Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 18 de 18
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Poult Sci ; 86(1): 118-22, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-17179425

RESUMO

Inulin, a prebiotic, is a fermentable oligosaccharide that may affect the intestinal mucosal architecture and the electrophysiological parameters. The effects of a diet with added inulin were tested on the jejunal morphology and electrogenic transport of Glc and Gln from the jejunal mucosa in broilers. Short-circuit current and transmucosal tissue resistance of jejunal flaps were measured in Ussing chambers. The feeding experiment was carried out in broilers (n = 40) using 1% inulin with an application period of 5 wk. The inulin-containing diet resulted in longer jejunal villi (P < 0.05) and deeper crypts (P < 0.01) than in control birds without affecting villus:crypt depth. Basal short-circuit current value remained unaffected by dietary treatment. Inulin supplementation did not modify the electrogenic transport of Glc and Gln in the jejunal mucosa. The basal value of transmucosal tissue resistance was significantly lower (P < 0.001) in the inulin-fed group compared with the control group. In conclusion, inulin supplementation affected the jejunal mucosal architecture but did not modify the electrogenic transport of Glc and amino acid under present experimental condition.


Assuntos
Galinhas/anatomia & histologia , Glucose/metabolismo , Glutamina/metabolismo , Inulina/farmacologia , Jejuno/anatomia & histologia , Jejuno/efeitos dos fármacos , Sódio/metabolismo , Ração Animal , Fenômenos Fisiológicos da Nutrição Animal , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Galinhas/metabolismo , Dieta/veterinária , Inulina/administração & dosagem , Jejuno/metabolismo
2.
Mol Reprod Dev ; 68(3): 327-34, 2004 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-15112326

RESUMO

The nucleolus formation was studied as an indirect marker of the ribosomal RNA (rRNA) genes activation in porcine embryos following oocyte maturation, fertilization, and culture in vitro. Nucleologenesis was assessed by transmission electron microscopy (TEM), light microscopical autoradiography following 20 min of 3H-uridine incubation, and immunocytochemical localization of key nucleolar proteins involved in rRNA transcription (upstream binding factor (UBF), topoisomerase I, and RNA polymerase I) and processing (fibrillarin, nucleophosmin, nucleolin) by confocal laser scanning microscopy. During the first four post-fertilization cell cycles, TEM revealed spherical nucleolus precursor bodies (NPBs), consisting of densely packed fibrils, as the most prominent intra-nuclear entities of the blastomeres. Fibrillo-granular nucleoli were observed in some blastomeres in a single embryo during the 5th cell cycle, i.e., the tentative 16-cell stage, where formation of fibrillar centres (FC), a dense fibrillar component, and a granular component on the surface of the NPBs was seen. In this embryo, autoradiographic labeling was detected over the nucleoplasm and in particular over the nucleoli. Fibrillarin was immunocytochemically localized in the presumptive NPBs of the pronuclei. This protein was again localized to the presumptive NPBs together with nucleolin from late during the 3rd cell cycle, i.e., the four-cell stage in some embryos. UBF, RNA polymerase I, and nucleophosmin were localized to the presumptive NPBs in a proportion of the embryos at the 4th cell cycle, i.e., the tentative eight-cell stage and onwards. Toposiomerase I was not localized to intra-nuclear entities even during the 5th post-fertilization cell cycle. Moreover, a considerable proportion of the blastomere nuclei apparently did not show localization of other nucleolar proteins. In conclusion, porcine embryos produced in vitro display a substantial delay in or even lack of the development of functional nucleoli.


