RESUMO
Mycoplasma pneumoniae and Streptococcus pneumoniae are the most common bacterial causes of pneumonia in children. The clinical characteristics of pneumonia differ significantly between the two bacteria. We aimed to elucidate the differences in pathogenesis between M. pneumoniae and S. pneumoniae by characterizing the respiratory epithelial cell immune response to both pathogens. Using primary human bronchial epithelial cells in air-liquid interface cultures, we observed lower production of the proinflammatory cytokines interleukin-6 (IL-6) and IL-8 in response to M. pneumoniae than to S. pneumoniae. In contrast to the differences in proinflammatory cytokine production, Toll-like receptor 2 (TLR2)-mediated signaling in response to M. pneumoniae was stronger than to S. pneumoniae. This difference largely depended on TLR1 and not TLR6. We found that M. pneumoniae, but not S. pneumoniae, also induced signaling of TLR10, a coreceptor of TLR2 that has inhibitory properties. M. pneumoniae-induced TLR10 signaling on airway epithelial cells was partially responsible for low IL-8 production, as blocking TLR10 by specific antibodies increased cytokine production. M. pneumoniae maintained Th2-associated cytokine production by epithelial cells, which concurs with the known association of M. pneumoniae infection with asthma. M. pneumoniae left IL-33 levels unchanged, whereas S. pneumoniae downregulated IL-33 production both under homeostatic and Th2-promoting conditions. By directly comparing M. pneumoniae and S. pneumoniae, we demonstrate that M. pneumoniae avoids induction of proinflammatory cytokine response despite its ability to induce robust TLR2 signaling. Our new findings suggest that this apparent paradox may be partially explained by M. pneumoniae-induced signaling of TLR2/TLR10.
Assuntos
Mycoplasma pneumoniae , Streptococcus pneumoniae , Criança , Citocinas , Células Epiteliais , Humanos , Interleucina-33 , Interleucina-8 , Receptor 2 Toll-Like/genéticaRESUMO
BACKGROUND: Anaemia and iron deficiency are major public health problems with great implications on quality of life. AIMS: To establish the general prevalence of anaemia and iron deficiency in the adult Portuguese population and the prevalence by age, gender and region. METHODS: This was a population-based, cross-sectional study (EMPIRE study) based on a representative sample of 7980 adults residing in mainland Portugal, which were selected using a random route sampling method. Levels of haemoglobin, ferritin, creatinine and C-reactive protein were measured by Point-of-Care assays; participants also completed a questionnaire about demography and medical history. RESULTS: The measured prevalence of anaemia was 19.9% (95% confidence interval: 19.0-20.8%); 84% of cases were previously undiagnosed. Anaemia was more prevalent among women (20.8%), young adults (18-34 years) (22.8-30.5%), older adults (21.0%), and pregnant women (54.2%). Anaemia varied across regions: from 15.5% in the Center region to 24.9% in the South. Iron deficiency was also highly prevalent: 16.7% (ferritin <15 ng/mL), 31.9% (<30 ng/mL), 53.3% (<50 ng/mL) and 84.3% (<100 ng/mL). Iron deficiency anaemia represented most anaemia cases: 29.0% (ferritin <15 ng/mL), 54.8% (<30 ng/mL), 75.4% (<50 ng/mL) and 92.5% (<100 ng/mL). CONCLUSION: Anaemia and iron deficiency are highly prevalent in Portugal and largely undiagnosed. Women, young adults and older individuals are more prone to present these conditions and there are marked regional asymmetries. Nationwide strategies for prevention, diagnosis and treatment of these conditions should be implemented.
