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Azzi A, Ryangga D, Pawiro SA. Comparison of Air-Gaps Effect in a Small Cavity on Dose Calculation for 6 MV Linac. J Biomed Phys Eng 2021; 11:17-28. [PMID: 33564636 PMCID: PMC7859373 DOI: 10.31661/jbpe.v0i0.2004-1096] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/18/2020] [Indexed: 11/29/2022]
Abstract
Background: Many authors stated that cavities or air-gaps were the main challenge of dose calculation for head and neck with flattening filter medical linear accelerator (Linac) irradiation. Objective: The study aimed to evaluate the effect of air-gap dose calculation on flattening-filter-free (FFF) small field irradiation. Material and Methods: In this comparative study, we did the experimental and Monte Carlo (MC) simulation to evaluate the presence of heterogeneities in radiotherapy. We simulated the dose distribution on virtual phantom and the patient’s CT image to determine the air-gap effect of open small field and modulated photon beam, respectively. The dose ratio of air-gaps to tissue-equivalent was calculated both in Analytical Anisotropic Algorithm (AAA) and MC. Results: We found that the dose ratio of air to tissue-equivalent tends to decrease with a larger field size. This correlation was linear with a slope of -0.198±0.001 and -0.161±0.014 for both AAA and MC, respectively. On the other hand, the dose ratio below the air-gap was field size-dependent. The AAA to MC dose calculation as the impact of air-gap thickness and field size varied from 1.57% to 5.35% after the gap. Besides, patient’s skin and oral cavity on head and neck case received a large dose discrepancy according to this study. Conclusion: The dose air to tissue-equivalent ratio decreased with smaller air gaps and larger field sizes. Dose correction for AAA calculation of open small field size should be considered after small air-gaps. However, delivered beam from others gantry angle reduced this effect on clinical case.
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Morfini M, Azzi A, Mannucci PM. B19 Parvovirus Withstands “Super Heating” in Antihemophilic Concentrates. Thromb Haemost 2018. [DOI: 10.1055/s-0038-1650672] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Fallahi P, Ferrari SM, Colaci M, Ruffilli I, Vita R, Azzi A, Ferri C, Antonelli A, Ferrannini E. Hepatitis C virus infection and type 2 diabetes. LA CLINICA TERAPEUTICA 2014; 164:e393-404. [PMID: 24217842 DOI: 10.7417/ct.2013.1620] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Hepatitis C virus (HCV) infection and Type 2 diabetes mellitus (T2DM) are two worldwide, major public health problems with increasing complication and mortality rates. Many epidemiological studies have demonstrated the significant association between T2DM and chronic HCV infection. In this paper we have reviewed the increasing evidence linking HCV infection and DM in more than one field (epidemiology, pathogenesis, clinical aspects, prevention and treatment). We have considered T2DM, acute and chronic HCV infection, and cirrhotic patients. Moreover, we have considered some particular populations, solid organ transplant recipients or HCV/human immunodeficiency virus (HIV) coinfected patients. In the final part we have analyzed the potential effect of the association between HCV infection and the development of DM in term of outcome and possibilities for prevention and treatment.
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Abdulkadir M, Azzi A, Zhao D, Lowndes I, Azzopardi B. Liquid film thickness behaviour within a large diameter vertical 180° return bend. Chem Eng Sci 2014. [DOI: 10.1016/j.ces.2013.12.009] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
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Corcioli F, Arvia R, Pierucci F, Clausi V, Bonizzoli M, Peris A, Azzi A. HA222 polymorphism in Influenza A(H1N1) 2009 isolates from Intensive Care Units and ambulatory patients during three influenza seasons. Virus Res 2014; 180:39-42. [DOI: 10.1016/j.virusres.2013.12.010] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 12/05/2013] [Accepted: 12/11/2013] [Indexed: 10/25/2022]
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Mathy C, Cedraschi C, Azzi A, Broonen JP, Henrotin Y. Volition and low back pain: What patients tell us. Ann Phys Rehabil Med 2013. [DOI: 10.1016/j.rehab.2013.07.222] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Puzelli S, Azzi A, Santini MG, Di Martino A, Facchini M, Castrucci MR, Meola M, Arvia R, Corcioli F, Pierucci F, Baretti S, Bartoloni A, Bartolozzi D, de Martino M, Galli L, Pompa MG, Rezza G, Balocchini E, Donatelli I. Investigation of an imported case of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection in Florence, Italy, May to June 2013. ACTA ACUST UNITED AC 2013; 18. [PMID: 23987829 DOI: 10.2807/1560-7917.es2013.18.34.20564] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
On 31 May 2013, the first case of Middle East Respiratory Syndrome Coronavirus (MERS-CoV) infection in Italy was laboratory confirmed in a previously healthy adult man, who developed pneumonia with moderate respiratory distress after returning from a holiday in Jordan. Two secondary cases were identified through contact tracing, among family members and colleagues who had not previously travelled abroad. Both secondary cases developed mild illness. All three patients recovered fully.
