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1.
Zhonghua Yi Xue Za Zhi ; 104(30): 2817-2822, 2024 Aug 06.
Artículo en Chino | MEDLINE | ID: mdl-39085149

RESUMEN

Objective: To investigate the effect of increased cardiac output induced by dobutamine on cerebral blood flow (CBF) in healthy volunteers using magnetic resonance 3D-pseudo-continuous arterial spin labeling technology. Methods: A prospective study was conducted on 48 healthy volunteers recruited by handy sampling from June 2021 to January 2022. Physiological parameters before (at rest state) and after (under stress state) dobutamine-induced increase in cardiac output were analyzed. Quantitative CBF maps were generated by using arterial spin labeling difference imaging and proton density weighted reference image processing, and CBF changes under the rest and stress states were compared. Multivariable logistic regression model was used to analyze factors associated with reduced CBF. Results: A total of 48 subjects were included, with an age [M (Q1, Q3)] of 25.0 (24.0, 28.0) years, including 43 men and 5 women. Compared with the rest state, the CBF in the anterior cerebral artery [(36.2±6.9) vs (34.5±6.5) ml·(100 g)-1·min-1, P=0.006] and the middle cerebral artery perfusion area [(35.8±6.5) vs (34.1±6.4) ml·(100 g)-1·min-1, P=0.006] decreased under the stress state, however there was no statistically significant change in CBF in the posterior cerebral artery and the vertebral-basilar artery perfusion area (all P>0.05). Logistic regression analysis showed that the decrease in CBF in the anterior cerebral artery and middle cerebral artery supply regions during the stress state were correlated with an increase in diastolic blood pressure [OR (95%CI): 0.887 (0.796-0.989) and 0.895 (0.805-0.994), both P<0.05]. Conclusions: Dobutamine-induced increase in cardiac output leads to a decrease in CBF in anterior cerebral circulation but has no effect on posterior circulation. The increase in diastolic blood pressure is associated with decreased CBF under the stress state. Changes in CBF should be considered in the context of increased cardiac output.


Asunto(s)
Gasto Cardíaco , Circulación Cerebrovascular , Dobutamina , Imagen por Resonancia Magnética , Humanos , Masculino , Femenino , Circulación Cerebrovascular/efectos de los fármacos , Dobutamina/farmacología , Adulto , Imagen por Resonancia Magnética/métodos , Estudios Prospectivos , Adulto Joven
2.
Eur Rev Med Pharmacol Sci ; 27(20): 9478-9498, 2023 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-37916315

RESUMEN

OBJECTIVE: Transient receptor potential (TRP) channels are a superfamily of permeable cation channels activated by various mechanisms and play a role in nearly all types of sensory signal transduction. In academia, few have comprehensively discussed the research status of TRP channels. This study aims to summarize the knowledge structure and research hotspots of TRP channels using bibliometrics. MATERIALS AND METHODS: TRP channel-related publications from 2003 to 2022 were searched in the Web of Science Core Collection (WoSCC) database. VOSviewer was used for the bibliometric analysis of the literature. RESULTS: We included 12,242 articles from 102 countries, primarily from the United States, China, and Japan. Our research indicates that the number of publications related to TRP channels has increased annually from 2003 to 2022. The leading research institutions are KU Leuven, Harvard University, and the Chinese University of Hong Kong. The Journal of Biological Chemistry is the foremost in this field. The main research topics include the structure and function of TRP channels, their role in pathogenesis, and potential therapeutic strategies for diseases such as pain and respiratory diseases. Among these, "transient receptor potential vanilloid 1 (TRPV1)", "transient receptor potential ankyrin 1 (TRPA1)", "TRPV4", "pain", and "therapy" are emerging research hotspots. CONCLUSIONS: This study offers a comprehensive summary of the current research status and development trends of TRP channels and pinpoints the research hotspots in this field. It not only aids individuals interested in TRP channel-related research in quickly gauging the trends but may also guide the future research directions of researchers.


