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1.
Genes Cells ; 26(2): 65-82, 2021 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-33290632

RESUMEN

G-quadruplex (G4), a non-canonical higher-order structure formed by guanine-rich nucleic acid sequences, affects various genetic events in cis, including replication, transcription and translation. Whereas up-regulation of innate immune/interferon-stimulated genes (ISGs) is implicated in cancer progression, G4-forming oligonucleotides that mimic telomeric repeat-containing RNA suppress ISG induction in three-dimensional (3D) culture of cancer cells. However, it is unclear how G4 suppresses ISG expression in trans. In this study, we found that G4 binding to splicing factor 3B subunit 2 (SF3B2) down-regulated STAT1 phosphorylation and ISG expression in 3D-cultured cancer cells. Liquid chromatography-tandem mass spectrometry analysis identified SF3B2 as a G4-binding protein. Either G4-forming oligonucleotides or SF3B2 knockdown suppressed ISG induction, whereas Phen-DC3, a G4-stabilizing compound, reversed the inhibitory effect of G4-forming oligonucleotides on ISG induction. Phen-DC3 inhibited SF3B2 binding to G4 in vitro. SF3B2-mediated ISG induction appeared to occur independently of RNA splicing because SF3B2 knockdown did not affect pre-mRNA splicing under the experimental conditions, and pharmacological inhibition of splicing by pladienolide B did not repress ISG induction. These observations suggest that G4 disrupts the ability of SF3B2 to induce ISGs in cancer. We propose a new mode for gene regulation, which employs G4 as an inhibitory trans-element.


Asunto(s)
G-Cuádruplex , Regulación de la Expresión Génica , Inmunidad Innata/genética , Ácidos Nucleicos/metabolismo , Factores de Empalme de ARN/metabolismo , Línea Celular Tumoral , Citocinas/genética , Citocinas/metabolismo , Compuestos de Anillos Fusionados/farmacología , Regulación de la Expresión Génica/efectos de los fármacos , Técnicas de Silenciamiento del Gen , Ontología de Genes , Humanos , Inmunidad Innata/efectos de los fármacos , Ligandos , Modelos Biológicos , Oligonucleótidos/metabolismo , Unión Proteica/efectos de los fármacos , Empalme del ARN/efectos de los fármacos , Empalme del ARN/genética , Factor de Transcripción STAT1/metabolismo , Transducción de Señal/efectos de los fármacos , Ubiquitinas/genética , Ubiquitinas/metabolismo
2.
Nucleic Acids Res ; 42(16): e125, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25034687

RESUMEN

To identify and characterize transcript structures ranging from transcriptional start sites (TSSs) to poly(A)-addition sites (PASs), we constructed and analyzed human TSS/PAS mate pair full-length cDNA libraries from 14 tissue types and four cell lines. The collected information enabled us to define TSS cluster (TSC) and PAS cluster (PAC) relationships for a total of 8530/9400 RefSeq genes, as well as 4251/5618 of their putative alternative promoters/terminators and 4619/4605 intervening transcripts, respectively. Analyses of the putative alternative TSCs and alternative PACs revealed that their selection appeared to be mostly independent, with rare exceptions. In those exceptional cases, pairs of transcript units rarely overlapped one another and were occasionally separated by Rad21/CTCF. We also identified a total of 172 similar cases in which TSCs and PACs spanned adjacent but distinct genes. In these cases, different transcripts may utilize different functional units of a particular gene or of adjacent genes. This approach was also useful for identifying fusion gene transcripts in cancerous cells. Furthermore, we could construct cDNA libraries in which 3'-end mate pairs were distributed randomly over the transcripts. These libraries were useful for assembling the internal structure of previously uncharacterized alternative promoter products, as well as intervening transcripts.


