Determination of the force constant of a single-beam gradient trap by measurement of backscattered light

A single-beam gradient trap could potentially be used to hold a stylus for scanning force microscopy. With a view to development of this technique, we modeled the optical trap as a harmonic oscillator and therefore characterized it by its force constant. We measured force constants and resonant frequencies for 1-4-mu m-diameter polystyrene spheres in a single-beam gradient trap using measurements of back-scattered light. Force constants were determined with both Gaussian and doughnut laser modes, with powers of 3 and 1 mW, respectively. Typical values for spring constants were measured to be between 10(-6) and 4 x 10(-6) N/m. The resonant frequencies of trapped particles were measured to be between 1 and 10 kHz, and the rms amplitudes of oscillations were estimated to be around 40 nm. Our results confirm that the use of the doughnut mode for single-beam trapping is more efficient in the axial direction. (C) 1996 Optical Society of America.

Derivation and external validation of a simple prediction model for the diagnosis of type 2 Diabetes Mellitus in the Brazilian urban population

A risk score model was developed based in a population of 1,224 individuals from the general population without known diabetes aging 35 years or more from an urban Brazilian population sample in order to select individuals who should be screened in subsequent testing and improve the efficacy of public health assurance. External validation was performed in a second, independent, population from a different city ascertained through a similar epidemiological protocol. The risk score was developed by multiple logistic regression and model performance and cutoff values were derived from a receiver operating characteristic curve. Model`s capacity of predicting fasting blood glucose levels was tested analyzing data from a 5-year follow-up protocol conducted in the general population. Items independently and significantly associated with diabetes were age, BMI and known hypertension. Sensitivity, specificity and proportion of further testing necessary for the best cutoff value were 75.9, 66.9 and 37.2%, respectively. External validation confirmed the model`s adequacy (AUC equal to 0.72). Finally, model score was also capable of predicting fasting blood glucose progression in non-diabetic individuals in a 5-year follow-up period. In conclusion, this simple diabetes risk score was able to identify individuals with an increased likelihood of having diabetes and it can be used to stratify subpopulations in which performing of subsequent tests is necessary and probably cost-effective.

PHASE I/II STUDY OF ERLOTINIB COMBINED WITH CISPLATIN AND RADIOTHERAPY IN PATIENTS WITH LOCALLY ADVANCED SQUAMOUS CELL CARCINOMA OF THE HEAD AND NECK

Purpose: Erlotinib, an oral tyrosine kinase inhibitor, is active against head-and-neck squamous cell carcinoma (HNSCC) and possibly has a synergistic interaction with chemotherapy and radiotherapy. We investigated the safety and efficacy of erlotinib added to cisplatin and radiotherapy in locally advanced HNSCC. Methods and Materials: In this Phase I/II trial 100 mg/m(2) of cisplatin was administered on Days 8, 29, and 50, and radiotherapy at 70 Gy was started on Day 8. During Phase I, the erlotinib dose was escalated (50 mg, 100 mg, and 150 mg) in consecutive cohorts of 3 patients, starting on Day 1 and continuing during radiotherapy. Dose-limiting toxicity was defined as any Grade 4 event requiring radiotherapy interruptions. Phase 11 was initiated 8 weeks after the last Phase I enrollment. Results: The study accrued 9 patients in Phase I and 28 in Phase II; all were evaluable for efficacy and safety. No dose-limiting toxicity occurred in Phase I, and the recommended Phase 11 dose was 150 mg. The most frequent nonhematologic toxicities were nausea/vomiting, dysphagia, stomatitis, xerostomia and in-field dermatitis, acneiform rash, and diarrhea. Of the 31 patients receiving a 150-mg daily dose of erlotinib, 23 (74%; 95% confidence interval, 56.8%-86.3%) had a complete response, 3 were disease free after salvage surgery, 4 had inoperable residual disease, and 1 died of sepsis during treatment. With a median 37 months` follow-up, the 3-year progression-free and overall survival rates were 61% and 72%, respectively. Conclusions: This combination appears safe, has encouraging activity, and deserves further studies in locally advanced HNSCC. (C) 2010 Elsevier Inc.