Assuntos
Anemia Ferropriva/diagnóstico , Anemia Ferropriva/epidemiologia , Vigilância da População , Adolescente , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Gravidez , Prevalência , Adulto JovemRESUMO
Angiotensin-(1-7) (Ang-(1-7)), a peptide constituent of the renin-angiotensin system, has been shown to act as a vasodilator mediator in pre-existing (skin) and newly formed vasculatures (14-day-old sponge implants). Blood flow was determined by the outflow rate of sodium fluorescein applied intradermally or intraimplant and the results were expressed in t(1/2) values (time taken for the fluorescence to reach 50% of the peak in the systemic circulation). We showed that the t(1/2) value was significantly lower (4.1+/-0.46) in the implants compared with the cutaneous vasculature (5.7+/-0.5). Ang-(1-7) 20 ng was able to decrease t(1/2) values in both vasculatures. The specific receptor antagonist, D-Ala7-Ang-(1-7) (A-779), prevented Ang-(1-7)-induced vasodilation and altered the basal vascular tone of the implants. The vasodilator effect was also abolished by nitric oxide (NO) synthase inhibitors in both vasculatures and by indomethacin in the implant. Selective AT(1) and AT(2) receptor antagonists did not alter the vasodilation induced by the peptide. These results establish the vasodilator effect of Ang-(1-7) in the cutaneous and implant vasculature and that the peptide is produced endogenously by the fibrovascular tissue, and suggest that this peptide contributes for the vasodilation found in newly formed vascular beds (wound healing, chronic inflammatory processes and tumors).
Assuntos
Angiotensina I/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Fragmentos de Peptídeos/farmacologia , Pele/irrigação sanguínea , Vasodilatadores/farmacologia , Antagonistas de Receptores de Angiotensina , Animais , Velocidade do Fluxo Sanguíneo/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacologia , Fluoresceína/farmacocinética , Masculino , Camundongos , Neovascularização Fisiológica/fisiologia , Tampões de Gaze Cirúrgicos , Distribuição Tecidual , Vasodilatação/efeitos dos fármacos , Sistema Vasomotor/efeitos dos fármacosRESUMO
Functional and molecular changes in glutamate transporters during kindling epileptogenesis were investigated in hippocampus CA1-region of rats. In control animals total glutamate transporter activity was indicated by the stimulatory effect of the high-affinity transporter blocker L-trans-pyrrolidine-2,4-dicarboxylate on extracellular glutamate and aspartate concentrations, as measured by in vivo microdialysis. This blocker-induced elevation was absent already early during epileptogenesis. CA1 levels of the glutamate transporter subtypes GLAST and GLT-1, analyzed by quantitative immunoblotting, did not change during kindling epileptogenesis. However, the 60% decrease in EAAC-1 level observed in age-matched controls was fully compensated for in kindled animals 4-5 weeks after the last generalized seizure. These results indicate a compensatory change of the neuronal EAAC-1 glutamate transporter in CA1 region during kindling epileptogenesis, which may be the consequence of a decrease in total transporter activity.
Assuntos
Adaptação Fisiológica , Proteínas de Transporte/metabolismo , Epilepsia/etiologia , Hipocampo/metabolismo , Excitação Neurológica , Simportadores , Transportadores de Cassetes de Ligação de ATP/metabolismo , Sistema X-AG de Transporte de Aminoácidos , Animais , Ácido Aspártico/metabolismo , Ácidos Dicarboxílicos/farmacologia , Transportador 1 de Aminoácido Excitatório , Transportador 3 de Aminoácido Excitatório , Espaço Extracelular/metabolismo , Proteínas de Transporte de Glutamato da Membrana Plasmática , Ácido Glutâmico/metabolismo , Immunoblotting , Microdiálise , Pirrolidinas/farmacologia , Ratos , Ratos WistarRESUMO
We investigated angiogenesis, inflammatory cells accumulation and endogenous production of cytokines in sponge implants of tumor-bearing mice. Seven days after inoculation of Ehrlich tumor cells (2.5 x 10(6)), sponge discs were implanted subcutaneously in the dorsa of mice to induce the formation of fibrovascular tissue. The implants of tumor-bearing and non tumor-bearing animals were assessed for neovascularization and leukocyte accumulation, together with levels of relevant cytokines, vascular endothelial growth factor VEGF), tumor necrosis factor alpha (TNF-alpha), CXCL1-3/KC and CCL2/JE. In the implants of tumor-bearing animals angiogenesis (assessed by hemoglobin content and VEGF levels in the implants) and leukocyte accumulation (assessed by myeloperoxidase -MPO- and N- acetylglucosaminidase-NAG-enzyme activities) were all significantly less than those in the implants of non tumor-bearing animals. Although the chemokine CXCL1-3/KC was lower in the implants of tumor-bearing animals, the chemokine CCL2/JE was increased in this group. The production of TNF-alpha in the implants was not modified by the presence of the subcutaneous tumor. The combination of the methodologies used in this study has provided a novel approach to investigate the interaction between two distinct proliferating tissues that share common features (angiogenesis, cell recruitment, inflammation) and has shown that the predominant inhibitory effect of a tumor mass over repair process is associated with altered cytokine production.
