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1.
J Anus Rectum Colon ; 8(2): 126-131, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38689784

RESUMEN

Objectives: Chronic constipation is a common gastrointestinal disorder, and management is crucial. Computed tomography (CT) is useful for evaluating rectal fecal mass but limited owing to radiation exposure, cost, and inaccessibility at certain facilities. Ultrasonography (US) avoids these pitfalls, but it is unknown whether it accurately assesses rectal feces. In this study, we evaluated the diagnostic performance of US compared with CT as the gold standard for assessing rectal feces. Methods: We prospectively evaluated rectal fecal mass retention using US performed within 1 h of CT to assess the degree of agreement between methodologies. Rectal stool findings were evaluated on three levels: no stool (R1), presence of stool (R2), and hard stool filling (R3). Results: The sample included 100 patients (55 men, 45 women), of whom 47 were constipated. The kappa coefficients for rectal content detection were excellent between US and CT (p <0.001). Eighty-two cases (R1: 46 cases; R2: 28 cases; R3: 8 cases) were matched with CT and US findings, and 18 were not. Cases that did not match had low urine or high gas volumes. CT and US findings showed high agreement in constipation (kappa coefficient 0.674, p <0.001) and non-constipation groups (kappa coefficient 0.677, p <0.001). All cases with R3 on CT were found in the constipation group, while more than half of the cases with R1 on CT were in the non-constipation group. Conclusions: CT and US showed high agreement in evaluating rectal fecal mass retention, indicating that US can substitute CT.

2.
J Hepatobiliary Pancreat Sci ; 31(3): 203-212, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38014632

RESUMEN

BACKGROUND/PURPOSE: There is currently no consensus on the use of endoscopic papillectomy (EP) for early stage duodenal ampullary adenocarcinoma. This study aimed to evaluate the feasibility of EP for patients with early stage duodenal ampullary adenocarcinoma. METHODS: Patients who underwent EP for ampullary adenocarcinomas were investigated. Complete and clinical complete resection rates were evaluated. Clinical complete resection was defined as either complete resection or resection with positive or unknown margins but no cancer in the surgically resected specimen, or no recurrence on endoscopy after at least a 1-year follow-up. RESULTS: Adenocarcinoma developed in 30 patients (carcinoma in situ [Tis]: 21, mucosal tumors [T1a(M)]: 4, tumors in the sphincter of Oddi [T1a(OD)]: 5). The complete resection rate was 60.0% (18/30) (Tis: 66.7% [14/21], T1a[M]: 50.0% [2/4], and T1a[OD]: 40.0% [2/5]). The mean follow-up period was 46.8 months. The recurrence rate for all patients was 6.7% (2/30). The clinical complete resection rates of adenocarcinoma were 89.2% (25/28); rates for Tis, T1a(M), and T1a(OD) were 89.4% (17/19), 100% (4/4), and 80% (4/5), respectively. CONCLUSIONS: EP may potentially achieve clinical complete resection of early stage (Tis and T1a) duodenal ampullary adenocarcinomas.


Asunto(s)
Adenocarcinoma , Ampolla Hepatopancreática , Neoplasias del Conducto Colédoco , Neoplasias Pancreáticas , Humanos , Ampolla Hepatopancreática/cirugía , Ampolla Hepatopancreática/patología , Resultado del Tratamiento , Estudios Retrospectivos , Adenocarcinoma/cirugía , Adenocarcinoma/patología , Endoscopía Gastrointestinal , Neoplasias del Conducto Colédoco/diagnóstico por imagen , Neoplasias del Conducto Colédoco/cirugía , Neoplasias del Conducto Colédoco/patología , Neoplasias Pancreáticas/patología
3.
Kyobu Geka ; 76(13): 1127-1130, 2023 Dec.
Artículo en Japonés | MEDLINE | ID: mdl-38088078

RESUMEN

An 97-year-old woman was diagnosed with complete atrioventricular block and underwent pacemaker implantation( PMI). Three days after the PMI, computed tomography revealed cardiac perforation and migration of the lead to the abdominal cavity. Surgical procedure through median sternotomy was performed, and the penetrated lead was removed. The holes of the right ventricle and diaphragm were repaired. Abdominal organ was not injured. She was discharged 14 days after the surgical procedure.


