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The aim of this study was to look for osteogenesis imperfecta (O.I.) specific features in collagen synthesised by skin fibroblast cultures obtained from patients with severe progressive deforming O.I. type III. Results from 17 O.I. type III cultures were contrasted with results from 6 relatives, 3 unrelated controls, 6 O.I. type II, 7 O.I. type IV and 7 O.I. type I cultures. Biosynthesised radiolabelled collagen types I and III were extracted and separated by gel electrophoresis as intact alpha chains or as cyanogen bromide digested peptides. Various abnormalities of type I collagen synthesis were detected in cultures from 13/17 O.I. type III patients. In conclusion, synthesised collagen abnormalities were detected in cells from most O.I. type III patients studied and were O.I.-specific, not O.I. type III-specific at the individual level. However, the frequency of detection of these features was partially specific to the O.I. type III phenotype.

1. Skin fibroblast lines were cultured from nine patients who had the features of idiopathic juvenile osteoporosis, six relatives, five unrelated control subjects and three unrelated patients with osteogenesis imperfecta type I. Some patients with idiopathic juvenile osteoporosis were adults whose previous osteoporosis was in remission. Two patients with idiopathic juvenile osteoporosis were siblings and one patient with idiopathic juvenile osteoporosis had a daughter with severe osteogenesis imperfecta (type III). 2. The ratio of type III to type I collagen, synthesized by fibroblasts, was increased in two of the patients with osteogenesis imperfecta type I and in the daughter with osteogenesis imperfecta type III, but was normal in all the other patients with idiopathic juvenile osteoporosis and the other relatives. 3. Radiolabelled collagen was digested by cyanogen bromide and separated on SDS-PAGE. Unreduced collagen peptides migrated normally, except those from both the two siblings with idiopathic juvenile osteoporosis. In these two lines, abnormal migration suggested the presence of collagen I mutations. 4. The secretion of synthesized collagen by these two idiopathic juvenile osteoporosis lines and two others was reduced to only 43-45% as compared with a line from a 13-year-old control subject, which was defined as 100%. The three osteogenesis imperfecta type I lines secreted 18-37%, the other five idiopathic juvenile osteoporosis lines secreted 57-75%, the relatives (including the daughter with severe osteogenesis imperfecta) secreted 49-115% and the controls secreted 69-102%.(ABSTRACT TRUNCATED AT 250 WORDS)

In Dupuytren's contracture there is an increase in the ratio of type III to type I collagen. The objective of this study was to determine if fibroblasts from patients with Dupuytren's contracture have an intrinsic aberration in collagen production or whether local factors govern the collagen changes in Dupuytren's contracture. Using a new collagen micro-method, we found that fibroblasts cultured from palmar fascia affected by Dupuytren's contracture produced similar collagen to fibroblasts derived from the palmar fascia of age- and sex-matched patients with carpal tunnel syndrome. Furthermore, the collagen changes of Dupuytren's contracture could be reproduced in all cell lines by increasing fibroblast density. At high fibroblast density, type I collagen production was inhibited: a finding that could account for the increased types III/I collagen ratio in Dupuytren's contracture. These results suggest that a genetic defect in collagen production is unlikely and that the important phenomenon is an increase in fibroblast density.

Samples of discs and disc attachments were extracted by dissociative methods and the resultant collagenous residues cleaved with cyanogen bromide. Soluble peptides thus released were characterized by their electrophoretic mobility following SDS-PAGE and by Western blot staining with specific antibodies against type I and type III collagens. Type III collagen was identified in samples taken from the posterior discal attachments. This may explain why this disc is prone to detachment and internal derangement and the high incidence of patients with temporomandibular joint dysfunction.

Collagen biosynthesis was measured in skin biopsies taken from 13 patients with rheumatoid arthritis before and after at least 6 months' continuous treatment with D-penicillamine, 1.0 g/day. There was a significant 36% reduction in mean collagen biosynthesis (p less than 0.0125) as assayed by 14C-hydroxyproline formation from 14C-proline during 24 h of tissue culture. The changes in 14C-hydroxyproline formation were correlated with the total doses of D-penicillamine taken (r = 0.71, p less than 0.01) and the falls in ESR (r = 0.72, p less than 0.01). No significant change in general protein syntehsis was observed. 500 microgram/mlD-penicillamine added to skil cultures in vitro inhibited both collagen and general protein synthesis (p less than 0.01). It is suggested that the clinical improvement induced by D-penicillamine could reflect an inhibition of collagen proliferation in the synovium.

The structural polymeric collagen of the skin of 19 patients with osteogenesis imperfecta has been examined. In those with severe bone disease, who often have white sclerae, this collagen fraction is less resistant to depolymerization than that of age-matched controls, though the total amount is normal. In patients with less severe bone disease, whose sclerae are usually blue, the polymeric collagen may have normal stability but the total amount is reduced. These results suggest defective cross-linking of collagen in severe osteogenesis imperfecta.

