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Biomedical subjects

A J Bailey

Publications and source records attributed to A J Bailey.

At least 145 records · Page 8Linked to original sources
PubMed1980

The chemistry of the collagen cross-links. Purification and characterization of cross-linked polymeric peptide material from mature collagen containing unknown amino acids.

A polymeric form of the alpha 1-chain C-terminal peptide alpha 1 CB6 (poly-alpha 1 CB6) was purified from CNBr digests of insoluble bovine tendon type-I-collagen by gel filtration and ion-exchage chromatography. The purified material had a molecular weight of 1.5 x 10(6)-5 x 10(6) on gel filtration and an amino acid content virtually identical with that of monomeric peptide alpha 1 CB6. The material could be adsorbed on affinity gels containing immobilized anti-(alpha 1 CB6-peptide non-helical region) antibodies and was an inhibitor of haemagglutination by the same antibodies of alpha 1 CB6-peptide-coated sheep erythrocytes. Periodate treatment of the material had no effect. Alkali hydrolysates were shown to contain two unknown amino acids, which were purified by gel filtration and ion-exchange chromatography in volatile buffers and are believed to be components of the mature cross-link of collagen.

Amino Acids↗
PubMed1980

An investigation of pyridinoline, and putative collagen cross-link.

A component, termed pyridinoline, has been reported to be derived from 'lysine aldehyde' (2,6-diaminohexanaldehyde) and designated as the stable cross-link of mature collagen. Commerically prepared collagen and freshly obtained mature bovine tendon collagen were both investigated with regard to their pyridinoline content. Both sources of material could be depleted of this component by mild washing procedures. Pepsin-solubilized collagen and peptides derived from CNBr cleavage of intact collagen did not contain the compound. Pure pyridinoline was isolated and shown to be hydrolysed by water, as previously reported, but neither hydroxylysine nor lysine could be ds not a cross-linking component of collagen.

Amino Acids↗
PubMed1980

Identification of cyanogen bromide peptides involved in intermolecular cross-linking of bovine type III collagen.

Cyanogn bromide peptides derived from bovine type III collagen and containing reducible cross-links were isolated and identified. Two peptides, alpha 1 (III)CB7 and alpha 1 (III)CB9B, from within the helical portion of the molecule were shown to contain the 'amino donor' residues cross-linked to non-helical 'aldehyde donor' residues in the formation of cross-links. This information, in conjunction with previously published data for the order of the cyanogen bromide peptides [Fietzek, Allman, Rauterberg & Wachter (1977) Proc. Natl. Acad. Sci. U.S.A. 74, 84-86], suggests that in type III collagen intermolecular cross-links are located in the end-overlap regions, so as to stabilize a quarter-stagger arrangement of molecules within the fibre in a similar manner to that proposed for type I and type II collagens.

Amino Acids↗
PubMed1980

Natural family planning. II. Basal body temperature and estimated time of ovulation.

Four points on the basal body temperatures (BBT) curve have been correlated with the estimated time of ovulation (ETO), as determined by indirect hormonal parameters, in 74 menstrual cycles from 24 subjects. Only 10 of 66 hormonally normal cycles exhibited a BBT dip (D), and the ETO ranged from D - 2 through D + 3. In 63 of 66 hormonally normal cycles, a BBT nadir (N), first day of BBT rise (F), and BBT coverline endpoint (C) were identified. In these 63 cycles, the ETO ranged from N - 5 through N + 4, F - 6 through F + 3, and C - 5 through C + 4. Biphasic curves were observed in 72 of the cycles (97.3%) and monophasic curves in 2 cycles (2.7%). In at least 5 of 74 cycles (6.8%) the BBT curve gave incorrect information on the ovulatory status of the cycle.

Adult↗
PubMed1980

The Ehlers-Danlos syndrome: an analysis of the structure of the collagen fibres of the skin.

The structure of the collagen fibres of the skin in the Ehlers-Danlos syndrome (ED-S) was studied in eight patients with ED-S Type I, three patients with ED-S Type II and three patients with the X-linked Type V. The results show that the reducible cross-links are present and undergo the same maturation process to non-reducible cross-links as in normal skin. Transmission electron microscopy revealed a normal ultrastructure of the collagen fibrils. At a higher morphological level of organization scanning electron microscopy demonstrated progressive increase in fibre bundle disorder from the X-linked to mitis, to gravis, in which the fibres making up the large fibre bundles demonstrated a considerable inability to aggregate.

Adolescent↗
PubMed1980

Biochemistry and histology of the connective tissue of Dupuytren's disease lesions.

