Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 19 de 19
Filtrar
1.
Sci Rep ; 12(1): 2488, 2022 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-35169194

RESUMO

In vitro fertilization is typically associated with high failure rates per transfer, leading to an acute need for the identification of embryos with high developmental potential. Current methods are tailored to specific times after fertilization, often require expert inspection, and have low predictive power. Automatic methods are challenged by ambiguous labels, clinical heterogeneity, and the inability to utilize multiple developmental points. In this work, we propose a novel method that trains a classifier conditioned on the time since fertilization. This classifier is then integrated over time and its output is used to assign soft labels to pairs of samples. The classifier obtained by training on these soft labels presents a significant improvement in accuracy, even as early as 30 h post-fertilization. By integrating the classification scores, the predictive power is further improved. Our results are superior to previously reported methods, including the commercial KIDScore-D3 system, and a group of eight senior professionals, in classifying multiple groups of favorable embryos into groups defined as less favorable based on implantation outcomes, expert decisions based on developmental trajectories, and/or genetic tests.


Assuntos
Implantação do Embrião , Transferência Embrionária/métodos , Desenvolvimento Embrionário , Fertilização in vitro/métodos , Feminino , Humanos
2.
Br Poult Sci ; 62(5): 771-782, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34009070

RESUMO

1. The protective layer formed by intestinal epithelial cells acts as a barrier preventing the adhesion of pathogenic bacteria, aids digestion and passage of nutrients and reduces damage caused from toxins on the gastrointestinal tract. This study was conducted to investigate the effects of a yeast cell wall-based product (YCW), on broiler intestinal integrity, digestive enzyme capacity and immune function.2. A 35-d trial involving 246, one-d-of-hatch male broiler chickens was carried out at a trial facility at Agri-Food Biosciences Institute (AFBI, Belfast, UK). Birds were randomly allocated into 6 pens at day of hatch (41 birds/pen; 123 birds/group). Pens were divided into two groups: (1) basal diet and (2) basal diet that incorporated YCW at the manufacturers' recommended inclusion levels (Alltech Inc., Lexington, Kentucky, USA).3. In this study, YCW supplementation affected broiler intestinal morphology resulting in greater crypt depth, villus height and surface area, goblet cell density and mucus layer thickness and lower muscularis mucosae thickness. The digestive enzymes, maltase, sucrase and alkaline phosphatase, were significantly higher in the YCW supplemented group compared to the control. The expression levels of pro-inflammatory cytokines, IL-1ß, IL-12 and IL-18, were significantly lower as was necroptotic cell death in YCW supplemented birds.4. In conclusion, under the conditions of this study, YCW supplementation positively affected intestinal health parameters in broilers following 35-d supplementation.


Assuntos
Galinhas , Saccharomyces cerevisiae , Ração Animal/análise , Animais , Parede Celular , Dieta/veterinária , Suplementos Nutricionais , Masculino
4.
Hum Reprod ; 32(6): 1282-1292, 2017 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-28387858

