Study of telomerase activity, proliferation and differentiation characteristics in umbilical cord blood mesenchymal stem cells

In recent years, considerable advances have been made in the field of regenerative medicine. Unlike embryonic stem cells, which pose the problems of ethical concerns and cause severe immunological reactions as well as neoplasma formation after transplantation, umbilical cord blood is a primitive source of mesenchymal stem cells that covers the benefits of both embryonic and adult stem cells

It has been determined that the proliferation capacity of cells is critically linked to the maintenance of the length of telomeres by telomerase activity. Since there is no information accessible regarding the pattern of telomerase activity in UCB-MSCs through several passages, the aim of this study was the evaluation of telomerase activity in UCB-MSCs, as a predisposing factor for cell immortalization

No telomerase activity was detected in UCB-MSCs from several passages applying telomerase rapid amplification protocol [TRAP]

Since there is a direct correlation between the activation of telomerase expression and neoplasma formation in adult somatic cells, UCB can be assumed as an excellent source of MSCs for therapeutic application with a high level of safety. According to the histological results, RT-PCR and biochemical assays, MSCs derived from UCB showed high differentiation capacity to bone and cartilage. UCB-MSCs showed very low level of differentiation potential to adipocytes. Our results showed that UCB-MSCs maintain their self-renewal and differentiation potential through several passages. Since a large number of metabolically active cells must be available in cell therapy, high proliferation capacity through several passages is a great advantage for large scale expansion of UCB-MSCs?

[Comparative studies on the effect of the enzyme ficin on the solubility and electrophoretic pattern of ovine and bovine meat proteins]

Different techniques have been employed to improve the technological properties of meat. One of the most important techniques is adding proteolytic enzymes which could simultaneously increase the tenderization and solubility of meat proteins. The purpose of this investigation was to study the effect of different levels of the enzyme ficin on ovine and bovine meat and to determine the best condition for solubilization of meat proteins. Ficin was partially purified from figs tree latex by cationic exchange chromatography. Meat samples were treated wilh different activities of ficin and the effect ofenzyme was followed by measuring nitrogen solubility index [NSI] and electrophoresis. NSI was determined by homogenization of ficin-treated meat in the presence of buffers, centrifugation and nitrogen determination of the supernatant by kjeldal. The solubility of meat proteins increases with increase in the activity of added ficin and with increase in the incubation time [p<0.001]. Presence of salt significantly increased the solubility of meat proteins up to 65% [p<0.01]. The SDS-PAGE pattern of soluble proteins showed the molecular weight of proteins was in the range of 15-105 KDa and was similar in ovine and bovine meat. Also by increasing the unit activity of enzyme form 0.8 to 2.6 units. most protein bands were disappeared or decreased in intensity. These results indicated that the velry high activity of ficin results in disruption of the structure of myofibrillar proteins and excessive break down of these proteins to smaller peptides which either precipitate or cannot be detected by electrophoresis

Nucleotide sequence of cDNA encoding for preprochymosin in native goat [Capra hircus] from Iran

Prochymosin is one of the most important aspartic proteinases used as a milk-clotting enzyme in cheese production. In the present investigation we report sequence of cDNA encoding goat [Capra hircus] preprochymosin and compare its nucleotide and deduced amino acid sequences with sequences of other ruminants preprochymosin. As bovine prochymosin, the caprine prochymosin cDNA encodes 365 amino acids with a prosegment of 42 amino acids and the mature goat chymosin begins with glycine. The preprochymosin nucleotide sequence reported in this study differs from other reported goat sequence [AY389343] in three nucleotides, two of which alter the amino acids at positions 19p and 139

