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Biomedical subjects

F R Ellis

Publications and source records attributed to F R Ellis.

At least 37 records · Page 2Linked to original sources
PubMed1993

Genetic mapping of the beta 1- and gamma-subunits of the human skeletal muscle L-type voltage-dependent calcium channel on chromosome 17q and exclusion as candidate genes for malignant hyperthermia susceptibility.

Malignant hyperthermia susceptibility (MHS) is an autosomal dominant disorder of skeletal muscle which manifests as a life-threatening hypermetabolic crisis triggered by commonly-used inhalation anaesthetics and depolarizing muscle relaxants. Defects in the ryanodine receptor (RYR1) protein have been proposed to underly MHS, but significant genetic heterogeneity in MHS has recently been demonstrated. In order to investigate the potential roles played by other skeletal muscle calcium channels in MHS, we isolated cosmids containing the gene encoding the beta 1-subunit of skeletal muscle L-type voltage-dependent calcium channel (CACNLB1). We identified a new, highly polymorphic dinucleotide repeat motif close to this gene, and linkage analysis placed the marker proximal to the HOX2B locus, previously localized to chromosome segment 17q21-q22. We recently identified a novel marker within the gamma-subunit locus (CACNLG) at band 17q24, and since both markers are within the 17q11.2-q24 region reported to contain the MHS2 locus, we tested them for linkage in MHS families whose disease trait has been shown not to co-segregate with markers for the RYR1 region on chromosome 19q13.1. Our results exclude CACNLB1 and CACNLG as candidate genes for MHS2, and do not support the reported chromosome 17q localization for the MHS2 locus in our families.

Base Sequence↗
PubMed1993

Estimation of the correct length of tracheal tubes in adults.

Estimation of the correct length of a tracheal tube is extremely important and should be tailored to the needs of the individual patient. One hundred and eight patients who required tracheal intubation during anaesthesia were studied. The predicted length was estimated in each patient before induction of anaesthesia. The upper end of the cuff was aligned externally with the cricoid cartilage, while the more proximal part of the tube lay alongside the neck to the angle of the mandible. The tube was then curved forwards towards the upper incisor teeth, and the length at the teeth or gums was noted. The anaesthetist, who was unaware of the predicted length, intubated the trachea after induction of anaesthesia. The length of tube inserted was standardised in relation to the vocal cords, and the actual length of tube inserted was recorded. The estimated length was within 1.0 cm and 1.5 cm of the actual length in 91% and 97% of patients respectively.

Adolescent↗
PubMed1992

Effect of addition of hyaluronidase to bupivacaine during axillary brachial plexus block.

We have studied in 22 patients the effect of adding hyaluronidase to bupivacaine during axillary brachial plexus block (BPB) in a double-blind design. Patients received BPB using bupivacaine 2 mg kg-1 with adrenaline 1 in 200,000, either with or without hyaluronidase 3000 iu, in a volume of 0.5 ml per 2.54 cm of the patient's height. The use of hyaluronidase did not increase the speed of onset of anaesthesia or reduce the incidence of inadequate nerve block. Hyaluronidase produced a significant reduction in the duration of anaesthesia. Changes in grip strength and skin temperature were useful in assessing the onset and progress of BPB.

Adult↗
PubMed1992

Does postoperative pyrexia indicate malignant hyperthermia susceptibility?

We are frequently asked if patients, in whom only postoperative pyrexia has been observed, should be considered as potentially susceptible to malignant hyperthermia (MHS). Of 30 patients of this type studied in this Unit, none was shown to be MHS. We consider that postoperative pyrexia alone is unlikely to signify MH.

Disease Susceptibility↗
PubMed1992

Esmolol hydrochloride for management of the cardiovascular stress responses to laryngoscopy and tracheal intubation.

In a double-blind, randomized, controlled prospective study, 30 grade ASA I/II patients received a continuous i.v. infusion of normal saline or esmolol hydrochloride before induction of anaesthesia and tracheal intubation. Arterial pressure and heart rate were measured to assess the pressor response to laryngoscopy and intubation. The heart rate decreased in the esmolol group before induction of anaesthesia. The pressor response to laryngoscopy was significantly less marked in the esmolol group.

Anesthesia, General↗
PubMed1992

Is the "K-type" caffeine-halothane responder susceptible to malignant hyperthermia?

The "K-type" designation is used to describe a patient being investigated for malignant hyperthermia (MH) when concurrent administration of caffeine and halothane induces muscle contracture (rigidity, spasm) in vitro, but when halothane and caffeine given separately produce a normal response. It is accepted in some centres that K-type individuals are susceptible to malignant hyperthermia (MHS). In this paper, the K-type is shown not to correlate with the MH susceptible (MHS) status as accepted by the European MH group.

Caffeine↗
PubMed1992

Evaluation of spin resonance spectroscopy of red blood cell membranes to detect malignant hyperthermia susceptibility.

We have evaluated a spin labelled electron spin resonance technique to identify malignant hyperthermia susceptible (MHS) patients. We studied 19 patients, 10 MHS and nine MHN (normal), using the standard European procedure. We were unable to obtain any evidence that this technique could be used to diagnose MH susceptibility. Furthermore, there was no significant difference in the fluidity of the red blood cell membranes between the two groups, which would have been indicative of a generalized membrane abnormality in MH.

Disease Susceptibility↗
PubMed1992

A study into the incidence of methaemoglobinaemia after 'three-in-one' block with prilocaine.

A 34-year-old female patient developed methaemoglobinaemia following a femoral nerve block using prilocaine. The concentrations of methaemoglobin in the blood of the next eight patients receiving this block were assayed, and found to be significantly increased above baseline concentrations, but very significantly less than the concentration in the patient with symptomatic methaemoglobinaemia. Pulse oximetry was of value in making the diagnosis.

Adult↗
PubMed1991

Evidence for related myopathies in exertional heat stroke and malignant hyperthermia.

Malignant hyperthermia may be a human stress syndrome, of which heat stroke is one manifestation. Two men in military service who had episodes of exertional heat stroke, and their immediate family members, were tested for susceptibility to malignant hyperthermia by in-vitro contracture tests on skeletal muscle samples. Muscle from both patients had a normal response to caffeine but an abnormal response to halothane. Muscle from the father of one patient had an abnormal response to halothane, and that from the father of the second patient had an abnormal response to ryanodine. The results indicate that clinical heat stroke may be associated with an underlying inherited abnormality of skeletal muscle that is similar, but not identical, to that of malignant hyperthermia.

Adult↗
PubMed1991

Ryanodine contracture: a potentially specific in vitro diagnostic test for malignant hyperthermia.

In vitro contracture tests used currently for malignant hyperthermia (MH) do not possess absolute specificity. This is potentially a great problem in the study of the genetic approach which offers the best prospect for the development of a non-invasive diagnostic test for the condition. The calcium release channel of the sarcoplasmic reticulum has been proposed as the site of the MH defect. Ryanodine, which binds avidly to this channel, was shown to differentiate between muscle of MH susceptible and normal patients in terms of in vitro contracture response. This ryanodine contracture response is proposed as a potentially specific in vitro diagnostic test for MH.

Culture Techniques↗
PubMed1991

Evaluation of local anaesthetic blockade of the lateral femoral cutaneous nerve.

An assessment of local anaesthetic blockade of the lateral femoral cutaneous nerve using a standard technique was made. The rate of successful blockade was high, but the area of sensory loss was inconsistent between patients and was more anterior and distal than described in textbooks of anatomy.

Evaluation Studies as Topic↗