Widespread monoclonal IgE antibody convergence to an immunodominant, proanaphylactic Ara h 2 epitope in peanut allergy.

BACKGROUND: Despite their central role in peanut allergy, human monoclonal IgE antibodies have eluded characterization. OBJECTIVE: We sought to define the sequences, affinities, clonality, and functional properties of human monoclonal IgE antibodies in peanut allergy. METHODS: We applied our single-cell RNA sequencing-based SEQ SIFTER discovery platform to samples from allergic individuals who varied by age, sex, ethnicity, and geographic location in order to understand commonalities in the human IgE response to peanut allergens. Select antibodies were then recombinantly expressed and characterized for their allergen and epitope specificity, affinity, and functional properties. RESULTS: We found striking convergent evolution of IgE monoclonal antibodies (mAbs) from several clonal families comprising both memory B cells and plasmablasts. These antibodies bound with subnanomolar affinity to the immunodominant peanut allergen Ara h 2, specifically a linear, repetitive motif. Further characterization of these mAbs revealed their ability to single-handedly cause affinity-dependent degranulation of human mast cells and systemic anaphylaxis on peanut allergen challenge in humanized mice. Finally, we demonstrated that these mAbs, reengineered as IgGs, inhibit significant, but variable, amounts of Ara h 2- and peanut-mediated degranulation of mast cells sensitized with allergic plasma. CONCLUSIONS: Convergent evolution of IgE mAbs in peanut allergy is a common phenomenon that can reveal immunodominant epitopes on major allergenic proteins. Understanding the functional properties of these molecules is key to developing therapeutics, such as competitive IgG inhibitors, that are able to stoichiometrically outcompete endogenous IgE for allergen and thereby prevent allergic cascade in cases of accidental allergen exposure.

Development and Evaluation of Tacrolimus Loaded Nano-Transferosomes for Skin Targeting and Dermatitis Treatment.

Tacrolimus (TRL) is used for the treatment of atopic dermatitis (AD) due to its T-cell stimulation effect. However, its significantly poor water solubility, low penetration and cytotoxicity have reduced its topical applications. Herein, tacrolimus loaded nano transfersomes (TRL-NTs) were prepared, followed by their incorporation into chitosan gel to prepare tacrolimus loaded nano transfersomal gel (TRL-NTsG). TEM analysis of the TRL-NTs was performed to check their morphology. DSC, XRD and FTIR analysis of the TRL-NTs were executed after lyophilization. Similarly, rheology, spreadability and deformability of the TRL-NTsG were investigated. In vitro release, ex vivo permeation and in vitro interaction of TRL-NTsG with keratinocytes and fibroblasts as well as their co-cultures were investigated along with their in vitro cell viability analysis. Moreover, in vivo skin deposition, ear thickness, histopathology and IgE level were also determined. Besides, 6 months stability study was also performed. Results demonstrated the uniformly distributed negatively charged nanovesicles with a mean particle size distribution of 163 nm and zeta potential of -27 mV. DSC and XRD exhibited the thermal stability and amorphous form of the drug, respectively. The TRL-NTsG showed excellent deformability, spreadability and rheological behavior. In vitro release studies exhibited an 8-fold better release of TRL from the TRL-NTsG. Similarly, 6-fold better permeation and stability of the TRL-NTsG with keratinocytes and fibroblasts as well as their co-cultures was observed. Furthermore, the ear thickness (0.6 mm) of the TRL-NTsG was found significantly reduced when compared with the untreated (1.7 mm) and TRL conventional gel treated mice (1.3 mm). The H&E staining showed no toxicity of the TRL-NTsG with significantly reduced IgE levels (120 ng/mL). The formulation was found stable for at least 6 months. These results suggested the efficacy of TRL in AD-induced animal models most importantly when incorporated in NTsG.

Melatonin delivered in solid lipid nanoparticles ameliorated its neuroprotective effects in cerebral ischemia.

