Recombinant cytomegalovirus glycoprotein gB (UL55) induces an autoantibody response to the U1-70 kDa small nuclear ribonucleoprotein.

Human cytomegalovirus (CMV) infection can be life threatening in the immune compromised and is associated with congenital defects and / or mental retardation in the neonate. The demonstrated association between CMV infection and rheumatoid factor (RF) raised the possibility of an induction of an autoimmune response upon vaccination with a candidate CMV vaccine, glycoprotein gB (UL55). The antibody responses generated after injections of an adenovirus-gB construct (Ad-gB) were studied in autoimmune-prone (MRL/mpj) and normal (BALB.k, C3H, and BALB/c) mice. Enzyme-linked immunosorbent assay and immunoblot analyses were done to identify the autoantibodies produced following immunization. Immunization with Ad-gB induced a significant IgG anti-viral response in all strains tested (p < 0.0001) compared to phosphate-buffered saline or HeLa controls. Ad-gB induced a significant IgG autoantibody response (p > 0.005) to the U1-70 kDa spliceosome protein in both autoimmune and normal strains whereas immunization with recombinant human La/SS-B did not. Autoantibodies to U1-70 kDa are part of the anti-ribonucleoprotein response seen in systemic lupus erythematosus and mixed connective tissue disease. Low levels of IgG RF and anti-double-stranded DNA antibodies were also induced. This study raises concern that immunization with CMV gB in individuals genetically predisposed to autoimmunity could trigger the development or acceleration of an autoimmune disease.

Effects of recombinant amelogenin on hydroxyapatite formation in vitro.

To determine the role of amelogenin in the mineralization of dental enamel, the effects of the recombinant mouse amelogenin rM179 on in vitro hydroxyapatite formation have been studied. In a steady-state agarose gel assay for hydroxyapatite nucleation, rM179 lacked significant activity at concentrations up to 300 microgram/ml. In an autotitration assay for inhibition of de novo hydroxyapatite formation, rM179 had no significant activity at concentrations up to 30 microgram/ml. Using selected-area dark-field electron microscopy, it was shown that rM179, at concentrations up to 30 microgram/ml, did not significantly affect the length of hydroxyapatite crystals formed in steady-state agarose gels. These findings suggest that amelogenins do not possess the specific crystal-modulating properties characteristic of certain acidic mineralized tissue proteins proteins.

A method for determining rates of sexual activity in schoolchildren.

This report details a novel methodology for determining rates of sexual activity in schoolchildren. The method has been found to be acceptable to schools, parents and students, it receives a high level of co-operation, a low (1%) parental withdrawal, and a low number (3%) of inadequate responses. A marked advantage of this method is the absence of direct questioning about first intercourse which is often considered inappropriate within schools. Validation conducted by interview at the time of the questionnaire and one year postal questionnaire follow-up indicates that this method gives a good estimate of sexual activity for school populations.

Teenage relationships and sex education.

Most of the consequences of early intercourse affect the woman and much research has focused upon her. As part of a study on teenage pregnancy, where 137 women were interviewed, 46 men were also interviewed. They were less likely to have had teaching about sex from parents and were subject to less parental supervision than the women. Both sexes had had similar experience of school sex education. Just under half of the men started having intercourse before 16 years. Over half of both sexes were initiated by an experienced partner and for 15/25 (60%) of the men this was within the first month of a relationship. Most men had had several partners and 27/99 (27%) of teenage women at least three, most in the context of stable relationships. 'Serial monogamy' exposes each partner indirectly to their partners previous partners (with the associated medical risks). Education must help teenagers make decisions about sexual involvement that take account of these facts and the implications for their own future health and happiness.

Teenage sexual intercourse and pregnancy.

One hundred and one pregnant girls aged under 18 years were interviewed to collect information about the development of their sexual awareness, attitudes towards relationships, and about their social context. The data show that the girls were likely to come from homes where the parents were divorced, where the mother married when she was under 21 years of age, and where her first child was conceived out of wedlock. Altogether 76 of these pregnant girls first had intercourse before they were 16 years old. The younger the girl at first intercourse the sooner it occurred in the relationship and for almost half of the girls first intercourse was unplanned. Although almost half used contraception on the first occasion, only one third of the girls used contraceptives regularly. Most expressed the wish that they had delayed intercourse until they were older.

Mercury as a health hazard.

Pink disease has virtually disappeared since teething powders were withdrawn. We describe a case in a boy who was exposed to metallic mercury vapour. We discuss the potential health hazard of spilled elemental mercury in the house and the difficulties of removing it from the environment.