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It is known that extranodal head and neck diffuse large B cell lymphomas (eHN-DLBCL) can affect various anatomical structures what is not well-known, however, is whether they differ in terms of clinical presentation and outcome. Clinical data of the multi-institutional series, the largest of its kind as yet, has been analysed with the aim of answering these open questions and providing long-term follow-up information. Data from 488 patients affected by stage I/II eHN-DLBCL was collected: 300 of the Waldeyer's Ring (WR), 38 of the parotid and salivary glands (PSG), 48 of the thyroid gland (TG), 53 of the nasal cavity and paranasal sinuses (NPS), 24 of the palate and oral cavity (POC) and 25 with more than one involved site. Different eHN-DLBCL arising have distinct characteristics at presentation. The intermediate high risk-modified IPI was 67 % in TG, 44 % in WR, 38 % in PSG and POC and 20 % in MS. The worst 5-year survival rate had TG-DLBCL (61 %) due to the 61 % of patients with a mIPI >1. The addition of radiotherapy (cRT) to remitters did not translate into a survival advantage (5-year disease-free survival of 67 % in the cRT group vs. 70 % in the other). Three of four central nervous system recurrences occurred in NPS-DLBCL. Survival of HN-DLBCL was inferior to nodal DLBCL. This study showed that eHN-DLBCL remitters have an inferior survival when compared to nodal DLBCL, and that the addition of cRT does not provide a survival advantage. Since the standard of care nowadays is chemo-immunotherapy, survival of these patients might have been improved.
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The LHC is putting bounds on the Higgs boson mass. In this Letter we use those bounds to constrain the minimal supersymmetric standard model (MSSM) parameter space using the fact that, in supersymmetry, the Higgs mass is a function of the masses of sparticles, and therefore an upper bound on the Higgs mass translates into an upper bound for the masses for superpartners. We show that, although current bounds do not constrain the MSSM parameter space from above, once the Higgs mass bound improves big regions of this parameter space will be excluded, putting upper bounds on supersymmetry (SUSY) masses. On the other hand, for the case of split-SUSY we show that, for moderate or large tanß, the present bounds on the Higgs mass imply that the common mass for scalars cannot be greater than 10(11) GeV. We show how these bounds will evolve as LHC continues to improve the limits on the Higgs mass.
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BACKGROUND: Nasal T/natural killer (NK)-cell lymphoma is an aggressive type of non-Hodking's lymphoma associated with Epstein-Barr virus (EBV) and striking geographical variations worldwide. AIM: To characterise nasal NK/T-cell lymphoma associated with genotypes of EBV in Chile, a Latin American country, where multiple strains of EBV, including two new recombinant strains, in healthy individuals were recently found. METHODS: Cases with diagnosis of primary nasal lymphoma were selected for histological and immunohistochemical analysis (CD3, CD3e, CD4, CD8, CD79a, CD56, CD57 and TIA-1) and in-situ hybridisation, serology and genotyping analysis for EBV. RESULTS: Out of 22 cases, 9 (41%) cases fulfilled the World Health Organization criteria for nasal NK/T-cell lymphoma; of these 7 (78%) cases were positive for EBV. Genotyping analysis revealed 6 cases of type 1 EBV and wildtype F at the BamHI-F region, 4 cases type "i" EBV at the BamHI-W1/I1 region; XhoI wild type was found in 2 and XhoI loss in 4 cases, respectively. Cosegregation analysis of the BamHI-W1/I1 region and XhoI restriction site showed the new recombinant strain type "i"/XhoI loss in 3 cases and type "i"/XhoI wild-type strain in 1 case. Most patients were treated with combined anthracycline-containing regimens. Half of the cases attained complete remission. CONCLUSION: Although nasal NK/T-cell lymphomas from Chile share similar clinicopathological features, high association with EBV and unfavourable prognosis with those described elsewhere, genotype analysis shows that the new recombinant type "i"/XhoI loss strain might contribute to explain the intermediate incidence of nasal NK/T-cell lymphomas in Latin America.
