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1.
Heliyon ; 10(17): e36606, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39263076

RESUMO

Assessing and predicting quality of groundwater is crucial in managing groundwater availability effectively. In the current study, groundwater quality was thoroughly appraised using various indexing methods, including the drinking water quality index (DWQI), pollution index of heavy metals (HPI), pollution index (PI), metal index (MI), degree of contamination (Cd), and risk indicators, like hazard quotient (HQ) and total hazard indicator (HI). The assessments were augmented through multivariate analytical techniques, models based on recurrent neural networks (RNNs), and integration of geographic information system (GIS) technology. The analysis measured physicochemical parameters across 48 groundwater wells from El-Menoufia region, revealing distinct water types influenced by ion exchange, rock-water interactions, and silicate weathering. Notably, the groundwater showed elevated levels of certain metals, particularly manganese (Mn) and lead (Pb), exceeding the drinking water limits. The DWQI deemed the bulk of the tested samples suitable for consumption, assigning them to the "good" category, whereas a small number were considered inferior quality. The HPI, MI, and Cd indices indicated significant pollution in the central study region. The PI revealed that Pb, Mn, and Fe were significant contributors to water pollution, falling between classes IV (strongly affected) and V (seriously affected). HQ and HI analyses identified the central area of the study as particularly prone to metal contamination, signifying a high risk to children via oral and dermal routes and to adults through oral exposure alone (non-carcinogenic risk). The adults had no health risks due to dermal contact. Finally, the RNN simulation model effectively predicted the health and water quality indices in training and testing series. For instance, the RNN model excelled in predicting the DWQI, with three key parameters being crucial. The model demonstrated an excellent fit on the training set, achieving an R2 of 1.00 with a very low root mean of squared error (RMSE) of 0.01. However, on the testing set, the model's performance slightly decreased, showing an R2 of 0.96 and an RMSE of 2.73. Regarding HPI, the RNN model performed exceptionally well as the primary predictor, with R2 values of 1.00 (RMSE = 0.01) and 0.93 (RMSE = 27.35) for the training and testing sets, respectively. This study provides a unique perspective for improving the integration of various techniques to gain a more comprehensive understanding of groundwater quality and its associated health risks, with a strong focus on feature selection strategies to enhance model accuracy and interpretability.

2.
Sci Rep ; 14(1): 17805, 2024 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-39090209

RESUMO

The current research study evaluated the health and environmental risks issues associated with potentially toxic elements (PTEs) in the complex terminal aquifer located in the Algerian desert. The methods used included principal component and cluster (dendrogram) analysis to estimate source of ions and contamination. Various indices such as the Heavy Metal Pollution Index (HPI), Metal Index, hazard quotient, hazard index (HI), and cancer risk (CR) were applied to assess both environmental and human health risks. Furthermore, the Monte Carlo method was applied for probabilistic assessment of carcinogenic and non-carcinogenic risks through oral and dermal exposure routes in both adults and children. The results revealed that approximately 16% of the samples fell within the low pollution category (HPI < 100), indicating relatively lower levels of heavy metal contamination. However, the remaining 84% of the samples exhibited high pollution levels, indicating a significant presence of heavy metal pollutants in the northeastern part of the investigated area. The calculated average risk index (RI) for the collected samples was 18.99, with a range from 0.03 to 103.21. This indicates that a large portion, 82% of the samples, could cause low ecological risk (RI < 30), whereas the remaining 18% indicate a significant environmental pollution risk. The HI for oral ingestion showed that adults had HI values ranging from 0.231 to 1.54, while children exhibited higher values, ranging from 0.884 to 5.9 (Fig. 5a). For dermal exposure, HI values in adults ranged from 2.71E-07 to 8.74E-06 and in children, from 2.18E-06 to 7.03E-05. These findings highlight the potential non-carcinogenic risks associated with oral exposure to PTEs and underscore the increased vulnerability of children to metals such as Fe, Mn, Pb, and Cr. Most samples showed CR exceeding 1 × 10-4 for chromium (Cr) and lead (Pb), indicating a significant vulnerability to carcinogenic effects in both children and adults.