Assuntos
Inibidores da Angiogênese/metabolismo , Carcinoma de Ehrlich/metabolismo , Quimiotaxia de Leucócito/fisiologia , Tecido de Granulação/irrigação sanguínea , Neovascularização Patológica , Animais , Carcinoma de Ehrlich/patologia , Quimiocinas/metabolismo , Tecido de Granulação/metabolismo , Tecido de Granulação/patologia , Leucócitos Mononucleares/enzimologia , Leucócitos Mononucleares/patologia , Masculino , Camundongos , Próteses e Implantes , Tampões de Gaze Cirúrgicos , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Thalidomide, clinically used as an antiinflammatory and antitumoral drug, inhibited sponge-induced angiogenesis when administered systemically (100 mg/kg(-1)) in mice. However, it failed to inhibit solid Ehrlich tumor in the same mouse strain. We have used functional, biochemical and histological parameters to assess neovascularization and fibrovascular tissue infiltration of the mice sponge granuloma. The neovascularization growth as detected by development of blood flow and hemoglobin content extracted from the implants showed that thalidomide inhibited fibrovascular tissue formation by 40%. The functional and biochemical parameters correlated well with the histological study. Thalidomide had no inhibitory effect in the development of Ehrlich tumor. The detection of this selective action using the same animal strain bearing two different processes, supports the hypothesis that rather than species specificity, thalidomide is tissue specific. This approach may be used to identify the specificity of other therapeutic agents against distinct angiogenesis-dependent diseases.
Assuntos
Inibidores da Angiogênese/farmacologia , Carcinoma de Ehrlich/irrigação sanguínea , Carcinoma de Ehrlich/tratamento farmacológico , Neovascularização Patológica/tratamento farmacológico , Talidomida/farmacologia , Animais , Carcinoma de Ehrlich/patologia , Granuloma de Corpo Estranho/tratamento farmacológico , Granuloma de Corpo Estranho/etiologia , Granuloma de Corpo Estranho/patologia , Masculino , Camundongos , Neovascularização Patológica/patologiaRESUMO
Clotrimazole (CLT), clinically used as an antifungal drug, inhibited sponge-induced angiogenesis and granulation tissue metabolic activity when administered systemically (120 mg/kg) in rats. We have used functional, biochemical and histological parameters to assess neovascularization and fibrovascular tissue infiltration of the rat sponge granuloma. The sequential development of local blood flow as determined by the outflow rate of sodium fluorescein applied intraimplant, showed that the t1/2 values for the fluorescence peak in the bloodstream decreased in the control group from an initial value of 11 +/- 0.87 min (avascular implants, day 1) to 7.6 +/- 1.5 min at day 7 postimplantation. By contrast t1/2 values in the CLT-treated group remained stable during the 7-day period. The hemoglobin content extracted from the control implants was 2.7 +/- 0.14 microgramsHb/w.w vs. 1.8 +/- 0.18 microgramsHb/w.w in the treated group. The functional and biochemical parameters correlated well with the histological study. Furthermore, the metabolic activity of the sponge-induced granulomas was inhibited by CLT. Because CLT is an inhibitor of signal transduction interfering with the ionic fluxes across the cell membranes, our results suggest that the onset and maintenance of inflammatory angiogenesis induced by subcutaneous implantation of sponge matrix may be regulated by ionic fluxes.
