Prospective isolation of nonhematopoietic cells of the niche and their differential molecular interactions with HSCs.

A major limitation preventing in vivo modulation of hematopoietic stem cells (HSCs) is the incomplete understanding of the cellular and molecular support of the microenvironment in regulating HSC fate decisions. Consequently, murine HSCs cannot be generated, maintained, or expanded in culture over extended periods of time. A significantly improved understanding of the bone marrow niche environment and its molecular interactions with HSCs is pivotal to overcoming this challenge. We here prospectively isolated all major nonhematopoietic cellular niche components and cross-correlate them in detail with niche cells defined by lineage marking or tracing. Compiling an extensive database of soluble and membrane-bound ligand-receptor interactions, we developed a computational method to infer potential cell-to-cell interactions based on transcriptome data of sorter-purified niche cells and hematopoietic stem and progenitor cell subpopulations. Thus, we establish a compendium of the molecular communication between defined niche components and HSCs. Our analysis suggests an important role for cytokine antagonists in the regulation of HSC functions.

Surgical anatomy of lateral recess in paediatric auditory brainstem implant patients and its clinical correlates including grades of flocculus.

INTRODUCTION: Auditory brainstem implant (ABI), a standard technique in treatment of profound sensorineural hearing loss in patients with neurofibromatosis 2, is now being increasingly employed in children with congenital bilateral sensorineural hearing loss, as in Michele's deformity. A detailed knowledge of the relevant surgical anatomy of the lateral recess and its anatomical landmarks including the flocculus, the choroid plexus and the root entry zones of facial-vestibulocochlear and glossopharyngeal-vagus nerve complexes and their anatomical variants is mandatory, as it is the conduit for electrode array placement. The placement of electrode may be eased or impeded by these variations. MATERIALS AND METHODS: Thirty-two children with congenital bilateral hearing loss underwent surgery through retromastoid suboccipital approach for placement of auditory brainstem implant. The preoperative anatomy was reviewed in detail during procedure and again later in the operative videos. RESULTS: The flocculus was classified into four grades based on its anatomy and relations. Among these, grade II (11 children) was the commonest while grade IV (five children) was least common. Choroid plexus was variable in size across grades of flocculus. Difficulty in defining the anatomy was significantly more (p value = 0.003) in the group with higher grade flocculus (grade III and IV) than in lower grade flocculus (grade I and II). CONCLUSION: The flocculus in these patients is classifiable into one of the four grades and the surgical nuances such as difficulty in defining the anatomy for placement of ABI are dependent on the characteristics exhibited by the floccular anatomy and relations.

Case series of trigonal meningiomas.

BACKGROUND: Trigonal meningiomas have unique clinical presentation, unlike those in other areas of brain. Situated deep in the brain, the surgical nuances of this tumour are distinctive. We present our experience with this tumour including a discussion of surgical corridors that may be employed. METHODS: At our centre, 12 trigonal meningiomas were operated over past two decades. A retrospective analysis of case records of these cases was undertaken as regards age, sex clinical presentation, imaging and surgical approach. RESULTS: Mean time from heralding symptom to presentation was 10.4 months. At presentation, the most commonly encountered symptoms were those of non-localising symptoms attributable to raised ICP. Majority of lesions were more than 6 cm and on left side and the preferred surgical approach was inferior temporo-parietal. Most symptoms were relieved on long-term follow-up except homonymous hemianopia. CONCLUSION: The incidence of deficit is low on employing the "shortest route" approach, even in the dominant hemisphere and through eloquent area. This may be secondary to possible shift of eloquent area function due to longstanding lesion and may thus be a "workable" surgical option, especially in resource-limited centres where such resources as neuronavigation and tractography may be unavailable.

Quad Fever: Treatment through Lowering of Ambient Temperature.

Hyperpyrexia is a rare and at times fatal condition seen in an Intensive Care Unit setup. We encountered a case of a 65-year-old patient with road traffic accident presenting with dorsal spine fracture at D10 level. He underwent decompression and fusion for the same. He developed hyperpyrexia of sudden onset on the 10th day of admission with no source of infection and adequate broad-spectrum antibiotic coverage with adequate thrombo-embolic prevention in place. The patient showed no response to antipyretic agents and other cooling methods. The origin of hyperthermia was idiopathic, and we speculate that the cause was secondary to hyperthermic thermoregulatory dysfunction often quoted as "quad fever," seen in spinal cord injury. We present a brief review of literature and the importance of early identification and treatment of this potentially fatal condition.

Covalent docking of large libraries for the discovery of chemical probes.

