Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Materials (Basel) ; 14(2)2021 Jan 09.
Artigo em Inglês | MEDLINE | ID: mdl-33435266

RESUMO

This study employs first-principles calculations to investigate how introducing Yb into aluminum nitride (AlN) leads to a large enhancement in the material's piezoelectric response (d33). The maximum d33 is calculated to be over 100 pC/N, which is 20 times higher than that of AlN. One reason for such a significant improvement in d33 is the elastic-softening effect, which is indicated by a decrease in the elastic constant, C33. The strain sensitivity (du/dε) of the internal parameter, u, is also an important factor for improving the piezoelectric stress constant, e33. On the basis of mixing enthalpy calculations, YbxAl1-xN is predicted to be more stable as a wurtzite phase than as a rock salt phase at composition up to x ≈ 0.7. These results suggest that Yb can be doped into AlN at high concentrations. It was also observed that the dielectric constant, ε33, generally increases with increasing Yb concentrations. However, the electromechanical coupling coefficient, k332, only increases up to x = 0.778, which is likely because of the relatively lower values of ε33 within this range.

2.
J Trauma Acute Care Surg ; 89(3): e28-e33, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32833413

RESUMO

BACKGROUND: Hemostatic resuscitation strategy using blood components with a balanced ratio is adopted in the civilian trauma setting. However, there is usually limited availability of blood components in the austere setting. Warm fresh whole blood (WFWB) has been used for trauma patients with life-threatening hemorrhage necessitating massive transfusions in the Okinawa Islands, Japan. The purpose of this study was to evaluate the safety and feasibility of WFWB use in the austere civilian trauma setting. METHODS: We conducted a retrospective cohort study between January 1999 and June 2019, including trauma patients who received WFWB within 24 hours of admission. Immediately after WFWB was collected from blood donors, the sample was typed and screened for transmissible infectious diseases. Approximately half of the study population received irradiated WFWB to prevent graft versus host disease. We evaluated the incidence of transfusion-associated adverse events. Transfusion requirements and patient outcomes were compared between early and late WFWB use. RESULTS: A total of 28 patients from three civilian institutions were eligible. Of those, 93% sustained blunt trauma. The median Injury Severity Score was 37 (interquartile range, 32-49). All patients required operative hemostatic intervention, and half of the patients required both operative and endovascular hemostatic interventions. Patients received a median of 1,800 mL WFWB transfusions from seven volunteer blood donors. None of our subjects developed hemolytic reactions, transmissible infectious diseases, or graft versus host disease. Early WFWB use (within 4 hours of admission) was associated with a significant reduction in platelet transfusion requirement compared with the late WFWB group in univariate analysis (16 units vs. 47 units, p = 0.002). CONCLUSION: Warm fresh whole blood use is safe and feasible in an austere civilian trauma setting. Prospective studies with larger cohorts are necessary to determine whether early WFWB use will affect patient outcomes, transfusion requirement, and treatment cost. LEVEL OF EVIDENCE: Therapeutic, Level IV.


Assuntos
Transfusão de Sangue , Ressuscitação/métodos , Choque Hemorrágico/terapia , Adulto , Idoso , Transfusão de Componentes Sanguíneos , Doadores de Sangue , Tratamento de Emergência , Feminino , Humanos , Japão , Masculino , Pessoa de Meia-Idade , Medicina Militar , Estudos Retrospectivos , Ferimentos não Penetrantes/complicações
3.
J Fish Biol ; 97(1): 121-136, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32232856

RESUMO

Lutjanid snappers belonging to the subfamilies Apsilinae and Etelinae are commercially valuable components of tropical deep-water fisheries throughout much of the Indo-Pacific region. Based on age assessment using sagittal otoliths, the age-specific demographic characteristics of four deep-water snappers, Etelis coruscans, Paracaesio caerulea, Pristipomoides filamentosus and Pristipomoides sieboldii, in the Okinawa Islands, southwestern Japan, were examined, and the results were discussed for fishery management. Age validation using edge-type analysis demonstrated that opaque zones in all species were formed once per year and were considered valid annual growth increments. The von Bertalanffy growth equations were also determined for each species. These snappers are long-lived (>50 years for E. coruscans and P. caerulea and >30 years for the two species of Pristipomoides) and relatively slow-growing. The age of acquiring sexual maturity in females was relatively later in E. coruscans, P. caerulea and P. filamentosus than in P. sieboldii. The results revealed differences in the biological traits among these four species; E. coruscans and P. caerulea with long life spans and late maturation are particularly more vulnerable to fishing impact than the two Pristipomoides species. Therefore, further approaches to decrease and control fishing intensity, such as networking of marine-protected areas and regulation to control the numbers of boats and/or the total allowable catch, are necessary for the management of the stock of these species, especially for E. coruscans and P. caerulea.


