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1.
Physiol Mol Biol Plants ; 29(10): 1437-1456, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-38076769

RESUMEN

Unravelling genetic networks regulating developmental programs are key to devising and implementing genomics assisted trait modification strategies. It is crucial to understand the role of small RNAs, and the basis of their ability to modify traits. MIR159 has been previously reported to cause defects in anther development in Arabidopsis; however, the complete spectrum and basis of the defects remained unclear. The present study was therefore undertaken to comprehensively investigate the role of miR159 from Brassica juncea in modulating vegetative and reproductive traits. Owing to the polyploid nature of Brassica, paralogous and homeologous copies of MIR159A, MIR159B, and, MIR159C were identified and analysis of the precursor uncovered extensive structural and sequence variation. The MIR159 locus with mature miR159 with perfect target complimentarily with MYB65, was cloned from Brassica juncea var. Varuna for functional characterization by generating constitutively over-expressing lines in Arabidopsis thaliana Col-0. Apart from statistically significant difference in multiple vegetative traits, drastic differences were observed in stamen and pistil. Over-expression of miR159a led to shortening of filament length and loss of tetradynamous condition. Anthers were apiculate, with improper lobe formation, and unsynchronized cellular growth between connective tissue and another lobe development. Analysis revealed arrested meiosis/cytokinesis in microspores, and altered lignin deposition pattern in endothecial walls thus affecting anther dehiscence. In the gynoecium, flaccid, dry stigmatic papillae, and large embryo sac in the female gametophyte was observed. Over-expression of miR159a thus severely affected pollination and seed-set. Analysis of the transcriptome data revealed components of regulatory networks of anther and carpel developmental pathway, and lignin metabolism that are affected. Expression analysis allowed us to position the miR159a-MYB65 module in the genetic network of stamen development, involved in pollen-grain maturation; in GA-mediated regulation of stamen development, and in lignin metabolism. The study, on one hand indicates role of miR159a-MYB65 in regulating multiple aspects of reproductive organ development that can be manipulated for trait modification, but also raises several unaddressed questions such as relationship between miR159a and male-meiosis, miR159a and filament elongation for future investigations. Accession numbers: KC204951-KC204960. Project number PRJNA1035268. Supplementary Information: The online version contains supplementary material available at 10.1007/s12298-023-01377-7.

2.
Mol Genet Genomics ; 294(3): 693-714, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30840147

RESUMEN

Whole-genome and segmental duplications coupled with sequence and functional diversification are responsible for gene family expansion, and morphological and adaptive diversity. Although broad contours of such processes are understood, detailed investigations on regulatory elements, such as miRNA-transcription factor modules, especially in non-model crop plants with complex genomes, are few. The present study was performed to understand evolutionary history of MIR159 family, and changes in the miRNA-binding site (MBS) of the targets MYB33, MYB65, and MYB101 that may affect post-transcriptional gene silencing. We established orthology and paralogy between members of MIR159 family by reconstructing the phylogeny based on 240 precursor sequences sampled across green plants. An unambiguous paralogous relationship between MIR159A and MIR159B was observed only in Brassicaceae which prompted us to analyze the origin of this paralogy. Comparative micro-synteny of ca. 100 kb genomic segments surrounding MIR159A, MIR159B, and MIR159C loci across 15 genomes of Brassicaceae revealed segmental duplication that occurred in the common ancestor of Brassicaceae to be responsible for origin of MIR159A-MIR159B paralogy; extensive gene loss and rearrangements were also encountered. The impact of polyploidy was revealed when the three sub-genomes-least fractionated (LF), moderately fractionated (MF1), and most fractionated (MF2) sub-genomes of Brassica and Camelina sativa-were analyzed. Extensive gene loss was observed among sub-genomes of Brassica, whereas those in Camelina were largely conserved. Analysis of the target MYBs revealed the complete loss of MYB33 homologs in a Brassica lineage-specific manner. Our findings suggest that mature miR159a/b /c are capable of targeting MYB65 across Brassicaceae, MYB33 in all species except Brassica, and MYB101 only in Arabidopsis thaliana. Comparative analysis of the mature miRNA sequence and the miRNA-binding site (MBS) in MYB33, MYB65, and MYB101 showed the complexity of regulatory network that is dependent on strict sequence complementarity potentially leading to regulatory diversity.


