RESUMEN
Most of the elderly population is afflicted by periodontal diseases, creating a health burden worldwide. Cellular senescence is one of the hallmarks of aging and associated with several chronic comorbidities. Senescent cells produce a variety of deleterious secretions, collectively termed the senescence-associated secretory phenotype (SASP). This disrupts neighboring cells, leading to further senescence propagation and inciting chronic inflammation, known as "inflammaging." Detrimental repercussions within the tissue microenvironment can trigger senescence at a younger age, accelerate biological aging, and drive the initiation or progression of diseases. Here, we investigated the biological signatures of senescence in healthy and diseased gingival tissues by assessing the levels of key senescence markers (p16, lipofuscin, and ß-galactosidase) and inflammatory mediators (interleukin [IL]-1ß, IL-6, IL-8, matrix metalloproteinase [MMP]-1, MMP-3, and tumor necrosis factor-α). Our results showed significantly increased senescence features including p16, lipofuscin, and ß-galactosidase in both epithelial and connective tissues of periodontitis patients compared with healthy sites in all age groups, indicating that an inflammatory microenvironment can trigger senescence-like alterations in younger diseased gingival tissues as well. Subsequent analyses using double staining with specific cell markers noted the enrichment of ß-galactosidase in fibroblasts and macrophages. Concurrently, inflammatory mediators consistent with SASP were increased in the gingival biopsies obtained from periodontitis lesions. Together, our findings provide the first clinical report revealing susceptibility to elevated senescence and inflammatory milieu consistent with senescence secretome in gingival tissues, thus introducing senescence as one of the drivers of pathological events in the oral mucosa and a novel strategy for targeted interventions.
Asunto(s)
Senescencia Celular , Encía , Lipofuscina , Periodontitis , beta-Galactosidasa , Humanos , Senescencia Celular/fisiología , beta-Galactosidasa/metabolismo , beta-Galactosidasa/análisis , Persona de Mediana Edad , Adulto , Periodontitis/metabolismo , Encía/metabolismo , Encía/patología , Lipofuscina/metabolismo , Lipofuscina/análisis , Masculino , Anciano , Femenino , Metaloproteinasa 3 de la Matriz/análisis , Fenotipo Secretor Asociado a la Senescencia , Inhibidor p16 de la Quinasa Dependiente de Ciclina/metabolismo , Inhibidor p16 de la Quinasa Dependiente de Ciclina/análisis , Metaloproteinasa 1 de la Matriz/análisis , Metaloproteinasa 1 de la Matriz/metabolismo , Interleucina-1beta/análisis , Factor de Necrosis Tumoral alfa/análisis , Factor de Necrosis Tumoral alfa/metabolismo , Interleucina-6/análisis , Mediadores de Inflamación/metabolismo , Biomarcadores/análisis , Interleucina-8/análisis , Interleucina-8/metabolismo , Adulto JovenRESUMEN
PURPOSE: Chemoradiotherapy is regarded as a standard scheme for inoperable and unresectable esophageal cancers. Our aims were to explore the prognostic factors relevant to esophageal squamous cell carcinoma (ESCC) following intensity-modulated radiation therapy (IMRT) plus chemotherapy. MATERIAL AND METHODS: Totally 495 ESCC patients undergoing IMRT combined with chemotherapy in our hospital between 2011 and 2020 were retrospectively analyzed. Potential clinical prognosis-related factors were assessed by uni- and multivariate analyses. RESULTS: The median overall survival (OS) and progression-free survival (PFS) of the ESCC patients were 2.25 and 1.24years, respectively. Uni- and multivariate analyses demonstrated the relevant independent prognostic factors of OS and PFS were gender, T stage, N stage, clinical stage, and tumor location (P<0.05), but not chemotherapy or radiotherapy dose. We further compared the 5-year OS rates among different T stages, N stages, clinical stages, genders, and tumor locations. The survival rate at the higher clinical stage was significantly lower (P<0.001). The 5-year OS in the upper thorax of the tumor was 46.0% and exceeded other tumor locations (P<0.05). The 5-year OS was 56.1% among females and 33.3% among males (P=0.001). CONCLUSIONS: For ESCC patients receiving IMRT combined with chemotherapy, their long-term curative effects are influenced by T stages, N stages, clinical stages, genders, and tumor locations. ESCC patients who are females, or have upper thoracic tumor, or are at early clinical stage own better prognosis.
