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1.
J Trop Pediatr ; 67(2)2021 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-34037787

RESUMO

BACKGROUND: Dengue and malaria co-infection has been reported in several case reports. We aim to study effect of malaria co-infection on clinical outcomes of dengue infection. METHODS: Records of 623 children with dengue infection, based on NS-1 antigen and IgM ELISA testing, were collected. Malaria co-infection was identified in 20 cases, based on peripheral blood smear examination. Clinical and hematological parameters were compared in two groups (malaria co-infection vs. dengue mono-infection). RESULTS: Duration of hospitalization was significantly higher in co-infected group. Significantly higher proportion of malaria co-infection cases had hepatosplenomegaly, hemoglobin ≤8 g/dl, serum albumin ≤3 g/dl, serum bilirubin ≥1 mg/dl, serum aspartate aminotransferase ≥500 U/l and serum alanine aminotransferase ≥300 U/l. Number of transfusions (PRBC and platelets) required in malaria co-infection group was higher. CONCLUSION: Malaria co-infection in dengue impacts clinical presentation, hematological parameters, requirement of blood transfusion and morbidity. High index of suspicion is warranted while evaluating febrile patients.


Assuntos
Coinfecção , Dengue , Malária , Criança , Coinfecção/epidemiologia , Dengue/complicações , Dengue/diagnóstico , Dengue/epidemiologia , Febre , Hospitalização , Humanos , Malária/complicações , Malária/diagnóstico , Malária/epidemiologia
2.
Environ Sci Technol ; 53(21): 12379-12388, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31553874

RESUMO

Predicting the activation of submicrometer particles into cloud droplets in the atmosphere remains a challenge. The importance of surface tension, σ (mN m-1), in these processes has been evidenced by several works, but information on the "surfactants" lowering σ in actual atmospheric particles remains scarce. In this work, PM1 aerosols from urban, coastal, and remote regions of Europe (Lyon, France, Rogoznica, Croatia, and Pallas, Finland, respectively) were investigated and found to contain amphiphilic surfactants in concentrations up to 2.8 µg m-3 in the air and 1.3 M in the particle dry volume. In Pallas, correlations with the PM1 chemical composition showed that amphiphilic surfactants were present in the entire range of particle sizes, supporting recent works. This implied that they were present in hundreds to thousands of particles cm-3 and not only in a few large particles, as it has been hypothesized. Their adsorption isotherms and critical micelle concentration (CMC) were also determined. The low CMC obtained (3 × 10-5-9 × 10-3 M) implies that surface tension depression should be significant for all the particles containing these compounds, even at activation (growth factor ∼ 10). Amphiphilic surfactants are thus likely to enhance the CCN ability of submicrometer atmospheric particles.


Assuntos
Poluentes Atmosféricos , Tensoativos , Adsorção , Aerossóis , Europa (Continente) , Finlândia , França
3.
BMC Plant Biol ; 18(1): 123, 2018 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-29914379

RESUMO

BACKGROUND: Although the draft genome of sorghum is available, the understanding of gene function is limited due to the lack of extensive mutant resources. Virus-induced gene silencing (VIGS) is an alternative to mutant resources to study gene function. This study reports an improved and efficient method for Brome mosaic virus (BMV)-based VIGS in sorghum. METHODS: Sorghum plants were rub-inoculated with sap prepared by grinding 2 g of infected Nicotiana benthamiana leaf in 1 ml 10 mM potassium phosphate buffer (pH 6.8) and 100 mg of carborundum abrasive. The sap was rubbed on two to three top leaves of sorghum. Inoculated plants were covered with a dome to maintain high humidity and kept in the dark for two days at 18 °C. Inoculated plants were then transferred to 18 °C growth chamber with 12 h/12 h light/dark cycle. RESULTS: This study shows that BMV infection rate can be significantly increased in sorghum by incubating plants at 18 °C. A substantial variation in BMV infection rate in sorghum genotypes/varieties was observed and BTx623 was the most susceptible. Ubiquitin (Ubiq) silencing is a better visual marker for VIGS in sorghum compared to other markers such as Magnesium Chelatase subunit H (ChlH) and Phytoene desaturase (PDS). The use of antisense strand of a gene in BMV was found to significantly increase the efficiency and extent of VIGS in sorghum. In situ hybridization experiments showed that the non-uniform silencing in sorghum is due to the uneven spread of the virus. This study further demonstrates that genes could also be silenced in the inflorescence of sorghum. CONCLUSION: In general, sorghum plants are difficult to infect with BMV and therefore recalcitrant to VIGS studies. However, by using BMV as a vector, a BMV susceptible sorghum variety, 18 °C for incubating plants, and antisense strand of the target gene fragment, efficient VIGS can still be achieved in sorghum.


