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Biomedical subjects

P Phelan

Publications and source records attributed to P Phelan.

At least 37 records · Page 2Linked to original sources
PubMed1994

13C-n.m.r. of the cyanylated beta-lactoglobulins: evidence that Cys-121 provides the thiol group of beta-lactoglobulins A and B.

The thiol groups of beta-lactoglobulins A and B have been cyanylated using [13C]KCN. The samples of [cyanato-13C]-cyanylated-beta-lactoglobulins A and B which we prepared had signals at 109.7 p.p.m. and 114.4 p.p.m. We conclude that the thiocyanate carbon having a chemical shift of 109.7 p.p.m. is in an apolar environment similar to a cyclohexane solvent, whereas the thiocyanate carbon having a chemical shift of 114.4 p.p.m. is in a polar environment similar to water. The signals with chemical shifts of 109.7 p.p.m. are assigned to the thiocyanate carbons of the native [cyanato-13C]cyanylated-beta-lactoglobulins A and B. We deduce that the signal at 114.4 p.p.m. is due to an irreversibly denatured/unfolded species produced by alkaline denaturation, which is caused by intramolecular thiol/disulphide exchange occurring during our cyanylation procedure. We propose that Cys-119 is cyanylated in the irreversibly denatured species and Cys-121 is cyanylated in the native [cyanato-13C]cyanylated-beta-lactoglobulins A and B. We suggest that the same intramolecular thiol-disulphide exchange reactions occurred when McKenzie and co-workers [McKenzie, Ralston and Shaw (1972) Biochemistry 11, 4539-4547] alkylated beta-lactoglobulins with iodoacetamide. Therefore the one mol of thiol/mol of monomer in the native beta-lactoglobulins is due to the thiol of Cys-121 and is not due to an equimolar mixture of Cys-119 and Cys-121 as they suggested.

Animals↗
PubMed1993

Characterisation of high-affinity and low-affinity receptors for ciliary neurotrophic factor.

Ciliary neurotrophic factor (CNTF) supports the survival of a wide variety of neuronal cells in culture. To characterise the receptor(s) mediating the biological responses of CNTF we measured the binding of radiolabelled CNTF to chick sympathetic neurons and human neuroblastoma cells. Two distinct CNTF-binding sites with high and low affinity for the ligand were identified by steady-state binding experiments. Furthermore, two low-affinity binding sites could be discriminated on the basis of the dissociation rates. Cross-linking experiments showed that CNTF interacts with two proteins, one of 80 kDa and one of 140 kDa. The identity of the 80-kDa protein was determined by transient transfection experiments with the rat CNTF-binding protein CNTFR alpha while the properties of the 140-kDa protein correspond to those of gp130. Antisense experiments confirmed that CNTFR alpha is necessary for high affinity binding of 125I-CNTF and therefore a necessary subunit of the high-affinity receptor.

Animals↗
PubMed1991

Assessment and treatment of childhood asthma.

In June 1990 a meeting of Paediatric Respiratory Physicians was held near Adelaide. The guidelines for assessing and treating asthma as prepared by the Thoracic Society of Australia and New Zealand for the management of patients with asthma was considered. Although not explicitly stated, these guidelines were designed for adult asthmatics. There was complete agreement that a companion statement was needed to take into account differences between the management of children and adults. This document fulfils that role. Further recommendations are found in a statement prepared by Australian and New Zealand respiratory paediatricians following a workshop in June 1989. This present statement should be read in association with the previous documents.

Asthma↗
PubMed1991

The problem of neonatal diagnosis related groups.

There is, as yet, no satisfactory set of Diagnosis Related Groups to measure the casemix and consumption of hospital resources in the care of newborn infants. To obtain further information, infants less than 28 days when admitted to the Royal Children's Hospital and Royal Women's Hospital, Melbourne were analysed. Both Refined Diagnosis Related Groups and Pediatric Modified Diagnosis Groups were used. Neonatal groups of the Pediatric Modified system included all infants aged less than 28 days on admission, whereas Refined Diagnosis Related Groups includes only those newborn infants who have diagnoses specific to the newborn period. Refined Diagnosis Related Groups and their higher order contained 1,237 discharges. Standard deviation and coefficient of variation and length of stay in these RDRG were high. However, if the patients in these RDRGs were further grouped according to PMDRGs, there appeared to be more homogeneous missing. The R2 values were four times higher. It is recommended that a satisfactory form of neonatal DRGs is to regroup patients in neonatal RDRGs through a PMDRG grouper.

Australia↗
PubMed1990

Steroids in croup: do they increase the incidence of successful extubation?

Between January 1983 and July 1988, 2623 patients with croup were admitted to the Royal Children's Hospital, Melbourne. A total of 416 patients (16%) were admitted to the Intensive Care Unit and 176 of these patients required intubation. Of these patients 117 patients were successfully extubated at the first attempt and 59 needed reintubation. Of the patients who were reintubated 35 were given steroids prior to subsequent extubation attempts. Only one patient who had received steroids failed extubation. Of those who did not receive steroids 59% required reintubation. In patients with croup who fail the first extubation the results of this study suggest that steroids significantly increase the success of subsequent extubations.

Adolescent↗
PubMed1990

Diagnosis related groups, refined diagnosis related groups and pediatric modified diagnosis related groups in specialist children's hospitals.

