Structural features of human leukocyte interferon A as determined by circular dichroism spectroscopy*

The solution structure of human leukocyte (alpha) interferon-A (LeIF-A) purified from E. coli extracts was investigated by circular dichroism spectroscopy. At pH 8.2, the native molecule exhibits 40–70%α-helix and no clearly detectable β-structure. The tertiary structure includes a closely-packed interior containing at least one tryptophan side-chain. Titration to pH 1.5 produces a partial loss of structural features which are rapidly regained on return to neutral pH.     

CLINICAL USE OF THE WIDE FIELD SPECULAR MICROSCOPE

The Pocklington (Keeler-Konan) wide field specular microscope has been in use for 18 months at the Corneal Diseases Unit, The Royal Victorian Eye and Ear Hospital, Melbourne.
In this study, the microscope has been applied clinically to assess the state of the corneal endothelium and to evaluate comparative endothelial cell density and morphology in certain anterior segment microsurgical procedures. The clinical conditions studied are primary posterior chamber intraocular tens implantatbn, secondary intraocular lens implantation, intraocular lens exchange, and penetrating keratoplasty.     

A note on the elimination of polyneuronal innervation of skeletal muscles in neonatal rats

The elimination of the polyneuronal innervation was reinvestigated in normal rats from the tenth day after birth. The extent of polyneuronal innervation was measured by intracellular recordings in cut muscle fibre preparations (Barstad 1962). This preparation has the advantage that it favours the recording of small signals. With this increased sensitivity we detected a class of small end-plate potentials which may represent nerve terminal function in the course of elimination. These small potentials were always observed in fibres with an additional large end-plate potential and were occassionally present even in one-month old rats.     

IMMUNOLOGICAL FEATURES OF HLA-B27 ANTERIOR UVEITIS

Analysis ol the immunological features of anterior Uveitis (AU) revealed a dichotomy of abnormalities defined in terms of the HLA-B27 status of the patient. HLA-B27-positive AU was characterised by the occurrence of ins autoantibodies and an absolute T cell lymphopenia during active disease which returned to normal with recovery. This phenomenon was not observed in HLA-B27-negative AU or in controls and could not be attributed to antilymphocyte antibodies as these were not detected. Furthermore, there were no changes in T-cell subsets (helper and suppressor T lymphocytes). Compared with HLA-B27-positive AU patients, the HLA-B27-negative group demonstrated elevated lgE levels and increased prevalence of smooth muscle autoantibodies. Key words: anterior Uveitis, HLA-B27, immunological abnormalities, T lymphocytes, autoantibodies.     

The effect of lymphokines on proliferation and collagen synthesis of cultured human synovial cells

Abstract. Human mononuclear cell supernatants were obtained by incubating 3 times 10⁶ cells per ml of Dulbecco's modified Eagles medium at 37°C for 24 h or 48 h, either in presence or absence of phytohaemagglutinin. After removal of intact cells, the supernatants were dialysed and diluted (1:1, 1:2, 1:5, 1:10) again using the above medium. The diluted supernatants, containing a final concentration of 10% (v/v) human platelet-factor poor serum, were found to stimulate the proliferation of human synovial cells in culture and to increase both the total amount of collagen and the percentage of Type III collagen synthesized by these cells. Incubation of the mononuclear cells in presence of phytohaemagglutinin appeared to further enhance the stimulatory effects of the supernatants upon the synovial cells. Since activated mononuclear leucocytes such as lymphocytes and macrophages are present in rheumatoid synovia, this study suggests that factors released from activated mononuclear leucocytes may play an important role in the proliferation of rheumatoid synovial tissue and development of the pannus.