Assuntos
Bromovirus , Inativação Gênica , Sorghum/genética , Bromovirus/genética , DNA Antissenso/genética , Flores/virologia , Folhas de Planta/virologia , Sorghum/metabolismo , Sorghum/virologia , Temperatura , Ubiquitina/metabolismo
4.
Environ Sci Technol ; 51(16): 8992-9004, 2017 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-28730822

RESUMO

The distributions, correlations, and source apportionment of aromatic acids, aromatic ketones, polycyclic aromatic hydrocarbons (PAHs), and trace metals were studied in Canadian high Arctic aerosols. Nineteen PAHs including minor sulfur-containing heterocyclic PAH (dibenzothiophene) and major 6 carcinogenic PAHs were detected with a high proportion of fluoranthene followed by benzo[k]fluoranthene, pyrene, and chrysene. However, in the sunlit period of spring, their concentrations significantly declined likely due to photochemical decomposition. During the polar sunrise from mid-March to mid-April, benzo[a]pyrene to benzo[e]pyrene ratios significantly dropped, and the ratios diminished further from late April to May onward. These results suggest that PAHs transported over the Arctic are subjected to strong photochemical degradation at polar sunrise. Although aromatic ketones decreased in spring, concentrations of some aromatic acids such as benzoic and phthalic acids increased during the course of polar sunrise, suggesting that aromatic hydrocarbons are oxidized to result in aromatic acids. However, PAHs do not act as the major source for low molecular weight (LMW) diacids such as oxalic acid that are largely formed at polar sunrise in the arctic atmosphere because PAHs are 1 to 2 orders of magnitude less abundant than LMW diacids. Correlations of trace metals with organics, their sources, and the possible role of trace transition metals are explained.


Assuntos
Cetonas , Hidrocarbonetos Policíclicos Aromáticos , Aerossóis , Regiões Árticas , Canadá , Ácidos Carboxílicos , Monitoramento Ambiental , Metais
5.
J Trop Pediatr ; 63(4): 324-327, 2017 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-28013254

RESUMO

Diabetic ketoacidosis (DKA) can present with various neurological complications, but stroke is rare. Here, we present three children with recent-onset diabetes with DKA, two of them had deep coma not responding to standard DKA regimen and the third one had seventh nerve palsy noted after recovering from coma. Computed tomography scan of head showed hemorrhage in the area of midbrain in one patient and infarcts in two patients. In any child of DKA with severe neurological impairment, possibility of stroke should be entertained.


Assuntos
Edema Encefálico/diagnóstico por imagem , Cetoacidose Diabética/complicações , Acidente Vascular Cerebral/complicações , Acidente Vascular Cerebral/etiologia , Edema Encefálico/etiologia , Criança , Pré-Escolar , Cetoacidose Diabética/tratamento farmacológico , Feminino , Humanos , Insulina/administração & dosagem , Masculino , Acidente Vascular Cerebral/diagnóstico por imagem , Tomografia Computadorizada por Raios X , Resultado do Tratamento
6.
J Biol Chem ; 290(41): 24636-48, 2015 Oct 09.
Artigo em Inglês | MEDLINE | ID: mdl-26245904

