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1.
Acta Diabetol ; 61(3): 323-331, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37907768

RESUMEN

AIMS: The most common pathogenic mitochondrial mutation associated with mitochondrial disease is m.3243A>G. Increased obstetric complications, such as spontaneous abortion, gestational diabetes (GDM), preterm delivery, and preeclampsia, have been reported in women carrying this mutation. We aimed to determine the fetal and maternal outcomes in pregnant women with mitochondrial disease. METHODS: We retrospectively studied the obstetric and perinatal outcomes in 88 pregnancies of 26 women with genetically confirmed mitochondrial disease (m.3243A>G in the MTTL1 gene (n = 25); m.12258C>A in the MT-TS2 gene (n = 1)). Outcomes included pregnancy related complications, mode of delivery, gestational age at delivery and birthweight. RESULTS: Mean heteroplasmy rate was 18%. The miscarriage rate was higher than background at 25%. 21 pregnancies (24%) were complicated by GDM; 9 pregnancies (13.6%) had a preterm delivery and 2 of them (3%) an extreme premature delivery < 32 weeks. One woman had preeclampsia and one had a postpartum hemorrhage. The caesarean section (CS) rate was 20%. For every unit increase in maternal heteroplasmy levels there was a 26% increased risk of undergoing an assisted operative vaginal delivery (OR 1.26, 95% CI 1.04-1.53, P = 0.002, Bonferroni corrected P = 0.005) and an 18% increased risk of undergoing a CS (OR 1.18, 95% CI 1.01-1.39, P = 0.01, Bonferroni corrected P = 0.03) compared to a spontaneous vaginal delivery. There was a statistical significant correlation between maternal and offspring heteroplasmy levels. Spearman correlation rho = 0.96, 95% CI 0.78-0.99, P = 0.0002. CONCLUSION: Women with mitochondrial disease appear to have more frequent obstetric complications including miscarriage and GDM. Pre-pregnancy diagnosis of m.3243A>G will enable the counseling of women and increase awareness of possible obstetric complications.


Asunto(s)
Aborto Espontáneo , Diabetes Gestacional , Enfermedades Mitocondriales , Preeclampsia , Complicaciones del Embarazo , Nacimiento Prematuro , Recién Nacido , Embarazo , Femenino , Humanos , Resultado del Embarazo , Estudios Retrospectivos , Preeclampsia/epidemiología , Preeclampsia/genética , Preeclampsia/diagnóstico , Nacimiento Prematuro/epidemiología , Aborto Espontáneo/etiología , Aborto Espontáneo/genética , Cesárea , Diabetes Gestacional/epidemiología , Diabetes Gestacional/genética , Diabetes Gestacional/diagnóstico , Complicaciones del Embarazo/epidemiología , Enfermedades Mitocondriales/genética
2.
Ann Oncol ; 34(3): 300-314, 2023 03.
Artículo en Inglés | MEDLINE | ID: mdl-36494005

RESUMEN

BACKGROUND: New precision medicine therapies are urgently required for glioblastoma (GBM). However, to date, efforts to subtype patients based on molecular profiles have failed to direct treatment strategies. We hypothesised that interrogation of the GBM tumour microenvironment (TME) and identification of novel TME-specific subtypes could inform new precision immunotherapy treatment strategies. MATERIALS AND METHODS: A refined and validated microenvironment cell population (MCP) counter method was applied to >800 GBM patient tumours (GBM-MCP-counter). Specifically, partition around medoids (PAM) clustering of GBM-MCP-counter scores in the GLIOTRAIN discovery cohort identified three novel patient clusters, uniquely characterised by TME composition, functional orientation markers and immune checkpoint proteins. Validation was carried out in three independent GBM-RNA-seq datasets. Neoantigen, mutational and gene ontology analysis identified mutations and uniquely altered pathways across subtypes. The longitudinal Glioma Longitudinal AnalySiS (GLASS) cohort and three immunotherapy clinical trial cohorts [treatment with neoadjuvant/adjuvant anti-programmed cell death protein 1 (PD-1) or PSVRIPO] were further interrogated to assess subtype alterations between primary and recurrent tumours and to assess the utility of TME classifiers as immunotherapy biomarkers. RESULTS: TMEHigh tumours (30%) displayed elevated lymphocyte, myeloid cell immune checkpoint, programmed cell death protein 1 (PD-1) and cytotoxic T-lymphocyte-associated protein 4 transcripts. TMEHigh/mesenchymal+ patients featured tertiary lymphoid structures. TMEMed (46%) tumours were enriched for endothelial cell gene expression profiles and displayed heterogeneous immune populations. TMELow (24%) tumours were manifest as an 'immune-desert' group. TME subtype transitions upon recurrence were identified in the longitudinal GLASS cohort. Assessment of GBM immunotherapy trial datasets revealed that TMEHigh patients receiving neoadjuvant anti-PD-1 had significantly increased overall survival (P = 0.04). Moreover, TMEHigh patients treated with adjuvant anti-PD-1 or oncolytic virus (PVSRIPO) showed a trend towards improved survival. CONCLUSIONS: We have established a novel TME-based classification system for application in intracranial malignancies. TME subtypes represent canonical 'termini a quo' (starting points) to support an improved precision immunotherapy treatment approach.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Humanos , Glioblastoma/tratamiento farmacológico , Microambiente Tumoral , Recurrencia Local de Neoplasia , Inmunoterapia/métodos , Neoplasias Encefálicas/tratamiento farmacológico
3.
Pharmacogenomics J ; 21(4): 510-519, 2021 08.
Artículo en Inglés | MEDLINE | ID: mdl-33731881

