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Biomedical subjects

S Thompson

Publications and source records attributed to S Thompson.

At least 343 records · Page 19Linked to original sources

A detailed study of the effects of in vitro interferon treatment on the growth of two variants of the B16 mouse melanoma in the lungs: evidence for non-specific effects.

Interferon treatment increases the ability of tumour cells to colonize the lungs. Although it has been suggested that this effect can be explained by increases in the expression of MHC molecules the precise mechanism is still uncertain. The growth in the lungs of a low (F1) and a high colonizing variant (BL6) of the B16 mouse melanoma have been studied after in vitro treatment with interferon. Interferon-gamma, but not interferon-alpha/beta, increased the number of lung colonies formed after intravenous injection, but not after subcutaneous administration. Treatment also increased the sizes of the lung colonies formed and the number of radiolabelled cells retained by the lungs. However, no clear relationship was observed between the number of colonies formed and the concentration of interferon used. The effect of interferon on F1 was greater than on BL6, but the overall number of colonies formed was very similar. These results suggest that interferon increases the adhesiveness of these cell lines in a fairly non-specific manner, that seems unlikely to involve MHC molecules. As a results of this and other studies the importance of interferon in the process of tumour spread seems very questionable.

Animals↗

Unequal pupils. A flow chart for sorting out the anisocorias.

When anisocoria is present, the ophthalmologist knows that something is wrong. However, location of the lesion and diagnosis of the problem can be difficult. A step-by-step flow chart for diagnosis of unequal pupils is presented, with explantation of various signs and descriptions of appropriate diagnostic tests.

Adie Syndrome↗

Descriptive analysis of multiple response topographies of challenging behavior across two settings.

Time-based lag sequential analyses were conducted on 23 topographies of challenging behavior shown by five young people with severe mental retardation across two settings. Potential behavioural functions were identified for 21 of the 23 behaviors. Responses classes, including two or more distinct behaviors, were identified for four of the five participants. Two participants showed evidence of two functionally distinct response classes; for one person each response class included both self-injurious and stereotypic behaviors. For 9 of the 11 behaviors for which data were available, the hypothesised function of behaviors was consistent across settings. For one person, data suggested that the function of one self-injurious behavior was contextually determined. Cross-validation with brief experimental analyses resulted in agreement on the general behavioral function for 12 of the 14 instances in which both approaches positively identified a potential function for a behavior. Implications for future research and practice are discussed.

Adolescent↗

Comparative vitellogenic responses in three teleost species: extrapolation to in situ field studies.

Induction of vitellogenin (VTG) was compared among three teleostean species to determine their relative sensitivity of exposure to 17 beta-estradiol (E2). Japanese medaka (Oryzias latipes), sunshine bass (Morone saxatalis x Morone chrysops) and channel catfish (Ictalurus punctatus) were exposed to aqueous concentrations of E2 ranging from 10 to 100,000 ng/l for 21 days. Respective EC50 values for plasma VTG detected by western blot in medaka, catfish and bass were 200, 170 and 1560 ng E2/l. Since these EC50 values are based on VTG induction curves calculated relative to control values, they indicate differences in species' sensitivity to E2 exposure. Catfish and bass VTG responses obtained in laboratory exposures were compared to VTG responses previously observed with 21-day wastewater treatment plant effluent exposures. Plasma VTG induction in effluent-exposed fish ranged from 14 to 82% above reference values depending on species. Extrapolation of field responses with laboratory-exposed fish indicate catfish and bass were exposed to the equivalent of 27-240 ng E2/l in sewage effluent.

Animals↗

Targetted correction of a mutant HPRT gene in mouse embryonic stem cells.

Two recent developments suggest a route to predetermined alterations in mammalian germlines. These are, first, the characterization of mouse embryonic stem (ES) cells that can still enter the germline after genetic manipulation in culture and second, the demonstration that homologous recombination between a native target chromosomal gene and exogenous DAN can be used in culture to modify specifically the target locus. We here use gene targetting functionally to correct the mutant hypoxanthine-guanine phosphoribosyl transferase (HPRT) gene in the ES cell line which has previously been isolated and used to produce an HPRT-deficient mouse. This modification of a chosen gene in pluripotent ES cells demonstrates the feasibility of this route to manipulating mammalian genomes in predetermined ways.

Animals↗

Interactive relationships between hospital patients' noise-induced stress and other stress with sleep.

OBJECTIVE: The purpose of this study was to test the hypothesis that hospital noise-induced subjective stress would interact with other subjective environmental and personal stress in a relationship with poorer patient sleep. METHODS: A secondary data analysis was done using correlations and hierarchical multiple regression. Ninety-seven cardiac patients participated after transfer from critical care to a general unit. The independent variables were assessed with Topf's 24-item Disturbance Due to Hospital Noise Scale and 5-point items for other environmental stress (ie, bed, lights) and personal stress (ie, pain, anxiety). Sleep was evaluated with the Verran and Snyder-Halpern Sleep Scale. RESULTS: Hierarchical multiple regression led to a multiple R of 0.435 (P <.01). An interaction term, subjective noise stress x subjective bed stress x subjective pain x subjective anxiety accounted for a significant amount of sleep variance (12%, F = 13.63, P =.000). Subjective bed stress x subjective pain accounted for an additional 5% (F = 6.4, P =.013). CONCLUSIONS: Studies using research designs that assess relationships between multiple patient stress variable interactions and sleep or other stress-related outcomes may produce more accurate results than studies on the independent effects of different types of stress.

Adult↗

Murine embryonal carcinoma cells express class I MHC-like antigens.

Previous work has concluded that murine embryonal carcinoma (EC) cells, the oncogenic stem cells of teratocarcinomas, do not express class-I, H-2K or D/L gene encoded products. Experiments using cell-mediated lysis, serological and molecular biological approaches show that EC cells do express some major histocompatibility complex (MHC) class I or class I-like molecules.

Animals↗

Perioperative corticosteroid supplementation and dento-alveolar surgery.

Patients are referred to hospital for dento-alveolar surgical procedures requiring supplemental corticosteroid administration. However, it has been reported that medically compromised patients who require routine dental treatment are being referred unnecessarily. This article reports a retrospective study undertaken at a Regional Maxillofacial Unit over a 24-month period, which reveals the referral pattern and management of patients specifically referred for outpatient dental treatment with corticosteroid supplementation. The paper highlights the dilemma confronting practitioners when reviewing the literature on corticosteroid supplementation and the confusion that still exists in both the primary and secondary care settings as to which patients should be prescribed supplemental corticosteroids. A simplified guide is proposed for the clinical management of these patients.

Adrenal Insufficiency↗

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Clinical Competence↗