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1.
J Clin Pharm Ther ; 40(5): 590-593, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26291693

RESUMO

WHAT IS KNOWN AND OBJECTIVE: Non-adherence to controller asthma medications is an important public health problem. It is estimated to occur in 30-70% of individuals and is a significant risk factor for asthma morbidity and mortality. The aim of this study was to determine the level of adherence, as indicated by refill rates, to controller asthma medications in a community pharmacy setting. METHODS: Secondary analyses of a community pharmacy dispensing database in 15 locations throughout Utah. RESULTS AND DISCUSSION: The dispensing records of 2193 patients who received controller medications for asthma in a 12-month period, and had a minimum of 6-month potential coverage (180 days) from the date of their first receipt of a controller medication in that period, were examined. Using standard metrics to gauge adherence, the proportion of days covered (PDC) and the medication possession ratio (MPR), the average coverage for controller asthma medications across a 6-month period (180 days) was poor, averaging less than 50% of days' availability. Standard cut-offs (≥80% medication availability) indicated that only 14-16% of patients had 'satisfactory' adherence over their 6-month follow-on period. Females and older patients had significantly greater satisfactory adherence. Medication adherence was significantly greater with inhaled corticosteroid (ICS)-long-acting ß2 -agonist (LABA) combinations than with ICS alone. WHAT IS NEW AND CONCLUSION: This study confirms the considerable scope of the asthma therapy non-adherence problem. Therefore, it is imperative to conduct survey-based research linked directly to pharmacy-based dispensing data to derive patient behavioural, attitudinal and environmental factors that may contribute to the issue, and then pilot and evaluate interventions for change.

2.
J Exp Med ; 167(2): 440-51, 1988 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-3346623

RESUMO

Oral immunization of an animal is generally hard to achieve unless large quantities of antigen are administered. In this study a number of antigens were tested for their ability to elicit a systemic immune response upon oral administration. It was found that bacterial pili, LTB, lectins, and a viral hemagglutinin were all able to elicit significant antibody titers upon oral feeding. The immune response thus generated to LTB and K99 pili could be completely abolished by cofeeding a number of sugars that have close structural homology to the terminal sugars of the GM1 and GM2 gangliosides to which these molecules are known to bind. All of the proteins that were active in oral immunization are known to possess "lectin or lectin-like" binding activities. It is therefore proposed that these molecules are able to bind to glycolipids and glycoproteins on the intestinal mucosa and to stimulate these cells to transport the proteins into the systemic circulation, thereby eliciting a systemic immune response. Molecules that did not possess this binding activity were unable to elicit significant responses at the doses tested.


Assuntos
Administração Oral , Anticorpos Antibacterianos/biossíntese , Antígenos de Bactérias/administração & dosagem , Proteínas de Bactérias/administração & dosagem , Vacinação , Animais , Antígenos de Bactérias/classificação , Antígenos de Bactérias/imunologia , Proteínas de Bactérias/classificação , Proteínas de Bactérias/imunologia , Carboidratos/administração & dosagem , Carboidratos/farmacologia , Relação Dose-Resposta Imunológica , Feminino , Imunossupressores/administração & dosagem , Imunossupressores/farmacologia , Mucosa Intestinal/análise , Camundongos , Camundongos Endogâmicos C57BL
3.
J Exp Med ; 160(5): 1476-84, 1984 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-6387035

RESUMO

The protein antigens of prototypes of five types of group B streptococcal strains were extracted with HCl or Triton X-100, separated by sodium dodecyl sulfate polyacrylamide electrophoresis, transferred to nitrocellulose, and examined by immunochemical staining. The Ibc proteins are shown to consist of at least two distinct protein antigens and their breakdown products. One antigen, the "beta" antigen, exists primarily as a 130,000 mol wt protein that is also able to bind human IgA. The "alpha" antigen, which has no known function, appears as a number of proteins of various molecular weights from 20,000 to 120,000. Another set of antigens, the R protein antigens of type III strains, has been identified as a group of acid-labile proteins varying in molecular weight from 100,000 to 130,000. In addition, two previously undescribed antigens have been found that are common to all five group B types.


