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Avicenna Journal of Medical Biotechnology - Volume:1 Issue: 3, Oct-Dec2009

Avicenna Journal of Medical Biotechnology
Volume:1 Issue: 3, Oct-Dec2009

  • تاریخ انتشار: 1388/10/11
  • تعداد عناوین: 8
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  • EDITORIAL
    Page 133
  • Page 135
    Severe hepatic failure accounts for many deaths and raises medical costs each year worldwide. Currently, liver transplantation is the most common therapeutic option for patients with end-stage chronic liver disease. Due to decrease in the number of organ donors, many in need of transplantation continue to remain on the waiting list. Hepatic Tissue Engineering is a step toward alleviating the need for organ donors. Regenerative medicine and tissue engineering require two complementary key ingredients as follows: 1) biologically compatible scaffolds that can be readily adopted by the body system without harm, and 2) suitable cells including various stem cells or primary cells that effectively replace the damaged tissues without adverse consequences. Yet many challenges must be overcome such as scaffold choice, cell source and immunological barriers. Today, hepatogenic differentiation of stem cells has created trust and promise for use of these cells in hepatic tissue engineering and liver replacement. However, using suitable scaffolds is an important key to achieving the necessary functions required for hepatic replacement. In recent years, different scaffolds have been used for liver tissue engineering. In this review, we have presented different concepts in using cell /scaffold constructs to guide hepatic tissue engineering.
  • Page 147
    The standard semen analysis is the first line and the most popular laboratory test in the diagnosis of male fertility. It evaluates sperm concentration, motility, morphology and their vitality. However, it is well-known that normal results of semen analysis can not exclude men from the causes of couples infertility. One of the most important parameters of sperm in its fertilizing potential is "Sperm chromatin integrity" that has direct positive correlation with Assisted Reproductive Techniques (ART) outcomes including; fertilization rate, embryo quality, pregnancy and successful delivery rate. It seems that sperm DNA chromatin integrity provides better diagnostic and prognostic approaches than standard semen parameters. For these reasons under-standing the sperm chromatin structure, etiology of sperm chromatin abnor-mality, identification factors that disturbs sperm chromatin integrity and the mechanism of their action can help in recognizing the causes of couples infertility. Various methods of its evaluation, its importance in male fertility, clinical relevance in the outcomes of ART and application of laboratory and medical protocols to improve this integrity have valuable position in diagnosis and treatment of male infertility. There has recently been interest in the subject and its application in the field of andrology. Therefore, with regard to the above mentioned importance of sperm chromatin integrity, this review article describes details of the useful information pertaining to sperm DNA damage including the origins, assessments, etiologies, clinical aspects, and prevention of it.
  • Page 161
    In this study TSGA10 has been demonstrated as a testis-specific human gene that encodes a protein localized in sperm-tail and conserved in ciliary structure. Further investigations showed TSGA10 signalling and expression during embryogenesis, brain development and some malignancies including brain tumors. Given the role of this protein in neuronal development and in certain tumors, it could potentially serve as a diagnostic marker and therapeutic target in brain tumors. Therefore, using immunohistochemistry, we evaluated the localization of TSGA10 in different regions of brain, and its pattern/level of expression in tissue microarray (Cybrdi) containing human brain tumors and normal brain. In rat specimens, TSGA10 was mainly expressed in subventricular zone, hippocampus and granular layer of cerebellum of the brain. The antibody also stained the diverse and different types of human brain cancers. The TSGA10 was strongly over-expressed in glioblastoma and astrocytoma when compared to normal human brain. The expression of TSGA10 was also confirmed in astrocyte derived from a human astroctyoma cell line by immunocytochemistry. This study indicates that TSGA10 can be used as an immunohistochemical marker for human neuroglia and astrocyte cells and is over-expressed in brain tumors.
  • Page 167
    Methanolic extract of whole plant of Amaranthus viridis L (MEAV), was screened for antinociceptive activity using acetic acid induced writhing test, hot plate test and tail immersion test in mice. In a similar way a screening exercise was carried out to determine the antipyretic potential of the extract using yeast induced pyrexia method in rats. Administration of the extracts was applied to both laboratory animals at the doses of 200 and 400 mg/kg body weight, respectively. The results of the statistical analysis showed that MEAV had significant (p<0.01) dose dependent antinociceptive and antipyretic properties at 200 and 400 mg/kg. Hence present investigation reveals the antinociceptive and antipyretic activities of methanolic extract of Amaranthus viridis.