Assuntos
Anti-Infecciosos Locais/uso terapêutico , Antifúngicos/uso terapêutico , Clotrimazol/uso terapêutico , Granuloma/tratamento farmacológico , Granuloma/fisiopatologia , Neovascularização Patológica/tratamento farmacológico , Animais , Anti-Infecciosos Locais/farmacologia , Antifúngicos/farmacologia , Clotrimazol/farmacologia , Masculino , Ratos , Ratos WistarRESUMO
Metaplastic change of the oesophageal epithelium from normal stratified squamous to columnar-lined with intestinal metaplasia results in an increased risk of development of adenocarcinoma. As a result, endoscopic surveillance has been recommended for the surgically-fit patient. The evidence that these programmes are altering clinical outcome to any major degree, however, is weak. This review highlights some of the areas of controversy and outstanding points that need to be clarified to allow establishment of evidence-based medicine for this condition.
Assuntos
Adenocarcinoma/etiologia , Adenocarcinoma/patologia , Esôfago de Barrett/patologia , Transformação Celular Neoplásica , Neoplasias Esofágicas/etiologia , Neoplasias Esofágicas/patologia , Humanos , Fatores de RiscoRESUMO
OBJECTIVE: To determine the prevalence of hepatitis B virus (HBV) markers in surgeons in a major city in Nigeria. DESIGN: A cross-sectional, descriptive study. SETTING: Three major hospitals in Lagos, Nigeria. SUBJECTS: One hundred and sixty seven surgeons (study group) and 193 administrative staff (controls). INTERVENTIONS: Blood samples were taken from subjects and analysed for hepatitis B virus markers (HBsAg, antiHBs and antiHBc) using the ELISA technique. MAIN OUTCOME MEASURES: Hepatitis B virus marker sero-positivity. RESULTS: The prevalence of hepatitis B surface antigen (HBsAg) in the surgeons was found to be 25.7% as compared to 15% in the control group (p=0.01). The frequency of antibody to the surface antigen (antiHBs) was 22.2% among the surgeons and 4.1% in the control group (p<0.001) and that of antibody to the core antigen (antiHBc) was 61.7% in the surgeons as compared to 53.4% in the control (p=0.11). At least one HBV marker was found in 76.6% of the surgeons as compared to 57% in the control group (p=0.0009). CONCLUSION: Health care workers should be immunised against HBV. In Nigeria, HBV immunisation should be considered for inclusion in the EPI.
Assuntos
Cirurgia Geral , Anticorpos Anti-Hepatite B/sangue , Antígenos de Superfície da Hepatite B/sangue , Hepatite B/epidemiologia , Hepatite B/imunologia , Doenças Profissionais/epidemiologia , Adulto , Ensaio de Imunoadsorção Enzimática , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Nigéria/epidemiologia , Estudos SoroepidemiológicosRESUMO
A case of undifferentiated sarcoma of the liver with heart, lung and liver metastases, is reported. We emphasised the role of ultrasound for the early diagnosis of cardiac metastases. As far as we know there is no other report on this tumour in portuguese literature.
