Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 117
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Rev Sci Instrum ; 87(6): 065104, 2016 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-27370494

RESUMO

A gas circulation and purification system was developed at the RIKEN Radioactive Isotope Beam Factory that can be used for gas-cell-based low-energy RI-beam production. A high-flow-rate gas cell filled with one atmosphere of buffer gas (argon or helium) is used for the deceleration and thermalization of high-energy RI-beams. The exhausted buffer gas is efficiently collected using a compact dry pump and returned to the gas cell with a recovery efficiency of >97%. The buffer gas is efficiently purified using two gas purifiers as well as collision cleaning, which eliminates impurities in the gas. An impurity level of one part per billion is achieved with this method.

2.
Insect Mol Biol ; 23(2): 165-74, 2014 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-24237591

RESUMO

Insect haemocytes play significant roles in innate immunity. The silkworm, a lepidopteran species, is often selected as the model for studies into the functions of haemocytes in immunity; however, our understanding of the role of haemocytes remains limited because the lack of haemocyte promoters for transgene expression makes genetic manipulations difficult. In the present study, we aimed to establish transgenic silkworm strains expressing GAL4 in their haemocytes. First, we identified three genes with strong expression in haemocytes, namely, lp44, Haemocyte Protease 1 (HP1) and hemocytin. Transgenic silkworms expressing GAL4 under the control of the putative promoters of these genes were then established and expression was examined. Although GAL4 expression was not detected in haemocytes of HP1-GAL4 or hemocytin-GAL4 strains, lp44-GAL4 exhibited a high level of GAL4 expression, particularly in oenocytoids. GAL4 expression was also detected in the midgut but in no other tissues, indicating that GAL4 expression in this strain is mostly oenocytoid-specific. Thus, we have identified a promoter that enables oenocytoid expression of genes of interest. Additionally, the lp44-GAL4 strain could also be used for other types of research, such as the functional analysis of genes in oenocytoids, which would facilitate advances in our understanding of insect immunity.


Assuntos
Bombyx/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica , Hemócitos/metabolismo , Proteínas de Insetos/genética , Proteínas de Saccharomyces cerevisiae/genética , Fatores de Transcrição/genética , Animais , Animais Geneticamente Modificados/genética , Animais Geneticamente Modificados/imunologia , Animais Geneticamente Modificados/metabolismo , Bombyx/crescimento & desenvolvimento , Bombyx/imunologia , Bombyx/metabolismo , Proteínas de Ligação a DNA/metabolismo , Imunidade Inata , Proteínas de Insetos/metabolismo , Larva/genética , Larva/imunologia , Larva/metabolismo , Lectinas/genética , Lectinas/metabolismo , Regiões Promotoras Genéticas , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo
3.
Neuroscience ; 210: 137-44, 2012 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-22441034

RESUMO

The cerebellar uvula (lobule IX), a part of the vestibulocerebellum, is extensively connected to the areas of the brainstem that participate in cardiovascular regulation and vestibular signal processing. This suggests that the uvula regulates blood pressure (BP) during postural alterations. Previous studies showed that lesions of the uvula affected the baroreceptor reflex and cardiovascular responses during postural alterations. To investigate the mechanisms underlying this BP regulation, it is necessary to have a method to selectively modulate the activity of Purkinje cells (PCs), the sole output neurons from the cerebellar cortex, without affecting other neuronal types such as local interneurons or nonlocal neurons that send their axons to the cerebellar cortex. We recently developed a novel technique using optogenetics to manipulate PC activity and showed that activation and inhibition of PCs in the uvula either decreased or increased the resting BP, respectively. This technique was employed in the current study to examine the roles of the uvula in BP regulation during postural alterations in anesthetized rats. Enhanced Natronomonas pharaonis halorhodopsin (eNpHR), a light-driven chloride ion pump, was selectively expressed in uvular PCs using a lentiviral vector containing the PC-specific L7 promoter. The eNpHR-expressing PCs were then illuminated by orange laser (593 nm) either during 30° head-up or 30° head-down tilts. The eNpHR-mediated photoinhibition of the uvula attenuated the extent of BP recovery after a BP increase induced by postural changes during head-down tilts. By contrast, photoinhibition had no statistically significant effect on BP recovery during head-up tilts. The effects of photoinhibition on BP during tilts were significantly different from those observed during the resting condition, indicating that cerebellar control of BP during tilts is dynamic rather than static. Taken together, these results suggest that PCs in the uvula dynamically regulates BP maintenance during postural alterations.


