302 research outputs found

    Idiopathic CD4+ T-lymphocytopenia with cryptococcal meningitis: first case report from Cambodia.

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    We report on a patient with cryptococcal meningitis with CD4+ T-lymphocytopenia and no evidence of HIV infection

    Sound and light from fractures in scintillators

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    Prompted by intriguing events observed in certain particle-physics searches for rare events, we study light and acoustic emission simultaneously in some inorganic scintillators subject to mechanical stress. We observe mechanoluminescence in Bi4Ge3O12{Bi}_4{Ge}_{3}{O}_{12}, CdWO4{CdWO}_{4} and ZnWO4{ZnWO}_{4}, in various mechanical configurations at room temperature and ambient pressure. We analyze how the light emission is correlated to acoustic emission during fracture. For Bi4Ge3O12{Bi}_4{Ge}_{3}{O}_{12}, we set a lower bound on the energy of the emitted light, and deduce that the fraction of elastic energy converted to light is at least 3×1053 \times 10^{-5}

    Comparison of two closed-path cavity-based spectrometers for measuring air-water CO<inf>2</inf> and CH<inf>4</inf> fluxes by eddy covariance

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    In recent years several commercialised closed-path cavity-based spectroscopic instruments designed for eddy covariance flux measurements of carbon dioxide (CO2), methane (CH4), and water vapour (H2O) have become available. Here we compare the performance of two leading models - the Picarro G2311-f and the Los Gatos Research (LGR) Fast Greenhouse Gas Analyzer (FGGA) at a coastal site. Both instruments can compute dry mixing ratios of CO2 and CH4 based on concurrently measured H2O, temperature, and pressure. Additionally, we used a high throughput Nafion dryer to physically remove H2O from the Picarro airstream. Observed air-sea CO2 and CH4 fluxes from these two analysers, averaging about 12 and 0.12 mmol m-2 day-1 respectively, agree within the measurement uncertainties. For the purpose of quantifying dry CO2 and CH4 fluxes downstream of a long inlet, the numerical H2O corrections appear to be reasonably effective and lead to results that are comparable to physical removal of H2O with a Nafion dryer in the mean. We estimate the high-frequency attenuation of fluxes in our closed-path set-up, which was relatively small (≤ 10 %) for CO2 and CH4 but very large for the more polar H2O. The Picarro showed significantly lower noise and flux detection limits than the LGR. The hourly flux detection limit for the Picarro was about 2 mmol m-2 day-1 for CO2 and 0.02 mmol m-2 day-1 for CH4. For the LGR these detection limits were about 8 and 0.05 mmol m-2 day-1. Using global maps of monthly mean air-sea CO2 flux as reference, we estimate that the Picarro and LGR can resolve hourly CO2 fluxes from roughly 40 and 4 % of the world's oceans respectively. Averaging over longer timescales would be required in regions with smaller fluxes. Hourly flux detection limits of CH4 from both instruments are generally higher than the expected emissions from the open ocean, though the signal to noise of this measurement may improve closer to the coast

    Physician-related determinants of cervical cancer screening among Caribbean women in Toronto

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    BACKGROUND: Minority women in Canada are less likely to be screened for cervical cancer than their counterparts in the general population, despite the fact that the proportion of these women who consult a general practitioner about their health each year is similar to minority women. This study examined the physician and practice characteristics associated with Pap testing and perceived barriers to Pap testing of family physicians serving the Caribbean community of Toronto. METHODS: A mail-back questionnaire was sent to Toronto family physicians practicing in neighborhoods with a high proportion of Caribbean Canadians. RESULTS: Although 79.7% of the 64 participating physicians reported that they were \u27very likely to include Pap testing during an annual check-up, nearly half did not believe that the majority of Caribbean patients were actually screened. The amount of time a physician spent on patient education was significantly associated with his/her likelihood of screening. Male physicians who reported a high proportion of Caribbean female patients in their practices were significantly less likely to screen for cervical cancer than those who saw fewer Caribbean patients. CONCLUSION: These findings suggest that an increased emphasis on patient education is important to increase screening practice and that physician gender may be of major importance to the Caribbean community

    MUC1 positive, Kras and Pten driven mouse gynecologic tumors replicate human tumors and vary in survival and nuclear grade based on anatomical location