Assuntos
Antígenos de Bactérias/análise , Polissacarídeos Bacterianos/imunologia , Streptococcus agalactiae/imunologia , Animais , Anticorpos Monoclonais , Antígenos de Bactérias/imunologia , Antígenos de Bactérias/isolamento & purificação , Colódio , Eletroforese em Gel de Poliacrilamida , Imunoglobulina A/metabolismo , Camundongos , Peso Molecular , Octoxinol , Polietilenoglicóis , Polissacarídeos Bacterianos/análise , Coelhos , Sorotipagem , Streptococcus agalactiae/metabolismo
4.
J Exp Med ; 160(5): 1467-75, 1984 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-6387034

RESUMO

A number of group B streptococcal strains of various serotypes, Ia, Ib, Ic, II, and III were examined for their ability to bind human IgG and IgA. No strains of group B streptococci were found to bind IgG, but many strains possessing the Ibc protein antigen(s) were found to bind a significant amount of IgA. The extent of IgA binding correlated with the amount of a 130,000 mol wt, detergent-extractable protein, and reactivity with the Ic typing sera. Using nitrocellulose blots, it was found that the 130,000 mol wt protein bound human IgA. A method was developed to purify the protein while retaining its ability to bind human IgA. Using solid phase radioimmunoassays, it was determined that the protein bound to the Fc region of monomeric or polymeric IgA and that it failed to bind IgM or any IgG isotype.


Assuntos
Antígenos de Bactérias/imunologia , Antígenos CD , Imunoglobulina A/metabolismo , Linfocinas/isolamento & purificação , Proteínas Secretadas pela Próstata , Receptores Fc/isolamento & purificação , Streptococcus agalactiae/imunologia , Especificidade de Anticorpos , Sítios de Ligação de Anticorpos , Ligação Competitiva , Eletroforese em Gel de Poliacrilamida , Humanos , Imunoglobulina G/metabolismo , Linfocinas/análise , Octoxinol , Polietilenoglicóis , Polissacarídeos Bacterianos/imunologia , Receptores Fc/análise , Streptococcus agalactiae/classificação , Streptococcus agalactiae/fisiologia
5.
J Frailty Aging ; 9(2): 111-117, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32259186

RESUMO

BACKGROUND: No study has performed an exercise intervention that included high-intensity, free-weight, functional resistance training, and assessed frailty status as an inclusion criteria and outcome measure via original, standardized tools, in pre-frail females. OBJECTIVES: Determine if the intervention strategy is not only feasible and safe, but can also improve frailty status, functional task performance, and muscle strength. DESIGN: Pilot, quasi-experimental. SETTING: Community. PARTICIPANTS: 20 older-adults with pre-frailty characteristics. INTERVENTION: 12-weeks (3 days/week, 45-60 minutes/session) of multi-component exercise, inclusive of aerobic, resistance, balance and flexibility exercises. The crux of the program was balance and resistance exercises, the latter utilized high-intensity, free-weight, functional resistance training. The control group maintained their usual care. MEASUREMENTS: 1) Feasibility and safety (dropout, adherence, and adverse event); 2) Frailty (Frailty Phenotype, Clinical Frailty Scale, and gait speed); 3) Functional task performance (grip strength and sit-to-stand time); and 4) Isometric and isotonic strength of the knee extensors and elbow flexors. RESULTS: No participants dropped out of the intervention or experienced an adverse event, and adherence averaged 88.3%. The exercise group became less frail, whereas the control group became more frail. There was a significant within-group improvement in exercise participants gait speed (p ≤ 0.01, +0.24 m/sec), grip strength (p ≤ 0.01, +3.9 kg), and sit-to-stand time (p ≤ 0.01, -5.0 sec). There was a significant within-group improvement in exercise participants knee extension isometric torque (p ≤ 0.05, +7.4 Nm) and isotonic velocity (p = ≤ 0.01, +37.5 ˚/sec). Elbow flexion isotonic velocity significantly declined within the control group (p ≤ 0.01, -20.2 ˚/sec) and demonstrated a significant between-group difference (p ≤ 0.05, 40.73 ˚/sec) post-intervention. CONCLUSIONS: The intervention strategy appears to be feasible and safe, and may also improve frailty status, functional task performance, and muscle strength. These results help calculate effect size for a future randomized controlled trial.