Assuntos
Pressão Sanguínea/fisiologia , Técnicas Genéticas , Postura/fisiologia , Células de Purkinje/fisiologia , Animais , Halorrodopsinas/genética , Halorrodopsinas/metabolismo , Masculino , Ratos , Ratos Wistar , Reação em Cadeia da Polimerase em Tempo Real , Transfecção
4.
Insect Mol Biol ; 21(1): 49-60, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21988597

RESUMO

Most aphids show reproductive polyphenism, i.e. they alternate their reproductive modes from parthenogenesis to sexual reproduction in response to short photoperiods. Although juvenile hormone (JH) has been considered a likely candidate for regulating the transition from asexual to sexual reproduction after photoperiod sensing, there are few studies investigating the direct relationship between JH titres and the reproductive-mode change. In addition, the sequencing of the pea aphid genome has allowed identification of the genes involved in the JH pathway, which in turn allows us to examine their expression levels in relation to the reproductive-mode change. Using liquid chromatography-mass spectrometry in the pea aphid, JHIII titre was shown to be lower in aphids producing sexual morphs under short-day conditions than in aphids producing parthenogenetic morphs under long-day conditions. The expression levels of genes upstream and downstream of JH action were quantified by real-time quantitative reverse-transcription-PCR across the reproductive-mode change. The expression level of JH esterase, which is responsible for JH degradation, was significantly higher in aphids reared under short-day conditions. This suggests that the upregulation of the JH degradation pathway may be responsible for the lower JHIII titre in aphids exposed to short-days, leading to the production of sexual morphs.


Assuntos
Afídeos/metabolismo , Sesquiterpenos/metabolismo , Animais , Afídeos/genética , Hidrolases de Éster Carboxílico/genética , Hidrolases de Éster Carboxílico/metabolismo , Feminino , Masculino , Partenogênese , Fotoperíodo
5.
Theriogenology ; 74(8): 1499-503, 2010 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-20615533

RESUMO

Although the Tsushima leopard cat (Prionailurus bengalensis euptilurus) is one of the most endangered mammals in Japan, its reproductive physiology and endocrinology have been not elucidated. The objective was to establish the non-invasive monitoring of reproductive endocrinology in a female Tsushima leopard cat and to identify the types of fecal reproductive steroid metabolites in this species. Fecal concentrations of estrogen and progestin were determined by enzyme immunoassays, from 60 d before to 60 d after the last copulation, during three pregnancies. Fecal estrogen metabolite concentrations were increased before/around the mating period and after mid-pregnancy. Fecal progestin metabolite concentrations increased after the last copulation and remained high during pregnancy. The gestation period was 65.0 ± 0.6 d (mean ± SD). Fecal extracts were separated by high-performance liquid chromatography for identification of fecal metabolites. Fecal estrogens were identified as estradiol-17ß and estrone. Fecal progestins during pregnancy contained 5α-reduced pregnanes: 5α-pregnan-3α-ol-20-one, 5α-pregnan-3ß-ol-20-one and 5α-pregnan-3,20-dione, and nonmetabolized progesterone was barely detected in feces. In conclusion, measurement of fecal estrogen and progestin metabolites was effective for noninvasive reproductive monitoring in the Tsushima leopard cat. An immunoassay for fecal estradiol-17ß concentrations seemed useful to monitor follicular activity, whereas an immunoassay with high cross reactivity for 5α-reduced pregnanes was useful to monitor ovarian luteal activity and pregnancy.


Assuntos
Estrogênios/metabolismo , Fezes/química , Felidae/fisiologia , Progestinas/metabolismo , Animais , Cromatografia Líquida de Alta Pressão , Espécies em Perigo de Extinção , Estrogênios/química , Felidae/metabolismo , Feminino , Gravidez , Progestinas/química
6.
Insect Mol Biol ; 19(4): 527-35, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20522120

RESUMO

Juvenile hormone esterases (JHEs) are required for the degradation of juvenile hormones (JHs) in insects. Here, we report the cloning and analysis of the jhe gene in the red flour beetle, Tribolium castaneum, a model insect of Coleoptera. The Tcjhe gene was strongly expressed at the final instar larva, as would be expected if it functioned to decrease the JH titer at this stage. A recombinant TcJHE protein efficiently degraded JH III, suggesting that the enzyme functions in vivo as a JH-specific degradation enzyme. This is the first report describing the developmental expression profile of the jhe gene whose enzymatic activity was shown in Coleoptera, and the new data reported here will aid elucidation of the mechanism of JH titer regulation in insects.