The current study explores the potential of melatonin (MLT)-loaded solid lipid nanoparticles (MLT-SLNs) for better neuroprotective effects in ischemic stroke. MLT-SLNs were prepared using lipid matrix of palmityl alcohol with a mixture of surfactants (Tween 40, Span 40, Myrj 52) for stabilizing the lipid matrix. MLT-SLNs were tested for physical and chemical properties, thermal and polymorphic changes, in vitro drug release and in vivo neuroprotective studies in rats using permanent middle cerebral artery occlusion (p-MCAO) model. The optimized MLT-SLNs showed particle size of ∼159 nm, zeta potential of -29.6 mV and high entrapment efficiency ∼92%. Thermal and polymorphic studies showed conversion of crystalline MLT to amorphous form after its entrapment in lipid matrix. MLT-SLNs displayed a sustained release pattern compared to MLT dispersion. MLT-SLNs significantly enhanced the neuroprotective profile of MLT ascertained by reduced brain infarction, recovered behavioral responses, low expression of inflammatory markers and improved oxidation protection in rats. MLT-SLNs also showed reduced hepatotoxicity compared to p-MCAO. From these outcomes, it is evidenced that MLT-SLNs have improved neuroprotection as compared to MLT dispersion and thereby present a promising approach to deliver MLT to the brain for better therapeutic outcomes in ischemic stroke.

Quality by design for sumatriptan loaded nano-ethosomal mucoadhesive gel for the therapeutic management of nitroglycerin induced migraine.

Migraine is a progressive neurological condition often accompanied by nausea and vomiting. Various drugs have recently been used in the treatment of migraine, including sumatriptan (SUT). However, SUT has poor pharmacological effects mainly due to its reduced permeability, blood brain barrier (BBB) effect, half-life and bioavailability. Herein, we developed SUT loaded nano-ethosomes (SUT-NEs) for intranasal (IN) delivery, after their incorporation into chitosan based mucoadhesive gel (SUT-NEsG). The observed mean particle size of SUT-NEs was 109.45 ± 4.03 nm with spherical morphology, mono dispersion (0.191 ± 0.001), negatively charged (-20.90 ± 1.98 mV) and with excellent entrapment efficiency (96.90 ± 1.85 %). Fourier-transform infrared (FTIR) spectra have depicted the compatibility of the components. Moreover, SUT-NEsG was homogeneous having suitable viscosity and mucoadhesive strength. In vitro release and ex vivo permeation analysis showed sustained release and improved permeation of the SUT-NEsG, respectively. Additionally, histopathological studies of nasal membrane affirmed the safety of SUT-NEsG after IN application. In vivo pharmacokinetic study demonstrated improved brain bioavailability of SUT-NEsG as compared to orally administered sumatriptan solution (SUT-SL). Furthermore, significantly enhanced pharmacological effect of SUT-NEsG was observed in behavioral and biochemical analysis, immunohistochemistry for NF-κB, and enzyme linked immuno assay (ELISA) for IL-1ß and TNF-α in Nitroglycerin (NTG) induced migraine model. It can be concluded that migraine may be successfully managed through IN application of SUT-NEsG owing to the direct targeted delivery to the brain.

A detailed insight of the tumor targeting using nanocarrier drug delivery system.

Human struggle against the deadly disease conditions is continued since ages. The contribution of science and technology in fighting against these diseases cannot be ignored exclusively due to the invention of novel procedure and products, extending their size ranges from micro to nano. Recently nanotechnology has been gaining more consideration for its ability to diagnose and treat different cancers. Different nanoparticles have been used to evade the issues related with conservative anticancer delivery systems, including their nonspecificity, adverse effects and burst release. These nanocarriers including, solid lipid nanoparticles (SLNs), liposomes, nano lipid carriers (NLCs), nano micelles, nanocomposites, polymeric and magnetic nanocarriers, have brought revolutions in antitumor drug delivery. Nanocarriers improved the therapeutic efficacy of anticancer drugs with better accumulation at the specific site with sustained release, improved bioavailability and apoptosis of the cancer cells while bypassing the normal cells. In this review, the cancer targeting techniques and surface modification on nanoparticles are discussed briefly with possible challenges and opportunities. It can be concluded that understanding the role of nanomedicine in tumor treatment is significant, and therefore, the modern progressions in this arena is essential to be considered for a prosperous today and an affluent future of tumor patients.