Assuntos
Blastômeros/ultraestrutura , Nucléolo Celular/ultraestrutura , Embrião de Mamíferos/ultraestrutura , Fertilização in vitro , Proteínas Nucleares/metabolismo , Suínos , Animais , Autorradiografia , Blastômeros/metabolismo , Nucléolo Celular/metabolismo , Proteínas Cromossômicas não Histona/metabolismo , DNA Topoisomerases Tipo I/genética , DNA Topoisomerases Tipo I/metabolismo , Embrião de Mamíferos/metabolismo , Imuno-Histoquímica , Microscopia Confocal , Microscopia Eletrônica de Transmissão , Proteínas Nucleares/genética , Nucleofosmina , Fosfoproteínas/metabolismo , Proteínas Pol1 do Complexo de Iniciação de Transcrição/genética , Proteínas Pol1 do Complexo de Iniciação de Transcrição/metabolismo , RNA Polimerase I/genética , RNA Polimerase I/metabolismo , RNA Ribossômico/genética , Proteínas de Ligação a RNA/metabolismo , Transcrição Gênica , Nucleolina
3.
Vet Parasitol ; 119(1): 37-50, 2004 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-15036575

RESUMO

Local and systemic immune responses were studied in six dogs experimentally infected with the dog/sheep tapeworm Echinococcus granulosus. All dogs developed similar IgG antibody response to parasite antigens. In contrast, IgE and IgA responses differed widely. No relationship between IgA responses and parasite burden at the end of the infection were observed. Further, clear differences in the anti-parasite IgA response in serum as compared with specific IgA forming cells in mesenteric lymph nodes were observed within the same dog. An inverse association of anti-parasite IgE and parasite load seemed to be present, with the strongest IgE response in the one dog that had no worms in the intestine at the end of the experiment. No differences were observed in the numbers of intestinal mast cells and goblet cells among all infected dogs. However, the dog with no detectable parasite load had a marked reduction of detected mast cells in the submuscular and muscular layer of the mucosa. Our data give new insight into the immune response of dogs during E. granulosus infection and provide information that may be useful for the rational design of vaccines for the control of hydatid disease.


Assuntos
Doenças do Cão/imunologia , Doenças do Cão/parasitologia , Equinococose/imunologia , Equinococose/veterinária , Echinococcus/imunologia , Animais , Anticorpos Anti-Helmínticos/sangue , Western Blotting/veterinária , Contagem de Células/veterinária , Cães , Equinococose/parasitologia , Ensaio de Imunoadsorção Enzimática/veterinária , Células Caliciformes/imunologia , Células Caliciformes/parasitologia , Histocitoquímica/veterinária , Isotipos de Imunoglobulinas/sangue , Intestino Delgado/imunologia , Intestino Delgado/parasitologia , Linfonodos/imunologia , Linfonodos/parasitologia , Mastócitos/imunologia , Mastócitos/parasitologia , Nódulos Linfáticos Agregados/imunologia , Nódulos Linfáticos Agregados/parasitologia
4.
Mycotoxin Res ; 19(1): 77-81, 2003 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-23604675

RESUMO

100 turkey poults (1 day of age) were housed in 16 boxes, each containing 6-7 animals. In each case 4 boxes constituted 4 feeding groups. One was the control group and the other three received a feed containing different quantities of the mycotoxin moniliformin (0.8; 1.6; 2.4 mg/kg) and beauvericin (0.8; 1.7; 2.5 mg/kg). The animals were fed for 12 weeks and then slaughtered. Pieces of the heart were examined by routine histology. The microscopical evaluation showed cell infiltration into the heart muscle and alterations of the heart muscle. However, a relation could be detected between the mycotoxin concentration in the feed and the frequency and the quality of heart alterations.

5.
Reprod Suppl ; 58: 175-89, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11980189

RESUMO

Embryo technological procedures such as in vitro production and cloning by nuclear transfer are not as advanced in pigs as in cattle and cannot yet be applied under field conditions. The present paper focuses on genome activation in in vivo-derived, in vitro-produced and nuclear transfer pig embryos with special emphasis on the development of embryonic nucleoli, where the ribosomal RNA (rRNA) genes transcribed can be used as markers for genome activity. In addition, contemporary data on gene expression in in vivo-derived pig embryos are reviewed. In in vivo-derived pig embryos, pronounced transcription is initiated at the four-cell stage (the third cell cycle after fertilization), when nucleoli develop. In parallel with the development of the nucleoli as a result of rRNA gene activation, a cascade of other genes is also likely to be transcribed. However, apart from identification of transcripts for the oestrogen receptor at the blastocyst stage, reports on mRNAs resulting from initial transcription of the pig embryonic genome are lacking, in contrast to the situation in cattle and, in particular, mice. More information is available on gene expression during elongation of pig conceptuses, when the genes for steroidogenic enzymes, extracellular matrix receptors, oestrogen receptors, growth factors and their receptors, as well as retinol binding protein and retinoic acid receptors, are expressed. Nucleolus development appears to be disturbed in in vitro-produced pig embryos and in pig embryos reconstructed by nuclear transfer of granulosa cells to enucleated metaphase II oocytes produced by oocyte maturation in vivo or in vitro, which is indicative of disturbances in activation of rRNA genes.