Asunto(s)
Brassicaceae/genética , Genómica/métodos , MicroARNs/genética , Proteínas de Plantas/genética , Proteínas Proto-Oncogénicas c-myb/genética , Interferencia de ARN , Secuencia de Aminoácidos , Brassicaceae/clasificación , Regulación de la Expresión Génica de las Plantas , Variación Genética , Genoma de Planta/genética , MicroARNs/clasificación , Filogenia , Proteínas Proto-Oncogénicas c-myb/clasificación , Homología de Secuencia de Ácido Nucleico
3.
Funct Integr Genomics ; 18(4): 369-383, 2018 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-29532337

RESUMEN

The impact of polyploidy on functional diversification of cis-regulatory elements is poorly understood. This is primarily on account of lack of well-defined structure of cis-elements and a universal regulatory code. To the best of our knowledge, this is the first report on characterization of sequence and functional diversification of paralogous and homeologous promoter elements associated with MIR164 from Brassica. The availability of whole genome sequence allowed us to identify and isolate a total of 42 homologous copies of MIR164 from diploid species-Brassica rapa (A-genome), Brassica nigra (B-genome), Brassica oleracea (C-genome), and allopolyploids-Brassica juncea (AB-genome), Brassica carinata (BC-genome) and Brassica napus (AC-genome). Additionally, we retrieved homologous sequences based on comparative genomics from Arabidopsis lyrata, Capsella rubella, and Thellungiella halophila, spanning ca. 45 million years of evolutionary history of Brassicaceae. Sequence comparison across Brassicaceae revealed lineage-, karyotype, species-, and sub-genome specific changes providing a snapshot of evolutionary dynamics of miRNA promoters in polyploids. Tree topology of cis-elements associated with MIR164 was found to re-capitulate the species and family evolutionary history. Phylogenetic shadowing identified transcription factor binding sites (TFBS) conserved across Brassicaceae, of which, some are already known as regulators of MIR164 expression. Some of the TFBS were found to be distributed in a sub-genome specific (e.g., SOX specific to promoter of MIR164c from MF2 sub-genome), lineage-specific (YABBY binding motif, specific to C. rubella in MIR164b), or species-specific (e.g., VOZ in A. thaliana MIR164a) manner which might contribute towards genetic and adaptive variation. Reporter activity driven by promoters associated with MIR164 paralogs and homeologs was majorly in agreement with known role of miR164 in leaf shaping, regulation of lateral root development and senescence, and one previously un-described novel role in trichome. The impact of polyploidy was most profound when reporter activity across three MIR164c homeologs were compared that revealed negligible overlap, whereas reporter activity among two homeologs of MIR164a displays significant overlap. A copy number dependent cis-regulatory divergence thus exists in MIR164 genes in Brassica juncea. The full extent of regulatory diversification towards adaptive strategies will only be known when future endeavors analyze the promoter function under duress of stress and hormonal regimes.


Asunto(s)
Brassica/genética , Variaciones en el Número de Copia de ADN , MicroARNs/genética , Regiones Promotoras Genéticas , Brassica/clasificación , Evolución Molecular , Filogenia
4.
J Biol Chem ; 289(33): 23256-23263, 2014 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-24975416