Asunto(s)
Regiones no Traducidas 3' , Biblioteca de Genes , Sitio de Iniciación de la Transcripción , Línea Celular , Cromatina/química , ADN Complementario , Células HEK293 , Células HeLa , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Células MCF-7 , Poli A , ARN Mensajero/química
3.
BMC Genomics ; 16: 154, 2015 Mar 06.
Artículo en Inglés | MEDLINE | ID: mdl-25879614

RESUMEN

BACKGROUND: Histone epigenome data determined by chromatin immunoprecipitation sequencing (ChIP-seq) is used in identifying transcript regions and estimating expression levels. However, this estimation does not always correlate with eventual RNA expression levels measured by RNA sequencing (RNA-seq). Part of the inconsistency may arise from the variance in RNA stability, where the transcripts that are more or less abundant than predicted RNA expression from histone epigenome data are inferred to be more or less stable. However, there is little systematic analysis to validate this assumption. Here, we used stability data of whole transcriptome measured by 5'-bromouridine immunoprecipitation chase sequencing (BRIC-seq), which enabled us to determine the half-lives of whole transcripts including lincRNAs, and we integrated BRIC-seq with ChIP-seq to achieve better estimation of the eventual transcript levels and to understand the importance of post-transcriptional regulation that determine the eventual transcript levels. RESULTS: We identified discrepancies between the RNA abundance estimated by ChIP-seq and measured RNA expression from RNA-seq; for number of genes and estimated that the expression level of 865 genes was controlled at the level of RNA stability in HeLa cells. ENCODE data analysis supported the idea that RNA stability control aids to determine transcript levels in multiple cell types. We identified UPF1, EXOSC5 and STAU1, well-studied RNA degradation factors, as controlling factors for 8% of cases. Computational simulations reasonably explained the changes of eventual mRNA levels attributable to the changes in the rates of mRNA half-lives. In addition, we propose a feedback circuit that includes the regulated degradation of mRNAs encoding transcription factors to maintain the steady state level of RNA abundance. Intriguingly, these regulatory mechanisms were distinct between mRNAs and lincRNAs. CONCLUSIONS: Integrative analysis of ChIP-seq, RNA-seq and our BRIC-seq showed that transcriptional regulation and RNA degradation are independently regulated. In addition, RNA stability is an important determinant of eventual transcript levels. RNA binding proteins, such as UPF1, STAU1 and EXOSC5 may play active roles in such controls.


Asunto(s)
Estabilidad del ARN , ARN/metabolismo , Antígenos de Neoplasias/metabolismo , Inmunoprecipitación de Cromatina , Proteínas del Citoesqueleto/metabolismo , Complejo Multienzimático de Ribonucleasas del Exosoma/metabolismo , Regulación de la Expresión Génica , Semivida , Células HeLa , Secuenciación de Nucleótidos de Alto Rendimiento , Histonas/metabolismo , Humanos , ARN/química , ARN Helicasas , ARN Largo no Codificante/química , ARN Largo no Codificante/metabolismo , ARN Mensajero/química , ARN Mensajero/metabolismo , Proteínas de Unión al ARN/metabolismo , Análisis de Secuencia de ARN , Transactivadores/metabolismo
4.
Gan To Kagaku Ryoho ; 40(12): 2372-4, 2013 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-24394116

RESUMEN

Case 1: Case 1 involved a 42-year-old woman who had been diagnosed as having advanced breast cancer (Stage III B). She had previously received 6 courses of cyclophosphamide, epirubicin, and 5-fluorouracil CEF, 14 courses of weekly paclitaxel, and 2 courses of vinorelbine( VNR). After the courses of chemotherapy, she underwent modified radical mastectomy with axillary lymph node dissection. Two years after surgery, lung metastases were found, and the patient received 6 courses of weekly paclitaxel and 13 courses of nab-paclitaxel. However, the lung metastases progressed after the courses of chemotherapy, and therefore, we decided to administer eribulin as third-line chemotherapy. Eribulin was effective against the lung metastases for more than 1 year. Case 2: Case 2 involved a 52-year-old woman who had been diagnosed as having Stage IIB breast cancer. She had received 4 courses of CEF and 4 courses of docetaxel as neo-adjuvant chemotherapy. After chemotherapy, she underwent breast-conserving surgery with axillary lymph node dissection. Five years postoperatively, multiple liver metastases were found, and the patient received 3 courses. However, the liver metastases progressed after this chemotherapy. Subsequently, we administered nab-paclitaxel; however, it produced severe side effects. We then decided to administer eribulin as second-line chemotherapy. Eribulin was effective against the liver metastases for more than 1 year.