RESUMEN

Previous research has identified differences in mutation frequency in genes implicated in chemotherapy resistance between mucinous and non-mucinous colorectal cancers (CRC). We hypothesized that outcomes in mucinous and non-mucinous CRC may be influenced by expression of genes responsible for chemotherapy resistance. Gene expression data from primary tumor samples were extracted from The Cancer Genome Atlas PanCancer Atlas. The distribution of clinical, pathological, and gene expression variables was compared between 74 mucinous and 521 non-mucinous CRCs. Predictors of overall survival (OS) were assessed in a multivariate analysis. Kaplan-Meier curves were constructed to compare survival according to gene expression using the log rank test. The median expression of 5-FU-related genes TYMS, TYMP, and DYPD was significantly higher in mucinous CRC compared to non-mucinous CRC (p < 0.001, p = 0.003, p < 0.001, respectively). The median expression of oxaliplatin-related genes ATP7B and SRPK1 was significantly reduced in mucinous versus non-mucinous CRC (p = 0.004, p = 0.007, respectively). At multivariate analysis, age (odds ratio (OR) = 0.96, p < 0.001), node positive disease (OR = 0.49, p = 0.005), and metastatic disease (OR = 0.32, p < 0.001) remained significant negative predictors of OS, while high SRPK1 remained a significant positive predictor of OS (OR = 1.59, p = 0.037). Subgroup analysis of rectal cancers demonstrated high SRPK1 expression was associated with significantly longer OS compared to low SRPK1 expression (p = 0.011). This study highlights that the molecular differences in mucinous CRC and non-mucinous CRC extend to chemotherapy resistance gene expression. SRPK1 gene expression was associated with OS, with a prognostic role identified in rectal cancers.


Asunto(s)
Neoplasias Colorrectales/genética , Resistencia a Antineoplásicos/genética , Inactivación Metabólica/genética , Anciano , ATPasas Transportadoras de Cobre/genética , Femenino , Expresión Génica/genética , Humanos , Masculino , Pronóstico , Proteínas Serina-Treonina Quinasas/genética
4.
Ann Oncol ; 31(12): 1679-1692, 2020 12.
Artículo en Inglés | MEDLINE | ID: mdl-32918998

RESUMEN

Glioblastoma represents the most common primary malignancy of the central nervous system in adults and remains a largely incurable disease. The elucidation of disease subtypes based on mutational profiling, gene expression and DNA methylation has so far failed to translate into improved clinical outcomes. However, new knowledge emerging from the subtyping effort in the IDH-wild-type setting may provide directions for future precision therapies. Here, we review recent learnings in the field, and further consider how tumour microenvironment differences across subtypes may reveal novel contexts of vulnerability. We discuss recent treatment approaches and ongoing trials in the IDH-wild-type glioblastoma setting, and propose an integrated discovery stratagem incorporating multi-omics, single-cell technologies and computational approaches.


Asunto(s)
Neoplasias Encefálicas , Glioblastoma , Adulto , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Metilación de ADN , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Humanos , Isocitrato Deshidrogenasa/genética , Mutación , Medicina de Precisión , Microambiente Tumoral
5.
Rev. esp. cir. ortop. traumatol. (Ed. impr.) ; 62(3): 190-196, mayo-jun. 2018. ilus, tab
Artículo en Español | IBECS | ID: ibc-177322

RESUMEN

Objetivo: Evaluar el diámetro de la emergencia del túnel tibial con relación a la técnica de reconstrucción del ligamento cruzado anterior, empleando isquiotibiales autógenos, y comparar las técnicas a través del portal anteromedial (PAM) y la convencional transtibial (TT). Métodos: Estudio prospectivo, aleatorizado y comparativo de 36 pacientes diagnosticados con insuficiencia del ligamento cruzado anterior, intervenidos en forma sucesiva mediante reconstrucción primaria, con las técnicas de reconstrucción a través de PAM (16 pacientes) y la TT convencional (20 pacientes) con isquiotibiales autógenos. Todos los pacientes fueron evaluados radiológicamente, con valoración del diámetro de emergencia tibial en los planos anteroposterior y lateral a las 6 semanas y a los 12 meses del procedimiento quirúrgico respecto al tamaño de la plastia utilizada en la cirugía. Se realizó un análisis estadístico comparando ambos grupos mediante la t de Student con un valor de significación de 0,05. Resultados: El diámetro de la emergencia tibial con relación al tamaño de la plastia utilizada, obtenido a las 6 semanas en la proyección anteroposterior, manifestó un incremento del 8,1%±2,9 con la técnica PAM y del 21,20%±11,87 con la técnica TT, mientras que en la proyección lateral fue de 71%±4,72 y del 17,64%±11,48, respectivamente. Las diferencias fueron estadísticamente significativas tanto en el plano anteroposterior como en el lateral. Conclusiones: El diámetro de la apertura tibial mostró ser significativamente mayor con la técnica TT a las 6 semanas y a los 12 meses de seguimiento radiológico tanto en la proyección anteroposterior como en la lateral


