283 research outputs found
Hydrophobic Silicone Elastomer Chamber for Recording Trajectories of Motile Porcine Sperms without Adsorption
Motile porcine sperms adhere to hydrophilic materials such as glass and plastics. The adsorption of sperms to a hydrophobic poly(dimethylsiloxane) (PDMS) membrane is less compared with that to glass. We investigated the linear velocity (LV) and amplitude of lateral head displacement (ALHD) of motile porcine sperm on glass and PDMS preparations using computer-assisted sperm analysis (CASA). Significant decreases were observed in the 15-min LV (P<0.05) and ALHD (P<0.05) in motile porcine sperm on glass preparations compared with those on PDMS preparations. These differences were due to adsorption of the head and/or neck to hydrophilic substrates. Because of the elasticity of PDMS, we propose that a PDMS membrane should be used for CASA. To investigate the dynamics of motile porcine sperms with microfluidics, we do not recommend plasma treatment to bond PDMS and glass in the microchannel preparation; instead, we suggest that a PDMS molding process without plasma treatment be used for preparation of microfluidic channels
Neuroendocrine Carcinoma of the Stomach: A Case Study
Gastric neuroendocrine carcinomas are rare and have a poor prognosis, and the diagnostic criteria for this disease have recently changed. We herein report a case of sporadic gastric neuroendocrine carcinoma. A 75-year-old man was referred to our hospital with epigastric pain. Endoscopic examination revealed a localized ulcerative lesion (diameter, 4 cm) at the upper stomach. The diagnosis on biopsy was neuroendocrine carcinoma. Total gastrectomy with D2 lymphadenectomy, splenectomy, and cholecystectomy was performed. Pathologically, the tumor infiltrated the subserosal layer, and 6/49 lymph nodes were involved. The tumor was uniform in shape and arranged in a rosette-like structure to form solid nests, with medium-sized, round-to-cuboid-shaped tumor cells and intense mitosis 46/10 HPF. It was positive for synaptophysin and chromogranin A, and the Ki-67 labeling index was 70–80%. The diagnosis of neuroendocrine carcinoma was made according to the WHO 2010 criteria. The patient was followed up for three years without recurrence
Histidine-rich Glycoprotein Could Be an Early Predictor of Vasospasm after Aneurysmal Subarachnoid Hemorrhage
Cerebral vasospasm (CVS) is a major contributor to the high morbidity and mortality of aneurysmal subarachnoid hemorrhage (aSAH) patients. We measured histidine-rich glycoprotein (HRG), a new biomarker of aSAH, in cerebrospinal fluid (CSF) to investigate whether HRG might be an early predictor of CVS. A total of seven controls and 14 aSAH patients (8 males, 6 females aged 53.4±15.4 years) were enrolled, and serial CSF and serum samples were taken. We allocated these samples to three phases (T1-T3) and measured HRG, interleukin (IL)-6, fibrinopeptide A (FpA), and 8-hydroxy-2’-deoxyguanosine (8OHdG) in the CSF, and the HRG in serum. We also examined the release of HRG in rat blood incubated in artificial CSF. In contrast to the other biomarkers examined, the change in the CSF HRG concentration was significantly different between the nonspasm and spasm groups (p<0.01). The rat blood/CSF model revealed a time course similar to that of the human CSF samples in the non-spasm group. HRG thus appears to have the potential to become an early predictor of CVS. In addition, the interaction of HRG with IL-6, FpA, and 8OHdG may form the pathology of CVS
Irrotational and Incompressible Binary Systems in the First Post-Newtonian Approximation of General Relativity
The first post-Newtonian (PN) hydrostatic equations for an irrotational fluid
are solved for an incompressible binary system. The equilibrium configuration
of the binary system is given by a small deformation from the irrotational
Darwin-Riemann ellipsoid which is the solution at Newtonian order. It is found
that the orbital separation at the innermost stable circular orbit (ISCO)
decreases when one increases the compactness parameter ,
in which and denote the mass and the radius of a star,
respectively. If we compare the 1PN angular velocity of the binary system at
the ISCO in units of with that of Newtonian order,
the angular velocity at the ISCO is almost the same value as that at Newtonian
order when one increases the compactness parameter. Also, we do not find the
instability point driven by the deformation at 1PN order, where a new sequence
bifurcates throughout the equilibrium sequence of the binary system until the
ISCO.
We also investigate the validity of an ellipsoidal approximation, in which a
1PN solution is obtained assuming an ellipsoidal figure and neglecting the
deformation. It is found that the ellipsoidal approximation gives a fairly
accurate result for the total energy, total angular momentum and angular
velocity. However, if we neglect the velocity potential of 1PN order, we tend
to overestimate the angular velocity at the ISCO regardless of the shape of the
star (ellipsoidal figure or deformed figure).Comment: 36 pages with 5 figures, revtex, Prog. Theor. Phys. in pres
Enhancement of peroxyoxalate chemiluminescence intensity by surfactants and its application to detect detergent.