Chemical probes that form a covalent bond with a protein target often show enhanced selectivity, potency and utility for biological studies. Despite these advantages, protein-reactive compounds are usually avoided in high-throughput screening campaigns. Here we describe a general method (DOCKovalent) for screening large virtual libraries of electrophilic small molecules. We apply this method prospectively to discover reversible covalent fragments that target distinct protein nucleophiles, including the catalytic serine of AmpC ß-lactamase and noncatalytic cysteines in RSK2, MSK1 and JAK3 kinases. We identify submicromolar to low-nanomolar hits with high ligand efficiency, cellular activity and selectivity, including what are to our knowledge the first reported reversible covalent inhibitors of JAK3. Crystal structures of inhibitor complexes with AmpC and RSK2 confirm the docking predictions and guide further optimization. As covalent virtual screening may have broad utility for the rapid discovery of chemical probes, we have made the method freely available through an automated web server (http://covalent.docking.org/).

Evolution of a unified, stereodivergent approach to the synthesis of communesin F and perophoramidine.

Expedient synthetic approaches to the highly functionalized polycyclic alkaloids communesin F and perophoramidine are described using a unified approach featuring a key decarboxylative allylic alkylation to access a crucial and highly congested 3,3-disubstituted oxindole. Described are two distinct, stereoselective alkylations that produce structures in divergent diastereomeric series possessing the critical vicinal all-carbon quaternary centers needed for each synthesis. Synthetic studies toward these challenging core structures have revealed a number of unanticipated modes of reactivity inherent to these complex alkaloid scaffolds. Additionally, several novel and interesting intermediates en route to the target natural products, such as an intriguing propellane hexacyclic oxindole encountered in the communesin F sequence, are disclosed. Indeed, such unanticipated structures may prove to be convenient strategic intermediates in future syntheses.

Design of reversible, cysteine-targeted Michael acceptors guided by kinetic and computational analysis.

Electrophilic probes that covalently modify a cysteine thiol often show enhanced pharmacological potency and selectivity. Although reversible Michael acceptors have been reported, the structural requirements for reversibility are poorly understood. Here, we report a novel class of acrylonitrile-based Michael acceptors, activated by aryl or heteroaryl electron-withdrawing groups. We demonstrate that thiol adducts of these acrylonitriles undergo ß-elimination at rates that span more than 3 orders of magnitude. These rates correlate inversely with the computed proton affinity of the corresponding carbanions, enabling the intrinsic reversibility of the thiol-Michael reaction to be tuned in a predictable manner. We apply these principles to the design of new reversible covalent kinase inhibitors with improved properties. A cocrystal structure of one such inhibitor reveals specific noncovalent interactions between the 1,2,4-triazole activating group and the kinase. Our experimental and computational study enables the design of new Michael acceptors, expanding the palette of reversible, cysteine-targeted electrophiles.

Reversible targeting of noncatalytic cysteines with chemically tuned electrophiles.

Targeting noncatalytic cysteine residues with irreversible acrylamide-based inhibitors is a powerful approach for enhancing pharmacological potency and selectivity. Nevertheless, concerns about off-target modification motivate the development of reversible cysteine-targeting strategies. Here we show that electron-deficient olefins, including acrylamides, can be tuned to react with cysteine thiols in a rapidly reversible manner. Installation of a nitrile group increased the olefins' intrinsic reactivity, but, paradoxically, eliminated the formation of irreversible adducts. Incorporation of these electrophiles into a noncovalent kinase-recognition scaffold produced slowly dissociating, covalent inhibitors of the p90 ribosomal protein S6 kinase RSK2. A cocrystal structure revealed specific noncovalent interactions that stabilize the complex by positioning the electrophilic carbon near the targeted cysteine. Disruption of these interactions by protein unfolding or proteolysis promoted instantaneous cleavage of the covalent bond. Our results establish a chemistry-based framework for engineering sustained covalent inhibition without accumulating permanently modified proteins and peptides.

Is functional mobility associated with quality of sitting in cerebral palsy? A cross-sectional study.

Objectives: A group of neuromuscular system anomalies associated with non-progressive issues in the developing fetal or newborn brain are known as cerebral palsy (CP). These abnormalities are typified by poor posture and motor development, which limits the execution of functional activities. Consequently, to achieve the same goals as peers who are typically developing, children with CP employ a variety of compensatory postures and techniques. Given that both sitting and mobility are essential for functioning, assessing each skill alone and in relation to the other is necessary. This study aims to determine if a child's functional mobility affects their sitting ability. Materials and Methods: Twenty CP (Gross Motor Function Classification System [GMFCS] levels I and II) children, aged 6-12, were enrolled in the research. The level of sitting scale (LSS) and the modified timed up and go (mTUG) test were utilized to evaluate sitting and functional mobility, respectively. Results: The quality of sitting was shown to have a substantial effect on functional mobility, as a significant difference in mTUG durations was established between LSS levels (P < 0.001) and persisted when analyzed within the same GMFCS level (P = 0.007). Conclusion: The importance of trunk control in functional mobility can be inferred from the link between sitting quality and mobility. To improve children with CP's functional mobility, this evidence may be utilized to design a well-informed and specific intervention program incorporating trunk control.

