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Biomedical subjects

S M Bell

Publications and source records attributed to S M Bell.

13 recordsLinked to original sources
PubMed1992

Effect of prone versus supine patient positioning on pelvic magnetic resonance image quality.

RATIONALE AND OBJECTIVES: Magnetic resonance imaging (MRI) of the pelvis in the prone position has been proposed as a means of reducing motion-related image blurring. The authors performed a randomized controlled trial to determine if patient positioning affects image quality. METHODS: All women undergoing pelvic MRI during a 7-month period, who could lie both prone and supine, were randomized to the supine or prone position. The quality of axial T2-weighted spin-echo images was rated by two radiologists using a 1-to-4 scale (1 = marked blurring to 4 = sharp definition of pelvic structures). RESULTS: Of 78 eligible women, 61 were randomized. Two patients could not complete the examination. The mean image quality rating of 2.8 for the 32 patients imaged prone was not significantly different from the mean rating of 2.9 for the 27 patients imaged supine (P = .5, Mann-Whitney U test). CONCLUSION: Patient positioning did not significantly affect pelvic MRI quality. The choice of patient position should be based on other considerations, such as patient comfort or ease of patient positioning.

Adult↗
PubMed1992

Beta-lactamase induction by imipenem in Yersinia enterocolitica.

Five strains of Yersinia enterocolitica belonging to 5 different biotypes were induced to beta-lactamase production with imipenem in broth culture at 28 degrees C. Strains belonging to biotypes 1A, 1B, 2 and 3 showed a 26 to 73 fold increase in beta-lactamase activity after 180 min in the presence of 0.5 mg/L imipenem. Biotype 4 strain, by contrast, did not show obvious enhancement of its beta-lactamase activity in the same experiments. Enzyme B in biotypes 1B, 2 and 3 and enzyme "B-like" in biotype 1A were shown to be responsible for the increase of the beta-lactamase activity, but neither enzyme nor any similar enzyme was found to be present in biotype 4 strain.

Culture Media↗
PubMed1977

Predicting patients' warfarin requirements.

In 34 patients undergoing anticoagulant therapy with warfarin a close relationship has been observed between the logarithm of the 'Thrombotest' response to a loading dose (10 mg/day for three days) and the maintenance dose required to achieve an anticoagulant response of 8-12% (thrombo-test). This relationship appears to be close enough to enable maintenance dosages to be predicted.

Administration, Oral↗
PubMed1977

Infant crying and maternal responsiveness: a rejoinder to Gewirtz and Boyd.

The criticisms leveled by Gewirtz and Boyd focus on 1 of 6 analyses upon which Bell and Ainsworth based their interpretation of findings--namely, cross-quarter correlations of measures of infant crying and maternal response. It is maintained that these measures were approximate, and that they were independent of each other in cross-quarter correlations. It is also maintained that the statistical procedures were appropriate to a small sample of subjects in naturalistic, longitudinal research. The three "illustrative" cases offered by Gewirtz and Boyd as ways of testing a contrary hypothesis are considered. These cases assumed maternal behavior patterns which, it is argued, do not occur. Finally, other evidence is cited, both from other studies and from within the Bell-Ainsworth paper itself, that supports the interpretation that Gewirtz and Boyd claim to have been unjustified.

Conditioning, Operant↗
PubMed1976

Further observations on the value of oral penicillins in chronic staphylococcal osteomyelitis.

This report confirms after periods of observation of up to nine years, the successful treatment with high oral doses of cloxacillin or phenoxymethylpenicillin of 19 patients suffering from chronic staphylococcal osteomyelits. The antibiotic treatment was closely supervised over long periods, and the satisfactory response initially reported has been maintained in each case. Brief reference is made also to the use of the same treatment in a further 191 patients with chronic staphylococcal bone infection. Observations of the progress of 136 of these patients are continuing. At this stage the response in these patients confirms the value in chronic osteomyelitis of the long-term treatment with these penicillins which was established in the first 19 patients treated.

