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Biomedical subjects

S Morris

Publications and source records attributed to S Morris.

At least 181 records · Page 10Linked to original sources
PubMed1993

Voluntary suppression of cough induced by inhalation of capsaicin in healthy volunteers.

The aim of the present study was to investigate the voluntary suppression of cough in response to capsaicin inhalation in healthy volunteers, and to determine if the dose-response curve to capsaicin was significantly altered when volunteers were asked to suppress their cough response. The quantification of the degree of voluntary suppression of induced cough could provide a new methodology for screening antitussive agents as antitussives may act by influencing voluntary control of cough. Cough was induced by inhalation of capsaicin. Two challenges were given 5 min apart, each comprising five ascending concentrations of capsaicin (1 x 10(-5) M-3.33 x 10(-4) M). During one of these challenges the volunteer was allowed to cough when required, and during the other they were asked to suppress cough. These two conditions were given in random order. The cough response was recorded by means of a microphone with the integrated sound trace displayed on a chart recorder. A dose-response relationship was obtained on administration of ascending concentrations of capsaicin. In the non-suppressed challenge 23/24 subjects coughed on inhalation of capsaicin (3.33 x 10(-4) M) with a mean number of coughs of 2.92 +/- 0.34, whereas in the suppressed challenge only 3/24 subjects coughed with a mean number of coughs of 0.29 +/- 0.18 (P < 0.001). These results demonstrate that cough induced by inhalation of capsaicin can be voluntarily suppressed. The mechanism of voluntary suppression of cough is discussed in relation to capsaicin challenge and the screening of antitussive medications.

Administration, Inhalation↗
PubMed1993

Restoration of the cAMP second messenger pathway enhances cardiac preservation for transplantation in a heterotopic rat model.

Current organ preservation strategies subject graft vasculature to severe hypoxia (PO2 approximately 20 Torr), potentially compromising vascular function and limiting successful transplantation. Previous work has shown that cAMP modulates endothelial cell (EC) antithrombogenicity, barrier function, and leukocyte/EC interactions, and that hypoxia suppresses EC cAMP levels. To explore the possible benefits of cAMP analogs/agonists in organ preservation, we used a rat heterotopic cardiac transplant model; dibutyryl cAMP added to preservation solutions was associated with a time- and dose-dependent increase in the duration of cold storage associated with successful graft function. Preservation was also enhanced by 8-bromo-cAMP, the Sp isomer of adenosine 3',5'monophosphorothioate, and types III (indolidan) and IV (rolipram) phosphodiesterase inhibitors. Neither butyrate alone nor 8-bromoadenosine were effective, and the cAMP-dependent protein kinase antagonist Rp isomer of adenosine 3',5'monophosphorothioate prevented preservation enhancement induced by 8-bromo-cAMP. Grafts stored with dibutyryl cAMP demonstrated a 5.5-fold increase in blood flow and a 3.2-fold decreased neutrophil infiltration after transplantation. To explore the role of cAMP in another cell type critical for vascular homeostasis, vascular smooth muscle cells were subjected to hypoxia, causing a time-dependent decline in cAMP levels. Although adenylate cyclase activity was unchanged, diminished oxygen tensions were associated with enhanced phosphodiesterase activity (59 and 30% increase in soluble types III and IV activity, respectively). These data suggest that hypoxia or graft ischemia disrupt vascular homeostasis, at least in part, by perturbing the cAMP second messenger pathway. Supplementation of this pathway provides a new approach for enhancing cardiac preservation, promoting myocardial function, and maintaining vascular homeostatic properties.

3',5'-Cyclic-AMP Phosphodiesterases↗
PubMed1993

Resident medical care utilization patterns in continuing care retirement communities.

This article presents the findings of an evaluation of medical care service utilization by two elderly cohorts: one living in continuing care retirement communities (CCRCs) and the other living in traditional community settings. CCRC residents' overall use of Medicare-covered medical services did not differ significantly from that of the traditional community-residing elders. Both groups incurred annual per capita expenditures of approximately $2,000. In their last year of life, however, CCRC residents displayed significantly lower expenditures for hospital care ($3,854 versus $7,268) but higher expenditures for Medicare or non-Medicare-covered nursing home care ($5,565 versus $3,533).

