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Biomedical subjects

M J Allen

Publications and source records attributed to M J Allen.

At least 127 records · Page 7Linked to original sources
PubMed1988

'Whiplash injuries' of the neck: a retrospective study.

This is a retrospective study of 102 patients with whiplash injuries of the neck followed up at approximately 2 years. The results show that 67 patients were asymptomatic by this time and the remaining 35 patients still exhibited symptoms. Prognostic indicators were found to be age, occipital headaches, referred symptoms, interscapular pain, abnormal neurological signs, positive radiological findings and osteoarthritic changes of the cervical spine. Symptoms that persisted for more than 2 months indicated prolonged disability.

Accidents, Traffic↗
PubMed1988

Atrial natriuretic peptide inhibits osmolality-induced arginine vasopressin release in man.

1. Eight normal volunteers were infused with 5% saline (5 g of NaCl/100 ml) at a rate of 0.06 ml min-1 kg-1 for 120 min to increase plasma osmolality and plasma arginine vasopressin. Human atrial natriuretic peptide (alpha-hANP; 100 micrograms) or placebo was given in random order in a double-blind cross-over design for the last 20 min of the saline infusion. 2. Compared with the placebo infusion, atrial natriuretic peptide (ANP) produced a 43% greater sodium excretion and a 34% greater urinary volume in the subsequent hour. 3. Mean plasma immunoreactive ANP did not increase in response to changes in osmolality and rose to a peak of 118 pg/ml during the alpha-hANP infusion. alpha-hANP produced significant suppression of mean plasma arginine vasopressin over the 60 min after the infusions. 4. We conclude that ANP is not released in response to increased osmolality in vivo, and that it inhibits osmolality-induced arginine vasopressin release in man.

Adult↗
PubMed1988

Domperidone, a DA2-specific dopamine antagonist, has no effect on the renal or haemodynamic response to atrial natriuretic peptide in man.

1. Animal experiments have suggested that the renal effects of atrial natriuretic peptide (ANP) are dependent on dopaminergic activation, predominantly of the DA1-receptor. In man, there is evidence of dependence on the DA2-receptor for the natriuresis produced by central blood volume expansion. 2. Six normal volunteers underwent infusions of alpha-human ANP preceded by domperidone (a DA2-antagonist) or placebo. Eight volunteers underwent a 3 h period of 10 degrees head-down tilt also preceded by domperidone or placebo. 3. Both the ANP infusion and head-down tilt produced a significant diuresis and natriuresis, neither of which was antagonized by the presence of domperidone. 4. The ANP infusion significantly reduced diastolic blood pressure and produced significant increases in the Doppler-measured aortic blood velocity variables of peak velocity and maximal acceleration. Domperidone had an independent effect of increasing blood pressure but did not appear to have a specific interaction with the haemodynamic effects of ANP. 5. Head-down tilt reduced mean arterial pressure and heart rate and increased maximal acceleration. Again, an independent effect of domperidone was seen on blood pressure. Heart rate and maximal acceleration showed similar changes in the presence of domperidone. 6. Domperidone does not antagonize the renal or haemodynamic effects of ANP and if dopaminergic activation is necessary for the renal action of ANP it is unlikely to be mediated by the DA2-receptor.

Atrial Natriuretic Factor↗
PubMed1988

Vascular responses to local atrial natriuretic peptide infusion in man.

1. The effect on skin and muscle blood flow of arterial infusion of atrial natriuretic peptide (ANP) directly into the forearm circulation, and on venous tone of direct infusion into a dorsal hand vein, was studied in normal subjects. 2. ANP produced a dose-dependent increase in both skin and muscle blood flow, but at equivalent doses, produced no dilatation of noradrenaline-preconstricted dorsal hand veins. These findings indicate that ANP acting locally, is an arterioselective dilator in the upper limb circulation in normal man. 3. Measurements of ANP in venous plasma during arterial infusion suggest marked clearance of ANP across the forearm vascular bed. Such peripheral clearance may, at least in part, account for the short plasma half-life of this peptide. 4. The lowest dose of ANP infused was calculated to produce plasma levels similar to those found in patients with heart failure. The findings with this dose suggest that, in heart failure, circulating levels of ANP may be within a range capable of influencing peripheral vascular resistance directly.

Adult↗
PubMed1988

National field evaluation of a defined substrate method for the simultaneous enumeration of total coliforms and Escherichia coli from drinking water: comparison with the standard multiple tube fermentation method.

A defined substrate method was developed to simultaneously enumerate total coliforms and Escherichia coli from drinking waters without the need for confirmatory or completed tests. It is a new method based on technology that uses a hydrolyzable substrate as a specific indicator-nutrient for the target microbes. No equipment other than a 35 degrees C incubator and long-wavelength (366-nm) light is necessary. To perform the test, one only has to add water to the powdered ingredients in a tube or flask. If total coliforms are present in the water sample, the solution will change from its normal colorless state (no target microbes present) to yellow. The specific presence of E. coli will cause the same tube to fluoresce under a longwave (366-nm) UV lamp. The test, called Autoanalysis Colilert (AC), was compared with Standard Methods for the Examination of Water and Wastewater 10-tube multiple tube fermentation (MTF) in a national evaluation. Five utilities, representing six U.S. Environmental Protection Agency regions, participated. All water samples came from distribution systems. Split samples from a wide variety of water sources were analyzed for the MPN-versus-MPN comparison. A total of 1,086 tubes were positive by MTF, and 1,279 were positive by AC. There was no statistical difference between MTF and AC. Species identifications from positive tubes confirmed the sensitivity of the AC. A national evaluation of the AC test showed that it: (i) was as sensitive as Standard Methods MTF, (ii) specifically enumerated 1 total coliform per 100 ml, in a maximum of 24 h, (iii) simultaneously enumerated 1 E. coli per 100 ml in the same analysis, (iv) was not subject to false-positive or false-negative results by heterotrophic bacteria, (v) did not require confirmatory tests, (vi) grew injured coliforms, (vii) was easy to inoculate, and (viii) was very easy to interpret.