Assuntos
Envelhecimento/fisiologia , Pesqueiros/organização & administração , Peixes/fisiologia , Distribuição Animal , Animais , Comércio , Feminino , Japão , Oceano Pacífico , Especificidade da Espécie
4.
Sci Rep ; 10(1): 4369, 2020 Mar 09.
Artigo em Inglês | MEDLINE | ID: mdl-32152367

RESUMO

Polarity is among the critical characteristics that could governs the functionality of piezoelectric materials. In this study, the polarity of aluminum nitride (AlN) thin films was inverted from Al-polar to N-polar by doping Si into AlN in the range of 1-15 at.%. Polarity inversion from Al-polar to N-polar also occurred when MgSi was codoped into AlN with Mg to Si ratio was less than 1. However, the polarity can be reversed from N-polar to Al-polar when the ratio of Mg and Si was greater than 1. The effect of Si and MgSi addition was investigated with regards to their crystal structure, lattice parameters, polarity distribution and the oxidation state of each elements. Furthermore, the effect of intermediate layer as well as the presence of point defect (i.e. aluminum vacancy) were investigated and how these factors influence the polarity of the thin films are discussed in this report.

5.
J Fish Biol ; 96(3): 631-641, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31900924

RESUMO

The early development and occurrence patterns of Argyrops bleekeri are described based on 87 specimens collected from Nakagusuku Bay on Okinawa Island in southwestern Japan. Larvae and juveniles of the genus Argyrops are distinguished from the other seabreams inhabiting the Western Pacific region by the strength and extent of head spination, body depth, dorsal-fin-ray counts and melanophore patterns. Argyrops bleekeri is easily distinguished from other members of this genus by the presence of a single rudimentary dorsal-fin spine on the first dorsal pterygiophore, melanophore patterns and an allopatric distribution. Argyrops bleekeri larvae [3.3-7.1 mm body length (BL)] and juveniles (6.7-13.0 mm BL) were found in the bay from January to May; nonetheless, they were not collected from the outer bay or in extremely shallow inshore areas such as tidal flats. The results suggest that Argyrops is the most derived red seabream because of its spiny morphology, and it may be a member of an expanding nearshore group of red seabreams, which originally inhabited offshore waters.


Assuntos
Distribuição Animal , Dourada/crescimento & desenvolvimento , Animais , Baías , Japão , Traços de História de Vida , Dourada/anatomia & histologia , Dourada/classificação
6.
ACS Omega ; 4(12): 15081-15086, 2019 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-31552351

RESUMO

The enhancement mechanism of piezoelectric properties by codoping Mg + X (X = Nb, Ti, Zr, Hf) into aluminum nitride (AlN) was investigated by first-principles calculations. Theoretically, the piezoelectric constant (d 33) can be increased when the elastic constant (C 33) is decreased and the piezoelectric stress constant (e 33) is increased. All components of e 33, which consists of the clamped e 33, the Born effective charge (Z 33), and the strain sensitivity (du/dε) of the internal parameter, were improved by the addition of Mg + X into AlN. The decrease in C 33 and the increase in du/dε that were observed in Mg + X-codoped AlN indicate the occurrence of elastic softening which was considered to be influenced by changes in the interatomic bond in the wurtzite structure. The bonding analysis of metal-nitrogen (Me-N) pairs in the Mg + X-codoped AlN system which was carried out by crystal orbital Hamilton populations showed that the covalent bonding (Me-N) was weaker than in pure AlN. Therefore, this weaker covalent bond is considered to be one of the origins of the elastic softening. Similar phenomena were also found for Sc-doped AlN which has higher piezoelectric response than that of pure AlN.

