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Biomedical subjects

M B Sweet

Publications and source records attributed to M B Sweet.

At least 37 records · Page 2Linked to original sources
PubMed1988

Serum biochemical and haematological markers of alcohol abuse in patients with femoral neck and intertrochanteric fractures.

Excessive alcohol intake causes bone loss. Alcohol abuse is a commonly associated disorder in femoral neck fractures in men, but little attention is given to such an association in women. Using serum biochemical and haematological markers (mean red cell volume MCV, gamma-glutamyl transpeptidase GGT, aspartate transaminase AST, uric acid UA and triglyceride TG) alcohol abuse was assessed in 14 men and 93 women with non-violent fractures of the hip. Abnormal elevations in one or more of the five test pairs known to correlate with increasing alcohol consumption (GGT/MCV, GGT/AST, AST/MCV, MCV/UA) were found in 7.1% of men, and 11.8% of women. When abnormal results in other test pairs were included the prevalence rose to 14.3% in men and 20.4% in women. These figures are higher than those reported for the general population of elderly people.

Adult↗
PubMed1987

Proteoglycans of articular cartilage in Mseleni joint disease.

Femoral heads were resected from patients with Mseleni joint disease, and cartilage present in 'islands' on the articulating surfaces and over marginal osteophytes was removed for study. Some specimens were grown in short-term organ culture and labelled with sulphur-35. Proteoglycans present in the tissue, and newly synthesised macromolecules were extracted, purified and assessed. The results indicated that very few of the proteoglycans present or synthesised during culture were capable of aggregation with hyaluronate and that the average size of the macromolecules was smaller than normal. In addition a large proportion of the proteoglycans were very small in size and were thought to resemble a molecule found in immature articular cartilage. The response to degenerative disease was unusual and may be peculiar to the Mseleni condition.

Cartilage, Articular↗
PubMed1987

A system of canals in semilunar menisci.

Semilunar menisci of young calves, and infants and young children were examined with the scanning electron microscope and the light microscope. Canal-like structures were noted opening onto the surface of the menisci. After filling the joints with Indian ink, ink was noted within canal-like structures deep in the substance of the tissue. The canals may play a part in the transport of fluid within the meniscus, or may carry nutrients from the synovial fluid or the blood vessels to the avascular sections of the meniscus.

Animals↗
PubMed1987

Radiographic features of the spine in fluoride therapy for osteoporosis.

In the search for a simple method of assessing the therapeutic efficacy of sodium fluoride, a prospective study of vertebral radiography during such treatment was carried out. Treatment of osteoporosis with sodium fluoride, calcium and vitamin D was found to enhance the vertical markings of the vertebral trabecular pattern in 69% of patients. This response was graded 1 (failure), 2 (good) and 3 (excellent); Grade 2 or 3 was attained after a mean treatment period of 31.7 months. Subsequent analysis of the vertebral fracture rate revealed that new vertebral fractures had occurred only in patients with Grade 1 and not in those with Grade 2 or 3. We recommend that treatment should aim at increasing the vertebral trabecular pattern to Grade 2 or 3 and that the duration of therapy should be approximately 30 months.

Adult↗
PubMed1982

Arthroplasty by osteocartilaginous graft in primates.

Joint surface grafting has evolved from use of cadaveric materials preserved chemically and physically, to viable allogeneic and autogenic grafts in nearly a century of surgical history. Technical problems arising at the interface between foreign substances and living tissues has limited engineering arthroplasty such that a biological grafting process is eagerly sought. If successful with long periods of joint functioning, the scope of application to human victims of trauma, disease, and tumors of joints is wide. Whereas rabbits and dogs have been extensively used as models, primates have not. Whereas osteochondral allografts in Papio ursinus (the South African baboon) have been quite successful in hip, knee and shoulder joints, but the follow-up has been no more than a few years. Human autografts have been successful with periods of 10 and 15 years, but the present series is inadequate for statistical assessment. Further investigations of allografts and autografts in human joints are warranted.

Adolescent↗
PubMed1981

Biochemical changes in intervertebral disc degeneration.

The distribution of the principal matrix components, collagen, proteoglycans and water, across the diameter of human normal and degenerate intervertebral discs was compared. Little difference in collagen distribution was noted between normal and degenerate tissue but water and proteoglycan content decreased with degeneration, particularly in the centre of the disc. Proteoglycans of the nucleus pulposus and annulus fibrosus of normal and degenerate intervertebral discs were examined. In comparison with monomers of normal tissues, degenerate disc proteoglycans were of larger average hydrodynamic size and had a higher glucosamine to galactosamine ratio. Proteoglycans were digested with chondroitinase ABC and passed over an HS-Sepharose 2B affinity column. A greater proportion of the keratan sulphate-protein cores from degenerate disc were capable of interaction with the immobilized hyaluronate. Loss of aggregating ability was associated with diminution in size of the core. It is suggested that a large proportion of proteoglycans from normal disc have undergone a degree of degradation in the hyaluronate binding region and that proteoglycan synthesis in this tissue is slower than in degenerate tissue.

Adult↗
PubMed1981

Characterization of a proteoglycan of high electrophoretic mobility.

