فصلنامه آزمایشگاه و تشخیص
پیاپی 20 (تابستان 1392)

Type 1 diabetes)T1D), is an autoimmune disease that targets insulin-secreting pancreatic beta cells for destruction. A fully mature, functional β cell produces and appropriately secretes the mature form of insulin, in response to glucose to maintain normal glycemic levels in the blood. The current treatment for T1D is long-term insulin replacement therapy. Pancreatic transplantation has been performed for T1D patients with success but the main limitations of this strategy are the low number of suitable donors and the risks of surgery. The replacement of β cells is a promising therapy for diabetic patients, but the process depends on the discovery of sources other than cadaveric pancreas. Stem cells are undifferentiated cells that are capable of self-renewal and differentiation into any cell type. Pancreatic stem cells would be an ideal source for β cell replacement since they are committed to differentiate into pancreatic cells, but their cellular marker phenotype and anatomic location has not yet been identified. Also, as pancreatic stem cells will likely be isolated from healthy patients, the immune system barrier to allogeneic transplants will also need to be addressed. Another alternative to Pancreatic stem cells is the differentiation of IPCs)Insulin producing cells) from ESCs)Embryonic stem cells) or iPSCs)induced pluripotent stem cells). But this first requires the development and acceptance of a standard methodology to generate them. IPCs differentiated by this standard methodology will have to be completely mature and functional. The generation of a well-defined homogenous population of transplantable pancreatic progenitors that can be identified with extracellular markers would be an alternative to IPCs. Finally, independently of the type of cell transplanted)ESC-IPC, iPSC- IPC, or pancreatic progenitors), the immunogenicity of these cells will have to be considered and determined to predict the potential and type of immune response to block before and after transplantation. The data collected from such analyses will aid in the establishment of strategies that can promote immune tolerance of these IPC grafts.

Approximately 450 million people worldwide are physically disabled; 70 million of them are deaf, with an average of hearing loss more than 35 dB. So far, in connection with the hearing, several genes have been identified. Inherited forms of hearing impairment are including autosomal dominant)20-15%), autosomal recessive)80%), X-linked)2-1%) and mitochondrial)from less than 1 to 20% in some populations). In this study, the mitochondrial MT-RNR1 gene mutations have been studied. We have not found any patient with m. 1555A>G mutation and incidence of this mutation in our population is very low. However, in seven patients (6. 5%) we have identified two sequence changes including; m. 921T>C and m. 1005T>C, that previously reported as associated to nonsyndromic and aminoglycoside hearing loss. Incidence of m. 921T>C and m. 1005T>C in our patients were estimated 0. 9% and 6% respectively. Reported frequency of these mutations in mtDB database is 0. 67% and 0. 26% respectively. In our study m. 1005T>C nucleotide change frequency was higher than previous reports. These data suggest the m. 1005T>C variant is more important than 1555A>G mutation in studied population. Moreover, we have found five patients (4. 6%) with three nucleotide changes in 12srRNA gene, including; m. 739C>T, 1245T>C, 1545T>C. Incidence of m. 739C>T, m. 1245T>C and m. 1545T>C in our patients were estimated 1. 8%, 1. 8%, 0. 9% respectively. Reported frequency of m. 739C>T in mtDB database was 0. 1%. Nucleotide substitutions at m. 1245T>C and m. 1545T>C has not been reported before in mtDB database. According to the study, it is suggested, in our country, with further studies, types of common mitochondrial mutations are identified, and prepare them to a panel of «Rapid Test» and patients be evaluated before taking any medication aminoglycoside, and use of these drugs in patients with mitochondrial mutations, is prevented.

