Progressive Decrease of Mitochondrial Motility during Maturation of Cortical Axons In Vitro and In Vivo

The importance of mitochondria for neuronal function is evident by the large number of neurodegenerative diseases that have been associated with a disruption of mitochondrial function or transport. Mitochondria are essential for proper biological function as a result of their ability to produce ATP through oxidative phosphorylation, buffer cytoplasmic calcium, regulate lipid biosynthesis, and trigger apoptosis. Efficient transport of mitochondria is thought to be particularly important in neurons in light of their compartmentalization, length of axonal processes, and high-energy requirements). However, the majority of these results were obtained using short-term, in vitro neuronal culture models, and very little is currently known about mitochondrial dynamics in mature axons of the mammalian CNS in vitro or in vivo. Furthermore, recent evidence has demonstrated that mitochondrial immobilization at specific points along the axon, such as presynaptic boutons, play critical roles in axon morphogenesis [4, 5]. We report that as cortical axons mature, motility of mitochondria (but not other cargoes) is dramatically reduced and this coincides with increased localization to presynaptic sites. We also demonstrate using photo-conversion that in vitro mature axons display surprisingly limited long-range mitochondrial transport. Finally, using in vivo two-photon microscopy in anesthetized or awake-behaving mice, we document for the first time that mitochondrial motility is also remarkably low in distal cortical axons in vivo. These results argue that mitochondrial immobilization and presynaptic localization are important hallmarks of mature CNS axons both in vitro and in vivo

The small GTPase ARF6 regulates GABAergic synapse development

ADP ribosylation factors (ARFs) are a family of small GTPases composed of six members (ARF1-6) that control various cellular functions, including membrane trafficking and actin cytoskeletal rearrangement, in eukaryotic cells. Among them, ARF1 and ARF6 are the most studied in neurons, particularly at glutamatergic synapses, but their roles at GABAergic synapses have not been investigated. Here, we show that a subset of ARF6 protein is localized at GABAergic synapses in cultured hippocampal neurons. In addition, we found that knockdown (KD) of ARF6, but not ARF1, triggered a reduction in the number of GABAergic synaptic puncta in mature cultured neurons in an ARF activity-dependent manner. ARF6 KD also reduced GABAergic synaptic density in the mouse hippocampal dentate gyrus (DG) region. Furthermore, ARF6 KD in the DG increased seizure susceptibility in an induced epilepsy model. Viewed together, our results suggest that modulating ARF6 and its regulators could be a therapeutic strategy against brain pathologies involving hippocampal network dysfunction, such as epilepsy. © 2020 The Author(s).1

Occurrence of microplastics in municipal sewage treatment plants: a review

Municipal sewage treatment plants (STPs) are thought to be important point sources of microplastics in freshwater systems and many peer-reviewed articles have been published on this issue since mid-2010s. In this review, we summarize existing literature on the occurrence of microplastics in STPs and experimental methods used for isolation and identification of microplastics. The number concentrations of microplastics in STP influents were 15.1-640 L-1, whereas those in the STP effluents were highly variable and ranged from not detectable to 65 L-1. For most of cases, conventional STPs are removing microplastics very effectively. Fragments and fibers are dominant shapes of microplastics. Thermoplastics (polyethylene and polypropylene) and polyester are the predominant materials recovered. Although further research is needed, size distribution of microplastics in STPs is likely to follow a power law, implying that different studies using different size cutoffs may be compared after establishing a power law relationship

Anatomical and Electrophysiological Myotomes Corresponding to the Flexor Carpi Ulnaris Muscle