Asunto(s)
Neoplasias de la Mama/tratamiento farmacológico , Furanos/uso terapéutico , Cetonas/uso terapéutico , Neoplasias Hepáticas/tratamiento farmacológico , Neoplasias Pulmonares/tratamiento farmacológico , Adulto , Neoplasias de la Mama/patología , Femenino , Humanos , Neoplasias Hepáticas/secundario , Neoplasias Pulmonares/secundario , Persona de Mediana Edad , Estadificación de Neoplasias , Factores de Tiempo
5.
Sci Rep ; 13(1): 7591, 2023 05 10.
Artículo en Inglés | MEDLINE | ID: mdl-37164992

RESUMEN

This study is the first to demonstrate that deep ocean water (DOW) has physiological significant effects on squid. After 36 h of rearing squids, those reared with DOW had significantly higher total and free cholesterol levels and lower alanine transaminase activity in hemolymph as compared with those reared with surface sea water (SSW). SSW rearing also resulted in 6.95% weight loss, while DOW rearing caused only 2.5% weight loss, which might be due to liver metabolism suppression. Furthermore, both monovalent (sodium, chloride, and potassium ions) and divalent (calcium, inorganic phosphorus, and magnesium ions) ions in hemolymph were elevated when reared with DOW compared to those when reared with SSW. A study of genes expressed in the brain revealed that five genes were specifically remarked in DOW rearing. Most altered genes were neuropeptides, including those from vasopressin superfamily. These neuropeptides are involved in cholesterol and/or mineral metabolisms and physiological significant effects on squid. This study is the first report the effects of DOW on cholesterol and mineral metabolism of squid and will contribute to squid aquaculture using DOW.


Asunto(s)
Decapodiformes , Agua , Animales , Decapodiformes/genética , Colesterol , Océanos y Mares , Minerales
6.
Gan To Kagaku Ryoho ; 39(12): 2080-2, 2012 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-23267983

RESUMEN

We report a case of breast cancer with lymph node metastases. A complete response was recognized in response to nab-paclitaxel as a first-line therapy after recurrence. The patient was a 50-year-old woman who had a tumor in her right breast. We palpated a mass with clear boundaries in her right breast. The tumor was 2 cm in diameter. Core-needle biopsy of the breast tumor led to a diagnosis of invasive ductal carcinoma (estrogen receptor-, progesterone receptor-, and human epidermal growth factor receptor 2-negative). She received 4 cycles of EC (E: 90 mg/m2/tri-weekly; C: 600 mg/m2 /tri-weekly) plus 4 cycles of TC(T: 75 mg/m2/tri-weekly; C: 600 mg/m2/tri-weekly)as preoperative adjuvant chemotherapy. After chemotherapy, she underwent quadrantectomy plus axillary lymph node dissection. Six months after the operation, lymph node metastases were observed in her right supraclavicular lymph nodes. She received 8 cycles of nab-paclitaxel(260 mg/m2/tri-weekly) therapy. After 8 cycles of treatment, ultrasonography and computed tomography revealed the disappearance of the metastatic lymph nodes. Therefore, a clinical complete response was observed.


