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Biomedical subjects

G M Hall

Publications and source records attributed to G M Hall.

At least 19 recordsLinked to original sources
PubMed1995

Markers of bone metabolism in postmenopausal women with rheumatoid arthritis. Effects of corticosteroids and hormone replacement therapy.

OBJECTIVE: To investigate bone metabolism in postmenopausal women with rheumatoid arthritis (RA) treated with or not treated with corticosteroids, and the response to hormone replacement therapy (HRT). METHODS: One hundred six RA patients were divided into those taking low-dose steroids (RA+; n = 35) and those not (RA-; n = 71) and randomly allocated to receive HRT or calcium for 2 years. Bone formation markers included serum osteocalcin (OC) and bone-specific alkaline phosphatase, and resorption markers included urinary deoxypyridinoline (DPyr) and CrossLaps (XL). Bone mineral density (BMD) was measured annually using dual x-ray absorptiometry. RESULTS: OC levels were significantly lower in both the RA+ and RA- groups compared with 112 healthy control subjects (P < 0.01 and P < 0.05, respectively), but were similar in the 2 RA groups. DPyr and XL levels were elevated in the RA+ group compared with the RA- group (P < 0.05) but were similar between the RA- group and controls. OC was negatively correlated with parameters of disease activity (P < 0.05). After HRT, XL excretion decreased significantly in the overall RA group. Three-month changes in XL correlated with 2-year changes in spinal BMD (P < 0.01). CONCLUSION: Bone metabolism may be uncoupled in chronic RA. Bone formation appears to be reduced, partly reflecting disease activity, whereas resorption is increased only in steroid users. HRT reduces resorption in RA irrespective of steroid usage, emphasizing its value in the treatment of postmenopausal women with RA.

Absorptiometry, Photon↗
PubMed1995

Metabolic control of non-insulin-dependent diabetic patients undergoing cataract surgery: comparison of local and general anaesthesia.

We studied 40 elderly patients undergoing cataract surgery. Ten non-insulin-dependent diabetes mellitus (NIDDM) patients received standardized general anaesthesia, 10 NIDDM patients received local anaesthesia using retrobulbar block, 10 non-diabetic control patients received general anaesthesia and 10 non-diabetic controls received retrobulbar block. We measured sequential changes in blood glucose, lactate and beta-hydroxybutyrate, serum cortisol and insulin, and plasma non-esterified fatty acid concentrations until 4 h after operation. The results showed that in both general anaesthesia groups, NIDDM and control, blood glucose and serum cortisol concentrations increased significantly during surgery, before returning to normal by 4 h after operation; in both local anaesthesia groups, glucose and cortisol concentrations changed little during surgery. Serum insulin concentrations increased 30 min after operation to coincide with the peak of the glucose increase in the non-diabetic patients who received general anaesthesia, but no insulin response was seen in the diabetic general anaesthesia patients. Blood glucose and insulin concentrations increased in patients who received local anaesthesia (NIDDM and controls) when they ate after operation. The results show that cataract surgery under local anaesthesia provides improved metabolic control for the diabetic patient. Its use maintains glucose homeostasis, prevents the increases in cortisol and glucose which are seen under general anaesthesia and obviates the need for postoperative starvation.

Aged↗
PubMed1995

Hormonal effects of thoracic extradural analgesia for cardiac surgery.

We have investigated the hormonal and metabolic effects of thoracic extradural analgesia with bupivacaine in addition to sufentanil 20 micrograms kg-1 in nine patients undergoing coronary artery bypass surgery. A control group received general anaesthesia alone. The catecholamine response was inhibited for 24 h after surgery in patients who had received extradural analgesia, and the cortisol response was suppressed during cardiopulmonary bypass. Blood glucose values were unchanged until 24 h after surgery in the extradural group. There were no significant differences in cardiac index between the two groups of patients, although heart rate and mean arterial pressure decreased before surgery in patients who received extradural analgesia. The benefits of this technique in terms of a reduction in postoperative morbidity remain to be determined.

Adult↗
PubMed1995

The effects of differing concentrations of bupivacaine on the epidural somatosensory evoked potential after posterior tibial nerve stimulation.

