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1.
Aust Vet J ; 102(3): 51-59, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38148575

RESUMEN

This was a prospective cohort study to determine how events from birth until first calving affect reproductive performance in the first lactation in pasture-based dairy herds in Victoria, Australia. Events during the preweaning (0 to 84 days), weaning to first breeding (85 to 473 days) and first breeding to first calving periods (474 to 804 days) were recorded and their association with reproductive performance during the first lactation was quantified. Reproductive performance outcomes included the number of days from first mating start date to first service (MSD-S1) and the number of days from first mating start date to first conception (MSD-CON). Predictors for reproductive performance included: passive transfer status as a calf; season of birth; age and breed of the dam; breed; the presence or absence of dystocia at the time of the heifer's birth; active feeding of colostrum versus being left on the dam for colostrum intake; presence of twinning; the presence or absence of preweaning diarrhoea; preweaning, prepubertal and postpubertal average daily gain; the presence or absence of periparturient disease at first calving; age at first calving; body condition score at first calving; sex of the first-born calf; the presence or absence of a stillborn calf at the first calving and requirement of assistance at first calving. Two Cox proportional hazards regression models were developed: the first for early life event variables associated with MSD-S1 and the second for early life events associated with MSD-CON. Heifers born in autumn and winter had 2.89 (95% CI 1.50 to 5.59, P = 0.002) times and 1.97 (95% CI 1.12 to 3.44, P = 0.018) times the daily hazard of being inseminated compared with heifers born in spring, respectively. For the MSD-S1 analyses heifers that gave birth to a live calf had 1.64 (95% CI 1.14 to 2.36, P = 0.008) times the daily hazard of being inseminated compared with heifers that had a stillborn calf. Increases in weight gain during the first breeding to first calving period by 0.1 kg/day increments increased the daily hazard of first insemination by a factor of 1.10 (95% CI 1.00 to 1.22, P = 0.043). Heifers that experienced periparturient disease had a significantly lower hazard of conception per day compared with heifers that did not experience periparturient disease at the first calving (HR 0.67, 95% CI 0.50 to 0.91, P = 0.009). Increases in weight gain during the first breeding to first calving period by 0.1 kg/day increased the daily hazard of conception by a factor of 1.10 (95% CI 1.01 to 1.21, P = 0.038). We conclude that of all the growth periods assessed in this study, events that occurred during the first breeding to first calving period (474 to 804 days) had the greatest association with reproductive performance in the first lactation. There should be a focus on increasing growth rates during this period and reducing the risk of stillbirth and periparturient disease to improve reproductive performance in the subsequent mating period after calving.


Asunto(s)
Lactancia , Reproducción , Humanos , Embarazo , Bovinos , Animales , Femenino , Estudios Prospectivos , Aumento de Peso , Victoria
2.
J Dairy Sci ; 101(4): 3488-3500, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29395140

RESUMEN

This was a prospective cohort study to determine how events from birth until first calving affect performance during the first lactation in pasture-based dairy herds in Victoria, Australia. Events during the preweaning (0-84 d), prepubertal (85-473 d), and postpubertal (474-804 d) periods were recorded in 6 herds, and their association with first-lactation 100-d and 250-d total milk, fat, and protein yields was quantified. Predictors of first-lactation performance included passive transfer status as a calf; season of birth; age of dam; the presence or absence of dystocia at the time of the heifer's birth; the presence or absence of preweaning diarrhea; preweaning, prepubertal, and postpubertal average daily weight gain; age at first calving; the presence or absence of periparturient disease at first calving; sex of the first-born calf; the presence or absence of a stillborn calf at the first calving; and requirement of assistance at the first calving. Lactation performance was quantified using cumulative 100-d and 250-d milk, fat, and protein yields estimated from herd recording. A multivariable linear regression model was developed for each outcome: cumulative 100-d milk, fat, and protein yield and cumulative 250-d milk, fat, and protein yield. Heifers that experienced dystocia at the time of their birth produced 7.6 kg [95% confidence interval (CI): 1.8-13.3] less fat and 4.8 kg (95% CI: 0.6-8.9) less protein at 100 d in milk in the first lactation compared with heifers that were delivered without dystocia. Heifers born in the summer and autumn produced 20 L (95% CI: 0.8-40) more milk and 20 kg (95% CI: 5.9-33) more protein at 250 d in milk in the first lactation compared with heifers born in the spring. For 100 g/d increases in prepubertal average daily gain, heifers produced an additional 182 L (95% CI: 149-216) of milk, 4.1 kg (95% CI: 2.8-5.5) of fat, and 4.0 kg (95% CI 3.1-5.0) of protein at 100 d in milk and an additional 345 L (95% CI 264-425) of milk, 6.1 kg (95% CI 3.2-9.0) of fat, and 7.5 kg (95% CI 5.3-9.7) of protein at 250 d in milk. Postpubertal average daily gain was positively associated with 100-d milk yield and 250-d milk yield and protein production. We conclude that of all the growth periods assessed in this study, events that occurred during the prepubertal period (85-473 d of age) had the greatest effect on first-lactation performance.