INTENSITY-MODULATED AND 3D-CONFORMAL RADIOTHERAPY FOR WHOLE-VENTRICULAR IRRADIATION AS COMPARED WITH CONVENTIONAL WHOLE-BRAIN IRRADIATION IN THE MANAGEMENT OF LOCALIZED CENTRAL NERVOUS SYSTEM GERM CELL TUMORS

Purpose: To compare the sparing potential of cerebral hemispheres with intensity-modulated radiotherapy (IMRT) and three-dimensional conformal radiotherapy (3D-CRT) for whole-ventricular irradiation (WVI) and conventional whole-brain irradiation (WBI) in the management of localized central nervous system germ cell tumors (CNSGCTs). Methods and Materials: Ten cases of patients with localized CNSGCTs and submitted to WVI by use of IMRT with or without a ""boost"" to the primary lesion were selected. For comparison purposes, similar treatment plans were produced by use of 3D-CRT (WVI with or without boost) and WBI (opposed lateral fields with or without boost), and cerebral hemisphere sparing was evaluated at dose levels ranging from 2 Gy to 40 Gy. Results: The median prescription dose for WVI was 30.6 Gy (range, 25.2-37.5 Gy), and that for the boost was 16.5 Gy (range, 0-23.4 Gy). Mean irradiated cerebral hemisphere volumes were lower for WVI with IMRT than for 3D-CRT and were lower for WVI with 3D-CRT than for WBI. Intensity-modulated radiotherapy was associated with the lowest irradiated volumes, with reductions of 7.5%, 12.2%, and 9.0% at dose levels., compared with 3D-CRT. Intensity-modulated radiotherapy provided of 20, 30, and 40 Gy, respectively statistically significant reductions of median irradiated volumes at all dose levels (p = 0.002 or less). However, estimated radiation doses to peripheral areas of the body were 1.9 times higher with IMRT than with 3D-CRT. Conclusions: Although IMRT is associated with increased radiation doses to peripheral areas of the body, its use can spare a significant amount of normal central nervous system tissue compared with 3D-CRT or WBI in the setting of CNSGCT treatment. (C) 2010 Elsevier Inc.

Congenital External Carotid Artery Aneurysm

An 8-month-old child presented with a right pulsatile neck mass. The tumor`s rapid increase in size and respiratory problems prompted image evaluation. An external carotid artery aneurysm was found, which was compressing other neck structures. The patient underwent aneurysm resection and ligation at its insertion on the common carotid artery. Recovery was uneventful and no further aneurysms on other arteries were found.

Extremely late development of pituitary carcinoma after surgery and radiotherapy

Introduction Pituitary carcinomas account for 0.1 or 0.2% of pituitary tumors. The authors report a rare case of a pituitary carcinoma mimicking a radio-induced meningioma. Case report Fifty-five years-old male presents a previous history of transcranial surgery in 1983 for invasive pituitary adenoma followed by whole-brain radiotherapy (5100 cGy). After three years he presented worsening of visual deficits and MRI evidenced recurrence of the lesion. In 1992, he underwent a transcranial approach to treat recurrent supraselar disease, followed by stereoctatic radiotherapy. In 2006, clinical condition was stable; however three right frontal extra-axial lesions were diagnosed by MRI, compatible with meningioma. The histological examination revealed pituitary adenoma. No lesions were found in craniospinal axis. Further treatment was not recommended by radiotherapists due previous actinic treatments. Two years radiological follow-up revealed no recurrence. Conclusion In these high risk cases, active and constant surveillance must be pertained, regardless the time of follow-up.

