Tissues from five patients who underwent revision operations for failed total hip replacements were found to contain large quantities of particulate titanium. In four cases this metal must have come from titanium alloy screws used to fix the acetabular component; in the fifth case it may also have originated from a titanium alloy femoral head. Monoclonal antibody labelling showed abundant macrophages and T-lymphocytes, in the absence of B-lymphocytes, suggesting sensitisation to titanium. Skin patch testing with dilute solutions of titanium salts gave negative results in all five patients. However, two of them had a positive skin test to a titanium-containing ointment.

Summary.The pattern and the sequence of tumour necrosis factor-a (TNFa) induced cell death in the acute T-lymphoblastic leukaemic cell line CCRF-CEM and its vinblastineresistant subline CEM/VLB 100 have been studied. Previously, we found that the CEM/VLB 100 cell line was more sensitive to TNFa-induced killing than its parental CCRF-CEM cell line. TNFa-induced cell death showed an apoptotic pattern, as detected by agarose electrophoresis, flow cytometry and transmission electron microscopy (TEM). TEM images revealed that autophagy and condensed mitochondria occurred earlier than nuclear fragmentation. The specific inhibitor of autophagy, 3-methyladenine (3MA), inhibited the formation of autophagosomes. TNFa-induced DNA fragmentation and cytolysis were completely inhibited by 10 mM 3MA. Inhibition of the fusion of lysosomes with autophagosomes by asparagine did not block TNFa-induced apoptosis. In addition, amino acid and protein deprivation enhanced TNFa-induced autophagy but not apoptosis. We propose that the early stages of autophagy are required for, but do not necessarily result in, TNFa-induced apoptosis.

The isolation and biochemical characterization of the human sperm tail fibrous sheath (FS) is described for the first time. Initially, the solubilization properties of the FS were assessed immunocytochemically using GDA-J/F3 and RT97 monoclonal antibodies (MoAbs) and morphologically by electron microscopy. Following extensive investigations to optimize the conditions for the FS isolation, a simple method was developed which involved sequential extraction of the flageller components with Triton-dithiothreitol (DTT) and urea-DTT. The procedure was monitored by phase contrast microscopy and the purity of the FS preparations was confirmed by electron microscopy. SDS-PAGE of the isolated FS revealed seven major protein bands with mol. wt of 97, 76, 62, 55, 33, 28 and 25 kDa. In Western blotting, the reaction of RT97 MoAb with supernatants from the various extraction steps and the isolated FS indicated that its target antigen (AJ-p97) was an integral FS product and that disulphide bonding was probably involved in its stabilization. The reactivity of normal and aprotruded sperm tails with GDA-J/F3 and RT97 MoAbs was not affected by Triton while the GDA-J/F3 staining of the cytoplasmic matrix of other abnormal spermatids was abolished, thus suggesting variation in the biochemical properties of GDA-J/F3 in normal and abnormal germ cells. These and other data indicate that the FS could be a modified form of intermediate filament.

In two members of an affected family with a hereditary syndrome of proctalgia fugax and constipation, a hypertrophied internal anal sphincter was found with histological features suggesting a myopathy of this muscle. In these two patients, and in an unrelated patient with a similar clinical syndrome, smooth muscle fibres of the internal anal sphincter showed numerous vacuoles, many of which contained ovoid inclusion bodies. The structural features and histochemical reactions of the inclusion bodies were consistent with a polyglucosan composition. Histological examination of the internal anal sphincter may reveal smooth muscle abnormalities in functional bowel disorders.