7.
Acta Histochem ; 118(2): 109-17, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-26686297

RESUMO

Osteoblast activating peptide (OBAP) was previously reported to be expressed in the rat stomach and to have a vital role in osteogenesis, but its distribution in rat stomach has not been determined. Thus, the aim of the present study was to identify the cell types expressing OBAP in the rat stomach. The stomachs of twelve 10-to-11-week-old male Jc1:SD rats were used. Samples were collected for immunohistochemistry, immunoelectron microscopy and dot blot assay. Immunohistochemical investigation revealed that OBAP was distributed mainly in parietal cells without any expression in chief cells, X/A-like cells or enterochromaffin-like cells. Moreover, OBAP-immunopositive cells were observed mainly in the upper and lower parts of the gastric gland. Significantly high optical density of immunopositive cells was observed in the upper and lower gastric gland regions. The dot blot assay confirmed that OBAP is secreted by parietal cells and that it is present in the gastric gland lumen. Immunoelectron microscopy demonstrated that OBAP was confined to the mitochondrial inner membrane within parietal cells and that the number of mitochondria in the upper and lower parts of the gastric epithelium was significantly larger than the number in the middle part of the gastric epithelium. Based on the results, it was concluded that OBAP is mainly produced by mitochondria of parietal cells in the upper and lower parts of the gastric epithelium. Moreover, the presence of OBAP in the gastric gland lumen suggests an exocrine mechanism of release.


Assuntos
Mucosa Gástrica/metabolismo , Peptídeos/metabolismo , Animais , Masculino , Mitocôndrias/fisiologia , Especificidade de Órgãos , Ratos , Estômago/citologia
8.
J Vet Med Sci ; 77(2): 175-9, 2015 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-25728250

RESUMO

The dog visual system is well suited to dim light conditions due to rod-dominated retina and the reflective tapetum. The topographical distributions of rods and thickness of the tapetum of the dog were quantified in retinal whole mounts stained with thionine, and spatial relationships among the tapetum, rod density and visual streak of high ganglion cell density were elucidated. The relationship between the retina and tapetum was analyzed in parasagittal sections stained with thionine or hematoxylin-eosin. The tapetum was thick in its center, and the thickest part consisted of 9 to 12 tapetal cell layers. Rod density ranged from 200,000 to 540,000/mm(2). Maximum rod density was found in the area dorsal to the visual streak, and the density in that area was significantly higher than the rod density in the visual streak and accorded spatially with the thickest part of the tapetum. The horizontal visual streak was found over the horizontal line through the optic disc in the temporal half and extended slightly into the nasal half. The central area of the highest density of ganglion cells was approximately located midway between the nasal and temporal ends of the visual streak. The visual streak was located within the tapetal area, but ventrally to the thick part of the tapetum.


Assuntos
Cães/anatomia & histologia , Retina/citologia , Células Fotorreceptoras Retinianas Bastonetes/citologia , Animais , Cães/fisiologia
9.
J Morphol ; 276(3): 290-300, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25388857

RESUMO

In teleosts, the spinal cord generally extends along the entire vertebral canal. The Tetraodontiformes, in which the spinal cord is greatly reduced in length with a distinct long filum terminale and cauda equina, have been regarded as an aberration. The aims of this study are: 1) to elucidate whether the spinal cord in all tetraodontiform fishes shorten with the filum terminale, and 2) to describe the gross anatomical and histological differences in the spinal cord among all families of the Tetraodontiformes. Representative species from all families of the Tetraodontiformes, and for comparison the carp as a common teleost, were investigated. In the Triacanthodidae, Triacanthidae, and Triodontidae, which are the more ancestral taxa of the Tetraodontiformes, the spinal cord extends through the entire vertebral canal. In the Triacanthidae and Triodontidae, the caudal half or more spinal segments of the spinal cord, however, lack gray matter and consist largely of nerve fibers. In the other tetraodontiform families, the spinal cord is shortened forming a filum terminale with the cauda equina, which is prolonged as far as the last vertebra. The shortened spinal cord is divided into three groups. In the Ostraciidae and Molidae, the spinal cord tapers abruptly at the cranium or first vertebra forming a cord-like filum terminale. In the Monacanthidae, Tetraodontidae, and Diodontidae, it abruptly flattens at the rostral vertebrae forming a flat filum terminale. The spinal cord is relatively longer in the Monacanthidae than that in the other two families. It is suggested by histological features of the flat filum terminale that shortening of the spinal cord in this group progresses in order of the Monacanthidae, Tetraodontidae, and Diodontidae. In the Balistidae and Aracanidae, the cord is relatively long and then gradually decreased in dorso-ventral thickness.