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Neoplasias Esofágicas , Carcinoma de Células Escamosas de Esófago , Radioterapia de Intensidad Modulada , Humanos , Femenino , Masculino , Carcinoma de Células Escamosas de Esófago/terapia , Neoplasias Esofágicas/patología , Radioterapia de Intensidad Modulada/efectos adversos , Estudios Retrospectivos , Pronóstico , Quimioradioterapia/efectos adversosRESUMEN
Aberrant activation of the JAK3-STAT signaling pathway is a characteristic feature of many hematological malignancies. In particular, hyperactivity of this cascade has been observed in natural killer/T-cell lymphoma (NKTL) cases. Although the first-in-class JAK3 inhibitor tofacitinib blocks JAK3 activity in NKTL both in vitro and in vivo, its clinical utilization in cancer therapy has been limited by the pan-JAK inhibition activity. To improve the therapeutic efficacy of JAK3 inhibition in NKTL, we have developed a highly selective and durable JAK3 inhibitor PRN371 that potently inhibits JAK3 activity over the other JAK family members JAK1, JAK2, and TYK2. PRN371 effectively suppresses NKTL cell proliferation and induces apoptosis through abrogation of the JAK3-STAT signaling. Moreover, the activity of PRN371 has a more durable inhibition on JAK3 compared to tofacitinib in vitro, leading to significant tumor growth inhibition in a NKTL xenograft model harboring JAK3 activating mutation. These findings provide a novel therapeutic approach for the treatment of NKTL.
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Janus Quinasa 3/antagonistas & inhibidores , Linfoma de Células T/tratamiento farmacológico , Piridonas/uso terapéutico , Pirimidinas/uso terapéutico , Factores de Transcripción STAT/metabolismo , Transducción de Señal , Animales , Apoptosis/efectos de los fármacos , Línea Celular Tumoral , Proliferación Celular/efectos de los fármacos , Xenoinjertos/efectos de los fármacos , Humanos , Janus Quinasa 3/metabolismo , Ratones , Células T Asesinas Naturales/patología , Piridonas/farmacología , Pirimidinas/farmacologíaAsunto(s)
Arthrodermataceae/aislamiento & purificación , Dermatomicosis/microbiología , Enfermedades de los Genitales Masculinos/microbiología , Escroto/microbiología , Adolescente , Adulto , Arthrodermataceae/patogenicidad , Arthrodermataceae/ultraestructura , Infecciones Asintomáticas , Dermatomicosis/diagnóstico , Dermatomicosis/patología , Enfermedades de los Genitales Masculinos/diagnóstico , Enfermedades de los Genitales Masculinos/patología , Humanos , Masculino , Microscopía Electrónica de Rastreo , Escroto/patología , Adulto JovenRESUMEN
Streptococcus suis serotype 2 (SS2) is considered as a major pathogen that causes sepsis and meningitis in piglets and humans, but knowledge of its antigenic proteins remains limited so far. The surface-related proteins of pathogens often play significant roles in bacterium-host interactions and infection. Here, we obtained the elongation factor Tu (EF-Tu) gene of Streptococcus suis and constructed the recombinant expression plasmid successfully. The target recombinant plasmid was then expressed in Escherichia coli and the immuno-protection of the recombinant protein was subsequently evaluated as well. The EF-Tu gene of Streptococcus suis is 1197 bp in length, encodes 398 amino acids. The target recombinant EF-Tu (rEF-Tu) protein can recognize the antiserum of Streptococcus suis and can provoke obvious humoral immune responses in rabbits and conferred protection to rabbits against Streptococcus suis ear-vein challenge, implying that the EF-Tu may be used as an attractive candidate antigen for a component of subunit vaccine.
