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PubMed1996

Cardioprotective Effects of Red Blood Cells on Ischemia and Reperfusion Injury in Isolated Rat Heart: Release of Nitric Oxide as a Potential Mechanism.

BACKGROUND: Circulating cells influence myocardial function during ischemia and reperfusion, (eg, neutrophils exacerbate, and platelets protect the myocardium from deterioration). This study was designed to determine the role of red blood cells on myocardial function following ischemia and reperfusion in isolated rat hearts. METHODS AND RESULTS: Exposure of buffer-perfused hearts to 40 minutes of total ischemia followed by 30 minutes of reperfusion resulted in myocardial dysfunction and injury, indicated by decrease in the force of cardiac contraction (FCC, -25 +/- 4%), increase in the coronary perfusion pressure (CPP, +20 +/- 3%) and decrease in myocardial superoxide dismutase (SOD, 2.5 +/- 0.2 vs 3.5 +/- 0.4 U/mg protein in sham ischemic hearts, P <.05). Perfusion of the hearts with washed rat red blood cells showed significant protective effects against ischemia and reperfusion, indicated by minimal change in FCC (-10 +/- 4%) and CPP (+3 +/- 3%) (both P <.01 vs buffer alone perfused hearts) and preservation of myocardial SOD activity (2.8 +/- 0.4 U/mg protein, P <.05 vs buffer alone perfused hearts). The cardioprotective effects of red blood cells were attenuated when the red blood cells were preincubated with the nitric oxide blood cells were attenuated when the red blood cells were preincubated with the nitric oxide blood cells were attenuated when the red blood cells were preincubated with the nitric oxide synthase inhibitors N(omicron)-nitro-l-arginine (l-NNA, 5 x 10(-4)M) or N(omicron)-nitro-l-arginine methyl ester (l-NAME, 5 x 10(-4)M) at 37 degrees C for 60 minutes before perfusion of the heart. Perfusion of hearts with the nitric oxide precursor l-arginine (2 x 10(-4)M) also exerted significant protective effects on FCC ( - 14 +/- 4%), CPP (+12 +/- 3%) and myocardial SOD activity (2.9 +/- 0.2 U/mg protein) following ischemia and reperfusion. In other studies, washed rat red blood cells expressed nitric oxide synthetase activity which was inhibited by both l-NNA and l-NAME. CONCLUSIONS: These results suggest that red blood cells exert cardioprotective effects against ischemia and reperfusion at least in part by the l-arginine-nitric oxide pathway in isolated rat hearts.

Journal Article↗

PubMed2025

Evolution of SARS-CoV-2 in white-tailed deer in Pennsylvania 2021-2024.

SARS-CoV-2 continues to transmit and evolve in humans and animals. White-tailed deer (Odocoileus virginianus) have been previously identified as a zoonotic reservoir for SARS-CoV-2 with high rates of infection and probable spillback into humans. Here we report sampling 1,127 white-tailed deer (WTD) in Pennsylvania, and a genomic analysis of viral dynamics spanning 1,017 days between April 2021 and January 2024. To assess viral load and genotypes, RNA was isolated from retropharyngeal lymph nodes and analyzed using RT-qPCR and viral whole genome sequencing. Samples showed a 14.64% positivity rate by RT-qPCR. Analysis showed no association of SARS-CoV-2 prevalence with age, sex, or diagnosis with Chronic Wasting Disease. From the 165 SARS-CoV-2 positive WTD, we recovered 25 whole genome sequences and an additional 17 spike-targeted amplicon sequences. The viral variants identified included 17 Alpha, 11 Delta, and 14 Omicron. Alpha largely stopped circulating in humans around September 2021, but persisted in WTD as recently as March of 2023. Phylodynamic analysis of pooled genomic data from Pennsylvania documents at least 12 SARS-CoV-2 spillovers from humans into WTD, including a recent series of Omicron spillovers. Prevalence was higher in WTD in regions with crop coverage rather than forest, suggesting an association with proximity to humans. Analysis of seasonality showed increased prevalence in winter and spring. Multiple examples of recurrent mutations were identified associated with transmissions, suggesting WTD-specific evolutionary pressures. These data document ongoing infections in white-tailed deer, probable onward transmission in deer, and a remarkable rate of new spillovers from humans.

