Localization and synthesis of collagen types III and V during remodelling and decidualization in rat uterus.

Uteri of pregnant rats on Days 6, 7 and 8 of pregnancy were studied to determine the histochemical distribution of collagen types III and V and the incorporation of [3H]glycine into fibrillar collagens during the period of embryonic implantation. Types III and V had a similar distribution in the non-decidual stromal region and muscle layers in implantation sites. They were found to have very low levels in the primary decidual tissue on Day 6 and were not detected in developing decidual tissues on Days 7 or 8. Following injection of labelled glycine, collagen was extracted and the specific activity of the collagens determined by fluorography and 3H incorporated into the collagen bands in the gels. It was found that incorporation of label into both types I and III was similar (33.4+/-12.0 and 31.8+/-18.1 cpm microg-1 collagen respectively) but 3.5 times that of type V (7.7+/-5.3 cpm microg-1). These studies suggest that although fibrillar collagens are metabolized or redistributed in the growing decidual tissue, they are incorporated rapidly into the extracellular matrix during remodelling of the outer stroma and muscle tissues.

Temporal changes to uterine collagen types I, III and V in relation to early pregnancy in the rat.

Uterine tissues of pregnant rats were extracted to define any changes to the proportions of collagens types I, III and V. The total concentration of extracted collagen was determined in tissue samples from implant and adjacent non-implant (NI) sites. Extracts were also subjected to polyacrylamide gel electrophoresis (PAGE), immunoblotting and gel densitometry to define the collagen types and to determine their relative proportions. By relating the proportions to the collagen concentrations in the extracts, type I was found to be the predominant collagen in both tissue regions although the concentration in the implant sites was lower than that in the NI sites. The concentration of Type I collagen decreased significantly over the period of observation in both implant and NI sites. Although the concentrations of collagen type III and type V also decreased in the implant sites, they did not alter in the NI sites. The results demonstrate that shortly after the initiation of implantation the uterus responds to the presence of the implanting embryo by decreasing the concentration of all three types of collagen. This indicates that their metabolism may, in part, be regulated by similar mechanisms. Furthermore, it was evident that a decrease in the concentration of collagen type I was initiated in uterine areas that, at the time of sampling, were not directly involved with implantation. During the study, it was found that the alpha 1 chain of collagen type V separated into two distinct bands when run on gels containing 3.8 M urea.(ABSTRACT TRUNCATED AT 250 WORDS)

Immunolocalization of collagen type I and laminin in the uterus on days 5 to 8 of embryo implantation in the rat.

This study investigated the immunohistochemical distribution of collagen type I and laminin during remodeling of the uterine extracellular matrix in response to embryo implantation in the rat. Collagen type I was found to be virtually absent around the embryo on the evening of day 5 of pregnancy. On days 6 to 8 of pregnancy the areas of primary and secondary decidualized tissue contained very little collagen in contrast to the outer nondecidualized stroma and myometrial tissues in which the staining patterns did not appear to alter. Day 8 of pregnancy was also notable for the appearance of collagen type I at the site of the developing placenta. Localization of laminin corresponded to areas of basement membrane and was associated with the redistribution of blood vasculature during implantation. By day 7 laminin staining was diminished in the basal areas of the lumenal epithelium around the implanting embryo. Laminin was also located in a punctate fashion at the margins of the primary decidual cells on day 6 of pregnancy, but by days 7 and 8 this staining pattern was no longer evident. This study has provided further evidence for a decline in a major fibrillar collagen during natural decidualization and also revealed a localized and transient expression of laminin in association with the differentiation of cells during primary decidual formation.

Collagen concentrations in dissected tissue compartments of rat uterus on days 6, 7 and 8 of pregnancy.