The somatosensory evoked potential (SEP) recorded from the cervical epidural space in response to stimulation of the posterior tibial nerve is often used to monitor spinal cord integrity during scoliosis surgery. Epidural analgesia may be used as part of the anesthetic technique for scoliosis surgery, but the effects of the local analgesic on the evoked potential must be determined to ensure that it does not interfere with the monitoring of spinal cord function. Therefore, we compared the effects of the administration of 10 mL of 0.25% (n = 8), 0.5% (n = 8), or 0.75% (n = 8) bupivacaine injected into the L3-4 epidural space on the somatosensory evoked potential to posterior tibial nerve stimulation in patients anesthetized with a propofol infusion, nitrous oxide and oxygen, immediately before scoliosis surgery. Compared with a control group (n = 8), a concentration-dependent effect of bupivacaine was found on overall amplitude of the evoked potentials and the amplitude of all peaks. There were no significant differences between 0.25% bupivacaine and the control group, but both 0.5% and 0.75% bupivacaine were associated with clinically and statistically significant decreases in overall amplitude (P < 0.002, 0.5% bupivacaine; P < 0.001, 0.75% bupivacaine). Latency increased similarly in all groups. We conclude that bupivacaine in concentrations greater than 0.25% is not suitable for scoliosis surgery, if spinal somatosensory evoked potentials (SSEP) are to be measured.

Adolescent↗
PubMed1994

Effect of hormone replacement therapy on bone mass in rheumatoid arthritis patients treated with and without steroids.

OBJECTIVE: To assess the effect of hormone replacement therapy (HRT) on bone mass in rheumatoid arthritis (RA) patients treated with and those not treated with steroids. METHODS: Two hundred postmenopausal women with RA (ages 45-65 years) were randomly allocated to receive transdermal estradiol (hormone replacement therapy; HRT) (50 micrograms daily) or calcium supplementation (400 mg daily) for 2 years. Forty-two of the patients (21%) were taking corticosteroids. Bone mineral density of the lumbar spine (BMDLS) and of the proximal femur (BMDF) was measured at study entry and at 12 months and 24 months. RESULTS: In the HRT group overall, mean BMDLS had changed by +2.22% (95% confidence interval [95% CI] +0.72, +3.72) and mean BMDF by -0.41% (95% CI -1.89, +1.07) after 24 months. In the calcium group, mean BMDLS changed by -1.19% (95% CI -2.29, -0.09) and mean BMDF by -0.56% (95% CI -2.60, +1.48). Differences between treatment groups were significant for the spine only (P < 0.001). In the 21 HRT-treated patients taking steroids, BMDLS increased by 3.75% (95% CI +0.72, +6.78) and BMDF by 1.62% (95% CI -1.27, +4.51). CONCLUSION: This study shows that HRT increases spinal BMD and maintains femoral BMD in postmenopausal RA. HRT is also an effective agent in preserving bone mass in patients taking low-dose corticosteroids.

Adrenal Cortex Hormones↗
PubMed1994

Effects of extradural anaesthesia on interleukin-6 and acute phase response to surgery.

Serum concentrations of the cytokine, interleukin-6 (IL-6), increase after surgical trauma. IL-6 mediates the synthesis of acute phase proteins and stimulates secretion of pituitary hormones. We have examined the time course of circulating IL-6, and cortisol and growth hormone responses in patients undergoing hysterectomy to determine if IL-6 contributes to the early pituitary hormone changes found during surgery. One group (n = 8) received a standardized general anaesthetic while the remaining patients (n = 8) received extradural analgesia to T4-S5 in addition to a similar general anaesthetic. In the general anaesthesia group, there was a significant increase in serum cortisol and growth hormone concentrations before any changes in IL-6 were detected. Furthermore, in the extradural group, in whom these hormonal responses were attenuated, circulating IL-6 concentrations did not differ significantly from the general anaesthesia group. There were no significant differences between the groups in the acute phase response, as measured by circulating concentrations of C-reactive protein and zinc, but the expected effects of extradural block on circulating metabolites and white cell count were demonstrated. We conclude that IL-6 is unlikely to contribute to the initial increases in secretion of pituitary hormones found during surgery, but a later effect of the cytokine on endocrine responses cannot be excluded.

Acute-Phase Proteins↗
PubMed1994

Etidocaine and extradural somatosensory evoked potentials after posterior tibial nerve stimulation.

We have examined the effects of lumbar extradural administration of 1% etidocaine 10 ml on somatosensory evoked potentials to posterior tibial nerve stimulation measured in the cervical extradural space. Eight patients, anaesthetized with propofol and nitrous oxide, were studied before hysterectomy and a control group received a similar anaesthetic and 0.9% sodium chloride solution 10 ml in the lumbar extradural space. Etidocaine decreased significantly overall amplitude of the evoked potentials and the amplitudes of all peaks, between 30 and 50 min after extradural injection. The effects of etidocaine on spinal cord conduction were greater than those found previously for lignocaine and bupivacaine, suggesting that it is the local analgesic of choice for inhibiting afferent conduction.

