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Biomedical subjects

B Morgan

Publications and source records attributed to B Morgan.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effect of age on myocardial infarction and thrombolysis.

Thrombolytic therapy has emerged as the treatment of choice for patients presenting with an acute myocardial infarction. Myocardial infarction is a major cause of morbidity and mortality in the elderly. Advancing age has been considered a relative contraindication to thrombolytic therapy despite the potential for the elderly to derive the greatest benefit from this therapy. This trend not to treat the elderly has been based on a perceived increased risk of complications. Available data pooled from several studies clearly show that the elderly benefit from thrombolytic therapy.

Aged↗
PubMed1995

The elective use of oxytocin infusion during labour in nulliparous women using epidural analgesia: a randomised double-blind placebo-controlled trial.

The obstetric outcome following the elective use of oxytocin infusion was determined in a randomised, double-blind placebo-controlled trial. 93 nulliparous women in a London hospital, who had requested epidural analgesia in labour (</= 6 cm.), were given an infusion of oxytocin (n = 46) or placebo (n = 47). The initial epidural dose was 15 ml of 0.125% bupivacaine, followed by an infusion at 10 ml per h, with 15 ml top-ups if required. When oxytocin was used electively there was a reduction in the length of the first stage of labour from 696 min to 578 min, (P < 0.05) even though more than half of the control group (53%) required oxytocin augmentation. There was no significant difference between the number of operative deliveries (34 [74%] vs 35 [74%]). The rotational delivery rate was less in the study group (2 [4%] vs 5 [11%]), though this did not reach significance. There were no adverse effects on the fetus, as judged by cord pH measurement, Apgar score, admission to the special care baby unit and neonatal jaundice. The prophylactic use of oxytocin in nulliparous women with epidurals reduces the length of the first stage of labour and appears to be safe. It does not reduce the operative delivery rate.

Journal Article↗
PubMed1995

Hypertension and sleep apnoea.

Epidemiological data indicate a link between sleep-disordered breathing and elevation of arterial pressure. Previous studies suggest increased activity of the sympathetic nervous system in patients with sleep apnoea. The response of muscle sympathetic nerve activity was further investigated in normal, awake subjects following exposure to 20 minutes of asphyxia. Sympathetic nerve traffic increased during exposure and remained elevated even after the return to room air breathing. These findings raise the possibility that this sustained elevation of sympathetic nerve traffic could play a role in the development of daytime hypertension in patients with sleep-disordered breathing.

Journal Article↗
PubMed1995

Blood pressure changes during labour and whilst ambulating with combined spinal epidural analgesia.

OBJECTIVE: To determine the influence of combined spinal epidural analgesia with fentanyl and low dose bupivacaine on maternal blood pressure and pulse rate in labour. Also, to evaluate the maternal cardiovascular response to mobilising with this form of analgesia in labour. Finally, to define the changes that occur in blood pressure and pulse rate during the second stage of labour and immediately postpartum when using combined spinal epidural analgesia. DESIGN: A prospective observational study. SUBJECTS AND METHODS: Blood pressure and pulse measurements were made at least every 10 minutes, using the SpaceLabs 90207 ambulatory blood pressure monitor, on 62 women in labour with combined spinal epidural analgesia. RESULTS: A significant fall in systolic blood pressure (> 20%) occurred in eight women (12%), all within 30 minutes of the spinal injection. Fifty-two women subsequently received an epidural dose (mean interval 90 minutes after spinal) and none of these women had a fall in systolic blood pressure of greater than 20%. No women had symptoms related to hypotension. Thirty-five women ambulated for more than 10 minutes on 65 occasions. Average blood pressure remained unchanged while ambulating (126/79 versus 126/79), but pulse rate was significantly increased (85 to 90, P < or = 0.001). The mean blood pressure in the second stage of labour (n = 41) did not rise with pushing (134/83 versus 134/83), but the pulse rate increased significantly (94 to 108, P < or = 0.001). Blood pressure remained unchanged immediately postpartum (n = 33) (134/83 versus 134/81) following ergometrine administration. CONCLUSION: The combined spinal epidural analgesia will only result in significant falls in systolic blood pressure within 30 minutes of the spinal injection. No further important changes in blood pressure occur when mobilising or with epidural top-ups. The combined spinal epidural analgesia may modify the normal compensatory mechanisms of blood pressure control, but does not cause significant maternal hypotension once the spinal injection has been given.

