Probing gigahertz coherent acoustic phonons in TiO2 mesoporous thin films.

Ultrahigh-frequency acoustic-phonon resonators usually require atomically flat interfaces to avoid phonon scattering and dephasing, leading to expensive fabrication processes, such as molecular beam epitaxy. Mesoporous thin films are based on inexpensive wet chemical fabrication techniques that lead to relatively flat interfaces regardless the presence of nanopores. Here, we report mesoporous titanium dioxide-based acoustic resonators with resonances up to 90 GHz, and quality factors from 3 to 7. Numerical simulations show a good agreement with the picosecond ultrasonics experiments. We also numerically study the effect of changes in the speed of sound on the performance of the resonator. This change could be induced by liquid infiltration into the mesopores. Our findings constitute the first step towards the engineering of building blocks based on mesoporous thin films for reconfigurable optoacoustic sensors.

Neuromyelitis optica spectrum disorders: beyond longitudinally extensive transverse myelitis.

AIM: To describe the neuroradiological features and their prevalence in patients with neuromyelitis optica (NMO). MATERIALS AND METHODS: Two neuroradiologists independently reviewed 35 spinal cord and 37 brain MRI studies from patients with NMO. The examinations were analysed for the presence of lesion, topography, enhancement, and brain lesions suggestive of multiple sclerosis and/or NMO. RESULTS: Seventy percent of the spinal cord lesions involved over three or more vertebral segments. Seventy-eight percent of brain scans were abnormal, and the most prevalent findings were non-specific foci of T2 hyperintensities in the cerebral white matter (55%) and brainstem lesions (52%). One patient had lesions disseminated in space compatible with multiple sclerosis according to 2010 revised McDonald criteria. Brain lesions suggestive of NMO occurred at least once in 17 (59%) patients. CONCLUSION: Spinal cord lesions were often longitudinally extensive and brain lesions were common, with the majority of patients having at least one distinctive NMO lesion.

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS): typical clinical and neuroimaging features in a Brazilian family / Ataxia espástica autossômica recessiva de Charlevoix-Saguenay (ARSACS): aspectos clínicos e de neuroimagem típicos em uma família brasileira

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is a neurodegenerative disorder characterized by late-infantile onset spastic ataxia and other neurological features. ARSACS has a high prevalence in northeastern Quebec, Canada. Several ARSACS cases have been reported outside Canada in recent decades. This is the first report of typical clinical and neuroimaging features in a Brazilian family with probable diagnosis of ARSACS.

A ataxia espástica autossômica recessiva de Charlevoix-Saguenay (ARSACS) é doença degenerativa do sistema nervoso, caracterizada por ataxia associada a espasticidade, entre outras manifestações neurológicas, de início na infância. A doença tem alta prevalência na região de Quebec, no Canadá. Muitos relatos de ARSACS têm sido descritos fora do Canadá nas últimas décadas. Nesse artigo, relatamos a primeira descrição dos aspectos clínicos e de neuroimagem típicos em uma família brasileira com provável diagnóstico de ARSACS.

Analysis of the masseter muscle in patients with systemic sclerosis: a study by magnetic resonance imaging.

OBJECTIVES: The aim of this study was to investigate the relationship between mandibular osteolysis and the T1 and T2 tissue signal strength and morphology of the masseter muscle in patients with systemic sclerosis (SS). METHODS: All patients with SS underwent panoramic radiography to detect mandibular osteolysis. MRI of the masseter was performed on 15 patients with SS and 10 healthy control subjects. RESULTS: All patients presented mean T1 values that were statistically equal. The patients with osteolysis presented mean T2 values that were the same as those of patients without osteolysis and normal individuals. The patients without osteolysis showed stronger T2 signals than did the normal individuals. The morphological analysis showed more atrophy, fatty replacement and rectified morphology in relation to the healthy subjects. CONCLUSIONS: The patients with SS presented more atrophy, fat replacement and rectification than did the normal individuals. The T2 signal was significantly stronger among the patients with SS without osteolysis than among normal individuals and among patients with SS and osteolysis.

Sexually transmitted infections, sexual risk behaviors and the risk of heterosexual spread of HIV among and beyond IDUs in St. Petersburg, Russia.