Electrophilic fragment-based design of reversible covalent kinase inhibitors.

Fragment-based ligand design and covalent targeting of noncatalytic cysteines have been employed to develop potent and selective kinase inhibitors. Here, we combine these approaches, starting with a panel of low-molecular-weight, heteroaryl-susbstituted cyanoacrylamides, which we have previously shown to form reversible covalent bonds with cysteine thiols. Using this strategy, we identify electrophilic fragments with sufficient ligand efficiency and selectivity to serve as starting points for the first reported inhibitors of the MSK1 C-terminal kinase domain. Guided by X-ray co-crystal structures, indazole fragment 1 was elaborated to afford 12 (RMM-46), a reversible covalent inhibitor that exhibits high ligand efficiency and selectivity for MSK/RSK-family kinases. At nanomolar concentrations, 12 blocked activation of cellular MSK and RSK, as well as downstream phosphorylation of the critical transcription factor, CREB.

Practice patterns of physiotherapists in neonatal intensive care units: A national survey.

OBJECTIVE: To determine practice pattern of physiotherapists in the neonatal intensive care units (ICUs) in India with regards to cardiopulmonary and neuromuscular physiotherapy. MATERIALS AND METHODS: A cross-sectional survey was conducted across India, in which 285 questionnaires were sent via e-mail to physiotherapists working in neonatal intensive care units. RESULTS: A total of 139 completed questionnaires were returned with a response rate of 48.7%, with a majority of responses from Karnataka, Maharashtra and Gujarat. More than 90% of physiotherapists performed chest physiotherapy in neonatal ICUs. Chest physiotherapy assessment predominantly focused on vital parameter assessment (86%) and in treatment predominantly focused on percussion (74.1%), vibration (75.5%), chest manipulation (73.3%), postural drainage (67.6%) and suction (65.4%). In neuromuscular physiotherapy more than 60% of physiotherapists used positioning, and parent education, whereas more than 45% focused on passive range of motion exercise and therapeutic handling. CONCLUSION: The practice pattern of physiotherapists for neonates in neonatal intensive care units involves both chest physiotherapy as well neuromuscular physiotherapy. Chest physiotherapy assessment focused mainly on vital parameter assessment (heart rate, respiratory rate and partial pressure of oxygen saturation SpO2). Treatment focused on airway clearance techniques including percussion, vibration, postural drainage and airway suction. In neuromuscular physiotherapy most physiotherapists focused on parent education and passive range of motion exercise, therapeutic handling, as well as positioning.

Oblique direction reach test: evaluating psychometric properties in stroke population.

Background: Post-stroke individuals are observed to have reduced limits of stability (LOS) in all directions. Functional activities are rarely performed in pure cardinal planes; instead, they are most likely to be performed in an oblique direction. Existing tools are either expensive or sophisticated to assess the LOS in an oblique direction. Therefore, this study's primary objective is to evaluate the intra-rater, inter-rater reliability, and validity of the oblique direction reach test (ODRT) among stroke subjects. Materials & Methods: A total of 96 first-time stroke patients with age, gender, height, and weight-matched healthy controls aged 18-80 years were recruited for the study. Oblique, forward, and lateral reach distances were assessed using the standard procedure of ODRT, Functional Reach Test (FRT), and Lateral Reach Test (LRT), respectively. Validity was tested by correlating the ODRT distance with the Berg Balance Scale (BBS) Score using Spearman's rank correlation coefficient. Intraclass correlation coefficients (ICCs) and Bland Altman analysis were used to establish inter-rater reliability. ICCs were used to find intra-rater reliability. The Mann-Whitney U test was used to establish the mean difference of the FRT, LRT, and ODRT. Spearman's rank correlation coefficient and linear regression were used to correlate the distance of FRT and LRT with ODRT. Results: A high concurrent validity was found between BBS and ODRT with an r-value of 0.905 (p < 0.001). Inter-rater reliability was high with an ICC of 0.997 (95% CI [0.996-0.998]), and intra-rater reliability was highly significant with an ICC of 0.996 (95% CI [0.994-0.998]). The stroke subjects reached a significantly shorter distance than healthy individuals in FRT, ODRT, and LRT. ODRT was highly correlated with FRT (r = 0.985) and LRT (r = 0.978) (p < 0.001) and had an R2 = 0.987. Conclusion: ODRT is a highly valid and reliable tool that can be used to evaluate balance in stroke patients. Individuals who reached less in the forward and lateral directions showed reduced reach distance in the oblique direction.