Proteoglycans from articular cartilage of young baboons (Papio papio) were fractionated on an associative density gradient. Material from the top of the gradient was shown to contain a proteoglycan of high electrophoretic mobility on large porosity gels. Associated and/or contaminating proteins were removed by ion-exchange chromatography on DEAE-cellulose and subsequent gel filtration on Sepharose 4B in the presence of 0.1% SDS. The electrophoretically homogeneous proteoglycan (Kd 0.43 on Sepharose 4B SDS) contained 39.7% protein, was rich in aspartate, glutamate, leucine and glycine and had a GalN : GluN molar ratio of 3.87.

Amino Acids↗
PubMed1979

Glycosaminoglycan synthesis by human chondrosarcoma.

Human chondrosarcoma of low-grade malignancy was cultured in the presence of 35S-sulphate and 3H-glucosamine. The glycosaminoglycans isolated were fractionated on Ecteola cellulose and electrophoresed on cellulose acetate membranes before and after treatment with chondroitinase AC or Streptomyces hyaluronidase. The results demonstrated the in vitro synthesis of hyaluronate, chondroitin sulphate and keratan sulphate. The presence of keratan sulphate of large average chain length (congruent to 15 monosaccharides) supports the contention that chain length of keratan sulphate is inversely proportional to the degree of malignancy.

Bone Neoplasms↗
PubMed1979

An oligosaccharide component in proteoglycans of articular cartilage.

Two types of sialic acid-containing component are released from articular cartilage proteoglycan monomer (D1) treated with 0.05 M NaOH containing 1 M NaBH4. The smaller component, which has not been described before, contains galactosamine, glucosamine, galactose and sialic acid (Molar ratio 1:1:1:2). It is eluted from ECTEOLA-cellulose with low molarity (0.4 M) sodium formate and has Kav of 0.70 on Bio-gel P30. Its presence on the proteoglycan monomer was demonstrated at all stages of foetal and adult life.

Aging↗
PubMed1979

Biochemical studies of the matrix of craniovertebral chordoma and a metastasis.

Glycosaminoglycans of human chordoma and a metastasis were studied. The glycosaminoglycans were derived from the extracellular matrix and consisted of chondroitin 4- and 6-sulphate, keratan sulphate and hyaluronate. The ratio of chondroitin sulphate to keratan sulphate was much lower in the metastasis than in the primary. Proteoglycan extracted with 4M guanidinium chloride and purified by associative density-gradient centrifugation was assessed on Sepharose 2B before and after reduction and alkylation. The result of this experiment suggested that only a small proportion of the proteoglycans were aggregated.

Chordoma↗
PubMed1978

Hyaluronate in articular cartilage: age-related changes.

Articular cartilage of fetal calves, calves, and steers together with normal and osteoarthrotic human cartilage was analyzed for hyaluronate. The hyaluronate content increased with maturation in healthy tissue, particularly in regions of maximum contact, but was low in diseased cartilage.

Aging↗
PubMed1978

Articular cartilage degradation and the pathology of haemophilic arthropathy.

Synovial membrane and specimens of articular cartilage, obtained from the affected knee joints of 5 haemophilic patients at the time of surgical synovectomy, were studied. All the synovial specimens showed villous proliferation and multiplication of synovial cells. Haemosiderin granules were present within synovial cells and in macrophages. There was congestion and capillary proliferation. An inflammatory infiltrate of plasma cells and lymphocytes was seen in some instances. Articular cartilage changes were classified into the following 4 grades according to severity: 1--an increase in the number of surface chondrocytes with fibrous metaplasia, and the appearance of superficial fissures; 2--a fibrous vascularized overgrowth, resembling rheumatoid pannus; 3--deep fissuring and necrosis of cartilage; 4--erosion and disappearance of articular cartilage with exposure of subchondral bone. In the first 3 grades, deep nests of chondrocytes containing haemosiderin were present. These cell aggregates became larger and more degenerate as cartilage degradation progressed. Damaged articular cartilage was deficient in glycosaminoglycan (acid mucopolysaccharide). No excess enzyme activity could be demonstrated within the cartilage matrix. Immunofluorescent studies were not helpful. Electron microscopical examination revealed siderosomes within degenerate chondrocytes and synovial cells. Granules resembling haemosiderin were also present in the cartilage matrix. It is considered that iron products affect both chondrocytes and matrix adversely and play a part in articular cartilage destruction in haemophilia.

Adolescent↗
PubMed1977

Regional distribution of water and glycosaminoglycan in immature articular cartilage.

The distribution of water and glycosaminoglycan in different functional regions of bovine immature articular cartilage were studied. There was always more water in each articulating than in the corresponding growing zone, but there was less water in both zones in the areas of maximum contact. There was more hyaluronate and much more keratan sulphate in the articulating areas of maximum contact than in the minimum contact areas. In the growing zone the distribution of these two glycosaminoglycans did not vary as significantly but there was slightly more keratan sulphate in the area of maximum contact. Regional variations in chondroitin sulphate content were also present although not as striking as those of keratan sulphate. The results suggest that some keratan sulphate may be synthesized as a reaction to load.

Animals↗