Asunto(s)
Canales de Potencial de Receptor Transitorio , Humanos , Bibliometría , China , Proteínas del Citoesqueleto , Dolor
5.
Beijing Da Xue Xue Bao Yi Xue Ban ; 52(5): 897-901, 2020 Oct 18.
Artículo en Chino | MEDLINE | ID: mdl-33047726

RESUMEN

OBJECTIVE: To evaluate the classification criteria of early rheumatoid arthritis (ERA) and compare the sensitivity and specificity with the criteria of 1987 American College of Rheumatology (ACR) criteria and 2010 ACR/European League Against Rheumatism (EULAR). METHODS: Patients from 4 hospitals, aged more than 16 years, with arthritis, whose disease duration was ≤1 year, and with ≥1 joint pain and swelling were enrolled in the study. The indicators including clinical manifestations, laboratory tests and imaging examinations were observed. The ERA patients were dignosed by two experienced rheumatologists based on the clinical features, drug therapy information and radiography features. RESULTS: (1) A total of 325 patients with arthritis were enrolled, including 98 males (30.15%) and 227 females (69.85%), The average age was (47.53±14.44) years, and the median disease duration was 5 (2, 8) months. Finally, 236 patients were dignosed with ERA, and 89 patients were dignosed with other diseases (Non-ERA, including osteoarthritis, reactive arthritis, undifferentiated arthritis, spondyloarthritis, etc). (2) The sensitivity of ERA criteria was 87.29%, and the specificity was 84.37%. The sensitivity was higher than that of 1987 ACR criteria (χ2=43.641, P < 0.001), and had no significant difference compared with 2010 ACR/EULAR criteria (χ2=0.446, P=0.593). But the specificity of ERA criteria was lower than that of 1987 ACR criteria (χ2=4.891, P=0.027), which was not statistically significant compared with 2010 ACR/EULAR criteria (χ2=0.044, P=1.000). (3) In the patients with arthritis whose disease duration was ≤3 months and ≤6 months, the sensitivity of ERA criteria was 81.71% and 86.79%, respectively, both were higher than the 1987 ACR criteria (χ2=7.131, P=0.008; χ2=22.015, P < 0.001) and had no statistically difference compared with the 2010 ACR/EULAR criteria (χ2=0.220, P=0.755; χ2=0.473, P=0.491). The differences of the three criteria in specificity were not statistically significant. (4) The three different classification criteria were consistent with the clinical diagnosis, among which the ERA criteria and 2010 ACR/EULAR criteria were slightly higher (Kappa>0.6). The results of the consistency comparison between the three criteria showed that the ERA criteria and 2010 ACR/EULAR criteria had a better consistency (Kappa=0.836). CONCLUSION: The sensitivity of ERA classification criteria in the diagnosis of ERA was higher than that of 1987 ACR criteria, and was equivalent to that of 2010 ACR/EULAR criteria. There is no significant difference in specificity between these three criteria. The ERA criteria can also identify patients with RA at a very early stage in arthritis with disease duration ≤3 months.


Asunto(s)
Artritis Reumatoide , Osteoartritis , Reumatología , Adolescente , Adulto , Artritis Reumatoide/diagnóstico , Artritis Reumatoide/diagnóstico por imagen , Femenino , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Sensibilidad y Especificidad , Estados Unidos
6.
Artículo en Chino | MEDLINE | ID: mdl-32629582

RESUMEN

Objective: To find the risk assessment model of [di (2-ethylhexyl) phthalate, DEHP] fitting well for producing companies. Methods: The Cluster Sampling method was used in selecting a DEHP producing company in the occupational health and workplace environment monitoring study conducted between July and August in 2017. Data was collected by site evaluating and workplace environment monitoring. According to GBZ/T 298-2017《Technical Guidelines for Occupational Health Risk Assessment of Chemical Hazards in the Workplace》, a qualitative assessment method and a semi-quantitative comprehensive index method were chosen as the models and were compared. Results: The occupational health risk of the two methods rated 4 (high risk) and 2 (negligible risk) . Conclusion: The semi-quantitative comprehensive index method is more comprehensive and accurate when used to assess the occupational health risk caused by DEHP.


