RESUMO
Heptavalent pneumococcal conjugate vaccine (PCV7) was introduced to Japan in 2010. We investigated the impact of PCV7 on childhood community-acquired pneumonia (CAP) and pneumococcal pneumonia (PP). Children aged <5 years living in Chiba city, Japan, who were admitted to hospitals were enrolled to estimate the incidence of CAP based on the mid-year population. PP was determined by the presence of Streptococcus pneumoniae in cultured blood and/or sputum samples of CAP patients. The incidence of CAP and S. pneumoniae isolated from PP patients was compared before (April 2008-March 2009) and after (April 2012-March 2013) the introduction of PCV7 immunization. The annual incidence of CAP was reduced [incidence rate ratio 0·81, 95% confidence interval (CI) 0·73-0·90]. When comparing post-vaccine with pre-vaccine periods, the odds ratio for PP incidence was 0·60 (95% CI 0·39-0·93, P = 0·024). PCV7-covered serotypes markedly decreased (66·6% in pre-vaccine vs. 15·6% in post-vaccine, P < 0·01), and serotypes 6C, 15A, 15C and 19A increased. Multidrug-resistant international clones in the pre-vaccine period (Spain6B-2/ST90, Taiwan19F-14/ST236) decreased, while Sweden15A-25/ST63 was the dominant clone in the post-vaccine period. A significant reduction in the incidence of both CAP hospitalizations and culture-confirmed PP of vaccine serotypes was observed at 2 years after PCV7 vaccination.
Assuntos
Vacina Pneumocócica Conjugada Heptavalente , Pneumonia Pneumocócica/epidemiologia , Pneumonia Pneumocócica/prevenção & controle , Streptococcus pneumoniae/classificação , Pré-Escolar , Infecções Comunitárias Adquiridas/epidemiologia , Infecções Comunitárias Adquiridas/microbiologia , Infecções Comunitárias Adquiridas/prevenção & controle , Farmacorresistência Bacteriana , Feminino , Hospitalização/tendências , Humanos , Incidência , Lactente , Japão , Masculino , Tipagem de Sequências Multilocus , Pneumonia Pneumocócica/microbiologia , Estudos Retrospectivos , Sorogrupo , Streptococcus pneumoniae/efeitos dos fármacosRESUMO
AIM: To analyse the effects of thyroid hormones on ß-cell function and glucose metabolism in people with prediabetes who are euthyroid. METHODS: A total of 111 people who were euthyroid underwent 75-g oral glucose tolerance tests, of whom 52 were assigned to the normal glucose tolerance and 59 to the prediabetes groups. Homeostatic model assessment of ß-cell function, insulinogenic index and areas under the curve for insulin and glucose were evaluated as indices of pancreatic ß-cell function. RESULTS: In both groups, BMI, fasting insulin, homeostasis model assessment ratio and HDL cholesterol correlated significantly with all indices of pancreatic ß-cell function. Free triiodothyronine correlated positively with all insulin secretion indices in the prediabetes group. Multiple linear regression analysis showed that free triiodothyronine was an independent variable that had a positive correlation with all indices of ß-cell function in the prediabetes group. By contrast, no such correlation was found in the normal glucose tolerance group. CONCLUSIONS: Free triiodothyronine is associated with both basal and glucose-stimulated insulin secretion in people with prediabetes who are euthyroid; therefore, the regulation of insulin secretion by thyroid hormones is a potentially novel therapeutic target for the treatment of diabetes.
