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At least 19 recordsLinked to original sources
PubMed1975

Characterization of an in vitro persistent-state measles virus infection: species characterization and interference in the BGM/MV cell line.

Serological methods of mixed agglutination and indirect immunofluorescence showed the BGM/MV cell line to possess monkey antigens. As a means of further characterizing the species constitution of the BGM/MV cell line, the species specificity of viral-induced interferon from these cells, as well as the response of these cells to exogenous interferons, was determined. Low titers of spontaneously elaborated interferon capable of protecting monkey but not mouse cells were detected in BGM/MV culture fluids. Interferon induced by Newcastle disease virus infection of BGM/MV cells was capable of conferring an antiviral state on monkey and, to a lesser extent, on mouse cells. Exogenous interferons of both homologous (BGM/MV) and heterologous sources failed to confer an antiviral state on BGM/MV cells. BGM/MV cells were found to be partially refractive to superinfection with measles virus but freely replicated mumps and vesicular stomatitis virus.

Animals↗
PubMed1978

Characterization of lymphocyte-activating factor (LAF) produced by a macrophage cell line, P388D1. II. Biochemical characterization of LAF induced by activated T cells and LPS.

Unstimulated P388D1 cells, as well as P388D1 cells stimulated with PHA-activated guinea pig T lymphocytes or LPS, produced a lymphocyte activating factor (LAF). In order to have a chemical basis for comparing this LAF with the LAF produced by normal macrophages, we have analyzed several biochemical characteristics of the P388D1-derived LAF. Sephadex G-75 chromatography of concentrated LAF-containing supernatants from cultures of unstimulated and T cell stimulated P388D1 cells demonstrated that the cell line LAF had a m.w. of approximately 16,000. On DEAE cellulose, the T cell-induced LAF fractionated into at least three major peaks and one minor peak. By using hydroxylapatite chromatography, two of the major peaks of LAF activity were separated from residual contaminating Lowry positive material. LPS-stimulated P388D1 also produced LAF with a m.w. of 16,000. However, the LPS-induced LAF appeared to lack one of the DEAE peaks of LAF activity observed with the T cell-derived LAF. In contrast to LPS, T cells may induce the synthesis and/or release of an additional LAF component or enzymatically modify one or more of the LAF species that are produced in response to both stimulants. Based on the results of chemical characterization studies, the P388D1-derived LAF appears to be similar in size and charge to the lymphocyte activating factor produced by normal macrophages.

Animals↗
PubMed1976

Isolation and characterization of an epithelial basement membrane glycoprotein from murine kidney and further characterization of an epithelial basement membrane glycoprotein secreted by murine teratocarcinoma cells in vitro.

A glycoprotein component of epithelial basement membranes (EBM) has been isolated from murine kidney homogenates by extraction with 0.05 M phosphate buffer, pH 7.2, precipitation with (NH4)2SO4 and chromatography on controlled pore glass. Antiserum produced against this glycoprotein reacts specifically with the basement membranes of renal glomeruli and tublules. The EBM glycoprotein of renal origin is antigenically identical with a glycoprotein component of epithelial basement membrane secreted by a murine teratocarcinoma grown in vitro, and the amino acid composition of the two EBM glycoproteins is markedly similar. Both glycoproteins were isolated as high molecular weight aggregates. Disaggregation with sodium dodecyl sulfate and 2-mercaptoethanol resulted in release of monomers of 32 000 and 34 000 daltons for kidney EBM glycoprotein and teratocarcinoma EBM glycoprotein, respectively. The difference in molecular weight is apparently due to increased amounts of fucose, mannose, N-acetylglucosamine and sialic acid in the glycoprotein secreted by the teratocarcinoma. In addition, both EBM glycoproteins contain galactose, glucose and N-acetylgalactosamine.

Amino Acids↗
PubMed1975

Characterization of an in vitro persistent-state measles virus infection: establishment and virological characterization of the BGM/MV cell line.