RESUMO

STUDY QUESTION: Does the amount of mitochondrial DNA (mtDNA) in blastocyst biopsy specimens have the potential to serve as a biomarker of euploid embryo implantation ability, independent of morphology? SUMMARY ANSWER: The results of this study strongly suggest that elevated mtDNA levels, above a previously defined threshold, are strongly associated with blastocyst implantation failure and represent an independent biomarker of embryo viability. WHAT IS KNOWN ALREADY: Improved methods of embryo selection are highly desirable in order to increase the efficiency of IVF treatment. At present, even the transfer of chromosomally normal embryos of high morphological grade cannot guarantee that a pregnancy will follow. Recently, it has been proposed that the quantity of mtDNA in embryonic cells may be an indicator of developmental potential, with higher levels of mtDNA associated with reduced implantation. However, thus far reported data sets have been relatively small and in some cases have lacked appropriate validation. STUDY DESIGN, SIZE, DURATION: This large, blinded, retrospective study involved the analysis of relative mtDNA levels in 1505 euploid blastocysts obtained from 490 couples undergoing preimplantation genetic testing for aneuploidy. Implantation outcomes were compared to mtDNA levels in order to determine the capacity of the method to predict viability and to assess the validity of previously established thresholds. PARTICIPANTS/MATERIALS, SETTING, METHODS: DNA from blastocyst biopsy samples was amplified and then subjected to aneuploidy analysis using next generation sequencing or array comparative genomic hybridization. Only those embryos classified as chromosomally normal had their mtDNA levels assessed. This analysis was undertaken retrospectively using quantitative real-time PCR, without knowledge of the outcome of embryo transfer. Predictions of implantation failure, based upon mtDNA levels were subsequently compared to the observed clinical results. All cycles involved the transfer of a single embryo. MAIN RESULTS AND THE ROLE OF CHANCE: Of all blastocysts analyzed, 9.2% (139/1505) contained mtDNA levels above a previously established viability threshold and were therefore predicted to have reduced chances of implantation. To the date of analysis, 282 euploid blastocysts had been transferred with an overall implantation rate of 65.6% (185/282). Of the transferred embryos, 249 contained levels of mtDNA in the normal range, 185 of which produced a pregnancy, giving an implantation rate of 74.3% for euploid embryos with 'normal' quantities of mtDNA. However, 33 of the transferred embryos were determined to have elevated mtDNA quantities. None of these led to a pregnancy. Therefore, the negative predictive value of mtDNA assessment in this cohort was 100% (33/33). The difference between the implantation rates for embryos with normal and elevated mtDNA levels was highly significant (P < 0.0001). The mtDNA thresholds, used for classification of embryos, were unaffected by female age or the clinic in which the IVF was undertaken. The probability of an embryo having elevated levels of mtDNA was not influenced by variation in embryo morphology. LIMITATIONS, REASONS FOR CAUTION: This study provides strong evidence that mtDNA quantification can serve as a valuable tool to assist the evaluation of blastocyst viability. However, to determine the true extent of any clinical benefits, other types of investigations, such as non-selection studies and randomized controlled trials, will also be necessary. WIDER IMPLICATIONS OF THE FINDINGS: The results of this study suggest that mtDNA quantity can serve as an independent biomarker for the prediction of euploid blastocyst implantation potential. Prospective studies should now be undertaken to confirm these results. Additionally, investigations into the underlying biological cause(s) of elevated mtDNA levels and an enhanced understanding of how they relate to diminished implantation potential would be invaluable. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by funding provided by Reprogenetics. None of the authors have any competing interests.


Assuntos
Blastocisto/metabolismo , DNA Mitocondrial/metabolismo , Regulação para Baixo , Ectogênese , Desenvolvimento Fetal , Infertilidade Feminina/terapia , Transferência de Embrião Único , Adulto , Biomarcadores/metabolismo , Estudos de Coortes , Características da Família , Feminino , Fertilização in vitro , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Infertilidade Feminina/metabolismo , Infertilidade Masculina , Masculino , Análise de Sequência com Séries de Oligonucleotídeos , Gravidez , Taxa de Gravidez , Reprodutibilidade dos Testes , Estados Unidos/epidemiologia
5.
J Pediatr Nurs ; 21(1): 59-66, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16428015

RESUMO

An in-depth exploratory study identified major stressors experienced by children diagnosed with cancer. Four themes were used to analyze data from a series of focus group discussions and individual interviews with children, parents, hospital professionals, and hospital teachers (N = 35). First, major stressful events were reported by the children, their parents, and hospital professionals. Second, the effects of major stressors on the well-being of the children, their families, school, and hospital personnel were determined. Third, the children reported the consequences of major stressors on their physical and emotional well-being. Fourth, the children's use of effective coping mechanisms was determined. The results revealed that the major stressors for children with cancer were treatment procedures (e.g., chemotherapy), loss of control, the hospital environment, relapses, and fear of dying. In addition, the children cited body image issues, ongoing lack of self-esteem, and issues relating to the preparation for transition back into real world situations (e.g., school).