Asunto(s)
Dietilhexil Ftalato/toxicidad , Salud Laboral , Monitoreo del Ambiente , Medición de Riesgo , Lugar de Trabajo
7.
AJNR Am J Neuroradiol ; 41(2): 246-254, 2020 02.
Artículo en Inglés | MEDLINE | ID: mdl-31974078

RESUMEN

BACKGROUND AND PURPOSE: Conventional imaging examinations are insufficient to accurately assess brain damage in patients with Moyamoya disease. Our aim was to observe brain microstructural changes in patients with Moyamoya disease by diffusional kurtosis imaging and provide support data for application of this technique in individualized assessment of disease severity and surgical outcome among patients with Moyamoya disease. MATERIALS AND METHODS: A total of 64 patients with Moyamoya disease and 15 healthy volunteers underwent diffusional kurtosis imaging, and a second scanning was offered to surgical patients 3-4 months after revascularization. The diffusional kurtosis imaging parameter maps were obtained for mean kurtosis, axial kurtosis, radial kurtosis, fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity. The parameter values were measured in sensory pathway-related regions for all subjects. Differences in diffusional kurtosis imaging parameters of these brain regions were examined for healthy volunteers, patients without acroparesthesia, and asymptomatic and symptomatic sides of patients with acroparesthesia. Changes in diffusional kurtosis imaging parameters of patients with Moyamoya disease before and after revascularization were compared. RESULTS: Compared with healthy volunteers, patients with Moyamoya disease showed decreased mean kurtosis, axial kurtosis, radial kurtosis, and fractional anisotropy in the corona radiata. Similarly, mean kurtosis, radial kurtosis, and fractional anisotropy decreased in the posterior limb of the internal capsule, whereas axial kurtosis decreased and radial kurtosis increased in the thalami of patients with Moyamoya disease compared with healthy volunteers. Compared with the asymptomatic contralateral hemisphere, the symptomatic group showed increased mean kurtosis in the contralateral primary somatosensory cortex, increased fractional anisotropy in the contralateral corona radiata and posterior limb of the internal capsule, and decreased axial kurtosis in the contralateral thalamus. Among patients with Moyamoya disease with acroparesthesia, mean kurtosis decreased in the primary somatosensory cortex on the operated side following revascularization. CONCLUSIONS: The diffusional kurtosis imaging technique is applicable to patients with Moyamoya disease for detecting brain microstructural changes in white and gray matter before and after revascularization; this feature is useful in the assessment of disease severity and surgical outcome.


Asunto(s)
Revascularización Cerebral , Imagen de Difusión por Resonancia Magnética/métodos , Enfermedad de Moyamoya/diagnóstico por imagen , Neuroimagen/métodos , Adolescente , Adulto , Anisotropía , Encéfalo/irrigación sanguínea , Encéfalo/diagnóstico por imagen , Encéfalo/cirugía , Femenino , Sustancia Gris/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Moyamoya/cirugía , Sustancia Blanca/diagnóstico por imagen , Adulto Joven
8.
Zhonghua Yi Xue Za Zhi ; 99(32): 2511-2515, 2019 Aug 27.
Artículo en Chino | MEDLINE | ID: mdl-31484278