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Peris A, Bonizzoli M, Zagli G, Azzi A. Virological screening in cases of ALI/ARDS. J Hosp Infect 2012; 82:300-1. [PMID: 23103251 DOI: 10.1016/j.jhin.2012.08.012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2012] [Accepted: 08/23/2012] [Indexed: 11/29/2022]
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Abdulkadir M, Zhao D, Azzi A, Lowndes I, Azzopardi B. Two-phase air–water flow through a large diameter vertical 180o return bend. Chem Eng Sci 2012. [DOI: 10.1016/j.ces.2012.05.029] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Azzi A, Alaaeddine N, Raad I, Wardi L, Serhal R, Hilal G. 218 Telomerase Inhibition by Constunolide Decreases Alpha-fetoprotein Secretion by Hepatocellular Carcinoma C3a Cell Line – Possible Role of PI3K/mTOR/STAT3 Pathway. Eur J Cancer 2012. [DOI: 10.1016/s0959-8049(12)70913-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
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Iorio A, Camilloni B, Lepri E, Neri M, Basileo M, Azzi A. Induction of Cross-Reactive Antibodies to 2009 Pandemic H1N1 Influenza Virus (pH1N1) After Seasonal Vaccination (Winters 2003/04 and 2007/08). ACTA ACUST UNITED AC 2011. [DOI: 10.1016/j.provac.2011.07.008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Puzelli S, Facchini M, De Marco MA, Palmieri A, Spagnolo D, Boros S, Corcioli F, Trotta D, Bagnarelli P, Azzi A, Cassone A, Rezza G, Pompa MG, Oleari F, Donatelli I. Molecular surveillance of pandemic influenza A(H1N1) viruses circulating in Italy from May 2009 to February 2010: association between haemagglutinin mutations and clinical outcome. ACTA ACUST UNITED AC 2010; 15. [PMID: 21087581 DOI: 10.2807/ese.15.43.19696-en] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Haemagglutinin sequences of pandemic influenza A(H1N1) viruses circulating in Italy were examined, focusing on amino acid changes at position 222 because of its suggested pathogenic relevance. Among 169 patients, the D222G substitution was detected in three of 52 (5.8%) severe cases and in one of 117 (0.9%) mild cases, whereas the D222E mutation was more frequent and evenly distributed in mild (31.6%) and severe cases (38.4%). A cluster of D222E viruses among school children confirms reported human-to-human transmission of viruses mutated at amino acid position 222.
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Azzi A, Al-Attiyah A, Qi L, Cheema W, Azzopardi B. Gas–liquid two-phase flow division at a micro-T-junction. Chem Eng Sci 2010. [DOI: 10.1016/j.ces.2010.03.037] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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De Santis R, Faggioni G, Ciammaruconi A, Fillo S, Clausi V, Corcioli F, Lista F, Azzi A. A FRET based melting curve analysis to detect nucleotide variations in HA receptor-binding site of H5N1 virus. Mol Cell Probes 2010; 24:298-302. [PMID: 20600823 DOI: 10.1016/j.mcp.2010.06.004] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2010] [Revised: 06/17/2010] [Accepted: 06/17/2010] [Indexed: 11/30/2022]
Abstract
Outbreaks of highly pathogenic H5N1 influenza A virus represent a major public health problem because of the possibility of direct transmission of these viruses from avian species to humans. For influenza H5N1 hemagglutinin, a switch from SA-a-2, 3-Gal to SA-a-2, 6-Gal receptor specificity is a critical step that could lead to inter-human transmission. The monitoring of the receptor-binding preference of H5N1 viruses represents an instrument to detect a potential pandemic virus. The aim of this study was to develop a method based on the fluorescence resonance energy transfer (FRET) technology and melting peaks analysis for rapid screening of pandemic H5N1 influenza A virus. Three selected probes corresponding to a 23bp nucleotide sequence of the avian receptor-binding site were used in a real-time RT-PCR to detect nucleotide variations. Five strains of avian influenza A viruses isolated from avian species and two synthesized HA gene were tested. The results showed that the melting peaks analysis is a reliable screening method for detecting the variability of the H5N1 receptor-binding site.
