Prognostic importance of human papillomavirus type 16 DNA in cervical cancer.

Human papillomavirus (HPV) type 16 DNA is frequent in invasive cervical cancers. Among 43 patients with invasive cervical cancer, HPV-16-positive tumors spread to the parametrial and pelvic lymph nodes significantly more often than did HPV-16-negative tumors (P less than 0.05). Demonstration of HPV-16 DNA in invasive cervical cancers may be an additional prognostic factor for this disease.     

Myosin isozymes in avian skeletal muscles. I. Sequential expression of myosin isozymes in developing chicken pectoralis muscles

Myosin has been purified from chicken pectoralis muscle at various stages of development, from 10 days' incubation to approximately 10 months after hatching. Embryonic myosin from the earliest stage showed a high level of ATPase activity, similar to that obtained for adult pectoralis myosin. Two-dimensional peptide mapping of partial chymotryptic digests showed, however, that is heavy chain is quite different from that of adult fast myosin. The immunological crossreactivity observed between embryonic myosin and adult fast (pectoralis) myosin is therefore due to shared antigenic determinants rather than the presence of any adult isoforms. In an accompanying paper we will show that embryonic myosin at 10 days' incubation is not a single species, but consists of at least two heavy chain isozymes. The minor fraction binds slow light chains preferentially, and appears to be largely responsible for the observed crossreactivity with slow (ALD) myosin. None of the embryonic myosins is equivalent to the adult forms. Prior to hatching, LC3f is present only in very small amounts (less than 5%), and the adult light chain pattern, containing LC1f and LC3f in equimolar amounts, is not generated until after one week post-hatching. At about that time a new heavy chain population is detected, different from either the embryonic heavy chain or the adult heavy chain. The adult heavy chain peptide pattern appears from about three weeks' post-hatching, but a map indistinguishable from that of adult myosin is not observed until about 26 weeks. None of the observed differences in peptide maps can be related to different strains of chicken; pectoralis myosin from adult White Rock gave an identical map to that from White Leghorn. Unexpectedly, posterior latissimus dorsi (PLD) myosin from White Leghorn appears to be different from pectoralis myosin from the same strain, despite the histochemical and immunocytochemical similarity of the two muscles. We conclude that myosin polymorphism is widespread in muscle tissue, and that the expression of myosin isozymes and their subunits is under developmental regulation.     

Increasing proportion of late diagnosis of HIV infection among patients with AIDS in Italy following introduction of combination antiretroviral therapy

We analyzed trends over time and determinants of late diagnosis of HIV infection among people diagnosed with AIDS in 1986 to 1998 in a tertiary care center in Rome, Italy. Information on the date of a first HIV test was collected prospectively, in addition to data routinely collected for AIDS reporting. Patients with AIDS were defined as "late testers" if the time interval between first positive HIV test result and AIDS diagnosis was < or = 3 months. Overall, 503 people with AIDS of 1977 included in the analysis (25.4%) were late testers. the proportion of late testers decreased from 62.5% in 1986 to 16% in 1995. Thereafter, this proportion increased to 20.5% in 1996, 33.7% in 1997, and 36.6% in 1998. In multivariate analysis, the following variables were significantly associated with late testing: AIDS diagnosis in years 1986 to 1993 or 1997 to 1998 compared with 1995, male gender, age > or = 45 years, men who have sex with men, heterosexual contacts, or having unknown transmission mode compared with intravenous drug users, and being born outside Italy. Since 1996, the overall number of AIDS cases diagnosed at our center began to decrease whereas the number of late-testing AIDS patients did not decrease, resulting in an increasing proportion of late testers during the last 3 years of the study. This findings may reflect the effect of combination antiretroviral therapy in slowing progression to AIDS of HIV-infected persons aware of their status. A relevant number of people still discover their HIV infection late and may therefore miss treatment opportunities. New testing strategies are needed to reach more people who engage in high-risk behaviors, especially those at risk for sexual transmission, and those born outside Italy.     

A novel inhibitor of the alternative complement pathway prevents antiphospholipid antibody-induced pregnancy loss in mice

Studies in gene-targeted mice have demonstrated that factor B of the alternative complement pathway plays an important role in several disease models, but an exogenous inhibitor of factor B has not previously been available. We have developed an inhibitory monoclonal antibody directed against a critical epitope on mouse factor B and have tested it in a model of antiphospholipid (aPL) antibody (Ab)-induced fetal loss. Gene-targeted factor B-deficient mice (fB-/-) were injected with a fusion protein comprised of the second and third short consensus repeat (SCR) domains of mouse factor B linked to a mouse IgG1 Fc domain. Hybridomas were made from splenocytes of the immunized mouse. One mAb, designated 1379, produced an IgG1 antibody that inhibited alternative pathway activation in vitro and in vivo by preventing formation of the C3bBb complex. Strikingly, this mAb inhibited alternative pathway activation in serum from mice, rats, humans, monkeys, pigs and horses. Fab fragments made from this mAb also inhibited alternative pathway activation. Epitope mapping demonstrated that this antibody binds to factor B within the third SCR domain. When mAb 1379 was administered to mice that also received human IgG containing antiphospholipid antibodies, it provided significant protection from antiphospholipid antibody-induced complement activation and fetal loss. Thus, this mAb to factor B has broad species reactivity and effectively inhibits alternative pathway activation. The mAb protects mice in an in vivo model of antiphospholipid antibody syndrome, demonstrating the therapeutic potential for the inhibition of factor B in this disease.     