Assuntos
Metais Pesados , Poluentes Químicos da Água , Argélia , Medição de Risco/métodos , Humanos , Metais Pesados/análise , Metais Pesados/toxicidade , Poluentes Químicos da Água/análise , Qualidade da Água , Monitoramento Ambiental/métodos , Criança , Adulto , Método de Monte Carlo , Exposição Ambiental/efeitos adversos , Exposição Ambiental/análise , Água Subterrânea/química , Água Subterrânea/análise
3.
Sci Rep ; 14(1): 18639, 2024 Aug 11.
Artigo em Inglês | MEDLINE | ID: mdl-39128943

RESUMO

Evaluation of water quality is crucial for managing surface water effectively, ensuring its suitability for human use, and sustaining the environment. In the lower Danube River basin, various methods were employed to assess surface water quality for irrigation, drinking, human health risk purposes and the main mechanism control the surface water chemistry. These methods included water quality indicators (WQIs), complex statistical analyses, geographic information systems (GIS), Monte Carlo simulation, and geochemical modeling. Physicochemical analyses of surface water samples revealed primarily Ca-Mg-HCO3- is the dominant water types. Principal component analysis (PCA), ionic ratios and piper, chloro alkaline index, Chadha, and Gibbs diagrams identified three distinct water characteristics influenced by water-rocks interaction, evaporation, ions exchange, and human activities. The geochemical modeling showed Danube River water's strong ability to dissolve gypsum, halite, and anhydrite (SI < 0) and precipitate aragonite, dolomite, and calcite with saturation index (SI) value greater than 0 along its flow path. The irrigation water quality index (IWQI = 99.6-107.6), sodium adsorption ratio (SAR = 0.37-0.68), sodium percentage (Na% = 13.7-18.7), soluble sodium percentage (SSP = 12.5-17.5), Potential Salinity (PS = 0.73-1.6), and Residual Sodium Carbonate (RSC = - 1.27-0.58) values were used, mainly indicating acceptable quality with some limitations. Danube River water was unsuitable for drinking based on WQI value (WQI = 81-104). Oral exposure of children to specific components showed a higher hazard index (HI > 1) compared to adults, indicating a 2.1 times higher overall non-carcinogenic risk hazard index. However, Monte Carlo simulation demonstrated negligible iron, manganese, and nitrate health hazards for both age groups. These findings are valuable for water quality management decisions, contributing to long-term resource sustainability.

4.
Environ Geochem Health ; 46(10): 409, 2024 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-39215896

RESUMO

Due to water shortages and the potential impact of Ethiopia's new dam on the Nile River, Egypt is seeking new water resources. This study assesses the drinking water quality and associated risks from potentially toxic elements (PTEs) in the Quaternary aquifer (QA) in Beni-Suef, Egypt. Using a comprehensive approach, including PHREEQC geochemical modeling, ionic ratios, multivariate statistical analyses, and the integrated weight water quality index (WQI), the study evaluated the sources of ion contamination and the mixing of Nile water with QA. Various indices, such as the Heavy Metal Pollution Index (HPI), ecological Risk Index (RI), Hazard Quotient (HQ), and Hazard Index (HI), were used to assess ecological and health risks. Monte Carlo simulations provided probabilistic assessments of non-carcinogenic risks for adults and children. GIS tools were used to map risk indices, identifying the most deteriorated locations for sustainable management. The hydrochemical analysis revealed water facies including Na-Cl, Ca-Mg-HCO3, and mixed types, influenced by carbonate dissolution, ion exchange, and silicate weathering. Contamination sources, particularly in the north and south, were linked to agricultural activities, irrigation return flow, municipal waste, and evaporation. The WQI indicated that 10.14% of samples were extremely poor, 21.7% were poor, 26% were medium, and 42% were good to excellent. PTE contamination varied, with HPI values indicating good water quality in the central area in 53.6% of the collected samples (HPI < 30), but contamination in the north and south is high (HPI > 51). Ecological Risk Index values were below the threshold in 100% of samples (RI < 30), confirming water safety regarding PTEs. In comparison, for hazard index (HI) through oral/ingestion, adults exhibited HI values ranging from 0.012 to 2.16, while children showed higher values, ranging from 0.045 to 8.25. However, the hazard index for oral/ingestion exceeded safe limits in the north and south (HI oral > 1), posing non-carcinogenic risks. Monte Carlo simulations revealed significant risks from oral exposure to manganese (HQ oral > 1), particularly in El-Wasta and El-Fashn, necessitating further treatment and management.


