Microbiological assessment of arterial allografts processed in a tissue bank.

The transmission of microbial infection through tissue allografts is one of the main risks that must be controlled in tissue banks. Therefore, microbiological monitoring controls and validated protocols for the decontamination of tissues during processing have been implemented. This study is based on the evaluation of data from microbiological cultures of arteries (mainly long peripheral arteries) processed in the tissue bank of Valencia (Spain). Donors' profile, pre- and post-disinfection tissue samples were assessed. The presence of residual antibiotics in disinfected tissues was determined and the antimicrobial potential of these tissues was tested. Our overall contamination rate was 23.69%, with a disinfection rate (after antibiotic incubation) of 87.5%. Most (76.09%) of the microbial contaminants were identified as Gram positive. Arterial allografts collected from body sites affected by prior organ removal showed higher risk of contamination. Only vancomycin was detected as tissue release. The antimicrobial effect on Candida albicans was lower than that for bacterial species. Risk assessment for microbial contamination suggested the donor's skin and the environment during tissue collection as the main sources for allograft contamination. Antibiotic-disinfected arterial allografts showed antimicrobial potential.

[Problem-based learning in an undergraduate medical school course on anesthesiology, recovery care, and pain management]. / El aprendizaje basado en problemas aplicado a la asignatura de pregrado de anestesiología, reanimación y terapéutica del dolor.

INTRODUCTION: We describe our experience with problem-based learning (PBL) in an undergraduate course in anesthesiology and recovery care. MATERIAL AND METHODS: The study was carried out over 5 consecutive academic years from 2000 through 2005. In total, 168 students took part. PBL was started in seminars in the first 3 years the course was given. In the last 2 years, PBL was used throughout the entire course, which consisted of 12 seminars. At the end, each student evaluated the activities overall, the tutor's intervention, the student's own participation, and the time invested in searching for information and preparing for discussions. RESULTS: In the first 3 years, most students considered they had better assimilated the knowledge presented and that they had participated more. In the last 2 years, assessment of the course overall reached a score of 8.47 (SD, 1.24); of the instructor, 8.84 (0.98); and of student participation, 7.38 (1.29). The students used 2.11 (1.43) hours to search for information and 1.74 (1.14) hours to prepare for discussion. CONCLUSIONS: The medical students' level of satisfaction with and acceptance of PBL in this anesthesiology course were high. The instructor's intervention and student participation were assessed highly. A large amount of time was used for study.

Nanocarriers for optimizing the balance between interfollicular permeation and follicular uptake of topically applied clobetasol to minimize adverse effects.

The treatment of various hair disorders has become a central focus of good dermatologic patient care as it affects men and women all over the world. For many inflammatory-based scalp diseases, glucocorticoids are an essential part of treatment, even though they are known to cause systemic as well as local adverse effects when applied topically. Therefore, efficient targeting and avoidance of these side effects are of utmost importance. Optimizing the balance between drug release, interfollicular permeation, and follicular uptake may allow minimizing these adverse events and simultaneously improve drug delivery, given that one succeeds in targeting a sustained release formulation to the hair follicle. To test this hypothesis, three types of polymeric nanocarriers (nanospheres, nanocapsules, lipid-core nanocapsules) for the potent glucocorticoid clobetasol propionate (CP) were prepared. They all exhibited a sustained release of drug, as was desired. The particles were formulated as a dispersion and hydrogel and (partially) labeled with Rhodamin B for quantification purposes. Follicular uptake was investigated using the Differential Stripping method and was found highest for nanocapsules in dispersion after application of massage. Moreover, the active ingredient (CP) as well as the nanocarrier (Rhodamin B labeled polymer) recovered in the hair follicle were measured simultaneously, revealing an equivalent uptake of both. In contrast, only negligible amounts of CP could be detected in the hair follicle when applied as free drug in solution or hydrogel, regardless of any massage. Skin permeation experiments using heat-separated human epidermis mounted in Franz Diffusion cells revealed equivalent reduced transdermal permeability for all nanocarriers in comparison to application of the free drug. Combining these results, nanocapsules formulated as an aqueous dispersion and applied by massage appeare to be a good candidate to maximize follicular targeting and minimize drug penetration into the interfollicular epidermis. We conclude that such nanotechnology-based formulations provide a viable strategy for more efficient drug delivery to the hair follicle. Moreover, they present a way to minimize adverse effects of potent glucocorticoids by releasing the drug in a controlled manner and simultaneously decreasing interfollicular permeation, offering an advantage over conventional formulations for inflammatory-based skin/scalp diseases.