Animals↗

PubMed2025

The R203M and D377Y mutations of the nucleocapsid protein promote SARS-CoV-2 infectivity by impairing RIG-I-mediated antiviral signaling.

The viral protein mutations can modify virus-host interactions during virus evolution, and thus alter the extent of infection or pathogenicity. Studies indicate that nucleocapsid (N) protein of SARS-CoV-2 participates in viral genome assembly, intracellular signal regulation and immune interference. However, its biological function in viral evolution is not well understood. SARS-CoV-2 N protein mutations were analyzed in Delta, Omicron, and original strains. Two mutations with a methionine (M) residue at site 203 and a tyrosine (Y) residue at site 377 of the N protein were found in Delta strain but not in Omicron and original strains, and promoted SARS-CoV-2 infection therein. Those mutations, R203M and D377Y, enhanced the inhibitory impact of N protein on the impairment of RIG-I-mediated antiviral signaling, such as IRF3 phosphorylation and IFN-β activation. The viral RNA-binding activity of N protein was promoted by these mutations, effectively attenuating the recognition and interaction of RIG-I with viral RNA compared to the original or other variants. The R203M/D377Y mutations thus enhanced the suppressive activity of the N protein on RIG-I-mediated interferon induction both in vitro and in vivo, which in turn promoted viral replication. This study helps to understand the variability of SARS-CoV-2 in regulating host immunity.

SARS-CoV-2↗

PubMed1977

[The determination of a small amount of chlorine in the atmosphere by using 4-nitroaniline (author's transl)].

The determination of small amount of chlorine in the atmosphere is carried on ordinarily by omicron-toluidine method at present. However, this method is not recommended because the issued colour is unstable and omicron-toluidine itself belongs in the first group member of the Ordinance on Prevention of Particular Chemical Hazards Substances. Authors recommend 4-nitroaniline method, reported by J. Gabbay etc., because this method is stable and more practical. Although the colour that issued from the reaction of chlorine with 4-nitroaniline is affected by the co-existence of reducing gas, e.g. SO2, H2S or organic gas, but this effect may be removed the co-existence of reducing gas, e.g. SO2, H2S or organic gas, but this effect may be removed by introducing the sample gas into the layer of H2SO4-52Cr2O7 mixture immersed in glassfiber filter for micro-analysis. In this paper, influence of pH of the issued colour, stability, stream velocity of samplegas and effect of reducing substance are discussed.

Air↗

PubMed1989

Demonstration of phenolic compounds in plant tissues by an osmium-iodide postfixation procedure.

A simple procedure to stain phenols in plant tissues is described. Postfixation with an aqueous solution prepared by mixing 2 cc of 2% osmium tetroxide and 8 cc of 3% potassium iodide yields brilliant visualization of phenol-containing vacuoles in different tissues of plants (e.g., coffee, oak, tobacco and spruce) bearing high concentration of phenolic compounds. Areas bearing phenols become dark gray to black. Chemical experiments demonstrate that osmium-potassium iodide (Os-KI) mixture reacts rapidly with several naturally occurring plant phenols, developing black solutions from which black solids precipitate. Phenols containing omicron-dihydroxy groups react with Os-KI solution more rapidly than other structurally different phenols. Therefore, omicron-dihydroxy units in an aromatic ring seem to function as primary sites of reactivity with the osmium-iodide complexes.

Histocytochemistry↗

PubMed1975

Capacity of sensitized thymus-derived lymphocytes to induce fatal lymphocytic choriomeningitis is restricted by the H-2 gene complex.