Assuntos
Atitude Frente a Saúde , Proteção da Criança , Saúde Mental , Neoplasias/psicologia , Estresse Psicológico/psicologia , Adaptação Psicológica , Adolescente , Atitude do Pessoal de Saúde , Imagem Corporal , Criança , Medo , Grupos Focais , Humanos , Acontecimentos que Mudam a Vida , Neoplasias/complicações , Papel do Profissional de Enfermagem , Pesquisa Metodológica em Enfermagem , Pais/psicologia , Enfermagem Pediátrica/organização & administração , Psicologia do Adolescente , Psicologia da Criança , Qualidade de Vida , Fatores de Risco , Autoimagem , Estresse Psicológico/etiologia , Estresse Psicológico/prevenção & controle , Inquéritos e Questionários
6.
Fertil Steril ; 66(5): 851-3, 1996 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-8893701

RESUMO

OBJECTIVE: To ascertain if hydrosalpinges are associated with reduced pregnancy rates and increased pregnancy loss after IVF-ET. Increased volume and leakage of hydrosalpinx fluid may exert negative effects on follicular development and embryo quality and/or render the uterine environment hostile to embryogenesis. We undertook this study to examine the effect of hydrosalpinx fluid on murine embryogenesis in vitro. DESIGN: Descriptive study. SETTING: Tertiary care facility. PATIENT(S): Premenopausal females undergoing salpingectomy or salpingostomy for hydrosalpinges. INTERVENTION(S): Collection of discarded hydrosalpinx fluid and development of a dose response curve for the effect of hydrosalpinx fluid on murine embryogenesis. MAIN OUTCOME MEASURE(S): Development of single cell mouse embryos in vitro. RESULT(S): All samples of tubal fluid obtained from hydrosalpinges demonstrated a significant embryo toxic effect at either the 100% or 10% concentration. Hydrosalpinx fluid demonstrated pH values (8.45 to 8.65) significantly higher than the physiologic range. Correction of pH to that of media did not affect cavitation rate. CONCLUSION(S): There is a well-defined and significant toxic effect of hydrosalpinx fluid. Procedures such as salpingectomy or proximal tubal occlusion to circumvent the passage of hydrosalpinx fluid into the uterine cavity may have beneficial effects on the developmental environment for embryos in vivo.


Assuntos
Desenvolvimento Embrionário e Fetal , Exsudatos e Transudatos , Doenças das Tubas Uterinas/fisiopatologia , Doenças das Tubas Uterinas/cirurgia , Tubas Uterinas/cirurgia , Teratogênicos/toxicidade , Animais , Técnicas de Cultura , Feminino , Humanos , Concentração de Íons de Hidrogênio , Camundongos , Camundongos Endogâmicos ICR , Concentração Osmolar , Gravidez
7.
J Assist Reprod Genet ; 13(8): 657-62, 1996 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8897126

RESUMO

BACKGROUND: A microchamber has been developed which allows motile sperm to swim from a central loading site to peripheral sidewells. The sidewells are designed such that oocytes may be placed within them for in vitro fertilization (IVF) or sperm may be harvested from them for use in standard IVF or micromanipulation. Because only motile sperm can reach the sidewells, the microchamber can select relatively high-quality sperm from a crude preparation. Moreover the steep walls of the sidewells create the potential to trap sperm. OBJECTIVE: The present study was under taken to compare sperm in the sidewells to those found in randomly sampled regions of microchamber after various periods of incubation. RESULTS: We find that the sidewells concentrate motile sperm and that a higher percentage of sperm removed from sidewells is acrosome reacted. Motile sperm from oligospermic patients can be harvested from microchamber sidewells for use in micromanipulation after loading the microchamber with unprocessed specimens. Results suggest that this microchamber could be used to enhance sperm:egg interaction in IVF or to harvest sperm for micromanipulation.


