Search

Copyright of Revista de Toxicología is the property of Asociacion Espanola de Toxicologia and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: PI susceptibility results from a complex interplay between protease and Gag proteins, with Gag showing wide variation across HIV-1 subtypes.We explored the impact of pre-treatment susceptibility on the outcome of lopinavir/ritonavir monotherapy. Methods: Treatment-naive individuals who experienced lopinavir/ritonavir monotherapy failure from the MONARK studywere matched (by subtype, viral load and baseline CD4 count) with those who achieved virological response (‘successes’). Successes were defined by viral load ,400 copies/mL after week 24 and ,50 copies/mL from week 48 to week 96. Full-length Gag–protease was amplified from patient samples for in vitro phenotypic susceptibility testing, with susceptibility expressed as fold change (FC) relative to a subtype B reference strain. Results: Baseline lopinavir susceptibility was lower in viral failures compared with viral successes, but the differences were not statistically significant (median lopinavir susceptibility: 4.4 versus 8.5, respectively, P¼0.17). Among CRF02_AG/G patients, there was a significant difference in lopinavir susceptibility between the two groups (7.1 versus 10.4, P¼0.047), while in subtype B the difference was not significant (2.7 versus 3.4, P¼0.13). Subtype CRF02_AG/G viruses had a median lopinavir FC of 8.7 compared with 3.1 for subtype B (P¼0.001). Conclusions: We report an association between reduced PI susceptibility (using full-length Gag–protease sequences) at baseline and subsequent virological failure on lopinavir/ritonavir monotherapy in antiretroviralnaive patients harbouring subtype CRF02_AG/G viruses. We speculate that this may be important in the context of suboptimal adherence in determining viral failure. [ABSTRACT FROM AUTHOR]

AbstractObjective??Aromatase inhibitors may decrease endometrial thickness in breast cancer patients previously having short-term tamoxifen treatment. There is a necessity to find out if aromatase inhibitors can also decrease endometrial thickness in patients previously treated with long-term tamoxifen treatment.Methods??Prospective comparison of the last ultrasonographic endometrial thickness measurement taken before discontinuation of long-term tamoxifen treatment in 36 postmenopausal breast cancer patients, with further measurements, performed following aromatase inhibitors administration.Results??There was a significant decrement of endometrial thickness, following 36.2???16.8?months of tamoxifen treatment, from a mean value of 9.1???5.8?mm, measured at the last ultrasonographic measurement performed before discontinuation of tamoxifen treatment, down to a mean value of 6.0???5.0?mm, measured following 5.8???5.8?months of aromatase inhibitors therapy (P?=?0.001). A second ultrasonographic measurement performed in 8 patients following of additional 7.5???4.0?months of aromatase inhibitors treatment revealed further decrement of mean endometrial thickness to 4.8???2.1?mm (P?=?0.002 compared to baseline).In 28 patients (77.8%), endometrial thickness was reduced following the administration of aromatase inhibitors, in four patients (11.1%) there was no change in endometrial thickness and four (11.1%) patients demonstrated an increase of endometrial thickness.Conclusions??Aromatase inhibitors may reverse endometrial thickening induced by long-term tamoxifen treatment in postmenopausal breast cancer patients. [ABSTRACT FROM AUTHOR]

The article explores racial differences in the prevalence of depression and its associated factors among older persons in the U.S. The authors adapted a model to allow an examination of independent variables and the nominal dependent variable consisting of three levels of depression. Race has an independent effect on the rate of subsyndromal depression and an interactive effect with stress on the rate of depression.

