Highly Sensitive Fluorescent pH Microsensors Based on the Ratiometric Dye Pyranine Immobilized on Silica Microparticles.

Pyranine (HPTS) is a remarkably interesting pH-sensitive dye that has been used for plenty of applications. Its high quantum yield and extremely sensitive ratiometric fluorescence against pH change makes it a very favorable for pH-sensing applications and the development of pH nano-/microsensors. However, its strong negative charge and lack of easily modifiable functional groups makes it difficult to use with charged substrates such as silica. This study reports a methodology for noncovalent HPTS immobilization on silica microparticles that considers the retention of pH sensitivity as well as the long-term stability of the pH microsensors. The study emphasizes the importance of surface charge for governing the sensitivity of the immobilized HPTS dye molecules on silica microparticles. The importance of the immobilization methodology, which preserves the sensitivity and stability of the microsensors, is also assessed.

Highly Sensitive Fluorescent pH Microsensors Based on the Ratiometric Dye Pyranine Immobilized on Silica Microparticles.

Invited for the cover of this issue are Anil Chandra, Loretta L. del Mercato and co-workers at the Institute of Nanotechnology of National Research Council and the University of Salento. The image depicts how negatively charged pH-sensitive pyranine (HPTS) molecules were successfully immobilized on silica microparticles (SMPs) without compromising the molecules' pH sensitivity. These resulting sensors can be used to measure pH in vitro and in vivo due to the cytocompatibility of HPTS molecules and SMPs. Read the full text of the article at 10.1002/chem.202101568.

Optical and magnetic resonance imaging approaches for investigating the tumour microenvironment: state-of-the-art review and future trends.

The tumour microenvironment (TME) strongly influences tumorigenesis and metastasis. Two of the most characterized properties of the TME are acidosis and hypoxia, both of which are considered hallmarks of tumours as well as critical factors in response to anticancer treatments. Currently, various imaging approaches exist to measure acidosis and hypoxia in the TME, including magnetic resonance imaging (MRI), positron emission tomography and optical imaging. In this review, we will focus on the latest fluorescent-based methods for optical sensing of cell metabolism and MRI as diagnostic imaging tools applied both in vitro and in vivo. The primary emphasis will be on describing the current and future uses of systems that can measure intra- and extra-cellular pH and oxygen changes at high spatial and temporal resolution. In addition, the suitability of these approaches for mapping tumour heterogeneity, and assessing response or failure to therapeutics will also be covered.

Probing the pH Microenvironment of Mesenchymal Stromal Cell Cultures on Additive-Manufactured Scaffolds.

Despite numerous advances in the field of tissue engineering and regenerative medicine, monitoring the formation of tissue regeneration and its metabolic variations during culture is still a challenge and mostly limited to bulk volumetric assays. Here, a simple method of adding capsules-based optical sensors in cell-seeded 3D scaffolds is presented and the potential of these sensors to monitor the pH changes in space and time during cell growth is demonstrated. It is shown that the pH decreased over time in the 3D scaffolds, with a more prominent decrease at the edges of the scaffolds. Moreover, the pH change is higher in 3D scaffolds compared to monolayered 2D cell cultures. The results suggest that this system, composed by capsules-based optical sensors and 3D scaffolds with predefined geometry and pore architecture network, can be a suitable platform for monitoring pH variations during 3D cell growth and tissue formation. This is particularly relevant for the investigation of 3D cellular microenvironment alterations occurring both during physiological processes, such as tissue regeneration, and pathological processes, such as cancer evolution.

Management of multiloculated hydrocephalus in children with emphasis on role of CT ventriculography.