RESUMO

Why mammalian cells possess multiple DNA glycosylases (DGs) with overlapping substrate ranges for repairing oxidatively damaged bases via the base excision repair (BER) pathway is a long-standing question. To determine the biological role of these DGs, null animal models have been generated. Here, we report the generation and characterization of mice lacking Neil2 (Nei-like 2). As in mice deficient in each of the other four oxidized base-specific DGs (OGG1, NTH1, NEIL1, and NEIL3), Neil2-null mice show no overt phenotype. However, middle-aged to old Neil2-null mice show the accumulation of oxidative genomic damage, mostly in the transcribed regions. Immuno-pulldown analysis from wild-type (WT) mouse tissue showed the association of NEIL2 with RNA polymerase II, along with Cockayne syndrome group B protein, TFIIH, and other BER proteins. Chromatin immunoprecipitation analysis from mouse tissue showed co-occupancy of NEIL2 and RNA polymerase II only on the transcribed genes, consistent with our earlier in vitro findings on NEIL2's role in transcription-coupled BER. This study provides the first in vivo evidence of genomic region-specific repair in mammals. Furthermore, telomere loss and genomic instability were observed at a higher frequency in embryonic fibroblasts from Neil2-null mice than from the WT. Moreover, Neil2-null mice are much more responsive to inflammatory agents than WT mice. Taken together, our results underscore the importance of NEIL2 in protecting mammals from the development of various pathologies that are linked to genomic instability and/or inflammation. NEIL2 is thus likely to play an important role in long term genomic maintenance, particularly in long-lived mammals such as humans.


Assuntos
DNA Glicosilases/deficiência , DNA Glicosilases/genética , DNA/metabolismo , Genoma/genética , Transcrição Gênica , Envelhecimento/genética , Envelhecimento/metabolismo , Animais , Linhagem Celular , DNA/genética , Dano ao DNA , Técnicas de Inativação de Genes , Instabilidade Genômica , Homeostase , Humanos , Inflamação/genética , Inflamação/metabolismo , Camundongos , Oxirredução , RNA Polimerase II/metabolismo , Telômero/genética
7.
Trends Genet ; 28(12): 624-31, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-22940096

RESUMO

Helicases are ubiquitous proteins that unwind DNA and participate in DNA metabolism including replication, repair, transcription, and chromatin organization. The highly conserved RecQ helicase family proteins are important in these transactions and have been termed the guardians of the genome. Humans have five members of this family: WRN, BLM, RECQL4, RECQL1, and RECQL5. The first three of are associated with premature aging and cancer prone syndromes, but the latter two proteins have not yet been implicated in any human disease. Although WRN and BLM have been fairly well characterized, RECQL4 has only recently been intensively investigated. The sum of this work to date has shown that RECQL4 has helicase activity and localizes to telomeres and mitochondria. In addition, new protein partners are emerging, implicating RECQL4 in novel processes. Here, we describe these recent findings which place RECQL4 at the crossroads of genomic instability and aging processes.


Assuntos
Envelhecimento/genética , Instabilidade Genômica , RecQ Helicases/genética , RecQ Helicases/metabolismo , Animais , Humanos , Camundongos , Mitocôndrias/genética , Mitocôndrias/metabolismo , RecQ Helicases/química , Síndrome de Rothmund-Thomson/genética , Telômero/genética , Telômero/metabolismo
8.
Carcinogenesis ; 35(11): 2415-24, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24942867

RESUMO

RECQL4, a member of the RecQ helicase family, is a multifunctional participant in DNA metabolism. RECQL4 protein participates in several functions both in the nucleus and in the cytoplasm of the cell, and mutations in human RECQL4 are associated with three genetic disorders: Rothmund-Thomson, RAPADILINO and Baller-Gerold syndromes. We previously reported that RECQL4 is recruited to laser-induced DNA double-strand breaks (DSB). Here, we have characterized the functional roles of RECQL4 in the non-homologous end joining (NHEJ) pathway of DSB repair. In an in vitro NHEJ assay that depends on the activity of DNA-dependent protein kinase (DNA-PK), extracts from RECQL4 knockdown cells display reduced end-joining activity on DNA substrates with cohesive and non-cohesive ends. Depletion of RECQL4 also reduced the end joining activity on a GFP reporter plasmid in vivo. Knockdown of RECQL4 increased the sensitivity of cells to γ-irradiation and resulted in accumulation of 53BP1 foci after irradiation, indicating defects in the processing of DSB. We find that RECQL4 interacts with the Ku70/Ku80 heterodimer, part of the DNA-PK complex, via its N-terminal domain. Further, RECQL4 stimulates higher order DNA binding of Ku70/Ku80 to a blunt end DNA substrate. Taken together, these results implicate that RECQL4 participates in the NHEJ pathway of DSB repair via a functional interaction with the Ku70/Ku80 complex. This is the first study to provide both in vitro and in vivo evidence for a role of a RecQ helicase in NHEJ.