OBJECTIVES/HYPOTHESIS:: High-resolution ultrasound and sestamibi scanning are regarded as the first-line methods for preoperative localization of parathyroid adenomas. The utility of ultrasound in reoperative cases has been questioned because of concern that scarring will obscure normal tissue planes and vascularity that are critical to identification of an adenoma using this imaging modality. The purposes of the study were to evaluate the ability of high-resolution ultrasound to accurately localize parathyroid adenomas in the reoperative exploration and to identify any factors that influence its accuracySTUDY DESIGN:: Retrospective chart review at a tertiary care academic medical center.METHODS:: All patients seen in referral for parathyroid surgery between May 1994 and September 2002 underwent high-resolution ultrasound as their initial diagnostic test. Patients who subsequently underwent exploration were included in the study. Intraoperative and ultrasound findings were compared.RESULTS:: One hundred forty-two patients were included, 116 without and 26 with prior exploration. The sensitivity and positive predictive value of ultrasound were 86.9% and 89.1%, respectively. These data were not significantly different in patients without (88.2% and 90%) and in patients with (80% and 84.2%) prior thyroid or parathyroid surgery. The overall accuracy was 79% with a false-negative rate of 11.3%. Thyroid nodularity was significantly more common (81.8%) in patients who had a false-positive or false-negative finding on ultrasound than in the total population (61.3%).CONCLUSION:: High-resolution ultrasound is an accurate method for localizing parathyroid adenomas even in patients who have previously undergone parathyroid exploration. However, the presence of thyroid nodules can interfere with its accuracy. [ABSTRACT FROM AUTHOR]

SUMMARY: OBJECTIVES/HYPOTHESIS Successful unilateral or minimal-access parathyroid exploration and reoperative surgery of the parathyroid glands requires accurate preoperative localization of parathyroid disease. Although ultrasound and nuclear imaging techniques have an established role in this regard, the use of computed tomography (CT) for parathyroid exploration is not well understood. The purpose of the present study was to better define the diagnostic utility of CT in preoperative localization of the abnormal gland in surgery for hyperparathyroidism.STUDY DESIGN Retrospective cohort study.METHODS All parathyroid explorations performed at Oregon Health and Science University (Portland, OR) between 2000 and 2002 were reviewed. The study group was limited to patients with hyperparathyroidism in whom localization failed preoperatively using ultrasound and/or sestamibi scanning and subsequent investigation using CT imaging was performed. Operative, pathological, and imaging reports were then analyzed to assess the accuracy of CT imaging for localizing parathyroid disease.RESULTS Twenty-two patients with hyperparathyroidism were investigated preoperatively using CT imaging. Parathyroid exploration was successful in all but one patient, leaving 21 patients in all in the cohort. The majority of cases (67%) were reoperative, and all patients had previously undergone inconclusive ultrasound and/or sestamibi scanning. Computed tomography correctly localized parathyroid disease in 18 (86%) of the 21 patients who underwent successful extirpation of parathyroid disease and was able to identify abnormal glands with equal utility in the neck and the chest.CONCLUSION When ultrasound or sestamibi are unsuccessful, CT imaging can provide valuable preoperative localizing information before surgery for hyperparathyroidism, particularly in patients with recurrent or persistent disease. [ABSTRACT FROM AUTHOR]

SUMMARY: OBJECTIVES/HYPOTHESIS Staple-assisted, endoscopic Zenker diverticulotomy has been shown to decrease both cost of treatment and length of convalescence when compared with the standard open approach. Although the endoscopic technique is generally considered to be safe, the feasibility of outpatient endoscopic Zenker diverticulotomy has never been reported.STUDY DESIGN Retrospective cohort study.METHODS All endoscopic Zenker diverticulotomy procedures performed at Oregon Health and Science University (Portland, OR) between 1998 and 2002 were reviewed. The study group was limited to patients whose surgeries were planned on an outpatient basis. Medical charts were reviewed for indications, demographics, operative findings, complications, and resolution of symptoms.RESULTS Of the 51 patients who underwent endoscopic, staple-assisted Zenker diverticulotomy, 40 were treated with the intent of outpatient management. Thirty-two cases were primary surgeries, and eight cases were revision treatments. The average patient age was 68 years (age range, 35-91 y), and the mean follow-up period was 5.9 months (range, 1-37 mo). Eight (20%) complications were noted in the study group. Intraoperative complications included 3 patients (7.5%) with mucosal disruptions. These patients underwent uneventful suture repair of small hypopharyngeal mucosal tears encountered intraoperatively and were temporarily observed in the hospital. One patient was admitted for postoperative urinary retention and another for fever and tachycardia 48 hours after surgery. One patient sustained a myocardial infarction. The remainder of patients were fed immediately and discharged home on the day of surgery. Two patients (5%) had iatrogenic tooth fracture.CONCLUSION Appropriately selected patients undergoing endoscopic, staple-assisted Zenker diverticulotomy can be managed safely on an outpatient basis. Intraoperative complications, such as a mucosal disruption, warrant conversion to inpatient monitoring. [ABSTRACT FROM AUTHOR]