Assuntos
Separação Celular/instrumentação , Fertilização in vitro/instrumentação , Micromanipulação/instrumentação , Espermatozoides , Acrossomo/fisiologia , Humanos , Masculino , Oligospermia/patologia , Motilidade dos Espermatozoides , Espermatozoides/fisiologia
8.
Antimicrob Agents Chemother ; 38(5): 959-62, 1994 May.
Artigo em Inglês | MEDLINE | ID: mdl-8067776

RESUMO

The beta-lactam hydrolysis of five cephalosporin 3'-quinolones (dual-action cephalosporins) by three gram-negative beta-lactamases was examined. The dual-action cephalosporins tested were the ester Ro 23-9424; the carbamates Ro 25-2016, Ro 25-4095, and Ro 25-4835; and the tertiary amine Ro 25-0534. Also tested were cephalosporins with similar side chains (cefotaxime, desacetylcefotaxime, cephalothin, cephacetrile, and Ro 09-1227 [SR 0124]) and standard beta-lactams (penicillin G, cephaloridine). The beta-lactamases used were the plasmid-mediated TEM-1 and TEM-3 enzymes and the chromosomal AmpC. The cephacetrile-related compounds Ro 25-4095 and Ro 25-4835 were hydrolyzed by all three beta-lactamases with catalytic efficiencies (relative to penicillin G) ranging from approximately 5 (TEM-1, AmpC) to approximately 25 (TEM-3). The cephalothin-related Ro 25-2016 was also hydrolyzed by all three beta-lactamases, particularly the AmpC enzyme (relative catalytic efficiency, 110). The cefotaxime-related compounds Ro 25-0534 and Ro 23-9424 were hydrolyzed to any significant extent only by the TEM-3 enzyme (relative catalytic efficiencies, 1.2 and 4.7, respectively.


Assuntos
Aminas/metabolismo , Anti-Infecciosos/metabolismo , Carbamatos/metabolismo , Cefotaxima/análogos & derivados , Fleroxacino/análogos & derivados , Fluoroquinolonas , beta-Lactamases/metabolismo , Cefotaxima/metabolismo , Ésteres/metabolismo , Fleroxacino/metabolismo , Hidrólise , Cinética , Plasmídeos , beta-Lactamases/biossíntese , beta-Lactamases/isolamento & purificação
9.
FEMS Microbiol Lett ; 108(2): 183-7, 1993 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-8387443

RESUMO

The lipopolysaccharide and porin profile of Escherichia coli ATCC 25922, a smooth strain commonly used in antibiotic susceptibility testing, and five isogenic rough mutants was examined. The lipopolysaccharide of the parent strain had the characteristic ladder pattern on polyacrylamide gels, while that of the mutants appeared similar to chemotypes Ra and Rc of Salmonella typhimurium with some changes in chemical composition. Of the porins, OmpC appeared markedly reduced in the parent strain while OmpF appeared markedly reduced in the mutants. In addition, a new outer-membrane protein of size intermediate to that of OmpC and OmpF was detected in all mutants. Neither parent nor mutants were susceptible to the LPS core-specific P1 phage or the porin-specific PA2 and K20 phages.


Assuntos
Proteínas da Membrana Bacteriana Externa/química , Escherichia coli/química , Escherichia coli/genética , Lipopolissacarídeos/química , Proteínas da Membrana Bacteriana Externa/genética , Genes Bacterianos/genética , Variação Genética , Mutação , Porinas
10.
Antimicrob Agents Chemother ; 36(8): 1601-5, 1992 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1416840

RESUMO

The accumulation of quinolones by Escherichia coli JF568, Pseudomonas aeruginosa PAO1, and Staphylococcus aureus ATCC 29213 was measured by a modified fluorometric assay (J. S. Chapman and N. H. Georgopapadakou, Antimicrob. Agents Chemother. 33:27-29, 1989). The quinolones examined were fleroxacin, pefloxacin, norfloxacin, difloxacin, A56620, ciprofloxacin, ofloxacin, and Ro 09-1168. In all three organisms, uptake was complete in less than 5 min and was proportional to extracellular quinolone concentrations between 2 and 50 micrograms/ml, which is consistent with simple diffusion. Washing cells with quinolone-free buffer decreased accumulation by up to 70% in E. coli and P. aeruginosa but not in S. aureus. Similarly, incubation with the uncouplers 2,4-dinitrophenol and carbonyl cyanide m-chlorophenylhydrazone increased accumulation up to fourfold in E. coli and P. aeruginosa, though not in S. aureus, suggesting endogenous, energy-dependent efflux. High quinolone hydrophobicity was generally associated with decreased accumulation in E. coli and P. aeruginosa (except in the case of pefloxacin) but was associated with increased accumulation in S. aureus (except in the case of difloxacin). Ciprofloxacin had the highest accumulation in E. coli and P. aeruginosa, while pefloxacin had the highest accumulation in S. aureus.