Asunto(s)
Lesiones Cardíacas , Marcapaso Artificial , Femenino , Humanos , Anciano de 80 o más Años , Ventrículos Cardíacos/diagnóstico por imagen , Ventrículos Cardíacos/cirugía , Diafragma/diagnóstico por imagen , Diafragma/cirugía , Marcapaso Artificial/efectos adversos , Tórax , Lesiones Cardíacas/diagnóstico por imagen , Lesiones Cardíacas/etiología , Lesiones Cardíacas/cirugía
4.
Cancers (Basel) ; 15(17)2023 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-37686686

RESUMEN

This retrospective cohort study compared the number of newly diagnosed patients, stage at diagnosis, and detection process of gastrointestinal cancers based on hospital-based cancer registry data at two tertiary Japanese hospitals. The pre-COVID-19 period was from January 2017 to February 2020, with phase 1 (midst of COVID-19 pandemic) from March to December 2020 and phase 2 (the transition period to the "new normal") from January to December 2021. Each month, the number of patients diagnosed with esophageal, gastric, colorectal, pancreatic, liver, and biliary tract cancers were aggregated, classified by stage and detection process, and compared, including a total of 6453 patients. The number of colorectal Stage 0-II patients decreased significantly in phase 1 and increased in phase 2. The total number of colorectal cancer patients returned to pre-COVID-19 levels (mean monthly patients [SD]: 41.61 [6.81] vs. 36.00 [6.72] vs. 46.00 [11.32]). The number of patients with gastric cancer Stage I significantly decreased in phase 2 following phase 1. The number of gastric cancer patients decreased significantly from pre-COVID-19 levels (30.63 [6.62] vs. 22.40 [5.85] vs. 24.50 [4.15]). During phase 2, the number of patients diagnosed after screening with colorectal cancer increased significantly, whereas that with gastric cancer remained considerably lower. The number of Stage III colorectal and gastric cancer patients increased significantly from the pre-COVID-19 levels. Thus, gastric cancer may not be optimally screened during phases 1 and 2. There was a significant increase in patients with Stage III colorectal and gastric cancers from the pre-COVID-19 period; hence, the stage at diagnosis may have progressed.

5.
J Cancer Res Clin Oncol ; 149(9): 5781-5790, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36581687

RESUMEN

PURPOSE: Lymphovascular infiltration (LVI) may play a critical role in radicality and prognostic assessment of early gastric cancer (EGC). However, risk factors for LVI in endoscopically resected EGC remain unknown. This study evaluated the clinicopathological characteristics and prognoses of patients who underwent endoscopic resection of EGC to identify potential risk factors of LVI. METHODS: A cross-sectional study of patients who received gastric endoscopic submucosal dissection between February 1, 2012, and December 31, 2019, at two institutions was conducted. Among 1,462 lesions, 943 met the criteria for radical treatment considering features other than LVI and were included. The lesions were classified based on the presence of LVI. The clinicopathological characteristics of the two groups were compared. RESULTS: LVI was detected in 17 lesions (1.8%). The positivity rates of LVI were 0.7% (7/903) for intramucosal cancer and 25% (10/40) for submucosally invasive cancer. The LVI positivity rate was significantly higher for mixed-type cancer (lesions containing differentiated and undifferentiated-type carcinoma) than for non-mixed-type cancer (35.3 vs. 2.8%; P < 0.001) and for submucosally invasive cancer than for intramucosal cancer (58.8 vs. 3.2%; P < 0.001). In the multivariate logistic regression analysis, independent risk factors for LVI were mixed-type cancer (odds ratio; 95% confidence interval: 23.9; 5.0-115; P < 0.001) and submucosal invasion (58.7; 16.0-215; P < 0.001). CONCLUSIONS: Mixed-type cancer and submucosal invasion were risk factors for LVI in endoscopically resected EGC. These factors may play a critical role in the radicality and prognostic assessment of EGC.