Assuntos
Células Secretoras de Insulina/metabolismo , Insulina/metabolismo , Estado Pré-Diabético/fisiopatologia , Glândula Tireoide/metabolismo , Tri-Iodotironina/metabolismo , Regulação para Cima , Adulto , Idoso , Índice de Massa Corporal , HDL-Colesterol/sangue , Feminino , Teste de Tolerância a Glucose , Humanos , Insulina/sangue , Resistência à Insulina , Secreção de Insulina , Masculino , Pessoa de Meia-Idade , Sobrepeso/complicações , Estado Pré-Diabético/sangue , Estado Pré-Diabético/complicações , Estado Pré-Diabético/metabolismo , Índice de Gravidade de Doença , Solubilidade , Tri-Iodotironina/sangue , Tri-Iodotironina/químicaRESUMO
A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/GII.P17-GII.17, this variant has a newly identified GII.P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important.
Assuntos
Substituição de Aminoácidos/genética , Infecções por Caliciviridae/genética , Surtos de Doenças , Disenteria/genética , Norovirus/classificação , Norovirus/genética , Infecções por Caliciviridae/epidemiologia , Proteínas do Capsídeo/genética , Disenteria/epidemiologia , Fezes/virologia , Genótipo , Humanos , Japão/epidemiologia , Norovirus/isolamento & purificação , RNA Viral/genética , RNA Polimerase Dependente de RNA/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNARESUMO
Volcanic acidification creates extreme soil conditions, where rhizotoxicity from extremely low pH (2-3) and high Al3+ strongly inhibit plant growth. C. angustisquama is a dominant extremophyte in highly acidic solfatara fields, where no other vascular plants can survive. Here we investigated the key abiotic stressor determining survival of this extremophyte. Soil analyses and topographic surveys were conducted to examine the effects of low pH and Al3+ , two major abiotic stressors in acidic soils, on the occurrence of C. angustisquama in solfatara fields. Hydroponic culture experiments were also performed to test its growth responses to these stressors. In field surveys, the spatial distribution of soil pH was consistent with vegetation zonation within a solfatara field. In contrast, soil exchangeable Al content was overall low due to strong eluviation. Statistical analysis also supported the significant role of soil pH in determining the distribution of C. angustisquama in a solfatara field. Furthermore, hydroponic culture experiments revealed a higher tolerance of C. angustisquama to low pH than a sister species, especially in the range pH 2-3, corresponding to the pH values of the actual habitats of C. angustisquama. Conversely, no significant interspecific difference was detected in Al3+ tolerance, indicating that both species had high Al3+ tolerance. This study suggests that low pH is a critical abiotic stressor leading to formation of the extremophyte in highly acidic solfatara fields. In contrast, C. angustisquama displayed high tolerance to Al3+ toxicity, probably acquired prior to speciation.
Assuntos
Carex (Planta) , Cyperaceae , Solo/química , Ecossistema , Concentração de Íons de HidrogênioRESUMO
OBJECTIVE: Given recent evidence that hydrogen sulfide (H(2)S), a gasotransmitter, promotes somatic pain through redox modulation of T-type Ca(2+) channels, the roles of colonic luminal H(2)S in visceral nociceptive processing in mice were examined. METHODS: After intracolonic administration of NaHS, an H(2)S donor, visceral pain-like behaviour and referred abdominal allodynia/hyperalgesia were evaluated. Phosphorylation of extracellular signal-regulated protein kinase (ERK) in the spinal dorsal horn was determined immunohistochemically. The whole-cell recording technique was used to evaluate T-type Ca(2+) currents (T-currents) in cultured dorsal root ganglion (DRG) neurons. RESULTS: Like capsaicin, NaHS, administered intracolonically at 0.5-5 nmol per mouse, triggered visceral nociceptive behaviour accompanied by referred allodynia/hyperalgesia in mice. Phosphorylation of ERK in the spinal dorsal horn was detected following intracolonic NaHS or capsaicin. The behavioural effects of intracolonic NaHS were abolished by a T-type channel blocker or an oxidant, but not inhibitors of L-type Ca(2+) channels or ATP-sensitive K(+) (K(ATP)) channels. Intraperitoneal NaHS at 60 micromol/kg facilitated intracolonic capsaicin-evoked visceral nociception, an effect abolished by the T-type channel blocker, although it alone produced no behavioural effect. In DRG neurons, T-currents were enhanced by NaHS. CONCLUSIONS: These findings suggest that colonic luminal H(2)S/NaHS plays pronociceptive roles, and imply that the underlying mechanisms might involve sensitisation/activation of T-type channels probably in the primary afferents, aside from the issue of the selectivity of mibefradil.