RESUMEN

The aspartate in the prototypical integrin-binding motif Arg-Gly-Asp binds the integrin ßA domain of the ß-subunit through a divalent cation at the metal ion-dependent adhesion site (MIDAS). An auxiliary metal ion at a ligand-associated metal ion-binding site (LIMBS) stabilizes the metal ion at MIDAS. LIMBS contacts distinct residues in the α-subunits of the two ß3 integrins αIIbß3 and αVß3, but a potential role of this interaction on stability of the metal ion at LIMBS in ß3 integrins has not been explored. Equilibrium molecular dynamics simulations of fully hydrated ß3 integrin ectodomains revealed strikingly different conformations of LIMBS in unliganded αIIbß3 versus αVß3, the result of stronger interactions of LIMBS with αV, which reduce stability of the LIMBS metal ion in αVß3. Replacing the αIIb-LIMBS interface residue Phe(191) in αIIb (equivalent to Trp(179) in αV) with Trp strengthened this interface and destabilized the metal ion at LIMBS in αIIbß3; a Trp(179) to Phe mutation in αV produced the opposite but weaker effect. Consistently, an F191/W substitution in cellular αIIbß3 and a W179/F substitution in αVß3 reduced and increased, respectively, the apparent affinity of Mn(2+) to the integrin. These findings offer an explanation for the variable occupancy of the metal ion at LIMBS in αVß3 structures in the absence of ligand and provide new insights into the mechanisms of integrin regulation.


Asunto(s)
Integrina alfaVbeta3/química , Integrina beta3/química , Manganeso/química , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/química , Secuencias de Aminoácidos , Sitios de Unión , Cationes Bivalentes/química , Humanos , Integrina alfaVbeta3/genética , Integrina beta3/genética , Complejo GPIIb-IIIa de Glicoproteína Plaquetaria/genética
5.
J Biol Chem ; 289(20): 13801-9, 2014 May 16.
Artículo en Inglés | MEDLINE | ID: mdl-24692540

RESUMEN

The function-blocking, non-RGD-containing, and primate-specific mouse monoclonal antibody 17E6 binds the αV subfamily of integrins. 17E6 is currently in phase II clinical trials for treating cancer. To elucidate the structural basis of recognition and the molecular mechanism of inhibition, we crystallized αVß3 ectodomain in complex with the Fab fragment of 17E6. Protein crystals grew in presence of the activating cation Mn(2+). The integrin in the complex and in solution assumed the genuflected conformation. 17E6 Fab bound exclusively to the Propeller domain of the αV subunit. At the core of αV-Fab interface were interactions involving Propeller residues Lys-203 and Gln-145, with the latter accounting for primate specificity. The Propeller residue Asp-150, which normally coordinates Arg of the ligand Arg-Gly-Asp motif, formed contacts with Arg-54 of the Fab that were expected to reduce soluble FN10 binding to cellular αVß3 complexed with 17E6. This was confirmed in direct binding studies, suggesting that 17E6 is an allosteric inhibitor of αV integrins.


Asunto(s)
Anticuerpos Monoclonales/química , Anticuerpos Monoclonales/inmunología , Fragmentos Fab de Inmunoglobulinas/metabolismo , Integrina alfaV/química , Integrina alfaV/inmunología , Integrina alfaVbeta3/química , Integrina alfaVbeta3/metabolismo , Secuencia de Aminoácidos , Animales , Línea Celular , Cristalografía por Rayos X , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Fragmentos Fab de Inmunoglobulinas/inmunología , Integrina alfaVbeta3/inmunología , Manganeso/farmacología , Modelos Moleculares , Datos de Secuencia Molecular , Primates , Estructura Terciaria de Proteína , Especificidad de la Especie
6.
Chem Commun (Camb) ; 60(33): 4495-4498, 2024 Apr 18.
Artículo en Inglés | MEDLINE | ID: mdl-38567462

RESUMEN

We have demonstrated that cisplatin (CP), an anticancer drug, showed a preference for binding the sulfated-L-iduronic acid (S-L-IdoA) unit over the sulfated-D-glucuronic acid unit of heparan sulfate. The multivalency of S-L-IdoA, such as in the proteoglycan mimic, resulted in distinct modes of cell-surface engineering in normal and cancer cells, with these disparities having a significant impact on CP-mediated toxicity.


