Archives of Advances in Biosciences
Volume:1 Issue: 2, Spring 2010

Chitosan is an amino polysaccharide which can be prepared from shrimp shells with several applications in medicine and tissue engineering. The most important parameter, that characterizes chitosan and its applications, is its degree of deacetylation. In this research the influence of deacetylation time on the quality of the produced chitosan was investigated by measuring the amount of glucosamine and acetyl glucosamine. The amount of glucosamine in the sample was measured using HPLC analysis based on derivation method. By deacetylation of the extracted chitin in 90 and 180 minutes, chitosan with deacetylation degree of 69.75% and 77.63% was obtained, respectively. Therefore, by increasing the deacetylation period in a constant temperature condition and NaOH concentration, the deacetylation degree is increased.

Polymorphisms of the size of heterochromatin regions and abnormalities of chromosomes have been well documented in human genome; they consist of DNA sequences that are not transcribed. The prime aim of the present study was to evaluate the heterochromatin polymorphism and numerical and structural abnormalities associated with chromosomes in drug addicts.No data exists in Iran regarding the cytogenetic characteristics of drug addiction lymphocytes. Therefore, cytogenetic investigations were performed in 93 drug addiction lymphocytes and 93 normal controls. This randomized collected study was conducted on 93 consecutive drug addiction individuals and 93 healthy individuals in Loghman and private hospitals, Tehran, Iran between the years 2007-2009. By applying Barium Hydroxide saline Giemsa (BSC) method, the variant heterochromatin polymorphism of chromosomes 1, 9 and 16 on lymphocyte cultures were evaluated. Cytogenetic analysis was performed in drug addicts� lymphocytes cultures.Constitutive heterochromatin polymorphism of chromosomes 1 in drug addicts revealed statistical significant when compared with chromosome of healthy controls P=0.004).� The differences were significant for chromosome 9 (P=0.029), it was P=0. 94.1% ��in drug addiction and 5.9% in the control group (P=0.196). The differences were also significant for chromosome 16: it was 91.9% in addicts and 8.1% in the control group (P=0.052). Also the frequency of partial and complete inversion did not show any significant differences between the drugs addicts and the control group. The occurrence of chromosomal defects including, chromatid break (12 addicts), chromatid gap (8 addicts), dicentric (2 addicts), was higher in our observation.Our constitutive heterochromatin polymorphism blocks and chromosomal abnormalities in drugs addicts chromosome may provide an opportunity to serve as a marker for the detection and characterization of the damages chromosomes in drug addicts.

One of the side effects of diabetes epidemic today in the world is painful neuropathy, the reasons and treatments of which are un- known. Due to the importance of the problem of pain treatment as one of the harmful phenomena in life, this research studies the effect of continued diabetes on the formalin induced pain and Baclofen analgesia in rats. Moreover, the effect of Baclofen as a non-opiate, analgesic drug on the increased pains in the quiescent phase as the model of diabetic pain is investigated. The method is experimental, evaluating the pain level through conducting the formalin test in 3 groups of rats. The first group was divided to control (injection normal saline) and diabetic (injection aloxan 100 mg/kg) which were tested, after one to four weeks from the beginning of diabetes, the second one was divided to a new control and diabetic group, and before performing formalin test, the Baclofen (10 mg/kg) was injected to them. And the third one was divided to two diabetic groups that received Baclofen and normal saline and then the pain of the quiescent phase was compared in them. The results indicate that diabetes increases formalin induced pain (P < 0.05) and remained with continued diabetes. It also indicates that diabetes establishes increased pain in the quiescent phase (P < 0.05), yet, it has had no influence on the Baclofen analgesic effect on the first phase of formalin test but increased it on the second phase. Moreover, Baclofen can quiet the increased pain in quiescent phase (P < 0.05) very well. Due to the results of this study it seems that diabetes, with the changes in the central and peripheral pathways of the pain and also pain control, increases the pain. More studies are required for determining its mechanisms. These changes are accompanied with weakening the internal anti pain systems such as Gaba ergic, which can be treated with Baclofen. Diabetes has no interaction with the Baclofen’s analgesic effect, so, Baclofen may be recommended as an effective drug to comfort painful diabetic Neuropathy.

The essential amino acid L-tryptophan (Trp) has importance as a pharmaceutical agent, especially in neuro-medicine. It is also added to feed products as a food fortifier. Furthermore, application of Trp is widespread in biotechnology. Trp is produced by a condensation reaction between indole and L-serine, which is catalyzed by bacterial tryptophanase activity. In this study, we have investigated Trp production using microbial system in the presence and absence of its precursors and Iranian cane molasses. The results showed that the optimum concentration of the molasses for maximum bacterial growth is 10 g/lit. Furthermore, in order to assay the amount of tryptophan produced, thin layer chromatography was used. The results showed that Iranian cane molasses contains considerable amounts of serine and indole, enough for Trp production (0.48 mM) in culture medium. But additional indole has inhibitory effects on Trp production. The data are compatible with previous reports on inhibitory effect of indole not only on cell growth but also on tryptophanase formation and function.