Estimation of peripheral dose from two linacs: Mevatron MX6700 and Mevatron KDS.

An empirical calculation method for high-energy beam peripheral dose estimation is described. The peripheral dose has been measured for a Siemens Mevatron MX6700 (6 MV) and a Siemens Mevatron KDS (6 and 18 MV) linear accelerators. The dose distribution is parameterized for each beam energy as a function of depth, distance from the edge of the field, and field size. A simple algorithm has been developed for dose calculation up to 100 cm from the field central axes. Predictions by this algorithm are compared with measurements in an Alderson phantom.

[Anesthesia recovery, gas exchange and postoperative hepatic and renal function in patients with morbid obesity undergoing bariatric surgery: comparison of the effects of halothane, isoflurane and fentanyl]. / Recuperación anestésica, intercambio gaseoso y función hepática y renal postoperatorios en pacientes con obesidad mórbida sometidos a cirugía bariátrica: comparación de los efectos del halotano, isoflurano y fentanilo.

OBJECTIVES: To compare the postoperative effects of three anesthetic agents, fentanyl, halothane and isoflurane, on recovery from anesthesia, changes in arterial blood gases, and tests of liver and kidney function in morbidly obese patients recovering from vertical ring gastroplasty. MATERIAL AND METHODS: Thirty-three patients were studied, randomly distributed into three groups of 11. Induction for all was with atracurium (5 mg), 2.5% thiopentone sodium (5-6 mg.kg-1), succinylcholine (1.5 mg.kg-1) and orotracheal intubation. Anesthesia was maintained with intermittent doses of fentanyl (group F), 2% halothane (group H) or 2.5% isoflurane (group I). All patients received a 50% O2/N2O mixture at a minute volume calculated on ideal weight. Muscle relaxation was achieved by continuous perfusion of atracurium. Postoperative analgesia was by morphine chloride through a lumbar epidural catheter. Time of eye opening and time of extubation were recorded. Arterial blood gas measurements were taken and the results of liver and kidney function tests were recorded until the 7th day after surgery. RESULTS: Eye opening after awakening was earlier in the fentanyl group (6 +/- 5 min), but no differences were found for time of extubation. Blood gas measurements for the 33 patients revealed a significant decrease in PaO2 (58 +/- 14 mmHg), a slight increase of PaCO2 (40 +/- 6 mmHg) and a lower pH (7.32 +/- 0.04) immediately after surgery. On day seven, PaO2 had not yet reached preoperative levels (p < 0.01). These results were independent of anesthetic agent used. Kidney function tests showed significant rises in SGOT (81 +/- 36 U/l), SGPT (150 +/- 110 U/l) and bilirubin (Bil: 15 +/- 5 mmol/l) and decreases in prothrombin activity (PT: 73 +/- 11%) 24 hours after surgery, with later normalization. Urea fell significantly throughout the seven-day period (3.2 +/- 1.3 mmol/l). These results were also independent of the anesthetic agent used. CONCLUSIONS: Morbidly obese patients undergoing gastroplasty recover from anesthesia in the same way regardless of the agent used. The early postoperative period is characterized by severe hypoxemia and transitory changes in kidney function tests. Neither of these findings is dependent on the agent used.

[Takotsubo syndrome. Usefulness of nuclear medicine studies]. / Síndrome de Takotsubo. Utilidad de los estudios de Medicina Nuclear.

Takotsubo syndrome can mimic an acute myocardial infarction. It is characterized by anginal chest pain with ST elevation in precordial leads, no coronary obstruction on angiography, and typical and reversible deformation of the left ventricular due to antero-apical ballooning with basal hyperkinesis. The pathophysiology of this syndrome is uncertain. It is probably multifactorial, cardiac adrenergic nervous dysfunction standing out in the acute phase. We report two cases performed within the diagnostic context of Takotsubo syndrome. Cardiac SPECT was performed using (123)I Metaiodobenzylguanidine (MIBG) and (99m)Tc-Tetrofosmin and the results of two cases were adrenergic denervation in the anterior wall without alterations in myocardial perfusion study. Identification of Takotsubo syndrome is of clinical importance because its management and prognosis differ significantly from that of acute myocardial infarction.

[Attention deficit disorder and hyperactivity: a pattern of evolution?]. / Trastorno por déficit de atención/hiperactividad: un patrón evolutivo?

