Increased phagocytic capacity of the blood,but decreased phagocytic activity per individual circulating neutrophil after an ultradistance run

The effect of a long strenuous endurance exercise on the phagocytic function of neutrophils was examined. 9 athletes [7 males, 2 females, age: 36–68 years, body mass: 64 (SD 10) kg, height: 175 (SD 10) cm] completed a competetive 100 km run in 8:07 (median value; range: 7:29–9:50 hours). In a whole blood assay the phagocytosis of opsonized E. coli, the receptor density of the Fc receptor 3 (CD16) and the complement receptor 3 (CD11b, direct immunofluorescence) of neutrophils were measured on a per cell basis by flow cytometry before and up to 3 hours after the race. The phagocytic rate (percentage of neutrophils incorporating bacteria) was unchanged after exercise, whereas the phagocytic activity (number of incorporated bacteria per cell) was significantly reduced by –34 (SD 8) % (Wilcoxon test, P<0.001). The total phagocytic capacity of the blood increased 2-3fold post exercise. The surface antigen expressions of CD11b and CD16 were unaffected by the ultradistance run. The results indicate either a reduced phagocytic function of neutrophils on a single cell basis or the mobilization of neutrophils of the marginal pool with a lower phagocytic activity. However, after a long endurance exercise the phagocytotic capacity of the blood was enhanced due to increased cell concentrations.     

Epitope mapping of the Brucella melitensis BP26 immunogenic protein: usefulness for diagnosis of sheep brucellosis

Sequencing of bp26, the gene encoding the Brucella sp. immunogenic BP26 periplasmic protein, was performed in the reference strains of Brucella abortus, B. suis, and B. ovis. The three bp26 sequences were almost identical to that published for B. melitensis 16M bp26, and only minor nucleotide substitutions, without modifying the amino acid sequence, were observed between species. The bp26 genes of the seven B. abortus biovar reference strains and B. abortus S19 and RB51 vaccine strains were also sequenced. Again, only minor differences were found. Surprisingly, the bp26 nucleotide sequence for B. abortus S19 was almost identical to that found for B. melitensis 16M and differed from the sequence described previously by others (O. L. Rossetti, A. I. Arese, M. L. Boschiroli, and S. L. Cravero, J. Clin. Microbiol. 34:165-169, 1996) for the same B. abortus strain. The epitope mapping of BP26, performed by using a panel of monoclonal antibodies and recombinant DNA techniques, allowed the identification of an immunodominant region of the protein interesting for the diagnosis of B. melitensis and B. ovis infection in sheep. A recombinant fusion protein containing this region of BP26 reacted indeed, in Western blotting, as the entire recombinant BP26 against sera from B. melitensis- or B. ovis-infected sheep while it avoided false-positive reactions observed with sera from Brucella-free sheep when using the entire recombinant BP26. Thus, use of this recombinant fusion protein instead the entire recombinant BP26 could improve the specific serological diagnosis of B. melitensis or B. ovis infection in sheep.     

Dominant-negative soluble PDGF-beta receptor inhibits hepatic stellate cell activation and attenuates liver fibrosis

Hepatic fibrogenesis is a consequence of hepatic stellate cells that become activated and transdifferentiate into a myofibroblastic phenotype with the ability to proliferate and synthesize large quantities of extracellular matrix components. In this process, platelet-derived growth factor (PDGF) is the most potent stimulus for hepatic stellate cell proliferation and migration, and is overexpressed during active hepatic fibrogenesis. This cytokine binds to the PDGF receptor type beta, activates Ras and sequentially propagates the stimulatory signal sequentially via phosphorylation of Raf-1, MEK and the extracellular-signal regulated kinases ERK1/ERK2. Hepatic injury is associated with both increased autocrine PDGF signaling and upregulation of PDGF receptor. In this study, we report that a dominant-negative soluble PDGF-beta receptor consisting of a chimeric IgG containing the extracellular portion of the PDGF receptor type beta blocks HSC activation and attenuates fibrogenesis induced by ligation of the common bile duct in rats. In culture-activated hepatic stellate cells, the soluble receptor blocks phosphorylation of endogenous PDGF receptor, phosphorylation of the ERK1/EKR2 signal and reduces proliferative activities of HSC. In vivo, both the delivery of the purified soluble PDGF antagonist and the administration of adenoviruses expressing the artificial transgene were able to reduce significantly the expression of collagen and alpha-smooth muscle actin. Our results demonstrate that PDGF plays a critical role in the progression and initiation of experimental liver fibrogenesis, and suggest that early anti-PDGF intervention should have a therapeutical impact on the treatment of liver fibrogenesis.     