Assuntos
Terapia por Exercício/métodos , Fragilidade/prevenção & controle , Adulto , Idoso , Exercício Físico/fisiologia , Feminino , Humanos , Força Muscular/fisiologia , Projetos Piloto , Treinamento Resistido , Resultado do Tratamento
6.
J Frailty Aging ; 9(2): 118-121, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32259187

RESUMO

Approaches to and benefits from resistance training for non-compromised older adults are well known. Less is understood about resistance training with pre-frail older adults, and even less information is available on the practical approaches to delivery. Herein, we describe an approach in pre-frail females who undertook a multi-component exercise intervention, inclusive of high-intensity, free-weight, functional resistance training. Capitalizing on the principle of overload is possible and safe for pre-frail females through constant reassurance of ability and adjustments in technique. Making exercise functionally relevant, for example, a squat is the ability to get on and off a toilet, resonates meaning. Older pre-frail females are affected by outside (clinical) influences. The exercise participant, and extraneous persons need to be educated on exercise approaches, to increase awareness, debunk myths, and enhance support for participation. Identification of individuality in a group session offers ability to navigate barriers for successful implementation.


Assuntos
Fragilidade/prevenção & controle , Treinamento Resistido , Idoso , Feminino , Humanos , Força Muscular/fisiologia , Condicionamento Físico Humano , Resultado do Tratamento
7.
J Control Release ; 117(3): 421-9, 2007 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-17239471

RESUMO

In spite of great potential, effective oral delivery of many vitamin B(12)-peptide/protein drug conjugates does not occur due to the limited uptake capacity of the VB(12) transport system, loss of bioactivity of native protein and/or intrinsic factor affinity of VB(12) and liability to GI degradation. In order to overcome these shortcomings in a two pronged way, we have endeavoured to develop a VB(12)-Nanoparticles (NPs) system to enhance the uptake capacity of both NPs and VB(12) transport to deliver orally effective insulin. NPs were prepared using different molecular weight dextrans and epichlorohydrin as cross-linker by an emulsion method. NPs surface was modified with succinic anhydride, and conjugated with amino VB(12) derivatives of carbamate linkage. VB(12) attachment was confirmed by IR, XPS analysis, and was quantified by HPLC (4.0 to 4.4% w/w of NPs). The pre-formed NPs conjugates (Zave=160-250 nm; polydisperse) were loaded with 2, 3 and 4% w/w of insulin, and the entrapment was found to be 45-70%. NPs conjugates were found to protect 65-83% of entrapped insulin against in vitro gut proteases. In vitro release studies exhibit an initial burst followed by diffusion controlled first order kinetics with 75-95% release within 48 h. After oral administration of these carriers (20 IU/kg), a nadir of 70-75% reduction in plasma glucose was found in 5 h, reached basal levels in 8-10 h, and a prolonged second phase was found until 54 h. The % pharmacological availability (PA) of 70 K NPs conjugate containing 2, 3 and 4% w/w insulin was 1.1, 1.9 and 2.6 fold higher, respectively compared to NPs without VB(12); consistent with the hypothesis that uptake was mediated by the vitamin B(12) transport. NPs of 70 K dextran showed 1.4 fold PA compared to 10 K while negligible action was observed with 200 K. The potential utilities of VB(12)-NPs carrier as an oral delivery platform of proteins, especially insulin via dextran-coated particles necessities further elaborate investigations.


Assuntos
Hipoglicemiantes/administração & dosagem , Hipoglicemiantes/química , Insulina/administração & dosagem , Insulina/química , Vitamina B 12/química , Vitaminas/química , Administração Oral , Animais , Área Sob a Curva , Ácidos Carboxílicos/química , Cromatografia Líquida de Alta Pressão , Reagentes de Ligações Cruzadas , Dextranos , Diabetes Mellitus Experimental/tratamento farmacológico , Portadores de Fármacos , Composição de Medicamentos , Desenho de Fármacos , Feminino , Hipoglicemiantes/uso terapêutico , Insulina/uso terapêutico , Microesferas , Tamanho da Partícula , Ratos , Ratos Wistar , Espectrometria por Raios X
8.
Biochim Biophys Acta ; 1490(1-2): 43-53, 2000 Jan 31.
Artigo em Inglês | MEDLINE | ID: mdl-10786616