Asunto(s)
Bovinos/fisiología , Lactancia , Crianza de Animales Domésticos , Animales , Femenino , Parto , Embarazo , Estudios Prospectivos , Victoria
3.
Aust Vet J ; 95(11): 421-426, 2017 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-29076220

RESUMEN

OBJECTIVE: The aim of this study was to identify factors affecting colostrum quality in dairy cattle. METHODS: Colostrum samples were collected from lactating dairy cows (n = 990) from nine commercial dairy herds in south-west Victoria. Colostrum quality was measured using an optical Brix refractometer. Cow-level factors thought to influence colostrum quality included season of calving, dam breed and age, volume of first-milking colostrum produced and whether the dam leaked colostrum prior to calving. Multivariable logistic regression was used to quantify the association between each cow-level factor and whether or not colostrum was assessed to be of poor quality. RESULTS: Cows older than 5 years of age were less likely to have poor-quality colostrum compared with primiparous heifers (odds ratio (OR) 0.62, 95% confidence interval (CI) 0.11-0.89, P = 0.009). The odds of having poor-quality colostrum was increased in cows and primiparous heifers that leaked colostrum prior to calving (OR 2.06, 95% CI, 1.33-3.17, P = 0.001). Cows and primiparous heifers that produced ≥ 8.5 L of colostrum were 1.76 times as likely to have poor-quality colostrum as individuals that produced < 8.5 L (95% CI, 1.10-2.82, P = 0.018). Visual assessment of colostrum by the herd manager was moderately correlated with colostrum quality, with 69% of poor-quality samples being correctly classified. CONCLUSION: Although this study identified factors that increase the risk of poor-quality colostrum, we concluded that objective assessment using a Brix refractometer is a more reliable means of assessing colostrum quality.


Asunto(s)
Bovinos/fisiología , Calostro/inmunología , Inmunoglobulina G/análisis , Animales , Industria Lechera , Femenino , Lactancia , Modelos Logísticos , Embarazo , Refractometría/veterinaria , Victoria
4.
Aust Vet J ; 91(4): 150-8, 2013 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-23521100

RESUMEN

OBJECTIVES: To determine the prevalence of failure of transfer of passive immunity (FTPI) and agammaglobulinaemia in calves in south-west Victorian dairy herds and identify associated risk factors for both outcomes. DESIGN: Cross-sectional study. METHODS: Serum total protein was measured in 1018 calves from 100 south-west Victorian dairy herds. The proportions of calves with FTPI and agammaglobulinaemia were determined and logistic regression with random effects used to identify calf- and herd-level variables associated with both conditions. RESULTS: In total, 38% of calves had FTPI and 8% of calves had agammaglobulinaemia. Two-thirds of herds had more than 25% of calves with FTPI. Jersey and Jersey-cross calves were less likely than Holstein-Friesian calves to have FTPI (odds ratio (OR) 0.53 and 0.57, respectively). Dairy-beef crossbreed calves were more likely to have agammaglobulinaemia than Holstein-Friesian calves (OR 3.52) and bull calves were more likely to have agammaglobulinaemia than heifer calves (OR 2.22). Removal of calves from the calving area less than twice a day was associated with increased odds of FTPI (OR 1.61) and agammaglobulinaemia (OR 1.97) relative to more frequent removal. CONCLUSION: There is considerable potential to improve the transfer of passive immunity in dairy herds in south-west Victoria. The prevalence of both FTPI and agammaglobulinaemia is likely to be reduced by collecting calves from the calving area twice daily and hand-feeding them extra colostrum immediately after their removal from the calving area.


