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1.
Osteoporos Int ; 33(4): 937-941, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34825920

RESUMO

Multiple myeloma (MM) remains incurable. Although early diagnosis improves outcomes, it has been unclear which populations to target for screening with serum electrophoresis, serum free light chains and urine electrophoresis. Here, we assessed the value of MM screening in a Fracture Liaison Service, finding that 1 per 195 fragility fractures has undiagnosed MM, which can be expedited to Haematology Services. PURPOSE: A key role of the Fracture Liaison Service (FLS) is screening for secondary causes of osteoporosis. In 2019, the Royal Osteoporosis Society recommended that all patients attending FLS who are recommended anti-osteoporosis therapy have universal screening for myeloma based on serum electrophoresis, serum free light chains and urine electrophoresis. Here, we examined the impact of universal myeloma screening within an FLS. METHODS: We sampled all patients seen by the Oxfordshire FLS between January and April 2018. The completion rates and outcomes of screening were checked using the hospital and FLS databases. RESULTS: Of 950 patients identified by the FLS, 628 were eligible for MM screening; 473 (75%) of these were female, and the average age was 78.4 years. Overall, 584 had some form of myeloma screening, of which 577 (92%) had serum electrophoresis, 525 (84%) had serum free light chains and 407 (65%) had urine electrophoresis measured. A total of 327 (59%) patients had complete screening. Three patients (0.5%) had newly diagnosed myeloma and were urgently referred to Haematology Services. Furthermore, 46 (8%) patients had a detectable serum paraprotein with a likely diagnosis of monoclonal gammopathy of uncertain significance (MGUS) and referred for community annual surveillance according to local guidelines. CONCLUSION: Addition of universal myeloma screening to laboratory testing identified myeloma in 1 per 195 patients, and its precursor state MGUS in 1 per 13 patients, which may have otherwise been missed. Further analysis with long-term follow-up is needed to clearly define the value of diagnosing MGUS within the FLS setting and establish the benefits vs. costs and methods to improve screening completion rates.


Assuntos
Gamopatia Monoclonal de Significância Indeterminada , Mieloma Múltiplo , Osteoporose , Fraturas por Osteoporose , Idoso , Atenção à Saúde , Feminino , Humanos , Mieloma Múltiplo/complicações , Mieloma Múltiplo/diagnóstico , Osteoporose/epidemiologia , Fraturas por Osteoporose/diagnóstico , Fraturas por Osteoporose/epidemiologia , Fraturas por Osteoporose/etiologia , Prevenção Secundária
2.
Ann Oncol ; 25(1): 9-15, 2014 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-24335854

RESUMO

The number of cancer patients in Europe is rising and significant advances in basic and applied cancer research are making the provision of optimal care more challenging. The concept of cancer as a systemic, highly heterogeneous and complex disease has increased the awareness that quality cancer care should be provided by a multidisciplinary team (MDT) of highly qualified healthcare professionals. Cancer patients also have the right to benefit from medical progress by receiving optimal treatment from adequately trained and highly skilled medical professionals. Built on the highest standards of professional training and continuing medical education, medical oncology is recognised as an independent medical specialty in many European countries. Medical oncology is a core member of the MDT and offers cancer patients a comprehensive and systemic approach to treatment and care, while ensuring evidence-based, safe and cost-effective use of cancer drugs and preserving the quality of life of cancer patients through the entire 'cancer journey'. Medical oncologists are also engaged in clinical and translational research to promote innovation and new therapies and they contribute to cancer diagnosis, prevention and research, making a difference for patients in a dynamic, stimulating professional environment. Medical oncologists play an important role in shaping the future of healthcare through innovation and are also actively involved at the political level to ensure a maximum contribution of the profession to Society and to tackle future challenges. This position paper summarises the multifarious and vital contributions of medical oncology and medical oncologists to today's and tomorrow's professional cancer care.