Asunto(s)
Albúminas/uso terapéutico , Antineoplásicos Fitogénicos/uso terapéutico , Neoplasias de la Mama/tratamiento farmacológico , Carcinoma Ductal de Mama/tratamiento farmacológico , Paclitaxel/uso terapéutico , Neoplasias de la Mama/patología , Carcinoma Ductal de Mama/secundario , Femenino , Humanos , Metástasis Linfática , Persona de Mediana Edad , Estadificación de Neoplasias
7.
J Nippon Med Sch ; 89(5): 494-499, 2022 Nov 09.
Artículo en Inglés | MEDLINE | ID: mdl-35644551

RESUMEN

BACKGROUND: Eribulin therapy has been reported to prolong overall survival (OS) but not progression-free survival, probably because it prevents the development of metastatic lesions; however, this effect has not yet been confirmed. METHODS: We reviewed the medical charts of 50 patients with metastatic breast cancer who underwent eribulin monotherapy at our hospital between 2014 and 2019. Patients were divided into two groups, namely, those who discontinued eribulin because of disease progression due to development of new lesions (NL group) and those who discontinued eribulin for other reasons, such as lesion growth and unacceptable side effects (non-NL group). Survival times were estimated for both groups and we investigated if eribulin-mediated suppression of new metastasis increased OS. RESULTS: Median OS for all patients, from eribulin initiation, was 14.4 months (range 1.2-60.1), whereas it was 4.6 months (range 1.7-24.7) in the NL group and 16.8 months (range 1.2-60.1) in the non-NL group. OS was significantly poorer in the NL group than in the non-NL group (p < 0.05). CONCLUSION: Eribulin monotherapy-mediated suppression of new metastatic lesions results in a better prognosis in patients with metastatic breast cancer.


Asunto(s)
Antineoplásicos , Neoplasias de la Mama , Humanos , Femenino , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/patología , Resultado del Tratamiento , Furanos/uso terapéutico , Cetonas/uso terapéutico , Pronóstico , Metástasis de la Neoplasia , Antineoplásicos/uso terapéutico
8.
Gan To Kagaku Ryoho ; 38(12): 2168-70, 2011 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-22202318

RESUMEN

A case is a 72-year-old woman with right breast lump detected by palpation. In the end of November 2009, we palpated a mass with clear boundaries in the right D area. Breast echography showed a nearly 3 cm tumor in the cyst. MRI showed an augmented effect of marginal irregular 3 cm in size. A diagnosis was adenomyoepithelioma by needle biopsy. We performed lumpectomy because a breast cancer was suspected. Histopathology findings were adenomyoepithelioma ER(+), PgR(-), HER2(0), α SMA(+). A diagnosis of adenomyoepithelioma is rather hard by means of imaging or biopsy. When this disorder was in doubt, a tissue analysis is indispensable for a determination of diagnosis because we were able to make a diagnosis by local excision without an excessive invasion. So we herein report our experience of adenomyoepithelioma with reference.


Asunto(s)
Adenomioepitelioma/patología , Neoplasias de la Mama/patología , Adenomioepitelioma/cirugía , Anciano , Biopsia con Aguja , Neoplasias de la Mama/cirugía , Femenino , Humanos , Invasividad Neoplásica
9.
Gan To Kagaku Ryoho ; 38(12): 2002-4, 2011 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-22202265

RESUMEN

We report an unmarried woman with papillary thyroid cancer. The patient was a 20-year-old woman who had neck tumor. The ultrasonography (US), CT, and aspiration biopsy cytology (ABC) were performed. The diagnosis of the tumor was papillary carcinoma of thyroid. The total thyroidectomy plus lymph nodes dissection (D2a) were performed. Two years after the first operation, we recognized lymph nodes swelling at her right neck. The US guided ABC was performed. The diagnosis was the metastasis of lymph node from thyroid cancer. We performed lymph nodes dissection again. Three years after the first operation, we detected the swelleing of lymph nodes again at her right neck. We performed lymph nodes dissection again. We recommended a therapeutic use of iodine radioisotopes. However, she rejected the therapy because she strongly wanted to be pregnant. Generally speaking, it is difficult to determine the therapeutic use of iodine radioisotopes for unmarried women. After seven years from the first operation, she delivered a baby girl. We plan to use of iodine radioisotopes for adjuvant therapy when she delivers her 2nd baby. This case suggested that a treatment strategy for unmarried thyroid cancer patients should be made thoughtfully with care.


