Highly selective and multicolor ultrasensitive assay of dipicolinic acid: The integration of terbium(III) and gold nanocluster.

A novel multicolor fluorescent nano-probe based on the hybridization of Tb3+ ion with gold nanoclusters (Au NCs) was synthesized to monitor and on-site visual assay of 2,6-pyridinedicarboxylic acid (DPA), a biomarker of bacterial spores. DPA can replace the water molecule in the center of Tb3+ and strongly coordinate with Tb3+ based on the analyte-triggered antenna effect. Simultaneously, the red fluorescence of Au NCs is not influenced after addition of DPA and can be used as steady inside fluorescence reference channel to measure background noise. On this basis, the multicolor fluorescence nano-probe based on Tb3+-doped Au NCs for fast analysis of DPA was fabricated. The linear range of this method is 0 to 12.5 µM and the limit of detection is 3.4 nM, which is well below the quantity of DPA concentration of 60 µM released by the spore transmission dose of anthrax infection. The proposed multicolor fluorescence nano-probe was successfully detecting DPA in actual sample with good sensitivity and specificity. In addition, the visual paper-based nano-probe is designed to detect DPA by using the color scanning application of smart phone. This developed platform possesses abroad application prospects with advantages of effective, convenient carrying, simple operation, good selectivity and repeatability.

Follow-up study of preterm infants with thyroid dysfunction after medication. / ç”²çŠ¶è ºåŠŸèƒ½å¼‚å¸¸æ—©äº§å„¿å¹²é¢„æ²»ç–—çš„éšè®¿ç ”ç©¶.

OBJECTIVES: To study the effect of levothyroxine sodium tablets on the growth and development and thyroid function in preterm infants with thyroid dysfunction. METHODS: A retrospective analysis was performed for 82 preterm infants who were born in the Department of Obstetrics of the First People's Hospital of Yunnan Province, from January 1, 2013 to December 31, 2017, and these infants were hospitalized after birth in the Department of Neonatology of the hospital. They were regularly followed up to observe growth and development and thyroid function at the outpatient service of the Department of Neonatology. According to thyroid function test results, they were divided into an abnormal thyroid function group (observation group; n=31) and a normal thyroid function group (control group; n=51). The infants in the observation group were given oral administration of levothyroxine sodium tablets, while those in the control group were not given any treatment. The two groups were compared in terms of the physical and intelligence development and thyroid function of preterm infants with various gestational ages (28-<32 weeks, 32-<34 weeks, and 34-<37 weeks) after regular follow-up to the corrected age of 12 months. RESULTS: There were no significant differences in physical development indices (body length, body weight, and head circumference) between the observation and control groups at various gestational ages after follow-up to the corrected age of 12 months (P>0.05). There were no significant differences between the two groups in the scores of each functional area of the Gesell Developmental Scale among the preterm infants with a gestational age of 28-<32 weeks and 32-<34 weeks after follow-up to the corrected age of 12 months (P>0.05). For the preterm infants with a gestational age of 34-<37 weeks, compared with the control group, the observation group had a significantly lower score of gross motor ability at the age of 3 and 12 months, significantly lower scores of fine motor ability, language ability, and adaptation ability at the age of 12 months (P<0.05), and a significantly lower score of personal-social ability at the age of 3 months (P<0.05). However, the score of personal-social ability in the observation group was not significantly different from the control group at the age of 12 months (P>0.05). After 2-4 weeks of treatment with levothyroxine sodium tablets, the thyroid function of the 31 preterm infants with thyroid dysfunction returned to normal. Among the 31 infants, 21 (68%) achieved complete drug withdrawal, with normal results of neonatal screening (100%); 10 infants (32%) failed to achieve drug withdrawal, and only 2 (20%) out of the 10 infants had normal neonatal screening results (P<0.05). CONCLUSIONS: Early diagnosis and reasonable treatment can reduce the impact on growth and development in preterm infants with thyroid dysfunction. Most preterm infants tend to have transient thyroid dysfunction, while those with positive results of neonatal screening are more likely to develop permanent thyroid dysfunction.