Asunto(s)
Agammaglobulinemia/veterinaria , Animales Recién Nacidos/inmunología , Bovinos/inmunología , Inmunización Pasiva/veterinaria , Agammaglobulinemia/epidemiología , Animales , Animales Lactantes/inmunología , Proteínas Sanguíneas/análisis , Calostro/inmunología , Estudios Transversales , Industria Lechera , Femenino , Inmunoglobulina G/sangre , Modelos Logísticos , Prevalencia , Factores de Riesgo , Victoria/epidemiología
5.
Clin Cancer Res ; 15(8): 2739-46, 2009 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-19351771

RESUMEN

PURPOSE: CD20-directed therapy with rituximab is effective in many patients with malignant lymphoma or follicular lymphoma. However, relapse frequently occurs within 1 year, and patients become increasingly refractory to retreatment. Our purpose was to produce a compact, single-chain CD20-targeting immunotherapeutic that could offer therapeutic advantages in the treatment of B-cell lymphoma. EXPERIMENTAL DESIGN: Rituximab is a chimeric antibody containing two heavy chains and two light chains. Here, we describe the properties of TRU-015, a small modular immunopharmaceutical specific for CD20, encoded by a single-chain construct containing a single-chain Fv specific for CD20 linked to human IgG1 hinge, CH2, and CH3 domains but devoid of CH1 and CL domains. RESULTS: TRU-015 mediates potent direct signaling and antibody-dependent cellular cytotoxicity but has reduced size and complement-mediated cytotoxicity activity compared with rituximab. TRU-015 is a compact dimer of 104 kDa that comigrates with albumin in size exclusion chromatography and retains a long half-life in vivo. TRU-015 induced growth arrest in multiple B lymphoma cell lines in vitro and showed effective antitumor activity against large, established subcutaneous Ramos or Daudi xenograft tumors in nude mice. TRU-015 also showed rapid, dose-dependent, and durable depletion of peripheral blood B cells following single-dose administration to nonhuman primates. CONCLUSION: These results indicate that TRU-015 may improve CD20-directed therapy by effectively depleting embedded malignant B cells and nonmalignant pathogenic B cells and do so with reduced complement activation.


Asunto(s)
Antígenos CD20/inmunología , Linfocitos B/efectos de los fármacos , Depleción Linfocítica , Linfoma de Células B/terapia , Proteínas Recombinantes de Fusión/uso terapéutico , Proteínas Recombinantes/uso terapéutico , Animales , Anticuerpos Monoclonales/uso terapéutico , Anticuerpos Monoclonales de Origen Murino , Citotoxicidad Celular Dependiente de Anticuerpos/inmunología , Linfocitos B/inmunología , Línea Celular Tumoral , Femenino , Humanos , Macaca fascicularis , Masculino , Ratones , Ratones Desnudos , Proteínas Recombinantes de Fusión/farmacología , Proteínas Recombinantes/farmacología , Rituximab , Trasplante Heterólogo/inmunología
6.
Neuropediatrics ; 38(6): 310-2, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-18461508

RESUMEN

Creatine deficiency syndromes (CDS) are newly identified genetic disorders that result in neurological impairment of cognition and communication. The purpose of our study was to screen 100 male subjects with autism spectrum disorder for mutations in the SLC6A8 gene in order to determine the frequency of this genetic disorder in this population. One hundred males ages 3-18 years diagnosed with autism spectrum disorder based on DSM-IV criteria were recruited. DNA sequence analysis was performed on all subjects for creatine transporter gene (SLC6A8) defects. One subject had a novel unclassified variant in the SLC6A8 gene exon 13: c.1890G>C. Given that autistic features are found in a number of patients with CDS, SLC6A8 deficiency as well as the treatable forms of CDS should be included in the differential diagnosis of patients with autism spectrum disorder.