Assuntos
Poluentes Químicos da Água , Qualidade da Água , Medição de Risco/métodos , Poluentes Químicos da Água/análise , Humanos , Egito , Monitoramento Ambiental/métodos , Método de Monte Carlo , Água Subterrânea/química , Metais Pesados/análise , Água Potável/química , Simulação por Computador
5.
Sci Rep ; 14(1): 1008, 2024 01 10.
Artigo em Inglês | MEDLINE | ID: mdl-38200086

RESUMO

This study assessed the environmental and health risks associated with heavy metals in the water resources of Egypt's northwestern desert. The current approaches included the Spearman correlation matrix, principal component analysis, and cluster analysis to identify pollution sources and quality-controlling factors. Various indices (HPI, MI, HQ, HI, and CR) were applied to evaluate environmental and human health risks. Additionally, the Monte Carlo method was employed for probabilistic carcinogenic and non-carcinogenic risk assessment via oral and dermal exposure routes in adults and children. Notably, all water resources exhibited high pollution risks with HPI and MI values exceeding permissible limits (HPI > 100 and MI > 6), respectively. Furthermore, HI oral values indicated significant non-carcinogenic risks to both adults and children, while dermal contact posed a high risk to 19.4% of samples for adults and 77.6% of samples for children (HI > 1). Most water samples exhibited CR values exceeding 1 × 10-4 for Cd, Cr, and Pb, suggesting vulnerability to carcinogenic effects in both age groups. Monte Carlo simulations reinforced these findings, indicating a significant carcinogenic impact on children and adults. Consequently, comprehensive water treatment measures are urgently needed to mitigate carcinogenic and non-carcinogenic health risks in Siwa Oasis.


Assuntos
Água Subterrânea , Metais Pesados , Adulto , Criança , Humanos , Método de Monte Carlo , Recursos Hídricos , Metais Pesados/toxicidade , Carcinogênese , Carcinógenos , Medição de Risco
6.
J Nat Prod ; 83(2): 268-276, 2020 02 28.
Artigo em Inglês | MEDLINE | ID: mdl-32077277

RESUMO

In a search for new secondary metabolites from mosses, leucobryns A-E, axially chiral 9,10-phenanthrenequinone dimers, were isolated from Paraleucobryum longifolium (1-5), together with diosmetin triglycoside. Leucobryns B (2) and C (3) were proved to be homodimeric atropodiastereomers containing both axial and central chirality elements, while leucobryns D (4) and E (5) were found to be heterodimeric atropodiastereomers containing central chirality in only one of the two monomeric units. Axial chirality of the compounds was determined by ECD measurements and sTDA ECD calculations, while the central chirality elements were assigned by TDDFT-SOR calculations. Leucobryns represent the first 9,10-phenanthrenequinone dimers, the monomers of which are linked through their C-8 atoms. Leucobryns B-E contain an uncommon C10 monoterpenoid side chain, in which isoprenoid units are joined by 3,4 linkages. Leucobryns A and B exhibited weak antiproliferative activity against several human cancer cell lines.