Assuntos
Anti-Infecciosos/metabolismo , Escherichia coli/metabolismo , Pseudomonas aeruginosa/metabolismo , Staphylococcus aureus/metabolismo , 4-Quinolonas , Anti-Infecciosos/química , Fenômenos Químicos , Físico-Química
11.
J Assist Reprod Genet ; 9(2): 149-54, 1992 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-1627931

RESUMO

Embryos from two strains of mice were used to assess the effect of incubation temperature on pronuclear and two-cell development to the morula/blastocyst (M/B) stage. Embryos from B6D2F2 and B6SJLF1 strains were cultured in medium M16 at either 37 or 39 degrees C until 120 hr post human chorionic gonadotropin (hCG) or 0, 24, or 48 hr at 37 degrees C and the remaining time at 39 degrees C. Overall M/B development for pronuclear embryos was 0.6, 0, 32.3, and 52.4% for 0-96, 24-72, 48-48, and 96-0 hr at 37 and 39 degrees C, respectively. Only 0-96 and 24-72 hr at 37 and 39 degrees C were not different (P greater than 0.10). Overall M/B development for two-cell embryos was 48.1, 78.1, and 98.0% for 0-72, 24-48, and 72-0 hr at 37 and 39 degrees C, respectively. Percentage development at each time was different (P less than .01) for each category. Additionally, the number of nuclei for morulae and blastocysts tended to be higher for embryos initiating culture at the two-cell stage compared to pronuclear embryos. The first cell cycle was most dramatically affected by a 2 degrees C increase in incubator temperature. More advanced embryos can tolerate slight increases in incubator temperature more readily than pronuclear embryos.


Assuntos
Blastocisto , Desenvolvimento Embrionário e Fetal , Temperatura Alta , Animais , Contagem de Células , Feminino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Mórula , Estresse Fisiológico/embriologia , Sobrevivência de Tecidos
12.
Bioconjug Chem ; 2(4): 211-6, 1991.
Artigo em Inglês | MEDLINE | ID: mdl-1772902

RESUMO

The active site cysteine residue of chalcone isomerase was rapidly and selectively modified under denaturing conditions with a variety of electrophilic reagents. These denatured and modified enzyme were renatured to produce enzyme derivatives containing a series of unnatural amino acids in the active site. Addition of methyl, ethyl, butyl, heptyl, and benzyl groups to the cysteine sulfur does not abolish catalytic activity, although the activity decreases as the steric bulk of the amino acid side-chain increases. Modification of the cysteine to introduce a charged homoglutamate or a neutral homoglutamine analogue results in retention of 22% of the catalytic activity. Addition of a methylthio group (SMe) to the cysteine residue of native chalcone isomerase preserves 85% of the catalytic activity measured with 2',4',4-trihydroxychalcone, 2',4',6',4-tetrahydroxychalcone, or 2'-hydroxy-4-methoxychalcone as substrates. The competitive inhibition constant for 4',4-dihydroxychalcone, the substrate inhibition constant for 2',4',4-trihydroxychalcone, and other steady-state kinetic parameters for the methanethiolated enzyme are very similar to those of the native enzyme. The strong binding of 4',4-dihydroxychalcone to the methanethiolated enzyme shows that there is no steric repulsion between this modified amino acid residue and the substrate analogue. This structure-activity study clearly demonstrates that the active site cysteine residue does not function as an acid-base or nucleophilic group in producing the catalysis or substrate inhibition observed with chalcone isomerase. The method presented in this paper allows for the rapid introduction of a series of unnatural amino acids into the active site as a means of probing the structure-function relationship.