When compared to age-matched control aponeurosis, lesions of Dupuytren's disease contain higher contents of water, collagen and chondroitin-sulphate, as well as increased proportions of soluble collagens and of reducible cross-links; these indicate synthesis of new collagen. The lesions show also increased amounts of type III collagen and an increased hydroxylation and glycosylation of the reducible cross-links. All these parameters are characteristic of granulation and scar tissues. Type III collagen was located by means of immunofluorescence on thin argyrophilic fibres and also within the large fibre bundles which appeared to be disrupted into microbundles. The increase of type III collagen and the presence of myofibroblasts in the apparently unaffected aponeurosis show that the disease is widespread and suggest that it is initiated within the aponeurosis and propagated by the cells migrating along the collagen bundles.

Adult↗
PubMed1980

Locust collagen: morphological and biochemical characterization.

Segment-long-spacing crystallites and reconstituted fibrils have been made from collagen extracted from the ejaculatory duct of the adult male locust, Locusta migratoria. These show the same banding pattern after positive staining as segment-long-spacing crystallites and fibrils made from mammalian type I collagen. Native fibrils show the same periodic pattern as type I fibrils, but it is not so distinct. Biochemical analysis of pepsin-digested locust collagen shows that there are two collagenous components. The alpha chains of the major component are similar to mammalian alpha 1 (I) chains, except that the number of hydroxylysine residues is elevated and the CNBr peptides differ. There are no alpha 2 chains; hence this locust collagen molecule is an alpha 1 trimer. The second component, which is present in only minute quantities, may be a type IV basement membrane collagen. It is concluded that the fibrous collagen molecule of the locust is very similar to that of mammalian type I trimers and to those of other invertebrates which have been examined.

Amino Acids↗
PubMed1980

Has collagen a role in muscle pattern formation in the developing chick wing? 1. An immunofluorescence study.

We have used antibodies to three of the isomorphic forms of collagen, types I, III and V, in an immunofluorescence microscopy study of myogenesis in the embryonic chick wing, concentrating on the period between stages 27 and 30 (5 to 7.5 days incubation) which is when the dorsal and ventral muscle masses separate into discrete muscle. We have demonstrated the presence of all three collagen types at the ectoderm-mesenchyme junction from stage 27 onwards. Type I collagen and then type III collagen are found in progressively deeper layers of the dermis at the later stages. Both types I and V collagen are initially present in the cartilage elements, but type I collagen becomes restricted to the periphery of these structure at later stages. The developing muscle areas show a lack of staining at all stages and it is only at the latest stages that types I and III collagen first appear in the surrounding epimysium. We discuss possible mechanisms for the division of the muscle masses in the light of this information on the distribution of collagen types.

Animals↗
PubMed1979

The chemotherapy of plasma-cell myeloma and the incidence of acute leukemia.

Previously untreated patients with myeloma were randomized to initial treatment with melphalan and prednisone (and to cyclophosphamide or carmustine if relapse or progression occurred)(Group A, 125 patients), melphalan, cyclophosphamide, carmustine and prednisone in alternating (Group B, 123 patients) or concurrent (Group C, 116 patients) schedules. The groups were similar with respect to known prognostic factors. Response rates and survival were also similar. We were unable to identify a subgroup of patients who responded or survived better on melphalan-cyclophosphamide-carmustine and prednisone than on melphalan and prednisone. We conclude that the combination of the four drugs is not better than melphalen and prednisone for inducing responses or prolonging the survival of patients with myeloma. Myelomas producing only gamma chains have a poorer prognosis (P greater than 0.001) than IgG, IgA, or kappa myeloma. Acute leukemia has developed in 14 patients. The actuarial risk of developing acute leukemia, has increased rapidly to 17.4 per cent at 50 months.

Acute Disease↗
PubMed1979

Characterization of dermal collagen in systemic sclerosis.

The amount of dermal collagen is increased in systemic sclerosis. However, unlike certain inflammatory conditions, the relative proportions of Type I and Type III collagens are closely similar to those found in normal adult dermis. Similarly, no change in the distribution of the collagen types could be detected by immunofluorescent staining, although a considerable thickening of the epidermis was clearly evident in all the sclerotic lesions examined.

Adult↗
PubMed1979

Home visiting: the part played by the "intermediary".

Home visits are usually initiated by someone other than the patient, whom we have called the ;intermediary'. It is seldom an objective decision on the part of the intermediary that a home visit is needed and is usually the result of his or her own anxieties. It is therefore important for the doctor consciously to aim at a diagnosis or formulation of the problems of the intermediary, and it may then become possible deliberately to help him or her with his needs and anxieties. If these are not considered, the strains or dissatisfaction of the intermediary which initiated the visit are likely to remain, and to influence both the way the doctor treats the patient and the doctor's sense of competence.

Adult↗