INTRODUCTION: When the frequency of a gene in the general population exceeds 1%, is not considered a random mutation but a mutation that has been positively selected during evolution. The high prevalence of attention deficit/hyperactivity disorder (ADHD) from 5-10% and its association with the seven-repeat allele of DRD4, which is positively selected in evolution, raising the possibility that ADHD increases the reproductive fitness of the individual and/or group. One of the main characteristics of ADHD is its diversity and is a well recognized fact that diversity confers many benefits to a population (eg. immunity). DEVELOPMENT: This article discusses the various studies that support this hypothesis and offers further explanations on the prevalence, age distribution and sex distribution of the severity and heterogeneity of ADHD. CONCLUSION: It is possible that the presence of altered gene combinations, as in ADHD, can bring concrete benefits to society but are detrimental to the individual.

[Statistical Process Control (SPC) can help prevent treatment errors without increasing costs in radiotherapy]. / El control estadístico de proceso puede ayudar a prevenir los errores de tratamiento sin aumentar los costes en radioterapia.

PURPOSE: Statistical Process Control (SPC) was applied to monitor patient set-up in radiotherapy and, when the measured set-up error values indicated a loss of process stability, its root cause was identified and eliminated to prevent set-up errors. MATERIALS AND METHODS: Set up errors were measured for medial-lateral (ml), cranial-caudal (cc) and anterior-posterior (ap) dimensions and then the upper control limits were calculated. Once the control limits were known and the range variability was acceptable, treatment set-up errors were monitored using sub-groups of 3 patients, three times each shift. These values were plotted on a control chart in real time. RESULTS: Control limit values showed that the existing variation was acceptable. Set-up errors, measured and plotted on a X chart, helped monitor the set-up process stability and, if and when the stability was lost, treatment was interrupted, the particular cause responsible for the non-random pattern was identified and corrective action was taken before proceeding with the treatment. CONCLUSION: SPC protocol focuses on controlling the variability due to assignable cause instead of focusing on patient-to-patient variability which normally does not exist. Compared to weekly sampling of set-up error in each and every patient, which may only ensure that just those sampled sessions were set-up correctly, the SPC method enables set-up error prevention in all treatment sessions for all patients and, at the same time, reduces the control costs.

Nortriptyline for smoking cessation: release and human skin diffusion from patches.

The objective of this work was to develop a simple and inexpensive transdermal formulation containing Nortriptyline Hydrochloride (NTH) for smoking cessation support therapy. Hydroxypropyl-methyl-cellulose was chosen as polymer and a mixture of transdermal enhancers (selected from previous research) was incorporated. The formulations were characterised in terms of appearance, thickness, uniformity of NTH content, release and skin permeation. Release studies demonstrated controlled release for four formulations. Diffusion studies were performed through human heat separated epidermis (HHSE) using Franz Diffusion Cells (FDC). Patches provided different fluxes varying from 20.39+/-7.09 microg/(cm(2) h) to 256.19+/-94.62 microg/(cm(2) h). The penetration profiles of NTH within the stratum corneum (SC) and deeper skin layers (DSL) were established after three administration periods (3 h, 6 h, and 24 h). Skin changes induced by the application of the patches were observed by confocal laser scanning microscopy (CLSM). The highest flux obtained would provide the recommended doses for smoke cessation support therapy (25-75 mg per day) with a 2 cm x 2 cm patch or a 3.5 cm x 3.5 cm patch, respectively, without skin damage evidence.

Acid aspiration prophylaxis in morbidly obese patients: famotidine vs. ranitidine.

Famotidine and ranitidine were compared as agents for the prevention of acid aspiration syndrome in 32 morbidly obese patients undergoing vertical banded gastroplasty. Single-dose oral famotidine or double-dose oral ranitidine were administered on a random basis before surgery. Gastric contents were aspirated through a gastric tube, manually aided by the surgeon with the abdomen open. Mean (SD) gastric volumes were 13.8 ml (6.7) and 12.1 ml (13.0) for the famotidine and ranitidine groups, respectively. Mean (SD) gastric pH values were 6.2 (1.5) and 6.8 (1.5), respectively. There were no significant differences between the groups and no patient was considered 'at risk' (pH less than 2.5 and gastric volume greater than 25 ml). We conclude that single-dose oral famotidine and double-dose oral ranitidine are equally effective for preventing acid aspiration syndrome in morbidly obese patients.