Prevention of selenite-induced cataract by L-cysteine and vitamin C in rats

Development of a drug which could prevent or delay the onset or progression of cataract will help to reduce the number of people getting blind due to cataract worldwide. This study was undertaken to evaluate the clinical and biochemical changes of the crystalline lens and gel-electrophoresis of water soluble proteins in a selenite- induced cataract and to assess the preventive role of L-Cysteine and vitamin C in rat as an animal model. Cataracts were induced in rats by administration of sodium selenite. In control group, saline was injected subcutaneously [SC]. In experimental groups [groups 2-5], sodium selenite [20 micro mol/kg] was injected SC. Rats in group 3 received SC injections of 0.1 ml of vitamin C [0.3 mM], in group 4 received SC injection of 0.1 ml of L-cysteine [0.05 micro mol] and those in group 5 received SC injection of 0.1 ml of L-cysteine [0.1 micro mol]. The development of cataract was assessed clinically. Then, the lenses were checked for total and soluble protein concentrations and eletrophoretic pattern [SDS-PAGE]. Sodium selenite could induce cataract and cause biochemical and eletrophoretic changes in the lens. L-cysteine and vitamin C were highly effective in preventing or minimizing selenite-induced cataract and in maintaining near-normal total protein and soluble protein concentrations of the lens. These reagents were also effective in restoring the near normal pattern of lens proteins in SDS-PAGE. L-cystein was more effective than vitamin C in prevention of cataract but the difference was not statistically significant. Our results showed that cataractous and biochemical changes of the crystalline lens proteins due to selenite can be minimized or prevented by L-cysteine and vitamin C

effect of ovalbumin and mannose-conjugated ovalbumin on the prevention of salmonella adherence to the intestinal epithelium of chickens

This investigation was designed to determine the effect of intact ovalbumin and mannose-conjugated ovalbumin on the prevention of Salmonella typhimurium adherence to the epithelium of small intestine of chickens. Mannose-conjugated ovalbumin was produced by Maillard-type reaction between chicken ovalbumin and D-mannose at 60[degree]C. The results revealed that incubation up to 96 hrs caused the highest amount of covalent attachment of mannose to the ovalbumin. In order to determine the effect of native ovalbumin and mannose-conjugated ovalbumin on the prevention of S. typhimurium adherence to chicken small intestine, 60 one-day-old chicks were randomly assigned to 3 groups, with two replicates and ten birds per pen. Groups 1, 2 and 3 received normal diet, diet containing 0.5% native ovalbumin and diet containing 0.5% mannose-conjugated ovalbumin, respectively, for 12 days. On day 3, all groups received 1.3 x 10[6] CFU of S. typhimurium orally. On days 4, 7 and 10, two chicks from each group were killed and mean log 10 of CFU [colony forming unit] of Salmonella per 1 g tissues of cecum, liver and spleen was determined. Four chickens from each group were killed on day 12 and were examined as described above. The results showed that in group 3, number of viable Salmonella in cecum, liver and spleen was lower than groups 1 and 2. However, the difference was significant only in cecum on days 4 and 7 [P<0.05]. These preliminary results suggest that mannose-conjugated ovalbumin might be effective in prevention of Salmonella colonization in the epithelium of small intestine if incorporated in the diet of chicks

[Study on activities of some enzymes and protein electrophoretic patterns in heat treated meat products]

Study on some enzymes and protein electrophoretic patterns in order to find an indicator for adequacy of heat treatment in meat products. Experimental study. The activities of some enzymes, including: lactate dehydrogenase [LDH], aspartate amino transferase [AST] and alanine amino transferase [ALT], were assayed in meat and heat treated meat products at different time- temperatures combinations. Extracts of samples were used for electrophoresis by SDS-PAGE method. Analysis of variance and Duncan's test. LDH was active and demonstrated a good stability in samples which were heated up to 65 [degree sign] C for 55 minute. However, its activity started to decline thereafter so that at 70 [degree sign] C no significant activity was observed. ALT and AST were more heat stable than LDH and their activities were still present in heat treated products at 70 [degree sign] C for 30 minutes and vanished at 75 [degree sign]C. Many protein bands disappeared in SDS-PAGE pattern of meatn products which heated at 65 [degree sign] C or above. LDH can be considered as a suitable indicator for meat products that have been heated at 70 [degree sign] C or above

Comparison of optic lens proteins among animals at different stages of development

