RESUMEN
Chitosan is a biopolymer derived from chitin deacetylation, present in the exoskeleton of crustaceans and insects. Chitosan has been evaluated as rumen modulator and silage additive due to its antimicrobial properties. The objective of this study was to determine the effects of both chitosan and a bacterial additive on microbiological quality, chemical composition, nutrient in vitro degradation, fermentative profile, and total losses of whole-soybean plant silage (SS) harvested at R6 stage. Four treatments in a factorial arrangement were randomly assigned to 40 experimental minisilos as no additives (CON), 8 g/t fresh forage of microbial inoculant (INO; Kera SIL, Kera Nutrição Animal, Bento Gonçalves, Brazil); 5 g/kg of fresh forage chitosan (CHI); and CHI + INO. Microbial inoculant was composed of Lactobacillus plantarum (4.0 × 1010 cfu/g) and Propionibacterium acidipropionici (2.6 × 1010 cfu/g). The CHI and INO alone increased counts of lactic bacteria and anaerobic bacteria and decreased counts of mold and yeast in SS. The CHI or INO alone increased in vitro degradation of dry matter, crude protein, and neutral detergent fiber, and decreased nonfiber carbohydrate content of SS. Chitosan increased NH3-N and lactate concentrations and decreased ethanol concentration in SS. The CHI increased dry matter recovery from SS; INO increased silage aerobic stability. The combination of CHI+INO showed the lowest value of gas losses. In general, the combination of CHI and INO had small positive effects on gas losses of SS; however, both CHI or INO alone improved nutrient in vitro degradation and decreased mold and yeast in SS. Chitosan or INO utilization improves SS quality.
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Alimentación Animal , Quitosano , Fermentación , Glycine max , Lactobacillus/crecimiento & desarrollo , Animales , Brasil , Ácido Láctico , Lactobacillales , Rumen/metabolismo , Ensilaje , Zea maysRESUMEN
WHAT IS KNOWN AND OBJECTIVE: Furanocoumarins, such as bergamottin (BG) and 6',7'-dihydroxybergamottin (DHB), isolated from grapefruit juice are clinically active constituents capable of inhibiting cytochrome P450 3A4. Furanocoumarins are also found in hassaku, pummelo and daidai. Several types of hybrid citrus fruits have recently been developed, and these may also contain furanocoumarins because they were produced by cross-breeding pummelo, daidai and other citrus fruits. In this study, we quantified BG and DHB levels in the flesh and peel of hybrid citrus fruits. METHODS: Extracts from flesh and peel were diluted with acetonitrile and analysed using high-performance liquid chromatography. RESULTS AND DISCUSSION: For flesh extracts, lime juice (24.13 µg/mL) contained a greater amount of BG than grapefruit juice (13.61 µg/mL). Lime (13.21 µg/mL) and sour orange (8.08 µg/mL) juices also contained greater amounts of DHB than grapefruit juice (7.54 µg/mL). For peel extracts, lime (1749.15 µg/g), Citrus kawachibankan (308.13 µg/g), lemon (203.44 µg/g) and sour orange (161.95 µg/g) contained greater amounts of BG than grapefruit (white) (78.80 µg/g). The hybrid sweetie (Citrus maxima × Citrus paradise; 173.32 µg/g) contained a greater amount of DHB than grapefruit (white) (85.27 µg/g). WHAT IS NEW AND CONCLUSION: The lime flesh and the sweetie peel contained the greatest amounts of furanocoumarins. Thus, caution is required during the simultaneous use of drugs metabolized by cytochrome P450 3A4 and consumption of these citrus fruits.