Adoptive immunization of syngeneic, immunosuppressed recipients infected with lymphocytic choriomeningitis (LCM) virus causes fatal neurologic disease within 2 to 4 days of cell transfer, providing that donors are sampled when the in vitro 51-Cr release assay shows maximal specific activity of sensitized thymus-derived lymphocytes (T cells). Prior treatment of immune spleen cells with AKR anti-omicron ascitic fluid and complement causes total abrogation of this in vivo activity. Fatal neurologic disease is induced only when donor and recipient share at least one set of H-2 antigenic specificities. Parent yields F1 and F1 yields parent combinations are as effective as syngeneic systems, but mice given allogeneic immune cells survive as long as controlsmdifferences at the M-locus in H-2 compatible mice do not inhibit effector activity. Homing of transferred lymphocytes to spleen is similar in syngeneic or allogeneic recipients, but only syngeneic immune cells cross the blood-cerebrospinal fluid (CSF) barrier and cause choriomeningitis. Fatal LCM, is, therefore, apparently induced by a specifically sensitized omicron-bearing cell population, activity of which is restricted by the H-2 gene complex.

Animals↗

PubMed2004

[Value of non-invasive continuous hemodynamic monitoring system in the differential diagnosis of the patients with dyspnea].

OBJECTIVE: To evaluate non-invasive continuous hemodynamic (IQ System) monitoring in the differential diagnosis of dyspnea. METHODS: According to the diagnosis on discharge, 48 patients diagnosed as pulmonary dyspnea were enrolled in control group and 38 patients with cardiac dyspnea were in heart failure group. Each patient underwent IQ monitoring on admission and after recovery. The difference in the diagnosis on admission and on discharge, and the difference in IQ index were analyzed. RESULTS: (1) Clinical diagnosis: 7 patients in heart failure group were missed on admission as 5 were diagnosed as pneumonia and 2 were diagnosed as chronic obstructive pulmonary disease (COPD). One patient with pneumothorax in control group was misdiagnosed as heart failure. (2) Indexes of cardiac function: base impedance (Zo), maximum value of dz/dt (dz/dt max) and Heather index (HI) of heart failure group were markedly lower than those of control group (all P<0.001). The respective values were (19.0+/-3.5) Omega vs. (28.8+/-5.5) Omega, (0.76+/-0.42) Omega/s vs. (1.40+/-0.72) Omega/s, and (7.04+/-4.25) Omega/s2 vs. (13.60+/-6.36) Omega/s2. If Zo value of patients with dyspnea was 22 omicron or less, the sensitivity in diagnosing heart failure was 79 percent, and its specificity was 94 percent. If Zo value was 18.0 omicron or less, the sensitivity in diagnosing heart failure was 47 percent, and its specificity was 100 percent. (3) Comparison within groups: Indexes of cardiac function of control group did not change obviously and Zo, dz/dt max, HI, stroke volume (SV) and acceleration contraction index (ACI) values of heart failure group rose significantly after recovery. (4) Pre-ejection period (PEP) and left ventricular ejection time (VET) in both groups had no statistical significance in differences. CONCLUSION: IQ System was valuable in differential diagnosis to judge if dyspnea is caused by heart failure. Zo, dz/dt max and HI, especially Zo, are reliable.

Aged↗

PubMed1989

[Physician praise in the province. Comments on 2 ancient epitaphs from Trikka (Thessalia)].

With respect to the meaning of a physician for life and health of men, the Iliad says about the physician pi omicron lambda lambda omega nu alpha nu tau alpha xi iota omicron sigma alpha lambda lambda omega nu and reports upon two famous physicians: Machaon and Podaleirios from Thessaly, sons of Asclepios. Like these the qualified physician proves to be a man of knowledge and a man of arts-not only in antiquity--, for he has one passion: science as incorporated in the tau epsilon chi nu eta of medicine. Very often inscriptions--above all grave epigrams--with their great tradition from various times and localities provide many good examples of daily life including valuable references to the practice, ethics and social situation of physicians. As examples of the social status and of the praise of physicians, two grave poems from ancient Trikka in Thessaly are discussed here: one from the first century B. C., the other from the third century A. D. These two poems are documents of the medical history of Thessaly; a region important because of the tradition of the cult of Asclepios and the life and work of late Hippocrates.