RESUMO

Intrinsic factor (IF) has been expressed previously in Baculovirus with a yield (0.1-1 mg/l) that was inadequate for structural and metabolic studies. IF cDNAs were cloned into the shuttle vector pPIC9 of P. pastoris, and the proteins were induced and purified by cobalamin (Cbl) affinity chromatography. Expression of recombinant proteins revealed a major band of 49 kDa for both human and rat IF. Expression of human IF was achieved at 1040 mg/l, but of rat IF at only 1-2 mg/l. Reaction of human IF with a photo-activatable derivative of Cbl was demonstrated by Western blotting, and detection of IF fragments by anti-Cbl monoclonal antibody and by amino-terminal sequencing revealed at least three regions (residues 129-151, 234-254, and +294) linked to Cbl. Both recombinant human and rat [125I]IF-Cbl bound to rat and guinea pig brush border membranes with similar affinity, but the binding capacity of human IF for the rat receptor was only 10% compared with rat IF. All six amino acids within the previously identified N-terminal binding region of human IF were mutated to be identical to rat IF, but the resulting chimeric IF still bound poorly to rat membranes. Mutations of residues 26/27 (Glu26 to Asp and Asn27 to Gln) and 32/34 (Ser32 to Thr and Tyr34 to Arg) showed changes in both Ka and Vmax, with great effects on Vmax. In conclusion, P. pastoris is an expression system that produces functional human IF at a higher yield than in the baculovirus system. Cbl binding was directly demonstrated at multiple sites along the linear sequence of human IF. The receptor binding function of the amino terminal sequence 25 62 has been confirmed, but it is insufficient to reproduce all the features of IF-Cbl binding.


Assuntos
Fator Intrínseco/biossíntese , Pichia/metabolismo , Animais , Linhagem Celular , Vetores Genéticos , Humanos , Fator Intrínseco/química , Fator Intrínseco/genética , Rim/metabolismo , Microvilosidades/metabolismo , Mutagênese Sítio-Dirigida , Pichia/genética , Ratos , Receptores de Superfície Celular/química , Receptores de Superfície Celular/metabolismo , Proteínas Recombinantes/biossíntese
9.
J Gen Physiol ; 89(5): 791-813, 1987 May.
Artigo em Inglês | MEDLINE | ID: mdl-3598560

RESUMO

Local measurements of the fall in oxygen pressure on stimulation of slices of the retina of the honeybee drone by flashes of light were made with oxygen microelectrodes and used to calculate the kinetics of the extra oxygen consumption (delta QO2) induced by each flash. The action spectrum for delta QO2 was obtained from response-intensity curves in response to brief (40 ms) monochromatic light flashes. The action spectrum of receptor potentials was obtained with the same experimental conditions. The two action spectra match closely: they deviate slightly from the photosensitivity spectrum of the drone rhodopsin (R). The deviation is thought to be due to wavelength-dependent light scattering and absorption in the preparation. In these experiments, the visual pigment was first illuminated with orange light, which is known to convert the bistable drone photopigment predominantly to the R state from the metarhodopsin (M) state. When long (300-900 ms) light flashes were used to elicit delta QO2, the responses to different wavelengths could not be matched in time course (as for the short flashes). Flashes producing large R-to-M conversions produced a prolonged delta QO2. The prolongation did not occur after double flashes, which produced both large R-to-M and M-to-R conversions. Similar changes in the length of afterpotentials in the photoreceptor cells and in a long-lasting decrease in photoreceptor intracellular K+ activity were found after long single or double flashes. The results are interpreted to show that the initial event for stimulation by light of metabolism in the drone retina is the same as that for stimulation of electrical responses (i.e., absorption of photons by R). Absorption of photons by M can produce an inhibitory effect on this stimulation.


Assuntos
Abelhas/metabolismo , Consumo de Oxigênio , Estimulação Luminosa , Células Fotorreceptoras/metabolismo , Animais , Técnicas In Vitro
10.
J Gen Physiol ; 82(4): 469-96, 1983 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-6644268

RESUMO

The relative absorption spectra of the bistable photopigment of single rhabdoms from the dorsal region of the retina of the honeybee drone were obtained using slices of retina fixed in glutaraldehyde; less accurate measurements on unfixed tissue gave difference spectra that were similar to those for fixed retinae. The method used was based on measurements of absorbance changes during saturating adaptations of the visual pigment to different monochromatic lights. It is similar to previous methods based on measurements of difference spectra amplitudes, but is simpler to use and more accurate. The predominant pigment has states that absorb maximally at 446 (rhodopsin) and 505 nm (metarhodopsin). In addition, there is a small amount of another pigment whose two states absorb maximally at approximately 340 (UV) and 460 nm.