Asunto(s)
Neoplasias de la Tiroides/cirugía , Biopsia , Carcinoma , Carcinoma Papilar , Femenino , Humanos , Metástasis Linfática , Cáncer Papilar Tiroideo , Neoplasias de la Tiroides/patología , Neoplasias de la Tiroides/radioterapia , Tiroidectomía , Tomografía Computarizada por Rayos X , Adulto Joven
10.
Gan To Kagaku Ryoho ; 38(12): 2005-7, 2011 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-22202266

RESUMEN

In this study, we evaluated the clinical presentation of patients with skin recurrence in breast cancer patients. We treated 1, 228 cases of breast cancer patients during 2004 to 2010. The skin recurrences were recognized in 11 patients. The duration of showing skin recurrence was 1 .8 years. The muscle preserving radical mastectomy was performed in all cases. And surgical margins of all cases were negative. All cases were not performed radiation therapy. Nine cases were received chemotherapy as adjuvant therapy. Seven cases received endocrine therapy. After recurrence, they were treated by multi- disciplinary therapy. The surgical resection was useful to judge the effect of other therapies. The observation period was 2. 2 years. Two patients died, but 8 other patients are still alive.


Asunto(s)
Neoplasias de la Mama/patología , Neoplasias Cutáneas/secundario , Adulto , Anciano , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Femenino , Humanos , Persona de Mediana Edad , Estadificación de Neoplasias , Pronóstico
11.
Gan To Kagaku Ryoho ; 38(12): 2011-3, 2011 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-22202268

RESUMEN

We report a locally advanced elderly breast carcinoma with skin invasion. The patient was a 96-year-old woman who had a breast lump. The palpable tumor was 3 .5 cm in diameter. Ultrasonography revealed a low echoic mass. A core needle biopsy for the breast tumor led to a diagnosis of an invasive ductal carcinoma positive for estrogen receptor and progesteron receptor, and negative for HER2/neu protein expression. She underwent a tumorectomy including the cancer invasive skin by local anesthesia. Because her respiratory function was unbearable to perform a muscle-preserving mastectomy with general anesthesia. The surgical margins of the resected specimen were negative. The clinicopathological stage, according to the UICC-pTNM classification, was Stage III C (T4b, N0, M0). After the operation, she was administered aromatase inhibitor. The patient has been well and remained disease-free during a follow-up period of 3 years. The surgical excision with local anesthesia was useful for locally advanced super senior breast cancer patients who were impossible to perform general anesthesia by various kinds of factors.


Asunto(s)
Neoplasias de la Mama/cirugía , Neoplasias Cutáneas/cirugía , Anciano de 80 o más Años , Biopsia , Neoplasias de la Mama/patología , Femenino , Humanos , Invasividad Neoplásica , Neoplasias Cutáneas/secundario , Tomografía Computarizada por Rayos X
12.
Gan To Kagaku Ryoho ; 38(12): 2014-6, 2011 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-22202269

RESUMEN

We report a case of non-palpating breast cancer with huge lymph node metastasis. The patient was a 58-year-old woman who had a huge tumor at her right armpit. The tumor was 4 cm in diameter. Aspiration biopsy cytology for the tumor was performed. The diagnosis is Class V. Mammography showed an ill-defined mass at her right breast. Ultrasonography revealed a low echoic mass at the C area of her right breast. A core needle biopsy for the breast tumor led to a diagnosis of an invasive ductal carcinoma positive for estrogen receptor and progesterone receptor, and negative for HER2/neu protein expression. She received 4 cycles of CEF (E: 60 mg/tri-weekly) plus 12 cycles of paclitaxe (l80 mg/weekly). After chemotherapy, she received muscle preserving mastectomy plus axillary lymph nodes dissection. In histopathology, there were no carcinoma cells in resected breast tissue and resected lymph nodes. Therefore, the effect of chemotherapy was diagnosed as a pathological complete response. After operation, she was administered aromatase inhibitor. The patient has been well and remained disease-free during a follow-up period of 6 years.


