Pasteur Institute of Iran
Iranian Biomedical Journal
1028-852X
2
2
1998
3
1
Transcriptional Coactivator CBP Facilitates Transcription Initiation and Reinitiation of HTLV-I and Cyclin D2 Promoter
49
57
EN
Janet F.
Duvall
Fatah
Kashanchi
HTLV-I is the etiologic agent for adult T-cell leukemia/lymphoma (ATL) and HTLV-I-associated myelopathy/tropical spastic paraparesis (HAM/TSP). Taxi, the major activator of this virus, is a 40- kDa (353 amino acid) phosphoprotein, predominantly localized in the nucleus of the host cell, which functions to trans-activate both viral and cellular promoters. Recently it has been shown that HTLV-I and /or Taxl expressing cells have altered gene expression of some of the cell cycle associated genes. Tax activates HTLV-I as well as number of other cellular promoters through CREB, NF-kB and SRE elements. In this study we analyzed the effect of a general coactivator, namely CBP, which may be involved in activation of many cellular genes. To analyze CBP transcription activation, we have utilized an in vitro transcription assay that allows the analysis of transcription initiation and reinitiation in the absence of chromatin effects. In this assay, which utilizes a G-free cassette downstream of the Tax-responsive 21 by repeats, polymerase II molecules responsible for the first round of transcription remain at the end of the G-free region, effectively blocking the complete elongation of reinitiated transcripts. Addition of Tax and a 682 amino acid fragment of CBP to the in vitro transcription reactions increased both full-length and shorter transcripts resulting from reinitiation. A CBP deletion mutant lacking the N-terminal activation domain was inactive. Preliminary data is also presented to show that, transactivation of HTLV-I and a cellular promoter, namely cyclin D2, takes place in early GO/G1 before the restriction point, "R", where Rb function has been implicated.
Pasteur Institute of Iran
Iranian Biomedical Journal
1028-852X
2
2
1998
3
1
Stress and Atherogenesis: Smooth Muscle Cell Mitogenic Activity and other Biochemical Changes Associated with Sera of "Stressed" Subjects
59
70
EN
Joseph M.
Wu
William H.
Gutstein
The proliferation of smooth muscle cells in the arterial wall (VSMC) is considered to play a key role in the development of atherosclerosis. To investigate the possible contribution of "stress" (experimentally-induced) to this process, blood from healthy volunteers, ages 21 to 65, screened to exclude major risk factors for coronary heart disease, was assayed for mitogenic activity after the subjects were exposed to one of 2 "stress" conditions. These consisted of a cognitive task with superimposed verbal harassment (group 1), and the cognitive task without harassment (group 2). Mitogenic activity was determined by studying the growth stimulatory effects of PDGF-depleted plasma derived serum (PDS) from "stressed" subjects added to cultured VSMC, as measured by incorporation of radioactive thymidine into DNA or increase in cell number. In addition, changes in the steady state of the mRNA for the c-myc protooncogene were also assayed in VSMC by Northern blot analysis, using sera showing the greatest differential "pre/post stress" mitogenic activity. Blood pressure (BP), heart rate (HR), cortisol, and serum total and HDL cholesterol were also evaluated. All measurements were made immediately before (baseline) and after a 30 min interval. Analysis of the data revealed that there were 33% of subjects in group 1 with an increase of thymidine incorporation 15% or greater than baseline, versus 21% in group 2. The average increases were 45% and 30%. A higher percentage (35-42%) of subjects in group 1 responded with increases in systolic and diastolic blood pressure, compared to subjects in group 2 (1520%) the average in blood pressure was 10-15%. Similarly, more subjects (52%) in group 1 had an elevated (average 10-15%) serum cortisol, compared to the 42% in group 2 subjects. HR, total HDL cholesterol showed slight changes only. These results suggest that psychoactive factors may affect cardiovascular systems via rapid elicited rises in serum mitogenic activity for VSMC.
