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3.
Cancer Immunol Immunother ; 70(5): 1305-1321, 2021 May.
Artigo em Inglês | MEDLINE | ID: mdl-33140189

RESUMO

Allogeneic natural killer (NK) cell transfer is a potential immunotherapy to eliminate and control cancer. A promising source are CD34 + hematopoietic progenitor cells (HPCs), since large numbers of cytotoxic NK cells can be generated. Effective boosting of NK cell function can be achieved by interleukin (IL)-15. However, its in vivo half-life is short and potent trans-presentation by IL-15 receptor α (IL-15Rα) is absent. Therefore, ImmunityBio developed IL-15 superagonist N-803, which combines IL-15 with an activating mutation, an IL-15Rα sushi domain for trans-presentation, and IgG1-Fc for increased half-life. Here, we investigated whether and how N-803 improves HPC-NK cell functionality in leukemia and ovarian cancer (OC) models in vitro and in vivo in OC-bearing immunodeficient mice. We used flow cytometry-based assays, enzyme-linked immunosorbent assay, microscopy-based serial killing assays, and bioluminescence imaging, for in vitro and in vivo experiments. N-803 increased HPC-NK cell proliferation and interferon (IFN)γ production. On leukemia cells, co-culture with HPC-NK cells and N-803 increased ICAM-1 expression. Furthermore, N-803 improved HPC-NK cell-mediated (serial) leukemia killing. Treating OC spheroids with HPC-NK cells and N-803 increased IFNγ-induced CXCL10 secretion, and target killing after prolonged exposure. In immunodeficient mice bearing human OC, N-803 supported HPC-NK cell persistence in combination with total human immunoglobulins to prevent Fc-mediated HPC-NK cell depletion. Moreover, this combination treatment decreased tumor growth. In conclusion,  N-803 is a promising IL-15-based compound that boosts HPC-NK cell expansion and functionality in vitro and in vivo. Adding N-803 to HPC-NK cell therapy could improve cancer immunotherapy.


Assuntos
Antineoplásicos/uso terapêutico , Interleucina-15/agonistas , Células Matadoras Naturais/imunologia , Leucemia/terapia , Células Progenitoras Linfoides/imunologia , Neoplasias Ovarianas/terapia , Proteínas Recombinantes de Fusão/uso terapêutico , Animais , Antígenos CD34/metabolismo , Antineoplásicos/farmacologia , Diferenciação Celular , Linhagem Celular Tumoral , Testes Imunológicos de Citotoxicidade , Modelos Animais de Doenças , Feminino , Humanos , Interferon gama/metabolismo , Células Matadoras Naturais/transplante , Leucemia/imunologia , Células Progenitoras Linfoides/transplante , Camundongos , Camundongos SCID , Neoplasias Ovarianas/imunologia , Proteínas Recombinantes de Fusão/farmacologia
4.
Exp Brain Res ; 237(2): 427-433, 2019 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-30430184

RESUMO

BACKGROUND: Spinocerebellar ataxias (SCAs) are a group of autosomal dominantly inherited degenerative diseases. As the pathological process probably commences years before the first appearance of clinical symptoms, preclinical carriers of a SCA mutation offer the opportunity to study the earliest stages of cerebellar dysfunction and degeneration. Eyeblink classical conditioning (EBCC) is a motor learning paradigm, crucially dependent on the integrity of the olivocerebellar circuit, and has been shown to be able to detect subtle alterations of cerebellar function, which might already be present in preclinical carriers. METHODS: In order to acquire conditioned responses, we performed EBCC, delay paradigm, in 18 preclinical carriers of a SCA3 mutation and 16 healthy, age-matched controls by presenting repeated pairings of an auditory tone with a supraorbital nerve stimulus with a delay interval of 400 ms. RESULTS: Preclinical carriers acquired significantly less conditioned eyeblink responses than controls and learning rates were significantly reduced. This motor learning defect was, however, not associated with the predicted time to onset. CONCLUSIONS: EBCC is impaired in preclinical carriers of a SCA3 mutation, as a result of impaired motor learning capacities of the cerebellum and is thus suggestive of cerebellar dysfunction. EBCC can be used to detect but probably not monitor preclinical cerebellar dysfunction in genetic ataxias, such as SCA3.


