141 research outputs found

    Inhibition of Tendon Cell Proliferation and Matrix Glycosaminoglycan Synthesis by Non-Steroidal Anti-Inflammatory Drugs in vitro

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    The purpose of this study was to investigate the effects of some commonly used non-steroidal anti-inflammatory drugs (NSAIDs) on human tendon. Explants of human digital flexor and patella tendons were cultured in medium containing pharmacological concentrations of NSAIDs. Cell proliferation was measured by incorporation of 3H-thymidine and glycosaminoglycan synthesis was measured by incorporation of 35S-Sulphate. Diclofenac and aceclofenac had no significant effect either on tendon cell proliferation or glycosaminoglycan synthesis. Indomethacin and naproxen inhibited cell proliferation in patella tendons and inhibited glycosaminoglycan synthesis in both digital flexor and patella tendons. If applicable to the in vivo situation, these NSAIDs should be used with caution in the treatment of pain after tendon injury and surgery

    Optimization of the Sampling Periods and the Quantization Bit Lengths for Networked Estimation

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    This paper is concerned with networked estimation, where sensor data are transmitted over a network of limited transmission rate. The transmission rate depends on the sampling periods and the quantization bit lengths. To investigate how the sampling periods and the quantization bit lengths affect the estimation performance, an equation to compute the estimation performance is provided. An algorithm is proposed to find sampling periods and quantization bit lengths combination, which gives good estimation performance while satisfying the transmission rate constraint. Through the numerical example, the proposed algorithm is verified

    Multi-parallel qPCR provides increased sensitivity and diagnostic breadth for gastrointestinal parasites of humans: field-based inferences on the impact of mass deworming

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    BACKGROUND: Although chronic morbidity in humans from soil transmitted helminth (STH) infections can be reduced by anthelmintic treatment, inconsistent diagnostic tools make it difficult to reliably measure the impact of deworming programs and often miss light helminth infections. METHODS: Cryopreserved stool samples from 796 people (aged 2-81 years) in four villages in Bungoma County, western Kenya, were assessed using multi-parallel qPCR for 8 parasites and compared to point-of-contact assessments of the same stools by the 2-stool 2-slide Kato-Katz (KK) method. All subjects were treated with albendazole and all Ascaris lumbricoides expelled post-treatment were collected. Three months later, samples from 633 of these people were re-assessed by both qPCR and KK, re-treated with albendazole and the expelled worms collected. RESULTS: Baseline prevalence by qPCR (n = 796) was 17 % for A. lumbricoides, 18 % for Necator americanus, 41 % for Giardia lamblia and 15% for Entamoeba histolytica. The prevalence was <1% for Trichuris trichiura, Ancylostoma duodenale, Strongyloides stercoralis and Cryptosporidium parvum. The sensitivity of qPCR was 98% for A. lumbricoides and N. americanus, whereas KK sensitivity was 70% and 32%, respectively. Furthermore, qPCR detected infections with T. trichiura and S. stercoralis that were missed by KK, and infections with G. lamblia and E. histolytica that cannot be detected by KK. Infection intensities measured by qPCR and by KK were correlated for A. lumbricoides (r = 0.83, p < 0.0001) and N. americanus (r = 0.55, p < 0.0001). The number of A. lumbricoides worms expelled was correlated (p < 0.0001) with both the KK (r = 0.63) and qPCR intensity measurements (r = 0.60). CONCLUSIONS: KK may be an inadequate tool for stool-based surveillance in areas where hookworm or Strongyloides are common or where intensity of helminth infection is low after repeated rounds of chemotherapy. Because deworming programs need to distinguish between populations where parasitic infection is controlled and those where further treatment is required, multi-parallel qPCR (or similar high throughput molecular diagnostics) may provide new and important diagnostic information

    Membrane diffusion- and capillary blood volume measurements are not useful as screening tools for pulmonary arterial hypertension in systemic sclerosis: a case control study