Asunto(s)
Trastorno Autístico/diagnóstico , Trastorno Autístico/metabolismo , Proteínas de Transporte de Membrana/deficiencia , Proteínas de Transporte de Membrana/genética , Adolescente , Niño , Preescolar , Exones/genética , Humanos , Masculino , Mutación/genética
8.
Neuropediatrics ; 33(5): 232-8, 2002 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-12536364

RESUMEN

BACKGROUND: Two inborn errors of metabolism of creatine synthesis as well as the X-linked creatine transporter (SLC6A8) deficiency have been recognized. This report describes the features of five identified male patients and their female relatives who are carriers of the X-linked creatine transporter deficiency syndrome. METHODS: Proton MR spectroscopy was used to recognize creatine deficiency in the patients. Molecular analysis of the SLC6A8 gene was performed, confirming the diagnosis of homozygous males and heterozygous females. RESULTS: We describe four families from a metropolitan area in the U. S. with X-linked creatine transporter deficiency. All affected males present with developmental delay and severe developmental language impairment. Proton MR spectroscopy shows significantly depressed to essentially absent creatine and phosphocreatine in the male patients. Nonsense mutations and amino acid deletions were found in the SLC6A8 gene in the affected families. CONCLUSION: Creatine transporter deficiency may be a more common X-linked genetic disorder than originally presumed. The affected males exhibit mental retardation with severe expressive language impairment.


Asunto(s)
Proteínas de Transporte de Membrana/deficiencia , Errores Innatos del Metabolismo/genética , Errores Innatos del Metabolismo/patología , Adulto , Niño , Preescolar , Femenino , Humanos , Imagen por Resonancia Magnética , Espectroscopía de Resonancia Magnética , Masculino , Proteínas de Transporte de Membrana/análisis , Errores Innatos del Metabolismo/metabolismo , Linaje
9.
Am J Respir Crit Care Med ; 164(4): 661-8, 2001 Aug 15.
Artículo en Inglés | MEDLINE | ID: mdl-11520734

RESUMEN

Lymphangioleiomyomatosis (LAM) and multifocal micronodular pneumocyte hyperplasia (MMPH) produce cystic and nodular disease, respectively, in the lungs of patients with tuberous sclerosis. The objective of this study was to prospectively characterize the prevalence, clinical presentation, and genetic basis of lung disease in TSC. We performed genotyping and computerized tomographic (CT) scanning of the chest on 23 asymptomatic women with tuberous sclerosis complex (TSC). Cystic pulmonary parenchymal changes consistent with LAM were found in nine patients (39%). These patients tended to be older than cyst-negative patients (31.9 +/- 7.6 yr versus 24.8 +/- 11.6 yr, p = 0.09). There was no correlation between presence of cysts and tobacco use, age at menarche, history of pregnancy, or estrogen-containing medications. Three of the cyst-positive patients had a prior history of pneumothorax. Pulmonary function studies revealed evidence of gas trapping but normal spirometric indices in the cyst-positive group. All nine cyst-positive patients had angiomyolipomas (AML), which were larger (p < 0.05) and more frequently required intervention (p = 0.08) than cyst-negative patients (8 of 14 with AMLs, p < 0.05). Ten patients (43%) had pulmonary parenchymal nodules. Pulmonary nodules were more common in women with cysts (78% versus 21%, p < 0.05), and 52% of all patients had either cystic or nodular changes. TSC2 mutations were identified in all cyst-positive patients who were tested (n = 8), whereas both TSC1 and TSC2 mutations were found in patients with nodular disease. Correlation of the mutational and radiographic data revealed one pair of sisters who were discordant for cystic disease, two mother- daughter pairs who were discordant for nodular disease, and no clear association between cyst development and a specific mutational type. This prospective analysis demonstrates that cystic and nodular pulmonary changes consistent with LAM and MMPH are common in women with TSC.


