Faris Q. Alenzi

A role for the Fas/Fas ligand apoptotic pathway in regulating myeloid progenitor cell kinetics

Bone marrow from wild-type mice and mice with mutated Fas (lpr) or mutated Fas ligand (gld) was used to investigate the role of the Fas/FasL system in the regulation of myeloid progenitor cell kinetics.Granulocyte-macrophage colony-forming cells (CFU-GM) were measured by a standard colony assay and the proliferative activity of CFU-GM was measured by replating primary colonies and observing secondary colony formation. Fas expression was restored to lpr mouse bone marrow cells by retrovirus-mediated gene transfer and gld mouse marrow cells were treated with soluble FasL. Wild-type marrow cells were treated with YVAD (a caspase inhibitor) or anti-Fas monoclonal antibodies. There were greater frequencies of myeloid progenitor cells (CFU-GM) in lpr and gld mouse marrow compared to wild-type (WT) marrow (p = 0.0008). The proliferative capacity of CFU-GM was also significantly greater for lpr and gld CFU-GM compared to WT CFU-GM (p = 0.0003 and 0.0001, respectively). Retrovirus-mediated restoration of Fas into lpr marrow, and provision of soluble FasL (sFasL) to gld CFU-GM reduced CFU-GM proliferation to WT levels. Treatment of WT CFU-GM with YVAD or anti-FasL monoclonal antibody increased CFU-GM proliferation to the levels found in lpr and gld CFU-GM. YVAD significantly increased and anti-Fas significantly reduced the proliferative capacity of human CFU-GM (p = 0.015 and 0.04, respectively).Fas, FasL, and caspase activation may play an important role in regulating myeloid progenitor cell kinetics.

Antioxidant Properties of Nigella sativa

Molecular oxygen (O2) is essential in all species for the production of energy within mitochondria; a process known as oxidative phosphorylation. The end products of this process include adenosine triphosphate (ATP), water (H2O) and carbon dioxide (CO2). In addition, very small amounts of reactive oxygen species (ROS) or free radicals are continuously produced as a consequence of normal metabolism of oxygen but which, on occasions when they become overabundant, may toxically damage cells, and therefore need to be biochemically neutralized or extruded from cells. Antioxidants are defined as substances capable of delaying or inhibiting production of ROS intermediates. Cells can either make these antioxidants endogenously, or receive them through the diet.

Circulating Serum miRNAs as Diagnostic Markers for Colorectal Cancer

Aim The study was designed to assess the possibility of using circulating miRNAs (serum miRNAs) as diagnostic biomarkers in colorectal cancer (CRC) and to identify their possibility as candidates for targeted therapy. Methods The study involved two sample sets: 1- a training set which included 90 patients with colorectal related disease (30 with CRC, 18 with inflammatory bowel disease (IBD), 18 with colonic polyps (CP) and 24 with different colonic symptoms but without any colonoscopic abnormality who were enrolled as control group) and 2- a validation set which included 100 CRC patients. Serum miRNAs were extracted from all subjects to assess the expression profiles for the following miRNAs (miR-17, miR-18a, miR-19a, miR-19b, miR-20a, miR-21, miR-146a, miR-223, miR-24, miR-454, miR-183, miR-135a, miR- 135b and miR- 92a) using the custom miScript miRNA PCR-based sybergreen array. The area under the receiver operating characteristic curve (AUC) was used to evaluate the diagnostic performance of the studied miRNAs for colorectal cancer diagnosis. Results Data analysis of miRNA from the training set showed that; compared to control group, only miR-19b was significantly up-regulated in patients with IBD group (fold change = 5.24, p = 0.016), whereas in patients with colonic polyps, miR-18a was significantly up-regulated (fold change = 3.49, p-value = 0.018). On the other hand, miR-17, miR-19a, miR-20a and miR-223 were significantly up-regulated (fold change = 2.35, 3.07, 2.38 and 10.35; respectively and p-value = 0.02, 0.015, 0.017 and 0.016; respectively in CRC patients. However, the validation set showed that only miR-223 was significantly up-regulated in CRC patients (fold change = 4.06, p-value = 0.04). Conclusion Aberrant miRNA expressions are highly involved in the cascade of colorectal carcinogenesis. We have found that (miR-17, miR-19a, miR-20a and miR-223) could be used as diagnostic biomarkers for CRC. On the other hand, miR-19b and miR-18a could be used as diagnostic biomarkers for CP and IBD respectively.

Stem cells: Biology and clinical potential

Stem cell technology has developed rapidly in recent years to the point that we can now envisage its future use in a variety of therapeutic areas. This review seeks to summarize the types and sources of stem cells that may be utilized in this way, their pattern of development, their plasticity in terms of differentiation and transdifferentiation, their ability to self-renew, the privileged microenvironment in which they are housed, their cell surface markers used to track them, issues relating to their transfection, and their fate. Particular reference is made, as prime examples, to how both the function of mesenchymal and neural stem cells are being studied experimentally, and currently used clinically in certain circumstances, towards the ultimate aim of their mainstream therapeutic use. Key words: Stem cells, apoptosis, differentiation, mesenchymal and neural stem cells, therapy.

Apoptosis as a tool for therapeutic agents in haematological diseases

Apoptosis, an active mechanism of cell death, is an important process in many biological systems. Apoptosis is thought to contribute to many disease processes. This notion has raised expectations that therapeutic opportunities will naturally follow once a better understanding of these processes has been achieved. The regulation of apoptosis in normal and malignant haematological diseases represents an important theraputic approach in the treatment of leukaemia and lymphoma. This review summarises recent developments in the clinical manipulation of apoptosis pathways in haematological therapy.

