Showing 292 results for Le
Farzaneh Malekian, Nasim Rahmani, Maryam Mostafanejad, Dr Seyed Davar Siadat, Zahra Jalali, Dr Delaram Doroud,
Volume 0, Issue 0 (1-2024)
Abstract
Fariba S. Mozafari, Valery V. Bakayev ,
Volume 1, Issue 4 (10-1997)
Abstract
A new strategy for construction of synthetic gene encoding human basic fibroblast growth factor comprising DNA annealing-ligation and augmentation by polymerase chain reaction was introduced. The sequence of the gene and corresponding amino acid chain were modified in order to increase stability of the protein. First, 300 bp and 160 bp fragments of the gene were assembled from 18 oligonucleotides and ligated separately. Then, the shorter fragment was completed by using PCR and combined with the longer one in a proper orientation in pUC 19. One extra nucleotide that had been found in the gene after DNA sequencing and resulted in frame shift, was rectified through the use of PCR directed mutagenesis. Finally, 5'-terminal region of the gene was augmented by means of PCR in order to restore the N-terminal part of the protein and to introduce the NdeI recognition site. The gene was subcloned into the inducible pET-3a expression vector under control of T7 promoter and expressed in Escherichia coli. The identity of the recombinant protein and level of expression were detected by using Western blot analysis and immunoassay. The proposed method has provided a useful strategy for synthesizing modified proteins that might be applied for protein engineering.
Mohammad Hossein Alimohammadian, Zahra Fariba Kojori, Haiedeh Darabi, Shirin Malekzadeh, Mohsen Yousef-Beig, Fahime Irvani-Nia,
Volume 1, Issue 4 (10-1997)
Abstract
Delayed-type hypersensitivity reaction measured by skin testing, is an important tool for evaluation of cellular immune response in leishmaniasis and has been used recently as an indication of exposure to infection. Skin testing in leishmania infection needs a standard reagent with high specificity, sensitivity, and potency. In the present work, a soluble leishmanin, and three whole parasite preparations from Leishmania major, i.e. thimerosal, phenol, and autoclaved leishmanins, were prepared under standard conditions. These antigens were evaluated and compared in different foci of leishmaniasis. The sensitivity and potency of reagents were tested in both recovered cases and patients with active ulcer in two areas endemic to urban and rural leishmaniasis. Data obtained showed that, the sensitivity of thimerosal, phenol, and soluble leishmanins are almost equal, but are higher than autoclaved one. Moreover, the potency of soluble leishmanin was also proved to be higher than other reagents. The purity of soluble leishmanin is higher than other three particulate preparations, and it lacks the majority of membrane antigens. As a result this reagent can be used as a standard and ideal antigen for skin testing in human leishmaniasis.
Shirin Malekzadeh, Hossein Hosseini, Haiedeh Darabi, Mohammad Hossein Alimohammadian,
Volume 2, Issue 1 (1-1998)
Abstract
Partially purified antigenic fractions of Leishmania major promastigotes were obtained by sodium dodecyl sulfate (SDS-PAGE) and electro-elution. Three isolated protein fractions designated as fractions (Fr.) 1, 2, and 3 correspond to 40-60, 60-80, 80-100 kilodalton (kDa) respectively. They were used for immunization of BALB/c mice against Leishmaniasis. The effects of these fractions on immune response of BALB/c mice against leishmanial infections was investigated by studying the infection course in infected mice, delayed type hypersensitivity (DTH) skin test, lymphocyte proliferation assay (LTT) in them. Subcutaneous immunization of mice with fraction 2 in conjugation with Complete Freund's Adjuvant (CFA) developed partial immunity against Leishmania major infection, and induced specific DTH response. Meanwhile this fraction exhibited no exacerbating effect on leishmanial infection course. Subcutaneous immunization with fraction 1 also induced partial protection in lesser extent than fraction 2 against leishmanial infection.
Ahmad R. Bahrmand, Mehrdad H. Babaie, Nader Shahrokhi, Mohammad M. Feizabadi, Valery V. Bakayev,
Volume 2, Issue 1 (1-1998)
Abstract
Three tuberculous, twenty-one non-tuberculous mycobacterial (NTM) reference strains and seventy two isolates classified by biochemical tests were shown to produce specific sets of DNA fragments in a polymerase chain reaction with single universal primer (UP-PCR). A rather wide limit of tolerance for variations in procedure of PCR mixture preparation and thermocycling parameters was found. There was good correlation between UP-PCR pattern obtained in an agarose gel for each strain and the absolute majority of isolates tested. The PCR products of M. tuberculosis and M. bovis were shown to be very similar and well distinctive from that of all NTM strains tested. When image analysis system was applied to profile the UP-PCR patterns, all M. tuberculosis complex isolates were well differentiated from NTM species according to their specific profiles. Thus, UP-PCR profiling could give an efficient means for discriminating mycobacteria that utilizes the least time and applicable to controversial cases of suspected tuberculosis.
