Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47
Filtrar
2.
Acta Paediatr ; 112(9): 1892-1897, 2023 09.
Artículo en Inglés | MEDLINE | ID: mdl-37306278

RESUMEN

AIM: We aimed to determine stillbirth, preterm birth, perinatal complications, and the developmental outcome of children born preterm during the COVID-19 pandemic in Germany. METHODS: National data from the perinatal survey of preterm and term infants born in 2017-2020 between 22 March and 31 December were evaluated. Neurodevelopment of preterm infants at 2 years corrected age was tested with the Parent Report of Children's Abilities-Revised questionnaire and by clinical testing with Bayley scales, either before or during the COVID-19 pandemic. Statistical significance was calculated using a Pearson's chi-square-independence test and a linear regression model. RESULTS: In 2020, there was an increase of stillbirths of 0.02% (p = 0.01) and a decrease in preterm births by 0.38% (p < 0.001). No changes were found in a representative subgroup of infants with regard to neurodevelopmental scores (mental developmental index and psychomotor developmental index) or in parent survey data (non-verbal cognition scale and language development scale). CONCLUSION: Increasing rates of stillbirths and decreasing preterm births in Germany were observed. Existing networks might stabilise neurodevelopment of preterm infants during the COVID-19 pandemic.


Asunto(s)
COVID-19 , Nacimiento Prematuro , Lactante , Embarazo , Femenino , Niño , Recién Nacido , Humanos , Recien Nacido Prematuro , Nacimiento Prematuro/epidemiología , Desarrollo Infantil , Mortinato/epidemiología , Pandemias , COVID-19/epidemiología
3.
Sci Rep ; 11(1): 13777, 2021 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-34215818

RESUMEN

Necrotizing enterocolitis (NEC) and focal intestinal perforation (FIP) are two of the most common emergencies of the gastrointestinal tract in preterm infants with very low birth weight (VLBW, birth weight < 1500 g). Identification of risk factors among these children is crucial for earlier diagnosis and prompt intervention. In this study, we investigated a relationship between ABO blood groups and the risk for surgical NEC/FIP. We genotyped the ABO locus (rs8176746 and rs8176719) in VLBW infants enrolled in a prospective, population-based cohort study of the German Neonatal Network (GNN). Of the 10,257 VLBW infants, 441 (4.3%) had surgical NEC/FIP. In univariate analyses, the blood group AB was more prevalent in VLBW infants with surgical NEC/FIP compared to non-AB blood groups (OR 1.51, 95% CI 1.07-2.13, p = 0.017; absolute risk difference 2.01%, 95% CI 0.06-3.96%). The association between blood group AB and surgical NEC/FIP was observed in a multivariable logistic regression model (OR of 1.58, 95% CI 1.10-2.26, p = 0.013) as well. In summary, our study suggests that the risk of surgical NEC and FIP is higher in patients with blood group AB and lower in those having non-AB blood groups.


Asunto(s)
Sistema del Grupo Sanguíneo ABO/sangre , Enterocolitis Necrotizante/epidemiología , Enfermedades del Recién Nacido/epidemiología , Enfermedades del Prematuro/epidemiología , Perforación Intestinal/epidemiología , Preescolar , Enterocolitis Necrotizante/sangre , Enterocolitis Necrotizante/patología , Enterocolitis Necrotizante/cirugía , Femenino , Enfermedades Fetales/sangre , Enfermedades Fetales/patología , Enfermedades Fetales/cirugía , Edad Gestacional , Humanos , Lactante , Recién Nacido , Enfermedades del Recién Nacido/sangre , Enfermedades del Recién Nacido/patología , Enfermedades del Recién Nacido/cirugía , Recien Nacido Prematuro/sangre , Enfermedades del Prematuro/patología , Enfermedades del Prematuro/cirugía , Recién Nacido de muy Bajo Peso , Perforación Intestinal/sangre , Perforación Intestinal/patología , Perforación Intestinal/cirugía , Masculino , Factores de Riesgo
4.
Clin Infect Dis ; 69(2): 268-277, 2019 07 02.
Artículo en Inglés | MEDLINE | ID: mdl-30329017

