RESUMO
In Australia, bortezomib-based induction (V-IND) is used in >90% of newly diagnosed transplant-eligible multiple myeloma (MM) patients. Four cycles of V-IND with bortezomib-cyclophosphamide-dexamethasone or bortezomib-lenalidomide-dexamethasone are available via the Pharmaceutical Benefits Scheme prior to autologous stem cell transplantation (ASCT). Patients who demonstrate suboptimal response or who are refractory to V-IND demonstrate inferior survival, representing a subgroup of MM where an unmet need persists. We evaluated an early, response-adapted approach in these patients by switching to an intensive sequential therapeutic strategy incorporating daratumumab-lenalidomide-dexamethasone-based (DRd) salvage, high-dose melphalan ASCT followed by DRd consolidation and R maintenance. The overall response rate following four cycles of DRd salvage was 72% (95% credible interval: 57.9-82.4); prespecified, dual, Bayesian proof-of-concept criteria were met. Euro-flow minimal residual disease (MRD) negativity was 46% in the intention-to-treat population and 79% in the evaluable population following 12 cycles of DRd consolidation. At the 24-month follow-up, median progression-free survival and overall survival were not reached. DRd salvage was well tolerated with grade 3 and 4 events reported in 24% and 8% respectively. Response-adapted DRd combined with ASCT achieves high rates of MRD negativity and durable disease control in this functional high-risk group.
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We evaluated re-induction incorporating carfilzomib-thalidomide-dexamethasone (KTd) and autologous stem cell transplantation (ASCT) for newly diagnosed multiple myeloma (NDMM) refractory, or demonstrating a suboptimal response, to non-IMID bortezomib-based induction. KTd salvage consisted of thalidomide 100 mg daily and dexamethasone 20 mg orally combined with carfilzomib 56 mg/m2 days 1, 2, 8, 9, 15 and 16, of each 28-day cycle. Following four cycles, patients achieving a stringent complete response proceeded to ASCT whereas those who did not received a further two cycles then ASCT. Consolidation consisted of two cycles of KTd then Td to a total of 12 months post-ASCT therapy. Primary end-point was the overall response rate (ORR) with KTd prior to ASCT. Fifty patients were recruited. The ORR was 78% with EuroFlow MRD negativity of 34% in the intention-to-treat population and 65% in the evaluable population at 12 months post-ASCT. With follow-up >38 months median PFS and OS have not been reached with PFS and OS at 36 months of 64% and 80%, respectively. KTd was well tolerated with grade 3 and grade ≥4 adverse events rates of 32% and 10%, respectively. Response adaptive utilisation of KTd with ASCT is associated with both high-quality responses and durable disease control in functional high-risk NDMM.
Assuntos
Transplante de Células-Tronco Hematopoéticas , Leucemia , Linfoma , Mieloma Múltiplo , Humanos , Mieloma Múltiplo/tratamento farmacológico , Talidomida , Dexametasona , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Transplante Autólogo , Bortezomib/uso terapêutico , Leucemia/tratamento farmacológico , Linfoma/tratamento farmacológicoRESUMO
We present a novel deflectometry implementation termed Infinite Deflectometry. The technique provides a full aperture surface reconstruction sag map of freeform surfaces, including previously challenging to measure optics such as highly convex surfaces. The method relies on the creation of a virtual source enclosure around the tested optic, which creates a virtual 2π-steradian measurement range. To demonstrate the performance, a fast f/1.26 convex optical surface was measured with a commercial interferometer and with the Infinite Deflectometry system. After removing Zernike terms 1 through 37, the metrology tests resulted in absolute RMS surface values of 18.48 nm and 16.26 nm, respectively. Additionally, a freeform Alvarez lens was measured with the new technique and measured 22.34 ðm of surface sag RMS after piston, tip/tilt, and defocus had been removed. The result deviated by 488 nm RMS from a profilometer measurement while standard interferometry failed to measure the Alvarez lens due to its non-nulled wavefront dynamic range limitation.