Funeral Rites↗

PubMed1983

Differential diagnosis of arterial disease of the lower limb using Doppler ultrasound.

Doppler arterial waveforms from the femoral and ankle arteries of 55 normal control subjects and 76 arteriopaths were analysed for Laplace transform coefficients, delta and omega omicron, and pulsatility index (PI). At the femoral artery delta was superior to PI in accurately detecting mild and moderate aortoiliac stenosis, as assessed from arteriograms. In the femoropopliteal segment, the ratio of omega omicron from femoral to ankle level compared favourably with PI damping factor in the detection of occlusive disease. The Laplace transform system provides a helpful diagnostic method in lower limb arterial disease.

Aorta↗

PubMed1983

[Generation of membrane potential by aerobic bacteria Micrococcus lysodeikticus. Correlation between coupled and uncoupled respiration].

The effects of cyanide and nonylhydroxyquinoline-N-oxide on membrane potential generation and oxidase activities in intact cells and membrane particles of M. lysodeikticus were studied. Low concentrations of the inhibitors interacting with the components of one branch of a branched respiratory chain of M. lysodeikticus strongly inhibit the membrane potential generation and only slightly reduce the total respiration rate. It was assumed that the generation of delta psi takes place in the b-c locus of the respiratory chain branch terminated with cytochrome oxidase; over 90% of total O2 uptake provides for the uncoupled respiration via cytochrome omicron. Inside the b-c locus two sites responsible for delta psi generation were singled out; these sites differ in their sensitivities towards nonylhydroxyquinoline-N-oxide. Based on the data obtained and the effect of "extra-reduction" of cytochrome b566 a hypothetical model of the respiratory chain of M. lysodeikticus was developed, which includes the branching of the electron flux to two terminal pathways and redox equivalent transport cyclization via the menaquinone cycle. The physiological role of uncoupled respiration through cytochrome omicron is discussed.

Aerobiosis↗

PubMed2026

Dynamic case-control sampling for rapid estimation of vaccine effectiveness against an emerging infectious disease variant.

New SARS-CoV-2 variants arise frequently with different viral properties that can impact the effectiveness of the vaccines. Updating estimates of vaccine effectiveness (VE) in public health surveillance can be limited by the necessity of conducting a distinct study that entails analysis of prospective cohort data or using a test-negative design. We introduce a method for dynamically updating estimates of VE using data that accumulate in real time. Our method uses dynamic case-control sampling to estimate VE against a newly emerging variant relative to a previous variant. Dynamic case-control sampling is a technique that continuously updates VE estimates by comparing individuals infected with a newly emerging variant (defined as "cases") to those infected with a previously circulating variant (defined as "controls"). We use this estimate in combination with information about VE from the previous variant (these estimates are typically available from larger, traditional studies) to infer VE against the emerging variant. We demonstrate the utility of this method on the BA.1 and BA.2 sub-lineages of the Omicron variant. The method produces estimates of VE comparable to those produced using traditional methods, although with increased SE. The increase in error, however, is reasonable given a much smaller sample size than other studies, and error ranges of the estimates could be significantly improved by sequencing a larger proportion of identified cases. Our method, which assumes only a fraction of the new cases are being sequenced, can be applied by health departments using routinely collected data to produce timely, rigorous VE estimates to rapidly identify potential changes in VE.

Humans↗

PubMed1991

Brain amino acid reductions in one family with chromosome 6p-linked dominantly inherited olivopontocerebellar atrophy.