The purpose of this investigation was to study and compare the electrophoretic patterns of optic lens proteins of different species of domestic animals at pre- and post-natal ages. Optic lenses were removed from the embryo or adult sheep, cattle, goat, camel and chicken at the slaughter-house then homogenized and subjected to sodium dodecylsulfate polyacrylamide gel electrophoresis [SDS-PAGE]. In all animals, except chicken, majority of proteins had molecular weights of less than 33 kDa and their concentrations were not affected by the age of animals at pre- or post-natal stages. A 9 kDa protein which was present in adult sheep optic lens was absent in sheep fetal lenses at different age groups. Prominent differences were observed in camel and chicken. In camel, proteins with molecular weights of 30 and 38 kDa were present, the concentration of which was much lower in other animals. A protein of 57 kDa which constituted the major protein of chicken optic lens was absent in other species of animals. The concentration of proteins in the range of 25-30 kDa increased with the age of chicken embryos. These proteins were remarkably different from those of adult chicken lens proteins except the 57 kDa protein which was also the predominant protein in the embryo. The 38 kDa protein disappeared and a 20 kDa protein appeared in the chicken embryo lens as compared with adult chicken lens. These data indicate extensive differences in the lens proteins of animals and suggest different physiological functions of lens proteins in different animals at different stages of development

Biochemical properties and biological functions of the enzyme rhodanese in domestic animals

The enzyme rhodanese [thiosulfate: cyanide sulfurtransferase] is a ubiquitous enzyme and its activity is present in all living organisms. Many functions including cyanide detoxification, formation of iron-sulfur centers and participation in energy metabolism have been attributed to this enzyme. The enzyme catalyzes the transfer of a sulfur atom from sulfane containing compounds'[such as thiosulfate] to thiophilic anions [such as cyanide]. The sulfhydryl group ofcysteine-247 in the molecule of rhodanese participates in a double displacement of sulfur transfer mechanism. In this review attempt will be made to summarize the latest information available on the molecular properties and the pattern Of distribution of rhodanese in different tissues of domestic animals and to combine these different lines of research to arrive at a plausible explanation regarding the biological function of this important enzyme in living organisms

[Application of a new method for arginase as a liver function test in dogs]

Arginase catalyzes the conversion of arginine to urea and omithine in the liver of urectelic animals. Higher activity of this enzyme has been detected in the sera of patients with hepatic diseases. Many difficulties inherent in current methods for arginase have hamperd wide use of this enzyme as a liver function test. A new colorimetric method for determination of arginase has been developed in this laboratory. This method is based on the determination of remaining arginine, after its conversion, by reaction with p-nitrophenyl glyoxal [PNPG] at pH 9.0 to produce a color which absorbs maximally at 480 nm. The decrease in the absorbance in the presence of arginase is correlated with the enzyme activity. This method was used to measure the level of arginase in the sera of dogs in which liver necrosis had been experimentally induced by oral administration of carbon terrachoride. The results indicate that PNPG can be used as a reliable method for determination of arginase and might be applied in parallel with other enzymes that are currently used for liver function test

Determination of serum arginase in an animal model of liver necrosis

Arginase catalyzes the conversion of arginine to urea and ornithine in the liver of ureotelic animals. Higher activity of this enzyme has been detected in the sera of patients with hepatic diseases. Many difficulties inherent in current methods for arginase have hampered widespread use of this enzyme as a liver function test. We have developed a simple colorimetric method for determination of arginase. This method is based on the determination of remaining arginine, after its conversion, by reaction with p-nitrophenyl glyoxal [PNPG] at pH 9.0 to produce a color which absorbs maximally at 480 nm. The decrease in the absorbance in the presence of arginase is correlated with the enzyme activity. In this simple method color development as well as termination of enzyme activity is achieved by addition of a single reagent, i.e. PNPG, to the incubation mixture, thereby obviating the use of many chemicals ordinarily used in other methods for arginase. This method was used to measure the level of arginase in the sera of animals in which liver necrosis had been experimentally induced by oral administration of carbon tetrachloride, The results were compared with other enzyme that are currently used for liver function test. No arginase could be detected in the sera of healthy animals. Serum arginase elevated after 6 hours following administration of carbon tetrachloride, reached highest level after 24 hours and returned to normal at 72 hours. A similar pattern was observed for alkaline phosphatase and rhodanese, while the level of AST remained elevated for 48 hours and declined gradually thereafter. The Implication of these studies in human medicine are discussed