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Citrus/química , Inhibidores Enzimáticos del Citocromo P-450/química , Furocumarinas/química , Bebidas/análisis , Citrus paradisi/química , Citocromo P-450 CYP3A/metabolismo , Interacciones Alimento-Droga/fisiología , Jugos de Frutas y Vegetales/análisis , HumanosRESUMEN
We developed a set of universal PCR primers (MiFish-U/E) for metabarcoding environmental DNA (eDNA) from fishes. Primers were designed using aligned whole mitochondrial genome (mitogenome) sequences from 880 species, supplemented by partial mitogenome sequences from 160 elasmobranchs (sharks and rays). The primers target a hypervariable region of the 12S rRNA gene (163-185 bp), which contains sufficient information to identify fishes to taxonomic family, genus and species except for some closely related congeners. To test versatility of the primers across a diverse range of fishes, we sampled eDNA from four tanks in the Okinawa Churaumi Aquarium with known species compositions, prepared dual-indexed libraries and performed paired-end sequencing of the region using high-throughput next-generation sequencing technologies. Out of the 180 marine fish species contained in the four tanks with reference sequences in a custom database, we detected 168 species (93.3%) distributed across 59 families and 123 genera. These fishes are not only taxonomically diverse, ranging from sharks and rays to higher teleosts, but are also greatly varied in their ecology, including both pelagic and benthic species living in shallow coastal to deep waters. We also sampled natural seawaters around coral reefs near the aquarium and detected 93 fish species using this approach. Of the 93 species, 64 were not detected in the four aquarium tanks, rendering the total number of species detected to 232 (from 70 families and 152 genera). The metabarcoding approach presented here is non-invasive, more efficient, more cost-effective and more sensitive than the traditional survey methods. It has the potential to serve as an alternative (or complementary) tool for biodiversity monitoring that revolutionizes natural resource management and ecological studies of fish communities on larger spatial and temporal scales.
RESUMEN
A retrospective study was carried out to compare the preventive effects of single and repeat treatment with dexamethasone (DEX) on delayed nausea and emesis in patients who had received carboplatin (CBDCA)-based combination chemotherapy. Sixty-four patients were evaluated. Efficacy was assessed using the nausea and emesis score, food intake score and the requirement for antiemetic medication. These forward scores were categorized as three-grade during the first 5 days after chemotherapy. Acute nausea and emesis were well controlled in both groups on day 1. Mean values of the nausea and emesis score on day 3 evening and the food intake score on day 4 morning in the repeat-treatment group was 1.31 ± 0.93 and 3.46 ± 1.03, respectively, which were significantly better when compared with the single-treatment group (2.00 ± 1.52; P = 0.028 and 2.79 ± 1.12; P = 0.018, respectively). Multivariate logistic regression analysis revealed that less frequent dispensing of antiemetic medication was significantly associated with the repeat-treatment group (adjusted odds ratio, 0.153; 95% confidence interval, 0.026-0.734; P = 0.018). These results suggest that repeat-dose DEX may be more effective than single-dose DEX for the prevention of delayed nausea and emesis after CBDCA-based combination chemotherapy.