Bruton tyrosine kinase gene mutations in Argentina

The block in differentiation from pro-B to pre-B cells results in a selective defect in the humoral immune response characteristic of human X-linked agammaglobulinemia (XLA). Mutations of Bruton tyrosine kinase (BTK) gene have been identified as the cause of XLA. Mutation detection is the most reliable method for making a definitive diagnosis, except when clinical and laboratory findings are distinctive and coupled with history of X-linked inheritance. To provide a definitive diagnosis to 40 families incorporated in the Argentinian Primary Immunodeficiencies Registry we analysed the BTK gene by SSCP analysis as screening method for XLA, followed by direct sequencing. The molecular defect was localized in 45 patients from 34 unrelated families. From the 34 independent mutations identified, 16 were previously undescribed, 31 were unique mutations, 22 were exonic single nucleotide changes (16 missense and 6 nonsense) and four intronic mutations. Because five families had clinical, immunological and inheritance data sufficient for a definitive diagnosis, our study allowed 37 patients from 29 families previously categorized probable/ possible XLA, have now definitive diagnosis leading to appropriate genetic counseling.     

Comparative studies of purified subviral component vaccines and formalin-treated mammary tumor viruses from four inbred strains of mice

Formalin-treated virus vaccines were prepared from purified murine mammary tumor viruses (MuMTV) from 4 inbred strains of mice: RIII/Imr, GR/Imr, C3H/Imr, and A/Imr. In addition, subviral components were isolated from these 4 strains and purified to homogeneity. The inactivated viruses, their major envelope glycoproteins (gp50-gp55), and their major internal core protein (p28) were emulsified in complete Freund's adjuvant and used as vaccines for prevention of mammary tumors in mice. All 4 Formalin-treated virus vaccines reduced significantly the incidence of mammary tumors in "virus-free" C57BL and BALB/c mice when inoculated prior to challenge with live MuMTV. The RIII-, GR-, and A-MuMTV strains showed extensive heterologous cross-protection, whereas the C3H-MuMTV strain showed significant protection only against C3H- and A-MuMTV challenge. The major viral glycoproteins gp50-gp55 reduced significantly the tumor incidence when mice were challenged with isologous infectious virus after immunization, although these glycoproteins showed different degrees of cross-protection than did the same virus strains used as "intact" but Formalin-treated preparations. RIII-gp55 and GR-gp55 cross-protected against each other but not against challenge with C3H- and A-MuMTV strains; the A-gp50 protected against challenge with A- and RIII-MuMTV strains; C3H-gp55 demonstrated limited activity against C3H-MuMTV challenge only. The internal viral core proteins (p28) were ineffective in all systems studied. The same vaccines were tested in MuMTV-positive, high-tumor-incidence strains from which they were derived. At best, the appearance of spontaneous tumors was delayed in a few experimental sets; eventually, all mice developed mammary tumors. The foster-nursed C3HfC57BL strain of mice, which is not exposed to exogenous MuMTV during suckling and which develops mammary tumors after activation of the endogenous virus genome later in life, was responsive only when the heterologous GR-MuMTV Formalin-treated vaccine was used. The association between the ability of virus vaccines to protect a mouse strain and the degree of natural virus expression in that strain is discussed.     

Immunologic studies with mouse mammary tumor viruses: comparative studies with spontaneous mammary tumor cell vaccines from five inbred mouse strains

Vaccines were prepared from cells of primary spontaneous mammary tumors (MT) of RIII/Imr, GR/Imr, C3H/Imr, A/Imr, and C3HfC57BL/Imr mice. Each vaccine was used to immunize "murine mammary tumor virus (MuMTV)-free" BALB/c/Imr and C57BL/Imr mice before challenge with infectious RIII-MuMTV, GR-MuMTV, C3H-MuMTV, and A-MuMTV. RIII-MT and C3H-MT cells protected mice against tumorigenesis by all four MuMTV's; GR-MT cells protected against all but the RIII-MuMTV challenge; A-MT cells were ineffective against challenge by all four MuMTV's and significantly enhanced development of A-MuMTV-induced tumors. The activity of the C3H-MT cells was not seen when C3HfC57BL cells, free of the standard C3H-MuMTV, were used. The same cell vaccines were inoculated into the five donor strains of mice in attempts to prevent spontaneous MT in these high-incidence strains, which are naturally infected with MuMTV at birth. None of the vaccines prevented tumorigenesis in these mouse strains although delays in the appearance of tumors were observed in RIII and GR mice inoculated with either isologous MT cells or C3Hf-MT cells. The role of viral antigens acting alone or in concert with cellular antigens is discussed.     

Safety and efficacy of pedicle screw placement for adult spinal deformity with a pedicle-probing conventional anatomic technique

A prospective study of 50 adults treated with fusion, realignment, and segmental spinal instrumentation for spinal deformity was conducted to assess the safety, accuracy, and efficacy of the free-hand pedicle screw placement technique. Postoperative computed tomographic scans were performed to evaluate the placement of 282 screws and were correlated with patients' clinical outcomes. Five screws were placed at T12, 26 at L1, 39 at L2, 48 at L3, 73 at L4, 35 at L5, and 50 at S1. Nine screws (3%) were misplaced and included three screws (1.06%) that violated the medial wall with no clinical sequelae or revision surgery needed. There were no neurologic deficits related to screw placement. The free-hand technique is a safe and cost-effective method for pedicular screw placement during surgery for adult spine deformities.