Asunto(s)
Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/genética , Linfangiomioma/diagnóstico por imagen , Linfangiomioma/genética , Alveolos Pulmonares/citología , Alveolos Pulmonares/patología , Tomografía Computarizada por Rayos X , Esclerosis Tuberosa/complicaciones , Esclerosis Tuberosa/genética , Adolescente , Adulto , Análisis Mutacional de ADN/métodos , Femenino , Genotipo , Humanos , Hiperplasia , Enfermedades Renales/genética , Persona de Mediana Edad , Linaje , Prevalencia , Estudios Prospectivos , Pruebas de Función Respiratoria , Nódulo Pulmonar Solitario , Espirometría
10.
Ann Neurol ; 49(3): 401-4, 2001 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11261517

RESUMEN

Recent reports highlight the utility of in vivo magnetic resonance spectroscopy (MRS) techniques to recognize creatine deficiency syndromes affecting the central nervous system (CNS). Reported cases demonstrate partial reversibility of neurologic symptoms upon restoration of CNS creatine levels with the administration of oral creatine. We describe a patient with a brain creatine deficiency syndrome detected by proton MRS that differs from published reports. Metabolic screening revealed elevated creatine in the serum and urine, with normal levels of guanidino acetic acid. Unlike the case with other reported creatine deficiency syndromes, treatment with oral creatine monohydrate demonstrated no observable increase in brain creatine with proton MRS and no improvement in clinical symptoms. In this study, we report a novel brain creatine deficiency syndrome most likely representing a creatine transporter defect.


Asunto(s)
Encéfalo/metabolismo , Creatina/deficiencia , Errores Innatos del Metabolismo/sangre , Errores Innatos del Metabolismo/orina , Niño , Humanos , Espectroscopía de Resonancia Magnética , Masculino
11.
Development ; 127(24): 5523-32, 2000 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-11076771

RESUMEN

Knotted1-like homeobox (knox) genes are expressed in specific patterns within shoot meristems and play an important role in meristem maintenance. Misexpression of the knox genes, KNAT1 or KNAT2, in Arabidopsis produces a variety of phenotypes, including lobed leaves and ectopic stipules and meristems in the sinus, the region between lobes. We sought to determine the mechanisms that control knox gene expression in the shoot by examining recessive mutants that share phenotypic characteristics with 35S::KNAT1 plants. Double mutants of serrate (se) with either asymmetric1 (as1) or asymmetric2 (as2) showed lobed leaves, ectopic stipules in the sinuses and defects in the timely elongation of sepals, petals and stamens, similar to 35S::KNAT1 plants. Ectopic stipules and in rare cases, ectopic meristems, were detected in the sinuses on plants that were mutant for pickle and either as1 or as2. KNAT1 and KNAT2 were misexpressed in the leaves and flowers of single as1 and as2 mutants and in the sinuses of leaves of the different double mutants, but not in se or pickle single mutants. These results suggest that AS1 and AS2 promote leaf differentiation through repression of knox expression in leaves, and that SE and PKL globally restrict the competence to respond to genes that promote morphogenesis.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Genes Homeobox , Genes de Plantas , Proteínas de Homeodominio/genética , Proteínas de Plantas/genética , Regulación del Desarrollo de la Expresión Génica , Microscopía Electrónica de Rastreo , Mutación , Fenotipo , Brotes de la Planta/crecimiento & desarrollo , Plantas Modificadas Genéticamente
12.
Genes Dev ; 12(8): 1145-54, 1998 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-9553044