Aged↗
PubMed1993

Two human FLT4 receptor tyrosine kinase isoforms with distinct carboxy terminal tails are produced by alternative processing of primary transcripts.

FLT4 is a recently cloned gene encoding a transmembrane tyrosine kinase related to the FLT1 and KDR/FLK1 vascular endothelial growth factor receptors. We have previously shown that FLT4 is expressed as transcripts of 4.5 and 5.8 kb in several human fetal and adult tissues. Here we show that these transcripts encode two polypeptides, FLT4s (short) and FLT41 (long), which are proteolytically processed in transfected cells and leukemia cells and which have different carboxy terminal tails. The 3' coding region of the 5.8 kb mRNA was found to be 65 codons longer than that of the the 4.5 kb mRNA. Analysis of the genomic structure of the region encoding the two carboxy termini revealed that the two transcripts are generated by alternative polyadenylation and subsequent alternative splicing during RNA processing. Our findings thus show regulation of FLT4 structure in the carboxy terminal tail considered important for receptor function. The significance of the two forms may relate to the role of additional potential autophosphorylation sites in the FLT4 long form.

Alternative Splicing↗
PubMed1992

What kind of people want to become dentists? General Dental Council Recruitment Working Party survey of first year undergraduate dental students.

Above all, the survey has provided a clear, if complex, description of the population of first year dental students: who they are and where they have come from; why they are doing the course and what they want to achieve from it. A number of specific conclusions about recruitment gaps can be drawn from the information received from the survey, namely: i) Girls at mixed-sex schools are apparently less likely to enter dentistry than their counterparts at all-girls' schools. This, however, is part of a much wider issue which encompasses the question of science versus arts choices amongst male and female pupils. ii) Some dental schools have a very high concentration of students whose home is the local region. Wider national publicity for these schools could be attempted. iii) In East Anglia, the East Midlands, Yorkshire and Humberside and the West Midlands, the number of qualified school leavers who become dental students is below average. iv) Family dentists and orthodontists are in a very strong position to encourage interested patients to enter the profession beginning at an early age, and with guidance could encourage these children towards additional sources of information and advice, such as the General Dental Council, which at the moment appear to be under-used. v) The information on dentistry provided by most careers advisers could be improved. In particular, careers teachers and form teachers/tutors are a widely contacted source of guidance but the information they were able to provide was not rated highly. University open days and residential courses are successful and might be used further.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

An evaluation of the TEAMWORK programme.

The TEAMWORK training programme for DSAs is being used extensively, by experienced staff updating their skills even more than by new recruits. Practitioners are actively involved in the programme and are supporting its use, but there is little awareness of local courses to back up the training being provided. However, specific needs have been identified and could be built upon. Overall, the programme is rated very highly by both training supervisors and trainees, and most practices would use it again.

Dental Assistants↗
PubMed1992

Rate-corrected mean velocity of fiber shortening-stress at peak systole as a load-independent measure of contractility.

The relation of mean velocity of fiber shortening-stress at end-systole is a good load-independent index of left ventricular contractility, but involves simultaneous M-mode echocardiography, carotid tracing and blood pressure determination, which may be impractical in children. As stress at peak systole and end-systole are closely related, this study examined whether the relation of mean velocity of fiber shortening-stress at peak systole could be used as a simpler method of assessing left ventricular contractility in a normal population of children. In addition, the cross-sectional normal range for a pediatric population was obtained. In 25 normal children aged 4 to 17 years (mean age 11), rate-corrected mean velocity of fiber shortening (MVCFc), stress at peak systole (sigma PS), and end-systolic stress (sigma ES) were determined using echocardiography, carotid pulse tracing and blood pressure measurement. Six patients with cardiomyopathy (mean age 8 years) were also studied. The relation of stress at peak systole and end-systolic stress was sigma PS = 1.004 sigma ES + 12.0 (r = 0.91, SEE = 4.98; p less than 0.001) for the normal group, and sigma PS = 1.083 sigma ES + 7.7 (r = 0.99, SEE = 4.07; p less than .001) for the cardiomyopathic group. This slope of the regression line was slightly higher and the difference was statistically significant. The slope of MVCFc = 0.0066 sigma PS + 1.55 (SEE = 0.131, r = -0.52) was nearly identical to that of MVCFc = 0.0065 sigma ES + 1.46, (SEE = 0.135, r = -0.46), with no difference in the regression coefficients.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Mutation in codon 713 of the beta amyloid precursor protein gene presenting with schizophrenia.