Assuntos
Abelhas/fisiologia , Células Fotorreceptoras/fisiologia , Retina/fisiologia , Espectrofotometria/métodos , Animais , Masculino , Pigmentos da Retina/fisiologia , Espectrofotometria/instrumentação
11.
J Gen Physiol ; 94(4): 633-47, 1989 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-2614369

RESUMO

Light-evoked membrane currents were recorded with suction electrodes from the outer segments of individual photoreceptors enzymatically dissociated from the skate retina. The intensity-response relation of dark-adapted cells closely followed a Michaelis function for which a half-saturating response was elicited by a flash intensity that produced about 36 photoisomerizations. Dim-light responses, as well as the early rising phase of the responses to a wide range of flash intensities, could be described by a reaction scheme that involved a series of four first-order delay stages. The number of delay stages required to model the rising phase of the photocurrents did not change in light adaptation. However, background illumination that reduced sensitivity by 1.5 log units, or a bleaching exposure that resulted in a nearly equivalent desensitization, shortened significantly the time scale of the responses. In both instances there were two- to threefold increases in the rate constants of the transitional delays, and almost complete suppression of the tail current that characterized the response of the dark-adapted cell. These findings suggest that although light adaptation alters the gain and kinetics of the transduction mechanism, the nature of the intervening processes is the same in dark- and light-adapted photoreceptors. Moreover, the results show clearly that there is no need to postulate the existence of a second class of cone-like rods to account for the remarkable ability of skate photoreceptors to respond to incremental stimuli presented on "saturating" background fields or after exposure to an intense bleaching light.


Assuntos
Peixe Elétrico/fisiologia , Células Fotorreceptoras/fisiologia , Retina/fisiologia , Rajidae/fisiologia , Potenciais de Ação , Animais , Adaptação à Escuridão/fisiologia , Eletrodos , Técnicas In Vitro , Estimulação Luminosa
12.
J Gen Physiol ; 102(3): 483-502, 1993 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-8245820

RESUMO

Visual pigment bleaching desensitizes rod photoreceptors greatly in excess of that due to loss of quantum catch. Whether this phenomenon also occurs in cone photoreceptors was investigated for isolated salamander red-sensitive cones. In parallel experiments, (a) visual pigment depletion by steps of bleaching light was measured by microspectrophotometry, and (b) flash sensitivity was measured by recording light-sensitive membrane current. In isolated cones, visual pigment bleaching permanently reduced flash sensitivity significantly below that due to the reduction in quantum catch, and there was little spontaneous recovery of visual pigment. The "extra" desensitization due to bleaching was most prominent up to bleaches of approximately 80% visual pigment and reached a level approximately 1 log unit beyond that due to loss of quantum catch. At higher bleaches, the effect of loss of quantum catch became more important. Bleaching did not greatly reduce the maximum light-suppressible membrane current. A 99% reduction of the visual pigment permanently reduced the circulating current by only 30%. Visual pigment bleaching speeded up the kinetics of dim flash responses. All electrical effects of bleaching were reversed on exposure to 11-cis retinal, which probably caused visual pigment regeneration. Light adaptation in photopic vision is known to involve significant visual pigment depletion. The present results indicate that cones operate with a maintained circulating current even after a large pigment depletion. It is shown how Weber/Fechner behavior may still be observed in photopic vision when the contributions of bleaching to adaptation are included.


Assuntos
Adaptação Ocular/fisiologia , Cor de Olho/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Absorciometria de Fóton , Ambystoma , Animais , Eletrofisiologia , Cor de Olho/efeitos da radiação , Técnicas In Vitro , Cinética , Larva , Luz , Potenciais da Membrana/fisiologia , Microeletrodos , Modelos Biológicos , Células Fotorreceptoras Retinianas Cones/química , Células Fotorreceptoras Retinianas Cones/efeitos da radiação , Retinaldeído/farmacologia , Espectrofotometria
13.
J Gen Physiol ; 108(4): 333-40, 1996 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-8894981

RESUMO

Psychophysical experiments have shown an equivalence between sensitivity reduction by background light and by bleaches for the human scotopic system. We have compared the effects of backgrounds and bleaches on the light-sensitive membrane-current responses of isolated rod photoreceptors from the salamander Ambystoma tigrinum. The quantum catch loss was factored out from the desensitization due to bleaching to give the fraction of "extra" desensitization due to adaptation. For backgrounds, desensitization is well described by the Weber/Fechner equation. The extra desensitization after bleaches can also be described by the Weber/Fechner equation, if an "equivalent" background produced by bleaching is made linearly proportional to the fraction of pigment bleached. A background which produces an extra desensitization of a factor of two is equivalent to a fractional bleach of approximately 6%. Equivalent background and bleaching desensitizations were associated with similar reductions in circulating current. There is a linear relation between log flash sensitivity and decrease in circulating current. Equivalent background and bleaching desensitizations were associated with similar increases in cGMP phosphodiesterase and guanylate cyclase activity. These were inferred from membrane current changes after steps into lithium or IBMX solutions. There were also similar reductions in the integration times of dim flash responses for equivalent desensitizations produced by backgrounds and bleaches. These results suggest that the equivalence between background and bleaching found psychophysically may arise at the very earliest stages of visual processing and that these two processes of desensitization have similar underlying mechanisms.