This study was designed to investigate the incidence of lateral root of the ulnar nerve through cadaveric dissection and to analyze its impact on myotomes corresponding to the flexor carpi ulnaris (FCU) assessed by electrodiagnostic study. Dissection of the brachial plexus (BP) was performed in 38 arms from 19 cadavers, and the connecting branches between the lateral cord and medial cord (or between lateral cord and ulnar nerve) were investigated. We also reviewed electrodiagnostic reports from January 2006 to May 2008 and selected 106 cases of single-level radiculopathy at C6, C7, and C8. The proportion of abnormal needle electromyographic findings in the FCU was analyzed in these patients. In the cadaver study, branches from the lateral cord to the ulnar nerve or to the medial cord were observed in 5 (13.1%) of 38 arms. The incidences of abnormal electromyographic findings in the FCU were 46.2% (36/78) in C7 radiculopathy, 76.5% (13/17) in C8 radiculopathy and 0% (0/11) in C6 radiculopathy. In conclusion, the lateral root of the ulnar nerve is not an uncommon anatomical variation of the BP and the FCU commonly has the C7 myotome. Needle EMG of the FCU may provide more information for the electrodiagnosis of cervical radiculopathy and brachial plexopathy

Distal Cholangiocarcinoma with Gastric Metastasis Mimicking Early Gastric Cancer

We report an unusual case of distal cholangiocarcinoma with gastric metastasis mimicking early gastric cancer. A 67-year-old woman presented with a 4-month history of abdominal pain after eating. Computed tomography showed a malignant tumor of the common bile duct located just above the intrapancreatic segment, and endoscopy revealed a 2-cm, flat, elevated lesion with convergence of the surrounding folds, situated at the gastric angle. Based on the endoscopic biopsy results, an adenocarcinoma, thought to be an early gastric cancer, was diagnosed. The patient underwent Whipples's operation. Histopathological findings showed that the adenocarcinomatous tissue was clearly demarcated and infiltrated the gastric mucosa and submucosa, leaving the gastric superficial mucosa intact. Both tumors showed similar pathological features and were positive for cytokeratin (CK)-19 and CK-7. These finding suggest distal cholangiocarcinoma with gastric metastasis

Assessment of organic acid and sugar composition in apricot, plumcot, plum, and peach during fruit development

Variation in content of organic acids and soluble sugars, and in physical characteristics was evaluated in apricot (P. armeniaca L. cv. Harcot), plumcot (plum-apricot hybrid, P. salicina ⅹ P. armeniaca L. cv. Harmony), plum (P. salicina Lindl. cv. Formosa), and peach (P. persica L. Batsch cv. Jinmi). The content of organic acids and sugars, as well as parameters of fruit quality (weight, dimensions, firmness, total soluble solids, and total acidity) in Prunus fruits during fruit development were determined. Organic acids, including oxalic acid, quinic acid, malic acid, shikimic acid, citric acid, and quinic acid, sugars, including sucrose, fructose, glucose, and sugar alcohol (sorbitol), were identified and quantified using HPLC. Organic acid mostly increased during the early stages of fruit growth (30 - 60 days after full bloom) and decreased until fruits were fully ripened. In general, plum was the highest in most organic acids compared with the other fruits, while apricot contained the lowest acid content except for citric acid. Sucrose, fructose, and glucose content increased with fruit development, unlike content of sorbitol. Plumcot contained the highest fructose, and peach showed the maximum content of sucrose at full maturation stages. Total soluble solids averaged 17.5, 14.8, 11.9, and 10.6 ºBrix in apricot, plumcot, plum, and peach, respectively, whereas total acidity was 0.9, 1.4, 0.5, and 0.3% in four Prunus cultivars at ripened stages. Shikimic acid was significantly correlated with oxalic acid in apricot, plumcot, and plum, but not in peach. Fructose and glucose were highly correlated in plumcot, plum, and peach.