Asunto(s)
Neoplasias Gástricas , Humanos , Neoplasias Gástricas/cirugía , Neoplasias Gástricas/patología , Estudios Transversales , Metástasis Linfática/patología , Pronóstico , Factores de Riesgo , Gastrectomía , Mucosa Gástrica , Estudios Retrospectivos
6.
Diseases ; 12(1)2023 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-38275566

RESUMEN

The impact of the COVID-19 pandemic was very broad and substantial, affecting a variety of fields worldwide. In Japan, the infection began spreading in March 2020. At that time, the government alerted people to cancel overseas travel, and encouraged wearing of masks, handwashing, sanitizing and keeping social distance. We sought to determine how COVID-19 infections affected other infectious diseases by investigating the trends in seven gastrointestinal infections that are listed among the 77 important infectious diseases designated by the National Institute of Infectious Diseases. We compared seven gastrointestinal infectious diseases, namely cholera, bacterial dysentery, enterohemorrhagic Escherichia coli, typhoid fever, paratyphoid fever, amoebic dysentery, and giardiasis, in terms of numbers of new cases before the COVID-19 pandemic (2012-2019) and during the pandemic (2020-2022). During the COVID-19 pandemic period (2020-2022), the incidence of the seven infections decreased significantly (p < 0.05) compared with before the pandemic (2012-2019). The sharp and significant decline in incidence of these seven infections in Japan during the COVID-19 pandemic period (2020-2022) appears to be due to restrictions on overseas travel and strict anti-infection measures, such as self-quarantine and encouragement of handwashing and sanitizing. The number of new cases of gastrointestinal infections in Japan is expected to increase in 2024 as these measures lapse. It is important for physicians to continue to monitor trends in gastrointestinal infections and educate people about proper infection prevention.

7.
Cancer Prev Res (Phila) ; 15(10): 661-668, 2022 10 04.
Artículo en Inglés | MEDLINE | ID: mdl-36083855

RESUMEN

Leukotriene receptor antagonists (LTRA) are widely used drugs for treating allergic asthma, and they have recently been suggested to have a suppressive effect on carcinogenesis and cancer cell proliferation. Aberrant crypt foci (ACF) are considered a reliable surrogate biomarker of colorectal cancer. This prospective study explored the chemopreventive effect of an LTRA on colonic ACF formation and the safety of the medicine in patients as a pilot trial leading to a colorectal cancer chemoprevention trial.This was a nonrandomized, open-label, controlled trial in patients with colorectal ACFs. The participants were allocated to LTRA or observation groups. Patients in the LTRA group received 10 mg of montelukast orally daily for 8 weeks. After the intervention, colonoscopy was performed to evaluate the changes in the number of ACFs.From November 2017 to March 2020, 40 patients were enrolled. The first 30 were assigned to the LTRA group, and the remaining 10 were assigned to the observation group. In the LTRA group, the mean change in the number of ACFs per patient at 8 weeks from baseline was -2.4 ± 2.2, while the mean change in the observation group was 0.4 ± 2.3 (P = 0.002). There were no severe adverse events.This is the first study to explore the effect of LTRAs against colorectal ACF formation in humans. LTRAs are potential candidates for chemoprevention in colorectal cancer. PREVENTION RELEVANCE: We conducted the first LTRA chemoprevention trial for human rectal ACFs, which is considered a surrogate marker of colorectal carcinogenesis. 8-week treatment with LTRA suppressed ACF formation and cell proliferation in colonic epithelium. LTRAs are possible candidates for chemoprevention in colorectal cancer. See related Spotlight, p. 637.


