Biomedical subjects
Publications and source records attributed to M Toledano.
We've done an analitical study in 60 dental clinics about their illuminating systems in clinical and no clinical areas. We propose ideal values for light intensity in oral and ambiental illumination in clinical areas. Following these instructions you'll get: An increasing in productivity and rentability due to a bigger comfort in your working areas. To decrease the visual fatigue for you and your dental assistants.
Incubation of human lymphocytes with recombinant interleukin-2 (rIL-2) results in the generation of lymphokine-activated killer (LAK) cells capable of lysing a wide variety of tumor cells. The present study was undertaken to examine the effect of recombinant gamma interferon (rIFN-gamma) on LAK cell cytotoxicity generated from different peripheral blood mononuclear cell (PBMC) subpopulations. When unseparated PBMC were stimulated by rIL-2 and rIFN-gamma, the latter induced a transient enhancement after 2 days followed by a suppression of LAK cell cytotoxicity at day 6. Enhancement of LAK cell cytotoxicity was moderate and inconstant, whereas the inhibition was strong and observed with all the donors tested. This suppression was not associated with a decrease in the [3H]thymidine uptake. PBMC depleted of adherent cells were more sensitive to the stimulation by rIL-2 and the induced cytotoxicity was not modified by rIFN-gamma. Monocyte-enriched plastic-adherent cells, when incubated with rIL-2 and rIFN-gamma, became cytotoxic after 2-3 days of culture and inhibited LAK cell activity after 5-6 days. Collectively, our results suggest that rIFN-gamma affects LAK cell cytotoxicity through the activation of plastic-adherent, monocyte-rich, cells which modulate natural killer cells, first in a positive, then in a negative way.
The catalytic effect of thyroxine and triiodothyronine on the reaction between cerium(IV) and arsenic(III) was studied by using photometric and fluorimetric measurements. The kinetic - photometric studies were based on measurement of the decrease in absorbance of cerium(IV), whereas the rate of formation of fluorescent cerium(III) was measured in the kinetic - fluorimetric studies. A modular stopped-flow system was coupled to a spectrophotometer in order to develop stopped-flow methods for the determination of thyroxine and triiodothyronine. The proposed methods were compared and applied to the determination of these hormones in pharmaceutical preparations.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Congenital anomalies of the gallbladder are rare and can be accompanied by other malformations of the biliary or vascular tree. Being difficult to diagnose during routine preoperative studies, these anomalies can provide surgeons with an unusual surprise during laparoscopic surgery. The presence of any congenital anomaly or the mere suspicion of its existence demands that we exercise surgical prudence, limit the use of electrocoagulation, and ensure that no structure be divided until a clear picture of the bile ducts and blood vessels is obtained. If necessary, perform intraoperative cholangiography to further define the biliary system. However, if the case remains unclear, or if laparoscopy does not provide enough information, open surgery should be considered before undesirable complications occur.
OBJECTIVE: The laparoscopic treatment of eventrations and ventral hernias has been little used, although these hernias are well suited to a laparoscopic approach. The objective of this study was to investigate the usefulness of a laparoscopic approach in the surgical treatment of ventral hernias. METHODS: Between January 1994 and July 1998, a series of 100 patients suffering from major abdominal wall defects were operated on by means of laparoscopic techniques, with a mean postoperative follow-up of 30 months. The mean number of defects was 2.7 per patient, the wall defect was 93 cm2 on average. There were 10 minor hernias (<5 cm), 52 medium-size hernias (5-10 cm), and 38 large hernia (>10 cm). The origin of the wall defect was primary in 21 cases and postsurgical in 79. Three access ports were used, and the defects were covered with PTFE Dual Mesh measuring 19 x 15 cm in 54 cases, 10 x 15 cm in 36 cases, and 12 x 8 cm in 10 cases. An additional mesh had to be added in 21 cases. In the last 30 cases, PTFE Dual Mesh Plus with holes was employed. RESULTS: Average surgery time was 62 minutes. One procedure was converted to open surgery, and only one patient required a second operation in the early postoperative period. Minor complications included 2 patients with abdominal wall edema, 10 seromas, and 3 subcutaneous hematomas. There were no trocar site infections. Two patients developed hernia relapse (2%) in the first month after surgery and were reoperated with a similar laparoscopic technique. Oral intake and mobilization began a few hours after surgery. The mean stay in hospital was 28 hours. CONCLUSIONS: Laparoscopic technique makes it possible to avoid large incisions, the placement of drains, and produces a lower number of seromas, infections and relapses. Laparoscopic access considerably shortens the time spent in the hospital.
The role of the collagen fibers in dentin adhesion has not clearly been established. Therefore, this laboratory study evaluated the microleakage at resin-dentin and resin-enamel interfaces of Class V composite restorations after etching enamel and dentin with phosphoric acid (H3PO4) or after etching with H3PO4 followed by deproteinization with 5% sodium hypochlorite (NaOCl) to prevent the formation of a hybrid layer. Ten extracted human molars were used to prepare standardized Class V cavities on both buccal and lingual surfaces. The teeth were randomly divided in two groups: 1) Class V cavities that were etched with H3PO4 for 15 seconds; b) Class V cavities that were etched with H3PO4 for 15 seconds followed by collagen removal with 5% NaOCl for two minutes. The cavities were restored using the Prime & Bond 2.1 bonding system and TPH resin composite. The specimens were stored in water for 24 hours at 37 degrees C and thermocycled 500 times between water baths kept at 5 degrees C and 55 degrees C. After thermocycling, specimens were immersed in a 0.5% aqueous solution of basic fuchsin for 24 hours. Three longitudinal sections of each restoration were obtained and examined with a stereomicroscope for qualitative evaluation of microleakage. The data were statistically analyzed by Mann-Whitney U and Wilcoxon matched pairs signed ranked tests. Extra specimens were analyzed with the scanning electron microscope (SEM). Occlusal margins (enamel margins) resulted in statistical lower degree of leakage than gingival margins (dentin/cementum margins) in both treatment groups. For each type of margin, there were no statistically significant differences between the etched and the etched and deproteinized groups. Under the SEM, occlusal surfaces showed no detachment between enamel and dentin, while dentin/cementum resulted in gap formation.
