NIR-Driven Self-Healing Phase-Change Solid Slippery Surface with Stability and Promising Antifouling and Anticorrosion Properties.

Slippery liquid-infused porous surfaces (SLIPSs) have great potential to replace traditional antifouling coatings due to their efficient, green, and broad-spectrum antifouling performance. However, the lubricant dissipation problem of SLIPS severely restricts its further development and application, and the robust SLIPS continues to be extremely challenging. Here, a composite phase-change lubricant layer consisting of paraffin, silicone oil, and MXene is designed to readily construct a stable and NIR-responsive self-healing phase-change solid slippery surface (PCSSS). Collective results showed that PCSSS could rapidly achieve phase-change transformation and complete self-healing under NIR irradiation and keep stable after high-speed water flushing, centrifugation, and ultrasonic treatment. The antifouling performance of PCSSS evaluated by protein, bacteria, and algae antiadhesion tests demonstrated the adhesion inhibition rate was as high as 99.99%. Moreover, the EIS and potentiodynamic polarization experiments indicated that PCSSS had stable and exceptional corrosion resistance (|Z|0.01Hz = 3.87 × 108 Ω·cm2) and could effectively inhibit microbiologically influenced corrosion. The 90 day actual marine test reveals that PCSSS has remarkable antifouling performance. Therefore, PCSSS presents a novel, facile, and effective strategy to construct a slippery surface with the prospect of facilitating its application in marine antifouling and corrosion protection.

Application of real-time PCR-based multicolor melting curve with automatic analysis system in pregestational and prenatal thalassemia diagnoses.

BACKGROUND: To evaluate the value of the real-time PCR-based multicolor melting curve analysis (MMCA) with an automatic analysis system used in a mass thalassemia screening and prenatal diagnosis program. METHODS: A total of 18,912 peripheral blood samples from 9456 couples and 1150 prenatal samples were detected by MMCA assay. All prenatal samples were also tested by a conventional method. Samples with unknown melting peaks, unusual peak height ratios between a wild allele and a mutant allele, or a discordant phenotype-genotype match were further studied by using multiplex ligation-dependent probe amplification (MLPA) or Sanger sequencing. All MMCA results were automatically analyzed and manually checked. The consistency between MMCA assay and conventional methods among prenatal samples was investigated. RESULTS: Except for initiation codon (T > G) (HBB:c.2T > G), all genotypes of thalassemia inside the scope of conventional methods were detected by MMCA assay. Additionally, 27 carriers with 10 rare HBB variants, 13 with α fusion gene, 1 with a rare deletion in α globin gene, and 1 with rare HBA variant were detected by using MMCA assay. CONCLUSION: MMCA can be an alternative approach used in routine thalassemia carrier screening and prenatal diagnosis for its high throughput, sufficient stability, low cost, and easy operation.

Utilization of multiple genetic methods for prenatal diagnosis of rare thalassemia variants.

Background: Thalassemia is the most prevalent monogenic disorder caused by an imbalance between the α- and ß-globin chains as a result of pathogenic variants in the α- or ß-globin genes. Novel or complex structural changes in globin genes are major hurdles for genetic consulting and prenatal diagnosis. Methods: From 2020 to 2022, genetic analysis was performed on 1,316 families suspected of having children with thalassemia major, including 42 pregnant couples suspected of being thalassemia carriers with rare variants. Multiple techniques including multiplex ligation-dependent probe amplification (MLPA), Sanger sequencing, targeted next-generation sequencing, and single-molecule real-time (SMRT) sequencing were used to diagnose rare thalassemia. Results: The rate of prenatal diagnosis for rare thalassemia variants was 3.19% (42/1,316). The most prevalent alleles of α- and ß-thalassemia are Chinese Gγ(Aγδß)0and -- THAI deletion. In addition, ten rare complex genotypes include one Chinese Gγ(Aγδß)0 deletion combined with HBG1-HBG2 fusion, two rare deletions at HBB gene (hg38, Chr11: 5224211-5232470, hg38, Chr11: 5224303-5227790), one complete 7,412 bp fusion gene for anti-Lepore Hong Kong, two complex rearrangements of the α-globin gene cluster, two novel duplications, and two rare large deletions in the α-globin gene cluster. Conclusion: Accurate gene diagnosis for probands with combined molecular biology techniques is the key to prenatal diagnosis of rare thalassemia.