The parameters of a persistent-state measles virus infection in BGM/MV cells were examined. The BGM/MV cell line was established by cocultivation of measles virus-infected primary C3H mouse brain cells with a stable line of African green monkey kidney cells (BGM). Initially, a morphologically mixed population of cells existed:BGM-like (epithelioid) and fibroblasts. Gradually the fibroblasts were replaced by BGM-like cells, resulting in a morphologically homogeneous population. Measles cytopathic effect was noted 2 days after initiation of this culture and persisted for approximately 290 days. The time of disappearance of viral cytopathic effect corresponded to the time at which morphological homogeneity was reached. Low titers of infectious measles virus were detected in the BGM/MV culture up to 20 days postseeding; thereafter none was observed. After 440 days in culture, 100% of BGM/MV cells demonstrated intractyoplasmic measles antigen by immunofluorescence. Nuclear fluorescence was never observed. Electron microscopy revealed the presence of measles virus mucleocapsid within the almost completely filling the cytoplasm of BGM/MV cells. The plasma membrane of these cells appeared normal; no maturing or budding particles were observed. Measles virus hemagglutinin was not detected in either clarified cell lysates or in supernatant culture fluids. Cell membrane alteration by measles virus was detected in less than 1% of these cells by hemadsorption and by membrane immunofluorescence. The hemadsorption activity of the cells could be enhanced (30 to 70%) by treatment with actinomycin D or enucleation with cytochalasin B; these treatments, however, were unsuccessful in inducing detectable levels of measles hemagglutinin. Treatment of BGM/MV cells with 5-bromo-2'-deoxyuridine (BUdR) at 5 to 50 mug/ml and cytosine arabinoside at 1 to 50 mug/ml failed to enhance hemadsorption activity. Doses of 5-bromo-2'-deoxyuridine ranging from 5 to 200 mug/ml and of actinomycin D ranging from 0.1 to 10 mug/ml were ineffective in inducing the synthesis of infectious virus. Various physical methods of induction of infectious virus was also unsuccessful.

Animals↗
PubMed1976

[On the biological characterization of the outbred strain of Chbb : NMRI (SPF) mice / 1st comm.: Characterization of breeding stock under constant conditions of nutrition (Part II) (author's transl)].

The second part continued the biological characteization of the outbred strain Chbb : NMRI (SPF) (formerly NMRI/Tübingen/Kisslegg/Biberach) mice. The results obtained from 7 generations (F9 to F 15-generations) refer to the following parameters: loss of breeding animals, conception rate, ability to build a nest, litter size at birth and weaning, loss of young animals, litter weight at birth and weaning, intervals between two births and efficienty quota.

Animals↗
PubMed1977

Isolation and characterization of immunoregulatory factors from normal human serum. I. Preliminary biochemical and biological characterization of immunosuppressive factors.

Normal human serum was shown to inhibit the mitogenic effects of bacterial lipopolysaccharide and Con A on mouse spleen lymphocytes and reduce the in vitro antibody response to SRBC by these cells. Furthermore, it was demonstrated that immune suppression occurred without loss of lymphocyte viability. Fractionation of normal human serum resulted in isolation of several immunoenhancing and immunoinhibitory fractions. Electrophoretic analysis of the immunoinhibitory fractions revealed a complex array of serum proteins. The most prominent proteins on polyacrylamide electrophoresis stained for both proteins and carbohydrate. The heterogeneity of immunoinhibitory fractions were further substantiated by their differential susceptibility to trypsin, periodate, and 2-mercaptoethanol treatment. Heterogeneity of the fractions was also shown to be related to difference in their biologic activity as expressed in their effects on mitogenicity and immunogenicity of LPS in mouse splenic cultures. This study lends evidence to the consideration that normal human serum contains several immunoregulatory factors with differing biochemical characteristics and cellular sites of action.

Animals↗
PubMed1978

[Characterization of a protease from Thermoactinomyces vulgaris (thermitase). 2. Single-step fine purification and protein-chemical characterization].

The fine purification of an alkaline protease (thermitase) from Thermoactinomyces vulgaris by means of isoelectrical focussing in the flat-bed procedure using granulated gel is reported. An Na2SO4-precipitated crude product serves as the starting material. Isoelectrical focussing leads in a single step to a highly purified protein with an uniform N-terminal end group. The enzyme has an IP at 9.0 and a mol. wt. of 37,400; it consists of a polypeptide chain with arginine as the N-terminal, and tyrosine as the C-terminal end group. In addition to an essential serine residue, a SH group could be demonstrated which is hardly accessible in the native enzyme. Furthermore, the influence of different protease inhibitors was studied.

Isoelectric Focusing↗
PubMed2026

Genomic characterization and therapeutic potential of five broad-spectrum lytic bacteriophages against multidrug-resistant avian pathogenic Escherichia coli (APEC).

