71 research outputs found

    Long-term Reconstruction and Analysis of White River Streamflow

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    A 281-year reconstruction of White River annual runoff at Clarendon, Arkansas, was developed from a regional average of nine Oklahoma, Missouri, and Arkansas tree-ring chronologies (six post oak, Quercus stellata, and three baldcypress, Taxodium distichum). Inhomogeneity of the gaged series was detected with both double mass analysis (using state average total annual Arkansas precipitation) and regression (using the regional tree-ring average). Simple regression calibrated the homogeneous runoff data with the average ring width data from 1930 to 1980. Comparing the reconstruction with independent data verified the regression model. Variance of the reconstruction increases significantly during the 20th century, a change that may be caused by climatic shifts or by anthropogenic disturbances in the watershed. Years of surplus and deficit runoff are non-randomly distributed in both gaged and reconstructed series. This non-randomness appears to be caused by a significant tendency for inter-annual persistence of runoff extremes, which may provide a basis for improvement of probabilistic forecasts of White River runoff

    A new concurrent chemotherapy with vinorelbine and mitomycin C in combination with radiotherapy in patients with locally advanced squamous cell carcinoma of the head and neck

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    Objective: The purpose of this pilot study was to evaluate the feasibility and toxicity of concurrent chemotherapy with vinorelbine and mitomycin C in combination with accelerated radiotherapy (RT) in patients with locally advanced cancer of the head and neck. Patients and Methods: Between January 2003 and March 2004, 15 patients with T4/N2-3 squamous cell carcinoma (12/15) and with N3 cervical lymph node metastases of carcinoma of unknown primary (3/15) were treated with chemotherapy and simultaneous accelerated RT. Results: 11 patients completed therapy without interruption or dose reduction. Grade 3 - 4 acute mucosal toxicity was observed in 9/15 patients, grade 4 hematologic toxicity in 6/15 patients. At a median follow-up of 7.5 months, 2 patients have died of intercurrent disease, 2 patients have experienced local relapse; 5 patients are alive with no evidence of disease at the primary tumor site. Discussion: The described regimen is highly effective, but led to remarkable side effects

    Novel SPG11 mutations in Asian kindreds and disruption of spatacsin function in the zebrafish

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    Autosomal recessive hereditary spastic paraplegia with thin corpus callosum (HSP-TCC) maps to the SPG11 locus in the majority of cases. Mutations in the KIAA1840 gene, encoding spatacsin, have been shown to underlie SPG11-linked HSP-TCC. The aim of this study was to perform candidate gene analysis in HSP-TCC subjects from Asian families and to characterize disruption of spatacsin function during zebrafish development. Homozygosity mapping and direct sequencing were used to assess the ACCPN, SPG11, and SPG21 loci in four inbred kindreds originating from the Indian subcontinent. Four novel homozygous SPG11 mutations (c.442+1G>A, c.2146C>T, c.3602_3603delAT, and c.4846C>T) were identified, predicting a loss of spatacsin function in each case. To investigate the role of spatacsin during development, we additionally ascertained the complete zebrafish spg11 ortholog by reverse transcriptase PCR and 5′ RACE. Analysis of transcript expression through whole-mount in situ hybridization demonstrated ubiquitous distribution, with highest levels detected in the brain. Morpholino antisense oligonucleotide injection was used to knock down spatacsin function in zebrafish embryos. Examination of spg11 morphant embryos revealed a range of developmental defects and CNS abnormalities, and analysis of axon pathway formation demonstrated an overall perturbation of neuronal differentiation. These data confirm loss of spatacsin as the cause of SPG11-linked HSP-TCC in Asian kindreds, expanding the mutation spectrum recognized in this disorder. This study represents the first investigation in zebrafish addressing the function of a causative gene in autosomal recessive HSP and identifies a critical role for spatacsin during early neural development in vivo

    A meta-analysis of hyperfractionated and accelerated radiotherapy and combined chemotherapy and radiotherapy regimens in unresected locally advanced squamous cell carcinoma of the head and neck

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    BACKGROUND: Former meta-analyses have shown a survival benefit for the addition of chemotherapy (CHX) to radiotherapy (RT) and to some extent also for the use of hyperfractionated radiation therapy (HFRT) and accelerated radiation therapy (AFRT) in locally advanced squamous cell carcinoma (SCC) of the head and neck. However, the publication of new studies and the fact that many older studies that were included in these former meta-analyses used obsolete radiation doses, CHX schedules or study designs prompted us to carry out a new analysis using strict inclusion criteria. METHODS: Randomised trials testing curatively intended RT (≥60 Gy in >4 weeks/>50 Gy in <4 weeks) on SCC of the oral cavity, oropharynx, hypopharynx, and larynx published as full paper or in abstract form between 1975 and 2003 were eligible. Trials comparing RT alone with concurrent or alternating chemoradiation (5-fluorouracil (5-FU), cisplatin, carboplatin, mitomycin C) were analyzed according to the employed radiation schedule and the used CHX regimen. Studies comparing conventionally fractionated radiotherapy (CFRT) with either HFRT or AFRT without CHX were separately examined. End point of the meta-analysis was overall survival. RESULTS: Thirty-two trials with a total of 10 225 patients were included into the meta-analysis. An overall survival benefit of 12.0 months was observed for the addition of simultaneous CHX to either CFRT or HFRT/AFRT (p < 0.001). Separate analyses by cytostatic drug indicate a prolongation of survival of 24.0 months, 16.8 months, 6.7 months, and 4.0 months, respectively, for the simultaneous administration of 5-FU, cisplatin-based, carboplatin-based, and mitomycin C-based CHX to RT (each p < 0.01). Whereas no significant gain in overall survival was observed for AFRT in comparison to CFRT, a substantial prolongation of median survival (14.2 months, p < 0.001) was seen for HFRT compared to CFRT (both without CHX). CONCLUSION: RT combined with simultaneous 5-FU, cisplatin, carboplatin, and mitomycin C as single drug or combinations of 5-FU with one of the other drugs results in a large survival advantage irrespective the employed radiation schedule. If radiation therapy is used as single modality, hyperfractionation leads to a significant improvement of overall survival. Accelerated radiation therapy alone, especially when given as split course radiation schedule or extremely accelerated treatments with decreased total dose, does not increase overall survival