Assuntos
Ambystoma/fisiologia , Luz , Células Fotorreceptoras Retinianas Bastonetes/fisiologia , Células Fotorreceptoras Retinianas Bastonetes/efeitos da radiação , Adaptação Fisiológica , Ambystoma/crescimento & desenvolvimento , Animais , Condutividade Elétrica , Guanilato Ciclase/metabolismo , Homeostase , Larva , Modelos Biológicos , Diester Fosfórico Hidrolases/metabolismo , Fatores de Tempo
14.
Mol Endocrinol ; 5(12): 1836-44, 1991 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-1791833

RESUMO

Although both promoter and enhancer sequences of the PRL gene 5'-flanking DNA are required for cell-specific, high level expression in transgenic animals, reports of the relative contributions of these elements determined in transient transfection experiments have varied. In this study we examined the transcriptional activities of proximal promoter (-422/+33) and distal enhancer (-1956/-1530) sequences of the rat (r) PRL gene by transient transfection of hybrid genes containing these sequences into two rat pituitary cell lines, GC and 235-1. These cell lines exhibit characteristics either of mammosomatotropes, which express both PRL and the evolutionarily related GH gene (GC), or lactotropes, which express only PRL (235-1). As lactotropes are thought to differentiate from a mammosomatotrope precursor cell, comparisons between these cell lines provide the opportunity to examine the mechanisms that activate PRL and GH genes during development. We show that the relative contributions of promoter and enhancer elements differ between GC and 235-1 cells. Although maximal enhancer-driven activity was similar between these cell lines, promoter sequences were more active in GC (5-10% maximal) than 235-1 cells (1-2% maximal). However, no apparent differences in factor binding to the rPRL promoter region could be correlated with differences in activity, suggesting that differential factor modification, rather than different factors, is involved. As the rGH promoter exhibited a similar pattern of activity in these cell lines, these observations suggest that promoter as well as enhancer elements contribute to the cell specificity of PRL and GH gene expression.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Elementos Facilitadores Genéticos/genética , Neoplasias Hipofisárias/patologia , Prolactina/genética , Regiões Promotoras Genéticas/genética , Animais , DNA de Neoplasias/genética , Regulação Neoplásica da Expressão Gênica/genética , Hormônio do Crescimento/genética , Neoplasias Hipofisárias/genética , Neoplasias Hipofisárias/metabolismo , Prolactina/metabolismo , Ratos , Transfecção , Células Tumorais Cultivadas/metabolismo , Células Tumorais Cultivadas/patologia
15.
AIDS ; 15(13): 1657-63, 2001 Sep 07.
Artigo em Inglês | MEDLINE | ID: mdl-11546940

RESUMO

OBJECTIVES: To quantify the percentage of the two major subpopulations of blood dendritic cells (DC) in HIV-1-seropositive Ugandan individuals infected with non-clade B viruses and compare this with that seen in clade B HIV-1 infected non-African individuals. DC maturation/activation status was also investigated via the expression of CD86. METHODS: The percentage of blood DC was quantified by using flow cytometry. DC were identified as the lineage (CD3, CD14, CD16, CD19, CD20, CD56)-negative, HLA-DR-positive population and the two major subpopulations were differentiated by CD11c expression. RESULTS: The percentage of blood DC was reduced significantly in HIV-1-seropositive African individuals when compared with controls (0.21 and 0.39% respectively). A similar reduction was also seen in non-African patients residing in the UK (0.19% compared with 0.36% for controls). However, there was no selective loss in either CD11c-positive or CD11c-negative subpopulations. The percentage of blood DC expressing CD86 was significantly greater in HIV-1-seropositive individuals when compared with controls and the increased expression was largely confined to CD11c-negative DC. CONCLUSIONS: Africans infected with non-clade B HIV-1 showed similar reductions in the percentage of blood DC to non-Africans infected with clade B viruses. There was no selective loss of either DC subpopulation, suggesting that the ability of DC to acquire and present antigens or to produce interferon-alpha may both be impaired in HIV-1 infection.