UNLABELLED: Colibacillosis, caused by avian pathogenic Escherichia coli (APEC), results in substantial economic losses in global poultry production. The emergence of multidrug-resistant (MDR) APEC poses zoonotic risks through horizontal transfer of antimicrobial resistance (AMR) genes. Bacteriophage therapy emerges as a safe alternative to antibiotherapy; however, comprehensive characterization of phages targeting MDR-APEC from diverse geographical regions remains limited. We isolated five lytic bacteriophages from poultry fecal samples collected from five Indian states and characterized them through morphological analysis, physiological stability testing, whole-genome sequencing, and in vivo efficacy assessment. Host range was determined against APEC isolates, and therapeutic potential was validated in the Galleria mellonella infection model. All phages showed Myovirus-like morphology and stability across physiologically relevant temperatures (up to 55°C-70°C) and pH conditions (3-11). Phages were classified as Escherichia phage vB_EcoM_fRPOT1, vB_EcoM_fDMYT1, vB_EcoM_fBSZT1, vB_EcoM_fUAMT1, and vB_EcoM_fPKPT2. Their genome size ranges from 170 to 356 kb, belonging to three distinct genera: Dhakavirus, Gaprivervirus, and Asteriusvirus. Genomic analysis confirmed the absence of antimicrobial resistance, virulence, toxin, or lysogeny genes. Fifty-one APEC strains were isolated, of which 23 (45.1%) were MDR. Individual phages lysed 37%-51% of tested APEC and 17%-39% of MDR strains. Three phages (fBSZT1, fUAMT1, and fPKPT2) significantly improved larval survival to 60%-80% at an MOI of 10 in G. mellonella infection models compared to the untreated control. This study establishes a well-characterized phage bank targeting MDR-APEC strains, providing a foundation for developing phage-based interventions to reduce antibiotic dependency and mitigate AMR transmission risks under the One Health framework. IMPORTANCE: The overuse of antibiotics in poultry farming has created a crisis. The multidrug-resistant (MDR) bacteria threaten both animal health and human safety through the food chain. When antibiotics fail, farmers face devastating losses, and resistant bacteria can transfer to humans through consumption or environmental contamination. Bacteriophages offer a practical solution as they kill target bacteria without harming beneficial microbes or leaving chemical residues. Our comprehensive characterization confirms that these five phages are safe and effective as they lack any resistance or toxin genes and rescue 60%-80% of infected larvae. This represents a characterized phage bank targeting the specific resistant strains in Indian poultry. By providing a validated alternative to antibiotics, this work supports sustainable food production while reducing the spread of antimicrobial resistance from farms to humans.

Animals↗
PubMed2026

Genomic and phenotypic characterization of Klebsiella pneumoniae phage KP Ø1: a novel lytic Slopekvirus targeting uropathogenic multidrug-resistant Klebsiella pneumoniae.

The rise of multidrug-resistant (MDR) uropathogenic gram-negative bacteria (GNB) necessitates the development of alternative therapeutic strategies. This study aimed to isolate, phenotypically characterize, and perform whole-genome sequencing of the bacteriophage demonstrating the broadest host range against MDR uropathogens. Fifty MDR GNB isolates were screened for lytic phages. The most promising candidate, Klebsiella pneumoniae phage KP Ø1, was characterized using plaque assay, Transmission Electron Microscopy (TEM), and pH/thermal stability testing. Genomic characterization was performed via whole-genome sequencing (WGS), with functional annotation and lifestyle prediction using PhaBOX and PhageScope software. Klebsiella pneumoniae was the most prevalent MDR uropathogen. Klebsiella pneumoniae phage KP Ø1 exhibited a 50% host range and high lytic titer (10⁸ PFU/mL). TEM revealed an icosahedral head and short contractile tail. Genomic characterization by WGS revealed that Klebsiella pneumoniae phage KP Ø1 possesses a 174,591 bp double-stranded deoxyribonucleic acid (dsDNA) genome containing 274 predicted open reading frames (ORFs). No lysogeny-related genes, toxins, or antibiotic resistance markers were detected, confirming its strictly lytic nature and supporting its potential as a candidate for phage therapy applications. The phage remained stable (10⁸ PFU/mL) across temperatures of - 20 °C to 50 °C; supporting its suitability for long-term biobanking and suggesting potential activity at physiological temperature, and across a pH range of 7-9. Klebsiella pneumoniae phage KP Ø1 is a novel, obligately lytic Slopekvirus whose genomic architecture, stability profile, and absence of lysogeny-associated, virulence, and antimicrobial resistance genes ( AMR) collectively support its candidacy for further preclinical evaluation as a phage therapy agent against uropathogenic MDR Klebsiella pneumoniae.

Klebsiella pneumoniae↗
PubMed1979

Intracellular marking with lucifer yellow CH and horseradish peroxidase of cells electrophysiologically characterized as glia in the cerebral cortex of the cat.