Implantation and non-implantation sites were dissected into myometrial and stromal components; a decidual/embryonic region was obtained on Days 7 and 8 of pregnancy. The concentration of collagen (as a percentage of the dry weight of tissue), measured by hydroxyproline analysis, was significantly lower in the implantation regions than in the non-implant regions in all areas studied. The concentrations in the antimesometrial myometrium and stroma of the implantation region remained the same over the days studied. In contrast, the mesometrial collagen concentration in the implantation region declined from Day 6 to Day 8 of pregnancy. Collagen concentration was low within the decidual/embryonic tissue on Days 7 and 8 of pregnancy. Remodelling of collagen within the embryonic area appears to be an important feature of the uterine response to implantation in rats.

Decreased collagen concentration in rat uterine implantation sites compared with non-implantation tissue at days 6-11 of pregnancy.

Collagen concentrations at implantation sites in the rat uterus were found to be significantly decreased compared with concentrations in adjacent non-involved uterine tissue in early pregnancy (75% by Day 11). The decrease in collagen was most marked in primary decidua and was also observed to a lesser extent (20%) in myometrium at the implantation site. There was a decrease of 20% in the concentration of total proteins at Day 7 (as measured by the ninhydrin method) and a slight increase in water content (2%) at Days 6 and 7. The differences in total protein and water content were transient, but the difference in collagen was maintained throughout early pregnancy. The localized changes in collagen content observed in this study, along with previously reported morphological changes in fibrillar and basement-membrane collagens in the uterus, give support to a theory of remodelling in early pregnancy involving simultaneous synthesis and degradation of extracellular proteins during decidualization.

Production of peptides inducing chemotaxis and lysosomal enzyme release in human neutrophils by intestinal bacteria in vitro and in vivo.

Low molecular weight (Mr 200-1500) N-formylated peptides that stimulate many leucocyte functions, including chemotaxis and lysosomal enzyme release, have previously been isolated from Escherichia coli cultures. We have used high-performance liquid chromatography and bioassay techniques to study production of such peptides by intestinal bacteria in vitro and their activity in intestinal luminal contents, obtained by in vivo dialysis methods. Bioactivity was detected in culture supernatants of all 11 species of bacteria so far investigated, was resistant to digestion with aminopeptidase, but was destroyed by carboxypeptidase, confirming that bioactive moieties were amino-terminal-blocked peptides. By similar isolation procedures, pronase-sensitive bioactive factors have been demonstrated in human rectal dialysates from normal subjects and patients with Crohn's disease. In the patients, bioactivity in dialysates was not observed after treatment with broad-spectrum poorly absorbed antibiotics. The gut may be a reservoir or source of bacterial peptides that could promote an inflammatory response should they cross the 'mucosal barrier'.

Heat shrinkage of extraocular muscle tendon.

We have designed and employed a bipolar heating device to shorten extraocular muscles. Treatment involves placing the unidirectional heating device on the sclera with the active surface beneath the tendinous portion of the extraocular-muscle. When power is applied, visible tissue shrinkage occurs. Heat-induced extraocular muscle shrinkage was performed on live rhesus monkeys. Two months later, thermal tendinoplasty-treated extraocular muscles were surgically isolated and evaluated for strength. Biopsies were then performed on these muscles. It was our clinical impression that treated tissues retained their strength, while histologic and electron-microscopic evaluation of heat-treated tendon revealed evidence of shrinkage and compaction of collagen bundles. Thermal tendinoplasty may offer a sutureless method of correcting strabismus by shortening and thereby strengthening extraocular muscles.

The cored sponge model of in vivo leucocyte chemotaxis.

A method has been developed for the in vivo measurement of leucocyte chemotaxis in response to the bacterial chemotactic peptide F-met-leu-phe (FMLP). Polyurethane sponges were pre-treated with FMLP and implanted subcutaneously in rats and after a suitable interval removed for determination of leucocyte influx. In vivo concentration gradients of chemotactic factors within intact sponges were shallow and leucocyte accumulation unsatisfactory. Accordingly a cored sponge model was developed in which the cylindrical core only was treated with chemotactic factor and the sponge reassembled prior to subcutaneous implantation. Steep concentration gradients were established within the outer sponge matrix with marked effects on leucocyte accumulation, permitting studies of the time course of in vivo chemotaxis. With cored sponges test to control cell number ratios were maximal at 4 hours using both free and albumin-bound FMLP. This model of in vivo chemotaxis may prove useful in several areas of inflammation research.