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    Activating mutations of Kras oncogene and deletions of Pten tumor suppressor gene play important roles in cancers of the female genital tract. We developed here new preclinical models for gynecologic cancers, using conditional (Cre-loxP) mice with floxed genetic alterations in Kras and Pten. The triple transgenic mice, briefly called MUC1KrasPten, express human MUC1 antigen as self and carry a silent oncogenic KrasG12D and Pten deletion mutation. Injection of Cre-encoding adenovirus (AdCre) in the ovarian bursa, oviduct or uterus activates the floxed mutations and initiates ovarian, oviductal, and endometrial cancer, respectively. Anatomical site-specific Cre-loxP recombination throughout the genital tract of MUC1KrasPten mice leads to MUC1 positive genital tract tumors, and the development of these tumors is influenced by the anatomical environment. Endometrioid histology was consistently displayed in all tumors of the murine genital tract (ovaries, oviducts, and uterus). Tumors showed increased expression of MUC1 glycoprotein and triggered de novo antibodies in tumor bearing hosts, mimicking the immunobiology seen in patients. In contrast to the ovarian and endometrial tumors, oviductal tumors showed higher nuclear grade. Survival for oviduct tumors was significantly lower than for endometrial tumors (p = 0.0015), yet similar to survival for ovarian cancer. Oviducts seem to favor the development of high grade tumors, providing preclinical evidence in support of the postulated role of fallopian tubes as the originating site for high grade human ovarian tumors. © 2014 Tirodkar et al

    Pyoderma gangrenosum associated with left iliac vein compression syndrome: presentation of difficult diagnosis

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    Pyoderma gangrenosum is a rare neutrophilic dermatosis of unknown etiology, of which the most frequent clinical manifestations are ulcers. The diagnosis difficulty is, among other things, to rule out other causes of ulcers, since it is considered a diagnosis of exclusion. Skin ulcerations may also occur in the iliac vein compression syndrome, which, like pyoderma gangrenosum, mainly affects young women. Because they have such similar characteristics, the presence of vascular disease may hinder the diagnosis of concurrent pyoderma gangrenosum. Because of the clinical relevance of ulcerated lesions and scars, the early diagnosis and treatment of this condition is considered extremely important. We report a case in which the two diseases were associated, hampering the diagnosis of pyoderma gangrenosum.Univ Fed Sao Paulo Unifesp, Sao Paulo, SP, BrazilUniv Fed Sao Paulo EPM Unifesp, Dept Dermatol, Escola Paulista Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo EPM Unifesp, Dept Dermatol, Outpatient Clin Geriatr Dermatol, Escola Paulista Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo EPM Unifesp, Dept Pathol, Escola Paulista Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo Unifesp, Sao Paulo, SP, BrazilUniv Fed Sao Paulo EPM Unifesp, Dept Dermatol, Escola Paulista Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo EPM Unifesp, Dept Dermatol, Outpatient Clin Geriatr Dermatol, Escola Paulista Med, Sao Paulo, SP, BrazilUniv Fed Sao Paulo EPM Unifesp, Dept Pathol, Escola Paulista Med, Sao Paulo, SP, BrazilWeb of Scienc

    In vivo effects of traditional ayurvedic formulations in Drosophila melanogaster model relate with therapeutic applications

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    Background: Ayurveda represents the traditional medicine system of India. Since mechanistic details of therapy in terms of current biology are not available in Ayurvedic literature, modern scientific studies are necessary to understand its major concepts and procedures. It is necessary to examine effects of the whole Ayurvedic formulations rather than their “active” components as is done in most current studies. Methods: We tested two different categories of formulations, a Rasayana (Amalaki Rasayana or AR, an herbal derivative) and a Bhasma (Rasa-Sindoor or RS, an organo-metallic derivative of mercury), for effects on longevity, development, fecundity, stress-tolerance, and heterogeneous nuclear ribonucleoprotein (hnRNP) levels of Drosophila melanogaster using at least 200 larvae or flies for each assay. Results: A 0.5% (weight/volume) supplement of AR or RS affected life-history and other physiological traits in distinct ways. While the size of salivary glands, hnRNP levels in larval tissues, and thermotolerance of larvae/adult flies improved significantly following feeding either of the two formulations, the median life span and starvation resistance improved only with AR. Feeding on AR or RS supplemented food improved fecundity differently. Feeding of larvae and adults with AR increased the fecundity while the same with RS had opposite effect. On the contrary, feeding larvae on normal food and adults on AR supplement had no effect on fecundity but a comparable regime of feeding on RS-supplemented food improved fecundity. RS feeding did not cause heavy metal toxicity. Conclusions: The present study with two Ayurvedic formulations reveals formulation-specific effects on several parameters of the fly's life, which seem to generally agree with their recommended human usages in Ayurvedic practices. Thus, Drosophila, with its very rich genetic tools and well-worked-out developmental pathways promises to be a very good model for examining the cellular and molecular bases of the effects of different Ayurvedic formulations

