The lack of mitogenic response of neuraminidase-treated and untreated human blood lymphocytes to divalent, hexavalent, or insoluble Helix pomatia a hemagglutinin

The mitogenic effects on human blood lymphocytes of Helix pomatia A hemagglutinin (HP) were measured by assaying incorporation of [¹⁴C]thymidine into cellular DNA. This highly purified lectin binds to human lymphocytes, treated with neuraminidase, but not to untreated lymphocytes. HP, which is hexavalent in its native form, totally failed to induce DNA synthesis in neuraminidase-treated as well as in untreated cells. Divalent HP, prepared by partial reduction and alkylation, and HP insolubilized by coupling to nylon sheets, also lacked mitogenicity. Control experiments indicated that neuraminidase-treated lymphocytes responded well to mitogenic lectins such as PHA. The lack of mitogenicity of HP was in contrast to the effects of soy bean agglutinin (SBA), which resembled HP in regard to carbohydrate specificity and ability to bind to neuraminidase-treated lymphocytes only. SBA was strongly mitogenic for neuraminidase-treated lymphocytes. The mitogenic effects of SBA were not inhibited by including varying doses of HP in the incubation mixtures. The results indicate that binding of lectin to carbohydrate receptors on the lymphocyte surface is not by itself sufficient to trigger DNA-synthesis.     

Patterns of Human Papillomavirus Types in Multiple Infections: An Analysis in Women and Men of the High Throughput Human Papillomavirus Monitoring Study

Background

To evaluate the pattern of co-infection of human papillomavirus (HPV) types in both sexes in Sweden.

Methods

Cell samples from genital swabs, first-void urine, and genital swabs immersed in first-void urine were collected in the present cross-sectional High Throughput HPV Monitoring study. Overall, 31,717 samples from women and 9,949 from men (mean age 25) were tested for 16 HPV types using mass spectrometry. Multilevel logistic regression was used to estimate the expected number of multiple infections with specific HPV types, adjusted for age, type of sample, and accounting for correlations between HPV types due to unobserved risk factors using sample-level random effects. Bonferroni correction was used to allow for multiple comparisons (120).

Results

Observed-to-expected ratio for any multiple infections was slightly above unity in both sexes, but, for most 2-type combinations, there was no evidence of significant departure from expected numbers. HPV6/18 was found more often and HPV51/68 and 6/68 less often than expected. However, HPV68 tended to be generally underrepresented in co-infections, suggesting a sub-optimal performance of our testing method for this HPV type.

Conclusions

We found no evidence for positive or negative clustering between HPV types included in the current prophylactic vaccines and other untargeted oncogenic types, in either sex.     

Replication slippage may cause parallel evolution in the secondary structures of mitochondrial transfer RNAs

Presence of the dihydrouridine (D) stem in the mitochondrial cysteine tRNA is unusually variable among lepidosaurian reptiles. Phylogenetic and comparative analyses of cysteine tRNA gene sequences identify eight parallel losses of the D-stem, resulting in D-arm replacement loops. Sampling within the monophyletic Acrodonta provides no evidence for reversal. Slipped-strand mispairing of noncontiguous repeated sequences during replication or direct replication slippage can explain repeats observed within cysteine tRNAs that contain a D-arm replacement loop. These two mechanisms involving replication slippage can account for the loss of the cysteine tRNA D-stem in several lepidosaurian lineages, and may represent general mechanisms by which the secondary structures of mitochondrial tRNAs are altered.      

Unbiased Approach for Virus Detection in Skin Lesions

To assess presence of virus DNA in skin lesions, swab samples from 82 squamous cell carcinomas of the skin (SCCs), 60 actinic keratoses (AKs), paraffin-embedded biopsies from 28 SCCs and 72 kerathoacanthomas (KAs) and fresh-frozen biopsies from 92 KAs, 85 SCCs and 92 AKs were analyzed by high throughput sequencing (HTS) using 454 or Ion Torrent technology. We found total of 4,284 viral reads, out of which 4,168 were Human Papillomavirus (HPV)-related, belonging to 15 known (HPV8, HPV12, HPV20, HPV36, HPV38, HPV45, HPV57, HPV59, HPV104, HPV105, HPV107, HPV109, HPV124, HPV138, HPV147), four previously described putative (HPV 915 F 06 007 FD1, FA73, FA101, SE42) and two putatively new HPV types (SE46, SE47). SE42 was cloned, sequenced, designated as HPV155 and found to have 76% similarity to the most closely related known HPV type. In conclusion, an unbiased approach for viral DNA detection in skin tumors has found that, although some new putative HPVs were found, known HPV types constituted most of the viral DNA.     

cDNA cloning of a developmentally regulated hemocyanin subunit in the crustacean Cancer magister and phylogenetic analysis of the hemocyanin gene family

The complete cDNA sequence and protein reading frame of a developmentally regulated hemocyanin subunit in the Dungeness crab (Cancer magister) is presented. The protein sequence is aligned with 18 potentially homologous hemocyanin-type proteins displaying apparent sequence similarities. Functional domains are identified, and a comparison of predicted hydrophilicities, surface probabilities, and regional backbone flexibilities provides evidence for a remarkable degree of structural conservation among the proteins surveyed. Parsimony analysis of the protein sequence alignment identifies four monophyletic groups on the arthropodan branch of the hemocyanin gene tree: crustacean hemocyanins, insect hexamerins, chelicerate hemocyanins, and arthropodan prophenoloxidases. They form a monophyletic group relative to molluscan hemocyanins and nonarthropodan tyrosinases. Arthropodan prophenoloxidases, although functionally similar to tyrosinases, appear to belong to the arthropodan hexamer- type hemolymph proteins as opposed to molluscan hemocyanins and tyrosinases.      

Prospective seroepidemiological study of role of human papillomavirus in non-cervical anogenital cancers.

OBJECTIVE: To evaluate the association between infection with the major oncogenic types of human papillomavirus and the risk of developing non-cervical anogenital cancers in a cohort followed up prospectively. DESIGN: Data from two large serum banks to which about 700,000 people had donated serum samples were followed up for a mean of 8 years. People who developed non-cervical anogenital cancers during follow up were identified by registry linkage with the nationwide cancer registries in Finland and Norway. Within this cohort a nested case-control study was conducted based on the serological diagnosis of infection with human papillomavirus types 16, 18, and 33. SUBJECTS: 81 cases and 240 controls matched for sex, age, and storage time of serum samples. MAIN OUTCOME MEASURES: Odds ratios of developing non-cervical anogenital cancers in presence of IgG antibodies to specific micro-organisms. RESULTS: Subjects seropositive for human papillomavirus type 16 had an increased risk of developing non-cervical anogenital cancers (odds ratio 3.1 (95% confidence interval 1.4 to 6.9)). Subjects seropositive for type 33 also had an increased risk (odds ratio 2.8 (1.0 to 8.3)) but not significantly after adjustment for infection with type 16. Seropositivity for human papillomavirus type 16 was associated with an increased risk of developing vulvar and vaginal cancers (odds ratio 4.5 (1.1 to 22)) and a strongly increased risk of developing preinvasive vulvar and vaginal lesions (odds ratio infinity (3.8 to infinity)). Seropositivity for human papillomavirus type 18 increased the risk of developing preinvasive lesions (odds ratio 12 (1.2 to 590)). High, but non-significant odds ratios for types 16 and 33 were seen for penile cancers. CONCLUSIONS: This study provides prospective seroepidemiological evidence that infection with human papillomavirus type 16 confers an increased risk of developing non-cervical genital cancers, particularly vulvar and vaginal cancers.