The Infrared Thermography Toolbox: An Open-access Semi-automated Segmentation Tool for Extracting Skin Temperatures in the Thoracic Region including Supraclavicular Brown Adipose Tissue

Infrared thermography (IRT) is widely used to assess skin temperature in response to physiological changes. Yet, it remains challenging to standardize skin temperature measurements over repeated datasets. We developed an open-access semi-automated segmentation tool (the IRT-toolbox) for measuring skin temperatures in the thoracic area to estimate supraclavicular brown adipose tissue (scBAT) activity, and compared it to manual segmentations. The IRT-toolbox, designed in Python, consisted of image pre-alignment and non-rigid image registration. The toolbox was tested using datasets of 10 individuals (BMI = 22.1 ± 2.1 kg/m², age = 22.0 ± 3.7 years) who underwent two cooling procedures, yielding four images per individual. Regions of interest (ROIs) were delineated by two raters in the scBAT and deltoid areas on baseline images. The toolbox enabled direct transfer of baseline ROIs to the registered follow-up images. For comparison, both raters also manually drew ROIs in all follow-up images. Spatial ROI overlap between methods and raters was determined using the Dice coefficient. Mean bias and 95% limits of agreement in mean skin temperature between methods and raters were assessed using Bland-Altman analyses. ROI delineation time was four times faster with the IRT-toolbox (01:04 min) than with manual delineations (04:12 min). In both anatomical areas, there was a large variability in ROI placement between methods. Yet, relatively small skin temperature differences were found between methods (scBAT: 0.10 °C, 95%LoA[-0.13 to 0.33 °C] and deltoid: 0.05 °C, 95%LoA[-0.46 to 0.55 °C]). The variability in skin temperature between raters was comparable between methods. The IRT-toolbox enables faster ROI delineations, while maintaining inter-user reliability compared to manual delineations. (Trial registration number (ClinicalTrials.gov): NCT04406922, [May 29, 2020]).

Increased sensitivity through maximizing the extinction ratio of SOI delay-interferometer receiver for 10G DPSK

We present an optimized design for a 10G- differential-phase-shift-keyed (DPSK) receiver based on a silicon-on-insulator (SOI) unbalanced tunable Mach-Zehnder interferometer (MZI) switch in sequence with a Mach-Zehnder delay interferometer (MZDI). The proposed design eliminates the limitation in sensitivity of the device produced by the waveguide propagation losses in the delay line. A 2.3 dB increase in receiver sensitivity at a bit-error-rate (BER) of 10(-9) is experimentally measured over a standard implementation. The enhanced sensitivity is achieved with zero power consumption by tuning the operating wavelength or with less than 5 mW for a fixed wavelength using microheaters. Also the foot-print of the device is minimized to 0.11 mm(2) by the use of compact spirals.

Detection of genetic polymorphism among and within Echinococcus granulosus strains by heteroduplex analysis of a microsatellite from the U1 snRNA genes

Polymerase chain reaction of a pentanucleotide microsatellite in the U1 snRNA gene complex generated a multiple band pattern due to the priming of paralogous sequences. Denaturation and slow renaturation of polymerase chain reaction products allow the formation of heteroduplex DNA that can be detected by its differential mobility in polyacrylamide gel electrophoresis. Heteroduplex analysis was used to determine if the U1 snRNA microsatellite could be a useful genetic marker in Echinococcus granulosus. A U1 snRNA microsatellite fragment from E. granulosus was isolated and characterized by Southern blot and sequencing. Four E. granulosus strains were analyzed: sheep, Tasmanian sheep, cattle, and camel strains. The former two showed polymorphism and shared three of the six patterns found for sheep strain. The cattle strain displayed two patterns, and the camel strain was monomorphic. The electrophoretic profiles were used for statistical analysis in order to determine genetic distance and the relationship among strains. Heteroduplex analysis can be helpful in genotyping E. granulosus strains and is useful in detecting polymorphism within strains.

High polymorphism in genes encoding antigen B from human infecting strains of Echinococcus granulosus

Echinococcus granulosus antigen B (AgB) is encoded by a gene family and is involved in the evasion of the host immune response. E. granulosus exists as a number of strains (G1-G10) that differ in biological characteristics. We used PCR-SSCP followed by DNA sequencing to evaluate sequence variation and transcription profile of AgB in 5 E. granulosus strains. Twenty-four genomic sequences were isolated and clustered in 3 groups related to 2 of the 5 reported AgB genes. AgB4 genes were present in almost all strains, whereas AgB2 were present as functional genes exclusively in G1/G2 cluster, and as non-functional genes in G5 and the G6/G7 cluster, suggesting inter-strain variation. The AgB transcription patterns, analysed by RT-PCR, showed that AgB2 and AgB4 genes were transcribed in G1, while only the AgB4 gene was transcribed in G7 strain. Cysts from the same strain or cluster shared more genomic and cDNA variants than cysts from different strain or cluster. The level of nucleotide and deduced amino acid sequence variation observed is higher than that reported so far for coding genes of other helminths. Neutrality was rejected for AgB2 genes. These data show the genetic polymorphism of antigen-coding genes among genetically characterized strains of E. granulosus.

