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Biomedical subjects

I G Mackie

Publications and source records attributed to I G Mackie.

At least 19 recordsLinked to original sources
PubMed1989

Osteoporotic bone microstructure by collagenase etching.

Collagenase etching has been used to show the microstructure of bone from patients suffering from primary osteoporosis. Both polished and unpolished surfaces of trabecular bone from femoral heads were treated with collagenase solution before study in the scanning electron microscope. The polished surfaces show the mineral component of this bone as small rounded units approximately 10-20 nm across, which aggregate to form a continuous phase of contiguous spheroidal particles approximately 100 nm across. Lamellations are clearly seen to be due to the removal of collagen fibres up to approximately 200 nm across, fibres in adjacent lamellae being arranged approximately perpendicular to each other. The unpolished surfaces also show small rounded units, which aggregate into rods of mineral approximately 100 nm across. Although these rods form a connected system, they are loosely packed, compatible with their being interspersed with the collagen fibres in vivo. This model for the detailed microstructure of bone is consistent with specimens from a number of other sources and shows no features unique to osteoporosis.

Aged↗
PubMed1989

Treatment of bone weakness in patients with femoral neck fracture by fluoride, calcium and vitamin D.

Twenty-three of 46 patients, aged 56 to 95 years, with fracture of the femoral neck (FNF) completed the first trial of 10 months treatment with oral sodium fluoride 60 mg and calcium 1800 mg on alternate days and 1 micrograms of vitamin D1 daily. Pre-treatment and post-treatment biopsy specimens and microradiographs of the iliac crest and metacarpal and spinal radiographs were evaluated together with biopsy material from seven untreated age-matched controls with FNF. In 17 patients the treatment improved the amount and quality of trabecular bone. Cortical thickness increased in nine patients and there were no losses of amount or mineralisation. The treatment was well tolerated by most patients and there were no major side-effects or signs of bone demineralisation. The study also revealed an unexpected rapid post-fracture deterioration of bone tissue in untreated FNF patients; thus there is an increased risk of further fractures which calls for the use of an effective treatment to increase bone mass.

Aged↗
PubMed1989

Human bone microstructure studied by collagenase etching.

Bone samples from the iliac crest of patients with no signs of bone disorder were treated with collagenase to remove the collagen component and so allow detailed observation of the mineral hydroxyapatite. Both polished and unpolished surfaces were studied in the scanning electron microscope and they showed that the mineral component of bone is composed of small rounded units about 10 nm across which are fused together to form larger spheroidal units roughly 100 nm in diameter. In the unpolished surfaces these 100 nm units are seen to aggregate to form columns approximately parallel to their neighbours and with numerous interconnections forming a continuous mineral phase. The polished sections also show the hydroxyapatite as a continuous phase of contiguous spheroids and the holes from which the collagen fibres were removed are clearly revealed. Lamellations in the surface are interpreted as resulting from adjacent layers of collagen fibres having orientations approximately perpendicular to each other.

Bone and Bones↗
PubMed1988

Experience with the A.O. locking femoral nail.

A series of 21 fractures of the femur unsuitable for ordinary closed nailing have been treated using the A.O. locking femoral nail. The results obtained have been good with one case of non-union and no cases of deep infection, despite the complex nature of the fractures. The procedure is technically demanding and exposes the surgeon to the risks of ionizing radiation. Practical points to simplify the procedure and reduce exposure to radiation are discussed.

Adolescent↗
PubMed1988

Late rupture of the extensor pollicis longus tendon: the case against attrition.

The authors report the case of a 23-year-old man who sustained ipsilateral volar Barton's and scaphoid fractures which were complicated by a late rupture of the extensor pollicis longus tendon. The anatomy of the injury precluded attrition as the cause of the tendon rupture and the alternative theory of ischaemic rupture is examined. Clinicians should be aware that injuries other than the Colles' fracture may be complicated by rupture of extensor pollicis longus.

Adult↗
PubMed1988

A nonbacterial cause of post-traumatic soft-tissue gas.

A young male sustained a wound on the lateral aspect of the right thigh, presenting 24 hours later with subcutaneous crepitus over the thigh. He was systemically well, Gram stains and wound culture were negative. The cause was a sucking wound due to the valvelike action of the iliotibial band.

Adult↗
PubMed1984

The dangers of sclerotherapy in the treatment of ganglia.

Sixteen ganglia were treated by injection with sclerosant (Sodium Tetradecyl Disulphate), fifteen failed to respond. We present radiological and electron microscopical data together with animal studies to explain the failure and to show the inherent dangers of this therapy.

Animals↗
PubMed1983

Forum. Femoral neck surgery using a local anaesthetic technique.

Thirty cases of femoral sub-capital fractures, Garden grades 1-4, were reduced and internally fixed with crossed Garden screws using femoral nerve block. In addition, sedation and analgesia was provided by low dose ketamine and diazepam. No deaths or other complications occurred in these patients. In a similar group of patients who received spinal analgesia in the same unit under similar conditions there was one death and two cerebrovascular accidents.

Aged↗
PubMed1983

The contaminated skin-knife. A surgical myth.

The scalpel blades used during 187 operations were cultured. At each procedure the knife used to incise the skin was discarded immediately and a fresh knife was used to complete the operation. The results showed that there was no difference in the bacterial growth between the two knives. From these results it would appear that the practice of changing blades after incising the skin is an unnecessary precaution in the prevention of bacterial contamination of clean wounds.

Bacteriological Techniques↗