AIMS: This study investigates whether sexual transmitted behaviors and infections (STIs) among injection drug users (IDUs) may promote the spread of HIV among and beyond IDUs in Russia. METHODS: We conducted a cross-sectional survey of behavior and tested for STIs in a convenience sample of 159 IDUs in St. Petersburg, Russia. RESULTS: The median age was 27 and 57% were male. Almost all were sexually active, half had casual partners and 40% reported > or =2 sex partners in the previous 3 months. Of those who answered, 81% reported sex without condoms, 44% reported having sex with at least one partner who was not an IDU. Of 139 (87%) subjects who were actively injecting, 29% reported receptive syringe sharing. Twenty percent of subjects were seropositive for HIV-1 and 42% of HIV-1-negative subjects tested positive for an STI. CONCLUSIONS: The sample exhibited high levels of sexual risk behaviors and STIs, and a large proportion had sexual partners who were not IDUs. This population requires comprehensive interventions that ensures access to condoms and sterile injection supplies and that encourage safer sexual behaviors in an attempt to keep sexual transmission of HIV low.

Can HIV-1-contaminated syringes be disinfected? Implications for transmission among injection drug users.

Bleaching of syringes has been advocated to prevent HIV-1 transmission among injection drug users (IDUs). Bleach is frequently distributed by needle exchange, outreach, and educational programs targeting IDUs. We applied a sensitive HIV-1 microculture assay to determine the effectiveness of bleach in disinfecting syringes contaminated with HIV-1. This study demonstrates that in a laboratory environment designed to replicate injection behaviors, undiluted bleach is highly effective in reducing the viability of HIV-1 even after minimal contact time. However, it did not reduce the HIV-1 recovery to zero. Furthermore, three washes with water were nearly as effective as a single rinse with undiluted bleach in reducing the likelihood that contaminated syringes harbored viable HIV-1. Given the reality that IDUs share syringes and may not have access to a new, sterile syringe for each injection, the results suggest that they should be encouraged through harm reduction interventions to clean their syringes, preferably with undiluted bleach.

Use of ethylene vinyl alcohol copolymer for tubal sterilization by selective catheterization in rabbits.

PURPOSE: To assess the efficacy of ethylene vinyl alcohol copolymer (Uryx) in nonsurgically occluding the fallopian tube and achieving tubal sterilization in the rabbit model. MATERIALS AND METHODS: Ten mature virgin female New England rabbits underwent transvaginal selective bilateral fallopian tube cannulation with use of a coaxial catheter system under general anesthesia. Selective salpingography was performed bilaterally to assess patency of the fallopian tubes. Ethylene vinyl alcohol copolymer was injected unilaterally through a microcatheter to completely fill the middle portion of the tube. Three to seven days after injection, each animal was bred. Conception was determined by ultrasonography (US) 7-19 days after effective breeding. If pregnant, the rabbit was killed. Otherwise, it was permitted to rebreed until pregnancy was achieved. Histologic specimens of the fallopian tubes were prepared and analyzed. RESULTS: Patency of the fallopian tubes was demonstrated bilaterally in all animals by the free spillage of contrast material into the peritoneum. The delivery of ethylene vinyl alcohol copolymer into the fallopian tubes was successful in all animals but one, in which most of the plug almost immediately extruded into the uterus. Pregnancy was detected by US in the untreated fallopian tube in the nine rabbits that were receptive to breeding. No pregnancies were detected in the injected side. Histologic analysis demonstrated variable degrees of occlusion, fibrosis, and inflammation, with the majority of specimens demonstrating mild to moderate inflammation and moderate to marked fibrosis. CONCLUSION: Ethylene vinyl alcohol copolymer can reliably be placed nonsurgically via the transvaginal approach into the fallopian tubes with use of a coaxial catheter system. Ethylene vinyl alcohol copolymer appears to result in less fibrosis than previously investigated agents and demonstrates a 100% early sterilization rate in the rabbit model.

Viability of HIV-1 in syringes: implications for interventions among injection drug users.

We have determined that the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs can exceed 6 weeks. The percentage of syringes with viable virus varied with the volume of blood remaining in the syringes and the temperature at which syringes were stored. These experiments underscore the need for needle exchange programs and other HIV prevention interventions that promote the availability of clean syringes and the removal of potentially infectious ones from circulation.

Survival of HIV-1 in syringes: effects of temperature during storage.