SUMMARY: OBJECTIVES/HYPOTHESIS The existing literature on postoperative donor extremity function describes a spectrum of morbidity in the long term (>3 mo after surgery). However, the consensus is that there is minimal to no impact of flap harvest on patients' activities of daily living. No previous reports have examined functional donor site morbidity in the early postoperative period; such may affect patients' overall perioperative progress, especially with respect to donor extremity dominance. The authors' objective was to quantify functional morbidity of the donor site in radial forearm fasciocutaneous free flaps during the early postoperative period.STUDY DESIGN Retrospective case series review.METHODS Patient data were obtained from hospital records of 12 consecutive patients who underwent head and neck reconstruction with radial forearm fasciocutaneous free tissue transfer over a 6-month period at a tertiary academic medical center. Functional results of each patient's donor extremity obtained preoperatively and at 5 to 8 days after surgery were determined by quantifying forearm supination and pronation, wrist flexion and extension, and sharp and dull hand sensations in radial, median, and ulnar nerve distributions.RESULTS Mean patient age was 57 years (age range, 42-71 y). The nondominant extremity was the donor site in 9 of 12 patients. Using the paired two-tailed t test, statistically significant differences were demonstrated in preoperative versus postoperative forearm supination (P < .032), pronation (P < .006), wrist flexion (P < .000), and wrist extension (P < .000). Three of 12 patients demonstrated diminished sharp sensation in the “anatomical snuffbox” distribution.CONCLUSION The authors describe statistically significant functional forearm and wrist range-of-motion morbidity associated with the harvest of a radial forearm fasciocutaneous free flap in the early postoperative period. [ABSTRACT FROM AUTHOR]

OBJECTIVES/HYPOTHESIS Studies of immediate postoperative facial nerve function following parotidectomy focus on benign disease. The purpose of the study was to compare facial nerve function with regard to benign or malignant disease in patients undergoing superficial parotidectomy.STUDY DESIGN Retrospective cohort study of consecutive patients undergoing parotidectomy between 1995 to 2002.METHODS House-Brackmann (HB) grade was recorded or assigned at the first postoperative visit. For patients with HB grade of III or greater, final resolution of facial nerve function was recorded. A χ2 analysis for independence was conducted between patients with HB grade of II or less and those with HB grade of III or greater and final pathological finding (benign vs. malignant disease). Mean and median times to resolution were determined for patients with HB grade of III or greater. Times to resolution for benign and malignant disease for those with HB grade of III or greater were compared (Kaplan-Meier method).RESULTS Sixty-seven patients with benign disease and 52 with malignant disease were included. Ninety-four percent of patients with benign disease had HB grade of II or less at first postoperative visit (mean period, 11.6 d) compared with 76.9% of patients with malignant disease (mean period, 12.4 d). A χ2 analysis found this difference significant (χ2 = 7.36, P = .0067). Time to resolution for HB grade of III or greater was 253.8 days (±168.2 d) with median time of 229.5 days for benign disease and 182.4 days (±134.6 d) with median time of 138 days for malignant disease. Kaplan-Meier comparison found no significant differences in time to final resolution (P = .83). Three patients in the group with malignant disease had unresolved dysfunction (one patient for >2 y).CONCLUSIONS Patients with benign disease have a greater chance of having HB grade of II or less immediately following surgery; however, whether the disease is benign or malignant, long-term final facial nerve function is the same. [ABSTRACT FROM AUTHOR]