Assuntos
Blastocisto/fisiologia , Implantação do Embrião/genética , Suínos/fisiologia , Animais , Clonagem de Organismos , Desenvolvimento Embrionário/genética , Desenvolvimento Embrionário e Fetal/fisiologia , Feminino , Expressão Gênica , Técnicas de Transferência Nuclear , Gravidez
6.
Mycotoxin Res ; 17 Suppl 1: 37-40, 2001 Mar.
Artigo em Alemão | MEDLINE | ID: mdl-23605756

RESUMO

Four groups of 16 cyclic sows were fed with 50, 100, 500 or 1000 µg zearalenone per kg feed for 10 days. Afterwards the genital organs were examined routine histologically and lectinhistochemically. Alterations of the lectin binding pattern of the glandular and surface epithelial cells was seen in all four groups, while the routine histology often showed normal results by the two lower concentrations. Macroscopically detectable organ alterations were seen only in the two groups with the highest concentration steps, but not constantly. Clinical symptoms of hyperestrogenismen were very seldom seen.

7.
Anim Reprod Sci ; 60-61: 49-60, 2000 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-10844184

RESUMO

Transcription of ribosomal RNA (rRNA) genes occurs in the nucleolus resulting in ribosome synthesis. In cattle and swine embryos, functional ribosome-synthesizing nucleoli become structurally recognizable towards the end of the fourth and third post-fertilization cell cycle, respectively. In cattle, a range of important nucleolar proteins become localized to the nucleolar anlage over several cell cycles and this localization is apparently completed towards the end of the fourth cell cycle. In swine, the localization of these proteins to the anlage is more synchronous and occurs towards the end of the third cell cycle and is apparently completed at the onset of the fourth. The rRNA gene activation and the associated nucleolus formation may be used as a marker for the activation of the embryonic genome in mammalian embryos and, thus, serve to evaluate the developmental potential of embryos originating from different embryo technological procedures. By this approach, we have demonstrated that in vitro produced porcine embryos display a lack of localization of nucleolar proteins to the nucleolar anlage as compared with in vivo developed counterparts. Similarly, bovine embryos produced by nuclear transfer from morulae display such deviations as compared with in vitro produced counterparts. Collectively, this information may help to explain the appearance of abnormalities seen in a certain proportion of offspring derived from in vitro produced embryos and after cloning.


Assuntos
Bovinos/embriologia , Desenvolvimento Embrionário/genética , RNA Ribossômico/genética , Suínos/embriologia , Animais , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Gravidez , Ativação Transcricional
8.
Hum Reprod ; 15 Suppl 5: 87-97, 2000 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11263540