Assuntos
Hidrolases de Éster Carboxílico/genética , Tribolium/enzimologia , Tribolium/genética , Sequência de Aminoácidos , Animais , Hidrolases de Éster Carboxílico/química , Hidrolases de Éster Carboxílico/metabolismo , Clonagem Molecular , Éxons/genética , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Íntrons/genética , Cinética , Dados de Sequência Molecular , Filogenia , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Tribolium/crescimento & desenvolvimento
7.
Insect Mol Biol ; 19(3): 399-408, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20337748

RESUMO

Juvenile hormone epoxide hydrolases (JHEHs) degrade juvenile hormones (JHs) and are important for JH titre regulation. Here, we report the cloning and analysis of five jheh-related (jheh-r1-r5) genes in the red flour beetle, Tribolium castaneum, a model species for the coleopteran insects. T. castaneum JHEH-r (TcJHEH-r) proteins show high homology to lepidopteran JHEHs and also to human microsomal epoxide hydrolase. In the phylogenetic tree, Tcjheh-rs were clustered, and interestingly, they were also clustered in the genome. Examination of enzymatic activities using recombinant TcJHEH-r proteins showed that TcJHEH-r3 had strong degradation activity for JH III, whereas TcJHEH-r4 had weak activity. The study has yielded significant information that will facilitate further analysis of JHEHs and epoxide hydrolases.


Assuntos
Epóxido Hidrolases/genética , Tribolium/enzimologia , Tribolium/genética , Sequência de Aminoácidos , Animais , Clonagem Molecular , Ensaios Enzimáticos , Epóxido Hidrolases/química , Epóxido Hidrolases/metabolismo , Éxons/genética , Etiquetas de Sequências Expressas , Genoma/genética , Íntrons/genética , Dados de Sequência Molecular , Filogenia , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Análise de Sequência de Proteína
8.
Insect Mol Biol ; 19(3): 291-301, 2010 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-20041962

RESUMO

The lipid modifications which occur on Bombyx mori Ras proteins BmRas1, BmRas2 and BmRas3 were studied by metabolic labelling in an insect cell-free protein synthesis system and in a baculovirus expression system, using specific inhibitors of protein prenylation and protein palmitoylation. In addition, the subcellular localization of BmRas proteins was examined using EGFP fusion proteins of constitutively active forms of BmRas proteins transiently expressed in Sf9 cells. As a result, it was revealed that the three B. mori Ras proteins BmRas1, BmRas2 and BmRas3 are neither farnesylated nor palmitoylated but are geranylgeranylated for localization to the plasma membrane of insect cells. Thus, the mechanism of membrane binding of insect Ras proteins is quite different from that reported for mammalian Ras proteins.


Assuntos
Bombyx/metabolismo , Proteínas de Insetos/metabolismo , Lipoilação , Prenilação , Proteínas ras/metabolismo , Sequência de Aminoácidos , Animais , Baculoviridae/genética , Bombyx/citologia , Linhagem Celular , Membrana Celular/metabolismo , Sistema Livre de Células , Evolução Molecular , Vetores Genéticos/genética , Humanos , Proteínas de Insetos/química , Proteínas de Insetos/genética , Dados de Sequência Molecular , Biossíntese de Proteínas , Transporte Proteico , Coloração e Rotulagem , Proteínas ras/química , Proteínas ras/genética
9.
Proc Natl Acad Sci U S A ; 103(18): 6988-93, 2006 May 02.
Artigo em Inglês | MEDLINE | ID: mdl-16627621

RESUMO

Histone acetylation affects many nuclear processes including transcription, chromatin assembly, and DNA damage repair. Acetylation of histone H3 lysine 56 (H3 K56ac) in budding yeast occurs during mitotic S phase and persists during DNA damage repair. Here, we show that H3 K56ac is also present during premeiotic S phase and is conserved in fission yeast. Furthermore, the H3 K56ac modification is not observed in the absence of the histone chaperone Asf1. asf1delta and H3 K56R mutants exhibit similar sensitivity to DNA damaging agents. Mutational analysis of Asf1 demonstrates that DNA damage sensitivity correlates with (i) decreased levels of H3 K56ac and (ii) a region implicated in histone binding. In contrast, multiple asf1 mutants that are resistant to DNA damage display WT levels of K56ac. These data suggest that maintenance of H3 K56 acetylation is a primary contribution of Asf1 to genome stability in yeast.


