Incremental value of non-invasive myocardial work for the evaluation and prediction of coronary microvascular dysfunction in angina with no obstructive coronary artery disease

Background

Evidence suggests that patients suffering from angina with no obstructive coronary artery disease (ANOCA) experience coronary microvascular dysfunction (CMD). We aimed to understand the diagnosis value of noninvasive myocardial work indices (MWIs) with left ventricular pressure-strain loop (LV PSL) by echocardiography in ANOCA patients with CMD.

Methods

97 patients with ANOCA were recruited. All subjects underwent standard echocardiography with traditional ultrasound parameters, two-dimensional speckle-tracking echocardiography with global longitudinal strain (GLS), LV PSL with MWIs include global work index (GWI), global constructive work (GCW), global waste work (GWW) and global work efficiency (GWE). In addition, all enrolled cases underwent high-dose adenosine stress echocardiography (SE) with coronary flow velocity reserve (CFVR). CMD was defined as CFVR <2.0.

Results

Of the 97 patients with ANOCA, 52 were placed in the CMD group and 45 in the control group. GWI and GCW were decreased significantly in the CMD group compared with the control group (P < 0.001 for both). GWI and GCW were moderately correlated with CFVR (r = 0.430, P < 0.001 and r = 0.538, P < 0.001, respectively). In the multiple logistic regression analyses, GCW was identified as the only independent echocardiography parameter associated with CMD after adjusting for age and baseline APV [OR (95%CI) 1.009 (1.005-1.013); P < 0.001]. Moreover, the best predictor of CMD in patients with ANOCA using receiver operating characteristic (ROC) curve was GWI and GCW, with an area under the curve (AUC) of 0.800 and 0.832, sensitivity of 67.3% and 78.8%, specificity of 80.0% and 75.6%, respectively.

Conclusion

MWIs with LV PSL is a new method to detect LV systolic function noninvasively in ANOCA patients with CMD.

Radiological features of Rosai-Dorfman disease: case series and review of the literature

AIM

To improve the accuracy of diagnosis of Rosai-Dorfman disease (RDD) by summarising the computed tomography (CT) and magnetic resonance imaging (MRI) characteristics.

MATERIALS AND METHODS

The clinical manifestations, imaging findings, and pathological characteristics of 14 patients with histopathologically confirmed RDD were analysed retrospectively and a literature review was undertaken.

RESULTS

Of the 14 patients, nine had multiple lesions and five had single lesions. Eight patients had extranodal lesions, while six had mixed-type lesions. In patients with head and neck lesions, plain CT/MRI revealed irregularly shaped, well-defined, homogeneous, and mainly progressive lesions, with marked homogeneous enhancement on multiphasic contrast-enhanced imaging. One patient had dural lesions, one of which iso-intense to grey matter, with patchy hypo-intensity on T2-weighted imaging, meningeal tail signs, and characteristic crabfoot-like enhancement. Three patients with skeletal system involvement exhibited osteolytic bone destruction without sclerosis at the edges, associated soft-tissue masses, or periosteal reactions. Two patients had well-defined subcutaneous lesions, inhomogeneous density, and progressive parenchymal enhancement on contrast-enhanced CT. One patient had multiple intestinal lesions with inhomogeneous nodular thickening of the blind ascending colon and ileum, with marked and progressive enhancement.

CONCLUSION

RDD involvement is mainly multifocal, primarily in the head and neck regions. Plain CT/MRI revealed well-defined, irregularly shaped lesions with homogeneous density/signal, with marked and progressive enhancement on multiphasic contrast-enhanced imaging; however, histopathology is still required to confirm the diagnosis of RDD.

Diffuse Primary Malignant Pericardial Mesothelioma with Myocardial involvement: A Comprehensive Assessment Using Multimodel Echocardiography

Diffuse primary malignant pericardial mesothelioma (PMPM) is an extremely rare and highly invasive tumor of pericardium. The tumor can infiltrate myocardium in part of cases, and will contribute to grave prognosis. Herein, we reported a 58-year-old man of diffuse PMPM with myocardial involvement, and summarized 39 cases of diffuse PMPM. Multimodal echocardiography, which combined conventional, tissue Doppler and speckle tracking echocardiography, was applied to diagnose diffuse PMPM with myocardial involvement, and assess the myocardial function. The common features were pericardial effusion, pericardial masses and thickened pericardium. The other echocardiographyic characteristics were extensive and heterogenous echo, adhesion with pericardium and myocardium, reduced motion of adhered myocardium, and constriction performance. Diffuse PMPM with myocardial involvement revealed decreased LV diastolic function, and decreased LV and RV systolic function. Especially in systolic function, the unique strain features were reduced longitudinal strains from segmental to global and from epicardial to endocardial, relative 'septal sparing' pattern, and decreased transmural gradient of longitudinal strain. Our findings suggested that multimodal echocardiography not only can identify this disease, but also can provide detailed information of myocardial dysfunction, which provides a reference for clinicians to develop an optimal individualized treatment.