The Alzheimer`s Association external quality control program for cerebrospinal fluid biomarkers

Background: The cerebrospinal fluid (CSF) biomarkers amyloid beta (A beta)-42, total-tau (T-tau), and phosphorylated-tau (P-tau) demonstrate good diagnostic accuracy for Alzheimer`s disease (AD). However, there are large variations in biomarker measurements between studies, and between and within laboratories. The Alzheimer`s Association has initiated a global quality control program to estimate and monitor variability of measurements, quantify batch-to-batch assay variations, and identify sources of variability. In this article, we present the results from the first two rounds of the program. Methods: The program is open for laboratories using commercially available kits for A beta, T-tau, or P-tau. CSF samples (aliquots of pooled CSF) are sent for analysis several times a year from the Clinical Neurochemistry Laboratory at the Molndal campus of the University of Gothenburg, Sweden. Each round consists of three quality control samples. Results: Forty laboratories participated. Twenty-six used INNOTEST enzyme-linked immunosorbent assay kits, 14 used Luminex xMAP with the INNO-BIA AlzBio3 kit (both measure A beta-(1-42), P-tau(181P), and T-tau), and 5 used Mesa Scale Discovery with the A beta triplex (A beta N-42, A beta N-40, and A beta N-38) or T-tau kits. The total coefficients of variation between the laboratories were 13% to 36%. Five laboratories analyzed the samples six times on different occasions. Within-laboratory precisions differed considerably between biomarkers within individual laboratories. Conclusions: Measurements of CSF AD biomarkers show large between-laboratory variability, likely caused by factors related to analytical procedures and the analytical kits. Standardization of laboratory procedures and efforts by kit vendors to increase kit performance might lower variability, and will likely increase the usefulness of CSF AD biomarkers. (C) 2011 The Alzheimer`s Association. All rights reserved.

Assessment of disease-free survival in patients with laryngeal squamous cell carcinoma treated with radiotherapy associated or not with chemotherapy

In early stage (I and II) laryngeal squamous cell carcinoma, both surgery and radiotherapy results in significant local and regional control. In advanced tumors (III and IV), radiotherapy alone has local-regional control rates of 32-43%. Aim: To assess disease-free survival in SCC laryngeal carcinoma patients submitted to radiotherapy alone and/or associated with chemotherapy. Materials and Methods: Retrospective study involving 84 cases of laryngeal SCC treated with radiotherapy or chemotherapy together with radiotherapy. Fifty-three cases were treated with intension to cure and 31 because of impossibility to resect the disease. As to clinical stage (CS), 12 were CS I, 15 II, 21 III and 5 IV. In the second group, 11 cases were EC III and 20 IV. Results: Mean age was 60 years, 84.5% were men. Fifty-eight (69.1%) cases had complete response and 26 (30.9%) had persistent or residual disease. Five-year disease-free survival was of 42.5%; 62.5% of the patients with organ preservation indication and 9.75 in the group of irressecable disease. Conclusion: disease-free survival of those patients submitted to radiotherapy because of laryngeal SCC was of 62.5%

Esophageal Contractions in Patients with Chronic Progressive External Ophthalmoplegia

Background Chronic progressive external ophthalmoplegia is a mitochondrial myopathy that causes muscular or multisystem symptoms and has dysphagia as one manifestation. Aim To evaluate esophageal contractions in patients with chronic progressive external ophthalmoplegia. Methods We studied 14 patients with chronic progressive external ophthalmoplegia and 16 asymptomatic volunteers. The diagnosis of the disease was established by the clinical picture and by mitochondrial DNA analysis in skeletal muscle. We used the manometric method with a perfusion catheter that recorded the esophageal contractions at 2, 7, 12, 17, and 22 cm from the lower esophageal sphincter (LES). All subjects performed in the supine position 20 swallows of a 5-ml bolus of water at room temperature, ten every 30 s and ten every 10 s. Results The amplitude, duration, and area under the curve of contractions at 17 and 22 cm from the LES were lower in patients than in volunteers for swallows performed at 10-s and 30-s intervals (P < 0.01). There was no difference in contractions at 7 and 2 cm, except for the contractions at 2 cm after swallows performed at 30-s intervals. The interval between the onset of contractions between 7 and 2 cm and between 22 and 2 cm was lower in patients than in volunteers, with swallows performed every 10 s and every 30 s. Conclusions There is impairment of esophageal contractions in patients with chronic progressive external ophthalmoplegia, mainly in the proximal esophageal body.