[Association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy].

OBJECTIVE: To study the association of copy number of SMN1 and SMN2 with clinical phenotypes in children with spinal muscular atrophy (SMA). METHODS: A total of 45 children with SMA were enrolled. Multiplex ligation-dependent probe amplification was used to measure the gene copy numbers of SMN1 and SMN2. The association of copy number of SMN1 and SMN2 with clinical phenotypes was analyzed. RESULTS: Of the 45 children with SMA, 42 (93%) had a homozygous deletion of SMN1 exons 7 and 8, and 3 (7%) had a deletion of SMN1 exon 7 alone. No association was found between SMA clinical types and the deletion types of SMN1 exons 7 and 8 (P>0.05). There was a significant difference in the distribution of SMN2 gene copy numbers between the children with SMA and the healthy children (P<0.05). The children with SMA usually had two or three copies of SMN2 gene, while the healthy children usually had one or two copies of SMN2 gene. There was a significant difference in the distribution of SMN2 copy numbers among the children with different SMA clinical types (P<0.05). The children with two copies of SMN2 gene had a significantly lower age of onset than those with three or four copies. Most of the children with type I SMA had two or three copies of SMN2 gene. Most of the children with type II SMA had three copies of SMN2 gene. Most of the children with type III SMA had three or four copies of SMN2 gene. Children with a higher copy number of SMN2 gene tended to have an older age of onset and better motor function and clinical outcome, and there was a significant association between SMN2 gene copy number and clinical outcome (P<0.05). CONCLUSIONS: The SMN2 gene can reduce the severity of SMA via the dosage compensation effect. SMN2 copy number is associated with the phenotype of SMA, and therefore, it can be used to predict disease severity.

[Analysis of treatment efficacy for congenital hypothyroidism in some regions of Yunnan Province, China].

OBJECTIVE: To observe the effects of initial doses and treatment timing of levothyroxine (L-T4) on the clinical efficacy in children with congenital hypothyroidism (CH). METHODS: This study included 98 children who had an abnormal level of thyroid stimulating hormone (TSH) in neonatal screening in four regions of Yunnan Province and who finally had a confirmed diagnosis of CH. They received treatment with L-T4 and were divided into standard dose group (10-15 µg/kg per day) and low dose group (<10 µg/kg per day) by the therapeutic dose of L-T4. Meanwhile, these patients were also classified into two treatment groups based on the starting time of L-T4 treatment, namely under 2 months old group and more than 2 months old group. The thyroid function and physical and neural development were examined before and after treatment. RESULTS: Compared with the low dose group, the standard dose group had a significantly lower TSH level and a significantly higher free thyroxine (FT4) level at 2 weeks after treatment (P<0.05). There were no significant differences in TSH and FT4 levels at other time points after treatment between the standard and low dose groups (P>0.05). The physical and neural development were not significantly different between the two dose groups before and at all time points after treatment (P>0.05). At all time points after treatment, the levels of TSH and FT4 and physical development were not significantly different between the different starting time groups (P>0.05). However, the Gesell score was significantly higher in the under 2 months old group than in the more than 2 months old group at all time points after treatment (P<0.05). CONCLUSIONS: The standard dose group has a better treatment outcome than the low dose group, whereas the symptoms of hyperthyroidism deserve close attention. The treatment timing is vital to the neurodevelopment of children with CH. Once diagnosed, the patients should receive treatments immediately.

[Gene Analysis of Thalassemia in Han and Dai Ethnic Childbearing-aged Population of Chinese Yunnan Province].