Assuntos
Infecções por Vírus Epstein-Barr/complicações , Herpesvirus Humano 4/genética , Células Matadoras Naturais/patologia , Linfoma de Células T/virologia , Neoplasias Nasais/virologia , Adulto , Infecções por Vírus Epstein-Barr/virologia , Feminino , Genótipo , Herpesvirus Humano 4/classificação , Herpesvirus Humano 4/isolamento & purificação , Humanos , Técnicas Imunoenzimáticas , Imunofenotipagem , Hibridização In Situ/métodos , Linfoma de Células T/imunologia , Linfoma de Células T/patologia , Linfoma de Células T/terapia , Masculino , Pessoa de Meia-Idade , Neoplasias Nasais/imunologia , Neoplasias Nasais/patologia , Neoplasias Nasais/terapia , RNA Viral/genética , Resultado do TratamentoRESUMO
The activity concentration of 222Rn, 226Ra and total uranium in groundwater samples collected from wells distributed throughout the state of Chihuahua has been measured. The values obtained of total uranium activity concentration in groundwater throughout the state run from <0.03 up to 1.34 Bq l-1. Generally, radium activity concentration was <0.16 Bq l-1, with some exceptions; in spring water of San Diego de Alcalá, in contrast, the value reached approximately 5.3 Bq l-1. Radon activity concentration obtained throughout the state was from 1.0 to 39.8 Bq l-1. A linear correlation between uranium and radon dissolved in groundwater of individual wells was observed near Chihuahua City. Committed effective dose estimates for reference individuals were performed, with results as high as 134 microSv for infants in Aldama city. In Aldama and Chihuahua cities the average and many individual wells showed activity concentration values of uranium exceeding the Mexican norm of drinking water quality.
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Rádio (Elemento)/análise , Radônio/análise , Urânio/análise , Poluentes Radioativos da Água/análise , Água , Humanos , Lactente , México , Monitoramento de Radiação , Abastecimento de ÁguaRESUMO
Infant acute leukemia (IAL) frequently involves breakage and recombination of the MLL gene with one of several potential partner genes. These gene fusions arise in utero and are similar to those found in leukemias secondary to chemotherapy with inhibitors of topoisomerase II (topo-II). This has led to the hypothesis that in utero exposures to chemicals may cause IAL via an effect on topo-II. We report a pilot case-control study of IAL across different countries and ethnic groups. Cases (n = 136) were population-based in most centers. Controls (n = 266) were selected from inpatients and outpatients at hospitals serving the same populations. MLL rearrangement status was derived by Southern blot analysis, and maternal exposure data were obtained by interviews using a structured questionnaire. Apart from the use of cigarettes and alcohol, very few mothers reported exposure to known topo-II inhibitors. Significant case-control differences were apparent for ingestion of several groups of drugs, including herbal medicines and drugs classified as "DNA-damaging," and for exposure to pesticides with the last two being largely attributable, respectively, to one nonsteroidal anti-inflammatory drug, dipyrone, and mosquitocidals (including Baygon). Elevated odds ratios were observed for MLL+ve (but not MLL-ve) leukemias (2.31 for DNA-damaging drugs, P = 0.03; 5.84 for dipyrone, P = 0.001; and 9.68 for mosquitocidals, P = 0.003). Although it is unclear at present whether these particular exposures operate via an effect on topo-II, the data suggest that specific chemical exposures of the fetus during pregnancy may cause MLL gene fusions. Given the widespread use of dipyrone, Baygon, and other carbamate-based insecticides in certain settings, confirmation of these apparent associations is urgently required.