Assuntos
Oncologia/educação , Neoplasias/terapia , Papel do Médico , Europa (Continente) , Medicina Baseada em Evidências , Humanos , Comunicação Interdisciplinar , Oncologia/normas , Neoplasias/diagnóstico , Relações Médico-Paciente , Qualidade da Assistência à Saúde
3.
FEMS Microbiol Rev ; 47(5)2023 09 05.
Artigo em Inglês | MEDLINE | ID: mdl-37437902

RESUMO

Microbiologically influenced corrosion (MIC) is a phenomenon of increasing concern that affects various materials and sectors of society. MIC describes the effects, often negative, that a material can experience due to the presence of microorganisms. Unfortunately, although several research groups and industrial actors worldwide have already addressed MIC, discussions are fragmented, while information sharing and willingness to reach out to other disciplines are limited. A truly interdisciplinary approach, which would be logical for this material/biology/chemistry-related challenge, is rarely taken. In this review, we highlight critical non-biological aspects of MIC that can sometimes be overlooked by microbiologists working on MIC but are highly relevant for an overall understanding of this phenomenon. Here, we identify gaps, methods, and approaches to help solve MIC-related challenges, with an emphasis on the MIC of metals. We also discuss the application of existing tools and approaches for managing MIC and propose ideas to promote an improved understanding of MIC. Furthermore, we highlight areas where the insights and expertise of microbiologists are needed to help progress this field.


Assuntos
Biofilmes , Metais , Corrosão
4.
Adv Dent Res ; 24(2): 94-7, 2012 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-22899688

RESUMO

Streptococcus mutans has been implicated as the major acid-producing (cariogenic) bacterium. Dietary sugars and other factors may cause an imbalance of oral microflora that enables S. mutans to become dominant in the multi-species biofilms on the tooth surface, which could lead to dental caries. The application of broad-spectrum antimicrobials often results in re-colonization and re-dominance of S. mutans within oral flora, while in contrast, therapies capable of selective elimination of S. mutans from oral microbial communities may help to re-establish the normal flora and provide long-term protection. C16G2, a novel synthetic antimicrobial peptide with specificity for S. mutans, was found to have robust killing efficacy and selectivity for S. mutans in vitro. A subsequent pilot human study found that a single application of C16G2 in the oral cavity (formulated in a mouthrinse vehicle) was associated with a reduction in plaque and salivary S. mutans, lactic acid production, and enamel demineralization during the entire 4-day testing period. C16G2 is now being developed as a new anticaries drug.


Assuntos
Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/farmacologia , Cárie Dentária/microbiologia , Streptococcus mutans/efeitos dos fármacos , Anti-Infecciosos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Biofilmes/efeitos dos fármacos , Cárie Dentária/prevenção & controle , Placa Dentária/microbiologia , Humanos
5.
Gene Ther ; 18(3): 294-303, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20981110

RESUMO

In this study, we describe a simple system in which human keratinocytes can be redirected to an alternative differentiation pathway. We transiently transfected freshly isolated human skin keratinocytes with the single transcription factor OCT4. Within 2 days these cells displayed expression of endogenous embryonic genes and showed reduced genomic methylation. More importantly, these cells could be specifically converted into neuronal and contractile mesenchymal cell types. Redirected differentiation was confirmed by expression of neuronal and mesenchymal cell mRNA and protein, and through a functional assay in which the newly differentiated mesenchymal cells contracted collagen gels as efficiently as authentic myofibroblasts. Thus, to generate patient-specific cells for therapeutic purposes, it may not be necessary to completely reprogram somatic cells into induced pluripotent stem cells before altering their differentiation and grafting them into new tissues.


