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1.
J Biosci ; 472022.
Artigo em Inglês | MEDLINE | ID: mdl-36222128

RESUMO

The prophenoloxidase (PPO) activation system is an important innate immune defense mechanism in arthropods. Actias selene is a rare and important wild silk insect that can spin high-quality cocoon silk, but, other than its morphology, its molecular mechanism is rarely reported. Here, we report the purification and characterization of a novel KSPI gene from A. selene (AsKSPI, which can negatively regulate PPO activation. Its open reading frame (ORF) was 291 bp, encoding 96 amino acids. Real-time quantitative PCR (RT-qPCR) showed that AsKSPI mRNA was significantly expressed in the fat body. Immunostimulatory tests showed that the mRNA levels of AsKSPI in the fat body were up-regulated following injection of Micrococcus luteus, Escherichia coli, Beauveria bassiana, and nuclear polyhedrosis virus (NPV). Enzyme activity experiments showed that the purified recombinant AsKSPI could inhibit the activation of PPO in hemolymph of A. selene, but did not affect phenoloxidase (PO) activity after PPO had been activated. So, AsKSPI could regulate the innate immunity of A. selene through the PPO cascade. These findings will contribute to the understanding of the immune mechanism of wild silkworm and provide a basis for better protection and utilization of special economic insect resources.


Assuntos
Bombyx , Serpinas , Aminoácidos/metabolismo , Animais , Bombyx/genética , Escherichia coli/genética , Escherichia coli/metabolismo , Imunidade Inata/genética , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Monofenol Mono-Oxigenase/metabolismo , RNA Mensageiro/metabolismo , Inibidores de Serina Proteinase/farmacologia , Serpinas/genética , Serpinas/metabolismo , Seda/metabolismo
2.
IEEE Trans Biomed Circuits Syst ; 16(6): 1250-1260, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36150001

RESUMO

Many efforts have been made to improve the neuron integration efficiency on neuromorphic chips, such as using emerging memory devices and shrinking CMOS technology nodes. However, in the fully connected (FC) neuromorphic core, increasing the number of neurons will lead to a square increase in synapse & dendrite costs and a high-slope linear increase in soma costs, resulting in an explosive growth of core hardware costs. We propose a co-designed neuromorphic core (SRCcore) based on the quantized spiking neural network (SNN) technology and compact chip design methodology. The cost of the neuron/synapse module in SRCcore weakly depends on the neuron number, which effectively relieves the growth pressure of the core area caused by increasing the neuron number. In the proposed BICS chip based on SRCcore, although the neuron/synapse module implements 1∼16 times of neurons and 1∼66 times of synapses, it only costs an area of 1.79 × 107 F2, which is 7.9%∼38.6% of that in previous works. Based on the weight quantization strategy matched with SRCcore, quantized SNNs achieve 0.05%∼2.19% higher accuracy than previous works, thus supporting the design and application of SRCcore. Finally, a cross-modeling application is demonstrated based on the chip. We hope this work will accelerate the development of cortical-scale neuromorphic systems.


Assuntos
Redes Neurais de Computação , Neurônios , Neurônios/fisiologia , Computadores , Sinapses , Tecnologia
3.
Sci Rep ; 12(1): 12983, 2022 07 28.
Artigo em Inglês | MEDLINE | ID: mdl-35902602

RESUMO

This paper proposes an advanced encryption standard (AES) cryptosystem based on memristive neural network. A memristive chaotic neural network is constructed by using the nonlinear characteristics of a memristor. A chaotic sequence, which is sensitive to initial values and has good random characteristics, is used as the initial key of AES grouping to realize "one-time-one-secret" dynamic encryption. In addition, the Rivest-Shamir-Adleman (RSA) algorithm is applied to encrypt the initial values of the parameters of the memristive neural network. The results show that the proposed algorithm has higher security, a larger key space and stronger robustness than conventional AES. The proposed algorithm can effectively resist initial key-fixed and exhaustive attacks. Furthermore, the impact of device variability on the memristive neural network is analyzed, and a circuit architecture is proposed.