Assuntos
Aminoácidos/química , Liases Intramoleculares , Isomerases/química , Alquilação , Sítios de Ligação , Cisteína/química , Cisteína/metabolismo , Isomerases/metabolismo , Metanossulfonato de Metila/análogos & derivados , Metanossulfonato de Metila/química , Relação Estrutura-Atividade , Ureia/farmacologia
13.
J Reprod Fertil ; 92(1): 119-24, 1991 May.
Artigo em Inglês | MEDLINE | ID: mdl-2056482

RESUMO

Bovine ova (n = 326) collected at the 1-4-cell stage were cultured in TCM-199 + 10% foetal calf serum with or without oviducal cells. The bovine oviducal cells were collected and seeded either on the day of ovum recovery (BOC-0) or 3 days earlier (BOC-3). In Exp. 1, the effect of age of oviducal cells in co-culture on ovum development was examined. In the BOC-0 and BOC-3 treatments, respectively, 36/46 (78%) and 30/37 (81%) of ova developed to morulae or blastocysts, while no ova developed past the 8-16-cell stage in the absence of oviducal cells. In Exp. 2, the effect of age of oviducal cells and of physical contact between the oviducal cells and ova on ovum development was examined. In the BOC-0 and BOC-3 treatments, respectively, 29/42 (69%) and 23/43 (53%) of the ova developed to morulae or blastocysts, while 1/42 (2%) developed to the morula stage in the absence of oviducal cells. Physical separation of the ova using a microporous membrane inserted between the oviducal cells and the ova did not affect ovum development, with 26/42 (62%) and 22/42 (52%) of ova developing to morulae or blastocysts in the BOC-0 and BOC-3 treatments, respectively. A high proportion of the morulae and blastocysts in Exp. 1 (57/66, 86%) and Exp. 2 (67/100, 67%) were of quality grades 1 or 2, with mean nuclei counts of 85 for morulae and 111 for blastocysts.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Bovinos , Óvulo/crescimento & desenvolvimento , Animais , Blastocisto/fisiologia , Comunicação Celular/fisiologia , Contagem de Células , Separação Celular , Células Cultivadas , Feminino , Mórula/fisiologia , Fatores de Tempo
14.
Can J Comp Med ; 48(1): 51-7, 1984 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6713257

RESUMO

Renal calcium and magnesium handling was studied in rats with chronic thyroid hormone deficiency or excess, hyperthyroidism. Mean kidney weight of the thyroid deficient rats was 42% of age matched, euthyroid and hyperthyroid animals and glomerular filtration rate was 71% of normal. Fractional sodium excretion was consistently elevated in thyroid deficient rats (0.26%) as compared to euthyroid (0.07%) and hyperthyroid animals (0.07%). Urinary calcium excretion (0.39%) was also elevated and parallel to sodium excretion in thyroid deficiency. Despite this renal leak of sodium and calcium, thyroid deficient animals conserved magnesium much more efficiently than either euthyroid or hyperthyroid rats (5.7% vs 17.4% respectively). Plasma magnesium concentration was elevated by acute MgCl2 infusions to determine the reabsorptive capacity of magnesium. Thyroid deficient rats reabsorbed 15-30% more of the filtered magnesium at any given plasma concentration. Although these effects on electrolyte reabsorption are modest compared to the hemodynamic alterations, the data suggest that thyroid hormone has a direct effect on the tubule which if chronically absent results in subtle sodium and calcium wasting and renal retention of magnesium. Administration of thyroid hormone to euthyroid or thyroid deficient rats twenty-four hours prior to experimentation had no effect on calcium and magnesium handling.