Assuntos
Diferenciação Celular/fisiologia , Queratinócitos/citologia , Fator 3 de Transcrição de Octâmero/metabolismo , Transfecção/métodos , Western Blotting , Linhagem Celular , Metilação de DNA , Primers do DNA/genética , Citometria de Fluxo , Humanos , RNA/isolamento & purificação , Reação em Cadeia da Polimerase Via Transcriptase Reversa
6.
Nat Cell Biol ; 1(2): 94-7, 1999 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10559880

RESUMO

MAPKAP kinase 2 (MK2) is one of several kinases that are regulated through direct phosphorylation by p38 MAP kinase. By introducing a targeted mutation into the mouse MK2 gene, we have determined the physiological function of MK2 in vivo. Mice that lack MK2 show increased stress resistance and survive LPS-induced endotoxic shock. This is due to a reduction of approximately 90% in the production of tumor necrosis factor-alpha (TNF-alpha) and not to a change in signalling from the TNF receptor. The level and stability of TNF-alpha mRNA is not reduced and TNF-alpha secretion is not affected. We conclude that MK2 is an essential component in the inflammatory response which regulates biosynthesis of TNF-alpha at a post-transcriptional level.


Assuntos
Citocinas/genética , Regulação da Expressão Gênica/fisiologia , Lipopolissacarídeos/farmacologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Fator de Necrose Tumoral alfa/genética , Animais , Citocinas/biossíntese , Regulação da Expressão Gênica/efeitos dos fármacos , Inflamação/genética , Inflamação/imunologia , Peptídeos e Proteínas de Sinalização Intracelular , Camundongos , Camundongos Endogâmicos , Camundongos Knockout , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Mutagênese , Fosforilação , Proteínas Serina-Treonina Quinases/deficiência , RNA Mensageiro/metabolismo , Mapeamento por Restrição , Salmonella typhi , Baço/imunologia , Transcrição Gênica , Fator de Necrose Tumoral alfa/biossíntese , Proteínas Quinases p38 Ativadas por Mitógeno
7.
Caries Res ; 45(5): 415-28, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21860239

RESUMO

BACKGROUND/AIMS: Streptococcus mutans, the major etiological agent of dental caries, has a measurable impact on domestic and global health care costs. Though persistent in the oral cavity despite conventional oral hygiene, S. mutans can be excluded from intact oral biofilms through competitive exclusion by other microorganisms. This suggests that therapies capable of selectively eliminating S. mutans while limiting the damage to the normal oral flora might be effective long-term interventions to fight cariogenesis. To meet this challenge, we designed C16G2, a novel synthetic specifically targeted antimicrobial peptide with specificity for S. mutans. C16G2 consists of a S. mutans-selective 'targeting region' comprised of a fragment from S. mutans competence stimulation peptide (CSP) conjoined to a 'killing region' consisting of a broad-spectrum antimicrobial peptide (G2). In vitro studies have indicated that C16G2 has robust efficacy and selectivity for S. mutans, and not other oral bacteria, and affects targeted bacteria within seconds of contact. METHODS: In the present study, we evaluated C16G2 for clinical utility in vitro, followed by a pilot efficacy study to examine the impact of a 0.04% (w/v) C16G2 rinse in an intra-oral remineralization/demineralization model. RESULTS AND CONCLUSIONS: C16G2 rinse usage was associated with reductions in plaque and salivary S. mutans, lactic acid production, and enamel demineralization. The impact on total plaque bacteria was minimal. These results suggest that C16G2 is effective against S. mutans in vivo and should be evaluated further in the clinic.


Assuntos
Anti-Infecciosos/uso terapêutico , Peptídeos Catiônicos Antimicrobianos/uso terapêutico , Proteínas de Bactérias/uso terapêutico , Antissépticos Bucais/uso terapêutico , Streptococcus mutans/efeitos dos fármacos , Desmineralização do Dente/prevenção & controle , Adolescente , Adulto , Idoso , Animais , Anti-Infecciosos/farmacologia , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Proteínas de Bactérias/síntese química , Proteínas de Bactérias/farmacologia , Biofilmes/efeitos dos fármacos , Bovinos , Técnicas de Cultura de Células , Sobrevivência Celular/efeitos dos fármacos , Placa Dentária/microbiologia , Placa Dentária/prevenção & controle , Gengiva/citologia , Gengiva/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Ácido Láctico/metabolismo , Meliteno/farmacologia , Pessoa de Meia-Idade , Mucosa Bucal/citologia , Mucosa Bucal/efeitos dos fármacos , Antissépticos Bucais/farmacologia , Projetos Piloto , Saliva/efeitos dos fármacos , Saliva/microbiologia , Especificidade da Espécie , Sacarose/metabolismo , Desmineralização do Dente/microbiologia , Remineralização Dentária/métodos , Adulto Jovem
8.
Opt Express ; 18(9): 9722-7, 2010 Apr 26.
Artigo em Inglês | MEDLINE | ID: mdl-20588821

