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Biomedical subjects

R J Newman

Publications and source records attributed to R J Newman.

At least 73 records · Page 4Linked to original sources
PubMed1986

A safe and effective low pressure tourniquet. A prospective evaluation.

An unusually wide pneumatic tourniquet has recently become available; we provide a simple formula for its use with a low but effective inflation pressure. A prospective, randomised and controlled trial in 600 lower limb and 150 upper limb operations is reported. The wide tourniquet (12.5 cm) was as effective at low pressure as was a conventional tourniquet (9 cm) inflated to significantly higher pressures. Fewer patients suffered from painful paraesthesiae after operation using the broad, low-pressure tourniquet.

Adult↗
PubMed1986

Nuclear magnetic resonance spectroscopy.

Nuclear magnetic resonance spectroscopy has progressed far since the original description of the phenomenon (30,31) and now permits noninvasive and harmless measurements to be repeatedly made of tissue biochemistry. Currently, there is a paucity of NMR data on normal human metabolism and the interpretation of spectra recorded from diseased tissues must be circumspect. This is further complicated by the inability of NMR spectroscopy to render accurate quantitative measurements and all observations must be considered to be compatible with, rather than diagnostic of, specific diseases. Nevertheless, NMR is an important addition to the clinician's armamentarium and these relatively expensive instruments should be situated in regional referral centres. Undoubtedly the most significant advances in NMR will only occur following the successful combination of the imaging and spectroscopic techniques, since that will enable anatomical and metabolic data to be obtained from a single site without the need for biopsy. Nuclear magnetic resonance spectroscopy has much to offer and the practical hazards appear to be few. In the next few years we will undoubtedly see an improvement in the quality of the data obtainable an a growing diversity of clinical applications.

Humans↗
PubMed1985

An in vivo study of muscle phosphate metabolism in Becker's dystrophy by 31P NMR spectroscopy.

The forearm flexor muscles of five patients with Becker's dystrophy were examined by the painless and noninvasive technique of high resolution phosphorus nuclear magnetic resonance spectroscopy. In the mildly affected cases, the ratios of the signals of phosphocreatine to ATP and to inorganic phosphate were normal but they were reduced in the patients with advanced disease. Absolute quantitation under the conditions of the study was not feasible, but it was probable that whereas in advanced Becker's dystrophy the intramyocellular concentration of phosphocreatine was reduced, that of ATP was unchanged. The intramyocellular pH was normal in three of the four patients in whom this could be measured and an additional unidentified signal between those of phosphocreatine and inorganic phosphate was recorded in two patients. This study emphasizes some metabolic similarities between Becker's and Duchenne type muscular dystrophy and suggests that nuclear magnetic resonance spectroscopy may be a useful and objective technique with which to investigate the biochemistry of these and other muscle diseases.

Adenosine Triphosphate↗
PubMed1985

Nuclear magnetic resonance studies of fracture repair.

High-resolution phosphorus nuclear magnetic resonance spectroscopy was used to monitor noninvasively the local pH changes that occur in vivo throughout fracture repair in rats. During the healing of a fractured shaft of tibia, the pH of the fracture hematoma changed from 7.2 on day two to 7.5 on day 20, i.e., alkaline with respect to the pH of normal extracellular fluid. This did not occur in a hematoma created by the direct injection of blood. Deposition of radio-opaque callus occurred mainly during the alkaline phase. Abnormalities in the control of local pH may be important in the etiology of delayed union, and future forms of local therapy may be usefully directed toward influencing this parameter.

Animals↗
PubMed1984

Rupture of the thoracic aorta and its relationship to road traffic accident characteristics.

A 3-year prospective study of road traffic accidents was carried out in Oxfordshire by a combined team of surgeons and engineers. This liaison permitted the comparison of injuries with details of the collisions. Twelve cases of rupture of the thoracic aorta were recorded and in 10 cases the lesion was just distal to the origin of the left subclavian artery. The mean velocity change during the impacts was 38.3 mph, and it is suggested that oblique and transverse forces to the chest as well as rapid deceleration are aetiological factors in this condition.

