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Biomedical subjects

S Chapman

Publications and source records attributed to S Chapman.

At least 145 records · Page 8Linked to original sources

Prenatal diagnosis of tuberous sclerosis with intracerebral signs at 14 weeks' gestation.

We report the ultrasound detection of cranial abnormalities at 14 weeks' gestation in a fetus subsequently confirmed as having tuberous sclerosis using DNA linkage analysis within the affected family. The presence of asymmetrical ventricular enlargement persisted antenatally. Magnetic resonance imaging at 26 weeks indicated the possibility of poor gyral formation consistent with a neuronal migration disorder. Cardiac rhabdomyomata were not visualized on ultrasound scan until 30 weeks' gestation. Postnatal cranial ultrasound confirmed the significant neuropathology which was manifested by severe developmental delay and intractable fits in the child. The potential benefits of earlier diagnosis of tuberous sclerosis by cranial imaging are discussed, although in this patient the routine booking scan resulted in a path of prenatal diagnosis being undertaken which had originally been declined. A mechanism is proposed to explain the variable expression of tuberous sclerosis within this family based on altered TSC2 activity affecting neuronal migration.

Adult↗

Review of 17 cases of pneumonia caused by Streptococcus pyogenes.

Streptococcus pyogenes is an uncommon cause of community-acquired pneumonia and there have been few recent specific accounts of the condition. To describe the current nature of this disease in the UK, data was gathered on patients with clinical pneumonia from whom Streptococcus pyogenes was cultured principally from blood or other relevant normally sterile sites. In the Harrogate and Northallerton districts of North Yorkshire, pneumonia accounted for nine (20%) cases and a quarter of all deaths in a complete sequence of 45 patients with Streptococcus pyogenes bacteraemia detected during the 16-year-period 1981-1996. An analysis is presented of those cases together with eight recent cases from counties York, Durham and Isle of Wight during 1995-1997. Of the total 17 cases, nine occurred in women and eight in men; the age range was 30-92 years. The organism was isolated from blood culture in 15 (88%) patients. Eight (47%) patients died, five within 1 day of hospitalisation. Fourteen (82%) cases occurred in the winter months October to March, including all the fatal cases and all eight in which a clinical 'viral' prodrome was observed. Predisposing medical or surgical conditions were present in 65% of the patients. Major complications included septicaemia, pleural reaction, shock, pulmonary cavitation, osteomyelitis and metastatic abscesses. Seven serotypes of Streptococcus pyogenes were encountered, with M-type 1 predominating (the cause in 60% of cases). All infections were community acquired; two small clusters of fatal pneumonia were seen.

Adult↗

Should the corticosteroid to bronchodilator ratio be promoted as a quality prescribing marker?

In recent years the ratio of inhaled corticosteroid:bronchodilator (C:B) prescribing has been promoted as a quality marker for asthma treatment and cross-sectional data indicate an association with hospital admissions. If prescribing advice has been followed then it can be hypothesised that the C:B ratio will have increased and hospitalisation decreased. The West Midlands General Practice Research Database was used to monitor changes in the C:B ratio and hospital referrals for asthma between 1993 and 1996. The C:B ratio increased from 0.5 to 0.6 (P<0.001) and hospital referrals decreased from 7% to 4% per annum (P<0.001). Overall, 38% of the variation in hospital referrals was explained by the C:B ratio. This is higher than previous studies, perhaps because the study was longitudinal and the ratio assessed accurately in terms of volume rather than prescription items. When measured in defined daily doses, the C:B ratio does appear to have validity as an indicator of good prescribing in primary care. The General Practice Research Database offers an opportunity for assessing the validity of prescribing indicators before they are considered for wider use by Primary Care Groups and Health Authorities.

Administration, Inhalation↗

The new pariahs: discourse on the tobacco industry in the Sydney press, 1993-97.