Assuntos
Colo/metabolismo , Sulfeto de Hidrogênio/efeitos adversos , Nociceptores/efeitos dos fármacos , Animais , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio Tipo T/metabolismo , Capsaicina/farmacologia , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Gânglios Espinais/metabolismo , Sulfeto de Hidrogênio/farmacologia , Imuno-Histoquímica , Masculino , Mibefradil/farmacologia , Camundongos , Dor/metabolismo , Técnicas de Patch-Clamp , Fosforilação , Sulfetos/farmacologiaRESUMO
Droplet microfluidics has become a powerful tool in precision medicine, green biotechnology, and cell therapy for single-cell analysis and selection by virtue of its ability to effectively confine cells. However, there remains a fundamental trade-off between droplet volume and sorting throughput, limiting the advantages of droplet microfluidics to small droplets (<10 pl) that are incompatible with long-term maintenance and growth of most cells. We present a sequentially addressable dielectrophoretic array (SADA) sorter to overcome this problem. The SADA sorter uses an on-chip array of electrodes activated and deactivated in a sequence synchronized to the speed and position of a passing target droplet to deliver an accumulated dielectrophoretic force and gently pull it in the direction of sorting in a high-speed flow. We use it to demonstrate large-droplet sorting with ~20-fold higher throughputs than conventional techniques and apply it to long-term single-cell analysis of Saccharomyces cerevisiae based on their growth rate.
Assuntos
Microfluídica , Saccharomyces cerevisiae , Eletrodos , Microfluídica/métodosRESUMO
OBJECTIVE: Accumulating evidence suggests that B-cell depletion therapy by rituximab may be effective for autoimmune disorders. However, an optimal dose of rituximab and a mechanism of its action remain to be established. We performed a dose-escalation study for treatment of Japanese patients with autoimmune diseases including eight with SLE and one with Evans' syndrome. METHODS: Rituximab was infused intravenously, weekly 4 times in a dose-escalating fashion at three different doses of 100, 250 or 375 mg/m(2) to three patients each. Immunological parameters were monitored at certain points until 12 months after the treatment. RESULTS: Rituximab was well tolerated and safe in these patients. Seven out of eight SLE patients and one with Evans' syndrome clinically responded completely or partially to the treatment. Four patients achieved long-term remission (18-30 months) without any additional treatment. In these patients, a significant decrease in circulating B cells continued for 6 months after the treatment. The mean fluorescence intensities of CD19, CD21, CD40 and BR3 on the residual B cells as well as the percentage of CD69+ CD4+ T cells decreased significantly. Serum TNF-alpha levels decreased significantly on day 2. The Th1/Th2 balance of CD4+ T cells gradually shifted towards a Th1 type by 6 months. CONCLUSION: In addition to B-cell depletion, modification of B-cell and T-cell phenotypes as well as cytokine profiles may be involved in the action of rituximab.