ß-Thalassemia Intermedia Caused by the ß-Globin Gene 3' Untranslated Region: Another Case Report.

The 3' untranslated region (3'UTR) is associated with mRNA stability because of its involvement in 3' end processing, polyadenylation, and mRNA capping. Mutations located in this area can cause a phenotype compatible with ß+-thalassemia (ß+-thal). We report a Chinese subject with ß-thal intermedia (ß-TI) who developed transfusion-dependent anemia. Molecular studies revealed that the patient was a compound heterozygote for two ß-thal alleles: codons 41/42 (-TTCT) (HBB: c.126_129delCTTT) and term codon +32 (A>C) (HBB: c.*32A>C).

Detection of rare thalassemia mutations using long-read single-molecule real-time sequencing.

Gap- polymerase chain reaction (PCR), reverse dot-blot assay (RDB), real-time PCR based multicolor melting curve analysis (MMCA assay), multiplex ligation-dependent probe amplification (MLPA) and Sanger sequencing are conventional methods to diagnose thalassemia but all of them have limitations. In this study, we applied single-molecule real-time (SMRT) sequencing following multiplex long-range PCR to uncover rare mutations in nine patients and their family members. The patients with different results between Gap-PCR and MMCA assay or with phenotype not matching genotype were included. Using SMRT sequencing, we first identified the carriers with αααanti3.7/HKαα, -α762bpα/αα (chr16:172,648-173,409), ααfusion/αQSα (in a trans configuration), two cases with novel gene rearrangements and another case with a novel 341 bp insertion in α-globin gene cluster, respectively. One carrier with --SEA/αααanti4.2, and two carriers with the coexistence of globin variant and an α-globin gene duplication were also found. Most importantly, we could determine two defects in α-globin gene cluster being a cis or trans configuration in a single test. Our results showed that SMRT has great advantages in detection of α-globin gene triplications, rare deletions and determination of a cis or trans configuration. SMRT is a comprehensive and one-step method for thalassemia screening and diagnosis, especially for detection of rare thalassemia mutations.

Contribution of maternal mosaicism to false-positive chromosome X loss associated with noninvasive prenatal testing.

OBJECTIVE: To report the frequency of maternal mosaicism contributing to false-positive chromosome X loss associated with noninvasive prenatal testing (NIPT) at a single center. METHODS: Pregnancies undergone NIPT using massively parallel sequencing at Guangzhou Women and Children's Medical Center between February 2015 and May 2020 were included in this study. Fetal karyotyping, quantitative fluorescence PCR (QF-PCR) or microarray analysis was provided to patients with abnormal sex chromosomal aneuploidy (SCA) results for confirmatory testing, and QF-PCR was also employed to detect maternal sex chromosome status. RESULTS: cffDNA testing of 40682 pregnancies revealed 86 cases with NIPT results positive for chromosome X loss (0.21%). Among the 86 high-risk cases, 73 women had undergone confirmatory testing in our center, whereas 13 declined. Of the 73 women verified by invasive prenatal diagnosis, 27.4% (20/73) were true positive cases including six cases of monosomy X, two cases of microdeletion of Xp22.33, one case of deletion Xq27.2q28, one case of 47, XXX and ten cases with fetal sex chromosome mosaicism. Of the remaining 53 patients with fetal normal results, 30 cases had undergone QF-PCR analysis of maternal white blood cells. QF-PCR indicated that 36.7% (11/30) patients had an altered or mosaic maternal sex chromosome status. Statistical analysis indicated that cell-free fetal DNA (cffDNA) concentration estimated by chromosome X in maternal mosaic cases was significantly higher than that in the non-maternal mosaicism group (p < .05) and was related to maternal mosaicism rate (r = 0.88, p < .05). CONCLUSIONS: Our findings indicated that maternal mosaicism of sex chromosome was not uncommon in false-positive NIPT chromosome X loss cases. We recommend that this information should be disclosed to pregnancies during clinical counseling and maternal sex chromosome status should be confirmed for the cases with NIPT chromosome X loss.