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Options for treatment of elderly patients with multiple myeloma have expanded substantially following the development of immunomodulatory drugs (IMiD), proteasome inhibitors and with enhancement in safety of high-dose therapy and autologous stem cell transplant (HDT + ASCT). The recognition of biological heterogeneity among elderly patients has made delivery of therapy more challenging. An individualised approach to treatment selection is recommended in an era in which highly efficacious treatment options are available for transplant-ineligible patients. Here, we summarise recommendations for patients who are considered unsuitable for HDT + ASCT, including pretreatment considerations, and induction, maintenance and supportive care therapies.
Assuntos
Comitês Consultivos/normas , Fundações/normas , Mieloma Múltiplo/epidemiologia , Mieloma Múltiplo/terapia , Transplante de Células-Tronco , Austrália/epidemiologia , Humanos , Fatores Imunológicos/uso terapêutico , Mieloma Múltiplo/diagnóstico , Inibidores de Proteassoma/uso terapêutico , Transplante Autólogo , Resultado do TratamentoRESUMO
The survival of patients with multiple myeloma (MM) has improved substantially since the introduction in the late 1980s of high-dose chemotherapy (HDT) supported by autologous stem cell transplantation (ASCT). Further improvements have been observed following the availability of immunomodulatory drugs (IMiD) such as thalidomide and lenalidomide, and the proteasome inhibitor, bortezomib. Here, we summarise the recommendations of the Medical Scientific Advisory Group to the Myeloma Foundation of Australia for patients considered suitable for HDT + ASCT as part of initial therapy. These recommendations incorporate the various phases of treatment: induction, HDT conditioning and maintenance therapy.
Assuntos
Transplante de Células-Tronco Hematopoéticas/normas , Mieloma Múltiplo/tratamento farmacológico , Guias de Prática Clínica como Assunto , Sociedades Científicas , Comitês Consultivos , Austrália/epidemiologia , Intervalo Livre de Doença , Humanos , Mieloma Múltiplo/epidemiologia , Taxa de Sobrevida/tendências , Transplante Autólogo , Resultado do TratamentoRESUMO
Systemic AL amyloidosis is a plasma cell dyscrasia with a characteristic clinical phenotype caused by multi-organ deposition of an amyloidogenic monoclonal protein. This condition poses a unique management challenge due to the complexity of the clinical presentation and the narrow therapeutic window of available therapies. Improved appreciation of the need for risk stratification, standardised use of sensitive laboratory testing for monitoring disease response, vigilant supportive care and the availability of newer agents with more favourable toxicity profiles have contributed to the improvement in treatment-related mortality and overall survival seen over the past decade. Nonetheless, with respect to the optimal management approach, there is a paucity of high-level clinical evidence due to the rarity of the disease, and enrollment in clinical trials is still the preferred approach where available. This review will summarise the Clinical Practice Guidelines on the Management of Systemic Light Chain (AL) Amyloidosis recently prepared by the Medical Scientific Advisory Group of the Myeloma Foundation of Australia. It is hoped that these guidelines will assist clinicians in better understanding and optimising the management of this difficult disease.
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Comitês Consultivos/normas , Amiloidose/terapia , Gerenciamento Clínico , Fundações/normas , Mieloma Múltiplo/terapia , Amiloidose/diagnóstico , Amiloidose/epidemiologia , Austrália/epidemiologia , Humanos , Mieloma Múltiplo/diagnóstico , Mieloma Múltiplo/epidemiologiaRESUMO
The causes of multiple myeloma (MM) remain obscure and there are few known risk factors; however, natural killer T (NKT) cell abnormalities have been reported in patients with MM, and therapeutic targeting of NKT cells is promoted as a potential treatment. We characterized NKT cell defects in treated and untreated patients with MM and determined the impact of lenalidomide therapy on the NKT cell pool. Lenalidomide is an immunomodulatory drug with co-stimulatory effects on NKT cells in vitro and is an approved treatment for MM, although its mode of action in that context is not well defined. We find that patients with relapsed/progressive MM had a marked deficiency in NKT cell numbers. In contrast, newly diagnosed patients had relatively normal NKT cell frequency and function prior to treatment, although a specific NKT cell deficiency emerged after high-dose melphalan and autologous stem cell transplantation (ASCT) regimen. This also impacted NK cells and conventional T cells, but the recovery of NKT cells was considerably delayed, resulting in a prolonged, treatment-induced NKT cell deficit. Longitudinal analysis of individual patients revealed that lenalidomide therapy had no in-vivo impact on NKT cell numbers or cytokine production, either as induction therapy, or as maintenance therapy following ASCT, indicating that its clinical benefits in this setting are independent of NKT cell modulation.
