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Biomedical subjects

L Thompson

Publications and source records attributed to L Thompson.

At least 73 records · Page 4Linked to original sources
PubMed1995

Complete nucleotide sequence of RNA segment 3 of bluetongue virus serotype 2 (Ona-A). Phylogenetic analyses reveal the probable origin and relationship with other orbiviruses.

The nucleotide sequence of the RNA segment 3 of bluetongue virus (BTV) serotype 2 (Ona-A) from North America was determined to be 2772 nucleotides containing a single large open reading frame of 2703 nucleotides (901 amino acid). The predicted VP3 protein exhibited general physiochemical properties (including hydropathy profiles) which were very similar to those previously deduced for other BTV VP3 proteins. Partial genome segment 3 sequences, obtained by polymerase chain reaction (PCR) sequencing, of BTV isolates from the Caribbean were compared to those from North America, South Africa, India, Indonesia, Malaysia and Australia, as well as other orbiviruses, to determine the phylogenetic relationships amongst them. Three major BTV topotypes (Gould, A.R. (1987) Virus Res. 7, 169-183) were observed which had nucleotide sequences that differed by approximately 20%. At the molecular level, geographic separation had resulted in significant divergence in the BTV genome segment 3 sequences, consistent with the evolution of distinct viral populations. The close phylogenetic relationship between the BTV serotype 2 (Ona-A strain) from Florida and the BTV serotypes 1, 6 and 12 from Jamaica and Honduras, indicated that the presence of BTV serotype 2 in North America was probably due to an exotic incursion from the Caribbean region as previously proposed by Sellers and Maaroof ((1989) Can. J. Vet. Res. 53, 100-102) based on trajectory analysis. Conversely, nucleotide sequence analysis of Caribbean BTV serotype 17 isolates suggested they arose from incursions which originated in the USA, possibly from a BTV population distinct from those circulating in Wyoming.

Amino Acid Sequence↗
PubMed1995

Impact of polyunsaturated fatty acids on human colonic bacterial metabolism: an in vitro and in vivo study.

Dietary polyunsaturated fatty acids (PUFA) reduce colonic proliferation and exert a mild laxative effect. We have studied the effect of the highly unsaturated eicosapentaenoic acid ethyl ester (EPA-EE) on the growth and metabolism of colonic bacteria in vitro, and in vivo. For the in vitro study, growth was assessed by viable counts. Bacteroides thetaiotaomicron was significantly inhibited in anaerobic media containing EPA-EE at concentrations > 7 milligrams. Escherichia coli was apparently resistant even at 100 milligrams. For the in vivo study, ten healthy volunteers ingested 18 g EPA-EE/d for 7 d. Stool frequency, 24 h stool weight and whole-gut transit time were assessed together with breath H2 and 14CO2 excretion following oral ingestion of 15 g lactitol labelled with 0.18 MBq [14C]lactitol. The area under the breath-H2-time curve was significantly reduced by EPA-EE, from a control value of 690.3 (SE 94.2) ppm.h to 449.5 (SE 91.7) ppm.h. Percentage dose of 14CO2 excreted, total stool weight and whole-gut transit time were unaltered, being respectively 24 (SE 2)%, 281 (SE 66) g and 45 (SE 4) h with EPA-EE v. control values of 27 (SE 1)%, 300 (SE 89) g and 42 (SE 5) h. It is concluded that dietary supplementation with EPA-EE reduces breath H2 excretion without apparently impairing overall colonic carbohydrate fermentation. The observed reduction may reflect utilization of H2 to hydrogenate the five double bonds of EPA-EE.

Adult↗
PubMed1995

Colonic protein fermentation and promotion of colon carcinogenesis by thermolyzed casein.

