Glioma-Induced Disruption of Resting-State Functional Connectivity and Amplitude of Low-Frequency Fluctuations in the Salience Network

BACKGROUND AND PURPOSE:Cognitive challenges are prevalent in survivors of glioma, but their neurobiology is incompletely understood. The purpose of this study was to investigate the effect of glioma presence and tumor characteristics on resting-state functional connectivity and amplitude of low-frequency fluctuations of the salience network, a key neural network associated with cognition.MATERIALS AND METHODS:Sixty-nine patients with glioma (mean age, 48.74 [SD, 14.32] years) who underwent resting-state fMRI were compared with 31 healthy controls (mean age, 49.68 [SD, 15.54] years). We identified 4 salience network ROIs: left/right dorsal anterior cingulate cortex and left/right anterior insula. Average salience network resting-state functional connectivity and amplitude of low-frequency fluctuations within the 4 salience network ROIs were computed.RESULTS:Patients with gliomas showed decreased overall salience network resting-state functional connectivity (P = .001) and increased amplitude of low-frequency fluctuations in all salience network ROIs (P < .01) except in the left dorsal anterior cingulate cortex. Compared with controls, patients with left-sided gliomas showed increased amplitude of low-frequency fluctuations in the right dorsal anterior cingulate cortex (P = .002) and right anterior insula (P < .001), and patients with right-sided gliomas showed increased amplitude of low-frequency fluctuations in the left anterior insula (P = .002). Anterior tumors were associated with decreased salience network resting-state functional connectivity (P < .001) and increased amplitude of low-frequency fluctuations in the right anterior insula, left anterior insula, and right dorsal anterior cingulate cortex. Patients with high-grade gliomas had decreased salience network resting-state functional connectivity compared with healthy controls (P < .05). The right anterior insula showed increased amplitude of low-frequency fluctuations in patients with grade II and IV gliomas compared with controls (P < .01).CONCLUSIONS:By demonstrating decreased resting-state functional connectivity and an increased amplitude of low-frequency fluctuations related to the salience network in patients with glioma, this study adds to our understanding of the neurobiology underpinning observable cognitive deficits in these patients. In addition to more conventional functional connectivity, amplitude of low-frequency fluctuations is a promising functional-imaging biomarker of tumor-induced vascular and neural pathology.

Detrimental effects of cancer on cognitive function and, consequently, on the quality of life are emerging as a key focus of cancer survivorship both in research and clinical practice.^1,2 Brain tumors have been shown to affect memory, processing, and attention in patients; however, their underlying neurobiology is incompletely understood.³ Using resting-state functional MR imaging (rsfMRI) to evaluate changes in cognitive resting-state networks may provide a better understanding of the pathology underlying the observable cognitive disruptions in gliomas, the most common primary brain tumor in adults.A “triple network model” of neurocognitive pathology has been proposed, which encompasses the default mode network, involved in mind wandering; the central executive network, involved in decision-making; and the salience network (SN), implicated in modulating activation of the default mode network and central executive network by detecting the presence of salient stimuli.^4-8 While previous rsfMRI research has largely focused on tumor-induced changes in the default mode network,^9,10 our study examined the less-studied SN, a network rooted in the anterior insula and the dorsal anterior cingulate cortex.⁶Prior studies evaluating gliomas and SN resting-state functional connectivity (RSFC) provided conflicting results in small patient samples: Maesawa et al¹⁰ found no significant differences in the SN in 12 patients, while Liu et al¹¹ more recently found decreased SN connectivity in 13 patients. Gliomas impact the integrity of the neurovascular unit to varying degrees, resulting in neurovascular uncoupling that has been reported to confound fMRI interpretations in patients with brain tumors.^12-14 Additionally, research has reported neuronal plasticity manifested by structural reorganization and functional remodeling of neural networks in patients with gliomas with possible alterations in clinically observable cognitive manifestations.^15-17 An rsfMRI metric, the amplitude of low-frequency fluctuations (ALFF), has recently shown promise as a biomarker for brain plasticity and hemodynamic characterization, including neurovascular uncoupling in patients with gliomas.^15-19The purpose of this study was to investigate the effect of glioma presence and tumor characteristics on overall RSFC and regional normalized ALFF within the SN in a large patient population. We hypothesized that there would be decreased average SN RSFC and altered ALFF in patients with gliomas compared with healthy controls. Recent studies have acknowledged that gliomas have variable effects on network integrity based on lesion location and proximity to network ROIs,^20-22 and unilateral gliomas can be associated with plasticity in both the ipsilateral and contralateral hemispheres.^11,17 Research also supports differences in resting-state network reorganization in aggressive high-grade gliomas compared with slower-growing low-grade gliomas.^20,23 Therefore, we also hypothesized that there would be differences in average SN RSFC and regional ALFF in patients based on the anterior-versus-posterior location, hemispheric side, and grade of glioma.     

