Occurrence and living habit of bathyal bobtail squid, Heteroteuthis hawaiiensis (Cephalopoda: Sepiolidae) from off the Ogasawara Islands, Japan

A small school of the bobtail squid Heteroteuthis hawaiiensis was observed on the ocean floor at a depth of 912m near the Ogasawara Islands. This is the first report of an observation on the living deep-sea bobtail squid

Una nueva especie de Mirocaris (Crustacea: Decapoda: Caridea: Alvinocaridinae) asocia con fuentes hidrotermales en la Dorsal Central Índica, Océano Índico

Mirocaris indica, a new species of the caridean family Alvinocarididae, is described based on 17 specimens from hydrothermal vent fields on the Central Indian Ridge near the Rodriguez Triple Junction. The new species closely resembles the only known representative of Mirocaris, the Atlantic species M. fortunata (Martin and Christiansen). Shared major characters include the dorsoventrally flattened, unarmed rostrum, the presence of epipods on the third maxilliped through to the fourth pereopod with corresponding setobranchs on the first to fifth pereopods, and the lack of appendices internae on the third and fourth pleopods. However, the lack of submarginal rows of short to long stiff setae on the external surfaces of the fingers of the first chela distinguishes M. indica from M. fortunata, and may reflect a difference in feeding habit between the two species. Further, M. indica may attain a larger adult size than M. fortunata does.Mirocaris indica, una nueva especie de la família caridea Alvinocarididae, se describe basándose en 17 especímenes obtenidos en campos de fuentes hidrotermales de la Dorsal Central Índica cerca de la Triple Convergencia de Rodríguez. La nueva especie es muy parecida al único representante de Mirocaris, la especie atlántica M. fortunata (Martin y Christiansen). Los principales caracteres compartidos incluyen el rostro inerme, aplanado dorsoventralmente, la presencia de epipodios en el tercer maxilípedo hasta el cuarto pereiópodo con correspondientes setobránquias en los pereiópodos primero a quinto, así como la falta de appendices internae en los pleópodos tercero y cuarto. La falta de filas submarginales de cortas a largas sedas rígidas sobre las superfícies externas de los dedos de la primera quela distinguen, no obstante, M. indica de M. fortunata, y pueden reflejar una diferencia en hábitos alimenticios entre las dos especies. Adicionalmente, M. indica alcanza una talla adulta superior a la de M. fortunata

The complete mitochondrial genome sequence of the hydrothermal vent galatheid crab Shinkaia crosnieri (Crustacea: Decapoda: Anomura): A novel arrangement and incomplete tRNA suite

<p>Abstract</p> <p>Background</p> <p>Metazoan mitochondrial genomes usually consist of the same 37 genes. Such genes contain useful information for phylogenetic analyses and evolution modelling. Although complete mitochondrial genomes have been determined for over 1,000 animals to date, hydrothermal vent species have, thus far, remained excluded due to the scarcity of collected specimens.</p> <p>Results</p> <p>The mitochondrial genome of the hydrothermal vent galatheid crab <it>Shinkaia crosnieri </it>is 15,182 bp in length, and is composed of 13 protein-coding genes, two ribosomal RNA genes and only 18 transfer RNA genes. The total AT content of the genome, as is typical for decapods, is 72.9%. We identified a non-coding control region of 327 bp according to its location and AT-richness. This is the smallest control region discovered in crustaceans so far. A mechanism of cytoplasmic tRNA import was addressed to compensate for the four missing tRNAs. The <it>S. crosnieri </it>mitogenome exhibits a novel arrangement of mitochondrial genes. We investigated the mitochondrial gene orders and found that at least six rearrangements from the ancestral pancrustacean (crustacean + hexapod) pattern have happened successively. The codon usage, nucleotide composition and bias show no substantial difference with other decapods. Phylogenetic analyses using the concatenated nucleotide and amino acid sequences of the 13 protein-coding genes prove consistent with the previous classification based upon their morphology.</p> <p>Conclusion</p> <p>The present study will supply considerable data of use for both genomic and evolutionary research on hydrothermal vent ecosystems. The mitochondrial genetic characteristics of decapods are sustained in this case of <it>S. crosnieri </it>despite the absence of several tRNAs and a number of dramatic rearrangements. Our results may provide evidence for the immigrating hypothesis about how vent species originate.</p

