Preliminary results of proton magnetic resonance spectroscopy in motor neurone disease (amytrophic lateral sclerosis).

Possible changes in brain metabolites in motor neurone disease/amytrophic lateral sclerosis (MND/ALS) were investigated using 1H magnetic resonance spectroscopy (MRS). A series of normal, healthy volunteer controls and MND patients have been studied using a spin echo (SE) 135 ms sequence, acquiring spectra from the region of the motor cortex. A further limited series of studies have been made for similar groups of volunteers and MND patients using a STEAM 20 ms sequence (stimulated echo). Analysis of the SE 135 ms spectra indicates there are statistically significant differences in the ratios of N-acetyl-aspartate to creatine and N-acetyl-aspartate to choline between controls and MND patients. Furthermore, metabolites identified using the STEAM 20 ms may be of great importance in the investigations of free radical mediated mechanisms, which have been postulated as being important contributors to the disease process. Preliminary results indicate that 1H MRS may provide important data to help understand the disease processes in MND and it could form a useful method for monitoring the effects of future trial treatment regimens.

Serum fructosamine and glycated haemoglobin measurements in diabetic control.

Serum fructosamine and glycated haemoglobin (HbA1) were measured in capillary samples from diabetic children and compared with samples from non-diabetic children. Glycaemic control was assessed clinically and by average daily glucose values recorded by home monitoring. Fructosamine correlated with HbA1 and with average glucose values measured over 30 days. HbA1 also correlated with average glucose values measured over 60 days. Changes in fructosamine with time tended to parallel those of HbA1, and advance indication of deteriorating or improving glycaemic control was possible by observing changes in these. Fructosamine has many advantages over HbA1 measurement such as speed, technical ease, and low cost, and is a reliable alternative to HbA1 estimation as an indication of glycaemic control.

The diagnostic value of glycated haemoglobin levels in post-mortem blood.

Glycated haemoglobin (HbA1) in post mortem blood was estimated following electrophoretic separation. HbA1 was measured in preserved and unpreserved specimens and its stability in vitro was studied. No significant change in the proportion of HbA1 was observed in samples stored for more than 40 days at 4 degrees C. Specimens were analysed for glucose and HbA1. There was poor correlation between these parameters, and no significant difference between the mean values of HbA1 in specimens collected within 24, 48 and 72 or more hours following death, from subjects with no previous history of diabetes. The levels were within the laboratory reference range, whilst eight specimens collected from diabetic subjects demonstrated elevated levels. There was no significant difference in HbA1 levels collected from different sites in the body even though the glucose levels showed some variation. The measurement and apparent stability of HbA1 post mortem may be a more useful diagnostic test than glucose alone where diabetes may be suspected.

The estimation of serum fructosamine: an alternative measurement to glycated haemoglobin.

A method is presented for the estimation of fructosamine using a Cobas Bio centrifugal analyser. The effect of three different preparations of human serum albumin used for construction of calibration curves of 1-deoxy-1-morpholinofructose is described. The selection of serum albumin and the concentration used in the standard solutions is critical since the dose-response curve is affected differently and will therefore influence the estimated values. Normal ranges were obtained for non-diabetic subjects with normal protein status and for a group of females with reduced albumin levels due to pregnancy or oestrogen therapy. There was no significant difference between fructosamine levels in these populations. Fructosamine was also estimated in 250 patients attending a diabetic out-patient department and this correlated well with haemoglobin A1 estimated simultaneously. The method is rapid, technically simple and inexpensive and may prove to be a useful and reliable alternative to HbA1 estimation.

Physiological changes and sleep responses during and following a world record continuous walking record.

Physiological changes, and subsequent sleep responses, were recorded in a male subject during and following 338 miles of continuous walking and consequent sleep deprivation. One hundred and thirty hours of walking and a seventy-two hours post-walk recovery period were monitored. The subject walked at approximately 55% of maximum oxygen uptake (VO2 max), heart rate ranged between 102-106 b/min, and blood lactate (LA) remained below the 2 mmol/l level. No electrocardiograph abnormalities were observed either during the walk or pre- and post-functional diagnostic graded exercise test (FDGXT). Creatine kinase (CK) and creatine kinase isoenzyme (CK-MB) levels rose throughout the walk but exhibited differing depletion patterns. The ratio of CK-MB to CK (MB/CK%) did not exceed levels which are suggestive of myocardial ischaemia. Haematological variables demonstrated signs of anaemia towards the end of the walk. Catecholamine levels rose throughout the walk, with greater rises being observed in nor-adrenaline and dopamine. During the post-walk recovery phase, adrenaline concentration remained elevated. Following this extreme period of exertion, the subject demonstrated very short sleep latency and rapid entry into slow wave sleep (SWS). These sleep patterns were compared to sleep recordings made over a similar period (72 h) six months post-walk, when the subject was not exercising. Nocturnal growth hormone (GH) levels were significantly raised on the post-walk nights.