Isolation of a new high molecular weight protein associated with desmin and vimentin filaments from avian embryonic skeletal muscle

Filaments with a diameter of 80-120 Å have been prepared from 14-d-old chick embryonic skeletal muscle, using a physiological salt solution and gel filtration chromatography. The filaments obtained are composed of the two known muscle intermediate-filament proteins, vimentin and desmin, as well as the vimentin- and desmin-associated high molecular weight protein, synemin (230,000 mol. wt). In addition, they contain a previously unidentified high molecular weight protein (280,000 mol wt) which differs from synemin by isoelectric point, molecular weight, and immunological reactivity. Immunofluorescence on cultured myogenic cells,using antisera to the 280,000-dalton polypeptide, has revealed that this protein has the same spatial distribution as desmin, vimentin, and synemin in both early myotubes, where it associates with cytoplasmic filaments, and late in myotubes, where it is associated with myofibril Z lines. Examination by immunofluorescence of frozen sections of developing embryonic skeletal muscle reveals a gradual diminution in the presence of the 280,000-dalton protein. The 280,000-dalton protein is undetectable in adult skeletal and smooth muscle, as shown by immunofluorescence and immunoautoradiography. In chick embryonic fibroblasts grown in tissue culture, only a subpopulation of the cells is reactive with antibodies to the 280,000-dalton protein even though all these cells contain vimentin. In the reactive cells, vimentin and the 280,000-dalton polypeptide exhibit an indistinguishable cytoplasmic filamentous network, which aggregates into filamentious bundles when the cells are exposed to colcemid. These results suggest that this newly identified high molecular weight protein is closely associated with intermediate filaments containing either vimentin alone or vimentin, desmin and synemin. The expression of this protein appears to be developmentally regulated and does not appear to parallel the expression of any of the other three intermediate-filament proteins. The absence of the 280,000-dalton polypeptide in adult muscle cells and its gradual reduction during development implies that is probably not required for the maintenance of Z-disk structure after the assembly of the sarcomere

Role of Mechanical Bowel Preparation and Perioperative Antibiotics in Pediatric Pull-Through Procedures

Background There are no clear guidelines for the use of mechanical bowel preparation and postoperative antibiotics in children undergoing elective colorectal pull-through surgery. The objective of this study was to determine whether preoperative bowel preparation administration or duration of postoperative antibiotics impacted the rate of complications after elective pediatric pull-through surgery. Materials and methods Patients aged <18 y who underwent a pull-through procedure between 2011 and 2017 were retrospectively identified. Patient data included diagnosis, procedure, administration of mechanical bowel preparation, and duration of perioperative intravenous (IV) antibiotics. Outcomes of interest included surgical site infections and anastomotic complications. Results A total of 180 patients met inclusion criteria, of which 47.2% received mechanical bowel preparation. The combined rate of infectious and anastomotic complications was 12.2%. There was no significant difference in combined complication rate among those receiving bowel preparation compared with those who did not (14.1% versus 10.5%, P = 0.46). Administration of bowel preparation in the perineal anoplasty subgroup was associated with higher rates of wound infection (33.3% versus 3.3%, P = 0.05). One hundred five patients (58.3%) received perioperative IV antibiotics for ≤24 h. This group had similar rates of complications (13.3%) compared with those receiving IV antibiotics for longer than 24 h (11.6%, P = 0.74). Conclusions Although mechanical bowel preparation did not affect the overall complication rate for pull-through procedures, it was associated with more wound infections in those undergoing perineal anoplasty. Duration of postoperative IV antibiotics was not significantly associated with the rate of wound and anastomotic complications

Effects of oral glucose on exercise thermoregulation in men after water immersion

To test the hypothesis elevated blood glucose would attenuate the rise in exercise rectal temperature, six men age 35 plus or minus S.D. 7 years participated in each of three trials by 4-hr water immersion to the neck: (1) 2.0 g/kg body wt of oral glucose (33.8 percent wt./vol.) was consumed followed by 80 min controlled rest (Glu/Rest), and 70 min horizontal supine cycle exercise at 62.8 percent plus or minus S.E. 0.5 percent (1.97 plus or minus 0.02 L/min) of peak O2 uptake followed by 10 min recovery (2) with (Glu/Ex) and (3) without prior flucose (No Glu/Ex). Blood samples were taken at -25, 0, 15, 45, and 68 min of exercise and after plus 10 min of recovery for measurement of hemoglobin, hematocrit, and blood glucose. Both mean skin (T sub sk) (from six sites) and rectal temperatures (T sub re) were monitored continuously. Sweat rate was measured by resistanc hygrometry. The mean of delta PV for the exercise trials was -12.2 plus or minus 2.1 percent. Mean blood glucose for the Glu/Ex trial was higher than that of the No Glu/Ex trial was (108.4 equal or minus 3.9 and 85.6 plus or minus 1.6 mg/dl, respectively, P less than 0.05. At the end of exercise T(sub sk) for the Glu/Ex trial was lower than for No Glu/Ex(32.0 plus or minus 0.3 and 32.4 equals or minus 0.2 C, respectively, P less than 0.05); T(sub re) for the Glu/Ex trial was lower than for No Glu/Es (38.22 plus or minus 0.17 and 38.60 plus or minus 0.11 C, respectively, P less than 0.05); and forearm sweat rate for the Glu/Ex trial (0.34 plus or minus 0.04 and 0.43 plus or minus g/sq cm, respectively, P less than 0.05). These data suggest that elevation of blood glucose prior to horizontal exercise following hypohydration attenuates the increase in body temperature without altering heat production or exercise hypovolemia

Bioenergetic analysis of human peripheral blood mononuclear cells

Leukocytes respond rapidly to pathogenic and other insults with responses ranging from cytokine production through to migration and phagocytosis. These are bioenergetically expensive and increased glycolytic flux provides ATP rapidly to support these essential functions. However, much of this work is from animal studies. To better understand the relative role of glycolysis and oxidative phosphorylation in human leukocytes, especially their utility in a translational research setting, we undertook a study of human peripheral blood mononuclear cells (MNCs) bioenergetics. Glycolysis was essential during LPS-mediated IL-1, IL-6, and TNF production as 2-deoxy-D-glucose significantly decreased output of all three cytokines. After optimising cell numbers and the concentrations of all activators and inhibitors, oxidative phosphorylation and glycolysis profiles of fresh and cryopreserved/resuscitated MNCs were determined to explore the utility of MNCs for determining the bioenergetics health profile in multiple clinical settings. While the LPS-induced cytokine response did not differ significantly between fresh and resuscitated cells from the same donors, cryopreservation/resuscitation significantly affected some measures of oxidative phosphorylation mostly, but also glycolysis. Bioenergetics analysis of human MNCs provides a quick, effective means to measure the bioenergetics health index of many individuals but cryopreserved cells are not suitable for such an analysis. The translational utility of this approach was tested by comparing MNCs of pregnant and non-pregnant women to reveal increased bioenergetics health index with pregnancy but significantly reduced basal glycolysis and glycolytic capacity. More detailed analysis of discrete leukocyte populations would be required to understand the relative roles of glycolysis and oxidative phosphorylation during inflammation and other immune responses