Assuntos
Anemia Hemolítica Autoimune/tratamento farmacológico , Anticorpos Monoclonais/administração & dosagem , Subpopulações de Linfócitos B/efeitos dos fármacos , Lúpus Eritematoso Sistêmico/tratamento farmacológico , Subpopulações de Linfócitos T/efeitos dos fármacos , Adulto , Anemia Hemolítica Autoimune/imunologia , Anticorpos Monoclonais/efeitos adversos , Anticorpos Monoclonais/uso terapêutico , Anticorpos Monoclonais Murinos , Antígenos de Superfície/metabolismo , Subpopulações de Linfócitos B/imunologia , Citocinas/sangue , Relação Dose-Resposta a Droga , Feminino , Humanos , Imunossupressores/administração & dosagem , Imunossupressores/efeitos adversos , Imunossupressores/uso terapêutico , Lúpus Eritematoso Sistêmico/imunologia , Masculino , Pessoa de Meia-Idade , Projetos Piloto , Rituximab , Subpopulações de Linfócitos T/imunologia , Células Th1/imunologia , Células Th2/imunologiaRESUMO
OBJECTIVE: To quantify the activated B cells in the peripheral blood and salivary glands of patients with Sjögren's syndrome (SS) by analyzing the expression of RP105 molecule on the B cells. METHODS: The expression of RP105 on the peripheral blood B cells of patients with SS (19 cases) was analyzed by flow cytometry. RP105-positive and negative B cells were sorted and cultured in vitro and the amount of immunoglobulins (IgG and IgM) produced in the supernatant was measured by enzyme-linked immunosorbent assay (ELISA). Salivary gland biopsy samples from 9 SS patients were histologically evaluated and the sequential frozen sections were separately immunostained by anti-RP105 and anti-CD20 monoclonal antibodies. RESULTS: A significantly higher proportion of peripheral blood RP105-negative B cells was found in SS patients than in healthy individuals. RP105-negative, but not positive, B cells from SS patients were capable of producing IgG and IgM spontaneously in vitro, which was enhanced by the addition of Staphylococcus aureus Cowan I strain (SAC) or IL-6. Salivary glands from 2 of 9 SS patients were found to have lymphoid follicles whose germinal centers consisted of RP105-negative B cells. Moreover, a larger proportion of B cells extensively infiltrating the area other than lymphoid follicles was also RP105-negative. CONCLUSION: RP105-negative B cells, a subset of highly activated and well differentiated B cells, which are increased in number in the peripheral blood and extensively infiltrate salivary glands, may be responsible for the production of class-switched immunoglobulin in SS. In addition, those cells might be associated with the inflammation and tissue damage of the salivary glands.
Assuntos
Antígenos CD/análise , Linfócitos B/química , Glândulas Salivares/citologia , Síndrome de Sjogren/patologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Antígenos CD/sangue , Feminino , Citometria de Fluxo , Humanos , Imunoglobulina G/análise , Imunoglobulina M/análise , Ativação Linfocitária/fisiologia , Contagem de Linfócitos , Masculino , Pessoa de Meia-Idade , Síndrome de Sjogren/sangueAssuntos
Proteínas de Peixes/genética , Gadus morhua/embriologia , Células Germinativas/fisiologia , Salmo salar/embriologia , Animais , Movimento Celular , Proteínas de Peixes/metabolismo , Marcadores Genéticos , Células Germinativas/citologia , Hibridização In Situ/veterinária , Microinjeções/veterinária , Dados de Sequência Molecular , Especificidade de Órgãos , Análise de Sequência de DNA/veterináriaRESUMO
Intrauterine growth restriction (IUGR) has a multifactorial pathogenesis and is an important cause of perinatal mortality. The relationship between fetal weight and placental blood flow in an animal model of IUGR has been investigated, showing that fetal growth is regulated by placental blood flow. The aim of the present study was to determine whether ischemia-reperfusion (I/R) injury stimulates the prostaglandin E2 (PGE2) system or the vascular endothelial growth factor (VEGF) system in the placenta of a rat IUGR model. COX-2 is reported to be involved in ischemic damage in many organs. There are 4 types of PGE2 receptor (EP1, EP2, EP3 and EP4). It is well known that EP1 and EP3 is associated with vasoconstriction. In the present study, vessels were occluded in the right uterine horn on day 17 of pregnancy in rats, and the clamps were removed after 30 min of ischemia. At 24h, 48 h, and 5 days after I/R injury, the live fetuses and placentas were obtained by cesarean section. This study revealed that I/R injury caused IUGR 5 days after the treatment. COX-2 expression and EP3 receptor expression were significantly elevated at 24h after I/R injury, but VEGF mRNA expression was not altered in the placenta from the ischemic horn compared with the non-ischemic horn. These results suggested that induction of the COX-2-EP3 system in the placenta may be one of the causes of IUGR induced by uterine ischemia, because the EP3 receptor and PGE2 are well known to mediate vasoconstriction in many organs.