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Fatores Imunológicos/administração & dosagem , Mieloma Múltiplo , Células T Matadoras Naturais , Talidomida/análogos & derivados , Citocinas/sangue , Citocinas/imunologia , Feminino , Humanos , Lenalidomida , Contagem de Linfócitos , Masculino , Mieloma Múltiplo/sangue , Mieloma Múltiplo/tratamento farmacológico , Mieloma Múltiplo/imunologia , Mieloma Múltiplo/patologia , Células T Matadoras Naturais/imunologia , Células T Matadoras Naturais/metabolismo , Células T Matadoras Naturais/patologia , Talidomida/administração & dosagemRESUMO
INTRODUCTION: Management of the airway in the perioperative period for patients requiring major head and neck ablative surgery has commonly included the performance of elective surgical tracheostomy. This has been standard practice in most maxillofacial units across the UK, including ours. However, the COVID-19 pandemic and emerging guidelines on aerosol-generating procedures required us to revisit the need for a perioperative tracheostomy. METHODS: We present our series of 29 consecutive cases, cared for during the first wave of the COVID-19 pandemic, that were managed either using surgical tracheostomy or overnight tracheal intubation. RESULTS: Out of 29 patients 3 received a surgical tracheostomy. The average duration of tracheostomy use was 8 days. Twenty patients were managed using a period of overnight tracheal intubation. Average duration of tracheal intubation was 1.2 days, with an average intensive care unit stay of 1.7 days. The average duration of hospital stay was 15.8 days for patients managed with overnight tracheal intubation and 30.1 days for patients who received a surgical tracheostomy. The return to theatre rate was 13.8% for reasons including flap failure and neck space infection. There were no airway issues reported in this series of patients. CONCLUSIONS: Our findings suggest that overnight tracheal intubation can be a safe alternative to surgical tracheostomy in the majority of cases.
Assuntos
COVID-19 , Traqueostomia , Humanos , Traqueostomia/métodos , COVID-19/epidemiologia , Pandemias , Estudos Retrospectivos , Intubação Intratraqueal/métodosAssuntos
Benzoatos/uso terapêutico , Hidrazinas/uso terapêutico , Púrpura Trombocitopênica Idiopática/tratamento farmacológico , Pirazóis/uso terapêutico , Receptores Fc/uso terapêutico , Receptores de Trombopoetina/agonistas , Proteínas Recombinantes de Fusão/uso terapêutico , Trombopoetina/uso terapêutico , Idoso , Avaliação de Medicamentos , Quimioterapia Combinada , Feminino , Infecções por HIV/complicações , Hepatite C/complicações , Humanos , Imunossupressores/uso terapêutico , Masculino , Pessoa de Meia-Idade , Contagem de Plaquetas , Prednisolona/uso terapêutico , Púrpura Trombocitopênica Idiopática/etiologia , Fatores de TempoRESUMO
BACKGROUND: Bortezomib has been shown to be a safe and efficacious for the treatment of relapsed and refractory multiple myeloma (MM). Here we report a subset analysis of Australian and New Zealand data from the International Extended Access Programme for bortezomib. METHODS: Patients with more than or equal to two prior lines of therapy were given bortezomib 1.3 mg/m(2) (i.v. bolus days 1, 4, 8, 11) for up to eight 21-day cycles (C). Dexamethasone, 20 mg/day p. o. on the day of, and day after, bortezomib was added after C2 for progressive disease or after C4 for stable disease. Efficacy was assessed using modified Southwest Oncology Group criteria in the intent-to-treat group. Results were compared between the Australian and New Zealand and international cohort. RESULTS: One hundred and eleven patients from 16 centres (55% men, median age 61.9 years) had a median of 5.2 +/- 2.8 treatment cycles of bortezomib. Among them, 82% had > or =3 prior therapies. Grade 3-4 treatment-related adverse events were reported in 57 patients (52%); the most common were thrombocytopenia (25.7%), anaemia (8.3%), peripheral neuropathy (7.3%) and diarrhoea (7.3%). Responses were evaluable in 106 patients: 22% achieved a best response of complete response/response and 20% partial response (overall response rate of 42%). Median times to first and best responses were 42 days and 69 days, respectively. Compared with the international cohort, the cohorts from Australian and New Zealand showed inferior overall response rates (54 vs 42%, P = 0.001), possibly due to heavier pretreatment (82% greater than or equal to three prior therapies vs 68%, P < 0.001). CONCLUSION: Our analysis confirms that bortezomib is safe and effective in relapsed and refractory MM in a real-life clinical setting.
