Search PubMed⌕ Search

Biomedical subjects

S Morris

Publications and source records attributed to S Morris.

At least 163 records · Page 9Linked to original sources
PubMed1994

Teaching fibreoptic intubation. Effect of alfentanil on the haemodynamic response.

A technique for teaching fibreoptic orotracheal intubation in patients under general anaesthesia is described and evaluated. A standard general anaesthetic was administered to 60 patients presenting for elective gynaecological surgery. Patients were randomly assigned to receive either alfentanil 10 micrograms.kg-1 or a placebo, and to be intubated either by a consultant experienced in the use of the fibreoptic bronchoscope or by an inexperienced trainee under instruction. Heart rate, arterial pressure and oxygen saturation were monitored continuously. The time to achieve tracheal intubation in the trainee group was significantly prolonged (p < 0.001), but no patient developed arterial desaturation. The hypertensive response to fibreoptic intubation was suppressed in those patients who received alfentanil (p < 0.001). The increase in heart rate was not suppressed, but was attenuated when these patients were compared with those who had received the placebo (p < 0.001). Alfentanil 10 micrograms.kg-1 minimises the haemodynamic response when teaching fibreoptic orotracheal intubation under general anaesthesia.

Adolescent↗
PubMed1994

An assessment of prilocaine as a topical anaesthetic agent for fibreoptic bronchoscopy in comparison with lidocaine.

We have evaluated prilocaine as a topical anaesthetic agent for fibreoptic bronchoscopy in comparison with lidocaine in terms of efficacy and safety. Forty patients were included in a randomised double-blind parallel-group study. Efficacy was assessed using visual analogue scales, a patient ranking scale and the number of doses of local anaesthetic and intravenous sedative required. Measures of toxicity included peak plasma concentration of local anaesthetic, whether supplementary oxygen was needed and change in methaemoglobin concentration. For most of the outcome variables, the medians and quartiles were similar for the two local anaesthetics. However, the median peak plasma concentration of prilocaine (0.5 micrograms.ml-1) was less than one-third that of lidocaine (1.76 micrograms.ml-1). The merits and hazards of using multiple-regression modelling to improve the precision of the analysis of the results are considered. We conclude that prilocaine can be used successfully as a topical anaesthetic agent for fibreoptic bronchoscopy and is associated with a lower risk of toxicity.

Adult↗
PubMed1994

Transcranial Doppler sonography in headache-free migraineurs.

We used transcranial Doppler ultrasonography to determine whether intracranial blood velocities in 182 headache-free migraineurs (60 with aura, 122 without aura) differed from velocities in 38 nonheadache prone control subjects. During the headache-free period, migraineurs with and without aura had significantly elevated mean velocities in all intracranial arteries except the right internal carotid artery at the level of the siphon. Velocities in migraineurs with aura did not differ significantly from velocities in those without aura. Markedly increased velocities were noted in a subset of interictal migraineurs. Two explanations are possible: 1) Blood flow velocities may increase in response to a decrease in the cross sectional area of a vessel at or near the point of insonation. 2) Alterations at the level of the cerebral arteriole may affect regional cerebral blood flow, thereby changing blood flow velocities at the point of insonation. Transcranial Doppler sonography alone cannot sort out which process is responsible for the vascular response. This work may have therapeutic as well as diagnostic implications. When interictal flow velocities are markedly increased, it is possible that therapeutic agents with vasoconstrictor action might cause an excessive response. Further study is needed to clarify the sites of vasoreactivity as well as the magnitude of drug-induced vasoconstrictor response.

Adult↗
PubMed1994

Clinical features and treatment outcome for children with CD30+ large-cell non-Hodgkin's lymphoma.

