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1.
Phys Rev Lett ; 125(11): 117701, 2020 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-32975985

RESUMO

Hybrid quantum devices expand the tools and techniques available for quantum sensing in various fields. Here, we experimentally demonstrate quantum sensing of a steady-state magnon population in a magnetostatic mode of a ferrimagnetic crystal. Dispersively coupling the magnetostatic mode to a superconducting qubit allows for the detection of magnons using Ramsey interferometry with a sensitivity on the order of 10^{-3} magnons/sqrt[Hz]. The protocol is based on dissipation as dephasing via fluctuations in the magnetostatic mode reduces the qubit coherence proportionally to the number of magnons.

2.
Phys Rev Lett ; 123(20): 207401, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31809102

RESUMO

Brillouin light scattering in ferromagnetic materials usually involves one magnon and two photons and their total angular momentum is conserved. Here, we experimentally demonstrate the presence of a helicity-changing two-magnon Brillouin light scattering in a ferromagnetic crystal, which can be viewed as a four-wave mixing process involving two magnons and two photons. Moreover, we observe an unconventional helicity-changing one-magnon Brillouin light scattering, which apparently infringes the conservation law of the angular momentum. We show that the crystal angular momentum intervenes to compensate the missing angular momentum in the latter scattering process.

3.
Phys Rev Lett ; 120(13): 133602, 2018 Mar 30.
Artigo em Inglês | MEDLINE | ID: mdl-29694172

RESUMO

A ferromagnetic sphere can support optical vortices in the form of whispering gallery modes and magnetic quasivortices in the form of magnetostatic modes with nontrivial spin textures. These vortices can be characterized by their orbital angular momenta. We experimentally investigate Brillouin scattering of photons in the whispering gallery modes by magnons in the magnetostatic modes, zeroing in on the exchange of the orbital angular momenta between the optical vortices and magnetic quasivortices. We find that the conservation of the orbital angular momentum results in different nonreciprocal behavior in the Brillouin light scattering. New avenues for chiral optics and optospintronics can be opened up by taking the orbital angular momenta as a new degree of freedom for cavity optomagnonics.

4.
Phys Rev Lett ; 116(22): 223601, 2016 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-27314717

RESUMO

We experimentally implement a system of cavity optomagnonics, where a sphere of ferromagnetic material supports whispering gallery modes (WGMs) for photons and the magnetostatic mode for magnons. We observe pronounced nonreciprocity and asymmetry in the sideband signals generated by the magnon-induced Brillouin scattering of light. The spin-orbit coupled nature of the WGM photons, their geometrical birefringence, and the time-reversal symmetry breaking in the magnon dynamics impose the angular-momentum selection rules in the scattering process and account for the observed phenomena. The unique features of the system may find interesting applications at the crossroad between quantum optics and spintronics.

5.
Nat Commun ; 11(1): 3683, 2020 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-32703942

RESUMO

The rapid development in designs and fabrication techniques of superconducting qubits has made coherence times of qubits longer. In the future, however, the radiative decay of a qubit into its control line will be a fundamental limitation, imposing a trade-off between fast control and long lifetime of the qubit. Here, we break this trade-off by strongly coupling another superconducting qubit along the control line. This second qubit, which we call "Josephson quantum filter" (JQF), prevents the first qubit from emitting microwave photons and thus suppresses its relaxation, while transmitting large-amplitude control microwave pulses due to the saturation of the quantum filter, enabling fast qubit control. This device functions as an automatic decoupler between a qubit and its control line and could help in the realization of a large-scale superconducting quantum processor by reducing the heating of the qubit environment and the crosstalk between qubits.

