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Biomedical subjects

M J Allen

Publications and source records attributed to M J Allen.

At least 145 records · Page 8Linked to original sources
PubMed1986

Cross-reactivity of a monoclonal antibody to the catalytic subunit of chicken gizzard desmin-specific calpain.

The desmin-specific calpain I from chicken gizzard smooth muscle is a dimer of 83 and 35 kDalton subunits. A monoclonal antibody to the large subunit did not cross-react with chicken gizzard and hamster skeletal muscle calpain II, but it did recognize hamster skeletal muscle desmin-specific calpain I and the denatured calpain II from chicken gizzard smooth muscle. These results indicate that different desmin-specific calpains have similar large subunits which differ significantly from the large subunit of calpain II in the same tissue.

Animals↗
PubMed1986

A radiological analysis of lateral ligament injuries of the ankle.

Patients who presented within 5 days of an inversion injury to the ankle joint, were clinically selected for early radiological investigation and diagnosis of rupture of the lateral ligament of the ankle. Stress tenography was performed in 142 cases, and normal ranges for talar tilt and anterior draws were established in 216 normal ankles. In addition 38 cadaveric ankles were examined by peroneal tenography. No normal connection between the tendon sheath and the ankle joint was demonstrated. Sixty-five patients had positive peroneal tenograms; nine of these were positive only after manipulation. No complications occurred. Surgery was performed on 20 patients and demonstrated that common peroneal tenography was 95% accurate in diagnosing rupture of the calcaneo-fibular ligament. Of the 19 patients with proven calcaneo-fibular ligament rupture, six had a positive anterior draw sign, and nine had talar tilt. In this series both the talar tilt and anterior draw signs were found to be inaccurate. Common peroneal tenography is recommended as the method of choice for demonstrating acute rupture of the calcaneo-fibular component of the lateral ligament.

Adolescent↗
PubMed1986

Weakness of foot dorsiflexion and changes in compartment pressures after tibial osteotomy.

Weakness of dorsiflexion of the foot is a common complication of proximal tibial osteotomy and it has been suggested that this may be caused by an anterior tibial compartment syndrome. A prospective study of 20 patients undergoing tibial osteotomy was undertaken, in which compartment pressures were recorded and related to clinical signs. In 10 of the patients, the operation site was drained, and in 10 no drainage was employed. The undrained group showed significant elevation (greater than 45 mmHg) of the anterior compartment pressure in seven patients, and five of these had transient clinical signs. Only one patient had any permanent deficit, a minor asymptomatic weakness of extensor hallucis longus. In the drained group the pressures remained below 30 mmHg in all except two patients, who both had only a minor pressure rise and no significant early clinical signs. However, two patients from this group later developed weakness of dorsiflexion, probably due to common peroneal nerve injury, the cause of which is not clear.

Compartment Syndromes↗
PubMed1986

Exercise pain in the lower leg. Chronic compartment syndrome and medial tibial syndrome.

The aetiology of pain in the lower leg during exercise has been studied in 110 athletes by monitoring intracompartmental pressure during exercise and by technetium bone scans. Patients were assigned to three diagnostic groups: chronic compartment syndrome, medial tibial syndrome and those with non-specific findings. Our results indicate that subcutaneous fasciotomy of the affected compartment(s) is the treatment of choice for chronic compartment syndrome. The treatment of patients with medial tibial syndrome, either by operation or conservatively, has been unsuccessful; non-specific symptoms have been treated conservatively with success.

Adolescent↗
PubMed1985

In vitro dissolution of cholesterol gallstones. A study of factors influencing rate and a comparison of solvents.

Models of the common bile duct and gallbladder were constructed to study conditions that affect the rate of cholesterol gallstone dissolution by monooctanoin and other potential solvents. In the bile duct model, the rate of monooctanoin infusion was not an important factor in accelerating dissolution time. In contrast, the exclusion of bile from interfering with solvent-stone contact or the enhancement of solvent-stone contact by stirring significantly accelerated stone dissolution. The combination of both bile exclusion and stirring increased the dissolution rate of gallstones by monooctanoin 15-fold. When compared with two other ethers and with monooctanoin, methyl tert-butyl ether was found to be the most potent gallstone solvent. Methyl tert-butyl ether completely dissolved 219-mg cholesterol stones within 60 min. In the gallbladder model, in the absence of stirring both methyl tert-butyl ether and monooctanoin floated on bile, whereas the gallstones sank resulting in minimal stone-solvent contact. To increase the stone-solvent contact, we used a pump to create sufficient turbulence to mix the solvent with bile. Pump stirring of monooctanoin in the presence of bile achieved rates of stone dissolution approaching that of stirred monooctanoin without bile. Stirring of methyl tert-butyl ether and bile, however, did not achieve sufficient solvent-stone contact to appreciably accelerate dissolution in the presence of 50% bile. Stone-solvent contact was a critical factor in determining the rate of gallstone dissolution in both gallbladder and common bile duct models. Efforts to enhance contact include bile exclusion and intraluminal stirring--both of which are clinically applicable. Methyl tert-butyl ether is a potent new cholesterol gallstone solvent with excellent potential for use in humans. Even with this potent agent, however, rapid gallstone dissolution is likely to require removal of most of the bile from the dissolution medium.