Assuntos
Proteínas de Ciclo Celular/metabolismo , Histonas/metabolismo , Lisina/metabolismo , Meiose/fisiologia , Chaperonas Moleculares/metabolismo , Fase S/fisiologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Acetilação , Proteínas de Ciclo Celular/química , Proteínas de Ciclo Celular/genética , Dano ao DNA , Modelos Moleculares , Chaperonas Moleculares/genética , Fenótipo , Conformação Proteica , Saccharomyces cerevisiae/citologia , Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/metabolismo , Proteínas de Saccharomyces cerevisiae/química , Proteínas de Saccharomyces cerevisiae/genética , Esporos Fúngicos/metabolismo
10.
Anim Reprod Sci ; 95(1-2): 134-43, 2006 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-16289554

RESUMO

The Japanese black bear (Ursus thibetanus japonicus) is an endangered species in some areas of Japan, and semen collection and cryopreservation are important means to preserve genetic resources and prevent extinction. The aim of the present study was to improve the methods for electroejaculation and cryopreservation in these bears. We collected the semen from captive mature Japanese black bears during the mating season by the electroejaculation method using maximum stimulus voltages of 10 V (n=9) and 7 V (n=15), and compared the characteristics of fresh semen after collection. None of the variables examined (i.e. total sperm count, motility, viability, morphology, and rate of urine contamination) were statistically different between the two electro-stimulus voltages. After the semen obtained was cryopreserved, the effects of three different diluents (egg yolk-TRIS-citrate-glucose, egg yolk-TRIS-citrate-fructose, and egg yolk-TRIS-citrate-fructose-lactose-raffinose; n=10) and two different incubation times (1-1 and 3-0 h of cooling-glycerol equilibration times; n=12) on frozen-thawed spermatozoa. None of the variables examined (i.e. motility, viability and morphology) were statistically different among the three diluents and between the two incubation times. The results indicate that, in the collection and cryopreservation of Japanese black bear semen: (1) a maximum voltage of 7 V may be enough to obtain ejaculates; (2) the three diluents examined were useful; and (3) glycerol equilibration time may be omitted with prior cooling for 3h.


Assuntos
Criopreservação/veterinária , Preservação do Sêmen/veterinária , Sêmen , Ursidae/fisiologia , Acrossomo/fisiologia , Animais , Sobrevivência Celular/fisiologia , Conservação dos Recursos Naturais , Criopreservação/métodos , Ejaculação/fisiologia , Estimulação Elétrica , Japão , Masculino , Preservação do Sêmen/métodos , Contagem de Espermatozoides/veterinária , Motilidade dos Espermatozoides/fisiologia
11.
Rev Sci Tech ; 22(3): 873-7, 2003 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-15005545

RESUMO

A study was conducted to determine the prevalence of bovine herpesvirus-1 (BHV-1), which causes infectious bovine rhinotracheitis, in cattle destined for market in Southern Province, Zambia. A total of 116 nasal secretion samples were tested using the direct fluorescent antibody test, while blood samples from the same cattle were examined by a commercial enzyme-linked immunosorbent assay kit. The prevalence of the BHV-1 antigens in cattle was 23.28% (27/116), while the mean prevalence of the BHV-1 antibodies was 48.28% (56/116). This study showed that cattle in transit to markets could easily spread the virus, which was reactivated by the stress of trekking for long distances under unfavourable conditions, to the other cattle with which they came into contact. Thus, these transit cattle posed a serious threat to other bovines. Systems of cattle trading where cattle must be transported a long wayto market should be reviewed by the authorities to minimise the conditions that may exacerbate the spread of infection.