RESUMEN

BACKGROUND: Gut dysbiosis has been suggested as a major risk factor for the development of late-onset sepsis (LOS), a main cause of mortality and morbidity in preterm infants. We aimed to assess specific signatures of the gut microbiome, including metabolic profiles, in preterm infants <34 weeks of gestation preceding LOS. METHODS: In a single-center cohort, fecal samples from preterm infants were prospectively collected during the period of highest vulnerability for LOS (days 7, 14, and 21 of life). Following 16S rRNA gene profiling, we assessed microbial community function using microbial metabolic network modeling. Data were adjusted for gestational age and use of probiotics. RESULTS: We studied stool samples from 71 preterm infants with LOS and 164 unaffected controls (no LOS/necrotizing enterocolitis). In most cases, the bacteria isolated in diagnostic blood culture corresponded to the genera in the gut microbiome. LOS cases had a decelerated development of microbial diversity. Before onset of disease, LOS cases had specific gut microbiome signatures with higher abundance of Bacilli (specifically coagulase-negative Staphylococci) and a lack of anaerobic bacteria. In silico modeling of bacterial community metabolism suggested accumulation of the fermentation products ethanol and formic acid in LOS cases before the onset of disease. CONCLUSIONS: Intestinal dysbiosis preceding LOS is characterized by an accumulation of Bacilli and their fermentation products and a paucity of anaerobic bacteria. Early microbiome and metabolic patterns may become a valuable biomarker to guide individualized prevention strategies of LOS in highly vulnerable populations.


Asunto(s)
Disbiosis/complicaciones , Microbioma Gastrointestinal , Recien Nacido Prematuro , Metaboloma , Sepsis Neonatal/patología , Anaerobiosis , Análisis por Conglomerados , ADN Bacteriano/química , ADN Bacteriano/genética , ADN Ribosómico/química , ADN Ribosómico/genética , Heces/química , Heces/microbiología , Humanos , Lactante , Recién Nacido , Masculino , Metabolómica , Metagenómica , Filogenia , Estudios Prospectivos , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
5.
Blood Cancer J ; 7(2): e523, 2017 02 03.
Artículo en Inglés | MEDLINE | ID: mdl-28157215

RESUMEN

In the search for genes that define critical steps of relapse in pediatric T-cell acute lymphoblastic leukemia (T-ALL) and can serve as prognostic markers, we performed targeted sequencing of 313 leukemia-related genes in 214 patients: 67 samples collected at the time of relapse and 147 at initial diagnosis. As relapse-specific genetic events, we identified activating mutations in NT5C2 (P=0.0001, Fisher's exact test), inactivation of TP53 (P=0.0007, Fisher's exact test) and duplication of chr17:q11.2-24.3 (P=0.0068, Fisher's exact test) in 32/67 of T-ALL relapse samples. Alterations of TP53 were frequently homozygous events, which significantly correlated with higher rates of copy number alterations in other genes compared with wild-type TP53 (P=0.0004, Mann-Whitney's test). We subsequently focused on mutations with prognostic impact and identified genes governing DNA integrity (TP53, n=8; USP7, n=4; MSH6, n=4), having key roles in the RAS signaling pathway (KRAS, NRAS, n=8), as well as IL7R (n=4) and CNOT3 (n=4) to be exclusively mutated in fatal relapses. These markers recognize 24/49 patients with a second event. In 17 of these patients with mostly refractory relapse and dire need for efficient treatment, we identified candidate targets for personalized therapy with p53 reactivating compounds, MEK inhibitors or JAK/STAT-inhibitors that may be incorporated in future treatment strategies.


Asunto(s)
Leucemia-Linfoma Linfoblástico de Células T Precursoras/genética , Niño , Preescolar , Supervivencia sin Enfermedad , Humanos , Leucemia-Linfoma Linfoblástico de Células T Precursoras/patología , Pronóstico , Factores de Riesgo
6.
Leukemia ; 30(4): 844-53, 2016 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-26658840

RESUMEN

Nodular lymphocyte predominant Hodgkin lymphoma (NLPHL)-a subtype of Hodgkin lymphoma (HL)-is characterized by a low content of tumor cells, the lymphocyte predominant (LP) cells. Transformation into diffuse large B-cell lymphoma (DLBCL) occurs in about 10% of patients. We performed whole-genome mutation analysis of the DLBCL components from two composite lymphomas consisting of clonally related NLPHL and DLBCL as a means to identify candidate tumor suppressor genes and oncogenes in NLPHL. The analysis of LP cells for selected mutations of the DLBCL revealed that most mutations are also present in the LP cells, indicating a close relationship between the two components. The analysis of 62 selected genes in NLPHL by targeted ultra-deep sequencing revealed three novel highly recurrently mutated genes (each mutated in ~50% of cases), that is, DUSP2, SGK1 and JUNB. SGK1 was expressed in the LP cells of primary NLPHL cases and in the NLPHL cell line DEV. Administration of an SGK1 inhibitor induced apoptosis in the NLPHL cell line DEV and the DLBCL cell line Farage, suggesting a pathogenetic role of SGK1 in the LP and DLBCL cells. In summary, the present study identifies SGK1, DUSP2 and JUNB as novel key players in the pathogenesis of NLPHL.