Accidents, Traffic↗
PubMed1984

Chest wall injuries and the seat belt syndrome.

A 3-year prospective study of road traffic accidents in which injuries of the chest wall were accurately recorded and related to the use of seat belts was performed in Oxfordshire by a combined team of surgeons and engineers. An increased incidence of soft tissue injuries was noted in restrained front seat occupants though this was not the case for fractures of the clavicle or sternum. The overall incidence of broken ribs in front seat passengers was not affected by the wearing of belts but the incidence of those with four or more broken ribs was considerably reduced by wearing belts.

Accidents, Traffic↗
PubMed1984

Hypophosphataemic osteomalacia and myopathy: studies with nuclear magnetic resonance spectroscopy.

A patient with familial adult-onset hypophosphataemia, whose myopathy was closely related to the plasma phosphate concentration, was investigated by phosphorus nuclear magnetic resonance spectroscopy (31P n.m.r.) in vivo of the right flexor digitorum superficialis muscle. During hypophosphataemia induced by stopping oral phosphate a significant reduction in measured muscle strength occurred, but the ratios of the intramyocellular levels of phosphocreatine (PCr), adenosine triphosphate (ATP) and inorganic phosphate (Pi) remained unchanged at rest. During exercise these levels changed, as did the intramyocellular pH, but they did not differ from the pattern previously recorded in normal subjects. In four adults with inherited infantile-onset hypophosphataemia (vitamin D-resistant rickets, VDRR) without myopathy, the n.m.r. measurements were normal at rest and during exercise. In one patient with inherited hyperphosphataemia (tumoral calcinosis) the resting PCr: Pi ratio was significantly reduced.

Adenosine Triphosphate↗
PubMed1984

The relationship between plasma catecholamines and severity of injury in man.

The relationship between plasma catecholamines and injury severity was investigated in order to determine: a) whether a correlation existed between the severity of injury as assessed by the Injury Severity Score (ISS), and circulating noradrenaline and adrenaline; and b) whether such measurements were of prognostic value. It was found that in the immediate postinjury period, both noradrenaline and adrenaline correlated positively with ISS over the range of injury studied (ISS = 0-54; r = 0.67, p less than 0.01). It appeared that part of the response might be attributed to psychological rather than physical factors; at lower levels of injury (ISS less than 9) these psychological factors were possibly responsible for the whole of the observed effect. In the subsequent recovery period (greater than 24 hr postinjury) no clear relationship between plasma catecholamines and injury severity was maintained. Studies on patients who died as a consequence of their injuries failed to confirm the previously suggested prognostic value of plasma catecholamine determinations in this later postinjury period. However, plasma noradrenaline levels in this group were significantly higher on admission than in the casualties who survived serious injury (p less than 0.05). It is concluded that plasma catecholamine concentrations, in combination with other indices of injury severity, may provide useful information on the response to injury in man, and aid in the assessment of its overall severity in physiologic terms.

Accidents, Traffic↗
PubMed1984

A prospective study of 413 consecutive car occupants with chest injuries.

A 3-year prospective study of road traffic accidents was performed in Oxfordshire by a combined team of surgeons and engineers. This liaison permitted the identification of injury sources and allowed the accurate comparison of injuries with collision severity. This was measured using the velocity change of the occupant's vehicle during the impact and was calculated using the CRASH 2 computer programme. It was shown that the pattern of chest injury varied with the direction of impact and the severity was related to the velocity change. Seatbelt use resulted in a reduction in injury severity and also modified the pattern of injuries sustained.

Accidents, Traffic↗
PubMed1984

Metabolic effects of tourniquet ischaemia studied by nuclear magnetic resonance spectroscopy.