In a previous paper we demonstrated that HIV-1 survival in syringes was strongly associated with the volume of blood remaining and with the duration of storage at room temperature. The current study was performed to determine the effects of storage temperature upon the survival of HIV-1 inside syringes. At 4 degrees C, 50% of all syringes contained viable HIV-1 at 42 days of storage, the longest storage duration tested. At room temperature (20 degrees C), the last day that syringes with 2 microL of infected blood were positive was Day 21, and viable HIV-1 was recovered from 8% of syringes. The last day on which syringes with 20 microL were positive was Day 42, and viable HIV-1 was recovered from 8% of syringes. Above room temperature (27, 32, and 37 degrees C), the likelihood of encountering syringes with viable HIV-1 when periods of storage exceeded 1 week decreased to less than 1%. The temperatures at which drug injectors are likely to store their used syringes will vary according to climate, season, and circumstances faced by the injector. The survival of HIV-1 in contaminated syringes varied over a range of temperatures, and this may be a factor influencing the syringe-borne transmission of HIV-1.

[Multiple gliomas. Illustrative cases of 4 different presentations]. / Gliomas múltiplos: casos ilustrativos de quatro formas de apresentação.

Multiple gliomas are uncommon and may be classified according to: a) the time of presentation in early (at diagnosis) or late (during treatment); b) the characteristics of computed tomography or magnetic resonance imaging (CT/MRI) in multifocal (with evidence of spread) and multicentric (without evidence of spread). From 212 patients with histopathologic diagnosis of glioma evaluated from March/90 to September/99, 15 (7%) had multiple lesions. We describe 4 patients: early multicentric, late multicentric, early multifocal and late multifocal, with emphasis on characteristics of CT/MRI and possible differential diagnosis. The differential diagnosis of multiple lesions in the central nervous system includes mainly infectious/inflammatory diseases and metastasis, however multiple gliomas should always be considered, even in patients with known systemic cancer, as described by others. Considering that CT/MRI features are not definite, the diagnosis should always be confirmed by histopathologic examination.

Survival of HIV-1 in syringes.

We performed a study to determine the duration of survival of HIV-1 in syringes typically used by injectors of illicit drugs (IDUs). We describe the effectiveness of a microculture assay in detecting viable virus in volumes of blood typical of those commonly found inside used syringes. Using this assay and modeling the worse-case situation for syringe sharing, we have recovered viable, proliferating HIV-1 from syringes that have been maintained at room temperature for periods in excess of 4 weeks. The percentage of syringes with viable virus varied with the volume of residual blood and the titer of HIV-1 in the blood. These experiments provide a scientific basis for needle exchange schemes, harm reduction, and other interventions among IDUs that support the nonsharing and removal of used syringes from circulation.

HIV-1 transmission in injection paraphernalia: heating drug solutions may inactivate HIV-1.

In response to recent concerns about risk of HIV-1 transmission from drug injection paraphernalia such as cookers, ethnographic methods were used to develop a descriptive typology of the paraphernalia and practices used to prepare and inject illegal drugs. Observational data were then applied in laboratory studies in which a quantitative HIV-1 microculture assay was used to measure the recovery of infectious HIV-1 in cookers. HIV-1 survival inside cookers was a function of the temperature achieved during preparation of drug solutions; HIV-1 was inactivated once temperature exceeded, on average, 65 degrees C. Although different types of cookers, volumes, and heat sources affected survival times, heating cookers 15 seconds or longer reduced viable HIV-1 below detectable levels.

[Germinoma of the basal ganglia and thalamus with brain stem invasion: case report]. / Germinoma localizado nos núcleos da base e tálamo com invasão do tronco cerebral. Relato de caso.

We report an unusual case of germinoma arising from the basal ganglia and thalamus with brain stem invasion, with emphasis on computed tomography and magnetic resonance findings. Diagnosis was confirmed by histopathologic examination. Early detection of this tumor is important due to its potential response to treatment.

[Magnetic resonance in HTL-I associated myelopathy. Leukoencephalopathy and spinal cord atrophy]. / Ressonância magnética na mielopatia associada ao HTLV-I. Leucoencefalopatia e atrofia medular.