Livestock trade history, geography, and parasite strains: the mitochondrial genetic structure of Echinococcus granulosus in Argentina

A sample of 114 isolates of Echinococcus granulosus (Cestoda: Taeniidae) collected from different host species and sites in Argentina has been sequenced for 391 bp from the mitochondrial cytochrome c oxidase subunit I gene to analyze genetic variability and population structure. Nine different haplotypes were identified, 5 of which correspond to already characterized strains. Analysis of molecular variance and nested clade analysis of the distribution of haplotypes among localities within 3 main geographic regions indicate that geographic differentiation accounts for the overall pattern of genetic variability in E. granulosus populations. Significant geographic differentiation is also present when the sheep strain alone is considered. Our results suggest that geographic patterns are not due to actual restricted gene flow between regions but are rather a consequence of past history, probably related to the time and origin of livestock introduction in Argentina.

Isolation and characterization of microsatellites from the tapeworm Echinococcus granulosus

The Echinococcus granulosus genome was searched for microsatellites using 8 different repeated oligonucleotides as probes (GT15, CT15, AT15, CG15, CAT10, CAA10, CGG10 and CATA10). Southern blot experiments revealed that DNA regions containing GT, CAA, CATA and CT repeats are the most frequent in the E. granulosus genome. AT and CG probes showed no hybridization signal. Two loci containing CA/GT (Egmsca1 and Egmsca2) and 1 locus containing GA/CT (Egmsga1) repeats were cloned and sequenced. The locus Egmsca1 was analysed in 73 isolates from Brazil and Argentina whose strains were previously characterized. Brazilian isolates from cattle strain and Argentinean isolates from camel strain were monomorphic and shared the allele (CA)7. Argentinean isolates of sheep and Tasmanian sheep strains shared 2 alleles [(CA)8 and (CA)10] with Brazilian isolates of sheep strain. The allele (CA)11 was found only in Brazilian isolates of sheep strain at a low frequency. The Brazilian and the Argentinean sheep strain populations were tested for the Hardy-Weinberg equilibrium, and only the former was in agreement with the expectations. No polymorphism was found among individual protoscoleces from a single hydatid cyst, validating the utilization of pooled protoscoleces from 1 cyst, grouped as an isolate, in population studies. This work describes for the first time the isolation and characterization of microsatellites from E. granulosus.

Growth hormones reverse desensitization of P2Y(2) receptors in rat mesangial cells

Rat glomerular mesangial cells (GMC) express P2Y(2) purinoceptors and respond to nucleotide stimuli with a transient increase in the cytosolic Ca(2+) concentration and the receptors desensitize upon repeated stimulation with nucleotide. We demonstrate that there is a cross-talk from the signaling of tyrosine kinase to P2Y(2) receptors. For most cells repeated applications of ATP completely abolished the response, as did activation of PKC with 500 nM PMA. In contrast, preincubation with the PKC inhibitor chelerythrine (100 nM) prevented desensitization. Desensitization after application of ATP was reversed by subsequent incubation with PDGF-BB (50 ng/ml) or insulin (660 mU/ml). We conclude that the desensitization is caused by phosphorylation due to PKC and is under the control of growth factors. The findings support the hypothesis that growth hormones potentiate nucleotides as proinflammatory mediators and we hypothesize that they have bearing on the hyperfiltration seen in diabetes.

Trace elements and electrolytes in human resting mixed saliva after exercise

OBJECTIVES

Exercise is known to cause changes in the concentration of salivary components such as amylase, Na, and Cl. The aim of this investigation was to evaluate the effect of physical exercise on the levels of trace elements and electrolytes in whole (mixed) saliva.

METHODS

Forty subjects performed a maximal exercise test on a cycle ergometer. Samples of saliva were obtained before and immediately after the exercise test. Sample concentrations of Fe, Mg, Sc, Cr, Mn, Co, Cu, Zn, Se, Sr, Ag, Sb, Cs, and Hg were determined by inductively coupled plasma mass spectrometry and concentrations of Ca and Na by atomic absorption spectrometry.