Assuntos
Ciclo-Oxigenase 2/metabolismo , Retardo do Crescimento Fetal/metabolismo , Receptores de Prostaglandina E/metabolismo , Animais , Modelos Animais de Doenças , Feminino , Peso Fetal , Imuno-Histoquímica , Placenta/metabolismo , Gravidez , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores de Prostaglandina E Subtipo EP3 , Traumatismo por Reperfusão/metabolismo , Fatores de Tempo , Útero/irrigação sanguínea , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
OBJECTIVE: [corrected] To determine the clinical characteristics of patients with myelodysplastic syndrome (MDS)-associated Behçet's disease (BD) in Japan. METHODS: 54 Japanese cases of MDS-associated BD obtained from the literature and from our own clinical experience were reviewed. The clinical features of MDS-associated BD were compared with those of the 1991 nationwide BD survey in Japan. RESULTS: In MDS-associated BD, the average age at onset was 42.6 years, which was 6.9 years later than for all BD patients; females developed disease more frequently than males (male: female ratio = 0.80). In MDS-associated BD cases, the occurrence of eye lesions was significantly lower, the frequency of intestinal lesions was markedly higher, and the rate of HLA-B51 positivity was lower than that in all BD. BD and MDS developed nearly simultaneously in 49.0% of cases; BD preceded MDS in 31.4% of the cases. The distribution of the age at BD onset showed two peaks, one in the 3rd decade and the other in the 6th decade. Females were more likely to develop younger-onset disease, while men were more likely to develop older-onset MDS-associated BD. Furthermore, in the older-onset group, BD was diagnosed together with or after the diagnosis of MDS, while half of the younger-onset group developed BD earlier than MDS. CONCLUSION: MDS-associated BD patients form a distinct subset of patients. There may, in fact, be two major groups of MDS-associated BD patients based on age, gender, and temporal relationship of the two diseases.
Assuntos
Síndrome de Behçet/complicações , Síndromes Mielodisplásicas/complicações , Adolescente , Adulto , Idade de Início , Idoso , Idoso de 80 Anos ou mais , Síndrome de Behçet/etnologia , Síndrome de Behçet/patologia , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Japão , Masculino , Pessoa de Meia-Idade , Síndromes Mielodisplásicas/etnologia , Síndromes Mielodisplásicas/patologia , Estudos Retrospectivos , Razão de MasculinidadeRESUMO
INTRODUCTION: n-3 Polyunsaturated fatty acids such as eicosapentaenoic acid (EPA), which are abundant in fish oil, have been shown to delay the onset of cardiovascular events. We previously established DahlS.Z-Leprfa/Leprfa (DS/obese) rats, which are derived from a cross between Dahl salt-sensitive and Zucker rats, as a model of metabolic syndrome. This study has now explored the influence of highly purified EPA on cardiac and adipose tissue pathophysiology in this animal model. MATERIALS AND METHODS: DS/obese rats were administered EPA (300 or 1,000 mg kg-1 d-1, per os) or vehicle from age 9 to 13 weeks. Homozygous lean (DahlS.Z-Lepr+/Lepr+, or DS/lean) littermates were studied as controls. RESULTS: Whereas EPA had no effect on body weight, food intake or systolic blood pressure in DS/obese rats, it attenuated cardiac fibrosis, diastolic dysfunction, oxidative stress and inflammation in these animals. In addition, EPA did not affect insulin resistance but reduced adipocyte hypertrophy and inflammation in visceral fat of DS/obese rats. Moreover, EPA increased circulating levels of adiponectin as well as attenuated both the down-regulation of AMP-activated protein kinase phosphorylation and the up-regulation of phosphorylation of the p65 subunit of nuclear factor-kB in the heart of DS/obese rats. CONCLUSIONS: Treatment of DS/obese rats with EPA did not affect hypertension but reduced cardiac fibrosis and diastolic dysfunction, with the latter effects being accompanied by AMP-activated protein kinase activation and inactivation of nuclear factor-kB signalling in the heart, possibly as a result of an increase in adiponectin secretion. EPA may be suitable for the treatment of cardiac injury associated with metabolic syndrome.
