in the kidney and aorta respectively. Compared to control, SBP was higher in the leptin-only treated group (P<0.001) and lower in rats treated with xanthenone alone (P<0.01). Proteinuria, markers of endothelial activation were significantly higher than controls in leptin-only treated rats (P<0.05). ACE2 activity and expression were lower in leptin-only treated rats when compared to controls (P<0.05). It seems, leptin administration during pregnancy significantly increases SBP, proteinuria, endothelial activation, but decreases ACE2 level and expression. These effects are prevented by concurrent administration of xanthenone.

Tocotrienol preserves ovarian function in cyclophosphamide therapy.

Introduction: Cyclophosphamide (CPA) chemotherapy leads to ovarian failure and infertility. Tocotrienol (T3) is an antioxidant and anti-inflammatory agent. The role of T3 in ovarian protection throughout chemotherapy remains unclear. Aim: To investigate the role of T3 in the preservation of female fertility in CPA treatment. Method: Sixty female mice were divided into five treatment groups, namely, normal saline, corn oil only, T3 only, CPA and CPA + T3. The treatment was given for 30 days, followed by administration of gonadotrophin to induce ovulation. After killing, both ovaries were collected and examined histologically. Results: There was significant reduction in ovarian size in the CPA group compared with the normal group (CPA versus normal, mean area ± SD; 0.118 ± 0.018 vs. 0.423 ± 0.024 cm2; p ≤ 0.005), whilst concurrent administration of T3 with CPA leads to conservation of ovarian size (CPA + T3 vs. CPA, mean area ± SD; 0.285 ± 0.032 vs. 0.118 ± 0.018 cm2; p ≤ 0.005). Ovaries in CPA group showed abnormal folliculogenesis with accompanied reduced ovulation rate, follicular oedema, increased vascularity and inflammatory cell infiltration. These changes were reversed by concurrent T3 administration. Conclusion: Co-administration of T3 with CPA confers protection of ovarian morphology and function in vivo. These findings contribute to the further elucidation of CPA effect on ovary and suggest the potential of T3 use in preserving fertility in chemotherapy.

Which is the best method of sterilization for recycled bone autograft in limb salvage surgery: a radiological, biomechanical and histopathological study in rabbit.

BackgroundLimb salvage surgery is a treatment of choice for sarcomas of the extremities. One of the options in skeletal reconstruction after tumour resection is by using a recycled bone autograft. The present accepted methods of recycling bone autografts include autoclaving, pasteurization and irradiation. At the moment there is lack of studies that compare the effectiveness of various sterilization methods used for recycling bone autografts and their effects in terms of bone incorporation. This study was performed to determine the effects of different methods of sterilization on bone autografts in rabbit by radiological, biomechanical and histopathological evaluations.MethodsFresh rabbit cortical bone is harvested from the tibial diaphysis and sterilized extracorporeally by pasteurization (n = 6), autoclaving (n = 6), irradiation (n = 6) and normal saline as control group (n = 6). The cortical bones were immediately reimplanted after the sterilization process. The subsequent process of graft incorporation was examined over a period of 12 weeks by serial radiographs, biomechanical and histopathological evaluations. Statistical analysis (ANOVA) was performed on these results. Significance level (α) and power (β) were set to 0.05 and 0.90, respectively.ResultsRadiographic analysis showed that irradiation group has higher score in bony union compared to other sterilization groups (p = 0.041). ANOVA analysis of ‘failure stress’, ‘modulus’ and ‘strain to failure’ demonstrated no significant differences (p = 0.389) between treated and untreated specimens under mechanical loading. In macroscopic histopathological analysis, the irradiated group has the highest percentage of bony union (91.7 percent). However in microscopic analysis of union, the pasteurization group has significantly higher score (p = 0.041) in callus formation, osteocytes percentage and bone marrow cellularity at the end of the study indicating good union potential.ConclusionsThis experimental study shown that both irradiation and pasteurization techniques have more favourable outcome in terms of bony union based on radiographic and histopathological evaluations. Autoclaving has the worst outcome. These results indicate that extracorporeal irradiation or pasteurization of bone autografts, are viable option for recycling bone autografts. However, pasteurization has the best overall outcomes because of its osteocytes preservation and bone marrow cellularity.