PURPOSE: To determine the frequency of CD30 expression and its relationship to clinical features, immunophenotype, histotype, and outcome in childhood large-cell non-Hodgkin's lymphoma (NHL). PATIENTS AND METHODS: We reviewed 45 cases of large-cell NHL in children treated at St Jude Children's Research Hospital from 1975 to 1990 for whom there was sufficient tissue to perform immunophenotypic studies. All 45 were screened with a panel of antibodies to detect the presence of CD30 and T-cell and B-cell antigens. Cases were classified according to the National Cancer Institute (NCI) Working Formulation and the Kiel classification system. Clinical features, immunophenotype, pathologic classification, and treatment outcome were compared for CD30+ and CD30- cases. RESULTS: CD30 expression was documented in 18 cases (40%). These 13 boys and five girls had a median age of 13 years at diagnosis. Most (n = 14) had advanced-stage (III and IV) disease. Nodal disease was equally common in CD30+ and CD30- cases, whereas skin involvement was significantly more frequent in CD30+ cases (P = .007). There was no significant association of CD30 expression with histologic subtype according to the NCI Working Formulation, but CD30+ cases were more likely to be anaplastic by the Kiel classification (P < .001). All CD30+ cases had either T-cell or null-cell phenotype, while the majority of CD30- cases were B-cell phenotype (P < .001). Among patients with limited-stage disease, the mean +/- SE estimated 5-year event-free survival (EFS) was 75% +/- 22% for CD30+ cases and 92% +/- 9% for CD30- cases (P = .10); estimates for advanced-stage disease were 57% +/- 17% and 29% +/- 17%, respectively (P = .096). For patients with advanced-stage disease, CD30 expression was associated with a significantly better overall 5-year survival probability (84% +/- 12% v 27% +/- 16%, P = .0016). CONCLUSION: CD30 is frequently expressed in pediatric large-cell NHL and is significantly associated with T-cell or null-cell phenotype, anaplastic morphology, skin involvement, and better overall survival among advanced-stage patients.

Adolescent↗
PubMed1994

EXERCISE IN THE TERRESTRIAL CHRISTMAS ISLAND RED CRAB GECARCOIDEA NATALIS - BLOOD GAS TRANSPORT

The respiratory and circulatory physiology of the terrestrial Christmas Island red crab Gecarcoidea natalis was investigated with respect to exercise in the context of its annual breeding migration. Red crabs were allowed to walk for predetermined periods of up to 45 min. During this exercise period, blood gas measurements were made on venous, pulmonary and arterial samples to assess the function of the lungs in gas exchange and the performance of the circulatory system in gas transport and to determine the role and importance of the haemocyanin. The lungs of G. natalis were very efficient at O2 uptake, pulmonary blood being 80&shy;90 % saturated throughout the 45 min exercise period. The maximum O2-carrying capacity was 1.1 mmol l-1, and haemocyanin (Hc) delivered 86 % of oxygen in resting crabs and 97 % during exercise. Oxygen delivery to the tissues was diffusion-limited during exercise. Indirect evidence, from the changes in haemolymph pH during transit through the lungs, suggested that the lung is the site of CO2 excretion. The Bohr shift was high at high pH (pH 7.8&shy;7.5, phi=-1.23) but decreased at low pH (pH 7.1&shy;6.8, phi=-0.48). The decreased Hc affinity for O2 during the exercise period facilitated O2 delivery to the tissues without impairing O2 loading at the lungs. The decrease in pH was sufficient to explain the change of affinity of Hc for O2 during the exercise period. The marked acidosis (0.8 pH unit decrease) was largely metabolic in origin, especially during sustained locomotion, but less than could be predicted from concomitant lactate production.

Journal Article↗
PubMed1994

EXERCISE IN THE TERRESTRIAL CHRISTMAS ISLAND RED CRAB GECARCOIDEA NATALIS - ENERGETICS OF LOCOMOTION

The respiratory and circulatory physiology of exercising Christmas Island red crabs Gecarcoidea natalis were investigated with respect to their annual breeding migration. Red crabs were allowed to walk for up to 45 min. During this exercise period, the functioning of the circulatory system in gas transport and the energy status of the red crabs were quantified. Energy production during exercise required both aerobic and anaerobic contributions. The aerobic scope of G. natalis was low, with only a doubling of the resting rate of oxygen consumption (resting M(dot)O2=95&plusmn;15 &micro;mol kg-1 min-1). Maximal O2 consumption was attained within the first 5 min of exercise and the level remained stable thereafter. The anaerobic contribution to energy production was directly related to the speed of locomotion. l-lactate levels in blood and leg muscle were similar throughout the exercise period; blood lactate concentration was 33.39&plusmn;2.29 mmol l-1 after 45 min of exercise. Heart rate in resting animals was 56&plusmn;7 beats min-1. At the onset of exercise, heart rate also doubled, but without a significant increase in cardiac output. Increased O2 delivery was facilitated by increased extraction from the blood. During the 45 min of exercise, glucose levels increased rapidly in the muscle tissue (from 2.30&plusmn;0.54 to 8.78&plusmn;1.20 mmol l-1) and subsequently in the blood (from 1.22&plusmn;0.26 to 2.12&plusmn;0.17 mmol l-1), fuelling increased glycolysis during locomotion. The energy production from stored glucose/glycogen was sufficient to support the energetic needs of locomotion, since the energy charge remained stable at 0.82. Haemolymph l-lactate levels in crabs sampled in the field after migration were high compared with levels in many crustacean species but equivalent to l-lactate levels in laboratory animals exercised for less than 10 min. During their migration, therefore, the red crabs avoid exceptional l-lactate build-up in the blood by either walking very slowly or intermittently. However, G. natalis are exceptionally well adapted to cope with exhaustive locomotion and the resultant severe metabolic acidosis.