Asunto(s)
Proteínas Bacterianas/metabolismo , Regulación Bacteriana de la Expresión Génica/fisiología , Factor Tu de Elongación Peptídica/metabolismo , Streptococcus suis/metabolismo , Animales , Anticuerpos Antibacterianos/sangre , Proteínas Bacterianas/genética , Vacunas Bacterianas/inmunología , Clonación Molecular , Factor Tu de Elongación Peptídica/genética , Conejos , Serogrupo , Infecciones Estreptocócicas/microbiología , Infecciones Estreptocócicas/prevención & control , Streptococcus suis/genética , Streptococcus suis/inmunologíaRESUMEN
Autophagy has been linked to the regulation of both the prevention and progression of cancer. IFN-γ has been shown to induce autophagy in multiple cell lines in vitro. However, whether IFN-γ can induce autophagy and whether autophagy promotes malignant transformation in healthy lactating bovine mammary epithelial cells (BMECs) remain unclear. Here, we provide the first evidence of the correlation between IFN-γ treatment, autophagy and malignant transformation and of the mechanism underlying IFN-γ-induced autophagy and subsequent malignant transformation in primary BMECs. IFN-γ levels were significantly increased in cattle that received normal long-term dietary corn straw (CS) roughage supplementation. In addition, an increase in autophagy was clearly observed in the BMECs from the mammary tissue of cows expressing high levels of IFN-γ. In vitro, autophagy was clearly induced in primary BMECs by IFN-γ within 24 h. This induced autophagy could subsequently promote dramatic primary BMEC transformation. Furthermore, we found that IFN-γ promoted arginine depletion, activated the general control nonderepressible-2 kinase (GCN2) signalling pathway and resulted in an increase in autophagic flux and the amount of autophagy in BMECs. Overall, our findings are the first to demonstrate that arginine depletion and kinase GCN2 expression mediate IFN-γ-induced autophagy that may promote malignant progression and that immunometabolism, autophagy and cancer are strongly correlated. These results suggest new directions and paths for preventing and treating breast cancer in relation to diet.
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Autofagia , Transformación Celular Neoplásica/metabolismo , Dieta , Células Epiteliales/metabolismo , Interferón gamma/metabolismo , Proteínas de Neoplasias/metabolismo , Proteínas Serina-Treonina Quinasas/metabolismo , Animales , Bovinos , Transformación Celular Neoplásica/patología , Células Cultivadas , Células Epiteliales/patologíaRESUMEN
Plasma membrane proteolipid 3 (PMP3) is a class of small hydrophobic proteins found in many organisms including higher plants. Some plant PMP3 genes have been shown to respond to abiotic stresses and to participate in the processes of plant stress tolerance. In this study, we isolated the cassava (Manihot esculenta Crantz) MePMP3-2 gene and functionally characterized its role in tolerance to abiotic stress by expressing it in rice (Oryza sativa L.). MePMP3-2 encodes a 77-amino acid protein belonging to a subgroup of plant PMP3s that have long hydrophylic C-terminal tails of unknown function. In silico analysis and co-localization studies indicated that MePMP3-2 is a plasma membrane protein with two transmembrane domains, similar to other PMP3s. In cassava leaves, MePMP3-2 expression was up-regulated by salt and drought stresses. Heterologous constitutive expression of MePMP3-2 in rice did not alter plant growth and development but increased tolerance to salt and drought stresses. In addition, under stress conditions MePMP3-2 transgenic plants accumulated less malondialdehyde, had increased levels of proline, and exhibited greater up-regulation of the stress-related genes OsProT and OsP5CS, but led to only minor changes in OsDREB2A and OsLEA3 expression. These findings indicate that MePMP3-2 may play an important role in salt and drought stress tolerance in transgenic rice.