Nasser Khodai Booran, Mahdi Assmar, A Hovanesian, N. Nikolaova, Valery V. Bakayev,
Volume 2, Issue 2 (3-1998)
Abstract
Evidences from many studies suggested a polymerase chain reaction (PCR) as a valuable method for diagnosing infectious disease in the transplant recipients. We used this method for detection of Toxoplasma, gondii and human cytomegalovirus in blood specimens from patients after bone marrow or kidney transplantation. DNA of both infectious agents were detected using two separate sets of nested primers in the PCR. The conditions for a multiplex nested PCR providing simultaneous identification of both pathogens in one tube were optimized. This assay provides an application in clinical research for diagnosis of infections in post-transplant recipients.
Majid Cheraghali, Rakesh Kumar, Kevin W. Morin, Edward E. Knaus, Leonard I. Wiebe,
Volume 2, Issue 3 (7-1998)
Abstract
(+)-Trans-(5R,6R)-5-bromo-6-ethoxy-5-ethyl-5,6-dihydro-2'-deoxyuridine [(5R,6R)-BEEDU], a potential brain-targeted prodrug of 5-ethyl-2'-deoxyuridine (EDU), was synthesized by the regiospecific addition of BrOEt to the 5,6-olefinic bond of EDU. (5R,6R)-BEEDU is more lipophilic (log P = 0.04) than EDU (log P = -1.09). In vitro incubation of (5R,6R)-BEEDU with rat whole blood and brain homogenate resulted in a 53% and 16% conversion, respectively, to EDU. In contrast, (5R,6R)-BEEDU was not converted to EDU upon incubation with glutathione (GSH) at 37°C for 36 hours. After i.v. injection into rats, (5R,6R)-BEEDU was rapidly converted to EDU, which was then further metabolized like EDU. However, (5R,6R)-BEEDU provided a substantially higher Ryncentration of EDU in blood, relative to that when EDU was injected. A biodistribution study of [4- C]-(5R,6R)-BEEDU in Balb/c mice showed that (5R,6R)-BEEDU provided significantly higher (P < 0.05) radirctivityievels in brain samples at 8, 18 and 30 min post injection than observfid after injection of [4- C]-EDU. The higher repioactivity levels in liver samples after injection of [4- C]-(5R,6R)-BEEDU, relative to those after [4- C]-EDU, indicates that the 5,6-dihydro derivative undergoes a higher hepatic extraition than EDU. Clearance of radioactivity from blood qv' excretion into urine, after injection of [4 C]EDU, was much faster than that after injection of [4- C]-(5R,6R)-BEEDU.
Behrokh Farahmand, Mohamad Javad Rasaee, Naser Maleknia, Mohamad Malekaneh,
Volume 2, Issue 3 (7-1998)
Abstract
An enzyme-linked immunosorbent assay (ELISA) for progesterone measurement in serum or plasma samples using penicillinase as label enzyme is reported. A C3 and C11 derivatives of progesterone were prepared and conjugated to bovin serum albumin (BSA). Polyclonal antibody against these two immunogens were prepared in New Zealand white rabbits. Purified Ig fractions of antibodies were immobilized onto the wells of microtiter plates. Progesterone 3-(O-carboxymethyl ) oxime was linked to penicillinase and used as tracer (enzyme-conjugate). The standard assay completed within three hours had a low limit of detection, from 5 pg/well (50 pg/ml) covering up to 1 ng/well (10 ng/ml). For the first time in this assay the color development in case of penicillinase as enzyme label was measured in the wells directly. Recoveries were measured to be within the range of 95-98%. Percent Coefficient of variations (CV%) obtained between and within runs of several assays were 3% and 7% respectively. When compared between values of progesterone measured by radioimmunoassay (RIA) and present ELISA method, a correlation value of r = 0.9 was obtained. Freeze-dried progesterone-enzyme conjugate was found stable for at least three months at 4° C without using any other preservative.