OBJECTIVE: To investigate the common mutation spectrum of α- and ß-thalassemia in Yunnan childbearing-aged population. METHODS: The common mutation types of α- or ß-globin genes were detected by multiple Gap-PCR and the PCR-reversed dot blotting, and the unknown mutation types were determined by DNA sequencing in DNA samples of hypochromic microcytic anemia patients and carriers who were confirmed to be positive by serologic screaning, then the mutation types of globin in Yunnan population were analyzed statistically. RESULTS: A total of 40 kinds of mutation types were detected in 685 detected persons, among them the 3 commonest mutation types of α-globin genes were --(SEA)/αα (49.09%), -α(3.7)/αα (36.67%) and α(CS)α/αα (8.79%), the 3 commonest genetypes of ß-globin gene were CD26(GAG>AAG)/N (43.78%), CD41-42(-CTTT)/N (20.1%) and CD17(AAG>TAG)/N (18.9%). There were 348 Han and 212 Dai ethnic persons in 685 cases, but their mutation of globin genes were different between these 2 ethnic groups. The results also showed that the gene mutation types were mostly concentrated in Dai ethnic individuals, since 28 of 38 detected α-ß-thalassemia cases were Dai ethnic individuals. CONCLUSION: The mutation spectrums of α- and ß-globin genes in Yunnan childbearing-aged population are diverse and different from that in other areas of China.

[Analysis of neonatal screening results for congenital hypothyroidism in parts of Yunnan Province, China].

OBJECTIVE: To summarize and analyze neonatal screening results for congenital hypothyroidism (CH) in parts of Yunnan Province, China. METHODS: A total of 236 218 newborns (121 463 males and 114 755 females) who were born in Zhaotong City, Qujing City, Lijiang City, and Diqing Tibetan Autonomous Prefecture of Yunnan Province, China, between July 2012 and April 2014 were screened for CH. The original blood smear was re-tested if the thyroid stimulating hormone (TSH) level in heel blood was ≥8 µIU/L in the initial screening. The newborns with positive TSH results were called back for further diagnosis by measuring blood TSH and free thyroxine (FT4) levels. RESULTS: Among 236 218 newborns, the pass rate of blood smears, re-acquisition rate of unqualified blood smears, and recall rate of suspected cases were 96.67%, 81.75%, and 73.02%, respectively. Sixty-six cases of CH were confirmed, among which 36 were male infants and 30 were female infants (P>0.05). The incidence rate of CH was 1/3 579, which was significantly lower than the national average rate (1/2 034; P<0.01). The gestational age of CH newborns was mostly between 37 to 42 weeks, and only 3% were born at a gestational age of >42 weeks. Most of the CH newborns had normal birth weight. The CH newborns with a body length of <50 cm accounted for 32%. CONCLUSIONS: The incidence of CH in Yunnan Province is lower than the national average. There are no specific clinical features in CH newborns. The neonatal screening in Yunnan Province needs further improvement.

[A study on gene mutation spectrums of α- and ß-thalassemias in populations of Yunnan Province and the prenatal gene diagnosis].