Assuntos
Ataxina-3/genética , Piscadela/fisiologia , Condicionamento Palpebral/fisiologia , Sintomas Prodrômicos , Proteínas Repressoras/genética , Ataxias Espinocerebelares/genética , Ataxias Espinocerebelares/fisiopatologia , Adulto , Eletromiografia , Feminino , Heterozigoto , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem
5.
J Dent Res ; 97(12): 1355-1364, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-29863959

RESUMO

Tooth enamel is manufactured by the inner enamel epithelium of the multilayered enamel organ. Msx2 loss-of-function mutation in a mouse model causes an abnormal accumulation of epithelial cells in the enamel organ, but the underlying mechanism by which Msx2 regulates amelogenesis is poorly understood. We therefore performed detailed histological and molecular analyses of Msx2 null mice. Msx2 null ameloblasts and stratum intermedium (SI) cells differentiated normally in the early stages of amelogenesis. However, during subsequent developmental stages, the outer enamel epithelium (OEE) became highly proliferative and transformed into a keratinized stratified squamous epithelium that ectopically expressed stratified squamous epithelium markers, including Heat shock protein 25, Loricrin, and Keratin 10. Moreover, expression of hair follicle-specific keratin genes such as Keratin 26 and Keratin 73 was upregulated in the enamel organ of Msx2 mutants. With the accumulation of keratin in the stellate reticulum (SR) region and subsequent odontogenic cyst formation, SI cells gradually lost the ability to differentiate, and the expression of Sox2 and Notch1 was downregulated, leading to ameloblast depolarization. As a consequence, the organization of the Msx2 mutant enamel organ became disturbed and enamel failed to form in the normal location. Instead, there was ectopic mineralization that likely occurred within the SR. In summary, we show that during amelogenesis, Msx2 executes a bipartite function, repressing the transformation of OEE into a keratinized stratified squamous epithelium while simultaneously promoting the development of a properly differentiated enamel organ competent for enamel formation.


Assuntos
Órgão do Esmalte/metabolismo , Epitélio/metabolismo , Proteínas de Homeodomínio/metabolismo , Ameloblastos/metabolismo , Animais , Diferenciação Celular , Proliferação de Células , Cistos/embriologia , Cistos/metabolismo , Microanálise por Sonda Eletrônica , Órgão do Esmalte/embriologia , Epitélio/embriologia , Genótipo , Hibridização In Situ , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Knockout , Microscopia Eletrônica de Transmissão , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Microtomografia por Raio-X
6.
Dalton Trans ; 46(14): 4530-4541, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28272641

RESUMO

Heteroatomic bridged paracyclophanes were obtained by two independent synthetic approaches. The required precursors consist of para R2SiCl (R = Me, iPr) substituted aromatic rings (2 and 4). They were subsequently functionalised by using NH3, [LiPH2(dme)] or LiAl(PH2)4. In the case of the Me-substituted species 2, the reaction with NH3 directly yielded the Si2N bridged paracyclophane 5. The Si2P incorporated derivative 10 was obtained by lithiation of p-C6H4(SiiPr2PH2)2 (9) and subsequent salt metathesis with the chlorosilane 4. The second approach involves the use of GaEt3 in the formation of four membered (GaPn)2 cycles (Pn = N, P). p-[C6H4{SiiPr2N(H)GaEt2}2]2 (11) and p-[C6H4{SiiPr2P(H)GaEt2}2]2 (12) represent the first examples of stable (GaPn)2cis isomers as the trans species did not appear in solution. Although 11 and 12 show a similar coordination pattern, they differ in the orientation of the aromatic systems: in the solid structure, 11 adopts a - for paracyclophanes so far unique - T-shape conformation of the phenyl rings, while 12 shows the predominant coplanar orientation. All cyclophanes were characterized by X-ray diffraction, elemental analysis, NMR and IR spectroscopy.

7.
CNS Drugs ; 28(12): 1139-53, 2014 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-25391707

RESUMO

BACKGROUND AND OBJECTIVES: Cerebellar ataxia can be induced by a large number of drugs. We here conducted a systemic review of the drugs that can lead to cerebellar ataxia as an adverse drug reaction (ADR). METHODS: We performed a systematic literature search in Pubmed (1966 to January 2014) and EMBASE (1988 to January 2014) to identify all of the drugs that can have ataxia as an ADR and to assess the frequency of drug-induced ataxia for individual drugs. Furthermore, we collected reports of drug-induced ataxia over the past 20 years in the Netherlands by querying a national register of ADRs. RESULTS: Drug-induced ataxia was reported in association with 93 individual drugs (57 from the literature, 36 from the Dutch registry). The most common groups were antiepileptic drugs, benzodiazepines, and antineoplastics. For some, the number needed to harm was below 10. Ataxia was commonly reversible, but persistent symptoms were described with lithium and certain antineoplastics. CONCLUSIONS: It is important to be aware of the possibility that ataxia might be drug-induced, and for some drugs the relative frequency of this particular ADR is high. In most patients, symptoms occur within days or weeks after the introduction of a new drug or an increase in dose. In general, ataxia tends to disappear after discontinuation of the drug, but chronic ataxia has been described for some drugs.