Administration, Oral↗
PubMed1976

Treatment with gentamicin monitored by serum antibiotic assay.

Gentamicin is very widely accepted as the most effective antibiotic for treatment of a number of serious Gram-negative infections, but one disadvantage associated with its use is the risk of toxicity particularly affecting the eighth nerve. An account is given of eight years' experience with this antibiotic in which obvious ototoxicity was avoided in hospitalized patients in whom gentamicin treatment was monitored by assay of the residual amounts of antibiotic present in the serum. The relationship between accumulation of gentamicin in patients with renal impairment and ototoxicity is discussed. Attention is drawn also to the presence of an increased risk of ototoxicity in patients, particularly the elderly, in whom mild-to-moderate degrees of renal impairment may be overlooked. In such patients modification of the frequency of the dose of gentamicin is necessary and a schedule of treatment based on the results of assay of residual serum levels of gentamicin is given.

Aged↗
PubMed1976

Quantitative throat-swab culture in the diagnosis of streptococcal pharyngitis in children.

A striking difference in the detection of a heavy growth of Streptococcus pyogenes in throat swabs taken from 1054 children with pharyngitis compared with those from 462 normal children was demonstrated when a standardised technique of quantitative culture was used. In patients with pharyngitis 71% of the isolates were heavy whereas a heavy culture was obtained in only 1-7% of healthy children. Also, a significant correlation between the clinical observations suggestive of streptococcal pharyngitis and the results of culture was confined to those patients whose throat swabs yielded a heavy growth of streptococci. It is concluded that bacteriological examination is of value as a diagnostic test only when the results of culture are quantitatively assessed.

Age Factors↗
PubMed1975

Relevance of "significant bacteriuria" to aetiology and diagnosis of urinary-tract infection.

28 of 74 female domiciliary patients who presented with urinary-tract symptoms did not fulfil the usually accepted laboratory criterion required for confirmation of urinary-tract infection (i.e., a urinary bacterial viable count in excess of 100 000/ml). The progress of the disease was similar in non-bacteriuric and bacteriuric patients. In addition, a significant proportion of the bacteriuric group did not show the response to therapy expected from the results of in-vitro tests of antibiotic sensitivity and urinary antibacterial activity. To explain these findings, it is postulated that bacteria may not be primary pathogens in uncomplicated urinary-tract infection even where "significant bacteriuria" is demonstrated.

Adolescent↗
PubMed1975

New satellitism test for isolation and identification of Haemophilus influenzae and Haemophilus parainfluenzae in sputum.

A new satellitism test designed to facilitate the isolation and identification of Haemophilus influenzae and Haemophilus parainfluenzae is described. In the basal medium, nicotinamide adenine dinucleotide is incorporated at a concentration of 0.2 mug per ml, an amount adequate for H. influenzae but not for H. parainfluenzae. Two disks are placed on the surface of the medium, one disk being impregnated with 60 mug of hemin and the other with 15 mug of nicotinamide adenine dinucleotide. Under these conditions, H. influenzae strains grow around the hemin disk only and the majority of H. parainfluenzae grow around the nicotinamide adenine dinucleotide disk. This procedure gives results which are more clear cut than other established methods, especially in sputum culture.

Bacteriological Techniques↗
PubMed1975

Two types of information in picture memory.

It is assumed that recognition memory for pictures is based on two types of information. The first is information about specific details in a picture. The process of encoding this type of information is identified with what N. H. Mackworth and others have termed looking at "informative areas" in pictures. The second informational component is designated as "general visual information." Two experiments were carried out investigating (a) the extent to which recognition responses to pictures are based on specific detail vs. general visual information, (b) whether the amount of specific detail information may be manipulated by varying the complexity of a target picture, and (c) the rate at which the two types of information are acquired. The results indicate that the rate of encoding specific details varies with the number of potential informative areas in a pictures and, given that a detail is encoded, memory performance is not substantially affected by target complexity, exposure time, or presence or absence of a mask.

Acoustic Stimulation↗