Objective: Evaluate the enlargement effect of the tibial tunnel emergence of 2 different of anterior cruciate ligament reconstruction techniques: antero-medial portal (AMP) vs. transtibial (TT) technique. Methods: A prospective, randomized controlled study was performed in 36 consecutive patients who underwent anterior cruciate ligament reconstruction with autologous hamstring tendon grafts employing the AMP and conventional TT techniques. Lateral and antero-posterior radiographs were obtained for each patient at 6 weeks and 12 months postoperatively. The sclerotic margins of the tibial tunnels were measured at the widest dimension of the tunnel as well as the diameter of the tibial emergence and were compared with the initially drilled tunnel size after correction for radiographic magnification. Statistical analysis was performed to compare the 2 groups by use of the independent-samples t test, with significance set at .05. Results: The mean percentage increase in the diameter of tibial tunnel emergence at 6 weeks after surgery was 8.1%±2.9 for the PAM technique and 21.20%±11.87 for the TT technique on the anteroposterior x-ray view. However, the mean percentage increase in the diameter of the tibial tunnel emergence on the lateral view was 7.1%±4.72 for the medial portal technique and 17.64%±11.48 for the transtibial technique. This difference was statistically significant on both anteroposterior and lateral views. Conclusions: The diameter of the tibial tunnel emergence for hamstring autologous anterior cruciate ligament reconstructions was significantly lower for the medial portal technique when compared with the conventional TT technique


Asunto(s)
Humanos , Masculino , Femenino , Adolescente , Adulto Joven , Adulto , Persona de Mediana Edad , Lesiones del Ligamento Cruzado Anterior/cirugía , Músculos Isquiosurales/trasplante , Tibia/cirugía , Fémur/cirugía , Estudios Prospectivos , Resultado del Tratamiento , Recuperación de la Función
6.
Artículo en Inglés, Español | MEDLINE | ID: mdl-29574163

RESUMEN

OBJECTIVE: Evaluate the enlargement effect of the tibial tunnel emergence of 2 different of anterior cruciate ligament reconstruction techniques: antero-medial portal (AMP) vs. transtibial (TT) technique. METHODS: A prospective, randomized controlled study was performed in 36 consecutive patients who underwent anterior cruciate ligament reconstruction with autologous hamstring tendon grafts employing the AMP and conventional TT techniques. Lateral and antero-posterior radiographs were obtained for each patient at 6 weeks and 12 months postoperatively. The sclerotic margins of the tibial tunnels were measured at the widest dimension of the tunnel as well as the diameter of the tibial emergence and were compared with the initially drilled tunnel size after correction for radiographic magnification. Statistical analysis was performed to compare the 2 groups by use of the independent-samples t test, with significance set at .05. RESULTS: The mean percentage increase in the diameter of tibial tunnel emergence at 6 weeks after surgery was 8.1%±2.9 for the PAM technique and 21.20%±11.87 for the TT technique on the anteroposterior x-ray view. However, the mean percentage increase in the diameter of the tibial tunnel emergence on the lateral view was 7.1%±4.72 for the medial portal technique and 17.64%±11.48 for the transtibial technique. This difference was statistically significant on both anteroposterior and lateral views. CONCLUSIONS: The diameter of the tibial tunnel emergence for hamstring autologous anterior cruciate ligament reconstructions was significantly lower for the medial portal technique when compared with the conventional TT technique.


Asunto(s)
Lesiones del Ligamento Cruzado Anterior/cirugía , Reconstrucción del Ligamento Cruzado Anterior/métodos , Tendones Isquiotibiales/trasplante , Tibia/cirugía , Adolescente , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Trasplante Autólogo , Resultado del Tratamiento , Adulto Joven
7.
Br J Cancer ; 114(2): 188-98, 2016 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-26657652

RESUMEN

BACKGROUND: Resistance to temozolomide (TMZ) greatly limits chemotherapeutic effectiveness in glioblastoma (GBM). Here we analysed the ability of the Inhibitor-of-apoptosis-protein (IAP) antagonist birinapant to enhance treatment responses to TMZ in both commercially available and patient-derived GBM cells. METHODS: Responses to TMZ and birinapant were analysed in a panel of commercial and patient-derived GBM cell lines using colorimetric viability assays, flow cytometry, morphological analysis and protein expression profiling of pro- and antiapoptotic proteins. Responses in vivo were analysed in an orthotopic xenograft GBM model. RESULTS: Single-agent treatment experiments categorised GBM cells into TMZ-sensitive cells, birinapant-sensitive cells, and cells that were insensitive to either treatment. Combination treatment allowed sensitisation to therapy in only a subset of resistant GBM cells. Cell death analysis identified three principal response patterns: Type A cells that readily activated caspase-8 and cell death in response to TMZ while addition of birinapant further sensitised the cells to TMZ-induced cell death; Type B cells that readily activated caspase-8 and cell death in response to birinapant but did not show further sensitisation with TMZ; and Type C cells that showed no significant cell death or moderately enhanced cell death in the combined treatment paradigm. Furthermore, in vivo, a Type C patient-derived cell line that was TMZ-insensitive in vitro and showed a strong sensitivity to TMZ and TMZ plus birinapant treatments. CONCLUSIONS: Our results demonstrate remarkable differences in responses of patient-derived GBM cells to birinapant single and combination treatments, and suggest that therapeutic responses in vivo may be greatly affected by the tumour microenvironment.