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Antieméticos/uso terapéutico , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Dexametasona/uso terapéutico , Náusea/tratamiento farmacológico , Vómitos/tratamiento farmacológico , Adulto , Factores de Edad , Anciano , Anciano de 80 o más Años , Antieméticos/administración & dosificación , Carboplatino/administración & dosificación , Dexametasona/administración & dosificación , Esquema de Medicación , Quimioterapia Combinada , Femenino , Humanos , Masculino , Persona de Mediana Edad , Náusea/inducido químicamente , Estudios Retrospectivos , Factores de Riesgo , Antagonistas del Receptor de Serotonina 5-HT3/uso terapéutico , Factores Sexuales , Vómitos/inducido químicamenteRESUMEN
BACKGROUND AND STUDY AIMS: A small amount of free air, visible on CT but not on plain chest radiography, which appeared following endoscopic submucosal dissection (ESD) of a gastric neoplasm without endoscopically visible perforation, was defined as a "transmural air leak", and a prospective, consecutive entry study was performed to determine its incidence and clinical significance. PATIENTS AND METHODS: Between January 2006 and September 2008, ESD was performed for 246 gastric lesions in 246 consecutive patients. Abdominal CT scan was performed 1 day after ESD. In addition, chest radiography and blood biochemistry tests were performed at different time points before and after ESD. RESULTS: Two hundred and nineteen lesions (89 %) were curatively removed by ESD. Among the total of 246 patients, we encountered endoscopically visible perforation during ESD in 2 patients (0.8 %), and clinically suspected perforation diagnosed by the presence of free air on chest radiography but invisible during ESD in 3 patients (1 %), while transmural air leak was observed in another 33 (13 %). Air leak occurred in cases where resection size was larger, procedure time longer, and the muscularis propria on the ulcer base was exposed at the end of ESD. Patients with air leaks developed pyrexia at a higher rate than those without (36 % vs. 16 %, P = 0.018). These patients recovered with antibiotics and required no endoscopic or surgical intervention. The presence of an air leak did not affect the duration of hospital stay. CONCLUSIONS: A transmural air leak was observed in 13 % of the patients undergoing ESD. Larger resection size, prolonged procedure time, and exposure of the muscularis propria on the ulcer base were risk factors for transmural air leak, but the outcome of patients with this complication was good.
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Adenocarcinoma/cirugía , Adenoma/cirugía , Gastroscopía/efectos adversos , Neoplasias Gástricas/cirugía , Estómago/lesiones , Tomografía Computarizada por Rayos X , Adulto , Anciano , Anciano de 80 o más Años , Aire , Disección/efectos adversos , Femenino , Mucosa Gástrica/cirugía , Humanos , Incidencia , Masculino , Persona de Mediana Edad , Complicaciones Posoperatorias/diagnóstico por imagen , Complicaciones Posoperatorias/etiología , Estudios ProspectivosAsunto(s)
Fístula Cutánea/terapia , Dilatación/instrumentación , Endoscopios Gastrointestinales , Fístula Gástrica/terapia , Gastrostomía/efectos adversos , Fístula Intestinal/terapia , Yeyunostomía/efectos adversos , Fístula Cutánea/etiología , Fístula Gástrica/etiología , Humanos , Fístula Intestinal/etiología , Enfermedades del Yeyuno/etiología , Enfermedades del Yeyuno/terapia , Resultado del TratamientoAsunto(s)
Endoscopía/métodos , Gastroscopios , Gastrostomía/métodos , Yeyunostomía/métodos , Nutrición Enteral/métodos , Femenino , Estudios de Seguimiento , Gastrostomía/efectos adversos , Humanos , Yeyunostomía/instrumentación , Masculino , Reoperación , Medición de Riesgo , Muestreo , Resultado del TratamientoRESUMEN
A global lunar topographic map with a spatial resolution of finer than 0.5 degree has been derived using data from the laser altimeter (LALT) on board the Japanese lunar explorer Selenological and Engineering Explorer (SELENE or Kaguya). In comparison with the previous Unified Lunar Control Network (ULCN 2005) model, the new map reveals unbiased lunar topography for scales finer than a few hundred kilometers. Spherical harmonic analysis of global topographic data for the Moon, Earth, Mars, and Venus suggests that isostatic compensation is the prevailing lithospheric support mechanism at large scales. However, simple rigid support is suggested to dominate for the Moon, Venus, and Mars for smaller scales, which may indicate a drier lithosphere than on Earth, especially for the Moon and Venus.