RESUMO

In cattle, in-vitro production (IVP) of embryos has become a standardized technique; however, increased frequencies of calving problems and larger calves have been reported. In swine, IVP has resulted in only a limited number of piglets. In this paper we present information on cattle and swine embryos produced in vitro by oocyte maturation, fertilization and further embryo culture to the blastocyst stage in vitro. Control in-vivo developed embryos were collected after superovulation. The cattle embryos were processed for fluorescence in-situ hybridization (FISH) with two chromosome-specific probes to detect numerical chromosome aberrations. The swine embryos were processed for transmission electron microscopy and immunocytochemistry with an antibody against RNA polymerase I [essential for ribosomal RNA (rRNA) gene transcription] in order to highlight the post-fertilization development of the nucleolus as a marker for rRNA gene activation. The FISH analyses of the cattle embryos revealed that 72% of IVP blastocysts were mixoploid, i.e. contained both diploid and polyploid cells, versus 25% in vivo. Chromosome abnormalities were observed from the 2-cell stage onwards. The immunocytochemical analyses of the swine embryos revealed that during in-vivo development, RNA polymerase I became localized to multiple foci in the developing nucleoli late during the 4-cell stage. This focal localization of RNA polymerase I was not observed in IVP embryos. In conclusion, IVP embryos may display aberrations in chromosome numbers and rRNA gene activation. The significance of these deviations for fetal and perinatal viability, however, remains unknown. The survival of most calves derived from IVP indicates that a considerable number of these embryos are able to compensate for the adverse effects of the in-vitro procedures.


Assuntos
Aberrações Cromossômicas , Embrião de Mamíferos/fisiologia , Fertilização in vitro/efeitos adversos , RNA Ribossômico/genética , Suínos , Animais , Bovinos/crescimento & desenvolvimento , Células Cultivadas , Feminino , Regulação da Expressão Gênica no Desenvolvimento , Gravidez , Suínos/crescimento & desenvolvimento , Ativação Transcricional
9.
Graefes Arch Clin Exp Ophthalmol ; 237(10): 824-9, 1999 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-10502057

RESUMO

PURPOSE: The authors report their surgical experience after sustained-release ganciclovir treatment, as well as replacing empty ganciclovir implants in patients with acquired immune deficiency syndrome (AIDS) and cytomegalovirus (CMV) retinitis. METHODS: Between November 1995 and August 1998, 79 eyes of 49 patients received 99 intravitreal ganciclovir implants. Patients were examined monthly after implant surgery. Follow-up periods ranged from 6 to 128 weeks. RESULTS: At the first 3-week postoperative visit, 73 eyes (97.2%) of 46 patients exhibited stable conditions. In 6 eyes (3.8%) of 3 patients, further progression was noted due to resistance to ganciclovir. The most common early complication (within 6 weeks after implantation) was cystoid macular edema, observed in 7 eyes receiving implants. Retinal detachment was the most common late complication (over 6 weeks after implantation) in 11 eyes. In almost all eyes with CMV retinitis and retinal detachment, involvement of more than 25% of the retina was observed. Additional severe complications included extrusion of the first pellet in 2 eyes and cataract as a late complication in 5 eyes. A total of 28 eyes (35.4%) of 16 patients receiving a second implant did not experience significant three-line loss by the end of the follow-up period. CONCLUSION: In the treatment of CMV retinitis, sustained-release ganciclovir implantation seems to be an alternative to intravenous ganciclovir. Early implantation and additional replacement of the device has the potential to decrease the risk of developing retinal detachment. We would recommend additional systemic antiviral CMV therapy to avoid infection of the fellow eye and CMV disease.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Antivirais/administração & dosagem , Retinite por Citomegalovirus/tratamento farmacológico , Implantes de Medicamento/efeitos adversos , Ganciclovir/administração & dosagem , Descolamento Retiniano/etiologia , Infecções Oportunistas Relacionadas com a AIDS/complicações , Adolescente , Adulto , Anticorpos Antivirais/análise , Citomegalovirus/imunologia , Retinite por Citomegalovirus/complicações , Feminino , Seguimentos , HIV/imunologia , Humanos , Masculino , Pessoa de Meia-Idade , Descolamento Retiniano/diagnóstico , Descolamento Retiniano/cirurgia , Estudos Retrospectivos , Vitrectomia , Corpo Vítreo/cirurgia , Corpo Vítreo/virologia
10.
Anim Reprod Sci ; 46(1-2): 47-53, 1997 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-9231246

RESUMO

Five hundred and seventy three follicular bovine cumulus oocyte complexes were matured in vitro and in vitro fertilization (IVF) carried out with the native semen of a brown bull. Half the cultures were fertilized with transmigrated spermatozoa (TM), the other with sperm suspensions prepared using the swim-up (SU) process. Five, six and seven h after IVF the oocytes were fixed and stained. Using a phase-contrast microscope, both the incidence of penetration and polypenetration and the stage of development of a pronucleus were determined. With the TM samples, five hours after IVF penetration was observed in 39.3 per cent of the oocytes, whereas with the SU samples the first instances of penetration were observed only two hours later (4.2%). By this time a normal-looking pronucleus was observed in 16.4 per cent of the oocytes in the TM group. Polypenetration was seen only after seven hours of incubation. This study showed that TM spermatozoa penetrate the oocyte earlier than SU spermatozoa.