RESUMEN

Objective: To analyze the clinical characteristics and treatment of female stress urinary incontinence (SUI) combined with bladder neck obstruction (BNO). Methods: The clinical data of 17 cases of female SUI patients with BNO, who was admitted to the Urology department, Beijing Chaoyang hospital from November 2011 to April 2018, were retrospectively analyzed. The mean age was (60.3±2.6) years old and the mean body mass index was (23.8±0.5) kg/m(2). All patients had the first stage bladder neck incision with the second stage suprapubic urethral support sling. The clinical characteristics, curative effects and outcomes were analyzed. Results: The maximum flow rate was increased significantly after the bladder neck incision compared with preoperative [(9.3±0.5) vs (25.6±0.8) ml/s, P<0.001]. The postvoid residual urine volume and PdetQmax were decreased significantly than that preoperative [(167.5±4.4) vs (4.1±0.5) ml, P<0.001; (49.4±1.3) vs (24.9±0.7) cmH(2)O, P<0.001]. The incontinence questionnaire-short form score was significantly lower after the second stage suprapubic urethral support sling [(2.4±0.4) vs (14.9±0.3), P<0.001]. The number of subjective and objective case of suprapubic urethral support sling was 13, and the treatment effect of other patients was improved. The hospitalization and operation time of the bladder neck incision and the suprapubic urethral support sling were short. All patients had no intraoperative complications, two cases had dysuria and one case had groin pain after the suprapubic urethral support sling operation. Conclusions: The patients of female SUI combined with BNO are most elderly and obese population. The effectiveness and safety of the first stage bladder neck incision and the second stage suprapubic urethral support sling are high, and the surgeries can effectively relieve the obstruction and improve the quality of patients' life.


Asunto(s)
Cabestrillo Suburetral , Obstrucción del Cuello de la Vejiga Urinaria , Incontinencia Urinaria de Esfuerzo , Femenino , Humanos , Persona de Mediana Edad , Estudios Retrospectivos , Obstrucción del Cuello de la Vejiga Urinaria/complicaciones , Incontinencia Urinaria de Esfuerzo/etiología , Incontinencia Urinaria de Esfuerzo/terapia , Procedimientos Quirúrgicos Urológicos
9.
J Microbiol Methods ; 158: 93-98, 2019 03.
Artículo en Inglés | MEDLINE | ID: mdl-30742840

RESUMEN

Bacterial fruit blotch (BFB) of cucurbits, caused by Acidovorax citrulli, is a major threat to commercial watermelon and melon production worldwide. At present, there are at least two genetically distinct sub-populations (group I and II) of A. citrulli that differ in host preference among cucurbit species and copper sensitivity. In this study, we analyzed the pilA gene sequences of 103 A. citrulli strains from China and other countries. Based on these data, we classified all tested A. citrulli strains into three types. The pilA-based type 1 strains in this study coincided with the previously established group I strains; while the type 2 strains coincided with group II strains. Ten strains that did not cluster with group I or II strains were classified into a new type, designated type 3. Based on differences in pilA sequences, we designed a multiplex PCR assay to distinguish the three A. citrulli pilus types. This multiplex PCR assay has proven to be viable for strain typing of 139 A. citrulli strains and for the detection of this pathogen in artificially inoculated seeds and leaves and naturally infected leaves and fruits. This assay proved to be rapid, accurate, reliable and applicable for early distinction of A. citrulli types associated with BFB epidemics. It may also inform the judicious and environmentally sound use of bactericides, especially copper-based compounds.


Asunto(s)
Comamonadaceae/genética , Proteínas Fimbrias/clasificación , Proteínas Fimbrias/genética , Reacción en Cadena de la Polimerasa Multiplex , Frutas/microbiología , Enfermedades de las Plantas/microbiología
10.
Clin Transl Oncol ; 18(1): 47-57, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26243393

RESUMEN

PURPOSE: To study the feasibility and clinical value of dynamic contrast-enhanced (DCE) computed tomography (CT) for early evaluation of targeted therapy efficacy in non-small cell lung cancer (NSCLC). METHODS: We measured tumor diameter, peak height (PH), time to peak (TP), tumor mass-aortic peak height ratio (M/A), and blood perfusion (BP) in 20 patients with advanced NSCLC using DCE-CT before and 7 days after treatment. Therapy efficacy was assessed with conventional CT 4-6 weeks post-treatment. RESULTS: Patients were grouped into those with partial response (PR), stable disease (SD), and progressive disease (PD) according to the therapy efficacy assessment at 4-6 weeks post-treatment. The PR group primary tumor diameter (P = 0.0007) and BP (P = 0.0225) were reduced at 7 days post-treatment; the SD group DCE-CT value changes were not significant. The PD group M/A (P = 0.0443) and BP (P = 0.0268) were increased 7 days post-treatment. The BP decrease group had significantly longer progression-free survival than the BP increase group (median, 54 vs. 6 weeks). CONCLUSION: DCE-CT can evaluate targeted therapy efficacy at 7 days post-treatment. Decreased primary tumor diameter and BP indicate tumor sensitivity to therapy; increased BP with unchanged tumor diameter suggests the tumor is not sensitive to therapy. Reduced BP suggests treatment effectiveness.