Asunto(s)
Focos de Criptas Aberrantes , Neoplasias Colorrectales , Focos de Criptas Aberrantes/tratamiento farmacológico , Focos de Criptas Aberrantes/prevención & control , Carcinogénesis , Quimioprevención , Neoplasias Colorrectales/tratamiento farmacológico , Neoplasias Colorrectales/prevención & control , Humanos , Antagonistas de Leucotrieno/uso terapéutico , Estudios Prospectivos
8.
Surg Endosc ; 36(10): 7577-7587, 2022 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-35411460

RESUMEN

BACKGROUND AND AIMS: New image-enhanced endoscopy (IEE), blue Light Imaging (LED-BLI) is launched in USA and Europe, whereas Blue Laser Imaging (Laser-BLI) is available only Asian and some countries. No studies have directly compared the diagnostic accuracy of narrow band imaging (NBI), Laser-BLI and LED-BLI for colorectal tumors. The present study aimed to compare the diagnostic accuracy of the three methods for colorectal tumor using the NBI international colorectal endoscopic (NICE) classification and the Japanese NBI Expert Team (JNET) classifications. METHODS: This was a multi-center evaluator-blinded, randomized control trial of patients who underwent endoscopic colorectal tumor resection. The patients were randomly assigned to NBI, Laser-BLI or LED-BLI. Cropped images were sent to blinded external evaluators and diagnosed according to NICE and JNET classifications. The diagnostic accuracy of each endoscopy system was compared with non-inferiority test. RESULTS: A total of 619 colonic tumors were resected from 230 patients and evaluated by external four evaluators. The diagnostic accuracy of NBI for NICE 1, NICE 2, NICE 3 was 90.6%, 90.3% and 99.5%, respectively and for JNET 1, JNET 2A, JNET 2B and JNET 3, it was 94.6%, 72.0%, 79.2% and 99.1%, respectively. In non-inferiority test, Laser-BLI and LED-BLI revealed non-inferiority to NBI in all NICE and JNET categories (p<0.001). CONCLUSIONS: Laser-BLI and LED-BLI had high diagnostic accuracy and non-inferiority of NBI, especially for hyperplastic polyp/sessile serrated lesion and low-grade dysplasia. This is first trial to compare the diagnostic accuracy with NBI, Laser-BLI and LED-BLI and useful to understand the position of each IEE. This trial was registered as UMIN000032107.


Asunto(s)
Pólipos del Colon , Neoplasias Colorrectales , Pólipos del Colon/diagnóstico por imagen , Pólipos del Colon/cirugía , Colonoscopía/métodos , Neoplasias Colorrectales/diagnóstico por imagen , Neoplasias Colorrectales/patología , Humanos , Aumento de la Imagen , Rayos Láser , Imagen de Banda Estrecha/métodos
9.
PLoS One ; 15(7): e0236050, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32678832

RESUMEN

Neurotrophic factors have been regarded having promising potentials for neuronal protection and regeneration, and thus promoting beneficial effects of kinesiological functions. They can be suspected to play important roles in cell/tissue grafting for various neural diseases. The clinical applications of such trophic factors to the central nervous system (CNS), however, have caused problematic side effects on account of the distinctive bioactive properties. In the course of developing synthetic compounds reflecting beneficial properties of basic fibroblast growth factor (bFGF), we conducted screening candidates that stimulate to trigger the intracellular tyrosine phosphorylation of FGF receptor and lead to the subsequent intracellular signaling in neurons. A small synthetic molecule SUN13837 was characterized by mimicking the beneficial properties of bFGF, which have been known as its specific activities when applied to CNS. What is more remarkable is that SUN13837 is eliminated the bioactivity to induce cell proliferation of non-neuronal somatic cells. On the bases of studies of pharmacology, behavior, physiology and histology, the present study reports that SUN13837 is characterized as a promising synthetic compound for treatment of devastating damages onto the rat spinal cord.


Asunto(s)
Materiales Biomiméticos/farmacología , Factor 2 de Crecimiento de Fibroblastos/metabolismo , Recuperación de la Función/efectos de los fármacos , Bibliotecas de Moléculas Pequeñas/farmacología , Traumatismos de la Médula Espinal/fisiopatología , Animales , Axones/efectos de los fármacos , Axones/fisiología , Femenino , Proyección Neuronal/efectos de los fármacos , Fosforilación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Regeneración/efectos de los fármacos , Traumatismos de la Médula Espinal/metabolismo , Traumatismos de la Médula Espinal/patología
10.
Bioorg Med Chem Lett ; 28(14): 2528-2532, 2018 08 01.
Artículo en Inglés | MEDLINE | ID: mdl-29871846

RESUMEN

A series of compounds was discovered that induce the production of VGF mRNA in SH-SY5Y cells and exhibit cytoprotection under tunicamycin induced endoplasmic reticulum (ER) stress. The aminophenol ring and linker chain of the template SUN N8075 (1) was modified to yield compounds with higher efficacy and lower propensity for adverse effects.