Assuntos
Segurança Computacional , Redes Neurais de Computação , Algoritmos , Coleta de Dados
5.
Oncol Lett ; 10(4): 2403-2409, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26622860

RESUMO

Multiple myeloma is a type of malignancy, which affects the plasma cells of the bone marrow. Recent studies have found that malignant plasma cells may express urokinase plasminogen activator (uPA) and uPA receptor (uPAR), and that initiation of proteolytic events by this system contributes to the process of invasion and destruction of the bone marrow. Studies have also suggested that the level of the soluble form of uPAR (suPAR) may act as a marker for prognosis in patients with multiple myeloma, and that there is an association between uPAR/suPAR expression, and clinical characteristics, efficacy of treatment in disease control and patient survival. In order to investigate this, the present study used flow cytometry to detect the monoclonal antibodies associated with multiple myeloma, specifically, uPAR (CD87), CD56 and CD38. Patients with multiple myeloma were divided into the following groups: The effective groups (remission and stable disease) and the ineffective group (progressive disease). suPAR expression in the effective groups was 257.6±32.47 pg/ml and 331.0±99.80 pg/ml respectively, which was not significantly different from that of the normal control group (P>0.05). By contrast, the suPAR level in the invalid group was 562.2±291.0 pg/ml, which was significantly different from the levels in the normal control group (P<0.01) and the effective groups (P<0.05). suPAR levels were positively correlated with disease stage (P<0.01), renal function (P<0.05), C-reactive protein (P<0.005), ß2-microglobulin (P<0.001), extramedullary involvement (P<0.001), chromosome 13 deletion (P<0.01) and survival >2 years (P<0.01). They were was negatively correlated with hemoglobin concentration. No correlation was observed between uPAR expression and suPAR levels. The present study also indicated that the stage of disease and suPAR expression were independent factors, which predicted survival of <2 years. In conclusion, high suPAR expression appears to predict disease progression, a shortened survival period and early extramedullary infiltration.

6.
J Hand Surg Eur Vol ; 40(7): 735-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26056128

RESUMO

UNLABELLED: We compared the short-term (3 months) and long-term (2 years) outcomes and complications of percutaneous release of 187 trigger digits of 154 patients treated between 2009 and 2012, all treated by a single surgeon. The 154 patients included 48 patients with diabetes mellitus and 106 non-diabetic patients. The only short-term complication was pain, occurring in three digits (5%) in the diabetic patients and six digits (5%) in the non-diabetic patients. The long-term complications were pain in 15 digits (25%) in the diabetic patients and 18 digits (14%) in the non-diabetic patients. This was not significant (p = 0.058). Recurrent triggering occurred in nine digits (15%) in the diabetic patients, which was significantly greater than the six digits (5%) in the non-diabetic patients (p = 0.013). The non-diabetic patients were significantly more satisfied. LEVEL OF EVIDENCE: level III.


Assuntos
Complicações do Diabetes , Dedo em Gatilho/cirurgia , Adulto , Idoso , Idoso de 80 Anos ou mais , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Dor Pós-Operatória/etiologia , Satisfação do Paciente/estatística & dados numéricos , Recidiva , Dedo em Gatilho/complicações
7.
Neurogastroenterol Motil ; 25(5): e324-38, 2013 May.
Artigo em Inglês | MEDLINE | ID: mdl-23495930

RESUMO

BACKGROUND: Enteric glia form a network in the intestinal mucosa and have been suggested to engage in multidirectional interactions with the epithelium, blood vessels, nerves, and immune system. However, due to the dispersed nature of the glial network, standard histology cannot provide a global view of the network architecture. We prepared transparent human colon mucosa for three-dimensional (3-D) confocal microscopy with S100B immunostaining to reveal the location-dependent glial network for qualitative and quantitative analyses. METHODS: Full-thickness human colons were acquired from colectomies performed for colorectal cancer. We targeted the mucosa away from the tumor site to characterize the glial network morphology. Optical clearing (use of immersion solution to reduce scattering) was applied to generate transparent specimens for deep-tissue microscopy. KEY RESULTS: Two features of the glial network were seen: (i) A dense glial population resides at the crypt base/mucosal boundary in contact with the lymphatic vessels, and (ii) from the base, the glial network elongates along the crypt axis with peri-cryptic and peri-vascular connections toward the opening. We quantified the mucosal glia as the S100B-positive cells with at least two processes extending from the cell body. Examples of the global and in-depth imaging of adenoma were given to illustrate the morphological correlation between the loss of glial fibers and the aberrant crypts. CONCLUSIONS & INFERENCES: We have established a useful approach for 3-D imaging, panoramic illustration, and quantitation of the enteric glia in the human colon mucosa to help characterize their roles with mucosal components in health and disease.


