Detecting rare thalassemia in children with anemia using third-generation sequencing.

BACKGROUND: In China, conventional genetic testing methods can only detect common thalassemia variants. Accurate detection of rare thalassemia is crucial for clinical diagnosis, especially for children that need long-term blood transfusion. This study aims to explore the application value of third-generation sequencing (TGS) in the diagnosis of rare thalassemia in children with anemia. METHODS: We enrolled 20 children with anemia, excluding from iron deficiency anemia (IDA). TGS was employed to identify both known and novel thalassemia genotypes, while sanger sequencing was used to confirm the novel mutation detected. RESULTS: Among the 20 samples, we identified 5 cases of rare thalassemia. These included ß-4.9 (hg38,Chr11:5226187-5231089) at HBB gene, α-91(HBA2:c.*91delT), αCD30(HBA2:c.91-93delGAG), Chinese Gγ+(Aγδß)0(NG_000007.3: g .48795-127698 del 78904) and delta - 77(T > C)(HBD:c.-127T>C). Notably, the -SEA/α-91α genotype associated with severe non-deletional hemoglobin H disease (HbH disease) has not been previously reported. Patients with genotypes ß654/ß-4.9 and -SEA/α-91α necessitate long-term blood transfusions, and those with the -SEA/αCD30α, Chinese Gγ+(Aγδß)0 and delta thalassemia demonstrate mild anemia. CONCLUSIONS: TGS demonstrates promising potential as a diagnostic tool for suspected cases of rare thalassemia in children, especially those suspected to have transfusion-dependent thalassemia (TDT).

Identification of a Novel Hb H Disease with Glucose-6-Phosphate Dehydrogenase Deficiency Using Whole Genome Sequencing.

With the development of sequencing technology, more and more rare thalassemia types have been found. In this article, we found a novel Hb H disease combined with glucose-6-phosphate dehydrogenase (G6PD) deficiency through whole genome sequencing (WGS), which was verified by Sanger sequencing and polymerase chain reaction (PCR)-reverse dot-blot hybridization, respectively.

Protein Restriction with Amino Acid-Balanced Diets Shrinks Circulating Pool Size of Amino Acid by Decreasing Expression of Specific Transporters in the Small Intestine.

Dietary protein restriction is not only beneficial to health and longevity in humans, but also protects against air pollution and minimizes feeding cost in livestock production. However, its impact on amino acid (AA) absorption and metabolism is not quite understood. Therefore, the study aimed to explore the effect of protein restriction on nitrogen balance, circulating AA pool size, and AA absorption using a pig model. In Exp.1, 72 gilts weighting 29.9 ± 1.5 kg were allocated to 1 of the 3 diets containing 14, 16, or 18% CP for a 28-d trial. Growth (n = 24), nitrogen balance (n = 6), and the expression of small intestinal AA and peptide transporters (n = 6) were evaluated. In Exp.2, 12 barrows weighting 22.7 ± 1.3 kg were surgically fitted with catheters in the portal and jejunal veins as well as the carotid artery and assigned to a diet containing 14 or 18% CP. A series of blood samples were collected before and after feeding for determining the pool size of circulating AA and AA absorption in the portal vein, respectively. Protein restriction did not sacrifice body weight gain and protein retention, since nitrogen digestibility was increased as dietary protein content reduced. However, the pool size of circulating AA except for lysine and threonine, and most AA flux through the portal vein were reduced in pigs fed the low protein diet. Meanwhile, the expression of peptide transporter 1 (PepT-1) was stimulated, but the expression of the neutral and cationic AA transporter systems was depressed. These results evidenced that protein restriction with essential AA-balanced diets, decreased AA absorption and reduced circulating AA pool size. Increased expression of small intestinal peptide transporter PepT-1 could not compensate for the depressed expression of jejunal AA transporters for AA absorption.

LIM-homeodomain transcription factor Isl-1 mediates the effect of leptin on insulin secretion in mice.

In addition to the well known regulating effects of leptin on energy balance and glucose homeostasis through the central nervous system, circulating leptin has a direct effect on pancreatic islet and insulin secretion through its receptor (OBRb). The LIM-homeodomain transcription factor Isl-1 is expressed in all classes of pancreatic endocrine cells and is involved in regulating both islet development and insulin secretion. Both OBRb and Isl-1 mutations result in obesity-related diabetes. However, the interactions and physiological significance of leptin and Isl-1 in pancreatic islets remain to be established. Here, we show that most of leptin target cells in pancreatic islets and NIT beta cells express Isl-1. Both in vivo and in vitro results demonstrate that leptin suppresses Isl-1 expression and insulin secretion in islet in physiological and pathophysiological conditions, e.g. high fat diet. This effect of leptin on insulin secretion is lost in leptin receptor-defective db/db and Isl-1-inducible knock-out mice. We conclude that the action of leptin on insulin secretion is at least partly mediated by Isl-1. Another new finding of this study is that Isl-1 acts as a direct downstream target of leptin signaling molecule STAT3 to influence the effect of leptin on insulin secretion, whereas inversely, insulin has feedback regulating effects on Isl-1 expression through JAK-STAT3 pathway. These findings are crucial for understanding the mechanisms regulating insulin secretion and metabolism in related diseases, such as obesity and type 2 diabetes.