Assuntos
Cálcio/metabolismo , Rim/metabolismo , Magnésio/metabolismo , Animais , Peso Corporal , Taxa de Filtração Glomerular , Hipertireoidismo/metabolismo , Hipotireoidismo/metabolismo , Inulina , Rim/anatomia & histologia , Masculino , Tamanho do Órgão , Ratos , Ratos Endogâmicos
15.
Am J Physiol ; 238(5): F363-71, 1980 May.
Artigo em Inglês | MEDLINE | ID: mdl-7377348

RESUMO

Furosemide 20 mg/kg was given intravenously to 12 anesthetized dogs with clamped renal pedicles. Thoracic duct lymph flow (TDLF) increased promptly by 38% (P less than 0.05), an increment that lasted 80 min. Because in 6 of 12 dogs there was a transient increase in splanchnic blood flow, in separate groups splanchnic blood flow was either markedly constricted or markedly increased by intravenous isoproterenol. Thoracic duct lymph flow increased by 95 and 90%, respectively, following furosemid despite no further change in splanchnic blood flow. Furosemide had no effect on blood pressure, lymph protein, or plasma sodium. In four chronic caval dogs, TDLF was increased by 400%, yet furosemide produced a further increment in lymph flow of 30% (P less than 0.05). Infusion of a 25% albumin solution to contract the interstitial fluid did not abolish the furosemide effect, but a 10% mannitol solution did. Furosemide increased TDLF even after the infusion of papaverine reduced blood pressure to 60 mmHg. We conclude that furosemide increases TDLF by acting directly on splanchnic capillaries to allow increased filtration of fluid in the absence of increased splanchnic blood flow or capillary hydrostatic pressure.


Assuntos
Furosemida/farmacologia , Linfa/fisiologia , Abdome/irrigação sanguínea , Angiotensina II/farmacologia , Animais , Proteínas Sanguíneas/fisiologia , Cálcio/farmacologia , Cães , Espaço Extracelular/fisiologia , Feminino , Isoproterenol/farmacologia , Rim/fisiologia , Masculino , Papaverina/farmacologia , Fluxo Sanguíneo Regional/efeitos dos fármacos , Saralasina/farmacologia , Nitrito de Sódio/farmacologia , Ducto Torácico/fisiologia
17.
Kidney Int ; 16(4): 459-69, 1979 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-548592

RESUMO

The peritoneal clearance of creatinine and inulin during isotonic peritoneal dialysis was studied in dogs before and after the administration of two vasodilators: isoproterenol and glucagon. One-liter exchanges with 15-min dwell times were used. Blood flow in the superior mesenteric artery was recorded with an electromagnetic flow probe and used as an index for total splanchnic flow. Intravenous isoproterenol (2.4 microgram/min) increased blood flow by 88%, but did not alter peritoneal clearance. When isoproterenol was given i.p. (0.5 microgram/ml dialysis fluid), blood flow increased by 81%, and inulin clearance rose by 26.8% (2.06 +/- 0.18 to 2.61 +/- 0.23 ml/min; P less than 0.05). Creatinine clearance increased by 17.5%, from 10.94 +/- 0.32 to 12.85 +/- 0.34 ml/min (P less than 0.05). When blood flow was returned to control levels with a clamp, clearances also returned to control levels. Glucagon given i.p. (1.0 microgram/ml) had no effect on any measured variable. Glucagon given i.v. at 10 microgram/min caused blood flow to rise by 81% and inulin clearance to rise by 25% from 1.88 +/- 0.16 to 2.35 +/- 0.19 ml/min (P less than 0.05). Cp, inulin clearance remained at control levels. Vasodilators seem to exercise two effects in augmenting clearance of small and middle-sized molecules: a direct permeability effect and a blood-flow related effect, possibly in increasing the surface area available for exchange and/or increasing permeability of the capillary endothelium.


Assuntos
Creatinina/metabolismo , Inulina/metabolismo , Diálise Peritoneal , Peritônio/metabolismo , Vasodilatadores/farmacologia , Animais , Cães , Feminino , Glucagon/farmacologia , Isoproterenol/farmacologia , Masculino , Artérias Mesentéricas , Taxa de Depuração Metabólica , Peritônio/irrigação sanguínea , Peritônio/efeitos dos fármacos , Fluxo Sanguíneo Regional/efeitos dos fármacos , Salicilatos/metabolismo , Vasodilatadores/administração & dosagem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...