Cerebral white matter lesions and spinal cord atrophy have been frequently reported in patients with HTLV-I associated myelopathy (HAM). The exact frequency and the clinical relevance of these findings still remain to be elucidated. Twenty-nine patients with HAM were studied by magnetic resonance imaging of the brain and spine. Cerebral white matter lesions equal or over 3 mm in diameter were considered abnormal. The spinal cord size was evaluated using an index we have called "spinal cord index". The radiological findings were correlated to the clinical features of the myelopathy. Cerebral white matter lesions occurred in 52% of the patients, and spinal cord atrophy in 74%. There was no significant correlation between these abnormalities and the clinical features studied. These findings suggest that the resonance imaging is a useful method for detection of cerebral and spinal cord abnormalities in HAM patients. The absence of correlation between cerebral white matter lesions and either patient age or risk factors for cardiovascular disease suggests a possible association between the leukoencephalopathy and the infection.

[Orbital phlebography evaluation in 8 cases of Tolosa-Hunt syndrome]. / Avaliação da flebografia orbitária em oito casos de síndrome de Tolosa-Hunt.

Tolosa-Hunt syndrome (THS), or painful ophthalmoplegia is associated to a non-specific granulomatosis of unknown etiology, that involves the superior orbital fissure and its nervous and vascular structures. The clinical picture that responds to steroid therapy, is variable and is always associated with pain. Inflammatory conditions, tumors and aneurysms can produce similar symptoms. Computed tomography, cerebral angiography and orbital phlebography are the imaging methods of choice for making the diagnosis. We revised the results of these radiological examinations of eight patients seen at the Hospital São Paulo from 1989 to 1991, with the diagnosis of THS according to Hunt and Hannerz criteria. The analysis of orbital phlebographic changes based upon Hannerz et al. systematization showed non-specific features, but those were able to help the diagnosis.

Avaliaçäo da flebografia orbitária em oito casos de síndrome de Tolosa-Hunt / Orbital phlebography evaluation in 8 cases of Tolosa-Hunt syndrome

A Síndrome de Tolosa-Hunt (STH) ou oftalmoplegia dolorosa é associada a granulomatose inespecifica de etiologia desconhecida que acomete a fissura orbitária superior. Compromete estruturas nervosas e vasculares causando quadro clínico variável que sempre se associa a dor e apresenta resposta favorável à corticoterapia. Processos inflamatório, tumores e anmeurismas dessa regiäo podem causar sintomas semelhantes. A tomografia computadorizada, a angiografia cerebral e a flebografia orbitária säo métodos de imagem indicados para orientar o diagnóstico. Revisamos os resultados destes exames radiológicos de oito pacientes atendidos no Hospital Säo Paulo no período 1989 a 1991, com diagnóstico de STH segundo os critérios de Hunt e Hannerz. A análise das alteraçöes da flebografia orbitária, de acordo com a sistematizaçäo feita por Hannerz e col. Mostrou ser este exame inespecífico, porém capaz de orientar melhor mo diagnóstico

[Computed tomography in methanol intoxication]. / Tomografia computadorizada na intoxicação por metanol. Relato de caso.

We had the opportunity to follow a methanol intoxication case with CT scans, at the 1st and 6th day after admission. Symmetrical putaminal and white matter lesions were seen on the last CT examination, and occurred with the worsening of neurological manifestations, despite the appropriated treatment. The CT demonstration of brains lesions disclosed the toxic effect of the methanol and could be a guideline to the neurological prognosis.

Tomografia computadorizada na intoxicaçäo por metanol: relato de caso / Computed tomography in methanol intoxication

Tivemos a oportunidade de acompanhar com exames de TC caso de intoxicaçäo por metanol. O paciente foi submetido ao exame no momento da internaçäo e após seis dias, pela persistência de quadro neurológico grave. Observou-se nesta última a presença de lesöes putaminais simétricas e da substância branca subcortical, apesar do tratamento adequado. A comprovaçäo tomográfica de lesöes cerebrais evidenciou efeito tóxico do metanol e pode orientar o prognóstico neurológico

Measles and measles vaccination in isolated Amerindian tribes. II. The 1978/79 Xingu epidemic.

Vaccine induced measles antibody titers in the Upper Xingu Indians remained at satisfactory levels without evidence of decline over a period of six years without re-exposure. However, in another area, a vaccination program which used a reduced dose of vaccine was only 63% effective. When measles virus was introduced to the latter area a protracted epidemic ensued with 23% of the population becoming ill and six deaths. The deaths occurred exclusively under 13 months or over 40 years of age.