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Identification and characterization of sporadic isolates of Streptococcus iniae isolated from humans.

Seven reference strains and seven clinical isolates of Streptococcus iniae, submitted to the Centers for Disease Control and Prevention Streptococcus Reference Laboratory between 2001 and 2004, were successfully identified by a conventional identification system. The seven randomly submitted clinical isolates were sensitive to beta-lactams, macrolides, quinolones, and vancomycin. Two of the seven clinical isolates were resistant to tetracycline. All seven strains grew well and multiplied in a phagocytosis assay. One of the seven randomly submitted strains was more similar to the type strain of S. iniae than to the other six strains. The latter six strains were similar if not identical to representative strains from a cluster of disease in Canada (M. R. Weinstein et al., N. Engl. J. Med. 337:589-594, 1997).

Animals↗

Isolation, characterization, and epidemiological assessment of shiga toxin-producing Escherichia coli O84 isolates from New Zealand.

Shiga toxin-producing Escherichia coli O84 isolates (n = 22) were examined using culture- and molecularly based methods in order to compare their phenotypic and genotypic characteristics. These analyses directly linked Shiga toxin-producing Escherichia coli O84 isolates from cattle and sheep with human isolates indicating that New Zealand livestock may be a reservoir of infection.

Animals↗

The primary sequence of rhesus monkey rhadinovirus isolate 26-95: sequence similarities to Kaposi's sarcoma-associated herpesvirus and rhesus monkey rhadinovirus isolate 17577.

The primary sequence of the long unique region L-DNA (L for low GC) of rhesus monkey rhadinovirus (RRV) isolate 26-95 was determined. The L-DNA consists of 130,733 bp that contain 84 open reading frames (ORFs). The overall organization of the RRV26-95 genome was found to be very similar to that of human Kaposi sarcoma-associated herpesvirus (KSHV). BLAST search analysis revealed that in almost all cases RRV26-95 coding sequences have a greater degree of similarity to corresponding KSHV sequences than to other herpesviruses. All of the ORFs present in KSHV have at least one homologue in RRV26-95 except K3 and K5 (bovine herpesvirus-4 immediate-early protein homologues), K7 (nut-1), and K12 (Kaposin). RRV26-95 contains one MIP-1 and eight interferon regulatory factor (vIRF) homologues compared to three MIP-1 and four vIRF homologues in KSHV. All homologues are correspondingly located in KSHV and RRV with the exception of dihydrofolate reductase (DHFR). DHFR is correspondingly located near the left end of the genome in RRV26-95 and herpesvirus saimiri (HVS), but in KSHV the DHFR gene is displaced 16,069 nucleotides in a rightward direction in the genome. DHFR is also unusual in that the RRV26-95 DHFR more closely resembles HVS DHFR (74% similarity) than KSHV DHFR (55% similarity). Of the 84 ORFs in RRV26-95, 83 contain sequences similar to the recently determined sequences of the independent RRV isolate 17577. RRV26-95 and RRV17577 sequences differ in that ORF 67.5 sequences contained in RRV26-95 were not found in RRV17577. In addition, ORF 4 is significantly shorter in RRV26-95 than was reported for RRV17577 (395 versus 645 amino acids). Only four of the corresponding ORFs between RRV26-95 and RRV17577 exhibited less than 95% sequence identity: glycoproteins H and L, uracil DNA glucosidase, and a tegument protein (ORF 67). Both RRV26-95 and RRV17577 have unique ORFs between positions 21444 to 21752 and 110910 to 114899 in a rightward direction and from positions 116524 to 111082 in a leftward direction that are not found in KSHV. Our analysis indicates that RRV26-95 and RRV17577 are clearly independent isolates of the same virus species and that both are closely related in structural organization and overall sequence to KSHV. The availability of detailed sequence information, the ability to grow RRV lytically in cell culture, and the ability to infect monkeys experimentally with RRV will facilitate the construction of mutant strains of virus for evaluating the contribution of individual genes to biological properties.