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Cosseau C, Azzi A, Rognon A, Boissier J, Gourbière S, Roger E, Mitta G, Grunau C. Epigenetic and phenotypic variability in populations of Schistosoma mansoni- a possible kick-off for adaptive host/parasite evolution. OIKOS 2010. [DOI: 10.1111/j.1600-0706.2009.18040.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
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Mannelli E, Murtigni M, Andreani M, Cianferoni S, Colosimo D, Zagli G, Bonizzoli M, Azzi A, Peris A. Time course of RT-PCR positivity in H1N1-induced ARDS. Crit Care 2010. [PMCID: PMC2934224 DOI: 10.1186/cc8320] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Menconi MC, Maggi F, Zakrzewska K, Salotti V, Giovacchini P, Farina C, Andreoli E, Corcioli F, Bendinelli M, Azzi A. Effectiveness of nanofiltration in removing small non-enveloped viruses from three different plasma-derived products. Transfus Med 2009; 19:213-7. [PMID: 19706139 DOI: 10.1111/j.1365-3148.2009.00931.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The objective of this study was to assess the ability of nanofiltration of albumin solution, prothrombin complex (PTC) and factor IX (FIX) to remove two small, non-enveloped DNA viruses, parvovirus B19 (B19V) and torque teno virus (TTV). Virus removal was investigated with down-scale experiments performed with sequential steps of 35-nm and 15-nm nanofiltrations of products spiked with virus DNA-positive sera. Viral loads were determined by real-time PCRs. The 15-nm nanofiltration removed more than 4.0 B19V log from all the products, TTV was reduced of more than 3.0 log from albumin solution and FIX by 35-nm and 15-nm nanofiltrations, respectively, being viral DNA undetectable after these treatments. Traces of TTV were still found in PTC after the 15-nm nanofiltration. In conclusion, nanofiltration can be efficacious in removing small naked viruses but, since viruses with similar features can differently respond to the treatment, a careful monitoring of large-scale nanofiltration should be performed.
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Viana M, Villacorta L, Bonet B, Indart A, Munteanu A, Sánchez-Vera I, Azzi A, Zingg JM. Effects of aldehydes on CD36 expression. Free Radic Res 2009; 39:973-7. [PMID: 16087478 DOI: 10.1080/10715760500073758] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
INTRODUCTION During the oil frying process lipid peroxidation compounds are formed. These products can modulate gene expression and alter cellular behaviour. The cellular uptake of oxidized LDL, a key step in the development of atherosclerosis, is mediated by the CD36 scavenger receptor, whose expression is down-regulated by alpha-tocopherol. OBJECTIVE To determine the effects of water-soluble aldehydes, obtained from thermally oxidized sunflower oil on the expression of CD36 scavenger receptor in human monocytes (THP-1 cells). We also wanted to study the effects of alpha-tocopherol on CD36 expression in the presence of water-soluble aldehydes. MATERIALS AND METHODS Sunflower oil was heated in a frying pan, at 180--200 degrees C for 40 min, water-soluble aldehydes were isolated, and the content of thiobarbituric acid reacting substances (TBARS) was determined. THP-1 monocytes were cultured in RPMI medium during 24 h and incubated with increasing concentrations of the water-soluble aldehydes (ranging from 0.05 to 1 microM) and with or without 50 microM of alpha-tocopherol. In parallel, THP-1 cells were cultured with the same volume of an extract obtained from non-oxidized oil or distilled water. The CD36 expression at the cell surface was studied with fluorescence-activated cell sorting (FACS). RESULTS Monocytes incubated in a medium containing water-soluble aldehydes, showed a dose dependent increase in the expression of the CD36 protein on the cell surface, compared to with the control groups. When the cells were treated simultaneously with 50 microM of alpha-tocopherol a significant reduction in the expression of the CD36 protein was observed. CONCLUSION Water-soluble aldehydes, extracted from thermally oxidized culinary oil, increase the expression of CD36. This effect is partially decreased by the presence of alpha-tocopherol.