6.
Orphanet J Rare Dis ; 15(1): 269, 2020 09 29.
Artigo em Inglês | MEDLINE | ID: mdl-32993765

RESUMO

STUDY OBJECTIVES: Niemann-Pick type C (NPC) is an autosomal recessive and congenital neurological disorder characterized by the accumulation of cholesterol and glycosphingolipids. Symptoms include hepatosplenomegaly, vertical supranuclear saccadic palsy, ataxia, dystonia, and dementia. Some cases frequently display narcolepsy-like symptoms, including cataplexy which was reported in 26% of all NPC patients and was more often recorded among late-infantile onset (50%) and juvenile onset (38%) patients. In this current study, we examined CSF orexin levels in the 10 patients of NPC with and without cataplexy, which supports previous findings. METHODS: Ten patients with NPC were included in the study (5 males and 5 females). NPC diagnosis was biochemically confirmed in all 10 patients, from which 8 patients with NPC1 gene were identified. We compared CSF orexin levels among NPC, narcoleptic and idiopathic hypersomnia patients. RESULTS: Six NPC patients with cataplexy had low or intermediate orexin levels. In 4 cases without cataplexy, their orexin levels were normal. In 5 cases with Miglustat treatment, their symptoms stabilized or improved. For cases without Miglustat treatment, their conditions worsened generally. The CSF orexin levels of NPC patients were significantly higher than those of patients with narcolepsy-cataplexy and lower than those of patients with idiopathic hypersomnia, which was considered as the control group with normal CSF orexin levels. DISCUSSION: Our study indicates that orexin level measurements can be an early alert of potential NPC. Low or intermediate orexin levels could further decrease due to reduction in the neuronal function in the orexin system, accelerating the patients' NPC pathophysiology. However with Miglustat treatment, the orexin levels stabilized or improved, along with other general symptoms. Although the circuitry is unclear, this supports that orexin system is indeed involved in narcolepsy-cataplexy in NPC patients. CONCLUSION: The NPC patients with cataplexy had low or intermediate orexin levels. In the cases without cataplexy, their orexin levels were normal. Our study suggests that orexin measurements can serve as an early alert for potential NPC; furthermore, they could be a marker of therapy monitoring during a treatment.


Assuntos
Cataplexia , Doença de Niemann-Pick Tipo C , 1-Desoxinojirimicina/análogos & derivados , 1-Desoxinojirimicina/uso terapêutico , Cataplexia/tratamento farmacológico , Feminino , Humanos , Masculino , Doença de Niemann-Pick Tipo C/diagnóstico , Doença de Niemann-Pick Tipo C/tratamento farmacológico , Orexinas
7.
J Phys Condens Matter ; 21(29): 296002, 2009 Jul 22.
Artigo em Inglês | MEDLINE | ID: mdl-21828541

RESUMO

The effect of Mn substitution in paramagnetic metal CaRuO(3) was studied by magnetization and neutron diffraction measurements. Development of ferromagnetic order is observed for x≥0.2 in CaRu(1-x)Mn(x)O(3). For the sample with x = 0.4, the Curie temperature of ∼160 K is obtained from the Arrott plot and the ratio of effective moment and saturation moment P(eff)/M(0) is estimated to be ∼4.8. We further found that the magnetization is significantly suppressed with decreasing temperature T below ∼90 K. In the neutron diffraction experiment at T = 15 K, we observed the evolution of a magnetic Bragg peak originating from the G-type antiferromagnetic order as well as the ferromagnetic one. This strongly suggests that both ferromagnetic and antiferromagnetic states are coexistent with each other at low temperatures. In the M(T)(0)(2) against T(2) plot (here, M(T)(0) is a spontaneous magnetization estimated from the Arrott plot), M(T)(0)(2) linearly increases with decreasing T(2) in the ferromagnetic region between ∼90 and 160 K. The ferromagnetic properties of the CaRu(1-x)Mn(x)O(3) system (x≤0.5) are well explained in terms of spin fluctuation theory based on the itinerant electron model rather than the localized spin model.