Asunto(s)
Adaptación Fisiológica , Regulación de la Expresión Génica de las Plantas , Manihot/fisiología , Proteínas de la Membrana/fisiología , Oryza/fisiología , Proteínas de Plantas/fisiología , Plantas Modificadas Genéticamente , Secuencia de Aminoácidos , Simulación por Computador , Sequías , Manihot/genética , Manihot/metabolismo , Proteínas de la Membrana/química , Proteínas de la Membrana/genética , Proteínas de la Membrana/metabolismo , Datos de Secuencia Molecular , Oryza/genética , Oryza/metabolismo , Filogenia , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/metabolismo , Proteolípidos/fisiología , Tolerancia a la Sal , Alineación de Secuencia , Regulación hacia ArribaRESUMEN
We describe a case of primary cutaneous mucormycosis in a 44-year-old man with an 18-month history of infiltrative erythematous plaques and haemorrhagic crusting on the dorsum of his left hand. The isolate was identified as Mucor irregularis (formerly Rhizomucor variabilis) based on the fungus morphology and DNA sequencing results. Improvement was observed after a 6-month treatment course of itraconazole. No recrudescence was seen during a follow-up of 23 months after treatment.
Asunto(s)
Dermatomicosis/microbiología , Dermatosis de la Mano/microbiología , Mucormicosis/microbiología , Rhizomucor/aislamiento & purificación , Adulto , Antifúngicos/uso terapéutico , Dermatomicosis/tratamiento farmacológico , Dermatosis de la Mano/tratamiento farmacológico , Humanos , Itraconazol/uso terapéutico , Masculino , Mucormicosis/tratamiento farmacológico , Resultado del TratamientoRESUMEN
Plant responses to elevated CO2 and high temperature are critically regulated through a complex network of phytohormones and redox homeostasis. However, the involvement of abscisic acid (ABA) in plant adaptation to heat stress under elevated CO2 conditions has not been thoroughly studied. This study investigated the interactive effects of elevated CO2 (800 µmol·mol(-1) ) and heat stress (42 °C for 24 h) on the endogenous level of ABA and the cellular redox state of two genotypes of tomato with different ABA biosynthesis capacities. Heat stress significantly decreased maximum photochemical efficiency of PSII (Fv/Fm) and leaf water potential, but also increased levels of malondialdehyde (MDA) and electrolyte leakage (EL) in both genotypes. Heat-induced damage was more severe in the ABA-deficient mutant notabilis (not) than in its parental cultivar Ailsa Craig (Ailsa), suggesting that a certain level of endogenous ABA is required to minimise the heat-induced oxidative damage to the photosynthetic apparatus. Irrespective of genotype, the enrichment of CO2 remarkably stimulated Fv/Fm, MDA and EL in heat-stressed plants towards enhanced tolerance. In addition, elevated CO2 significantly strengthened the antioxidant capacity of heat-stressed tomato seedlings towards a reduced cellular redox state for a prolonged period, thereby mitigating oxidative stress. However, elevated CO2 and heat stress did not alter the endogenous level of ABA or the expression of its biosynthetic gene NCED2 in either genotype, indicating that ABA is not involved in elevated CO2 -induced heat stress alleviation. The results of this study suggest that elevated CO2 alleviated heat stress through efficient regulation of the cellular redox poise in an ABA-independent manner in tomato plants.
Asunto(s)
Adaptación Fisiológica , Dióxido de Carbono/metabolismo , Solanum lycopersicum/fisiología , Ácido Abscísico/metabolismo , Antioxidantes/metabolismo , Genotipo , Homeostasis , Calor , Solanum lycopersicum/genética , Malondialdehído/metabolismo , Oxidación-Reducción , Estrés Oxidativo , Fotosíntesis , Reguladores del Crecimiento de las Plantas/metabolismo , Hojas de la Planta/genética , Hojas de la Planta/fisiología , Plantones/genética , Plantones/fisiología , Estrés Fisiológico , Agua/metabolismoRESUMEN
The genomic expression profile of the super-hybrid rice Liangyoupeijiu female parent Pei'ai 64S in different tissues at different developmental stages under low temperature, drought, and high temperature stresses were detected using an Affymetrix GeneChip Rice Genome Array to screen upregulated and downregulated genes. In this study, we screened the drought-resistant gene OsRCI2-5, after which a constitutive OsRCI2-5 construct was created and transferred into Nipponbare. After polyethylene glycol-6000 and drought treatment, we found that the OsRCI2-5 gene improved the drought resistance of Nipponbare. Gene expression profiling showed that the OsRCI2-5 gene was expressed in the rice leaves, stems, and flower organs. Subcellular localization revealed that the gene was located in the membranes, and hence, we can deduce that a membrane signal peptide was responsible for signal transduction.