Transdermal delivery of allopurinol-loaded nanostructured lipid carrier in the treatment of gout.

BACKGROUND: Allopurinol (ALP), a xanthine oxidase inhibitor, is a first line drug for the treatment of gout and hyperuricemia. Being the member of BCS class II drugs, ALP has solubility problem, which affects its bioavailability. Also, ALP has shorter half-life and showed GI related problems. In present study, ALP was encapsulated in nanostructured lipid carriers (NLCs) to ensure enhanced bioavailability, improved efficacy and safety in vivo. METHODOLOGY: ALP-loaded NLCs were fabricated by micro-emulsion technique. The prepared NLCs were optimized via design expert in term of particle size, zeta potential and entrapment efficiency. FTIR, PXRD and TEM analysis were carried out to check chemical interaction, polymorphic form and surface morphology of the optimized formulation. ALP-loaded NLCs were then loaded into HPMC based poloxamer-407 gel and were characterized. In vitro and ex vivo analysis were carried out via dialysis membrane method and franz diffusion cell, respectively. Uric acid was used for induction of gout and the anti-gout activity of ALP-loaded NLCs gel was performed and compared with ALP suspension. RESULTS: The optimized formulation had particles in nano-range (238.13 nm) with suitable zeta potential (-31.5 mV), poly-dispersity index (0.115) and entrapment of 87.24%. FTIR results confirmed absence of chemical interaction among formulation ingredients. XRD indicated amorphous nature of ALP-loaded NLCs, whereas TEM analysis confirmed spherical morphology of nanoparticles. The optimized formulation was successfully loaded in to gel and characterized accordingly. The in vitro release and drug release kinetics models showed sustained release of the drug from ALP-loaded NLCs gel. Furthermore, about 28 fold enhanced permeation was observed from ALP-loaded NLCs gel as compared to conventional gel. Skin irritation study disclosed safety of ALP-loaded NLCs gel for transdermal application. Furthermore, ALP-loaded NLCs gel showed significantly enhanced anti-gout activity in Sprague-Dawley rats after transdermal administration as compared to oral ALP suspension. CONCLUSION: ALP-loaded NLCs gel after transdermal administration sustained the drug release, avoid gastrointestinal side effects and enhance the anti-gout performance of ALP. It can be concluded, that NLCs have the potential to deliver drugs via transdermal route as indicated in case of allopurinol.

After the Floods! Healthcare Response and Concerns.

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Superwoman Schema, Racial Identity, and Cellular Aging Among African American Women.

BACKGROUND AND OBJECTIVES: African American women experience faster telomere shortening (i.e., cellular aging) compared with other racial-gender groups. Prior research demonstrates that race and gender interact to influence culturally specific norms for responding to socially-relevant stress and other stress-coping processes, which may affect healthy aging. RESEARCH DESIGN AND METHODS: Data are from African American Women's Heart & Health Study participants who consented to DNA extraction (n = 140). Superwoman Schema (SWS) was measured using 5 validated subscales: presenting strength, emotion suppression, resisting vulnerability, motivation to succeed, and obligation to help others. Racial identity was measured using 3 subscales from the Multidimensional Inventory of Black Identity: racial centrality, private regard, and public regard. Relative telomere length (rTL) was measured using DNA extracted from blood samples. Path analysis tested associations and interactions between SWS and racial identity dimensions with rTL. RESULTS: For SWS, higher resistance to being vulnerable predicted longer telomeres. For racial identity, high private regard predicted longer telomeres while high public regard predicted shorter telomeres. Interactions were found between public regard and 2 SWS dimensions: among women with high public regard, emotion suppression (ß = 0.20, p < .05) and motivation to succeed (ß = 0.18, p < .05) were associated with longer rTL. The interaction between high centrality and emotion suppression predicted shorter rTL (ß = -0.17, p < .05). DISCUSSION AND IMPLICATIONS: Culturally specific responses to gendered racism and racial identity, developed early in life and shaped over the life course, are important psychosocial determinants of cellular aging among African American women.

