Rapid membrane capture PCR-based method for detection of Listeria species.
Explore the source record for details and available documents.
Bacterial Adhesion↗
Biomedical subjects
L O'Connor
Publications and source records attributed to L O'Connor.
Emigration of mature T cells from the thymus is inhibited by the imidazole-based compound 2-acetyl-4-tetrahydroxybutylimidazole.
The primary role of the thymus is to provide mature T cells for the peripheral immune system. The mechanisms involved in the cellular export processes are as yet unknown. In this study, we examined the ability of 2-acetyl-4-tetrahydroxybutylimidazole (THI), an agent widely used as a component of ammonia caramel food colouring, to inhibit T-cell export from the thymus. BALB/c mice were maintained on drinking water containing THI for 5 days. The mice showed a twofold increase in the total number of mature medullary thymocytes (CD4+CD8- and CD4-CD8+) as well as a slight decrease in the total number of immature double-positive cells (CD4+CD8+). The mature single-positive thymocytes were found to express high levels of the homing molecule L-selectin, suggesting that these potential emigrants were prevented from leaving the thymus. To confirm this, THI-treated mice were injected intrathymically with fluorescein isothiocyanate and the number of labelled T cells appearing in the lymph nodes and spleen was determined 16 hr later. A 10-fold decrease in the number of CD4+ and CD8+ recent thymic emigrants in the lymph nodes and spleen of THI-treated mice was observed. Previous studies have shown that THI does not affect other aspects of thymocyte development, such as proliferation and differentiation. Taken together, these results suggest that the immunosuppressive effects of THI may be due, in part, to preventing of the final step of T-cell export out of the thymus.
Animals↗
Rapid hybridoma screening method for the identification of monoclonal antibodies to low-abundance cytoplasmic proteins.
Screening assays are the most time-consuming and labor-intensive part of generating monoclonal antibodies (MAbs). Antibodies identified by enzyme-linked immunosorbent assay (ELISA) screening often are not suitable for their intended application such as immunofluorescence staining. We describe here a rapid and efficient flow cytometric screening procedure for the identification of MAbs directed against low-abundance cytoplasmic proteins, in our case, the pro-apoptotic molecule Bim. Cells from an equal mixture of a parental cell line and a subline expressing Bim were fixed, permeabilized and incubated with hybridoma supernatants. The supernatants were derived from a fusion of Sp2/0 plasmacytoma cells and spleen cells from a rat immunized with recombinant glutathione-S-transferase (GST)-BimL fusion protein. Secondary staining with fluorochrome-labeled anti-rat Ig antibodies allowed detection of clones expressing Bim-specific antibodies. The screening procedure was rapid and efficient, and most monoclonal antibodies identified were proven to be useful for immunofluorescence staining and other applications.
Animals↗
A legend in ET nursing: a tribute to the memory of Ruth Kules, RN, CETN.
Explore the source record for details and available documents.
History, 20th Century↗
AbiG, a genotypically novel abortive infection mechanism encoded by plasmid pCI750 of Lactococcus lactis subsp. cremoris UC653.
AbiG is an abortive infection (Abi) mechanism encoded by the conjugative plasmid pCI750 originally isolated from Lactococcus lactis subsp. cremoris UC653. Insensitivity conferred by this Abi manifested itself as complete resistance to phi 712 (936 phage species) with only partial resistance to phi c2 (c2 species). The mechanism did not inhibit phage DNA replication. The smallest subclone of pCI750 which expressed the Abi phenotype contained a 3.5-kb insert which encoded two potential open reading frames. abiGi (750 bp) and abiGii (1,194 bp) were separated by 2 bp and appeared to share a single promoter upstream of abiGi. These open reading frames showed no significant homology to sequences of either the DNA or protein databases; however, they did exhibit the typical low G+C content (29 and 27%, respectively) characteristic of lactococcal abi genes. In fact, the G+C content of a 7.0-kb fragment incorporating the abiG locus was 30%, which may suggest horizontal gene transfer from a species of low G+C content. In this context, it is notable that remnants of IS elements were observed throughout this 7.0-kb region.
Amino Acid Sequence↗
Lessons from bcl-2 transgenic mice for immunology, cancer biology and cell death research.