Evaluation of intervention strategy of thalassemia for couples of childbearing ages in Centre of Southern China.

BACKGROUND: To describe the free intervention strategy of thalassemia for childbearing couples in Guangzhou. METHODS: Routine hematology examinations were conducted for 137,222 couples. Among them, 37,501 couples who had mean corpuscular volume (MCV) <82 fL or mean corpuscular hemoglobin <27 pg were elected for Hb analysis and the deletions of four common α-thalassemia mutation. Reverse dot blot for common nondeletional α-thalassemia and ß-thalassemia was selectively used. Three thousand twenty-two couples randomly selected were offered all those tests as a control group. Sanger sequencing, multiplex ligation-dependent probe amplification and next-generation sequencing were used for rare thalassemia. High-risk couples were offered prenatal diagnosis at 10-13 weeks' gestation based on informed consent. RESULTS: The carrier rates of α-, ß-, and αß-thalassemia and 뫧 thalassemia/deletional HPFH were 7.7%, 3.02%, 0.5% and 0.059% respectively. Of them, 1.37% were identified as at-risk couples and 345 couples terminated the pregnancy. No severe α- and ß-thalassemia births were observed. In the control group, two ß- thalassemia carriers and one case with -α3.7 /ααQS were misdiagnosed, but all at-risk couples were found, and we could save 1,523,774 ¥ using our strategy. The cut-off points of 73.46 fL and 23.25 pg would be useful to find -α+ /αT thalassemia. CONCLUSION: The intervention strategy was cost-effective and offered reference in population thalassemia screening.

Hb Lepore-Hong Kong: First Report of a Novel δ/ß-Globin Gene Fusion in a Chinese Family.

We describe a new δ/ß fusion gene causing ß-thalassemia (ß-thal) trait and its formation mechanism. The proband was a 39-year-old woman who presented with persistent microcytic microcytosis without iron deficiency. Molecular diagnoses revealed a 뫧 configuration within a 54 bp region between the Cap site (+22) and codon 8, causing a deletion (NG_000007.3: g.63154_70565del). This results in a variant that has been named Hb Lepore-Hong Kong and shows a decreased ß-globin mRNA in carriers compared to that of normal subjects. It is assumed that combination of this variant with ß-thal may cause severe ß-thal syndrome.

Detection of an α-Globin Fusion Gene Using Real-Time Polymerase Chain Reaction-Based Multicolor Melting Curve.

Genetic recombination between homologous sequences on the human globin gene clusters can lead to the creation of fusion genes. In this study, we report the detection of an α-globin fusion gene by using real-time polymerase chain reaction (qPCR)-based multicolor melting curve analysis (MMCA). The carriers of this fusion gene had a mild α-thalassemia phenotype with a normal hemoglobin (Hb) value and borderline hematological indices. Sequence analysis revealed that the mutant gene was the result of a fusion between the α2 and ψα1 genes. Our results indicate that the MMCA has the ability to detect the fusion gene, which is helpful for genetic counseling in thalassemia prevalent areas.

Hb Westmead (HBA2: c.369C>G): Hematological Characteristics in Heterozygotes with and without α0-Thalassemia.

Hb Westmead (α122(H5)His>Gln) (HBA2: c.369C>G) is a common α-globin variant causing α-thalassemia (α-thal) in Mainland China. In this study, we report the hematological characteristics in Hb Westmead carriers in a Chinese population. There were 546 individuals carrying Hb Westmead based on their molecular diagnosis: 514 Hb Westmead heterozygotes and 32 compound heterozygotes for Hb Westmead and α0-thal. Compared to common deletional α+-thal, Hb Westmead was associated with higher mean corpuscular hemoglobin (Hb) (MCH) values. Compound heterozygotes for Hb Westmead and α0-thal showed significantly higher Hb, mean corpuscular volume (MCV) and MCH values than subjects with deletional Hb H disease. When compared to α0-thal carriers, compound heterozygotes for Hb Westmead and α0-thal showed similar Hb values, but significantly lower MCV and MCH values. Our results indicate that Hb Westmead is a silent nondeletional α+-thal, with a deficiency of α-globin chain milder than deletional α+-thal, and compound heterozygotes for Hb Westmead/α0-thal have a phenotype similar to simple α0-thal.