Assuntos
Neoplasias Hepáticas/diagnóstico , Sarcoma/diagnóstico , Fatores Etários , Feminino , Humanos , Pessoa de Meia-IdadeRESUMO
To investigate the effects of metformin on angiogenesis, on inflammatory cell accumulation and on production of endogenous cytokines in sponge implant in mice. Polyester-polyurethane sponges were implanted in Swiss mice and metformin (40 or 400mg/kg/day) was given orally for six days. The implants collected at day 7 postimplantation were processed for the assessment of hemoglobin (Hb), myeloperoxidase (MPO), N-acetylglucosaminidase (NAG) e collagen used as indexes for angiogenesis, neutrophil and macrophage accumulation and extracellular matrix deposition, respectively. Relevant inflammatory, angiogenic and fibrogenic cytokines were also determined. Metformin treatment attenuated the main components of the fibrovascular tissue, wet weight, vascularization (Hb content), macrophage recruitment (NAG activity), collagen deposition and the levels of transforming growth factor (TGF-beta1) intraimplant. A regulatory function of metformin on multiple parameters of main components of inflammatory angiogenesis has been revealed giving insight into the potential therapeutic underlying the actions of metformin.
Assuntos
Inibidores da Angiogênese/uso terapêutico , Anti-Inflamatórios/uso terapêutico , Reação a Corpo Estranho/tratamento farmacológico , Inflamação/prevenção & controle , Metformina/uso terapêutico , Neovascularização Patológica/prevenção & controle , Inibidores da Angiogênese/farmacologia , Animais , Anti-Inflamatórios/farmacologia , Quimiocina CCL2/biossíntese , Quimiocina CCL2/genética , Quimiotaxia de Leucócito/efeitos dos fármacos , Colágeno/biossíntese , Colágeno/genética , Avaliação Pré-Clínica de Medicamentos , Reação a Corpo Estranho/metabolismo , Reação a Corpo Estranho/fisiopatologia , Inflamação/fisiopatologia , Masculino , Metformina/farmacologia , Camundongos , Peroxidase/análise , Tampões de Gaze Cirúrgicos , Fator de Crescimento Transformador beta1/biossíntese , Fator de Crescimento Transformador beta1/genética , Fator de Necrose Tumoral alfa/biossíntese , Fator de Necrose Tumoral alfa/genética , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator A de Crescimento do Endotélio Vascular/genéticaAssuntos
Hepatite B/epidemiologia , Especialidades Cirúrgicas/estatística & dados numéricos , Anticorpos Antivirais/sangue , Biomarcadores/sangue , Estudos Transversais , Hepatite B/sangue , Antígenos do Núcleo do Vírus da Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/imunologia , Humanos , Nigéria/epidemiologia , Prevalência , Testes Sorológicos , Cirurgia Bucal/estatística & dados numéricosRESUMO
BACKGROUND AND AIMS: Nucleotides form the building blocks of DNA and are marketed as dietary supplements, alone or in combination with other ingredients, to promote general health. However, there has been only limited scientific study regarding the true biological activity of orally administered nucleotides. We therefore tested their efficacy in a variety of models of epithelial injury and repair. METHODS: Effects on proliferation ([3H] thymidine incorporation) and restitution (cell migration of wounded monolayers) were analysed using HT29 and IEC6 cells. The ability of a nucleotide mixture to influence gastric injury when administered orally and subcutaneously was analysed using a rat indomethacin (20 mg/kg) restraint model. RESULTS: In both cell lines, cell migration was increased by approximately twofold when added at 1 mg/ml (p<0.01); synergistic responses were seen when a mixture of nucleotides was used. Cell proliferation was stimulated by adenosine monophosphate (AMP) in HT29, but not in IEC6, cells. Gastric injury was reduced by approximately 60% when gavaged at 4-16 mg/ml (p<0.05), concentrations similar to those likely to be found in consumers taking nucleotide supplements. Systemic administration of nucleotides was unhelpful. CONCLUSIONS: Nucleotides possess biological activity when analysed in a variety of models of injury and repair and could provide a novel inexpensive approach for the prevention and treatment of the injurious effects of non steroidal anti-inflammatory drugs and other ulcerative conditions of the bowel. Further studies on their potential benefits (and risks) appear justified.