Assuntos
Medula Espinal/anatomia & histologia , Tetraodontiformes/anatomia & histologia , Animais , Carpas/anatomia & histologia , Cauda Equina/anatomia & histologia , Especificidade da Espécie
10.
Microscopy (Oxf) ; 63 Suppl 1: i18, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25359810

RESUMO

Nanoparticles, which have multi-shell structure, are expected to be stable and high efficient for the light-emitting devices. The efficiency of luminescence is considered to be affected by the multi-shell structure. In order to understand the mechanism of high efficiency luminescence, it is necessary to evaluate the multi-shell structure and dielectric properties from each particle. High energy-resolution electron energy-loss spectroscopy (HR-EELS) based on TEM is a powerful tool for this purpose. By comparing between the experimental and the simulated results, it is possible to evaluate the effect of the size and physical property of each shell material on the dielectric properties of multi-shell nanoparticles. In this study, simulations of EELS spectra of multi-shell nanoparticle (core: CdSe, inner shell: CdS, outer shell: ZnS) and mono-shell nanoparticle (core: CdSe, shell: CdS) were conducted by the dielectric continuum theory[1].Figure 1 shows calculated EELS spectra of multi and mono shell nanoparticles. The spectra are calculated from dielectric functions of single CdSe, CdS and ZnS crystals, which were experimentally derived from HR-EELS spectra by using Kramers-Kronig analysis. The radius of 6.9 nm for the nanoparticle in the simulation corresponds to the average size of actual synthesized nanoparticles. Energy positions of arrows in the inset correspond to band gap energies of CdSe, CdS and ZnS[2]. In the spectrum of multi-shell nanoparticle, the intensity corresponding to interband transition near band gap of CdSe is suppressed comparing with that of the mono shell nanoparticle. This result indicates that ZnS outer shell affects the intensity profile of EELS spectrum near band gap. This effect should be sensitive for the thickness of the shells. Thus, there is a possibility that the effect of size and thickness of each core and shell on dielectric properties of multi-shell nanoparticles could be evaluated by using HR-EELS technique.jmicro;63/suppl_1/i18/DFU039F1F1DFU039F1Fig. 1.Calculated EELS spectra.

11.
Sci Rep ; 4: 7199, 2014 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-25425181

RESUMO

Wet chemical reduction of metal ions, a common strategy for synthesizing metal nanoparticles, strongly depends on the electric potential of the metal, and its applications to late transition metal clusters have been limited to special cases. Here, we describe copper nanoclusters grown by synchrotron radiolysis in concert with wet chemistry. The local structure of copper aggregates grown by reducing Cu(II) pentanedionate using synchrotron x-ray beam was studied in situ by x-ray absorption spectroscopy. A detailed analysis of the XANES and EXAFS spectra, compared with DFT calculations and full-potential non-muffin-tin multiple scattering calculations, identified the nanocluster as Cu13 with icosahedral symmetry. The novel "charged" nanoclusters tightly bound to electron-donating amido molecules, which formed as a result of photo-induced deprotonation of ligand amines, were stabilized by irradiation. Monodispersive deposition of nanoclusters was enabled by controlling the type and density of "monomers", in remarkable contrast to the conventional growth of metallic nanoparticles.

12.
J Vet Med Sci ; 2014 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-25141781

RESUMO

This article released online on July 30, 2014 as advance publication has been retracted by the Editorial Board of Journal of Veterinary Medical Science due to a violation of the journal's "Information for Authors".

13.
J Vet Med Sci ; 76(8): 1099-103, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24784162

RESUMO

We aimed to document macroscopic variations in the cellular tapetum in the dog, to provide a histologic description of the macroscopic results and to evaluate the correlation between the macroscopic appearance and aging. Fifty three dogs including 5 beagles, 1 Chihuahua and 47 mixed breeds of each gender were used. For a macroscopic study, the fresh tapetal fundi were photographed using digital camera. For a histological study, the glutaraldehyde-formalin fixed eyes were embedded in nitrocellulose and stained with hematoxylin-eosin or thionine. The normal tapetum was triangular with the rounded angles and the smooth contour. The atypical tapetum was smaller and more variable in shape, contour and color than the normal one. In severe cases, the fundus was devoid of the tapetum. The atypical tapetum tended to increase in frequency with aging. Retinal pigment epithelial cells on the normal tapetum were unpigmented. In the eye with the atypical tapetum, regardless of tapetal size and shape, unpigmented retinal pigment epithelial cells showed a similar distribution to that on the normal tapetum, even in a dog without a tapetum. Although there is a congenitally hypoplastic tapetum, the atypical tapetum tends to increase in incidence and severity with aging.


