Construction and identification of mutation of pgm gene attenuate the virulent of Brucella melitensis strain 16 / 中国地方病学杂志

Objective The construction of suicide plasmid vector could be used to make mutation of pgm gene which attenuates the virulent of Brucella melitensis strain 16, the research may lay a foundation for the development of novel live attenuated vaccines. Methods Sucrose sensitive gene as forward screening sign and fusion sequences of kanamycin resistance gene were constructed based on plasmid pucl9; pucS1.6K suicide plasmid vector was established by modifying pgm gene with fusion sequences of kanamycin resistance gene (insertion mutation); pgm gene mutation of Brucella melitensis strain 16 was obtained by electro transformation and mutation was confirmed by PCR amplification. Results The results showed that the identified Brucella melitensis strain 16 pgm gene was inactivated after insertion of kanamycin resistance gene, and the mutant pgm gene DNA fragment length was approximately 3525 bp, in line with expectations, Brucella pgm gene mutant melitensis strain 16 was successfully constructed. Conclusions The construction of suicide plasmid vector and precise mutation of Brucella melitensis strain 16 is successful, the study is not only provided an effective technology platform for constructing mutants of Brucella but also lays a foundation for the development of novel live attenuated vaccines.

Diagnosis and treatment of cervical Castleman disease presenting as a neck mass / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To investigate the clinical and pathological features, diagnosis and treatment of Castleman disease (CD).</p><p><b>METHODS</b>Clinical features and related information on diagnosis and treatment of eight cases of CD were retrospectively analyzed. The size of involved lymph nodes ranged from (2 cm x 2 cm x 3 cm) - (4 cm x 3 cm x 2 cm). The lymph nodes were found in level I (1 case), level II (3 cases), level III (3 cases) and level IV (1 case). CT examination in eight patients showed the lesions manifested as ellipse soft masses. Dynamic contrast CT scan in four patients showed ring-enhanced area around the masses. Blood routine examination in eight patients were generally normal, with six patients had mild anemia.</p><p><b>RESULTS</b>Based on the clinical classification, all lesions in this group were localized CD. Histopathology indicated that all lesions were of hyaline-vascular type. After surgery, there was no recurrence during the follow-up period.</p><p><b>CONCLUSIONS</b>Patients with localized CD mainly have lymphadenectasis in a single location. The CT scan can give some evidence. Surgery should be given first priority.</p>