Multimodal Imaging for Total Anomalous Systemic Venous Drainage Diagnosis and Preoperative Planning: A Case Report and Literature Review

Total anomalous systemic venous drainage (TASVD) is a rare congenital heart malformation. Here, we report a case of a 40-year-old male patient who had a total anomalous systemic venous drainage. It was diagnosed as the TASVD for the first time through multimodal imaging combined Transthoracic (TTE), transesophageal (TEE) and three-dimensional (3D-TTE) echocardiography, contrast echocardiography and computed tomography angiography (CTA). We review 15 published reports on TASVD and summarize the ultrasonographic characteristics. After intracardiac repair through ectopic venous drainage in cardiac surgery, the patient's cyanosis symptoms were alleviated greatly. Echocardiography was the first-line examination for TASVD. Multimodal imaging combined TTE, TEE, 3D TEE, contrast echocardiography and CTA was necessary for confirmed diagnosis of TASVCD.

Circular RNA CircMTO1 suppressed proliferation and metastasis of osteosarcoma through miR-630/KLF6 axis

OBJECTIVE

Circular RNAs (circRNAs) could regulate gene expression which may induce tumor occurrence and progression. In the current study, we first investigated the expression of circMTO1 in osteosarcoma, and the underlying mechanism was further elucidated.

PATIENTS AND METHODS

Circular RNA microarrays were used to identify the differential expression of circRNAs in osteosarcoma tissues and the corresponding normal tissues. qRT-PCR was used to examine the level of circMTO1 in osteosarcoma tissues and cell lines. In addition, circMTO1 overexpression was constructed using lentiviral transfection in cell lines. Subsequently, the Cell Counting Kit-8 (CCK8), cell migration and invasion, and flow cytometry were used to investigate the effect of circMTO1 on the biological functions of cells. The Western Blot and the recovery experiments were used to explore the potential mechanism.

RESULTS

Here, we measured 20 circRNAs which were downregulated in osteosarcoma tissues using circRNA microarray. CircMTO1 expression was decreased in osteosarcoma cell lines. Besides, circMTO1 could inhibit cell proliferation, migration and invasion, and induced apoptosis in osteosarcoma cells. Bioinformatics analysis showed that circMTO1 serves as a sponge for miR-630 and KLF6 is a direct target of miR-630. Furthermore, circMTO1 functions through regulation of miR-630/KLF6 axis.

CONCLUSIONS

Our study suggests circMTO1 could suppress osteosarcoma progression by regulating miR-630/KLF6 axis, which may highlight the diagnostic and therapeutic potential of these molecules in osteosarcoma treatment.

Catalpol ameliorates diabetes-induced testicular injury and modulates gut microbiota

AIMS

To explore the mechanisms of diabetes mellitus (DM)-induced testicular injury caused by modulation of testicular glycolysis and gut microbiota (GM), and evaluation of the efficacy of catalpol in reversing testicular morbidity.

MAIN METHODS

A model of DM-induced testicular injury was established using a high-fat diet in KK-Ay mice. Microbial communities in the feces of mice in normal, model and catalpol (Cat) groups were analyzed by 16S gene sequencing. Correlations between the GM and lactate metabolism levels, lactate dehydrogenase activity, and indicators of testicular injury were analyzed.

KEY FINDINGS

Cat significantly reduced general indicators of diabetes in mice with DM-induced reproductive injury, mitigated damage to the testicular tissue, and increased sperm count and motility. Additionally, the levels of products of glycolysis metabolism (e.g. lactate) increased following Cat treatment compared with the Model group. Disorders in the GM were also reversed in the Cat group.

SIGNIFICANCE

Cat ameliorated DM-induced testicular injury in KK-Ay mice by increasing the energy available to germ cells through glycolysis, principally through modulation of the GM and a reduction in the quantities of associated pathogenic bacteria.