Antibacterial peptides belongs to the large group of bioactive peptides. They are evolutionarily conserved component of the innate immune response and are found among all classes of life. These peptides are potent, broad spectrum antibiotics which demonstrate potential as novel therapeutic agents. Unlike the majority of conventional antibiotics it appears as though antimicrobial peptides may also have the ability to enhance immunity by functioning as immunomodulators. Fundamental differences exist between prokaryotic and eukaryotic cells that may represent targets for antimicrobial peptides. Antibacterial peptides have been demonstrated to kill Gram negative and Gram positive bacteria)including strains that are resistant to conventional antibiotics), mycobacterium)including Mycobacterium tuberculosis), enveloped viruses, fungi and even transformed or cancerous cells. Although the potency of these antimicrobial peptides against the more susceptible pathogens is normally not as strong as certain conventional antibiotics, one of their major strengths is their ability to kill multi-drug-resistant bacteria at similar concentrations. overall, several cases of successful use of antimicrobial peptides in agriculture and food industry indicate a promising future for extensive application of these peptides.

Helicobacter pylori)H. Pylori) bacteria Colonize human stomach mucosa where establish a long– term infection association with acute or chronic gastric inflammation. Cytotoxic – associated gene A (cag A) is related to higher grades of gastric inflammation and carcinoma. In this study we detetrmined CagA seropositive strain in Dyspeptic patients with H. Pylori infection. Patients Six hundred adult dyspeptic patients examined for anti H. Pylori and anti - cag A antibodies by Enzyme – linked Immunoassay (ELISA) method.All the cases were from East – Azarbijan in North – west of Iran and enrolled in this study in a five – year period)2003 – 2008). 85.5% of dyspeptic patients were positive for H. Pylori infection Anti – cag A antibody was detectable in 35.6% of patients with H. Pylori infection. Screening of H. Pylori infection by ELISA method showed that most)85.5%) of the dyspeptic patients are seropositive for H. Pylori. Determining of photogenic strains of H. Pylori by anti – Cag A antibody could have diagnostic validity in sever gastric infections.

PSA is produced almost exclusively in the Prostate, gland abnormalities of this Antigen is frequency associated with increased serum concentration. Because PSA,S lack of specificity for prostate cancer, however many patients undergo unnecessary biopsies or treatment for benign or latent tumors, respectively. Recently the focus has been on creating fast, reiable and cost – effective assays for biomarkers in blood. The PSA test and its variation Velocity, Density, free vs bound, proisoforms have limited usefulness in diagnosis of Prostate Cancer. Now molecular- based biomarkers hold the Promise of answering crucial clinical question such as who should be screened, who has Prostate Cancer and who needs treatment, Now these new markers are in various stages of development that promising more specific diagnosis of prostate cancer. This review of Cap biomarkers shows that there is a hope that the use of panels of markers can improve the diagnosis and prognosis in Prostate Cancer.

Leptin is a protein hormone that composed of 167 amino acids with a molecular weight of 16 kDa, which is secreted by adipose tissue. Obesity is a common condition that has affected almost a third of people in most countries and the cost of their treatment is very high burden for countries. Of years ago, scientists follow a substance that can control and treatment of these biology complications; Until the year 1994, Friedman and his colleagues discovered a hormone that is produced by the ob gene and it is called Leptin)meaning thin). With discovery of this hormone, the scientists created big hopes for the treatment of obese individual; So that in a short time, more than three thousand articles were published in this regard. Leptin is generated in fat cells and to a lesser extent in the intestinal epithelium and the placenta. Leptin receptors are expressed in the brain mainly in arcuate nucleus ventromedial hypothalamic nuclei neurons that regulate eating behavior. Leptin acts via two receptors in the body. Long-receptors are in the parts of the brain and the hypothalamus. This type of receptors are family of type one cytokine receptors and activation of these receptors by the hormone leptin inhibits neuropeptide Y in the hypothalamus and suppress appetite and increase metabolism through effects on thyroid and adrenal hormones. The second form of leptin receptors are found in peripheral tissues such as muscles, fat, liver and intestines that with their activation, applied many metabolic effects related to energy and body weight regulation.