Journal Article↗
PubMed1994

Heterothermy, torpor, respiratory gas exchange, water balance and the effect of feeding in Gould's long-eared bat Nyctophilus gouldi.

The effects of temperature and nutritional status on the metabolic rate of Nyctophilus gouldi were examined. Bats fed marked meals first defecated approximately 1.34 h after feeding and were calculated to have a mean retention time of 5.38 +/- 0.57 h but to be truly post-absorptive after 9 h. Over the temperature range 1-35 degrees C, the metabolic rate (Vo2) and body temperature (Tb) of fasted bats were extremely labile. Below 30 degrees C, the bats all entered torpor and between 10 and 15 degrees C showed a mean 84% reduction over the maximal Vo2. Body temperature was also minimal over this range (Tb = 12.5 degrees C, Ta = 10-15 degrees C). Both total and dry thermal conductance increased in a curvilinear manner with temperature, total conductance from 3.38 +/- 0.65 J g-1 h-1 degree C-1 at 1 degree C to 24.25 +/- 1.99 J g-1 h-1 degree C-1 at 35 degrees C (mean +/- S.E.M.), while the rate of evaporative water loss increased with Ta by a maximum of 10-fold from 0.21 mg g-1 h-1 at 5 degrees C to 2.69 mg g-1h-1 at 35 degrees C. Between 10 and 25 degrees C, intermittent respiration characterised by episodic bouts of breathing/gas exchange and periods of apnoea with no measurable Vo2 occurred. Although the duration of apnoea decreased when temperature was increased, the volume of oxygen taken up in each episode did not change. Mean respiratory exchange ratio (RER) was low (0.64-0.77) in post-absorptive bats, typical of fat utilisation, but during torpor ranged from near 0 to near 2, indicating discontinuous and disproportional gas exchange. Feeding produced a condition of relatively sustained homeothermy and high RER in the bats which persisted for 9 h, after which the N. gouldi became torpid. Immediately after feeding, the Vo2 of the bats increased fivefold above the post-absorptive level, while the Vco2 increased by more than eightfold. Similarly, body temperature also increased, declining to torpid values after 9. The RER in immediately post-feeding bats was near 1.0 but subsequently declined to near 0.7, indicating a switch from carbohydrate to fat utilisation. Therefore, the N. gouldi were heterothermic, exhibited a highly labile metabolic rate, and rates of heat and water loss, and Tb which were influenced both by ambient temperature and by nutritional status.

Animal Feed↗
PubMed1994

A paired comparison of dot blot hybridization and PCR amplification for HPV testing of cervical scrapes interpreted as CIN 1.

The rate of Human Papillomavirus (HPV) detection in CIN 1 lesions is quite variable for several reasons. Amongst these, the sensitivity level of the HPV detection system probably ranks supreme. The prevalence of HPV DNA in cervical scrape samples from 234 patients referred for colposcopic investigation of a CIN 1 lesion was compared using dot blot hybridization (DBH) and polymerase chain reaction (PCR) amplification. Both methods were performed on the same patient sample so that determinants of HPV positivity other than the detection system could be controlled. Probes and primers to HPV 6, 11, 16, 18, 31, 33, and 35, and consensus HPV primers were used. The overall HPV positivity rate was 24% using DBH and 70% using PCR. Identified types by DBH and PCR respectively were; HPV 6/11: 1% and 2%, HPV 16/18: 16% and 41%, and HPV 31/33/35: 7% and 14%. PCR detected unidentified types in 13%. Since PCR resulted in a 2.9 times higher HPV DNA detection rate, the choice of detection system has a major impact on the HPV status of cervical smears interpreted as CIN 1.