    Carbonic anhydrase inhibition selectively prevents amyloid b neurovascular mitochondrial toxicity

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    Mounting evidence suggests that mitochondrial dysfunction plays a causal role in the etiology and progression of Alzheimer’s disease (AD). We recently showed that the carbonic anhydrase inhibitor (CAI) methazolamide (MTZ) prevents amyloid b (Ab)-mediated onset of apoptosis in the mouse brain. In this study, we used MTZ and, for the first time, the analog CAI acetazolamide (ATZ) in neuronal and cerebral vascular cells challenged with Ab, to clarify their protective effects and mitochondrial molecular mechanism of action. The CAIs selectively inhibited mitochondrial dysfunction pathways induced by Ab, without affecting metabolic function. ATZ was effective at concentrations 10 times lower than MTZ. Both MTZ and ATZ prevented mitochondrial membrane depolarization and H2O2 generation, with no effects on intracellular pH or ATP production. Importantly, the drugs did not primarily affect calcium homeostasis. This work suggests a new role for carbonic anhydrases (CAs) in the Ab-induced mitochondrial toxicity associated with AD and cerebral amyloid angiopathy (CAA), and paves the way to AD clinical trials for CAIs, FDA-approved drugs with a well-known profile of brain delivery

    Basement membrane proteins as a substrate for efficient Trypanosoma brucei differentiation in vitro

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    The ability to reproduce the developmental events of trypanosomes that occur in their mammalian host in vitro offers significant potential to assist in understanding of the underlying biology of the process. For example, the transition from bloodstream slender to bloodstream stumpy forms is a quorum-sensing response to the parasite-derived peptidase digestion products of environmental proteins. As an abundant physiological substrate in vivo, we studied the ability of a basement membrane matrix enriched gel (BME) in the culture medium to support differentiation of pleomorphic Trypanosoma brucei to stumpy forms. BME comprises extracellular matrix proteins, which are among the most abundant proteins found in connective tissues in mammals and known substrates of parasite-released peptidases. We previously showed that two of these released peptidases are involved in generating a signal that promotes slender-to-stumpy differentiation. Here, we tested the ability of basement membrane extract to enhance parasite differentiation through its provision of suitable substrates to generate the quorum sensing signal, namely oligopeptides. Our results show that when grown in the presence of BME, T. brucei pleomorphic cells arrest at the G0/1 phase of the cell cycle and express the differentiation marker PAD1, the response being restricted to differentiation-competent parasites. Further, the stumpy forms generated in BME medium are able to efficiently proceed onto the next life cycle stage in vitro, procyclic forms, when incubated with cis-aconitate, further validating the in vitro BME differentiation system. Hence, BME provides a suitable in vitro substrate able to accurately recapitulate physiological parasite differentiation without the use of experimental animals

    Sleep oscillation-specific associations with Alzheimer’s disease CSF biomarkers : novel roles for sleep spindles and tau

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    Background: Based on associations between sleep spindles, cognition, and sleep-dependent memory processing, here we evaluated potential relationships between levels of CSF Aβ42, P-tau, and T-tau with sleep spindle density and other biophysical properties of sleep spindles in a sample of cognitively normal elderly individuals. Methods: One-night in-lab nocturnal polysomnography (NPSG) and morning to early afternoon CSF collection were performed to measure CSF Aβ42, P-tau and T-tau. Seven days of actigraphy were collected to assess habitual total sleep time. Results: Spindle density during NREM stage 2 (N2) sleep was negatively correlated with CSF Aβ42, P-tau and T-tau. From the three, CSF T-tau was the most significantly associated with spindle density, after adjusting for age, sex and ApoE4. Spindle duration, count and fast spindle density were also negatively correlated with T-tau levels. Sleep duration and other measures of sleep quality were not correlated with spindle characteristics and did not modify the associations between sleep spindle characteristics and the CSF biomarkers of AD. Conclusions: Reduced spindles during N2 sleep may represent an early dysfunction related to tau, possibly reflecting axonal damage or altered neuronal tau secretion, rendering it a potentially novel biomarker for early neuronal dysfunction. Given their putative role in memory consolidation and neuroplasticity, sleep spindles may represent a mechanism by which tau impairs memory consolidation, as well as a possible target for therapeutic interventions in cognitive decline
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