0550 Insomnia is Associated with Greater Arterial Stiffness and Cardiac Dysfunction

Introduction

Insomnia is a novel and modifiable risk factor for incident cardiovascular disease (CVD). However, identification of early markers of subclinical CVD in diagnosed insomnia is understudied. Our aim for this ongoing study is to contrast markers of cardiovascular structure and function between people with insomnia and good-sleeping controls.

Methods

Persons with insomnia (met ICSD-III criteria) and good sleeping controls (&lt;8 Insomnia Severity Index, mean 8-night SOL and WASO&lt;31min) were recruited from the community. Twenty-two adults (21-39y; 55% women) with no history of CVD, diabetes, inflammatory conditions, significant hypertension, or current sleep-disordered breathing (WatchPat200, Itamar Medical) were enrolled and underwent fasting cardiovascular testing. Testing included: Central augmented aortic pressure (AP) and carotid-femoral pulse wave velocity (cfPWV) for vascular stiffness; brachial artery flow mediated dilation (FMD) to assess endothelial function; and 2D echocardiography to assess ejection fraction (EF%), left ventricular global longitudinal strain (LVGLS), left atrial volume index (LAVI), mitral valve E/e’ ratio (E/e’), and lateral e’. ANCOVA models, adjusting for age, comparing persons with insomnia (n=6) to good sleeping controls (n=16) on each cardiovascular measure were conducted.

Results

AP (range:-5,10mmHg), cfPWV (range: 4.8-7.6m/s), EF% (range:55.0-72.0%), LVGLS (range:-26,-19%) LAVI (range:14.1-26.7mL/m2), E/e’ (range:3.2-7.8), and lateral e’ (range:0.09-0.22cm/sec) were all within normal ranges according to age and sex normative standards. Mean FMD was 8.8% (SD=4.3, range:4.3-19.8%). Age adjusted ANCOVA models indicated that the insomnia group had significantly worse cardiovascular function than good sleeping controls on cfPWV (M=6.8±0.3 vs. M=5.7±0.2; p=0.004), EF% (M=60.0±1.7 vs. M=65.2±1.0; p=0.017), LVGLS (M=-21.6±0.6 vs. M=-24.3±0.4; p=0.001), and lateral e’ (M=0.12±0.01 vs. M=0.18±0.01; p=0.003). No group differences were found for AP, FMD, LAVI, and E/e’.

Conclusion

Among relatively healthy young adults, people with insomnia had greater arterial stiffness and worse left ventricular systolic and diastolic functioning.

Support

American Academy of Sleep Medicine Foundation Focused Projects Award for Junior Investigators 179-FP-18

Loganin alleviates testicular damage and germ cell apoptosis induced by AGEs upon diabetes mellitus by suppressing the RAGE/p38MAPK/NF-κB pathway

Diabetes mellitus (DM) damages male reproduction at multiple levels, such as endocrine secretion, spermatogenesis and penile erection. We herein investigated the protective effects and mechanism of loganin targeting the advanced glycation end products (AGEs)/receptor for AGEs (RAGE)/p38 mitogen-activated protein kinase (p38MAPK)/NF-κB signalling pathway. Loganin relieved the general DM symptoms and decreased the blood glucose level of KK-Ay DM mice. Haematoxylin-eosin staining demonstrated that loganin ameliorated testicular histology and function and enhanced the activities of testis-specific markers lactate dehydrogenase (LDH), acid phosphatase (ACP) and gamma-glutamyl transferase (γ-GT). Loganin also showed evident anti-oxidative stress, anti-apoptotic and anti-inflammatory effects on DM-induced reproductive damage by restoring glutathione (GSH) level and superoxide dismutase (SOD) activity, as well as reducing reactive oxygen species (ROS) level and Bax/Bcl-2 ratio in vivo and in vitro. Western blotting exhibited that loganin significantly inhibited the AGEs/RAGE/p38MAPK/NF-κB signalling pathway. Acridine orange and ethidium bromide staining (AOEB) and Western blotting showed that loganin in combination with inhibitors of RAGE, p38MAPK and NF-κB exerted stronger anti-apoptotic effects on AGE-induced GC-2 cell damage compared with loganin alone. In conclusion, loganin can protect against DM-induced reproductive damage, probably by suppressing the AGEs/RAGE/p38MAPK/NF-κB pathway.