Crescent posterior fossa durotomy for occipito-marginal venous sinus preservation: a pilot study.

PURPOSE: The standard approach of midline suboccipital craniectomy entails sacrifice of the Occipito-marginal sinus. We have attempted to preserve this venous channel by using a durotomy technique which preserves this system. In a pilot study initiative, two groups of patients using this technique versus the standard approach, were compared in terms of per and post operative benefits, morbidity and complications. The literature with reference to the anatomy and venous flow dynamics of the occipital and marginal sinuses and their significance has been reviewed. Similarly, literature regarding dural closure technique with reference to postoperative complications has also been reviewed. METHODS: In this novel approach, the dura is opened as a crescent to avoid damage to the occipital sinus. This technique was compared with the standard midline dural opening technique by random usage of both techniques in 24 patients. RESULTS: The 'crescent' approach has been found to reduce the need for duroplasty, with comfortable primary closure and to reduce the risk of postoperative pseudomeningocele. CONCLUSIONS: This is a novel dural opening technique which attempts to preserve the normal venous flow physiology. In essence it helps in increased primary dural closures and reduction of Pseudomeningiocele/CSF leak as well as blood loss and venous hypertension.

Trans-Thoracic Extra-Pleural Percutaneous Spinal Fixation-A Technical Note.

Study Design: Cross-sectional analysis of defined parameters of patients who underwent the presented technique. Patients undergoing thoracic spine fixation for various pathologies. Objective: This technique attempts to limit the incision size in extrapleural thoracotomy for multi-level spinal fixation. Summary of Background Data: Dorsal spine is traditionally approached by either transpleural or extrapleural approach. The extrapleural approach carries a limitation of being restricted in number of levels it can address. By incrementally modifying the present technique, we were able to employ the approach in greater number of levels with lesser morbidities. Method: Classical extrapleural thoracotomy approach is employed with incision size limited to the levels of pathology (~5 cm). Thereafter, proper exposure using Kittner dissection and defining of screw entry points follows. Stab incision is made and screws placed percutaneously through a K-wire-defined trajectory. Results: Eighteen patients underwent fixation through this technique, of which 11 were infectious, four were traumatic, and the rest were neoplastic in pathology. None except three patients had ICU stay of more than 1 day. All patients had a pain score of 6 or lower except for two. Conclusion: Combining the technique of percutaneous screw placement with traditional extrapleural thoracotomy reduces the size of the incision, tissue damage, and morbidity while reducing the cost and duration of hospitalization without comprising the extent of pathology that can be dealt with.

Effectiveness of structured early mobilization protocol on mobility status of patients in medical intensive care unit.

INTRODUCTION: Patients admitted to the intensive care units (ICU) have limited mobility due to their illness and its management and are at a risk for immobility-related complications. Early mobilization has been suggested to prevent or limit physical dysfunction due to these complications. Effectiveness of early mobilization protocols is studied using various outcomes. OBJECTIVE: To study the effectiveness of an early mobilization protocol on mobility status of patients in Medical ICU. METHODS: Patients admitted to Medical ICU were screened for eligibility and allotted into two groups. Intervention group received mobilization according to a protocol while control group received mobilization as per usual mobilization practices in our ICU. Mobility was assessed using the Perme ICU mobility score on the first day of ICU, first day of rehabilitation and last day of rehabilitation. RESULTS: 63 patients were included in the study. The median difference in the Perme ICU mobility score from first day of rehabilitation to last day of rehabilitation was 9 and 2 in the intervention group and control group respectively. Significant improvements in the mobility scores were not present from first day of ICU to first day of rehabilitation in both, the intervention (p = .069) and control group (p = .124). Improvement in the scores from first day of rehabilitation to last day of rehabilitation was significant within and between both the groups (p < .001). CONCLUSION: Early Mobilization Protocol was effective in improving mobility status of patients in Medical ICU.

Falcine and parasagittal intracranial chondrosarcomas of the classical variant: report of two cases with review of literature.

Intracranial primary extraskeletal chondrosarcomas are extremely rare. We report two cases of the classical variant which were dural based: one falcine and the other parasagittal are presented. Only 10 cases of this variant have been reported in this location. The pathology and management of these lesions have been reviewed.