RESUMEN

The orderly production of meristems with specific fates is crucial for the proper elaboration of plant architecture. The maize inflorescence meristem branches several times to produce lateral meristems with determinate fates. The first meristem formed, the spikelet pair meristem, produces two spikelet meristems, each of which produces two floral meristems. We have identified a gene called indeterminate spikelet1 (ids1) that specifies a determinate spikelet meristem fate and thereby limits the number of floral meristems produced. In the absence of ids1 gene function, the spikelet meristem becomes indeterminate and produces additional florets. Members of the grass family vary in the number of florets within their spikelets, suggesting that ids1 may play a role in inflorescence architecture in other grass species. ids1 is a member of the APETALA2 (AP2) gene family of transcription factors that has been implicated in a wide range of plant development roles. Expression of ids1 was detected in many types of lateral organ primordia as well as spikelet meristems. Our analysis of the ids1 mutant phenotype and expression pattern indicates that ids1 specifies determinate fates by suppressing indeterminate growth within the spikelet meristem.


Asunto(s)
Genes de Plantas , Proteínas de Homeodominio/genética , Proteínas Nucleares/genética , Proteínas de Plantas/genética , Factores de Transcripción/genética , Zea mays/genética , Zea mays/fisiología , Secuencia de Aminoácidos , Secuencia de Bases , ADN de Plantas , Expresión Génica , Genes Recesivos , Meristema , Microscopía Electrónica de Rastreo , Datos de Secuencia Molecular , Mutación , Homología de Secuencia de Aminoácido , Factores de Transcripción/química
13.
Am J Med Genet ; 64(4): 531-5, 1996 Sep 06.
Artículo en Inglés | MEDLINE | ID: mdl-8870917

RESUMEN

Hunter syndrome (mucopolysaccharidosis type II, or MPS II) results from a deficiency of iduronate-2-sulfatase (IDS) activity due to a primary genetic defect in the X-chromosomal iduronate-2-sulfatase gene. We have studied a 10-year-old male, diagnosed with Hunter syndrome at age 2 years, who underwent bone marrow transplantation (BMT) at age 5 years. To evaluate the metabolic effect of BMT, biochemical and enzymatic studies were performed. Urinary glycosaminoglycans (GAGs) were quantitated, and iduronate-2-sulfatase activity was measured in serum, leukocytes, and liver homogenates. Decreased urinary glycosaminoglycan excretion and increased iduronate-2-sulfatase activity in serum and leukocytes were observed. Furthermore, molecular analysis was performed using reverse transcriptional polymerase chain reaction (RT-PCR) sequencing and restriction enzyme assay. The patient was found to have a novel nonsense mutation, L279X (TTA to TGA) in exon 6 of the IDS gene, inherited from his mother. A comparison of the DNA contents of cultured skin fibroblasts prior to BMT with leukocyte DNA after BMT showed coexisting host mutant and donor normal alleles in post-BMT leukocyte DNA. We postulate that the L279X mutation is a severe disease-causing mutation for Hunter syndrome.


Asunto(s)
Trasplante de Médula Ósea , Mucopolisacaridosis II/genética , Niño , Humanos , Masculino , Linaje , Reacción en Cadena de la Polimerasa
14.
Plant Cell ; 8(8): 1277-89, 1996 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-8776897

RESUMEN

Plant development depends on the activity of apical meristems, which are groups of indeterminate cells whose derivatives elaborate the organs of the mature plant. Studies of knotted1 (kn1) and related gene family members have determined potential roles for homeobox genes in the function of shoot meristems. The Arabidopsis kn1-like gene, KNAT1, is expressed in the shoot apical meristem and not in determinate organs. Here, we show that ectopic expression of KNAT1 in Arabidopsis transforms simple leaves into lobed leaves. The lobes initiate in the position of serrations yet have features of leaves, such as stipules, which form in the sinus, the region at the base of two lobes. Ectopic meristems also arise in the sinus region close to veins. Identity of the meristem, that is, vegetative or floral, depends on whether the meristem develops on a rosette or cauline leaf, respectively. Using in situ hybridization, we analyzed the expression of KNAT1 and another kn1-like homeobox gene, SHOOT MERISTEMLESS, in cauliflower mosaic virus 35S::KNAT1 transformants. KNAT1 expression is strong in vasculature, possibly explaining the proximity of the ectopic meristems to veins. After leaf cells have formed a layered meristem, SHOOT MERISTEMLESS expression begins in only a subset of these cells, demonstrating that KNAT1 is sufficient to induce meristems in the leaf. The shootlike features of the lobed leaves are consistent with the normal domain of KNAT1's expression and further suggest that kn1-related genes may have played a role in the evolution of leaf diversity.