Loganin and catalpol exert cooperative ameliorating effects on podocyte apoptosis upon diabetic nephropathy by targeting AGEs-RAGE signaling

BACKGROUND/AIMS

Rehmanniae Radix (RR) and Cornus officinalis (CO) are a typical herbal pair used to treat diabetic nephropathy (DN) in clinical practice. DN can be effectively treated by catalpol (Cat) and loganin (Log), the main active components of RR and CO respectively, through combating apoptosis, oxidative stress and inflammation. Herein, a spontaneous DN and podocyte injury model induced by advanced glycation end products (AGEs), i.e. KK-Ay mice, was used to explore the cooperative effects of Log and Cat on DN and the mechanism targeting the AGEs-RAGE (receptor for AGE) pathway.

METHODS AND KEY FINDINGS

Log and Cat alone or in combination mitigated diabetic symptoms, decreased the level of fasting blood glucose, and increased that of serum insulin. The two drugs alone or in combination protected renal function from damage, prevented extracellular matrix hyperplasia and glycogen deposition, as well as alleviated the loss of podocytes detected by histological assay and immunohistochemistry. Flow cytometry revealed that Log and Cat alone or in combination relieved the apoptosis of AGEs-induced podocytes in vitro. Silencing RAGE by RNA interference played a protective role in podocyte apoptosis, whereas overexpression of it worked oppositely. Western blot exhibited that Log and Cat alone or in combination inhibited the activation of RAGE/p38 MAPK/p65 NF-κB and RAGE/Nox4/p65 NF-κB pathways in podocytes. The inhibitory effects of drug combination were more evident than those of individual treatments.

SIGNIFICANCE

Log and Cat cooperatively resisted the apoptosis of podocytes upon DN by targeting AGEs-RAGE and its downstream pathways p38 MAPK and Nox4.

Evidence for the paternal mitochondrial DNA in the crucian carp-like fish lineage with hybrid origin

In terms of taxonomic status, common carp (Cyprinus carpio, Cyprininae) and crucian carp (Carassius auratus, Cyprininae) are different species; however, in this study, a newborn homodiploid crucian carp-like fish (2n=100) (2nNCRC) lineage (F₁-F₃) was established from the interspecific hybridization of female common carp (2n=100)×male blunt snout bream (Megalobrama amblycephala, Cultrinae, 2n=48). The phenotypes and genotypes of 2nNCRC differed from those of its parents but were closely related to those of the existing diploid crucian carp. We further sequenced the whole mitochondrial (mt) genomes of the 2nNCRC lineage from F₁ to F₃. The paternal mtDNA fragments were stably embedded in the mt-genomes of F₁-F₃ generations of 2nNCRC to form chimeric DNA fragments. Along with this chimeric process, numerous base sites of F₁-F₃ generations of 2nNCRC underwent mutations. Most of these mutation sites were consistent with the existing diploid crucian carp. Moreover, the mtDNA organization and nucleotide composition of 2nNCRC were more similar to those of the existing diploid crucian carp than those of the parents. The inheritable chimeric DNA fragments and mutant loci in the mt-genomes of different generations of 2nNCRC provided important evidence of the mtDNA change process in the newborn lineage derived from hybridization of different species. Our findings demonstrated for the first time that the paternal mtDNA were transmitted into the mt-genomes of homodiploid lineage, which provided new insights into the existence of paternal mtDNA in the mtDNA inheritance.

Effects of sequential application of immunosuppressive agents according to the cell cycle in adriamycin-induced nephropathy rats

OBJECTIVE

The aim of this study was to observe the therapeutic effects of three sequential drug-based treatments according to the cell cycle in rats with adriamycin-induced nephropathy.

MATERIALS AND METHODS

A rat model of adriamycin-induced nephropathy was prepared by two injections, and three experimental groups were set up: control group (n=8); adriamycin-induced nephropathy rat group (n=8); and Meprednisone (MP), Ciclosporin (CsA), and mycophenolate (MMF) treatment group (n=8). Twenty-four-hour urine protein was quantified and serum total protein (TP), albumin (ALB), cholesterol (Chol), triglyceride (TG), urea nitrogen (BUN), and serum creatinine (Scr) were measured by an automatic biochemical analyzer. Pathological changes in renal tissues were observed by light microscopy. Serum matrix metalloproteinase-2 (MMP-2), MMP-9, and transforming growth factor-β1 (TGF-β1) were evaluated by double-antibody sandwich enzyme-linked immunosorbent assay (ELISA). Connective tissue growth factor (CTGF) expression was measured by Western blotting. Expression of nephrin and podocin in podocytes was compared by immunohistochemistry and quantitative Real Time-Polymerase Chain Reaction (qRT-PCR).