OBJECTIVES/HYPOTHESIS There are many treatments available for advanced oropharyngeal cancer. Organ-sparing protocols reserve surgery for salvage and are thought to provide adequate rehabilitation. Surgical resection with free tissue transfer may also provide adequate functional rehabilitation. The objective was to describe swallowing status and time to decannulation in a series of patients treated with combined-modality therapy that included free flap reconstruction.STUDY DESIGN Retrospective chart review.METHODS Patient data were obtained from medical records of 20 patients with stage III or IV oropharyngeal carcinoma, who were consecutively treated with surgical tumor extirpation, free flap reconstruction, and postoperative irradiation at a tertiary academic center from 1985 to 2002. The following variables were identified: patient and tumor characteristics, free flap type, irradiation data, and airway and swallowing status before and after treatment.RESULTS One patient underwent total laryngopharyngectomy, and the remaining 19 patients underwent tracheotomy at the time of definitive surgery. Free flap reconstructions included 1 ulnar and 15 radial forearm fasciocutaneous flaps and 4 fibula osteocutaneous flaps. Postoperatively, all 19 tracheotomized patients had successful decannulation. Average time to decannulation was 15 days (range, 3-42 d). After surgery and before irradiation, 13 patients initiated oral intake, on average, at 19.5 days (range, 7-28 d); 6 patients required no additional supplementation. By 4 months after surgery, having completed radiation therapy, 10 patients were consuming all nutrition orally; the other 10 patients still required tube-feed supplementation, although 6 of these patients were also eating by mouth.CONCLUSION Combined-modality treatment that includes free flap reconstruction for advanced-stage oropharyngeal cancer may provide reasonable functional rehabilitation with respect to postoperative airway and swallowing. [ABSTRACT FROM AUTHOR]

OBJECTIVES To summarize the findings relevant to otolaryngology from the annual meeting of the Blood-Brain Barrier Disruption Consortium in Gleneden Beach, Oregon, March 10, 2001.STUDY DESIGN Summaries are provided by the speakers, as well as related data from the published literature. Findings in otology and oncology regarding ototoxicity that were discussed at the meeting are included.RESULTS Data considered included physiological research, animal studies, and clinical trials that relate to platinum-based chemotherapy and prevention of toxicity.CONCLUSIONS The dose-limiting side effects of platinum-based chemotherapy are preventable, but questions about the effect of the protective agents on oncological efficacy remain. Strategies for prevention of chemotherapy-induced toxicity include temporal or anatomical separation of cisplatin or carboplatin from sodium thiosulfate, D-methionine, or N-acetyl-cysteine. Clinical application of these methods has begun. The mechanisms presumably involve free radicals or drug conjugation, or both. Understanding the role of free radicals in medicine is likely to become important in the future. [ABSTRACT FROM AUTHOR]

OBJECTIVES/HYPOTHESIS Standard-sized tracheostomy tubes often fit morbidly obese patients poorly because of increased submental and anterior cervical girth. The surgeon has two options to overcome this problem: Modify the tracheostomy tube to fit the patient or recontour the neck to accommodate a standard tube. The purpose of the study was to assess the safety and morbidity of the latter technique, the “defatting” tracheotomy.STUDY DESIGN Retrospective cohort study of 23 patients treated between 1994 and 2001 with cervical lipectomy and tracheotomy.METHODS Medical charts were reviewed for indications, demographics, body mass index, tracheotomy-related complications, and decannulation results.RESULTS The average age of patients was 50 years (age range, 34-77 y). The mean preoperative body mass index was 55.9 (range, 39.2-73.5). Indications for the procedure were respiratory failure requiring chronic ventilation in 16 patients (70%) and obstructive sleep apnea in 7 (30%). Four patients died postoperatively from causes unrelated to tracheotomy. The mean follow-up time of survivors was 23 months. The overall tracheotomy-related complication rate was 43%. Four patients developed wound infections in the perioperative period, one patient developed a neck abscess, and one patient required neck exploration for control of hemorrhage. Four patients (22%) developed late complications including tracheitis (1), neck abscess (1), and stenosis of the tracheocutaneous tract (2). Eight patients (44%) ultimately had decannulation.CONCLUSIONS Defatting tracheotomy is a safe technique that allows for the placement of a standard tracheostomy tube in morbidly obese patients. It is associated with a high rate of minor infectious complications. Even so, we think that cervical lipectomy with tracheostomy tube placement is the preferred surgical option for this patient population. [ABSTRACT FROM AUTHOR]