Assuntos
Ácidos Borônicos/uso terapêutico , Mieloma Múltiplo/tratamento farmacológico , Pirazinas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Austrália/epidemiologia , Ácidos Borônicos/efeitos adversos , Bortezomib , Estudos de Coortes , Feminino , Gastroenteropatias/induzido quimicamente , Gastroenteropatias/epidemiologia , Humanos , Cooperação Internacional , Masculino , Pessoa de Meia-Idade , Mieloma Múltiplo/epidemiologia , Mieloma Múltiplo/prevenção & controle , Nova Zelândia/epidemiologia , Pirazinas/efeitos adversos , Recidiva , Resultado do TratamentoRESUMO
The in vitro oxidation of vitamin E (alpha tocopherol) in rat brain synaptosomes and mitochondria by 2,2'-azo-bis-(2'-amidinopropane) dihydrochloride (ABAPH), a free radical generator, was studied. Subcellular fractions (300 micrograms total protein) were suspended in different buffers at pH 7.4 and incubated at 37 degrees C. In the presence of 0.5 mM ABAPH the mitochondrial alpha tocopherol began to get oxidized after a lag time or induction time of 15 min compared with a lag time of 30 min for the synaptosomal fraction. Thus the reserve of reducing compounds that are responsible for delaying tocopherol oxidation is less in mitochondria than in synaptosomes. More tocopherolquinone was produced during incubations without ABAPH compared with incubations in the presence of ABAPH suggesting that the mechanism of oxidation of tocopherol differs under these two conditions. When mitochondria were incubated in buffer without oxidants the production of tocopherolquinone preceded that of thiobarbituric acid reactive substances, an indicator of peroxidation of fatty acids. Therefore, alpha tocopherol is active as an anti-oxidant in mitochondrial membranes and the production of alpha tocopherolquinone could be a monitor of mild membrane oxidation under in vitro conditions. The ease of oxidation of mitochondrial tocopherol suggests a general vulnerability of the mitochondrial membranes to oxidation. Adding vitamin E or its water soluble analogs during in vitro experiments may improve the stability and viability of mitochondria. Furthermore, antioxidant protection by vitamin E may be crucial for the maintenance of tissues, such as brain, whose function is critically dependent upon the availability of high energy phosphates.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Encéfalo/metabolismo , Mitocôndrias/metabolismo , Sinaptossomos/metabolismo , Vitamina E/metabolismo , Amidinas/farmacologia , Animais , Encéfalo/ultraestrutura , Radicais Livres , Cinética , Masculino , Oxirredução , Ratos , Ratos Endogâmicos F344 , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo , Vitamina E/análogos & derivadosRESUMO
The kinetics of oxidation of endogenous antioxidants such as vitamins C and E and thiols as well as membrane cholesterol in isolated rat brain mitochondria were studied. Oxidation was induced by incubating the mitochondria at 37 degrees C with the free radical generators 2,2' azobis (2'-amidinopropane) dihydrochloride (ABAPH) and 2,2' azobis (2,4-dimethyl) valeronitrile (ABDVN) which undergo thermal decomposition to yield free radicals. An approximate order for the in vitro ease of oxidation was: ascorbate >> alpha-tocopherol > sulfhydryls >> cholesterol. However, small amounts of ascorbate were present in the mitochondria when alpha-tocopherol and sulfhydryl compounds were getting oxidized. This observation is different from those with more homogeneous biological substrates like blood plasma or serum. The order of oxidation of the various compounds is a function of not only the redox potentials but also the (a) concentrations of the oxidized and reduced species, (b) compartmentation of the compounds and (c) enzymatic and nonenzymatic systems for the repair or regeneration of the individual antioxidants. Even though ascorbate levels are quite low within mitochondria this nutrient may play a major role as a first line of defense against oxidative stress. The lipid-soluble ABDVN was much more potent in oxidizing membrane alpha-tocopherol and thiols than the water-soluble ABAPH. With both free radical generators the rate of oxidation of the antioxidants consisted of two phases. The initial phase, that is more rapid, may represent a pool of antioxidant that is involved in immediate antioxidant protection of the organelle with the slower compartment being responsible for replenishing the faster pool whenever needed.(ABSTRACT TRUNCATED AT 250 WORDS)
