Risk factors for posterior to right recurrent laryngeal nerve lymph node metastasis in papillary thyroid carcinoma.

OBJECTIVES: To identify the risk factors for posterior right recurrent laryngeal nerve lymph node metastasis (PRRLN-LNM) in papillary thyroid carcinoma (PTC). METHODS: We conducted a retrospective study of 389 patients with primary PTC who underwent right lobectomy or total thyroidectomy, and comprehensive right or bilateral central compartment dissection (CCD) with or without lateral neck dissection (LND) between January 2010 and May 2013 at the Department of Head and Neck Surgery, Institute of Micro-Invasive Surgery of Zhejiang University, Zhejiang, China. The clinicopathological findings were investigated, and relative risk factors for PRRLN-LNM were analyzed. RESULTS: Central compartment LNM were present in 50.9% (198/389), and PRRLN-LNM were present in 12.6% (49/389) of patients, wherein 3.1% (12/389) had PRRLN-LNM only. A multivariate analysis revealed that younger age (≤ 35 years), extrathyroidal extension (ETE), lateral compartment LNM, prelaryngeal LNM, pretracheal, and right paratracheal LNM were independent predictors of PRRLN-LNM. CONCLUSION: This study revealed that younger age (≤ 35 years), ETE, prelaryngeal LNM, lateral compartment LNM, and pretracheal and right paratracheal lymph nodes (anterior to the right recurrent laryngeal nerve [level VIa]), LNM were independent factors of PRRLN-LN (level VIb). Therefore, comprehensive right CCD should be routinely performed for such patients.

[Improvement of immunogenicity of Streptococcus pneumoniae psaA DNA vaccine by prime and boost strategy].

OBJECTIVE: To study on the preparation of Streptococcus pneumoniae psaA DNA vaccine and to analyse the immunogenicity by the prime-boost strategy. METHODS: The psaA gene was amplified from the genome of Streptococcus pneumoniae by PCR, and then was inserted into plasmid pVAX1 and pET28a to construct recombinant expression vectors respectively. 293T cells were transiently transfected with pVAX1-psaA, and RT-PCR analysis of total cell RNA extracts showed successful expression of psaA. BALB/c mices (n = 5) were intramuscularly injected with 100 microg psaA DNA vaccine for three times, and then boosted with 50 microg recombinant PsaA protein. The antibody response against PsaA was measured by ELISA. RESULTS: The psaA gene was amplified and subcloned successfully. The constructed psaA DNA vaccine was confirmed by DNA sequencing, and the recombinant PsaA protein was purified by the one-step Ni(2+) affinity chromatography. Expression of the PsaA was observed in cells transfected with pVAX1-psaA. The animal experiment results showed that the anti-PsaA level of the DNA prime-protein boosting mice was higher significantly than the other groups (t = 87.518, P < 0.05). CONCLUSION: The psaA DNA vaccine was prepared successfully, and the immunogenicity of Streptococcus pneumoniae psaA DNA vaccine could be improved significantly by the DNA prime and protein boost strategy.