RESUMO
OBJECTIVES: Chronic stress affects the central nervous system as well as endocrine, metabolic and immune systems. However, the effects of cold stress on cardiovascular and metabolic disorders in metabolic syndrome (MetS) have remained unclear. We recently characterized DahlS.Z-Lepr(fa)/Lepr(fa) (DS/obese) rats, derived from a cross between Dahl salt-sensitive and Zucker rats, as a new animal model of MetS. We have now investigated the effects of chronic cold stress and glucocorticoid receptor (GR) blockade on cardiac and adipose tissue pathology as well as on metabolic parameters in this model. METHODS: DS/obese rats were exposed to cold stress (immersion in ice-cold water to a depth of 1-2 cm for 2 h per day) with or without subcutaneous injection of the GR antagonist RU486 (2 mg kg(-1)day(-1)) for 4 weeks beginning at 9 weeks of age. Age-matched homozygous lean (DahlS.Z-Lepr(+)/Lepr(+)) littermates served as a control. RESULTS: Chronic cold stress exacerbated hypertension as well as left ventricular (LV) hypertrophy, fibrosis and diastolic dysfunction in DS/obese rats in a manner sensitive to RU486 treatment. Cold stress with or without RU486 did not affect body weight or fat mass. In contrast, cold stress further increased cardiac oxidative stress as well as macrophage infiltration and proinflammatory gene expression in LV and visceral fat tissue, with all of these effects being attenuated by RU486. Cold stress also further increased GR and 11ß-hydroxysteroid dehydrogenase type 1 mRNA and protein abundance in LV and visceral adipose tissue, and these effects were again inhibited by RU486. In addition, RU486 ameliorated the stress-induced aggravation of dyslipidemia, glucose intolerance and insulin resistance in DS/obese rats. CONCLUSIONS: Our results implicate GR signaling in cold stress-induced exacerbation of cardiac and adipose tissue pathology as well as of abnormal glucose and lipid metabolism in a rat model of MetS.
Assuntos
Tecido Adiposo/efeitos dos fármacos , Temperatura Baixa , Coração/efeitos dos fármacos , Mifepristona/farmacologia , Receptores de Glucocorticoides/antagonistas & inibidores , Estresse Fisiológico/efeitos dos fármacos , 11-beta-Hidroxiesteroide Desidrogenase Tipo 1/metabolismo , Tecido Adiposo/patologia , Animais , Modelos Animais de Doenças , Fibrose/tratamento farmacológico , Intolerância à Glucose , Coração/fisiopatologia , Hipertrofia Ventricular Esquerda/tratamento farmacológico , Hipertrofia Ventricular Esquerda/metabolismo , Masculino , Síndrome Metabólica/tratamento farmacológico , Ratos , Ratos Endogâmicos Dahl , Ratos Zucker , Receptores de Glucocorticoides/metabolismo , Receptores para Leptina/metabolismoRESUMO
Activation of P2X7 receptor (P2X7R), a purinergic receptor, expressed by neurons is well-known to induce their death, but whether or not their sensitivity to ATP depends on its expression levels remains unclear. Here, we examined the effect of the expression level of P2X7Rs on cell viability using pure neuron cultures, co-cultures with astrocytes derived from SJL- and ddY-strain mice, and mouse P2X7R-expressing HEK293T cell systems. Treatment of pure neuron cultures with 5mM ATP for 2h, followed by 3-h incubation in fresh medium, resulted in death of both types of neurons, and their death was prevented by administration of P2X7R-specific antagonists. In both SJL- and ddY-neurons, ATP-induced neuronal death was inhibited by a mitochondrial permeability transition pore inhibitor cyclosporine A, mitochondrial dysfunction being involved in their death. The ATP-induced neuronal death was greater for SJL-neurons than for ddY-ones, this being correlated with the expression level of P2X7R in them, and the same results were obtained for the HEK293T cell systems. Co-culture of neurons with astrocytes increased the ATP-induced neuronal death compared to the case of pure neuron cultures. Overall, we reveal that neuronal vulnerability to ATP depends on the expression level of P2X7R, and co-existence of astrocytes exacerbates ATP-induced neuronal death.
