Cerebral cortical thickness in chronic pain due to knee osteoarthritis: the effect of pain duration and pain densitization

Objective This study investigates associations between cortical thickness and pain duration, and central sensitization as markers of pain progression in painful knee osteoarthritis. Methods Whole brain cortical thickness and pressure pain thresholds were assessed in 70 participants; 40 patients with chronic painful knee osteoarthritis (age = 66.1± 8.5 years, 21 females, mean duration of pain = 8.5 years), and 30 healthy controls (age = 62.7± 7.4, 17 females). Results Cortical thickness negatively correlated with pain duration mainly in fronto-temporal areas outside of classical pain processing areas (p<0.05, age-controlled, FDR corrected). Pain sensitivity was unrelated to cortical thickness. Patients showed lower cortical thickness in the right anterior insula (p<0.001, uncorrected) with no changes surviving multiple test correction. Conclusion With increasing number of years of suffering from chronic arthritis pain we found increasing cortical thinning in extended cerebral cortical regions beyond recognised pain-processing areas. While the mechanisms of cortical thinning remain to be elucidated, we show that pain progression indexed by central sensitization does not play a major role

Oral maxillofacial neoplasms in an East African population a 10 year retrospective study of 1863 cases using histopathological reports

<p>Abstract</p> <p>Background</p> <p>Neoplasms of the oral maxillofacial area are an interesting entity characterized by differences in nomenclature and classification at different centers.</p> <p>We report neoplastic histopathological diagnoses seen at the departments of oral maxillofacial surgery of Muhimbili and Mulago referral hospitals in Tanzania and Uganda respectively over a 10-year period.</p> <p>Methods</p> <p>We retrieved histopathological reports archived at the departments of oral maxillofacial surgery of Muhimbili and Mulago referral hospitals in Tanzania and Uganda respectively over a 10-year period from June 1989–July 1999.</p> <p>Results</p> <p>In the period between June 1989 and July 1999, 565 and 1298 neoplastic oro-facial cases were retrieved of which 284 (50.53%) and 967 (74.54%) were malignant neoplasms at Muhimbili and Mulago hospitals respectively. Overall 67.28% of the diagnoses recorded were malignant with Kaposi's sarcoma (21.98%), Burkiits lymphoma (20.45%), and squamous cell carcinoma (15.22%) dominating that group while ameloblastoma (9.23%), fibromas (7.3%) and pleomorphic adenoma (4.95%) dominated the benign group.</p> <p>The high frequency of malignancies could be due to inclusion criteria and the clinical practice of selective histopathology investigation. However, it may also be due to higher chances of referrals in case of malignancies.</p> <p>Conclusion</p> <p>There is need to reexamine the slides in these two centers in order to bring them in line with the most recent WHO classification so as to allow for comparison with reports from else where.</p

SUBLIMATION OF HIGHER FULLERENES AND THEIR INTERACTION WITH SILICON(100) SURFACE

The heat of sublimation of C-60, C-70, C-78, C-84, and C-96 is measured by modulated molecular beam mass spectrometry (MMBMS). For a mixture of these fullerenes the heat of sublimation is 39 +/- 5, 43 +/- 5, 47 +/- 18, 59 +/- 6, and 65 +/- 11 kcal/mol, respectively, and did not change with the variation in composition. The partial pressure of C-84 is estimated to be P-84 = 7.0 x 10(12) exp[-59.4 kcal/mol/RT] Torr. The scattering of C-70 and C-84 from Si(100) is also investigated by MMBMS. The behavior of C-84 is quite similar to that of C-60 reported earlier By Hamza, Balooch, and Moalem (Surf. Sci. 1994, 317, L1129) except that the onset of surface decomposition of the fullerene occurs at 850 g, 150 K lower than for C-60. When the surface temperature reaches 1000 K, total decomposition of the incident C-84 is observed. The behavior of C-70 is surprisingly different from both C-60 and C-84 Twenty percent of the incident C-70 decomposes at 1000 K, and the remaining 80% does not decompose until a target temperature of 1200 K is reached. At surface temperatures below 800 K, for the interaction of C-70 and C-84 with silicon, the dominant surface processes are adsorption with near perfect sticking probability, followed by surface diffusion to the edge of the specimen and desorption. The ratio of desorption rate constant kd, to diffusion coefficient, D-s, for C-70 and C-84 was calculated to be 2.7 x 10(16) exp(-40 (kcal/mol/RT) and 7.8 x 10(7) exp(-22 (kcal/mol/RT) cm(-2), respectively

Structure of low-density nanoporous dielectrics revealed by low-vacuum electron microscopy and small-angle X-ray scattering

Aerogels (AGs) are ultralow-density nanoporous solids that have numerous potential applications. However, as most AGs are strong insulators with poor mechanical properties, direct studies of the complex nanoporous structure of AGs by methods such as atomic force and conventional scanning electron microscopy (SEM) have not proven feasible. Here, we use low-vacuum SEM to image directly the ligament and pore size and shape distributions of representative AGs over a wide range of length scales (∼100-105 nm). The structural information obtained is used for unambiguous, real-space interpretation of small-angle X-ray scattering curves for these complex nanoporous systems. Low-vacuum SEM permits imaging of both cross-sections and skin layers of AG monoliths. Images of skin layers reveal the presence of microcracks, which alter the properties of cast monolithic AGs. © 2007 American Chemical Society