Asunto(s)
Protocolos de Quimioterapia Combinada Antineoplásica/farmacología , Apoptosis/efectos de los fármacos , Neoplasias Encefálicas/patología , Dacarbazina/análogos & derivados , Dipéptidos/farmacología , Glioblastoma/patología , Indoles/farmacología , Proteínas Inhibidoras de la Apoptosis/antagonistas & inhibidores , Animales , Western Blotting , Caspasa 8/efectos de los fármacos , Caspasa 8/metabolismo , Línea Celular Tumoral , Supervivencia Celular/efectos de los fármacos , Dacarbazina/farmacología , Resistencia a Antineoplásicos/efectos de los fármacos , Citometría de Flujo , Humanos , Técnicas In Vitro , Ratones , Ratones Endogámicos NOD , Ratones SCID , Microscopía de Contraste de Fase , Trasplante de Neoplasias , Temozolomida , Ensayos Antitumor por Modelo de Xenoinjerto
8.
Br J Cancer ; 107(6): 904-9, 2012 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-22871884

RESUMEN

BACKGROUND: Optimal adherence to imatinib therapy is of paramount importance to maximise treatment effectiveness in patients with chronic myeloid leukaemia (CML). The main objective of this study was to investigate patient-reported personal factors associated with adherence behaviour. METHODS: Analysis was conducted on 413 CML patients receiving long-term therapy with imatinib. Adherence behaviour was measured with the Morisky Medication Adherence Scale and personal factors investigated included: quality of life, perceived social support, fatigue, symptom burden, psychological wellbeing and desire for additional information. Key socio-demographic and treatment-related factors were also taken into account. Univariate and multivariate logistic regression analyses were used to investigate factors associated with optimal adherence to therapy. RESULTS: In all, 53% of patients reported an optimal adherence behaviour. The final multivariate model retained the following variables as independent predictors of optimal adherence to therapy: desire for more information (ref. no), odds ratio (OR)=0.43 (95% confidence interval (CI), 0.29-0.66; P<0.001), social support (higher score representing greater support), OR=1.29 (95% CI, 1.11-1.49; P<0.001) and concomitant drug burden (ref. no), OR=1.82 (95% CI, 1.18-2.80; P=0.006). CONCLUSION: This study suggests that a higher level of social support, satisfaction with information received and concomitant drug burden are the main factors associated with greater adherence to long-term imatinib therapy.


Asunto(s)
Antineoplásicos/administración & dosificación , Fatiga , Conducta en la Búsqueda de Información , Leucemia Mielógena Crónica BCR-ABL Positiva/tratamiento farmacológico , Cumplimiento de la Medicación , Piperazinas/administración & dosificación , Pirimidinas/administración & dosificación , Calidad de Vida , Apoyo Social , Adulto , Anciano , Anciano de 80 o más Años , Análisis de Varianza , Antineoplásicos/efectos adversos , Benzamidas , Fatiga/etiología , Fatiga/psicología , Femenino , Humanos , Mesilato de Imatinib , Modelos Logísticos , Masculino , Cumplimiento de la Medicación/psicología , Cumplimiento de la Medicación/estadística & datos numéricos , Persona de Mediana Edad , Oportunidad Relativa , Piperazinas/efectos adversos , Pirimidinas/efectos adversos , Factores de Riesgo , Resultado del Tratamiento
9.
Plant Physiol ; 127(3): 1053-64, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11706186

RESUMEN

Heat stress inhibits photosynthesis by reducing the activation of Rubisco by Rubisco activase. To determine if loss of activase function is caused by protein denaturation, the thermal stability of activase was examined in vitro and in vivo and compared with the stabilities of two other soluble chloroplast proteins. Isolated activase exhibited a temperature optimum for ATP hydrolysis of 44 degrees C compared with > or =60 degrees C for carboxylation by Rubisco. Light scattering showed that unfolding/aggregation occurred at 45 degrees C and 37 degrees C for activase in the presence and absence of ATPgammaS, respectively, and at 65 degrees C for Rubisco. Addition of chemically denatured rhodanese to heat-treated activase trapped partially folded activase in an insoluble complex at treatment temperatures that were similar to those that caused increased light scattering and loss of activity. To examine thermal stability in vivo, heat-treated tobacco (Nicotiana rustica cv Pulmila) protoplasts and chloroplasts were lysed with detergent in the presence of rhodanese and the amount of target protein that aggregated was determined by immunoblotting. The results of these experiments showed that thermal denaturation of activase in vivo occurred at temperatures similar to those that denatured isolated activase and far below those required to denature Rubisco or phosphoribulokinase. Edman degradation analysis of aggregated proteins from tobacco and pea (Pisum sativum cv "Little Marvel") chloroplasts showed that activase was the major protein that denatured in response to heat stress. Thus, loss of activase activity during heat stress is caused by an exceptional sensitivity of the protein to thermal denaturation and is responsible, in part, for deactivation of Rubisco.


Asunto(s)
Cloroplastos/metabolismo , Fotosíntesis/fisiología , Proteínas de Plantas/metabolismo , Ribulosa-Bifosfato Carboxilasa/metabolismo , Adenosina Trifosfato/metabolismo , Activación Enzimática , Calor , Immunoblotting , Luz , Pisum sativum/metabolismo , Fosfotransferasas (Aceptor de Grupo Alcohol)/metabolismo , Proteínas de Plantas/química , Desnaturalización Proteica , Ribulosa-Bifosfato Carboxilasa/química , Tiosulfato Azufretransferasa/farmacología , Nicotiana/metabolismo
10.
J Mol Biol ; 306(2): 239-50, 2001 Feb 16.
Artículo en Inglés | MEDLINE | ID: mdl-11237597