Amino Acid Sequence↗

State of adenovirus 2 deoxyribonucleic acid in the nucleus and its mode of transcription: studies with isolated viral deoxyribonucleic acid-protein complexes and isolated nuclei.

Newly replicated adenovirus 2 deoxyribonucleic acid (DNA) can be isolated from the nucleus of HeLa cells by a gentle lysis procedure as a fairly homogeneous complex with a sedimentation of 73S. The viral DNA complex can be prepared completely free from host cell DNA. The viral complex is slightly active in ribonucleic acid (RNA) synthesis in vitro. Treatment of the complex with Pronase and sodium dodecyl sulfate converts the DNA to a form which sediments at 43S. Nuclei isolated from adeno-infected cells synthesize high-molecular-weight virus-specific RNA in vitro. Optimal RNA synthesis requires a divalent cation, preferentially manganese, and relatively high salt concentrations. The synthesis of virus-specific RNA by the isolated nuclei is strongly inhibited by low doses of alpha-amanitine. The latter experimental result is discussed in terms of the polymerase used to transcribe the adenovirus DNA in vivo.

Adenoviridae↗

Hyperkalemia enhances the effect of adenosine on IK,ADO in rabbit isolated AV nodal myocytes and on AV nodal conduction in guinea pig isolated heart.

BACKGROUND: The atrioventricular (AV) node is insensitive to changes in extracellular potassium concentration, [K+]o, because of the absence of the inward rectifier potassium current (IK1). However, we propose that in the presence of adenosine, elevated [K+]o should increase the adenosine-activated inward rectifier potassium current (IK,ADO) in AV nodal myocytes and hence augment the negative dromotropic effect of the nucleoside. METHODS AND RESULTS: The effects of normal (4.8 mmol/L) and high (8.0 mmol/L) [K+]o on adenosine-induced changes in resting membrane potential (Vm), IK,ADO, and membrane resistance (Rm) in rabbit isolated AV nodal myocytes and in AV nodal conduction delay (atrium-to-His bundle, AH, interval) in guinea pig isolated hearts were determined with the use of whole-cell patch-clamp and His bundle electrogram techniques, respectively. High [K+]o alone did not significantly affect membrane current, Rm, or Vm in AV nodal myocytes. However, high [K+]o in the presence of adenosine (3 micromol/L) markedly increased Im (-0. 249+/-0.038 to -0.571+/-0.111 nA, P<0.05) at -100 mV and reduced Rm (151+/-21 to 77+/-8 MOmega, P<0.02). Adenosine still hyperpolarized Vm from -48+/-2 to -65+/-1 mV (P<0.001). High [K+]o alone did not significantly affect the AH interval in isolated hearts. However, high [K+]o markedly lengthened the AH interval prolongation caused by adenosine (4 micromol/L, 7.9+/-0.8 vs 22.1+/-3.0 ms, P<0.001). The potentiating effect of high [K+]o on adenosine-induced delay in AV nodal conduction was abolished by BaCl2 (100 micromol/L). CONCLUSIONS: By increasing IK,ADO and decreasing Rm of AV nodal myocytes, elevated [K+]o, augments the depressant effect of adenosine on AV nodal conduction.

Adenosine↗

Isolation of swine infertility and respiratory syndrome virus (isolate ATCC VR-2332) in North America and experimental reproduction of the disease in gnotobiotic pigs.

A recent epizootic of swine infertility and respiratory syndrome (SIRS) in a Minnesota swine herd was investigated. Examination of a sow, neonatal piglets, and stillborn fetuses obtained during the epizootic from the affected herd revealed interstitial pneumonitis, lymphomononuclear encephalitis, and lymphomononuclear myocarditis in the piglets and focal vasculitis in the brain of the sow. Fetuses did not have microscopic lesions. No cause for the infertility and respiratory syndrome was determined. Therefore, attempts were made to experimentally reproduce the disease. Eleven 3-day-old gnotobiotic piglets exposed intranasally to tissue homogenates of piglets from the epizootic became inappetent and febrile by 2-4 days postexposure and had interstitial pneumonitis and encephalitis similar to that seen in the field outbreak. After 2 blind passages in gnotobiotic piglets, tissue homogenates were cultured on continuous cell line CL2621, and a cytopathic virus (ATCC VR-2332), provisionally named SIRS virus, was isolated. Gnotobiotic piglets exposed intranasally to the SIRS virus developed clinical signs and microscopic lesions that were the same as those in piglets exposed to the tissue homogenates, and the virus was reisolated from their lungs. This is the first isolate of SIRS virus in the United States that fulfills Koch's postulates in producing the respiratory form of the disease in gnotobiotic piglets and the first report of isolation and propagation of the virus on a continuous cell line (CL2621). The virus is designated as American Type Culture Collection VR-2332.

Animals↗

Isolation of nucleic acid binding proteins: an approach for isolation of cell surface, nucleic acid binding proteins.

An approach for isolation of cell surface, nucleic acid binding proteins is described. This approach relies on affinity modification of the proteins of living cells with reactive oligonucleotides bearing a haptenic group. Covalently modified proteins were isolated by hapten-specific affinity chromatography with subsequent SDS-PAGE. Isolated 68-kDa proteins responsible for the binding of oligonucleotides were MS/MS sequenced and identified as keratin K1, keratin K10, keratin K2e, and albumin.

Carcinoma, Squamous Cell↗

Is circumferential pulmonary vein isolation preferable to stepwise segmental pulmonary vein isolation for patients with paroxysmal atrial fibrillation?

BACKGROUND: Stepwise segmental pulmonary vein isolation (SPVI) and circumferential pulmonary vein isolation (CPVI) have been developed to treat patients with atrial fibrillation (AF), but the preferable approach for paroxysmal AF (PAF) has not been established. METHODS AND RESULTS: One hundred and ten patients with symptomatic PAF were randomized into a stepwise SPVI group (n=55) or CPVI group (n=55). Systemic SPVI combined with left atrial linear ablation tailored by inducibility of AF was performed in the stepwise SPVI group. Circumferential linear ablation around the left and right-sided pulmonary veins (PVs) guided by 3-dimensional electroanatomic mapping was performed in the CPVI group. The endpoints of ablation are non-induciblity of AF in the stepwise SPVI group and continuity of circular lesions combined with PV isolation in the CPVI group. After the initial procedures, atrial tachyarrhythmis (ATa) recurred within the first 3 months in 23 of the 55 patients (41.8%) who underwent stepwise SPVI and in 20 of the 55 patients (36.4%) who had CPVI (p=0.69). Repeat procedures were performed in 7 patients from the stepwise SPVI group and 5 from the CPVI group (p=0.76). During the 3-9 months after the last procedure, 46 patients (83.6%) from the CPVI group and 43 (78.2%) from the stepwise SPVI group did not have symptomatic ATa while not taking anti-arrhythmic drugs (p=0.63). Severe subcutaneous hematoma or PV stenosis occurred in 3 patients. CONCLUSIONS: The efficacy of stepwise SPVI is comparable to that of CPVI for patients with PAF.

Adult↗

Activities of ACTH-potentiating substances isolated from rat serum on steroidogenesis in isolated rat adrenal cells.

Peptides that potentiate the response of adrenal cells to ACTH1-24 were isolated from rat serum. ACTH-potentiating activity was found in fractions of 9,000-40,000 in molecular weight (APS-Fr) and of smaller molecular weight (SM-Fr) on Sephadex G-100 gel filtration of the serum extract. The peptides were isolated from APS-Fr by preparative acid polyacrylamide gel electrophoresis and named d1, d, d2, e, f and g. Their molecular weights, estimated by Sephadex G-75 gel filtration, were 41,000, 33,000, 24,000, 17,500, 17,500 and 16,000, respectively. All of these peptides were glycopeptides. The isoelectric point of peptide d was 8.45 and some of the others, such as f and g, were more basic. Sodium dodecyl sulfate (SDS) polyacrylamide gel electrophoresis revealed that these peptides were decomposed into various fragments. ACTH-potentiating activity was highest in peptide d1 and lowest in peptide e. The maximum activity of peptide d was observed at 3 X 10(-8) M when steroidogenesis was induced by 9 X 10(-12) M ACTH1-24. While these peptides did not show any ACTH-like activity at any stage of isolation, the fractions of these peptides eluted from a Sephadex G-75 column showed more or less ACTH-like activity. These peptides therefore seemed to possess latent ACTH-like activity. The molecular weight of SM-Fr was smaller than ACTH1-24. The ACTH-potentiating activity of SM-Fr was low, and SM-Fr did not show any ACTH-like activity. SM-Fr therefore seems to be the smallest structure which has ACTH-potentiating activity. The similarity of these peptides to proopiomelanocortin-related substances was discussed.

Adrenal Cortex Hormones↗

Functional and metabolic effects of cardioplegia induced by a young's solution (YNG solution) as assessed in isolated atrial preparations and in isolated perfused heart preparations of the guinea pig.

p6e protective effects of Young's solution (YNG solution), a cardioplegic solution, on the myocardial function and metabolism were assessed in isolated atrial preparations and isolated perfused heart preparations of the guinea pig. In atrial preparations, the time to arrest of the contraction became shorter as the concentrations of the K+, Mg++, and K+-Mg++ solutions increased, while the time to resumption of the contraction was lengthened. There was no difference in the time to arrest between K+ and K+-Mg++ solutions, but the time to resumption was reduced with K+-Mg++ solution to about half the value with K+ solution. YNG solution represented an optimum solution for obtaining a quick cardiac arrest and quick resumption of contraction. In the isolated perfused heart, the time to arrest was similar for all the cardioplegic solutions used and the heart stopped in diastole. However, the time to arrest was longer with cold Krebs-Henseleit's solution (cold cardioplegia). The time to resumption of the contraction was the shortest with YNG solution, which yielded the highest mitochondrial respiratory control ratio (RCR) and ADP/O ratio. There was a negative correlation between the time to resumption of contraction and mitochondrial RCR or ADP/O ratio (r = -0.50 and -0.58, respectively).

Animals↗

Studies on isolated smooth muscle cells. IX. Application of papain for isolation of single smooth muscle cells from guinea-pig taenia coli.

To prepare single smooth muscle cells from the taenia coli of guinea pig, the application of papain to the enzymatic solution was examined under two conditions: 1) the isolation in a modified Tyrode solution (containing 0.18 mM Ca2+: 0.18 mM Ca2+-Tyrode solution) and 2) the isolation in a high-K+ Tyrode solution (Na+ was replaced by K+, and Ca2+ was not added: high-K+ Tyrode solution). The presence of papain during collagenase digestion reduced contamination of broken cells and cell debris. In the case of the high-K+ Tyrode solution, papain increased the yield of single cells significantly. The cells were contracted in a dose-dependent manner by Ca2+ in the high-K+ Tyrode solution and by carbachol in 0.18 mM Ca2+-Tyrode solution; furthermore, the contractions were antagonized by verapamil and atropine, respectively. Treatment with papain did not affect cell sensitivity to the stimulants. Therefore, our results suggest that the addition of papain is useful for the isolation of single cells to investigate the physiological and pharmacological characteristics of smooth muscle.

Animals↗

Establishment of a novel collagenase perfusion method to isolate rat pancreatic stellate cells and investigation of their gene expression of TGF-beta1, type I collagen, and CTGF in primary culture or freshly isolated cells.

In studies of the pathogenesis of pancreatic fibrosis, pancreatic stellate cells (PSCs) have recently gained attention. In the present study, we established a new collagenase perfusion method through thoracic aorta cannulation to isolate PSCs, and we studied gene expression of TGF-beta1, type I collagen, and connective tissue growth factor using primary cultured PSCs. Our method facilitated PSC isolation, and by our new method, 4.3 +/- 1.2 x 10(6) PSCs were obtained from a rat. In comparing the expression of these genes with that of hepatic stellate cells (HSCs), we observed a similar pattern, although PSCs expressed type I collagen gene earlier than did HSCs. These results suggest that PSCs may play an important role in fibrosis of the pancreas, as HSCs do in liver fibrosis; in addition, PSCs may exist in a preactivated state or may be more easily activated than are HSCs. We also isolated the PSCs from a WBN/Kob rat, the spontaneous pancreatitis rat, and compared the gene expression with that from a normal rat.

Animals↗

Isolation and characterization of halophilic lactic acid bacteria isolated from "terasi" shrimp paste: a traditional fermented seafood product in Indonesia.

Lactic acid bacteria from "terasi" shrimp paste, a highly popular fermented seafood in Indonesia were isolated and characterized. Viable cell counts were 10(4) to 10(6) cfu/g on MRS medium. All the isolates were catalase-negative, gram-positive cocci and were able to grow at 15% NaCl. Numerical phenotypic analysis showed that the isolates clustered into one group. However, they could be classified into two types: the Tetragenococcus halophilus group and the T. muriaticus group as revealed by a restriction fragment length polymorphism (RFLP) analysis and sequencing of the 16S rRNA gene. This study is the first to show that both species of Tetragenococcus are distributed in Indonesian fermented foods.

Colony Count, Microbial↗

Effects of lysosomal inhibitors on 125I-insulin and 125I-asialofetuin degradation by the isolated, perfused rat liver and isolated rat hepatocytes.

To further evaluate the role of the lysosomal system in insulin degradation, we have compared the effects of inhibitors of lysosomal function on the degradation of 125I-insulin with 125I-asialofetuin, a lysosomally targeted molecule, by the intact, perfused rat liver and the isolated rat hepatocyte. The inhibitors employed were chloroquine (125 microM), NH4Cl (10 mM), and leupeptin (50 micrograms/ml). In the intact, perfused liver the observed inhibition of 125I-asialofetuin degradation at 30 min was as follows: chloroquine, 38%; NH4Cl, 32%; and leupeptin, 86%. Chloroquine also inhibited 125I-insulin degradation in the intact, perfused liver (29%), but NH4Cl and leupeptin had no effect. Using the isolated hepatocyte, the observed values for inhibition of 125I-asialofetuin at 60 min were: chloroquine, 85%; NH4Cl, 76%; and leupeptin, 81%. Chloroquine produced a 28% inhibition of 125I-insulin degradation, while NH4Cl and leupeptin had no effect. Chloroquine and NH4Cl decreased cell-associated radioactivity when isolated hepatocytes were incubated with 125I-asialofetuin (leupeptin had no effect), whereas chloroquine caused a 107% increase in cell-associated radioactivity when 125I-insulin was added to the incubation media (NH4Cl and leupeptin had no effect). These results indicate that the effects of chloroquine on insulin degradation are an extralysosomal action and that lysosomes appear not to be involved in the physiologic degradation of the insulin molecule.

Ammonium Chloride↗

Resistance pattern of 2816 isolates isolated from 17631 blood cultures and etiology of bacteremia and fungemia in a single cancer institution.

The resistance pattern of 2816 isolates from 17631 blood cultures and the etiology of isolates causing bacteremia and fungemia among 14591 admissions were investigated in an 80-bed single cancer institute during seven years (1990-1996) under the same empiric therapeutic antibiotic policy but with different prophylactic strategies. No change was found in the proportion of Gram-positive versus Gram-negative bacteria isolated from bacteremias (70% vs. 30%) during the past seven years. Furthermore, the proportion of coagulase-negative staphylococci and enterococci was about the same before and after the introduction of ofloxacin in prophylaxis. However, the proportion of Pseudomonas aeruginosa and Stenotrophomonas maltophilia causing bacteremia increased. There was no increase in Candida krusei and Candida glabrata after the introduction of fluconazole into our prophylactic regimen in 1992. Penicillin-resistance in viridans streptococci increased after penicillin was introduced into prophylaxis in acute leukemia in 1993. Until 1995 no quinolone-resistant Enterobacteriaceae were observed. Susceptibility to quinolones did not significantly change within the past seven years in Enterobacteriaceae after their introduction to prophylaxis in 1991, but Pseudomonas aeruginosa decreased from 90 to 58.2%. Glycopeptide resistance in enterococci and staphylococci was minimal in the observed period (0.9-4.3%).

Aminoglycosides↗

Effects of stroma-free hemoglobin solutions on isolated perfused rabbit hearts and isolated perfused rat kidneys.

"Stroma-free" hemoglobin solutions (SFH) cause hemodynamic alterations indicative of vasoconstriction. We studied vasoconstrictor activity in isolated rabbit hearts and rat kidneys of unmodified SFH and of SFH modified by pyridoxylation or glyoxylation, with or without glutaraldehyde cross-linking. The purity and chemical composition of the solutions, all prepared by other laboratories, were not characterized by us. In isolated hearts SFH prepared by conventional methods had potent vasoconstrictor activity. Pyridoxylation or purification by ion exchange chromatography did not alter the constrictor activity. Decreased constrictor activity was observed with human SFH cross-linked by glutaraldehyde treatment, or purified by affinity chromatography, and with bovine SFH purified by ultrafiltration and preparative HPLC. In isolated kidneys modified and unmodified SFH increased renal vascular resistance and decreased glomerular filtration rate with no morphologic evidence of tubular damage.

Animals↗

An isolate of Arthroderma benhamiae with Trichophyton mentagrophytes var. erinacei anamorph isolated from a four-toed hedgehog (Atelerix albiventris) in Japan.

A female four-toed hedgehog probably imported from Africa and kept as a pet by a family suffered from depilation and mite (Caparinia tripilis) infection. Depilated quills were inoculated on a commercially available medium and an isolate of the dermatophytes was obtained. A giant colony after 14 days incubation on yeast extract Sabourauds agar had a central umbo with white granular surface and a yellow pigment ring in the reverse. The hedgehog isolate produced numerous elongated microconidia singly attached along the sides of hyphae. Macroconidia were somewhat irregular in shape and size and 2-6 septa. Abundant intermediate sized spores between micro- and macro conidia and few spirals were observed. Hair perforation and urease activity tests were positive. Maximum growth temperature was 40 C. In the mating tests using the tester strains of both African and Americano-European races of Arthroderma benhamiae, the strain produced numerous gymnothecia only when paired with the African race mating type minus(-). In addition, 591 bases of the internal transcribed spacer region of the ribosomal RNA gene including the 5.8S region (ITS1-5.8S-ITS2) were sequenced and corresponded to those of T. mentagrophytes var. erinacei (DDBJ/EMBL/GenBank accession numbers Z97996 and Z97997) by more than 99.7%. Therefore, our case is the first isolation of A. benhamiae with T. mentagrophytes var. erinacei anamorph in Japan.

Animals↗

Nocardia anaemiae sp. nov. isolated from an immunocompromised patient and the first isolation report of Nocardia vinacea from humans.

Two actinomycete strains that were isolated from patients in Japan were assigned provisionally to the genus Nocardia based on their morphological characteristics. The two isolates were further studied to determine their specific taxonomic status. Detailed chemotaxonomic characterization and 16S rDNA sequence data for the strains showed that they are most similar to Nocardia vinacea. DNA-DNA hybridization experiments indicated that strain IFM 0344 should be identified as N. vinacea, and that strain IFM 0323T is classifiable as a new species. This report describes the first isolation of N. vinacea from clinical samples. A new species of the genus Nocardia is proposed based on their phenotypic and phylogenetic characteristics: Nocardia anaemiae for IFM 0323T (=NBRC 100462T=JCM 12396T=DSM 44821T).

DNA, Ribosomal↗