781 research outputs found
Effects of spectral domain optic coherence tomography in monitoring glaucomatous progression of POAG
AIM: To evaluate the ability of spectral domain optic coherence tomography(SD-OCT)parameters to detect progressive structural damage in primary open angle glaucoma(POAG)by contrasting with visual field. METHODS: Retrospectively we evaluated 48 subjects(48 eyes)of POAG, followed up 14 to 62mo. The parameters of SD-OCT and visual field were obtained. The correlation between the change of visual field measurements and OCT measurements were analyzed. Visual field progression was defined as reproducible drop of at least 2dB of mean deviation(MD)from the baseline visit. ROC curve was made to evaluated the ability of OCT parameters in detect progression of POAG. RESULTS: The 25 eyes were classified in progression group and 23 eyes were in non-progression group. No significant correlation was seen between OCT parameters and visual field in non-progression group. In progression group, OCT parameters which were significantly correlated with MD reduce were rim volume(r=-0.5997,P=0.0007), C/D vertical ratio(r=-0.6309, P=0.0003), RNFL(r=0.4201, P=0.0260), and GCC(r=0.7080,PP=0.013). CONCLUSION: Part parameters of SD-OCT can reflect the progression of POAG accurately and provided a new method to detect the damage of visual function of POAG
Deficiency of Mkrn2 causes abnormal spermiogenesis and spermiation, and impairs male fertility.
Although recent studies have shed insights on some of the potential causes of male infertility, new underlining molecular mechanisms still remain to be elucidated. Makorin-2 (Mkrn2) is an evolutionarily conserved gene whose biological functions are not fully known. We developed an Mrkn2 knockout mouse model to study the role of this gene, and found that deletion of Mkrn2 in mice led to male infertility. Mkrn2 knockout mice produced abnormal sperms characterized by low number, poor motility, and aberrant morphology. Disruption of Mkrn2 also caused failure of sperm release (spermiation failure) and misarrangement of ectoplasmic specialization (ES) in testes, thus impairing spermiogenesis and spermiation. To understand the molecular mechanism, we found that expression of Odf2, a vital protein in spermatogenesis, was significantly decreased. In addition, we found that expression levels of Odf2 were decreased in Mkrn2 knockout mice. We also found that MKRN2 was prominently expressed in the sperm of normal men, but was significantly reduced in infertile men. This result indicates that our finding is clinically relevant. The results of our study provided insights into a new mechanism of male infertility caused by the MKRN2 downregulation
Autophagy and its therapeutic potential in diabetic nephropathy
Diabetic nephropathy (DN), the leading cause of end-stage renal disease, is the most significant microvascular complication of diabetes and poses a severe public health concern due to a lack of effective clinical treatments. Autophagy is a lysosomal process that degrades damaged proteins and organelles to preserve cellular homeostasis. Emerging studies have shown that disorder in autophagy results in the accumulation of damaged proteins and organelles in diabetic renal cells and promotes the development of DN. Autophagy is regulated by nutrient-sensing pathways including AMPK, mTOR, and Sirt1, and several intracellular stress signaling pathways such as oxidative stress and endoplasmic reticulum stress. An abnormal nutritional status and excess cellular stresses caused by diabetes-related metabolic disorders disturb the autophagic flux, leading to cellular dysfunction and DN. Here, we summarized the role of autophagy in DN focusing on signaling pathways to modulate autophagy and therapeutic interferences of autophagy in DN
Spermidine improves the antioxidant capacity and morphology of intestinal tissues and regulates intestinal microorganisms in Sichuan white geese
IntroductionIntestinal health is very important to the health of livestock and poultry, and is even a major determining factor in the performance of livestock and poultry production. Spermidine is a type of polyamine that is commonly found in a variety of foods, and can resist oxidative stress, promote cell proliferation and regulate intestinal flora.MethodsIn this study, we explored the effects of spermidine on intestinal health under physiological states or oxidative stress conditions by irrigation with spermidine and intraperitoneal injection of 3-Nitropropionic acid (3-NPA) in Sichuan white goose.Results and discussionOur results showed that spermidine could increase the ratio of intestinal villus to crypt and improve intestinal morphology. In addition, spermidine can also reduce malondialdehyde (MDA) accumulation caused by 3-NPA by increasing superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPX) enzyme activity, thus alleviating intestinal damage. Furthermore, spermidine can regulate intestinal digestive enzyme activities and affect intestinal digestion and absorption ability. Spermidine can also promote an increase in intestinal microbial diversity and abundance and alleviate the change of microflora structure caused by 3-NPA. In conclusion, spermidine promotes the production of beneficial intestinal metabolites such as Wikstromol, Alpha-bisabolol and AS 1–5, thus improving the level of intestinal health. Taken together, these results indicate that spermidine can improve intestinal health by improving intestinal morphology, increasing antioxidant capacity and regulating intestinal flora structure