Maryam Ayatollahi, Zahra Malek-Hosseini, Mohammad-Taghi Imani, Sohaila Joubeh, Hossein Mortazavi, Abbas Ghaderi,
Volume 3, Issue 3 (7-1999)
Abstract
For the evaluation of autoantibodies in Pemphigus vulgaris (PV), an indirect ELISA assay was developed by using a semi-purified human epidermal skin extracted with approximately a molecular weight (M.W.) of 130-160 kDa. The evaluation of Pemphigus IgG, IgM and IgA autoantibodies in 75 patients and 50 control sera indicated that this indirect ELISA assay was a useful method for the detection of Pemphigus autoantibodies. Data of this study suggested that the mean OD (Optical Density) of specific IgG autoantibody was elevated in PV patients compared with the controls. The percentages of the total serum IgM and IgA antibodies were not statistically significant between patients and controls.
Nasser Naghdi, Nahid Majlessi,
Volume 4, Issue 1 (1-2000)
Abstract
Data on the effects of serotonin reuptake inhibitors on learning and memory processes are not consistent. In the present study, the effects of citalopram, a very potent and completely selective inhibitor of the serotonin reuptake on spatial discrimination in the T-maze and Morris water maze, were assessed in mice and/or rats. Animals received different doses of citalopram (1, 2, 4, 8 or 16 mg/kg, i.p.) or its vehicle (saline) 30 min before training each day. The results showed no significant effects of citalopram on T-maze discrimination task in mice and rats. However, there was dose-dependent increases in latencies to find the invisible platform and traveled distances in citalopram received groups compared to the control group with the peak effect at doses of 4 and 8 mg/kg in Morris task. Therefore, it appears that citalopram can cause learning deficits in complex spatial tasks.
Mohammad Azizi, Alexis Musacchio, Ornaldo Pardo, Nelvis Figueroa, Verena Muzio,
Volume 4, Issue 1 (1-2000)
Abstract
DNA coding for the core antigen from hepatitis B Virus (HBcAg) was amplified, cloned and propagated in E. coli. The core protein was expressed in E. coli and the product was readily detected by Western blot. This protein can be used as a diagnostic material in serum screening tests. To increase the level of expression of this antigen in bacteria, two plasmids were constructed in which the gene coding for N-terminal part of the human IL-2 has been fused to 5¢ -terminus of the core antigen gene under control of the tryptophan promoter. Although the expression level of core antigen from hepatitis B Virus in E. coli was increased in fusion forms, but the size of fusion partner could affect the antigenicity, particle formation and assembly of the core antigen. The native and the two fusion forms of the core antigens from hepatitis B Virus were evaluated as a diagnostic material in serum screening.
Masoumeh T. Kheiri, Eleonora Feketeova, Zheng Wang, Raphael J. Mannino, Susan Gould-Fogerite,
Volume 5, Issue 1 (1-2001)
Abstract
High morbidity and mortality of influenza virus infection makes it an important disease world-wide. Mouse is a very well-studied animal model for this disease with similar manifestation to human disease. It would be desirable to induce mucosal as well as circulating immune responses to obtain protection from infection and to decrease the spread of the virus. Cell mediated immunity (proliferative and cytolytic responses) is needed for long-term immunity. A new type of influenza subunit vaccine which can be given orally or parenterally has been developed to induce mucosal and circulating immune responses. This vaccine consists of membrane proteins rolled up in a unique phospholipid structures called protein cochleates. BALB/c mice were immunized three times with influenza glycoprotein-containing cochleates orally or intramuscularly, or they were primed orally or intramuscularly followed by two boosts with the alternate routes. Proliferation assays of spleen cells and ELISA for IgA, IgG, and IgM of the sera and saliva from these mice shown some differences in the immune responses induced by different immunization regimens. Mucosal administration of the formulation led to secretory IgA in saliva while parenteral immunization resulted in circulating IgG. Increased proliferative responses as well as IgG following 2nd and 3rd administration, indicated the effect of boosting in all immunization regimens. Oral immunization with influenza virus envelope glycoprotein-containing cochleates led to protection from infection in the lungs and trachea following intranasal challenge with the live virus.