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Proteínas de Ligação a DNA/genética , Inibidores Enzimáticos/efeitos adversos , Leucemia Mieloide/induzido quimicamente , Leucemia-Linfoma Linfoblástico de Células Precursoras/induzido quimicamente , Efeitos Tardios da Exposição Pré-Natal , Proto-Oncogenes , Inibidores da Topoisomerase II , Fatores de Transcrição , Doença Aguda , Fusão Gênica Artificial , Estudos de Casos e Controles , Inibidores Enzimáticos/farmacocinética , Feminino , Histona-Lisina N-Metiltransferase , Humanos , Lactente , Recém-Nascido , Leucemia Mieloide/genética , Masculino , Troca Materno-Fetal , Proteína de Leucina Linfoide-Mieloide , Projetos Piloto , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Gravidez , Fatores de RiscoRESUMO
Exposure among dentistry students has not been assessed or regulated in Mexico. This work assessed the average exposure of 35 dentistry students during their training with the aid of LiF:Mg,Cu,P+PTFE thermoluminescent dosimeters. For the students in the roles of dentist and observers, maximum accumulated equivalent dose obtained was 2.59±0.11 and 4.64±0.39 mSv, respectively. Students in the role as patients received a maximum accumulated effective dose of 28.41±0.31 mSv. If compared to occupational dose limits, this latter value is 56% of the recommended value of 50 mSv in any year. It was found that in all cases, values of equivalent dose to the women breasts were equal to the background dose. Results are discussed and compared to previous published work. Suggested recommendations were given to authorities in order to minimize exposure of the students in the role as patients.
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Educação em Odontologia , Exposição à Radiação , Radiologia/educação , Estudantes de Odontologia , Feminino , Humanos , Masculino , México , Doses de Radiação , Exposição à Radiação/prevenção & controle , Dosimetria Termoluminescente , Adulto JovemRESUMO
This paper reports a case of adult T-cell leukemia/lymphoma associated with human T-cell lymphotropic virus type I (HTLV-I) diagnosed in a Chilean patient who developed after 1 1/2 years a crisis with a progressive sensorimotor polyneuropathy. Serum and cerebrospinal fluid HTLV-I antibody tests were positive and HTLV-I DNA was clonally integrated in peripheral lymphocytes. This case is unusual in having simultaneous neurological disease. Along with other recent data from South America, this suggests that the endemic area of HTLV-I may spread far beyond the Caribbean area.
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Leucemia-Linfoma de Células T do Adulto/complicações , Doenças do Sistema Nervoso Periférico/complicações , Adulto , Feminino , HumanosRESUMO
We have analyzed the sequence of 40 VDJ rearrangements of the immunoglobulin heavy chain gene locus on 32 unselected children from Chile with precursor B cell ALL at diagnosis. Rearrangements were derived by PCR with VH gene family-specific primers and sequenced directly. The number of VDJ rearrangements, and the pattern of VH, DH and JH gene usage was identical to the one reported by groups from developed countries. CDR3 regions represented an unbiased repertoire; VH to JH joinings were in frame in 36% of cases. Absent N nucleotides in the DJ border, suggestive of fetal origin of ALL, were seen in 9/40 rearrangements but they did not correlate with younger age. More than one rearrangement was sequenced in six patients, representing independent events with no signs of clonal evolution. One patient was analyzed at first bone marrow relapse showing persistence of one rearrangement and evolution of a second one which conserved the DJ border. The subset of B cell precursors which suffer malignant transformation to ALL appear to be common in different parts of the world.
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Rearranjo Gênico do Linfócito B , Genes de Imunoglobulinas , Cadeias Pesadas de Imunoglobulinas/genética , Leucemia-Linfoma Linfoblástico de Células Precursoras/genética , Adolescente , Sequência de Bases , Criança , Pré-Escolar , Chile , DNA Complementar , Feminino , Humanos , Região de Troca de Imunoglobulinas/genética , Lactente , Masculino , Dados de Sequência Molecular , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Análise de Sequência de DNARESUMO
We describe the clinical and laboratory features of nine patients born in Chile with HTLV-I-positive adult T-cell leukemia/lymphoma (ATLL). All were adults (median age 51 years) of Caucasian origin without evidence of Indian or foreign extraction and none had been out of the country. The main disease features were organomegaly, cutaneous lesions, hypercalcemia and leukemia with atypical polylobed lymphocytes displaying a CD2+, CD3+, CD4+, CD8-, CD7- T-cell phenotype. Eight patients presented with acute type ATLL and one had a chronic form lasting for 16 months prior to the development of the acute phase. Lymph node histology (three cases) was consistent with a T-cell non-Hodgkin's lymphoma (large and small cells). Antibodies to HTLV-I were detected by ELISA and particle agglutination in the serum from eight of nine patients. DNA analysis showed HTLV-I proviral DNA in all seven cases investigated, including the single serologically negative patient. In five cases, HTLV-I was monoclonally integrated and in one case oligoclonal. In the seventh case viral DNA clonal status was ambiguous. Response to therapy was poor and median survival was 3 months (range 2-20 months). This study provides further evidence that HTLV-I is endemic in Chile, a non-tropical country where the two main diseases associated with HTLV-I, ATLL and TSP, are found.