Assuntos
Sistema Nervoso Entérico/citologia , Imageamento Tridimensional/métodos , Mucosa Intestinal/citologia , Neuroglia/citologia , Idoso de 80 Anos ou mais , Colo/citologia , Feminino , Humanos , Masculino , Microscopia Confocal/métodos , Pessoa de Meia-Idade , Coloração e Rotulagem
8.
Neurogastroenterol Motil ; 23(10): e446-57, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21895876

RESUMO

BACKGROUND: Due to the dispersed nature of neurites and fibers, the microtome-based 2-dimensional histology provides only a limited perspective of the enteric nervous system. To visualize the enteric plexus, we applied optical clearing to avoid scattering in the human ileum to facilitate photon penetration for 3-dimensional (3-D) microscopy of the neural tissue. METHODS: Human ileal specimens were derived by trimming the donor bowel due to its excess length during the clinical trial of small intestinal transplantation. The pan-neuronal marker PGP9.5 was used as the immunostaining target to reveal the enteric plexuses. The labeled tissues were immersed in the optical-clearing solution prior to deep-tissue confocal microscopy. The serial sections were digitally analyzed and processed by reconstruction algorithms for 3-D visualization. KEY RESULTS: Optical clearing of the ileal specimen led to less fluorescence signal decay along the focal path in the tissue and a higher signal-to-noise ratio of the confocal micrographs in comparison with the untreated saline control. Taking advantage of the high signal-to-noise ratio images, we applied software-based signal analysis to identify the presence of the nerve fibers and quantify the signal peaks. The image stacks derived from the serial anatomic micrographs created panoramic views of the gut wall innervations with their associated microstructures. CONCLUSIONS & INFERENCES: We provide an optical approach to improve the imaging depth in 3-D neurohistology of the human ileum. This methodology has significant promise in facilitating our understanding of the enteric nervous system in health and disease.


Assuntos
Sistema Nervoso Entérico/anatomia & histologia , Íleo/inervação , Imageamento Tridimensional/métodos , Microscopia Confocal/métodos , Algoritmos , Humanos , Processamento de Imagem Assistida por Computador
9.
J Cardiovasc Pharmacol ; 36(5 Suppl 1): S75-7, 2000 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-11078341

RESUMO

Experiments were carried out in mutant 129/SvEv mice lacking the endothelin-A (ET(A))-receptor to determine whether endothelin-1 (ET-1), acting as a messenger for oxygen constriction, is responsible for closure of the ductus arteriosus at birth. The isolated ductus from ET(A) -/- fetuses, unlike that from ET(A) +/+ littermates, contracted marginally to oxygen and ET-1 but responded to a thromboxane analog. In vivo, reduction in ductus lumen was equally pronounced in tracheotomized ET(A) -/- and ET(A) +/+ newborns. Conversely, no such vessel narrowing was seen in hyperoxic ET(A), -/- fetuses, although it occurred in ET(A) +/+ littermates. Notwithstanding the uneven behaviour of the ductus in vitro and in vivo, no ET(A) genotype-related difference was noted in the morphology of the vessel on both light and electron microscopy. We conclude that ET-1 mediates the ductus constriction to oxygen. Without ET-1, however, the vessel still closes postnatally probably as a result of the withdrawal of the relaxing influence of prostaglandin E2 (PGE2).


Assuntos
Canal Arterial/fisiologia , Oxigênio/farmacologia , Receptores de Endotelina/fisiologia , Vasoconstrição/efeitos dos fármacos , Animais , Feminino , Técnicas In Vitro , Camundongos , Camundongos Endogâmicos , Gravidez , Receptor de Endotelina A
10.
Biol Neonate ; 77(4): 253-60, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10828577

RESUMO

Isolated pulmonary resistance arteries from term fetal lambs have nitric oxide (NO)- and prostaglandin-mediated relaxing mechanisms which are activated when PO(2) is raised from fetal to neonatal levels. The same vessels contract under hypoxia, and the contraction has been ascribed to endothelin-1 (ET-1). We have now studied these vasoeffector mechanisms before term (0.7 and 0.65 gestation) with the objective of determining whether their activity correlates with the development of susceptibility to oxygen changes. Experiments were carried out at neonatal PO(2), when expectedly relaxing mechanisms are maximally expressed, or under hypoxia. At either fetal age, the NO synthesis inhibitor, N(G)-nitro-L-arginine methyl ester (100 microM), had no effect on basal tone, while indomethacin (2.8 microM) was a weak constrictor. Premature arteries did not contract when first exposed to hypoxia, but they responded marginally to a second exposure. The same arteries contracted strongly to a thromboxane A(2) analogue (ONO-11113, 0.1 microM) and ET-1 (10 nM), while their contraction to activating solution (5 mM Ca(2+) in K(+)-Krebs solution) was small and variable. At 0.7 gestation, bradykinin (0.1-100 nM), acetylcholine (0.01-10 microM), and sodium nitroprusside (0.1 nM to 10 microM) dose-dependently relaxed arteries precontracted with ONO-11113. Conversely, at 0.65 gestation the relaxation to bradykinin and acetylcholine was not dose-dependent and tended to be weaker. We conclude that preterm pulmonary arteries have viable effector mechanisms for contraction and relaxation. However, the capability for these mechanisms to be activated by PO(2) changes is markedly curtailed.