Enhancement of phase separation in the InGaN layer for self-assembled In-rich quantum dots

The enhancement of phase separation in the InGaN layer grown on a GaN layer with a rough surface was investigated for the formation of self-assembled In-rich quantum dots(QDs) in the InGaN layer. Transmission electron microscopy images showed that In-rich QDs with a size of 2–5 nm were formed even in an InGaN layer with a low indium content, and a layer thickness less than the critical thickness. The room-temperature photoluminescence(PL) spectrum of this layer showed emission peaks corresponding to In-rich QDs. The temperature-dependent PL spectra showed dominant peak shifts to the lower energy side, indicating that the self-assembled In-rich QDs are formed in the InGaN layer grown on a rough GaNsurface and that the carriers are localized in In-rich QDs

Percutaneous Transhepatic Release of an Impacted Lithotripter Basket and Its Fractured Traction Wire Using a Goose-Neck Snare: a Case Report

In a patient with a distal common bile duct stone, a fracture of the traction wire of the basket occurring during the performance of mechanical lithotripsy resulted in the impaction of the lithotripter basket with a stone. The impacted lithotripter basket combined with a fracture of the traction wire is a rare complication of endoscopic stone removal. We were able to pull the impacted basket using an Amplatz goose-neck snare inserted via the percutaneous transhepatic route, which resulted in the freeing of the entrapped stone into the dilated supra-ampullary bile duct. The fractured traction wire and basket could be safely removed by pulling the traction wire from the mouth. The present report is the first to describe the safe and effective use of an Amplatz goose-neck snare for the management of a lithotripter basket impacted with a stone and a fractured traction wire

ER-mitochondria tethering by PDZD8 regulates Ca2+ dynamics in mammalian neurons

Interfaces between organelles are emerging as critical platforms for many biological responses in eukaryotic cells. In yeast, the ERMES complex is an endoplasmic reticulum (ER)-mitochondria tether composed of four proteins, three of which contain a SMP (synaptotagmin-like mitochondrial-lipid binding protein) domain. No functional ortholog for any ERMES protein has been identified in metazoans. Here, we identified PDZD8 as an ER protein present at ER-mitochondria contacts. The SMP domain of PDZD8 is functionally orthologous to the SMP domain found in yeast Mmm1. PDZD8 was necessary for the formation of ER-mitochondria contacts in mammalian cells. In neurons, PDZD8 was required for calcium ion (Ca2+) uptake by mitochondria after synaptically induced Ca2+-release from ER and thereby regulated cytoplasmic Ca2+ dynamics. Thus, PDZD8 represents a critical ER-mitochondria tethering protein in metazoans. We suggest that ER-mitochondria coupling is involved in the regulation of dendritic Ca2+ dynamics in mammalian neurons

Association between vitamin D level and hematuria from a dipstick test in a large scale population based study: Korean National Health and nutrition examination survey

Background Vitamin D deficiency is an important health concern because it is related to several comorbidities and mortality. However, its relationship with the risk of hematuria remains undetermined in the general population. In this study, we analyzed the association between vitamin D deficiency and hematuria. Methods We conducted cross-sectional analysis using data of participants from the Korean National Health and Nutrition Examination Survey (KNHANES) 2010–2014. A total of 20,240 participants, aged ≥18 years old, were analyzed. Serum 25-hydroxyvitamin D (25(OH)D) levels were measured in a central laboratory and hematuria was defined as ≥1+ on a dipstick test. Multivariate logistic regression was conducted to calculate the odds ratio (OR) of hematuria risk according to serum 25(OH)D quartiles, after adjusting several covariates. Results A total 3144 (15.5%) participants had hematuria. The mean 25(OH)D level was 17.4 ± 6.2 ng/mL (median, 16.6 ng/mL (interquartile range, 13.1–20.8 ng/mL)). The 3rd and 4th quartiles had a higher risk of hematuria than the 1st quartile, with adjusted ORs 1.26 (1.114–1.415) and 1.40 (1.240–1.572) in the 3rd and 4th quartiles, respectively. However, this relationship was only significant in women, not in men. When stratified analyses were conducted according to menopausal status, there was a significant increase of hematuria risk according to quartiles in postmenopausal but not in premenopausal women. Conclusion We found that vitamin D deficiency is correlated with hematuria in women, particularly after menopause. Further interventional studies are warranted to address whether correcting vitamin D deficiency can lower the risk of hematuria