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Leucemia-Linfoma de Células T do Adulto/epidemiologia , Adulto , Idoso , Chile/epidemiologia , DNA Viral/análise , Saúde da Família , Feminino , Anticorpos Anti-HTLV-I/análise , Vírus Linfotrópico T Tipo 1 Humano/genética , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Humanos , Imunofenotipagem , Leucemia-Linfoma de Células T do Adulto/imunologia , Leucemia-Linfoma de Células T do Adulto/virologia , Masculino , Pessoa de Meia-Idade , Provírus/genéticaRESUMO
We describe a case of neonatal mixed lineage leukaemia which presented with a dominant B progenitor lymphoblast population plus a minor monocytic component. Treatment of the patient with corticosteroid and Ara-C resulted in loss of lymphoblasts and a rapid (within 7 days) increase and dominance of the monocytic component. The common clonal origin of the two cell types was evident from the identical rearrangement in the MLL gene and a shared rearrangement of one IGH allele. In common with other neonatal or infant ALL with MLL gene rearrangements, this leukaemia may have originated in a common B-monocytic lineage stem cell during foetal haemopoiesis. The observations further suggest that the therapeutic impact of the MLL gene rearrangement is to some extent dependent on the cellular context in which it is expressed.
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Proteínas de Ligação a DNA/genética , Rearranjo Gênico , Leucemia/genética , Proto-Oncogenes , Fatores de Transcrição , Histona-Lisina N-Metiltransferase , Humanos , Recém-Nascido , Leucemia/congênito , Leucemia/metabolismo , Masculino , Proteína de Leucina Linfoide-MieloideRESUMO
Childhood acute lymphoblastic leukemia (ALL) T and B precursor subtypes have been identified by standardised immunophenotyping in different geographic and ethnic settings. Comparison of the relative frequencies and estimated incidence rates of the major subtypes indicates very similar values, with the striking exception of black childhood populations in Africa in which there appears to be a significant and selective deficit in the incidence of the common (B-cell precursor) subset of ALL. There is suggestive evidence for a similar bias in ALL subtypes in South Africans of mixed ethnic origin and in Mapuche Indians from Chile. Several interpretations of these data are possible but the one favoured attributes these differences primarily to socio-economic factors and patterns of infection in infancy.
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Leucemia-Linfoma Linfoblástico de Células Precursoras/epidemiologia , Adolescente , Fatores Etários , Antígenos CD/análise , Criança , Pré-Escolar , Feminino , Humanos , Imunofenotipagem , Lactente , Subpopulações de Linfócitos , Masculino , Leucemia-Linfoma Linfoblástico de Células Precursoras/imunologia , Grupos RaciaisRESUMO
This paper reports (222)Rn concentrations in ground and drinking water of nine cities of Chihuahua State, Mexico. Fifty percent of the 114 sampled wells exhibited (222)Rn concentrations exceeding 11Bq/L, the maximum contaminant level (MCL) recommended by the USEPA. Furthermore, around 48% (123 samples) of the tap-water samples taken from 255 dwellings showed radon concentrations over the MCL. There is an apparent correlation between total dissolved solids and radon concentration in ground-water. The high levels of (222)Rn found may be entirely attributed to the nature of aquifer rocks.
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Radônio/análise , Poluentes Radioativos da Água/análise , Abastecimento de Água , Cidades , México , Controle de Qualidade , Monitoramento de Radiação/normas , Monitoramento de Radiação/estatística & dados numéricos , Radônio/normas , Poluentes Radioativos da Água/normas , Abastecimento de Água/normasRESUMO
A panel of monoclonal antibodies were used to define acute myeloblastic leukaemia (AML) and acute lymphoblastic leukaemia (ALL) with its different subgroups. Thirty-three patients were studied in a period of one year. ALL was diagnosed in 80% of the children and 20% of the adults. AML was present in 22% of the children and 78% of adults. In children, only one of seven was common ALL, three of seven were T-ALL and three of seven were B-ALL. Five of 12 were unclassifiable (U-ALL). In adults the 4 ALL were U-ALL.