8.
Cytotherapy ; 10(8): 842-56, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-19016372

RESUMO

BACKGROUND: Human gammadelta T cells can be activated by phospho-antigens and aminobisphosphonates such as zoledronate. Because they can kill tumor cells in a major histocompatibility complex (MHC)-unrestricted manner, adoptive transfer of activated gammadelta T cells may represent a novel cancer immunotherapy. We tested whether gammadelta T cells from advanced cancer patients can be expanded by zoledronate. METHODS: Peripheral blood mononuclear cells from healthy donors and patients with advanced non-small cell lung cancer, bone metastatic breast or prostate cancer, or lung metastatic colorectal cancer, were stimulated with zoledronate (5 microM) and interleukin (IL)-2 (1000 IU/mL) for 14 days. The phenotype and function of the expanded gammadelta T-cell populations from healthy donors and cancer patients were compared. RESULTS: Gammadelta T cells from cancer patients and healthy donors responded to zoledronate equally well in terms of both phenotype and function. gammadelta T cells grew rapidly in vitro and expression of effector molecules, such as interferon (IFN)-gamma, tumor necrosis factor (TNF)-alpha, perforin, granzyme B, FasL and TRAIL, increased over time. Cytotoxicity peaked on days 12-14, and proliferation continued up to 14 days, during which time>1x10(9) gammadelta T cells could be obtained from a starting sample of 45-70 mL peripheral blood. DISCUSSION: Using the agent zoledronate, already widely used in the clinic, we have established that efficient large-scale ex vivo expansion of gammadelta T cells from cancer patients is possible. These cells exert potent cytotoxicity and may be used for autologous cellular immunotherapy of cancer.


Assuntos
Neoplasias Ósseas/terapia , Neoplasias da Mama/terapia , Carcinoma Pulmonar de Células não Pequenas/terapia , Proliferação de Células/efeitos dos fármacos , Neoplasias Colorretais/terapia , Citocinas/metabolismo , Citotoxicidade Imunológica/efeitos dos fármacos , Difosfonatos/farmacologia , Imidazóis/farmacologia , Imunoterapia Adotiva , Neoplasias Pulmonares/terapia , Neoplasias da Próstata/terapia , Receptores de Antígenos de Linfócitos T gama-delta/metabolismo , Linfócitos T/patologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Neoplasias Ósseas/imunologia , Neoplasias Ósseas/secundário , Neoplasias da Mama/imunologia , Neoplasias da Mama/patologia , Carcinoma Pulmonar de Células não Pequenas/imunologia , Carcinoma Pulmonar de Células não Pequenas/patologia , Células Cultivadas , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/patologia , Citocinas/genética , Feminino , Humanos , Imunofenotipagem , Neoplasias Pulmonares/imunologia , Neoplasias Pulmonares/patologia , Masculino , Pessoa de Meia-Idade , Estadiamento de Neoplasias , Neoplasias da Próstata/imunologia , Neoplasias da Próstata/patologia , RNA/análise , Receptores de Antígenos de Linfócitos T gama-delta/genética , Linfócitos T/metabolismo , Ácido Zoledrônico
9.
Nat Commun ; 9(1): 1291, 2018 03 29.
Artigo em Inglês | MEDLINE | ID: mdl-29599432

RESUMO

Information thermodynamics bridges information theory and statistical physics by connecting information content and entropy production through measurement and feedback control. Maxwell's demon is a hypothetical character that uses information about a system to reduce its entropy. Here we realize a Maxwell's demon acting on a superconducting quantum circuit. We implement quantum non-demolition projective measurement and feedback operation of a qubit and verify the generalized integral fluctuation theorem. We also evaluate the conversion efficiency from information gain to work in the feedback protocol. Our experiment constitutes a step toward experimental studies of quantum information thermodynamics in artificially made quantum machines.