Assuntos
Antígenos Nucleares/genética , Reparo do DNA por Junção de Extremidades/genética , Proteínas de Ligação a DNA/genética , RecQ Helicases/genética , Síndrome de Rothmund-Thomson/genética , Quebras de DNA de Cadeia Dupla/efeitos da radiação , Proteína Quinase Ativada por DNA/genética , Raios gama , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Autoantígeno Ku , Tolerância a Radiação/genética , RecQ Helicases/antagonistas & inibidores , Síndrome de Rothmund-Thomson/patologia , Proteína 1 de Ligação à Proteína Supressora de Tumor p53
9.
Nucleic Acids Res ; 40(14): 6632-48, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22544709

RESUMO

Bacteria and yeast possess one RecQ helicase homolog whereas humans contain five RecQ helicases, all of which are important in preserving genome stability. Three of these, BLM, WRN and RECQL4, are mutated in human diseases manifesting in premature aging and cancer. We are interested in determining to which extent these RecQ helicases function cooperatively. Here, we report a novel physical and functional interaction between BLM and RECQL4. Both BLM and RECQL4 interact in vivo and in vitro. We have mapped the BLM interacting site to the N-terminus of RECQL4, comprising amino acids 361-478, and the region of BLM encompassing amino acids 1-902 interacts with RECQL4. RECQL4 specifically stimulates BLM helicase activity on DNA fork substrates in vitro. The in vivo interaction between RECQL4 and BLM is enhanced during the S-phase of the cell cycle, and after treatment with ionizing radiation. The retention of RECQL4 at DNA double-strand breaks is shortened in BLM-deficient cells. Further, depletion of RECQL4 in BLM-deficient cells leads to reduced proliferative capacity and an increased frequency of sister chromatid exchanges. Together, our results suggest that BLM and RECQL4 have coordinated activities that promote genome stability.


Assuntos
Instabilidade Genômica , RecQ Helicases/metabolismo , Linhagem Celular , DNA/metabolismo , Dano ao DNA , Guanina/análogos & derivados , Guanina/metabolismo , Células HeLa , Humanos , Domínios e Motivos de Interação entre Proteínas , RecQ Helicases/química , Fase S , Troca de Cromátide Irmã , Timina/análogos & derivados , Timina/metabolismo
10.
Trop Doct ; 54(2): 112-115, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38073124

RESUMO

Enteric fever remains a significant public health problem in low- and middle-income countries with further challenges from emerging antimicrobial resistance. Our prospective study evaluated the current clinical and antimicrobial susceptibility profile of enteric fever in 88 children and compared it to previously established literature. Enteric fever usually presents with nonspecific signs and symptoms, with predominant respiratory complaints. A paradigm shift in the antimicrobial sensitivity pattern has been noted, with increasing resistance for first-line antibiotics and older antibiotics such as ampicillin, cotrimoxazole, and chloramphenicol showing good sensitivity. Thus, the introduction of the latter merits consideration.


Assuntos
Anti-Infecciosos , Febre Tifoide , Criança , Humanos , Febre Tifoide/diagnóstico , Febre Tifoide/tratamento farmacológico , Febre Tifoide/epidemiologia , Salmonella typhi , Estudos Prospectivos , Testes de Sensibilidade Microbiana , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Resistência Microbiana a Medicamentos
11.
Rev Sci Instrum ; 95(8)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39145696

RESUMO

Sensing and quantification of gas at low concentrations is of paramount importance, especially with highly flammable and explosive gases such as hydrogen. Standard gas sensing setups have a limit of measuring ultra-low concentrations of few parts per billion unless the external gas cylinders are changed to ones with low concentrations. In this work, we describe a home-built resistance based gas sensing setup that can sense across a wide concentration range, from parts per billion to parts per million, accurately. This was achieved using two dilution chambers: a process chamber and a feedback assembly where a part of the output gas from the dilution chamber is fed back to the inlet mass flow controller, enabling enhanced dilutions without increasing the number of mass flow controllers. In addition, the gas-sensing setup can measure across a large temperature range of 77-900 K. The developed setup was then calibrated using palladium thin films and ZnO nanoparticle thin films. The setup was tested for reproducibility, concentration response, temperature response, etc. Corresponding sensitivity values were calculated and found to be in good agreement with published values, validating our setup design.