Asunto(s)
Factores de Crecimiento Nervioso/biosíntesis , Piperazinas/farmacología , Línea Celular Tumoral , Citoprotección , Relación Dosis-Respuesta a Droga , Estrés del Retículo Endoplásmico/efectos de los fármacos , Humanos , Estructura Molecular , Piperazinas/síntesis química , Piperazinas/química , ARN Mensajero/biosíntesis , Relación Estructura-Actividad , Tunicamicina/farmacología
11.
ACS Appl Mater Interfaces ; 9(11): 9902-9909, 2017 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-28247759

RESUMEN

Anthra[2,3-b]thieno[2,3-d]thiophene (ATT), which is readily accessed from thieno[3,2-b]thiophene and 2,3-naphthalenedicarboxylic anhydride, allows for selective substitution at the terminal thiophene ring, thereby providing asymmetric monoalkyl and monoalkylthienyl thienoacenes. Alkyl-substituted ATT (CnATT, n = 6, 8, 10, 12) has characteristics of a p-type field-effect transistor (FET), with mobility on the order of 0.01 cm2 V-1 s-1, which is the same as ATT. Conversely, alkylthienyl-substituted ATT (CnTATT, n = 6, 8, 10, 12) exhibits FET mobility of 0.15-1.9 cm2 V-1 s-1, which is up to 2 orders of magnitude greater than that of ATT and CnATT. Moreover, CnTATT forms crystalline thin films both by spin coating and drop casting, and C8TATT in particular exhibits a mobility of up to 1.6 cm2 V-1 s-1 in the drop-cast film. X-ray diffraction patterns of CnTATT thin films indicate that the molecules become oriented edge-on at the substrate surface with a highly ordered structure in the in-plane direction. Accordingly, CnTATT serves as a solution-processable p-type organic field-effect transistor, where the additional thiophene ring contributes significantly to the highly ordered thin-film structure and the high carrier mobility.

12.
Pharmacol Res Perspect ; 3(3): e00140, 2015 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-26171223

RESUMEN

Huntington's disease (HD) is an inherited genetic disorder, characterized by cognitive dysfunction and abnormal body movements, and at present there is no effective treatment for HD. Therapeutic options for HD are limited to symptomatic treatment approaches and there is no cure for this devastating disease. Here, we examined whether SUN N8075, (2S)-1-(4-amino-2,3,5-trimethylphenoxy)-3-{4-[4-(4-fluorobenzyl)phenyl]-1-piperazinyl}-2-propanol dimethanesulfonate, which exerts neuroprotective effects by antioxidant effects and induction of VGF nerve growth factor inducible (VGF), has beneficial effects in STHdh cells derived from striatum of knock-in HD mice and R6/2 HD mice. In an in vitro study, SUN N8075 inhibited the cell death caused by mutant huntingtin (mHtt) and upregulated the VGF mRNA level via the phosphorylation of extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, 30 amino acid of VGF C-terminal peptide, AQEE-30 inhibited the cell death and the aggregation of mHtt. In an in vivo study, SUN N8075 improved the survival and the clasping response in the R6/2 mice. Furthermore, SUN N8075 increased the number of surviving neurons in the striatum of the R6/2 mice. These findings suggest that SUN N8075 may be an effective candidate for HD treatments.