Thermolyzed casein is known to promote the growth of aberrant crypt foci (ACF) and colon cancer when it is fed to rats that have been initiated with azoxymethane. We speculated that the promotion was a consequence of increased colonic protein fermentation (i.e., that the thermolysis of the casein decreases its digestibility, increases the amount of protein reaching the colon, and increases colonic protein fermentation and that the potentially toxic products of this fermentation promote colon carcinogenesis). We found that the thermolysis of casein reduces its digestibility and increases colonic protein fermentation, as assessed by fecal ammonium and urinary phenol, cresol, and indol-3-ol. Thermolysis of two other proteins, soy and egg white protein, also increases colonic protein fermentation with increased fecal ammonia and urinary phenols, and thermolysis of all three proteins increases the levels of ammonia and butyric, valeric, and i-valeric acids in the cecal contents. We found, however, that the increased protein fermentation observed with thermolysis is not associated with promotion of colon carcinogenesis. With casein, the kinetics of protein fermentation with increasing thermolysis time are clearly different from the kinetics of promotion of ACF growth. The formation of the fermentation products was highest when the protein was thermolyzed for one hour, whereas promotion was highest for protein that had been thermolyzed for two or more hours. With soy and egg white, thermolysis increased colonic protein fermentation but did not promote colon carcinogenesis. Thus, although thermolysis of dietary casein increases colonic protein fermentation, products of this fermentation do not appear to be responsible for the promotion of colon carcinogenesis. Indeed, the results suggest that protein fermentation products do not play an important role in colon cancer promotion.

Animals↗
PubMed1995

Cloning, expression, and characterization of the lon gene of Erwinia amylovora: evidence for a heat shock response.

The gene encoding the Lon protease of Erwinia amylovora has been cloned by complementation of an Escherichia coli lon mutant. Analysis of the determined nucleotide sequence of the lon gene revealed extensive homology to the nucleotide sequences of cloned lon genes from E. coli, Myxococcus xanthus, and Bacillus brevis. The predicted amino acid sequence of the E. amylovora Lon protease was 94, 59, and 54% identical to the predicted amino acid sequences of the Lon proteases of E. coli, M. xanthus, and B. brevis, respectively. The -10 and -35 promoter regions of the cloned lon gene had extensive homology to the respective consensus sequences of E. coli heat shock promoters. Promoter mapping of the lon gene located the start site 7 bases downstream of the -10 region. Cloning of the lon promoter upstream of a cat reporter gene demonstrated that expression of the E. amylovora lon gene was inducible by a heat shock. This is the first demonstration of a heat shock-regulated gene in E. amylovora. Site-directed mutagenesis of the -10 region of the lon promoter confirmed that the heat shock expression of the E. amylovora lon gene may be mediated by a sigma 32-like factor. Insertional inactivation of the E. amylovora chromosomal lon gene confirmed that the lon gene was not essential for either vegetative growth or infection of apple seedlings. E. amylovora lon mutants had increased sensitivity to UV irradiation and elevated levels of extracellular polysaccharide, suggesting comparable roles for the Lon proteases in both E. amylovora and E. coli.

ATP-Dependent Proteases↗
PubMed1995

Social factors associated with behavioral problems in children with asthma.

The objective of this study was to describe the proportion of children with a behavior problem and examine which independent variables are associated with the presence of a behavior problem in a group of 392 inner-city children with asthma. Data on child asthma symptoms, medication use, health-care utilization, and school absences were obtained from the parent during a structured telephone interview. Included in the interview was a measure of behavior problems and social support questions. Children classified with a high level of asthma symptoms were more than twice as likely to experience a behavior problem than children classified with a low level of asthma symptoms (P = 0.002). Use of theophylline medication was not correlated with behavior problems (P = 0.45). Significant variables were low level of social support and high or moderate level of asthma symptoms. We have identified a group of children at risk for behavior problems, specifically in families that lack adequate social and financial resources.

Black or African American↗
PubMed1995

[Primary HIV infection. Clinical and serologic characteristics].

An acute clinical picture of variable intensity may occur during the initial primary phase of HIV infection, it may however pass unnoticed. We report 12 seronegative subjects (11 male homosexuals, 1 female heterosexual, aged 18 to 44 years old), that presented an acute clinical picture preceding seroconversion. All had a sudden beginning, resembling an acute mononucleosis in 10 and with an aseptic meningitis in two. Intensity and duration were variable, lasting a mean of 14 (range 5-44) days an remaining asymptomatic thereafter. Most patients presented a discrete leukopenia with lymphopenia at the expense of CD4 lymphocytes, followed by an absolute lymphocytosis in some, with an increase in CD8 lymphocytes. All became positive for HIV; circulating HIV antigen was identified in three and IgM anti-HIV antibodies were detected during the symptomatic period by third generation ELISA in other three. It is concluded that the clinical picture of primary HIV infection has identifiable clinical serological and immunological features and its recognition has diagnostic and preventive implications.