Asunto(s)
Cisplatino , Proteoglicanos , Heparitina Sulfato/química , Ácido Glucurónico/metabolismo , Ácido Idurónico , Sulfatos
7.
J Immunol ; 187(12): 6393-401, 2011 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-22095715

RESUMEN

A central feature of integrin interaction with physiologic ligands is the monodentate binding of a ligand carboxylate to a Mg(2+) ion hexacoordinated at the metal ion-dependent adhesion site (MIDAS) in the integrin A domain. This interaction stabilizes the A domain in the high-affinity state, which is distinguished from the default low-affinity state by tertiary changes in the domain that culminate in cell adhesion. Small molecule ligand-mimetic integrin antagonists act as partial agonists, eliciting similar activating conformational changes in the A domain, which has contributed to paradoxical adhesion and increased patient mortality in large clinical trials. As with other ligand-mimetic integrin antagonists, the function-blocking mAb 107 binds MIDAS of integrin CD11b/CD18 A domain (CD11bA), but in contrast, it favors the inhibitory Ca(2+) ion over the Mg(2+) ion at MIDAS. We determined the crystal structures of the Fab fragment of mAb 107 complexed to the low- and high-affinity states of CD11bA. Favored binding of the Ca(2+) ion at MIDAS is caused by the unusual symmetric bidentate ligation of a Fab-derived ligand Asp to a heptacoordinated MIDAS Ca(2+) ion. Binding of the Fab fragment of mAb 107 to CD11bA did not trigger the activating tertiary changes in the domain or in the full-length integrin. These data show that the denticity of the ligand Asp/Glu can modify the divalent cation selectivity at MIDAS and hence integrin function. Stabilizing the Ca(2+) ion at MIDAS by bidentate ligation to a ligand Asp/Glu may provide one approach for designing pure integrin antagonists.


Asunto(s)
Anticuerpos Bloqueadores/metabolismo , Ácido Aspártico/inmunología , Antígeno CD11b/metabolismo , Antígenos CD18/metabolismo , Calcio/metabolismo , Animales , Anticuerpos Bloqueadores/química , Ácido Aspártico/metabolismo , Sitios de Unión de Anticuerpos/inmunología , Antígeno CD11b/química , Antígenos CD18/química , Cationes Bivalentes/metabolismo , Adhesión Celular/inmunología , Cristalografía por Rayos X , Relación Dosis-Respuesta Inmunológica , Diseño de Fármacos , Humanos , Fragmentos Fab de Inmunoglobulinas/química , Fragmentos Fab de Inmunoglobulinas/metabolismo , Células K562 , Ligandos , Neutrófilos/inmunología , Neutrófilos/metabolismo , Ratas
8.
Carbohydr Res ; 532: 108919, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37557021

RESUMEN

Heparan sulfate (HS) is ubiquitous polysaccharide on the surface of all mammalian cells and extracellular matrices. The incredible structural complexity of HS arises from its sulfation patterns and disaccharide compositions, which orchestrate a wide range of biological activities. Researchers have developed elegant synthetic methods to obtain well-defined HS oligosaccharides to understand the structure-activity relationship. These studies revealed that specific sulfation codes and uronic acid variants could synergistically modulate HS-protein interactions (HSPI). Additionally, the conformational flexibility of l-Iduronic acid, a uronic acid unit has emerged as a critical factor in fine-tuning the microenvironment to modulate HSPI. This review delineates how uronic acid composition in HS modulates protein binding affinity, selectivity, and biological activity. Finally, the significance of sulfated homo-oligo uronic acid as heparin mimics in drug development is also discussed.