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    <p>Abstract</p> <p>Background</p> <p>There is no optimal screening tool for the assessment of pulmonary arterial hypertension (PAH) in patients with systemic sclerosis (SSc). A decreasing transfer factor of the lung for CO (TLCO) is associated with the development of PAH in SSc. TLCO can be partitioned into the diffusion of the alveolar capillary membrane (Dm) and the capillary blood volume (Vc). The use of the partitioned diffusion to detect PAH in SSc is not well established yet. This study evaluates whether Dm and Vc could be candidates for further study of the use for screening for PAH in SSc.</p> <p>Methods</p> <p>Eleven SSc patients with PAH (SScPAH+), 13 SSc patients without PAH (SScPAH-) and 10 healthy control subjects were included. Pulmonary function testing took place at diagnosis of PAH. TLCO was partitioned according to Roughton and Forster. As pulmonary fibrosis in SSc influences values of the (partitioned) TLCO, these were adjusted for fibrosis score as assessed on HRCT.</p> <p>Results</p> <p>TLCO as percentage of predicted (%) was lower in SScPAH+ than in SScPAH- (41 ± 7% <it>vs</it>. 63 ± 12%, p < 0.0001, respectively). Dm% in SScPAH+ was decreased as compared with SScPAH- (22 ± 6% <it>vs</it>. 39 ± 12%, p < 0.0001, respectively), also after adjustment for total fibrosis score (before adjustment: B = 17.5, 95% CI 9.0–25.9, p = < 0.0001; after adjustment: B = 14.3, 95% CI 6.0–21.7, p = 0.008). No difference was found in Vc%. There were no correlations between pulmonary hemodynamic parameters and Dm% in the PAH groups.</p> <p>Conclusion</p> <p>SScPAH+ patients have lower Dm% than SScPAH- patients. There are no correlations between Dm% and hemodynamic parameters of PAH in SScPAH+. These findings do not support further study of the role of partitioning TLCO in the diagnostic work- up for PAH in SSc.</p

    Infection of the malaria mosquito, Anopheles gambiae, with two species of entomopathogenic fungi: effects of concentration, co-formulation, exposure time and persistence

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    <p>Abstract</p> <p>Background</p> <p>Entomopathogenic fungi <it>Metarhizium anisopliae </it>and <it>Beauveria bassiana </it>isolates have been shown to infect and reduce the survival of mosquito vectors.</p> <p>Methods</p> <p>Here four different bioassays were conducted to study the effect of conidia concentration, co-formulation, exposure time and persistence of the isolates <it>M. anisopliae </it>ICIPE-30 and <it>B. bassiana </it>I93-925 on infection and survival rates of female <it>Anopheles gambiae sensu stricto</it>. Test concentrations and exposure times ranged between 1 × 10<sup>7 </sup>- 4 × 10<sup>10 </sup>conidia m<sup>-2 </sup>and 15 min - 6 h. In co-formulations, 2 × 10<sup>10 </sup>conidia m<sup>-2 </sup>of both fungus isolates were mixed at ratios of 4:1, 2:1, 1:1,1:0, 0:1, 1:2 and 1:4. To determine persistence, mosquitoes were exposed to surfaces treated 1, 14 or 28 d previously, with conidia concentrations of 2 × 10<sup>9</sup>, 2 × 10<sup>10 </sup>or 4 × 10<sup>10</sup>.</p> <p>Results</p> <p>Mosquito survival varied with conidia concentration; 2 × 10<sup>10 </sup>conidia m<sup>-2 </sup>was the concentration above which no further reductions in survival were detectable for both isolates of fungus. The survival of mosquitoes exposed to single and co-formulated treatments was similar and no synergistic or additive effects were observed. Mosquitoes were infected within 30 min and longer exposure times did not result in a more rapid killing effect. Fifteen min exposure still achieved considerable mortality rates (100% mortality by 14 d) of mosquitoes, but at lower speed than with 30 min exposure (100% mortality by 9 d). Conidia remained infective up to 28 d post-application but higher concentrations did not increase persistence.</p> <p>Conclusion</p> <p>Both fungus isolates are effective and persistent at low concentrations and short exposure times.</p

    DNA Vaccines against Dengue Virus Type 2 Based on Truncate Envelope Protein or Its Domain III