We measured the levels of aspartate, glutamate, gamma-aminobutyric acid (GABA), and other amino acids in autopsied brain of 6 patients from one family (Pedigree S) with dominantly inherited olivopontocerebellar atrophy. A previous demonstration of reduced aspartate concentration in plasma of affected members of this family suggested the possibility of a generalized disorder of amino acid metabolism affecting the brain. As compared with the control levels, mean levels of aspartate and glutamate were markedly reduced by about 70 and 40%, respectively, in the degenerated cerebellar cortex from the patients. Since the cerebellar aspartate reduction likely exceeds the amount that could be explained by neuronal loss, other factors such as abnormal aspartate metabolism, neurotransmitter turnover, or both are probably involved. Mean aspartate, glutamate, and GABA levels were also reduced by about 10 to 30% in most of the 16 examined extracerebellar brain areas in which no or, at most, mild neuronal cell loss was observed by semiquantitative estimation. Concentrations of taurine, glutamine, and omicron-phosphoethanolamine were normal in all brain areas examined. Our biochemical data provide support to the presence of a generalized, but quantitatively mild, disturbance in amino acid metabolism in patients with olivopontocerebellar atrophy from Pedigree S. The regionally widespread amino acid reductions in the brain, of as yet unknown pathophysiological significance, could be due to a failure of one or more enzymes involved in aspartate and glutamate metabolism.

Adult↗

PubMed1991

Endogenous plasma N-acetylcysteine and single dose oral bioavailability from two different formulations as determined by a new analytical method.

A method to quantitate N-acetylcysteine in plasma using reductive cleavage with tributylphosphine and post-HPLC column derivatisation with omicron-phthalaldehyde is described. Using this method, endogenous average concentrations of 0.08 microM were measured in 10 volunteers participating in a crossover study to compare the bioavailability of two different formulations of N-acetylcysteine. The drug was detected in plasma for up to 12 h after administration of a single oral dose (200 mg); the Cmax values were up to 20 times the endogenous levels. The sensitivity and selectivity of the method should thus enable the behaviour of N-acetylcysteine after oral administration to be properly described and bioavailability studies to be performed.

Acetylcysteine↗

PubMed1977

Mechanochemical studies of enzymatic degradation of insoluble collagen fibers.

A mechanochemical method was developed for studying the enzymatic degradation of insoluble collagen fibers. The method involves stretching the collagen fiber to a fixed extension in the presence of a solution of collagenase and measuring the rate of relaxation of the force induced in the fiber. In this work, bacterial collagenase was used for reasons of availability. We observed invariably an exponential decrease in force with respect to ttime. The slope of the linear plot of logarithm of the force versus time was taken as a measure of the rate of enzymatic degradation. This rate was found a) to vary linearly with collagenase concentration; b) to be maximal at pH 7-8; c) to vary with temperature according to the Arrhenius relationship in the range 10-56 degrees C; d) to be reduced to varying extent by addition of EDTA omicron-phenanthroline, 2,3-dimercaptopropanolol, and D,L-cysteine; e) to be minimal when the strain on the fiber was ca. 4%; f) to be increased dramatically by denaturation of the collagen fiber; and g) to be reduced by an increase in the crosslink density of the collagen fiber. Except for the effect of strain, which can not be conveniently studied by existing methods these results are consistent with those observed by other methods for the study of the enzymatic degradation of collagen. The mechanochemical method is, however, uniquely suited to monitor continuously the enzymatically induced decay in the stress-bearing ability of collagen fibers. It has also been found useful in the design of collagenous implants with specified resistance to enzymatic degradation in vivo.

Collagen↗

PubMed2007

Lifetime of alumina- and zirconia ceramics used for crown and bridge restorations.

The lifetime of a ceramic is dependent on the presence of incidental cracks and their gradual propagation under the conditions of the oral cavity. The objective of this study was to examine the long-term strength of glass-infiltrated alumina- and various zirconia ceramics currently used in CAD/CAM systems to manufacture crown and bridge frameworks. Fracture mechanics were applied to determine characteristic strength (sigma(omicron)), Weibull modulus (m), fracture toughness (K(Ic)), and the subcritical crack growth parameters n and B. Based on these parameters, lifetime diagrams were generated which allowed the evaluation of the long-term behavior. The results showed that in a moist environment, the glass-infiltrated alumina- and some zirconia ceramics have a high susceptibility to subcritical crack growth. Zirconia ceramics with an alumina oxide content of 0.25 wt %, however, exhibited the highest initial and most favorable long-term strength, and should therefore be suitable for crown and bridge restorations.