RESUMO

Enhanced optical transmission (EOT) through a single aperture is usually achieved by exciting surface plasmon polaritons with periodic grooves. Surface plasmon polaritons are only excited by p-polarized incident light, i.e. with the electric field perpendicular to the direction of the grooves. The present study experimentally investigates EOT for s-polarized light. A subwavelength slit surrounded on each side by periodic grooves has been fabricated in a gold film and covered by a thin dielectric layer. The excitation of s-polarized dielectric waveguide modes inside the dielectric film strongly increases the s-polarized transmission. A 25 fold increase is measured as compared to the case without the dielectric film. Transmission measurements are compared with a coupled mode method and show good qualitative agreement. Adding a waveguide can improve light transmission through subwavelength apertures, as both s and p-polarization can be efficiently transmitted.

9.
J Cell Biol ; 129(3): 805-17, 1995 May.
Artigo em Inglês | MEDLINE | ID: mdl-7537274

RESUMO

DNAs coding for seven murine connexins (Cx) (Cx26, Cx31, Cx32, Cx37, Cx40, Cx43, and Cx45) are functionally expressed in human HeLa cells that were deficient in gap junctional communication. We compare the permeabilities of gap junctions comprised of different connexins to iontophoretically injected tracer molecules. Our results show that Lucifer yellow can pass through all connexin channels analyzed. On the other hand, propidium iodide and ethidium bromide penetrate very poorly or not at all through Cx31 and Cx32 channels, respectively, but pass through channels of other connexins. 4,6 Diamidino-2-phenylindole (DAPI) dihydrochloride shows less transfer among Cx31 or Cx43 transfectants. Neurobiotin is weakly transferred among Cx31 transfectants. Total junctional conductance in Cx31 or Cx45 transfected cells is only about half as high as in other connexin transfectants analyzed and does not correlate exactly with any of the tracer permeabilities. Permeability through different connexin channels appears to be dependent on the molecular structure of each tracer, i.e. size, charge and possibly rigidity. This supports the hypothesis that different connexin channels show different permeabilities to second messenger molecules as well as metabolites and may fulfill in this way their specific role in growth control and differentiation of cell types. In addition, we have investigated the function of heterotypic gap junctions after co-cultivation of two different connexin transfectants, one of which had been prelabeled with fluorescent dextran beads. Analysis of Lucifer yellow transfer reveals that HeLa cells expressing Cx31 (beta-type connexin) do not communicate with any other connexin transfectant tested but only with themselves. Two other beta-type connexin transfectants, HeLa-Cx26 and -Cx32, do not transmit Lucifer yellow to any of the alpha-type connexins analyzed. Among alpha-type connexins, Cx40 does not communicate with Cx43. Thus, connexins differ in their ability to form functional heterotypic gap junctions among mammalian cells.


Assuntos
Comunicação Celular/fisiologia , Permeabilidade da Membrana Celular/fisiologia , Conexinas/fisiologia , Junções Comunicantes/fisiologia , Canais Iônicos/fisiologia , Animais , Conexina 26 , Conexinas/biossíntese , Conexinas/genética , Condutividade Elétrica , Imunofluorescência , Células HeLa , Humanos , Immunoblotting , Camundongos , Sondas Moleculares , RNA Mensageiro/análise , Transfecção
10.
Science ; 151(3708): 349-52, 1966 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-5903345

RESUMO

The perivacuolar cytoplasm of Noctiluca miliaris contains approximately 10(4) microsources of luminescence, with dimensions of 0.5 to 1.5 microns, which exhibit marked fluorescence with ultraviolet excitation. Local invasion by an action potential elicits light emission (microflashes) from these sources with a coupling latency of about 2 milliseconds. Magnitudes of the microflash vary directly with the dimensions of the source. Time courses of the microflash resemble that of the macroflash emitted by the whole cell but have somewhat shorter time constants. The small discrepancy induration between micro- and macroflash can be explained by the 5- to 10-millisecond asynchrony of microsource triggering that results from the conduction time of the action potential. Reversible gradations in amplitude of the macroflash, as from potentiation or fatigue, result from parallel summation of graded changes in microflash intensity. Thus the macroflash gives a reasonably true picture of the subcellular kinetics of luminescence.