Proximal and distal changes in collagen content of peripheral nerve that follow transection and crush lesions.

Collagen content of rat sciatic nerve was measured 10 weeks after either nerve transection or nerve crush. Nerve transection led to a significant increase in fascicular collagen in nerve segments 2.5 mm proximal and distal to the injury site. Remote from the transection, fascicular collagen was also significantly increased, this effect being most marked distally. Nerve crush by comparison resulted in only a small increase in fascicular collagen, significantly less than after transection. The greater amount of fascicular collagen far distal to the nerve injury could relate to a predominantly caudal endoneurial flow of inflammatory or growth factors. Differences in the amount of fascicular collagen formed after nerve transection compared with nerve crush are clearly due to factors other than axonal degeneration, and may relate to collagen synthesis by denervated Schwann cells or to the severity of the nerve injury.

Non-steroidal anti-inflammatory drugs in combination. Experimental observations.

Diflunisal in combinations with oxaprozin, indomethacin and sodium meclofenamate produced significant synergistic suppression of carrageenan-induced oedema of the rat foot-pad. Oxaprozin, benoxaprofen, indomethacin, diflunisal, sodium meclofenamate and auranofin in some paired combinations but not in others were associated with a greater effect than the component drugs used alone. Antagonism was demonstrated with other combinations of these drugs.

Morphological and biochemical comparison of convex and concave articular surfaces from adult subtalar and midtarsal joints.

Convex and concave articular cartilage from adult subtalar and midtarsal joints showed depressions over surface chondrocytes and linear arrays of surface fibres when examined by scanning electron microscopy (SEM). Full-thickness cartilage from concave surfaces contained significantly less collagen than cartilage from convex surfaces (40.8% vs. 47.4%, p less than 0.05). Plano-concave surfaces contained 44.7% collagen. Water and uronic acid content did not differ significantly for the different shapes. A higher collagen content in convex surfaces is consistent with the hypothesis that collagen networks in these surfaces are subjected to higher tensile stress under load than are those in concave ones.

Morphological and biomechanical studies of rheumatoid pannus and cartilage.

Invasive pannus or granulation tissue was observed in 0.2 mm thick slices of cartilage and adjacent subchondral bone taken from fresh metatarsal and metacarpal heads removed surgically from patients with rheumatoid arthritis. Application of stress to the slices showed "tracking" of pannus or invasive tissue between lacunae and through breaches in the subchondral plate. Softened regions in the cartilage matrix became creased and were easily distinguished from regions of normal consistency. The pannus-matrix interface was not disrupted by stresses as high as 30 g/mm2.

Diurnal and sequential grip functions in normal subjects and effects of temperature change and exercise of the forearm on grip function in patients with rheumatoid arthritis and in normal controls.

Rate of grip development (power), time to reach maximum grip strength and fatigue were not affected by the diurnal variation known to influence maximum grip strength and work during grip formation in normal subjects. Rheumatoid hands were less affected by exercise or temperature change of the forearm than were normal hands. Cold more consistently produced change in hand function than did warmth or exercise. Environmental changes affected the dynamic (rates of grip development and release and power) more than the static parameters (maximum grip strength and work) of grip. Measurement of power, fatigue and rate of grip release provide additional parameters useful in the assessment of hand function in patients with arthritis.

Ibuprofen and diflunisal in rheumatoid arthritis: a double-blind comparative trial.

Both diflunisal (750 mg/day) and ibuprofen (1600 mg/day) were shown to be superior to placebo in the treatment of rheumatoid arthritis in a double-blind cross-over trial. Neither drug affected lymphocyte transformation to plant mitogens. Diflunisal scored better than ibuprofen at the dose levels chosen but the differences did not reach significance.