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Abstract Background Protein A, protein G and protein L are three well-defined immunoglobulin (Ig)-binding proteins (IBPs), which show affinity for specific sites on Ig of mammalian hosts. Although the precise functions of these molecules are not fully understood, it is thought that they play an important role in pathogenicity of bacteria. The single domains of protein A, protein G and protein L were all demonstrated to have function to bind to Ig. Whether combinations of Ig-binding domains of various IBPs could exhibit useful novel binding is interesting. Results We used a combinatorial phage library which displayed randomly-rearranged various-peptide-linked molecules of D and A domains of protein A, designated PA(D) and PA(A) respectively, B2 domain of protein G (PG) and B3 domain of protein L (PL) for affinity selection with human IgG (hIgG), human IgM (hIgM), human IgA (hIgA) and recombinant hIgG1-Fc as bait respectively. Two kinds of novel combinatorial molecules with characteristic structure of PA(A)-PG and PA(A)-PL were obtained in hIgG (hIgG1-Fc) and hIgM (hIgA) post-selection populations respectively. In addition, the linking peptides among all PA(A)-PG and PA(A)-PL structures was strongly selected, and showed interestingly divergent and convergent distribution. The phage binding assays and competitive inhibition experiments demonstrated that PA(A)-PG and PA(A)-PL combinations possess comparable binding advantages with hIgG/hIgG1-Fc and hIgM/hIgA respectively. Conclusion In this work, a combinatorial phage library displaying Ig-binding domains of protein A, protein G, or protein L joined by various random linking peptides was used to conducted evolutional selection in vitro with four kinds of Ig molecules. Two kinds of novel combinations of Ig-binding domains, PA(A)-PG and PA(A)-PL, were obtained, and demonstrate the novel Ig binding properties.

Objective: To analyze retrospectively the abnormal karyotypes, and the indications of prenatal diagnosis, and to follow-up survey those fetuses with abnormal karyotypes, so as to provide references for genetic counseling. Methods: Chromosomal karyotype analysis was performed in 15 413 cases with the indications of prenatal diagnosis, using fetal samples by amniocentesis or umbilical cord puncture with the informed consent. Total 220 pairs with abnormal karyotype fetuses were surveyed follow-up by phone, and their child were checked chromosomal karyotypes using peripheral blood samples. Results: Total success rate of cell culture was 99.6% (15 349/15 413), including 99.76%(11 299/11 326) in amniotic fluid samples and 99.1%(4 050/4 087) in umbilical cord blood samples. The rate of chromosomal abnormalities was 11.20% (1 719/15 349), including 8.70% (1 335/ 15 349) normal polymorphism, 1.72% (264/15 349) abnormal number of chromosomes and 0.79% (121/15 349) structural abnormalities of chromosomes. Classified according to the indications of prenatal diagnosis, the rates of chromosomal abnormalities were as follows, 10.67% (879/8 236) Down's syndrome, 9.76% (128/1 312) elderly pregnant women, 12.27% (138/1 125) history of adverse pregnancy, 11.40% (124/1 087) abnormality found by B-ultrasound, 23.91% (132/552) abortion due to fetal malformation. In those chromosomal abnormalities, 108 abnormal karyotypes were from mothers, 69 from fathers, 43 from spontaneous abnormalities. Conclusions: The prenatal diagnosis and chromosomal analysis in those high-risk pregnant women are helpful to reduce birth defects. [ABSTRACT FROM AUTHOR]

Objective: To investigate the genotypes and clinical features of children with HbH disease in Guangxi Zhuang Autonomous Region, China., Methods: A total of 595 children from Guangxi were recruited. Single-tube multiplex polymerase chain reaction combined with agarose gel electrophoresis, as well as reverse dot blotting, were performed to detect the three α-globin gene deletion mutations (--(SEA), -α(3.7), and -α(4.2)) and three non-deletion mutations (Hb Westmead, Hb Constant Spring, and Hb Quong Sze) which are common in the Chinese population., Results: Among the 595 cases, five common genotypes were identified, which were --(SEA)/-α(3.7) (232 cases), --(SEA)/α(CS)α (174 cases), --(SEA)/-α(4.2) (122 cases), --(SEA)/α(WS)α (35 cases), and --(SEA)/α(QS)α (24 cases). The genotype of THAI deletion associated with α-thalassemia-2 was detected in eight cases. Six β-mutations including CD41-42, CD17-28, CD26, IVS-II-654, IVS-I-1, and CD27-28 were identified in 23 cases. All children with HbH disease had microcytic hypochromic anemia; children with HbH-CS disease had the most severe anemia, and those with HbH-WS disease had the mildest anemia., Conclusions: Deletional HbH disease is the main type in children with HbH disease in Guangxi, and some patients also have mild beta-thalassemia. Non-deletional HbH disease shows more severe phenotype than deletional HbH disease.