Assuntos
Anticorpos Antivirais/sangue , Antígenos Virais/análise , Herpesvirus Bovino 1/imunologia , Rinotraqueíte Infecciosa Bovina/epidemiologia , Animais , Bovinos , Ensaio de Imunoadsorção Enzimática/veterinária , Técnica Direta de Fluorescência para Anticorpo/veterinária , Herpesvirus Bovino 1/isolamento & purificação , Mucosa Nasal/virologia , Prevalência , Zâmbia/epidemiologia
12.
Ann Hematol ; 81(10): 588-92, 2002 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-12424541

RESUMO

We report here three cases of peripheral T-cell lymphoma unspecified (PTCL-US), which presented with bone marrow infiltration and hepatosplenomegaly and were successfully treated with high-dose chemotherapy (HDCT) and autologous peripheral blood stem cell transplantation (auto-PBSCT). The patients were all characterized by cytokine-induced symptoms such as fever, anasarca, cytopenia, poor general condition, and disseminated intravascular coagulation syndrome. Laboratory data showed extremely high levels of soluble interleukin-2 receptor, beta(2)-microglobulin, and ferritin. All three patients were negative for anti-adult T-cell leukemia antibody. In one patient, hemophagocytosis was revealed by a histological examination of the bone marrow. The International Prognostic Index was high for all three patients, and they all achieved complete remission after the intensive chemotherapy for remission induction. During complete remission, they were treated with HDCT [modified interleukin-converting enzyme regimen] followed by auto-PBSCT. The recovery of hematopoiesis after auto-PBSCT was prompt and sustained engraftment was obtained. No serious adverse effects other than myelosuppression were noted. One patient died due to cerebrovascular disease without relapse 18 months after auto-PBSCT. The other two patients are still alive and have not suffered from relapse. Our observations suggest that auto-PBSCT following HDCT may be an effective and safe therapeutic modality for high-risk PTCL-US patients characterized by hepatosplenomegaly and cytokine-induced syndrome.


Assuntos
Protocolos de Quimioterapia Combinada Antineoplásica/administração & dosagem , Linfoma de Células T Periférico/terapia , Transplante de Células-Tronco de Sangue Periférico , Idoso , Citocinas/sangue , Feminino , Rearranjo Gênico , Genes Codificadores da Cadeia beta de Receptores de Linfócitos T , Hepatomegalia/terapia , Humanos , Linfoma de Células T Periférico/complicações , Masculino , Pessoa de Meia-Idade , Esplenomegalia/terapia , Transplante Autólogo
13.
Ann Hematol ; 81(4): 224-7, 2002 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11976826

RESUMO

We experienced a rare case of a lymphomatous polyp of mantle cell type forming a polypoid mass lesion in the duodenum bulbous together with advanced gastric cancer. A total gastrectomy was performed, and the specimen revealed atypical small- to medium-sized lymphoid cells with indented nuclei, which infiltrated the Peyer's patch and formed a nodular mass in the lamina propria and submucosa of the duodenum. The lymphoma cells also infiltrated the lymphoid follicle of the gastric mucosa, spleen, and regional lymph node with a typical mantle zone pattern. Flow cytometric analysis of the single cells of the lymph node and immunohistochemistry of a paraffin-embedded specimen revealed that the lymphoma cells expressed surface CD5, CD19, CD20, and nuclear cyclin D1. Chromosomal analysis of this single cell suspension revealed that these lymphoma cells have trisomy 3 in conjunction with t(11;14)(q13;q32), which is frequently seen in mucosa-associated lymphoid tissue lymphomas (MALToma) in the stomach and is also reported in mantle cell lymphoma as a secondary genetic alteration. Our report suggests that trisomy 3 may be a common chromosomal abnormality in lymphomatous polyps of mantle cell type.


Assuntos
Cromossomos Humanos Par 11 , Cromossomos Humanos Par 14 , Neoplasias Duodenais/patologia , Pólipos Intestinais/patologia , Linfoma de Célula do Manto/patologia , Neoplasias Gástricas/patologia , Translocação Genética , Adenocarcinoma/diagnóstico , Adenocarcinoma/genética , Adenocarcinoma/patologia , Cromossomos Humanos Par 3 , Células Clonais/imunologia , Células Clonais/patologia , Análise Citogenética , Neoplasias Duodenais/diagnóstico , Neoplasias Duodenais/genética , Humanos , Imunofenotipagem , Pólipos Intestinais/diagnóstico , Pólipos Intestinais/genética , Linfoma de Célula do Manto/diagnóstico , Linfoma de Célula do Manto/genética , Masculino , Pessoa de Meia-Idade , Invasividade Neoplásica/patologia , Segunda Neoplasia Primária/diagnóstico , Segunda Neoplasia Primária/genética , Segunda Neoplasia Primária/patologia , Neoplasias Gástricas/diagnóstico , Neoplasias Gástricas/genética , Trissomia
14.
Biol Reprod ; 65(4): 1006-13, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11566720