10.
Cancer Res ; 51(16): 4310-5, 1991 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-1868453

RESUMO

The murine monoclonal antibody A7 (Mab A7) against human colon cancer was chemically modified with methoxypolyethylene glycol (PEG) (Mr 5000). A high substitution of PEG molecules on Mab A7 produced a progressive reduction in antibody-binding activity. The pharmacokinetic and immunological properties of PEG-modified monoclonal antibody A7 (Mab A7) and the PEG-modified F(ab')2 fragment, which retained their antibody-binding activity, were assessed and compared with the parent Mab A7 and the parent F(ab')2 fragment. Blood clearance of PEG-modified antibodies appeared to be diminished by PEG modification and was fitted by a two-compartment model. Low PEG-substituted Mab A7 showed less organ uptake in the liver and spleen and similar uptake in the lung and kidney, compared with the parent Mab A7. PEG-F(ab')2 showed less uptake in the liver and kidney. Both preparations exhibited less tissue:blood ratios in all resected organs as compared with parent antibodies. Tumor localization was enhanced by PEG modification for the F(ab')2 fragment, but not by PEG modification for the whole Mab A7. Multiple i.v. administration of PEG-modified antibody to rabbit did not appear to elicit a measurable immune response to the antibody portion of the conjugate. In conclusion, PEG-modified antibodies are promising reagents as drug carriers to the target tumor.


Assuntos
Anticorpos Monoclonais/farmacocinética , Radioisótopos do Iodo/farmacocinética , Polietilenoglicóis/farmacocinética , Animais , Anticorpos Monoclonais/uso terapêutico , Portadores de Fármacos , Feminino , Fragmentos Fab das Imunoglobulinas , Radioisótopos do Iodo/uso terapêutico , Camundongos , Camundongos Endogâmicos BALB C/imunologia , Camundongos Nus , Polietilenoglicóis/uso terapêutico , Distribuição Tecidual
11.
Cancer Res ; 52(22): 6323-8, 1992 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-1423277

RESUMO

This report investigates the application of monoclonal antibody A7 and its drug conjugate in locally controlling colorectal cancer. The experimental protocol consisted of local retention, lymphatic delivery, normal organ distribution, systemic toxicity, and tumoricidal effects. When 125I-labeled monoclonal antibody (Mab) A7 was injected into the pelvis and the thigh of Balb/c mice, a high local retention unrelated to antigen-antibody interaction was observed at the injected site for 24 h after injection. An analysis of local retension properties related to antigen-antibody interaction, conducted by intratumorally or peritumorally injecting 125I-Mab A7 into the tumor-bearing athymic nude mice, revealed a significantly higher tumor localization of Mab A7 in comparison to i.v. injection. 125I-Mab A7 accumulated to a great extent in the ipsilateral regional lymph node but not in the contralateral regional lymph node. Normal organ accumulation of Mab A7 was lower in the locally injected group than in the i.v. injected group. Intratumoral injection of Mab A7-neocarzinostatin (A7-NCS) led to the complete remission of established tumor in 5 of 6 antigen-positive xenograft-bearing mice but exhibited a complete remission in only 1 of 6 antigen-negative xenograft-bearing mice. A single local injection of A7-NCS inhibited tumor development in 12 of 16 and 5 of 15 antigen-positive tumor-bearing mice and antigen-negative tumor-bearing mice, respectively, whereas neither a systemic injection of A7-NCS and NCS nor a local injection of NCS and saline had a notable inhibitory effect on tumor development. Systemic toxicity of NCS was markedly reduced when it was locally administered in the antibody-conjugated form. These findings indicate that local injection of immunoconjugate is a promising new field for controlling the local recurrence of colorectal cancer.


Assuntos
Neoplasias Colorretais/tratamento farmacológico , Imunotoxinas/uso terapêutico , Recidiva Local de Neoplasia/prevenção & controle , Zinostatina/uso terapêutico , Animais , Anticorpos Monoclonais/imunologia , Anticorpos Monoclonais/metabolismo , Neoplasias Colorretais/imunologia , Neoplasias Colorretais/prevenção & controle , Humanos , Imunotoxinas/efeitos adversos , Imunotoxinas/metabolismo , Injeções Intralesionais , Injeções Intravenosas , Radioisótopos do Iodo , Linfonodos/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , Recidiva Local de Neoplasia/imunologia , Transplante de Neoplasias , Distribuição Tecidual , Células Tumorais Cultivadas , Zinostatina/efeitos adversos
12.
Hum Mutat ; 16(3): 270-1, 2000 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10980538