OBJECTIVE: The authors performed a retrospective review of children diagnosed with multiloculated hydrocephalus (MLH) in our institute. The goal was to analyze the different diagnostic and therapeutic modalities used with special emphasis on CT ventriculography (CTV). METHODS: Male and female patients below the age of 18 years diagnosed with MLH were included. Cases of uniloculated hydrocephalus like entrapped temporal horn or isolated fourth ventricle were excluded. We used iohexol for CTV and gadodiamide for MR ventriculography. Neuroendoscopic procedures performed were endoscopic fenestration, endoscopic third ventriculostomy (ETV), endoscopic septostomy, endoscopic aqueductoplasty, or a combination of the above. The cohort was divided into two groups (endoscopic or shunt) based on initial surgical intervention. RESULTS: A total of 52 patients were included, with 43 boys and 9 girls. The average age of presentation was 7.7 months. The most common predisposing factor for MLH was neonatal meningitis seen in 30 patients. Mean duration of follow-up was 39 months. CTV was used in 26 patients and MR ventriculography in three patients. In one patient, the diagnosis of MLH was ruled out after ventriculography. Patients who underwent ETV only had the best outcome with 71.4% success rate. At the end of follow-up, 14 patients (27%) were shunt independent. CONCLUSIONS: The present study indicates that CTV helps to accurately define the anatomy of the ventricles and determine the site of physiological CSF obstruction. This helps in therapeutic planning and in avoiding misdiagnoses. Further, neuroendoscopy has the potential to lead to shunt independence in some patients.

Traumatic Pediatric Extradural Hematoma: An Institutional Study of 228 Patients in Tertiary Care Center.

BACKGROUND: Extradural hematoma (EDH) is one of the most common causes of mortality and morbidity after traumatic brain injury in pediatric patients. Early surgical intervention in these patients produces excellent results. OBJECTIVE: We reviewed surgical experience at our center, examining and presenting symptomatology and outcome analysis. MATERIALS AND METHODS: A retrospective study of 228 pediatric patients of EDH from July 2007 to August 2017 was performed. Patients were evaluated in terms of demographic profile, clinical features, pupillary size and reaction, computed tomography findings, operative measures, and several other parameters. Neurological status was assessed using motor component (M) of Glasgow Coma Scale score. Best motor response was considered as a criterion to classify severity of traumatic brain injury and for the assessment of outcome. RESULTS: Most of the patients were in the age group of 13-18 years (n = 122, 53.5%). Majority of them were male (n = 182, 79.8%). The commonest mode of injury was fall from height (n = 116, 50.9%) followed by road traffic accident (n = 92, 40.4%). Most common site of hematoma was frontal region (n = 66, 28.9%) followed by parietal region (n = 54, 23.7%). The volume of hematoma was between 30 and 50 mL in majority of the patients (n = 186, 81.6%), and most of the patients had a motor responses of M5 (n = 88, 38.6%) and M6 (n = 108, 47.4%). The association between hematoma site and volume was not significant (χ2 = 5.910, p = 0.749), whereas statistically significant association was noted between volume of hematoma and motor response (χ2 = 93.468, p ≤ 0.001), volume and age (χ2 = 7.380, p ≤ 0.05), and volume to time between trauma and surgery (χ2 = 8.469, p ≤ 0.05). Maximum mortality was in patients of low motor (M1-M3) response and who were operated 24 h after injury. CONCLUSION: Mortality in patients of EDH can be significantly reduced with gratifying results if operated early. Best motor response at presentation, pupillary abnormalities, time between injury to surgery, and location of hematoma have been identified as the important factors determining outcome in patients of EDH.

Extra-Axial Cerebellopontine Angle Medulloblastoma in an Infant.

Medulloblastoma is a common tumor of the posterior fossa, representing 20-25% of all pediatric neoplasms. It commonly occurs in the midline (cerebellar vermis) and rarely at the cerebellopontine angle. Most of them are intra-axial, and an extra-axial location of this tumor is very rare. Extra-axial cerebellopontine angle medulloblastoma is extremely uncommon and has never been reported in an infant. We report an extra-axial cerebellopontine angle medulloblastoma in a 1-year-old child.