Asunto(s)
Neoplasias de la Mama/patología , Biopsia , Neoplasias de la Mama/tratamiento farmacológico , Neoplasias de la Mama/cirugía , Terapia Combinada , Femenino , Humanos , Metástasis Linfática , Imagen por Resonancia Magnética , Mamografía , Persona de Mediana Edad
13.
Gan To Kagaku Ryoho ; 38(12): 2078-80, 2011 Nov.
Artículo en Japonés | MEDLINE | ID: mdl-22202289

RESUMEN

In this study, we evaluated the clinical presentation of patients with T4b breast cancer, and analyzed the impact of non- inflammatory skin involvement on long-term survival. We treated 1 228 cases of breast cancer patients during 2004 to 2010. The T4b breast cancers were 52 cases out of these 1,228 patients. The primary treatment methods of these T4b patients were chemotherapy (67.3%), surgical therapy (26.9%), endocrine therapy (5.8%), and radiation therapy (0%). The probability that surgical resection was performed over the duration of treatment was 88. 5%. The mean time to progression (TTP) was 3.9 years. The disease specific mean survival time (MST) of T4b breast cancer patients was 5.9 years. There was no difference among the surgical and non-surgical therapy groups in the long-term survival period, but the surgical therapy group was much better than non-surgical therapy group in terms of non-recurrent survival ratio. In viewing from the control of bleeding of the patients, the surgical therapy was effective and improved the quality of life during a time of the therapy.


Asunto(s)
Neoplasias de la Mama/patología , Neoplasias Cutáneas/secundario , Adulto , Anciano , Anciano de 80 o más Años , Neoplasias de la Mama/terapia , Femenino , Humanos , Persona de Mediana Edad , Invasividad Neoplásica , Pronóstico , Neoplasias Cutáneas/terapia
14.
Drug Des Devel Ther ; 12: 1045-1051, 2018.
Artículo en Inglés | MEDLINE | ID: mdl-29750017

RESUMEN

INTRODUCTION: Telaprevir, a reversible selective inhibitor of viral protease and a potential blocker of viral replication, is indicated for the treatment of hepatitis C virus genotype 1 infection. In this study, the pharmacokinetic profile, safety, and tolerability of telaprevir and the effect of food on telaprevir exposure were evaluated in healthy Korean subjects, and compared with data from a previous study in Japanese male subjects. METHODS: The single ascending dose study was conducted in 3 dose-based groups (500, 750, and 1,250 mg, six subjects each) in a fasted state. In the multiple dose study, eight subjects in the fed state received 750 mg of telaprevir once on Day 1 and every 8 hours from Day 2 until the morning of Day 6. Serial blood samples for pharmacokinetic analysis were collected for up to 24 hours in the single ascending dose study and for 6 days in the multiple dose study. Individual pharmacokinetic parameters were calculated using a non-compartmental analysis method. Safety and tolerability profiles were evaluated throughout the study. RESULTS: Following multiple administrations of telaprevir, maximum plasma concentrations (Cmax), area under the concentration-time curve (AUC0-8), and Ctrough (concentration at 8 h after drug administration) increased by ~2.41-fold. Compared to fasted state values, mean Cmax and AUC0-24 increased by 4.92- and 4.81-fold, respectively, after food intake. The Cmax and AUCinf of Korean subjects were 26%-34% higher than those of Japanese subjects; however, these differences were not clinically significant. All observed adverse events were mild and there was no discontinuation due to AEs. CONCLUSION: In conclusion, the telaprevir's pharmacokinetic characteristics were similar in Korean and Japanese subjects. Telaprevir was well tolerated in a single dose of up to 1,250 mg and in multiple doses of 750 mg.