1. The relative amounts of type III and type I collagen, determined as the ratio of their constituent alpha 1(III) and alpha 1(I) chains, have been measured by interrupted electrophoresis of pepsin extracts of skin collagen from 31 patients with osteogenesis imperfecta of varying severity, and from six clinically unaffected family members. In 18 patients the ratio of the alpha 1(I) to alpha 2 chains of type I collagen has also been measured. 2. In the 15 patients with osteogenesis imperfecta classified as mild or the 18 with type I disease the ratio alpha 1(III)/alpha 1(I) was significantly increased (P less than 0.001) and the ratio alpha 1(I)/alpha 2 significantly decreased (P less than 0.005) compared with age-matched control subjects. 3. In three infants with lethal (type II) osteogenesis imperfecta the ratio alpha 1(III)/alpha 1(I) was normal, contrasting with the high ratio observed by others in fibroblast cultures from some apparently similar patients. 4. The ratio of alpha 1(I)/alpha 2 and of alpha 1(III)/alpha 2(I) was increased in both clinically normal parents of a child with severe disease, and in the mother of two children with osteogenesis imperfecta (one lethal and one severe) the ratio alpha 1(III)/alpha 1(I) was increased. 5. In the remaining patients with severe bone deformity (types III and IV) the relative amounts of the different collagen chains varied. 6. These data support previous suggestions that mild or type I osteogenesis imperfecta results from a generalized inability to form sufficient type I collagen, the predominant collagen of adult bone, and imply that in many cases this may result from defective production of the alpha 1(I) chain rather than of the alpha 2 chain. Some patients with severe disease demonstrate a similar defect; but in the remainder other abnormalities of collagen or connective tissue maturation are presumably involved.

In a clinical, radiological and biochemical study of forty-two patients from Oxford with osteogenesis imperfecta, it was found that patients could be divided simply into mild, moderate and severe groups according to deformity of long bones. In the severe group (seventeen patients) a family history of affected members was uncommon and fractures began earlier and were more frequent than in the mild group (twenty-two patients); sixteen patients in the severe group had scoliosis and eleven had white sclerae; no patients in the mild group had white sclerae or scoliosis. Radiological examination of the femur showed only minor modelling defects in patients in the mild group, whereas in the severe group five distinct appearances of bone (thin, thick, cystic and buttressed bones, and those with hyperplastic callus) were seen. The polymeric (structural) collagen from skin was unstable to depolymerisation in patients in the severe group, but normal in amount, whereas the reverse was found in the mild group. This division according to long bone deformity may provide, a basis for future research more useful than previous classifications.

Amino acid analyses were carried out on dentin proteins obtained from 33 normal teeth and 59 teeth from osteogenesis imperfecta patients. The analyses revealed that in the control teeth approximately 95% of the insoluble dentin fraction was collagen. The majority of the analyses for teeth obtained from the O.I. patients were biochemically abnormal (55 out of 59). Specifically, there was a significant increase in the acidic amino acids, with a corresponding decrease in the basic amino acids. A small group of patients showed double peaks in the histidine, hydroxylysine, and lysine areas of the chromatograms. These results emphasize that despite the fact that the teeth of O.I. patients may appear to be clinically normal, all but four of the teeth examined had abnormal dentin collagen.

1. Skin collagen from fifteen patients with idiopathic adolescent scoliosis, three with congenital scoliosis, and fourteen patients with various degrees of Marfan's syndrome has been examined. 2. The stability of a polymeric collagen fraction, extracted from the skin of these patients, to depolymerization, has been compared with that from thirty-one matched control subjects. 3. The mean polymeric collagen stability was significantly reduced (P less than 0-01) in the group of fifteen patients with idiopathic adolescent scoliosis. The individual reductions in stability were greater in the younger patients and no reduction was found in two patients aged 19 years who had a mature skeleton. 4. The mean stability of polymeric skin collagen from the group of patients with Marfan's syndrome was not significantly abnormal, although there were individual low values. 5. Polymeric collagen of low stability was present in individual patients from each clinical group. Instability of collagen (from whatever cause) at a time of rapid growth may contribute to the high incidence of scoliosis in adolescent girls. In boys, adolescent scoliosis is less common and the maximum growth rate occurs at a time when collagen stability is less reduced.

To ascertain if the features of osteogenesis imperfecta could be due to an abnormality in two genetically distinct collagens, Type III and Type I, we measured, in pepsin digests of skin, the ratio of the alpha 1, (III) to alpha 1 (I) chains derived from the two types, using a method of interrupted polyacrylamide-gel electrophoresis. In 40 control subjects this ratio decreased from about 0.45 in early fetal life to a mean (+/-2 S.D.) of 0.14 +/- 0.06 in 14 adults. Seven of nine adult patients with mild osteogenesis imperfecta had ratios of more than 4 S.D., above this mean, as did two of five patients with severe osteogenesis imperfecta. The increased ratio was probably due to a reduction of Type I collagen. If this reduction were generalized it could contribute to the bony fragility of osteogenesis imperfecta, since mineralized bone contains Type I collagen only.

1. Medium sized biopsies (100 mm2) of human skin from 14 subjects yielded sufficient polymeric collagen for depolymerisation and ultrastructural investigations. 2. The yields obtained from one skin specimen by the alpha-amylase, EDTA and lyotropic relaxation (water) methods of extracting polymeric collagen are similar. 3. The responses to depolymerisation treatments of the three polymeric collagen samples extracted by each of the three methods from one skin specimen are cross-correlated. There are however electron microscopical differences between the three polymeric collagen samples. 4. The results show that it feasible to study the polymeric collagen of normal and diseased human skin from medium sized biopsies.