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Biomedical subjects

C English

Publications and source records attributed to C English.

At least 19 recordsLinked to original sources

ICP34.5 deleted herpes simplex virus with enhanced oncolytic, immune stimulating, and anti-tumour properties.

Herpes simplex virus type-1 (HSV1) in which the neurovirulence factor ICP34.5 is inactivated has been shown to direct tumour-specific cell lysis in several tumour models. Such viruses have also been shown to be safe in Phase I clinical trials by intra-tumoral injection in glioma and melanoma patients. Previous work has used serially passaged laboratory isolates of HSV1 which we hypothesized may be attenuated in their lytic capability in human tumour cells as compared to more recent clinical isolates. To produce ICP34.5 deleted HSV with enhanced oncolytic potential, we tested two clinical isolates. Both showed improved cell killing in all human tumour cell lines tested compared to a laboratory strain (strain 17+). ICP34.5 was then deleted from one of the clinical isolate strains (strain JS1). Enhanced tumour cell killing with ICP34.5 deleted HSV has also been reported by the deletion of ICP47 by the up-regulation of US11 which occurs following this mutation. Thus to further improve oncolytic properties, ICP47 was removed from JS1/ICP34.5-. As ICP47 also functions to block antigen processing in HSV infected cells, this mutation was also anticipated to improve the immune stimulating properties of the virus. Finally, to provide viruses with maximum oncolytic and immune stimulating properties, the gene for human or mouse GM-CSF was inserted into the JS1/34.5-/47- vector backbone. GM-CSF is a potent immune stimulator promoting the differentiation of progenitor cells into dendritic cells and has shown promise in clinical trials when delivered by a number of means. Combination of GM-CSF with oncolytic therapy may be particularly effective as the necrotic cell death accompanying virus replication should serve to effectively release tumour antigens to then induce a GM-CSF-enhanced immune response. This would, in effect, provide an in situ, patient-specific, anti-tumour vaccine. The viruses constructed were tested in vitro in human tumour cell lines and in vivo in mice demonstrating significant anti-tumour effects. These were greatly improved compared to viruses not containing each of the modifications described. In vivo, both injected and non-injected tumours showed significant shrinkage or clearance and mice were protected against re-challenge with tumour cells. The data presented indicate that JS1/ICP34.5-/ICP47-/GM-CSF acts as a powerful oncolytic agent which may be appropriate for the treatment of a number of solid tumour types in man.

Animals↗

Predictors of therapy resistant asthma: outcome of a systematic evaluation protocol.

BACKGROUND: It has been suggested that asthmatic subjects with persisting symptoms despite adequate maintenance therapy should be systematically evaluated to identify factors contributing to poor control. The aims of this study were to examine the prevalence of these factors in a cohort of sequentially referred poorly controlled asthmatics, and to determine if any factor or combination of factors predicted true therapy resistant asthma (TRA). METHODS: Patients were evaluated using a systematic evaluation protocol including induced sputum analysis, psychiatric assessment, ear, nose and throat examination, pulmonary function testing, high resolution CT scan of the thorax, and 24 hour dual probe ambulatory oesophageal pH monitoring; any identified provoking factor was treated. Asthma was managed according to BTS guidelines. RESULTS: Of 73 subjects who completed the assessment, 39 responded to intervention and 34 had TRA. Subjects with TRA had a greater period of instability, a higher dose of inhaled steroids at referral, more rescue steroid use, and a lower best percentage forced expiratory volume in 1 second (FEV(1)%). Oesophageal reflux, upper airway disease, and psychiatric morbidity were common (57%, 95%, 49%, respectively) but were not more prevalent in either group. Using multivariate logistic regression analysis, inhaled steroid dose >2000 micro g BDP, previous assessment by a respiratory specialist, and initial FEV(1)% of <70% at referral predicted a final diagnosis of TRA. CONCLUSIONS: In poorly controlled asthmatics there is a high prevalence of co-morbidity, identified by detailed systematic assessment, but no difference in prevalence between those who respond to intervention and those with TRA. Targeted treatment of identified co-morbidities has minimal impact on asthma related quality of life in those with therapy resistant disease.

Administration, Inhalation↗

Pathogenesis of H7 influenza A viruses isolated from ostriches in the homologous host infected experimentally.

