Molecular recognition and proteoglycan mimic arrangement: modulating cisplatin toxicity.

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.

MIR159 regulates multiple aspects of stamen and carpel development and requires dissection and delimitation of differential downstream regulatory network for manipulating fertility traits.

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.

Synergestic interplay of uronic acid and sulfation composition of heparan sulfate on molecular recognition to activity.

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.

Analysis of vertical and horizontal offsets in displaced femoral neck fracture in elderly treated with indigenous bicentric bipolar hip device.

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.

Blindness Following Carotid Artery Stenting Due to Ocular Hyperperfusion - Report and Review of Literature.

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.

Continuous-Flow Accelerated Sulfation of Heparan Sulfate Intermediates.

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.

Comparative genomics reveals origin of MIR159A-MIR159B paralogy, and complexities of PTGS interaction between miR159 and target GA-MYBs in Brassicaceae.

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.

Natural variation in Brassica FT homeologs influences multiple agronomic traits including flowering time, silique shape, oil profile, stomatal morphology and plant height in B. juncea.

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.

Sequence and functional characterization of MIRNA164 promoters from Brassica shows copy number dependent regulatory diversification among homeologs.

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.

Comparison between caudal bupivacaine and bupivacaine with ketamine for postoperative analgesia in children: A prospective randomized clinical study.

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.

Endovascular glue embolization of dissecting aneurysm of type-3 accessory middle cerebral artery: A contralateral approach.

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.

Undetected hypoparathyroidism: An unusual cause of perioperative morbidity.

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.

The α-subunit regulates stability of the metal ion at the ligand-associated metal ion-binding site in ß3 integrins.

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.

Atomic basis for the species-specific inhibition of αV integrins by monoclonal antibody 17E6 is revealed by the crystal structure of αVß3 ectodomain-17E6 Fab complex.

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.

Early presentation of postintubation tracheoesophageal fistula: Perioperative anesthetic management.

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.