Assuntos
Briófitas/química , Flavonoides/química , Fenantrenos/isolamento & purificação , Flavonoides/metabolismo , Humanos , Estrutura Molecular , Fenantrenos/química
7.
Eur Respir J ; 53(6)2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-31023847

RESUMO

Our systematic analysis of anion channels and transporters in idiopathic pulmonary arterial hypertension (IPAH) showed marked upregulation of the Cl- channel TMEM16A gene. We hypothesised that TMEM16A overexpression might represent a novel vicious circle in the molecular pathways causing pulmonary arterial hypertension (PAH).We investigated healthy donor lungs (n=40) and recipient lungs with IPAH (n=38) for the expression of anion channel and transporter genes in small pulmonary arteries and pulmonary artery smooth muscle cells (PASMCs).In IPAH, TMEM16A was strongly upregulated and patch-clamp recordings confirmed an increased Cl- current in PASMCs (n=9-10). These cells were depolarised and could be repolarised by TMEM16A inhibitors or knock-down experiments (n=6-10). Inhibition/knock-down of TMEM16A reduced the proliferation of IPAH-PASMCs (n=6). Conversely, overexpression of TMEM16A in healthy donor PASMCs produced an IPAH-like phenotype. Chronic application of benzbromarone in two independent animal models significantly decreased right ventricular pressure and reversed remodelling of established pulmonary hypertension.Our findings suggest that increased TMEM16A expression and activity comprise an important pathologic mechanism underlying the vasoconstriction and remodelling of pulmonary arteries in PAH. Inhibition of TMEM16A represents a novel therapeutic approach to reverse remodelling in PAH.


Assuntos
Anoctamina-1/metabolismo , Hipertensão Pulmonar Primária Familiar/metabolismo , Miócitos de Músculo Liso/metabolismo , Proteínas de Neoplasias/metabolismo , Remodelação Vascular , Vasoconstrição , Adulto , Idoso , Animais , Anoctamina-1/genética , Estudos de Casos e Controles , Proliferação de Células , Modelos Animais de Doenças , Hipertensão Pulmonar Primária Familiar/patologia , Feminino , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Músculo Liso Vascular/fisiopatologia , Miócitos de Músculo Liso/patologia , Proteínas de Neoplasias/genética , Técnicas de Patch-Clamp , Artéria Pulmonar/fisiopatologia , Ratos , Ratos Sprague-Dawley , Regulação para Cima
8.
Molecules ; 23(7)2018 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-29937511

RESUMO

One-hundred and sixty-eight aqueous and organic extracts of 42 selected bryophyte species were screened in vitro for antiproliferative activity on a panel of human gynecological cancer cell lines containing HeLa (cervix epithelial adenocarcinoma), A2780 (ovarian carcinoma), and T47D (invasive ductal breast carcinoma) cells using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and for antibacterial activity on 11 strains using the disc-diffusion method. A total of 99 extracts derived from 41 species exerted ≥25% inhibition of proliferation of at least one of the cancer cell lines at 10 µg/mL. In the cases of Brachythecium rutabulum, Encalypta streptocarpa, Climacium dendroides, Neckera besseri, Pleurozium schreberi, and Pseudoleskeella nervosa, more than one extract was active in the antiproliferative assay, whereas the highest activity was observed in the case of Paraleucobryum longifolium. From the tested families, Brachytheciaceae and Amblystegiaceae provided the highest number of antiproliferative extracts. Only 19 samples of 15 taxa showed moderate antibacterial activity, including the most active Plagiomnium cuspidatum, being active on 8 tested strains. Methicillin-resistant Staphylococcus aureus (MRSA) and Staphylococcus aureus were the most susceptible to the assayed species. This is the first report on the bioactivities of these 14 species.