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Azzi A, Corcioli F, Zakrzewska K, Fanci R. P.034 Human parvovirus PARV4 persistence in bone marrow and solid tissues. J Clin Virol 2009. [DOI: 10.1016/s1386-6532(08)70097-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Ginevri F, Azzi A, Hirsch HH, Basso S, Fontana I, Cioni M, Bodaghi S, Salotti V, Rinieri A, Botti G, Perfumo F, Locatelli F, Comoli P. Prospective monitoring of polyomavirus BK replication and impact of pre-emptive intervention in pediatric kidney recipients. Am J Transplant 2007; 7:2727-35. [PMID: 17908275 DOI: 10.1111/j.1600-6143.2007.01984.x] [Citation(s) in RCA: 185] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Polyoma BK virus (BKV)-associated nephropathy (PVAN) is a relevant cause of poor renal allograft survival. In a prospective analysis, we monitored BKV DNA in blood and urine samples from 62 consecutive pediatric kidney recipients. In patients with BKV replication, we analyzed the impact of reduction of maintenance immunosuppression on viral load kinetics and PVAN in patients with BKV replication. BKV-specific immunity was concomitantly evaluated on blood samples of viremic patients, by measuring the frequency of BKV-specific interferon-gamma-producing and cytotoxic T cells, and BKV IgG antibody levels. At a median follow-up of 24 months, BK viruria was observed in 39 of 62 patients, while BK viremia developed in 13 patients (21%). In all viremic patients, immunosuppression reduction resulted in the clearance of viremia, and prevented development of PVAN, without increasing the rate of acute rejection or causing graft dysfunction. As a consequence of immunosuppression adjustment, an expansion of BKV-specific cellular immunity was observed that coincided with viral clearance. We conclude that treating pediatric kidney transplant patients pre-emptively with immunosuppression reduction guided by BKV DNA in blood is safe and effective to prevent onset of PVAN. BKV-specific cellular immunity may be useful to guide this intervention.
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Djennaoui N, Kibboua R, Azzi A. Filtration d’une solution de billes en polyéthylène à l’aide d’un dispositif de Couette-Taylor: comparaison à la plasmaphérèse. Ing Rech Biomed 2007. [DOI: 10.1016/j.rbmret.2007.06.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Wang T, Zou YS, Zhu DW, Azzi A, Liu WY, Lin SX. Cinnamomin: separation, crystallization and preliminary X-ray diffraction study. Amino Acids 2007; 34:239-43. [PMID: 17404804 DOI: 10.1007/s00726-006-0490-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2006] [Accepted: 12/08/2006] [Indexed: 10/23/2022]
Abstract
Cinnamomin from Cinnamonum camphora seeds, a type II ribosome-inactivating protein that interferes with protein biosynthesis in mammalian cells, can induce the apoptosis of carcinoma cells and be used as an insecticide. A rapid and improved method has been developed for the extraction and purification of cinnamomin from camphora seed. Purification of cinnamomin is achieved with two successive steps of hydrophobic interaction chromatography carried out on a fast protein liquid chromatography (FPLC) system. Crystals suitable for X-ray diffraction analysis were obtained by vapor diffusion method. A complete data set at 2.8 A resolution has been collected. Data indexation and refinement indicate that the crystal is orthorhombic with space group P2(1)2(1)2(1) and unit cell dimensions a = 52.39 A, b = 126.33 A, c = 161.45 A. There are two molecules per asymmetric unit. Initial phasing by molecular replacement method yielded a solution, which will contribute to the structure determination. A molecular model will further the understanding of the mechanism of cinnamomin function. The latter will be combined with bio-informatics to facilitate the medical and other applications of cinnamomin.
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Ginevri F, Azzi A, Botti G, Comoli P. [Polyomavirus BK-associated nephropathy after kidney transplantation]. GIORNALE ITALIANO DI NEFROLOGIA : ORGANO UFFICIALE DELLA SOCIETA ITALIANA DI NEFROLOGIA 2006; 23:575-84. [PMID: 17173264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Polyomavirus BK (BKV) infection has been lately recognized as a major cause of renal allograft dysfunction. BKV-related interstitial nephropathy (PVAN) may affect 1-10% of renal allograft recipients, occurring more frequently in the first 6 months after transplantation. Progression to irreversible allograft failure has been observed in up to 45% of all cases; thanks to increased PVAN awareness and improved diagnostic techniques, the rate of graft loss has lowered, more consistently in centres with active screening and intervention programs. PVAN pathogenesis is characterized by multiple synergizing factors, among which immunodepression plays a key role. PVAN diagnosis requires the evaluation of a renal biopsy showing polyomavirus cytopathic changes and confirming BKV through an ancillary technique such as immunohistochemistry. Given the focal nature of the disease, early diagnosis may be difficult to obtain. Thus, quantification of BKV-DNA in plasma has been suggested as surrogate marker for PVAN. To date, given the lack of controlled trials, there is no consensus on a 'standard' management of PVAN. However, evidence based on reported observations suggests that a step-wise reduction of immunosuppression, preceded by pulsed steroids in case of coexistent acute rejection, may improve outcomes. Additional options may be represented by drugs with antiviral activity, such as cidofovir, leflunomide or quinolones. Application of a preventive treatment based on viremia monitoring has been recently proposed.