RESUMO

Lysinuric protein intolerance is an autosomal recessive disease characterized by defective transport of the dibasic aminoacids. Mutational analysis of LPI patients in the northern part of Japan revealed that six were homozygous for the R410X mutation and two others were compound heterozygotes of R410X and other unknown mutations. In the population epidemiology study in a local cluster in the northern part of Iwate, ten heterozygotes were found in 1190 newborn babies leading to an estimated LPI incidence of 1/57,000. Polymorphism analysis revealed two major alleles, A and B, in intron 8. While the population frequency of allele A was 0.9 and that of allele B was 0.1 in the northern part of Japan the R410X mutations were exclusively on allele B in 31 chromosomes suggesting a founder effect. Genetic analysis in patients revealed strong linkage disequilibrium with D14S283 and TCRA indicating that the R410X mutation occurred before at least 130 generations ago (about 2600 years). The R410X mutation was shown to be useful as a molecular marker for screening LPI patients in the northern part of Japan.


Assuntos
Erros Inatos do Metabolismo dos Aminoácidos/epidemiologia , Erros Inatos do Metabolismo dos Aminoácidos/genética , Proteínas de Transporte/genética , Efeito Fundador , Lisina/metabolismo , Diamino Aminoácidos/metabolismo , Triagem de Portadores Genéticos , Humanos , Recém-Nascido , Japão/epidemiologia , Linhagem
13.
Adv Drug Deliv Rev ; 52(3): 197-207, 2001 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-11718944

RESUMO

A novel cationic cholesterol derivative with a hydroxyethyl amino head group (I) has been synthesized and used for liposome-mediated gene transfection. Cationic liposomes with derivative (I) greatly facilitated gene transfection into various cultured cells. The efficiency of transfection by liposomes with derivative (I) was much higher than that using liposomes with DC-chol (II) or lipofectine. Atomic force microscopy and confocal laser scanning microscopy revealed the molecular mechanism of gene transfection by cationic liposomes. The results showed that at least two steps were involved in gene transfection mediated by cationic liposomes. One was endocytosis, where the liposome-DNA complex was internalized into target cells, and the other was membrane fusion between the liposome vectors and endosomes, where DNA transferred from the liposome to the nucleus. In addition we found that microtubules were involved in the intracellular dynamics of gene transfection.


Assuntos
Colesterol/química , Lipossomos/química , Microscopia de Força Atômica/métodos , Microscopia Confocal/métodos , Transfecção/métodos , Animais , Cátions/química , Colesterol/análogos & derivados , Humanos , Camundongos
14.
Endocrinology ; 113(2): 672-6, 1983 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-6307646

RESUMO

Postnatal ontogeny of rat liver alpha 1-adrenergic receptor was examined using alpha 1-specific radioligand [3H]prazosin in control and propylthiouracil-treated congenital hypothyroid rats at various ages. Partially purified rat liver membranes prepared by the Neville method had 8-fold purification of 5'-nucleotidase from the crude homogenates from postnatal day 5 to adulthood. [3H]Prazosin binding was typical of an alpha 1-adrenergic receptor, and (-)epinephrine affinity for the [3H]prazosin-binding sites was not altered in the presence of 10(-5) M guanylyl-imidodiphosphate. The receptor density was lower in 5- and 15-day-old rats than in 28-day-old or older rats in both control and hypothyroid groups. (P less than 0.01). At 28-34 days of age, hypothyroid pups had significantly lower alpha 1-receptor density than controls (399 +/- 10 vs. 869 +/- 40 fmol mg protein-1; P less than 0.01). Replacement therapy with daily T4 injection from postnatal days 16-27 restored 54% of the deficit in PTU-treated hypothyroid pups at 28 days. The dissociation constant of [3H] prazosin did not change with advancing age or with different treatment and was consistent at 0.1 nM. These findings indicate that the normal ontogeny of plasma membrane alpha 1-adrenergic receptors is dependent upon thyroid hormone and matures postnatally in rat liver.