Hematological Characteristics of Hb Constant Spring (HBA2: c.427T>C) Carriers in Mainland China.

Hb Constant Spring (Hb CS) (HBA2: c.427T>C) is a common α-globin variant causing α-thalassemia (α-thal) phenotypes in mainland China. In this study, we evaluated the efficiency of erythrocyte parameters and capillary electrophoresis (CE) in the determination of Hb CS in blood samples from Hb CS carriers. Based on molecular diagnosis, there were 462 patients carrying Hb CS: 411 Hb CS heterozygotes, seven carried Hb H-Hb CS disease, 18 compound heterozygotes for Hb CS/α+-thal, and 26 double heterozygotes for Hb CS and ß-thalassemia (ß-thal). Forty-three cases had no Hb CS peak visible on CE, including all 26 cases of double heterozygotes for Hb CS and ß-thal, and 17 cases of heterozygotes carrying only Hb CS. Hb CS heterozygotes, those without a Hb CS peak, presented with lower hemoglobin (Hb), mean corpuscular volume (MCV) and mean corpuscular Hb (MCH) values than those with a Hb CS peak. The MCV <80.0 fL yielded a detection rate of 87.8% for screening individuals carrying Hb CS. Therefore, we emphasize that if one partner of a couple has tested positive for α0-thal, the other should be subjected to detailed screening for this nondeletional allele using molecular analysis, regardless of his/her red cell indices and electrophoretic chromatogram.

Molecular epidemiology and hematologic characterization of 뫧-thalassemia and hereditary persistence of fetal hemoglobin in 125,661 families of greater Guangzhou area, the metropolis of southern China.

BACKGROUND: Individuals with δß-thalassemia/HPFH and ß-thalassemia usually present with intermedia or thalassemia major. No large-scale survey on HPFH/δß-thalassemia in southern China has been reported to date. The purpose of this study was to examine the molecular epidemiology and hematologic characteristics of these disorders in Guangzhou, the largest city in Southern China, to offer advice for thalassemia screening programs and genetic counseling. METHODS: A total of 125,661 couples participated in pregestational thalassemia screening. 654 subjects with fetal hemoglobin (HbF) level ≥ 5% were selected for further investigation. Gap-PCR combined with Multiplex ligation dependent probe amplification (MLPA) was used to screen for ß-globin gene cluster deletions. Gene sequencing for the promoter region of HBG1 /HBG2 gene was performed for all those subjects. RESULTS: A total of 654 individuals had hemoglobin (HbF) levels≥5, and 0.12% of the couples were found to be heterozygous for HPFH/δß-thalassemia, including Chinese Gγ (Aγδß)0-thal, Southeast Asia HPFH (SEA-HPFH), Taiwanese deletion and Hb Lepore-Boston-Washington. The highest prevalence was observed in the Huadu district and the lowest in the Nansha district. Three cases were identified as carrying ß-globin gene cluster deletions, which had not been previously reported. Two at-risk couples (0.0015%) were required to receive prenatal diagnosis. We also found 55cases of nondeletional-HPFH (nd-HPFH), including 54 with Italian nd-HPFH and one with the Aγ-197C-T heterozygous state. It is difficult to discriminate between Chinese Gγ (Aγδß)0-thal and Italian nd-HPFH carriers using hemoglobin (Hb) analysis. CONCLUSIONS: This study is the first to describe the familial prevalence of HPFH/δß-thalassemia and the high-risk rate in Greater Guangzhou Area, and the findings will support the implementation of thalassemia screening for three common deletions by gap-PCR. We also presented a systematic description of genotype-phenotype relationships which will be useful for genetic counseling and prenatal diagnostic services for ß-thalassemia intermedia.