Asunto(s)
Proteínas de Arabidopsis , Arabidopsis/crecimiento & desarrollo , Arabidopsis/genética , Genes de Plantas , Proteínas de Homeodominio/genética , Proteínas de Plantas/genética , Arabidopsis/anatomía & histología , Evolución Biológica , Caulimovirus/genética , Expresión Génica , Microscopía Electrónica de Rastreo , Especificidad de Órganos , Plantas Modificadas Genéticamente , Transformación Genética
15.
Philos Trans R Soc Lond B Biol Sci ; 350(1331): 45-51, 1995 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-8577849

RESUMEN

The maize homebox gene knotted1 (kn1) is expressed in vegetative and floral meristems and is down-regulated at the site of primordia formation. kn1-related genes from maize and other species also show meristem-specific expression and offer additional tools for studying the activities of shoot meristems. Members of this gene family are expressed early in embryogenesis, providing molecular markers for meristem initiation. Ectopic expression of either kn1 or a related Arabidopsis gene, KNAT1, causes dramatic alterations in Arabidopsis and tobacco leaf morphology. Most significantly, meristems form on the leaf, producing small shoots. We discuss whether the phenotypes can be interpreted as changes in positional information or timing of determination.


Asunto(s)
Genes Homeobox/fisiología , Genes de Plantas/fisiología , Meristema/genética , Regulación de la Expresión Génica de las Plantas/genética , Fenotipo
16.
J Pediatr Surg ; 30(7): 959-65; discussion 966, 1995 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-7472953

RESUMEN

Increased oxidation of fat is an important host response to sepsis, and carnitine is essential for long-chain fatty acid oxidation. Because neonates have low levels of carnitine, their ability to respond to a septic insult may be impaired. The purpose of this study was to compare fatty acid and carnitine metabolism in septic weanling (60 to 85 g) and septic adult (285 to 310 g) rats. Sepsis was induced in weanling and adult male Sprague-Dawley rats by cecal ligation and puncture (CLP). The rats were killed 16 hours after CLP or sham operation, and serum glucose, lactate, beta-hydroxybutyrate, fatty acid, carnitine, liver fatty acid, and tissue carnitine levels were measured. The data suggest that during sepsis weanling rats may be more dependent on fatty acid oxidation than adult rats are, as evidenced by their elevated serum fatty acid and acylcarnitine levels, and relative hypoglycemia and hyperketonemia. In addition, although total serum carnitine levels were increased in both adult and weanling septic rats, tissue carnitine levels of weanling rats became significantly depleted during sepsis, unlike in adult rats. This study supports further investigation regarding the role of exogenous carnitine in newborn sepsis.


Asunto(s)
Envejecimiento/metabolismo , Infecciones Bacterianas/metabolismo , Carnitina/metabolismo , Ácidos Grasos/metabolismo , Ácido 3-Hidroxibutírico , Animales , Glucemia/análisis , Carnitina/sangre , Ácidos Grasos/sangre , Ácidos Grasos no Esterificados/sangre , Ácidos Grasos no Esterificados/metabolismo , Hidroxibutiratos/sangre , Hipoglucemia/sangre , Cetonas/sangre , Riñón/metabolismo , Lactatos/sangre , Hígado/metabolismo , Masculino , Músculo Esquelético/metabolismo , Miocardio/metabolismo , Oxidación-Reducción , Ratas , Ratas Sprague-Dawley , Distribución Tisular , Destete
17.
Plant Cell ; 5(4): 371-378, 1993 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-12271068