12.
J Biol Chem ; 287(1): 196-209, 2012 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-22039056

RESUMO

Telomeres are structures at the ends of chromosomes and are composed of long tracks of short tandem repeat DNA sequences bound by a unique set of proteins (shelterin). Telomeric DNA is believed to form G-quadruplex and D-loop structures, which presents a challenge to the DNA replication and repair machinery. Although the RecQ helicases WRN and BLM are implicated in the resolution of telomeric secondary structures, very little is known about RECQL4, the RecQ helicase mutated in Rothmund-Thomson syndrome (RTS). Here, we report that RTS patient cells have elevated levels of fragile telomeric ends and that RECQL4-depleted human cells accumulate fragile sites, sister chromosome exchanges, and double strand breaks at telomeric sites. Further, RECQL4 localizes to telomeres and associates with shelterin proteins TRF1 and TRF2. Using recombinant proteins we showed that RECQL4 resolves telomeric D-loop structures with the help of shelterin proteins TRF1, TRF2, and POT1. We also found a novel functional synergistic interaction of this protein with WRN during D-loop unwinding. These data implicate RECQL4 in telomere maintenance.


Assuntos
Proteínas Mutantes/metabolismo , Mutação , RecQ Helicases/metabolismo , Síndrome de Rothmund-Thomson/genética , Telômero/metabolismo , Afidicolina/farmacologia , Sequência de Bases , DNA/biossíntese , DNA/química , DNA/metabolismo , Replicação do DNA/efeitos dos fármacos , Exodesoxirribonucleases/metabolismo , Técnicas de Silenciamento de Genes , Células HeLa , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Dados de Sequência Molecular , Proteínas Mutantes/genética , Conformação de Ácido Nucleico/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , RNA Interferente Pequeno/genética , RecQ Helicases/deficiência , RecQ Helicases/genética , Síndrome de Rothmund-Thomson/metabolismo , Síndrome de Rothmund-Thomson/patologia , Telômero/efeitos dos fármacos , Telômero/genética , Proteína 2 de Ligação a Repetições Teloméricas/metabolismo , Proteína 1 de Ligação à Proteína Supressora de Tumor p53 , Helicase da Síndrome de Werner
13.
J Ultrasound ; 26(2): 385-391, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35947294

RESUMO

OBJECTIVES: To assess the advantage of the addition of shear wave elastography (SWE) to gray-scale sonography in the diagnosis of plantar fasciitis. METHODS: 30 subjects between 18-60 years of age with unilateral heel pain who were clinically suspected of having plantar fasciitis were included in this study. Their affected feet were taken as cases; while their contralateral feet served as controls. On gray-scale ultrasound, the thickness of plantar fascia, its echopattern, presence of hypoechoic areas, and perifasicular collections were recorded. SWE was done by placing seven ROIs within the plantar fascia; and the mean of their Young's modulus was taken in kPa. RESULTS: Plantar fascial thickening more than 4 mm had 70% sensitivity and 66.7% specificity, echopattern had 90% sensitivity and 96.7% specificity, hypoechoic areas had 80% sensitivity and 96.7% specificity, and perifascial edema had 26.7% sensitivity and 100% specificity for diagnosing plantar fasciitis. Using the ROC curve, the cut-off value of Young's modulus for the diagnosis of plantar fasciitis was found to be ≤ 99.286 kPa. This predicted plantar fasciitis with 97% sensitivity and 100% specificity. The primary diagnostic feature of ultrasound of plantar fascia thickness more than 4 mm detected 21 out of 30 cases of plantar fasciitis; whereas elastography detected an additional 8 cases which would have been missed on B-mode ultrasound alone. CONCLUSIONS: SWE is a useful supplement and improves the diagnostic accuracy of gray-scale ultrasound in plantar fasciitis.