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Leucemia Linfoide/imunologia , Leucemia Mieloide Aguda/imunologia , Adolescente , Adulto , Anticorpos Monoclonais , Antígenos de Superfície , Criança , Chile , Feminino , Humanos , Leucemia Linfoide/classificação , Leucemia Linfoide/epidemiologia , Leucemia Mieloide Aguda/classificação , Leucemia Mieloide Aguda/epidemiologia , Masculino , Fatores Sexuais , Fatores SocioeconômicosRESUMO
The relationship between blood lactate concentration ([La]) and O2 uptake (VO2) during incremental exercise remains controversial: does [La] increase smoothly as a function of VO2 (continuous model), or does it begin to increase abruptly above a particular metabolic rate (threshold model)? The dynamic characteristics of the underlying physiological system are investigated using system identification analysis techniques. A multivariate deterministic time series model of the [La] and VO2 response to incremental changes in work rate was fitted to simulated and experimental data. Time-varying system response parameters were determined through the application of a weighted recursive least squares algorithm. The model, using the identified time-varying parameters, provided a good fit to the data. The variation of these parameters over time was then examined. Two major transitions in the parameters were found to occur at intensity levels equivalent to 53 +/- 8% and 77 +/- 9% maximal VO2 (experimental data). These changes in the model parameters indicate that the best linear dynamic model that fits the observed system behavior has changed. This implies that the system has changed its operation in some way, by altering its structure or by moving to a different operating region. The identified parameter changes over time suggest that the exercise intensity range (from rest to maximal VO2) is divided into three main intensity domains, each with distinct dynamics. Further study of this three-phase system may help in the understanding of the underlying physiological mechanisms that affect the dynamics of [La] and VO2 during exercise.
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Exercício Físico/fisiologia , Lactatos/metabolismo , Modelos Teóricos , Oxigênio/metabolismo , Humanos , Estatística como Assunto , Fatores de TempoRESUMO
We document an unusual case of HTLV-I positive adult T-cell leukaemia lymphoma (ATLL) in a 25 year old Chilean patient who presented with primary small intestinal involvement and during evolution developed a leukaemic phase. Duodenal biopsy showed infiltration by pleomorphic lymphoid cells with a CD45RO+ CD20- phenotype. Circulating lymphocytes had a convoluted nucleus and displayed a mature T-cell phenotype: CD2+, CD3+, CD4+, CD8-, CD25+, HLA-Dr+. HTLV-I serology was positive and HTLV-I retroviral sequences were demonstrated by PCR in the tissue. The patient was treated with chlorambucil and is well, disease free five years from diagnosis. Intestinal lymphoma as initial manifestation of ATLL is extremely uncommon, but when a T-cell lymphoma is detected in this localisation, in patients from a HTLV-I endemic area, retroviral studies are recommended in order to exclude an association with this retrovirus.