Asunto(s)
Inhibidores de la Angiogénesis/uso terapéutico , Carcinoma de Pulmón de Células no Pequeñas/diagnóstico por imagen , Carcinoma de Pulmón de Células no Pequeñas/tratamiento farmacológico , Neoplasias Pulmonares/diagnóstico por imagen , Neoplasias Pulmonares/tratamiento farmacológico , Tomografía Computarizada Espiral/métodos , Adulto , Anciano , Carcinoma de Pulmón de Células no Pequeñas/patología , Medios de Contraste , Femenino , Humanos , Neoplasias Pulmonares/patología , Masculino , Persona de Mediana Edad , Terapia Molecular Dirigida , Pronóstico , Factores de Tiempo , Resultado del Tratamiento
11.
Br J Radiol ; 86(1026): 20130035, 2013 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-23652630

RESUMEN

OBJECTIVE: CT imaging may be an effective diagnostic method for assessing the extent and progression of pulmonary injury in patients with acute paraquat (PQ) poisoning. METHODS: A retrospective review of 78 patients with acute PQ poisoning (survivor group, n=42; non-survivor group, n=36) was conducted to examine the lung segment involvement and CT image characteristics from baseline (first CT scan at a mean of 2.4 days after poisoning) to treatment time (second CT scan 3 days after the first). We examined the association between prognosis and pulmonary lesions indicated by characteristic effusion, fibrosis and consolidation in CT images. RESULTS: Significant differences were apparent in CT images at baseline and after 3 days between the survivor and the non-survivor groups, with higher levels of pulmonary segment involvement, effusion, consolidation and fibrosis observed in the non-survivor group at baseline (p<0.05). The non-survivor group also showed rapid lesion progression. The receiver operating characteristic curve indicated that the best prognostic value of baseline CT scanning was achieved when performed 2-3 days following the initial exposure. CONCLUSION: Prognosis correlated with increasing lung segment involvement, extent of disease characteristics visualised using CT and speed of lesion progression from baseline. Prognostic evaluation using CT scanning can be used to effectively provide earlier treatment for patients at risk for severe complications associated with PQ toxicity, such as acidosis; leukocytosis; and renal, hepatic and pancreatic failures. ADVANCES IN KNOWLEDGE: Chest CT scan can be used 2-3 days following acute PQ poisoning to determine prognosis.


Asunto(s)
Herbicidas/envenenamiento , Lesión Pulmonar/diagnóstico por imagen , Pulmón/patología , Paraquat/envenenamiento , Fibrosis Pulmonar/diagnóstico por imagen , Tomografía Computarizada por Rayos X , Adulto , China/epidemiología , Femenino , Humanos , Lesión Pulmonar/inducido químicamente , Lesión Pulmonar/mortalidad , Masculino , Pronóstico , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/mortalidad , Estudios Retrospectivos , Población Rural
12.
Mycologia ; 103(4): 703-9, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21289105

RESUMEN

The diversity of ericoid mycorrhizal fungi isolated from Rhododendron decorum Franch. in Yunnan, southwestern China, was examined for the first time. In total 300 hair-root samples were collected from 13 R. decorum individuals in two adjacent wild population sites and one cultivated population site. Two hundred eighteen slow-growing isolates were obtained; the ability of some to form ericoid mycorrhiza was tested in vitro. One hundred twenty-five isolates formed hyphal structures morphologically corresponding to ericoid mycorrhiza, and these were determined by morphological and molecular means to belong to 12 fungal species. There were hardly any differences in species among the three sampled populations. The sequences of several isolates were similar to those of Oidiodendron maius and ericoid mycorrhizal fungi from Helotiales, accounting respectively for 18.4% and 24.8% of the total culturable ericoid mycorrhizal fungi assemblage. Dark septate endophytes were detected in the sampled hair roots by microscopy.