Objective: To evaluate the effect of combined use of stanazolol (ST) on the final adult height (FAH) in girls with idiopathic central precocious puberty (ICPP) and apparently decreased linear growth during gonadotropin-releasing hormone analog (GnRHa) therapy., Method: Sixty-three girls with ICPP and decreased velocity of growth of height (HV<4 cm/yr) during GnRHa therapy were divided into 3 groups based on the following types of interventions:group 1 (n = 20), GnRHa+ST [25-30 µg/(kg·d) every 3-month followed by 3-month discontinuation], group 2 (n = 21), GnRHa+recombinant human growth hormone [rhGH, 1-1.1 U/(kg·w)], group 3 (n = 22), GnRHa alone.HV, the advancement of bone age (BA) for chronological age (CA) (ΔBA/ΔCA) and FAH were compared among groups., Result: (1)Total duration of ST combination therapy was (12.22 ± 3.62) months, while total duration of combination of rhGH was (13.22 ± 6.80) months. (2)HV increased significantly in both group 1 [ (2.79 ± 0.60) cm/yr vs. (6.27 ± 1.98) cm/yr, P < 0.01] and in group 2 [(2.80 ± 0.50) cm/yr vs. (6.25 ± 1.98) cm/yr, P < 0.01] during combined therapy, but maintained at low levels in group 3 [(3.95 ± 1.10) cm/yr vs. (3.34 ± 0.95) cm/yr, P > 0.05].No significant differences of ΔBA/ΔCA were found among the three groups [0.25(0.11∼0.28), 0.22(0.15∼0.31),0.19(0.10∼0.32), P > 0.05]. (3)FAH was significantly higher than predicted adult height (PAH) before combined therapy, as well as higher than target height (THt) in both group 1 [(156.25 ± 2.90) cm vs. (150.78 ± 3.70) cm, P < 0.01, (156.25 ± 2.90) cm vs. (153.94 ± 2.62) cm, P < 0.01], and in group2 [ (157.33 ± 4.69) cm vs. (152.61 ± 3.92) cm, P < 0.01, (157.33 ± 4.69) cm vs. (154.39 ± 4.72) cm, P = 0.01].In group 3, FAH was similar to PAH [(153.88 ± 2.6) cm vs. (152.54 ± 5.86) cm, P > 0.05], and was less than THt [(153.88 ± 2.6) cm vs. (155.60 ± 4.52) cm, P = 0.02]. (4)In girls treated with ST, no hirsutism, clitorism or hoarse voice was recorded.No polycystic ovary syndrome was found by B-mode ultrasound., Conclusion: Intermittent combined use of low dose ST therapy can increase HV and thus improve FAH in girls with ICPP and apparently decreased linear growth during GnRHa therapy.

Objective: To assess the utility of serum steroids measurement in monitoring the treatment of children with congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency (21OHD)., Method: Nineteen Patients with CAH 21OHD aged (3.67±1.54) years treated with hydrocortisone and fluorocortisone replacement were followed up at an intervals of 0.33 - 1.0 years over a period of (1.47±0.7) years. At each visit, roentgenograms of the hands and wrists were taken, fasting peripheral blood were collected to test serum dehydroepiandrosterone sulfate, progesterone, 17-hydroxyprogesterone (17-OHP), androstenedione (Δ4-A), testosterone, free testosterone, estrone, and estradiol concentrations at 8 AM in the morning before the first dose of glucocorticoid. Then the patients were classified as being in "Good Control" or in "Poor Control" based on clinical criteria including signs of androgen excess, growth velocity and bone age increment at each interval. Comparisons were carried out between the serum steroid concentrations of the two groups. The receiver operating characteristic (ROC) curves were used to determine the cut-off values for diagnosing "Poor Control"., Result: Both of serum Δ4-A and 17-OHP concentrations were higher in "Poor Control" group than those in "Good Control" group [5.95 (2.23-11.2) nmol/L versus 1.05 (1.05-9.89) nmol/L, t=2.19; 13.85 (6.06-20) µg/L versus 3.67 (0.42-21.1) µg/L, t=2.17; P<0.05, respectively]. The ROC curves for serum Δ4-A concentrations, serum 17-OHP concentrations, serum Δ4-A in combination with 17-OHP concentrations were constructed with areas under the ROC curves (95%CI) of 0.76 (0.62, 0.90), 0.75 (0.62, 0.88), 0.69 (0.54, 0.84), P<0.05, respectively. Serum Δ4-A of 3.9 nmol/L had 0.78 of sensitivity and 0.75 of specificity in diagnosing "Poor Control". Serum 17-OHP of 7.1 µg/L has 0.67 of sensitivity and 0.71 of specificity in diagnosing "Poor Control"., Conclusion: Each of serum 17-OHP or/and Δ4-A concentration was of significance in diagnosing "Poor Control" during the glucocorticoid replacement treatment of CAH 21OHD, with the diagnostic efficacy being serum Δ4-A concentration, serum 17-OHP concentration and serum Δ4-A in combination with 17-OHP concentration in descending order. Serum Δ4-A and 17-OHP concentrations may be used as the biochemical indicators to monitor the therapy of CAH 21OHD.

In the study, a gene encoding Tat protein N terminal 1- 21 amino acid residues-deleted mutant (Tat22-101) was amplified by PCR from a full length Tat gene of human immunodeficiency virus type 1, and the prokaryotic expression plasmid pET32a-Tat22-101 was constructed. After identification by digestion with endonucleases and sequencing, the recombinant plasmid pET32a-Tat22-101 was transformed into E. coli BL21(DE3) and expressed with IPTG induction. The mutant fusion protein with deleted Tat N terminal was purified by an affinity chromatography column Ni(2+)-NTA and subsequently identified by SDS-PAGE and Western blotting. The results showed that the molecular weight of the mutant protein was approximately 26.9kD. Furthermore, BALB/c mice were immunized with the mutant protein and the anti-sera were collected. ELISA results showed that the mutant protein preserved its immunogenicity, particularly it could improve the production of antibodies to other epitopes in addition to the N terminal epitope of Tat protein, which might provide some valuable information for the study of Tat functions as well as for development of potential novel HIV Tat vaccine.