Assuntos
Ácido Ascórbico/metabolismo , Encéfalo/efeitos dos fármacos , Colesterol/metabolismo , Mitocôndrias/efeitos dos fármacos , Compostos de Sulfidrila/metabolismo , Vitamina E/metabolismo , Amidinas/farmacologia , Animais , Compostos Azo/farmacologia , Encéfalo/metabolismo , Encéfalo/ultraestrutura , Membranas Intracelulares/metabolismo , Masculino , Mitocôndrias/metabolismo , Nitrilas/farmacologia , Oxirredução , Ratos , Ratos Endogâmicos F344RESUMO
Schizophrenia is characterized by thought disorders, hallucinations and delusions. Genetic studies have shown a high linkage at chromosome 6q16-21. Among the genes located in this region is the glutamate receptor ionotropic kainate 2 gene (GRIK2 or GLUR6), a functional candidate for susceptibility to schizophrenia. In this study, transmission of GRIK2 was evaluated in 356 schizophrenic patients from three different clinical centers. Whereas paternal transmission shows equilibrium, we observed maternal transmission disequilibrium of GRIK2 in the largest population (p=0.03), which was still significant when all populations were added (p=0.05). These results are similar to the maternal GRIK2 transmission disequilibrium previously reported for autism, and support the presence of a susceptibility gene for schizophrenia at 6q16.
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Desequilíbrio de Ligação , Mães , Receptores de Ácido Caínico/genética , Esquizofrenia/genética , Alelos , Estudos de Casos e Controles , Cromossomos Humanos Par 6 , Suscetibilidade a Doenças , Feminino , Genômica , Genótipo , Humanos , Masculino , Polimorfismo de Nucleotídeo Único , Receptor de GluK2 CainatoRESUMO
A sensitive ELISA method for determining transthyretin (prealbumin) in human cerebrospinal fluid (CSF) is described. The method utilizes goat antihuman transthyretin antibody (IgG fraction) for capture and peroxidase conjugated antibody for color development. The assay has a linear range of 1-4 ng transthyretin added per well. The within-day and between-day coefficients of variation are 5.1 and 6.1%, respectively. The concentration of transthyretin in CSF (ranging from 5 to 20 mg per L) correlated significantly with the corresponding serum concentrations (range 170-420 mg/l). This suggests that synthesis of transthyretin in the brain and peripheral tissues is under similar biological control in normal subjects. The transthyretin concentrations in CSF did not correlate with total CSF protein concentration or age of the subject.
Assuntos
Ensaio de Imunoadsorção Enzimática/métodos , Pré-Albumina/líquido cefalorraquidiano , Adulto , Idoso , Ensaio de Imunoadsorção Enzimática/estatística & dados numéricos , Humanos , Masculino , Microquímica , Pessoa de Meia-Idade , Nefelometria e Turbidimetria , Pré-Albumina/análiseRESUMO
An earlier report from this laboratory showed that tocopherol in human platelets is oxidized when the platelets are incubated in vitro in Tyrode medium with arachidonate (or other oxidants). Arachidonate is a more potent oxidizing agent in 50 mM potassium phosphate buffer at pH 7.4 with 0.1 mM ethylenediaminetetraacetic acid (EDTA) than in Tyrode medium. Forty to fifty percent of total platelet tocopherol was oxidized upon incubation with 40-50 microM arachidonate in the phosphate-buffered medium. The tocopherol oxidation took place within 15 min after the addition of arachidonate. Preincubation of platelets with ascorbate blocked the oxidation of tocopherol. This is one of the first direct in vitro demonstrations of the vitamin E-sparing action of vitamin C in media containing biological cellular material. Other compounds which blocked the oxidation of platelet tocopherol were ascorbyl palmitate, propyl gallate, butylated hydroxytoluene, hydroquinone and glutathione. If ascorbate or glutathione was added after the tocopherol was oxidized to the quinone there was no reversal of the oxidation.