    COL4A1 Mutations Cause Ocular Dysgenesis, Neuronal Localization Defects, and Myopathy in Mice and Walker-Warburg Syndrome in Humans

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    Muscle-eye-brain disease (MEB) and Walker Warburg Syndrome (WWS) belong to a spectrum of autosomal recessive diseases characterized by ocular dysgenesis, neuronal migration defects, and congenital muscular dystrophy. Until now, the pathophysiology of MEB/WWS has been attributed to alteration in dystroglycan post-translational modification. Here, we provide evidence that mutations in a gene coding for a major basement membrane protein, collagen IV alpha 1 (COL4A1), are a novel cause of MEB/WWS. Using a combination of histological, molecular, and biochemical approaches, we show that heterozygous Col4a1 mutant mice have ocular dysgenesis, neuronal localization defects, and myopathy characteristic of MEB/WWS. Importantly, we identified putative heterozygous mutations in COL4A1 in two MEB/WWS patients. Both mutations occur within conserved amino acids of the triple-helix-forming domain of the protein, and at least one mutation interferes with secretion of the mutant proteins, resulting instead in intracellular accumulation. Expression and posttranslational modification of dystroglycan is unaltered in Col4a1 mutant mice indicating that COL4A1 mutations represent a distinct pathogenic mechanism underlying MEB/WWS. These findings implicate a novel gene and a novel mechanism in the etiology of MEB/WWS and expand the clinical spectrum of COL4A1-associated disorders

    A PKC-Dependent Recruitment of MMP-2 Controls Semaphorin-3A Growth-Promoting Effect in Cortical Dendrites

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    There is increasing evidence for a crucial role of proteases and metalloproteinases during axon growth and guidance. In this context, we recently described a functional link between the chemoattractive Sema3C and Matrix metalloproteinase 3 (MMP3). Here, we provide data demonstrating the involvement of MMP-2 to trigger the growth-promoting effect of Sema3A in cortical dendrites. The in situ analysis of MMP-2 expression and activity is consistent with a functional growth assay demonstrating in vitro that the pharmacological inhibition of MMP-2 reduces the growth of cortical dendrites in response to Sema3A. Hence, our results suggest that the selective recruitment and activation of MMP-2 in response to Sema3A requires a PKC alpha dependent mechanism. Altogether, we provide a second set of data supporting MMPs as effectors of the growth-promoting effects of semaphorins, and we identify the potential signalling pathway involved

    Solitary median maxillary central incisor (SMMCI) syndrome

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    Solitary median maxillary central incisor syndrome (SMMCI) is a complex disorder consisting of multiple, mainly midline defects of development resulting from unknown factor(s) operating in utero about the 35th–38th day(s) from conception. It is estimated to occur in 1:50,000 live births. Aetiology is uncertain. Missense mutation in the SHH gene (I111F) at 7q36 may be associated with SMMCI. The SMMCI tooth differs from the normal central incisor, in that the crown form is symmetric; it develops and erupts precisely in the midline of the maxillary dental arch in both primary and permanent dentitions. Congenital nasal malformation (choanal atresia, midnasal stenosis or congenital pyriform aperture stenosis) is positively associated with SMMCI. The presence of an SMMCI tooth can predict associated anomalies and in particular the serious anomaly holoprosencephaly. Common congenital anomalies associated with SMMCI are: severe to mild intellectual disability, congenital heart disease, cleft lip and/or palate and less frequently, microcephaly, hypopituitarism, hypotelorism, convergent strabismus, oesophageal and duodenal atresia, cervical hemivertebrae, cervical dermoid, hypothyroidism, scoliosis, absent kidney, micropenis and ambiguous genitalia. Short stature is present in half the children. Diagnosis should be made by eight months of age, but can be made at birth and even prenatally at 18–22 weeks from the routine mid-trimester ultrasound scan. Management depends upon the individual anomalies present. Choanal stenosis requires emergency surgical treatment. Short stature may require growth hormone therapy. SMMCI tooth itself is mainly an aesthetic problem, which is ideally managed by combined orthodontic, prosthodontic and oral surgical treatment; alternatively, it can be left untreated

    Fibroblast growth factor receptor signaling in hereditary and neoplastic disease: biologic and clinical implications

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