Assuntos
Bovinos/fisiologia , Fertilização in vitro , Oócitos/fisiologia , Capacitação Espermática/fisiologia , Interações Espermatozoide-Óvulo/fisiologia , Espermatozoides/fisiologia , Animais , Feminino , Masculino , Fatores de Tempo
11.
Ophthalmologe ; 94(10): 713-8, 1997 Oct.
Artigo em Alemão | MEDLINE | ID: mdl-9432239

RESUMO

UNLABELLED: We performed an open clinical trial to assess the safety and efficacy of a 1 microgram/h ganciclovir implant for the treatment of newly and pretreated cytomegalovirus (CMV) retinitis in patients with the acquired immunodeficiency syndrome (AIDS). PATIENTS AND METHODS: Thirty-two eyes (20 patients) received the ganciclovir intraocular device and were prospectively followed up from 30 to 365 days. We used a modified technique for fixation of the device in half of the patients. The modification improved the fixation of the implant with a two-hole technique in the strut. RESULTS: Thirty eyes showed stabilization of the retinitis over the time, but in two patients resistance against ganciclovir and other nucleoside analogue compounds developed. Postoperative complications included vitreous hemorrhage (n = 1), cataract (n = 1), and uveitis anterior (n = 1). Late retinal detachment was seen in five eyes (25%) at 30 to 60 days after implantation. Followup until 1 year after implantation did not show progression of CMV retinitis in 18 to 20 patients. All received antiviral CMV therapy to protect noninfected eyes and intestinum against CMV infection. CONCLUSIONS: The ganciclovir intraocular device seemed to be effective in most cases of CMV retinitis and offers a promising alternative for cytomegalovirus retinitis. Patients pretreated longer than 6 months with i.v. ganciclovir have to be carefully selected for implantation, because resistance against ganciclovir could be three times more likely than in i.v.-therapy naive patients.


Assuntos
Infecções Oportunistas Relacionadas com a AIDS/tratamento farmacológico , Antivirais/administração & dosagem , Retinite por Citomegalovirus/tratamento farmacológico , Ganciclovir/administração & dosagem , Adolescente , Adulto , Antivirais/efeitos adversos , Criança , Preparações de Ação Retardada , Portadores de Fármacos , Implantes de Medicamento , Desenho de Equipamento , Feminino , Seguimentos , Ganciclovir/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Resultado do Tratamento
12.
J Reprod Immunol ; 30(2-3): 115-32, 1996 May.
Artigo em Inglês | MEDLINE | ID: mdl-8816328

RESUMO

A monoclonal antibody (GZS-1) has been generated by fusion of mouse myeloma cells with spleen cells from BALB/c mice immunised with human sperm cells. The antibody was determined to be an IgG1. The corresponding antigen is present on the whole surface of ejaculated human spermatozoa. It is not detectable on spermatozoa of other mammalian species (rabbit, cat, dog, sheep, boar, bull, horse). In human male genital organs, immunostaining with GZS-1 is observed on sperm cells in the epididymis and the ductus deferens together with the lining epithelium of those organs. No reactivity of sperm cells or germ cell precursors in the testis has been detected. Functional tests using the antibody show a strong inhibitory effect of human sperm in the hamster egg penetration assay. Furthermore, the GZS-1 antigen is detectable on the surface of human lymphocytes and monocytes by immunogold electron microscopy and FACS analysis. By Western blotting of human sperm and seminal plasma performed under reducing conditions immunostaining was detected at 21-25, 31, 51-54, and 62 kDa. The reaction with human lymphocytes shows one major band at 62 kDa and additional bands at 31 and 54 kDa. The results suggest that the monoclonal antibody GZS-1 may recognise an antigen which is secreted from the epithelial cells of the epididymis and binds to ejaculated spermatozoa as a sperm coating antigen. This component may be involved in the capacitation of the sperm and the acrosome reaction. Molecules that are expressed both on sperm and on immunocompetent cells may be relevant for the regulation of immunological processes or for the development of the related immunological tolerance of sperm in the female reproductive tract.