Liver fluke infections in herbivores are common in many countries, including Iran. Meat-inspection records in an abattoir located in Ahwaz (capital of Khuzestan Province, in southwestern Iran), from March, 20, 1999 to March, 19, 2008 were used to determine the prevalence and long term trend of liver fluke disease in sheep, goats and cattle in the region. A total of 3186755 livestock including 2490742 sheep, 400695 goats and 295318 cattle were slaughtered in the 9-year period and overall 144495 (4.53%) livers were condemned. Fascioliasis and dicrocoeliosis were responsible for 35.01% and 2.28% of total liver condemnations in this period, respectively. Most and least rates of liver condemnations due to fasciolosis in slaughtered animals were seen in cattle and sheep, respectively. The corresponding figures from dicrocoeliosis were goats and sheep, respectively. The overall trend for all livestock in liver fluke was a significant downward during the 9- year period. The prevalence of liver condemnations due to fasciolosis decreased from 7.37%, 1.80%, and 4.41% in 1999–2000 to 4.64%, 1.12%, and 2.80% in 2007–2008 for cattle, sheep and goats, respectively. Dicrocoeliosis was less prevalent than fascioliasis, but similarly declined from 0.35 % and 0.15% in 1999–2000 to 0.00% and 0.08 % in 2007–2008 in cattle and sheep, respectively. Data showed significant seasonal pattern for Dicrocoelium dendriticum in sheep and goats, but for Fasciola spp. in different animals there were no statistically significant differences with respect to season. Liver condemnations due to fasciolosis and dicrocoeliosis were more prevalent in cattle slaughtered during summer, whereas they were higher in winter for both sheep and goats. The odds ratio showed a slightly different pattern in some years; however, the overall declining trend was still observed. This survey provides baseline data for the future monitoring of these potentially important parasitic infections in the region, and demonstrating possible long term trends.

Embryonic stem (ES) cells are derived from the pluripotent inner cell mass (ICN) cells of blastocysts with the potential to maintain an undifferentiated state indefinitely. The derivation process involves plating of the blastocysts on mouse embryonic fibroblast (MEF) and expansion of the outgrowth in to established ES cell line. ES cell are capable of unlimited self-renewal by symmetric division and differentiated cells to all primitive embryonic germ layers. The capacity of ES cells to differentiate in to almost all the cell types of human body highlights their potential to play a promising role in cell replacement therapies for treatment of human diseases. In this study, MEFs have been replaced with human mesenchymal stem cells (hMSCs). C4 mES cell (mouse embryonic stem cell line) colonies are cultured on inactivated hMSCs amplified ≥ 600-folds during the 30 days of continuous culture. The longest continuous expansion of C4 mES cells on hMSC was 30 passages. In this study the gene expression for Oct-4, Nanog, Rex1, Brachyury, LIF, LIFR, TERT, B2M, Stat3, Sox2, Fgf4 in mES cells using reverse transcriptase polymerase chain reaction (RT-PCR) and in which genes expression for Stat3, Sox2, Fgf4 genes was negative whilst the gene expansion for Oct-4, Nanog, Rex1, Brachyury, LIF, LIFR, TERT, B2M genes was positive. There was also a karyotype analysis for ES which showed normal result. The immunocytochemical analysis of Oct4 transcriptional factor for ES cells was made which showed positive result for this factor. These genes may be novel candidates to play critical roles in the regulation of ES Cell pluripotency and self-renewal.

The present study seeks to investigate the scientific products among the three countries of Islamic Republic of Iran, Turkey, and Greece as they have entered the 3rd Millennium (during the years 2000-2008) upon the data obtained from ISI Web of Knowledge. In the past, these nations had possessed original, rich, and great civilizations; moreover, these countries had had (and still have) borders with each other so that Iran reflects itself as an Asian nation, Turkey as that of a Euro-Asian country, and Greece as a European nation. The findings show that at the turn of the 3rd Millennium (the year 2000); Turkey and Greece (with a little difference) had a higher level for the scientific products followed by Iran with a significant difference. After four years (in the year 2004), Turkey had taken the lead, followed by Greece and Iran. However, in the year 2008, Turkey had still had the lead in the generation of scientific products, while Iran had surpassed Greece.

Tissue hypoxia occurs where there is an imbalance between oxygen supply and consumption. Growing evidence from experimental and clinical studies points to the fundamental and patho-physiologic role of hypoxia in cancer, ischemic tolerance, and stroke. Hypoxia-induced changes in ion homeostasis, erythropoiesis, angiogenesis, proliferation and differentiation. This review outlines hypoxia effect at molecular level and describes briefly hypoxia role in the physiological and pathological conditions.