RESUMEN

Polyhydric alcohols are widely found in nature and can be accumulated to high concentrations as a protection against a variety of environmental stresses. It is only recently, however, that these molecules have been shown to be active in protection against heat stress, specifically in the use of sorbitol by the silverleaf whitefly, Bemisia argentifolii. We have determined the structure of the enzyme responsible for production of sorbitol in Bemisia argentifolii, NADP(H)-dependent ketose reductase (BaKR), to 2.3 A resolution. The structure was solved by multiwavelength anomalous diffraction (MAD) using the anomalous scattering from two zinc atoms bound in the structure, and was refined to an R factor of 21.9 % (R(free)=25.1 %). BaKR belongs to the medium-chain dehydrogenase family and its structure is the first for the sorbitol dehydrogenase branch of this family. The enzyme is tetrameric, with the monomer having a very similar fold to the alcohol dehydrogenases (ADHs). Although the structure determined is for the apo form, a phosphate ion in the active site marks the likely position for the adenyl phosphate of NADP(H). The catalytic zinc ion is tetrahedrally coordinated to Cys41, His66, Glu67 and a water molecule, in a modification of the zinc site usually found in ADHs. This modified zinc site seems likely to be a conserved feature of the sorbitol dehydrogenase sub-family. Comparisons with other members of the ADH family have also enabled us to model a ternary complex of the enzyme, and suggest how structural differences may influence coenzyme binding and substrate specificity in the reduction of fructose to sorbitol.


Asunto(s)
Oxidorreductasas de Alcohol/química , Hemípteros/enzimología , Cetosas/metabolismo , NADP/metabolismo , Oxidorreductasas/química , Oxidorreductasas de Alcohol/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Cristalografía por Rayos X , Cetoprofeno , Modelos Moleculares , Datos de Secuencia Molecular , Oxidorreductasas/metabolismo , Estructura Cuaternaria de Proteína , Alineación de Secuencia , Sorbitol/metabolismo , Especificidad por Sustrato , Zinc/metabolismo
11.
J Insect Physiol ; 47(4-5): 423-32, 2001 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-11166307

RESUMEN

The major soluble carbohydrates in the silverleaf whitefly, Bemisia argentifolii, were glucose, alpha,alpha-trehalose and an unknown sugar. Analysis of the unknown sugar and its chemical and enzymatic digestion products by high-performance liquid chromatography (HPLC) showed that it was probably a trisaccharide, consisting entirely of glucose, and containing both alpha,alpha-trehalose and isomaltose moieties. Matrix-assisted laser desorption mass spectrometry, mass spectrometry and 13C and 1H nuclear magnetic resonance spectroscopy confirmed that the sugar was a trisaccharide with the following structure: O-alpha-D-glucopyranosyl-(1-->6)-O-alpha-D-glucopyranosyl-(1<-->1)-alpha-D-glucopyranoside. This trisaccharide, found primarily in the bodies of B. argentifolii and not in their honeydew, is structurally similar to bemisiose [O-alpha-D-glucopyranosyl-(1-->4)-O-alpha-D-glucopyranosyl-(1<-->1)-alpha-D-glucopyranoside], a sugar first identified in Bemisia honeydew. Consequently, the common name isobemisiose is proposed for the newly identified sugar. Isobemisiose, which has not been previously reported to occur in nature, constituted as much as 46% (w/w) of the ethanol-soluble sugars in adult B. argentifolii, equivalent to approximately 10% of their dry weight. It was also found in similar quantities in immature B. argentifolii. Isobemisiose was detected in two other whitefly species and in several species of aphids, but at lesser concentrations than in B. argentifolii. Labeling and pulse-chase experiments using [14C]sucrose supplied to B. argentifolii in an artificial diet revealed that label accumulated in and was chased from isobemisiose more slowly than for either glucose or trehalose. Incubation of isobemisiose with cell-free extracts of B. argentifolii demonstrated that these whiteflies contained the necessary complement of enzymes to fully degrade isobemisiose to glucose. These labeling and digestion experiments indicate that isobemisose is probably a storage carbohydrate in B. argentifolii.

12.
Planta ; 214(1): 117-25, 2001 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11762161

RESUMEN

Ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco; EC 4.1.1.39) activase mRNA and protein synthesis were measured in the leaves of cotton (Gossypium hirsutum L.) plants under control (28 degrees C) or heat-stress (41 degrees C) conditions. A decline in activase transcript abundance occurred rapidly during the photoperiod and was unaffected by heat stress. In response to high temperature, de novo protein synthesis rapidly shifted from mainly expression of Rubisco large and small subunits to the major heat-shock proteins, while de novo synthesis of the constitutively expressed 47- and 43-kDa activase polypeptides was not appreciably altered. However, heat stress induced the synthesis of a 46-kDa polypeptide that immunoprecipitated with antibodies monospecific to activase. Expression of the 46-kDa polypeptide ceased within 1 h of the return of heat-stressed plants to control conditions. Activase precursors of 55 and 51 kDa were detected among the in vitro translation products of RNA from control and heat-stressed plants. In addition, a 53-kDa polypeptide that also immunoprecipitated with anti-activase IgG was among the in vitro translation products of RNA from heat-stressed plants. This putative activase precursor did not occur among the in vitro translation products of RNA from plants that had recovered from heat stress. The levels of the constitutive 47- and 43-kDa activase polypeptides were similar in control and heat-stressed plants, based on immunoblotting with antibodies to activase. However, a 46-kDa cross-reacting polypeptide was also present in heat-stressed plants and constituted about 5% of the total activase after 48 h at high temperature. The identity of the heat-induced 46-kDa polypeptide as activase was confirmed by protein sequencing, which showed that its N-terminal sequence was identical to that of the constitutive 47-kDa activase polypeptide. The presence of multiple isoforms for both the 47- and 43-kDa activase polypeptides on immunoblots of two-dimensional gels and the complex banding pattern on Southern blots together suggest the existence of more than one activase gene and the possibility that the synthesis of the heat-induced activase polypeptide may be regulated transcriptionally. Induction of a new form of activase may constitute a mechanism of photosynthetic acclimation to heat stress in cotton.