Assuntos
Anticorpos Monoclonais/imunologia , Antígenos CD/análise , Leucócitos Mononucleares/imunologia , Espermatozoides/imunologia , Reações Cruzadas/imunologia , Técnica Indireta de Fluorescência para Anticorpo , Humanos , Imuno-Histoquímica , Masculino
13.
Zentralbl Veterinarmed A ; 42(2): 139-43, 1995 Apr.
Artigo em Alemão | MEDLINE | ID: mdl-8592888

RESUMO

The effect of two semen-preparation methods and the presence and absence of capacitation-inducing supplements in the fertilization medium on IVF-results were examined in a 2 x 2 factorial design. In vitro matured oocytes were fertilized either with transmigrated (TM) or with swim-up (SU) prepared native semen. In the first group, the fertilization medium contained 0.8 microgram/ml heparin, 1.2 micrograms/ml hypotaurine and 0.2 microgram/ml epinephrine. However, in the second group, no capacitation-inducing or motility-enhancing substances were used. After SU-treatment, the supplements were necessary to obtain sufficient fertilization results. In the second group (non-supplemented medium), the percentages of penetrated and fertilized oocytes were decreased significantly (P < 0.001). By contrast, transmigrated semen required no additional supplementation of the fertilization medium. The penetration and fertilization rates of this semen-preparation method were equal in both groups.


Assuntos
Meios de Cultura/normas , Fertilização in vitro/veterinária , Sêmen/fisiologia , Capacitação Espermática/fisiologia , Animais , Bovinos , Meios de Cultura/análise , Epinefrina/análise , Epinefrina/farmacologia , Feminino , Fertilização in vitro/métodos , Fertilização in vitro/normas , Heparina/análise , Heparina/farmacologia , Masculino , Sêmen/citologia , Capacitação Espermática/efeitos dos fármacos , Motilidade dos Espermatozoides/efeitos dos fármacos , Motilidade dos Espermatozoides/fisiologia , Interações Espermatozoide-Óvulo/efeitos dos fármacos , Interações Espermatozoide-Óvulo/fisiologia , Taurina/análogos & derivados , Taurina/análise , Taurina/farmacologia
14.
Nurs Diagn ; 5(1): 36-42, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-8192950

RESUMO

The purpose of this study was to examine content validity of two nursing diagnoses in the home health setting: impaired skin integrity and altered urinary elimination: total incontinence. Eighty-two home health nurses rated the importance of each of the defining characteristics for the two nursing diagnoses. Diagnostic content validity scores (DCV) were calculated for each defining characteristic for both diagnoses using the method described by Fehring (1986). Four characteristics for each diagnosis had DCV scores greater than .75, indicating characteristics were critical indicators for the diagnosis. Erythema, denuded skin, disruptions of dermal and epidermal tissue, and lesions were critical indicators for impaired skin integrity. Lack of awareness of incontinence, constant flow of urine, lack of awareness of bladder cues to void, and incontinence refractory to other treatments were critical indicators for alteration in urinary elimination: total incontinence.