Durdi Qujeq, Laia Hossini, M. Taghi Salehi Omran,
Volume 5, Issue 2 (3-2001)
Abstract
Recent studies have documented the importance of lipids and lipoproteins as determinants of serum total homocysteine concentrations in persons with myocardial infarction, and in healthy subjects. Associations between various biological systems and total homocysteine have also been reported. However, some of these associations are poorly understood. The purpose of our study was to measure serum total homocysteine concentrations in men and women who were selected for health and myocardial infarction to determine the relations of triglycerides, cholesterol and diastolic blood pressure. The study group consisted of 136 patients, 77 male and 59 females, aged 39-73 (mean 46.75 3.91). The control group consisted of 145 normal volunteers, 81 males and 64 females, aged 31-63 (mean 41.72 6.89). Serum total homocysteine was determined by gas chromatograph. Serum cholesterol and triglyceride were measured enzymatically on a spectrophotometer. Our results showed that serum total homocysteine concentrations were significantly positive correlated with cholesterol, triglyceride and diastolic blood pressure.
Daryoush Shahbazi-Gahrouei, Mark Williams, Barry J. Allen,
Volume 5, Issue 2 (3-2001)
Abstract
Two new potential magnetic resonance imaging contrast agents, Gd-hematoporphyrin (Gd-H) and Gd-tetra-carboranylmethoxyphenyl-porphyrin (Gd TCP), were synthesized and applied to nude mice with human melanoma (MM 138) xenografts. These agents showed a high relaxivity because of their greater potential to coordinate water molecules. The reduction of T1 relaxation times of 16 and 21% was observed in human melanoma tumors grafted in the nude mice 24 h after injection of Gd-TCP and Gd-H, respectively. The percent of injected Gd, that localized to the tumor and measured by inductively coupled plasma atomic emission spectroscopy (ICP-AES), was approximately 21% for Gd-TCP and 28% for Gd-H. A higher concentration of Gd was achieved compared with control indicating selective delivery of Gd-porphyrins to the melanoma xenografts. The data indicate that Gd-TCP can be used as a dual probe for diagnosis in MR imaging and for therapy in boron neutron capture therapy (BNCT).
Nasser Naghdi, Nahid Majlessi , Fahshideh Broofar,
Volume 5, Issue 4 (4-2001)
Abstract
In the present study, the effect of 5-HT2A receptor blockers in CA1 region of rat hippocampus on spatial learning was assessed in a T-maze, a spatial discrimination task. Rats were canulated bilaterally and injected daily vehicle (saline), 5-HT2A-selective antagonist, ketanserin (0.6, 1.2 or 2.4 µg/0.5 µl) and pirenperone (0.1, 0.3, 1.2 or 2.4 µg/0.5 µl) into the cannula 30 minutes before training. Results indicated that ketanserin and pirenperon did not affect spontaneous alternation and also did not induce a significant effect on trials to reach criterion and errors made by animals throughout spatial discrimination and reversal learning. But, in the rats that recieved ketanserin produced dose dependent decrease in the latencies to enter the chosen arm in both learning and reversal stages. During extinction, no change was observed in the choice of the previously reinforced arm in both ketanserin and pirenperone groups. The slope of latency in the ketanserin group that had received the highest dose of ketanserin (2.4 µg) than the sham operated group but not in the pirenperone group. These findings suggest that 5-HT2A receptors blockade (ketanserin, but not pirenperone) in the CA1 region may decrease decision time and increase behavioural flexibility in T-maze.
Abdolvahab Moradi, Ethel-Michele de Villiers, Talat Mokhtari-Azad, Mahmoud Mahmoudi, Bahman Hazrati, Ezzat-Elah Ghaemi, Rakhshandeh Nategh,
Volume 6, Issue 1 (1-2002)
Abstract
Human papillomavirus (HPV) DNA has been identified in esophageal carcinomas. However, the incidence of HPV varies significantly in different geographical locations. In this study, neoplasms from Turkmen Sahra, a region in Golestan province in northeast part of Iran, with a high incidence of squamous cell carcinoma were analyzed for the presence of HPV DNA. Turkmen Sahra is located in the cancer belt in Asia. Eighty-five squamous cell carcinomas were examined for the presence of HPV DNA. PCR was utilized to amplify a 124-bp segment of the HPV L1 gene using the consensus primers. The amplified region was subsequently sequenced to identify the HPV. The results indicated that the rates of HPV detection in squamous cell carcinoma specimen for men and women were 52.8% and 43.7% respectively. The positive cases included HPV-16 (54.7%), HPV-18 (4.8%), HPV-6 (14.3%), HPV-66 (7.1%), HPV-52 (4.8%) and 14.3% of cases were positive for more than one type of HPV. Human papillomavirus type 16 that can be potentially oncogenic was prevalent in 54.8% of the cases of esophageal squamous cell carcinoma. Our results confirm the previously reported HPV involvement in the esophageal squamous cell carcinoma, and support the possible role of HPV as an etiological agent in esophageal carcinogenesis.
