Pathologic material and the records of 29 patients with laryngeal papillomatosis were reviewed. The relationship between the type of human papillomavirus (HPV) and the presence of viral coinfections was correlated with clinical outcome. Using polymerase chain reaction, paraffin-embedded specimens were analyzed for the presence of HPV, Epstein-Barr virus (EBV), cytomegalovirus (CMV), and herpes simplex virus (HSV). The HPV type could be identified in 24 patients' specimens. Twenty-one patients were infected with HPV type 6. The other 3 were infected with HPV type 11 or 16. Three patients developed squamous cell carcinoma, of whom 2 had HPV type 11 or 16. We found HSV, EBV, and CMV in 50%, 12.5%, and 0% of specimens, respectively. An aggressive clinical course was observed in 17 patients. Evidence of coinfection with other viruses was identified in 11 (65%) of these patients. In contrast, a benign clinical course was observed in 7 patients, of whom 2 (29%) had viral coinfections. We conclude that the HPV type and the presence of viral coinfections may be predictive of an aggressive clinical course.

Tomato is the most economically important fruit/vegetable crop grown worldwide. However, viral diseases remain an important factor limiting its productivity, with estimated quantitative and qualitative yield losses in tomato crops often reaching up to 100%. Many viruses infecting tomato have been reported, while new viral diseases have also emerged. The climatic changes the world is experiencing can be a contributing factor to the successful spread of newly emerging viruses, as well as the establishment of disease in areas that were previously either unfavourable or where the disease was absent. Because antiviral products are not available, strategies to mitigate viral diseases rely on genetic resistance/tolerance to infection, control of vectors, improvement in crop hygiene, roguing of infected plants and seed certification. Tomato brown rugose fruit virus (ToBRFV) is an emerging viral threat to tomato productivity and is currently spreading into new areas, which is of great concern to the growing global production in the absence of mitigation measures. This review presents the current knowledge about ToBRFV and future prospects for an improved understanding of the virus, which will be needed to support effective control and mitigation of the impact it is likely to cause.

The clinical significance of specimens with low sample-to-cutoff (S/Co) ratios in the Ortho VITROS chemiluminescence assay (CIA) for detection of antibodies to hepatitis C virus (HCV) was evaluated. In one study of 482 CIA-reactive samples, none of the 83 samples with S/Co ratios of <5 was HCV RNA positive. In a subsequent study, 332 samples with S/Co ratios of between 1 and 20 were tested with the recombinant immunoblot assay (RIBA). None of the 163 samples with S/Co ratios of <5 was RIBA positive, 83% were RIBA negative, and 28 samples (18%) were RIBA indeterminate. HCV RNA and/or clinical evidence of hepatitis was not found in the 27 indeterminate cases examined. These results show that over 99% of samples with very low S/Co ratios (<5) have no evidence of HCV infection. Therefore, we suggest that the HCV antibody testing algorithm for the VITROS assay might be modified to eliminate supplemental testing of samples with very low S/Co ratios.Assays for the detection of hepatitis C virus (HCV) antibodies have high false-positive rates, particularly in low-prevalence populations. Therefore, other tests such as recombinant immunoblot assay (RIBA) or HCV RNA PCR are used to confirm positive HCV antibody screening tests. To facilitate usage of the supplemental testing, the Centers for Disease Control and Prevention (CDC) published guidelines that incorporate anti-HCV assay signal-to-cutoff (S/Co) ratios into reflex testing algorithms for HCV antibody testing, in order to provide a more systematic approach for the laboratory diagnosis of HCV and minimize the number of specimens that require supplemental testing (2). Data obtained with three anti-HCV screening assays were used for these recommendations: two enzyme immunoassays (EIAs) (Abbott HCV EIA 2.0 and ORTHO HCV version 3.0 enzyme-linked immunosorbent assay) and one enhanced chemiluminescence immunoassay (CIA) (VITROS anti-HCV assay; Ortho-Clinical Diagnostics).The VITROS anti-HCV CIA has recently been shown to be at least as specific and sensitive as conventional EIAs (7, 9), and use of this CIA has been increasing. However, detailed studies of the CIA S/Co ratio value predictive of a positive supplemental HCV test have been limited (7, 9). The CDC guidelines have suggested reflex supplemental testing for samples with S/C ratios of Ͻ8.0 in the VITROS anti-HCV assay based on the evaluation of a total of 1,326 reactive samples, with only 142 of these specimens having S/Co ratios of Յ7.9 (2).We started using the VITROS anti-HCV assay shortly after its Food and Drug Administration approval in August 2001 and have prospectively applied reflex supplemental testing to all samples with S/Co ratios of between 1.00 and 20.0 in the setting of a population of U.S. veterans (8). The objectives of the present study were (i) to determine the S/Co ratio predictive of detectable HCV RNA; (ii) to evaluate, in samples with low S/Co ratios (between 1 and 20), the relationship between S/Co ratios and the number and types of bands detected by RIBA; (iii) to assess, for samples with i...

Bacteroides gingivalis produces large amounts of proteolytic enzymes which may play a role in its virulence. These enzymes may participate in the tissue destruction of the inflammatory process. In this study, the characteristics of two such enzymes, N‐CBz‐glycyl‐glycyl‐arginyl peptidase (N‐CBz‐Gly‐Gly‐Arg peptidase) and glycyl‐prolyl peptidase (Gly‐Pro peptidase) were investigated. The enzymes eluted in different peaks from an anion exchange column. N‐CBz‐Gly‐Gly‐Arg peptidase was associated with cells up to 48 h in culture. If cultured longer, it also released in the supernatant. It exhibited optimal activity between pH of 7.0 and 7.5 and was readily inactivated by heat treatment (45°C for 15 min). The enzyme activity was inhibited by p‐chloromercuribenzoic acid (PCMB), leupeptin and antipain, suggesting that it is a thiol protease. The B. gingivalis N‐CBz‐Gly‐Gly‐Arg peptidase was different from the serum enzyme that digests the same substrate. The serum enzyme was more resistant to heat treatment and was inhibited by diisopro‐pylfluorophosphate (DFP). B. gingivalis also produced Gly‐Pro peptidase that is released in the supernatant. The enzyme has an optimal pH range between 7.5 and 8.0. The B. gingivalis Gly‐Pro peptidase was inhibited by DFP, suggesting that it represents a serine protease. The serum Gly‐Pro peptidase did not differ from the bacterial enzyme with respect to its sensitivity to inhibitors; however, they were markedly different in heat sensitivity. The bacterial enzyme was completely inactivated at 60°C for 30 min, whereas the serum enzyme was not inactivated even at 1 h at 60°C.

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