Silent cerebral infarction predicts vascular events in hemodialysis patients

Silent cerebral infarction predicts vascular events in hemodialysis patients.BackgroundCardiovascular disease is the leading cause of death in hemodialysis (HD) patients. We have previously reported a higher incidence of silent cerebral infarction (SCI) in HD patients compared with the control group using MRI studies. In the present study, we examined whether or not SCI could predict vascular events in HD patients.MethodsCranial magnetic resonance imaging (MRI) was performed on 119 HD patients without symptomatic cerebrovascular disease. SCI was detected by MRI, and the patients were prospectively followed up. The end points of the study were the incidence of major events related to vascular events (cerebral events, cardiac events, and sudden deaths). We investigated the prognostic role of SCI in cerebral, cardiac, and vascular events by using the Kaplan-Meier method and Cox proportional hazards analysis.ResultsThe prevalence of SCI was 49.6% in HD patients. During a follow-up period of maximum 60 months, vascular events, which included 13 cerebral events, 5 cardiac events, and 3 sudden deaths, occurred in 21 patients. The presence of SCI was predictive for a higher cerebral and vascular morbidity compared to the absence of SCI [18.6% (N = 11) vs. 3.3% (N = 2), P = 0.0169, and 30.5% (N = 18) vs. 5.0% (N = 3), P = 0.0006, respectively]. By multivariate Cox proportional hazards analysis, SCI remained a powerful independent predictor of cerebral and vascular events (hazard ratio for cerebral events 7.33, 95% CI 1.27–42.25: for vascular events 4.48, 95% CI 1.09–18.41).ConclusionThe findings of the present study indicate that the presence of SCI is a new risk factor for vascular events in HD patients

Astrocytic gliomas: MRI and pathological grade.

The relationship between MR configuration and pathological grade was studied in 41 histologically verified supratentorial astrocytic gliomas with a 0.5T superconductive MR system. The gliomas included 13 low-grade astrocytomas (LGAs), 14 anaplastic astrocytomas (AAs) and 14 glioblastoma multiformes (GBMs). MRI configurations were classified into nine criteria which were scored and statistically analyzed. The mean values of LGAs, AAs and GBMs were 0.45 +/- 0.31, 1.18 +/- 0.20 and 1.47 +/- 0.22. In each grade, MRI score increased as pathological grades increased (p &#60; 0.01-0.001). LGAs had significantly lower values than AAs in five of the nine criteria (55.6%); heterogeneity, cyst or necrosis, edema or mass effect, border definition, and the degree of contrast enhancement, and lower values than GBMs in eight criteria (88.9%) except for hemorrhage. Three criteria (33.3%), heterogeneity, cyst or necrosis, and flow void sign were significantly higher in GBMs than AAs. The four variables, heterogeneity, cyst or necrosis, edema or mass effect and border definition, proved to be important factors related to the pathological grade in a multiple regression analysis.</p

Sclerite formation in the hydrothermal-vent “scaly-foot” gastropod — possible control of iron sulfide biomineralization by the animal

A gastropod from a deep-sea hydrothermal field at the Rodriguez triple junction, Indian Ocean, has scale-shaped structures, called sclerites, mineralized with iron sulfides on its foot. No other organisms are known to produce a skeleton consisting of iron sulfides. To investigate whether iron sulfide mineralization is mediated by the gastropod for the function of the sclerites, we performed a detailed physical and chemical characterization. Nanostructural characterization of the iron sulfide sclerites reveals that the iron sulfide minerals pyrite (FeS2) and greigite (Fe3S4) form with unique crystal habits inside and outside of the organic matrix, respectively. The magnetic properties of the sclerites, which are mostly consistent with those predicted from their nanostructual features, are not optimized for magnetoreception and instead support use of the magnetic minerals as structural elements. The mechanical performance of the sclerites is superior to that of other biominerals used in the vent environment for predation as well as protection from predation. These characteristics, as well as the co-occurrence of brachyuran crabs, support the inference that the mineralization of iron sulfides might be controlled by the gastropod to harden the sclerites for protection from predators. Sulfur and iron isotopic analyses indicate that sulfur and iron in the sclerites originate from hydrothermal fluids rather than from bacterial metabolites, and that iron supply is unlikely to be regulated by the gastropod for iron sulfide mineralization. We propose that the gastropod may control iron sulfide mineralization by modulating the internal concentrations of reduced sulfur compounds