Racial Discrimination and Telomere Length in Midlife African American Women: Interactions of Educational Attainment and Employment Status.

BACKGROUND: Over the life course, African American (AA) women have faster telomere attrition, a biological indicator of accelerated aging, than White women. Race, sex, age, and composite socioeconomic status (SES) modify associations of institutional racial discrimination and telomere length. However, interactions with everyday racial discrimination have not been detected in AA women, nor have interactions with individual socioeconomic predictors. PURPOSE: We estimated statistical interaction of institutional and everyday racial discrimination with age, education, employment, poverty, and composite SES on telomere length among midlife AA women. METHODS: Data are from a cross-section of 140 AA women aged 30-50 years residing in the San Francisco Bay Area. Participants completed questionnaires, computer-assisted self-interviews, physical examinations, and blood draws. Adjusted linear regression estimated bootstrapped racial discrimination-relative telomere length associations with interaction terms. RESULTS: Racial discrimination did not interact with age, poverty, or composite SES measures to modify associations with telomere length. Interactions between independent SES variables were nonsignificant for everyday discrimination whereas institutional discrimination interacted with educational attainment and employment status to modify telomere length. After adjusting for covariates, we found that higher institutional discrimination was associated with shorter telomeres among employed women with lower education (ß = -0.020; 95% confidence interval = -0.036, -0.003). Among unemployed women with higher education, higher institutional discrimination was associated with longer telomeres (ß = 0.017; 95% confidence interval = 0.003, 0.032). Factors related to having a post-high school education may be protective against the negative effects of institutional racism on cellular aging for AA women.

Diagnostic Value of Mean Elasticity Index as a Quantitative Shear Wave Elastography Parameter for Prediction of Malignancy in Small Suspicious Solid Thyroid Nodules.

OBJECTIVE: To determine the diagnostic accuracy of mean elasticity index (Emean) on quantitative shear wave elastography (SWE) in detection of malignancy in small solid suspected malignant thyroid nodules on ultrasound, taking histopathology as the gold standard. STUDY DESIGN: Analytical study. PLACE AND DURATION OF STUDY:  Department of Radiology, Dow Medical College, Dow University of Health Sciences (DUHS) and Dr. Ruth K. M. Pfau Civil Hospital, Karachi from September 2017 to March 2018. METHODOLOGY: Adult patients of either gender with suspected malignant thyroid nodules (solid, ≤10 mm) were subjected to SWE examination. All patients underwent thyroid surgery later. Histopathological findings were used as the gold standard for determining sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy, at a cut-off Emean of 66 kilo pascals (KPa). These values were further stratified for gender, age (below or above 40 years), single or multiple nodule(s), and known duration of nodules (more or less than 10 months). RESULTS: The average age of 109 women (69.43%) and 48 men (30.57%, n=157) was 37.64 ±9.44 years. The mean nodule size was 6.83 ±3.16 mm. The overall sensitivity, specificity, PPV, NPV and accuracy of the studied parameter in detection of malignancy was 81.5%, 92.3%, 68.8%, 96% and 90.5%, respectively. Diagnostic accuracy was higher for females, age over 40 years, single nodule, and known duration for longer than 10 months. CONCLUSION: Emean - a quantitative SWE parameter - showed high diagnostic accuracy in predicting thyroid malignancy, particularly in older adults with sub-cm solid nodules of more than 10 months duration. Where available, SWE should be used to complement routine thyroid ultrasonography, which may be helpful to reduce unnecessary intervention. Key Words: Mean elasticity index (Emean), Thyroid nodule, Malignancy, Shear wave elastography, Solid nodule.