Assuntos
Anti-Infecciosos/farmacologia , Antineoplásicos Fitogênicos/farmacologia , Briófitas/química , Extratos Vegetais/farmacologia , Anti-Infecciosos/química , Antineoplásicos Fitogênicos/química , Bacillus subtilis/efeitos dos fármacos , Bacillus subtilis/crescimento & desenvolvimento , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/patologia , Feminino , Humanos , Concentração Inibidora 50 , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Testes de Sensibilidade Microbiana , Moraxella catarrhalis/efeitos dos fármacos , Moraxella catarrhalis/crescimento & desenvolvimento , Extratos Vegetais/química
9.
Stem Cells ; 33(3): 726-41, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25388207

RESUMO

Retinoids are morphogens and have been implicated in cell fate commitment of embryonic stem cells (ESCs) to neurons. Their effects are mediated by RAR and RXR nuclear receptors. However, transcriptional cofactors required for cell and gene-specific retinoid signaling are not known. Here we show that protein arginine methyl transferase (PRMT) 1 and 8 have key roles in determining retinoid regulated gene expression and cellular specification in a multistage neuronal differentiation model of murine ESCs. PRMT1 acts as a selective modulator, providing the cells with a mechanism to reduce the potency of retinoid signals on regulatory "hotspots." PRMT8 is a retinoid receptor target gene itself and acts as a cell type specific transcriptional coactivator of retinoid signaling at later stages of differentiation. Lack of either of them leads to reduced nuclear arginine methylation, dysregulated neuronal gene expression, and altered neuronal activity. Importantly, depletion of PRMT8 results in altered expression of a distinct set of genes, including markers of gliomagenesis. PRMT8 is almost entirely absent in human glioblastoma tissues. We propose that PRMT1 and PRMT8 serve as a rheostat of retinoid signaling to determine neuronal cell specification in a context-dependent manner and might also be relevant in the development of human brain malignancy.


Assuntos
Células-Tronco Embrionárias/citologia , Neurônios/citologia , Proteína-Arginina N-Metiltransferases/metabolismo , Receptores do Ácido Retinoico/metabolismo , Animais , Diferenciação Celular/fisiologia , Linhagem Celular Tumoral , Células-Tronco Embrionárias/enzimologia , Células-Tronco Embrionárias/metabolismo , Expressão Gênica , Glioblastoma , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Neurônios/enzimologia , Neurônios/metabolismo , Proteína-Arginina N-Metiltransferases/genética , Proteínas Repressoras/genética , Proteínas Repressoras/metabolismo , Transdução de Sinais
10.
J Neurosci ; 25(45): 10520-36, 2005 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-16280590

RESUMO

Presynaptic metabotropic glutamate receptors (mGluRs) show a highly selective expression and subcellular location in nerve terminals modulating neurotransmitter release. We have demonstrated that alternatively spliced variants of mGluR8, mGluR8a and mGluR8b, have an overlapping distribution in the hippocampus, and besides perforant path terminals, they are expressed in the presynaptic active zone of boutons making synapses selectively with several types of GABAergic interneurons, primarily in the stratum oriens. Boutons labeled for mGluR8 formed either type I or type II synapses, and the latter were GABAergic. Some mGluR8-positive boutons also expressed mGluR7 or vasoactive intestinal polypeptide. Interneurons strongly immunopositive for the muscarinic M2 or the mGlu1 receptors were the primary targets of mGluR8-containing terminals in the stratum oriens, but only neurochemically distinct subsets were innervated by mGluR8-enriched terminals. The majority of M2-positive neurons were mGluR8 innervated, but a minority, which expresses somatostatin, was not. Rare neurons coexpressing calretinin and M2 were consistently targeted by mGluR8-positive boutons. In vivo recording and labeling of an mGluR8-decorated and strongly M2-positive interneuron revealed a trilaminar cell with complex spike bursts during theta oscillations and strong discharge during sharp wave/ripple events. The trilaminar cell had a large projection from the CA1 area to the subiculum and a preferential innervation of interneurons in the CA1 area in addition to pyramidal cell somata and dendrites. The postsynaptic interneuron type-specific expression of the high-efficacy presynaptic mGluR8 in both putative glutamatergic and in identified GABAergic terminals predicts a role in adjusting the activity of interneurons depending on the level of network activity.