Infections of ostriches with avian influenza A viruses are generally associated with clinical disease, but the occasional high mortality in young birds does not appear to be related directly to virus pathotype. In this study we investigated the pathogenesis of two H7 viruses for 11-wk-old ostriches inoculated intranasally, and clinical symptoms, virus excretion, and immune response were studied. One of the viruses (A/Ostrich/Italy/1038/00) was highly pathogenic for chickens, whereas the other (A/Ostrich/South Africa/1609/91) was of low pathogenicity for chickens. Clinical signs in ostriches receiving virulent virus were slight depression and hemorrhagic diarrhea, while the group receiving avirulent virus was clinically normal except for green diarrhea. Both viruses were transmitted to in-contact sentinel birds housed with the infected groups 3 days postinfection. Postmortem examination of the birds infected (including the sentinel bird) with virus highly pathogenic for chickens were grossly normal except for localized pneumonic lesions. The results of the study are presented and discussed.

Amino Acid Sequence↗

Evaluation of dopaminergic presynaptic integrity: 6-[18F]fluoro-L-dopa versus 6-[18F]fluoro-L-m-tyrosine.

The effectiveness of 6-[18F]fluoro-L-m-tyrosine (6FMT) to evaluate dopamine presynaptic integrity was compared to that of 6-[18F]fluoro-L-dopa (6FDOPA) in vivo by positron emission tomography (PET). Six normal and six 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-lesioned monkeys received 6FDOPA and 6FMT PET scans on separate occasions with identical scanning protocols. Four measures, the rate of uptake of tracer into striatum using either the arterial input function (Ki) or the activity in the occipital cortex as the input function (Kc), the rate of loss of striatal radioactivity (k(loss)), and an index of "effective turnover" of dopamine (k(loss)/Ki), were obtained for both tracers during extended PET studies. 6-[18F]Fluoro-L-m-tyrosine was as effective as 6FDOPA in separating normals from MPTP-lesioned subjects on the basis of the uptake rate constants Ki and Kc. However, in contrast to 6FDOPA, it was not possible to differentiate the normal from the lesioned animal using k(loss) or k(loss)/Ki for 6FMT. Thus, FMT appears to be a reasonable, highly specific tracer for studying the activity of aromatic dopa decarboxylase enzyme as an index of presynaptic integrity. However, if one is interested in investigating further the metabolic pathway and obtaining an in vivo estimate of the effective turnover of dopamine (after pharmacologic manipulation, for example), 6FDOPA remains the tracer of choice.

Animals↗

Reproducibility of the distribution of carbon-11-SCH 23390, a dopamine D1 receptor tracer, in normal subjects.

UNLABELLED: The reproducibility of [11C]SCH 23390 in PET was studied in 10 normal human subjects. METHODS: The scan-to-scan variation of several measures used in PET data analysis, including the radioactivity ratio, plasma-input Logan total distribution volume (DV), plasma-input Logan DV ratio (DVR) and tissue-input Logan Bmax/Kd values, was determined. RESULTS: There were significant correlations among the radioactivity ratio, plasma-input DVR and tissue-input Bmax/Kd. With the cerebellum as the reference region, these three measures also had high reliability (86%-95%), high between-subject s.d. (7.7%-11.3%) and small within-subject s.d. (2.3%-3.6%), indicating that they are comparable and useful measures for the assessment of dopamine D1 receptor binding. CONCLUSION: The radioactivity ratio and the tissue-input Bmax/Kd may be preferred methods for the evaluation of dopamine D1 receptor binding because these two methods do not require arterial blood sampling and metabolite analysis. Our results show that cerebellum is a reliable reference region for SCH 23390. When the Logan plasma-input function method is used in data analysis for SCH 23390, DVRs rather than total DV values should be used because of the poor reliability of the DV values and their lack of correlation with other measures. Carbon-11-SCH 23390 is thus a reliable and reproducible ligand for the study of dopamine D1 receptor binding by PET.

Benzazepines↗

Changes in patient screening for a clinical study of dental implants after increased awareness of tobacco use as a risk factor.

Independent external monitoring committees are an important part of scientific clinical trials. They monitor patient safety, study progress, investigators' performance, and accurate interpretation/reporting of the study data. Data trends observed by a study monitoring committee detected a change in the pattern of patient screening by investigators after an increased awareness that tobacco use could directly compromise the osseointegration of root-form dental implants. This increased awareness is believed to have altered the number of active smokers accepted into a multicenter prospective dental implant study. Recent data analyses indicate that the success ratios were improved by alterations in this discretionary inclusion-exclusion criterion.

Data Interpretation, Statistical↗

Academic measures available in sophomore year can predict application and admission to dietetic supervised practice programs.