Asunto(s)
Heparitina Sulfato , Ácidos Urónicos , Animales , Heparitina Sulfato/química , Oligosacáridos/química , Heparina/metabolismo , Unión Proteica , Mamíferos/metabolismo
9.
J Clin Orthop Trauma ; 13: 143-146, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33717886

RESUMEN

OBJECTIVES: To analyze the effect of indigenous bicentric bipolar prosthesis on horizontal and vertical offsets in fracture neck of femur when compared to contralateral normal hip and to evaluate functional outcomes. We hypothesized that our non-modular bipolar device restores satisfactory offsets in such patients. METHODS: All active elderly patients with displaced fracture NOF having contralateral normal hip were included. We used an indigenous bicentric bipolar hip-prosthesis, which is a non-modular single-piece device in all cases by lateral Hardinge approach. Postoperative radiograph AP view was taken in 15° internal rotation to decrease the effect of limb rotation on offset. CT scan was also used to evaluate offsets using ADW4.6 ADVANCED GE optima 128 slice software system. Subjects were followed for a minimum of 12 months postoperatively and functional outcome of effect of offsets change were evaluated by modified Harris Hip Score. RESULTS: There is minimal difference in horizontal and vertical offset after bicentric bipolar hemi-replacement which is statistically insignificant supporting our hypothesis. The clinical outcomes were good to fair according to modified Harris Hip Score. The mean value of horizontal offset after our bipolar hemireplacement was 42.4 ± 2.04 mm and of normal hip was 41.8 ± 1.81 mm and P-value=0.08 in plain radiographs and value of horizontal offset in CT scan was 40.73 ± 0.27on bipolar side and 41.19 ± 0.77 on normal side. Vertical offset after bicentric bipolar was 32.67 ± 2.85 mm and vertical offset of normal hip was 32.53 ± 2.73 mm. Mean 9.77 ± 1.09 mm of calcar was preserved. Modified Harris Hip Score at 6 and 12 months postoperatively was 75.78 ± 4.16 and 79.53 ± 3.95 respectively. There was no incidence of hip dislocation. CONCLUSION: Our study data clearly demonstrates that vertical and horizontal offsets are effectively maintained by the indigenous bicentric hip device. There was insignificant change in offsets as compared to contralateral normal side due to its design modifications. Indigenous bicentric non-modular bipolar device offers an excellent option for femur neck fractures in elderly patients in resource constrained situations. It allows rapid rehabilitation due to reduced surgical time, minimal blood loss and early return to function and activities of daily living.

10.
Transgenic Res ; 19(3): 385-97, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19771527

RESUMEN

During differential screening of inflorescence-specific cDNA libraries from Oryza sativa indica, an arabinogalactan protein (OSIAGP) cDNA (586 bp) expressing preferentially in the inflorescence has been isolated. It encodes an arabinogalactan protein of 59 amino acids (6.4 kDa) with a transmembrane domain and a secretory domain at the N terminus. The protein shows homology with AGP23 from Arabidopsis, and its homologue in japonica rice is located on chromosome 6. OSIAGP transcripts also accumulate in shoots and roots of rice seedling grown in the dark, but light represses expression of the gene. Analysis of a genomic clone of OSIAGP revealed that its promoter contains several pollen-specificity and light-regulatory elements. The promoter confers pollen-preferential activity on gus, starting from the release of microspores to anther dehiscence in transgenic tobacco, and is also active during pollen tube growth. Analysis of pollen preferential activity of the promoter in the transgenic rice system revealed that even the approximately 300 bp fragment has activity in pollen and the anther wall and further deletion down to approximately 100 bp completely abolishes this activity, which is consistent with in-silico analysis of the promoter. Arabinogalactan proteins have been shown to be involved in the cell elongation process. The homology of OSIAGP with AGP23 and the fact that seedling growth in the dark and pollen tube growth are events based on cell elongation strengthen the possibility of OSIAGP performing a similar function.


Asunto(s)
Galactanos/genética , Oryza/genética , Tubo Polínico/crecimiento & desarrollo , Polen/crecimiento & desarrollo , Regiones Promotoras Genéticas/genética , Secuencia de Aminoácidos , Secuencia de Bases , Northern Blotting , Clonación Molecular , Cartilla de ADN/genética , ADN Complementario/genética , Biblioteca Genómica , Glucuronidasa/metabolismo , Datos de Secuencia Molecular , Polen/genética , Tubo Polínico/genética , Análisis de Secuencia de ADN , Homología de Secuencia
11.
Neurol India ; 68(4): 897-899, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32859837

