Identification of an anti-idiotypic antibody that defines a B-cell subset(s) producing xenoantibodies in primates

Synthetic anti-idiotypic antibodies represent a potentially valuable tool for the isolation and characterization of B cells that produce xenoantibodies. An anti-idiotypic antibody that binds to a subset of B cells producing antibodies encoded by the variable-region heavy chain 3 (V(H)3) germline genes DP35 [immunoglobulin variable-region heavy chain 3-11 (IGHV3-11)], DP-53 and DP-54 plus a small number of V(H)4 gene-encoded antibodies in humans has recently been identified. These germline progenitors also encode xenoantibodies in humans. We tested whether the small, clearly defined group of B cells identified with this anti-idiotypic antibody produce xenoantibodies in non-human primates mounting active immune responses to porcine xenografts. Peripheral blood B cells were sorted by flow cytometry on the basis of phenotype, and cDNA libraries were prepared from each of these sorted groups of cells. Immunoglobulin V(H) gene libraries were prepared from the sorted cells, and the V(H) genes expressed in each of the sorted groups were identified by nucleic acid sequencing. Our results indicate that xenoantibody-producing peripheral blood B cells, defined on the basis of binding to fluorescein isothiocyanate (FITC)-conjugated galactose alpha(1,3) galactose-bovine serum albumin (Gal-BSA) and the anti-idiotypic antibody 2G10, used the IGHV3-11 germline gene to encode xenoantibodies and were phenotypically CD11b+ (Mac-1+) and CD5-. This novel reagent may be used in numerous applications including definition of xenoantibody-producing B-cell subsets in humans and non-human primates and immunosuppression by depletion of B cells producing anti-Gal xenoantibodies.     

Urinary cobalt as a measure of exposure in the wet sharpening of hard metal and stellite blades

 The measurement of urinary cobalt as an estimator of exposure to airborne cobalt was evaluated during the wet sharpening of hard metal and stellite blades. The following possible confounding factors were also studied: smoking habits, personal hygiene, cobalt absorption through the skin, beer drinking, and vitamin B₁₂ consumption. The study was conducted in 16 different workplaces manufacturing or maintaining blades and in laboratory experiments. Cobalt contamination and its removal from workers’ hands were studied with different hand-washing methods, and cobalt from used gloves was also analyzed. The Finnish biomonitoring action level of 600 nmol/l (35.4 μg/l) was exceeded in 4 of the 16 workplaces, and the mean concentration of urinary cobalt was 241 (8–2705) nmol/l [14.2 (0.5–160)  μg/l]. The coefficient of correlation between the cobalt concentrations in the air and in the workers’ urine was 0.753. The urinary cobalt concentration corresponding to the Finnish occupational exposure limit for airborne cobalt (0.05 mg/m³) was 686 nmol/l (40.5 μg/l). The level of personal hygiene affected the urinary cobalt concentrations, and cobalt was absorbed through the skin. Beer and vitamin B₁₂ consumption did not have any effect on the urinary levels of cobalt. The workers who smoked had higher urinary concentrations of cobalt than the nonsmoking workers. High concentrations of cobalt in coolants contaminated the workers’ skin, and hand-washing did not remove cobalt very effectively. The results indicate that urinary cobalt can be used reliably to assess workers’ exposure to airborne cobalt when wet-tip grinding processes are used. The results also show that workers’ exposure to cobalt can be reduced by improving skin protection and personal hygiene in workplaces. Received: 29 January 1996 / Accepted: 2 May 1996     

Cardiovascular complications in patients with advanced prostatic cancer treated by means of orchiectomy or polyestradiol phosphate

OBJECTIVE: To evaluate the cardiovascular (CV) complications associated with orchiectomy (OE) and parenteral polyestradiol phosphate (PEP) therapy (240 mg/month), taking into account the effect of pretreatment diseases and pretreatment medication. MATERIAL AND METHODS: A total of 244 T3-4 M0 patients and 200 T1-4 M1 patients were randomized to either OE or PEP therapy. The two groups of patients were analyzed separately. The follow-up period was 36 months. The effect of pretreatment vascular and other diseases and pretreatment medication which may be associated with a risk of CV complications was evaluated. RESULTS: In the T3-4 M0 patients, the treatment (PEP versus OE) and the presence of pretreatment vascular diseases were statistically significantly associated with a risk of CV complications (p=0.01 and 0.003, respectively). In the T1-4 M1 patients, such an association was not found. No association was observed between pretreatment medication and CV complications. There was no difference in progression-free time between the therapy groups in either the T3-4 M0 or T1-4 M1 patients. CONCLUSION: In patients with locally advanced prostatic cancer, PEP therapy is associated with a statistically significantly higher risk of CV complications compared to OE.     