Assuntos
Hipocampo/citologia , Neurônios/metabolismo , Terminações Pré-Sinápticas/metabolismo , Receptores de Glutamato Metabotrópico/metabolismo , Ácido gama-Aminobutírico/metabolismo , Animais , Western Blotting/métodos , Calbindina 2 , Linhagem Celular , Membrana Celular/metabolismo , Colecistocinina/metabolismo , Cricetinae , Cricetulus , Diagnóstico por Imagem/métodos , Glutamato Descarboxilase/metabolismo , Imuno-Histoquímica/métodos , Hibridização In Situ/métodos , Interneurônios/metabolismo , Interneurônios/ultraestrutura , Microscopia Imunoeletrônica/métodos , Neurônios/citologia , Parvalbuminas/metabolismo , Terminações Pré-Sinápticas/ultraestrutura , Precursores de Proteínas/metabolismo , Ratos , Ratos Wistar , Receptor Muscarínico M2/metabolismo , Proteína G de Ligação ao Cálcio S100/metabolismo , Sinapses/classificação , Sinapses/metabolismo , Sinapses/ultraestrutura , Transfecção/métodos , Peptídeo Intestinal Vasoativo/metabolismo , Proteínas Vesiculares de Transporte de Aminoácidos Inibidores/metabolismo
11.
Plant Mol Biol ; 59(3): 449-67, 2005 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-16235110

RESUMO

Vernalization, the requirement of a period of low temperature to induce transition from the vegetative to reproductive state, is an evolutionarily and economically important trait in the Triticeae. The genetic basis of vernalization in cultivated barley (Hordeum vulgare subsp. vulgare) can be defined using the two-locus VRN-H1/VRN-H2 model. We analyzed the allelic characteristics of HvBM5A, the candidate gene for VRN-H1, from ten cultivated barley accessions and one wild progenitor accession (subsp. spontaneum), representing the three barley growth habits - winter, facultative, and spring. We present multiple lines of evidence, including sequence, linkage map location, and expression, that support HvBM5A being VRN-H1. While the predicted polypeptides from different growth habits are identical, spring accessions contain a deletion in the first intron of HvBM5A that may be important for regulation. While spring HvBM5A alleles are typified by the intron-localized deletion, in some cases, the promoter may also determine the allele type. The presence/absence of the tightly linked ZCCT-H gene family members on chromosome 4H perfectly correlates with growth habit and we conclude that one of the three ZCCT-H genes is VRN-H2. The VRN-H2 locus is present in winter genotypes and deleted from the facultative and spring genotypes analyzed in this study, suggesting the facultative growth habit (cold tolerant, vernalization unresponsive) is a result of deletion of the VRN-H2 locus and presence of a winter HvBM5A allele. All reported barley vernalization QTLs can be explained by the two-locus VRN-H1/VRN-H2 model based on the presence/absence of VRN-H2 and a winter vs. spring HvBM5A allele.


Assuntos
Hordeum/genética , Proteínas de Plantas/genética , Alelos , Mapeamento Cromossômico , Cromossomos de Plantas/genética , Clonagem Molecular , Temperatura Baixa , DNA Complementar/química , DNA Complementar/genética , DNA de Plantas/química , DNA de Plantas/genética , DNA de Plantas/isolamento & purificação , Flores/genética , Flores/crescimento & desenvolvimento , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Genótipo , Hordeum/crescimento & desenvolvimento , Íntrons/genética , Proteínas de Domínio MADS/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Estações do Ano , Análise de Sequência de DNA , Especificidade da Espécie
12.
Mol Genet Genomics ; 273(1): 54-65, 2005 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-15690172