Disappearance of the Hemorrhagic Component of the Frontal Contusion Possibly due to Redistribution of the Hematoma within the Subarachnoid Space: A Case Report.

Posttraumatic hemorrhagic contusions are a common sequel of traumatic brain injuries. They occur in around 8% of all traumatic brain injuries. Spontaneous resolution of acute subdural and acute extradural hematomas, although rare, is a recognized entity, but spontaneous resolution of the hemorrhagic component of a contusion within 24 h has not been reported in the literature. We present a patient in whom the hemorrhagic component of her contusion resolved spontaneously over a period of 24 h after injury. The rarity of this case prompted us to this study.

A randomized controlled study of operative versus nonoperative treatment for large spontaneous supratentorial intracerebral hemorrhage.

CONTEXT: Spontaneous intracerebral haemorrhage (ICH) accounts for 4-14% of all strokes and has a high mortality rate of 30-50% during the first month. Management of large hematomas is controversial, with some advocating medical management while others favoring surgical evacuation. AIM: This study was undertaken to compare the outcome of patients with a spontaneous supratentorial intracerebral hemorrhage (SSICH) managed with or without surgical evacuation. SETTINGS AND DESIGN: Four hundred and eighty-two SSICH patients admitted from September 2013 to August 2015 were evaluated based on the inclusion and exclusion criteria. MATERIALS AND METHODS: Among a total of 61 patients with Glasgow Coma Scale (GCS) of 4-14 and hematoma volume of> 30 ml, 27 were randomized to receive medical management (MM) alone and the remaining 34 were randomized to combined surgical as well as medical management (SM). Primary and secondary outcomes were mortality and dependency at 3 months, respectively. STATISTICAL ANALYSIS USED: Student's t-test and X2 test were used for univariate analysis, and logistic regression analysis was employed for multiple variables. RESULTS: On univariate analysis, mortality was significantly lower in the SM group (n = 21,61.8%) compared to the MM group (n = 23,85.2%) (P = 0.043); however, the groups showed no significant difference in dependency at 3 months. Further subgroup analysis showed that a hematoma volume of 30-60 ml, a deeply located hematoma, associated intraventricular hemorrhage, and a Glasgow Coma Scale (GCS) of 4-8 had a significantly lesser mortality in the SM group (P < 0.05). On multivariate analysis, a significant association was found between the mortality and the treatment arm (P = 0.006). CONCLUSIONS: In patients with SSICH, mortality was found to be significantly associated with the treatment arm and the results were in favour of SM among the patients presenting with GCS 4-8, hematoma volume 31-60 ml, midline shift of more than 5 mm, and intraventricular extension of the hematoma.

Transdural herniated lumbar disc disease with muscle patch for closure of durotomy - A Brief review of literature.

PURPOSE: Intradural migration of disc (IDMD) is a rare clinical entity accounting for 0.27-0.33% of all herniated disc diseases. Flimsy or dense adhesion between the ventral dural surface and the opposing posterior longitudinal ligament (PLL) is the principal pathology for intradural migrated disc. The most commonly affected lumbar segments are L4-5 (55%), L3-4 (16%), L5-S1 (10%) and less commonly L2L3 and L1L2. No imaging feature is characteristic and the management protocol of durotomy via an endoscopic method is unclear. METHODS: An L5S1 disc disease was operated by endoscopic method. Difficulty in separating the dural sac from PLL, dense adhesions prompting sharp dissection at this location and a calcified disc are the earliest evidence of intradural migration. MRI features of an intradural location are loss of continuity of posterior longitudinal ligament, beak-like appearance also known as "Hawk-beak sign", peripheral enhancement around an intradural disc, fluid-filled intradural cyst. Magnification either by Microscope or Endoscope is of importance when dissecting the intradural disc so as to avoid the nerve root injury. Liberal use of fibrin glue and augmentation with muscle patch was performed. RESULTS: Ambulated by 48h and discharged by 5th day. Two and 9 months follow up showed no evidence of pseudomeningocoele. CONCLUSION: Autologous muscle patch with fibrin glue for dural rent closure is a simple and effective method which can be performed by endoscopic or minimally invasive approaches. Suturing the dura, being a tedious and cumbersome procedure can be avoided.