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Mucosa Gástrica/cirugía , Gastroscopios , Gastroscopía/métodos , Neoplasias Gástricas/cirugía , Estudios de Seguimiento , Mucosa Gástrica/patología , Gastrostomía/instrumentación , Gastrostomía/métodos , Humanos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Estadificación de Neoplasias , Medición de Riesgo , Muestreo , Neoplasias Gástricas/patología , Resultado del TratamientoRESUMEN
In this study we examined the behavioral pharmacological side effects after recovery from the loss of righting reflex induced by three benzodiazepine receptor agonists - zolpidem, brotizolam and flunitrazepam - in ddY mice. All agents caused marked motor incoordination in the rotarod test and muscle flaccidity in the traction test until 15 min after recovery of righting reflex. Thereafter, the short-acting hypnotics zolpidem and brotizolam showed a faster recovery than the long-acting benzodiazepine flunitrazepam. However, head twitch responses were observed in the mice treated with flunitrazepam, but zolpidem and brotizolam had no such effect. The flunitrazepam-induced head twitch response was antagonized by ketanserin, a 5- HT(2A) receptor antagonist. These results indicate that flunitrazepam, a long-acting benzodiazepine that is nonselective for type I and II benzodiazepine receptors, induces head twitch responses with muscle flaccidity after recovery from the loss of righting reflex caused by these drugs. In addition, these findings suggest the involvement of a 5-HT(2A)-GABA(A) receptor/benzodiazepine interaction in this phenomenon.
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Conducta Animal/efectos de los fármacos , Agonistas del GABA/farmacología , Agonistas de Receptores de GABA-A , Hipnóticos y Sedantes/farmacología , Reflejo , Animales , Azepinas/efectos adversos , Azepinas/farmacología , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas , Flunitrazepam/efectos adversos , Flunitrazepam/farmacología , Agonistas del GABA/efectos adversos , Hipnóticos y Sedantes/efectos adversos , Ketanserina/farmacología , Masculino , Ratones , Ratones Endogámicos , Piridinas/efectos adversos , Piridinas/farmacología , Antagonistas del Receptor de Serotonina 5-HT2 , Antagonistas de la Serotonina/farmacología , Factores de Tiempo , ZolpidemRESUMEN
BACKGROUND: Obesity is a risk factor for acute pancreatitis (AP), but the molecular mechanism remains unclear. Adiponectin, an adipose tissue-derived secretory factor, has anti-inflammatory properties in addition to various biological functions, and its plasma concentrations are reduced in obese subjects. However, the role of adiponectin in AP has not been investigated. AIM: To determine the effects of adiponectin on AP. METHODS: We investigated the effects of adiponectin on experimental AP by using adiponectin-knockout (APN-KO) mice and adenovirus-mediated adiponectin over-expression. AP was induced by 10 hourly intraperitoneal injections of low-dose caerulein (10 microg/kg) after 2 week feeding of normal chow or a high-fat diet (HFD) in wild-type (WT) and APN-KO mice. We evaluated the severity of AP biochemically and morphologically. RESULTS: Low-dose caerulein treatment did not induce pancreatic damage in either WT or APN-KO mice under normal chow feeding. APN-KO mice, but not WT mice, fed a HFD and then treated with caerulein developed pancreatic damage and inflammation, accompanied by increased macrophage/neutrophil infiltration and upregulation of pro-inflammatory mediators such as tumour necrosis factor alpha in the pancreas. Adenovirus-mediated over-expression of adiponectin attenuated the severity of HFD/caerulein-induced AP in APN-KO mice. CONCLUSIONS: Adiponectin plays a protective role in caerulein-induced AP in HFD-fed mice.
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Adiponectina/fisiología , Pancreatitis/prevención & control , Enfermedad Aguda , Adiponectina/metabolismo , Tejido Adiposo/metabolismo , Tejido Adiposo/patología , Animales , Ceruletida , Grasas de la Dieta/administración & dosificación , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones Noqueados , Obesidad/complicaciones , Pancreatitis/inducido químicamente , Pancreatitis/metabolismo , Pancreatitis/patología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Regulación hacia ArribaRESUMEN
The aim of this study was to evaluate the effects of bee products such as honey, royal jelly and propolis on 5-fluorouracil-induced experimental oral mucositis in hamsters. Oral mucositis was induced in hamsters through a combination of 5-fluorouracil and mild abrasions that were made on the cheek pouch. Honey, royal jelly and propolis were thereafter topically administered to the oral mucosa, and then the healing process was examined by measuring the size of the mucositis. Honey (1%, 10% and 100%) and propolis (0.3%, 1% and 3%) ointments did not reduce the size of the mucositis in comparison to the vaseline-treated control group. However, the royal jelly (3%, 10% and 30%) ointments significantly improved the recovery from 5-fluorouracil-induced damage in a dose-dependent manner. These results suggest the possibility that the topical application of royal jelly has a healing effect on severe oral mucositis induced by chemotherapy.