Asunto(s)
Ascomicetos/clasificación , Micorrizas/clasificación , Rhododendron/microbiología , Ascomicetos/genética , Ascomicetos/aislamiento & purificación , Secuencia de Bases , Biodiversidad , China , Dermatoglifia del ADN/métodos , ADN de Hongos/química , ADN de Hongos/genética , ADN Espaciador Ribosómico/genética , Datos de Secuencia Molecular , Micorrizas/genética , Micorrizas/aislamiento & purificación , Filogenia , Raíces de Plantas/genética , Raíces de Plantas/microbiología , Polimorfismo de Longitud del Fragmento de Restricción , Nódulos de las Raíces de las Plantas/clasificación , Nódulos de las Raíces de las Plantas/genética , Nódulos de las Raíces de las Plantas/microbiología
13.
J Viral Hepat ; 12(2): 168-75, 2005 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-15720532

RESUMEN

During the course of lamivudine administration in hepatitis B virus (HBV)-infected patients, a dynamic development of the viral population in serum is observed. Total HBV level is initially reduced, then lamivudine-resistant mutants appear, and finally, the viral level is increased. All methods of mutant detection so far described can only identify mutants in the serum, and cannot determine the proportion of those mutants. In this paper, we report the development of a novel technique that can quantify the relative proportion of mutants in serum utilizing gene microarray technology. Based on the nucleotide sequence at the loci of the mutations in lamivudine-resistant HBV mutants, 28 probes were designed and dotted on glass film to prepare the oligonucleotide microarray. Ten standard curves were established by employing 15 reference plasmids as templates. Ten standard math functions were simulated, which allowed quantification of the proportion of mutants in the sample by measuring the value of fluorescent intensity on the microarray. By utilizing the standard math function, the relative proportion of two different mutation sequences in the mixed template could be detected with an error <10%. The HBV-lamivudine oligonucleotide microarray is reliable to quantify the relative proportion of wild-type HBV vs HBV mutants in patient's sera.


Asunto(s)
Virus de la Hepatitis B/efectos de los fármacos , Virus de la Hepatitis B/genética , Hepatitis B/tratamiento farmacológico , Lamivudine/uso terapéutico , Mutación , Reacción en Cadena de la Polimerasa , Secuencia de Bases , Estudios de Cohortes , ADN Viral/análisis , Farmacorresistencia Viral , Femenino , Hepatitis B/sangre , Hepatitis B/genética , Humanos , Masculino , Datos de Secuencia Molecular , Análisis de Secuencia por Matrices de Oligonucleótidos , Sensibilidad y Especificidad , Resultado del Tratamiento , Carga Viral
14.
Comp Biochem Physiol C Toxicol Pharmacol ; 133(4): 575-85, 2002 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-12458185

RESUMEN

This study measured the chemical uptake of three hydrophobic chemicals (1,2,4-trichlorobenzene (1,2,4-TCB), 1,2,3,4,5-pentachlorobenzene (PeCB) and 2,2',4,4',6,6'-hexachlorobiphenyl (HCBP) with differing octanol-water partition coefficients (log K(ow) values of 3.95, 5.05 and 7.55, respectively) in juvenile rainbow trout (Oncorhynchus mykiss) after 2-day and 4-day aqueous exposures. Because of the affinity of hydrophobic compounds for dissolved organic carbon (DOC) and previous work demonstrating that fish gills take up these three hydrophobic chemicals, we predicted that chemical uptake into the fish would be lowered by the addition of humic acid to the water (1.54, 4.81 and 14.3 mg/l) compared with control fish (no humic acid added to the water). As predicted, humic acid concentrations of >or=4.81 mg/l significantly reduced the whole body concentrations of all three chemicals when compared with 1.54 mg/l humic acid. This effect of humic acid was greatest for HCBP, the chemical with the highest log K(ow), such that chemical uptake was reduced by 3.4-fold for 14.3 mg/l humic acid compared with the control exposure. However, an unexpected finding was that, compared with the control exposure, the lowest concentration of humic acid tested (1.54 mg/l humic acid) significantly increased chemical uptake by up to 112% for the two chemicals with the lower log K(ow), PeCB and 1,2,4-TCB, and did not affect uptake of the high log K(ow) chemical HCBP. We conclude that the ability of DOC to inhibit aqueous uptake of hydrophobic chemicals was dependent on both the concentration of DOC and the log K(ow) of the chemical, but that low humic acid concentrations of approximately 1.5 mg/l can significantly increase uptake of certain chemicals with a log K(ow) between 4 and 5.