Assuntos
Ataxia Cerebelar/induzido quimicamente , Ataxia Cerebelar/epidemiologia , Bases de Dados de Produtos Farmacêuticos , Humanos , Países Baixos/epidemiologia
8.
Nano Lett ; 14(11): 6356-60, 2014 Nov 12.
Artigo em Inglês | MEDLINE | ID: mdl-25310377

RESUMO

We report the experimental realization of an optical metamaterial composed of a hexagonal array of coaxial plasmonic metal/insulator/metal waveguides that shows strong polarization-independent optical mode index dispersion in the ultraviolet/blue. The metamaterial is composed of silicon coaxes with a well-defined diameter in the range of 150-168 nm with extremely thin sidewalls (13-15 nm), embedded in a silver film, fabricated using a combination of electron beam lithography, physical vapor deposition, reactive ion etching, and focused ion beam polishing. Using a Mach-Zehnder interferometer the phase advance is measured on several metamaterial samples with different dimensions in the UV/visible part of the spectrum. For all geometries the spectral features as well as the geometry dependence of the data correspond well with numerical finite-difference time domain simulations and the calculated waveguide dispersion diagram, showing a negative mode index between 440 and 500 nm.

9.
10.
Clin Pharmacol Ther ; 96(5): 616-24, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25062063

RESUMO

The summary of product characteristics (SPC) should provide information for the safe prescription and use of a drug. We evaluated the consistency of critical interaction warnings, the quality of presentation of undesirable effects as well as concordance of critical information of representative drugs marketed in the United States, the UK, and Germany. Reciprocal warnings regarding drug-drug interactions that constitute contraindications were frequently missing in the SPCs of the drugs concerned (all countries >40%). Most SPCs did not explicitly exclude adverse reactions considered not reasonably attributable to the use of the drug. Comparing SPCs of different generic brands of the same drug, only 60, 10, and 20% of the US, UK, and German SPCs, respectively, provided identical contraindications. Current SPCs contain inconsistencies and misleading data that are not compatible with the purpose of SPCs, which is to provide a basis for the safe prescription and use of drugs.


Assuntos
Serviços de Informação sobre Medicamentos , Interações Medicamentosas , Medicamentos Genéricos/efeitos adversos , Indústria Farmacêutica , Alemanha , Humanos , Reino Unido , Estados Unidos , United States Food and Drug Administration
13.
Minerva Med ; 103(4): 253-66, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22805618

RESUMO

Idiopathic membranous nephropathy is the most common cause of nephrotic syndrome. In patients who present with nephrotic range proteinuria the clinical course is variable, with 50% of patients developing end stage renal disease after extended follow-up without therapy. We review the various immunosuppressive treatment modalities. The efficacy of alkylating agents is demonstrated in randomized trials, although side effects are a major drawback. Calcineurin inhibitors, rituximab and possibly adrenocorticotropic hormone (ACTH) are able to induce remission of proteinuria, which portends a good prognosis. However, the efficacy of these agents must be confirmed in randomized trials with adequate renal end points. Immunosuppressive treatment should be restricted to high risk patients. The use of immunosuppressive therapy has improved outcome of patients with iMN, with nowadays less than 10% of patients progressing to end stage renal disease (ESRD).


Assuntos
Glomerulonefrite Membranosa/tratamento farmacológico , Imunossupressores/uso terapêutico , Corticosteroides/uso terapêutico , Hormônio Adrenocorticotrópico/uso terapêutico , Anticorpos Monoclonais Murinos/uso terapêutico , Inibidores de Calcineurina , Glomerulonefrite Membranosa/complicações , Humanos , Terapia de Imunossupressão/métodos , Quimioterapia de Indução/métodos , Falência Renal Crônica/etiologia , Proteinúria/tratamento farmacológico , Rituximab
14.
Vet Microbiol ; 152(3-4): 304-14, 2011 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-21664078