Assuntos
Trifosfato de Adenosina/farmacologia , Morte Celular/fisiologia , Neurônios/metabolismo , Receptores Purinérgicos P2X7/metabolismo , Animais , Astrócitos/metabolismo , Western Blotting , Morte Celular/efeitos dos fármacos , Células Cultivadas , Técnicas de Cocultura , Células HEK293 , Humanos , Imuno-Histoquímica , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/patologia , Neurônios/efeitos dos fármacos , Reação em Cadeia da PolimeraseRESUMO
Hog mucosal heparin (N-sulfate, 0.84 mol; O-sulfate, 1.55 mol; N-acetyl, 0.12 mol; anticoagulant activity assayed by the method of U.S. Pharmacopeia, 161 USP units/mg) or its partially N-desulfated heparin (N-sulfate, 0.71 mol; O-sulfate, 1.47 mol; N-acetyl, 0.12 mol; anticoagulant activity, 117 USP units/mg/ was reacted with 5-isothiocyanatofluorescein in 0.5 M carbonate buffer (pH 8.5) at 35 degrees C for 6 h to yield the corresponding N-fluoresceinylthiocarbamoyl heparins (lambdaem 516 nm, lambdaex 491 nm; degree of substitution 0.006 and 0.013, respectively, anticoagulant activity, 174 and 140 USP units/mg, respectively). The fluorescent heparin (degree of substitution, 0.006; 174 USP units/mg) was injected into rabbits intravenously. The half-life of the fluorescent heparin determined by fluorometry was 24 min, that determined by the clotting time assay was 39 min. The time-course of concentration and the half-life of the fluorescent heparin and of the starting heparin obtained by the clotting time assay were virtually identical.
Assuntos
Fluoresceínas , Heparina , Animais , Bioensaio , Fluoresceínas/sangue , Meia-Vida , Heparina/sangue , Cinética , Coelhos , Espectrometria de Fluorescência , SuínosRESUMO
Clostridial collagenase (EC 3.4.24.3) catalyzes the hydrolysis of (Pro-Pro-Gly)5 at minimum of three different rates, producing Pro-Pro, Gly-Pro-Pro and Gly-Pro-Pro-Gly, and various intermediate peptides. The intermediate and final products were separated by cation-exchange column chromatogrphy and identified, and their rates of formation were measured. Pro-Pro was released most rapidly with formation of the tridecapeptide. After the initial release of the N-terminal Pro-Pro, hexa- and heptapeptides were formed in larger amounts than tri-, tetra-, nona- and decapeptides from the tridecapeptide. The rates of disappearance of the intermediates decreased in the order trideca- greater than deca- and nona- greater than heptapeptide. The results indicate that the enzyme hydrolyzes inner linkages of the tridecapeptide having N- and C-terminal Gly residues, forming large peptides, preferentially to outer linkages, forming the tri- and tetrapeptides.