Analgesia, Epidural↗
PubMed1994

A novel and major isoform of tyrosine hydroxylase in Drosophila is generated by alternative RNA processing.

We report that two isoforms of Drosophila tyrosine hydroxylase protein are encoded via alternatively spliced exons. The major isoform (Type II) contains a novel acidic extension of 71 amino acids in the amino-terminal regulatory domain, which is likely to alter the regulatory properties of the tyrosine hydroxylase protein. The minor isoform (Type I) corresponds to the cDNA sequence reported previously. We also report the structure of the Drosophila tyrosine hydroxylase (DTH) gene and the diversity and tissue localization of its transcripts. At least three types of DTH mRNA are generated from a single primary transcript through alternative splicing and polyadenylation. Type II mRNA is the most abundant tyrosine hydroxylase transcript in Drosophila and is found predominantly in the hypoderm throughout all stages of development. Type I mRNA is present only in the CNS, where it is the primary form. The DTH transcripts detected in the CNS contain a longer 3'-untranslated region than the transcript expressed in the hypoderm, due to differential polyadenylation. In contrast, the same start site is used for DTH gene transcription in both tissues. These results show unexpected diversity in the DTH transcripts and point out possible mechanisms for differential regulation of tyrosine hydroxylase activity in the CNS and in the hypoderm.

Alternative Splicing↗
PubMed1994

Spying on mothers.

Explore the source record for details and available documents.

Airway Obstruction↗
PubMed1993

Posture and the spread of hyperbaric bupivacaine in parturients using the combined spinal epidural technique.

This study was undertaken to analyze the effect of posture on the spread of hyperbaric bupivacaine in pregnant women using a combined spinal extradural technique, and to assess the quality of analgesia provided by 10 mg bupivacaine when using this technique. Fifty parturients undergoing elective Caesarean section under regional anaesthesia were randomly allocated to receive 2.0 ml hyperbaric bupivacaine 0.5% in either the sitting or left lateral position. Spinal injection was performed with a 27 gauge, 120 mm long spinal needle using a single space combined spinal extradural technique. The onset time to analgesia at T4, and grade 3 motor block was on average 7.7 min and 6.9 min respectively in the lateral group, compared with 10.8 min (P < 0.05) and 9.4 min (P < 0.05) in the sitting group. Nine women in the sitting group and one woman (P < 0.05) in the lateral group required epidural supplementation. Hypotension occurred in 48% of the parturients in the lateral group and in 13% (P < 0.05) of the parturients in the sitting group. Nausea was noted in 61% of the parturients in the lateral group and in 22% (P < 0.05) of the parturients in the sitting group. There was no difference between the two groups in neonatal outcome. Overall, the position of the patient during induction of spinal anaesthesia does influence the rate of onset of analgesia and motor blockade. Injection of 10 mg hyperbaric bupivacaine in the sitting position would not provide adequate analgesia for Caesarean section when using a single space combined spinal extradural technique.

Adult↗
PubMed1993

Effect of epidural opioids on gastric emptying in labour.

The effect of epidural opioids on gastric emptying was studied in 36 women in labour. Women who had received one dose of epidural bupivacaine were randomised to receive 10 ml of bupivacaine 0.25% alone (n = 8) with fentanyl 50 microg (n = 8) or with diamorphine 2.5 mg (n = 8), or 10 ml of bupivacaine 0.125% alone (n = 4) or with fentanyl 100 microg (n = 4) or with diamorphine 5 mg (n = 4) when they first requested a top-up. Mean+/-SD fentanyl concentrations measured at delivery were, in maternal venous plasma (MV) 0.72+/-0.19 ng/ml and in umbilical venous plasma (UV) 0.75+/-0.3 ng/ml. The mean dose-delivery interval was 280 min (range 107-608 min) and there was a negative correlation between UV/MV and dose-delivery interval. Gastric emptying was assessed by measuring paracetamol absorption following an oral dose of 1.5 g given 30 minutes after the study top-up. Time to peak plasma paracetamol concentration was significantly delayed in the groups given fentanyl 50 and 100 microg and diamorphine 5 mg, compared to the groups given bupivacaine alone, and peak concentration was significantly reduced in the group given diamorphine 5 mg. It is concluded that epidural fentanyl 50 and 100 mg and epidural diamorphine 5 mg delay gastric emptying. The addition of 2.5 mg diamorphine has no significant effect.