RESULTS

Compared with the control group, 24-h urine protein in nephropathy group was significantly reduced at 2, 4, 8, and 12 weeks (p<0.01). Twenty-four-hour urine protein in the three treatment groups was significantly decreased compared with nephropathy group at 8 and 12 weeks (p<0.05). There were no significant differences among treatment groups (p>0.05), but their levels were higher than those in control group. TP and ALB levels in nephropathy group were decreased compared with control group (p<0.01) and increased compared with treatment groups (p<0.05), while TG and Chol levels in nephropathy group were increased compared with control group (p<0.01) and decreased compared with treatment group (p<0.05). There were no significant differences in biochemical parameters among the treatment groups. TGF-β1 levels were decreased, MMP-2 and MMP-9 levels were increased, and CTGF expression was reduced in the three therapeutic groups. Among the treatment groups, the combination of MP, CsA, and Rapa significantly inhibited fibrosis. The protein and mRNA levels of nephrin and podocin were significantly decreased in nephropathy group and their expression and distribution were partially restored in treatment groups.

CONCLUSIONS

The present findings suggest that the sequential therapeutic treatments based on the cell cycle significantly improved the pathological changes in adriamycin-induced nephropathy rats. The sequential treatments significantly reduced urine protein levels, increased TP, ALB, MMP-2, and MMP-9 levels, decreased TG, Chol, and TGF-β1 levels, restored expression of nephrin and podocin in renal tissues, and significantly improved renal fibrosis.

Protective effects of catalpol on diabetes mellitus-induced male reproductive damage via suppression of the AGEs/RAGE/Nox4 signaling pathway

AIMS

Diabetes mellitus (DM)-induced reproductive damage is an important cause of infertility for male DM patients, we herein evaluated the effects of catalpol on diabetic reproductive damage through the suppression of the AGEs/RAGE/Nox4 signaling pathway.

METHODS

KK-Ay diabetic reproductive damage mice were administered with catalpol for 8 weeks, the testis/body weight ratio, testicular histopathology, the levels of endogenous hormone and the activity of testicular marker enzymes were determined. In vitro, the GC-2 cell injury model was induced by advanced glycation end-products (AGEs) and pretreated with catalpol. Cell viability, apoptosis, and oxidative stress markers were detected and the mechanism based on the AGEs/RAGE/Nox4 pathway was explored.

KEY FINDINGS

Catalpol showed remarkable capacity on protecting diabetic reproductive damage by improving the histomorphology of the testes, increasing the testis/body weight ratio and activity of acid phosphatase (ACP), lactate dehydrogenase (LDH), gamma-glutamyl transferase (γ-GT). The reduced testosterone (T), luteinizing hormone (LH) and follicle-stimulating hormone (FSH) levels in DM mice were also reversed with catalpol intervention. Moreover, catalpol showed markedly effects of anti-oxidative in vivo and in vitro, which significantly down-regulated reactive oxygen species (ROS) levels and restored superoxide dismutase (SOD) activity, meanwhile decreased GC-2 cell apoptosis and Bax/Bcl-2 ratio. Moreover, the over-expression of receptors for AGEs (RAGE), NADPH oxidase type 4 (Nox4) and phosphorylation of nuclear transcription factor-κB p65 (NF-κB p65) were suppressed by catalpol.

SIGNIFICANCE

Catalpol could alleviate DM-induced male reproductive damage by inhibiting oxidative stress-induced apoptosis and inflammation mediated by AGEs/RAGE/Nox4 signaling pathway.

Chimeras Linked to Tandem Repeats and Transposable Elements in Tetraploid Hybrid Fish

The formation of the allotetraploid hybrid lineage (4nAT) encompasses both distant hybridization and polyploidization processes. The allotetraploid offspring have two sets of sub-genomes inherited from both parental species, and therefore, it is important to explore its genetic structure. Herein, we construct a bacterial artificial chromosome library of allotetraploids, and then sequence and analyze the full-length sequences of 19 bacterial artificial chromosomes. Sixty-eight DNA chimeras are identified, which are divided into four models according to the distribution of the genomic DNA derived from the parents. Among the 68 genetic chimeras, 44 (64.71%) are linked to tandem repeats (TRs) and 23 (33.82%) are linked to transposable elements (TEs). The chimeras linked to TRs are related to slipped-strand mispairing and double-strand break repair while the chimeras linked to TEs benefit from the intervention of recombinases. In addition, TRs and TEs can also result in insertions/deletions of DNA segments. We conclude that DNA chimeras accompanied by TRs and TEs coordinate a balance between the sub-genomes derived from the parents. It is the first report on the relationship between formation of the DNA chimeras and TRs and TEs in the polyploid animals.