OBJECTIVE: To review the principal sub-texts contained in all press coverage and references to the tobacco industry in a major Sydney newspaper over five years. METHOD AND SAMPLE: After excluding value-neutral financial page reports, thematic analysis of all value-laden references to the tobacco industry in the Sydney Morning Herald, January 1993 to December 1997. RESULTS: Some 155 articles containing 221 separate references to the tobacco industry were identified. Eight sub-texts (callous merchants of death; conspiracy/cover-up; blood money; toxic pied pipers; corporate leviathans; beleaguered/legitimate industry; index case of unethical or corrupt practice; and bumbling fools) accounted for all 221 references. Eighty-nine per cent of references to the industry framed it negatively. Journalists or regular newspaper columnists authored 56% of the references. Only 5% of comments were attributed to tobacco company sources. CONCLUSIONS: In press reports, the tobacco industry is routinely framed as a corporate pariah by journalists, the public, government spokespeople and tobacco control advocates. IMPLICATIONS: Routine negative publicity about the tobacco industry is likely to significantly reduce its public credibility and political influence.

Humans↗

Growth in Sotos syndrome.

Although there are several reports on infant and childhood growth in patients with Sotos syndrome, there is little information on the final height achieved and puberty. Growth data on 40 patients (20 female and 20 male) aged 2-31 years were collected. These showed that patients with Sotos syndrome are excessively tall at birth, during infancy, and during childhood. Disproportionately long limbs constitute much of the increase in stature. However, the combination of advanced bone age and early onset of menarche led to a mean (SD) final height of 172.9 (5.7) cm in women. This is within the normal range for the population. Most of the men also attained a final height (mean, 184.3 cm; SD, 6.0) within the normal range, although exceptions were more likely in men than in women. Therefore, these results show that most patients with Sotos syndrome do not require intervention to limit their adult height.

Acromegaly↗

The impact of smoke-free workplaces on declining cigarette consumption in Australia and the United States.

OBJECTIVES: This study estimates the contribution of smoke-free workplaces to the recent national declines in cigarette consumption in Australia and the United States. METHODS: Nineteen studies of the impact of smoke-free workplaces on workday cigarette consumption were reviewed. The number and cost of cigarettes forgone were calculated and extrapolated to a scenario in which all indoor work areas were smoke-free. RESULTS: Of the 19 studies, 18 reported declines in daily smoking rates, and 17 reported declines in smoking prevalence. Smoke-free workplaces are currently responsible for an annual reduction of some 602 million cigarettes, or 1.8% of all cigarettes that might otherwise be consumed, in Australia, and an annual reduction of 9.7 billion cigarettes (2%) in the United States. Approximately 22.3% of the 2.7 billion decrease in cigarette consumption in Australia between 1988 and 1995 can be attributed to smoke-free workplaces, as can 12.7% of the 76.5 billion decrease in the United States between 1988 and 1994. CONCLUSIONS: If workplaces were universally smoke-free, the number of cigarettes forgone annually would increase to 1.14 billion (3.4%) in Australia and 20.9 billion (4.1%) in the United States.

Australia↗

The involvement of the NMDA receptor complex in the protective effect of anticholinergic drugs against soman poisoning.

Organophosphate poisoning is associated with adverse effects on the central nervous system such as seizure/convulsive activity and long term changes in neuronal networks. This study reports on investigations designed to assess the consequences of soman exposure on excitatory amino acids receptors in the rat brain. In addition, the protective effects of caramiphen which acts at these receptors, and scopolamine, which does not, was determined on soman-induced alteration in rat brain functions. Administration of soman (1xLD50) to pyridostigmine pretreated rats produced seizure activity (measured by EEG monitoring) in all animals tested. Estimation of [3H]MK-801 binding to brain membranes from intoxicated rats revealed a marked decrease in Bmax value 24 but not 2 hrs following soman administration. The specific nature of these effects of soman was demonstrated by the findings that [3H]flunitrazepam binding to central benzodiazepine receptors remained unchanged in soman-poisoned rat brain membranes. Both scopolamine and caramiphen, when used prophylactically prevented the lethal effect of soman and completely blocked the development of electrographic seizure activity (EGSA). In contrast, only caramiphen abolished soman-induced modifications in NMDA/ion channel characteristics. Caramiphen displaced [3H]MK-801 bound to the NMDA/ion channel complex, possibly by interacting with the Zn2+ site whereas scopolamine did not. Moreover, caramiphen, but not scopolamine, partially protected mice from NMDA-induced lethality. Thus, it is suggested that an important component of the protective efficacy of caramiphen against organophosphate poisoning might be attributed to its ability to modulate NMDA receptors in addition to its anticholinergic properties.

Animals↗