The purpose of the study was to determine whether college grade point average (GPA) and application and admission to supervised practice programs could be predicted from measures available in the sophomore year. The sample consisted of 193 graduates of a didactic program in a research university in class years 1986 to 1993. Variables tested included GPA in required dietetics program courses, SAT scores, high school class rank, and age. prediction equations were developed using data from class years 1986 to 1992 and tested on subjects in class year 1993. Subjects who applied to and were admitted to supervised practice programs had significantly higher GPAs. In class years 1986 to 1992, GPAs and SAT math scores of sophomores explained 88% of the variance in the college GPA, whereas the sophomore GPA for professional courses correctly classified 63% of applicants and 73% of admitted subjects. Using these prediction equations for the class of 1993, college GPA of subjects was accurately predicted and 84% of applicants and 75% of admitted subjects were correctly classified. The results of this study provide valuable information for didactic program directors to counsel students into or out of a dietetics program, and could decrease the number of graduates who do not complete registration requirements.

Adult↗

Molecular characterization of Vibrio cholerae O139 isolates from Asia.

In 1992, a serologically novel clone of Vibrio cholerae, designated O139, caused large epidemics of diarrhea in India and Bangladesh. To determine the extent of the spread of V. cholerae O139 worldwide, 484 V. cholerae non-O1 strains isolated from different patients with diarrhea in Thailand, Indonesia, the Philippines, and Peru in 1993 were tested for agglutination in O139 antisera. One hundred fifty-one of these 484 isolates were examined for genes encoding cholera toxin, zonula occlulans toxin, the repetitive sequence 1, and the toxin coregulated pilin A (the V. cholerae virulence gene complex). Thirty-three percent (122 of 364) of V. cholerae non-O1 strains isolated from different patients with diarrhea in Thailand agglutinated in O139 antisera. Ninety-eight percent (120 of 122) of V. cholerae O139 contained the V. cholerae virulence gene complex. None of the 104 V. cholerae non-O1 strains isolated from patients with diarrhea in Indonesia or the 14 strains from patients with diarrhea in the Philippines were serotype O139. Four different ribotypes were found in V. cholerae O139 isolated in Asia. Twenty-three (47%) of 49 Thai O139 strains examined were of different ribotypes than isolates from India and Bangladesh; V. cholerae strains that were not O1 or O139 that were isolated from flies and water in Thailand 11 years previously in 1981 contained the same V. cholerae virulence gene complex found in V. cholerae O1 and O139. This suggests that other unidentified virulence determinants are involved in V. cholerae O139 pathogenesis.

Cholera↗

Meckel syndrome: what are the minimum diagnostic criteria?

Two sibs are described, the first of whom presented the classic Meckel syndrome triad of encephalocele, postaxial polydactyly, and characteristic renal cystic changes. The second sib had none of these abnormalities, but did show urethral atresia and preaxial polydactyly, two features previously described in some patients with Meckel syndrome. The two cases illustrate both the wide phenotypic spectrum of Meckel syndrome and the difficulty of attempting to define minimum diagnostic criteria for the disorder. The clinical implications arising from this problem are discussed.

Abnormalities, Multiple↗

Self-reported and measured weights and heights of participants in community-based weight loss programs.

Self-reported weights and heights of 82 adults were compared with measured weights and heights 1 to 3 years after participation in community weight loss programs. The mean self-reported weight was 2.3 +/- 1.9 kg lower than measured weight (P < .05). Differences in underreporting were not significant for gender or age group. Heavier individuals misreported their weight to a greater extent (P < .05) than lighter persons, and individuals who had not recently weighed themselves underreported their weight to a greater extent than those who had weighed recently (P < .05). On the average, height was overreported by a mean of 1.8 +/- 2.7 cm. Overreporting increased with increasing height, and men overestimated their height to a greater extent than women (P < .05). Younger subjects reported their height more accurately than those older than 60 years. Results of our study are similar to those of previous investigations that examined self-reporting bias in subjects enrolled in weight loss programs. The mean discrepancy in body weight, however, was greater than that reported in samples drawn from the general population. Our findings indicate that self-reported weight and height values in overweight populations should be interpreted with caution.

Adult↗

An overview of implant hardware.

This paper overviews dental implants emphasizing design concepts, material composition, and prosthetic abutments. Within the space limitations, all systems can not be shown in total and we do not infer superiority or inferiority with the inclusion or exclusion of any design, concept, or abutment.

Dental Implantation, Endosseous↗