259 research outputs found

    Median nerve neuropathy in the forearm due to recurrence of anterior wrist ganglion that originates from the scaphotrapezial joint: Case Report

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    <p>Abstract</p> <p>Background</p> <p>Median nerve neuropathy caused by compression from a tumor in the forearm is rare. Cases with anterior wrist ganglion have high recurrence rates despite surgical treatment. Here, we report the recurrence of an anterior wrist ganglion that originated from the Scaphotrapezial joint due to incomplete resection and that caused median nerve neuropathy in the distal forearm.</p> <p>Case presentation</p> <p>A 47-year-old right-handed housewife noted the appearance of soft swelling on the volar aspect of her left distal forearm, and local resection surgery was performed twice at another hospital. One year after the last surgery, the swelling reappeared and was associated with numbness and pain in the radial volar aspect of the hand. Magnetic resonance imaging revealed that the multicystic lesion originated from the Scaphotrapezial joint and had expanded beyond the wrist. Exploration of the left median nerve showed that it was compressed by a large ovoid cystic lesion at the distal forearm near the proximal end of the carpal tunnel. We resected the cystic lesion to the Scaphotrapezial joint. Her symptoms disappeared 1 week after surgery, and complications or recurrent symptoms were absent 13 months after surgery.</p> <p>Conclusions</p> <p>A typical median nerve compression was caused by incomplete resection of an anterior wrist ganglion, which may have induced widening of the cyst. Cases with anterior wrist ganglion have high recurrence rates and require extra attention in their treatment.</p

    Bilateral Cataract in a Cynomolgus Monkey

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    Severe bilateral cataract was found in a 7 year-old naïve female cynomolgus monkey (Macaca fascicularis) 3 months before necropsy. During macroscopic examination, severe opacity and thinning of the lens were observed in both eyes. Histopathology revealed that the lens nuclei and majority of cortex lens fibers had disappeared and become excavated, while the lens fibers in the subcapsular area were swollen and distorted. Other observations included atrophy and vacuolation in the lens epithelial cells and proliferation of spindle cells and collagen fiber beneath the anterior capsule of the right eye. Immunohistochemical staining of these spindle cells revealed the presence of vimentin, cytokeratin and α-smooth muscle actin (α-SMA), which were considered to be derived from lens epithelial cells. This is a rare case of spontaneous, bilateral, hypermature cataract in a cynomolgus monkey

    Fetal and Neonatal Goiter in Cynomolgus Monkeys Following Administration of the Antithyroid Drug Thiamazole at High Doses to Dams During Pregnancy

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    To evaluate morphologic alterations in the thyroid gland in the second generation in cynomolgus monkeys, pregnant dams were exposed to high doses of thiamazole. In Experiment A, dams received thiamazole intragastrically via a nasogastric catheter from gestation day (GD) 50 to GD 150 or on the day before delivery. Initially, the dose level was 20 mg/kg/day (10 mg/kg twice daily); however, the dose level was subsequently decreased to 5 mg/kg/day (2.5 mg/kg twice daily), since deteriorated general conditions were observed in two dams. Six out of seven neonates died on the day of birth. The cause of neonatal death was tracheal compression and suffocation from goiter. The transplacental exposure to thiamazole affected the fetal thyroid glands and induced goiter in all neonates. The surviving neonate was necropsied 767 days after discontinuation of thiamazole exposure and showed reversibility of the induced changes. In Experiment B, dams were intragastrically administered thiamazole at 5 mg/kg/day (2.5 mg/kg twice daily) for treatment periods from GDs 51 to 70, 71 to 90, 91 to 110, 111 to 130 and 131 to 150. All fetuses showed enlarged thyroid glands but were viable. Histopathologically, hypertrophy and/or hyperplastic appearance of the follicular epithelium of the thyroid gland was observed at the end of each treatment period. The most active appearance of the follicular epithelium, consisting of crowded pedunculated structure, was demonstrated at end of the treatment period from GD 131 to 150. This is the first report on the morphology of fetal and neonatal goiter in the cynomolgus monkey

