Spraguea (Microsporida: Spraguidae) infections in the nervous system of the Japanese anglerfish, Lophius litulon (Jordan), with comments on transmission routes and host pathology     

Freeman MA  Yokoyama H  Osada A  Yoshida T  Yamanobe A  Ogawa K 《Journal of fish diseases》2011,34(6):445-452

Anglerfish from the genus Lophius are a globally important commercial fishery. The microsporidian Spraguea infects the nervous system of these fish resulting in the formation of large, visible parasitic xenomas. Lophius litulon from Japan were investigated to evaluate the intensity and distribution of Spraguea xenomas throughout the nervous system and to assess pathogenicity to the host and possible transmission routes of the parasite. Spraguea infections in L. litulon had a high prevalence; all fish over 403 mm in standard length being infected, with larger fish usually more heavily infected than smaller fish. Seventy percent of all fish examined had some gross visible sign of infection. The initial site of development is the supramedullary cells on the dorsal surface of the medulla oblongata, where all infected fish have parasitic xenomas. As the disease progresses, a number of secondary sites typically become infected such as the spinal, trigeminal and vagus nerves. Fish with infection in the vagus nerve bundles often have simultaneous sites of infection, in particular the spinal nerves and along the ventral nerve towards the urinary bladder. Advanced vagus nerve infections sometimes form xenomas adjacent to kidney tissue. Spraguea DNA was amplified from the contents of the urinary bladders of two fish, suggesting that microsporidian spores may be excreted in the urine. We conclude that supramedullary cells on the hindbrain are the primary site of infection, which is probably initiated at the cutaneous mucous glands where supramedullary cells are known to extend their peripheral axons. The prevalence of Spraguea infections in L. litulon was very high, and infections often extremely heavy; however, no associated pathogenicity was observed, and heavily infected fish were otherwise normal.  相似文献   

cDNA cloning of Japanese oyster stress protein homologous to the mammalian 78-kDa glucose regulated protein and its induction by heatshock   总被引：1，自引：0，他引：1  

Yoshihiro Yokoyama  Hisashi Hashimoto  Satoshi Kubota  Akira Kuriyama  Yoichi Ogura  Shoshi Mizuta  Reiji Yoshinaka  Haruhiko Toyohara 《Fisheries Science》2006,72(2):402-409

ABSTRACT:    The 78-kDa glucose regulated protein (GRP78), a member of stress proteins, was cloned from a cDNA library of Japanese oyster Crassostrea gigas . The analysis on Japanese oyster GRP78 clone of approximately 2.6 kb revealed that the entire open reading frame was 1983 bp long and encoded 661 amino acid residues. At the DNA sequence level, the coding region of Japanese oyster GRP78 gene was 72, 62, and 62% identical to those of chicken GRP78, Japanese flounder HSP70, and Japanese flounder HSC71 genes, respectively. Deduced amino acid sequence of Japanese oyster GRP78 was 84, 62, and 62% identical to those of chicken GRP78, Japanese flounder HSP70, and Japanese flounder HSC71, respectively. Japanese oyster GRP78 contained an 18-residue sequence at the N-terminus that exhibits characteristics of a cleavable signal sequence. It also contained an ATPase domain, and a peptide-binding domain in addition to a Lys-Asp-Glu-Leu (KDEL) peptide motif that is involved in determining endoplasmic reticulum localization. Northern blot analysis showed that GRP78 mRNA was induced with heatshock treatment in the oyster tissues.  相似文献   

Embryological evidence identifies wing digits in birds as digits 1, 2, and 3     

Tamura K  Nomura N  Seki R  Yonei-Tamura S  Yokoyama H 《Science (New York, N.Y.)》2011,331(6018):753-757