RESUMO

In April 2009 a new influenza A/H1N1 strain, currently named "pandemic (H1N1) influenza 2009" (H1N1v), started the first official pandemic in humans since 1968. Several incursions of this virus in pig herds have also been reported from all over the world. Vaccination of pigs may be an option to reduce exposure of human contacts with infected pigs, thereby preventing cross-species transfer, but also to protect pigs themselves, should this virus cause damage in the pig population. Three swine influenza vaccines, two of them commercially available and one experimental, were therefore tested and compared for their efficacy against an H1N1v challenge. One of the commercial vaccines is based on an American classical H1N1 influenza strain, the other is based on a European avian H1N1 influenza strain. The experimental vaccine is based on reassortant virus NYMC X179A (containing the hemagglutinin (HA) and neuraminidase (NA) genes of A/California/7/2009 (H1N1v) and the internal genes of A/Puerto Rico/8/34 (H1N1)). Excretion of infectious virus was reduced by 0.5-3 log(10) by the commercial vaccines, depending on vaccine and sample type. Both vaccines were able to reduce virus replication especially in the lower respiratory tract, with less pathological lesions in vaccinated and subsequently challenged pigs than in unvaccinated controls. In pigs vaccinated with the experimental vaccine, excretion levels of infectious virus in nasal and oropharyngeal swabs, were at or below 1 log(10)TCID(50) per swab and lasted for only 1 or 2 days. An inactivated vaccine containing the HA and NA of an H1N1v is able to protect pigs from an infection with H1N1v, whereas swine influenza vaccines that are currently available are of limited efficaciousness. Whether vaccination of pigs against H1N1v will become opportune remains to be seen and will depend on future evolution of this strain in the pig population. Close monitoring of the pig population, focussing on presence and evolution of influenza strains on a cross-border level would therefore be advisable.


Assuntos
Vírus da Influenza A Subtipo H1N1/fisiologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/veterinária , Doenças dos Suínos/imunologia , Doenças dos Suínos/prevenção & controle , Animais , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H3N2/genética , Vírus da Influenza A Subtipo H3N2/imunologia , Infecções por Orthomyxoviridae/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Vírus Reordenados/imunologia , Sus scrofa , Suínos , Doenças dos Suínos/virologia , Vacinas de Produtos Inativados/imunologia
15.
Rofo ; 183(7): 631-40, 2011 Jul.
Artigo em Alemão | MEDLINE | ID: mdl-21528467

RESUMO

PURPOSE: The purpose of this study was to develop quantitative and qualitative MRI criteria to differentiate between healthy and pathological Achilles tendons. MATERIALS AND METHODS: 364 Achilles tendons were examined on a 1.5 T MRI scanner. 264 patients had Achilles tendon complaints, 100 asymptomatic Achilles tendons served as a control. T 1-weighted, T 2-weighted and a STIR sequence were performed in sagittal and axial orientation. Images were evaluated in consensus by two radiologists. Quantitative and qualitative criteria were assessed. A Mann-Whitney-U-Test and a regression analysis were used for statistical analysis. RESULTS: There were statistically significant differences between the patients with disorders and the control group concerning the depth (12.0 mm and 6.3 mm, p < 0.001) and length (83.2 mm and 45.9 mm, p < 0.001) of the tendon, the area of the tendon cross section (1.60 mm (2) and 061 mm (2), p < 0.001), as well as the length of the bursa retrocalcanea (8.3 mm and 5.3 mm, p < 0.001). There was a sensitivity of 97 % and a specificity of 91 % using a formula including the 3 criteria: tendon depth (A4), length of bursa (A5) and area of tendon (F). CONCLUSION: The measurement of the Achilles tendon and the binary-logistic regression analysis allow differentiation between normal and pathological Achilles tendons.


Assuntos
Tendão do Calcâneo/lesões , Tendão do Calcâneo/patologia , Aumento da Imagem/métodos , Interpretação de Imagem Assistida por Computador/métodos , Imageamento por Ressonância Magnética/métodos , Tendinopatia/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Valores de Referência , Ruptura , Sensibilidade e Especificidade , Tendinopatia/etiologia , Tendinopatia/patologia , Adulto Jovem
16.
Vaccine ; 29(8): 1545-50, 2011 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-21219983