We present a new method of constructing a fully robust qubit in a three-level system. By the application of continuous driving fields, robustness to both external and controller noise is achieved. Specifically, magnetic noise and power fluctuations do not operate within the robust qubit subspace. Whereas all the continuous driving based constructions of such a fully robust qubit considered so far have required at least four levels, we show that in fact only three levels are necessary. This paves the way for simple constructions of a fully robust qubit in many atomic and solid state systems that are controlled by either microwave or optical fields. We focus on the NV-center in diamond and analyze the implementation of the scheme, by utilizing the electronic spin sub-levels of its ground state. In current state-of-the-art experimental setups the scheme leads to improvement of more than two orders of magnitude in coherence time, pushing it towards the lifetime limit. We show how the fully robust qubit can be used to implement quantum sensing, and in particular, the sensing of high frequency signals. [ABSTRACT FROM AUTHOR]

We report a measurement of the nuclear polarization of laser-cooled, optically pumped 37K atoms which will allow us to precisely measure angular correlation parameters in the -decay of the same atoms. These results will be used to test the V − A framework of the weak interaction at high precision. At the Triumf neutral atom trap (Trinat), a magneto-optical trap confines and cools neutral 37K atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of , which is significantly more precise than previous measurements with this technique. Since our current measurement of the β-asymmetry has statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to , allowing for a measurement of angular correlation parameters to this level of precision, which would be competitive in searches for new physics. [ABSTRACT FROM AUTHOR]

A proposal for a phase gate and a Mølmer–Sørensen gate in the dressed state basis is presented. In order to perform the multi-qubit interaction, a strong magnetic field gradient is required to couple the phonon-bus to the qubit states. The gate is performed using resonant microwave driving fields together with either a radio-frequency (RF) driving field, or additional detuned microwave driving fields. The gate is robust to ambient magnetic field fluctuations due to an applied resonant microwave driving field. Furthermore, the gate is robust to fluctuations in the microwave Rabi frequency and is decoupled from phonon dephasing due to a resonant RF or a detuned microwave driving field. This makes this new gate an attractive candidate for the implementation of high-fidelity microwave based multi-qubit gates. The proposal can also be realized in laser-based set-ups. [ABSTRACT FROM AUTHOR]

Event horizons are the defining physical features of black hole spacetimes, and are of considerable interest in studying black hole dynamics. Here, we reconsider three techniques to find event horizons in numerical spacetimes: integrating geodesics, integrating a surface, and integrating a level-set of surfaces over a volume. We implement the first two techniques and find that straightforward integration of geodesics backward in time is most robust. We find that the exponential rate of approach of a null surface towards the event horizon of a spinning black hole equals the surface gravity of the black hole. In head-on mergers we are able to track quasi-normal ringing of the merged black hole through seven oscillations, covering a dynamic range of about 105. Both at late times (when the final black hole has settled down) and at early times (before the merger), the apparent horizon is found to be an excellent approximation of the event horizon. In the head-on binary black hole merger, only some of the future null generators of the horizon are found to start from past null infinity; the others approach the event horizons of the individual black holes at times far before merger. [ABSTRACT FROM AUTHOR]