Asunto(s)
Clorobencenos/metabolismo , Sustancias Húmicas/farmacología , Interacciones Hidrofóbicas e Hidrofílicas , Oncorhynchus mykiss/metabolismo , Bifenilos Policlorados/metabolismo , Animales , Sustancias Húmicas/metabolismo , Solubilidad
15.
Arch Environ Contam Toxicol ; 39(3): 369-77, 2000 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-10948288

RESUMEN

This study assessed the relative contributions of aqueous versus dietary uptake of three hydrophobic chemicals, 1,2, 4-trichlorobenzene (1,2,4-TCB), 1,2,3,4,5-pentachlorobenzene (PeCB), and 2,2',4,4',6,6'-hexachlorobiphenyl (HCBP). Juvenile rainbow trout (Oncorhynchus mykiss) were exposed separately to chemically spiked water and food for 4 days and 12 days, respectively. Chemical concentrations were measured in the food, water, and tissues, and this allowed calculation of uptake rate constants (k(1) from water exposure, k(d) from food exposure). The k(1) values for the three test chemicals were approximately five orders of magnitude greater than the k(d) values. Using these measured uptake rate constants, a simulation model was used to predict the relative aqueous versus dietary uptake when fish were exposed simultaneously to water and food contaminated with these hydrophobic chemicals. The model predicted for all three test chemicals that the two uptake routes would contribute equally to the chemical body burden in fish whenever the food:water chemical concentration ratio was near 10(5). However, using food:water chemical concentration ratios that might be expected in nature, the model predicted that gill uptake could account for over 98% of fish body burden for both 1,2,4-TCB and PeCB uptake (log K(ow) values of 3.98 and 5.03, respectively). For HCBP (log K(ow) of 7.55), the model predicted that the dietary uptake could contribute over 85% of the body burden. Thus, depending on the actual food:water chemical concentration ratio, aqueous uptake via the gills can predominate even when the chemicals have a log K(ow) value greater than 5.0. In addition, we confirmed that dietary uptake of hydrophobic xenobiotics increases with increasing log K(ow).


Asunto(s)
Clorobencenos/química , Bifenilos Policlorados/química , Trucha/metabolismo , Contaminantes Químicos del Agua/metabolismo , Algoritmos , Animales , Carga Corporal (Radioterapia) , Clorobencenos/metabolismo , Clorobencenos/toxicidad , Dieta , Modelos Teóricos , Bifenilos Policlorados/metabolismo , Bifenilos Policlorados/toxicidad
16.
Sheng Li Xue Bao ; 49(5): 585-8, 1997 Oct.
Artículo en Chino | MEDLINE | ID: mdl-9813501

RESUMEN

In the present study, the sleep-waking cycle and the immunoreactivity of 5-HT-containing neurons in rats receiving intraperitoneal injections of N-Nitro-L-arginine (L-NNA, 50 mg/kg) and L-arginine (L-arg, 110 mg/kg) were observed respectively. The results showed that injection of L-NNA suppressed both slow wave sleep (SWS) and rapid eye movement sleep (REMS) and increased mean arterial pressure (MAP). L-arg markedly attenuated MAP, whereas SWS and REMS were unchanged. The effects of L-NNA on sleep and MAP were reversed by preinjection of L-arg. In comparison with control group, the positive cells in dorsal raphe nucleus (DR) and raphe magus nucleus (MnR) increased 2 h after injection of L-NNA. The effect was attenuated by preadministration of L-arg. All these results suggest that L-arg: NO pathway is involved in the regulation of sleep-waking cycle and the increment of the positive immunoreactivity of the 5-HT-containing neurons in the DR may be related to the sleep-suppressive effects induced by L-NNA.