Siep’s test: A novel test for checking wound integrity in small-incision cataract surgery

Purpose:This study was conducted to ensure the integrity of surgery wounds.Methods:This was a randomized prospective trial of 300 patients who underwent small-incision cataract surgery (SICS) at our hospital over a one-year period. We used 2–3 drops of 5% povidone-iodine at the end of each case, not only to disclose any wound leaks but also to sterilize the surface of the eye.Results:Three hundred patients underwent SICS. One hundred ten patients had postoperative wound leak in SICS due to surgical complications. Premature entry comprising 75% (83 cases), followed by floppy iris syndrome comprising 20% (22 cases) and 5% (6 cases) comprising pseudoexfoliation (PXF) syndrome. There was a drop in the number of re-surgeries from 12 to 3 cases since we started implementing this technique.Conclusion:The simple procedure is very handy and economical in identifying the leak and can reduce further complications such as endophthalmitis and re-surgeries. Among residents, this can be a boon where povidone-iodine acts as a riverbank for the outflow of aqueous, outlining the speed, location, and quantity of the leak. Siep’s test plays an important role in identifying any postoperative wound leaks and also sterilizing the eye surface post surgery.     

Willingness to Respond in a Disaster: A Pediatric Nurse Practitioner National Survey

ObjectiveThe objective of this study was to examine factors associated with pediatric nurse practitioners (PNPs) reporting to work in the event of a disaster.MethodsAn anonymous national survey of PNPs was conducted. Several domains were explored, including demographics, personal preparedness plans, disaster training, prior disaster experience, and likelihood of responding in the event of a disaster. A logistic regression analysis was conducted to determine which factors were associated with the respondent’s likelihood of responding in the event of a disaster.ResultsFactors associated with increased likelihood of responding included gender (being a male PNP), military experience, and disaster training. The most significant factor associated with an increased likelihood of responding to work during a disaster was having a specified role in the workplace disaster plan. PNPs with a specified role were three times more likely to respond than were those without a specified role.ConclusionsPNPs are health care workers with advanced skill sets. This untapped resource is available to provide care for a vulnerable population: our children. Disaster planners should explore the possibility of utilizing these highly skilled health care workers in their disaster plans.     

Fabrication and design of transdermal fluconazole spray

The objective of the present study was to formulate fluconazole transdermal spray for obtaining modified drug transport using eutectic mixture, ethyl cellulose, polyethylene oxide and alcohol. The formulated products were characterized. The selection of the optimized batch was done considering the results of drug transport in the first hour, the time required for 90% drug transport, viscosity and spray angle of the formulations. The inclusion of eutectic mixture, consisting of equal parts of camphor and menthol, showed improved drug transport through rat skin. The optimized batch exhibited larger mean zone of inhibition (antifungal activity), efficient in vivo activity and short term stability.     

Deep Brain Stimulation for the Treatment of Resistant Hypertension

Endothelial dysfunction is a key feature of preeclampsia and may contribute to increased cardiovascular disease risk years after pregnancy. Flow-mediated dilation (FMD) is a non-invasive endothelial function test that predicts cardiovascular event risk. New protocols allow researchers to measure three components of the FMD response: FMD, low flow-mediated constriction, and shear stimulus. This review encourages researchers to think beyond “low FMD” by examining how these three components may provide additional insights into the mechanisms and location of vascular dysfunction. The review then examines what FMD studies reveal about vascular dysfunction in preeclampsia while highlighting opportunities to gain greater mechanistic insight from new protocols. Studies using traditional protocols show that FMD is low in mid-pregnancy prior to preeclampsia, at diagnosis, and for 3 years post-partum. However, FMD returns to normal by 10 years post-partum. Studies using new protocols are needed to gain more mechanistic insight.     

Formulation and evaluation of sublingual tablets of losartan potassium

ObjectiveSublingual tablets of Losartan Potassium were prepared to improve its bioavailability, to avoid pre-systemic metabolism in the gastrointestinal tract and hepatic first pass elimination.MethodsThe Sublingual tablets were prepared by direct compression procedure using different concentration of Starch 1500 and microcrystalline cellulose. Compatibility studies of drug and polymer were performed by FTIR spectroscopy and DSC. Preformulation property of API was evaluated. Postcompressional parameters such disintegration time, wetting time, water absorption ratio, in vitro drug release and in vivo bioavailability study of optimized formulation were determined.ResultsFTIR spectroscopy and DSC study revealed that there was no possible interaction between drug and polymers. The precompression parameters were in acceptable range of pharmacopoeial specification. The disintegration time of optimized formulation (F3) was upto 48 sec. The in vitro release of Losartan Potassium was upto 15 min. The percentage relative bioavailability of Losartan Potassium from optimized sublingual tablets was found to be 144.7 %.ConclusionsSublingual tablets of Losartan Potassium were successfully prepared with improved bioavailability.     

Congenital urethrocutaneous fistula in an adolescent male

A urethrocutaneous fistula is a common complication after hypospadias repair, but congenital fistula is a rare anomaly. We present a 16-year-old boy with this unusual anomaly. Its etiology, embryology, and management are discussed in brief.KEY WORDS: Adolescent, congenital fistula of penile urethra, urethroplasty