Assuntos
Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Plaquetas/efeitos dos fármacos , Glutationa/farmacologia , Vitamina E/sangue , Adulto , Antioxidantes/síntese química , Ácido Araquidônico , Ácidos Araquidônicos/farmacologia , Plaquetas/metabolismo , Hidroxitolueno Butilado/farmacologia , Cromatografia Líquida de Alta Pressão , Jejum , Humanos , Técnicas In Vitro , Masculino , Pessoa de Meia-Idade , Oxirredução , Fatores de Tempo , Vitamina E/análogos & derivadosRESUMO
Cholesterol and alpha-tocopherol oxidations were studied in brain subcellular fractions isolated from cerebral hemispheres of 4-month-old, male Fischer 344 rats. The fractions were suspended in buffered media (pH 7.4, 37 degrees C0 and oxidized by adding (i) ferrous iron (Fe2+) with or without ascorbate or (ii) peroxynitrite (an endogenous oxidant produced by the reaction of superoxide and nitric oxide). Treatment of subcellular fractions with Fe2+ in the presence or absence of ascorbate produced primarily 7-keto- and 7-hydroxy-cholesterols and small amounts of 5 alpha, 6 alpha-epoxycholesterol. Since brain contains high levels of ascorbate, and release of iron could result in oxysterol formation. Peroxynitrite oxidized alpha-tocopherol but not cholesterol. Hence, the toxicity of peroxynitrite or nitric oxide could not be due to cytotoxic oxysterols. When synaptosomes were incubated for 5 min in the presence of 0.5 to 2 microM Fe2+ and ascorbate, alpha-tocopherol was oxidized while cholesterol remained unchanged. Thus, alpha-tocopherol is functioning as an antioxidant, protecting cholesterol. Diethylenetriaminepentaacetic acid blocked production of oxysterols, whereas citrate, ADP and EDTA did not. A significant percentage of mitochondrial cholesterol was oxidized by treatment with Fe2+ and ascorbate. Hence, mitochondrial membrane properties dependent on cholesterol could be particularly susceptible to oxidation. The oxysterols formed were retained within the membranes of synaptosomes and mitochondria. The 7-oxysterols produced are known to be inhibitors of membrane enzymes and also can modify membrane permeability. Hence, oxysterols may plan an important role in brain tissue damage during oxidative stress.
Assuntos
Encéfalo/metabolismo , Colesterol/metabolismo , Mitocôndrias/metabolismo , Sinaptossomos/metabolismo , Animais , Antioxidantes/farmacologia , Ácido Ascórbico/farmacologia , Boroidretos/metabolismo , Quelantes/farmacologia , Colesterol/análogos & derivados , Cromatografia Gasosa , Compostos Ferrosos/farmacologia , Masculino , Nitratos/farmacologia , Oxirredução , Estresse Oxidativo , Ratos , Ratos Endogâmicos F344 , Vitamina E/metabolismoRESUMO
A rapid method for the simultaneous determination of cholesterol and its oxidation products as well as alpha-to-copherol and tocopherolquinone in brain subcellular fractions is described. The samples are saponified and extracted with hexane. It is not necessary to remove cholesterol in the sample before analyzing for oxysterols. The hexane extract can be used for the assay of cholesterol compounds by capillary gas chromatography and tocopherol compounds by liquid chromatography using a procedure reported previously. Oxidation of synaptosomes by a mixture of Fe2+ plus ascorbate resulted in the production of 7-keto-, 7 alpha-hydroxy-, 7 beta-hydroxy-, and 5 alpha, 6 alpha-epoxycholesterols. The identities of these products were confirmed with gas chromatography/mass spectrometry. Cholesterol oxidase treatment did not result in the formation of any of the above compounds. Thus the types and amounts of the products of oxidation of cholesterol were dependent upon the oxidizing agent. Extraction of the oxysterols under milder conditions without saponification using sodium dodecyl sulfate cannot be used since such treatment results in low recovery of oxysterols. Oxidation of synaptosomes by low concentrations of ferrous iron and ascorbate resulted in (i) low levels of oxidation of cholesterol which could be followed by estimating the production of oxysterols and (ii) oxidation of a substantial percentage of alpha-tocopherol. The proposed procedure will be useful in monitoring the oxidation of small quantities of membrane cholesterol in vitro.