RESUMO

We examined changes in the concentrations of serum progesterone (P4), estradiol-17beta (E2), FSH, LH, prolactin (PRL), and inhibin to determine their interaction and their effect on the reproductive endocrine controls of pregnant and nonpregnant female Japanese black bears. Fourteen female bears were used in this study over a 2-yr period. In the first year, six of the bears were divided into two groups; a pseudopregnant group and a nonpregnant group. In the second year, the remaining eight bears were also divided into two groups; a pregnant group and a nonpregnant group. Pregnant and pseudopregnant bears had similar P4 trends with both groups exhibiting a significant increase in December, which is the suspected time of implantation in pregnant bears. These trends correlated with an increase in PRL levels, whereas low levels of LH were maintained throughout the year. Nonpregnant bears maintained low concentrations of P4, and compared with pregnant and pseudopregnant bears, they also exhibited a delayed elevation in PRL. Luteinizing hormone activity varied among individual animals, but regardless of reproductive status, fluctuation patterns of E2, FSH, and inhibin did not differ among bears. Our results suggest that PRL may play a luteotropic role in both pregnant and pseudopregnant bears, and is possibly responsible for inducing reactivation of the dormant corpus luteum that precedes implantation in the Japanese black bear.


Assuntos
Hormônios Esteroides Gonadais/sangue , Gonadotropinas Hipofisárias/sangue , Inibinas/sangue , Prolactina/sangue , Ursidae/sangue , Animais , Estradiol/sangue , Feminino , Hormônio Foliculoestimulante/sangue , Hormônio Luteinizante/sangue , Gravidez , Progesterona/sangue , Pseudogravidez/sangue , Estações do Ano
16.
J Vet Med Sci ; 63(3): 315-8, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11307933

RESUMO

Exposure and ecological risks to heavy metals (copper, zinc, manganese, iron) at Lochnivar and Blue Lagoon National Parks in wildlife dependent on the Kafue river contaminated with mining waste was evaluated. Samples included water, fish, grasses and Kafue Lechwe (Kobus leche kafuensis) liver. At both parks copper ranged from 0.03-0.04 mg/l; 3.0-6.0 mg/kg; 11.0-44.0 mg/kg; trace -199.0 mg/kg; while zinc was 0.01 mg/l; 32.0-82.0 mg/kg; 15.0-21.0 mg/kg; and 52.0-138.0 mg/kg; in water, fish, grasses and lechwe, respectively. Manganese ranges were 0.15-0.16 mg/l; 7.0-18.0 mg/kg; 51.0-145.0 mg/kg; and 40.0-53.0 mg/kg while iron ranges were 0.13-0.14 mg/l; 26.0-134.0 mg/kg; 1766.0-1797.0 mg/kg; and 131.0-856.0 mg/kg; in water, fish, grasses and lechwe, respectively. Levels in all samples except water were high indicating potential for adverse effects.


Assuntos
Antílopes/fisiologia , Exposição Ambiental , Peixes/fisiologia , Metais Pesados/análise , Poluentes Químicos da Água/análise , Animais , Água Doce/análise , Resíduos Industriais , Fígado/química , Metais Pesados/toxicidade , Mineração , Poaceae/química , Zâmbia
17.
Reproduction ; 121(4): 587-94, 2001 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-11277879