Cervix Uteri↗
PubMed1994

Adopt-A-School Program: recruitment initiative of New York Counties Registered Nurses Association. District 13 education committee.

The goal of this program was to alleviate the existing nursing shortage in New York City by developing recruitment models appropriate for students in the City's high schools. The rationale was that well-informed nurses could create an attractive image of nursing by presenting programs to students, teachers, and guidance counselors. The program was successful in clarifying misconceptions and increasing the knowledge base regarding health issues and concerns and the role of the nurse.

Education, Nursing↗
PubMed1993

Readership survey results.

A key stage in the BDJ's current program of renovations was the readership survey, carried out last autumn. Broadly, the survey aimed to find out how dentists rated the old style BDJ against the other general interest UK journals, and how they viewed its content and design.

Consumer Behavior↗
PubMed1993

FLT4 receptor tyrosine kinase gene mapping to chromosome band 5q35 in relation to the t(2;5), t(5;6), and t(3;5) translocations.

FLT4 is a recently cloned receptor tyrosine kinase cDNA, which is characterized by seven immunoglobulin-like loops in its extracellular domain. We have previously mapped the FLT4 gene to chromosome segment 5q33-qter using somatic cell hybrids. Here we have refined the localization to band 5q35 by fluorescence in situ hybridization and show that the gene is translocated to chromosomes 2 and 6 in the t(2;5)(p23;q35) and t(5;6)(q35;p21) translocations, respectively, of Ki-I-positive lymphomas, as well as to chromosome 3 in the t(3;5)(q25.1;q34) translocation, which is occasionally found in myelodysplastic syndromes and acute myeloid leukemia. No evidence was obtained for a rearrangement or deregulation of the translocated FLT4 gene. We further show that abundant FLT4 mRNA expression occurs only in erythroid and megakaryoblastoid cell lines among nine leukemia cell lines studied.

Chromosome Mapping↗
PubMed1993

Screening Alzheimer's disease patients for mutations in the amyloid precursor protein gene.

Over the past two years a series of different mutations has been discovered in the amyloid precursor protein (APP) gene in patients with Alzheimer's disease. All have been clustered in exons 16 and 17, a region encoding the beta A4 peptide found in the amyloid deposits of neuritic plaques and cerebral blood vessels. We have used the powerful technique of denaturing gradient gel electrophoresis to screen for mutations in exons 7, 16 and 17 of the APP gene in a cohort of 105 patients with presenile dementia of the Alzheimer type and 71 patients with autopsy-confirmed senile Alzheimer's disease. No new mutations were found, confirming earlier suggestions that APP mutations account for only a small proportion of cases of familial and sporadic Alzheimer's disease.

Adult↗
PubMed1993

Follicle stimulating hormone levels on cycle day 3 predict ovulation stimulation response.

AIM: To determine the value of basal follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) levels on cycle day 3 in predicting the ovulation stimulation response in patients receiving exogenous gonadotropins for in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT). METHODS: One hundred eleven consecutive females with infertility due to various etiologies were investigated. Cycle day 3 serum levels of FSH, LH, and E2 were determined prior to ovulation induction with a combination of clomiphene citrate and human gonadotropins. Follicular growth was monitored ultrasonically, and when appropriate, oocytes were recruited, counted, graded, and then used, as prearranged, for either IVF or GIFT. Basal hormone levels were compared to the peak E2 concentration, the number of follicles aspirated, and the number of preovulatory oocytes recovered following drug therapy. Details of resulting pregnancies were also recorded. RESULTS: Patients with low basal FSH levels (< 11.5 mIu/ml) yielded a higher mean number of preovulatory oocytes than those with high values (> 11.5 mIu/ml), i.e., 6.7 oocytes per cycle vs 2.5 oocytes (P < 0.001). In the low group 97% of cycles yielded more than three fertilizable oocytes compared to 42% in the high group (P < 0.5). There were 16 term pregnancies (16%) in the low group and 1 (8.3%) in the high group. Basal LH and E2 levels did not improve on the ability to distinguish between different populations of infertile females who responded differently to ovulation induction. CONCLUSION: Cycle day 3 FSH levels are predictive of the ovulation response and probability of pregnancy in stimulated cycles and can be of value in patient selection and counseling in IVF and GIFT programs.

Abortion, Spontaneous↗