Bacteriological Techniques↗
PubMed1988

Achilles paratendonitis: an evaluation of steroid injection.

A prospective, randomised, double-blind study of 28 patients presenting with Achilles paratendonitis was undertaken in order to evaluate the role of peritendonous injection of methy prednisolone acetate (Depo Medrone). At presentation patients were either administered peri-tendonous injection of 40 mgs of methyl prednisolone acetate suspended in 1 ml of 0.25% marcaine or 2 ml of 0.25% marcaine alone. Response was gauged by resolution of pain, tenderness and return to normal activity. Patients who failed to respond to initial treatment were crossed over to the other group at 12 weeks. All patients received standardised physiotherapy. Results indicate that peri-tendonous injection of methyl prednisolone acetate is of no value in Achilles paratendonitis.

Achilles Tendon↗
PubMed1988

Accommodative rock via computer.

A technique is presented for using a computer for the measurement as well as the training of accommodative facility. The testing and training are accomplished optically without any mechanically moving parts.

Accommodation, Ocular↗
PubMed1988

Does oedema following lower limb revascularisation cause compartment syndromes?

Oedema of the leg, particularly the calf, is a well-recognised complication following lower limb reconstructive vascular surgery, but its effect on the limb is unknown. In this study, anterior compartment pressures and calf circumference were measured in both the operated and non-operated limbs following femoropopliteal bypass in 15 patients. All the patients developed lower limb swelling, which was significantly greater than the non-operated limb, P less than 0.05 paired t test (day 2-5). There was a significant difference in the mean anterior compartment pressures between the operated and non-operated limbs on the third and fourth postoperative days for the overall and below knee group, P less than 0.05 (paired t test). However, none of the patients developed signs, symptoms or pressures indicative of a compartment syndrome. These results suggest that the oedema following reconstructive vascular surgery is subcutaneous rather than compartmental in origin and that compartment pressure measurements should only be undertaken if a fasciotomy is being contemplated.

Adult↗
PubMed1987

Who should treat epistaxis?

A prospective study was undertaken of 75 patients complaining of epistaxis who presented to an Accident and Emergency Department. The patients were placed into four groups according to their presenting features, and various forms of appropriate management applied. It was found that in the group that had ceased bleeding on presentation, whether or not a bleeding point was visible, there was no benefit obtained by treatment. If the nose was still bleeding on presentation, and the bleeding point was visible, successful management could be obtained by cauterising the bleeding point. This is a treatment that could be carried out by either the General Practitioner or the Accident Department. If the nose was actively bleeding, and the bleeding point could not be seen, then even initially successful treatment by the Accident Department was usually found to be ineffective within forty-eight hours. It is suggested that this group should be referred to an ENT unit on presentation.

Adolescent↗
PubMed1987

A review of cervical-spine radiographs in casualty patients.

This study reviews the radiographs and clinical case notes of 897 patients who attended the Accident and Emergency (A & E) Department of Leicester Royal Infirmary, over an 8-month period, for whom radiographs of the cervical spine were requested. The radiological interpretations by the casualty officers and junior radiologists in training were compared with those by a consultant radiologist and large discrepancies were observed. There was a predominance of fractures and subluxations at the levels of C1 and C2, and at C7 and T1. A study of the adequacy of the radiographs has shown that 90% of the lateral radiographs included C7 but only 57% included T1. Through-the-mouth views were adequate for interpretation in 67% of cases. The practice of the A & E and radiology departments at the Leicester Royal Infirmary is briefly described. The poor performance of the casualty officers and junior radiologists is discussed and suggestions made which might improve the accuracy of the radiological diagnosis of cervical-spine injuries in the A & E department.

Adolescent↗
PubMed1987

A measles outbreak at university medical settings involving health care providers.

In 1985, a measles outbreak involved 14 students and non-student contacts in Michigan. Eight transmissions occurred at university medical facilities; five of these were likely airborne transmissions. Medical students and a medical resident were involved in the outbreak's propagation. Health care providers need to be immune to measles. Measles should be suspected in young adults with compatible illnesses; persons suspected to have measles should be placed in stringent respiratory isolation to preclude airborne transmission.

Academic Medical Centers↗
PubMed1987

Minimal change glomerulonephritis in the elderly--the role of renal biopsy.

We describe the case histories of three septuagenarians with nephrotic syndrome who would not have been thought likely to have had minimal change disease on clinical grounds. Yet in the three patients all non-sclerosed glomeruli were normal on light microscopy and glomerular immunofluorescence was negative. All three showed a good clinical response to steroids. It is clear from our findings that, in the elderly, clinical criteria are not a reliable guide to renal histology and may lead to a potentially treatable condition, minimal change nephropathy, being overlooked. Because of the high incidence of side effects, a trial of steroids in the elderly is hazardous. From the evidence given we conclude that renal biopsy, in adults with nephrotic syndrome, becomes increasingly useful with advancing age.

Age Factors↗