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Zhou M, Azzi A, Xia X, Wang ED, Lin SX. Crystallization and preliminary X-ray diffraction analysis of E. coli arginyl-tRNA synthetase in complex form with a tRNAArg. Amino Acids 2006; 32:479-82. [PMID: 17061034 DOI: 10.1007/s00726-006-0436-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2006] [Accepted: 09/09/2006] [Indexed: 10/24/2022]
Abstract
Amino acids are building blocks of proteins, while aminoacyl-tRNA synthetases (aaRSs) catalyze the first reaction in such building: the biosynthesis of proteins. The E. coli arginyl-tRNA synthetase (ArgRS) has been crystallized in complex form with tRNA(Arg) (B. stearothermophilus), at pH 5.6 using ammonium sulfate as a precipitating agent. Two crystal forms have been identified based on unit cell dimension. The complete data sets from both crystal forms have been collected with a primitive hexagonal space group. A data set of Form II crystals at 3.2 A and 94% completeness has been obtained, with unit cell parameters a = b = 98.0 A, c = 463.2 A, and alpha = beta = 90 degrees , gamma = 120 degrees , being different from a = b = 110.8 A, c = 377.8 A for form I. The structure determination will demonstrate the interaction of these two macromolecules to understand the special mechanism of ArgRS that requires the presence of tRNA for amino acid activation. Such complex structure also provides a wide opening for inhibitor search using bioinformatics.
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Lin SX, Shi R, Qiu W, Azzi A, Zhu DW, Dabbagh HA, Zhou M. Structural basis of the multispecificity demonstrated by 17beta-hydroxysteroid dehydrogenase types 1 and 5. Mol Cell Endocrinol 2006; 248:38-46. [PMID: 16480815 DOI: 10.1016/j.mce.2005.11.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
17Beta-hydroxysteroid dehydrogenases/ketosteroid reductases (17beta-HSDs/KSRs) catalyze the last step of sex steroid synthesis or the first step of their degradation, and are thus critical for many physiological processes. The multispecificity demonstrated by 17beta-HSDs is important for steroid metabolism in gonadal and peripheral tissues, and is a consequence of the architecture of their binding and catalytic sites. Structurally, most of the family members are short chain dehydrogenase-reductases (SDRs) except the type 5 enzyme, which is an aldo-keto reductase (AKR). 17Beta-HSD type 1, a representative of the SDR family, has been studied extensively since the 1950s. However, its structure was not determined until the 1990s. It has always been considered as estrogen specific, in accord with the narrow binding tunnel that has been structurally determined and has been found to be complementary to estrogens. A recent study revealed that, in spite of the enzyme's narrow binding tunnel, the pseudo-symmetry of C19 steroids leads to its alternative binding, resulting in the multispecificity of the enzyme. Expressed in ovary, breast and placenta, the enzyme catalyzes the formation of another estrogen A-diol from DHEA in addition to the biosynthesis of estradiol; it also inactivates the most active androgen DHT by both 17beta-hydroxysteroid oxidation and 3-ketosteroid reduction. Type 5 17beta-HSD (AKR1C3) differs significantly from the type 1 enzyme by possessing a spacious and flexible steroid-binding site. This is estimated to be about 960 or 470 A3 in ternary complex with testosterone or 4-dione, respectively, whereas the binding site volume of 17beta-HSD1 is only about 340 A3. This characteristic of the 17beta-HSD5 binding site permits the docking of various steroids in different orientations, which encompasses a wider range of activities from 20alpha-, 17beta- and 3alpha-HSD/KSR to prostaglandin 11-ketoreductase. The in vitro activities of the enzyme are significantly lower than the type 1 enzyme. In the ternary complex with testosterone, the steroid C3-C17 position is quasi-reversed as compared to the complex with 4-dione. The multi-specificity contributes significantly to steroid metabolism in peripheral tissues, due to the high levels of 17beta-HSD5 mRNA in both breast and prostate tissues.
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