Adv Exp Med Biol
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Because of the bi-genomic origin of the OXPHOS system, mitochondrial disease-associated mutations have been found in both mtDNA and nuclear structural genes. In the last years, interest has shifted toward mendelian genetics in mitochondrial disease, not only because the majority of the OXPHOS system subunits are encoded by the nuclear genome, but also because a large number of yet unknown nuclear proteins, such as regulatory proteins and assembly factors, are likely involved in its biogenesis and function. A clinical-genetic classification can be proposed for nuclear defects that affect the biogenesis of the OXPHOS system, as follows: (i) disorders due to nuclear gene defects encoding structural components or assembly factors of the OXPHOS complexes, (ii) disorders due to gene defects in the biogenesis of protein constituents of the OXPHOS system, (iii) disorders due to defects in the biosynthesis of non-protein constituents of the respiratory chain, and (iv) disorders due to gene defects encoding proteins involved in mitochondrial dynamics.
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Pentraxins are a family of evolutionarily conserved pattern-recognition proteins that are made up of five identical subunits. Based on the primary structure of the subunit, the pentraxins are divided into two groups: short pentraxins and long pentraxins. C-reactive protein (CRP) and serum amyloid P-component (SAP) are the two short pentraxins. ⋯ In addition, data in gene-targeted mice show that PTX3 is essential in female fertility, participating in the assembly of the cumulus oophorus extracellular matrix. PTX3 is therefore a nonredundant component of the humoral arm of innate immunity as well as a tuner of inflammation. Thus, in conjunction with the other components of innate immunity, the pentraxins use their pattern-recognition property for the benefit of the host.
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For adequate development and functioning of the neonatal brain, sufficient oxygen (O2) should be available. With a fast sampling (f(s) > 50 Hz) continuous wave NIRS device, arterial (SaO2) and venous (SvO2) saturation can be measured using the physiological fluctuations in the oxyhemoglobin (O2Hb) and total hemoglobin (tHb) concentrations due to heart action and respiration. Before using this technique in a neonatal setting, the method was verified on adult volunteers (n=7) by decreasing inspired oxygen down to an arterial saturation of 70% using a pulse oximeter as reference. ⋯ A good agreement between calculated SaO2 and reference SaO2 from pulse oximetry was found (bias range -3.5% to 5.2%, SD of the residuals 1.3% to 3.5%). Optode spacing of 15 mm yielded a negative bias compared to optode spacing of 45 mm. It was not always possible to calculate SvO2 because the respiration peak could not always be detected.
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Intracranial pressure (ICP) monitoring is indispensable in the assessment of neurotrauma in humans and animal models. It was shown that cerebellar ICP, leaving the cortical area intact, can replace cerebral ICP in rats. While cerebral probes may induce spreading depression, the effects of a miniature cerebellar probe on near infrared spectroscopy (NIRS) measurements and cerebral hemodynamics are not known. ⋯ Because the decreased CBF was accompanied by an increased arterio-venous oxygen difference (p=0.026) and unaltered cerebral metabolic rate of oxygen (p=0.485), this suggests an uncoupling. These data suggest that a cerebellar miniature Codman ICP probe induces an uncoupling of cerebral metabolism and CBF. In addition, NIRS is found to be a robust technique: even when path lengths are altered after probe insertion, physiological alterations can still be examined.
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The objective was to assess the ability of near infrared spectrophotometry (NIRS) to detect changes in tissue oxygenation due to alterations in oxygen delivery. Ten hemodynamically stable preterm neonates with a median gestational age of 27.9 weeks (range 25.1-31.2), a median birth weight of 840g (range 690-1310), and a postnatal age of 29 days (range 2-45) were included in this prospective trial. ⋯ This decrease correlated positively with the weight matched amount of packed red cell transfusion (r2=0.40, p<0.05) and with the increase in hematocrit (r2=0.58, p<0.005). The OEI obtained by a NIRS may allow to monitor changes in tissue oxygenation.