Brazilian experience with two conditioning regimens in patients with multiple sclerosis: BEAM/horse ATG and CY/rabbit ATG

Studies have shown that autologous hematopoietic SCT (HSCT) can be used as an intensive immunosuppressive therapy to treat refractory patients and to prevent the progression of multiple sclerosis (MS). This is a prospective multicentric Brazilian MS trial comparing two conditioning regimens: BEAM/horse ATG and CY/rabbit ATG. Most (80.4%) of the 41 subjects in the study had the secondary progressive MS subtype and the mean age was 42 years. The baseline EDSS score in 58.5% of the subjects was 6.5 and 78% had a score of 6.0 or higher, respectively. The complication rate during the intra-transplantation period was 56% for all patients: 71.4% of the patients in the BEAM/hATG group and 40% in the CY/rATG group (P = 0.04). Three subjects (7.5%) died of cardiac toxicity, sepsis and alveolar hemorrhage, all of them in the BEAM/ATG group. EFS was 58.54% for a ll patients: 47% in the BEAM/hATG group and 70% in the CY/rATG group (P = 0.288). In conclusion, the CY/rATG regimen seems to be associated with similar outcome results, but presented less toxicity when compared with the BEAM/hATG regimen. Long-term follow-up would be required to fully assess the differences in therapeutic effectiveness between the two regimens. Bone Marrow Transplantation (2010) 45, 239-248; doi:10.1038/bmt.2009.127; published online 6 July 2009

Audiological findings in pacients treated with radiotherapy for head and neck tumors

Radiotherapy has been widely used given its increase in the successful outcomes and cure of some cancers. Aim: To evaluate the functionality of the auditory system in patients who underwent radiotherapy treatment for head and neck tumors. Materials and Methods: From May 2007 to May 2008, otorhinolaryngological and audiological evaluation (Pure Tone Audiometry (air and bone conduction), Speech Audiometry, Tympanometry, Acoustic Reflex testing and Distortion Product Otoacoustic Emissions) were performed in 19 patients diagnosed with head and neck neoplasia and treated with radiotherapy. Prospective case series study. Results: 10.5% left ears and 26.3% right ears had bilateral hearing loss soon after radiotherapy according to ASHA criteria. Conclusions: Radiotherapy treatment for head and neck cancer has ototoxic effects. Early programs of auditory rehabilitation should be offered to these patients.

Tc-99m-labeled dextran for mammary lymphoscintigraphy in dogs

Lymphoscintigraphy is the technique of choice for sentinel lymph node detection in women with early breast cancer, but there is limited information evaluating the value of this technique in animals. We investigated mammary lymphatic drainage in 25 young female mongrel dogs by intramammary injection of 18.5 MBq of Tc-99m-dextran (70,000 Da). Lymph node anatomical referencing was obtained using an external marker, bone scintigraphy, or scintiscanning the body contour. Cranial and caudal thoracic mammary glands drained into the cranial sternal lymph node and axillary lymph center. The cranial thoracic mammary gland also drained into the superficial cervical lymph node in two of five animals. The cranial abdominal gland was drained by the axillary lymph center. The caudal abdominal mammary gland was drained by the superficial inguinal lymph node in all animals and simultaneously by medial iliac lymph nodes in four of five animals. In one dog, this mammary gland was also drained by the mediastinal and the superficial cervical lymph nodes. The inguinal mammary gland was drained by superficial inguinal lymph nodes and simultaneously via the medial iliac lymph node in one animal. Lymphatic communications between lymph nodes were identified in 11 of 25 (44%) animals. Tc-99m-dextran mammary lymphoscintigraphy was easy and rapid to perform and may provide valuable information for further studies.