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Neoplasias Duodenais/patologia , Leucemia-Linfoma de Células T do Adulto/patologia , Adulto , Antineoplásicos Alquilantes/uso terapêutico , Chile , Clorambucila/uso terapêutico , DNA Viral/isolamento & purificação , Diarreia/etiologia , Neoplasias Duodenais/complicações , Neoplasias Duodenais/tratamento farmacológico , Vírus Linfotrópico T Tipo 1 Humano/isolamento & purificação , Humanos , Imunofenotipagem , Leucemia-Linfoma de Células T do Adulto/complicações , Leucemia-Linfoma de Células T do Adulto/tratamento farmacológico , Masculino , Reação em Cadeia da Polimerase , Provírus/isolamento & purificação , Indução de RemissãoRESUMO
We describe the clinical and laboratory features in three Caucasian Chilean patients with tropical spastic paraparesis (TSP) associated with/or preceded by a lymphoproliferative disorder involving cutaneous lesions and localised lymphadenopathy. The neurological symptoms and signs were characteristic of TSP and CSF examination revealed the presence of oligoclonal bands. All three patients had a moderate leucocytosis (10-14 x 10(9)/l) with eosinophilia and a minority (2-4%) of circulating atypical polylobed or ATLL-like lymphocytes. Lymph node histology showed a diffuse pattern of infiltration (1 case) and marked expansion of the paracortical zone with convoluted lymphocytes and immunoblasts (2 cases). Skin biopsy demonstrated a dermal lymphoid infiltration with epidermotropism. Antibodies to HTLV-I were detected in the serum and CSF in the three patients and Southern blot analysis of peripheral blood mononuclear cells showed a monoclonal integration of HTLV-I proviral DNA in one case whereas in the two others the pattern was indicative of low level polyclonal integration. All three patients were treated with prednisolone and one with PUVA with transient partial response on the skin and neurological manifestations. Two patients died months to 5 years from presentation and the other is alive 12 years from diagnosis with active neurological and skin disease. The simultaneous occurrence of HTLV-I associated TSP with smouldering ATLL and a cutaneous ATLL or pre-leukaemic form is discussed.
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Leucemia de Células T/complicações , Paraparesia Espástica Tropical/complicações , Adulto , Anticorpos Antivirais/sangue , Anticorpos Antivirais/líquido cefalorraquidiano , Anticorpos Antivirais/imunologia , Antígenos CD/imunologia , Southern Blotting , Dermatite Esfoliativa/complicações , Feminino , Humanos , Leucemia de Células T/patologia , Leucemia de Células T/virologia , Masculino , Pessoa de Meia-Idade , Terapia PUVA , Paraparesia Espástica Tropical/tratamento farmacológico , Paraparesia Espástica Tropical/patologia , Paraparesia Espástica Tropical/virologia , Prednisolona/uso terapêutico , Provírus/isolamento & purificação , Pele/patologia , Linfócitos T/imunologia , Linfócitos T/patologiaRESUMO
Evaluation of success or failure of therapy for patients with cystic fibrosis (CF) commonly relies on the results of a single pulmonary function test (PFT). Most PFT measurements reflect different functional aspects of the lung. Although no single parameter can summarize all aspects of lung function, a combination of several may provide an advantage by reflecting the overall abnormality of lung function in one number. Cropp et al. (1982, Am Rev Respir Dis 126:211-216) developed a multiparameter pulmonary function score (PFS) using the results of six separate parameters obtained from a PFT. In CF, there is also the potential for declining nutritional status (NS), leading to malnutrition and skeletal muscle wasting. Our aim was to expand the PFS by including weighted information on NS, and to determine whether the expanded score (nutritional-pulmonary function score, NPFS) was more sensitive in detecting change in outcome variables than the PFS. Individual PFT parameters, percent ideal body weight (%IBW), and an index of anaerobic performance (AP) were measured in 21 patients on admission to the hospital and again at discharge. In the group as a whole, in-hospital therapy resulted in improvement (P < 0.01) in individual PFT parameters, %IBW, PFS, and NPFS, and no change in AP. While the PFS more effectively reflected improvement in lung function than did any single PFT parameter, the NPFS resulted in an even more sensitive index of change. Based on these results, we believe that the NPFS, which includes both lung and nutritional status, provides an effective and sensitive index of disease severity that can be used as a unifying measure to: 1) detect disease progression; 2) guide rehabilitation and training; 3) stratify patients for clinical trials; or 4) evaluate the effects of a therapeutic intervention.