RESULTS

After exercise, Mg and Na levels showed a significant increase (p < 0.05) while Mn levels fell (p < 0.05). Zn/Cu molar ratios were unaffected by exercise.

CONCLUSIONS

Intense physical exercise induced changes in the concentrations of only three (Na, Mg, and Mn) of the 16 elements analysed in the saliva samples. Further research is needed to assess the clinical implications of these findings.

Ca2+ response of rat mesangial cells to ATP analogues

The aim of this investigation was to characterise the effects of ATP analogues and UTP on the single cell intracellular Ca2+ concentration ([Ca2+]i) in cultured rat mesangial cells. Typically, there were two phases in the Ca2+ response to the agonists, an initial fast transient peak and a subsequent slower decline, or plateau, phase. For the peak amplitude in [Ca2+]i the agonists had about equal effect. But when taking in consideration the percentage of responding cells and the integrated Ca2+ response over 1 min, the order of efficacy of nucleotide agonists (100 microM) was UTP = ATP > ATPgammaS > ADP = 2MeS-ATP (2-methylthio-ATP). Adenosine, AMP and beta,gamma-Me-ATP (100 microM) had no effect. Suramine (100 microM) and reactive blue (50 microM) decreased the number of responding cells. Removing Ca2+ from the bath diminished neither the peak in [Ca2+]i nor the percentage of responding cells, but the average [Ca2+]i increase in 1 min was significantly reduced. The results indicate that P2Y2 receptors are present in rat mesangial cells but it cannot be excluded that there are receptors distinct from P2Y2 which also mediate a rise in [Ca2+]i.

Effects of stimulation and inhibition of protein kinase C on the cytosolic calcium concentration in rabbit afferent arterioles

The effect of the protein kinase C (PKC) inhibitor chelerytrine (Ch) and the PKC activator 12-0-tetradecanoyl-phorbol-13-acetate (TPA) on the cytosolic calcium concentration ([Ca2+]i) in isolated intact rabbit afferent arterioles was investigated. [Ca2+]i was measured in the proximal and distal parts of the arteriole. Administration of 1 microM Ch gave rise to a peak followed by an elevated level of [Ca2+]i in both these parts. Neither the peak nor the elevated level of [Ca2+]i was significantly reduced by 1 microM nifedipine. The relative peak increase in [Ca2+]i in response to 1 microM noradrenaline (NA) or to 10 nM angiotensin II (AII) was significantly blunted in both parts after preincubation with 1 microM Ch. Depolarization with 25 mM K+ increased [Ca2+]i in both parts. Preincubation with Ch did not affect the increase in [Ca2+]i induced by 25 mM K+. TPA (10 and 100 nM) did not significantly affect the basal [Ca2+]i in the afferent arteriole. The [Ca2+]i response to NA or 25 mM K+ was not affected by TPA. We conclude that blockade of PKC increases [Ca2+]i in afferent arteriolar smooth muscle by a mechanism independent of L-type voltage-sensitive calcium channels. Inhibition of PKC blunts the relative increase in [Ca2+]i in response to AII and, to a lesser extent, that induced by NA. We conclude that PKC might be important in modulating the calcium changes that occur in response to these vasoconstrictors.

Cell calcium concentration in glomerular afferent and efferent arterioles under the action of noradrenaline and angiotensin II

The glomerular arterioles in the juxtaglomerular apparatus seem to function as effectors of the tubuloglomerular feedback mechanism. In this mechanism increased delivery of fluid to the distal nephron activates the macula densa cells through transport via an Na-2Cl-K cotransporter. This activation may lead to vasoconstriction of the afferent arteriole. Furthermore, vasoactive substances seem to affect both afferent and efferent arterioles. There are morphological differences along the afferent arteriole, some parts containing epithelioid cells with renin granules and others regular smooth muscle cells. The aim of the present experiments was to determine whether noradrenaline (10(-6) M) and angiotensin II (10(-6) M) had differential effects on the cell calcium concentration [Ca2+]i and on contraction in isolated perfused afferent and efferent arterioles and in the mesangial region. [Ca2+]i was measured with fura-2, an intensified videocamera and a digital imaging system. From the proximal to the distal part of the arteriole [Ca2+]i increased from about 100 to 250 nM. A [Ca2+]i increase and a contraction were caused by noradrenaline alone in the proximal part of the afferent arteriole and by angiotensin II alone in the distal part of this arteriole. In the mesangial region there was a high basal [Ca2+]i but no response to the vasoactive substances. In the efferent arteriole, application of both noradrenaline and angiotensin II led to an increase in [Ca2+]i and a contraction. The present experiments indicate that the two vasoactive substances tested act in a similar fashion along the whole length of the efferent arteriole, while in the afferent arteriole their actions are not equally distributed.