RESUMEN

Cerebral hyperperfusion syndrome is a well-recognised phenomenon following carotid revascularisation. It is defined as cerebral blood flow increase of more than 100% of the baseline. A similar phenomenon can occur in the eye and maybe termed as ocular hyperperfusion syndrome. We present a 65-year-old male who developed an ipsilateral red eye with visual loss following carotid artery stenting. There was a past history of recurrent right middle cereberal artery (MCA) territory embolic infarcts and recurrent trasient episodes of vision loss in the right eye. Flow reversal was noted in the ophthalmic artery on Transcranial doppler (TCD). Digital subtraction angiography (DSA) showed more than 95% stenosis in right internal carotid artery (ICA) ostium and completely occluded left ICA. Following carotid artery, stenting patient developed severe headache and right eye pain along with vision loss despite intensive blood pressure monitoring and control. NCCT head showed mild right cortical SAH and the intra-ocular pressure (IOP) in the right eye was high. It was hypopthesised that aqueous over production due to neovascularity secondary to chronic ocular ischemia, lack of outflow and sudden change in ocular hemodynamics post stenting was the pathogenic mechanism. The patient was commenced on measures to reduce aqueous production along with strict blood pressure control. Prestenting evalvation for chronic ocular ischemia with tanscranial dopplar and angiographic flow reversal in ophthalmic artery, fluorescein angiography to look for watershed zones and slit lamp for neovascularity and angle closure can help in identifing high-risk patients, particularly in patients with bilateral carotid artery disease.


Asunto(s)
Estenosis Carotídea , Anciano , Ceguera , Arterias Carótidas , Arteria Carótida Interna/diagnóstico por imagen , Arteria Carótida Interna/cirugía , Estenosis Carotídea/complicaciones , Estenosis Carotídea/diagnóstico por imagen , Estenosis Carotídea/cirugía , Circulación Cerebrovascular , Humanos , Masculino , Stents/efectos adversos
12.
Org Lett ; 22(9): 3402-3406, 2020 05 01.
Artículo en Inglés | MEDLINE | ID: mdl-32310663

RESUMEN

We report for the first time a continuous-flow strategy to execute O-sulfation modification of heparan sulfate (HS) oligosaccharides. A systematic investigation of the influence of the flow parameters on the installation of the sulfate group on glucosamine monosaccharide can aid the development of a comprehensive, quick, and reliable strategy for O-sulfation of HS oligosaccharide precursors. Deprotection of the sulfated heparin intermediates led to the development of a comprehensive biologically inspired oligosaccharide library to understand the crucial structure-function relationship of HS.


Asunto(s)
Heparitina Sulfato/química , Oligosacáridos/química , Técnicas de Química Sintética/métodos , Etilaminas/química , Heparitina Sulfato/síntesis química , Relación Estructura-Actividad , Óxidos de Azufre/química
13.
Plant Sci ; 277: 251-266, 2018 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-30466591

RESUMEN

Natural structural variants of regulatory proteins causing quantitative phenotypic consequences have not been reported in plants. Herein, we show that 28 natural structural variants of FT homeologs, isolated from 6 species of Brassica, differ with respect to amino-acid substitutions in regions critical for interactions with FD and represent two evolutionarily distinct categories. Analysis of structural models of selected candidates from Brassica juncea (BjuFT_AAMF1) and Brassica napus (BnaFT_CCLF) predicted stronger binding between BjuFT and Arabidopsis thaliana FD. Over-expression of BjuFT and BnaFT in wild type and ft-10 mutant backgrounds of Arabidopsis validated higher potency of BjuFT in triggering floral transition. Analysis of gain-of-function and artificial miRNA mediated silenced lines of B. juncea implicated Brassica FT in multiple agronomic traits beyond flowering, consistent with a pleiotropic effect. Several dependent and independent traits such as lateral branching, silique shape, seed size, oil-profile, stomatal morphology and plant height were found altered in mutant lines. Enhanced FT levels caused early flowering, which in turn was positively correlated to a higher proportion of desirable fatty acids (PUFA). However, higher FT levels also resulted in altered silique shape and reduced seed size, suggesting trait trade-offs. Modulation of FT levels for achieving optimal balance of trait values and parsing pair-wise interactions among a reportoire of regulatory protein homeologs in polyploid genomes are indeed future areas of crop research.