Adult↗
PubMed1994

Circulating fluoride changes and hepatorenal function following sevoflurane anaesthesia.

Sevoflurane, a new volatile inhalational agent, undergoes biotransformation to fluoride which is potentially nephrotoxic. We compared the effects of sevoflurane or isoflurane anaesthesia on hepatorenal function and serum fluoride concentrations in 50 ASA 1-3 patients undergoing major intra-abdominal surgery. No patient developed renal or hepatic dysfunction. Mean (SEM) peak fluoride concentrations were 23.1 (1.5) mumol.l-1 for sevoflurane and 5.4 (0.4) mumol.l-1 for isoflurane (p < 0.001). There was a significant correlation in the sevoflurane group between the total dose of agent (MAC h), the total fluoride production (r = 0.78, p = 0.0001) and peak fluoride concentration (r = 0.57, p = 0.003). There was no correlation between these variables in the isoflurane group.

Adult↗
PubMed1994

Sevoflurane anaesthesia for major intra-abdominal surgery.

The cardiovascular effects and recovery characteristics of sevoflurane and isoflurane anaesthesia were compared in 30 gynaecological and 20 general surgical patients undergoing elective intra-abdominal surgery. Patients were randomly allocated to receive either sevoflurane or isoflurane as the volatile agent, in a balanced anaesthetic technique including morphine and atropine premedication and thiopentone, fentanyl, vecuronium and nitrous oxide. The concentration of volatile agent was titrated according to clinical variables. Mean heart rate, systolic and diastolic arterial pressure and duration of surgery did not differ between the two groups. Time to emergence from anaesthesia in the gynaecological patients was significantly faster after sevoflurane compared with isoflurane (p < 0.005). Sevoflurane provided stable anaesthesia during major intra-abdominal surgery.

Abdomen↗
PubMed1994

Growth hormone suppression and glutamine flux associated with cardiac surgery.

Pharmacological doses of growth hormone (GH) in humans and rats increase plasma and muscle glutamine values. As major surgery results in a physiological rise in serum GH concentration, we investigated whether this physiological increase in GH altered glutamine metabolism. Eighteen patients undergoing coronary artery bypass graft (CABG) surgery were randomly assigned to receive somatostatin, 100 micrograms subcutaneously at induction of anaesthesia and 8 hourly for 48 h, or placebo. Somatostatin effectively blocked the physiological surge of GH following injury but did not affect plasma or muscle glutamine concentrations, which fell significantly in both groups. Plasma glutamine decreased by 31% (P < 0.01) and 28% (P < 0.01) in the control and somatostatin groups respectively. Muscle glutamine was reduced 45% (P < 0.001) in the control group and 50% (P < 0.001) in the somatostatin group. There was no difference in muscle or circulating glutamate, alanine or branched chain amino acid concentrations or in metabolite values between the somatostatin-treated patients and the control group. There was no relationship between the GH response to surgery and glutamine metabolism following major surgery.

Blood Glucose↗
PubMed1992

Granulocyte margination in the human lung and its response to strenuous exercise.

1. It is widely believed that the lung is an important site of granulocyte margination and releases most of the granulocytes of the peripheral neutrophilia of exercise. 2. We measured granulocyte margination in the lung in terms of the lung total blood granulocyte pool and the lung circulating granulocyte pool in eight patients without inflammatory disease or evidence of lung pathology by comparing the regional gamma-camera lung count rate of 111In-labelled granulocytes with that of 111In-labelled erythrocytes. According to the respective 111In activities in peripheral blood samples taken between 5 and 40 min after granulocyte injection, the lung marginating granulocyte pool was 0.78 (SEM 0.045) of the lung total blood granulocyte pool or 4.6 (0.92) of the lung circulating granulocyte pool 5 min after injection, decreasing to plateau values of 0.57 (0.053) and 1.53 (0.28) from 20 min after injection. This compared with corresponding whole-body ratios of about 0.6 and 1.5, respectively. 3. After 4 min of maximal exercise in four normal subjects given 111In-labelled granulocytes 60 min before exercise, the 111In-labelled granulocyte count rate over the lung increased to 1.23 (0.05) of the pre-exercise value with a time course that was essentially identical with the time course of the peripheral native neutrophilia. The spleen 111In signal decreased with the same time course, reaching a minimum of 0.63 (0.05) of the pre-exercise level at 5-10 min after the end of exercise.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Intrasplenic blood cell kinetics in man before and after brief maximal exercise.