Environmental surveillance of wild poliovirus circulation in Egypt--balancing between detection sensitivity and workload

Examination of sewage specimens for poliovirus (environmental surveillance) was adopted as a supplementary tool in the surveillance of poliomyelitis in Egypt. Sewage samples were concentrated about 50-fold using a simple two-phase separation technique, and inoculated in cell cultures in two collaborating laboratories in parallel. All but 9 of the 293 (97%) samples collected from January 2001 to December 2002 contained poliovirus and/or other enteroviruses, with polioviruses being detected in 84% of the samples. The proportion of specimens containing type 1 wild poliovirus (PV1W, the North-East African (NEAF) genotype) was less in 2002 (16%) than in 2001 (57%), and further decreased in 2003. While the overall sensitivity to detect PV1W was similar in the two collaborating laboratories, the specimens scored positive were not identical. Parallel cultures inoculated with aliquots of a given specimen very frequently resulted in isolation of different viruses. Moreover, partial sequence analysis occasionally revealed representatives of different genetic lineages of PV1W in a given specimen. These results emphasize the need to use intensive laboratory analysis to optimise sample sensitivity in environmental poliovirus surveillance, and the difficulties in reproducing the isolation results by simple re-inoculation of samples containing a mixture of different viruses.     

Transmission of high-risk human papillomavirus (HPV) between parents and infant: a prospective study of HPV in families in Finland

The Finnish HPV Family Study is a prospective cohort study assessing the dynamics of human papillomavirus (HPV) transmission between parents and infant. Serial genital and oral scrapings from 76 families, including mother, father, and infant, and semen samples were collected over 2 years of follow-up, analyzed by nested PCR, and confirmed by hybridization with 12 high-risk (HR) HPV types. The most common HPV profile was HR HPV in all family members (29%), followed by HPV-positive mother-infant pairs (26%). HPV-positive father-infant pairs were less frequent (11%), and in six (8%) families, only the infant was HR HPV positive. The prevalence of genital HR HPV in the parents ranged from 13 to 25%, and that of oral HPV ranged from 8 to 34%. In the infants, HPV DNA was detected in 15% of the genital and 10% of the oral samples at birth, reaching peaks of 18 and 21%, respectively, at 6 months, and declining to 10% at 24 months. Persistent HPV in the mother was a risk factor for oral HPV in the infant (odds ratio [OR], 5.69; 95% confidence interval [95% CI], 1.5 to 21.3), while oral HPV in the mother at 6 months was a risk factor for genital HR HPV (OR, 6.38; 95% CI, 1.15 to 35.32). No such independent risk could be attributed to subclinical HPV in the father. Persistent maternal cervical HPV and subclinical oral HPV affect the risk of infant HPV. The age of 6 months is a critical point for the infant to acquire or be free of HR HPV DNA.     

Local Immune Responses to Chlamydia pneumoniae in the Lungs of BALB/c Mice during Primary Infection and Reinfection

Cell-mediated immune (CMI) responses play a major role in protection as well as pathogenesis of many intracellular bacterial infections. In this study, we evaluated the infection kinetics and assessed histologically the lymphoid reactions and local, in vitro-restimulated CMI responses in lungs of BALB/c mice, during both primary infection and reinfection with Chlamydia pneumoniae. The primary challenge resulted in a self-restricted infection with elimination of culturable bacteria by day 27 after challenge. A mild lymphoid reaction characterized the pathology in the lungs. In vitro CMI responses consisted of a weak proliferative response and no secretion of gamma interferon (IFN-γ). The number of lung-derived mononuclear cells increased substantially during the primary infection; the largest relative increase was observed in B cells (B220⁺). After reinfection, the number of lung-derived mononuclear cells increased further, and the response consisted mainly of T cells. The reinfection was characterized in vivo by significant protection from infection (fewer cultivable bacteria in the lungs for a shorter period of time) but increased local lymphoid reaction at the infection site. In vitro, as opposed to the response in naive mice, acquired immunity was characterized by a strongly Th1-biased (IFN-γ) CMI response. These results suggest that repeated infections with C. pneumoniae may induce Th1-type responses with similar associated tissue reactions, as shown in C. trachomatis infection models.     

Virus excretion and strain specific antibody responses after oral poliovaccine in previously immunised children

A nation-wide campaign with trivalent oral poliovirus vaccine was organized in Finland in February-March 1985 in order to stop the unexpected outbreak of poliomyelitis. Excretion time of the vaccine viruses and antibody responses due to vaccination were studied in a group of healthy 6-year-old children who were classmates to one of the patients during the outbreak and who also had been screened for excretion of the epidemic poliovirus type 3 strain. While faecal excretion of at least one of the three vaccine virus serotypes was documented in all 19 children, only one throat specimen out of 106 studied was positive in the virus isolation test. The mean excretion times for types 1, 2, and 3 were 13, 21, and 21 days, respectively, and five children were still excreting a vaccine virus strain at 5 wk. Faecal excretion of the type 3 vaccine virus was not seen in children who had been excreting the epidemic type 3 strain 4 mo earlier. Excretion of a respective vaccine virus strain was usually well correlated to a booster response in serum neutralising antibodies to types 2 and 3 but not to type 1 poliovirus. A relatively high prevaccination antibody level did not always prevent the take of the corresponding vaccine virus strain. An increase in the level of neutralising serum antibodies towards at least one poliovirus serotype was observed in all but one of the 17 children studied. Antibody responses to the live vaccine strains were similar to those towards the corresponding nonattenuated strains while the absolute antibody titres against the epidemic P3/Finland/23127/84 strain remained relatively low in most sera studied.(ABSTRACT TRUNCATED AT 250 WORDS)