AIDS Serodiagnosis↗
PubMed1995

Pregnant women and smoking.

One study estimates that smoking cessation programs for pregnant women could prevent several thousand low birthweight babies and save numerous lives each year. Cessation must be encouraged and supported at any point during pregnancy.

Canada↗
PubMed1995

Families' perceptions of their resources for caring for children with developmental disabilities.

Factors related to families' perceptions of internal resources when raising children with developmental disabilities were examined. Families enrolled in a Cash Subsidy Program were surveyed about their resources, use of services, and helpfulness of social supports. Parents saw their basic resources for daily life as adequate. However, they reported that their time, discretionary money, and child-care resources were not adequate for caring for their children. Helpfulness of social supports, the children's characteristics, and income were related to perception of resource adequacy. Findings suggest that support services must be flexible in the types and amounts of services provided.

Adolescent↗
PubMed1995

Preventing pulmonary hypertensive crisis in the pediatric patient after cardiac surgery.

Pulmonary hypertension is seen in infants and young children who have congenital heart defects resulting in excess pulmonary blood flow. The critical care nurse can implement several interventions in the immediate postoperative period to help prevent the potentially lethal complication of pulmonary hypertensive crisis in a cardiac surgery patient. Respiratory interventions include hyperventilation, maintaining an alkalotic pH, supplemental oxygen, and low positive end-expiratory pressure. In addition, the nurse must consider the serum potassium, hematocrit, and patient temperature, and administer appropriate medications.

Cardiac Surgical Procedures↗
PubMed1995

[Fluconazole in treatment of urinary candidiasis. Experience with 24 patients].

Since fluconazole achieves high urine concentrations, we assessed its usefulness in the treatment of urinary candidiasis. We studied 24 patients (8 male) aged 23 to 97 years old, that presented pyuria with a negative urine culture for bacteria and fungal colony counts in urine of 10(4) CFU/ml or more. Isolated strains were Candida albicans in 20 cases, Candida kefyr in one case, Candida glabrata in one case and Candida spp in two cases. All patients were treated with fluconazole in doses of 50 to 100 mg/day for 2 to 4 weeks. The fungus was eradicated in 21 patients (88%), the infection persisted in two (8.5%) and one had a relapse (4.2%). Two patients had transient elevations of transaminases, one had abdominal pain and one, a purpuric syndrome without thrombocytopenia in whom the drug was discontinued. It is concluded that fluconazole is efficacious and safe in the treatment of urinary candidiasis.

Adult↗
PubMed1994

2D and 3D high resolution gradient echo functional imaging of the brain: venous contributions to signal in motor cortex studies.

Recent emphasis on high resolution gradient echo studies in functional imaging has led to the conclusion that there are likely three domains of response to the blood circulation in the brain when considering field inhomogeneity effects of the venous blood pre- and during activation. The first is a coherent effect due to large or macroscopic vessels on the order of the size of the voxel (ca 200-500 microns in most studies). These can lead to very large signal changes (up to 100%). The second is at the venule level (ca 50-200 microns) and is associated with smaller parenchymal changes (usually ca 10% or less). The third is at the capillary level and is associated with much smaller signal changes at 1.5 T and even up to 4 T. The actual signal changes depend on field strength and sequence design. In this paper, we present our experience in detecting the first two domains with 2D and 3D gradient echo imaging at 1.5 T. We find that high resolution enables visualization of the larger small veins in motor cortex studies and that, on occasion, it is possible to see the venule effects as well. We suggest a simple model to explain the large signal changes based on susceptibility changes and partial volume effects. Comparisons of the functional imaging data to this model and to MR angiographic studies are also shown as evidence of the venous sources of the susceptibility changes.

Brain↗
PubMed1994

Clinical pharmacology and tissue disposition studies of 131I-labeled anticolorectal carcinoma human monoclonal antibody LiCO 16.88.