Asunto(s)
Fosfatasa 2 de Especificidad Dual/genética , Enfermedad de Hodgkin/genética , Proteínas Inmediatas-Precoces/genética , Mutación/genética , Proteínas Serina-Treonina Quinasas/genética , Factores de Transcripción/genética , Adulto , Análisis Mutacional de ADN , Secuenciación de Nucleótidos de Alto Rendimiento , Enfermedad de Hodgkin/patología , Humanos , Inmunofenotipificación , Ganglios Linfáticos/metabolismo , Ganglios Linfáticos/patología , Linfocitos/metabolismo , Linfocitos/patología , Linfoma Folicular/genética , Linfoma Folicular/patología , Linfoma de Células B Grandes Difuso/genética , Linfoma de Células B Grandes Difuso/patología , Masculino , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico
7.
J Phys Chem A ; 116(24): 6312-6, 2012 Jun 21.
Artículo en Inglés | MEDLINE | ID: mdl-22512328

RESUMEN

The significance of the (often implicit) choice of standard state in the analysis and interpretation of heterogeneous chemical processes is not well acknowledged. This paper attempts to illuminate how the specific choice of standard state influences the numerical values of the parameters obtained from such analysis. Examples are drawn from air-solution and air-surface equilibria.


Asunto(s)
Atmósfera/química , Temperatura , Cinética
8.
Case Rep Med ; 2012: 239719, 2012.
Artículo en Inglés | MEDLINE | ID: mdl-22312369

RESUMEN

Posttransplant lymphoproliferative disorder (PTLD) is a potentially fatal complication of solid organ transplantation. The majority of PTLD is of B-cell origin, and 90% are associated with the Epstein-Barr virus (EBV). Lymphomatoid granulomatosis (LG) is a rare, EBV-associated systemic angiodestructive lymphoproliferative disorder, which has rarely been described in patients with renal transplantation. We report the case of a patient with renal transplantation for SLE, who presented, 9 months after renal transplantation, an EBV-associated LG limited to the intracranial structures that recovered completely after adjustment of her immunosuppressive treatment. Nine years later, she developed a second PTLD disorder with central nervous system initial manifestation. Workup revealed an EBV-positive PTLD Burkitt lymphoma, widely disseminated in most organs. In summary, the reported patient presented two lymphoproliferative disorders (LG and Burkitt's lymphoma), both with initial neurological manifestation, at 9 years interval. With careful reduction of the immunosuppression after the first manifestation and with the use of chemotherapy combined with radiotherapy after the second manifestation, our patient showed complete disappearance of neurologic symptoms and she is clinically well with good kidney function. No recurrence has been observed by radiological imaging until now.

9.
Eur Respir J ; 32(3): 694-704, 2008 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-18385170

RESUMEN

Airway epithelial cells are exposed to environmental toxicants that result in airway injury. Naphthalene (NA) causes site-selective damage to Clara cells in mouse distal airways. N-terminally truncated recombinant human keratinocyte growth factor (DeltaN23-KGF) protects against acute lung injury. The present study investigated whether or not DeltaN23-KGF protects against NA-induced acute Clara cell damage by measuring airway responses specifically and in order to identify underlying molecular mechanisms. Mice were treated with DeltaN23-KGF or PBS 33 h prior to injection of 200 mg.kg body weight(-1) NA. Lung function was analysed by head-out body plethysmography. Distal airways isolated by microdissection were assessed for cell permeability using ethidium homodimer-1. Immunohistochemistry of Clara cell-specific protein in conjunction with a physical dissector was used to quantify Clara cell numbers. RNA was isolated from frozen airways in order to analyse gene expression using quantitative RT-PCR. DeltaN23-KGF prevented NA-induced airflow limitation and Clara cell permeability, and resulted in twice as many Clara cells compared with PBS pre-treatment. DeltaN23-KGF-pre-treated mice exhibited increased expression of proliferating cell nuclear antigen mRNA. Cytochrome P(450) isoform 2F2, which converts NA into its toxic metabolite, was reduced by approximately 50%. The present results demonstrate that pre-treatment with N-terminally truncated recombinant human keratinocyte growth factor protects against naphthalene-induced injury. This suggests that N-terminally truncated recombinant human keratinocyte growth factor exerts its beneficial effect through a decrease in the expression of cytochrome P(450) isoform 2F2.