Asunto(s)
Gossypium/enzimología , Calor , Hojas de la Planta/enzimología , Proteínas de Plantas/biosíntesis , Ribulosa-Bifosfato Carboxilasa/biosíntesis , Anticuerpos , Northern Blotting , Southern Blotting , Activación Enzimática , Inducción Enzimática , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Gossypium/genética , Proteínas de Choque Térmico/genética , Proteínas de Choque Térmico/metabolismo , Isoenzimas/biosíntesis , Isoenzimas/genética , Isoenzimas/metabolismo , Fotosíntesis/fisiología , Hojas de la Planta/genética , Proteínas de Plantas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , ARN de Planta/genética , ARN de Planta/metabolismo , Ribulosa-Bifosfato Carboxilasa/genética , Transcripción Genética
13.
Proc Natl Acad Sci U S A ; 97(24): 13430-5, 2000 Nov 21.
Artículo en Inglés | MEDLINE | ID: mdl-11069297

RESUMEN

Net photosynthesis (Pn) is inhibited by moderate heat stress. To elucidate the mechanism of inhibition, we examined the effects of temperature on gas exchange and ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) activation in cotton and tobacco leaves and compared the responses to those of the isolated enzymes. Depending on the CO(2) concentration, Pn decreased when temperatures exceeded 35-40 degrees C. This response was inconsistent with the response predicted from the properties of fully activated Rubisco. Rubisco deactivated in leaves when temperature was increased and also in response to high CO(2) or low O(2). The decrease in Rubisco activation occurred when leaf temperatures exceeded 35 degrees C, whereas the activities of isolated activase and Rubisco were highest at 42 degrees C and >50 degrees C, respectively. In the absence of activase, isolated Rubisco deactivated under catalytic conditions and the rate of deactivation increased with temperature but not with CO(2). The ability of activase to maintain or promote Rubisco activation in vitro also decreased with temperature but was not affected by CO(2). Increasing the activase/Rubisco ratio reduced Rubisco deactivation at higher temperatures. The results indicate that, as temperature increases, the rate of Rubisco deactivation exceeds the capacity of activase to promote activation. The decrease in Rubisco activation that occurred in leaves at high CO(2) was not caused by a faster rate of deactivation, but by reduced activase activity possibly in response to unfavorable ATP/ADP ratios. When adjustments were made for changes in activation state, the kinetic properties of Rubisco predicted the response of Pn at high temperature and CO(2).


Asunto(s)
Dióxido de Carbono/metabolismo , Gossypium/fisiología , Nicotiana/fisiología , Fotosíntesis , Hojas de la Planta/fisiología , Proteínas de Plantas/metabolismo , Plantas Tóxicas , Ribulosa-Bifosfato Carboxilasa/metabolismo , Activación Enzimática , Gossypium/enzimología , Calor , Cinética , Proteínas de Plantas/aislamiento & purificación , Ribulosa-Bifosfato Carboxilasa/aislamiento & purificación , Termodinámica , Nicotiana/enzimología
14.
Haematologica ; 85(8): 855-64, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10942933

RESUMEN

The lung is one of the organs most severely affected by complications during the course of hematologic disorders. In the last years an impressive amount of progress has been made in clarifying the pathogenesis of lung diseases, particularly those occurring in conditions of severe immunosuppression such as bone marrow transplantion, acquired immunodeficiency syndrome or leukemia. Peculiar anatomical characteristics render the lung parenchyma highly susceptible to infections, but the clinical outcome is due not only to the injury induced by the pathogens but also to their interactions with inflammatory cells and particularly to the effects of a wide network of secreted cytokines. Polymorphonuclear cells, macrophages, lymphocytes and structural pulmonary cells (epithelial cells, interstitial cells) generate a variety of cytokines and growth factors which, in turn, may be responsible for the majority of the clinical effects in response to infections, such as those of Pneumocystis carinii and cytomegalovirus, but also to certain drugs or to radiation. The pathogenesis of graft-versus-host disease (GVHD) is still poorly understood, but animal models seem to demonstrate the involvement of a number of cytokines and growth factors, together with toxic effects induced by conditioning regimens.