Shamsi Yari, Davoud Nouri Inanlou, Fatemeh Yari, Maryam Saleh, Behrokh Farahmand, Azim Akbarzadeh,
Volume 6, Issue 1 (1-2002)
Abstract
In this study, mutant forms of Bacillus thuringiensis spp. israelensis (H14) were produced. These mutants were identified when the cells were cultured on chloramphenicol plates and stained with crystal violet. Protoplasts of the mutants were isolated by enzymatic digestion (lysozyme) of the cell walls at the presence of an osmotic stabilizer. The protoplasts were induced to fuse to each other in the presence of PEG 6000. The frequency of regeneration and recombination was 80% and 2´10-4, respectively. In order to survey the effect of protoplast fusion on production of toxin, anti-serum against pure toxin was raised in rabbit and was used in single radial immunodiffusion. The comparison of d-endotoxin concentration between B. thuringiensis fusion and the wild type strains showed that B. thuringiensis fusion has 1.48 time more toxin than wild type.
Eskandar Omidinia, Heshmatollah Taherkhani, Yasuhisa Asano, Shohreh Khathami, Alireza Omumi, Ata-Allah Ghadiri, Daniel van der Lelie, Roya Rashidpouraie, Hassan Mirzahoseini, Abbas Samadi,
Volume 6, Issue 1 (1-2002)
Abstract
Cloning and expression of the L-phenylalanine dehydrogenase gene, from B. sphaericus in E. coli were done. The gene was cloned in the vector pET16b and transformed into E. coli BL21 (DE3). The functional form of the L-phenylalanine dehydrogenase enzyme was purified by affinity purification techniques, taking advantage of the ability of this enzyme to bind to the nucleotide site affinity dye, Reactive Blue 4. Approximately 3 mg of highly purified recombinant enzyme was obtained from 950 mg cell pellet (wet weight). The Relative molecular mass of the L-phenylalanine subunits was about 41 kDa by 10% SDS-PAGE. Using this method, the enzyme was obtained with a yield of 28%, and had a specific activity of 577.3 U/mg protein, which is purified 88 times. This method was provided a facile and effective way for preparing the enzyme with a good yield that suitable for analytical purposes.
Nader Shahrokhi, Anis Jafari, Valery V Bakayev, Reinhold Schirmbeck, Jorg Reimann, Saeid Bouzari,
Volume 6, Issue 2 (3-2002)
Abstract
Hepatitis B surface antigen is the first genetically engineered vaccine licensed for human use. Various strategies have been proposed to obtain a vaccine that would bypass the need for injection. In this study, a non-toxic portion of heat-stable enterotoxin of Escherichia coli that is capable of adhering to epithelial cells was inserted at amino acid position 112 of hepatitis surface antigen. The construct was used for transfection of human embryonic kidney cells in order to assess the expression of the hybrid protein. The data obtained showed a very low level of expression. In vivo antibody production and cytotoxic T lymphocyte response in B6 mice were assessed using DNA immunization. Three out of five injected mice responded with titers >10 mIU/ml anti-HBsAg and cytotoxic T-lymphocyte response was much higher with construct encoding the chimeric protein. Although this study proves that the chimeric protein is capable of eliciting both humoral and cellular responses, but further work is required to fully explore the feasibility of combining the properties of the two proteins .
Kamran Mousavi Hosseini, Houri Rezvan, Zabihollah Motalleb, Sedigheh Chabokpey, Vida Mirbod,
Volume 6, Issue 4 (10-2002)
Abstract
Sodium salt of N-acetyl-DL-tryptophan (AT) and octanoic acid (caprylic acid CA) individually and in combination were studied as thermal stabilizer with different concentrations in heat treatment of human albumin solution. HPLC protein profiles before pasteurization of albumin showed less than 1% polymer. In free stabilizer albumin solution during pasteurization visible clot was formed. But by using variation of the above mentioned stabilizers, the amount of polymer was increased to about 4% during pasteurization (60° C, 10 h). By increasing the heat to the visible clot formation point, the most effective stabilizer against visible clot formation was found to be CA. However, in drug formulation it is important to choose the variety and concentration of stabilizers in accordance with regulations.