Asunto(s)
Lesión Pulmonar Aguda/prevención & control , Bronquiolos/efectos de los fármacos , Sistema Enzimático del Citocromo P-450/efectos de los fármacos , Células Epiteliales/efectos de los fármacos , Factor 7 de Crecimiento de Fibroblastos/administración & dosificación , Proteínas Recombinantes/administración & dosificación , Lesión Pulmonar Aguda/inducido químicamente , Animales , Bronquiolos/citología , Bronquiolos/metabolismo , Sistema Enzimático del Citocromo P-450/metabolismo , Modelos Animales de Enfermedad , Células Epiteliales/metabolismo , Ratones , Naftalenos/toxicidad , Pletismografía Total
11.
Plant Biol (Stuttg) ; 9(5): 565-72, 2007 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-17853356

RESUMEN

In higher plants, the redox-active tripeptide glutathione (GSH) fulfills a plethora of functions. These include its pivotal role for maintaining the cellular redox poise and its involvement in detoxification of heavy metals and xenobiotics. Intimately linked to these functions, GSH also acts as a cellular signal, mediating control of enzyme and/or regulatory protein activities, either directly or via glutaredoxins. The redox potential of the GSH/GSSG couple is not only affected by the GSH/GSSG ratio but also by changes in GSH synthesis and/or degradation. As this couple operates as redox buffer in several cellular compartments, the regulation of GSH biosynthesis and transport (both intra- and intercellularly) are fundamental to the maintenance of cellular redox homeostasis during plant development and, even more so, when plants are exposed to biotic or abiotic stress. This review highlights novel aspects of GSH biosynthesis and transport with a focus on the regulation of the GSH1 (= gamma-glutamylcysteine synthetase) enzyme. Interestingly, GSH1 appears to be exclusively confined to the plastids, whereas the second biosynthetic enzyme, GSH2, is predominantly localized in the cytosol. GSH1 expression and enzyme activity are under multiple controls, extending from transcriptional regulation to post-translational redox control. Now that the plant GSH1 protein structure has been solved, the molecular basis of GSH1 function and redox regulation can be addressed. The review concludes with a discussion of the simultaneous changes observed for GSH synthesis, transport, and metabolism during Cd-induced phytochelatin accumulation.


Asunto(s)
Glutatión/biosíntesis , Plantas/metabolismo , Cadmio/farmacología , Citosol/metabolismo , Glutamato-Cisteína Ligasa/metabolismo , Plantas/efectos de los fármacos , Plantas/enzimología , Plastidios/efectos de los fármacos , Plastidios/metabolismo
12.
J Exp Bot ; 52(365): 2381-5, 2001 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11709588

RESUMEN

Wounding of sugar beet tap-root causes an induction of invertase activity, which contributes to post-harvest sucrose losses. In this first comprehensive monitoring of wound-induced invertase mRNAs, proteins, enzyme activities, and tissue hexose concentrations, the VI isoform responsible for wound-induced hexose accumulation in mature tap-root could be identified.


Asunto(s)
Beta vulgaris/metabolismo , Proteínas Fúngicas/metabolismo , Glicósido Hidrolasas/metabolismo , Raíces de Plantas/metabolismo , Proteínas de Schizosaccharomyces pombe , Sacarosa/metabolismo , Vacuolas/metabolismo , Adaptación Fisiológica , Beta vulgaris/enzimología , Pared Celular/metabolismo , Fructosa/metabolismo , Glucosa/metabolismo , Isoenzimas , Raíces de Plantas/enzimología , ARN de Planta , Vacuolas/enzimología , beta-Fructofuranosidasa
13.
Nat Biotechnol ; 17(7): 708-11, 1999 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-10404166

RESUMEN

We have transformed potato with Nt-inhh cDNA, encoding a putative vacuolar homolog of a tobacco cell wall invertase inhibitor, under the control of the CaMV 35S promoter. In transgenic tubers, cold-induced hexose accumulation was reduced by up to 75%, without any effect on potato tuber yield. Processing quality of tubers was greatly improved without changing starch quantity or quality, an important prerequisite for the biotechnological use of Nt-inhh for potato transformation.