Asunto(s)
Enfermedades Hematológicas/complicaciones , Enfermedades Pulmonares/etiología , Pulmón/patología , Quimiotaxis de Leucocito , Citocinas/fisiología , Susceptibilidad a Enfermedades , Enfermedad Injerto contra Huésped/complicaciones , Sustancias de Crecimiento/fisiología , Enfermedades Hematológicas/inmunología , Humanos , Pulmón/inmunología , Enfermedades Pulmonares/inducido químicamente , Enfermedades Pulmonares/fisiopatología , Linfocitos/fisiología , Macrófagos Alveolares/fisiología , Neutrófilos/fisiología , Neumonía/etiología , Neumonía/microbiología , Neumonía/virología , Eosinofilia Pulmonar/etiología , Neumonitis por Radiación/etiología , Radioterapia/efectos adversos , Acondicionamiento Pretrasplante/efectos adversos
16.
Acta Biomed Ateneo Parmense ; 71 Suppl 1: 493-5, 2000.
Artículo en Italiano | MEDLINE | ID: mdl-11424795

RESUMEN

OBJECTIVES: The aim of this epidemiological research is to evaluate the prevalence of genetic diseases and malformative syndromes in paediatric population living in the Macerata county. MATERIAL AND METHODS: All the data were collected through a careful analysis of a specific questionnaire sent to all the family paediatricians. RESULTS: 23,379 children living in Macerata county, aged 0 to 9 years, were evaluated (93.8% of all this paediatric population). Among those were found N 400 cases of genetic diseases and malformative syndromes: Malformations Tot.N. 255 cases (63.3% of the reported cases); Malformative Syndromes Tot. N. 55 cases (27.8% of the reported cases); Endocrinology and Metabolic Diseases Tot. N. 41 cases (10.3% of the reported cases); Osteochondrodysplasia Tot. N. 22 cases (5.7% of the reported cases); Other Tot. N. 28 cases (7.0% of the reported cases); Male population was found more affected than female: M/F ratio = 1.4. The analysis of the data showed an increasing trend in detecting these pathological conditions, consistent with the increase in geographic altitude (3 areas considered): 0-100 meter = 0.88%; 100-600 m.a.s. = 1.34%; over 600 m.a.s. = 1.88%. CONCLUSION: The knowledge of the number of children affected by genetic and malformative diseases in the Macerata county is relevant in order to establish a Genetic Service with the aim to better support the medical assistance of these patients and counselling service for the families.


Asunto(s)
Anomalías Congénitas/epidemiología , Niño , Preescolar , Femenino , Humanos , Lactante , Recién Nacido , Italia , Masculino , Sistema de Registros
17.
Arch Insect Biochem Physiol ; 45(3): 117-28, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11169751

RESUMEN

The involvement of alpha-glucosidase in the partitioning of ingested sucrose between excretion and incorporation was investigated in the silverleaf whitefly (Bemisia argentifolii). Approximately half of the alpha-glucosidase activity in adult whiteflies was soluble and the remainder was associated with membranes. In contrast, almost all of the trehalulose synthase was membrane-associated. Isoelectric focusing revealed that soluble and membrane-associated alpha-glucosidases were each composed of several isozymes in the pH 5 to 6.5 range, but the distribution of activity among the various isozymes was different. Bromoconduritol, an inhibitor of glucosidases, inhibited trehalulose synthase and alpha-glucosidase activities in whitefly extracts. Inhibition was greatest when bromoconduritol was incubated with extracts prior to the addition of sucrose, consistent with the irreversible nature of this inhibitor. Addition of bromoconduritol to artificial diets decreased the extractable trehalulose synthase and alpha-glucosidase activities by about 30 and 50%, respectively. Ingestion of bromoconduritol reduced the amount of carbohydrate excreted by about 80% without changing the distribution of the major honeydew sugars or causing an increase in the proportion of sucrose that was excreted. Ingestion of bromoconduritol did not affect respiration, the content and distribution of soluble carbohydrates in whitefly bodies, or the conversion of labeled sucrose into glucose, trehalose and isobemisiose. The results indicate that partitioning of ingested carbon between excretion and metabolism in whiteflies is highly regulated, probably involving multiple forms of alpha-glucosidase that facilitate a separation of the processes involved in the metabolic utilization of sucrose from those involved in excretion of excess carbohydrate. Arch. Insect Biochem. Physiol. 45:117-128, 2000. Published 2001 Wiley-Liss, Inc.


Asunto(s)
Inhibidores Enzimáticos/farmacología , Inhibidores de Glicósido Hidrolasas , Hemípteros/metabolismo , Inositol/farmacología , Sacarosa/metabolismo , Animales , Ciclohexenos , Disacáridos/metabolismo , Ingestión de Alimentos/efectos de los fármacos , Hemípteros/enzimología , Inositol/análogos & derivados , Focalización Isoeléctrica , Ligasas/antagonistas & inhibidores , Ligasas/metabolismo , alfa-Glucosidasas/metabolismo
18.
Leuk Lymphoma ; 39(3-4): 301-10, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-11342310

RESUMEN

We attempted to analyze whether the use of high-dose cyclophosphamide (CTX 7g/m2, group A) plus hematopoietic growth factor (G-CSF) or G-CSF alone (10 microg/Kg, group B) as a mobilizing regimen, could result in harvesting different numbers of CD34+ cells, committed progenitors and CD34+ cells subsets. The number of CD34+ cells considered as the target for each high-dose chemotherapy was > or = 2 x 10(6) /Kg/bw. Fifteen leukaphereses procedures were necessary in group A, while 16 procedures were performed in group B. We did not observe any difference between the two groups in terms of CD34+ cells/microl in the peripheral blood (117 vs 78; p = NS), whereas in the aphereses product we found a significant difference between the two groups of patients in terms of CD34+ cells (6.41 vs 2.89 x 10(6) /Kg/bw; p = .009), CFU-GM (82.5 vs 52.3 x 10(4) /Kg/bw; p = .04). Interestingly, we noted a different distribution of CD34+/33- cells between the 2 groups (mean value 39% vs 65%; p < .05), whereas we did not find any differences regarding CD34+/38-, CD34+/Thy1+, CD34+/HLADR-. The higher number of CFU-GM/Kg/bw collected in the former group did not translate into a superior plating efficiency (27.75 vs 30.29). Furthermore, we observed a strong correlation between CD34+ cells/microl in the peripheral blood and the total number of CD34+ cells in the leukaphereses product (r = 0.97), whereas this correlation was not found in group B (r = 0.15). In both groups of patients the number of CD34+ cells collected correlated well with CFU-GM (r = 0.93; r = 0.94), but definitely we did not observe any correlation between CD34+ cells/microl and CFU-GM in patients mobilized with G-CSF alone and this did not allow us to predict the harvest accurately. Finally, we evaluated the engraftment kinetics and we did not observe any statistically significant difference between the two groups of patients.