Aluminum Oxide↗

PubMed1993

An assessment of spin-echo rotating-frame imaging for spatially localized determination of short T2 relaxation times in vivo.

The rotating frame of localized spectroscopy can be augmented by the inclusion of a refocusing pulse to enable the measurement of T2 relaxation times. This technique is particularly appropriate for determining short relaxation parameters due to the absence of time consuming switched B(omicron) field gradients. We have evaluated the accuracy of this protocol by measuring localized T2s in the range of 1 to 20 ms. Preliminary data obtained from muscle and liver of normal and iron overloaded human subjects are also presented.

Magnetic Resonance Imaging↗

PubMed1977

Extra-chromosomal inheritance of rhodamine 6G resistance in Saccharomyces cerevisiae.

Rhodamine 6G was found to be a specific inhibitor of aerobic growth of yeast, having no effect on fermentative growth. A single step spontaneous mutant of S. cerevisiae resistant to rhodamine 6G was isolated, which showed cross-resistance to the ATPase inhibitors venturicidin and triethyltin, to the uncoupler 1799, to bongkrekic acid and to cycloheximide, but not to oligomycin or to the inhibitors of mito chondrial protein synthesis, chloramphenicol and erythromycin. The genetic analysis of this mutant showed that both nuclear and cytoplasmic (but apparently not mitochondrial) factors may be involved in the determination of the mutation. The behaviour is discussed as a possible function for 2 micron circular (omicron) DNA.

Cross Reactions↗

PubMed1995

Identification, characterization, and localization to chromosome 17q21-22 of the human TBX2 homolog, member of a conserved developmental gene family.

The T-box motif is present in a family of genes whose structural features and expression patterns support their involvement in developmental gene regulation. Previously, sequence comparisons among the T-box domains of ten vertebrate and invertebrate T-box (Tbx) genes established a phylogenetic tree with three major branches. The Tbx2-related branch includes mouse Mm-Tbx2 and Mm-Tbx3, Drosophila optomotor-blind (Dm-Omb), and Caenorhabditis elegans Ce-Tbx2 and Ce-Tbx2 and Ce-Tbx7 genes. From the localization of Mm-Tbx2 to Chromosome (Chr) 11, we focused our search for the human homolog, Hs-TBX2, within a region of synteny conservation on Chr 17q. We used Dm-Omb polymerase chain reaction (PCR) primers to amplify a 137-basepair(bp)_ product from human genomic, Chr 17 monochromosome hybrid, and fetal kidney cDNA templates. The human PCR product showed 89% DNA sequence identity and 100% peptide sequence identity to the corresponding T-box segment of Mm-Tbx2. The putative Hs-TBX2 locus was isolated within a YAC contig that included three anonymous markers, D17S792, and D17S948, located at Chr 17q21-22. Hybridization-and PCR-based screening of a 15-week fetal kidney cDNA library yielded several TBX2 clones. Sequence analysis of clone lambda omicron TBX2-1 confirmed homology to Mm-TBx2-90% DNA sequence identity over 283 nt, and 96% peptide sequence identity over 94 amino acids. Similar analysis of Hs-TBX2 cosmid 154F11 confirmed the cDNA coding sequence and also identified a 1.7-kb intron located at the same relative position as in Mm-Tbx2. Phylogenetic analyses of the T-box domain sequences found in several vertebrate and invertebrate species further suggested that the putative human TBX2 and mouse Tbx2 are true homologs. Northern blot analysis identified two major TBX2 expression fetal kidney and lung; and in adult kidney, lung, ovary, prostate, spleen, and testis. Reduced expression levels were seen in heart, white blood cells, small intestine, and thymus. These results suggest that Hs-TBX2 could play important roles in both developmental and postnatal gene regulation.

Amino Acid Sequence↗