Assuntos
Clostridium/enzimologia , Glicina , Colagenase Microbiana/metabolismo , Peptídeos/metabolismo , Prolina , Modelos Biológicos , Peso Molecular , Oligopeptídeos/metabolismoRESUMO
Peptide inhibitors of angiotensin I-converting enzyme (peptidyldipeptide hydrolase, EC 3.4.15.1) were produced by digesting gelatin with bacterial collagenase. The inhibitors were isolated from the digests with a combination of alcohol fractionation, treatment with Amberlite CG-50 column, gel filtration through Sephadex G-25, and Dowex 50 column and paper chromatography. Nine peptide fractions were purified to apparent homogeneity judging by thin-layer and ion-exchange column chromatography, and amino acid composition. Amino acid sequences of the peptides were determined: 2 were found to be mixtures of peptides and the sequence of another was only partially determined. Six of the peptides were potent inhibitors of the converting enzyme, while the other three were less active. 6 peptides were substrates for the enzyme. The enzyme released a dipeptide, Ala-Hyp from one peptide and was strongly inhibited by this dipeptide. The remainder of the parent peptides was a less effective inhibitor.
Assuntos
Carboxipeptidases/antagonistas & inibidores , Gelatina , Lisina Carboxipeptidase/antagonistas & inibidores , Colagenase Microbiana , Peptídeos/farmacologia , Sequência de Aminoácidos , Inibidores Enzimáticos/isolamento & purificação , Peptídeos/isolamento & purificaçãoRESUMO
Hog mucosal heparin purified on Sephadex G-100 (anticoagulant activity assayed by the method of the United States Pharmacopoeia, 179 units/mg) was separated by hydrophobic interaction chromatography on Phenyl-Sepharose CL-4B into two groups, one with high affinity and another with low affinity for the gels. The former group was further separated into three fractions differing in hydrophobicity. The anticoagulant activities of the fractions with higher hydrophobicity ranged from 210 to 254 units/mg, whereas that of the fraction with lower hydrophobicity was 100 units/mg. The difference in antithrombin III-activation potency was much more prominent. The data obtained from affinity chromatography of these fractions on antithrombin III-Sepharose also substantiated the observed difference in anticoagulant activity. Analytical data of the fractions revealed a characteristic difference in both N-acetyl content and molecular size. While the N-acetyl content (mol/mol of hexosamine) and Kav value (on Ultrogel AcA44) of the fraction with the lowest hydrophobicity were 0.12 mol and 0.48, those of the fractions with higher hydrophobicity were 0.15-0.17 mol and 0.35-0.23, respectively.
Assuntos
Heparina/isolamento & purificação , Animais , Coagulação Sanguínea/efeitos dos fármacos , Fenômenos Químicos , Química , Cromatografia de Afinidade , Heparina/farmacologia , Técnicas In Vitro , Peso Molecular , SuínosRESUMO
A blood group A active substance was isolated from an acetone-dried powder of oyster viscera by extraction with 0.1 M NaCl after heating a homogenate with extraction medium, in boiling water. After the removal of the acidic fraction with cetylpyridinium chloride, the separated neutral fraction was digested successively with alpha-amylase and amyloglucosidase to remove glycogen. The blood group A-active portion was eluted from a Sepharose 4B column and purified by DEAE-Sephadex column chromatography. The purified active substance was homogeneous by polyacrylamide gel electrophoresis, and its molecular weight was estimated as 100 000 by sedimentation equilibrium. The sugar content of the purified active substance, expressed in percentage of dry weight, was galactosamine, 16.6; galactose, 12.5; fucose, 9.9; glucosamine, 4.6; and glucose, 3.3. Sialic acid was not detected. Total amino acid content was 23.0% and the main constituents were threonine, proline and serine. The ORD spectrum indicated that the hexosamines were N-acetylated. Absence of glycolipid was confirmed by the analysis of fatty acid and sphingosine base. This active substance had a strong blood group A activity (0.04 mug/ml) but neither B nor H activity; it interacted with lima bean lectin but not with concanavalin A.