Asunto(s)
Inhibidores Enzimáticos , Glicósido Hidrolasas/antagonistas & inhibidores , Hexosas/metabolismo , Nicotiana/genética , Proteínas de Plantas/genética , Plantas Tóxicas , Solanum tuberosum/genética , Secuencia de Aminoácidos , Biotecnología , Pared Celular/enzimología , Clonación Molecular , Frío , Regulación Enzimológica de la Expresión Génica , Glicósido Hidrolasas/metabolismo , Datos de Secuencia Molecular , Proteínas de Plantas/química , Proteínas de Plantas/metabolismo , Solanum tuberosum/enzimología , Nicotiana/enzimología , Transformación Genética , Vacuolas/enzimología , beta-Fructofuranosidasa
14.
Plant Mol Biol ; 39(4): 847-57, 1999 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-10350097

RESUMEN

The heavy-metal accumulator Brassica juncea L. is a high-biomass crop able to extract heavy-metal ions from the soil, a substantial part being translocated from root to shoot. Previous work has shown that Cd accumulation is accompanied by massive formation of phytochelatins (PCs). Rapid de novo synthesis of PCs in roots and leaves requires an increased synthesis of the tripeptide glutathione (GSH), which in turn depends on increased sulfur assimilation. Therefore. we have cloned cDNAs for three enzymes involved in sulfur assimilation, i.e. a putative low-affinity sulfate transporter (LAST) and two isoforms each for ATP sulfurylase (ATPS) and APS reductase (APSR). As degradation of glucosinolates might provide an additional sulfur source under stress, we also cloned a myrosinase (MYR). RNA blot analysis of transcript amounts indicated that upon Cd exposure (25 microM) the expression of ATPS and APSR in roots and leaves of 6-week-old Brassica juncea plants was strongly increased, whereas the expression of MYR was unaffected. LAST transcripts were significantly reduced in the root but remained unchanged in the leaves. Concomitant with Cd induction of ATPS and APSR mRNAs, cysteine concentrations in roots and leaves increased by 81% and 25%, respectively, whereas GSH concentrations decreased in roots and leaves by 39% and 48%, respectively. In agreement with our previous report on Cd induction of gamma-glutamylcysteine synthetase in B. juncea, the results indicate coordinate changes of expression for several sulfur assimilation enzymes in response to an increased demand for cysteine during PC synthesis.


Asunto(s)
Brassica/genética , Brassica/metabolismo , Compuestos de Cadmio/farmacología , Proteínas Portadoras/genética , Regulación de la Expresión Génica de las Plantas/efectos de los fármacos , Proteínas de Transporte de Membrana , Nitratos/farmacología , Oxidorreductasas actuantes sobre Donantes de Grupos Sulfuro , Oxidorreductasas/genética , Sulfato Adenililtransferasa/genética , Transcripción Genética/efectos de los fármacos , Secuencia de Aminoácidos , Evolución Biológica , Transporte Biológico , Compuestos de Cadmio/farmacocinética , Proteínas Portadoras/química , Proteínas Portadoras/metabolismo , Clonación Molecular , Inducción Enzimática , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Isoenzimas/genética , Cinética , Datos de Secuencia Molecular , Nitratos/farmacocinética , Oxidorreductasas/química , Oxidorreductasas/metabolismo , Proteínas Recombinantes/biosíntesis , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Sulfato Adenililtransferasa/química , Sulfato Adenililtransferasa/metabolismo , Transportadores de Sulfato , Sulfatos/metabolismo
15.
Plant Mol Biol ; 39(3): 463-75, 1999 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10092175