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Ácidos Grasos/administración & dosificación , Fluorouracilo/toxicidad , Estomatitis/inducido químicamente , Estomatitis/tratamiento farmacológico , Administración Tópica , Animales , Cricetinae , Sustancias de Crecimiento/fisiología , Miel , Mesocricetus , Própolis , Cicatrización de HeridasRESUMEN
OBJECTIVE: Recent studies have shown that serum cystatin C is a better marker for measuring the glomerular filtration rate (GFR) than the conventional method, using serum creatinine concentration. The purpose of this study is to evaluate the clinical application of serum cystatin C as a marker of GFR to determine the initial dosage of arbekacin, an antibiotic primarily excreted via the kidneys. In this study, the predictability of serum arbekacin peak and trough concentrations were assessed using estimated population mean GFR values calculated from either serum creatinine (Cockcroft-Gault equation) or cystatin C (Sjöström equation) concentrations. METHOD: Ninety-five patients treated with arbekacin for methicillin-resistant Staphylococcus aureus infection were divided into three groups according to their GFR values estimated by the serum cystatin C concentration as follows: normal to mild (GFR > 70 mL/min, n = 40), moderate (30 = GFR = 70 mL/min, n = 41) and severe (GFR < 30 mL/min, n = 14) renal impairment. RESULT: The mean GFR (+/-SD) of 95 patients predicted by serum cystatin C concentration (64.6 +/- 30.6 mL/min) was significantly lower (P < 0.001) than predicted by serum creatinine concentration (77.4 +/- 43.9 mL/min). Prediction (difference of mean prediction error, DeltaME) of the serum arbekacin concentration using the estimated GFR based on the serum cystatin C concentration was significantly less biased at the peak and trough concentrations than those determined using serum creatinine concentration. The accuracy of prediction (difference of the mean absolute error, DeltaMAE) using serum cystatin C concentration was significantly better than with serum creatinine for both serum peak and trough concentrations in patients with moderately decreased GFR. However, there were no significant differences in the DeltaMAE of normal to mild and severe renally impaired patients. CONCLUSION: These results suggest that serum cystatin C is a useful marker of GFR for determining the initial dosage of arbekacin, especially in patients with moderate impairment of renal function.
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Antibacterianos/administración & dosificación , Antibacterianos/farmacocinética , Cistatinas/sangre , Dibekacina/análogos & derivados , Tasa de Filtración Glomerular , Anciano , Anciano de 80 o más Años , Biomarcadores/sangre , Creatinina/sangre , Cistatina C , Dibekacina/administración & dosificación , Dibekacina/farmacocinética , Monitoreo de Drogas , Femenino , Hospitales Universitarios , Humanos , Masculino , Resistencia a la Meticilina , Insuficiencia Renal/sangre , Insuficiencia Renal/diagnóstico , Insuficiencia Renal/metabolismo , Infecciones Estafilocócicas/tratamiento farmacológico , Infecciones Estafilocócicas/metabolismoRESUMEN
OBJECTIVE: Some formulas using the serum cystatin C level to estimate the GFR have recently been reported. However, there has been no report of a serum cystatin C-based formula for adjusting the dosage of the drugs cleared by the kidney. In this study, we compared the predictive performance of the serum vancomycin trough concentration predicted using serum cystatin C-based formulas. METHOD: The data were collected from 158 hospitalized patients. Five formulas have been published to predict the GFR using serum cystatin C. The cystatin C-based formulas were divided into two groups, formulas with or without anthropometric data. We predicted the serum vancomycin trough concentrations using VCM-TDM S_edition ver. 1.00 software. RESULTS: In formulas with anthropometric data, the mean absolute error (MAE) using Hoek's formula was 2.38, the MAE using Grubb's 1 formula was 4.13, the MAE using Sjöström's formula was 2.90, and the MAE using Cockcroft and Gault formula based on creatinine was 4.42. On the other hand, in formulas without an anthropometric data group, the MAE using Larsson's formula was 3.07, and the MAE using Grubb's 2 formula was 3.63. CONCLUSION: These results suggested that Hoek's formula is the most useful formula for determining the initial dosage settings for vancomycin.