Asunto(s)
Regulación de la Expresión Génica de las Plantas , Oryza/genética , Transducción de Señal/genética , Sequías , Genoma de Planta/genética , Hojas de la Planta/metabolismo , Estrés Fisiológico/genética , TemperaturaRESUMEN
A high-performance liquid chromatography method was developed for the determination of related substances in an intravenous emulsion loaded with a paclitaxel-cholesterol complex. The separation was achieved using Agilent Eclipse XDB-C18 column (150×4.6 mm, 3.5 µm), which was kept at 40°. The gradient mobile phase consisted of acetonitrile and water with a flow rate of 1.2 ml/min. The ultraviolet detection wavelength was set at 227 nm. The preparation of the sample solution began with the addition of anhydrous sodium sulphate to break the emulsion. Then, methanol and ethyl ether were added to pick up the drug and remove the accessories of the emulsion by extraction and centrifugation. Finally, paclitaxel was enriched by a nitrogen blow method and resolved with a mixture of methanol:glacial acetic acid (200:1). The method was proven to be selective, sensitive, robust, linear, repeatable, accurate and suitable for the determination of paclitaxel-related substances in the emulsion formulations, and the major degradation products in the potential pharmaceutical product were 7-epipaclitaxel and 10-deacetylpaclitaxel.
RESUMEN
BACKGROUND AND OBJECTIVE: Periodontitis is a multifactorial disease influenced partly by genetics. Activation of pattern recognition receptors (PRRs) can lead to the up-regulation of inflammatory pathways, resulting in periodontal tissue destruction. Hence, functional polymorphisms located in PRRs can explain differences in host susceptibility to periodontitis. This study investigated single nucleotide polymorphisms of PRRs including toll-like receptor (TLR)2 (G2408A), TLR4 (A896G), TLR9 (T1486C), TLR9 (T1237C) and CD14 (C260T) in patients with chronic periodontitis and in periodontally healthy subjects. METHODS: One-hundred and fourteen patients with chronic periodontitis and 77 periodontally healthy subjects were genotyped using TaqMan® allelic discrimination assays. Fisher's exact test and chi-square analyses were performed to compare genotype and allele frequencies. RESULTS: The frequency of subjects with the CC genotype of CD14 (C260T) (24.6% in the chronic periodontitis group vs. 13% in the periodontally healthy group) and those expressing the T allele of CD14 (C260T) (CT and TT) (75.4% in the chronic periodontitis group vs. 87% in the periodontally healthy group) was statistically different among groups (p = 0.04). Homozygocity for the C allele of the CD14 (C260T) polymorphism (CC) was associated with a two--fold increased susceptibility to periodontitis (p = 0.04; odds ratio, 2.49; 95% confidence interval, 1.06-6.26). Individuals with the CC genotype of TLR9 (T1486C) (14.9% in the chronic periodontitis group vs. 28.6% in the periodontally healthy group) and those expressing the T allele of TLR9 (T1486C) (CT and TT) (85.1% in the chronic periodontitis group vs. 71.4% in the periodontally healthy group) were also significantly differently distributed between groups without adjustment (p = 0.03). Further analysis of nonsmokers revealed a significant difference in the distribution of genotypes between groups for TLR9 (T1486C; p = 0.017) and CD14 (C260T; p = 0.03), polymorphisms again without adjustment. CONCLUSION: The CC genotype of CD14 (C260T) is related to susceptibility to chronic periodontitis in Caucasians. In addition, differences observed in the distribution of TLR9 (T1486C) genotypes between groups warrant further investigation.