RESUMEN

The plant V-type H+-ATPase (V-ATPase) does not only serve basic housekeeping functions but is also involved in stress-induced NaCl sequestration during salinity stress. To address the question whether the same isoforms conferring housekeeping functions are equally involved in the response to high salinity, we have isolated cDNA clones for subunits A and c, as representing the peripheral V1 complex and the membrane-integral V0 complex, respectively, from the halotolerant sugar beet (Beta vulgaris L., diploid variety). RNA blot analysis with gene-specific probes revealed a coordinate expression of the cloned subunit A and c isoforms during plant development and in response to high salinity. Also, in rapidly dividing suspension-cultured cells with 10-fold increased transcript amounts as compared to young leaf tissue, the ratio of transcripts for both genes was similar to the ratio found for transcripts in leaves of different age. We have then isolated partial genomic clones (BVA/70 for Beta V-ATPase 70 kDa subunit; BVA/16-1 for Beta V-ATPase 16 kDa subunit), including the promoter regions. Transcription start mapping revealed long 5'-UTR leader sequences (230 and 172 bases, respectively) for both genes. Both promoters contain putative G-box motifs in similar distance to the TATA boxes. For a quantitative comparison of relative promoter strength, the BVA/70 and BVA/16-1 promoters linked to the luciferase reporter gene (LUC) were delivered to sugar beet suspension-cultured cells by particle bombardment. The BVA/16-1 promoter showed a 1.7-fold higher activity as compared with the BVA/70 promoter. Salt treatment induced an increase of BVA/70 (+70%) and BVA/16-1 (+57%) promoter activities, concomitant with increased transcript amounts. The following sequences have been deposited at the EMBL database X98767: Beta vulgaris V-ATPase subunit A, cDNA clone; X98851, B. vulgaris V-ATPase subunit c isoform 1, cDNA clone; Y11038, B. vulgaris V-ATPase subunit A, partial genomic clone; Y11037, B. vulgaris V-ATPase subunit c isoform 1, partial genomic clone.


Asunto(s)
Chenopodiaceae/genética , ADN Complementario/genética , ADN de Plantas/genética , Isoenzimas/genética , ATPasas de Translocación de Protón/genética , ATPasas de Translocación de Protón Vacuolares , Secuencia de Aminoácidos , Secuencia de Bases , Células Cultivadas , Chenopodiaceae/enzimología , Chenopodiaceae/crecimiento & desarrollo , Clonación Molecular , ADN Complementario/química , ADN de Plantas/química , Regulación de la Expresión Génica/efectos de los fármacos , Regulación del Desarrollo de la Expresión Génica , Regulación Enzimológica de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas/genética , Genes Reporteros/genética , Glucuronidasa/genética , Intrones , Luciferasas/genética , Datos de Secuencia Molecular , Regiones Promotoras Genéticas/genética , Proteínas Recombinantes de Fusión/efectos de los fármacos , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Cloruro de Sodio/farmacología , Transcripción Genética , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/genética
16.
Neurogastroenterol Motil ; 10(3): 263-70, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9659670

RESUMEN

The radio-opaque marker technique (ROMT) is a safe and noninvasive method to determine total colonic (TCTT) and segmental colonic transit times (SCTT). Previous results have shown that smoking volunteers had significantly longer TCTT than nonsmokers, but the underlying mechanism was not clear. We investigated the effect of transdermal nicotine application in two different doses in a non-blind randomized experiment involving three distinct phases. In phase 1 baseline transit times were determined with an abdominal X-ray after a 6-day period of marker ingestion and again after the following bowel movement to study the influence of a bowel movement just before the X-ray. TCTT was nearly twice as high before than after defaecation (42.6 h vs. 25.1 h, P < 0.05). The main acceleration was found in the rectosigmoid (RS) (18.6 h vs 7.1 h, P < 0.05) with no significant changes in right (RC) and left colon (LC). In phase 2 and 3 nicotine was applied in two doses of 17.5 mg day-1 and 35 mg day-1 in random order. Both doses resulted in a significant decrease of TCTT compared to the predefaecation baseline (42.6 h vs 32.2 h/28.2 h, respectively, P < 0.05). Again the main effect was located in the RS (18.6 h vs 9.9 h/7.6 h, P < 0.05). Short-term application nicotine results in a decrease of TCTT which is due to an accelerated transit in the RS.


