Biomedical subjects
Publications and source records attributed to N J Smith.
Previous epidemiological studies of Chlamydia trachomatis frequently have required expansion of isolates in tissue culture. The possibility that C. trachomatis omp1 might undergo mutation during such expansion has not been examined systematically. We found no differences in the omp1 sequences from 10 clinical specimens before and after 20 in vitro passages.
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We carried out a prospective randomised study comparing medial epicondylectomy with anterior transposition for the treatment of ulnar neuropathy at the elbow. The mean follow-up period was 4.5 years and we assessed the patients neurologically and orthopaedically. Neither procedure appeared to have a significant effect on elbow function. Our study showed better results after medial epicondylectomy; in particular patient satisfaction was higher than after ulnar nerve transposition. There were no significant differences in motor power or nerve-conduction rates and sensory fibres appeared to be more vulnerable to devascularisation.
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The effects of rabbit T lymphocytes on rabbit aortic smooth muscle cell (SMC) phenotype and proliferation were investigated in vitro. SMCs seeded at confluent density in primary culture had a volume fraction of myofilaments (Vvmyo) of 49.8 +/- 2.6% after 3 days of culture, not significantly different from that of freshly dispersed cells (Vvmyo, 54.1 +/- 2.1%). Sister cultures of SMCs to which Concanavalin A-activated T lymphocytes or T lymphocyte-conditioned medium was added had significantly lower Vvmyo (35.5 +/- 2.2% and 31.6 +/- 2.3%, respectively) at the same time point. We have previously shown that a decrease in Vvmyo could be induced by the heparan sulfate-degrading activity of living macrophages and by commercial preparations of heparinase. While activated T lymphocytes also completely degraded heparan sulfate-rich 35S-labeled extracellular matrix (an effect inhibited by the addition of 10 micrograms/mL heparin), no heparanase-like activity was detected in T lymphocyte-conditioned medium, indicating that for this cell type SMC phenotypic change is induced by a different mechanism. Incubation of the T lymphocyte-derived cytokine interferon gamma (IFN-gamma) with freshly isolated rat SMCs caused a significant reduction in Vvmyo at day 2 in primary culture from 54.3 +/- 2.1% (control) to 35.4 +/- 3.0%. Furthermore, a neutralizing antibody specific for IFN-gamma removed the effect of T lymphocytes and medium conditioned by them, thus positively identifying IFN-gamma as the T lymphocyte factor responsible for this activity. T lymphocyte-conditioned medium was mitogenic for passaged (low Vvmyo) SMCs.(ABSTRACT TRUNCATED AT 250 WORDS)
A study of film reject and repeat rates was undertaken in the Department of Dental Radiology of King's College School of Medicine and Dentistry over a 6 month period. The aim of the study was to assess the effects of changes implemented after a previous audit, and to carry out a more detailed analysis of the factors influencing the reject and repeat rates using a larger volume of data. The information recorded included the equipment and projection used, and the age of the patient if under 16 years. The overall reject rate was 3.06%, 1.84% less than recorded in the earlier study, and the repeat rate was 0.93%. Positioning errors were the most frequent cause for rejection. Significant differences in reject rates were noted between different projections, and also between qualified staff and those in training. The rejection rate for patients under 16 years was not significantly higher than for patients over 16 years, the most frequent cause of rejection was still positioning faults, but patient movement accounted for a larger proportion of the rejects than was the case in adult patients. The results demonstrate the role of audit in isolating factors leading to additional exposures. The effectiveness of changes implemented following a reject film analysis is also shown.
OBJECTIVE: To examine the efficacy, dose, and safety profile, including neurophysiological testing of thalidomide used in 59 patients (including 23 with Behçet's disease) to treat severe oral or genital ulceration (OGU). METHODS: We identified prospectively subjects (including women of childbearing potential) who had persistent OGU over periods lasting one to 40 years and whose active ulceration was not controlled by other therapies. They were treated with thalidomide. Retrospectively, we identified the number of subjects with complete resolution of the ulcers at one and two months of thalidomide therapy, and the dose required to maintain that improvement in those individuals who relapsed after stopping thalidomide. The decrease from the baseline sensory nerve action potential (baseline SNAP) amplitude value (derived from median, radial and sural nerve SNAPs) at which the development of paraesthesiae was likely to occur was also determined. RESULTS: Complete resolution of the ulcers occurred in 81% of patients within one month of thalidomide therapy at doses of 200 mg/day. No further thalidomide was required by 20% of patients responding and in the remainder improvement was maintained with smaller doses (7-200 mg/day). Using an approximate 50% decrease from baseline SNAP as an indication to discontinue thalidomide, the incidence of symptomatic neuropathy was 13.5%. No patients with a decrease of less than 42% developed neuropathy, and a further 13.5% were asymptomatic with a decrease in SNAP between 42 and 69%. Other side effects were seen in 44% of patients. There were no pregnancies and no requirement for urgent pregnancy testing. CONCLUSIONS: Thalidomide provided a useful therapeutic option in severe oral and genital ulceration which had not responded to other therapies. The physician must remain vigilant to the continuing danger of axonal neuropathy and teratogenesis at all times during thalidomide therapy.
This paper, which is based on a submission to the Nuffield Report, is proposing that there should be an alternative route to qualification as a dental surgeon. This might consist of a series of graded clinical modules separated by periods of paid employment as a dental auxiliary. During those periods of employment the auxiliary would have to follow a distance learning programme consisting of appropriate academic modules. Licence for independent practice as a dental surgeon would be given on completion of this modular degree course.