RESUMO

In 2009 a new influenza A/H1N1 virus strain ("pandemic (H1N1) 2009", H1N1v) emerged that rapidly spread around the world. The virus is suspected to have originated in swine through reassortment and to have subsequently crossed the species-barrier towards humans. Several cases of reintroduction into pigs have since been reported, which could possibly create a reservoir for human exposure or ultimately become endemic in the pig population with similar clinical disease problems as current swine influenza strains. A soluble trimer of hemagglutinin (HA), derived from the H1N1v, was used as a vaccine in pigs to investigate the extent to which this vaccine would be able to protect pigs against infection with the H1N1v influenza strain, especially with respect to reducing virus replication and excretion. In a group of unvaccinated control pigs, no clinical symptoms were observed, but (histo)pathological changes consistent with an influenza infection were found on days 1 and 3 after inoculation. Live virus was isolated from the upper and lower respiratory tract, with titres up to 10(6) TCID(50) per gram of tissue. Furthermore, live virus was detected in brain samples. Control pigs were shedding live virus for up to 6 days after infection, with titres of up to 10(5) TCID(50) per nasal or oropharyngeal swab. The soluble H1N1v HA trimer diminished virus replication and excretion after a double vaccination and subsequent challenge. Live virus could not be detected in any of the samples taken from the vaccinated pigs. Vaccines based on soluble HA trimers provide an attractive alternative to the current inactivated vaccines.


Assuntos
Glicoproteínas de Hemaglutininação de Vírus da Influenza/imunologia , Vírus da Influenza A Subtipo H1N1/imunologia , Vacinas contra Influenza/imunologia , Infecções por Orthomyxoviridae/prevenção & controle , Animais , Anticorpos Antivirais/sangue , Testes de Inibição da Hemaglutinação , Testes de Neutralização , Infecções por Orthomyxoviridae/imunologia , Proteínas Recombinantes/imunologia , Suínos , Vacinas Sintéticas/imunologia , Eliminação de Partículas Virais
17.
J Intern Med ; 269(3): 349-61, 2011 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-21175900

RESUMO

BACKGROUND: Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis causing endothelial dysfunction, an early sign of atherogenesis. Symmetric dimethylarginine (SDMA) does not inhibit NO synthases. Peripheral arterial disease (PAD) is a systemic indication of atherosclerosis. METHODS: We assessed the associations between both ADMA and SDMA blood levels and major cardiovascular and cerebrovascular events or death from any cause within a 5-year follow-up in the multicentre getABI trial. From a cohort of 6821 primary care patients, aged ≥65 years, all 1260 patients with prevalent PAD were compared with a random sample of 1187 non-PAD controls. A total of 11,544 patient-years were documented. Multivariate risks were calculated by Cox proportional hazard models, adjusting for PAD, renal dysfunction and other important cardiovascular risk factors. RESULTS: We documented 390 deaths, 296 cardiovascular events and 98 cerebrovascular events. Increased ADMA levels in the 4th quartile were significantly associated with total mortality [hazard ratio (HR) 1.41; 95% CI 1.14-1.74] and with cardiovascular events (HR 1.32; 95% CI 1.03-1.69), but there was a nonsignificant association with cerebrovascular events (HR 1.50; 95% CI 0.98-2.29). Increased SDMA was only just significantly associated with mortality (HR 1.27; 95% CI 1.01-1.59). In PAD patients compared with non-PAD controls, only mean SDMA concentration was considerably increased (0.52 µmol L(-1) vs. 0.48 µmol L(-1); P < 0.001) mainly because of a highly significant association with impaired renal function. CONCLUSION: These data suggest that ADMA but not SDMA is an independent risk marker for death from any cause or from cardiovascular events. The association between SDMA and mortality is in part explained by a close link between SDMA and renal function.


Assuntos
Arginina/análogos & derivados , Doença Arterial Periférica/sangue , Idoso , Arginina/sangue , Biomarcadores/sangue , Doenças Cardiovasculares/sangue , Doenças Cardiovasculares/mortalidade , Transtornos Cerebrovasculares/sangue , Transtornos Cerebrovasculares/mortalidade , Inibidores Enzimáticos/sangue , Métodos Epidemiológicos , Feminino , Alemanha/epidemiologia , Humanos , Masculino , Óxido Nítrico Sintase/antagonistas & inibidores , Doença Arterial Periférica/mortalidade , Prognóstico
18.
J Thromb Haemost ; 8(12): 2662-70, 2010 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-20961392