Rational and practical use of imaging in COVID-19 pneumonia.

The severe form of the COVID-19 pandemic caused by the SARS-CoV-2 virus, has largely manifested as a predominant respiratory illness causing severe pneumonia characterized by bilateral, subpleural ground glass haze, progressing to consolidation, and fibrosis on imaging. There is some discrepancy between the governmental guidelines, professional Societies and Radiology and Respiratory Medicine specialists with divided opinions between the use of the chest X-rays and CT scan, and whether the use be screening or diagnostic. So far, the most balanced recommendations have been proposed by the Fleischner Society, which are endorsed by the Radiological Society of Pakistan as well. This writeup describes the approach for a rational use of imaging to the best advantage in the current situation according to local resources, and restricting the spread of infection. The most practical compromise for Pakistan appears to be the use of portable digital radiography equipment, and point-of- care ultrasound; with CT scan reserved for clinical situations not explained by the above two modalities, or demanding disease stratification.

Radiology of COVID-19 - Imaging the pulmonary damage.

A large part of the world is presently in the grip of the coronavirus disease (COVID-19) by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2 virus), declared a pandemic in March 2020. This document is a brief commentary of the imaging modalities used in the screening, diagnosis and management of COVID-19 pneumonia. Chest x-rays, especially portable, still form a part of majority of official guidelines, with reports of the suggestive radiologic features. The potential of CT scan and ultrasound is also realised, with earlier detection rate. Typical radiologic findings of bilateral, asymmetrical, crazy-paved ground glass opacification, consolidation, reverse halo sign, opacities, progressing to fibrosis are well described for both the X-ray and CT scan. Atypical findings include airway changes, pleural effusion, pulmonary nodules and acute pulmonary embolism. Absence of lymphadenopathy, pleural effusion and pneumothorax is notable. The role of portable lung ultrasound, reported to be useful in emergency, is yet to be established in the guidelines. Disinfection of the equipment is a major concern. Governmental guidelines still advocate X-ray despite professional societies increasingly recommending CT scan.

Diagnostic accuracy of diffusion weighted MRI in differentiating benign and malignant meningiomas.

OBJECTIVE: To determine the diagnostic accuracy of DWI in differentiating benign and malignant meningiomas keeping histopathology as gold standard. METHODS: This was a descriptive analytical study conducted at Radiology Department, DUHS/Dr. Ruth K. M. Pfau Civil Hospital Karachi, from August 2016 to March 2018.It included152 patients clinically suspected of meningioma on conventional neuroimaging. Imaging features of DWI were compared with histopathology findings. The diagnostic accuracy of DWI was calculated in terms of sensitivity, specificity, accuracy, PPV and NPV using histopathology as gold standard. RESULTS: There were 59 male and 93 female patients with mean age of 55.38±9.8 years. Mean duration of sign and symptoms was 5.67±2.57 months. Out of 152 patients, 117(77%) and 35(23%) were differentiated into benign and malignant meningiomas respectively by DWI while 135(88.82%) and17(11.18%) patients were diagnosed respectively on histopathology. The sensitivity, specificity, PPV, NPV and accuracy of DWI of 84.4%, 82.3%, 97.4%, 40%, and 84.2% respectively keeping histopathology as gold standard. CONCLUSION: DWI features along with calculation of ADC values is a reliable non-invasive technique for differentiating benign and malignant meningiomas. However the low negative predictive value necessitates the use of histopathology.

Reviewers' Responses to Medical Research Articles.