Asunto(s)
Colon/efectos de los fármacos , Tránsito Gastrointestinal/efectos de los fármacos , Nicotina/farmacología , Administración Cutánea , Colon/fisiología , Defecación/fisiología , Humanos , Masculino , Persona de Mediana Edad , Valores de Referencia , Factores de Tiempo
17.
Plant Mol Biol ; 37(1): 87-97, 1998 May.
Artículo en Inglés | MEDLINE | ID: mdl-9620267

RESUMEN

In roots of Brassica juncea L. cadmium (Cd) exposure (25 microM) induces a massive formation of phytochelatins (PCs), which is accompanied by an only moderate decrease (-20%) of the putative PC precursor glutathione (GSH). As PC formation in roots could be the result of local GSH de novo synthesis and/or depend on GSH import from the shoot, we have analyzed the expression of the enzymes involved in GSH synthesis in the root, namely OAS(thiol)lyase (OAS-TL; catalysing the last step in Cys biosynthesis), gamma-glutamylcysteine synthetase (gamma-ECS), and glutathione synthetase (GSHS). cDNA clones were isolated from a cDNA library prepared from heavy metal exposed roots. Protein sequences from cDNA clones encoding OAS-TL, gamma-ECS, and GSHS, all exhibited putative mitochondrial targeting sequences, however, for OAS-TL also two putative cytosolic isoforms were isolated. Furthermore, we have cloned several metallothionein cDNAs of the MT2 group. Northern blot analysis with coding region probes revealed that in roots of Cd-exposed plants transcript amounts for OAS-TL and GSHS were only moderately increased, whereas gamma-ECS mRNA showed a stronger increase. Expression analysis with 3'-UTR probes indicated that among the putative mitochondrial OAS-TL, gamma-ECS and GSHS isoforms only gamma-ECS was up-regulated in response to Cd exposure. Conversely, transcripts for MT2 appeared to be slightly reduced. The results indicate that in roots Cd-induced PC synthesis correlates with a moderate increase of expression of genes involved in GSH synthesis, the change for gamma-ECS being most pronounced.


Asunto(s)
Brassica/genética , Cadmio/farmacología , Genes de Plantas , Glutamato-Cisteína Ligasa/biosíntesis , Glutatión/biosíntesis , Mitocondrias/enzimología , Secuencia de Aminoácidos , Brassica/efectos de los fármacos , Brassica/enzimología , Cloroplastos/enzimología , Cistationina gamma-Liasa/genética , Citoplasma/enzimología , ADN Complementario/genética , Inducción Enzimática , Expresión Génica , Biblioteca de Genes , Glutamato-Cisteína Ligasa/genética , Glutatión Sintasa/genética , Isoenzimas , Metaloproteínas/biosíntesis , Metalotioneína/genética , Metales Pesados/metabolismo , Datos de Secuencia Molecular , Fitoquelatinas , Proteínas de Plantas/biosíntesis , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/enzimología , Raíces de Plantas/genética , Análisis de Secuencia de ADN , Homología de Secuencia de Aminoácido , Compuestos de Sulfhidrilo/análisis
18.
Plant Physiol ; 116(2): 733-42, 1998 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-9489020

RESUMEN

Higher plants express several isoforms of vacuolar and cell wall invertases (CWI), some of which are inactivated by inhibitory proteins at certain stages of plant development. We have purified an apoplasmic inhibitor (INH) of tobacco (Nicotiana tabacum) CWI to homogeneity. Based on sequences from tryptic fragments, we have isolated a full-length INH-encoding cDNA clone (Nt-inh1) via a reverse transcriptase-polymerase chain reaction. Southern-blot analysis revealed that INH is encoded by a single- or low-copy gene. Comparison with expressed sequence tag clones from Arabidopsis thaliana and Citrus unshiu indicated the presence of Nt-inh1-related proteins in other plants. The recombinant Nt-inh1-encoded protein inhibits CWI from tobacco and Chenopodium rubrum suspension-cultured cells and vacuolar invertase from tomato (Lycopersicon esculentum) fruit, whereas yeast invertase is not affected. However, only in the homologous system is the inhibition modulated by the concentration of Suc as previously shown for INH isolated from tobacco cells. Highly specific binding of INH to CWI could be shown by affinity chromatography of a total cell wall protein fraction on immobilized recombinant Nt-inh1 protein. RNA-blot analysis of relative transcript ratios for Nt-inh1 and CWI in different parts of adult tobacco plants revealed that the expression of both proteins is not always coordinate.