Assuntos
Envelhecimento/fisiologia , Cães/anatomia & histologia , Epitélio Pigmentado da Retina/anatomia & histologia , Epitélio Pigmentado da Retina/fisiologia , Animais , Feminino , Técnicas Histológicas/veterinária , Masculino , Epitélio Pigmentado da Retina/citologia
14.
Neurosci Lett ; 561: 118-22, 2014 Feb 21.
Artigo em Inglês | MEDLINE | ID: mdl-24394912

RESUMO

Central projections originated from a single dorsal root ganglion (DRG) were studied in the chicken focusing on the rostrocaudal extension of primary afferents in each lamina by using anterograde labeling by lectin-HRP injection into either the 15th or the 24th DRG. In the injection into the 15th DRG, labeled fibers (LFs) were found in a wide rostrocaudal range of laminas IV (the spinal segment (SS) 1-20) and V (SS 4-18) and in a narrow range of other laminas. In the injection into the 24th DRG, LFs were distributed in a similar rostrocaudal range in all laminas except for laminas VIII and IX. LFs in laminas VIII and IX were restricted in the tracer injected segment. LFs in the lateral funiculus derived from both the enlargements projected into the rostral lamina III in addition to the lower medulla oblongata. There was little overlap in the extent of the primary terminal areas from both the enlargements.


Assuntos
Vias Aferentes/fisiologia , Galinhas/fisiologia , Gânglios Espinais/fisiologia , Animais , Galinhas/anatomia & histologia , Região Lombossacral , Bulbo/fisiologia , Pescoço
15.
Mar Drugs ; 11(12): 5024-35, 2013 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-24335526

RESUMO

Chondroitin sulfate (CS) has been suggested to be involved in bone formation and mineralization processes. A previous study showed that squid-derived CS (sqCS) has osteoblastogenesis ability in cooperation with bone morphogenetic protein (BMP)-4 in vitro. However, in vivo, osteogenic potential has not been verified. In this study, we created a critical-sized bone defect in the rat calvaria and implanted sqCS-loaded gelatin hydrogel sponges (Gel) into the defect with or without BMP-4 (CS/BMP/Gel and CS/Gel, respectively). At 15 weeks, bone repair rate of CS/Gel-treated defects and CS/BMP/Gel-treated defects were 47.2% and 51.1%, respectively, whereas empty defects and defects with untreated sponges showed significantly less bone ingrowth. The intensity of von Kossa staining of the regenerated bone was less than that of the original one. Mineral apposition rates at 9 to 10 weeks were not significantly different between all treatment groups. Although bone repair was not completed, sqCS stimulated bone regeneration without BMP-4 and without external mesenchymal cells or preosteoblasts. Therefore, sqCS is a promising substance for promotion of osteogenesis.


Assuntos
Regeneração Óssea/fisiologia , Sulfatos de Condroitina/metabolismo , Decapodiformes/metabolismo , Osteogênese/fisiologia , Crânio/metabolismo , Crânio/fisiologia , Animais , Proteína Morfogenética Óssea 4/metabolismo , Gelatina/metabolismo , Hidrogel de Polietilenoglicol-Dimetacrilato/metabolismo , Masculino , Células-Tronco Mesenquimais/metabolismo , Células-Tronco Mesenquimais/fisiologia , Ratos , Ratos Wistar
16.
J Anat ; 223(5): 509-18, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24102505

RESUMO

The tapetum lucidum is a light-reflective tissue in the eyes of many animals. Many ungulates have a fibrous tapetum. The horse has one of the largest eyes of any living animal and also has excellent vision in low-light environments. This study aimed to clarify the macroscopic tapetal shape, relationship between the tapetal thickness and the degree of pigmentation of the retinal pigment epithelium (RPE), spatial relationship between the visual streak and the tapetum, and wavelength of the light reflected from the tapetum in the horse. Macroscopically, weak light revealed the tapetum as a horizontal band located dorsal to and away from the optic disc. The tapetum expanded dorsally as the illumination increased. The tapetal tissue consisted of lamellae of collagen fibrils running parallel to the retinal surface; these spread over almost the entire ocular fundus and were thicker in the horizontal band dorsal to the disc. Only the horizontal band of the tapetum was covered by unpigmented RPE, suggesting that this band reflects light and is responsible for mesopic and scotopic vision. The visual streak was located in the ventral part of the horizontal band, ventral to the thickest part of the tapetum. The wavelength of the light reflected from the horizontal band of the tapetum was estimated from the diameter and interfibrous distance of the collagen fibrils to be approximately 468 nm. Therefore, the light reflected from the tapetum should be more effectively absorbed by rods than by cones, and should not interfere with photopic vision.