OBJECTIVE: To document the reviewers' responses in terms of reviewers' demographic and professional characteristics, promptness of reply, and duration of reply to the request to review medical research articles for a general biomedical research journal. STUDY DESIGN: Cross-sectional, observational study. PLACE AND DURATION OF STUDY: Department of Publications, College of Physicians and Surgeons Pakistan (CPSP), from October to December 2015. METHODOLOGY: Peer reviewed articles edited by a single staff editor were included. Editorials and correspondence were excluded. Manuscript category, discipline, and the total number of reviewers per manuscript were noted. Responses were divided into no response, regrets, and responded, i.e. provided with the review comments; and further sub-divided into timely response, i.e. within 21 days, or later. Total duration of response was counted in days from the date of dispatch to the date of receiving. Among those who provided a review, reviewers' characteristics were noted as designation, institute affiliation, qualification, and gender. Number and percentages of the studied variables were determined. Chi-square test of proportions was used for comparing the proportions with significance at p<0.05. RESULTS: Reviewers for 50 articles including 28 original articles, 15 case reports, three letters to the editor, two short communications, and two new techniques, were evaluated. A total of 598 reviewers were contacted for those 50 articles; forming an average of 11.96 reviewers contacted and 2.2 responded per manuscript. Four hundred and seventy (78.59%) did not reply at all, 18 (3.01%) regretted, and 110 (18.39%) responded (79/110=71.81% timely, and 31/110=28.18% late). Earliest reply was received in one day and the delayed reply in 87 days. Maximum number of reviewers was 24 for a single original article (internal medicine) and 22 for a case report (cardiology). Significantly, more fellows, professors and females (p=0.004, p=0.002, and p=0.017, respectively) provided timely response. CONCLUSION: An overwhelming majority of the reviewers did not reply at all despite the incentives of CME credits and honorarium, adversely affecting the processing time. Majority of those who replied, were on time. Reasons for those who did not reply need to be explored.

MRA-based evaluation of anatomical variation of circle of Willis in adult Pakistanis.

OBJECTIVE: To determine the frequency and patterns of normal anatomical variation of Circle of Willis on magnetic resonance angiogram in adults without cerebrovascular disease. METHODS: This descriptive cross-sectional study was conducted at the Radiology Department of Dow University of Health Sciences / Civil Hospital, Karachi, from January to December 2016, and comprised patients referred for magnetic resonance imaging of the brain and magnetic resonance angiogram without any clinical or radiological manifestation of cerebrovascular disease, primarily including those with suspected demyelination, infection, epilepsy or metastases. Three-dimensional time-of-flight magnetic resonance angiography was performed. The Circle of Willis was assessed for its completeness along with anatomical variations of anterior and posterior components of the circle. RESULTS: Of the 135 subjects, 70(51.8%) were males and 65(48.2%) were females with an overall mean age of 49.26±9.2 years. Among all the subjects, 30(22.2%) showed a complete circle, while 82 (60.7%) and 23(17.1%) had partially complete and incomplete circles respectively. The anterior part of the circle was completed in 108 (80%) subjects, showing type 'a' as the most common variant in 93(68.9%). The posterior part of the circle was completed in 30 (22.2%) subjects with type 'e' variant in 52(38.5%). CONCLUSIONS: There was a wide variability in the anatomy of the Circle of Willis in Pakistani adults asymptomatic for cerebrovascular disease.

Pseudoaneurysm of Left proximal Common Carotid Artery following penetrating trauma.

A 33-year male with history of penetrating trauma to left upper chest in 2006, presented through Medical unit to Radiology Department with complain of hemoptysis. Chest X-ray showed a soft tissue lesion in left upper lobe with a linear metallic foreign body. Contrast enhanced CT scan of chest and later CTA was performed which showed a saccular aneurysm arising from mediastinal part of left common aortic artery surrounded by thrombosis with a cylindrical linear metallic foreign body. He was planned for endovascular repair with stenting which he could not afford due to financial constraints. He is currently on conservative follow up. Vascular lesions can be serious complications resulting from blunt or penetrating trauma, when presenting with hemoptysis due to pseudaoneurysms formation even after so many years of trauma.