Molecular mimicry in the Guillain-Barré syndrome

Damage to the axon or myelin sheath of peripheral nerves leads to dysfunction called neuropathy. The type of dysfunction depends on the localization of the injured nerve and the type of nerve (motor. sensory. autonomic) involved. In addition to damage such as caused by metabolic disturbances. toxic substances or degenerative processes. it is well recognized that components of the immune system such as antibodies. complement T cells and macrophages can be found in affected nerves and are likely to be involved in the pathogenesis of neuropathies. This particular group of neurological disorders is called immune-mediated neuropathies. Patients with an immune-mediated neuropathy often have antibodies that react with components of peripheral nerves and respond favorably to immune-modulating therapies such as plasmapheresis and intravenous immunoglobulin (IVIg) treatment. The immunemediated neuropathies can be further subdivided according to their course, although the distinction between acute and chronic disease is made arbitrarily

Risk factors associated with Campylobacter jejuni infections in Curacao, Netherlands Antilles

A steady increase in the incidence of Guillain-Barre syndrome (GBS) with a seasonal preponderance, almost exclusively related to Campylobacter jejuni, and a rise in the incidence of laboratory-confirmed Campylobacter enteritis have been reported from Curacao, Netherlands Antilles. We therefore investigated possible risk factors associated with diarrhea due to epidemic C. jejuni. Typing by pulsed-field gel electrophoresis identified four epidemic clones which accounted for almost 60% of the infections. One hundred six cases were included in a case-control study. Infections with epidemic clones were more frequently observed in specific districts in Willemstad, the capital of Curacao. One of these clones caused infections during the rainy season only and was associated with the presence of a deep well around the house. Two out of three GBS-related C. jejuni isolates belonged to an epidemic clone. The observations presented point toward water as a possible source of Campylobacter infections

Influence of precursor concentration and temperature on the formation of nanosilver in chemical reduction method

Nanosilver particles (NSPs) were produced by the reduction of silver nitrate using glucose as reducer, poly (vinyl pyrrolidone) as stabilizer and sodium hydroxide as reaction enhancer. Two parameters were investigated which are silver nitrate concentration (0.1 M, 0.5 M and 1.0 M) and reaction temperature (60°C and 80°C). Through spectral analysis using ultraviolet-visible spectrophotometer (UV-vis), all the samples recorded the maximum peak in the range of 384-411 nm which verified the formation of NSPs. TEM images showed the nanoparticles have spherical shape with the size range of 25-39 nm. Particle size and zeta potential analysis recorded the hydrodynamic size of nanoparticles in the range of 85-105 nm and the zeta potential ranging from -25 to -30 mV, under the pH value of 8. X-ray diffraction analysis showed that the NSPs have face center cubic (FCC) structure. All the produced NSPs surprisingly showed ferromagnetic-like behaviour based on the magnetization curves. FTIR result confirmed the presence of poly (vinyl pyrrolidone) on the NSPs surface. Furthermore, at the reaction temperature 60°C, the crystallite size, physical size as well as hydrodynamic size increased as the precursor concentration increased from 0.1 M to 0.5 M. However, as the precursor concentration further increases to 1.0 M, the size become smaller due to incomplete reduction process. In contrast, at 80°C, the sizes was gradually increased as the precursor concentration increases up to 1.0 M. In terms of controlled precursor concentration, the crystallite size and physical size become smaller as the temperature increases

Current and Future Prospects of Nitro-compounds as Drugs for Trypanosomiasis and Leishmaniasis

Interest in nitroheterocyclic drugs for the treatment of infectious diseases has undergone a resurgence in recent years. Here we review the current status of monocyclic and bicyclic nitroheterocyclic compounds as existing or potential new treatments for visceral leishmaniasis, Chagas' disease and human African trypanosomiasis. Both monocyclic (nifurtimox, benznidazole and fexinidazole) and bicyclic (pretomanid (PA-824) and delamanid (OPC-67683)) nitro-compounds are prodrugs, requiring enzymatic activation to exert their parasite toxicity. Current understanding of the nitroreductases involved in activation and possible mechanisms by which parasites develop resistance is discussed along with a description of the pharmacokinetic / pharmacodynamic behaviour and chemical structure-activity relationships of drugs and experimental compounds.</p

A reconfigurable low-noise amplifier using a tunable active inductor for multistandard receivers

A reconfigurable low-noise amplifier (LNA) based on a high-value active inductor (AI) is presented in this paper. Instead of using a passive on-chip inductor, a high-value on-chip inductor with a wide tuning range is used in this circuit and results in a decrease in the physical silicon area when compared to a passive inductor-based implementation. The LNA is a common source cascade amplifier with RC feedback. A tunable active inductor is used as the amplifier output load, and for input and output impedance matching, a source follower with an RC network is used to provide a 50 Ω impedance. The amplifier circuit has been designed in 0.18 µm CMOS process and simulated using the Cadence Spectra circuit simulator. The simulation results show a reconfigurable frequency from 0.8 to 2.5 GHz, and tuning of the frequency band is achieved by using a CMOS voltage controlled variable resistor. For a selected 1.5 GHz frequency band, simulation results show S 21 (Gain) of 22 dB, S 11 of −18 dB, S 22 of −16 dB, NF of 3.02 dB, and a minimum NF (NFmin) of 1.7 dB. Power dissipation is 19.6 mW using a 1.8 V dc power supply. The total LNA physical silicon area is (200×150) µm2

Has CXCL13 an added value in diagnosis of neurosyphilis?

Contains fulltext : 155396.pdf (publisher's version ) (Open Access)In patients with syphilis, central nervous system (CNS) involvement is often difficult to determine. In patients who also are infected with human immunodeficiency virus (HIV), this is even more challenging, as cerebrospinal fluid (CSF) pleocytosis can be attributed to HIV, syphilis, or both. Hence, this study investigated (i) CSF chemokine (C-X-C motif) ligand 13 (CXCL13) as a potential marker to diagnose neurosyphilis in HIV-infected individuals and (ii) the added value of CSF CXCL13 to conventional CSF biomarkers, such as the rapid plasma reagin test (RPR), in diagnosing neurosyphilis. We included 103 syphilis patients from two centers in The Netherlands: 47 non-HIV-infected patients and 56 HIV-infected patients. A positive CSF-RPR was regarded as the gold standard for neurosyphilis. CSF CXCL13 levels were significantly higher in neurosyphilis patients when neurosyphilis was diagnosed by CSF-RPR (P = 0.0002) than in the syphilis control group. The sensitivity and specificity of CSF CXCL13 (cutoff of 76.3 pg/ml) to diagnose neurosyphilis by using positive CSF-RPR as the gold standard were 50% and 90%, respectively. CSF CXCL13 had an added value to CSF-RPR positivity in 70% of HIV-positive patients and in 33% of HIV-negative patients. Our data show that CSF CXCL13 might be a potential additional marker in neurosyphilis when other markers are not conclusive. The added value of CSF CXCL13 measurement to the current neurosyphilis gold standard appears to benefit HIV-positive patients more than HIV-negative patients