Assuntos
Feto/fisiologia , Artéria Pulmonar/embriologia , Resistência Vascular , Vasoconstrição/fisiologia , Vasodilatação/fisiologia , Acetilcolina/farmacologia , Animais , Bradicinina/farmacologia , Fármacos Cardiovasculares/farmacologia , Inibidores Enzimáticos/farmacologia , Idade Gestacional , Indometacina/farmacologia , NG-Nitroarginina Metil Éster/farmacologia , Nitroprussiato/farmacologia , Artéria Pulmonar/efeitos dos fármacos , Vasodilatadores/farmacologia , Sistema Vasomotor/efeitos dos fármacos
11.
Acta Physiol Scand ; 164(3): 245-50, 1998 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-9853011

RESUMO

The mammalian urinary bladder receives dual innervation. The excitatory innervation is considered to be partly cholinergic and partly mediated via NANC-receptors. Several (co-)transmitters have been suggested. The adrenergic inhibitory innervation is mediated via alpha- and beta-receptors. Female sex hormones could change autonomic influence of urogenital organs. It was considered to be of interest to characterize the spontaneous and nerve stimulation-induced muscular activity in the urinary bladder of the female guinea-pig during the oestrus cycle. Both the spontaneous activity and nerve-induced activity varied according to the hormonal status of the animal. An alpha-adrenergic inhibitory influence was identified. It was further confirmed that the excitatory innervation could not be blocked by the cholinergic antagonist scopolamine, while alpha-beta-methylene ATP partly inhibited nerve stimulation-induced smooth muscle response, most prominent at cycle day 6. Indomethacin did not impair spontaneous activity or nerve stimulation-induced activity. Nitric oxide reduced nerve stimulation-induced responses on cycle day 12. Imperative urinary bladder contractions are reported to diminish after oestrogen use and in the female a hormonal effect of the nervous influence on the urinary bladder smooth muscle is suggested.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Estro/fisiologia , Bexiga Urinária/inervação , Trifosfato de Adenosina/análogos & derivados , Trifosfato de Adenosina/farmacologia , Antagonistas Adrenérgicos alfa/farmacologia , Animais , Feminino , Cobaias , Indometacina/farmacologia , Músculo Liso/efeitos dos fármacos , Músculo Liso/fisiologia , Óxido Nítrico/farmacologia , Fentolamina/farmacologia , Escopolamina/farmacologia , Bexiga Urinária/efeitos dos fármacos
12.
Jpn J Physiol ; 47(2): 173-8, 1997 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-9201546

RESUMO

The effect of Tsusanli acupuncture point (S36 acupoint) stimulation on splenic natural killer (NK) cytotoxicity was examined in Fischer 344 (F344) rats. Electro-acupuncture stimulation (voltage intensity, 1 to 5 V; duration, 1 ms; frequency, 1 Hz) was applied to bilateral S36 acupoints once a day (1 h) for 3 d. NK cytotoxicity was measured by the standard 4-h 51Cr release assay. Successive acupuncture treatment for 3 d significantly enhanced splenic NK cytotoxicity (p < 0.001) on the first day after final treatment as compared to that of the control. However, similar stimulation to abdominal muscle did not influence splenic NK cytotoxicity. We also examined endogenous cytokine activities in aqueous spleen extracts prepared from acupunctured and control rats. The extracts from rats acupunctured at the S36 acupoint contained high levels of interleukin (IL)-2 and interferon (IFN)-gamma as compared to those of abdominal muscle acupunctured and non-acupunctured control rats (p < 0.01). Furthermore, a significant positive correlation (p < 0.01) was observed between the levels of each cytokine tested and splenic NK cytotoxicity. The same positive correlation was also observed between the levels of IL-2 and IFN-gamma (p < 0.01). These observations indicate that electro-acupuncture stimulation of the S36 acupoint enhances splenic NK cytotoxicity and that IL-2 and IFN-gamma may function, at least in part, in the regulation of NK cell activity in this system.