Intracellular microelectrodes filled with either Lucifer Yellow CH, a highly florescent dye, or horseradish peroxidase (HRP) were used to electrophysiologically characterize and mark cells in the cerebral cortex of cat. Fifty-eight cells, characterized electrophysiologically as glia, were marked with Lucifer Yellow CH. All were identified as protoplasmic astrocytes, and included cells in the glia limitans of the molecular layer. An additional 54 cells, similarly characterized as glia, were labeled with HRP. The results were the same; only protoplasmic astrocytes were labeled. The "staining quality" of the glia labeled with HRP was superior to that of cells injected with Lucifer Yellow; greater lengths of individual processes were revealed, and they could often be followed to blood vessels where they ended on the walls of vessels with expanded perivascular end-feet. The observations indicate that the many previously reported studies on presumed glial cells in the cat cerebral cortex have characterized the behavior of protoplasmic astrocytes. Neurons were also marked during these experiments. The "staining" quality of the Lucifer Yellow filled neurons was excellent; dendritic spines, axons, and axon collaterals were clearly visible. These fine neuronal details were not as well revealed after HRP labeling. High resting membrane potentials (RMP's) were not a prerequisite for obtaining well-marked neurons (mean RMP of Lucifer Yellow filled neurons was -33.6 mV; mean RMP of HRP filled neurons was 42.3 mV). In contrast, the mean RMPs of Lucifer Yellow and HRP marked glia was -68 Mv and -75 mV respectively, and the quality of "staining" appeared to be more closely related to the RMP.

Animals↗
PubMed2026

Admission whole-blood transcriptomic characterization of a neutrophil-predominant systemic immune response in patients with acute traumatic brain injury.

BACKGROUND: Acute traumatic brain injury (TBI) is accompanied by systemic immune responses, but their whole-blood transcriptomic features at hospital arrival remain incompletely characterized. We aimed to characterize these features in patients with acute TBI compared with healthy controls. METHODS: In this single-center prospective observational study, we performed whole-blood RNA sequencing on hospital-arrival samples from 42 patients with acute TBI and 21 healthy controls. Analyses included differential expression (limma-voom; FDR < 0.05, |log2FC| > 0.7), functional enrichment, Ingenuity Pathway Analysis, CIBERSORTx LM22 deconvolution, and per-sample neutrophil degranulation signature scoring. RESULTS: Differential expression analysis identified 996 upregulated and 863 downregulated genes, with marked upregulation of inflammation-, innate immunity-, and neutrophil-related genes including DUSP1, HMGB2, MMP9, and S100A8. Canonical pathways with positive IPA z-scores included Neutrophil degranulation, Neutrophil Extracellular Trap Signaling Pathway, and Toll-like Receptor Signaling; upstream regulators included TNF, IL1B, IFNG, and STAT3. Deconvolution identified 7 of 22 differing subsets (q < 0.05), with relatively higher myeloid and lower lymphoid fractions in TBI. The Neutrophil degranulation signature score correlated with Injury Severity Score within TBI (Spearman &#x3c1; = +0.55; q < 0.001). CONCLUSIONS: Admission whole-blood transcriptomics characterized a neutrophil-predominant systemic transcriptional response in patients with acute TBI. This response was also evident among patients without major extracranial injury and was associated with total ISS. However, because the study lacked an appropriately matched non-TBI trauma comparator, the findings should be interpreted as a descriptive characterization of a systemic injury response accompanying TBI and do not establish a TBI-specific molecular signature or mechanism.

gene expression↗
PubMed2026

First molecular detection and partial ORF1 characterization of psittacine beak and feather disease virus (PBFDV) in domesticated parrots of Northern Vietnam.

Psittacine beak and feather disease virus (PBFDV), currently classified within the species Circovirus parrot, is an infectious agent in avian species, particularly psittacine birds. PBFDV is the causative agent of psittacine beak and feather disease (PBFD), leading to feather loss, deformed beaks and nails, immunosuppression, and high mortality. However, there is limited information on PBFDV in Vietnam, particularly in domesticated parrots. This study aims to detect and molecularly characterize PBFDV in psittacine birds in Northern Vietnam. Among the 193 psittacine birds tested by conventional PCR, 48 were PBFDV-positive, corresponding to a positivity rate of 24.87%. Based on partial ORF1 characterization, phylogenetic tree analysis of the ten PBFDV sequences showed that genotype I, which exhibits genetic diversity, is circulating in Vietnam. This study highlights the importance of genomic characterization of PBFDV in domesticated exotic psittacine birds in Vietnam. Together with the recent cases of PBFD in domestic parrots, further surveillance is needed to elucidate the host specificity, transmission, and pathophysiology of PBFDV.

Animals↗