Biomedical subjects

S Wright

Publications and source records attributed to S Wright.

At least 361 records · Page 20Linked to original sources

PubMedDate not supplied

Video viewing as an alternative to sedation for young subjects who have cardiac ultrasound examinations.

Sedation is often required for extended or quantitative echocardiographic examination of young patients. To test the hypothesis that patient viewing of entertaining videotapes during echocardiographic examinations would reduce the need for sedation and that Doppler pressure gradients so obtained would correspond satisfactorily with subsequent catheterization pressure gradients, 38 patients (age, 5 to 64 months; mean age, 18.6 months) with a variety of cardiac defects were studied. Because of excessive activity, resistance, fear, or crying, all of these patients would have normally been sedated. Instead, an age-appropriate videotape was used for patient viewing. In 35 of 38 patients, complete examinations were obtained with video viewing with no sedation. Twelve study patients later underwent catheterization while receiving sedation. The Doppler pressure gradients obtained while patients were viewing videotapes corresponded well with catheterization (r = 0.94). However, those pressure gradients were higher than those obtained with catheterization (mean, 8.3 mm Hg), but there was only one significant discrepancy of 22 mm Hg. In this series, complete examinations were obtained without sedation in 92% of subjects who would have normally required sedation (p less than 0.001), with minimal reduction in the accuracy of prediction of subsequent sedated catheterization pressure gradients. This suggests that near baseline conditions existed while patients were viewing television. Video viewing during echocardiographic examinations appears to be advantageous.

Cardiac Catheterization↗

PubMedDate not supplied

Regulated expression of the human beta-globin gene family in murine erythroleukaemia cells.

Chemically induced differentiation of cultured murine erythroleukaemia (MEL) cells results in a several hundred-fold increase in transcription of the adult mouse globin genes and thus serves as a model for gene activation during erythropoiesis. One approach to study gene regulation in this system has been to analyse the expression of foreign globin genes introduced into MEL cells. By introducing cosmid DNA containing the human adult(beta), fetal(gamma) and embryonic(epsilon)-globin genes, we have shown here that expression of the beta, but not the gamma or epsilon genes, is regulated during MEL differentiation. Regulated expression of the human beta-globin gene was observed when it was introduced either as part of the intact globin gene cluster or as an individual gene with 1.5 kilobases (kb) of 5' flanking DNA. Transcription from a herpes simplex virus (HSV) promoter adjacent to the thymidine kinase (tk) gene is also inducible in MEL cells.

Animals↗

PubMedDate not supplied

Regulated expression of an introduced MHC H-2K bm1 gene in murine embryonal carcinoma cells.

The transplantation antigens H-2K, H-2D and H-2L are developmentally regulated, highly polymorphic cell surface proteins encoded by the major histocompatibility gene complex (MHC). First detectable on the early embryo, they are subsequently expressed on most somatic cells of the adult mouse in association with the protein beta2-microglobulin (beta 2 M; ref. 5). Cultured F embryonal carcinoma (EC) cells can be induced to differentiate along alternative pathways to form either parietal or visceral9 extra-embryonic endoderm, each concomitant with a change in morphology and pattern of gene expression. Previous reports have demonstrated an increased level of transplantation antigens in differentiated F9 EC cells, but the cell types expressing them were not defined. Here we show that the level of MHC H-2Kb and beta 2 M transcripts is increased during both pathways of this differentiation. Expression of a foreign MHC H-2Kbm1 gene was found to be regulated in a similar manner when the gene was introduced into EC cells. In contrast, an introduced rabbit beta-globin gene was not regulated but expressed constitutively.

Animals↗

PubMedDate not supplied

Increased MHC H-2K gene transcription in cultured mouse embryo cells after adenovirus infection.

