Phytochemicals That Interfere With Drug Metabolism and Transport, Modifying Plasma Concentration in Humans and Animals.

Phytochemicals (Pch) present in fruits, vegetables and other foods, are known to inhibit or induce drug metabolism and transport. An exhaustive search was performed in five databases covering from 2000 to 2021. Twenty-one compounds from plants were found to modulate CYP3A and/or P-gp activities and modified the pharmacokinetics and the therapeutic effect of 27 different drugs. Flavonols, flavanones, flavones, stilbenes, diferuloylmethanes, tannins, protoalkaloids, flavans, hyperforin and terpenes, reduce plasma concentration of cyclosporine, simvastatin, celiprolol, midazolam, saquinavir, buspirone, everolimus, nadolol, tamoxifen, alprazolam, verapamil, quazepam, digoxin, fexofenadine, theophylline, indinavir, clopidogrel. Anthocyanins, flavonols, flavones, flavanones, flavonoid glycosides, stilbenes, diferuloylmethanes, catechin, hyperforin, alkaloids, terpenes, tannins and protoalkaloids increase of plasma concentration of buspirone, losartan, diltiazem, felodipine, midazolam, cyclosporine, triazolam, verapamil, carbamazepine, diltiazem, aripiprazole, tamoxifen, doxorubicin, paclitaxel, nicardipine. Interactions between Pchs and drugs affect the gene expression and enzymatic activity of CYP3A and P-gp transporter, which has an impact on their bioavailability; such that co-administration of drugs with food, beverages and food supplements can cause a subtherapeutic effect or overdose. Therefore, it is important for the clinician to consider these interactions to obtain a better therapeutic effect.

Bioabsorbable implant as a tracheal wall substitute in young developing canines.

This study evaluated a polylactic and polyglycolic acid (PLA/PGA) implant as a partial tracheal substitute in young developing canines. This experimental and longitudinal study included local stray pups that received substitution of a short cervical tracheal segment with a PLA 85%/PGA 15% plaque. We measured clinical, endoscopic, and tomographic variables for 1 year, at which time we performed histomorphological evaluations of the implant using light and electron microscopy. There were no adverse events throughout the clinical progression. On endoscopic evaluation, the implant was covered with mucosal tissue beginning in the first month, without granulation or stenosis, and the circular shape of the trachea was altered. Tomographic images of the tracheal area at the implant site were similar to adjacent healthy areas (p = 0.423). At the end of the follow-up period, the plaque had biodegraded, and the space was covered by pseudostratified epithelium and ciliated cells similar to the neighboring tissue. Implantation of a PLA/PGA plaque constituted an effective (functional) replacement of a short semicircular cervical tracheal segment without limiting the growth of the recipient. Additional studies are required to prove the efficacy of these implants for larger tracheal segment replacements and in subjects at different stages of development.

[Publication profile (1991-2002) of a group of Mexican pediatric surgeons]. / Perfil de las publicaciones efectuadas por cirujanos pediatras mexicanos (1991-2002).

INTRODUCTION: This study was undertaken to determine the characteristics of scientific articles published by Mexican pediatric surgeons (MPS) available in the major electronic databases for international and national medical information. MATERIAL AND METHODS: An observational, descriptive and transversal study was performed. Articles written by pediatric surgeons were localized in the most frequently accessed electronic searches: Medline, EMBASE, LILACS, and ARTEMISA, in the period from January 1991 to December 2002. Articles were grouped into three categories. RESULTS: A total of 247 publications were analyzed, 199 devoted to clinical research, 11 to basic research, and 37 reviews. Of the clinical research studies, 189 were observational-descriptive studies, and 151 of these were retrospective. Only 7.6% of the pediatric surgeons certified by the Mexican Council for Pediatric Surgery published an article (61 authors). Most studies (80%) was performed at Mexico City institutions. CONCLUSIONS: Most studies published by pediatric surgeons describe common problems of the Mexican pediatric population. A smaller percentage focus on comparing therapeutic actions or diagnostic strategies; however, result reliability is questionable due to experimental design. The contribution by MPS to the generation of medical publications during the last decade has been sparse, and more so from places other than Mexico City.

Video-assisted thoracoscopy for diaphragmatic plication: experimental study in a canine model.

BACKGROUND: Plication of a nonfunctional hemidiaphragm usually restores altered ventilatory mechanics. This study compared two techniques in performing diaphragmatic plication: video-assisted thoracoscopy (group A) and thoracotomy (group B). MATERIALS AND METHODS: Twenty dogs with induced paralysis of the right hemidiaphragm were randomly assigned to one of the two groups. Evaluations were performed before and after plication of the respiratory frequency (f) and lung area (LA) of the affected side. Operative time, time to resumption of walking, ingestion of fluids and solid food, pain intensity, and postoperative complications were measured. RESULTS: Group A had less pain after the surgery (P < 0.0001), earlier fluid ingestion (P < 0.05), and earlier resumption of walking (P < 0.019). Four weeks after the procedure, LA was similar in both groups, while a significant decrease in f was recorded in group A (P < 0.02). The remaining evaluated variables showed no differences. CONCLUSION: Both approaches were effective. Pain recorded in the postoperative period was less and recovery was faster in group A. Complications and surgical times were similar. The video-assisted thoracoscopy is a safe and efficient option for performing diaphragmatic plication in dogs.

Effects of mesocaval shunt on the pharmacokinetics of metronidazole in young rats.

Prophylactic and therapeutic management of portosystemic encephalopathies is based on protein restriction in the diet, and the use of lactulose and antibiotics such as metronidazole. These actions intend to reduce the main source of intestinal ammonia production and release into the systemic circulation. The aim of this study was to evaluate the medium-term effects of mesocaval shunt on the pharmacokinetics of metronidazole in rats with healthy livers. Male Lewis rats were divided into two groups. The first group was subjected to mesocaval shunt (MCS) and the other employed as a control. The following tests were carried out in both groups: metronidazole pharmacokinetics, determination of ALT, AST, albumin, urea and ammonium, liver weight and histomorphology. A loss in body and liver weight was registered in rats subjected to MCS. AST levels also increased compared to controls. Significant differences in almost all pharmacokinetic parameters were detected between MCS and control rats, especially in Kel, AUC and Cmax. Modifications in metronidazole pharmacokinetics and liver weight changes without microstructural modification secondary to MCS were found. We suggest that individual drug-monitoring and pharmacokinetic analysis must be carried out in metronidazole medicated patients with modifications in portal circulation with or with out macro or micro liver structural alterations.