Tocotrienol rich fraction supplementation confers protection on the ovary from cyclophasphamide induced apoptosis

Abstract Introduction Cyclophosphamide (CPA) therapy leads to infertility via oxidative stress induced apoptosis of ovarian cells. Tocotrienol, vitamin E isoform, is a much more potent antioxidant compared to tocopherol, the more investigated vitamin E isoform. Tocotrienol rich fraction (TRF) is an affordable and available form of tocotrienol supplementation. The effect of concurrent TRF supplementation with CPA treatment is un-investigated. Objective To study the ovarian protective effect of tocotrienol rich fraction (TRF) when coadministered with CPA. Methods 60 female ICR mice, aged between 8 −10 weeks were divided into 5 treatment groups: CPA, CPA&TRF, normal saline, TRF only, and corn oil (TRF carriage vehicle) only. The treatment was given for 30 consecutive days, after which all animal were euthanized. At dissection, both ovaries were removed, fixed in 10% formalin, processed and embedded in paraffin to form tissue blocks. Terminal deoxynucleotidyl transferase–mediated deoxy-uridine triphosphate nick-end labelling (TUNEL) assay was performed on the tissue blocks. Results & Discussion There was a significant reduction of TUNEL positive cells in the combined CPA&TRF group compared to CPA only group (p Conclusion Co administration of TRF with CPA confers protection against apoptosis in ovaries. TRF is a potential candidate for ovarian conservation in chemotherapy associated damage.

Reduced in-vivo C-reactive protein aortic tissue expression following tocotrienol-enriched mixed fraction supplementation in cholesterol-induced atherosclerosis

Atherosclerosis is the underlying pathology behind cardiovascular disease, the main cause of death in worldwide. Inflammation plays a pivotal role in its pathogenesis. Tocotrienol is a palm derived vitamin E component, known have potent anti-inflammatory properties. The effect of tocotrienol on formation and progression of atherosclerosis is unknown. Aim: to determine the anti-inflammatory and anti-atherosclerotic effects of tocotrienol-enriched mixed fraction (TEMF) supplementation in hypercholesterolaemia induced rabbits. Methods: 20 New Zealand white rabbits were randomised into two groups and fed with 1% high cholesterol diet (HCD) for (i) 2 weeks in group A and (ii) 8 weeks in group B, followed by randomization into two treatment groups: (i) TEMF (15mg/kg) or (ii) placebo for 8 weeks. During the 8 week treatment duration, all the groups were given normal diet. Analyses of atherosclerotic lesions were performed while expression of inflammatory was evaluated using immunohistochemistry. Results: There were no significant reduction in atherosclerotic lesions with TEMF treatment for both groups A and B. However, there were significantly lower positive tissue expression in TEMF compared to placebo for CRP (3.01 ± 0.86 vs. 25.51 ± 10.85%; p=0.05) and SMA (3.91 ± 1.33 vs. 16.19 ± 4.08%; p=0.04) in early atherosclerosis. In addition, no significant differences were observed between TEMF and placebo in both groups A and B for NFκB, IL-6, ICAM-1, E-selectin and MMP-12. Conclusion: Eight weeks treatment with TEMF has neutral effects on atherosclerotic lesions in both early and severe atherosclerosis. However, TEMF treatment reduces aortic intimal tissue expression of CRP especially in early atherosclerosis indicating its in vivo anti-inflammatory effects.

Manifestation of Coronary Atherosclerosis in Klang Valley, Malaysia: An Autopsy Study

Aims: The present study aimed to determine the epidemiological aspects of medico-legal autopsies and manifestation of coronary atherosclerosis. Methods: This was a cross sectional study involving 222 cases recruited from National Institute of Forensic Medicine (NIFM) Hospital Kuala Lumpur (HKL) and Department of Forensic Medicine Hospital Sungai Buloh (HSgB) for a period of 15 months, from December 2012 to April 2014. Sociodemographic and autopsy findings, including the cause and manner of death were documented. Results: Male and female subjects aged 18–70 years were recruited. Males contributed to 86% of the total subjects and comprised 61% of young adults. Road traffic accidents were the primary cause of death, contributing almost 50% of the subjects. One third of the cases comprised of death due to natural causes, wherein almost 75% of the subjects within this category succumbed to sudden cardiac death. Coronary artery disease (CAD) contributed to 60% of the sudden cardiac death (SCD). Single and double-vessel diseases were the most common pattern of atherosclerosis. In almost 80% of CAD cases, atherosclerosis affected the left anterior descending artery (LAD). Conclusion: Cardiovascular diseases were the most significant natural cause of sudden death with a staggering figure of 75%. CAD was the single most commonly encountered pathology within the SCD. Most cases presented with single and double-vessel diseases, observed in all subjects, as well as the young adult population.