The identities of the digits of the avian forelimb are disputed. Whereas paleontological findings support the position that the digits correspond to digits one, two, and three, embryological evidence points to digit two, three, and four identities. By using transplantation and cell-labeling experiments, we found that the posteriormost digit in the wing does not correspond to digit four in the hindlimb; its progenitor segregates early from the zone of polarizing activity, placing it in the domain of digit three specification. We suggest that an avian-specific shift uncouples the digit anlagen from the molecular mechanisms that pattern them, resulting in the imposition of digit one, two, and three identities on the second, third, and fourth anlagens.  相似文献   

Enzymatic hydrolysis of wood with alkaline treatment     

Dai Oka  Kayoko Kobayashi  Noriyuki Isobe  Yu Ogawa  Tomoya Yokoyama  Satoshi Kimura  Ung-Jin Kim  Ken Tokuyasu  Masahisa Wada 《Journal of Wood Science》2013,59(6):484-488

Pulverized samples of wood, cedar and eucalyptus were treated with 5 N NaOH solutions at 25–150 °C. Hemicellulose and lignin content in the samples decreased with increasing treatment temperatures, while the recovery of glucose was maintained at nearly 90 %. X-ray diffraction analysis showed that the content of the original cellulose I structure in the samples decreased with increasing temperature, and most of the cellulose in the sample treated at 150 °C was converted to cellulose II by mercerization. Enzymatic hydrolysis of the alkaline-treated samples was carried out at 37 °C using solutions comprising a mixture of cellulase and β-glucosidase. The samples treated at higher temperatures showed better enzymatic degradability. Treatment with an alkaline solution of lower concentration (1 N NaOH) at 150 °C was also used. Despite significant quantities of hemicellulose and lignin being removed, mercerization was not induced. The enzymatic degradability was much lower than that of the sample treated with a 5 N NaOH solution at 150 °C. Thus, treatment with concentrated alkaline solution at high temperature led to not only the removal of hemicellulose and lignin, but also to modification of the cellulose structure, which resulted in high efficiency of enzymatic saccharification of the wood samples.  相似文献   

Correlation between skeletal muscle fiber type and responses of a taste sensing system in various beef samples     

Yusuke Komiya  Wataru Mizunoya  Kurumi Kajiwara  Issei Yokoyama  Hideki Ogasawara  Keizo Arihara 《Animal Science Journal》2020,91(1)

The difference of muscle fiber type composition affects several parameters related to meat quality; however, the relationship between muscle fiber types and meat taste is unclear. To elucidate this relationship, we determined the taste of various beef samples using a taste sensor (INSENT SA402B) and analyzed its correlation with different muscle fiber type composition. We used 22 kinds of beef samples and measured nine tastes, including the relative and change of membrane potential caused by adsorption (CPA) values, using six sensors (GL1, CT0, CA0, AAE, C00, and AE1). The taste sensor analysis indicated positive value outputs for the relative C00, AAE, and GL1 values as well as for the CPA value of AAE, which corresponded to bitterness, umami, sweetness, and richness, respectively. We found significant positive correlations of the myosin heavy chain 1 (MyHC1) composition with umami taste, and with richness. This result suggests that high levels of slow MyHC1 can induce strong umami taste and richness in beef. We expect that our results will contribute to the elucidation of the relationship between muscle fiber types and meat palatability.  相似文献   

Open Heart Surgery with Deep Hypothermia and Cardiopulmonary Bypass in Small and Toy Dogs     

Isamu Kanemoto DVM  PhD  Daisuke Taguchi DVM  Satoko Yokoyama DVM  Masashi Mizuno DVM  Hiromi Suzuki DVM  Tougaku Kanamoto DVM 《Veterinary surgery : VS》2010,39(6):674-679