Enhancement of peroxyoxalate chemiluminescence (PO-CL) intensity by a surfactant in the H(2)O(2)/bis(2,4,6-trichlorophenyl)oxalate (TCPO)/rhodamine B system was described. The effects of 15 surfactants were evaluated by comparing the ratio of a relative CL intensity (RCI) with surfactant to that of the blank in each system. In preliminary study, H(2)O(2)/imidazole-HNO(3) buffer/TCPO/rhodamine B system was used to study the effects of surfactants on PO-CL intensity. Fourteen surfactants reduced the CL intensity at the 2% concentration, where their relative CL intensities ranged from 0.6 to 93.5%. Some of these phenomena may be caused by a notable change of pH that was occurred by adding the surfactant. Additionally, enhancement of PO-CL intensity was studied by using system (1) H(2)O(2)/TCPO/rhodamine B and (2) H(2)O(2)/imidazole-HNO(3) buffer/TCPO/systems. In the system 1, the favorable enhancement of CL intensity (ranged from 124 to 472%) was observed with 9 surfactants at the 0.5% concentration. This result suggested that several surfactants might play a role as a catalyst in the PO-CL reaction. There was no tendency to enhance CL intensity among the surfactant types. In the system 2, the enhancement of CL intensity was also observed by adding with 11 surfactants, which might be mainly caused by the fluorescent impurities of surfactants used. Furthermore, detection of detergent commercially available was applied by using the system 1
An autopsy case of spinal arteriovenous malformation (Foix-Alajouanine syndrome).
An autopsy case of spinal arteriovenous malformation (AVM) was reported. The patient was a 75-year-old male and his initial neurologic symptoms were paraplegia, paresthesia below the umbilical level and urination difficulty. Subsequently night delirium and parkinsonism also appeared. The clinical and pathological findings in this case are identical with those in the spinal AVM except for Parkinson's disease. In addition, the lateral funiculus of the spinal cord in the middle thoracic segment showed pallor: Under light microscopy, the funiculus was spongiform, with a thinner wall of the myelin sheath, enlargement of the axon and the perivascular infiltration of phagocytes without plasma exudation. The changes in the lateral funiculus seemed to indicate early congestive changes.</p
Solving the Darwin problem in the first post-Newtonian approximation of general relativity
We analytically calculate the equilibrium sequence of the corotating binary
stars of incompressible fluid in the first post-Newtonian(PN) approximation of
general relativity. By calculating the total energy and total angular momentum
of the system as a function of the orbital separation, we investigate the
innermost stable circular orbit for corotating binary(we call it ISCCO). It is
found that by the first PN effect, the orbital separation of the binary at the
ISCCO becomes small with increase of the compactness of each star, and as a
result, the orbital angular velocity at the ISCCO increases. These behaviors
agree with previous numerical works.Comment: 33 pages, revtex, 4 figures(eps), accepted for publication in Phys.
Rev.
Characterization of tryptophan oxidation affecting D1 degradation by FtsH in the photosystem II quality control of chloroplasts
Photosynthesis is one of the most important reactions for sustaining our environment. Photosystem II (PSII) is the initial site of photosynthetic electron transfer by water oxidation. Light in excess, however, causes the simultaneous production of reactive oxygen species (ROS), leading to photo-oxidative damage in PSII. To maintain photosynthetic activity, the PSII reaction center protein D1, which is the primary target of unavoidable photo-oxidative damage, is efficiently degraded by FtsH protease. In PSII subunits, photo-oxidative modifications of several amino acids such as Trp have been indeed documented, whereas the linkage between such modifications and D1 degradation remains elusive. Here, we show that an oxidative post-translational modification of Trp residue at the N-terminal tail of D1 is correlated with D1 degradation by FtsH during high-light stress. We revealed that Arabidopsis mutant lacking FtsH2 had increased levels of oxidative Trp residues in D1, among which an N-terminal Trp-14 was distinctively localized in the stromal side. Further characterization of Trp-14 using chloroplast transformation in Chlamydomonas indicated that substitution of D1 Trp-14 to Phe, mimicking Trp oxidation enhanced FtsH-mediated D1 degradation under high light, although the substitution did not affect protein stability and PSII activity. Molecular dynamics simulation of PSII implies that both Trp-14 oxidation and Phe substitution cause fluctuation of D1 N-terminal tail. Furthermore, Trp-14 to Phe modification appeared to have an additive effect in the interaction between FtsH and PSII core in vivo. Together, our results suggest that the Trp oxidation at its N-terminus of D1 may be one of the key oxidations in the PSII repair, leading to processive degradation by FtsH
Striatal TRPV1 activation by acetaminophen ameliorates dopamine D2 receptor antagonists-induced orofacial dyskinesia
ジスキネジア新治療法の発見 --副作用を減らす併用薬から新しい創薬標的へ--. 京都大学プレスリリース. 2021-04-16.Antipsychotics often cause tardive dyskinesia, an adverse symptom of involuntary hyperkinetic movements. Analysis of the U.S. Food and Drug Administration Adverse Event Reporting System and JMDC insurance claims revealed that acetaminophen prevents the dyskinesia induced by dopamine D₂ receptor antagonists. In vivo experiments further showed that a 21-day treatment with haloperidol increased the number of vacuous chewing movements (VCMs) in rats, an effect that was inhibited by oral acetaminophen treatment or intracerebroventricular injection of N-(4-hydroxyphenyl)-arachidonylamide (AM404), an acetaminophen metabolite that acts as an activator of the transient receptor potential vanilloid 1 (TRPV1). In mice, haloperidol-induced VCMs were also mitigated by treatment with AM404 applied to the dorsal striatum, but not in TRPV1-deficient mice. Acetaminophen prevented the haloperidol-induced decrease in the number of c-Fos⁺/preproenkephalin⁺ striatal neurons in wild-type mice but not in TRPV1-deficient mice. Finally, chemogenetic stimulation of indirect-pathway medium spiny neurons in the dorsal striatum decreased haloperidol-induced VCMs. These results suggest that acetaminophen activates the indirect pathway neurons by activating TRPV1 channels via AM404
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