13.
Neuropharmacology ; 61(8): 1275-81, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-21816164

RESUMEN

The phosphodiesterase 10A (PDE10A) is highly expressed within dopaminoreceptive medium spiny neurons (MSNs) of the striatum, which are implicated in various neurodegenerative diseases and psychiatric disorders, such as Huntington's disease and schizophrenia. With its dual action on cAMP and cGMP, PDE10A has been proposed to affect several signaling cascades in the corticostriatothalamic circuits. In particular, papaverine, a selective PDE10A inhibitor has been shown to activate/phosphorylate ERK in striatum. We used acute rat striatal slices to further characterize the effects of papaverine on ERK activation/phosphorylation in D1- and D2-responsive striatal neurons. Incubation of striatal slices from male rats with papaverine increased the levels of phospho-ERK1/2 (p-ERK), an effect enhanced with a D1 agonist or a D2 antagonist, but decreased with a D1 receptor antagonist or a D2 receptor agonist. Papaverine-induced increase in p-ERK was localized in striatal neurons receiving D1-enriched presynaptic terminals, as well as in postsynaptic D2-enriched neurons in striatal slices. Interestingly, papaverine had almost no stimulatory effects on ERK1/2 phosphorylation in slices prepared from female rats. In striatal slices prepared from ovariectomized female rats, papaverine treatment stimulated ERK1/2 phosphorylation to levels similar to those in slices from male rats. Moreover, estrogen was found to regulate the levels of D2 but not D1 receptors in striatum. These results indicate that circulating levels of female hormones, and in particular estrogen, regulate the effects of PDE10A inhibition on ERK1/2 phosphorylation in medium spiny neurons, an effect possibly linked to estrogen's regulation of D2 receptors. Considering the variety of events modulated by ERK1/2 activity, these findings suggest that sex difference needs to be taken into consideration for the further investigation of the effects of PDE10A inhibitors.


Asunto(s)
Cuerpo Estriado/efectos de los fármacos , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Sistema de Señalización de MAP Quinasas/efectos de los fármacos , Papaverina/farmacología , Inhibidores de Fosfodiesterasa/farmacología , Caracteres Sexuales , 2,3,4,5-Tetrahidro-7,8-dihidroxi-1-fenil-1H-3-benzazepina/farmacología , Análisis de Varianza , Animales , Agonistas de Dopamina/farmacología , Antagonistas de Dopamina/farmacología , Estrógenos/farmacología , Femenino , Técnicas In Vitro , Masculino , Ovariectomía , Fosforilación/efectos de los fármacos , Ratas , Ratas Sprague-Dawley , Receptores de Dopamina D1/metabolismo , Receptores de Dopamina D2/metabolismo , Sulpirida/farmacología
14.
PLoS One ; 5(12): e15307, 2010 Dec 09.
Artículo en Inglés | MEDLINE | ID: mdl-21151573

RESUMEN

Amyotrophic lateral sclerosis (ALS) is the most frequent adult-onset motor neuron disease, and recent evidence has suggested that endoplasmic reticulum (ER) stress signaling is involved in the pathogenesis of ALS. Here we identified a small molecule, SUN N8075, which has a marked protective effect on ER stress-induced cell death, in an in vitro cell-based screening, and its protective mechanism was mediated by an induction of VGF nerve growth factor inducible (VGF): VGF knockdown with siRNA completely abolished the protective effect of SUN N8075 against ER-induced cell death, and overexpression of VGF inhibited ER-stress-induced cell death. VGF level was lower in the spinal cords of sporadic ALS patients than in the control patients. Furthermore, SUN N8075 slowed disease progression and prolonged survival in mutant SOD1 transgenic mouse and rat models of ALS, preventing the decrease of VGF expression in the spinal cords of ALS mice. These data suggest that VGF plays a critical role in motor neuron survival and may be a potential new therapeutic target for ALS, and SUN N8075 may become a potential therapeutic candidate for treatment of ALS.


Asunto(s)
Esclerosis Amiotrófica Lateral/genética , Retículo Endoplásmico/metabolismo , Mutación , Superóxido Dismutasa/genética , Compuestos de Anilina/farmacología , Animales , Muerte Celular , Supervivencia Celular , Modelos Animales de Enfermedad , Progresión de la Enfermedad , Humanos , Ratones , Ratones Transgénicos , Análisis de Secuencia por Matrices de Oligonucleótidos , Piperazinas/farmacología , Superóxido Dismutasa-1 , Factor A de Crecimiento Endotelial Vascular/metabolismo
15.
Drug Metab Pharmacokinet ; 19(3): 190-7, 2004 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-15499186