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Periodontitis Crónica/genética , Receptores de Lipopolisacáridos/genética , Polimorfismo de Nucleótido Simple/genética , Receptores Toll-Like/genética , Adenina , Citosina , Índice de Placa Dental , Femenino , Frecuencia de los Genes/genética , Predisposición Genética a la Enfermedad/genética , Genotipo , Guanina , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Pérdida de la Inserción Periodontal/genética , Índice Periodontal , Bolsa Periodontal/genética , Fumar , Timina , Receptor Toll-Like 2/genética , Receptor Toll-Like 4/genética , Receptor Toll-Like 9/genéticaRESUMEN
Toll-like receptor 9 (TLR9) expression is increased in periodontally diseased tissues compared with healthy sites indicating a possible role of TLR9 and its ligand, bacterial DNA (bDNA), in periodontal disease pathology. Here, we determine the immunostimulatory effects of periodontal bDNA in human monocytic cells (THP-1). THP-1 cells were stimulated with DNA of two putative periodontal pathogens: Porphyromonas gingivalis and Tannerella forsythia. The role of TLR9 in periodontal bDNA-initiated cytokine production was determined either by blocking TLR9 signaling in THP-1 cells with chloroquine or by measuring IL-8 production and nuclear factor-kappaB (NF-kappaB) activation in HEK293 cells stably transfected with human TLR9. Cytokine production (IL-1beta, IL-6, and TNF-alpha) was increased significantly in bDNA-stimulated cells compared with controls. Chloroquine treatment of THP-1 cells decreased cytokine production, suggesting that TLR9-mediated signaling pathways are operant in the recognition of DNA from periodontal pathogens. Compared with native HEK293 cells, TLR9-transfected cells demonstrated significantly increased IL-8 production (P < 0.001) and NF-kappaB activation in response to bDNA, further confirming the role of TLR9 in periodontal bDNA recognition. The results of PCR arrays demonstrated upregulation of proinflammatory cytokine and NF-kappaB genes in response to periodontal bDNA in THP-1 cells, suggesting that cytokine induction is through NF-kappaB activation. Hence, immune responses triggered by periodontal bacterial nucleic acids may contribute to periodontal disease pathology by inducing proinflammatory cytokine production through the TLR9 signaling pathway.
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Bacteroides/inmunología , Citocinas/biosíntesis , ADN Bacteriano/inmunología , Porphyromonas gingivalis/inmunología , Receptor Toll-Like 9/fisiología , Línea Celular Tumoral , Perfilación de la Expresión Génica , Humanos , Mediadores de Inflamación/metabolismo , Interleucina-1beta/biosíntesis , Interleucina-6/biosíntesis , Riñón/citología , Riñón/embriología , Monocitos/metabolismo , FN-kappa B/metabolismo , Transducción de Señal , Transfección , Factor de Necrosis Tumoral alfa/biosíntesisRESUMEN
A total of 10 surface soil samples representing the entire area of Linfen City were collected and analyzed for the presence of 16 polycyclic aromatic hydrocarbons. The total polycyclic aromatic hydrocarbon concentration ranged from 1.1 to 63.7 microg g(-1). Analysis of the sources of contamination revealed that polycyclic aromatic hydrocarbons in the soil were derived from combustion sources. Specifically, the primary source of polycyclic aromatic hydrocarbons was coal combustion, but the samples were also effected to varying degrees by traffic emissions. Furthermore, increased levels of contamination were observed in northeast Linfen due to the distribution of industrial plants.
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Compuestos Policíclicos/análisis , Contaminantes del Suelo/análisis , ChinaRESUMEN
This study was conducted to determine the concentration of 16 polycyclic aromatic hydrocarbons (PAHs) in sandstorm depositions in Beijing, China. The PAH concentrations in 13 samples collected in Beijing ranged from 0.18 to 3.52 microg g(-1). Analysis of the sources of contamination revealed that the PAHs were derived from a coal combustion source, although various effects of traffic emissions were also observed. Furthermore, the PAH levels in Beijing tended to be higher in the southeast. Finally, the nemerow composite index revealed that the degree of pollution in the sandstorm depositions varied widely among sampling sites.