Net uptake of lactate by rabbit hindlimb during hypoxia

Lactate uptake by normoxic tissues is a pH-dependent phenomenon that occurs with increases in arterial lactate concentration. In this study we sought to determine the effect of hypoxia on lactate uptake by the rabbit hindlimb at different arterial blood pH (pHa). Two groups of rabbits were subjected to 20 min of arterial hypoxemia (PaO2 approximately 20 mm Hg). One group was allowed to maintain normal pHa (approximately 7.40 to 7.45; n = 5), whereas the other group was hyperventilated, resulting in hypocarbia and alkalemia (pHa > 7.50; n = 5). Lactate uptake was computed from measurements of femoral blood flow and the arterio-venous lactate difference. We found decreases in hindlimb O2 consumption during hypoxemia from 0.79 +/- 0.08 to 0.33 +/- 0.06 ml/min in the normal pH group (p < 0.01) and from 0.49 +/- 0.06 to 0.24 +/- 0.02 ml/min in the high pH group (p < 0.01). At that time there was net uptake of lactate by the hindlimb of the normal pH group (8.1 +/- 2.0 mumol/min; p < 0.001) and lactate release by the alkalemic group (1.61 +/- 1.0 mumol/min). Furthermore, hindlimb lactate uptake was associated with increased glucose consumption (p < 0.001). We hypothesize that the mechanisms responsible for lactate uptake by resting skeletal muscle during hypoxia may be similar to those that regulate lactate uptake during normoxic exercise.

Role of tissue hypoxia as the mechanism of lactic acidosis during E. coli endotoxemia

We compared the hemodynamic and metabolic alterations produced in rabbits by similar decreases in cardiac output created by inflating a balloon placed in the right ventricle (n = 6) with those produced by an intravenous bolus of Escherichia coli lipopolysaccharide (LPS; SEP group; n = 6). We measured O2 consumption (VO2), O2 transport (TO2), and O2 extraction ratio (ERO2) for the whole animal and also for the left hindlimb. Both groups experienced similar decreases in cardiac output, systemic TO2, and VO2 and similar increases in ERO2. For the hindlimb, TO2 was similar, but VO2 and ERO2 were lower for the SEP group 30 min after LPS administration (P less than 0.05); however, this difference disappeared during the remainder of the experiment. Arterial lactate concentration was greater (P less than 0.05) for the SEP group. There were no differences in skeletal muscle PO2, measured with a multiwire surface electrode, or in cardiac and skeletal muscle concentrations of high-energy phosphates. We hypothesize that a direct effect of LPS on cellular metabolism may have resulted in greater arterial lactate concentration for the SEP group.

Myopic keratomileusis: short-term results

The first 97 eyes operated with keratomileusis by two surgeons starting to use this technique are evaluated. The 30- and 90-day postoperative results of this initial experience are reported. Average preoperative myopia was -10.53 D spherical equivalent (range -5.25 to -22.25 D); average refractive correction at 90 days was -10.20 D. Preoperative visual acuities without correction were between 0.01 and 0.15 Snellen scale (20/2000 to 20/133), and 90 days postoperatively they varied between 0.02 and 0.60 Snellen scale (20/1000 to 20/33) with an average of 0.29 (20/69). Average preoperative visual acuity with correction was 0.70 Snellen scale (20/29), and 90 days afterward it was 0.60 Snellen scale (20/33). Preoperative average refractive cylinder was 1.33 D and postoperative was 1.86 D, showing that significant amounts of astigmatism were not induced.

Abnormalities in sensory and mixed evoked potentials in ataxia-telangiectasia

Electromography, motor, sensory and mixed nerve conduction velocity, and H reflex were studied in four patients with ataxia-telangiectasia. The earliest and most striking electrophysiologial finding was the reduced amplitude of evoked nerve potentials. In the oldest patient, findings suggestive of spinal atrophy and mild reduction of the motor and sensory nerve conduction velocities were found. Reduced amplitude in the evoked nerve potentials can be observed without clinical evidence of peripheral neuropathy. Electrophysiological abnormalities are more severe in older than in young patients. Sural nerve biopsy in one patient showed mild changes: loss of the largest myelinated fibres and demyelination of some fibres. The ratio between maximum conduction velocity of the sural nerve and the diameter of the largest fibres was in the lower limits of the normal range. The resemblance between electrophysiological abnormalities in Friedreich's ataxia and ataxia-telangiectasia is discussed.