Isolated brachial artery aneurysm: a rare presentation of paediatric Behçet’s disease

Behçet’s disease is a rare disease characterised by recurrent oral ulcers, with systemic manifestations including genital ulcers, ocular disease, skin lesions, gastrointestinal disease, neurologic disease, vascular disease and arthritis. Most clinical manifestations of Behçet’s disease are believed to be due to vasculitis. The heterogeneous clinical spectrum is influenced by sex, ethnicity and country of residence. Vascular manifestation in the form of isolated large brachial artery aneurysm is rare in children. Treatment involves aneurysmorrhaphy to avoid rupture or ischaemic sequelae in addition to lifelong medical management to control vasculitis.     

Cochlear blood flow increases after systemic hemodilution: comparison of simultaneous laser Doppler flowmetry and radioactive microsphere measurements

Guinea pig cochlear blood flow was measured before and after systemic normovolemic hemodilution with high molecular weight dextran. Absolute determinations of blood flow (in the cochlea, brain, kidney and lung) were accomplished by use of radioactive-labeled (85Sr or 141Ce) microspheres. Relative measurements of the cochlear blood flow changes were made simultaneously by the use of a laser Doppler flowmeter. The flowmeter probe was placed on the first cochlear turn. Hemodilution to an average systemic hematocrit of 20% increased cochlear blood flow by 250% as measured with microspheres. The laser Doppler instrument significantly underestimated the actual flow increase giving an indication of 148%. Furthermore, the data, when analyzed on an individual trial basis, showed a very poor correlation between the two methods. The theoretical basis for these findings in relation to the use of the laser Doppler instrument is discussed.     

Accuracy assessment of three‐dimensional surface reconstructions of teeth from Cone Beam Computed Tomography scans

Summary The use of three‐dimensional (3D) models of the dentition obtained from cone beam computed tomography (CBCT) is becoming increasingly more popular in dentistry. A recent trend is to replace the traditional dental casts with digital CBCT models for diagnosis, treatment planning and simulation. The accuracy of these models was previously assessed through comparing linear physical and radiographical measurements. However, this assessment technique is both observer and landmark dependent. The accuracy of 3D CBCT teeth reconstructions is yet to be reliably measured. To assess the accuracy of 3D CBCT reconstructions of the teeth using a semi‐automated and observer‐independent method and to assess the influence of field of view (FoV) selection on reconstruction accuracy. Fully dentate upper and lower dry human jaws, placed in a plastic box and immersed in water, were scanned using CBCT with small, medium and large FoV. The teeth were then scanned separately using MicroCT. Cone beam computed tomography and MicroCT 3D teeth models were compared, and mean surface difference was calculated per tooth for each FoV. Mean and (maximum) differences between MicroCT and CBCT were 120 ± 40 (max. 679) μm, 157 ± 39 (max. 824) μ and 207 ± 80 (max. 862) μm for the small, medium and large FoV, respectively. Cone beam computed tomography models were larger than MicroCT because of larger voxel size. Our results indicate that CBCT may provide accurate 3D reconstructions of the teeth that can be useful for some clinical applications.     

Prevalence of HIV and hepatitis C markers among a cadaver population in Milan.

AIMS: To examine the distribution of serological markers for HIV and hepatitis C virus (HCV) infection in a medicolegal population; to compare prevalence of HIV and HCV markers and cause of death; and to evaluate the risk of potential infection to personnel involved in medicolegal incidents and procedures. METHODS: Blood samples were collected at necropsy from 328 males and 69 females, aged 16 to 50 years at time of death, and tested for antibodies to HIV and HCV. The individuals were classified according to cause of death and whether there was known antemortem risk of infection. RESULTS: Overall, 134 subjects gave positive test results: 20 for anti-HIV, 69 for anti-HCV, and 45 for both. By cause of death, the total number of positives (and negatives) with the pairs of figures referring, respectively, to patients with and without known antemortem risks were: natural causes 3 (1), 8 (32); AIDS 2 (0), 0 (0); homicide 0 (2), 5 (24); suicide 3 (0), 9 (69); road traffic accidents 1 (0), 9 (81); other accidents 2 (3), 1 (12); drug overdose 74 (17), 7 (9); unknown causes 3 (2), 7 (11). CONCLUSIONS: The cases tested represented a predominantly young male population with a high prevalence of serological markers for HIV and HCV infection. The distribution of HIV and HCV positivity varied with the cause of death, probably reflecting the known association between high risk behaviour and infection. However, a substantial number of cases with no known risks also had markers for HIV and HCV, suggesting that there is a large unrecognised pool of potential infection in medicolegal practice.     

The effects of Carbogen, carbon dioxide, and oxygen on noise-induced hearing loss.

An investigation into the effect of Carbogen (95% O2/5% CO2), 5% CO2/air, and 100% oxygen on cochlear threshold shifts caused by noise was undertaken. Five groups of eight pigmented guinea pigs were exposed to 105 dB broad band noise for 6 h per day for five consecutive days with each group receiving the various gaseous mixtures either during noise exposure or for 1 h immediately after noise exposure. A control group received the same noise exposure but respired air. Auditory threshold shifts, as measured by the auditory evoked brainstem response, were measured at 2,4,8,12,16, 20 and 24 kHz. Recordings were taken pre-exposure and at Day 1, 3, 5, and Weeks 2 and 3 after noise exposure. Carbogen, given during noise exposure, resulted in a trend toward less post noise exposure threshold shift (as compared to controls) which reached statistical significance by Week 3 at all frequencies except 2 and 20 kHz. Subjects given Carbogen after exposure also showed a general trend toward decreased noise induced threshold shifts, as compared to controls, but this was not statistically significant. The mixture of 5% CO2/air given during noise exposure yielded no difference in threshold shifts as compared to controls. When 100% oxygen was administered during noise exposure, a marked decrease in noise induced threshold shifts could be seen as compared to controls, with differences reaching statistical significance by day 5 at most frequencies. These results indicate that oxygen (i.e. cochlear-oxygenation) is a more important factor than CO2 (i.e., as a vasodilator) in protection of the cochlea from noise induced damage.     

The effect of noise exposure on the aging ear.

The effect of noise exposure on auditory sensitivity and inner ear morphology was compared in aged and young mature mice. Hearing thresholds were obtained by auditory evoked brain stem responses (ABR) before and after noise exposure, and hair cell loss was quantified. The study was done in two parts: first to assess the effect of noise exposure on subjects with presbycusis, and second to assess its effect on aged subjects without measurable presbycusis. In the first experiment C57BL/6 mice, with an age-related hearing loss, were used as a model for presbycusis. C57BL/6 mice exhibiting presbycusis were more susceptible to noise injury than age-matched CBA/Ca mice. In the second experiment CBA/Ca mice were used. These mice retain normal hearing even with advancing age. The aged CBA/Ca mice had the same susceptibility to noise injury as young CBA/Ca mice.