RESUMEN

The objective of this study is to evaluate the effect of acute renal or hepatic failure on the intestinal absorption of tacrolimus. Simultaneous perfusion study in rat small intestine revealed that the extent of absorption into blood vessels was decreased in the jejunum and the ileum of rat of acute renal failure due to the decrease in the uptake of tacrolimus into enterocytes. In contrast, there observed no significant changes in tacrolimus absorption in rat of acute hepatic failure. Since it has been reported that tacrolimus absorption is regulated mainly by Cytochrome P-450 (CYP) mediated metabolism in the jejunum, but by P-glycoprotein (P-gp) mediated efflux in the ileum, these factors might contribute to the changes in intestinal absorption of tacrolimus in rat of acute renal failure. Enzyme inhibitor, ketoconazole, was co-perfused with tacrolimus to specify the effect of CYP and P-gp. However, since ketoconazole failed to recover the permeability in the jejunum and ileum of rat of acute renal failure, it is considered that the changes in CYP or P-gp functions might not be involved in the decreased uptake of tacrolimus. This type of kinetic study in rats should be valuable to identify the precise mechanisms of drug absorption and the effects of various diseases on it, such as acute renal or hepatic failure.


Asunto(s)
Lesión Renal Aguda/metabolismo , Absorción Intestinal/fisiología , Intestino Delgado/metabolismo , Fallo Hepático Agudo/metabolismo , Tacrolimus/metabolismo , Animales , Masculino , Ratas , Ratas Wistar
16.
J Pharmacol Exp Ther ; 306(1): 310-6, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12676880

RESUMEN

The objective of this study was to evaluate the absorption of tacrolimus by means of simultaneous perfusion of intestinal lumen and blood vessels in rats. In our previous report, the permeability of tacrolimus was found to be higher in the jejunum than in the ileum or colon, suggesting the site-dependent absorption after oral administration. However, in this article, simultaneous perfusion technique revealed that the extent of absorption into blood vessels was similar in the jejunum and the ileum regardless of the site difference in permeability as the absorption rate. In addition to the multidrug resistance-associated protein-mediated efflux, cytochrome P450 (P450)-mediated metabolism could be a possible mechanism to explain the inconsistencies in the site dependence of tacrolimus absorption. Two enzyme inhibitors, ketoconazole and midazolam, were coperfused in rat intestinal lumen with tacrolimus to specify the effect of P-gp and P450. In the jejunum, both inhibitors significantly enhanced the absorbed amount of tacrolimus, whereas the permeability was not affected. It was suggested that both inhibitors mainly suppress P450-mediated metabolism in the upper region of the intestine. In contrast, in the ileum, ketoconazole significantly enhanced both the absorbed amount and the permeability of tacrolimus. However, midazolam failed to enhance the absorption of tacrolimus, indicating the dominant role of P-glycoprotein (P-gp)-mediated efflux in the lower region. From these findings, it is concluded that the site-dependent differences in P-gp and/or P450 activity could be the prime cause of large intra- and interindividual variability in the oral absorption of tacrolimus.


Asunto(s)
Inmunosupresores/farmacocinética , Intestino Delgado/metabolismo , Tacrolimus/farmacocinética , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/metabolismo , Animales , Transporte Biológico , Células CACO-2 , Humanos , Absorción Intestinal , Masculino , Ratas
17.
J Pharm Sci ; 91(3): 719-29, 2002 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-11920757

RESUMEN

The objective of this study is to investigate the role of P-glycoprotein (P-gp), a membrane efflux pump associated with multidrug resistance (MDR) and a known substrate for tacrolimus, in determining the regional intestinal permeability of tacrolimus in rats. Thus, isolated segments of rat jejunum, ileum, or colon were perfused with tacrolimus solutions containing polyethoxylated hydrogenated castor oil 60 surfactant, and with or without verapamil, a P-gp substrate used to reverse the MDR phenotype. The results indicated that the intrinsic permeability of tacrolimus in the jejunum, calculated on the basis of the concentration of non-micellized free tacrolimus, was quite high ( approximately 1.4 x 10(-4) cm/s). The apparent permeability (P(app)) in the jejunum was unaffected by the presence of verapamil; however, the P(app) in the ileum and the colon increased significantly in the presence of verapamil and were similar to the values observed in the jejunum. The results suggest that systemic absorption of tacrolimus from the gastrointestinal tract could be significantly affected by P-gp efflux mechanisms. It is also possible that differences in P-gp function at various intestinal sites in a subject or at a given intestinal site in various subjects could lead to large intra- and interindividual variability in bioavailability of tacrolimus following oral administration.


Asunto(s)
Inmunosupresores/química , Tacrolimus/química , Miembro 1 de la Subfamilia B de Casetes de Unión a ATP/química , Animales , Disponibilidad Biológica , Células CACO-2 , Cromatografía Líquida de Alta Presión , Humanos , Inmunosupresores/farmacocinética , Absorción Intestinal , Yeyuno/efectos de los fármacos , Yeyuno/metabolismo , Masculino , Modelos Biológicos , Perfusión , Ratas , Solubilidad , Tensoactivos/química , Tensoactivos/farmacología , Tacrolimus/farmacocinética , Agua/metabolismo
18.
Bioorg Med Chem ; 10(2): 371-83, 2002 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-11741786

RESUMEN

A series of novel 4-arylpiperidines and 4-aryl-4-piperidinols (2a-f, 3a-f and 4a-f) was synthesized and evaluated for blocking effects on both neuronal Na(+) and T-type Ca(2+) channels and binding affinity for dopamine D(2) receptors. Most of the compounds blockaded both ion channels with potency greater than or equal to flunarizine 1a which was adopted as a reference standard. In addition, these compounds had significantly reduced affinity for dopamine D(2) receptors which is common in this class of structure. Compounds 2a-f, 3a-f and 4a-f exhibited potent anticonvulsant effects following systemic (ip) administration on audiogenic seizures in DBA/2 mice, indicating their excellent brain permeability. The neuroprotective activity of 2a, 3a and 4a was also assessed in a transient middle cerebral artery occlusion (MCAO) model. These compounds significantly reduced neuronal damage without affecting ischemic hyperthemia, while flunarizine 1a produced only minor reductions. In particular, 4a had 1.7-fold the potency in this MCAO model but only 1/20 the affinity for dopamine D(2) receptors of 1a. The superposition of 2a, 3a and 4a on the basis of analyses of systematic conformation and similar structure has revealed that the cinnamyl, phenacyl and phenoxypropanol groups are likely to be structurally and biologically equivalent. Moreover, the superposition of 2a and 2f shows that diphenyl ether and biphenyl groups occupy a similar space, suggesting that both groups act as a bioisostere for the blockade of ion channels; however, this is not the case for dopamine D(2) receptors since only biphenyl compounds such as 2f had high affinity similar to flunarizine 1a. Compound 4a (SUN N5030) has a good pharmacological profile and may be useful in the alleviation and treatment of ischemic diseases.


Asunto(s)
Bloqueadores de los Canales de Calcio/química , Bloqueadores de los Canales de Calcio/farmacología , Éteres Fenílicos/química , Éteres Fenílicos/farmacología , Piperidinas/química , Piperidinas/farmacología , Receptores de Dopamina D2/metabolismo , Bloqueadores de los Canales de Sodio/química , Bloqueadores de los Canales de Sodio/farmacología , Animales , Bioquímica/métodos , Bloqueadores de los Canales de Calcio/metabolismo , Corteza Cerebral/efectos de los fármacos , Corteza Cerebral/metabolismo , Evaluación Preclínica de Medicamentos , Femenino , Flunarizina/química , Flunarizina/farmacología , Isquemia/tratamiento farmacológico , Masculino , Ratones , Ratones Endogámicos DBA , Fármacos Neuroprotectores/química , Fármacos Neuroprotectores/metabolismo , Fármacos Neuroprotectores/farmacología , Ratas , Ratas Wistar , Receptores de Dopamina D2/efectos de los fármacos , Convulsiones/tratamiento farmacológico , Bloqueadores de los Canales de Sodio/metabolismo , Relación Estructura-Actividad
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