Assuntos
Hipotireoidismo/fisiopatologia , Fígado/crescimento & desenvolvimento , Prazosina/metabolismo , Propiltiouracila/farmacologia , Quinazolinas/metabolismo , Receptores Adrenérgicos alfa/metabolismo , Receptores Adrenérgicos/metabolismo , Glândula Tireoide/fisiologia , Envelhecimento , Animais , Ligação Competitiva , Membrana Celular/metabolismo , Feminino , Cinética , Fígado/metabolismo , Masculino , Ratos , Ratos Endogâmicos , Receptores Adrenérgicos alfa/efeitos dos fármacos
15.
J Clin Endocrinol Metab ; 50(1): 27-32, 1980 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-6243131

RESUMO

Beta-Adrnergic receptor and beta-adrenergic sensitive adenylate cyclase were demonstrated in membrane fractions of human placenta. Placental membranes from normal term pregnancies bound the beta-adrenergic antagonist (-)[3H]dihydroalprenolol to a single saturable class of sites (Kd = 2.31 +/- 0.23 nM; n = 9; maximal capacity, 112 +/- 9 fmol/mg). Competition for binding was stereoselective for (-)isomers of propranolol, and beta-adrenergic agonists displayed competition for the placental receptor in the order (-)isoproterenol greater than (-)epinephrine greater than (-)norepinephrine, typical of a beta 2 type receptor. Beta-Adrenergic receptor was present in placental tissue as early as 10 weeks gestational age, and binding capacity decreased slightly with advancing gestation. [3H]Dihydroalprenolol binding was coupled to epinephrine-stimulated adenylate cyclase activity throughout gestation. The subcellular distribution of both beta-adrenergic receptors and epinephrine-stimulated adenylate cyclase suggest their localization primarily in nonbrush border membrane fractions, presumably from plasma membranes more closely related to the fetal rather than to the maternal circulation. Epinephrine-sensitive adenylate cyclase was not present in purified brush border preparations which were directly exposed to maternal blood in the intervillous space.


Assuntos
Adenilil Ciclases/metabolismo , Epinefrina/farmacologia , Placenta/metabolismo , Receptores Adrenérgicos beta/metabolismo , Receptores Adrenérgicos/metabolismo , Ligação Competitiva , Membrana Celular/metabolismo , Di-Hidroalprenolol/metabolismo , Feminino , Guanosina Trifosfato/farmacologia , Humanos , Membranas Intracelulares/metabolismo , Cinética , Microssomos/metabolismo , Microvilosidades/metabolismo , Gravidez
16.
FEBS Lett ; 433(1-2): 169-73, 1998 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-9738955

RESUMO

By confocal laser scanning microscopy (CLSM) we have studied the membrane fusion between cationic liposomes and the endosome membranes involved in gene transfection mediated by cationic liposomes. Antisense oligonucleotides were transferred by cationic liposomes with a cationic cholesterol derivative, cholesteryl-3beta-carboxyamidoethylenedimethylamine (I). Cationic liposomes were made by a mixture of the derivative I and DOPE. The intracellular distribution of fluorescein-conjugated antisense oligonucleotides (phosphorothioate) was studied by CLSM. The images showed that the antisense oligonucleotides were preferentially transferred into the nucleus of target cells (NIH3T3, COS-7 and HeLa cells) by the liposomes with derivative I. However, their transfection was completely blocked by nigericin which was able to dissipate the pH gradient across the endosome membranes, although the liposome/DNA complex was found in the cytoplasm of the target cells. This was quite in contrast with the fluorescence images of the target cells treated with wortmannin, an inhibitor of endocytosis. The results suggest that at least two steps are effective for gene transfection mediated by the cationic liposomes with cationic cholesterol derivatives. One is the endocytosis of the liposome/DNA complex into the target cells and the other is the removal of antisense oligonucleotides (plasmid DNAs) from the complex in the endosomes. The latter step was preferentially preceded by the membrane fusion between the cationic liposomes and the endosome membranes at around pH 5.0.