Assuntos
Eucariotos , Luminescência , Citoplasma , Fluorescência , Técnicas In Vitro , Cinética , Raios Ultravioleta
11.
Science ; 202(4373): 1203-6, 1978 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-103199

RESUMO

Under depolarizing voltage clamp of Paramecium an inward calcium current developed and subsequently relaxed within 10 milliseconds. The relaxation was substantially slowed when most of the extracellular calcium was replaced by either strontium or barium. Evidence is presented that the relaxation is not accounted for by a drop in electromotive force acting on calcium, or by activation of a delayed potassium current. Relaxation of the current must, therefore, result from an inactivation of the calcium channel. This inactivation persisted after a pulse, as manifested by a reduced calcium current during subsequent depolarization. Inactivation was retarded by procedures that reduce net entry of calcium, and was independent of membrane potential. The calcium channel undergoes inactivation as a consequence of calcium entry during depolarization. In this respect, inactivation of the calcium channel departs qualitatively from the behavior described in the Hodgkin-Huxley model of the sodium channel.


Assuntos
Cálcio/metabolismo , Canais Iônicos/metabolismo , Paramecium/metabolismo , Animais , Bário/farmacologia , Ácido Egtázico/farmacologia , Condutividade Elétrica , Canais Iônicos/efeitos dos fármacos , Potenciais da Membrana , Estrôncio/farmacologia
12.
Science ; 200(4340): 437-9, 1978 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-644308

RESUMO

Relations between calcium entry and activation of a calcium-dependent outward current during depolarization were examined under voltage clamp in dorid giant neurons injected with the calcium-sensitive photoprotein aequorin. Activation kinetics and amplitude of the slow calcium-dependent component were both found to be related to the rate and extent of free calcium accumulation and to the electromotive force acting on potassium ions, independent of the calcium activation kinetics. This indicates that the activation of the calcium-dependent outward current is more closely related to the transient intracellular accumulation of free calcium ions than to the movement of calcium through the plasma membrane during depolarization.


Assuntos
Cálcio/metabolismo , Neurônios/metabolismo , Potássio/metabolismo , Animais , Técnicas In Vitro , Cinética , Potenciais da Membrana , Moluscos , Neurilema/fisiologia
13.
Science ; 166(3913): 1633-5, 1969 Dec 26.
Artigo em Inglês | MEDLINE | ID: mdl-4982836

RESUMO

The cirri of the ciliate Euplotes all asslumne the "reversed" orientation whenever the cell is depolarized and the "forward" orientation whenever the cell is hyperpolarized. Potenitial changes arise spontaneolusly or are induced by electrical or mechanical stimuli. The orientation responses of thte cirri are appatently independent of intracellular "neuromotor" fibrils previously assigned a coordinating function, as they persist after the fibrils are transected.


Assuntos
Cílios/fisiologia , Potenciais da Membrana , Membrana Celular/fisiologia , Cilióforos , Potenciais Evocados , Neurofibrilas/fisiologia , Organoides/fisiologia
14.
Science ; 164(3882): 963-5, 1969 May 23.
Artigo em Inglês | MEDLINE | ID: mdl-5768366

RESUMO

A mechanical stimulus applied to the anterior part of Paramecium causes a transient increase in membrane permeability to calcium. This permits a calcium current to flow into the cell, causing the membrane potential to approach the equilibrium level for calcium. The transient depolarization which results elicits a reversal in the direction of ciliary beat. When the organisms are free-swimming this is seen as the reversed locomotion of Jennings' "avoiding reaction." In contrast, a mechanical stimulus applied to the posterior part results in increased permeability to potassium ions, and hence an outward potassium current. The hyperpolarization which results causes an increase in the frequency of ciliary beat in the normal direction. In free-swimming specimens this is seen as an increase in the velocity of forward locomotion.