Asunto(s)
Compuestos Policíclicos/análisis , China , Dióxido de SilicioRESUMEN
Ten soil samples collected in Linfen were analyzed for 21 organochlorine pesticides. The concentration of total organochlorine pesticides ranged from 4.3 to 23.2 ng g(-1) in soil from urban areas and from 26.3 to 247.4 ng g(-1) in soil from industrial plants. The highest levels of contamination were observed in northwest and central Linfen, reflecting the distribution of industrial plants. The HCH and DDT profiles revealed that the sources were associated mainly with lindane and technical DDT, respectively, while HCHs in the soil of industrial plants might originate from a new source.
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Hidrocarburos Clorados/análisis , Plaguicidas/análisis , Contaminantes del Suelo/análisis , China , Ciudades , Monitoreo del Ambiente , Hidrocarburos Clorados/química , Industrias , Plaguicidas/química , Contaminantes del Suelo/químicaRESUMEN
The effects of chilling on respiration (SHAM-resistant, cytochrome pathway and KCN-resistant, alternative pathway), temperature sensitivity, relative electrolyte conductivity, and degrees of oxidative stress (H(2)O(2) and malonaldehyde (MDA) contents) were separately examined in leaves and roots of cucumber (Cucumis sativus L.). After chilling at 8 degrees C for 4 days, both total respiration and KCN-resistant respiration in roots increased at different measurement temperatures. In contrast, SHAM-resistant respiration remained unchanged. In comparison, chilling significantly decreased the total respiration in leaves and this decrease was mostly due to a decrease in SHAM-resistant respiration. Chilling apparently decreased the sensitivity of KCN-resistant respiration to changes of temperature. The reduction levels of ubiquinone pool (UQr/UQt) increased both in chilled leaves and roots whilst pyruvate content increased only in chilled roots, but not in chilled leaves. Furthermore increases of H(2)O(2) and MDA contents were much greater in leaves than in roots. The same trend was also observed for ion leakage from tissues. Taken together, the results suggested that the higher chilling tolerance of roots was associated with their high total respiration and KCN-resistant respiration.
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Cucumis sativus/metabolismo , Consumo de Oxígeno , Hojas de la Planta/metabolismo , Raíces de Plantas/metabolismo , Frío , Resistencia a Medicamentos/efectos de los fármacos , Inhibidores Enzimáticos/farmacología , Peróxido de Hidrógeno/metabolismo , Malondialdehído/metabolismo , Consumo de Oxígeno/efectos de los fármacos , Cianuro de Potasio/farmacología , Ubiquinona/análogos & derivados , Ubiquinona/metabolismoRESUMEN
Usher syndrome (USH) is characterized by the associated findings of hearing loss and retinitis pigmentosa (RP), leading to progressive loss of vision. Three forms of USH can be distinguished clinically. In the most severe form, USH1, profound congenital deafness is associated with vestibular dysfunction and RP. To determine the frequency of USH1C mutations as a cause for USH1, 128 probands with Usher syndrome type 1 including seven from Acadian and 121 from non-Acadian populations were systematically screened for mutations in USH1C using a combined single-strand conformational polymorphisms (SSCP)/heteroduplex and sequencing method. All seven Acadian USH1 patients were found to be homozygous for both the 216G>A mutation and the 9-repeat VNTR which characterizes the Acadian allele, confirming previous evidence for a founder effect by haplotype analysis. However, USH1C mutations were identified in only two non-Acadian USH1 probands (1.65%) including one from Pakistan who was homozygous for a 238-239insC mutation and one from Canada was also homozygous for the Acadian allele. The low prevalence of USH1C mutations in the present study suggests that the high prevalence of the 238-239insC in Germany may reflect a founder effect. Comparison of the affected haplotypes in the Canadian patient with the Acadian USH1 patients yielded evidence for a founder effect. Our data suggest that USH1C is a relatively rare form of USH1 in non-Acadian populations and that in addition to the 216G>A Acadian mutation, the 238-239insC mutation appears to be common in some populations.