The protein product of the proto-oncogene bcl-2, originally discovered by virtue of its chromosomal translocation in human follicular centre B cell lymphoma, is a physiological inhibitor of programmed cell death, apoptosis. Initial studies in transgenic mice overexpressing Bcl-2 in B or T lymphocytes demonstrated that Bcl-2 can potently antagonise cell death induced by multiple independent signal transduction routes and can contribute to oncogenesis, particularly in combination with other oncogenes, like c-myc, that promote cell proliferation. Further investigations using crosses between bcl-2 transgenic mice and T cell receptor or immunoglobulin transgenic mice or mutant mice deficient in proper antigen receptor gene rearrangement demonstrated that Bcl-2 can only block death of cells that failed to receive a positive stimulus, "death by neglect', but not activation induced apoptosis. Collectively, these results provide evidence that distinct signalling pathways for apoptosis converge upon a common effector machinery where Bcl-2 acts as an antagonist, but that there also exists a mechanism that can either bypass the Bcl-2 checkpoint or override its protective function. These experimental data are reviewed here and discussed in context of current knowledge of lymphocyte differentiation, tumorigenesis and cell death regulation.
Animals↗
Relation of activity levels to body fat in infants 6 to 12 months of age.
We examined longitudinally the relation between body fatness and physical activity, adjusting for energy intake, in 31 healthy white infants. Measures of physical activity, dietary intake, and body composition were obtained at 6, 9, and 12 months of age. The percentage of body fat was inversely related to activity level, an association that became stronger with increasing age and remained significant after adjustment for dietary energy intake. The percentage of body fat was not related to energy consumed per lean body mass regardless of high or low activity level, nor was energy consumed related to physical activity. We conclude that the percentage of body fat in infants may be related more to their activity levels than to their energy intake.
Adipose Tissue↗
Pain assessment by patients and nurses, and nurses' notes on it, in early acute myocardial infarction. Part I.
Pain is a multi-dimensional phenomenon unique to each individual. Most of the research to date on acute pain has focused on oncology, medical and surgical patients. This pilot study was designed to explore the issues of pain assessment by patients and nurses in acute myocardial infarction, and the nurses' subsequent documentation of the pain assessment. Three research instruments were chosen to elicit the information required: A demographic questionnaire was constructed to elicit relevant data on patients and nurses. The Short Form McGill Pain Questionnaire (SFMPQ) was used to measure the quality and quantity of the patient's pain as perceived by the patient and nurse in a myocardial infarction situation. The Chart Audit Information Form (CAIF) was chosen to extract specific information from the nursing notes on the pain experience as recorded by the nurse. A convenience sample of patients comprised 10 males and 5 females. The nursing population comprised a convenience sample of 8 registered nurses holding a recognised coronary care course certificate. The pilot study was conducted in a coronary care unit (CCU) in a large teaching hospital in Dublin, Ireland. The data generated from the SFMPQ and the CAIF were coded prior to computerisation. Descriptive statistics were used to analyse the data. The findings of this pilot study indicated that nurses underestimated the patient's pain in 46% of myocardial infarction situations and overestimated in 13% of them. Furthermore, results indicated that while the majority of nurses documented location and verbal statements of pain, the documentation of quality, intensity and duration of pain was inadequate.(ABSTRACT TRUNCATED AT 250 WORDS)
Female↗
Pain assessment by patients and nurses, and nurses' notes on it, in early acute myocardial infarction. Part 2.
Explore the source record for details and available documents.
Adult↗
Analyzing the surgical hand scrub using CQI.
Explore the source record for details and available documents.
Disinfectants↗
Adverse effects of paternal opiate exposure on offspring development and sensitivity to morphine-induced analgesia.
We have shown previously that chronic morphine administration to adolescent male rats produced a number of gender specific deficits in their offspring. The purpose of the present studies was to extend our earlier observations by examining the acute, direct effects of morphine exposure to male rats on their fertility and the development of viable offspring. Sexually mature male rats were injected with a single dose of morphine (25 mg/kg) and 24 hr later were bred with drug-naive females. Fertility rates (vaginal plugs and pregnancies) were monitored throughout the breeding period as was the development of the offspring. Our results showed that a large, acute dose of morphine given to drug-naive male rats 24 hr before the initiation of breeding had no effect on fertility rates, but produced several adverse effects on fetal outcome. Litter sizes in morphine-derived offspring were considerably smaller than in controls and mortality rates were more than 6 times higher. Moreover, morphine-derived male, but not female, offspring had a significantly enhanced sensitivity to the antinociceptive effects of morphine. Collectively, these data suggest that acute paternal morphine exposure just before breeding with drug-naive females had no effect on fertility, but exerted negative effects on the viability and development of their offspring. These results represent the most compelling evidence to date that paternal opiate exposure can adversely affect fetal outcome and are particularly striking in that they were produced by a single injection of morphine. We are aware of no animal studies, clinical cases or anecdotal reports in humans in which such a phenomenon has been described.