RESUMO

The Japanese black bear, Ursus thibetanus japonicus, is a seasonal breeder and shows delayed implantation for several months during pregnancy. The objective of this study was to clarify the steroidogenic capability of the corpus luteum and placenta during pregnancy, including both delayed implantation and fetal development, by immunolocalization of steroidogenic enzymes in these organs of the Japanese black bear. Ovaries and placentae from 15 wild Japanese black bears, which had been killed legally by hunters and were thought to be pregnant, were used in an immunocytochemical study to localize the cholesterol side chain cleavage cytochrome P450 (P450scc), 3beta-hydroxysteroid dehydrogenase (3betaHSD), 17alpha-hydroxylase cytochrome P450 (P450c17) and aromatase cytochrome P450 (P450arom) by the avidin-biotin-peroxidase complex method using polyclonal antisera raised in mammals against P450scc, 3betaHSD, P450c17 and P450arom. P450scc and 3betaHSD were localized in all luteal cells throughout pregnancy. P450c17 was present in a few luteal cells, especially in the outer area of the corpus luteum throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. Cells positively immunostained for P450c17 were significantly smaller than negatively immunostained cells (P < 0.01). P450arom was present sporadically in a few luteal cells throughout pregnancy, but the number of positively immunostained cells decreased during the post-implantation period. The size of cells positively immunostained for P450arom was not significantly different from that of negatively immunostained cells. The whole placenta was negatively immunostained for P450scc, 3betaHSD and P450c17, but P450arom was present in the syncytiotrophoblasts and endothelial cells of maternal blood vessels. These results indicate that, in the Japanese black bear, corpora lutea are a source of progesterone which may play an important role in the maintenance of delayed implantation and fetal development during pregnancy. Corpora lutea have a minimum capability to synthesize androgen in small luteal cells and oestrogen in normal-sized luteal cells during pregnancy, and placentae have the ability to synthesize oestrogen during late pregnancy.


Assuntos
Corpo Lúteo/enzimologia , Placenta/enzimologia , Esteroides/biossíntese , Ursidae/metabolismo , 3-Hidroxiesteroide Desidrogenases/análise , Animais , Aromatase/análise , Enzima de Clivagem da Cadeia Lateral do Colesterol/análise , Implantação do Embrião , Desenvolvimento Embrionário e Fetal , Feminino , Técnicas Imunoenzimáticas , Ovário/enzimologia , Gravidez , Estações do Ano , Esteroide 17-alfa-Hidroxilase/biossíntese , Esteroide Hidroxilases/análise , Trofoblastos/enzimologia
18.
Theriogenology ; 55(3): 717-31, 2001 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-11245261

RESUMO

This study characterized semen collected from the Japanese black bear, Ursus thibetanus aponicus, to provide information on semen cryopreservation for artificial breeding. Preliminary studies using a beagle dog as the model species showed that sperm concentration and total sperm count were lower in semen collected by electroejaculation than in semen collected by digital manipulation, but that sperm motility, viability and morphology were similar. Characterization of semen obtained from Japanese black bears by electroejaculation under general anesthesia revealed that semen volume and total number of spermatozoa collected were lower; but that sperm concentration, motility, viability and morphology were equivalent to those reported in other ursids. When semen was collected via a catheter inserted into the urethra during the stimulation for ejaculation, the sperm concentration, total sperm count and motility were relatively higher than when semen was collected directly in a test tube. Specific normal semen characteristics (mean +/- SEM) were pH, 7.6 +/- 0.0; volume, 0.212 +/- 0.038 mL; sperm concentration, 361 +/- 100 x 10(6)/mL; total sperm count, 84.0 +/- 32.2 x 106; +++ motility, 30 +/- 5%; motility, 77 +/- 3%; viability 77 +/- 2%; and abnormal morphology, 11+/- 2%. These results suggest that semen can be collected from Japanese black bears by electroejaculation.


Assuntos
Cães/fisiologia , Sêmen/fisiologia , Coleta de Tecidos e Órgãos/veterinária , Ursidae/fisiologia , Animais , Criopreservação , Cães/sangue , Ejaculação , Estimulação Elétrica , Masculino , Preservação do Sêmen , Testosterona/sangue , Ursidae/sangue
20.
J Org Chem ; 65(14): 4326-4332, 2000 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-10891133

RESUMO

The beta-ethoxy-alpha-phosphonovinyl anion, generated from beta-(ethoxy)vinylphosphonate 1 and LDA, reacted with aldehydes and ketones or phenyl isocyanate to give the corresponding allylic alcohols 2a-m or 1,3-diphenyl-5-phosphonouracil 4 in good or moderate yields. Treatment of the alcohols 2a-d,g,h,j with trifluoroacetic acid led to alpha-formylvinylphosphonates 5a-d,g,h,j in excellent yields. Synthetic application of the alpha-formylvinylphosphonates 5a-d,g,h to phosphono-substituted heterocyclic compounds was studied.

SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...