The value of Diagnosis Related Groups, Refinement Diagnosis Related Groups and Pediatric Modified Diagnosis Related Groups in measuring the output of specialist children's hospitals was evaluated by the examination of discharge data for 1987-88 from three major Australian children's hospitals and four district hospitals. The study included all patients aged 0-18 years but excluded those with specific neonatal diagnoses. Findings indicated that Refinement Diagnosis Related Groups seem to give a better measure of the output of specialist children's hospitals than Version 5 Diagnosis Related Groups in that they explained a higher proportion of variation of length of stay. Pediatric Modified Diagnosis Related Groups developed in the United States of America for specialist children's hospitals overall did not seem to have major advantages over Refinement Diagnosis Related Groups but there were some specific Pediatric Groups that appeared beneficial. Further modification of the Refinement Diagnosis Related Groups could allow these advantages to be incorporated. Overall it seems preferable for there to be a similar system measuring output of both children's hospitals and general hospitals and this could be achieved by some minor changes to the Refinement Diagnosis Related Groups.

Adolescent↗
PubMed1988

Acute epiglottitis: a different approach to management.

Between January 1979 and October 1986, 349 patients with epiglottitis were admitted to the Royal Children's Hospital, Melbourne, Australia. Forty-five (13%) patients were not intubated, 291 (83%) were managed by nasotracheal intubation and spontaneous respiration without sedation, three (1%) received continuous positive airway pressure, and ten (3%) were ventilated. The 294 patients who were not ventilated were intubated for a mean of 18 +/- 9.5 (SD) h; 90% were extubated within 24 h. Criteria for extubation included resolution of fever (less than 37.5 degrees C), passage of time (12 to 16 h), and improvement in the general appearance of the child. Laryngoscopy was not performed before extubation. Providing there is always a doctor present who can reintubate if accidental extubation occurs, routine use of sedation, paralysis and mechanical ventilation, and pre-extubation laryngoscopy are not required for the management of children with uncomplicated epiglottitis, and their use may prolong the period of intubation.

Acute Disease↗
PubMed1986

The process of incest: biologic father and stepfather families.

This article compares incest between biologic fathers and their daughters and stepfathers and their stepdaughters. The term "incest" is applied to each of these types of families. The sample for the study was located in a mental health treatment facility designed to work specifically with incestuous families and includes 102 cases (56 stepfather families; 46 biologic father families). The data were obtained by interviews with the four primary program therapists. Differences in sexual behavior between the two groups indicated that biologic fathers more frequently engaged in full intercourse, more frequently involved multiple daughters and more frequently began the sexual activity when their daughters were adolescents than did stepfathers. Possible explanations of the differences are explored.

Adolescent↗
PubMed1985

Snoring in children: is it pathological?

Some children who snore heavily, have been shown to have periods of apnoea which, if frequent, are known as the obstructive sleep apnoea syndrome (OSA). Twenty patients with OSA, who presented to the Department of Thoracic Medicine, Royal Children's Hospital, Melbourne, over a three-year period, were reviewed. The findings indicated that OSA is more common than is generally supposed and that it can present with a wide range of symptoms. It is important that an early diagnosis of this syndrome is made, to prevent major complications and to allow appropriate therapy.

Adenoidectomy↗
PubMed1985

Sodium valproate stimulates the particulate form of glutamine synthetase in rat brain.

The anticonvulsant drug, sodium valproate, enhanced total activity of glutamine synthetase in cortical and cerebellar homogenates of the rat at concentrations of 25-50 mM, without significantly altering substrate affinity. This effect was due to a selective increase in the Vmax and substrate affinity of the enzyme in the particulate fraction. At the same concentration the drug caused little change in the Vmax of the cytosolic enzyme, although the substrate affinity was reduced. These effects cannot be attributed to isozymes of glutamine synthetase as only one form could be demonstrated by ion-exchange chromatography or electroblotting with antibodies to glutamine synthetase. This selective stimulation of particulate glutamine synthetase is suggested to be due to increases in membrane fluidity induced by the drug. The contribution of these effects to the mechanistic action of sodium valproate is discussed.

Animals↗
PubMed1985

Rib cage mobility in pectus excavatum.

Pectus excavatum is generally regarded as a cosmetic deformity; however, some children with pectus excavatum complain of chest pain and exercise limitation. Physiologic studies sometimes show mild restrictive changes and suggest an increased oxygen cost of breathing. Limitation of rib cage mobility related to the deformity may explain these findings. If rib cage mobility is limited, the ability of the actively inspiring rib cage to lower abdominal pressure would be decreased. If this were so, increased swings in abdominal pressure would be seen during the respiratory cycle, especially at times of stress such as during exercise. To test the hypothesis that pectus excavatum is associated with decreased rib cage mobility, we studied 11 patients with pectus excavatum and 11 control subjects. Four control subjects were also studied with rib cage mobility restricted by chest wall strapping sufficient to decrease vital capacity by 5, 10, and 40%. Gastric pressure was measured using balloon catheters and was used as an index of abdominal pressure. Flow at the mouth was recorded and integrated to give volume. Measurements were made at rest, immediately after exercise, and during graded voluntary inspiration to total lung capacity. Gastric pressure was related to tidal volume, and pressure-volume loops were constructed. There were no differences in abdominal pressure swings during respiration between the patients with pectus excavatum and the control subjects. Both groups showed moderate increase in gastric pressure during inspiration at rest and smaller increases or even decreases in abdominal pressure at end inspiration after exercise and at total lung capacity.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1978

Offspring of incest.

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Congenital Abnormalities↗