MRI demonstrates abnormalities of motor nerves and extraocular muscles in congenital fibrosis syndrome due to mutations in KIF21 A / 国际眼科杂志(Guoji Yanke Zazhi)

AIM:To observe the structural basis of ocular motility abnormalities in patients with congenital fibrosis of the extraocular muscles type Ⅰ ( CFEOM Ⅰ) due to missense mutations in the developmental kinesin KIF21A using high - resolution magnetic resonance imaging ( MRI) . METHODS: Totally 11 affected individuals reported KIF21A mutations were correlated with MRI studies demonstrating extraocular muscles ( EOMs ) size, location, contractility, and innervation. EOMs and the motor nerve in the orbits were imaged with T1 weighted in a triplanar scan using a dual-phased coils with 2. 0mm thick. Motor nerves were imaged at the brainstem using head coils and 3D-FIESTA with 0. 6-mm thick. RESULTS: Patients with CFEOM Ⅰ exhibited different degrees of hypoplasia of oculomotor nerve, the abducens nerve and the trochlear nerve were also affected, of which 8 cases of orbital section could see the signal of abnormal nerve dominated by oculomotor nerve to lateral rectus. The both sides of six EOMS in all patients exhibited variable atrophy and abnormal bright internal signal on T1 imaging, particularly severe for the superior rectus and levator muscles. CONCLUSION: High - resolution MRI can directly demonstrate pathology of motor nerves,affected EOMs, and ‘Pulley' hypoplasia caused by CFEOM Ⅰ due to mutations in KIF21A,and these findings suggest that the neuronal hypoplasia is the etiological factor of CFEOM.

Prokaryotic expression, purification, and immunogenicity analysis of Mycobacterium tuberculosis specific excretive proteins / 中国医学科学院学报

<p><b>OBJECTIVE</b>To obtain the recombinant rv1837c and rv3803c of Mycobacterium tuberculosis using gene engineering technology and explore their prokaryotic expression, purification, and immunogenicity.</p><p><b>METHODS</b>The Mycobacterium tuberculosis rv1837c and rv3803c genes were amplified by polymerase chain reaction, and then cloned into the vector pTA2, followed by the subclone into the expression vector pET30a (+). The resulting plasmids, named pET30a (+): rv1837c and pET30a (+): rv3803c, encode recombinant protein containing a hexa-histidine tag on its N-terminus. pET30a (+): rv1837c and pET30a (+): rv3803c were introduced into E. coli BL21 (DE3) by transformation respectively, and the recombinant gene was induced with 0.4 mmol/L isopropyl-D-thiogalactopyranoside. The expressed products were identified by Western blot with hexa-histidine tag antibody and serum from tuberculotic patients. The histidine tagged protein was purified by nickel nitrilotriacetic acid His-Bind resin. Rabbits were immunized with purified recombinant Rv1837c and Rv3803c proteins. Then the purified recombinant Rv1837c and Rv3803c proteins were used to detect antibody in rabbit serum, which had been immunized by Western blot.</p><p><b>RESULTS</b>After transformation of the E. coli and induction with 0.4 mmol/L of isopropyl-D-thiogalactopyranoside, recombinant target proteins Rv1837c (relative molecular mass: 92000) and Rv3803c (relative molecular mass: 38 000) were expressed in pET30a (+): rv1837c and pET30a (+): rv3803c system. The expressed protein existed in cytoplasm in an unsoluble form and amounted to 30% and 50% of the total proteins of E. coli. The purity of the purified protein reached 90%. The immunogenicity of the recombinant proteins Rv1837c and Rv3803c was strong, as identified by Western blot.</p><p><b>CONCLUSION</b>The prokaryotic expression recombinant plasmids pET30a (+): rv1837c and pET30a (+): rv3803c was successfully constructed and the recombinant proteins Rv1837c and Rv3803c were obtained, which laid a basis for the optimized diagnosis of active tuberculosis.</p>

Establishment and evaluation of nitrate reductase combined with mycobacteriophage assay / 中国医学科学院学报

<p><b>OBJECTIVE</b>To establish a rapid, inexpensive, and simple drug susceptibility test (DST) for Mycobacterium tuberculosis (M. tb) and evaluate its feasibility.</p><p><b>METHOD</b>We used nitrate reductase combined with mycobacteriophage assay (PhaB-NRA) to test 49 clinical M. tb isolates of, and the results were compared with those of PhaB-NRA and traditional absolute concentration method.</p><p><b>RESULTS</b>The sensitivity, specificity, and accuracy of PhaB-NRA for rifampicin were 89.1%, 91.67%, and 89.8%; on the contrary, those of isonicotinyl hydrazide were 86.21%, 90.0%, and 87.8%, respectively. The coincidence between PhaB-NRA and traditional assay were 0.746 for rifampicin and 0.750 for isonicotinyl hydrazide.</p><p><b>CONCLUSIONS</b>PhaB-NRA is an inexpensive, rapid, and simple DST method. It is a promising rapid screening technique for DST of M. tb.</p>

Relationship between the resuscitation promoting role of resuscitation promoting factor and the initial bacteria amount of dormant Mycobacterium tuberculosis / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the relationship between the resuscitation promoting role of resuscitation promoting factor and the initial bacteria amount of dormant Mycobacterium tuberculosis.</p><p><b>METHODS</b>Mycobacterium tuberculosis (dormant bacteria) was cultured for 100 days, then diluted into 1 mg/ml concentration with 7H9, and further diluted into 0.5, 0.25, 0.125, 0.0625, and 0.03125 mg/ml. Twelve new tubes added with 5 ml 7H9 and divided into two groups: the first group was added with the resuscitation-promoting factor protein, and the second group as control was added with 7H9. In each group the above diluted solutions were added. The tubes were located at 37 degrees C for culture. Optical density (OD) was detected on day 15, 25, 30, and 35. From each tube 1 microl culture solution was plated on 7H11 medium for colony counting.</p><p><b>RESULTS</b>OD detection showed that bacteria proliferation in each group had positive linear correlation (P < 0.05, P < 0.01), indicating that the resuscitation-promoting factor played a similiar role in solutions with different dilution concentrations. 7H11 results and the OD results show that these two detection methods in each group had linear correlation (P < 0.05, P < 0.01), indicating that these two methods showed consistent test results.</p><p><b>CONCLUSION</b>The resuscitation-promoting factor has no effect on the resuscitation of dormant Mycobacterium tuberculosis and its initial bacteria amount.</p>

Autosomal dominant congenital nuclear cataract caused by a deletion mutation in the beta A1-crystallin gene / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To identify the genetic defect causing automosal dominant congenital cataracts (ADCC) with nuclear opacities in a Chinese pedigree.</p><p><b>METHODS</b>Linkage analysis was carried out with the short tandem repeat polymorphisms flanking the candidate genes. Mutation analysis of the candidate gene in the critical region was performed to detect the potential mutation.</p><p><b>RESULTS</b>The cataract locus in this pedigree was mapped to 17q11.1-12, an 11.78 cM interval between markers D17S933 and D17S 1288. By means of sequencing the candiate gene, betaA1-crystallin (CRYBA1), a deletion mutation DeltaG91 in exon 4 was detected. This change cosegregated with the patients in the family but was not found in 50 normal unrelated individuals.</p><p><b>CONCLUSION</b>It is a deletion mutation DeltaG91 of CRYBA1 gene that causes autosomal dominant congenital nuclear cataract. This is the first report of an autosomal dominant congenital nuclear cataract caused by the mutation in this gene.</p>