Giant Interfrontal Encephalocele in an Infant: A Rare Entity.

Interfrontal encephalocele is one of the rare varieties of anterior encephalocele, and a giant interfrontal encephalocele is extremely rare. The authors could find only one case report of giant interfrontal encephalocele in the literature. Anterior encephaloceles are more prevalent in South-East Asia and some northern parts of India. Giant encephalocele poses a great challenge to neurosurgeons and neuroanesthetists during surgery, as these infants usually have a low birth weight and a large sac, thus making the infant prone to hypothermia and blood loss among other risks. We encountered a patient with a giant interfrontal encephalocele aged 1 month. The rarity of this case prompted us to this report.

Nasopalatine duct cyst mimicking an endodontic periapical lesion: a case report.

Lesions of nonendodontic origin, such as nasopalatine or globulomaxillary cysts, may mimic periapical radiolucencies associated with pulpal pathosis, and incorrect diagnosis may lead to unnecessary endodontic treatment. Horizontal root fractures most commonly affect the maxillary central and lateral incisors. Prognosis depends largely on the level of fracture; fractures in the apical third have the best prognosis, and those in the cervical third have the worst. This case report discusses surgical and restorative management of a patient who had a nasopalatine cyst that had been misdiagnosed and treated as an endodontic lesion of the maxillary right central incisor as well as a midroot horizontal fracture of the adjacent lateral incisor.

Hydrolytic enzymes conjugated to quantum dots mostly retain whole catalytic activity.

BACKGROUND: Tagging a luminescent quantum dot (QD) with a biological like enzyme (Enz) creates value-added entities like quantum dot-enzyme bioconjugates (QDEnzBio) that find utility as sensors to detect glucose or beacons to track enzymes in vivo. For such applications, it is imperative that the enzyme remains catalytically active while the quantum dot is luminescent in the bioconjugate. A critical feature that dictates this is the quantum dot-enzyme linkage chemistry. Previously such linkages have put constraints on polypeptide chain dynamics or hindered substrate diffusion to active site, seriously undermining enzyme catalytic activity. In this work we address this issue using avidin-biotin linkage chemistry together with a flexible spacer to conjugate enzyme to quantum dot. METHODS: The catalytic activity of three biotinylated hydrolytic enzymes, namely, hen egg white lysozyme (HEWL), alkaline phosphatase (ALP) and acetylcholinesterase (AChE) was investigated post-conjugation to streptavidin linked quantum dot for multiple substrate concentrations and varying degrees of biotinylation. RESULTS: We demonstrate that all enzymes retain full catalytic activity in the quantum dot-enzyme bioconjugates in comparison to biotinylated enzyme alone. However, unlike alkaline phosphatase and acetylcholinesterase, the catalytic activity of hen egg white lysozyme was observed to be increasingly susceptible to ionic strength of medium with rising level of biotinylation. This susceptibility was attributed to arise from depletion of positive charge from lysine amino groups after biotinylation. CONCLUSIONS: We reasoned that avidin-biotin linkage in the presence of a flexible seven atom spacer between biotin and enzyme poses no constraints to enzyme structure/dynamics enabling retention of full enzyme activity. GENERAL SIGNIFICANCE: Overall our results demonstrate for the first time that streptavidin-biotin chemistry can yield quantum dot enzyme bioconjugates that retain full catalytic activity as native enzyme.

Development of carrier-based formulation of root endophyte Piriformospora indica and its evaluation on Phaseolus vulgaris L.