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Limiar Anaeróbio , Peso Corporal , Fibrose Cística/fisiopatologia , Estado Nutricional , Testes de Função Respiratória , Adolescente , Adulto , Fibrose Cística/terapia , Feminino , Humanos , Pulmão/fisiopatologia , Masculino , Índice de Gravidade de Doença , Fatores de Tempo , Resultado do TratamentoRESUMO
PURPOSE: The mechanistic basis of the relationship between tissue [O2] and tissue or blood lactate (LA) concentration during tissue hypoxia are not fully understood. However, blood and tissue lactate accumulation are still used as indicators of tissue hypoxia in critically ill patients. To investigate this relationship, we applied a previously developed mathematical model of human bioenergetics to simulate the integrated responses (cellular, tissue, and whole body) to moderate (10% to 45%) and severe (50% to 80%) reductions in muscle blood flow. MATERIALS AND METHODS: Model simulations of muscle ischemia predicted metabolite concentration changes in muscle, splanchnic bed, and other tissues, and were compared with experimental data in humans for model validation. RESULTS: In general, simulations closely predicted the pattern of change in substrates and control metabolites to that observed experimentally. Specifically, simulations showed that most of the increase in muscle LA production during moderate ischemia was due to an increase in pyruvate (PY) and notto the change in redox state induced by a small decrease in O2 consumption. However, during severe ischemia, changes in [LA]/[PY] ratio in venous blood corresponded very closely to changes in tissue redox state. Because both blood [LA] and [LA]/[PY] tracked changes in tissue redox state very well, these can be used reliably as indices of tissue hypoxia during severe muscle ischemia. CONCLUSIONS: Based on the simulations, the commonly used threshold value for venous [LA]/[PY] = 14 as evidence of tissue hypoxia seems appropriate during severe ischemia.
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Isquemia/fisiopatologia , Ácido Láctico/metabolismo , Músculos/irrigação sanguínea , Músculos/metabolismo , Simulação por Computador , Glicólise/fisiologia , Humanos , Modelos Biológicos , Oxirredução , Oxigênio/metabolismo , Ácido Pirúvico/sangue , Fluxo Sanguíneo Regional , Fatores de TempoRESUMO
This study tested the robustness of our computational model of myocardial metabolism by comparing responses to two different inputs with experimental data obtained in pigs under similar conditions. Accordingly, an abrupt and a gradual reduction in coronary flow of similar magnitude were implemented and used as model input. After flow reductions reached 60% from control values, ischemia was kept constant for 60 min in both groups. Our hypotheses were that: (1) these two flow-reduction profiles would result in different transients (concentrations and flux rates) while having similar steady-state values and (2) our model-simulated responses would predict the experimental results in an anesthetized swine model of myocardial ischemia. The two different ischemia-induction patterns resulted in the same decrease in steady-state MVO2 and in similar steady-state values for metabolite concentrations and flux rates at 60 min of ischemia. While both the simulated and experimental results showed decreased glycogen concentration, accumulation of lactate, and net lactate release with ischemia, the onset of glycogen depletion and the switch to lactate efflux were more rapid in the experiments than in the simulations. This study demonstrates the utility of computer models for predicting experimental outcomes in studies of metabolic regulation under physiological and pathological conditions.
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Isquemia Miocárdica/metabolismo , Miocárdio/metabolismo , Animais , Simulação por Computador , Circulação Coronária , Modelos Animais de Doenças , Metabolismo Energético , Glicogênio/metabolismo , Ácido Láctico/metabolismo , Isquemia Miocárdica/etiologia , Miocárdio/patologia , Consumo de Oxigênio , Suínos , Fatores de TempoRESUMO
In an open study Diprolene Cream was administered to fifty patients with severe or resistant psoriasis, atopic dermatitis or other corticosteroid-responsive dermatoses. For a period of 14 days, patients applied 3.5 grams of medication twice daily. Efficacy was evaluated in forty-six patients, while tolerance and safety were evaluated in fifty patients. Therapeutic response in forty-one of forty-six patients was noted by treatment Day 3. By Day 14, mean total severity score of signs and symptoms in twenty-one patients with psoriasis was reduced by 88%. Similarly, in twenty-five patients with other severe or resistant corticosteroid-responsive dermatoses, a 99% decrease in the mean total severity score of signs and symptoms was evident. Of the patients evaluable for tolerance and safety, twenty-four of fifty reported transient, mild to moderate burning that occurred most often upon application of the study preparation. Therapy was not discontinued in any of these patients, and none required additional treatment for the local reaction. Morning plasma cortisol levels in monitored patients remained within normal limits throughout the study.