Following reports of mutations of codon 717 in exon 17 of the amyloid precursor protein (APP) gene in early-onset familial Alzheimer's disease, we screened exon 17 for new mutations in presenile dementia. The majority of the 105 patients screened had definite or probable Alzheimer's disease, but we also included atypical cases and some chronic schizophrenics. We identified a single abnormal case--a chronic schizophrenic with cognitive defects. Sequencing revealed a C to T nucleotide substitution which produces an alanine to valine change at codon 713. We were unable to detect the mutation in the remaining members of the original cohort nor in a further 100 chronic schizophrenics and 100 non-demented controls. Nonetheless, the position of the mutation in a critical portion of the APP gene suggests that it may well prove to be pathogenic.

Amino Acid Sequence↗
PubMed1992

Endorphin mediation of mesenteric blood flow after endotoxemia in sheep.

BACKGROUND AND METHODS: The administration of endotoxin in small dosages to sheep results in an acute decrease followed by an increase in cardiac output. It has previously been determined that the initial decrease in output was the result of a reduction in blood flow to the mesenteric areas. These changes were associated with increased blood concentrations of beta endorphin. The present study was accomplished to determine if the systemic cardiovascular response to endotoxin could be affected by the administration of an opiate receptor-blocking agent. Female range sheep (n = 12) were prepared for chronic study by implantation of cardiopulmonary catheters and a flow probe on the cephalic mesenteric artery. Endotoxin (Escherichia coli, 1 microgram/kg) was administered to these animals. Half of the sheep were treated with naloxone (2 mg/kg + 2 mg/kg.hr), and the remainder with an equivalent volume of sodium chloride (0.9%). RESULTS: In untreated sheep, cardiac indices decreased by 15% to 20% (5.1 +/- 0.1 to 4.2 +/- 0.4 L/min.m2) between 0 and 1 hr and 2 and 5 hrs after endotoxin (4.5 +/- 0.2 L/min.m2), and then increased to a value 40% (7.2 +/- 0.6 L/min.m2) above baseline by 12 hrs. Flow in the cephalic mesenteric artery decreased in a pattern similar to the reduction in cardiac index (962 +/- 152 [time, T = 0] to 379 +/- 111 [T = 0.8] and 384 +/- 88 mL/min [T = 4.0], p less than .05) but did not increase to the same extent (1008 +/- 153 mL/min [T = 4.0], p greater than .05). There was a concomitant increase in the plasma beta-endorphin concentrations as the blood flow decreased (5 +/- 4 [T = 0] to 40 +/- 15 pg/mL [T = 0.8; untreated group], p less than .05; and 10 +/- 4 to 50 +/- 7 pg/mL [T = 0.8; naloxone-treated group], p less than .05). In the naloxone-treated group, the same pattern of cardiac output change was noted with endotoxin; however, reduction of mesenteric artery flow was only 30% (1118 +/- 129 to 908 +/- 122 mL/min, p less than .05) of the value seen in the untreated animals (962 +/- 152 to 379 +/- 111 mL/min, p less than .05). These changes in mesenteric blood flow were statistically significant from one another. As the cardiac output increased in the sheep treated with the opiate antagonist, mesenteric blood flows increased 20% above the baseline value (1391 +/- 199 mL/min, p less than .05). CONCLUSIONS: The decrease in cardiac output noted with endotoxin can be accounted for by the decrease in the blood flow in the cephalic mesenteric artery. This phenomenon can be attributed, at least in part, to the release of endorphins. There is both a vasodilation and constriction during endotoxemia in the ovine model.