Uncovering the spatial heterogeneity of Ediacaran carbon cycling

Records of the Ediacaran carbon cycle (635-541 million years ago) include the Shuram excursion (SE), the largest negative carbonate carbon isotope excursion in Earth history (down to -12‰). The nature of this excursion remains enigmatic given the difficulties of interpreting a perceived extreme global decrease in the δ¹³ C of seawater dissolved inorganic carbon. Here, we present carbonate and organic carbon isotope (δ¹³ C_carb and δ¹³ C_org ) records from the Ediacaran Doushantuo Formation along a proximal-to-distal transect across the Yangtze Platform of South China as a test of the spatial variation of the SE. Contrary to expectations, our results show that the magnitude and morphology of this excursion and its relationship with coexisting δ¹³ C_org are highly heterogeneous across the platform. Integrated geochemical, mineralogical, petrographic, and stratigraphic evidence indicates that the SE is a primary marine signature. Data compilations demonstrate that the SE was also accompanied globally by parallel negative shifts of δ³⁴ S of carbonate-associated sulfate (CAS) and increased ⁸⁷ Sr/⁸⁶ Sr ratio and coastal CAS concentration, suggesting elevated continental weathering and coastal marine sulfate concentration during the SE. In light of these observations, we propose a heterogeneous oxidation model to explain the high spatial heterogeneity of the SE and coexisting δ¹³ C_org records of the Doushantuo, with likely relevance to the SE in other regions. In this model, we infer continued marine redox stratification through the SE but with increased availability of oxidants (e.g., O₂ and sulfate) limited to marginal near-surface marine environments. Oxidation of limited spatiotemporal extent provides a mechanism to drive heterogeneous oxidation of subsurface reduced carbon mostly in shelf areas. Regardless of the mechanism driving the SE, future models must consider the evidence for spatial heterogeneity in δ¹³ C presented in this study.

In vitro effect of IL-17D on human ovarian carcinoma cells and inherent immunity

This study explored the expression of interleukin 17D (IL-17D) secreted by human ovariancarcinoma cells and the effect of exogenous IL-17D transfection on MICA, which is the ligand of NKG2D, on the surface of ovary carcinoma cells. Human ovarian papillary serous adenocarcinoma cell line SKOV3, empty vector control cell line SKOV3/vector, exogenous human IL-17D stable-transfected cell line SKOV3/IL-17D, as well as cisplatin (CDDP)-resistant cell SKOV/CDDP were cultured; ovarian adenocarcinoma cell line OVCAR-3, empty vector control cell line OVCAR3/vector and OVCAE3/IL- 17D were observed under a microscope. In the study, methyl-thiazolyl-tetrazolium (MTT) method was used to detect the inhibition rate, resistance index and proliferation of SKOV3 and SKOV3/CDDP. It was found that the expression of IL-17 D in SKOV3/CDDP was much higher than that of its parent cell line SKOV3; IL-17D might be correlated to the drug resistance of cells; the proliferation of SKOV3 transfected with IL-17D was significantly accelerated, indicating IL-17D may be effective in promoting the growth of oncocyte.

Prediction of half-semiconductor antiferromagnets with vanishing net magnetization

Using a self-consistent DFT + U approach, we found that spin-polarized electrons and zero magnetization co-exist in a 2D semiconductor codoped with transition metal pairs, meaning that promising candidates for spintronics can be achieved.

Sub-visible particle quantitation in protein therapeutics

Biologics represent a large and growing segment of the therapeutic medicinal market. Sub-visible particles present in these products are a product quality attribute and a potential patient safety concern yet to be fully explored. Early and consistent particle quantitation and control throughout the product life cycle of these drugs from development to commercial lot release is critical in mitigating any concerns. This requires appropriate analytical methods which can be applied to biopharmaceuticals across a large variety of protein concentrations and modes of administration. The compendial light obscuration method for quantitating sub-visible particles in small volume parenterals is not ideally suited for therapeutic biologics. Approaches to modify the current compendial method so that it is applicable to biologics, including appropriate sample preparation, reduced assay sample volume, increased sizing information, and development of an appropriate sampling plan, are presented in this article. Successful applications of a modified light obscuration method to therapeutic protein products are demonstrated, and a strategy to utilise complimentary methods and techniques at different phases of product development is discussed.