A ß-Thalassemia Trait with Two Mutations in Cis in a Chinese Family.

A female of Chinese origin carried the codon 43 (G>T) (HBB: c.130G > T) and codons 71/72 (+A) (HBB: c.216_217insA) mutations of the ß-globin gene in cis, identified during prenatal thalassemia screening. The double in cis mutations were inherited from her mother. Both of the two carriers behave as a traditional heterozygote for ß-thalassemia (ß-thal) with microcytosis and a high Hb A2 level. This case report indicates that the possibility of multiple mutations in cis in a fetus with thalassemia trait has to be considered in a prenatal screening program.

[Clinical and molecular genetic analysis of a pediatric patient with Lowe syndrome].

OBJECTIVE: To explore the genetic etiology for a child with ocular dysplasia. METHODS: Clinical examination was carried out. Medical history of the child was collected. Genomic DNA was extracted from peripheral blood samples. Chromosomal microarray analysis (CMA) was used to detect potential genomic copy number variations. RESULTS: Ultrasonography revealed cataracts in both eyes of the child. MRI showed increased extracranial space, supratentorial ventricular dilatation, reduced white matter volume, increased T2WI signal and a large occipital cisterna. CMA showed that the patient carried a 249 kb microdeletion at Xq25q26.1 region, namely [hg19]arrXq25q26.1 (128 652 372 - 128 901 629)×0. CONCLUSION: The child was diagnosed with Lowe syndrome, for which the 249 kb microdeletion at Xq25q26.1 is probably accountable.

Pristimerin overcomes adriamycin resistance in breast cancer cells through suppressing Akt signaling.

Breast cancer remains a major public health problem worldwide. Chemotherapy serves an important role in the treatment of breast cancer. However, resistance to chemotherapeutic agents, in particular, multi-drug resistance (MDR), is a major cause of treatment failure in cancer. Agents that can either enhance the effects of chemotherapeutics or overcome chemoresistance are urgently needed for the treatment of breast cancer. Pristimerin, a quinonemethide triterpenoid compound isolated from Celastraceae and Hippocrateaceae, has been shown to possess antitumor, anti-inflammatory, antioxidant and insecticidal properties. The aim of the present study was to investigate whether pristimerin can override chemoresistance in MCF-7/adriamycin (ADR)-resistant human breast cancer cells. The results demonstrated that pristimerin indeed displayed potent cytocidal effect on multidrug-resistant MCF-7/ADR breast cancer cells, and that these effects occurred through the suppression of Akt signaling, which in turn led to the downregulation of antiapoptotic effectors and increased apoptosis. These findings indicate that use of pristimerin may represent a potentially promising approach for the treatment of ADR-resistant breast cancer.

[Pooled Umbilical Cord Blood Plasma for Culturing UCMSC and Ex Vivo Expanding Umbilical Cord Blood CD34⁺ Cells].