Animals↗
PubMed1992

Seasonal allergic rhinitis and its effects on eustachian tube function and middle ear pressure.

Middle ear pressure was recorded from 396 ears and aural symptoms inquired of 198 adult subjects with seasonal allergic rhinitis. Evidence of eustachian tube dysfunction was found in 24% of subjects. Increased duration of exposure to pollen over a further 2 weeks increased the incidence of eustachian tube dysfunction to 48%. The development of eustachian tube dysfunction did not correlate with the severity of nasal symptoms.

Adolescent↗
PubMed1992

Lack of effect of codeine in the treatment of cough associated with acute upper respiratory tract infection.

Codeine is often used as a standard antitussive against which new antitussives are compared. However there is little information available about the effects of codeine on cough associated with upper respiratory tract infection. The present study investigated the effects of codeine syrup B.P. (30 mg/10 ml, q.d.s.) or syrup vehicle on cough frequency and the subjective severity of cough during a 3-h laboratory phase and a 4-day home phase of treatment. Cough frequency and subjective scores of cough severity were significantly decreased during the 3-h laboratory phase but at no time point was there a significant difference between the codeine- and placebo-treated groups. The results of the 4-day home phase diary were similar to those of the laboratory phase as at no time point was there a significant difference between the mean scores for the codeine- and placebo-treated groups. The results indicate that codeine, either as a single 30-mg dose or in a total daily dose of 120 mg, is no more effective than the syrup vehicle in controlling cough associated with acute upper respiratory tract infection.

Acute Disease↗
PubMed1992

What are the benefits of routine breast cancer follow-up?

The value of follow-up after potentially curative treatment of breast cancer remains controversial. Recurrence-free women (n = 402) attending a breast clinic over a 3 month period were studied. The women attended 423 appointments, 412 of which were routine. Eleven were requested by the patient or general practitioner (interval appointments). All 11 interval and 19 of the routine appointments resulted in investigations for possible recurrence. Three (27%) interval appointments and four (1%) routine appointments resulted in the diagnosis of a recurrence (P < 10(-5). The attitudes of 285 patients to follow-up were investigated by questionnaire. Two hundred and twenty-three (78%) questionnaires were completed. Regular follow-up in the breast clinic was preferred to attendance only when symptomatic by 190 (85%) women and 169 (76%) preferred regular breast clinic visits to general practitioner follow-up. Most women (n = 174) (81%) said they felt reassured and less anxious having attended the breast clinic. Routine follow-up after potentially curative treatment of breast cancer is inefficient in the detection of recurrence. It is, however, highly rated for providing reassurance and reducing anxiety. Reassurance rather than detection of recurrence may be the most important function of the breast cancer follow-up clinic.

Adult↗
PubMed1992

Relationships between vital capacity, height and nasal airway resistance in asymptomatic volunteers.

Nasal airway resistance (NAR), vital capacity and height were measured in 76 asymptomatic volunteers aged between 18 and 71, mean age 28 +/- 1.4 years. Total NAR ranged from 0.15-0.39 Pa/cm3/s, with a mean total NAR of 0.23 +/- 0.006 Pa/cm3/s. Despite a good correlation between vital capacity and height in these subjects (r = 0.76) no relationships were found between either total NAR and vital capacity or total NAR and height. Physiological NAR is not related to vital capacity or height in normal healthy individuals.

Adult↗
PubMed1992

Scalp as a donor site for grafts to facial and neck burns in children.

In facial and neck burns, attention to cosmetic details, in addition to preservation of function, is crucial. The authors describe use of the scalp as a graft donor site for such burns. The advantages include excellent colour match of the graft and minimal morbidity at the donor site. The technique for graft harvest is outlined, and the potential pitfalls are described. Based on their experience with this technique, the authors believe the scalp should be considered as a donor graft site during the acute phase of facial and neck burns.

Burns↗