Journal Article↗
PubMed1993

Incremental spinal anaesthesia for elective caesarean section: maternal and fetal haemodynamic effects.

We have performed serial haemodynamic investigations in 20 women undergoing elective Caesarean section under continuous spinal anaesthesia with a 32-gauge catheter with 0.5% heavy bupivacaine. Cardiac output was measured by Doppler and cross-sectional echocardiography at the aortic valve. Doppler flow velocity waveforms were recorded also from the umbilical artery. A block to T4 or above was achieved in all patients. The median dose of 0.5% bupivacaine administered was 2.0 ml (range 1.5-4.5 ml). Mean cardiac output increased from 7 to 8 litre min-1 after preloading with Ringer lactate solution 1.5 litre and then remained unchanged after injection of bupivacaine. Two subjects developed hypotension, although mean values of arterial pressure and umbilical artery pulsatility index did not change. The median umbilical artery pH was 7.27 (range 6.98-7.32) and there was a significant correlation between pH and the maximum percentage decrease in cardiac output. The results suggest that continuous spinal anaesthesia is associated with greater haemodynamic stability than single bolus spinal injection.

Adult↗
PubMed1993

Caring for the community.

Humboldt Home Health Services, in Eureka, California, has stretched its vision of "good business" to include the development of many new programs that not only respond directly to patient and community needs, but are also economically viable, self-sustaining, and builders of staff self-esteem.

Acquired Immunodeficiency Syndrome↗
PubMed1993

Electronic dental anesthesia: a pilot study.

Electronic dental anesthesia uses the Gate Control Theory of transcutaneous electrical nerve stimulation. The battery-controlled Ultracalm electronic dental anesthesia unit is a noninvasive procedure to electrically block pain transmissions in dental patients. This pilot study to test the efficacy of electronic dental anesthesia for simple restorative procedures was subjectively reported by 20 patients who had never been exposed to this type of anesthesia. None of the patients indicated the procedure was uncomfortable, and 14 of 20 subjects indicated that they preferred electronic dental anesthesia to local anesthetic injection. Electronic dental anesthesia appears to be an effective means of obtaining local anesthesia for certain dental procedures.

Adolescent↗
PubMed1992

Effects of nerve growth factor and acetyl-L-carnitine arginyl amide on the human neuronal line HCN-1A.

The HCN-1A clonal cell line, derived from the cortical tissue of a patient with unilateral megencephaly, was shown to differentiate into a mature neuronal-like state in the presence of the nerve growth factor, dibutyryl cyclic adenosine, 3',5'-monophosphate and either 1-isobutyl-3-methylxanthine or forskolin. Differentiation was assessed by measuring the percentage of cells that displayed branched, varicose processes that stained for synaptophysin. Treatment of cultures with a cocktail containing forskolin increased immunocytochemical staining for gamma aminobutyric (GABA), neurofilament protein and the nerve growth factor receptor species p75NGFR. Treatment with acetyl-L-carnitine alone had some effects on the cell morphology while acetyl-L-carnitine arginyl amide and nerve growth factor together increased the GABA content. Positive staining levels for the neurotransmitters gamma aminobutyric acid, glutamate, somatostatin, cholecystokinin and vasoactive intestinal polypeptide were measured quantitatively for HCN-1A under basal conditions.

1-Methyl-3-isobutylxanthine↗
PubMed1992

Plasma total and free concentrations of bupivacaine and lignocaine in mother and fetus following epidural administration, singly or together.

Forty six women undergoing elective caesarean section under epidural blockade were given 20 ml of either bupivacaine 0.5% plain (B) or with adrenaline 5 microg/ml (B + A), lignocaine 2% with adrenaline 5 microg/ml (L + A) or a mixture of equal parts of L + A and B + A (BLA). Further doses of the same solution were given at 20 min if necessary. Free and total plasma concentrations of the local anaesthetics were measured in maternal venous plasma 10, 20, 40, 60 and 120 min after the main dose and in umbilical venous plasma at delivery. Protein binding of both drugs was significantly higher in mother than baby. Lignocaine did not affect bupivacaine binding but lignocaine binding was higher in group BLA than L + A. Otherwise the presence of one drug had little effect on the disposition of the other drug in mother or baby. No plasma concentrations were considered toxic. Adrenaline did not reduce maternal C(max) of free bupivacaine and appeared to be associated with increased fetal uptake of bupivacaine.

Journal Article↗