    Radical formation in cytochrome c oxidase

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    AbstractThe formation of radicals in bovine cytochrome c oxidase (bCcO), during the O2 redox chemistry and proton translocation, is an unresolved controversial issue. To determine if radicals are formed in the catalytic reaction of bCcO under single turnover conditions, the reaction of O2 with the enzyme, reduced by either ascorbate or dithionite, was initiated in a custom-built rapid freeze quenching (RFQ) device and the products were trapped at 77K at reaction times ranging from 50μs to 6ms. Additional samples were hand mixed to attain multiple turnover conditions and quenched with a reaction time of minutes. X-band (9GHz) continuous wave electron paramagnetic resonance (CW-EPR) spectra of the reaction products revealed the formation of a narrow radical with both reductants. D-band (130GHz) pulsed EPR spectra allowed for the determination of the g-tensor principal values and revealed that when ascorbate was used as the reductant the dominant radical species was localized on the ascorbyl moiety, and when dithionite was used as the reductant the radical was the SO2− ion. When the contributions from the reductants are subtracted from the spectra, no evidence for a protein-based radical could be found in the reaction of O2 with reduced bCcO. As a surrogate for radicals formed on reaction intermediates, the reaction of hydrogen peroxide (H2O2) with oxidized bCcO was studied at pH 6 and pH 8 by trapping the products at 50μs with the RFQ device to determine the initial reaction events. For comparison, radicals formed after several minutes of incubation were also examined, and X-band and D-band analysis led to the identification of radicals on Tyr-244 and Tyr-129. In the RFQ measurements, a peroxyl (ROO) species was formed, presumably by the reaction between O2 and an amino acid-based radical. It is postulated that Tyr-129 may play a central role as a proton loading site during proton translocation by ejecting a proton upon formation of the radical species and then becoming reprotonated during its reduction via a chain of three water molecules originating from the region of the propionate groups of heme a3. This article is part of a Special Issue entitled: “Allosteric cooperativity in respiratory proteins”

    Administration of oxygen ultra-fine bubbles improves nerve dysfunction in a rat sciatic nerve crush injury model

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    Ultra-fine bubbles (<200 nm in diameter) have several unique properties and have been tested in various medical fields. The purpose of this study was to investigate the effects of oxygen ultra-fine bubbles (OUBs) on a sciatic nerve crush injury (SNC) model rats. Rats were intraperitoneally injected with 1.5 mL saline, OUBs diluted in saline, or nitrogen ultra-fine bubbles (NUBs) diluted in saline three times per week for 4 weeks in four groups: (1) control, (sham operation + saline); (2) SNC, (crush + saline); (3) SNC+OUB, (crush + OUB-saline); (4) SNC+NUB, (crush + NUB-saline). The effects of the OUBs on dorsal root ganglion (DRG) neurons and Schwann cells (SCs) were examined by serial dilution of OUB medium in vitro. Sciatic functional index, paw withdrawal thresholds, nerve conduction velocity, and myelinated axons were significantly decreased in the SNC group compared to the control group; these parameters were significantly improved in the SNC+OUB group, although NUB treatment did not affect these parameters. In vitro, OUBs significantly promoted neurite outgrowth in DRG neurons by activating AKT signaling and SC proliferation by activating ERK1/2 and JNK/c-JUN signaling. OUBs may improve nerve dysfunction in SNC rats by promoting neurite outgrowth in DRG neurons and SC proliferation.Matsuoka H., Ebina K., Tanaka H., et al. Administration of oxygen ultra-fine bubbles improves nerve dysfunction in a rat sciatic nerve crush injury model. International Journal of Molecular Sciences 19, 1395 (2018); https://doi.org/10.3390/ijms19051395

    Discovery of soticlestat, a potent and selective inhibitor for cholesterol 24-hydroxylase (CH24H)