Assuntos
Suplementos Nutricionais , Nucleotídeos/farmacologia , Gastropatias/prevenção & controle , Administração Oral , Animais , Anti-Inflamatórios não Esteroides/toxicidade , Movimento Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Combinação de Medicamentos , Humanos , Indometacina/toxicidade , Injeções Subcutâneas , Masculino , Nucleotídeos/uso terapêutico , Ratos , Ratos Sprague-Dawley , Gastropatias/induzido quimicamente , Células Tumorais Cultivadas , Cicatrização/efeitos dos fármacosRESUMO
OBJECTIVES: A wide range of compounds inhibit formation of new blood vessels in a variety of models, accompanied by decreases in pro-angiogenic cytokines. The authors sought a surrogate marker for the complex process of neovascularization by correlating inhibition of cytokine production with anti-angiogenic effect. METHODS: Three anti-angiogenic compounds, clotrimazole (120 mg kg(-1) day(-1)), thalidomide (100 mg kg(-1) day(-1)), and rosiglitazone (10 mg kg(-1) day(-1)), were used to inhibit angiogenesis developing over 9 days, in sponges implanted subcutaneously in Swiss mice. Angiogenesis was assessed by hemoglobin content and by histology. Content of cytokines in implants was measured by specific immunoassays and accumulation of neutrophils or macrophages in implants by measuring myeloperoxidase or N-acetylglucosaminidase activity, respectively. RESULTS: These compounds caused equal inhibition of angiogenesis (about 40%). However, implant levels of vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF-alpha) or the macrophage chemoattractant cytokine, CCL2/MCP-1/JE, and accumulation of macrophages were more variably inhibited. Only the neutrophil chemokine, CXCL2/KC, was inhibited equally by the three compounds, in this model. CONCLUSIONS: Anti-angiogenic effect was most clearly and closely correlated with levels of the chemokine KC. Thus, measurement of the chemokine KC might provide an adequate surrogate marker for the functional process of neovascularization in our model.
Assuntos
Inibidores da Angiogênese/administração & dosagem , Citocinas/metabolismo , Tecido de Granulação/metabolismo , Neovascularização Patológica/metabolismo , Animais , Biomarcadores/metabolismo , Quimiocina CXCL1 , Quimiocinas , Quimiocinas CXC , Inflamação/metabolismo , Masculino , Camundongos , Infiltração de Neutrófilos/efeitos dos fármacosRESUMO
A crossover design was implemented using four nonlactating dairy cows [mean body weight (BW) = 678 kg] and two rations to measure the true absorption of Ca and P from corn silage. True absorption was calculated after dosing cows intravenously with 45Ca and 32P to measure endogenous fecal losses. Rations consisted mainly of corn silage and were formulated to supply 32 g/d of Ca and 20 g/d of P or 16 g/d of Ca and 12 g/d of P. The percentages of total Ca and P that came from corn silage were 95 and 77%, respectively, for ration 1, and 98 and 79%, respectively, for ration 2. Cows ate more dry matter (10.9 vs. 10.2 kg/d) when consuming the corn silage in ration 1 than when consuming the corn silage in ration 2. Calcium intake was greater for cows fed ration 1 than for cows fed ration 2 (32.6 vs. 16.1 g/d), and P intake was greater for cows fed ration 1 than for cows fed ration 2 (20.1 vs. 11.7 g/d). True absorption of Ca was 34.4 and 43.7% for rations 1 and 2, respectively, and true absorption of P was 84.5 and 93.9% for rations 1 and 2, respectively. True absorption of Ca was about equal to values currently used in the National Research Council (NRC) feeding standards, but true absorption of P was higher than values currently used by the NRC. Fecal endogenous excretion of Ca (mean = 8.23 mg/kg of BW per d) was one-half of the value currently used by the NRC, and fecal endogenous excretion of P (mean = 7.23 mg/kg of BW per d) was only slightly less than NRC values.