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Algoritmos , Cistatinas/sangre , Monitoreo de Drogas/métodos , Tasa de Filtración Glomerular , Vancomicina/farmacocinética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Antibacterianos/administración & dosificación , Antibacterianos/farmacocinética , Antibacterianos/uso terapéutico , Cistatina C , Recolección de Datos/métodos , Femenino , Inmunoensayo de Polarización Fluorescente/métodos , Humanos , Infusiones Intravenosas , Pacientes Internos , Riñón/metabolismo , Tasa de Depuración Metabólica , Persona de Mediana Edad , Reproducibilidad de los Resultados , Factores de Tiempo , Vancomicina/sangre , Vancomicina/uso terapéuticoRESUMEN
One of the clinical problems regarding the use of suppositories for patients is the discharge of the medication itself after the insertion of the suppository. The effects of the discharge of diazepam (DZP) suppositories from the rectum on the plasma DZP concentration and its anticonvulsant action were investigated in rats. The plasma DZP concentration reached a maximum at approx. 30 min after the rectal administration of a 5 mg/kg DZP suppository. The discharge of the DZP suppository from the rectum at 5 or 10 min after rectal administration significantly reduced the plasma DZP concentration and the anticonvulsant action of the DZP suppository against pentylenetetrazol-induced seizures. However, when the suppository was discharged from the rectum after 20 min, the plasma DZP concentration and the anticonvulsant action were only slightly but not significantly decreased. These results suggest that the discharge of the DZP suppository in the early phase, within 20 min, decreases the plasma concentration and the anticonvulsant action of the DZP suppository in rats. Therefore, when the suppository is discharged from the rectum immediately, sufficient observation and proper treatment are necessary.
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Anticonvulsivantes/sangre , Anticonvulsivantes/uso terapéutico , Diazepam/sangre , Diazepam/uso terapéutico , Convulsiones/prevención & control , Análisis de Varianza , Animales , Anticonvulsivantes/administración & dosificación , Disponibilidad Biológica , Diazepam/administración & dosificación , Relación Dosis-Respuesta a Droga , Absorción Intestinal , Masculino , Pentilenotetrazol , Ratas , Ratas Sprague-Dawley , Recto , Convulsiones/inducido químicamente , Supositorios , Factores de TiempoRESUMEN
Recently, the treatment of advanced gastric cancer by continuous infusion of 5-fluorouracil (5-FU) with low-dose cisplatin (CDDP) has improved efficacy without severe toxicities. The possible effectiveness of 5-FU+low-dose CDDP for colorectal cancer (CRC) is intriguing. One hundred fifty-five patients with far-advanced CRC including at least one measurable lesion were enrolled in a prospective randomized clinical trial funded by the Japanese Foundation for Multidisciplinary Treatment of Cancer. These patients were assigned to the two arms to assess the value of low-dose CDDP when added to a continuous intravenous infusion of 5-FU at a dose of 300 mg/m(2)/24 hrs in a one-week cycle consisting of 5 days of treatment and 2 days of rest for at least 12 weeks. CD-DP was given intravenously at a dose of 3 mg/m(2) on days 1-5 and days 8-12, and then at a dose of 7 mg/m(2) twice a week. Three patients were excluded from the trial. The response rate in the 5-FU+low-dose CDDP arm (n=75) was significantly higher than that in the 5-FU arm (n=77) (25.3% vs. 11.7%; P = 0.037). There was no significant difference in the median overall survival time between the 5-FU+low-dose CDDP arm and the 5-FU arm (479 and 491 days, respectively). Grades 3/4 toxicities occurred infrequently in both arms. The quality of life was almost the same between the arms. Low-dose CDDP improved the response rate while keeping toxicities within clinically acceptable limits. However, this combined treatment did not confer a survival advantage over treatment with continuous infusion of 5-FU alone for patients with far-advanced CRC; that might be attributable to the short CDDP administration setting of 12 weeks.