Bile↗
PubMed1985

The effect of seat belt legislation on injuries sustained by car occupants.

Details are given of the injuries sustained by 402 car drivers, 209 front seat passengers and 147 back seat passengers involved in road accidents during the two 4-month periods before and after the introduction of the compulsory wearing of seat belts on 1 February 1983. Comparisons are made between the injury patterns in those wearing and not wearing seat belts and in back seat passengers.

Accidents, Traffic↗
PubMed1985

A technique for the long term measurement of intra-compartmental pressure in the lower leg.

The early diagnosis of an acute compartmental pressure syndrome is often difficult, but can be facilitated by long term, up to several days, measurement of intra-compartmental pressures. A measuring system has been developed, together with its associated surgical and operational procedures, which may be applied in a variety of situations, including an immobile patient or a patient mobilized following surgery. If the technique is adopted as soon as the patient enters hospital, or immediately postoperatively, an acute compartmental syndrome may be recognized early and measures taken to alleviate its consequences.

Biomedical Engineering↗
PubMed1985

Cholelitholysis using methyl tertiary butyl ether.

We tested methyl tertiary butyl ether both in vitro and in vivo to evaluate its efficacy as a potential cholesterol gallstone solvent for direct instillation into the human gallbladder or bile duct. Like diethyl ether, methyl tertiary butyl ether is an aliphatic ether with an excellent cholesterol-solubilizing capacity. However, unlike diethyl ether which vaporizes at body temperature, methyl tertiary butyl ether remains a liquid having a boiling point of 55.2 degrees C. In vitro, methyl tertiary butyl ether dissolved human gallstones (40%-94% cholesterol) within 60-100 min. In contrast, monooctanoin, an established gallstone solvent, required greater than 50 h to dissolve similar stones. By direct catheter instillation in 6 dogs, methyl tertiary butyl ether required only 4-16 h to dissolve gallstones surgically implanted in the gallbladder. The dogs tolerated methyl tertiary butyl ether with only minor clinical, biochemical, or histologic effects. We conclude that further evaluation of methyl tertiary butyl ether for dissolution of human gallbladder and biliary duct cholesterol stones is warranted.

Animals↗
PubMed1985

The importance of the deep volar compartment in crush injuries of the forearm.

Two cases are described of blunt injury to the forearm in the absence of bone injury, resulting in an acute deep volar compartment syndrome. The importance of the deep flexor compartment of the forearm is noted. The diagnostic pitfalls and the use of intra-compartmental monitoring are discussed. We emphasize that all such cases must be admitted and carefully studied as a matter of routine. If operation is undertaken, both the superficial and deep volar compartments must be adequately decompressed.

Acute Disease↗
PubMed1985

Duodenal duplication cyst causing massive bleeding in an adult: an unusual complication of a duplication cyst of the digestive tract.

Duodenal duplication cysts are rare malformations that characteristically manifest with intestinal obstruction. In a 50-year experience, we found a duodenal duplication cyst in only three patients, one of whom had massive gastrointestinal bleeding as the initial symptom. Six other duplication cysts (two esophageal, one jejunal, and three ileal) were found. All patients who had extraduodenal intestinal cysts were neonates or infants who initially had an abdominal mass or obstruction. Of the two patients with an esophageal cyst, one had odynophagia and the other had respiratory obstruction. Unusual features of our series of patients were male preponderance (eight of nine patients), the low incidence of other developmental abnormalities, and, in the patients with the duodenal cysts, an age of 14 years or older at the time of onset of symptoms and diagnosis. In an adult, a duodenal duplication cyst may cause upper gastrointestinal hemorrhage. This cause of gastrointestinal bleeding should be considered in the differential diagnosis if an intramural duodenal mass is detected within the medial wall of the second portion of the duodenum distal to the papilla of Vater.

Adult↗
PubMed1985

Intracompartmental pressure monitoring of leg injuries. An aid to management.

Acute compartment syndromes often develop insidiously and are often recognised too late to prevent permanent disability. Management is difficult as the compartment involved is seldom clinically apparent. By continuously monitoring the intracompartmental pressure these problems can be avoided: transient compartment syndromes can be differentiated from established ones and the correct compartment can be surgically decompressed. Pressure monitoring techniques were used in 28 patients; three developed a compartment syndrome requiring surgical intervention, seven had a temporary increase of pressure and in 18 the pressure remained unaltered. Of the three with compartment syndromes, one was unusual in that it affected the thigh and another, unique in our experience, affected both the thigh and the calf. Intracompartmental pressure monitoring significantly altered the management of two cases giving successful results with minimal intervention.

Adolescent↗
PubMed1984

Major vascular injuries associated with orthopaedic injuries to the lower limb.

The management of 14 patients with combined orthopaedic and vascular injury of the lower limb have been reviewed. Six of the 14 limbs were amputated, 5 have a residual functional defect and 3 were restored to normal function. Delay in diagnosis and failure to treat the consequences of soft tissue injury and ischaemia were mainly responsible for the poor results. The results of internal fixation were poor and the possible use of external fixation has been discussed. The importance of a sound technique for vascular repair with post reconstruction on-table arteriography has also been discussed.

Adolescent↗