Assuntos
Enfermagem em Saúde Comunitária , Serviços de Assistência Domiciliar , Diagnóstico de Enfermagem/normas , Dermatopatias/enfermagem , Incontinência Urinária/enfermagem , Adulto , Idoso , Atitude do Pessoal de Saúde , Humanos , Pessoa de Meia-Idade , Pesquisa em Avaliação de Enfermagem , Recursos Humanos de Enfermagem/psicologia , Reprodutibilidade dos Testes
15.
Res Commun Chem Pathol Pharmacol ; 81(1): 53-67, 1993 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-8210690

RESUMO

The contribution of the stomach and the small intestine to the in vivo absorption of fluoride from disodium and calcium monofluorophosphates was studied in comparison with that observed when sodium fluoride is given to rats. In vitro experiments with ligated duodena were also carried out. Fasted rats were given orally 50 micrograms of fluoride in pH 6.3 buffered disodium monofluorophosphate solutions with and without 50 mM added calcium. The same amount of fluoride was administered in the form of an aqueous sodium fluoride solution. In both cases the fluoride solutions contained trace amounts of (14C)-labeled polyethyleneglycol as a marker for the study of water movement through the gastrointestinal tract. Results obtained show the small intestine as the main site of the absorption of the studied compounds. Under the fasting conditions employed in our study gastric absorption was in turn, almost negligible. While fluoride transport from sodium fluoride seems to occur through a difussion mechanism, disodium and calcium monofluorophosphates appear to be absorbed through a more complex mechanism involving an enzymatic hydrolysis and an independent and possibly parallel direct tissue absorption of a soluble, neutral calcium monofluorophosphate complex.


Assuntos
Fluoretos/metabolismo , Fluoretos/farmacologia , Mucosa Gástrica/metabolismo , Absorção Intestinal , Fosfatos/metabolismo , Fosfatos/farmacologia , Administração Oral , Animais , Transporte Biológico , Difusão , Duodeno/metabolismo , Jejum , Feminino , Fluoretos/administração & dosagem , Esvaziamento Gástrico , Técnicas In Vitro , Intestino Delgado/metabolismo , Fosfatos/administração & dosagem , Ratos , Ratos Wistar , Fluoreto de Sódio/administração & dosagem , Fluoreto de Sódio/metabolismo
17.
Neuroscience ; 17(3): 609-14, 1986 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3703251

RESUMO

In the present study we have investigated the relative rostrocaudal position of the neurons in the substantia nigra, which project to the ipsilateral or contralateral neostriatum. The retrograde tract tracer horseradish peroxidase was implanted into the striatum on one side. The substantia nigra, ventral tegmental area and retrorubral area ipsilateral and contralateral to the site of implantation were examined for labeled cells. The distributions of the cells which give rise to the crossed and uncrossed nigrostriatal projections were found to be inverse. More labeled cells were found in the rostral than the caudal part of the substantia nigra ipsilateral to the site of horseradish peroxidase implantation. In contrast, there was a greater likelihood of finding labeled cells in the middle and caudal parts of the contralateral substantia nigra than in the rostral part. Sparse projections from the ipsilateral and contralateral retrorubral area and ventral tegmental area were also found.


Assuntos
Mapeamento Encefálico , Corpo Estriado/anatomia & histologia , Lateralidade Funcional/fisiologia , Substância Negra/anatomia & histologia , Animais , Peroxidase do Rábano Silvestre , Injeções Intraventriculares , Masculino , Vias Neurais/anatomia & histologia , Neurônios/fisiologia , Ratos , Ratos Endogâmicos
18.
Brain Res Bull ; 15(5): 515-8, 1985 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-2415221

RESUMO

We examined the effect of training rats to perform an operant turning response on the crossed nigro-striatal projections. Rats were reinforced for circling behavior with water. After 7 days of reinforced circling, the animals were implanted with horseradish peroxidase in the striatum either ipsilateral or contralateral to the direction in which they had been trained to turn. Subsequently, the substantia nigra, ventral tegmental area, and retrorubral area in both hemispheres were examined for labeled cells. This analysis failed to reveal any relationship between the direction of reinforced circling and efferents from these areas to the striatum.


Assuntos
Condicionamento Operante/fisiologia , Corpo Estriado/fisiologia , Atividade Motora/fisiologia , Substância Negra/fisiologia , Animais , Mapeamento Encefálico , Peroxidase do Rábano Silvestre , Masculino , Vias Neurais/fisiologia , Ratos , Ratos Endogâmicos , Coloração e Rotulagem , Tegmento Mesencefálico/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...