Cellular and molecular themes in apoptosis

SummaryApoptosis, an active mechanism of cell death, is of central importance in many biological scenarios. Research in this area has the potential to contribute to our understanding of many diseases and raises several potential therapeutic opportunities. Given this potential and the speed with which our understanding of this field has advanced over recent years, it is timely to introduce the clinican to the background on which the clinical implications of this research will be built. This review begins with contrasting apoptosis with the other mechanism of cell death, necrosis, and then outlines the features by which apoptosis may be recognised. With a view to understanding the level at which this process may be involved in disease and therapeutics, it is important to be aware of the basic mechanistic features of the induction and execution of apoptosis. In this, surface molecules such as CD95 (Fas) and the cascade of intracellular enzymes involved at many levels in apoptosis, the caspases, are of central importance. In all this, the mitochondrion is crucial to the induction of apoptosis and the regulation of the whole process. In the last part of this review, we attempt to draw out the clinical relevance of all this information. It is clear that apoptosis has an important role in the pathophysiology of malignancy, particularly with respect to haematological cancers, but also other oncological diseases. Apoptosis is also very important in autoimmune disease and viral infection. Finally, it is clear that apoptosis may be manipulated therapeutically to the benefit of patients in various scenarios. This is clearly an exciting area for future development, but one which clearly depends on a thorough mechanistic understanding.

Review: Stem cells and gene therapy.

Both stem cell and gene therapy research are currently the focus of intense research in institutions and companies around the world. Both approaches hold great promise by offering radical new and successful ways of treating debilitating and incurable diseases effectively. Gene therapy is an approach to treat, cure, or ultimately prevent disease by changing the pattern of gene expression. It is mostly experimental, but a number of clinical human trials have already been conducted. Gene therapy can be targeted to somatic or germ cells; the most common vectors are viruses. Scientists manipulate the viral genome and thus introduce therapeutic genes to the target organ. Viruses, in this context, can cause adverse events such as toxicity, immune and inflammatory responses, as well as gene control and targeting issues. Alternative modalities being considered are complexes of DNA with lipids and proteins. Stem cells are primitive cells that have the capacity to self renew as well as to differentiate into 1 or more mature cell types. Pluripotent embryonic stem cells derived from the inner cell mass can develop into more than 200 different cells and differentiate into cells of the 3 germ cell layers. Because of their capacity of unlimited expansion and pluripotency, they are useful in regenerative medicine. Tissue or adult stem cells produce cells specific to the tissue in which they are found. They are relatively unspecialized and predetermined to give rise to specific cell types when they differentiate. The current review provides a summary of our current knowledge of stem cells and gene therapy as well as their clinical implications and related therapeutic options.

Cell type specific expression of the apoptosis stimulating protein (ASPP-2) in human tissues.

Apoptosis stimulating proteins of p53 (ASPP-l and ASPP-2) are a novel family of proteins that have been found to co-stimulate p53 activation of Bax (Bcl-2 associated protein X) inducing caspase-mediated apoptosis. Therefore, these proteins may play an important role in regulating apoptosis in normal and neoplastic cells. However, their cellular and tissue distribution has not been documented. The aim of this study was to determine the localization pattern of ASPP-2 in a variety of normal and malignant human tissues, including liver, lung, prostate, small intestine, kidney, ovary, bladder, cervix, breast, stomach, bowel, gallbladder, endometrium, pancreas, spleen and thyroid.The distribution and expression of ASPP-2 was assessed by immunohistochemistry in a range of formalin-fixed, paraffin embedded, benign and malignant human tissues, using a mouse monoclonal antibody against ASPP-2.The results showed a variable pattern of positivity of ASPP-2 within the tissues studied. ASPP-2 expression was localized in the cytoplasmic paranuclear granules in the epithelial cells of most of the organs we studied. The pattern of staining intensity of ASPP-2 correlated to the maturation state in benign tissue and to the differentiation state in the context of bladder cancer.This study indicates that ASPP-2 has a specific distribution pattern within tissues and cells in a way that appears to be related to differentiation. However, the patterns are neither simplistic nor straightforward and will require further investigation in order to appreciate fully their physiological/pathological significance.

Neglected Bilateral Posterior Shoulder Fracture Dislocation in an Uncontrolled Seizure patient.

Posterior dislocation of the shoulder is a rare injury that occurs secondary to trauma and seizures. Diagnosis is often missed and treatment is challenging. Neglected posterior dislocation is associated with Hill-Sachs lesion which leads to locking of dislocation. Correct diagnosis is achieved by history taking, a physical examination and appropriate imaging. In neglected shoulder dislocation with uncontrolled seizure and humeral head defects of up to 45% the McLaughlin procedure shows excellent results at follow-up.

Monoclonal gammopathy in a tertiary referral hospital

OBJECTIVE Monoclonal gammopathies reflect conditions of plasma B-cell disorders. Our objective was to identify the prevalence and types of these gammopathies in our population. METHODS A 10year retrospective study was conducted. Serum and/or urine protein electrophoresis were performed on 6624 samples. Positive bands were further tested by immunofixation (IFE). RESULTS Homogenous bands were detected in 7% of the patients. IFE method confirmed 6.3% in which 59% were males and 41% were females. The mean age was 64.7 for females and 66.5 for males. The sensitivity and specificity were 91% and 99% respectively. The most common protein was IgG kappa 41%, followed by IgG lambda 19%. Sixty-eight percent of these patients had monoclonal gammopathy of undetermined significance and 14.6% had multiple myeloma. CONCLUSION The majority of the studied population had MGUS. This observation is in concord with other western populations. The sensitivity and specificity of protein electrophoresis is diagnostically and reasonably acceptable.