Mutation detection analysis of a region of 16S-like ribosomal RNA gene of Entamoeba histolytica, Entamoeba dispar and Entamoeba moshkovskii

<p>Abstract</p> <p>Background</p> <p>The level of intra-species genetic variation in <it>Entamoeba histolytica, Entamoeba dispar </it>and <it>Entamoeba moshkovskii </it>populations in a localized geographic area, like Puducherry, India, remains unknown.</p> <p>Methods</p> <p>In the present study the existence of genetic variation in the nested multiplex polymerase chain reaction (NM-PCR) amplified region of the 16S-like ribosomal RNA genes of <it>E. histolytica, E. dispar </it>and <it>E. moshkovskii </it>was investigated by riboprinting and single strand conformation polymorphism (SSCP) analysis.</p> <p>Results</p> <p>We found that 70 stool specimens were positive for <it>E. histolytica</it>, 171 stool specimens were positive for <it>E. dispar</it>, and 37 stool specimens were positive for <it>E. moshkovskii </it>by NM-PCR. Ninety liver abscess pus specimens, 21 urine specimens, and 8 saliva specimens were positive for <it>E. histolytica </it>by NM-PCR. Riboprinting analysis detected a mutation in the PCR product of only one <it>E. histolytica </it>isolate from a stool specimen. However, SSCP analysis detected mutations in the PCR products of five <it>E. histolytica </it>isolates and three <it>E. moshkovskii </it>isolates from stool specimens, and one <it>E. histolytica </it>isolate from a saliva specimen. The mutations detected by riboprinting and SSCP analysis were confirmed by sequencing. All the nucleotide sequences showing mutations in this study have already been deposited into the NCBI GenBank database under accession numbers [GenBank: <ext-link ext-link-type="gen" ext-link-id="EF682200">EF682200</ext-link> to GenBank: <ext-link ext-link-type="gen" ext-link-id="EF682208">EF682208</ext-link>].</p> <p>Conclusion</p> <p>The present study has revealed the subsistence of mutations in the ribosomal RNA genes of <it>E. histolytica </it>and <it>E. moshkovskii</it>, which points towards the existence of intra-species genetic variation in <it>E. histolytica </it>and <it>E. moshkovskii </it>isolates infecting humans.</p

IFNAR1-Signalling Obstructs ICOS-mediated Humoral Immunity during Non-lethal Blood-Stage Plasmodium Infection

Funding: This work was funded by a Career Development Fellowship (1028634) and a project grant (GRNT1028641) awarded to AHa by the Australian National Health & Medical Research Council (NHMRC). IS was supported by The University of Queensland Centennial and IPRS Scholarships. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

A SCN9A gene-encoded dorsal root ganglia sodium channel polymorphism associated with severe fibromyalgia

<p>Abstract</p> <p>Background</p> <p>A consistent line of investigation suggests that autonomic nervous system dysfunction may explain the multi-system features of fibromyalgia (FM); and that FM is a sympathetically maintained neuropathic pain syndrome. Dorsal root ganglia (DRG) are key sympathetic-nociceptive short-circuit sites. Sodium channels located in DRG (particularly Nav1.7) act as molecular gatekeepers for pain detection. Nav1.7 is encoded in gene SCN9A of chromosome 2q24.3 and is predominantly expressed in the DRG pain-sensing neurons and sympathetic ganglia neurons. Several SCN9A sodium channelopathies have been recognized as the cause of rare painful dysautonomic syndromes such as paroxysmal extreme pain disorder and primary erythromelalgia. The aim of this study was to search for an association between fibromyalgia and several SCN9A sodium channels gene polymorphisms.</p> <p>Methods</p> <p>We studied 73 Mexican women suffering from FM and 48 age-matched women who considered themselves healthy. All participants filled out the Fibromyalgia Impact Questionnaire (FIQ). Genomic DNA from whole blood containing EDTA was extracted by standard techniques. The following SCN9A single-nucleotide polymorphisms (SNP) were determined by 5' exonuclease TaqMan assays: rs4371369; rs4387806; rs4453709; rs4597545; rs6746030; rs6754031; rs7607967; rs12620053; rs12994338; and rs13017637.</p> <p>Results</p> <p>The frequency of the rs6754031 polymorphism was significantly different in both groups (<it>P </it>= 0.036) mostly due to an absence of the GG genotype in controls. Interestingly; patients with this rs6754031 GG genotype had higher FIQ scores (median = 80; percentile 25/75 = 69/88) than patients with the GT genotype (median = 63; percentile 25/75 = 58/73; <it>P </it>= 0.002) and the TT genotype (median = 71; percentile 25/75 = 64/77; <it>P </it>= 0.001).</p> <p>Conclusion</p> <p>In this ethnic group; a disabling form of FM is associated to a particular SCN9A sodium channel gene variant. These preliminary results raise the possibility that some patients with severe FM may have a dorsal root ganglia sodium channelopathy.</p

Effects of amantadine on circulating neurotransmitters in healthy subjects

Considering that glutamatergic axons innervate the C1(Ad) medullary nuclei, which are responsible for the excitation of the peripheral adrenal glands, we decided to investigate catecholamines (noradrenaline, adrenaline and dopamine) plus indolamines (plasma serotonin and platelet serotonin) at the blood level, before and after a small oral dose of amantadine, a selective NMDA antagonist. We found that the drug provoked a selective enhancement of noradrenaline plus a minimization of adrenaline, dopamine, plasma serotonin and platelet serotonin circulating levels. Significant enhancement of diastolic blood pressure plus reduction of systolic blood pressure and heart rate paralleled the circulating parameter changes. The above findings allow us to postulate that the drug was able to enhance the peripheral neural sympathetic activity. Minimization of both adrenal sympathetic and parasympathetic activities was also registered after the amantadine challenge. The above findings supported the postulation that this drug should be a powerful therapeutic tool for treating diseases affected by adrenal sympathetic hyperactivity