The class I major histocompatibility complex (MHC) antigens are highly polymorphic cell-surface proteins whose expression is essential for the cellular immune response against virus-infected, abnormal and foreign cells. Transformation of primary rat cell cultures by the oncogenic adenovirus 12 (Ad12) results in suppression of the transplantation antigens, thus enabling the transformed cells to escape the immune response and efficiently form tumours in vivo. In contrast, transformation of the same cells with the non-oncogenic adenovirus 5 (Ad5) does not suppress the transplantation antigens and, consequently, they elicit an effective (MHC-restricted) immune response. Here, however, we show that infection of mouse embryo cells with both viruses initially increases the level of transcripts from the H-2Kb transplantation antigen gene. Both the adenovirus E1a (12S RNA) and E1b genes are required for activation of the H-2K gene and measurement of the relative rate of transcription indicates that the increase in the level of H-2K messenger RNA following infection is at least in part due to a gene-specific transcriptional activation. The newly transcribed H-2Kb mRNA is then properly transported to the cytoplasm.

Adenoviruses, Human↗

PubMedDate not supplied

The role of sub-lethal weapons in human rights abuse.

This article is based on two recent reports contracted by the European Parliament (EP), which assessed sub-lethal weapons as flexible tools of political control. It analyses the role and function of existing weapons systems in human rights abuses using examples from Indonesia, Israel, Kenya, Northern Ireland and Turkey. These weapons are designed to 'appear' rather than 'be' safe and, since they augment rather than replace lethal technologies, their use can distort conflicts and actually bridge the firewall between use of less-lethal and lethal technologies.

Child↗

PubMedDate not supplied

Intervention by an alcohol health worker in an accident and emergency department.

We have evaluated the effect of brief intervention by an alcohol health worker on alcohol consumption by 202 alcohol misusing patients. For 71 patients where questionnaires were successfully completed, 46 (65%) reported drinking less alcohol at 6 months as opposed to six (8.5%) who reported drinking more. The overall reduction was statistically significant (P < 0.001), with a mean reduction of 43%.

Adult↗

PubMedDate not supplied

Dr. Wilhelmine Key.

Explore the source record for details and available documents.

Genetics, Medical↗

PubMedDate not supplied

Magnetic resonance imaging of the Dandy-Walker malformation.

Five cases of the Dandy-Walker malformation are described using the magnetic resonance (MR) scan as a primary imaging technique. The patients' ages ranged from 34 weeks (in utero) to 41 years; their clinical and neuroanatomical characteristics encompassed the entire spectrum of the malformation. Clear visualization of the greatly enlarged posterior fossa, Dandy-Walker cyst, and absence of the inferior vermis established the pathological diagnosis and excluded other structural defects. In 3 patients, MR demonstration of the aqueduct and evidence of pressure on adjacent tissue aided in the surgical planning for ventricular decompression. The MR scan is a significant advancement in the radiological diagnosis of the Dandy-Walker malformation. The major technical advantage of the scan consists in its ability to delineate intracranial morphology in multiple planes.

Adult↗

PubMedDate not supplied

Effect of topically applied serotonin on local cerebral blood flow.

It has been hypothesized that acute lesions of the brain enlarge through an autodestructive process. Serotonin (5HT), a potent cerebral vasoconstrictor, is believed by some to mediate the process by reducing cerebral blood flow (CBF) in tissue surrounding the lesion. The hypothesis was tested in cynomologus monkeys anesthetized with ketamine and nitrous oxide. Craniectomies, 7 mm in diameter, were performed in each parietal area. The dura was opened and polarographical electrodes of thin platinum wire were inserted into the parietal lobe cortex of each hemisphere. Mock cerebrospinal fluid (CSF) was irrigated continously onto the brain surrounding the electrodes, from which local CBF was determined repeatedly by the hydrogen-clearance technique. After baseline CBF was established, solutions of 5HT in mock CSF (in concentrations of 5 X 10(-7) M, 5 X 10(-5) M, and 5 X 10(-3) M) were irrigated onto one hemisphere while the opposite hemisphere served as control. 5HT failed to change CBF. Although 5HT is a potent vasoconstrictor, under physiologic conditions it apparently is unable to effect hemodynamically significant constriction of the peripheral cerebral vasculature of the anesthetized monkey brain.

Administration, Topical↗

PubMedDate not supplied