Asunto(s)
Oligopéptidos/farmacocinética , Administración Oral , Adulto , Índice de Masa Corporal , Tolerancia a Medicamentos , Voluntarios Sanos , Humanos , Japón , Masculino , Persona de Mediana Edad , Oligopéptidos/administración & dosificación , Oligopéptidos/efectos adversos , República de Corea , Comprimidos , Adulto Joven
15.
Ground Water ; 43(5): 764-70, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-16149973

RESUMEN

A substantial body of research has been conducted on transboundary water, transboundary water law, and the mitigation of transboundary water conflict. However, most of this work has focused primarily on surface water supplies. While it is well understood that aquifers cross international boundaries and that the base flow of international river systems is often derived in part from ground water, transboundary ground water and surface water systems are usually managed under different regimes, resulting in what has been described as "hydroschizophrenia." Adding to the problem, the hydrologic relationships between surface and ground water supplies are only known at a reconnaissance level in even the most studied international basins, and thus even basic questions regarding the territorial sovereignty of ground water resources often remain unaddressed or even unasked. Despite the tensions inherent in the international setting, riparian nations have shown tremendous creativity in approaching regional development, often through preventive diplomacy, and the creation of "baskets of benefits," which allow for positive-sum, integrative allocations of joint gains. In contrast to the notion of imminent water wars, the history of hydropolitical relations worldwide has been overwhelmingly cooperative. Limited ground water management in the international arena, coupled with the fact that few states or countries regulate the use of ground water, begs the question: will international borders serve as boundaries for increased "flows" of hydrologic information and communication to maintain strategic aquifers, or will increased competition for shared ground water resources lead to the potential loss of strategic aquifers and "no flows" for both ground water users?


Asunto(s)
Cooperación Internacional , Abastecimiento de Agua , Conservación de los Recursos Naturales , Guías como Asunto , Política , Movimientos del Agua
16.
Biosci Biotechnol Biochem ; 66(8): 1628-34, 2002 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-12353620

RESUMEN

The bioavailability of a series of novel acylated ascorbic acid derivatives, 6-O-acyl-2-O-alpha-D-glucopyranosyl-L-ascorbic acids (6-Acyl-AA-2G), as an ascorbic acid (AA) supplement was investigated in rats and guinea pigs. Oral administration of 6-Acyl-AA-2G to rats resulted in an increase in the plasma AA level. However, the intact form was not detectable in the plasma by high-performance liquid chromatography, indicating its hydrolysis through the process of absorption. After an intravenous injection to rats of 6-Octa-AA-2G as a representative derivative, the intact form rapidly disappeared from the plasma, being followed by a prolonged and marked elevation of the plasma AA level. Various tissue homogenates from guinea pigs were examined for their releasing activity of AA, 2-O-alpha-D-glucopyranosyl-L-ascorbic acid (AA-2G) and 6-O-acyl-AA from 6-Acyl-AA-2G. High activity was observed in the small intestine. These hydrolytic activities to AA and 6-O-acyl-AA were completely inhibited by castanospermine, an alpha-glucosidase inhibitor, and AA-2G was observed as the only resulting hydrolysate, suggesting the participation of alpha-glucosidase and esterase in the in vivo hydrolysis of 6-Acyl-AA-2G. 6-Octa-AA-2G was found to exhibit an obvious therapeutic effect in scorbutic guinea pigs from its repeated oral administration. These results indicate that 6-Acyl-AA-2G is a readily available source of AA activity in vivo, and may be useful as an effective pharmacological agent and as a promising food additive.


Asunto(s)
Ácido Ascórbico/análogos & derivados , Ácido Ascórbico/farmacocinética , Animales , Ácido Ascórbico/sangre , Deficiencia de Ácido Ascórbico/tratamiento farmacológico , Deficiencia de Ácido Ascórbico/metabolismo , Disponibilidad Biológica , Encéfalo/metabolismo , Suplementos Dietéticos , Esterasas/metabolismo , Cobayas , Hidrólisis , Intestino Delgado/metabolismo , Hígado/metabolismo , Masculino , Ratas , Ratas Wistar , Escorbuto/metabolismo , Piel/metabolismo , alfa-Glucosidasas/metabolismo
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