The effects of low pre-pregnant lead exposure level on maternal bone turnover during gestation and lactation in mice / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the effects of low pre-pregnant lead exposure level on the mobilization of lead and calcium in maternal skeleton during gestation and lactation in mice.</p><p><b>METHODS</b>Seventy Kunming female mice were randomly divided into the lead exposure or control groups, 36 mice were exposed to lead by drinking water (50 mg/L) and 36 mice were exposed to deionized water for 4 weeks. The levels of calcium and lead in blood and femurs were measured on the 1st, 7th and 14th days during gestation and on the 1st,10th and 21st days during lactation with atomic absorption spectrophotometry using a heated graphite atomizer or flame atomic absorption spectrophotometry.</p><p><b>RESULTS</b>As compared with the pre-pregnant, at the end of lactation in exposure group the levels of calcium in blood and bones significantly decreased 18.5% and 17.75%, respectively, the levels of lead in blood significantly increased 65.22% and the levels of lead in bones significantly decreased 28.45% (P < 0.05). There was a significant negative correlation between the blood lead level and the bone lead level during gestation and lactation in exposure group (r = -0.904, P < 0.01). There were significant differences of lead and calcium levels during the gestation and lactation between exposure group and control group (P < 0.05).</p><p><b>CONCLUSION</b>The lead mobilization in maternal bone occurred during gestation and lactation in mice, which could be accelerated by the low pre-pregnant lead exposure.</p>

Combining approach with multiplex PCR and MLPA to detect deletion and duplication in DMD patients, carriers, and prenatal diagnosis / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>Applying multiplex PCR and multiplex ligation-dependent probe amplification (MLPA) in a clinical setting to detect deletions and duplications in the Duchenne/Becker muscular dystrophy (DMD/BMD) gene not only for patients, but also for identification of possible carriers and prenatal diagnosis.</p><p><b>METHODS</b>Multiplex PCR was used first in patients clinically diagnosed with DMD/BMD to examine 26 exons for a large deletion in the two hot regions of the dystrophin gene. For patients without a deletion detected in the aforementioned regions, MLPA was used to further examine all 79 exons to determine whether a deletion in the remaining non-hot regions or any duplication was present. A similar approach was applied to suspected carriers. In requested prenatal diagnosis cases, specific PCR was used to detect deletions, while MLPA was applied to detect duplications.</p><p><b>RESULTS</b>Multiplex PCR was used to examine 26 exons within the two hot regions in the Dystrophin gene for 22 patients with DMD; 13 (13/22) had multi-exon deletions. For the 9 patients without deletions in the 26 exons, MLPA was used to examine 79 exons. 3 patients had duplications, 1 patient had a single deletion in exon 18, and no deletions or duplications could be detected in the remaining 5 patients. Of the 16 carriers, 2 out of the 3 that had family history had deletions, while the other 13 carriers were mothers of affected children who were sporadic patients without family history. Of them, 8 mothers were carriers for either deletions or duplications. For prenatal diagnosis, 9 fetuses were examined (one case was twins). Of them, 2 fetuses had familial deletions or duplications detected. These results were verified after induced abortion. In 7 fetuses, no deletions or duplications were detected and all developed into children.</p><p><b>CONCLUSION</b>Multiplex PCR can detect 92.86% of deletions and is useful for prenatal diagnosis of deletions because it is simple, reliable and inexpensive. It can be the first choice in DMD/BMD gene diagnosis. MLPA is important for detecting deletions in non-hot regions/exons and duplications in the DMD/BMD gene, as well as for carrier detection.</p>

Diagnostic methods and clinic application for mtDNA A1555G and GJB2 and SLC26A4 genes in deaf patients / 中华耳鼻咽喉头颈外科杂志

<p><b>OBJECTIVE</b>To establish the method of clinic genetic testing for common deaf genes such as mtDNA nt1555, GJB2 gene and SLC26A4 (Pendrin's syndrome gene, PDS) gene.</p><p><b>METHODS</b>Three hundred and sixty seven sporadic patients with hearing loss from out-patient department of General Hospital of Chinese People's Liberation Army, 60 patients with history of maternal inherited hearing loss from 27 family, 20 congenital deaf patients from special educational school for deaf and dumb, 3 deaf patients with enlarged vestibular aqueduct (EVA) confirmed by CT scan, 50 control individuals with normal bone conductive hearing were analyzed. The genetic testing kit for mtDNA A1555G mutation was used to detect mtDNA A1555G mutation. The whole gene sequencing were accomplished in 20 congenital deaf patients. In 3 patients with EVA, fragments covering all exons of PDS gene were analyzed by denatured high productive liquid chromatogram and special exons were sequenced when DHPLC showed abnormal wave patterns of amplicons covering these exons.</p><p><b>RESULTS</b>Fifty nine patients from 26 family and 5 sporadic patients were found to carry mtDNA A1555G mutation. Among 20 congenital deaf patients, 2 cases were found to have homozygous GJB2 235 del C mutation, 1 case had compound 235del C and 299-300 del AT mutation. Other 2 cases carried heterozygous 109 A-G mutation. Among 3 patients with EVA, 1 case was found to have heterozygous PDS G316X mutation and other 2 cases had homozygous 919-2 A-G mutation. CONCLUSIONS Genetic testing for deafness is feasible procedure with remarkable clinic significance.</p>