Analgesia↗
Acute alcohol exposure markedly influences male fertility and fetal outcome in the male rat.
Although it is recognized that drugs ingested by pregnant females produce marked cognitive and physiological deficits in their offspring, the possibility that paternal exposure to drugs prior to mating may have adverse effects on fertility and fetal outcome has not received much attention. The purpose of the present studies was to examine whether a single, acute exposure to alcohol influences the subsequent ability of adult male rats to mate and produce healthy and viable litters. Our results showed that a relatively large dose of alcohol 24 hours prior to breeding had little effect on the mating behavior of male rats, but there were markedly fewer pregnancies in females mated with alcohol-exposed male rats than in controls. Of equal importance, we found that, even when conception occurred and live births were produced, there were striking differences in fetal outcome. Alcohol-treated males sired many fewer pups than control males and there was a markedly enhanced mortality rate in their offspring. Collectively, these data suggest that acute paternal alcohol administration 24 hours prior to breeding does not affect mating behavior, but results in a greatly diminished fertility rate and fewer and less viable offspring. These studies suggest that paternal alcohol use may be as important as maternal alcohol abuse as a negative variable in pregnancy and fetal outcome.
Animals↗
Efficacy of postoperative pain treatment regimens using both buprenorphine and papaveretum sequentially after abdominal hysterectomy.
We have undertaken a double-blind, controlled study to test the hypothesis that the efficacy of standard postoperative analgesia by papaveretum or buprenorphine is not compromised by previous or subsequent standard doses of the other agent. After total abdominal hysterectomy under a standardized general anaesthetic, 120 patients (four groups of 30) were allocated randomly to receive, on demand, a single i.v. dose of buprenorphine 0.15 mg or papaveretum 10 mg, followed sequentially by a single dose of i.m. buprenorphine 0.3 mg or papaveretum 20 mg. Three hours after the i.m. dose, all patients received sublingual buprenorphine 0.4 mg. Pain was scored using both a 10-cm horizontal visual analogue scale (VAS) and a nominal scale. Pain intensity differences and patient and nurse satisfaction with the regimens were recorded. Observations were continued for 8 h after operation. The efficacy of papaveretum or buprenorphine was not compromised by previous or subsequent standard doses of the other agent. All four treatment regimens were similarly well tolerated and gave acceptable analgesia in the immediate postoperative period.
Adolescent↗
A new focus of scrub typhus in tropical Australia.
A new focus of scrub typhus (Rickettsia tsutsugamushi) is described in a remote rain forest region of the Northern Territory of Australia. Five serologically confirmed cases, two near fatal with multisystem involvement, have occurred since the area became accessible to tourists. As tourism increases, other remote foci of vectors and organisms may also be recognized in tropical Australia.
Adult↗
Naloxone does not reverse the inhibitory effect of morphine on luteinizing hormone secretion in prepubescent male rats.
Morphine and naloxone exert age-dependent effects on secretion of luteinizing hormone (LH) in the male rat. Morphine suppresses LH secretion at very early stages of development, well before puberty, whereas naloxone does not increase LH until after puberty. The mechanisms underlying these age-dependent effects of opiates on the hypothalamic-pituitary-gonadal axis in pre- and postpubertal rats are poorly understood at the present time. The purpose of the present studies was to examine one plausible explanation of these effects: that morphine and naloxone act through different receptors in the pubescent male rat than they do in adults to influence LH secretion. Specifically, we examined whether naloxone blocks the effects of morphine on LH in prepubescent and adult rats which would be anticipated if both drugs were exerting their effects on LH via the same opiate receptor. Surprisingly, we found that naloxone did not reverse the effects of morphine on serum LH levels in the prepubescent animal, although it fully reversed this effect in adults. This non-naloxone-reversible effect of morphine appeared to be specific to LH, since naloxone antagonized morphine's effects on several other hormones (e.g., prolactin and corticosterone) and completely attenuated morphine's antinociceptive activity in prepubescent rats. Additionally, naloxone precipitated a withdrawal syndrome in the prepubescent morphine-dependent animal that was quantitatively and qualitatively the same as in adults.(ABSTRACT TRUNCATED AT 250 WORDS)
Aging↗
Life cycle issues affecting cancer rehabilitation.