RESUMO

AIM: Insufficient platelet inhibition by low-dose aspirin is associated with poor prognosis in patients with coronary heart disease (CHD). We sought to investigate the prevalence of this phenomenon in patients with stable CHD and to study whether oxidative stress plays a role in its pathogenesis. METHODS AND RESULTS: We studied the platelet response to long-term (≥ 6 months) low-dose (100 mg per day) aspirin in 130 consecutive patients with stable CHD (age 66 ± 8 years, 83% male). Among a wide distribution of platelet responses to collagen, ADP, and arachidonic acid, the vast majority of patients in the highest tertile of residual platelet activity (defined as 'aspirin low-responders') were characterized by lack of platelet inhibition by aspirin in vitro, significantly although not completely suppressed platelet TXB2 production and COX-1 activity, and significantly higher urinary 8-iso-prostaglandin F(2α) excretion [186 (147-230) vs. 230 (188-318) pg per mg creatinine; median (IQR), P < 0.001; measured by GC-MS]. CONCLUSION: A relevant proportion of patients with CHD show insufficient platelet inhibition by low-dose aspirin. Oxidative stress and lipid peroxidation causing isoprostane formation may underlie inadequate platelet inhibition in an aspirin-insensitive manner in patients with cardiovascular disease.


Assuntos
Aspirina/uso terapêutico , Plaquetas/patologia , Doença das Coronárias/metabolismo , Isoprostanos/biossíntese , Inibidores da Agregação Plaquetária/uso terapêutico , Idoso , Aspirina/administração & dosagem , Doença das Coronárias/tratamento farmacológico , Relação Dose-Resposta a Droga , Ensaio de Imunoadsorção Enzimática , Feminino , Cromatografia Gasosa-Espectrometria de Massas , Humanos , Isoprostanos/sangue , Isoprostanos/urina , Masculino , Pessoa de Meia-Idade , Oxirredução , Estresse Oxidativo , Inibidores da Agregação Plaquetária/administração & dosagem , Espectrometria de Massas em Tandem
19.
Phys Rev E Stat Nonlin Soft Matter Phys ; 81(2 Pt 2): 026401, 2010 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-20365659

RESUMO

The experimental data presented in this paper address the energy loss determination for argon at 4 MeV/u projectile energy in laser-generated carbon plasma covering a huge parameter range in density and temperature. Furthermore, a consistent theoretical description of the projectile charge state evolution via a Monte Carlo code is combined with an improved version of the CasP code that allows us to calculate the contributions to the stopping power of bound and free electrons for each projectile charge state. This approach gets rid of any effective charge description of the stopping power. Comparison of experimental data and theoretical results allows us to judge the influence of different plasma parameters.

20.
Transplant Proc ; 42(1): 381-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20172354

RESUMO

Islet transplantation is a potential cure for type 1 diabetes, but clinical results have been disappointing. Currently, islet isolation is by enzymatic digestion of the pancreas which has significant pitfalls: warm ischemia exposure, collagenase-induced damage to the islet mass and viability, poor reproducibility, high cost, a relatively low number of islets obtained per whole pancreas, and selection of islets for collagenase resistance rather than for glucose responsiveness. In the present study we performed a series of experiments in a porcine model to demonstrate the feasibility of a new isolation method based on selective osmotic shock (SOS) using very high glucose solutions, doubling or tripling physiological osmotic strength. The SOS method can be carried out at room temperature or in the cold eliminating warm ischemia time which damages the islets. The SOS method does not depend on the texture of the pancreas so all pancreases can be processed identically and the process can be fully automated. The SOS method isolates all the islets of the pancreas regardless of size and shape allowing a greater number of islets to be harvested. The SOS method avoids exposure to toxins in collagenase solutions, is inexpensive and selects for islets with high concentrations of Glut 2 transporters, representing the best glucose responding islets. The SOS method showed a comparable recovery of islets from young pig pancreas and the islets showed improved viability. We conclude that the selective osmotic shock (SOS) method of separating islets from the pancreatic tissue is superior to the collagenase method.


Assuntos
Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/fisiologia , Animais , Morte Celular , Separação Celular/métodos , Diabetes Mellitus Tipo 1/tratamento farmacológico , Diabetes Mellitus Tipo 1/cirurgia , Glucose/farmacologia , Transportador de Glucose Tipo 2/análise , Humanos , Hipoglicemiantes/uso terapêutico , Insulina/metabolismo , Insulina/uso terapêutico , Secreção de Insulina , Células Secretoras de Insulina/imunologia , Células Secretoras de Insulina/patologia , Ilhotas Pancreáticas/efeitos dos fármacos , Ilhotas Pancreáticas/metabolismo , Transplante das Ilhotas Pancreáticas , Pressão Osmótica , Suínos
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