Asunto(s)
Arginina/farmacología , Nitroarginina/farmacología , Núcleos del Rafe/fisiología , Sueño/efectos de los fármacos , Animales , Femenino , Inyecciones Intraperitoneales , Masculino , Neuronas/fisiología , Ratas , Ratas Wistar , Serotonina/fisiología
17.
Yao Xue Xue Bao ; 25(3): 215-9, 1990.
Artículo en Chino | MEDLINE | ID: mdl-2239337

RESUMEN

Since the bioavailability of the suspension and the tablet of DDB given orally is only 20-30%, we have prepared four kinds of DDB solid dispersion preparations (DDB pilule I with polyethylene glycol 6000 as the vehicle, DDB pilule II with polyethylene glycol 6000 and absorption accelerator as the vehicle, capsule of DDB-urea fusing mixture and DDB-polyvinyl pyrrolidone coprecipitate), and the bioavailability of these preparations were studied in rabbits, rats and human volunteers by HPLC method. All four preparations showed better absorption than the DDB tablet, and the area under serum DDB concentration-time curve of pilule II was 19 fold that of the tablet in rabbits, meaning that the absorption of pilule II is the best of the four preparations. After administration of the four solid dispersion preparations, the fecal excretion of DDB were all lower than the tablet in both animals and human volunteers. The protective action of pilule II against CCl4 hepatotoxicity was about six times stronger than that of the suspensions. Therefore, there are good reasons to use DDB pilule II instead of the tablets of suspension in the clinic.


Asunto(s)
Dioxoles/farmacocinética , Medicamentos Herbarios Chinos/farmacocinética , Animales , Disponibilidad Biológica , Intoxicación por Tetracloruro de Carbono/prevención & control , Cromatografía Líquida de Alta Presión , Dioxoles/administración & dosificación , Formas de Dosificación , Femenino , Humanos , Masculino , Conejos , Ratas , Comprimidos
18.
Yao Xue Xue Bao ; 24(10): 778-82, 1989.
Artículo en Chino | MEDLINE | ID: mdl-2618670

RESUMEN

Daidzein-PVP coprecipitates were preparated by solvent evaporation method. X-ray diffraction and microscope studies indicated that the ratio of PVP should be up to 1:5 (daidzein:PVP) to form the coprecipitates. Dissolution test, in vitro, indicated that the percent of dissolved daidzein increased remarkably by coprecipitation. The tablets made of the coprecipitates with some excipients released daidzein rapidly. Near complete release (90%) was obtained in about one hour when tested in water or simulated intestinal liquid.


Asunto(s)
Flavonoides , Isoflavonas , Povidona , Precipitación Química , Combinación de Medicamentos , Solubilidad , Comprimidos
19.
Yao Xue Xue Bao ; 24(11): 859-64, 1989.
Artículo en Chino | MEDLINE | ID: mdl-2618685

RESUMEN

DDB is poorly soluble in water. The solid dispersions of DDB with easily soluble carriers such as polyethylene glycol 6000 (PEG 6000), polyvinyl pyrrolidone (PVP) and urea were prepared by melting and solvent methods. The two DDB-PEG 6000 systems are thermodynamically stable interstitial solid solutions. The DDB-PVP system is an amorphous precipitate and the DDB-urea system is a simple eutectic physical mixture judged by X-ray diffraction and thermal analysis methods. The dissolution rate of DDB-PEG 6000 pilule and two kinds of DDB tablets were determined. The dissolution rate of DDB-PEG 6000 pilule was found to be faster. The physical dispersion state is an important factor in relation to the dissolution rate of DDB preparations.


Asunto(s)
Dioxoles , Solubilidad , Comprimidos
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