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Obese women are at higher risk for the development of both endometrial and ovarian carcinoma. Biochemical mechanisms represent documented causal factors but the role of psycho-social attitudes has received limited attention. This study examined the difference in the frequency of pelvic screening examinations between obese and non-obese women and the effect of physician and patient attitudes toward obesity on examination frequency. A total of 291 women subjects and 1316 physician subjects participated in this study. Data reported in this paper suggest that attitudes and behaviors are negatively influenced by weight. As subjects' weight went up, negative opinions about their appearance and reluctance to obtain pelvic examinations also increased while the likelihood of having annual pelvic examinations decreased. A substantial minority (17%) and an overwhelming majority (83%) of physicians indicated they were reluctant to perform pelvic examinations on obese and reluctant patients respectively. If physicians are more reluctant to perform pelvic examinations on obese and reluctant women and obese women are more reluctant to be examined, there may be a critical delay in detecting adenocarcinomas of the female genital tract.
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A multiple choice questionnaire was completed by 100 dental surgeons, both at the beginning and at the end of one of several one-day courses on radiation protection. These courses were designed to cover the 'core of knowledge' required by the Ionising Radiation (Protection of Persons Undergoing Medical Examination or Treatment) Regulations 1988. The mean score at the start of each day was 22.86 (out of a maximum possible score of 80), while at the end it was 48.52. The results cast doubt on the belief of the General Dental Council that 'following qualification, dentists will have updated themselves in this area of dental practice'.
The loss of somatosensory evoked potentials (SSEP's) was investigated in a feline model of intracranial hypertension. Threshold values of cerebral perfusion pressure (CPP) and cerebral blood flow (CBF) required for maintenance of SSEP's are defined using a mathematical model. The model describes loss of amplitude of SSEP's using the form of a dose-response curve. Amplitude of the SSEP's declined to 50% of control values at a CBF of 15 ml/100 gm/min and a CPP of 20 mm Hg in the normoxic animal; in the presence of mild hypoxia (8 to 9 kPa), a significant increase in these values to 18 ml/100 gm/min and 32 mm Hg, respectively, occurred. No reliable changes in latency or central conduction time were demonstrated. It is concluded that given adequate oxygenation, evoked electrical activity is lost at too low a level of CPP for this parameter to be useful in clinical monitoring. However, even mild hypoxia, when combined with intracranial hypertension, produces a major risk to neuronal integrity.
In a prospective study, eight patients with 15 hands affected by both vibration white finger and carpal tunnel syndrome were treated by surgical decompression of the carpal tunnel. On review six months later, the symptoms of carpal tunnel syndrome were improved in all cases and the symptoms of white finger were improved in half of the cases. Nerve conduction studies and palmar skin histology are discussed.
Gram negative colonisation and infection of the urinary tract is a well recognised complication of the neuropathic bladder caused by spinal cord injury (SCI). K. pneumoniae accounts for one third of all urinary tract infections in hospitalised SCI patients. Plasmid analysis has been shown to reliably fingerprint bacterial strains, particularly K. pneumoniae, so that growth from two separate locations in or on the body can be accurately analysed as to migration from a reservoir to a target location. Eighty seven hospitalised SCI patients on intermittent catheterisation for a total of 586 patient-weeks were studied. Twice weekly catheterised urine specimens and once weekly rectal swab cultures were taken from each patient. Thirty seven patients experienced at least one clinically significant (colony count greater than 10,000/mL) urinary tract colonisation caused by K. pneumoniae, representing 66 total colonisations. Further analysis of 31 of these 37 patients revealed: K. pneumoniae in all of their stool cultures (p less than 0.05) and the identical strain of K. pneumoniae in the urine as well as the stool in 72% of the 66 colonisations (p less than 0.05). Analysis of 14 patients without K. pneumoniae urinary colonisations showed absence of faecal K. pneumoniae in 3, and predominant growth in only 4. In 22 of the 37 patients, multiple K. pneumoniae urinary colonisations were noted, representing 27 pairs of colonisation. Fifteen of the pairs were found to be relapsing (caused by two identical bacterial strains), and 12 were recurrent (caused by two different bacterial strains). Thirteen of the 15 relapsing pairs also had identical urine and stool K. pneumonia strains (p less than 0.05). All colonisations were treated with appropriate antibiotics based on culture and sensitivity reports. Fourteen of the 15 relapsing colonisation pairs have identical antibiograms (p less than 0.05), while all 12 of the recurrent colonisation pairs had different antibiograms (p less than 0.05). The differences noted on sensitivity patterns (antibiograms) correlated with differences among strains of K. pneumoniae based upon plasmid analysis. Treatment of bacteriuria did not affect the nature of repeated colonisations regardless of the antibiotic chosen, the route of administration or the duration of treatment.
We have studied 12 healthy full-term babies, mean age 3.2 days, using physiological criteria--EEG, electrooculogram, electromyogram, respiratory regularity and visible movement--to assess sleep state, and a respiratory jacket to record changes in functional residual capacity (FRC). A total of 593 min of sleep data were analysed. Of the recordings, 39% were scored as quiet sleep, 40% as active and 21% as indeterminate sleep. The mean maximum variation in FRC overall was 29 ml (SD +/- 15.4 ml). Examination of these figures showed that FRC variations during sleep state changes were smaller than those seen within a defined sleep state. We conclude that changes in sleep state are not associated with variations in FRC.
A need for centralized access to biomedical databanks was identified at the Medical University of South Carolina. The library has taken a leadership role in administering selection, acquisition, storage, and dissemination of access to these databases. A discussion of established policies and procedures is included. The appendix describes the biomedical databanks and search software selected.