Assuntos
Cátions , Lipossomos , Fusão de Membrana , Transfecção , Células 3T3 , Animais , Células COS , Núcleo Celular/metabolismo , Cloranfenicol O-Acetiltransferase/genética , Ésteres do Colesterol , Endossomos/ultraestrutura , Corantes Fluorescentes , Células HeLa , Humanos , Ionóforos/farmacologia , Lasers , Camundongos , Microscopia Confocal , Nigericina/farmacologia , Oligonucleotídeos Antissenso/administração & dosagem , Oligonucleotídeos Antissenso/análise , Fosfatidiletanolaminas
17.
FEBS Lett ; 421(1): 69-72, 1998 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-9462842

RESUMO

Atomic force microscopy (AFM) was used for studying gene transfection mediated by cationic liposomes which contain a cationic cholesterol derivative with a different spacer arm. Cationic liposomes were made by a mixture of one of eight cationic cholesterol derivatives and 1,2-dioleoyl-sn-glycero-3-phosphatidyl ethanolamine (DOPE). AFM images showed that vesicles made of the liposome/DNA complex had various diameters depending on each cationic cholesterol derivative with a different spacer arm. The results showed that the diameter of the liposome/DNA complex was well related to the transfection activity of plasmid pSV2CAT DNA to a cultured cell line (NIH3T3). From the results it was found that the vesicles with moderate diameters (from 0.4 to 1.4 microm) were moste effective for gene transfection of plasmid pSV2CAT DNA into the target cell. Neither smaller vesicles (< 400 nm) nor larger vesicles (> 1.4 microm) were adequate for gene transfection. As the gene transfection by the cationic liposomes was mostly inhibited by wortmannin, an inhibitor of endocytosis, it is suggested that the vesicles with moderate diameters were useful for gene transfection by endocytosis.


Assuntos
Colesterol/análogos & derivados , Transfecção/métodos , Células 3T3 , Aminas , Animais , Cloranfenicol O-Acetiltransferase/biossíntese , Endocitose , Genes Reporter , Vetores Genéticos , Lipossomos , Camundongos , Microscopia de Força Atômica/métodos , Fosfatidiletanolaminas , Proteínas Recombinantes/biossíntese
18.
Pediatrics ; 88(1): 19-28, 1991 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-2057268

RESUMO

To determine if outcomes of low birth weight neonates with respiratory distress syndrome can be improved by the administration of multiple doses of bovine surfactant, we conducted two identical multicenter, controlled trials, and the results were combined for analysis. Seven hundred and ninety-eight neonates weighing 600 to 1750 g at birth who had developed respiratory distress syndrome within 6 hours of birth were assigned randomly to receive either 100 mg of phospholipid/kg of Survanta, a modified bovine surfactant (n = 402), or a sham dosing procedure (n = 396). Neonates whose respiratory distress persisted could be given up to three more doses, with all doses to be given in the first 48 hours after birth. Dosing was performed by investigators not involved in the clinical care of the neonates; nursery staff were kept blinded as to the treatment assignment. Fewer Survanta-treated neonates died of any cause (18.4% vs 27.3%, P = .002), died of respiratory distress syndrome (9.0% vs 20.3%, P less than .001), and either died or developed bronchopulmonary dysplasia due to respiratory distress syndrome (51.2% vs 64.6%, P less than .001). Neonates who received Survanta also had greater improvement in their oxygenation and ventilatory status from baseline to 72 hours than did control neonates. Survanta-treated neonates were at lowered risk for developing pulmonary interstitial emphysema (18.6% vs 39.3%, P less than .001) and other pulmonary air leaks (11.5% vs 25.9%, P less than .001). We conclude that multiple doses of Survanta given after diagnosis of respiratory distress syndrome reduce mortality and morbidity.