Asunto(s)
Brassica napus/metabolismo , Brassica napus/fisiología , Flores/metabolismo , Flores/fisiología , Arabidopsis/genética , Arabidopsis/metabolismo , Arabidopsis/fisiología , Brassica napus/genética , Ácidos Grasos/metabolismo , Flores/genética , MicroARNs/genética , Planta de la Mostaza/genética , Planta de la Mostaza/metabolismo , Planta de la Mostaza/fisiología , Estomas de Plantas/genética , Estomas de Plantas/metabolismo , Estomas de Plantas/fisiología , Sitios de Carácter Cuantitativo/genética
14.
Anesth Essays Res ; 10(3): 488-492, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27746538

RESUMEN

BACKGROUND: Efficacy of caudal bupivacaine plus ketamine on postoperative pain in children. AIMS: The aim of this study was to compare the analgesic efficacy and safety of caudal block with mixture of bupivacaine and ketamine to bupivacaine alone for postoperative analgesia in pediatric patients undergoing infraumbilical surgery. SETTINGS AND DESIGN: A prospective randomized study was conducted in a tertiary care teaching hospital. STATISTICAL ANALYSIS: Data were collected; mean value and standard deviation were computed for age, weight, duration of surgery, and duration of analgesia. Then, the mean values of the two groups were compared using ANOVA. P < 0.05 was considered statistically significant. MATERIALS AND METHODS: A total of 60 American Society of Anesthesiologists I and II pediatric patients of either sex, aged 1-10 years, undergoing herniotomy, orchidopexy, and urethroplasty were randomly allocated to receive one of the two analgesic regimens. Group A (30 patients) received caudal bupivacaine 0.25% in a dose of 1 ml/kg, and Group B received caudal block with 0.25% bupivacaine 1 ml/kg and preservative-free ketamine 0.5 mg/kg; duration of analgesia was recorded by objective pain scale to equate pain and discomfort in young children with changes in standardized behavioral and physiological parameters. RESULTS: Mean duration of analgesia in Group A was 5.63 ± 0.98 h while the mean duration of analgesia in Group B was 10.18 ± 2.24 h with P < 0.001. There were no differences between groups in the incidence of motor block and side effects. CONCLUSION: On the basis of results derived from this study, it is concluded that addition of ketamine 0.5 mg/kg to caudal bupivacaine 0.25% in a dose of 1 ml/kg significantly prolonged the postoperative analgesia compared with administration of caudal bupivacaine 0.25% in a dose of 1 ml/kg alone.

15.
Interv Neuroradiol ; 21(6): 664-8, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26508091

RESUMEN

Pediatric intracranial aneurysms are rare with a reported prevalence of 0.5-4.6%. Likewise, anomalous arterial patterns are uncommon in the cerebral circulation. Recognition of these variations and knowledge of vascular territory forms the key to managing pathological conditions associated with these anomalous vessels. Ruptured dissecting aneurysm of type-3 accessory middle cerebral artery (aMCA) has not been reported in the pediatric age group. In addition to type-3 aMCA, the child in this case report had an ipsilateral type-1 aMCA with cortical supply. We describe the patterns of accessory MCA and their vascular territory, state the perplexity involved in deciding the best management strategy, and describe the technical approach we undertook to catheterize this small caliber recurrent artery (type-3 aMCA) originating at an acute angle from the anterior cerebral artery.


