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Biomedical subjects

I A MacFarlane

Publications and source records attributed to I A MacFarlane.

100 records · Page 6Linked to original sources

Acromegaly due to production of a growth hormone releasing factor by a bronchial carcinoid tumor.

We have studied growth hormone production in a patient with a bronchial carcinoid and acromegaly. The absence of growth hormone from the carcinoid tumour was demonstrated by extraction, cell culture and immunoperosidase techniques. Using a linked perfusion culture system, effluent from the bronchial carcinoid tumour culture stimulated a rapid release of growth hormone from a rat pituitary monolayer. This is the first time evidence of growth hormone releasing activity by a bronchial carcinoid has been demonstrated in a production.

Acromegaly↗

Radiation-induced hyperprolactinaemia in a treated acromegalic.

A 31-year-old acromegalic was normoprolactinaemic after partial removal of her pituitary tumour. The post-operative external pituitary irradiation lowered the mean growth hormone (GH) level from 75 mU/1 to less than 1 mU/1 within 2 years. However, at the same time hyperprolactinaemia developed. These changes in the GH and prolactin levels were confirmed 3 and 4 years after irradiation. The cause of the hyperprolactinaemia was radiation-induced hypothalamic damage. Therefore it is suggested that similar damage may occur in patients receiving external pituitary irradiation for 'prolactinomas' and that this mechanism may contribute to the persistent hyperprolactinaemia observed in such patients.

Acromegaly↗

Endocrine morbidity in adults treated with cerebral irradiation for brain tumours during childhood.

Hypothalamic-pituitary function was assessed in 20 adult subjects who were treated with cerebral irradiation for brain tumours during childhood between 8 and 32 years earlier. Nine patients showed impaired growth hormone (GH) responses to hypoglycaemia, of whom, 7 are below the third centile for standing height. All GH deficient subjects received more than 2950 rads to the hypothalamic-pituitary axis with a maximum dose of approximately 5000 rads being used in one case. Three subjects have an elevated basal serum thyroid stimulating hormone (TSH) level and 2 of these show an exaggerated TSH response to thyrotrophin releasing hormone (TRH) but no patient was clinically or biochemically hypothyroid. The rest of hypothalamic-pituitary function was essentially normal. This study shows that multiple pituitary hormone deficiencies do no develop with time when the radiation dose is below a critical level. Thus it appears that there is a gradation of radiation damage to the hypothalamic-pituitary axis which is dependent primarily on the dose received rather than the time interval after radiotherapy.

Adolescent↗

How accurate is the smoking history in newly diagnosed diabetic patients?

A smoking history was obtained from 94 consecutive newly diagnosed diabetic patients referred to an adult diabetic clinic. The smoking load was measured using urinary cotinine/creatinine ratios (COT/Cr). Fifty-six patients (60%) claimed to be non-smokers, but COT/Cr suggested active smoking in five of these. The patients who admitted to smoking were given standardised anti-smoking advice. At 3 months, 32 smoking patients were reviewed and 21 (66%) claimed to have reduced or stopped smoking. However, the median COT/Cr in the 32 patients showed no significant reduction (11.15 vs. 9.30 micrograms/mg). Urinary COT/Cr indicated that 6 patients had stopped smoking (median COT/Cr 6.98 fell to 0.97 micrograms/mg), but several patients had a marked rise in COT/Cr, demonstrating that their smoking habit had increased considerably. Therefore the smoking history obtained from new diabetic patients can be very misleading. An objective measure of smoking habits in the initial assessment and follow-up of diabetes may be worthwhile. Anti-smoking counselling at diagnosis of diabetes may persuade some smokers to stop.

Adult↗

Electrical spinal-cord stimulation for painful diabetic peripheral neuropathy.

BACKGROUND: Conventional treatment for painful peripheral diabetic neuropathy is largely symptomatic and often ineffective, with unacceptable side-effects. We tested electrical spinal-cord stimulation for the management of chronic neuropathic pain. METHODS: Ten diabetic patients who did not respond to conventional treatment (mean age 51 [SD 9.3] years, six with type II diabetes, mean duration of diabetes 12 [6.3] years, mean duration of neuropathy 5 [2.1] years) were studied. The electrode was implanted in the thoracic/lumbar epidural space. Immediate neuropathic pain relief was assessed by visual analogue scale (VAS) after connecting the electrode, in a random order, to a percutaneous electrical stimulator or to a placebo stimulator. Exercise tolerance was assessed on a treadmill. FINDINGS: Eight subjects had statistically significant pain relief with the electrical stimulator (p < 0.02) and were therefore converted to a permanent system. Statistically significant relief of both background and peak neuropathic pain was achieved at 3 months (n = 7, p = 0.016), at 6 months (n = 7, p = 0.03), and at the end of the study (14 months, n = 7, background pain p = 0.06, peak pain p = 0.03). One patient died 2 months after the start of the study of unrelated cause while continuing to benefit from treatment and another patient ceased to benefit at 4 months. McGill pain questionnaire scores with the stimulator turned off did not change significantly from baseline scores, indicating that the severity of the underlying pain was unaltered. However, with the stimulator turned on, there was a statistically significant (p < 0.05) improvement in all four components of the score, by the end of the study. At the end of the study, six patients continued to gain significant pain relief and used the stimulator as the sole treatment for their neuropathic pain. For example, median background and peak pain scores at the end of study, were, respectively, 77 and 81 with the stimulator off and 23 and 20 with the stimulator on. Exercise tolerance significantly improved at 3 months (n = 7, median % increase 85 [IQR, 62-360], p = 0.015) and at 6 months (n = 6, 163 [61-425], p = 0.0007). Electrophysiological tests, vibration perception-threshold, and glycaemic control were unchanged. INTERPRETATION: Electrical spinal-cord stimulation offers a new and effective way of relieving chronic diabetic neuropathic pain and improves exercise tolerance. The technique should be considered in patients with neuropathic pain who do not respond to conventional treatment.