Asunto(s)
Inhibidores Enzimáticos , Glicósido Hidrolasas/antagonistas & inhibidores , Nicotiana/genética , Proteínas de Plantas/genética , Plantas Tóxicas , Secuencia de Aminoácidos , Secuencia de Bases , Clonación Molecular , ADN Complementario , Escherichia coli/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Datos de Secuencia Molecular , Proteínas de Plantas/metabolismo , Unión Proteica , Homología de Secuencia de Aminoácido , beta-Fructofuranosidasa
19.
Clin Nutr ; 17(3): 125-9, 1998 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-10205329

RESUMEN

UNLABELLED: Some dietary fibres have been shown to affect the rate of absorption of dietary carbohydrate, protein and fat as well as exocrine pancreatic function. The aim of the study was to examine the effect of partially hydrolysed guar gum (BENEFIBER), on normal absorption of glucose, amino acid (arginine) and fat. In addition hepatic, pancreatic, renal and haematological side effects were evaluated. METHODS: A double blind, randomized and cross-over design was used. Each subject served as its own control. Ten healthy male volunteers participated in the study. Each subject was randomly assigned to two different dietary regimes for a period of 7 days each. The study was repeated with the other diet for another 7-day period after an interval of at least 1 week. In one study period the subjects took liquid formula diet without fibre and during the other study period they took the same diet with fibre. RESULTS: The results of the study demonstrated that BENEFIBER did apparently not interfere with the normal absorption of glucose, amino acid and fat. In keeping with these observations, insulin release and exocrine pancreatic function were not affected. Haematological, renal and hepatic toxicity were not observed in association with BENEFIBER consumption. CONCLUSION: We conclude that BENEFIBER is a safe source of soluble fibre.


Asunto(s)
Carbohidratos de la Dieta/farmacocinética , Grasas de la Dieta/metabolismo , Proteínas en la Dieta/farmacocinética , Galactanos/farmacología , Absorción Intestinal/efectos de los fármacos , Mananos/farmacología , Adulto , Arginina/metabolismo , Estudios Cruzados , Método Doble Ciego , Prueba de Tolerancia a la Glucosa , Humanos , Hidrólisis , Masculino , Páncreas/efectos de los fármacos , Páncreas/fisiología , Gomas de Plantas
20.
Pediatr Emerg Care ; 14(6): 388-92, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9881980

RESUMEN

STUDY OBJECTIVE: To document the current epidemiology of pediatric injury-related deaths in a rural state and evaluate changes over time. DESIGN: Retrospective review of injury-related deaths in children less than 15 years of age. Data were obtained from death certificates and coroner, autopsy, prehospital, and hospital records. Analysis was done of the mechanism of injury, age, sex, race, location of incident, toxicology, and safety device use. Comparisons with analogous data collected from an earlier time period were made. SETTING: The state of Montana, from October 1989 to September 1992. MEASUREMENTS: Deaths per 100,000 population, intentionality of injury, mechanism of injury, use of protective devices, and comparisons with previous data (1980-1985) collected by Baker and Waller (Childhood injury: State by state mortality facts. Baltimore: Johns Hopkins Injury Prevention Center, 1989;148-152). RESULTS: Of 121 patients reviewed, 56% were male and 44% were female. Mean age was 7.0 years (median, 8.0). Eighty-one percent of patients were Caucasian, and 16% were Native American. The leading cause of injury was motor vehicle crashes, which was followed by drowning, unintentional firearm injuries, deaths related to house fires, homicides, and suicides. Overall, 87% of injuries were unintentional and 13% were intentional, with 62% of these suicides and 38% homicides. When considered independently of intent, firearm-related injuries ranked second. Earlier data showed motor vehicle crashes ranking second, unintentional firearm injuries seventh, and homicide fourth. Comparison of death rates per 100,000 people for the two time periods showed increases in suicide deaths (3.2 vs 0.8) and unintentional firearm injury deaths (2.3 vs 0.6). CONCLUSION: The epidemiology of rural pediatric injury-related deaths has changed. Deaths related to suicide and firearms have increased. Violent deaths related to injuries caused by firearms are at a magnitude approaching all other causes. These findings have implications for public health education and injury control strategies in rural areas.


Asunto(s)
Salud Rural , Población Rural/estadística & datos numéricos , Heridas y Lesiones/mortalidad , Heridas y Lesiones/prevención & control , Accidentes de Tránsito/mortalidad , Accidentes de Tránsito/estadística & datos numéricos , Adolescente , Causas de Muerte , Niño , Femenino , Humanos , Masculino , Montana/epidemiología , Estudios Retrospectivos , Suicidio/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Heridas y Lesiones/etiología , Heridas por Arma de Fuego/mortalidad , Heridas por Arma de Fuego/prevención & control , Prevención del Suicidio
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA