Recovery of an unusual Gram-negative bacterium from ulcerated rainbow trout, Oncorhynchus mykiss (Walbaum), in Scotland.
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Animals↗
Biomedical subjects
D A Austin
Publications and source records attributed to D A Austin.
Recovery of a new biogroup of Yersinia ruckeri from diseased rainbow trout (Oncorhynchus mykiss, Walbaum).
Cultures of a new biogroup of Yersinia ruckeri, the causal agent of enteric redmouth (ERM), were recovered in England from diseased rainbow trout (Oncorhynchus mykiss, Walbaum), which had been previously vaccinated with a commercial ERM vaccine. The bacterial isolates were confirmed as Y. ruckeri by the results of sequencing the 16S rRNA, but differed from the characteristics of the taxon by positivity for the Voges Proskauer reaction and a general lack of motility, and could not be equated with any of the existing serovars. Cultures were pathogenic in laboratory-based infectivity experiments with 100% mortalities occurring in juvenile rainbow trout (average weight = 10 g) within 4-days of intraperitoneal or intramuscular injection with 10(5) cells/fish. Protection against disease was achieved using a formalin-inactivated whole vaccine prepared against a representative isolate.
Agglutination Tests↗
Insulin activates phospholipase C-gamma1 via a PI-3 kinase dependent mechanism in 3T3-L1 adipocytes.
Previously we have shown that the insulin receptor and phospholipase C-gamma1 physically interact in the 3T3-L1 adipocyte cell line. In this study, we investigated the ability of insulin and PDGF to stimulate PLC-gamma1 enzyme activity as measured by PI-(4,5)P(2) hydrolysis. Both insulin and PDGF caused a rapid (<1 min) increase in PLC activity associated with the respective receptor. PDGF treatment resulted in a higher and more sustained stimulation of PLC-gamma1 activity compared to insulin (0.95 pmol/min/mg vs 0.68 pmol/min/mg). Furthermore, insulin and PDGF promoted increases in total cellular DAG, one of the products of PI-(4,5)P(2) hydrolysis. Insulin-stimulated PLC activity appears to be downstream of PI-3Kinase as the DAG increase was partially blocked by Wortmannin and addition of PI-(3,4,5)P(3) activated PLC-gamma1 in vitro. Inhibition of PLC using U73122 or an inhibitory peptide caused a decrease in insulin-stimulated 2-deoxyglucose transport and GLUT4 translocation that was rescued by the addition of OAG, a cell-permeable synthetic DAG.
3T3 Cells↗
Stimulation of MAPK cascades by insulin and osmotic shock: lack of an involvement of p38 mitogen-activated protein kinase in glucose transport in 3T3-L1 adipocytes.
Osmotic shock and insulin stimulate GLUT4 translocation and glucose transport via mechanisms that are for the most part distinct yet convergent. In this article, we investigated the effect of osmotic shock and insulin on the activation of the mitogen-activated protein kinase (MAPK) cascades in differentiated 3T3-L1 adipocytes. The MAPKs are activated by phosphorylation on conserved tyrosine and threonine residues. Both sorbitol and insulin strongly stimulated extracellular regulated kinase (ERK) 1 and 2 phosphorylation (8- and 18-fold, respectively). In contrast, c-jun-NH2-terminal kinase (JNK)/stress-activated protein kinase (SAPK) phosphorylation was stimulated only by sorbitol (sevenfold) and not by insulin. Phosphorylation of p38 MAPK was stimulated strongly by sorbitol (22-fold) but weakly by insulin (2.7-fold). Measurement of intrinsic JNK and p38 MAPK activity confirmed the phosphorylation studies. JNK and p38 MAPK were activated only significantly by sorbitol. The MAPKs are phosphorylated by dual-specificity kinases (mitogen-activated ERK-activating kinase [MEK] or MAPK kinase [MKK]). As expected, sorbitol and insulin both stimulated MEK phosphorylation. MKK4 was phosphorylated only in response to sorbitol, and neither of the stimuli caused phosphorylation of MKK3 or 6. To determine the functional significance of the observed activation of p38 MAPK in response to insulin and osmotic shock, we used three pyridinyl imidazole p38 MAPK inhibitors, SB203580, SB202190, and PD169316. Insulin and osmotic shock-stimulated glucose transport was not inhibited by any inhibitor at concentrations that were shown to block p38 MAPK activity. Furthermore, activation of the p38 MAPK pathway by treatment of cells with anisomycin did not stimulate glucose transport. These results suggest that activation of the p38 MAPK pathway is not involved in the stimulation of glucose transport.
3T3 Cells↗
Small subunit rRNA gene sequences of Aeromonas salmonicida subsp. smithia and Haemophilus piscium reveal pronounced similarities with A. salmonicida subsp. salmonicida.
The small subunit ribosomal RNA (SSU rRNA) encoding genes from reference strains of Aeromonas salmonicida subsp. smithia and Haemophilus piscium were amplified by polymerase chain reaction and cloned into Escherichia coli cells. Almost the entire SSU rRNA gene sequence (1505 nucleotides) from both organisms was determined. These DNA sequences were compared with those previously described from A. salmonicida subsp. salmonicida, subsp. achromogenes and subsp. masoucida. This genetic analysis revealed that A. salmonicida subsp. smithia and H. piscium showed 99.4 and 99.6% SSU rRNA gene sequence identity, respectively, with A. salmonicida subsp. salmonicida.
Aeromonas↗
An improved growth medium for Flavobacterium psychrophilum.
Supplementing cytophaga agar and broth with 0.5 g l-1 each of D(+) galactose, D(+) glucose, L-rhamnose and skimmed milk gave a dramatic improvement in the isolation of the fish pathogen Flavobacterium psychrophilum. By means of spread-plating, approximately double the number of colonies of larger size were obtained on the improved medium compared to cytophaga agar alone. In supplemented cytophaga broth, growth of Fl. psychrophilum was more rapid and generated greater biomass.
Animals↗
Vibrios associated with mortality in cultured plaice Pleuronectes platessa fry.
Fifty two bacterial strains, identified as Vibrio spp., were isolated from diseased plaice fry. The most numerous group comprised V. anguillarum (26/52), of which 3 isolates belonged to serogroup O2a, 16 corresponded to serogroup O18, and 7 isolates were non-typeable. All serogroup O18 isolates had identical ribotype patterns. Fourteen isolates were identified as V. splendidus biotype I (n = 11) or V. splendidus-like (n = 3). Seven isolates were V. fluvialis, representing the first isolation of this species in Denmark and the first description of V. fluvialis associated with diseased fish. All V. fluvialis isolates had identical ribotype patterns, indicating the presence of a single clone. The last 5 isolates belonged to 2 different, unidentified Vibrio species (n = 2 and 3, respectively). Although all isolates were recovered from diseased plaice fry, their exact role as pathogens for the fry is as yet uncertain. Selected isolates were tested for virulence to salmon and turbot. When injected into juvenile salmonid fish, the recorded LD50 values were higher than 10(6), indicating that their virulence was relatively low. However, virulence seemed to deteriorate upon subculturing, and therefore, the strains may have been more virulent upon primary isolation from the plaice fry.
Animals↗
Characterization of atypical Aeromonas salmonicida by different methods.
Fifty two isolates of atypical Aeromonas salmonicida, recovered from a wide range of hosts and geographical locations, were heterogeneous in terms of molecular and phenotypic characteristics, and represented taxa which could not be accommodated by the current classification of four subspecies. Generally, there was incongruence between the molecular (PCR, RAPD and ribotyping) and phenotypic methods in terms of cluster membership. By PCR, 6 groups were described of which Group 1 encompassed 12 isolates including the type strain of A. salmonicida subsp. smithia. Group 2 accommodated 23 isolates including the reference cultures of subspecies achromogenes and masoucida. The named culture of Haemophilus piscium was recovered in Group 6. By ribotyping and RAPD, the reference cultures were recovered in separate groups. All methods pointed to the uniqueness of subspecies smithia. Most isolates contained 2-6 plasmids, of 2.3 to 150 kb in length. Nevertheless, all isolates possessed certain key characteristics, including Gram-negativity, and the absence of motility.
Aeromonas↗
Isolation of Aeromonas salmonicida in association with purple-pigmented bacteria in sediment from a Scottish loch.
Aeromonas salmonicida was recovered in close association with an unidentified purple-pigmented organism, which was isolated from sediment in a Scottish loch during November (1997) and February (1998). However, there has not been any evidence of A. salmonicida infections, specifically furunculosis, associated with the fish in this loch.
Aeromonas↗
Typing of the fish pathogen Listonella (Vibrio) anguillara by pyrolysis mass spectrometry.
Twenty-eight representatives of Listonella (Vibrio) anguillara serovars O1, O2 and O3 were compared by Curie-point pyrolysis mass spectrometry (PyMS). The representatives of serovars O1 and O3 formed discrete, homogeneous groups in ordination plots of the PyMS data. Strains from serovar O2 were recovered in two groups, one of which encompassed six strains including the type strain of the species and the reference strain for serovar O2, and the other included two strains which showed cross-reactions between serovars O2 and O5. The almost complete agreement found between the PyMS and the serological data suggests that pyrolysis mass spectrometry will prove to be an effective method for interstrain comparison within the species Listonella anguillara.
Animals↗
Pathogenicity of Vibrio anguillarum serogroup O1 strains compared to plasmids, outer membrane protein profiles and siderophore production.
The virulence of 18 strains of Vibrio anguillarum serogroup O1 was compared to plasmid content, expression of siderophores and outer membrane proteins. All strains, irrespective of plasmid content, produced siderophores and inducible outer membrane proteins under iron-limited conditions. Only strains that carried the 67 kbp virulence plasmid or derivatives of it produced the outer membrane protein, OM2. All virulent strains harboured the 67 kbp plasmid or derivatives of it, indicating its importance for virulence. However, some strains carrying the virulence plasmid or a derivative of it, produced siderophores as well as OM2 but were non-pathogenic to fish. Likewise, among the virulent strains, considerable variation in LD50 values was recorded. Plasmid profiling and restriction analysis showed that the virulence plasmid existed in various molecular weights from 26 to 80 kbp, with 65-67 kbp being the most common, and that this plasmid displayed various restriction profiles. The presence of other plasmids did not seem to affect the pathogenic properties.
Animals↗
The process of obstetric triage: management by certified nurse-midwives.
The roles for certified nurse-midwives are growing, changing, and becoming more varied with the reform of health care systems. Versatility of clinical knowledge in antepartum, intrapartum, postpartum, and gynecologic care along with advanced practice skills of assessment, diagnosis, and treatment make nurse-midwives ideal providers to perform triage for a busy obstetric service. With health care dollars more limited and more scrutinized than ever before, it becomes essential to prioritize patient needs and match them with the most appropriate resources. The article demonstrates the process of triage provided by certified nurse-midwives in a high-volume university hospital setting. It describes management guidelines and admission criteria for the birth center, high-risk labor and delivery, and the observation unit. Examples of clinical evaluations and judgments as well as scenarios are included to illustrate how triage is unique and differs from care provided in other settings.
Birthing Centers↗
Critical care obstetrics: experts' round table discussion.
A panel of leading experts in critical care obstetric (CCOB) nursing met to discuss the specialty and its future, the impact of changes in the health care system, educational opportunities to learn and update CCOB nursing, formation and use of standards for the specialty, patient placement (dedicated obstetric intensive care units [OB ICU], labor and delivery intensive care units [L & D ICU], regular intensive care units [ICU]), patient populations, and interactions and working relationships with the physicians who care for CCOB patients (perinatologists, obstetricians, internists, obstetric medicine specialists, anesthesiologists, other subspecialists). The topics for discussion were chosen by Carol J. Harvey, RNC, MS, who acted as moderator and Mary Ellen Burke, RN, MS, coordinated the publication of the discussion.
Critical Care↗
Neurologic emergencies in pregnancy.
Neurologic emergencies during pregnancy are not encountered often but contribute significantly to maternal mortality. This chapter reviews neurologic emergencies with an emphasis on pathophysiology and related nursing care for patients with epilepsy, status epilepticus, eclampsia, intracranial hemorrhage, increased intracranial pressure, ischemic stroke, myasthenia gravis, autonomic hyperreflexia, Wernicke's encephalopathy, and chorea gravidarum.
Critical Care↗
Evaluation of a strategy for changing group stereotypes of the heroin user.
This study examined characteristics attributed to a person using an illegal narcotic drug (heroin) and sought to change established stereotypes by participation in a group education experience. Prior to the main study, 100 Advanced Psychology students generated lists of adjectives they would use to describe a heroin user. The most frequently mentioned characteristics were placed in structured lists as pre- and post-test measures. Both semantic differential and open-choice formats were used. The Prevention Role Play, a recently developed strategy in drug education, was used to challenge the group's stereotypes. Significant shifts in attributions were revealed between the pre- and post-test measures. After the Role Play students reduced their negative stereotype on a number of dimensions though they still described the heroin user as confused, insecure, troubled and lonely. The discussion considers possible strategies for facilitating positive attitude change.
Journal Article↗
Valvular disease in pregnancy.
The hemodynamics of pregnancy make this a time of great risk for the cardiac patient. RHD is still the most commonly seen lesion in women of childbearing age. When the mitral valve becomes stenotic, it severely limits flow into the left ventricle, resulting in a buildup of pressure in the left atrium and possibly the pulmonary artery. These patients are at risk for pulmonary edema and a decrease in cardiac output. Intrapartum care must focus on meticulous fluid management and alleviation of pain and anxiety to avoid the tachycardiac effect.
Delivery, Obstetric↗
Parent, peer and personal determinants of adolescent drinking.
This study examined direct and indirect influences of parents and peers on adolescent drinking. One hundred and six adolescents, their parents and a same-sex best friend of the adolescent each completed measures that tapped actual and perceived drinking behaviour, and normative standards for alcohol use. Of methodological interest was that adolescents of both sexes provided accurate reports of their parents' and peer's drinking, as well as drinking norms. Path analyses revealed different effects for male and female adolescents. Strongest predictors of alcohol use for males were their perceptions of their father's and mother's drinking, and their father's actual drinking. Best friend's drinking was positively related to the adolescent males' perceptions of themselves as a drinker. The single predictor of their internalized norms was the perception adolescent males had of their friend's drinking. Significantly, the adolescent male's own norms predicted how much and what they drank. For adolescent females, how much they believed their best friend drank, and their friend's normative standards, were the strongest predictors of alcohol use. Father's drinking also influenced the drinking practices of daughters, but mothers had no impact on their daughters' alcohol use. In contrast to young males, females' personal preferences or liking of alcohol successfully predicted most of their drinking behaviour.
Adolescent↗
Reproductive problems and birth defects in survivors of Wilms' tumor and their relatives.
In a retrospective cohort study of 47 Wilms' tumor survivors and their 77 sibling controls, female survivors had a fourfold excess risk (risk ratio, 4.1; 95% confidence interval, 1.7-10.1) for any adverse livebirth outcome, including birth defects, compared with their sibling controls. Wives of male survivors had no apparent excess risk for problem pregnancies. The families had a number of severe reproductive problems and major birth defects, such as primary amenorrhea in two survivors, bicornuate uterus in two survivors and one control, and mental retardation in one male survivor and a male control. The son of a female survivor died after bilateral Wilms' tumors. Birth defects in the offspring of female survivors are compatible either with intrauterine constraint, possibly due to radiation-induced fibrosis or with the complex of malformations associated with Wilms' tumor. Female survivors of Wilms' tumor appear to be at increased risk for a variety of reproductive problems, from sterility to fetal loss, early delivery, and birth defects in offspring. Furthermore, relatives of survivors of Wilms' tumor may be at risk of having associated birth defects, with clinically significant consequences.
Adolescent↗