Influence of scaffold thickness and scaffold composition on bioartificial graft survival

Biological scaffolds exhibit advantageous properties for tissue engineering of small diameter vessels. The influence of their extracellular matrix (ECM) components during in vivo repopulation is unknown. We implanted different xenogenic vascular matrices in a rat model to determine the influence of scaffold-thickness and ECM composition on in vivo repopulation. Decellularized ovine jugular vein (JV, n=42), carotid artery (CA, n=42) and aorta (AO, n=42) were implanted subcutaneously in the neck of adult male rats. Animals were sacrificed 2, 4 and 8 weeks after implantation. Cell and matrix morphology of explanted scaffolds were characterized by hematoxylin-eosin and pentachrome staining. Monoclonal anti-rat-CD31 was used to identify revascularization. Quantification of cell density was done by DNA-isolation.THICKNESS OF IMPLANTED XENOGENIC SCAFFOLDS VARIED ACCORDING TO THE MATERIAL USED (AO: 3.0-3.8mm; CA: 0.7-0.88mm; JV: 0.35-0.61mm). Immunohistology revealed complete repopulation of AO, CA, and JV scaffolds with endothelial cells and myofibroblasts within 2 weeks. After 8 weeks of implantation, AO scaffolds were completely covered by an endothelial monolayer and showed signs of a central matrix degeneration. JV scaffolds were completely degenerated at this stage. In contrast, CA scaffolds showed preserved ECM with a normal myofibroblast population and endothelial cell coverage.     

Frequent c-myc amplification in high-grade dysplasia and adenocarcinoma in Barrett esophagus

Barrett esophagus (BE) is a condition in which the normal squamous epithelium of the esophagus is replaced by a metaplastic columnar epithelium. BE is a premalignant lesion that represents the initial step in a metaplasia-dysplasia-carcinoma sequence. In the present study, amplification of the proto-oncogene c-myc was determined by means of differential polymerase chain reaction analysis of metaplastic specialized epithelium, low-grade dysplasia, high-grade dysplasia, and invasive adenocarcinoma obtained by microscopic dissection of 43 esophagectomy specimens. Amplification of c-myc was found in none of 29 specialized epithelial specimens, none of 23 low-grade dysplasia specimens, 6 of 24 high-grade dysplasia specimens, and 17 of 39 adenocarcinoma specimens. Our data indicate that amplification of c-myc is a late event in the metaplasia-dysplasia-carcinoma sequence in BE. Furthermore, determination of c-myc amplification may help identify high-risk patients who would benefit from intensified endoscopic surveillance or from immediate treatment.     

Ventilatory response to oscillating and non-oscillatingPa CO 2 in the anesthetized cat

Summary In 11 adult cats, lightly anesthetized with chloralose-urethane, blood from both common carotid arteries was led into a plastic chamber of 15–20 ml and returned to the carotids at a point 1.5 cm more cranial. By doing so arterial blood was assumed to pool within the chamber and lose itsP _{CO 2} oscillations which are normally known to exist as a result of the respiratory cycle. In control periods blood bypassed the chamber, thus maintaining respiratoryP _{CO 2} oscillations. Spontaneous ventilation was measured spirometrically. The animals were breathing pure O₂.Results. 1. When the sinus (carotid) nerves were intact or sectioned there was no significant difference in ventilation before or after switching from non-oscillating to oscillatingPa _{CO 2}. 2. When the vertebral arteries were ligated a drop in ventilation occurred after turning to oscillatingPa _{CO 2} which was followed by a slight rise above control values after 30–50 sec. This phenomenon was independent of sinus nerve integrity. Thus in hyperoxie condition the smallPa _{CO 2} oscillations known to occur in phase with respiration do not seem to provide a respiratory stimulus to resting ventilation above that generated by the mean level ofPa _{CO 2}. The ventilatory depression after vertebral artery ligation must at this time remain unexplained.     

Respiratory effects in two-dimensional Fourier transform MR imaging

Respiratory and other regular motions during two-dimensional Fourier transform magnetic resonance imaging produce image artifacts consisting of local blurring and more or less regularly spaced "ghost" images propagating along the direction of the phase-encoding magnetic field gradient. The patterns of these ghost artifacts can be understood in terms of the technique of image production and basic properties of the discrete Fourier transform. This understanding permits, without respiratory gating, production of images of improved quality in body regions in which there is significant respiratory motion. In particular, the ghosts can be maximally separated from the primary image by choosing intervals between phase-encoding gradient pulse increments that are equal to one-half the respiratory period; they can be minimally separated by choosing an interval equal to the respiratory period. Increasing the number of signal averages between each phase-encoding increment decreases the intensity of the ghosts.     

Osteopetrosis: MR characteristics at 1.5 T

Four patients with proved osteopetrosis (three with the infantile malignant form and one with the benign form) were examined with magnetic resonance imaging at 1.5 T. All patients were studied in the coronal and sagittal planes using both short and long repetition time/echo time sequences. The infantile malignant form was characterized by a complete lack of signal from the marrow alternating with a signal intensity equivalent to that of the intervertebral disks, resulting in a "stepladder" appearance. In the benign form or after successful marrow transplantation in the infantile malignant form, intermediate or high signal intensity in the vertebrae was noted, suggesting the presence of some marrow elements.     

Comparison of the three-level and the five-level versions of the EQ-5D

The European Journal of Health Economics - EQ-5D is a generic instrument to measure health-related quality of life. In 2009, a new version, EQ-5D-5L, was introduced as an attempt to reduce ceiling...     

Postmortem Stability of SARS-CoV-2 in Nasopharyngeal Mucosa

Analyses of infection chains have demonstrated that severe acute respiratory syndrome coronavirus 2 is highly transmissive. However, data on postmortem stability and infectivity are lacking. Our finding of nasopharyngeal viral RNA stability in 79 corpses showed no time-dependent decrease. Maintained infectivity is supported by virus isolation up to 35 hours postmortem.