Assuntos
Pontos de Acupuntura , Eletroacupuntura , Interferon gama/metabolismo , Interleucina-2/metabolismo , Células Matadoras Naturais/citologia , Baço/imunologia , Músculos Abdominais/fisiologia , Animais , Citotoxicidade Imunológica , Ensaio de Imunoadsorção Enzimática , Células Matadoras Naturais/fisiologia , Masculino , Ratos , Ratos Endogâmicos F344 , Baço/metabolismo
13.
Acta Physiol Scand ; 155(4): 405-14, 1995 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-8719260

RESUMO

Endothelin-1 (ET-1) is a strongly vasoactive polypeptide that may be involved in the regulation of the uteroplacental blood flow. In the present study we have examined the contractile response to ET-1 in human placental arteries in the presence of several agents that interfere with storage of intracellular calcium, e.g. caffeine, ryanodine and thapsigargin. We have also compared the contractile response to ET-1 in normal pregnancies with that of patients with foetal intrauterine growth retardation (IUGR), a condition with reduced uteroplacental blood flow. We found that the response to ET-1 in the placental arteries from women with normal pregnancies was reduced by 20% in the absence of extracellular calcium. Caffeine relaxed the basal tone of the vessels and reduced the contractile response to ET-1 by 51%. Nifedipine in addition to caffeine resulted in a reduction of 70%. Ryanodine also reduced the tone. Thapsigargin had no effect on the placental arteries at lower concentrations, but gave a progressive and slow contraction at 10(-6) M. The ET-1 induced contraction in placental arteries from IUGR patients was 67% more potent than in placental arteries from women with normal pregnancies, 129% as compared with 77% of the maximal K(+)-induced contraction. We conclude that the ET-1-induced contractile response in the human placental artery is dependent on influx of extracellular calcium as well as mobilization of calcium from intracellular stores. An increased sensitivity to ET-1 in placental arteries may contribute to the reduced uteroplacental blood flow in intrauterine growth retardation.


Assuntos
Cálcio/metabolismo , Endotelinas/farmacologia , Retardo do Crescimento Fetal/fisiopatologia , Contração Muscular/efeitos dos fármacos , Músculo Liso Vascular/fisiologia , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Adulto , Artérias/efeitos dos fármacos , Cafeína/farmacologia , Agonistas dos Canais de Cálcio/farmacologia , Bloqueadores dos Canais de Cálcio/farmacologia , ATPases Transportadoras de Cálcio/antagonistas & inibidores , Inibidores Enzimáticos/farmacologia , Feminino , Humanos , Técnicas In Vitro , Relaxamento Muscular/efeitos dos fármacos , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Nifedipino/farmacologia , Inibidores de Fosfodiesterase/farmacologia , Circulação Placentária/fisiologia , Gravidez , Rianodina/farmacologia , Terpenos/farmacologia , Tapsigargina
14.
Acta Physiol Scand ; 151(4): 477-84, 1994 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-7976421

RESUMO

In order to examine the possibility that endothelin might be important in the regulation of placental blood flow, human uteroplacental vessels were superfused in vitro to study the contractile effect of endothelin as compared with a known strong contractor of placental blood vessels, serotonin (5-HT). The contractile responses were compared in the presence and absence of calcium channel blocking agents, as well as in the presence of L-NMA, an inhibitor of EDRF/nitric oxide. Endothelin (ET, 10(-10)-10(-6) M) and 5-HT (10(-8)-10(-4) M) induced contractions in the vessels. Maximal contractions in the presence of endothelin were elicited at 10(-7) M, whereas 5-HT elicited maximal contractions at 10(-5) M. At 10(-7) M, ET was more potent than 5-HT. The calcium-channel blocking agents nifedipine, diltiazem and NiCl2 relaxed the vessels by 5-15% from baseline. The contractile response to ET in the presence of nifedipine or diltiazem was reduced by 55 and 67%, respectively. The response of 5-HT in the presence of nifedipine was reduced by 58%. The contractile response to 5-HT as well as ET in the presence of both nifedipine and NiCl2 was not significantly lower than in the presence of nifedipine only. The EDRF-inhibiting agent L-NMA caused a small contractile response at concentrations of 10(-6)-10(-5) M. ET as well as 5-HT added after pretreatment with L-NMA produced a larger contractile response than ET or 5-HT alone. The results show that ET has a strong contractile effect on placental blood vessels at concentrations likely to occur during labor and delivery. The mechanism whereby ET as well as 5-HT contracts placental vessel smooth muscle appears to partly involve nifedipine- and diltiazem-sensitive calcium channels, but almost half of the response depends on mobilization of calcium through other means.