Developmental stage of the person with cancer has a profound effect on the rehabilitation plan. Although the issues faced by the very young and the elderly are quite different, the struggle to maintain optimal function is universal. As we continue to see improved survival rates and cures, the need for comprehensive rehabilitative care for all persons experiencing cancer becomes a challenge. Our success in meeting this challenge will be realized in measurable outcomes that will direct future rehabilitative care.
Aged↗
Influence of morphine exposure during adolescence on the sexual maturation of male rats and the development of their offspring.
The effects of adolescent morphine exposure on the sexual maturation of male rats, their reproductive capacity and the development of their progeny were examined. Groups of prepubescent male rates (25-27 days of age) were implanted with morphine- or placebo-pellets (one on Day 1, then two pellets on Days 4, 7 and 10); the pellets were not removed to assure the sustained release of morphine for 3 to 4 weeks and to avoid the confounding effects of a precipitated withdrawal syndrome. Groups of animals were sacrificed at weekly intervals through adulthood for an assessment of reproductive endocrine function. A large group, however, was also bred with drug-naive primiparous females at 85 days of age (8 weeks after morphine or placebo pellet implantation), when the acute and chronic effects of morphine on reproductive endocrine parameters had dissipated; their fertility and the development of the male and female progeny was characterized. Our results indicated that morphine exposure during adolescence led to a pronounced inhibition of a number of indices of sexual maturation (e.g., serum testosterone and luteinizing hormone levels and reduced weights of the testes and seminal vesicles). Breeding morphine- and placebo-implanted male rats with drug-naive females resulted in smaller liters derived from morphine-treated fathers when compared to controls, but in all other respects the development of the offspring in the two groups were equivalent. However, upon reaching adulthood, a number of selective endocrine differences were detected in morphine-derived offspring when compared to controls.(ABSTRACT TRUNCATED AT 250 WORDS)
Animals↗
A specific inhibitor of the ubiquitin activating enzyme: synthesis and characterization of adenosyl-phospho-ubiquitinol, a nonhydrolyzable ubiquitin adenylate analogue.
A nonhydrolyzable analogue of ubiquitin adenylate has been synthesized for use as a specific inhibitor of the ubiquitination of proteins. Ubiquitin adenylate is a tightly bound intermediate formed by the ubiquitin activating enzyme. The inhibitor adenosyl-phospho-ubiquitinol (APU) is the phosphodiester of adenosine and the C-terminal alcohol derived from ubiquitin. APU is isosteric with the normal reaction intermediate, the mixed anhydride of ubiquitin and AMP, but results from the replacement of the carbonyl oxygen of Gly76 with a methylene group. This stable analogue would be expected to bind to both ubiquitin and adenosine subsites and result in a tightly bound competitive inhibitor of ubiquitin activation. APU inhibits the ATP-PPi exchange reaction catalyzed by the purified ubiquitin activating enzyme in a manner competitive with ATP (Ki = 50 nM) and noncompetitive with ubiquitin (Ki = 35 nM). AMP has no effect on the inhibition, confirming that the inhibitor binds to the free form of the enzyme and not the thiol ester form. This inhibition constant is 10-fold lower than the dissociation constants for each substrate and 30-1000-fold lower than the respective Km values for ubiquitin and ATP. APU also effectively inhibits conjugation of ubiquitin to endogenous proteins catalyzed by reticulocyte fraction II with an apparent Ki of 0.75 microM. This weaker inhibition is consistent with the fact that activation of ubiquitin is not rate limiting in the conjugation reactions catalyzed by fraction II. APU is similarly effective as an inhibitor of the ubiquitin-dependent proteolysis of beta-lactoglobulin.(ABSTRACT TRUNCATED AT 250 WORDS)
Adenosine Monophosphate↗