Localized Immunoglobulin Light-Chain Amyloidosis of the Ulnar Nerve

Amyloidosis is a disorder caused by extracellular tissue deposition of insoluble fibrils. Amyloidosis can be divided into systemic or localized disease. Primary systemic amyloidosis is a multisystem disease caused by the deposition of amyloid in various tissues. Localized amyloidosis has different characteristics than those of systemic amyloidosis. In this paper, we present the case of a middle-aged woman who presented with worsening ulnar nerve palsy. Electrophysiological examination and MRI indicated a tumor surrounding the ulnar nerve in the forearm. However, the operative findings revealed that ulnar nerve fascicles were replaced with a yellow tissue, which was diagnosed as amyloid light-chain λ amyloidosis, based on histopathological examination. Systemic amyloidosis was ruled out after the screening examinations. This paper is the first report of the ulnar nerve as the sole site of localized immunoglobulin light-chain amyloidosis manifestation

Optimization of environmental DNA analysis using pumped deep-sea water for the monitoring of fish biodiversity

Deep-sea ecosystems present difficulties in surveying and continuous monitoring of the biodiversity of deep-sea ecosystems because of the logistical constraints, high cost, and limited opportunities for sampling. Environmental DNA (eDNA) metabarcoding analysis provides a useful method for estimating the biodiversity in aquatic ecosystems but has rarely been applied to the study of deep-sea fish communities. In this study, we utilized pumped deep-sea water for the continuous monitoring of deep-sea fish communities by eDNA metabarcoding. In order to develop an optimum method for continuous monitoring of deep-sea fish biodiversity by eDNA metabarcoding, we determined the appropriate amount of pumped deep-sea water to be filtered and the practical number of filtered sample replicates required for biodiversity monitoring of deep-sea fish communities. Pumped deep-sea water samples were filtered in various volumes (5–53 L) at two sites (Akazawa: pumping depth 800 m, and Yaizu: pumping depth 400 m, Shizuoka, Japan) of deep-sea water pumping facilities. Based on the result of evaluations of filtration time, efficiency of PCR amplification, and number of detected fish reads, the filtration of 20 L of pumped deep-sea water from Akazawa and filtration of 10 L from Yaizu were demonstrated to be suitable filtration volumes for the present study. Fish biodiversity obtained by the eDNA metabarcoding analyses showed a clear difference between the Akazawa and Yaizu samples. We also evaluated the effect of the number of filter replicates on the species richness detected by eDNA metabarcoding from the pumped deep-sea water. At both sites, more than 10 sample replicates were required for the detection of commonly occurring fish species. Our optimized method using pumped deep-sea water and eDNA metabarcoding can be applied to eDNA-based continuous biodiversity monitoring of deep-sea fish to better understand the effects of climate change on deep-sea ecosystems

ALK7 is a novel marker for adipocyte differentiation

Transforming growth factor-β (TGF-β) family members regulate a variety of cellular functions and play important roles in cell differentiation. Activin receptor-like kinase 7 (ALK7), a receptor for TGF-β family members, was initially cloned from rats as an orphan receptor and has been recently shown to be a type I receptor for nodal, activin B and activin AB. ALK7 is expressed not only in neurons, but also in insulin-producing islet β cells and white and brown adipose tissues however, the specific functions of ALK7 in these tissues are not known. In order to test whether ALK7 is involved in adipocyte differentiation, we analyzed its expression during adipocyte differentiation. ALK7 expression was detected in the late phase of adipocyte differentiation by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blotting and immunofluorescence staining in 3T3-L1 cells. We also detected the expression of ALK7 by RT-PCR in stromal vascular fraction (SVF) cells. These results indicated that ALK7 is a novel marker specifically expressed during the late phase of adipocyte differentiation. Furthermore, our results suggest the possible involvement of nodal or activin B in adipocyte differentiation