[Development and clinical application of male human papillomavirus genotyping by membrane DNA chip].

OBJECTIVE: To develop a new method for the detection of male human papillomavirus (HPV) genotypes and to investigate its clinical application value. METHODS: With computer assistance and based on the classical common primers MY09/11, modified PGMY09/11 with 23 HPV subtypes for PCR and Genbank data on HPV, we designed probes for the simultaneous detection of 18 high-risk subtypes (HPV-16, 18, 31, 33, 35, 39, 45, 51, 52, 53, 56, 58, 59, 66, 68, 73, 83 and MM4) and 5 low-risk subtypes (HPV-6, 11, 42, 43 and 44) and fixed them to the special membrane to make a DNA chip. A total of 112 male urethral samples were collected with swabs and studied for the clinical value. Meanwhile the single subtypes of HPV positive were sequenced and the standard samples detected for their sensitivity. RESULTS: Of the total number, 25 samples were found to be HPV positive, 13 single HPV infection and 12 multiple infection. Nine HPV gene subtypes were noted in the samples: 6, 11, 16, 18, 33, 35, 43, 56 and 73, with sensitivity up to 10 copies of HPV DNA. CONCLUSION: Human papillomavirus genotyping by the membrane DNA chip is applicable to the diagnosis of male HPV infection as well as to the related epidemic and etiological investigation.

[Roles of CD8+ CD28- T regulatory cells in acute infectious mononucleosis in children].

OBJECTIVE: To explore the role of CD(8)(+)CD(28)(-) T regulatory cells (Tr) in the immunological pathogenesis of acute infection with Epstein-Barr virus in children. METHODS: The present study enrolled 25 children with infectious mononucleosis (IM) and 25 age-matched healthy children. Flow cytometric analysis was performed to detect the percentage of CD(3)(+), CD(3)(+)CD(4)(+), CD(3)(+)CD(8)(+), CD(8)(+)CD(28)(+) by determining the ratio of positive cells in lymphocytes. Reverse transcriptase-polymerase chain reaction (RT-PCR) and real-time PCR were used to analyze IL-6, IL-10, IFN-gamma expression in CD(8)(+)CD(28)(-) Tr cells and ILT-3, ILT-4 expression in monocytes/macrophages. RESULTS: The proportions of CD(8)(+)CD(28)(-)T cells in children with acute-phase IM was significantly higher than those in the controls (P < 0.01). The expression level of IL-6, IL-10, IFN-gamma, ILT-3, ILT-4 mRNA significantly increased compared to those of the controls (P < 0.01). CONCLUSION: The CD(28) expressed on CD(8)(+) T cells in vivo is gradually lost with age and CD(8)(+)CD(28)(-) cells increase up 50% to adult. EBV can directly infect B cells, trigger CD(8)(+) CTL response and destroy the target cells to cause serious immunopathological lesion. Therefore we speculate that the expansion of CD(8)(+)CD(28)(-) Tr cells in children with IM may be an adaptive immune response to avoid serious inflammation and autoimmune reactions.

[Construction of a novel Schistosoma japonicum DNA vaccine pBK-Sj14-3-3 and studies on its immunoprotection in mice].

OBJECTIVE: To prepare Sj14-3-3 DNA vaccine and observe its immunoprotection against Schistosoma japonicum in mice. METHODS: The Sj14-3-3 gene was amplified by reverse transcription-polymerase chain reaction (RT-PCR) and subcloned into eukaryotic expression vector pBK. The recombinant plasmid pBK-Sj14-3-3 was extracted, purified and inoculated into BALB/c mice by intramuscular injection. Mice were attacked by Schistosoma japonicum cercariae and then killed. Adult worm and egg were counted, respectively. Diameter of the egg granulomas in the liver of infected mice was measured. RESULTS: Electrophoresis on 1% agarose gel showed that the product of RT-PCR and the inserted fragment of recombinant plasmid digested with EcoR I and Xho I had the same size, about 765 bp, confirming the latter was the 14-3-3 encoding gene by nucleotide sequencing. Adult worm load declined by 27%, average egg load of per gram (EPG) of the liver tissues by 79%, average egg production per couple of adult worm (EPWP) by 51%, and mean diameter of egg granulomas by 29% in vaccinated mice. CONCLUSION: The recombinant plasmid pBK-Sj14-3-3 was successfully constructed, which had some immunoprotection against Schistosoma japonicum in infected mice, indicating its potential to be vaccine candidate molecule of Schistosoma japonicum.