Chronic Disease↗

Smoking habits and painful diabetic neuropathy.

In order to assess the relationship between chronic painful diabetic neuropathy and current--or lifetime--smoking habits, the smoking history of 49 diabetic patients was investigated and compared with that of 23 diabetic patients without chronic pain (age 51.0 +/- 1.9 years, mean +/- SEM). Current level of nicotine intake was measured using urinary cotinine (a nicotine metabolite), and expressed as cotinine/creatinine ratio (COT/Cr), and lifetime smoking load by pack years (20 cigarettes per day for 1 year equals 1 pack year). Current pain intensity was evaluated using a visual analogue scale (VAS). The presence of chronic painful diabetic neuropathy was based on clinical history and examination. Of those patients with painful neuropathy, 26% were current smokers (age 54.2 +/- 3.2 years, mean +/- SEM), 31% ex-smokers (age 57.0 +/- 2.9 years), and 43% lifelong nonsmokers (age 58.0 +/- 2.9 years). Pain duration and intensity were similar in all three groups. COT/Cr levels were similar in current diabetic smokers with pain [5.0 (0.2-10.6) micrograms/mg] and the diabetic control group of smokers without pain [6.8 (1.8-13.3) micrograms/mg, NS]. There was no relationship between VAS and either COT/Cr levels or pack years in current smokers, or between duration of pain and pack years in diabetic current or ex-smokers. In conclusion, we found no relationship between current or previous levels of smoking and severity or duration of chronic painful diabetic neuropathy.

Diabetes Mellitus, Type 1↗

A prospective study of painful symptoms, small-fibre function and peripheral vascular disease in chronic painful diabetic neuropathy.

Fifty diabetic patients with chronic painful sensorimotor neuropathy were studied prospectively to clarify the natural history of this condition and the roles of small-fibre damage and concomitant peripheral vascular disease (PVD). Initially, 30 patients had no significant PVD (ankle:brachial Doppler ratio > 1.0). Pain was assessed using a visual analogue scale (0-10 cm), and small-fibre function by thermal limen (TL), heat-pain threshold (HPT), and weighted pinprick threshold (PPT). At follow-up, on average 3.6 years later (range 3.0-4.1), 11 patients had died (6 with PVD) and contact had been lost with 6. Pain scores fell in subjects without PVD (n = 24; median (range), from 4.8 (0.5-10.0) to 2.0 (0.0-9.2) cm, p < 0.001) and also in those with PVD (n = 9; from 5.1 (2.0-8.2) to 2.1 (0.0-8.0) cm, p < 0.05). Seven patients (5 without PVD) became painfree; at presentation, these 7 patients had experienced pain for a shorter period of time. Despite this symptomatic improvement, small-fibre function generally deteriorated in both groups, with significant worsening (p < 0.05) of HPT and PPT in patients without PVD, and in HPT and TL in patients with PVD. Neuropathic pain therefore tends to improve with time and can resolve completely. By contrast, small-fibre function continues to deteriorate, indicating that these peripheral measures do not predict the evolution of painful symptoms. The presence or absence of PVD does not appear to affect the natural history of neuropathic pain or its symptomatology.

Adult↗

Home glucose monitoring in type 2 diabetes: is it a waste of time?

A cross-sectional study to assess home glucose monitoring practices was conducted in 200 non-insulin-treated diabetic patients consecutively attending our hospital clinic. Of the 200, 97 (48%) patients (Group 1) regularly monitored urine (n = 74), blood (n = 19) or both (n = 4); 103 (52%) patients (Group 2) performed no home monitoring. The two groups were similar in terms of age, sex, duration of diabetes and type of treatment. The prevalence of diabetic complications was also closely comparable and only peripheral neuropathy differed between the groups, being more common in Group 1 (n = 12) than Group 2 (n = 4); p < 0.05. There was also no significant difference between the HbA1 concentration (mean +/- SD) in Group 1 (9.7 +/- 2.2%) and Group 2 (9.4 +/- 2.0%). The mean frequency of home monitoring was four tests weekly, but only 21 (22%) kept a written record and 60 (62%) would never alter their treatment on the basis of their results. Almost a third of patients could not interpret the results of monitoring or give the normal range of values. Home glucose monitoring, particularly of urine, is widely practised in Type 2 diabetes, at considerable overall expense. However, convincing evidence of its value in helping patients improve their blood glucose control or preventing the complications of the disease is lacking.

Blood Glucose↗