OBJECTIVES: Laparoscopic cholecystectomy (LC) combined with endoscopic retrograde cholangiopancreatography (ERCP) has been widely used in the management of the acute biliopancreatic pathology. Nevertheless, controversy remains about the appropriate timing for retrograde cholangiopancreatography. METHODS: A retrospective study was undertaken on a consecutive series of 117 patients with acute biliary-pancreatic pathology, who underwent laparoscopic cholecystectomy between April 1995 and April 1999. Criteria for preoperative endoscopic retrograde cholangiopancreatography were defined, and the patients were divided into 3 groups based on the presence or absence of a preoperative retrograde cholangiopancreatography indication: (1) ERCP+LC group: patients with retrograde cholangiopancreatography indicated and performed (n = 30); (2) LC group: patients without retrograde cholangiopancreatography criteria treated only by LC (n = 47); (3) LC-ERCP group: patients with retrograde cholangiopancreatography criteria but not performed (n = 40). RESULTS: The groups were similar in age, sex, ASA, and clinical diagnosis. No statistical differences occurred in operative times (73.8 min, 68 min, 67 min), major complications (3.3%, 4.25%, 12.5%), and mean postoperative stay (3.7 +/- 4; 4.7 +/- 2; 5.7 +/- 2). Postoperative retrograde cholangiopancreatography had to be used, respectively, in 0%, 10.6%, and 7.5%. The best predictive criteria for common bile duct pathology were choledocholithiasis on an ultrasound scan and the presence of cholangitis. The other criteria tested had a low predictive value. CONCLUSIONS: Preoperative endoscopic retrograde cholangiopancreatography followed by early laparoscopic cholecystectomy can be performed safely in acute biliary-pancreatic pathology, avoiding 2-stage treatment of these patients and minimizing hospital stay and inconvenience to the patients. Nevertheless, this therapeutic/diagnostic tool must be used selectively.
This study tested the null hypothesis that there no difference between two-step and one-step self-etch adhesives in their compatibility with these composites. The microtensile bond strengths (microTBS) of two two-step systems (Clearfil SE Bond, Kuraray and Tyrian SPE/One-Step Plus, BISCO) were compared with two one-step systems (Xeno III, Dentsply DeTrey and Brush&Bond, Parkell) for their coupling to a dual-cured composite. Silver tracer penetration of the four adhesives bonded to a light-cured or a chemical-cured composite was examined using TEM. Significant differences in microTBSs between composite curing modes were seen only in the one-step adhesives. For one-step self-etch adhesives bonded to the chemical-cured composite, TEM revealed signs of frank composite uncoupling along the adhesive-composite interface, which may be attributed to the adverse chemical interaction between the acidic adhesive and the composite. In addition, "water trees" that represent channels of increased permeability with the polymerized adhesive layer were also observed in the one-step adhesives. Both features were absent along the resin-dentin interfaces when chemical-cured composites were coupled to the two-step self-etch adhesives.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
The purpose of this study was to evaluate the shear bond strength of brackets and the enamel morphology after using six methods for removal of adhesive after bracket debonding. A total of thirty-five recently extracted noncarious human premolars were used. The twin bracket Mini-Taurus was used with the Mono-Lok2 TM bonding system. Shear bond strength (MPa) was calculated. Immediately after the brackets were removed, the teeth were rinsed and dried, using an air-water syringe. The adhesive remnant index was calculated and the debonded teeth with residual adhesive material attached to the enamel surface were equally sorted in seven groups of five, as follows: Group 1. The residual adhesive was removed with a 12-blade tungsten carbide finishing bur in a high-speed handpiece, using water as the coolant. Group 2. The residual adhesive was removed with a 12-blade tungsten carbide finishing bur in a low-speed handpiece, using water as the coolant. Group 3. The residual adhesive was removed with an Arkansas stone: Dura-white stones for finishing composite in a high-speed handpiece using water as the coolant. Group 4. The residual adhesive was removed with an Arkansas stone: Dura-white stones for finishing composite in a low-speed handpiece, using water as the coolant. Group 5. The residual adhesive was removed with Sof-Lex aluminum oxide discs according to manufacturer's instructions in a low-speed handpiece, using water as the coolant. Group 6. The residual adhesive was removed with Enhance Composite Finishing Discs in a low-speed handpiece, using water as the coolant. In this group, the paste was not applied after the polishing discs. Group 7. The residual adhesive was removed with Enhance Composite Finishing Discs and Polishing Cups in a low-speed handpiece, using water as the coolant. Prisma-gloss polishing paste and ultrafine polishing paste were applied according to manufacturer's instructions. After removal of the adhesive, all teeth were evaluated with the scanning electron microscope. The results revealed a mean shear bond strength of 12.75 MPa. The higher the bond strength, the higher the percentage of ARI. The smoothest enamel surface was obtained when the Enhance system with the gloss polishing paste was used; the second smoothest enamel surface was obtained when using Sof-Lex discs. If the paste was not used with the Enhance system, the obtained surface was rougher than when using Sof-Lex discs.