Objective: To evaluate open heart surgery with deep surface‐induced hypothermia (sHT) and low‐flow cardiopulmonary bypass (CPB) in small and toy‐breed dogs. Study Design: Case series. Animals: Small breed dogs (n=8) weighing <5.5 kg with naturally occurring cardiac disease. Methods: Deep sHT under isoflurane anesthesia and low‐flow rate CPB with a small‐volume prime circuit were used. Ventricular septal defect was closed directly in 2 dogs and severe mitral regurgitation was corrected with mitral valvuloplasty (MVP) in 5 dogs and mitral valve replacement in 1 dog. Results: All dogs survived surgery; 1 dog died 6 days and 1 died 2 months after MVP. The other 6 dogs lived (mean follow‐up, 32.8 months; range, 12–65 months). Mean body weight at surgery was 3.6 kg (range, 2–5.3 kg). Mean lowest esophageal temperature was 21.4°C (range, 19.8–23.8°C). Mean lowest pump flow volume was 29.2 mL/kg/min (range, 9.4–57.7 mL/kg/min) during aortic cross‐clamping (mean, 53.5 minutes; range, 25–79 minutes). Mean hematocrit before CPB was 38.6% (range, 33–47%) and 20.3% (range, 13–24%) during CPB with a small circuit priming volume of 225–260 mL. Conclusion: Deep sHT with low‐flow rate CPB may be used for open heart surgery in small dogs weighing <5.5 kg. Clinical Relevance: Open heart surgery for selected congenital defects and acquired defects in small and toy‐breed dogs may be successfully performed using deep sHT and CPB.  相似文献   

Quantification of waste feed and fish faeces in sediments beneath yellowtail pens and possibility to reduce waste loading by co‐culturing with sea cucumbers: an isotopic study          下载免费PDF全文

Hisashi Yokoyama  Daiji Tadokoro  Masatsugu Miura 《Aquaculture Research》2015,46(4):918-927

To evaluate environmental impacts of yellowtail culture and to examine the efficiency of the sea cucumber Apostichopus japonicus in reduction of waste loading, surface sediments were sampled and A. japonicus were cultured at a yellowtail farm in Owase Bay, Japan. Waste feed‐ and faeces‐derived organic matter (WOM, FOM) in sedimentary organic matter (SOM) was estimated based on the δ¹³C and δ¹⁵N of the fish feed (?21.7‰, 9.2‰), yellowtail faeces (?20.6‰, 6.2‰) and SOM reference (?24.4‰, 4.4‰). Small WOM (0–22% in SOM) but substantial FOM (28–61%) loadings in the fish farm area and high sulphide concentrations in the sediments (1.0 mg g^?1) suggest that reduction in the fish stocks or mitigation of the faeces should be considered. A. japonicus juveniles were cultured in three cages deployed below a pen and growth was assessed after three different periods (62, 107, 181 days). A. japonicus grew well during the first 107 days (daily specific growth rate, 3.7%) and their survivorship was high (80–90%). Growth ceased after 107 days, probably due to fouling on the cages. The δ¹³C and δ¹⁵N of their hypothetical diet (–19.7‰, 5.5‰) were close to the FOM values, suggesting assimilation of FOM.  相似文献   

Progress of oxidation of non-phenolic lignin moiety in an oxygen bleaching process via the conversion of non-phenolic into phenolic lignin moiety   总被引：1，自引：1，他引：0  

Satoshi Ohmura  Tomoya Yokoyama  Yuji Matsumoto 《Journal of Wood Science》2012,58(3):243-250

To examine whether non-phenolic lignin moiety is converted into the new phenolic counterpart by the participation of active oxygen species (AOS) under oxygen bleaching conditions, a β-O-4 type dimeric lignin model compound, 2-(2-methoxyphenoxy)-1-(3,4-dimethoxyphenyl)propane-1,3-diol (I), 2-(3,5-difluorophenoxy)-1-(4-hydroxy-3-methoxyphenyl)propane-1,3-diol (III), or 2-(3,5-difluorophenoxy)-1-(3,4-dimethoxyphenyl)propane-1,3-diol (IV), was treated under conditions similar to those for oxygen bleaching. A phenolic compound, 4-hydroxy-3-methoxybenzyl alcohol, was added together to generate AOS in the reaction of compound I or IV. The results obtained suggested that AOS attack the side chains of compounds I, III, and IV accompanied by the β-O-4 bond cleavages and the liberations of the corresponding phenolic compounds, 2-methoxyphenol (II), 3,5-difluorophenol (V), and compound V, respectively. However, the rapid liberation of compound V in the oxygen-alkali treatment of compound III may mainly be caused by alkaline-induced reactions and/or some oxidation reactions of the primary degradation product of compound III, a muconic acid derivative.  相似文献   

