Gadolinium and nephrogenic systemic fibrosis: association or causation

SUMMARY:   With widespread availability of magnetic resonance imaging (MRI), it has become standard practice for patients with severe renal impairment or previous severe reactions to iodine-containing contrast media to receive gadolinium-based MRI contrast agents instead of traditional radiographic contrast agents, particularly for magnetic resonance angiography. However, there is growing concern about the use of gadolinium contrast agents in the presence of severe renal insufficiency, because of increasing reports of nephrogenic fibrosing dermopathy (NFD)/nephrogenic systemic fibrosis (NSF), associated with the exposure to certain gadolinium-containing contrast agents. In this review we explore the causal link between gadolinium exposure and NSF, using an established system of epidemiological criteria proposed by Bradford Hill. Though the current evidence makes gadolinium a strong suspect as an aetiologic agent for NSF in the presence of severe renal failure, the die is not cast yet. At this stage there needs to be cautious approach to the use of gadolinium-containing contrast agents in the presence of severe renal failure (glomerular filtration rate <30 mL/min per 1.73 m²).     

Repair of left coronary artery aneurysm, recurrent ascending aortic aneurysm, and mitral valve prolapse 19 years after Bentall's procedure in a patient with Marfan syndrome

A 45-year-old female with Marfan syndrome had a Bentall's procedure performed 19 years ago. She presented with a 4-year history of gradually worsening dyspnea and decreasing exercise tolerance. Investigations revealed severe mitral valve prolapse, a left main stem coronary artery (LMSCA) aneurysm, and a recurrent aneurysm of the ascending aorta. The mitral valve was replaced and the aortic aneurysmal sac and the LMSCA aneurysm were then repaired by a modified Bentall procedure. The patient made an uneventful recovery and was discharged home.     

Absence of Mycobacterium avium ss paratuberculosis-specific IS900 sequence in intestinal biopsy tissues of Indian patients with Crohn’s disease

Background and Objective  

The role of Mycobacterium avium ss paratuberculosis (MAP) in the etiopathology of Crohn’s disease (CD) remains controversial, because of conflicting reports demonstrating the presence of MAP-specific insertion sequence from intestinal biopsy tissues of patients clinically diagnosed for the disease. The present study was carried out to investigate the presence of MAP DNA in the intestinal tissues of CD patients to ascertain the relevance of MAP in Indian patients with CD.     

Safety and Biocompatibility of Carbohydrate-Functionalized Polyanhydride Nanoparticles

Carbohydrate functionalization of nanoparticles allows for targeting of C-type lectin receptors. This family of pattern recognition receptors expressed on innate immune cells, such as macrophages and dendritic cells, can be used to modulate immune responses. In this work, the in vivo safety profile of carbohydrate-functionalized polyanhydride nanoparticles was analyzed following parenteral and intranasal administration in mice. Polyanhydride nanoparticles based on 1,6-bis-(p-carboxyphenoxy)hexane and 1,8-bis-(p-carboxyphenoxy)-3,6-dioxaoctane were used. Nanoparticle functionalization with di-mannose (specifically carboxymethyl-α-d-mannopyranosyl-(1,2)-d-mannopyranoside), galactose (specifically carboxymethyl-β-galactoside), or glycolic acid induced no adverse effects after administration based on histopathological evaluation of liver, kidneys, and lungs. Regardless of the polymer formulation, there was no evidence of hepatic or renal damage or dysfunction observed in serum or urine samples. The histological profile of cellular infiltration and the cellular distribution and kinetics in the lungs of mice administered with nanoparticle treatments followed similar behavior as that observed in the lungs of animals administered with saline. Cytokine and chemokine profiles in bronchoalveolar lavage fluid indicated surface chemistry dependence on modest secretion of IL-6, IP-10, and MCP-1; however, there was no evidence of any deleterious histopathological changes. Based on these analyses, carbohydrate-functionalized nanoparticles are safe for in vivo applications. These results provide foundational information towards the evaluation of the capabilities of these surface-modified nanoparticles as vaccine delivery formulations.KEY WORDS: biocompatibility, carbohydrate, nanoparticles, polyanhydride, safety     

Structural elucidation of NASICON (Na3Al2P3O12) based glass electrolyte materials: effective influence of boron and gallium

Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries. In the research reported in this paper, NASICON-based NCAP glass (Na_2.8Ca_0.1Al₂P₃O₁₂) was selected as the parent glass. The present study demonstrates the changes in the Na⁺ ion conductivity of NCAP bulk glass with the substitution of boron (NCABP: Na_2.8Ca_0.1Al₂B_0.5P_2.7O₁₂) and gallium (NCAGP: Na_2.8Ca_0.1Al₂Ga_0.5P_2.7O₁₂) for phosphorus and the resulting structural variations found in the glass network. For a detailed structural analysis of NCAP, NCABP and NCAGP glasses, micro-Raman and magic angle spinning-nuclear magnetic resonance (MAS-NMR) spectroscopic techniques (for ³¹P, ²⁷Al, ²³Na, ¹¹B and ⁷¹Ga nuclei) were used. The Raman spectrum revealed that the NCAP glass structure is more analogous to the AlPO₄ mesoporous glass structure. The ³¹P MAS-NMR spectrum illustrated that the NCAP glass structure consists of a high concentration of Q⁰ (3Al) units, followed by Q⁰ (2Al) units. The ²⁷Al MAS-NMR spectrum indicates that alumina exists at five different sites, which include AlO₄ units surrounded by AlO₆ units, Al(OP)₄, Al(OP)₅, Al(OAl)₆ and Al(OP)₆, in the NCAP glass structure. The ³¹P, ²⁷Al and ¹¹B MAS-NMR spectra of the NCABP glass revealed the absence of B–O–Al linkages and the presence of B₃–O–B₄–O–P₄ linkages which further leads to the formation of borate and borophosphate domains. The ⁷¹Ga MAS-NMR spectrum suggests that gallium cations in the NCAGP glass compete with the alumina cations and occupy four (GaO₄), five (GaO₅) and six (GaO₆) coordinated sites. The Raman spectrum of NCAGP glass indicates that sodium cations have also been substituted by gallium cations in the NCAP glass structure. From impedance analysis, the dc conductivity of the NCAP glass (∼3.13 × 10⁻⁸ S cm⁻¹) is slightly decreased with the substitution of gallium (∼2.27 × 10⁻⁸ S cm⁻¹) but considerably decreased with the substitution of boron (∼1.46 × 10⁻⁸ S cm⁻¹). The variation in the conductivity values are described based on the structural changes of NCAP glass with the substitution of gallium and boron.

Understanding the conductivity variations induced by compositional changes in sodium super ionic conducting (NASICON) glass materials is highly relevant for applications such as solid electrolytes for sodium (Na) ion batteries.     

Novel Mn4+-activated LiLaMgWO6 far-red emitting phosphors: high photoluminescence efficiency,good thermal stability,and potential applications in plant cultivation LEDs

Double perovskite-based LiLaMgWO₆:Mn⁴⁺ (LLMW:Mn⁴⁺) red phosphors were synthesized by traditional solid-state route under high temperature, and they showed bright far-red emission under excitation of 344 nm. The crystal structure, luminescence performance, internal quantum efficiency, fluorescence decay lifetimes, and thermal stability were investigated in detail. All samples exhibited far-red emissions around 713 nm due to the ²E_g → ⁴A_2g transition of Mn⁴⁺ under excitation of near-ultraviolet and blue light, and the optimal doping concentration of Mn⁴⁺ was about 0.7 mol%. The CIE chromaticity coordinates of the LLMW:0.7% Mn⁴⁺ sample were (0.7253, 0.2746), and they were located at the border of the chromaticity diagram, indicating that the phosphors had high color purity. Furthermore, the internal quantum efficiency of LLMW:0.7% Mn⁴⁺ phosphors reached up to 69.1%, which was relatively higher than those of the reported Mn⁴⁺-doped red phosphors. Moreover, the sample displayed good thermal stability; the emission intensity of LLMW:0.7% Mn⁴⁺ phosphors at 423 K was 49% of the initial value at 303 K, while the activation energy was 0.39 eV. Importantly, there was a broad spectral overlap between the emission band of LLMW:Mn⁴⁺ phosphors and the absorption band of phytochrome P_FR under near-ultraviolet light. All of these properties and phenomena illustrate that the LLMW:Mn⁴⁺ phosphors are potential far-red phosphors for applications in plant cultivation LEDs.

Novel Mn⁴⁺-activated LiLaMgWO₆ far-red emitting double-perovskite phosphors with high photoluminescence efficiency and good thermal stability were developed for applications in plant cultivation LEDs.     

HIV Care Outcomes in Relation to Racial Redlining and Structural Factors Affecting Medical Care Access Among Black and White Persons with Diagnosed HIV—United States, 2017

AIDS and Behavior - Black/African American (Black) versus White persons are unequally burdened by human immunodeficiency virus (HIV) in the United States. Structural factors can influence social...     

Fatal aortic rupture during balloon dilatation of recoarctation.

In an eight year old boy with a patch aortoplasty, the aorta ruptured during balloon angioplasty for recoarctation. At necropsy a 1.5 cm long, full thickness tear and a separate, smaller, intimal tear were found. Histological examination showed thinning of the elastic laminae of the aorta. Angioplasty for recoarctation may be dangerous in patients with a patch aortoplasty.     

Diabetes mellitus and COVID-19: Understanding the association in light of current evidence

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections have posed a problematic healthcare situation worldwide since December 2019. Diabetes mellitus is associated with an increased risk and severity of coronavirus disease 2019 (COVID-19). While interacting with various other risk factors, high blood sugar was found to reduce immunity and increase the replication of SARS-CoV-2. Oxidative stress and the release of pro-inflammatory cytokines are greater in diabetic individuals than in healthy people, worsening the outcome of SARS-CoV-2 infection in diabetics. Increased expression of furin and angiotensin converting enzyme 2 (ACE-2) receptor in the hyperglycemic environment may promote the entry of SARS-CoV-2 in the host cell. COVID-19 infection primarily modulates immune and inflammatory responses, and may cause a cytokine storm, resulting in possible lethal outcomes in diabetics. An experimental report suggests that ACE expressed in the pancreas and the SARS-CoV-2 virus invariably destroy β-cells which contain ACE-2 receptors and results in acute diabetes. Moreover, COVID-19 also causes hyperglycemia in an individual with diabetes which may be related to insulin resistance and destruction of β-cells during SARS-CoV-2 infection. Early observations also suggest a correlation between oral hypoglycemic agents and the risk of COVID-19. This review focused on the possible cause and mechanism involved in SARS-CoV-2 infection in diabetics and the role of antidiabetic drugs in COVID-19.