OBJECTIVE: To investigate the feasibility of umbilical cord blood plasma (UCP) as a replacement for fetal bovine serum (FBS) for culturing mesenchymal stem cells (MSC) derived from umbilical cord, and to observe the supporting effects of these cells (served as a feeder layer) on ex vivo expanding of human umbilical cord blood CD34(+) cells. METHODS: Umbilical cord blood (UCB) units were suitable if the Guangzhou cord blood bank donor selection criteria strictly were fulfilled. UCP were ready to use after the collection from the plasma depletion/reduction during the processing and pooling of suitable UCB units (at least 30 units were screened for pathogens and microorganisms, and qualified). Umbilical cord mesenchymal stem cells (UCMSC) were harvested from the umbilical cord tissue of health full-term newborns after delivery by enzyme digestion and divided into 3 groups: group 1 and 2 were cultured in the presence of DMEM/F12 containing either FBS or UCP; and group 3 was cultured in serum-free medium (StemPro® MSC SFM CTS™). Morphology, proliferation and surface marker expression were examined by flow cytometry, and the differentiation toward adipogenic and osteogenic lineages was used for investigating the effect of media on UCMSC after 3-5 passages. Next, the cells cultured in the three different media were cryopreserved and thawed, then prepared as feeder layers with the name of UCMSC(FBS), UCMSC(UCP), and UCMSC(SFM), respectively. The CD34⁺ cells were separated from UCB by magnetic activated cell sorting (MACS) and divided into 4 groups cultured in StemPro(-34) SFM medium added with hematopoietic cytokine combination (StemSpan® CC100). The control group included only CD34⁺ cells as group A (blank control) and experimental groups included UCMSC(FBS) + CD34⁺ cells as group B, UCMSC(UCP) + CD34⁺ cells as group C, UCMSC(SFM) + CD34⁺ cells as group D, and cells in all groups were cultured ex vivo for 7 days. The nucleated cell (NC) number was counted by cell counter, CD34⁺ cells were measured by flow cytometry, and clonogenic assay was conducted at day 0 and 7 of culture. The expansion efficiency was assessed. RESULTS: The morphology (spindle-shaped and plastic-adherent), the immunophenotype (high positive percentage of CD73, CD90, CD105 and CD166) and the differentiation potential (osteogenic and adipogenic) were almost indistinguishable among the cells cultured in any of these three media except for the expression of CD105 in group 3 (serum-free medium) was lower than that in other 2 groups (P < 0.05). UCMSC grown in UCP medium demonstrated significantly higher proliferation rates than that in media containing FBS or commercial serum-free supplement (P < 0.05). After co-culture for 7 days, the CD34⁺ cell percentage decreased in all the groups, while NC were amplified effectively and the CD34⁺ cell number increased with the same order as group C or D group B or A (control group) (P < 0.05). As compared with the colony-forming unit (CFU) number at day 0, there was no significant difference in the expansion multiple between group C and D, while the expansion of CFU in group C were higher than that in group B and A. CONCLUSION: The UCP can be used as a better animal-free serum supplement for growth, maintenance and differentiation of UCMSC, thus would be a safe choice for clinical-scale production of human MSC.

Influence of maternal, infant, and collection characteristics on high-quality cord blood units in Guangzhou Cord Blood Bank.

BACKGROUND: The operation of cord blood banks (CBBs) requires immense labor, material, and financial resources. Thus, increasing the ratio of high-quality cord blood units (HQCBUs) in storage that are qualified for clinical use is critical for the efficient use of limited resources. Understanding the factors that contribute to HQCBUs, including maternal, fetal, and processing conditions, may improve the number of HQCBUs in storage. STUDY DESIGN AND METHODS: The maternal, fetal, and processing conditions of 4613 CBUs at the Guangzhou Cord Blood Bank were analyzed retrospectively to determine their effect on HQCBUs. All CBUs were obtained following strict standard operation procedures. RESULTS: Several factors may contribute to HQCBUs: fetal age older than 37 gestational weeks, female fetus, large cord blood (CB) volume (>80 mL), high birthweight (>3500 g), vaginal delivery, and a shorter amount of time between CB collection and processing (12 hr). We report for the first time that α-thalassemia carriers exhibit a postprocessing total nucleated cell count (p-TNCC) increase to at least 1.25 × 10(9) and an increase of the CD34+ cell count to at least 6.01 × 10(6) . Meconium-stained amniotic fluid and mothers younger than 25 years of age exhibited increased p-TNCC to at least 1.25 × 10(9) , and colony-forming units increased to at least 23.24 × 10(5) . CONCLUSIONS: We identified several factors that affect HQCBUs. These results may be used as a reference for updating CB collection strategies, with priority given to collecting CBUs from female fetuses older than 37 gestational weeks, at high birthweight, and born by vaginal delivery from mothers younger than 25 years of age, especially newborns with one parent carrying the trait or with meconium-stained amniotic fluid. The collected CBUs should be sent to the laboratory as soon as possible for priority processing, which will help to increase the number and ratio of HQCBUs and the effective use of CBB resources.