Pasteur Institute of Iran
Iranian Biomedical Journal
1028-852X
2
2
1998
3
1
Administration of Large Volume Hypertonic Solutions for Resuscitation of Hemorrhagic Shock in Rabbit
71
77
EN
Mehdi
Nematbakhsh
Mehrnoosh
Moghaddassi
Nepton
Soltani
Seyyed Hossein
Samarian
Parvin
Rajabi
An animal model was designed to study the effect of large volume Hypertonic Solutions (HTS) for resuscitation following a hypovolemic shock. Resuscitation in hypovolemic animals was performed by infusion of 15 ml/kg of normal saline (group I), 5% sodium bicarbonate (NaHCO3) (group II), 5% sodium chloride (NaCI) and 7.5 % NaHCO3 1:1 VN (group III), 5% NaC1 (group IV), and 5% NaCl and 5% serum albumin 2:1 VN (group V) via jugular vein. All animals were monitored sixty minutes post infusion. Then they were sacrificed to determine Brain Water Content (BWC), pathological investigation of heart, aorta and pulmonary tissues. Two other groups were also used for determination of normal BWC (group N) and aftershock BWC (group S). Mean Arterial Pressure (MAP) of groups H, IV and V were statistically different from group I (P <0.05). Albumin concentration and urine output were increased markedly in group V (P <0.05). Serum osmolality in groups III, IV, and V were significantly different from the first group (P <0.05). Acid-base parameters in groups II and III were raised toward normal, and they showed significant differences from group I (P <0.05). BWC were decreased in groups treated with HTS (p <0.05). No statistical differences were observed in pulse pressure, heart and respiration rates, sodium and potassium concentrations, and urine osmolality between the groups. No detectable pathological changes were observed in heart, aorta and pulmonary tissues.
Pasteur Institute of Iran
Iranian Biomedical Journal
1028-852X
2
2
1998
3
1
Cloning and Expression of Thermus Aquaticus DNA Polymerase Gene, Using a Thermo-Inducible Expression Vector
79
82
EN
Saeid
Bouzari
Veladimir O.
Rechinsky
DNA polymerase gene from Thermus aquaticus strain YT1 was amplified using VENTTM DNA po-lymerase and cloned under the control of X.PR promoter and expression was induced by a shift in tern perature. The culture was then sonicated, and after centrifugation the lysate was treated with polyethyleneimine followed by a salting-out step. Finally the protein was precipitated with ammonium sulfate and fractionated by gel filtration. The resulting enzyme preparation was stable and active.
Pasteur Institute of Iran
Iranian Biomedical Journal
1028-852X
2
2
1998
3
1
Isolation of Legionella Pneumophila Serogroups 1, 8 & 10 (Causative Agents of Legionnaires' Disease) from Water Sources in Tehran, Iran
83
87
EN
Mojtaba
Moosavian
Bahram
Fathollahzadeh
Kazem
Amoli
Nasrin
Moazzami
In this survey, 187 samples collected from 9 different sources of water in Tehran such as: water coolers, neonates incubators, water bathes (37° C), little pools in parks or squares, cooling towers, hot or cold water taps, were examined for Legionnaires' disease agents. Inoculating water samples on selective and nonselective media resulted in isolation of several strains of gram negative bacteria. Among them, seven strains of Legionella pneumophilla which did not grow on any of the above media, were identified by indirect fluorescent antibody technique (IFA) and biochemical tests. Following confirmation by "Center National De Reference Des Legionelloses, Faculte of Medicine Alexis Carrel, Lyon", the Center identified Legionella pneumophila of serogroups of 1, 8 and 10. Out of 6 hospitals, 5 showed contaminated water having pneumonic Legionellosis agents.
Pasteur Institute of Iran
Iranian Biomedical Journal
1028-852X
2
2
1998
3
1
Detection Of Toxoplasma Gondii and Human Cytomegalovirus DNA in Blood from Transplant Recipients Using Multiplex Nested Polymerase Chain Reaction
89
93
EN
Nasser
Khodai Booran
Mahdi
Assmar
A
Hovanesian
N.
Nikolaova
Valery V.
Bakayev
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.