Assuntos
Química Encefálica , Colesterol/análogos & derivados , Colesterol/análise , Sinaptossomos/química , Animais , Ácido Ascórbico/metabolismo , Colesterol/metabolismo , Cromatografia Gasosa , Radicais Livres/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Hidroxicolesteróis/análise , Ferro/metabolismo , Masculino , Lipídeos de Membrana/análise , Lipídeos de Membrana/química , Oxidantes/metabolismo , Oxirredução , Ratos , Ratos Endogâmicos F344RESUMO
Immunomodulatory drugs (IMiDs) are thalidomide analogues, which possess pleiotropic anti-myeloma properties including immune-modulation, anti-angiogenic, anti-inflammatory and anti-proliferative effects. Their development was facilitated by an improved understanding in myeloma (MM) biology and initiated a profound shift in the therapeutic approach towards MM. Despite the diverse effects of IMiDs in vitro, the relative contribution of each effect towards their ultimate anti-MM activity is still unclear. Based on in vitro data, it appears that anti-proliferative effects and downregulation of crucial cytokines are their most important anti-MM attributes. Although the co-stimulatory effects on T and NK cells have been heralded as a unique and important property of IMiDs towards enhancing anti-MM immune activity, these in vitro effects have yet to be firmly corroborated in vivo. Much is yet to be elucidated regarding the complex interplay of immunomodulatory cytokines that occurs in vivo, which ultimately dictates the net effects of IMiDs in MM-the understanding of which is necessary to facilitate optimal manipulation of these drugs in future MM management.
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Fatores Imunológicos/farmacologia , Mieloma Múltiplo/tratamento farmacológico , Talidomida/análogos & derivados , Inibidores da Angiogênese/farmacologia , Anti-Inflamatórios/farmacologia , Citotoxicidade Celular Dependente de Anticorpos , Antineoplásicos/farmacologia , Fatores de Transcrição Forkhead/análise , Humanos , Fatores Imunológicos/uso terapêutico , Células Matadoras Naturais/efeitos dos fármacos , Células Matadoras Naturais/imunologia , Ativação Linfocitária , Mieloma Múltiplo/imunologia , Osteoclastos/efeitos dos fármacos , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologiaRESUMO
Myelodysplastic syndrome (MDS) comprises a group of clonal bone marrow disorders characterized by ineffective hematopoiesis and increased predisposition to acute myeloid leukemia. The causes of MDS remain poorly defined, but several studies have reported the NKT cell compartment of patients with MDS is deficient in number and functionally defective. In support of a central role for NKT cells, a pilot clinical study reported that lenalidomide (an approved treatment for MDS) increased NKT cell numbers in patients with MDS, and several in vitro studies showed lenalidomide specifically promoted NKT cell proliferation and cytokine production. We tested this in a much larger study and confirm a moderate in vitro augmentation of some NKT cell functions by lenalidomide, but find no impact on the NKT cell compartment of patients treated with lenalidomide, despite a consistently positive clinical response. We further show that the frequency and cytokine production of NKT cells is normal in patients with MDS before treatment and remains stable throughout 10 months of lenalidomide therapy. Collectively, our data challenge the concept that NKT cell defects contribute to the development of MDS, and show that a clinical response to lenalidomide is not dependent on modulation of NKT cell frequency or function.