Assuntos
Técnicas de Imagem por Elasticidade , Fasciíte Plantar , Humanos , Fasciíte Plantar/diagnóstico por imagem , Estudos de Casos e Controles , Ultrassonografia , Dor
14.
Br J Radiol ; 96(1146): 20220913, 2023 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-36752595

RESUMO

Macropattern analysis of traumatic brachial plexopathy (TBP) by Magnetic Resonance Imaging (MRI) encompasses localization of injured segments and determination of the severity of injury. The micropattern analysis implies the correlation of the MRI features of TBP with Sunderland's grading of the nerve injury, thereby guiding the management protocol. This review article presents a simplified novel pentavalent approach for the radiological anatomy of brachial plexus, MRI acquisition protocol for the evaluation of brachial plexus, cardinal imaging signs of TBP, and their correlation with Sunderland's microanatomical grading.


Assuntos
Neuropatias do Plexo Braquial , Plexo Braquial , Radiologia , Humanos , Neuropatias do Plexo Braquial/diagnóstico por imagem , Neuropatias do Plexo Braquial/etiologia , Plexo Braquial/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodos
15.
Br J Radiol ; 96(1150): 20230552, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37660684

RESUMO

Carpal tunnel syndrome (CTS), the most common entrapment neuropathy, is compression of the median nerve deep to transverse carpal ligament at wrist. Ultrasonography and electrophysiological study are complementary in the diagnosis and grading of CTS in appropriate clinical settings. The initial management of patients with CTS is conservative with medical therapy and splinting. However, surgical interventions are indicated in patients in whom medical management has failed. With evolution of the concept of safe zone on ultrasonography and identification of the sonoanatomical landmarks of carpal tunnel in greater detail, Ultrasonography-guided interventions are safer and preferred over surgical management in CTS. The primary ultrasonography-guided interventions include perineural injection, perineural hydrodissection and ultrasonography-guided release of transverse carpal ligament. This review article presents the principles of ultrasonography-guided perineural injection, perineural hydrodissection in CTS, the merits and demerits of injectant used in perineural injection/ hydrodissection, and percutaneous ultrasonography-guided thread release of transverse carpal ligament utilizing the concept of safe zone of the ultrasonography-guided interventions for CTS.


Assuntos
Síndrome do Túnel Carpal , Humanos , Síndrome do Túnel Carpal/diagnóstico por imagem , Síndrome do Túnel Carpal/cirurgia , Ultrassonografia de Intervenção , Nervo Mediano/diagnóstico por imagem , Nervo Mediano/cirurgia , Ultrassonografia , Articulação do Punho
16.
Mutat Res ; 736(1-2): 15-24, 2012 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-21689668

RESUMO

Organisms are constantly exposed to various environmental insults which could adversely affect the stability of their genome. To protect their genomes against the harmful effect of these environmental insults, organisms have evolved highly diverse and efficient repair mechanisms. Defective DNA repair processes can lead to various kinds of chromosomal and developmental abnormalities. RecQ helicases are a family of evolutionarily conserved, DNA unwinding proteins which are actively engaged in various DNA metabolic processes, telomere maintenance and genome stability. Bacteria and lower eukaryotes, like yeast, have only one RecQ homolog, whereas higher eukaryotes including humans possess multiple RecQ helicases. These multiple RecQ helicases have redundant and/or non-redundant functions depending on the types of DNA damage and DNA repair pathways. Humans have five different RecQ helicases and defects in three of them cause autosomal recessive diseases leading to various kinds of cancer predisposition and/or aging phenotypes. Emerging evidence also suggests that the RecQ helicases have important roles in telomere maintenance. This review mainly focuses on recent knowledge about the roles of RecQ helicases in DNA double strand break repair and telomere maintenance which are important in preserving genome integrity.


Assuntos
Quebras de DNA de Cadeia Dupla , Reparo do DNA , RecQ Helicases/metabolismo , Telômero/fisiologia , Instabilidade Genômica , Humanos , Estresse Oxidativo
17.
Nucleic Acids Res ; 38(15): 5023-35, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20385586