Assuntos
Olho/anatomia & histologia , Cavalos/anatomia & histologia , Epitélio Pigmentado da Retina/anatomia & histologia , Animais , Colágeno/análise , Pigmentação , Epitélio Pigmentado da Retina/ultraestrutura
18.
Biomed Res ; 33(6): 355-61, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23268959

RESUMO

The aim of this study was to clarify the effects of myostatin, which is a negative regulator of skeletal muscle mass, on the proliferation of NIH3T3 fibroblasts and the synthesis of extracellular matrix (ECM) by them. A proliferation assay revealed that myostatin attenuated cell growth at any of the doses used. High doses of myostatin strongly inhibited cell proliferation. Moreover, myostatin receptor, activin receptor type-2B (ActRIIB), was found to be distributed on cells and it was also clarified that myostatin increased the expression of cyclin-dependent kinase inhibitor p21 (p21). These results suggested that a high dose of myostatin inhibits fibroblast proliferation by the same mechanism as that for inhibition of myoblast proliferation. We then examined the effects of myostatin on the mRNA expression of ECM molecules (decorin, biglycan, type I collagen, type III collagen, type IV collagen and type V collagen) by real-time PCR. Real-time PCR showed that myostatin increased the mRNA of decorin, biglycan and collagen (types I, IV and V) in fibroblasts. The results suggest that myostatin regulates ECM synthesis in cultured fibroblasts.


Assuntos
Proteínas da Matriz Extracelular/genética , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Miostatina/farmacologia , RNA Mensageiro/metabolismo , Receptores de Activinas Tipo II/genética , Receptores de Activinas Tipo II/metabolismo , Animais , Proliferação de Células , Inibidor de Quinase Dependente de Ciclina p21/genética , Inibidor de Quinase Dependente de Ciclina p21/metabolismo , Proteínas da Matriz Extracelular/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Células NIH 3T3 , Transporte Proteico
19.
Ann Anat ; 194(4): 329-33, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22405882

RESUMO

Cerebellar folia may increase in number in hypothyroid rats (Lauder et al., 1974; Hasebe et al., 2008a). In this study, we aimed to confirm the formation of an excess sublobule and to determine whether excess sublobules are consistently formed in conserved positions in hypothyroid rats. Instead of the foliation pattern partitioned by cerebellar fissures, we employed the bifurcation pattern of the internal granular layer for investigation of complexity of the cerebellar cortex in hypothyroid rats. The basic foliation pattern of the cerebellum was intact in hypothyroid rats, but lobules III to IX frequently showed an increase in the number of sublobules. The excess sublobules were mainly found in the folia and along the shallow region of the fissure. In other words, the excess sublobules were not located in random locations but rather in specific locations. The area in the internal granular layer of lobules V to IX was significantly larger than that in control rats. From the increased area of the internal granular layer it may be inferred that internal granular cells increase in number than those in normal rats. In our study, regions within the cerebellum that show an excess of sublobules correlate with regions that show an intermediate to late-forming internal granular layer (Altman, 1969). Our observations fit with the view that excess sublobules are formed by the external granular layer showing prolonged cell proliferation and hypothyroidism predominantly has an adverse impact on the intermediate to late phases in development of the internal granular layer.


Assuntos
Cerebelo/patologia , Hipotireoidismo/patologia , Rede Nervosa/patologia , Animais , Feminino , Humanos , Ratos
20.
J Vet Med Sci ; 74(4): 495-8, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22095164

RESUMO

The aim in this study is to elucidate the laterality of chicken spinocerebellar (SC) neurons that originate from the caudal cervical to caudal lumbosacral spinal cord. SC neurons in the spinal segment (SS) 17-20 consisted of a mixture of crossed and uncrossed axons. SC neurons in the more cranial and caudal SS than SS 17-20 (transitional zone) were generally uncrossed and crossed, respectively. In the transitional zone, SC neurons in spinal border cells and ventral border cells of the ventral horn changed dramatically from an uncrossed to a crossed type between SS 17 and SS 18. Chicken SC neurons are markedly different in laterality from mammalian SC neurons.


Assuntos
Galinhas/anatomia & histologia , Lateralidade Funcional/fisiologia , Neurônios/fisiologia , Medula Espinal/anatomia & histologia , Tratos Espinocerebelares/anatomia & histologia , Animais , Gatos , Galinhas/fisiologia , Histocitoquímica/veterinária , Neurônios/citologia , Medula Espinal/citologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...