Assuntos
Células Dendríticas/fisiologia , Infecções por HIV/imunologia , HIV-1 , Adulto , África , Antígenos CD/metabolismo , Antígeno B7-2 , Contagem de Linfócito CD4 , Diferenciação Celular , Células Dendríticas/citologia , Feminino , Citometria de Fluxo , Anticorpos Anti-HIV/sangue , Infecções por HIV/virologia , HIV-1/imunologia , Humanos , Integrina alfaXbeta2/metabolismo , Masculino , Glicoproteínas de Membrana/metabolismo , RNA Viral/sangue
16.
AIDS ; 7(6): 807-12, 1993 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-8363757

RESUMO

OBJECTIVE: To evaluate the potential of TraT to restore HIV-specific cell-mediated immunity. DESIGN: CD4+ T cell-associated antiviral and recall antigen-specific lymphoproliferative responses are generally impaired or absent in HIV-infected individuals. METHODS: Using peripheral blood mononuclear cells (PBMC) from a group of asymptomatic and symptomatic HIV-infected individuals, we compared the immunomodulatory effects of exogenous interleukin-2 (IL-2) with the effects elicited by the bacterial integral membrane protein, TraT. RESULTS: Exogenous IL-2 enhanced lymphoproliferation induced by an immunodominant synthetic HIV gp41 analogue, gp41[8] (amino acids 593-604), in four out of 10 asymptomatics and six out of 19 symptomatics. In contrast, TraT acted synergistically with gp41[8] to augment HIV-specific proliferation with higher frequency and greater magnitude than exogenous IL-2. Moreover, this TraT-mediated enhancement of HIV-specific lymphoproliferation occurred in the majority of HIV-infected individuals, irrespective of CD4+ T-cell count in peripheral blood or disease status, and thus appears not to be major histocompatibility complex-restricted. TraT also augmented lymphoproliferation induced by well-known recall antigens and other less immunodominant HIV analogues. CONCLUSIONS: These findings suggest that TraT, in combination with HIV-derived peptides, could be used to maintain or restore cell-mediated immune functions of HIV-infected individuals, as well as cellular immune functions in individuals suffering from other immunodeficiency disorders.


Assuntos
Adjuvantes Imunológicos/farmacologia , Proteínas da Membrana Bacteriana Externa/farmacologia , Proteínas de Escherichia coli , HIV/imunologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Sequência de Aminoácidos , Antígenos de Bactérias/imunologia , Proteínas da Membrana Bacteriana Externa/imunologia , Células Cultivadas , Escherichia coli , Proteína gp41 do Envelope de HIV/imunologia , Infecções por HIV/sangue , Antígenos HLA/genética , Antígenos HLA/imunologia , Haplótipos/genética , Humanos , Epitopos Imunodominantes/imunologia , Memória Imunológica , Interleucina-2/farmacologia , Dados de Sequência Molecular , Fragmentos de Peptídeos/imunologia , Subpopulações de Linfócitos T/imunologia
17.
Crit Rev Ther Drug Carrier Syst ; 15(6): 557-86, 1998.
Artigo em Inglês | MEDLINE | ID: mdl-9883390

RESUMO

The treatment of patients with most peptide and protein pharmaceuticals must currently be performed by injection, with the accompanying disadvantages of patient discomfort, increased medical costs, and reduced patient compliance. It would be much easier and more acceptable if these drugs could be given by the oral route. Unfortunately, this route cannot be used with most proteins and with peptides due to both the degradation of these molecules within the intestine and their poor uptake across the intestinal wall. In this review, an uptake system is described that potentially overcomes both these problems. This system relies upon the natural uptake mechanism for vitamin B12 to cotransport peptides and proteins linked to the vitamin B12 from the intestine to the circulation. In an exciting extension to this technology, it has been found that it is also possible to transport nanoparticles, linked to the vitamin B12, into the circulation. Such nanoparticles can potentially be loaded with peptides or proteins of choice, and so protect these molecules from degradation in the intestine, while simultaneously transporting them into the circulation. These findings are an important step in realizing the possibility of delivering almost all peptides and proteins via the oral route.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Proteínas/administração & dosagem , Vitamina B 12/metabolismo , Administração Oral , Animais , Humanos , Proteínas/farmacocinética , Especificidade da Espécie , Vitamina B 12/administração & dosagem
18.
AIDS Res Hum Retroviruses ; 16(9): 893-905, 2000 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-10875615