Assuntos
Cálcio/farmacocinética , Bovinos/metabolismo , Valor Nutritivo , Fósforo/farmacocinética , Silagem , Zea mays , Absorção , Animais , Digestão , Fezes , Feminino , Necessidades Nutricionais , GravidezRESUMO
A urine cup for continuous and complete collection of urine from cows was constructed from Plastisol, cotton webb strapping, Velcro Brand touch fasteners [corrected], snap-fasteners, denim patches, weather stripping, and vacuum hose. The urine cup was made from Plastisol using a heated lead mold. It was large enough to enclose a 9 cm x 6 cm area around the vulva of a cow and was attached by strapping and Velcro Brand touch fasteners [corrected] to patches glued to the rump. Urine cups were used repeatedly and provided for long-term collection of urine from cows, eliminating the need for indwelling catheters. Applications include long-term nutrient balance, radioisotope, and metabolism studies.
Assuntos
Bovinos/urina , Manejo de Espécimes/veterinária , Medicina Veterinária/instrumentação , Animais , FemininoRESUMO
A crossover experimental design with an extra period was used with four lactating cows (645 kg BW) and two diets to measure the true absorption of Ca and P from alfalfa hay and corn silage. True absorption was calculated after dosing cows intravenously with 45Ca and 32P to measure endogenous fecal losses. In alfalfa hay and alfalfa-corn silage diets, the Ca and P that came from the hay or hay and silage fraction was 94 and 98% and 63 and 84%, respectively. Cows ate more DM (22.7 vs. 20.6 kg/d) and produced more FCM (35.2 vs. 32.0 kg/d) when consuming alfalfa-corn silage compared with alfalfa hay. True absorption of Ca from alfalfa-corn silage was greater (42.2%) than from alfalfa hay (24.6%). Partial true absorption of Ca from alfalfa hay was 23.5% and from corn silage 51.5%. True P absorption for total diet was similar for both alfalfa hay (64.4%) and alfalfa-corn silage (74.6%). Partial true absorption of P from alfalfa hay (67.3%) was different from that from corn silage (80.0%). Fecal endogenous Ca excretion was nearly double the value (31 vs. 16 mg/kg BW) currently used by NRC. True absorption of Ca from alfalfa was lower and from corn silage was higher than currently used in NRC feeding standards. True absorption of P was higher than values currently used by NRC.
Assuntos
Ração Animal , Cálcio da Dieta/metabolismo , Bovinos/fisiologia , Absorção Intestinal/fisiologia , Fósforo/metabolismo , Silagem , Animais , Calcitriol/sangue , Cálcio da Dieta/análise , Feminino , Hidroxiprolina/sangue , Medicago sativa , Fósforo/análise , Distribuição Aleatória , Zea maysRESUMO
Sponge-induced angiogenesis in mice and pharmacological reactivity of the neovasculature have been determined by a fluorimetric method. Pharmacokinetic studies following subcutaneous, intradermal, and intraimplant administration of sodium fluorescein resulted in a biphasic curve from which estimation of t1/2 for absorption and elimination of the dye were possible. Following topical injection of the dye at days 1, 4, 7, 10, and 14 postimplantation, measurement of fluorchrome generated emission in the systemic circulation reflected the development of blood flow in and around the implants and the interaction of the angiogenic site with the systemic circulation. The t1/2 values for the fluorescence peak in the bloodstream decreased steadily from an initial value of 6.41 +/- 0.28 min (avascular implant) to 2.78 +/- 0.23 min in fully vascularized implants (day 14). The reactivity of the neovasculature to ET-1 was dose-dependent and similar to the skin vasculature. By contrast, no reactivity to histamine was detected in the implant blood vessels, whereas it was present in the skin. These results show that the pharmacological response of the neovasculature differs from the response of mature blood vessels. The angiogenic stimulus (bFGF, 300 ng daily) decreased t1/2 for the fluorescence peak, whereas dexamethasone (1 mg/kg) increased it. Parallel histological studies corroborated the functional findings. These observations indicate the suitability of this assay to study angiogenesis, functional and pharmacological characterization of the neovasculature, and the interaction of the angiogenic site with the systemic circulation.