Endophytic fungi are plant beneficial rhizospheric microorganisms often applied as bioinoculants for enhanced and disease-free crop production. The objectives of the present work were to develop a carrier-based formulation of root endophyte Piriformospora indica as a bioinoculant. Powder formulation of four different carrier materials viz., talcum powder, clay, sawdust and bioboost (organic supplement) were evaluated and a talc-based formulation was optimized for a longer shelf life with respect to microbial concentration, storage temperature and biological activity. Finally the effect of optimized talc formulation on plant productivity was determined. The application dosages were optimized by studies on plant growth parameters of Phaseolus vulgaris L. plants under green house conditions. Five percent formulation (w/w) of talcum powder was observed to be the most stable at 30 °C with 10(8) CFU g(-1) and effective for a storage period of 6 months. The application of this optimized formulation resulted in increase of growth parameters of P. vulgaris L. and better adaptation of plants under green house conditions.

Oral care needs, barriers and challenges among elderly in India.

OBJECTIVE: This paper presents an approach to the assessment of oral health needs of elderly and barriers to receive oral care in the life course. BACKGROUND: The dental needs of the elderly are changing and growing day by day. The management of older patients requires not only an understanding of the medical and dental aspects of ageing but also provide them good oral health service. In the life course of elderly there are many hurdles to receive proper oral care. The use of an assessment of oral health need will be essential in the development of care pathways to the elderly. METHODS: The proportion of older people is growing faster than that of any other age group. There is no sound database regarding the oral disease burden and treatment needs of the elderly in India. Physical and biological barriers with age can also affect oral health care either directly or indirectly. CONCLUSION: Oral care guidelines designed to assist elderly should consider not only prevention and treatment modalities but also the means of implementing such therapies in varying settings and utilizing the whole dental team.

Antibiotic prescription pattern among Indian oral healthcare providers: a cross-sectional survey.

OBJECTIVES: Inappropriate prescribing of antibiotics by healthcare professionals is a worldwide concern. The purpose of this study was to determine the pattern of antibiotic prescription among oral healthcare providers in India. METHODS: A one-page questionnaire was sent to 1600 oral healthcare practitioners registered under the Indian Dental Association by using multistage sampling; 552 (34.5%) responded to the survey. The data were analysed using the χ(2) test and multiple logistic regression analysis. RESULTS: Of 552 questionnaire respondents, 405 (73.4%) chose amoxicillin in non-allergic patients, alone [279 (50.5%)] or associated with clavulanic acid [126 (22.8%)]. The average duration of antibiotic therapy was 4.26 ±â€Š1.26 days. The drug of first choice for patients with an allergy to penicillin was erythromycin [242 (43.8%) of respondents]. A majority prescribed antibiotics for irreversible pulpitis and acute apical periodontitis [395 (71.6%)] and necrotic pulp, acute apical periodontitis and no swelling [326 (59.1%)]. Five hundred and ten (92.4%) of the oral healthcare providers overprescribed antibiotics. CONCLUSIONS: Oral healthcare providers in India are overprescribing, which could be a major contributor to the world problem of antimicrobial resistance. As there is overprescription of antibiotics by Indian oral healthcare providers, there is an urgent need to raise public and professional awareness regarding the risks of antibiotic use.

A randomized study of ventriculoperitoneal shunt versus endoscopic third ventriculostomy for the management of tubercular meningitis with hydrocephalus.