  • Page 173
    Sperm chromatin integrity has been being recognized as an important factor in male fertility. During normal fertilization, high quality sperm with intact chromatin are selected through natural selection in journey from vagina to fallopian tube. However, using Assisted Reproductive Techniques, particularly ICSI, the natural selection is bypassed. Therefore sperm with DNA breakage have the opportunity to fertilize the egg which may lead to decreased embryo quality and implantation rate. The aim of this study was to evaluate the effects of sperm chromatin integrity on ICSI outcomes. A total of 200 semen samples were collected from couples undergoing ICSI and were analyzed according to WHO criteria. Each sample was evaluated for sperm chromatin integrity using four cytochemical assays and semen processing by swim up method. The ICSI was carried out according to a long-term pituitary down-regulation protocol. The correlation between sperm parameters, sperm chromatin integrity and ICSI outcomes (fertilization rate and embryo quality) was examined. The mean number of oocyte, fertilization rate and cleavage embryos per cycles was 7.5±5.0, 74.06%±25 and 5.4±3.6, respectively. There was not significant correlation between the results of chromatin assays (AO, AB, TB, and CMA3) and fertilization outcomes following ICSI. The fertilization rate was significantly higher for a group with less than 10% chromatin abnormality (p<0.05). Sperm chromatin integrity is essential for successful fertilization, embryo development and normal pregnancy. A protamine deficiency appeared to affect fertilization rate and embryo quality. However, the presence of confounding factors such as selection of spermatozoa according to normal morphology may influence the effect of sperm chromatin status on ICSI outcomes.
  • The Effect of the Duration of In Vitro Maturation (IVM) on Parthenogenetic Development of Ovine Oocytes
    Page 181
    The aim of this study was to compare the effect of time of parthenogenetic activation (22 hr versus 27 hr after In Vitro Maturation-IVM) on in vitro development of ovine oocytes using either single (Ionomycin 5 M for 5 min or Ethanol 7% for 7 min) or combined (ionomycin and ethanol with 6-DMAP 2 mM for 3 hr) activation treatments. The abattoir-derived in vitro matured activated oocytes were cultured in modified synthetic oviductal fluid and assessed for the cleavage, blastocyst, and hatching rates. The single-activated oocytes had a reduction in cleavage, blastocyst and hatching rates compared to the combined-activated oocytes (except for the cleavage at 27 hr). In single-treated groups the rates of cleavage and blastocyst were increased as the maturation time was extended from 22 hr to 27 hr. The numbers of total cells and Inner Cell Mass (ICM), though insignificant, were greater in combined-treated groups compared to the single treatment. The number of ICM in Eth+6-DMAP group activated at 27 hr was lower than 22 hr. Nonetheless, irrespective of the activation protocol, development to the blastocyst stage, the numbers of total cell, ICM, and cell allocation (ICM/total cells) were significantly lower in parthenogenetic than fertilized embryos. In conclusion, though the cleavage and blastocyst rates in single-treated groups were positively influenced by the extension of duration of IVM (27 hr), there was a trend of decreased numbers of total cells and ICM in slightly aged oocytes. Moreover, developmental potential of ovine parthenotes, especially in young oocytes, was improved by the addition of 6-DMAP to the activation regimen.
  • Page 193
    Late-onset Alzheimer''s Disease (LOAD) is a neurodegenerative disorder and the most common form of dementia affecting people over 65 years old. Alzheimer’s disease is a complex disease with multi-factorial etiology. Inflammation has been approved to have an important role in the pathogenesis of Alzheimer’s disease (AD). TNF-α is a main pro-inflammatory cytokine that plays an essential role in initiation and regulation of inflammatory responses. Several studies have shown the probable association of polymorphism at TNF-α gene’s promoter with AD pathogenesis. This study was performed to determine whether this polymorphism contributes to the risk for late-onset Alzheimer''s disease (LOAD) in Iranian population. One hundred and forty AD patients and 158 healthy controls were recruited in the study. Following extraction of genomic DNA, using PCR/RFLP methods the genotype and allele frequencies were determined in case and control subjects. The statistical analysis showed no significant difference in the allele and genotype frequencies due to this polymorphism between the two groups. Also after stratifying the subjects by their APOE-ε4 status, no significant association was observed. Our results suggest that Tumor necrosis factor-alpha (TNF-) -308 G/A is not a risk or protective factor for late-onset Alzheimer’s disease in Iranian population. However, to confirm these results further study with a bigger sample size may be required.