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Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Neoplasias Colorrectales/tratamiento farmacológico , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/efectos adversos , Cisplatino/administración & dosificación , Neoplasias Colorrectales/mortalidad , Neoplasias Colorrectales/patología , Progresión de la Enfermedad , Esquema de Medicación , Femenino , Fluorouracilo/administración & dosificación , Humanos , Infusiones Intravenosas , Japón/epidemiología , Estimación de Kaplan-Meier , Masculino , Persona de Mediana Edad , Cooperación del Paciente , Estudios Prospectivos , Calidad de Vida , Resultado del TratamientoRESUMEN
In natural populations of Drosophila melanogaster, an amylase isozyme with the lowest alpha-amylase activity (AMY(1,1)) is predominant. To evaluate the selective significance of AMY(1,1) and its regulatory factor(s), we examined selection experiments in laboratory populations on two distinct food environments. After 300 generations, AMY(1,1) became predominant (89%) in a glucose (a product of AMY)-rich environment, while an isozyme with higher alpha-amylase activity, AMY(1,6), became predominant (83%) in a starch (substrate)-rich environment. We found that the identical alleles of the amylase (Amy) gene, which encodes each of AMY(1,1) and AMY(1,6), were shared between the two populations in the different food environments, employing the nucleotide sequencing of the duplicated Amy genes. Nevertheless, AMY(1,6) homozygotes selected in the starch-rich environment had a twofold higher AMY enzyme activity than those selected in the glucose-rich environment, suggesting a coadaptation of the coding region and its regulatory factor(s) on the genetic background. Such a difference in AMY enzyme activity was not detected between AMY(1,1) homozygotes, suggesting that the effect of the genetic background is epistatic. Our results indicate that natural selection is working on the Amy gene system as a whole for flies to adapt to the various food environments of local populations.
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Drosophila melanogaster/genética , alfa-Amilasas/genética , Adaptación Fisiológica/genética , Animales , Secuencia de Bases , Cartilla de ADN , Proteínas de Drosophila/genética , Drosophila melanogaster/enzimología , Evolución Molecular , Regulación Enzimológica de la Expresión Génica , Isoenzimas/genética , Selección GenéticaRESUMEN
BACKGROUND: The MPZ Thr124Met mutation is characterised by a late onset, pupillary abnormality, deafness, normal or moderate decreased motor nerve conduction velocity, and axonal damage in sural nerve biopsy. OBJECTIVE: To investigate the clinical manifestations of the axonal or demyelinating forms of the Japanese MPZ Thr124Met mutation originating in four different areas: Tottori, Nara, Aichi, and Ibaragi. RESULTS: Genotyping with DNA microsatellite markers linked to the MPZ gene on chromosome 1q22-q23 showed shared allelic characteristics between 12.65 cM and revealed a common haplotype in all Tottori families. Aichi and Ibaragi families shared parts of the haplotype around the MPZ gene. However, there was no consistency with a Nara family. CONCLUSIONS: The high frequency of this peculiar genotype in the Tottori CMT population is presumably due to a founder effect, but in Thr124 it might constitute a mutation hotspot in the MPZ gene.