Predominant formation of aromatic aldehyde and acid from a dimeric <Emphasis Type="Italic">β</Emphasis>-<Emphasis Type="Italic">O</Emphasis>-4-type lignin model compound under hydrogen peroxide bleaching conditions with high pH levels     

Pattaraporn Posoknistakul  Takuya Akiyama  Tomoya Yokoyama  Yuji Matsumoto 《Journal of Wood Science》2017,63(2):173-182

When a dimeric non-phenolic β-O-4-type lignin model compound, 2-(2-methoxyphenoxy)-1-(3,4-dimethoxyphenyl)propane-1,3-diol (veratrylglycerol-β-guaiacyl ether (VG)), was treated under alkaline oxygen or hydrogen peroxide bleaching conditions (O₂ or H₂O₂ system, respectively), 3,4-dimethoxybenzaldehyde (veratraldehyde) and 3,4-dimethoxybenzoic acid (veratric acid) formed with yields dependent on the system. The yield of veratraldehyde based on the mole amount of disappearing VG (VG disappearance) was about 30% in the O₂ system at a high pH level. However, the total yield of veratraldehyde and veratric acid was 70–80% based on VG disappearance in the H₂O₂ system at high pH levels, where H₂O₂ was added stepwise. A prolonged reaction with the further stepwise addition of H₂O₂ at the high pHs would further increase the formations of veratraldehyde and veratric acid with maintaining the yields based on VG disappearance. The yields (70–80%) are higher than those reported in the previous study, which employed VG, oxygen, and 1,10-phenanthroline and copper (II) sulfate as the catalysts. The high yields in the H₂O₂ system with high pH levels can be explained by the reactivity of oxyl anion radical, which is the most responsible active oxygen species at these high pHs and preferably attacks the aliphatic side-chain of VG rather than the aromatic nucleus.  相似文献   

Effects of dietary astaxanthin supplementation on survival,growth and stress resistance in larval and post‐larval kuruma shrimp,Marsupenaeus japonicus          下载免费PDF全文

Weilong Wang  Manabu Ishikawa  Shunsuke Koshio  Saichiro Yokoyama  Mahmoud AO Dawood  Yukun Zhang 《Aquaculture Research》2018,49(6):2225-2232

Two trials were conducted to evaluate the effects of chemically synthesized astaxanthin (Ax) on growth performance, survival, and stress resistance in larval and post‐larval kuruma shrimp (Marsupenaeus japonicus). Six dietary levels of Ax (0, 50, 100, 200, 400 and 800 mg/kg diet) were added to a baseline diet. As a first study, an 8‐day feeding trial was conducted on larval kuruma shrimp, with results showing that larvae‐fed diets supplemented with different Ax levels exhibited better performance during developmental and metamorphosis to postlarvae. Broken‐line regression analysis indicated that the optimal levels for growth and stress resistance of larvae were 168.9 mg/kg and 82.1 mg/kg diet, respectively. Second, a 30‐day feeding trial was conducted on post‐larval shrimp. Supplementation with 100 and 200 mg/kg Ax yielded significantly higher final body weight, body weight gain and specific growth rate than that in a control group. A cumulative mortality index for osmotic stress revealed significantly better performance in a group fed 200 mg/kg supplementation than in controls. Broken‐line regression analysis indicated that the optimal levels for growth and stress resistance of postlarvae were 108.7 mg/kg and 178.1 mg/kg diet, respectively. Based on these results, we suggest that carefully dosed Ax supplementation is a beneficial nutritional strategy for the early developmental stages of kuruma shrimp.  相似文献