The pathophysiological interplay between sleep-disordered breathing (SDB) and pulmonary hypertension (PH) is complex and can involve a variety of mechanisms by which SDB can worsen PH. These mechanistic pathways include wide swings in intrathoracic pressure while breathing against an occluded upper airway, intermittent and/or sustained hypoxemia, acute and/or chronic hypercapnia, and obesity. In this review, we discuss how the downstream consequences of SDB can adversely impact PH, the challenges in accurately diagnosing and classifying PH in the severely obese, and review the limited literature assessing the effect of treating obesity, obstructive sleep apnea, and obesity hypoventilation syndrome on PH.
View Article and Find Full Text PDFFriedreich ataxia (FA) is an autosomal recessive disease with a complex neurological phenotype, but the most common cause of death is heart failure. This study presents a systematic analysis of 15 fixed and 13 frozen archival autopsy tissues of FA hearts and 10 normal controls (8 frozen) by measurement of cardiomyocyte hypertrophy; tissue frataxin assay; X-ray fluorescence (XRF) of iron (Fe) and zinc (Zn) in polyethylene glycol-embedded samples of left and right ventricular walls (LVW, RVW) and ventricular septum (VS); metal quantification in bulk digests by inductively-coupled plasma optical emission spectrometry (ICP-OES); Fe histochemistry; and immunohistochemistry and immunofluorescence of cytosolic and mitochondrial ferritins and of the inflammatory markers CD68 and hepcidin. FA cardiomyocytes were significantly larger than normal and surrounded by fibrotic endomysium.
View Article and Find Full Text PDFWe investigated intra-specific variation in the response of salmon to infection with the myxozoan Ceratomyxa shasta by comparing the progress of parasite infection and measures of host immune response in susceptible and resistant Chinook salmon Oncorhynchus tshawytscha at days 12, 25 and 90 post exposure. There were no differences in invasion of the gills indicating that resistance does not occur at the site of entry. In the intestine on day 12, infection intensity and Ig(+) cell numbers were higher in susceptible than resistant fish, but histological examination at that timepoint showed more severe inflammation in resistant fish.
View Article and Find Full Text PDFBackground: Friedreich ataxia (FA) causes distinctive lesions of dorsal root ganglia (DRG), including neuronal atrophy, satellite cell hyperplasia, and absorption of dying nerve cells into residual nodules. Two mechanisms may be involved: hypoplasia of DRG neurons from birth and superimposed iron (Fe)- and zinc (Zn)-mediated oxidative injury. This report presents a systematic analysis of DRG in 7 FA patients and 13 normal controls by X-ray fluorescence (XRF) of polyethylene glycol-embedded DRG; double-label confocal immunofluorescence microscopy of Zn- and Fe-related proteins; and immunohistochemistry of frataxin and the mitochondrial marker, ATP synthase F1 complex V β-polypeptide (ATP5B).
View Article and Find Full Text PDFClinicoanatomic correlation in the spinocerebellar ataxias (SCA) and Friedreich's ataxia (FRDA) is difficult as these diseases differentially affect multiple sites in the central and peripheral nervous systems. A new way to study cerebellar ataxia is the systematic analysis of the "reciprocal cerebellar circuitry" that consists of tightly organized reciprocal connections between Purkinje cells, dentate nuclei (DN), and inferior olivary nuclei (ION). This circuitry is similar to but not identical with the "cerebellar module" in experimental animals.
View Article and Find Full Text PDFIn mammals, CCR7 is the chemokine receptor for the CCL19 and CCL21 chemokines, molecules with a major role in the recruitment of lymphocytes to lymph nodes and Peyer's patches in the intestinal mucosa, especially naïve T lymphocytes. In the current work, we have identified a CCR7 orthologue in rainbow trout (Oncorhynchus mykiss) that shares many of the conserved features of mammalian CCR7. The receptor is constitutively transcribed in the gills, hindgut, spleen, thymus and gonad.
View Article and Find Full Text PDFTeleost fish are the most primitive bony vertebrates that contain immunoglobulins. In contrast to mammals and birds, these species are devoid of immunoglobulin A (IgA) or a functional equivalent. This observation suggests that specialization of immunoglobulin isotypes into mucosal and systemic responses took place during tetrapod evolution.
View Article and Find Full Text PDFThe myxozoan parasite Ceratomyxa shasta infects salmonids causing ceratomyxosis, a disease elicited by proliferation of the parasite in the intestine. This parasite is endemic to the Pacific Northwest of North America and salmon and trout strains from endemic river basins show increased resistance to the parasite. It has been suggested that these resistant fish (i) exclude the parasite at the site of invasion and/or (ii) prevent establishment in the intestine.
View Article and Find Full Text PDFCeratomyxa shasta infects salmon and trout, causing ceratomyxosis, a disease characterized by parasite proliferation in the intestine and death. We used laboratory challenges to investigate the infective dose for 3 fish species: a susceptible strain of rainbow trout Oncorhynchus mykiss and comparatively resistant Chinook O. tshawytscha and coho salmon O.
View Article and Find Full Text PDFWe report that the halophilic archaeon Halobacterium sp. strain NRC-1 is highly resistant to desiccation, high vacuum and 60Co gamma irradiation. Halobacterium sp.
View Article and Find Full Text PDFWe report a remarkably high UV-radiation resistance in the extremely halophilic archaeon Halobacterium NRC-1 withstanding up to 110 J/m2 with no loss of viability. Gene knockout analysis in two putative photolyase-like genes (phr1 and phr2) implicated only phr2 in photoreactivation. The UV-response was further characterized by analyzing simultaneously, along with gene function and protein interactions inferred through comparative genomics approaches, mRNA changes for all 2400 genes during light and dark repair.
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