Assuntos
Surfactantes Pulmonares/administração & dosagem , Síndrome do Desconforto Respiratório do Recém-Nascido/mortalidade , Administração por Inalação , Animais , Displasia Broncopulmonar/epidemiologia , Displasia Broncopulmonar/mortalidade , Bovinos , Distribuição de Qui-Quadrado , Seguimentos , Humanos , Recém-Nascido de Baixo Peso , Recém-Nascido , Tábuas de Vida , Respiração Artificial , Síndrome do Desconforto Respiratório do Recém-Nascido/complicações , Síndrome do Desconforto Respiratório do Recém-Nascido/tratamento farmacológico , Fatores de Tempo
19.
Int J Epidemiol ; 19(4): 1083-5, 1990 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2150669

RESUMO

During the period 1980-1989 in Okinawa, Japan, serologic markers of hepatitis B infection (hepatitis B surface antigen; HBsAg, antibody to hepatitis B core antigen; anti-HBc) were investigated in nursery school children (1-4 years of age). Prevalences of HBsAg were 1.1-1.5% in the period from 1980-1984, but decreased to under 1.0% in the period from 1985. In 1989 there were two carriers in nursery schools, both born in 1985 or fathers who were HBsAg carriers. Prevalences of anti-HBc were 3.3-7.1% in the period from 1980-1983 with a decrease to 0.5% by 1988. Since hepatitis B vaccine was available for neonates whose mothers were HBsAg carriers with hepatitis Be antigen (HBeAg) and for nursery school children in 1983, hepatitis B virus infection among nursery school children and HBsAg carriers due to transmission from mother-to-child were markedly reduced. This strategy for immunization is useful in endemic areas. Immunization for children whose fathers are HBsAg carriers may also be necessary.


Assuntos
Hepatite B/epidemiologia , Pré-Escolar , Hepatite B/prevenção & controle , Vacinas contra Hepatite B , Humanos , Lactente , Japão/epidemiologia , Vacinas contra Hepatite Viral/administração & dosagem , Vacinas contra Hepatite Viral/uso terapêutico
20.
Int J Epidemiol ; 21(5): 989-94, 1992 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1468864

RESUMO

We examined the effects of various factors, including duration of breastfeeding, the status of mother's anti-p40tax, and titre of mother's anti-human T cell lymphototropic virus type-I (HTLV-I) on mother to child transmission of HTLV-I in 76 HTLV-I carrier mothers and 175 of their children. The overall prevalence of anti-HTLV-I among children was 16.0%. The prevalence of anti-HTLV-I among children breastfed for over 3 months was significantly higher (27.6%) than that of those breastfed for under 3 months (5.1%; P = 0.012). Of the 78 bottle-fed children, 10 (12.8%) were positive for anti-HTLV-I. In the children breastfed for over 3 months, the prevalence of anti-HTLV-I among 37 children of anti-p40tax positive mothers was 37.8% and that of 21 children of anti-p40tax negative mothers was 9.5%, a significant difference (P = 0.044). These data suggest that about 13% of bottle-fed children born to carrier mothers are infected with HTLV-I by routes other than breast milk, and that the mother's anti-p40tax can serve as a marker of infectivity of HTLV-I in the case of breastfeeding for over 3 months.


Assuntos
Aleitamento Materno , Anticorpos Anti-HTLV-I/análise , Infecções por HTLV-I/transmissão , Vírus Linfotrópico T Tipo 1 Humano/imunologia , Adolescente , Adulto , Portador Sadio/imunologia , Criança , Pré-Escolar , Feminino , Soropositividade para HIV , Anticorpos Anti-HTLV-I/imunologia , Humanos , Lactente , Masculino , Troca Materno-Fetal , Gravidez , Prevalência , Estudos Retrospectivos
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