RESUMEN

We report here the use of the maize transposable element Activator (Ac) to isolate a dicot gene. Ac was introduced into petunia, where it transposed into Ph6, one of several genes that modify anthocyanin pigmentation in flowers by affecting the pH of the corolla. Like other Ac-mutable alleles, the new mutation is unstable and reverts to a functional form in somatic and germinal tissues. The mutant gene was cloned using Ac as a probe, demonstrating the feasibility of heterologous transposon tagging in higher plants. Confirmation that the cloned DNA fragment corresponded to the mutated gene was obtained from an analysis of revertants. In every case examined, reversion to the wild-type phenotype was correlated with restoration of a wild-type-sized DNA fragment. New transposed Acs were detected in many of the revertants. As in maize, the frequency of somatic and germinal excision of Ac from the mutable allele appears to be dependent on genetic background.

19.
J Med Genet ; 21(5): 359-63, 1984 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-6438322

RESUMEN

Mucopolysaccharidosis type I (MPS I) is a lysosomal storage disorder characterised by the deficient activity of iduronidase and by the presence of MPS vacuoles in many tissues of affected patients. We studied whether these characteristics could be used for the antenatal diagnosis of the disease. We obtained amniotic fluid cells from two pregnancies at risk for MPS I, one pregnancy at risk for GSD II (another lysosomal disease), and eight normal control pregnancies. Measurements of iduronidase activity in cultured amniotic fluid cells indicated the presence of a MPS I fetus in one high risk pregnancy and an unaffected fetus in the other. This diagnosis was confirmed at delivery. On electron microscopy the uncultured amniotic fluid cells exhibited MPS-like vacuoles in the pregnancy with a GSD II fetus, in three of eight normal pregnancies, and in the pregnancy at risk for MPS I that had a normal fetus. No such vacuoles were seen in the pregnancy with the MPS I fetus. These false positive and false negative findings indicate that antenatal diagnosis of MPS I cannot be based on the electron microscopic presence or absence of MPS I vacuoles in uncultured amniotic fluid cells.


Asunto(s)
Mucopolisacaridosis II/diagnóstico , Mucopolisacaridosis I/diagnóstico , Líquido Amniótico/citología , Citoplasma/ultraestructura , Femenino , Humanos , Iduronidasa/análisis , Iduronidasa/deficiencia , Microscopía Electrónica , Embarazo , Diagnóstico Prenatal
20.
N Engl J Med ; 310(16): 1018-22, 1984 Apr 19.
Artículo en Inglés | MEDLINE | ID: mdl-6369132

RESUMEN

Glycogen-storage disease Type IIa is a fatal, genetically determined disease of infancy or early childhood that is characterized by deficient activity of acid alpha-glucosidase and by the presence of intracellular vacuoles full of glycogen, which are found in most tissues, including skin and liver. On electron microscopy these specific vacuoles are tightly packed accumulations of glycogen particles surrounded by a single membrane. We did electron-microscopical examinations on uncultured amniotic-fluid cells from 26 women whose fetuses were at risk for glycogen-storage disease Type IIa and from 8 normal control pregnant women. We found specific vacuoles in cells from 6 of the 26 high-risk patients. At delivery, glycogen-storage disease Type IIa was present in the infants of these 6 women and absent in those of the other 20 according to results of clinical, biochemical, and electron-microscopical studies of gestational products. After amniocentesis at 15 to 18 weeks of gestation, the prenatal diagnosis made by electron microscopy of uncultured amniotic-fluid cells was available in three to six days, whereas it took from three to six weeks to make the diagnosis by enzymatic analysis of the cultured amniotic-fluid cells. We conclude that the electron-microscopical prenatal diagnosis of glycogen-storage disease Type IIa is rapid, safe, and reliable. It should facilitate earlier diagnosis and thereby help to preserve parental options.


Asunto(s)
Amniocentesis , Líquido Amniótico/citología , Enfermedad del Almacenamiento de Glucógeno/diagnóstico , Femenino , Glucógeno/análisis , Humanos , Microscopía Electrónica , Embarazo , Vacuolas/ultraestructura , alfa-Glucosidasas/análisis
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