[Surgical management of non-palpable breast tumors]. / Nem tapintható emlodaganatok mutéti kezelésével szerzett tapasztalataink.

Due to the improvement of the diagnostic and screening methods for detecting breast cancer (e.g. mammography, breast ultrasonography, MR imaging, FNAC, core biopsy or vacuum-assisted core biopsy), non-palpable breast masses are more and more commonly discovered. Resection guided by a radiologically placed hookwire has gained outstanding importance in the surgical management of these non-palpable cases of breast malformations. In this retrospective study we analyzed the data of 830 patients operated in the past 5 years because of breast malformations. Of those, 36.9% of the breast surgeries were performed because of a non-palpable breast mass. In such cases we performed preoperative histological sampling to support setting up the surgical plan. We managed to get a precise histological diagnosis preoperatively in 78% of our cases. After the introduction of vacuum-assisted core biopsy, operations for histologically indeterminate breast tumors became less common. The surgical resections of breast masses which later prove to be benign are expected to decrease further. Intraoperative radiological analysis of the resection margins helps performing a definitive surgical resection. Specimen mammography and ultrasonography is part of our daily routine. When evaluating the histological samples, the question of resection margins is substantial. In absence of clear resection margins, re-resection is needed. Due to incomplete resection margins 5.5% of the cases re-resection was needed. To avoid unnecessary axillary lymph node dissection in case of early-stage breast cancers, sentinel lymph node biopsy is always carried out.

Novel gastroretentive dosage forms: evaluation of gastroretentivity and its effect on levodopa absorption in humans.

PURPOSE: To design novel expandable gastroretentive dosage form (GRDFs) and evaluate their gastroretentive properties. Then, to assess the pharmacokinetics of levodopa compounded in such a GRDF in healthy volunteers. METHODS: Thin (<0.07 cm), large-dimensioned (> or = 5 x 2.1 cm), multi layer dosage forms (DFs) with different rigid polymeric matrices an mechanical properties were folded into gelatin capsules and wer administered to healthy volunteers with a light breakfast. GRDF unfolding and physical integrity were evaluated in vitro and in vivo (by gastroscopy and radiology). The pharmacokinetics of levodopa GRDF were compared to Sinemet CR in a crossover design. RESULTS: The combination of rigidity and large dimension of the GRDFs was a decisive parameter to ensure prolonged gastroretentivity (> or = 5 h). Large-dimension DFs lacking rigidity had similar gastroretentivity as a nondisintegrating tablet (10 mm). The GRDF rapidly unfolded and maintained their mechanical integrity. The absorption phase of levodopa was significantly prolonged following GRDF administration in comparison to Sinemet CR. CONCLUSIONS: The combination of size and rigidity of the novel GRDF enables a significant extension of the absorption phase of a narrow absorption window drug such as levodopa. This approach is an important step toward the implementation of such GRDFs in the clinical setting.

Furosemide pharmacokinetics and pharmacodynamics following gastroretentive dosage form administration to healthy volunteers.

The objective of this study was to evaluate the pharmacokinetic and pharmacodynamic properties of furosemide following gastroretentive dosage from (GRDF) administration. A furosemide (60 mg) GRDF, releasing the drug during 6 hours in vitro, or an immediate-release tablet was administered to healthy male volunteers (N = 14) in a crossover design. Food and liquid intake were standardized; urine was collected, weighed, and assayed for furosemide and sodium concentrations. Pharmacokinetics of furosemide following the GRDF administration, as compared to the tablet, showed lower Cmax and indicated a prolonged absorption phase leading to longer mean residence time in the stomach. The sustained input of the drug significantly improved diuretic and natriuretic efficiencies during the first 5 hours and thereby increased the total effects measured over 24 hours. The unfolding controlled-release GRDF of furosemide improved the pharmacodynamic actions due to the sustained absorption in the stomach and jejunum, which delayed the body's counteractivity to the drug effect.