RESUMO

XRCC1 operates as a scaffold protein in base excision repair, a pathway that copes with base and sugar damage in DNA. Studies using recombinant XRCC1 proteins revealed that: a C389Y substitution, responsible for the repair defects of the EM-C11 CHO cell line, caused protein instability; a V86R mutation abolished the interaction with POLbeta, but did not disrupt the interactions with PARP-1, LIG3alpha and PCNA; and an E98K substitution, identified in EM-C12, reduced protein integrity, marginally destabilized the POLbeta interaction, and slightly enhanced DNA binding. Two rare (P161L and Y576S) and two frequent (R194W and R399Q) amino acid population variants had little or no effect on XRCC1 protein stability or the interactions with POLbeta, PARP-1, LIG3alpha, PCNA or DNA. One common population variant (R280H) had no pronounced effect on the interactions with POLbeta, PARP-1, LIG3alpha and PCNA, but did reduce DNA-binding ability. When expressed in HeLa cells, the XRCC1 variants-excluding E98K, which was largely nucleolar, and C389Y, which exhibited reduced expression-exhibited normal nuclear distribution. Most of the protein variants, including the V86R POLbeta-interaction mutant, displayed normal relocalization kinetics to/from sites of laser-induced DNA damage: except for E98K and C389Y, and the polymorphic variant R280H, which exhibited a slightly shorter retention time at DNA breaks.


Assuntos
Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Substituição de Aminoácidos , Animais , Células CHO , Cricetinae , Cricetulus , DNA/metabolismo , Reparo do DNA , Proteínas de Ligação a DNA/análise , Humanos , Proteína 1 Complementadora Cruzada de Reparo de Raio-X
18.
J Clin Orthop Trauma ; 28: 101869, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35494487

RESUMO

Targeted cannulation of the nidus and subsequent thermal ablation is the basis of CT-guided radiofrequency ablation (RFA) of osteoid osteoma, which is considered nowadays as the treatment of choice. The majority of complications during this procedure are due to thermal injury of adjacent structures. Specific measures as per the anatomical location of osteoid osteoma can avoid the majority of complications. This article enlists the possible complications and their necessary precautions and remedies to avoid these complications during CT-guided radiofrequency ablation of osteoid osteoma.

19.
Indian J Radiol Imaging ; 32(1): 113-123, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35722646

RESUMO

Evolution and functional necessities have compelled the great toe of the foot and its embryological kin, thumb, to have some tendoligamentous differences with a similar basic anatomical structure. This provides biomechanical advantage to these joints: the thumb is apposable and more mobile, ensuring hand dexterity and tool-handling, whereas the great toe is less mobile and more stable, ensuring weight bearing, strength, and stability for bipedal locomotion. This pictorial review will methodically illustrate the similarities and dissimilarities of the joint morphology and its tendoligamentous attachments at the level of carpometacarpal joint, metacarpophalangeal joint, and interphalangeal joints of thumb compared with tarsometatarsal joint, metatarsophalangeal joint, and interphalangeal joints of great toe. It intends to provide a comprehensive understanding of the normal anatomy of great toe and thumb to the radiologists, enabling better interpretation of the pathologies.

20.
J Neurosci Rural Pract ; 13(2): 211-217, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-35694062

RESUMO

Background Convulsive status epilepticus (CSE) is a common neurological emergency with high mortality, morbidity, and poor quality of life. There is a paucity of follow-up studies from developing nations in pediatric age group. Objectives This article looks for clinico-etiological profile of CSE and estimates the immediate and short-term mortality in children with CSE and its predictive factors. Methodology This prospective longitudinal study was done at a tertiary care institute of Northern India. The patients between the ages of 1 and 16 years with CSE were enrolled after informed consent, they were observed in the hospital, and survived patients were followed till 3 months after discharge. Results A total of 200 patients (58% males) were enrolled. Acute symptomatic (63.5%) was the most common etiology. Twenty-five (12.5%) patients died during hospital stay; at discharge, 160 (80%) had good recovery and rest had a varying range of disability. The predictive factors for poor outcome were female gender, duration of CSE > 1 hour at presentation, generalized seizures, Glasgow Coma Scale < 8 at presentation, refractory status epilepticus, need for critical care support, and acute symptomatic etiology. On follow-up, two patients died at 1-month and one at 3-month follow-up, the cause of death was probably seizures in two patients and feed aspiration in one patient. Seven patients deteriorated from good recovery scoring to moderate disability during the time interval between first and second follow-up, none of them reported apparent repeat seizures. Conclusion Pediatric CSE is associated with immediate poor outcome; risk of death and new disabilities persist after discharge thus proper follow-up is essential.

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