1. After a 4 min period of maximal exercise in 10 normal subjects (14 studies), there was a consistent decrease in total blood volume and a consistent increase in erythrocyte indices, which were maximal immediately after exercise. Peripheral platelet and leucocyte counts increased, but did not reach maximal values until 5-10 min after the end of exercise. 2. The distributions of 99mTc-labelled erythrocytes (five studies), 111In-labelled platelets (five studies) and 111In-labelled granulocytes (four studies) were monitored with a gamma-camera immediately after injection and before and after maximal exercise performed 60 min after injection. 3. Labelled erythrocytes equilibrated rapidly between the spleen and circulating blood after injection, whereas labelled platelets and granulocytes equilibrated more slowly. After exercise, each cell type was released from the spleen with a time course that was the reciprocal of the time course of the corresponding cell count in peripheral blood. Thus, whereas the radioactivity of 99mTc-labelled erythrocytes in the spleen, which fell to 0.46 (SD 0.09) of the pre-exercise value, increased towards its baseline value as soon as exercise was completed, the radioactivities of 111In-labelled platelets and 111In-labelled granulocytes decreased, to respective minimum values of 0.61 (0.09) and 0.63 (0.09) of the pre-exercise levels, 5-10 min after the end of exercise. The exercise-induced changes in lung radioactivity for each cell type, and their time courses, broadly reflected those in the corresponding cell counts in peripheral blood. Liver radioactivity tended to decrease for each cell type.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Keratan sulphate in rheumatoid arthritis, osteoarthritis, and inflammatory diseases.

Serum concentrations of antigenic keratan sulphate determined by an enzyme linked immunosorbent assay (ELISA) with a monoclonal antibody were studied in patients with rheumatoid arthritis (RA), osteoarthritis, ankylosing spondylitis, other inflammatory diseases, and a large control group of women without arthritis. Mean keratan sulphate concentrations were low in 117 women with RA compared with 227 female control subjects matched for age drawn from a community survey. There were significant correlations between serum keratan sulphate concentrations in patients with RA and serum C reactive protein and the erythrocyte sedimentation rate. Serum keratan sulphate concentrations were also low in 29 men and women with ankylosing spondylitis and 29 patients with arthritis and high concentrations of C reactive protein. In 98 women undergoing an operation for benign breast disease there were decreases in serum keratan sulphate concentrations after the operation which correlated with doses in serum C reactive protein. No differences were found in keratan sulphate concentrations in 137 women with osteoarthritis compared with controls. Within the group with osteoarthritis there were no differences for the various joint groups and there was no obvious correlation with radiographic severity or progression. These findings suggest serum keratan sulphate is unlikely to be useful as a diagnostic marker in osteoarthritis or RA but indicate a role for inflammation in the regulation of cartilage loss.

Acute-Phase Reaction↗
PubMed1992

The effects of gender and sex hormones on outcome in rheumatoid arthritis.

Disease patterns in RA vary between the sexes; the condition is more commonly seen in women, who exhibit a more aggressive disease and a poorer long-term outcome. Men, however, are more likely than women to die from extra-articular complications of rheumatoid disease. This chapter discusses the outcome and mortality studies that substantiate these conclusions and then examines the possible mechanisms that may account for them, including the HLA system, seropositivity, compliance, response to therapy and pain threshold. In particular, sex and sex hormones emerge as independent risk factors in rheumatoid disease. The epidemiological evidence points towards a peak age of onset of RA at the time of the menopause in women and towards later in life in men. Premenopausal women may fare better than postmenopausal women with RA. The possible protective effects of the oral contraceptive pill and the dramatic amelioration with pregnancy are well documented. In vivo and in vitro studies have demonstrated that sex hormones interfere with a number of the putative processes involved in the pathogenesis of RA, including immunoregulation, interaction with inflammatory mediators and the cytokine system, and direct effects on cartilage itself. All these observations point towards the importance of gonadal hormones. However, trials on the potential therapeutic use of sex hormones in RA are limited and, as yet, disappointing. Further work is necessary to determine whether the roles of sex hormones are as central protagonists or just supporting cast in the complex arena of rheumatoid disease.

Age Factors↗