Assuntos
Permeabilidade da Membrana Celular , Locomoção , Paramecium , Animais , Aprendizagem da Esquiva , Cálcio/metabolismo , Cílios , Potássio/metabolismo , Células Receptoras Sensoriais
15.
Science ; 216(4547): 730-3, 1982 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-6281880

RESUMO

Calcium ions enter and accumulate during depolarization of some cells, activating a potassium current, IK(Ca), that depends on the cytoplasmic concentration of calcium ions, [Ca]i. However, elevation of [Ca]i can depress IK(Ca) elicited by a subsequent membrane depolarization. The depression of IK(Ca) is ascribed here to a [Ca]i-mediated inactivation of the voltage-gated calcium conductance, which causes a net reduction in calcium ions available for the activation of IK(Ca). This suggests that other processes dependent on gated calcium entry may also be depressed by small background elevations in cytosolic free calcium ions.


Assuntos
Cálcio/fisiologia , Neurônios/fisiologia , Animais , Aplysia , Condutividade Elétrica , Canais Iônicos/fisiologia , Potenciais da Membrana
16.
Science ; 197(4302): 472-5, 1977 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-17921

RESUMO

Neuron cell bodies of Helix pomatia were voltage-clamped with a 300-millisecond depolarizing test pulse (pulse II) delivered I second after a depolarizing conditioning pulse (pulse I). The outward current, measured 200 milliseconds after the onset of pulse. II, exhibited a strong depression that was dependent on the presence of pulse. I. The maximum depression of the pulse II outward current occurred when pulse I voltages lay in the range over which calcium influx is inferred to be greatest; depression of the pulse II current subsided as pulse I potentials approached the putative calcium equilibrium potential. In the presence of extracellular [ethylenebis(oxyethylenenitrilo)]tetraacetic acid (EGTA) or D600, the intensity of the pulse II current became largely independent of pulse I, approaching the values of maximal depression seen in normal Ringer solution. On the other hand, lowering the intracellular pH with extracellular carbon dioxide-carbonate buffer had no measurable effect on the outward currents. Other experiments showed that it is primarily the calcium-dependent, outward-current hump of the N-shaped late current-voltage curve that is depressed by presentation of the conditioning pulse. It was concluded that distinct from an early potassium-activating role, calcium entering during a depolarization leads, during a subsequent depolarization, to a depression of the calcium-activated potassium system that persists for many seconds.


Assuntos
Cálcio/metabolismo , Neurônios/metabolismo , Potássio/metabolismo , Potenciais de Ação , Animais , Ácido Egtázico/farmacologia , Condutividade Elétrica , Estimulação Elétrica , Caracois Helix , Concentração de Íons de Hidrogênio , Cinética , Potenciais da Membrana
17.
Science ; 175(4028): 1375-7, 1972 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-5059568

RESUMO

Ciliated epithelial cells in the oviduct of Necturus maculosus were stimulated mechanically by brief dimpling with a microstylus. This treatment produlced a transient depolarization of the membrane, and a transient increase in the frequency of ciliary beating. The increase in frequency of ciliary beating was related to the concentration of extracellular calcium ion, decreasing with reductiotn in calcium. Addition of lanthanum was followed by a decrease in spontaneous ciliary aictivity and a hyperpolarization of the membrane. In the presence of lanthanum, the transietnt depolarization in response to mechanical stimulation had a shorter timte course, and the concomitant increase in ciliary frequency was greatly reduced. It is concluded that calciuml ions enter the cell as a result of mechanical stimulationi of the membrane, and that calcium influx leads to an increase in the frequency of ciliary activity.