Antibody LiCO 16.88 is a human IgM recognizing a 30- to 45-kDa intracytoplasmic antigen present in human adenocarcinoma cells. An 8-mg sample of antibody labeled with 5 mCi 131I was co-administered i.v. with 120 mg (three patients), 240 mg (three patients) or 480 mg (four patients) unlabeled antibody as a 4-h infusion. The plasma half-life was 24 +/- 1.2 h and the immediate apparent volume of distribution was 5.2 +/- 0.2 l at the 28-mg dose level. The plasma half-lives and the cumulative urinary excretion of radiolabel did not seem to vary significantly with increasing doses of unlabeled antibody. However, both the volume of distribution and the clearance rate from plasma increased significantly with increasing antibody dose. Uptake of antibody into tumor tissues obtained during laparotomy 8-9 days after administration varied between 0.00002% ID/g and 0.00127% ID/g. In five of seven patients, the tumor content of antibody was higher than that in adjacent normal tissue. Tumor-to-normal tissue ratios ranged from 0.8 to 10 (mean = 3.8 +/- 1.0). In general, the higher radioactivity(cpm)/g tumor was confirmed by both immunoperoxidase and autoradiography. Antibody 16.88 localizes in tumors after administration and may be considered for use in radioimmunotherapy trials.

Antibodies, Monoclonal↗
PubMed1994

Patient satisfaction with an antepartum home-care program.

Evaluation of patient satisfaction with alternative health-care delivery models is an important component of program evaluation. Patient satisfaction occurs when there is congruence between expected care and the care received. This descriptive study investigated patient satisfaction with the Antepartum Home Care Program in Winnipeg, Canada. A convenience sample of 66 pregnant women completed the Antepartum Home Care Program Evaluation Questionnaire. Most respondents were very satisfied with the physical and emotional care they received at home, including the information they received. Ninety-eight percent of the women indicated that the care they received from the program met their expectations. Being able to receive care at home, rather than in the hospital, was the most frequently identified benefit of the Antepartum Home Care Program. These results will assist program planners with decisions concerning program improvements and growth.

Adolescent↗
PubMed1994

Inhibitory effect of polyunsaturated fatty acids on the growth of Helicobacter pylori: a possible explanation of the effect of diet on peptic ulceration.

Diets high in polyunsaturated fatty acids may protect against duodenal ulcer, possibly through inhibiting the growth of Helicobacter pylori. This hypothesis was tested in vitro by incubating H pylori microaerophilically with a range of polyunsaturated fatty acids. omega-3 Linolenic acid significantly, but reversibly, inhibited growth at 1.8, 2.5, and 5 x 10(-4) M (p < 0.01), while concentrations of 10(-3) M killed virtually all organisms, with cell lysis observed by electron microscopy. Similar inhibitory effects were seen with other polyunsaturated fatty acids, at concentrations of 2.5 x 10(-4) M the relative inhibitory potencies were oleic (C18:1) < linoleic (C18:2) < arachidonic (C20:4) < omega-3 linolenic (C18:3) = omega-6 linolenic (C18:3) = eicosapentanoic (C20:5) acid. Cell fractionation studies with 14C labelled linolenic acid showed that the linolenic acid was associated with the membrane fraction. Commonly ingested dietary polyunsaturated fatty acids inhibit the growth of H pylori in vitro, an effect which deserves further in vivo study.

Diet↗
PubMed1994

Use of community health workers with inner-city children who have asthma.

Use of community health workers (CHWs) to obtain health, social, and environmental information from African-American inner-city children with asthma was one component of a larger intervention study designed to reduce morbidity in African-American children with asthma. A subset of 140 school-aged children with asthma was recruited and enrolled in a program to receive home visits by CHWs for the purposes of obtaining medical information and teaching basic asthma education to the families. Data obtained by the CHWs revealed low inhaled steroid use, high beta 2 agonist use, frequent emergency-room visits, decreased primary-care visits, and increased allergen and irritant exposure. Appropriately recruited and trained CHWs are effective in obtaining useful medical information from inner-city families with children with asthma and providing basic asthma education in the home.

Asthma↗