Asunto(s)
Aneurisma Roto/terapia , Disección Aórtica/terapia , Embolización Terapéutica/métodos , Aneurisma Intracraneal/terapia , Adhesivos Tisulares/uso terapéutico , Disección Aórtica/diagnóstico por imagen , Aneurisma Roto/diagnóstico por imagen , Angiografía Cerebral , Preescolar , Diagnóstico Diferencial , Femenino , Humanos , Aneurisma Intracraneal/diagnóstico por imagen , Imagen por Resonancia Magnética , Arteria Cerebral Media , Tomografía Computarizada por Rayos X
17.
Indian J Anaesth ; 58(4): 470-2, 2014 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-25197121

RESUMEN

Routine investigation of serum calcium is not recommended in ASA one and two patients unless abnormalities of calcium metabolism are clinically suspected. The clinical features of hypocalcaemia can often be subtle and may manifest in the presence of associated factors. Hypoparathyroidism, an important cause of hypocalcaemia, often presents as soft tissue calcification (ostosis). Ligamentum flavum ostosis can present with compressive myelopathy requiring laminectomy. We report a case of ligamentum flavum ostosis and subclinical hypocalcaemia due to hypoparathyroidism, who went undetected pre-operatively resulting in significant post-operative morbidity.

18.
Saudi J Anaesth ; 6(4): 358-62, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-23493652

RESUMEN

BACKGROUND: It has been postulated that Multiple sclerosis (MS) stems from a narrowing in the veins that drain blood from the brain, known medically as chronic cerebrospinal venous insufficiency, or CCSVI. It has been proposed that balloon angioplasty should alleviate the symptoms of MS. This procedure is also known as The "Liberation Procedure". Accordingly, a clinical study was undertaken to determine the effects of dexmedetomidine in patients undergoing the liberation procedure. AIMS: To assess the effectiveness of dexmedetomidine in providing adequate sedation and pain relief for patients undergoing the liberation procedure. SETTINGS AND DESIGN: A prospective, nonrandomized observational study of 60 consecutive adult patients undergoing the liberation procedure under monitored anesthesia care (MAC) who will receive dexmedetomidine as an anesthetic agent. METHODS: A total of 60 adult patients were enrolled in the study. Dexmedetomidine was administered to all patients in a loading dose of 1 mcg/kg, which was followed by a maintenance dose of 0.2-0.5 mcg/kg/h. The evaluation of quality of sedation was based on Ramsay Sedation and the quality of analgesia was assessed using the visual analog scale. The following parameters were measured continuously: heart rate, mean arterial pressure and hemoglobin oxygen saturation. Patients were asked to answer the question, "How would you rate your experience with the sedation you have received during surgery?" using a seven-point Likert-like verbal rating scale. STATISTICAL ANALYSIS: Repeated measurements were analyzed by repeated measures ANOVA for HR and BP. RESULTS: Most of our patients were satisfied with their sedation. In most of the patients, MAP and HR dropped after the bolus dose of dexmedetomidine, and the drop was statistically significant. CONCLUSIONS: Dexmedetomidine can be used as a sole sedative agent in patients undergoing the liberation procedure.

19.
J Anaesthesiol Clin Pharmacol ; 28(1): 114-6, 2012 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-22345958

RESUMEN

Tracheoesophageal fistula (TEF) in adults occurs as a result of trauma, malignancy, cuff-induced tracheal necrosis from prolonged mechanical ventilation, traumatic endotracheal intubation, foreign body ingestion, prolonged presence of rigid nasogastric tube, and surgical complication. Anesthetic management for repair of TEF is a challenge. Challenges include difficulties in oxygenation or ventilation resulting from placement of endotracheal tube in or above the fistula; large fistula defect causing loss of tidal volume with subsequent gastric dilatation, atelactasis, and maintenance of one lung ventilation. The most common cause of acquired nonmalignant TEF is postintubation fistula, which develops after prolonged intubation for ventilatory support. Acquired TEF, which occurs after prolonged intubation, usually develops after 12-200 days of mechanical ventilation, with a mean of 42 days. We present a rare case of TEF that developed after 7 days of intubation. It was a difficult case to be diagnosed as patient had a history of polytrauma, followed by emergency intubation and both these conditions can contribute to tracheobronchial injury.

20.
Indian J Anaesth ; 59(6): 380-2, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26195837
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