Assuntos
Cálcio/metabolismo , Cílios/fisiologia , Animais , Transporte Biológico , Células Epiteliais , Epitélio/fisiologia , Potenciais Evocados/efeitos dos fármacos , Lantânio/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Oviductos/citologia , Oviductos/metabolismo , Oviductos/fisiologia , Urodelos
18.
Int J Pharm ; 564: 225-236, 2019 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-31004716

RESUMO

At present, there is an increasing demand to improve the sustainability of surface-active compounds in dermal formulations. Biosurfactants, which are derived from living cells, are considered to be more environmentally friendly than synthetic surfactants. Thus, the use of biosurfactants is a promising strategy for the formulation of more environmentally friendly and sustainable dermal products. In this work, a biosurfactant extract (BS) obtained from corn wet-milling industry was studied for its potential use in dermal formulations. The corn derived BS possesses good surface-active properties and was found to be a suitable co-stabilizer for nanoemulsions and nanocrystals for dermal application. It also possesses antioxidative and skin protective properties and was also able to increase the dermal penetration efficacy for lipophilic actives. In dermal formulations the BS can therefore be used as co-stabilizer with antioxidative and penetration enhancing properties at the same time.


Assuntos
Antioxidantes/química , Tensoativos/química , Zea mays/química , Administração Cutânea , Animais , Antioxidantes/administração & dosagem , Portadores de Fármacos/administração & dosagem , Portadores de Fármacos/química , Emulsões , Nanopartículas/administração & dosagem , Nanopartículas/química , Pele/efeitos dos fármacos , Pele/metabolismo , Tensoativos/administração & dosagem , Suínos , Molhabilidade
20.
Oncogene ; 36(21): 2981-2990, 2017 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-27941875

RESUMO

Type 2 transglutaminase (TG2) is an important cancer stem cell survival protein that exists in open and closed conformations. The major intracellular form is the closed conformation that functions as a GTP-binding GTPase and is required for cancer stem cell survival. However, at a finite rate, TG2 transitions to an open conformation that exposes the transamidase catalytic site involved in protein-protein crosslinking. The activities are mutually exclusive, as the closed conformation has GTP binding/GTPase activity, and the open conformation transamidase activity. We recently showed that GTP binding, but not transamidase activity, is required for TG2-dependent cancer stem cell invasion, migration and tumour formation. However, we were surprised that transamidase site-specific inhibitors reduce cancer stem cell survival. We now show that compounds NC9, VA4 and VA5, which react exclusively at the TG2 transamidase site, inhibit both transamidase and GTP-binding activities. Transamidase activity is inhibited by direct inhibitor binding at the transamidase site, and GTP binding is blocked because inhibitor interaction at the transamidase site locks the protein in the extended/open conformation to disorganize/inactivate the GTP binding/GTPase site. These findings suggest that transamidase site-specific inhibitors can inhibit GTP binding/signalling by driving a conformation change that disorganizes the TG2 GTP binding to reduce TG2-dependent signalling, and that drugs designed to target this site may be potent anti-cancer agents.


Assuntos
Aminoaciltransferases/antagonistas & inibidores , Antineoplásicos/farmacologia , Proteínas de Ligação ao GTP/antagonistas & inibidores , Proteínas de Ligação ao GTP/química , Guanosina Trifosfato/metabolismo , Células-Tronco Neoplásicas/efeitos dos fármacos , Células-Tronco Neoplásicas/fisiologia , Transglutaminases/antagonistas & inibidores , Transglutaminases/química , Aminoaciltransferases/química , Sítios de Ligação/efeitos dos fármacos , Domínio Catalítico/efeitos dos fármacos , Domínio Catalítico/genética , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/genética , Células Cultivadas , Proteínas de Ligação ao GTP/genética , Proteínas de Ligação ao GTP/metabolismo , Técnicas de Inativação de Genes , Humanos , Terapia de Alvo Molecular , Ligação Proteica/efeitos dos fármacos , Conformação Proteica/efeitos dos fármacos , Proteína 2 Glutamina gama-Glutamiltransferase , Transglutaminases/genética , Transglutaminases/metabolismo
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