OBJECTIVE: To investigate mutation spectrums of α- and ß-haemoglobin genes in thalassemia patients and carriers in Yunnan province, and to establish procedures on prenatal gene diagnosis. METHODS: Totally 10 033 counseling couples and pregnant women, and 22 cases of children with moderate or severe thalassemia were recruited from 5 parts of Yunnan Province, middle, western, eastern, southern and northern areas, during July 2009 to July 2011. Medical records, including results of haemoglobin electrophoresis, blood routine examination, and gene diagnosis of subjects were collected and saved in an database in Excel software by the Key Laboratory for Birth Defects and Genetic Diseases. Using multiple gap-PCR and PCR-reversed dot blotting kits, DNA samples collected from 1077 cases of haematological positive thalassemia patients and carriers were tested to determine common mutations of the α- or ß-haemoglobin genes. The codon regions of haemoglobin genes were sequenced by the Sanger sequencing in cases that the mutation tests were negative. Mutation spectrums of α- and ß-haemoglobin genes were concluded. Prenatal gene diagnosis was offered to fetuses who had risk of thalassemia major. RESULTS: (1) In 1077 cases of haemological screen positive subjects, deletions and mutations of α-haemoglobin gene were tested in 119 subjects among 347 cases suspected as α-thalassemia patients and carriers. Five kinds of deletions and mutations on α-haemoglobin gene were found. In 104 subjects, four kinds of common deletions and mutations onα-haemoglobin gene were determined: --(SEA), -α(3.7), α(CS)α, -α(4.2). Other 14 subjects were double heterozygotes with haemoglobin H disease and severe α-thalassemia phenotypes. A rare mutation of insertion and deletion in α2 haemoglobin gene intron, α(301-24_301-23 indel), was found in one carrier subject. (2) In 1077 cases of haemological screen positive subjects, deletions and mutations of ß-haemoglobin gene were tested in 297 subjects among 730 cases suspected as ß-thalassemia patients and carriers. Sixteen kinds of ß-haemoglobin gene mutations were found, including 7 cases of rare abnormal haemoglobinopathy patients with ß-haemoglobin gene mutations. In one case with ß(+) phenotype patient, the Codon 5(-CT) mutation at ß-haemoglobin gene was found (firstly reported in China). (3) Three fetuses with high risks of α-thalassemia were accepted for prenatal diagnosis. One case of Hb Bart's hydrops syndrome fetus with the genotype --(SEA)/--(SEA), and one case of mild α-thalassemia fetus with the genotype α(CS)α/αα were found. Another one fetus was found with normal α-haemoglobin. In 6 fetuses accepted for prenatal diagnosis due to high risks of ß-thalassemia, one case of ß-thalassemia major with the genotype CD(17)(A→T)/-28(A→G) was found, 3 fetuses were heterozygote carriers, and 2 fetuses had normal genotypes without mutations found in their parents. Medical terminations for 2 fetuses with severe thalassemia were made according to the choice of pregnant women. Other 7 pregnancies continued to term. Anemia or growth retardation was not found in the 7 infants when following up after given-birth 6 to 12 months. CONCLUSIONS: The mutation spectrums of α- and ß-haemoglobin genes of thalassemia patients and carriers in Yunnan province are special, in which ß-haemoglobin gene exits more polymorphism in the mutation spectrum. Carrier screening in pregnant women, and offering prenatal gene diagnosis to the high risk pregnancies should be an efficient strategy to prevent thalassemia major.

Rapid detection of hepatitis C virus RNA by a reverse transcription loop-mediated isothermal amplification assay.

The usefulness of reverse transcription loop-mediated isothermal amplification (RT-LAMP) for the rapid diagnosis of hepatitis C virus (HCV) RNA was evaluated. This assay showed higher sensitivities than that of nested RT-PCR, with a detection limit of 600 IU mL(-1) , and no cross-reactivity was observed with hepatitis A virus, hepatitis B virus and hepatitis E virus. Furthermore, 106 stored sera from recently diagnosed cases were retrospectively investigated with real-time RT-PCR, the nested RT-PCR, in parallel with this new assay. The general detection rates of HCV RT-LAMP, real-time PCR and the nested RT-PCR for 106 stored sera samples were 95%, 96% and 88%, respectively. This study provides the first data on the usefulness of HCV RT-LAMP in the diagnosis of HCV RNA, especially in the early clinical diagnosis of acute HCV infection.

[FUT1 gene polymorphism and its association with litter size in pigs].

The genetic variations of FUT1 gene at nucleotide position 307 of its open reading frame were investigated by PCR-RFLP in a total of 245 pigs from 3 exotic pig breeds and 3 Chinese native pig breeds. Results showed that the genetic polymorphisms of the FUT1 locus were only detected in the 3 exotic pig breeds. There were 3 different genotypes and the majority were the susceptible forms including GG and AG. All Chinese native pig breeds only presented the susceptible genotype GG. Univariate analysis of variance components indicated that FUT 1 gene and the type of breeds significantly affected total number born, whereas parities did not. None of these factors significantly affected the number of liveborns.