RESUMO

The broad adaptability of wheat and barley is in part attributable to their flexible growth habit, in that spring forms have recurrently evolved from the ancestral winter growth habit. In diploid wheat and barley growth habit is determined by allelic variation at the VRN-1 and/or VRN-2 loci, whereas in the polyploid wheat species it is determined primarily by allelic variation at VRN-1. Dominant Vrn-A1 alleles for spring growth habit are frequently associated with mutations in the promoter region in diploid wheat and in the A genome of common wheat. However, several dominant Vrn-A1, Vrn-B1, Vrn-D1 (common wheat) and Vrn-H1 (barley) alleles show no polymorphisms in the promoter region relative to their respective recessive alleles. In this study, we sequenced the complete VRN-1 gene from these accessions and found that all of them have large deletions within the first intron, which overlap in a 4-kb region. Furthermore, a 2.8-kb segment within the 4-kb region showed high sequence conservation among the different recessive alleles. PCR markers for these deletions showed that similar deletions were present in all the accessions with known Vrn-B1 and Vrn-D1 alleles, and in 51 hexaploid spring wheat accessions previously shown to have no polymorphisms in the VRN-A1 promoter region. Twenty-four tetraploid wheat accessions had a similar deletion in VRN-A1 intron 1. We hypothesize that the 2.8-kb conserved region includes regulatory elements important for the vernalization requirement. Epistatic interactions between VRN-H2 and the VRN-H1 allele with the intron 1 deletion suggest that the deleted region may include a recognition site for the flowering repression mediated by the product of the VRN-H2 gene of barley.


Assuntos
Alelos , Proteínas de Ligação a DNA/genética , Hordeum/genética , Proteínas Repressoras/genética , Estações do Ano , Deleção de Sequência/genética , Triticum/genética , Argentina , Sequência de Bases , California , Primers do DNA , Hordeum/crescimento & desenvolvimento , Íntrons/genética , Dados de Sequência Molecular , Regiões Promotoras Genéticas/genética , Análise de Sequência de DNA , Triticum/crescimento & desenvolvimento
13.
Endocr Pathol ; 3(2): 93-98, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32357601

RESUMO

Most patients with dwarfism due to growth hormone (GH) deficiency have normal pituitary somatotroph morphology and GH response to GH-releasing hormone (GRH), consistent with decreased GRH synthesis, release, or delivery. Primary pituitary hyposecretion of GH may result from adenohypophysial tissue destruction caused by tumors, such as craniopharyngioma. We report a hitherto undescribed form of primary pituitary dwarfism associated with absence of adenohypophysial GH, prolactin (PRL), and thyrotropin (TSH). Two sisters had dwarfism, hypothyroidism, and hypoglycemia. The first child had craniofacial abnormalities and died at age 11/2 months of fluid overload. The second sibling died at age 4 years of pulmonary congestion. At autopsy, both pituitaries were small and acidophils were conspicuously absent. They contained a normal number of corticotrophs with intense adrenocorticotropin (ACTH) immunoreactivity, and gonadotrophs with normal content of α-subunit and ß-subunits of follicle-stimulating hormone (FSH) and luteinizing hormone (LH). No GH, PRL, or ß-TSH immunoreactivity was identified. The thyroid glandswere atrophic. Both children had marked pancreatic nesidioblastosis, with an increased number of insulin-containing cells. This clinicopathologic entity appears to represent a familial disorder in which there is defective development of three adenohypophysial cell types: somatotrophs, lactotrophs, and thyrotrophs. A common pituitary transcription factor, Pit-1, has been implicated in the differentiation of these three cell types. The pituitary changes in these two children resemble those described in Snell, Jackson, and Ames dwarf mice, which have recently been shown to be due to abnormalities of the Pit-1 gene. We suggest that this novel human disease is due to deficient or abnormal pituitary transcription factor Pit-1.

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