A model of tourniquet ischaemia was developed in the hind limb of the rat, and the metabolic changes that occurred in the calf muscles were monitored by the non-invasive technique of phosphorus-31 nuclear magnetic resonance spectroscopy. During ischaemia the intramyocellular pH became acidic as the level of phosphocreatine declined and that of inorganic phosphate rose. Phosphocreatine was no longer detectable after approximately 2 hours and ATP was depleted after approximately 3.5 hours. Metabolic recovery was rapid (1 hour) if ATP was present when the tourniquet was released but was prolonged (3 or more hours) if ATP was depleted. Hourly release of the tourniquet for 10 minutes ensured the maintenance of ATP and rapid metabolic recovery. Release for intervals of only 5 minutes did not have the same protective effect and in fact worsened tissue pH during the period of tourniquet ischaemia. Heparin and corticosteroids were without effect during and after periods of tourniquet ischaemia.

Adenosine Triphosphate↗
PubMed1983

Synovial fluid lactate and the diagnosis of septic arthritis.

To assess the value of synovial fluid lactate estimation in the diagnosis of septic arthritis, 238 specimens received for routine culture and 75 reference samples were examined using a rapid enzyme technique. Samples were collected without special treatment and the effect of delay in transport to the laboratory investigated. Raised levels were found in all cases of untreated septic arthritis, in six out of ten partially treated patients and in 19 out of 219 non-septic fluids. Special treatment of the sample was unnecessary if it was examined within six hours of aspiration. The predictive value of a negative result was 98 per cent and the value of the test appeared to be in the rapid exclusion of sepsis in untreated patients.

Arthritis, Infectious↗
PubMed1983

The myotoxicity of bupivacaine, a 31P n.m.r. investigation.

Phosphorus nuclear magnetic resonance (n.m.r.) spectroscopy is a recently introduced method for the non-invasive study of muscle biochemistry. It was shown in the rat that an intramuscular injection of the drug resulted in degeneration that was reflected spectroscopically in a progressive decrease in the intracellular concentrations of phosphocreatine and adenosine triphosphate without a corresponding rise in that of inorganic phosphate. Furthermore, ATP was depleted in the presence of significant levels of phosphocreatine. As regeneration occurred spectra returned to normal and this was complete by day 10. No such spectroscopic effects were demonstrated in man following the use of bupivacaine in an intravenous regional anaesthetic. It is suggested that further studies in man are required before this drug can be administered intramuscularly with confidence.

Adenosine Triphosphate↗
PubMed1983

Conservation of metatarsal heads in surgery of rheumatoid arthritis of the forefoot.

A new method of forefoot reconstruction for rheumatoid arthritis in 79 patients is described in which the metatarsal heads are preserved. The first metatarsophalangeal joint is fused and the bases of the proximal phalanges of only those rays involved with disease excised together with cysts and synovium. Post-operatively traction is used to maintain the length of the operated lateral toes. The results in 71 patients followed for 3-5 years after operation are reported. Excellent pain relief, improved stability and feet of normal length are achieved.

Adult↗
PubMed1982

Nuclear magnetic resonance studies of forearm muscle in Duchenne dystrophy.

The forearms of six patients with Duchenne dystrophy were examined by the painless and non-invasive technique of high-resolution nuclear magnetic resonance spectroscopy. The phosphorus spectrum was abnormal in that the ratios of phosphocreatine to adenosine triphosphate and to inorganic phosphate were reduced. Absolute quantification under the conditions of this experiment was not possible but it was probable that in dystrophy the concentration of phosphocreatine in muscle was appreciably reduced. A signal in the phosphodiester region of the spectrum was recorded consistently in patients with dystrophy but not in controls. The intracellular pH of the muscle in the dystrophic patients was abnormally alkaline. The clinical application of nuclear magnetic resonance spectroscopy remains to be proved, but it appears to be a promising non-invasive technique for investigating biochemical abnormalities of muscle disease.

Adenosine Triphosphate↗