OBJECTIVE: This study aims at generating knowledge to understand the conditions in which either of the two procedures (endoscopic third ventriculostomy (ETV) and shunt) are better options and to develop good practice guidelines for the treatment of tubercular meningitis (TBM) hydrocephalus. METHODS: This study was conducted on 48 patients in pediatric age group (less than or equal to 18 years) of TBM hydrocephalus. The patients were randomized to one of the cerebrospinal fluid diversion procedures (ETV or shunt). The two procedures were compared for their outcome, both radiologically and clinically. RESULTS: Twenty-four cases underwent shunt, out of which 13 (68%) cases were successful. Twelve (70.3%) cases belonged to grade 3, while one case was of grade 1. In ETV group, 10 (42%) cases had a successful outcome, out of which 7 (38.8%) cases were in grade 3, while 1 case each belonged to grades 1, 2, and 4. Incidence of ETV failure was more in younger age group, i.e., <2 years (n = 7), while no such correlation with age was found in shunt cases. CONCLUSION: Though with the present study it looks like that the relative risk of ETV failure is higher than that for shunt, but the risk becomes progressively lower with time. Therefore, if patients survive the early high-risk period, they could experience a long-term survival advantage devoid of life-long shunt-related complications. Though for definitive comparison, a long-term study is needed.

Fluorescent nano- and microparticles for sensing cellular microenvironment: past, present and future applications.

The tumor microenvironment (TME) demonstrates distinct hallmarks, including acidosis, hypoxia, reactive oxygen species (ROS) generation, and altered ion fluxes, which are crucial targets for early cancer biomarker detection, tumor diagnosis, and therapeutic strategies. Various imaging and sensing techniques have been developed and employed in both research and clinical settings to visualize and monitor cellular and TME dynamics. Among these, ratiometric fluorescence-based sensors have emerged as powerful analytical tools, providing precise and sensitive insights into TME and enabling real-time detection and tracking of dynamic changes. In this comprehensive review, we discuss the latest advancements in ratiometric fluorescent probes designed for the optical mapping of pH, oxygen, ROS, ions, and biomarkers within the TME. We elucidate their structural designs and sensing mechanisms as well as their applications in in vitro and in vivo detection. Furthermore, we explore integrated sensing platforms that reveal the spatiotemporal behavior of complex tumor cultures, highlighting the potential of high-resolution imaging techniques combined with computational methods. This review aims to provide a solid foundation for understanding the current state of the art and the future potential of fluorescent nano- and microparticles in the field of cellular microenvironment sensing.

Probing Single-Cell Fermentation Fluxes and Exchange Networks via pH-Sensing Hybrid Nanofibers.

The homeostatic control of their environment is an essential task of living cells. It has been hypothesized that, when microenvironmental pH inhomogeneities are induced by high cellular metabolic activity, diffusing protons act as signaling molecules, driving the establishment of exchange networks sustained by the cell-to-cell shuttling of overflow products such as lactate. Despite their fundamental role, the extent and dynamics of such networks is largely unknown due to the lack of methods in single-cell flux analysis. In this study, we provide direct experimental characterization of such exchange networks. We devise a method to quantify single-cell fermentation fluxes over time by integrating high-resolution pH microenvironment sensing via ratiometric nanofibers with constraint-based inverse modeling. We apply our method to cell cultures with mixed populations of cancer cells and fibroblasts. We find that the proton trafficking underlying bulk acidification is strongly heterogeneous, with maximal single-cell fluxes exceeding typical values by up to 3 orders of magnitude. In addition, a crossover in time from a networked phase sustained by densely connected "hubs" (corresponding to cells with high activity) to a sparse phase dominated by isolated dipolar motifs (i.e., by pairwise cell-to-cell exchanges) is uncovered, which parallels the time course of bulk acidification. Our method addresses issues ranging from the homeostatic function of proton exchange to the metabolic coupling of cells with different energetic demands, allowing for real-time noninvasive single-cell metabolic flux analysis.

Endodotic management of three-rooted maxillary first and second premolars: a case report.

A thorough knowledge of root canal anatomy is essential for successful root canal treatment, because the number of roots and root canals in any tooth can vary. Failing to detect an extra root or canal can cause root canal treatment to fail. It is essential that clinicians interpret radiographs correctly to detect any anatomic variations and treat them successfully. Anatomic variation occur frequently in the root canal system of maxillary premolars; however, the presence of the three separate root canals with three independent roots is rare. This article presents an unusual case of three-rooted maxillary first and second premolars, each with three distinct root canals.