Asunto(s)
Ciclofosfamida/administración & dosificación , Factor Estimulante de Colonias de Granulocitos/administración & dosificación , Movilización de Célula Madre Hematopoyética/métodos , Linfoma no Hodgkin/terapia , Adulto , Antígenos CD34/análisis , Antígenos CD34/efectos de los fármacos , Estudios de Cohortes , Ciclofosfamida/farmacología , Quimioterapia Combinada , Femenino , Factor Estimulante de Colonias de Granulocitos/farmacología , Movilización de Célula Madre Hematopoyética/normas , Células Madre Hematopoyéticas/citología , Humanos , Leucaféresis/normas , Linfoma no Hodgkin/tratamiento farmacológico , Masculino , Persona de Mediana Edad , Acondicionamiento Pretrasplante , Trasplante Autólogo/métodos
19.
Insect Biochem Mol Biol ; 29(2): 113-20, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10196734

RESUMEN

The silverleaf whitefly (Bemisia argentifolii, Bellows and Perring) accumulates sorbitol as a thermoprotectant in response to elevated temperature. Sorbitol synthesis in this insect is catalyzed by an unconventional ketose reductase (KR) that uses NADPH to reduce fructose. A cDNA encoding the NADPH-KR from adult B. argentifolii was cloned and sequenced to determine the primary structure of this enzyme. The cDNA encoded a protein of 352 amino acids with a calculated molecular mass of 38.2 kDa. The deduced amino acid sequence of the cDNA shared 60% identity with sheep NAD(+)-dependent sorbitol dehydrogenase (SDH). Residues in SDH involved in substrate binding were conserved in the whitefly NADPH-KR. An important structural difference between the whitefly NADPH-KR and NAD(+)-SDHs occurred in the nucleotide-binding site. The Asp residue that coordinates the adenosyl ribose hydroxyls in NAD(+)-dependent dehydrogenases (including NAD(+)-SDH), was replaced by an Ala in the whitefly NADPH-KR. The whitefly NADPH-KR also contained two neutral to Arg substitutions within four residues of the Asp to Ala substitution. Molecular modeling indicated that addition of the Arg residues and loss of the Asp decreased the electric potential of the adenosine ribose-binding pocket, creating an environment favorable for NADPH-binding. Because of the ability to use NADPH, the whitefly NADPH-KR synthesizes sorbitol under physiological conditions, unlike NAD(+)-SDHs, which function in sorbitol catabolism.


Asunto(s)
Isomerasas Aldosa-Cetosa/genética , Regulación de la Temperatura Corporal/fisiología , ADN Complementario/genética , Hemípteros/fisiología , Sorbitol/metabolismo , Isomerasas Aldosa-Cetosa/metabolismo , Secuencia de Aminoácidos , Animales , Arginina , Clonación Molecular , L-Iditol 2-Deshidrogenasa/genética , L-Iditol 2-Deshidrogenasa/metabolismo , Datos de Secuencia Molecular , NADP , Unión Proteica , Análisis de Secuencia , Temperatura
20.
Oncogene ; 18(1): 181-7, 1999 Jan 07.
Artículo en Inglés | MEDLINE | ID: mdl-9926933

RESUMEN

Genetic instability has been detected in many types of cancers but poorly investigated in hepatocellular carcinoma (HCC). We have studied the incidence of microsatellite instability (MI) at eight highly polymorphic microsatellite markers and the poly A tract BAT26 and tested for mutations at two sites of repetitive sequence (poly-A nucleotides 709-718 and GT repeat-nucleotides 1931-1936) in the Transforming Growth Factor beta (TGFbeta) type II receptor (RII) gene, in a group of 46 European HCCs and the surrounding nontumour tissue. This analysis showed that 63% of HCCs exhibit MI in at least one chromosome locus and 41% in two or more loci. No mutations of the TGFbetaRII gene were found in the MI positive tumours. No correlation was found with clinicopathological characteristics of the tumours such as cirrhosis, etiology, number of nodules, Edmondson's grade and vascular invasion. However, in patients who had a rearranged D16S402 microsatellite in their tumour, the recurrent disease and the number of nodules were significantly higher than in the others (P<0.005 and P<0.02, respectively). We propose to consider D16S402 rearrangement in HCC as a prognostic factor to identify patients presenting a higher risk of recurrence.


Asunto(s)
Carcinoma Hepatocelular/genética , Neoplasias Hepáticas/genética , Repeticiones de Microsatélite , Receptores de Factores de Crecimiento Transformadores beta/genética , Adolescente , Adulto , Anciano , Europa (Continente) , Femenino , Humanos , Masculino , Persona de Mediana Edad , Mutación , Proteínas Serina-Treonina Quinasas , Receptor Tipo II de Factor de Crecimiento Transformador beta , Estudios Retrospectivos
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