Clinical screening and genetic diagnosis for Prader-Willi syndrome / 中国当代儿科杂志

OBJECTIVE@#To study the clinical screening and genetic diagnosis of children suspected of Prader-Willi syndrome (PWS), as well as the differences in the scores of clinical diagnostic criteria among the children with a confirmed diagnosis of PWS.@*METHODS@#A total of 94 children suspected of PWS who were admitted from July 2016 to December 2018 were enrolled as subjects. Methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) was performed to confirm the diagnosis. For the children with a confirmed diagnosis of PWS, the scores of clinical diagnostic criteria were determined, and the perinatal characteristics were analyzed.@*RESULTS@#A total of 11 children with PWS were confirmed by MS-MLPA, with a detection rate of 12%, among whom there were 7 boys and 4 girls, with a median age of 3 years and 4 months (range 25 days to 6 years and 8 months) at the time of confirmed diagnosis. Among the 11 children with PWS, only 5 children (45%) met the criteria for clinical diagnosis. The main perinatal characteristics of the children with PWS were decreased fetal movement (9 cases, 82%), cesarean section birth (11 cases, 100%), hypotonia (11 cases, 100%), feeding difficulties (11 cases, 100%), and weak crying (11 cases, 100%).@*CONCLUSIONS@#Gene testing should be performed as early as possible for children suspected of PWS by clinical screening. PWS may be missed if only based on the scores of clinical diagnostic criteria.

INFLUENCE OF EXUDATES OF AMMONIUM-RESISTANT N_2 -FIXING BACTERIA ON THE GROWTH OF RICE SEEDLING / 微生物学通报

By using cup culture, influence of different strains (ammonium-resistant N2-fixing type, wild type, none N2-fixing type) of Klebsiella oxytoca on the growth of rice seedling was compared. It was discovered that ammonium-resistant N2 -fixing bacteria could excrete some plant growth promoting substance, which could be adsorbed by cation resin. It' s activity wouldn't be affected at 80℃. At optimal concentration, the weight of rice root and seedling were increased by

STUDY ON THE CHARACTERS OF AN HARPIN-PRODUCING BACTERIA STRAIN TOLERANT TO AMMONIUM AND NITROGEN-FIXING / 微生物学通报

The ability to induce hypersensity on leaves of tomato and the stability of double-plasmid of an harpin-producing, nitrogen-fixing engineered strain E4 were tested. Hypelsensitivity-inducing experiment indicated that the time and density of hypersensitivity-induction of E4 was similar to those of DH5, the positive control of pCPP430. Although E4 took the same time to induce hypersensitivity as 308R, another positive control of pCPP430, it induced weaker hypersen- sitivity on tobacco leaves. On tomato leaves, there was no difference in time and density of hypersensitivity between E4 and 308R (pCPP430). Results revealed that the two plasmids, pCPP430 and pMC73A, were unstable in host bacteria, with the losing rate of 100% at the 48th generation. The emergence probability of bacteria with either pCPP430 or pMC73A was almost the same.

STUDY ON HIGH-DENSITY CULTURE OF AMMONIUM-RESISTANT N_2-FIXING BACTERIUM KLEBSIELLA OXYTOCA / 微生物学通报

Based on the physiological properties of ammonium-resistant N2-fixingbacterium ( Klebsiella oxytoca NG13/pMC73A), the fermentation technology of it was studied. The basic medium of high-density culture was established, with glucose as carbon source coupled with appropriate nitrogen source and inorganic salts. At the middle and late phase of culture, glucose and ammonia were added to supply carbon source and nitrogen source, stabilizing the pHat 6.5 ~ 6.8. Optimal level of dissolved oxygen was kept by controlling aeration and stirring rate. Bacterium number of Klebsiella oxytoca NG13/pMC73A reached 600 ~ 700 x 10s cfu/mL at the end of culture. Compared with previous technology, bacterium number was increased by more than ten-fold with a comparable culture period.