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    Cholesterol 24-hydroxylase (CH24H, CYP46A1), a brain-specific cytochrome P450 (CYP) family enzyme, plays a role in the homeostasis of brain cholesterol by converting cholesterol to 24S-hydroxycholesterol (24HC). Despite a wide range of potential of CH24H as a drug target, no potent and selective inhibitors have been identified. Here, we report on the structure-based drug design (SBDD) of novel 4-arylpyridine derivatives based on the X-ray co-crystal structure of hit derivative 1b. Optimization of 4-arylpyridine derivatives led us to identify 3v ((4-benzyl-4-hydroxypiperidin-1-yl)­(2,4′-bipyridin-3-yl)­methanone, IC50 = 7.4 nM) as a highly potent, selective, and brain-penetrant CH24H inhibitor. Following oral administration to mice, 3v resulted in a dose-dependent reduction of 24HC levels in the brain (1, 3, and 10 mg/kg). Compound 3v (soticlestat, also known as TAK-935) is currently under clinical investigation for the treatment of Dravet syndrome and Lennox-Gastaut syndrome as a novel drug class for epilepsies

    Utility of Distal Forearm DXA as a Screening Tool for Primary Osteoporotic Fragility Fractures of the Distal Radius A Case-Control Study

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    Background: Osteoporotic fragility fractures frequently occur at the distal part of the radius. This suggests that initial osteoporosis evaluation at this site may inform screening and treatment to prevent additional fractures. The purpose of this study was to investigate the utility of distal forearm dual x-ray absorptiometry (DXA) as a screening tool to assess the risk of fragility fractures at the distal part of the radius. Methods: This retrospective, case-control study included postmenopausal women who had sustained a distal radial fracture (fracture group, n = 110) and postmenopausal women with no history of fracture (control group, n = 95). DXA measurements at the spine, hip, and distal part of the forearm (ultra-distal, mid-distal, and one-third distal sections) were compared between the groups on the basis of bone mineral density (BMD), T-score, and the proportion of patients with a T-score of £–2.5 standard deviations (SD). We also investigated the regional differences on the basis of T-score among the skeletal sites. Furthermore, the reliability of distal forearm DXA measurements was validated by assessing the statistical correlation (r) with volumetric BMD by computed tomography (CT). Results: Compared with the control group, the fracture group showed significantly lower BMD and T-scores and higher proportions of patients with a T-score of £–2.5 SD at the ultra-distal, mid-distal, and one-third distal forearm; however, the spine and hip measurements did not differ significantly between the 2 groups. With respect to regional differences, in the fracture group, T-scores were significantly lower and the proportions of patients with a T-score of £–2.5 SD were significantly higher for the 3 distal forearm sites compared with the spine and hip. DXA measurements at all 3 of the distal forearm regions exhibited high correlation with volumetric BMD by CT (r = 0.83 to 0.92). Conclusions: Some postmenopausal women were found to exhibit bone loss preferentially at the distal part of the radius, which may render them vulnerable to fragility fractures. Forearm DXA for the assessment of local bone loss may demonstrate benefit in screening for those at risk for distal radial fractures and facilitate the early identification of patients who require intervention for osteoporosis. Level of Evidence: Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.Miyamura S., Kuriyama K., Ebina K., et al. Utility of Distal Forearm DXA as a Screening Tool for Primary Osteoporotic Fragility Fractures of the Distal Radius A Case-Control Study. JBJS Open Access 5, E0036 (2020); https://doi.org/10.2106/JBJS.OA.19.00036

    Porencephaly in a Cynomolgus Monkey (Macaca Fascicularis)

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    Porencephaly was observed in a female cynomolgus monkey (Macaca fascicularis) aged 5 years and 7 months. The cerebral hemisphere exhibited diffuse brownish excavation with partial defects of the full thickness of the hemispheric wall, and it constituted open channels between the lateral ventricular system and arachnoid space. In addition, the bilateral occipital lobe was slightly atrophied. Histopathologically, fibrous gliosis was spread out around the excavation area and its periphery. In the roof tissue over the cavity, small round cells were arranged in the laminae. They seemed to be neural or glial precursor cells because they were positive for Musashi 1 and negative for NeuN and GFAP. In the area of fibrous gliosis, hemosiderin or lipofuscin were deposited in the macrophages, and activated astroglias were observed extensively around the excavation area
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