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    Two DNA vaccines were constructed encoding the ectodomain (domains I, II and III) of the DENV2 envelope protein (pE1D2) or only its domain III (pE2D2), fused to the human tissue plasminogen activator signal peptide (t-PA). The expression and secretion of recombinant proteins was confirmed in vitro in BHK cells transfected with the two plasmids, detected by immunofluorescence or immunoprecipitation of metabolically labeled gene products, using polyclonal and monoclonal antibodies against DENV2. Besides, results reveal that the ectodomain of the E protein can be efficiently expressed in vivo, in a mammalian system, without the prM protein that is hypothesized to act as a chaperonin during dengue infection. Balb/c mice were immunized with the DNA vaccines and challenged with a lethal dose of DENV2. All pE1D2-vaccinated mice survived challenge, while 45% of animals immunized with the pE2D2 died after infection. Furthermore, only 10% of pE1D2-immunized mice presented some clinical signs of infection after challenge, whereas most of animals inoculated with the pE2D2 showed effects of the disease with high morbidity degrees. Levels of neutralizing antibodies were significantly higher in pE1D2-vaccinated mice than in pE2D2-immunized animals, also suggesting that the pE1D2 vaccine was more protective than the pE2D2

    Adaptations for nocturnal vision in insect apposition eyes

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    Due to our own preference for bright light, we tend to forget that many insects are active in very dim light. The reasons for nocturnal activity are most easily seen in tropical areas of the world, where animals face severe competition for food and nocturnal insects are able to forage in a climate of reduced competition and predation. Generally nocturnal insects possess superposition compound eyes. This eye design is truly optimized for dim light as photons can be gathered through large apertures comprised of hundreds of lenses. In apposition eyes, on the other hand, the aperture consists of a single lens resulting in a poor photon catch and unreliable vision in dim light. Apposition eyes are therefore typically found in day-active insects and according to theoretical calculations should render bees blind by mid dusk. Nevertheless, the tropical bee Megalopta genalis and the wasp Apoica pallens have managed the transition to a nocturnal lifestyle while retaining their highly unsuitable apposition eye design. Far from being blind, these bees and wasps forage at extremely low light intensities. Moreover, M. genalis is the first insect shown to use landmark navigation at light intensities less than starlight. How do their apposition eyes permit such complex visual behaviour in so little light? Optical adaptations can significantly enhance sensitivity in apposition eyes. In bees and wasps, the major effect comes from their extremely wide photoreceptors, which are able to trap light reaching the eye from a large visual angle. These optical adaptations lead to a 30-fold increase in sensitivity compared to diurnal bees and wasps. This however is not sufficient for the 8 log units difference in light intensity between day and night. Our hypothesis is that neural adaptations in the form of spatial and temporal summation must be involved. By means of spatial summation the eyes could sum signals from large groups of visual units (ommatidia), in order to improve sensitivity at the cost of coarser spatial resolution. In nocturnal bees, spatial summation could be mediated via their wide laterally-spreading first-order interneurons (L-fibres) present in the first optic ganglion (lamina). These L-fibres have significantly larger dendritic fields than equivalent neurons in diurnal bees and the potential to sum photons from up to 18 visual units. Theoretical modelling further supports this hypothesis, as the optimal dendritic field size predicted by the model agrees well with the anatomical data

    Current and prospective pharmacological targets in relation to antimigraine action

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    Migraine is a recurrent incapacitating neurovascular disorder characterized by unilateral and throbbing headaches associated with photophobia, phonophobia, nausea, and vomiting. Current specific drugs used in the acute treatment of migraine interact with vascular receptors, a fact that has raised concerns about their cardiovascular safety. In the past, α-adrenoceptor agonists (ergotamine, dihydroergotamine, isometheptene) were used. The last two decades have witnessed the advent of 5-HT1B/1D receptor agonists (sumatriptan and second-generation triptans), which have a well-established efficacy in the acute treatment of migraine. Moreover, current prophylactic treatments of migraine include 5-HT2 receptor antagonists, Ca2+ channel blockers, and β-adrenoceptor antagonists. Despite the progress in migraine research and in view of its complex etiology, this disease still remains underdiagnosed, and available therapies are underused. In this review, we have discussed pharmacological targets in migraine, with special emphasis on compounds acting on 5-HT (5-HT1-7), adrenergic (α1, α2, and β), calcitonin gene-related peptide (CGRP 1 and CGRP2), adenosine (A1, A2, and A3), glutamate (NMDA, AMPA, kainate, and metabotropic), dopamine, endothelin, and female hormone (estrogen and progesterone) receptors. In addition, we have considered some other targets, including gamma-aminobutyric acid, angiotensin, bradykinin, histamine, and ionotropic receptors, in relation to antimigraine therapy. Finally, the cardiovascular safety of current and prospective antimigraine therapies is touched upon
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