Herpes simplex virus type 1 shedding in the oral cavity of seropositive patients

OBJECTIVE

Investigate the frequency of herpes simplex virus type 1 (HSV-1) reactivation in the oral cavity of seropositive patients with previous history of recurrent herpes labialis (recrudescent group) compared with those without any history of recrudescent lesions (asymptomatic HSV-1 infection). In addition, the relation between recrudescence and the presence of the virus in the saliva was assessed.

MATERIALS AND METHODS

Fourteen individuals with previous history of herpes labialis (recrudescent group) and 11 HSV-1 seropositive asymptomatic volunteers were included in the study. Swabs were performed periodically in all subjects and the presence of HSV-1 DNA was identified by nested PCR.

RESULTS

All the 25 subjects enrolled in the study, revealed at least one positive swab for HSV-1. The frequency of HSV-1 positivity in the group with recrudescent herpes labialis was not statistically different from the other group. Ten subjects of the recrudescent group presented with herpes labialis at least once during the study.

CONCLUSIONS

HSV-1 shedding in the oral cavity occurs independently of herpes labialis recrudescence.

Association of interleukin-1? polymorphism with recurrent aphthous stomatitis in Brazilian individuals

BACKGROUND

Recurrent aphthous stomatitis (RAS) is characterized by recurrent episodes of oral ulceration in an otherwise healthy individual. Some reports in the literature indicate that RAS may have immunological, psychological, genetic and microbiological bases. The purpose of the present study was to investigate the possible association between interleukin-1beta (IL-1beta) +3954 (C/T) genetic polymorphism and RAS in a sample of Brazilian patients.

SUBJECTS AND METHODS

Sixty-two consecutive subjects affected by minor and major forms of RAS and 62 healthy volunteers were genotyped at IL-1beta (+3954). The chi-squared test was used for statistical analysis.

RESULTS

A significant increase in the high production of IL-1beta genotype CT was observed in the group with RAS (P = 0.01). After stratifying RAS patients according to the mean number of lesions per episode, a significant difference was only observed between patients with >or=3 lesions in each episode and control.

CONCLUSION

There is an increased frequency of polymorphism associated with high IL-1beta production in RAS patients.

Molecular cloning and characterization of Phoneutria nigriventer toxins active on calcium channels

The aim of the present study was the molecular cloning of toxins active on calcium channels expressed by the spider Phoneutria nigriventer. Clones encoding the toxins Pn3-3A, Pn3-4A, Tx3-5, Pn3-5A, Tx3-6, Pn3-6A and Pn3-6B were identified from a cDNA library derived from the venom gland of this spider, revealing toxins of 49, 76, 45, 39, 55 and 58 amino acids residues, respectively, with polypeptide precursors being composed of three major portions: a signal peptide, a propeptide and finally, the mature toxin. A high degree of homology with the amino acid sequence was found between Pn3-3A and the neurotoxin Tx3-3 (identity of 79%), and between Pn3-4A and the neurotoxin Tx3-4 (identity of 95%). The deduced amino acid sequence for the mature polypeptides Tx3-5 and Tx3-6 confirms the polypeptide sequence previously published for these neurotoxins. In addition, the toxin Pn3-5A showed 58% identity to the Tx3-5 amino acid sequence, and the toxins Pn3-6A and Pn3-6B showed 85 and 33% identity, respectively, to the Tx3-6 amino acid sequence.

Cytomegalovirus shedding in the oral cavity of allogeneic haematopoietic stem cell transplant patients

OBJECTIVE

This study was designed to investigate the effect of allogeneic haematopoietic stem cell transplantation (HSCT) on cytomegalovirus (CMV) shedding in the saliva by nested polymerase chain reaction (nested PCR) and its impact on patient survival.

PATIENTS AND METHODS

One hundred and twenty-four HSCT patients and 124 healthy volunteers were included in the study. Oral swabs were taken before, after 100 days and 1 year of HSCT at the buccal mucosa. Nested PCR was used to detect CMV in the saliva. Time of death after HSCT was displayed, by means of the Kaplan-Meier method, for the following parameters: age and gender of the patient, donor gender, primary disease, stem cell source, platelet number, chronic graft vs host disease (cGVHD) of salivary glands and oral mucosa, and oral CMV shedding. Cox proportional hazards model was used for multivariate survival analysis.

RESULTS

While none of the individuals in the control group showed positive swabs for CMV, the frequency of positive CMV oral swabs in patients at day + 100 after HSCT (45.2%) was statistically higher than before (7.2%) and 1 year after HSCT (17.5%). The presence of CMV was not associated with cGVHD and did not have any impact on post-transplant survival.

CONCLUSIONS

The present study shows that oral CMV shedding occurs after HSCT, especially at day +100 post-transplant. Identification of CMV in the saliva might be important for the early diagnosis of CMV infection in allo-HSTC.