Assuntos
Bloqueadores dos Canais de Cálcio/farmacologia , Endotelinas/farmacologia , Óxido Nítrico/antagonistas & inibidores , Placenta/irrigação sanguínea , Útero/irrigação sanguínea , Vasoconstrição/efeitos dos fármacos , Adulto , Arginina/análogos & derivados , Arginina/farmacologia , Artérias/efeitos dos fármacos , Relação Dose-Resposta a Droga , Feminino , Humanos , Gravidez , Serotonina/farmacologia , ômega-N-Metilarginina
15.
Acta Physiol Scand ; 147(1): 131-6, 1993 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-8452039

RESUMO

The effect of endothelin (ET), a recently discovered 21-amino-acid polypeptide with powerful vasoconstrictor properties, was examined on human uterine myometrial strips in vitro. ET dose-dependently (10(-11)-10(-7) M) increased the contractile force (monitored as contraction amplitude) of the myometrium with significant effects at 10(-8) and 10(-7) M. ET (10(-8) M and up) also increased the basal tone of the myometrium. The calcium channel blocking agents nifedipine (10(-7) M) and diltiazem (10(-6) M) both inhibited the spontaneous tonic contractions of the myometrium. When ET was given in the presence of nifedipine, the tonic contractions were further inhibited, whereas the ET-induced increase in basal tone remained. The same result was obtained with diltiazem (10(-6) M). The results indicate that the contractility of human myometrium may be modulated by ET, and that the effects of ET on the human myometrium are only partly mediated by dihydropyridine-sensitive calcium channels.


Assuntos
Di-Hidropiridinas/farmacologia , Endotelinas/farmacologia , Miométrio/efeitos dos fármacos , Contração Uterina/efeitos dos fármacos , Diltiazem/farmacologia , Endotelinas/antagonistas & inibidores , Feminino , Humanos , Técnicas In Vitro , Pessoa de Meia-Idade , Nifedipino/farmacologia
16.
Pediatr Res ; 21(3): 296-300, 1987 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-3494227

RESUMO

Osteocalcin is a bone-specific protein whose concentration in blood is a direct reflection of bone turnover. In chronic renal failure, circulating osteocalcin is elevated. This elevation is due to decreased renal clearance and, in some patients, increased bone turnover secondary to renal osteodystrophy. In children receiving continuous ambulatory peritoneal dialysis, mean serum osteocalcin concentrations are substantially lower than in similar patients on hemodyalysis (1). This difference may be due to clearance of the protein by the peritoneal membrane. To test this possibility we examined osteocalcin in 16 infants and adolescents undergoing continuous ambulatory peritoneal dialysis with two commercially available glucose-based dialysis solutions (2.5 and 4.25% Dianeal). Mass transfer of osteocalcin over 5-h dialysis exchange periods was -18.9 +/- 2.8 and -28.4 +/- 7.8 micrograms for the low and high glucose solutions, respectively. Serum levels fell over the course of single exchange periods in concert with increasing dialysate concentrations. There were significant correlations between initial blood concentrations of osteocalcin and the total amount of osteocalcin transferred (r = 0.609 and 0.642 for the high and low glucose solutions, respectively, p less than 0.05). There were also strong correlations between the mass transfers of osteocalcin and those of creatinine (p less than 0.05) and total protein (p less than 0.01) with the 4.25% glucose exchange. The relationships were weaker with the 2.5% glucose exchange. Fractionation of serum revealed a single immunoreactive peak eluting coincident with intact osteocalcin, but two or three immunoreactive peaks were identified in matching dialysate samples, suggesting that both intact osteocalcin and circulating fragments are transferred by the peritoneal membrane.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Proteínas de Ligação ao Cálcio/sangue , Falência Renal Crônica/terapia , Diálise Peritoneal , Adolescente , Criança , Cromatografia em Gel , Cromatografia Líquida de Alta Pressão , Humanos , Lactente , Falência Renal Crônica/sangue , Concentração Osmolar , Osteocalcina
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