The Nearest Neutron Star Candidate in a Binary Revealed by Optical Time-domain Surveys
Recent studies have revealed the global deposition on Earth of radioactive
elements (e.g., Fe) resulting from the metal-enriched ejecta of nearby
(within pc) supernova explosions. The majority of neutron stars in
our Solar neighborhood remain to be discovered. Here we report the discovery of
the nearest ( pc) neutron star candidate in the single-lined
spectroscopic binary LAMOST J235456.76+335625.7 (hereafter J2354). Utilizing
the multi-epoch spectra and high-cadence periodic light curves, we measure the
mass of the visible star () and determine
the mass function of the invisible object ,
i.e., the mass of the unseen compact object is $M_{\rm inv} \geq 1.26 \pm 0.03\
M_{\odot}0.12.4<10^{30}\ {\rm erg\ s^{-1}}1.4<6.8\times 10^{23}\ {\rm erg\ s^{-1}}$). Hence, the
neutron star candidate in J2354 can only be discovered via our time-resolved
observations. The alternative scenario involving a nearby supramassive cold
white dwarf cannot be fully excluded. Our discovery demonstrates a promising
way to unveil the missing population of backyard inactive neutron stars or
supramassive cold white dwarfs in binaries by exploring the optical time
domain, thereby facilitating understanding of the supernovae explosion and
metal-enrichment history in our Solar neighborhood.Comment: 35 pages, 8 figures, to be submitte
Design & Optimization of the HV divider for JUNO 20-inch PMT
The Jiangmen Underground Observatory (JUNO) is a 20-kton liquid scintillator
detector that employs 20,000 20-inch photomultiplier tubes (PMTs) as photon
sensors, with 5,000 dynode-PMTs from HAMAMATSU Photonics K.K. (HPK), and 15,000
MCP-PMTs from North Night Vision Technology (NNVT) installed in pure water.
JUNO aims to provide long-lasting and the best performance operation by
utilizing a high-transparency liquid scintillator, high detection efficiency
PMTs, and specially designed electronics including water-proof potting for the
high voltage (HV) dividers of PMTs. In this paper, we present a summary of the
design and optimization of HV dividers for both types of 20-inch PMTs, which
includes collection efficiency, charge resolution, HV divider current, pulse
shape, and maximum amplitude restriction. We have developed and finalized four
schemes of the HV divider for different scenarios, including the final version
selected by JUNO. All 20,000 20-inch PMTs have successfully undergone
production and burning tests.Comment: 14pages,28figure
Protective effects of a novel drug RC28-E blocking both VEGF and FGF2 on early diabetic rat retina
AIM: To investigate protective effects of a novel recombinant decoy receptor drug RC28-E on retinal damage in early diabetic rats.
METHODS: The streptozotocin (STZ)-induced diabetic rats were randomly divided into 6 groups: diabetes mellitus (DM) group (saline, 3 μL/eye); RC28-E at low (0.33 μg/μL, 3 μL), medium (1 μg/μL, 3 μL), and high (3 μg/μL, 3 μL) dose groups; vascular endothelial growth factor (VEGF) Trap group (1 μg/μL, 3 μL); fibroblast growth factor (FGF) Trap group (1 μg/μL, 3 μL). Normal control group was included. At week 1 and 4 following diabetic induction, the rats were intravitreally injected with the corresponding solutions. At week 6 following the induction, apoptosis in retinal vessels was detected by TUNEL staining. Glial fibrillary acidic protein (GFAP) expression was examined by immunofluorescence. Blood-retinal barrier (BRB) breakdown was assessed by Evans blue assay. Ultrastructural changes in choroidal and retinal vessels were analyzed by transmission electron microscopy (TEM). Content of VEGF and FGF proteins in retina was measured by enzyme linked immunosorbent assay (ELISA). The retinal expression of intercellular cell adhesion molecule-1 (ICAM-1), tumor necrosis factor-α (TNF-α), VEGF and FGF genes was examined by quantitative polymerase chain reaction (qPCR).
RESULTS: TUNEL staining showed that the aberrantly increased apoptotic cells death in diabetic retinal vascular network was significantly reduced by treatments of medium and high dose RC28-E, VEGF Trap, and FGF Trap (all P<0.05), the effects of medium and high dose RC28-E or FGF Trap were greater than VEGF Trap (P<0.01). GFAP staining suggested that reactive gliosis was substantially inhibited in all RC28-E and VEGF Trap groups, but the inhibition in FGF Trap group was not as prominent. Evans blue assay demonstrated that only high dose RC28-E could significantly reduce vascular leakage in early diabetic retina (P<0.01). TEM revealed that the ultrastructures in choroidal and retinal vessels were damaged in early diabetic retina, which was ameliorated to differential extents by each drug. The expression of VEGF and FGF2 proteins was significantly upregulated in early diabetic retina, and normalized by RC28-E at all dosages and by the corresponding Traps. The upregulation of ICAM-1 and TNF-α in diabetic retina was substantially suppressed by RC28-E and positive control drugs.
CONCLUSION: Dual blockade of VEGF and FGF2 by RC28-E generates remarkable protective effects, including anti-apoptosis, anti-gliosis, anti-leakage, and improving ultrastructures and proinflammatory microenvironment, in early diabetic retina, thereby supporting further development of RC28-E into a novel and effective drug to diabetic retinopathy (DR)
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