RESUMO

HIV-specific CD4+ helper T cell responses, particularly to the envelope glycoproteins, are usually weak or absent in the majority of HIV-seropositive individuals. Since antibodies, by their capacity to alter antigen uptake and processing, are known to have modulatory effects on CD4+ T cell responses, we investigated the effect of antibodies produced by HIV-infected individuals on the CD4+ T cell response to HIV-1 gp120. Proliferative responses of gp120-specific CD4+ T cells were inhibited in the presence of either serum immunoglobulin from HIV-infected individuals or human monoclonal antibodies specific for the CD4-binding domain (CD4bd) of gp120. Human monoclonal antibodies to other gp120 epitopes did not have the same effect. The anti-CD4bd antibodies complexed with gp120 suppressed T cell lines specific for varying gp120 epitopes but did not affect T cell proliferation to non-HIV antigens. Moreover, inhibition by the anti-CD4bd/gp120 complexes was observed regardless of the types of antigen-presenting cells used to stimulate the T cells. These results indicate that the presence of anti-CD4bd antibodies complexed with gp120 can strongly suppress CD4+ helper T responses to gp120.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD4-Positivos/virologia , Anticorpos Anti-HIV/imunologia , Proteína gp120 do Envelope de HIV/imunologia , Ativação Linfocitária , Sequência de Aminoácidos , Anticorpos Monoclonais , Complexo Antígeno-Anticorpo , Células Apresentadoras de Antígenos/imunologia , Células Apresentadoras de Antígenos/virologia , Antígenos de Bactérias , Linhagem Celular , Epitopos/genética , Proteína gp120 do Envelope de HIV/genética , Humanos , Mycobacterium tuberculosis/imunologia
19.
Ann Thorac Surg ; 40(2): 139-43, 1985 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-3896173

RESUMO

We measured the rate of clearance of technetium 99m-labeled diethylenetriamine pentaacetate (99mTcDTPA) (molecular weight, 492 daltons) from the lung into the blood (T1/2LB) in 9 patients before and after operation with cardiopulmonary bypass (CPB). Two hours postoperatively, T1/2LB fell from 49.3 +/- 13.6 minutes (mean +/- standard deviation) to 24.0 +/- 12.8 minutes (p less than 0.001). In addition, alveolar-arterial oxygen tension difference P(A-a)O2 had increased from 73 +/- 28 mm Hg to 164 +/- 37 mm Hg (p less than 0.001). The rates of clearance of 99mTcDTPA had returned to preoperative times by 7 days after operation, although there was still a significant (p less than 0.05) elevation in P(A-a)O2. Postoperative respiratory failure developed in 1 patient. The only abnormality of lung function detected preoperatively was an increased clearance rate for 99mTcDTPA (T1/2LB, 18 minutes). This study has shown an increased clearance from the lung of a low-molecular-weight molecule following operation with CPB. This finding should allow a more rational approach to elucidating the mechanisms of injury to the gas-blood interface in the lung following this type of operation.


Assuntos
Ponte Cardiopulmonar , Pulmão/irrigação sanguínea , Alvéolos Pulmonares/fisiopatologia , Idoso , Capilares/fisiopatologia , Permeabilidade Capilar , Feminino , Humanos , Masculino , Taxa de Depuração Metabólica , Pessoa de Meia-Idade , Pressão Parcial , Ácido Pentético/sangue , Período Pós-Operatório , Troca Gasosa Pulmonar , Tecnécio/sangue , Pentetato de Tecnécio Tc 99m
20.
J Control Release ; 65(1-2): 49-54, 2000 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-10699269

RESUMO

Oral vaccination of animals and man, to provide effective mucosal and/or systemic immunity, is largely ineffective. This is due mainly to the very small quantity of antigen that survives degradation in the intestine and that crosses the intestinal wall. Over the past decade or so, a number of proteins have been identified that are effective at eliciting mucosal and systemic immune responses following oral administration. Uptake of these molecules by the gastro-intestinal tract (GIT) epithelium is dependent upon specific binding to the GIT epithelial cells. The identity of these molecules is discussed, as well as their possible application as 'carriers' for co-transporting haptens, proteins and nanoparticles across the GIT epithelium.


Assuntos
Vacinas/administração & dosagem , Administração Oral , Animais , Humanos , Vacinação/métodos
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