[Treatment response of a two-dose regimen of dose-adjusted inotuzumab ozogamicin in relapsed/refractory B-cell acute lymphoblastic leukemia]

Objective: To observe the treatment response of a two-dose regimen of inotuzumab ozogamicin (inotuzumab), a monoclonal antibody targeting CD22, for patients with heavily treated relapsed/refractory B-cell acute lymphoblastic leukemia (R/R B-ALL), including those failed or relapsed after chimeric antigen receptor (CAR) -T-cell therapy. Methods: Pediatric and adult patients who received two doses of inotuzumab and who were evaluated after inotuzumab treatment were included. Antibody infusions were performed between March 2020 and September 2022. All patients expressed CD22 antigen as detected by flow cytometry (>80% leukemic cells displaying CD22) before treatment. For adults, the maximum dosage per administration was 1 mg (with a total of two administrations). For children, the maximum dosage per administration was 0.85 mg/m(2) (no more than 1 mg/dose; total of two administrations). The total dosage administered to each patient was less than the standard dosage of 1.8 mg/m(2). Results: Twenty-one patients with R/R B-ALL were included, including five children (<18 years old) and sixteen adults. Seventeen patients presented with 5.0% -99.0% leukemic blasts in the bone marrow/peripheral blood or with extramedullary disease, and four patients were minimal residual disease (MRD) -positive. Fourteen patients underwent both CD19 and CD22 CAR-T-cell therapy, four underwent CD19 CAR-T-cell therapy, and three underwent blinatumomab therapy. Eleven patients underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT). After inotuzumab treatment, 14 of 21 patients (66.7% ) achieved a complete response (CR, one was MRD-positive CR), and all four MRD-positive patients turned MRD-negative. Four of six patients who failed recent CD22 CAR-T-cell therapy achieved a CR after subsequent inotuzumab treatment. Seven patients (33.3% ) demonstrated no response. Grade 1-3 hepatotoxicity occurred in five patients (23.8% ), one child with no response experienced hepatic veno-occlusive disease (HVOD) during salvage transplantation and recovered completely. Conclusion: For patients with heavily treated R/R B-ALL, including those who had undergone allo-HSCT and CD19/CD22 CAR-T-cell therapy, the two-dose regimen of inotuzumab resulted in a CR rate of 66.7%, and the frequency of hepatotoxicity and HVOD was low.

Organic matter enrichment mechanism of Youganwo Formation oil shale in the Maoming Basin

The Youganwo Formation oil shale located in the Maoming Basin represents a large commercially valuable lacustrine oil shale resource and a potential bio-shale gas reservoir in South China. With the aim of deepening the understanding of factors that influence organic matter enrichment, this research conducted a geochemical investigation to reconstruct the depositional paleoenvironment of bioproductivity, preservation and dilution. Youganwo Formation oil shale is mainly deposited in semi-deep to deep-lake environments with relatively warm and humid paleoclimate in the subtropical-temperate zone. The total organic carbon (TOC) content (1.46-11.85%), S₂ values (4.79-115.80 mg HC/mg rock) and HI (328-1040 mg HC/mg TOC) indicate that the oil shale has a good oil source rock potential. TOC content, (S₁ + S₂) values and vitrinite reflectance values show that its marginally mature organic matter (OM) belongs to kerogen type I-III with good oil-generating potential. A 3rd order sequence was identified in the Yougnwo formation. Subsequently, the multiple factors including bioproductivity, preservation and dilution that control the OM enrichment of oil shale within system tracts were discussed. Moderate-quality oil shales (O_y-1) were developed in the transgressive systems tract (TST) in an oxidizing condition with abundant detrital input. High-quality oil shales (O_y-2) were deposited during the high-stand systems tract (HST) with increased accommodation space, improved preservation conditions, warm and humid climate, higher water bioproductivity and minimum detrital matter input. During the regressive systems tract (RST, O_y-3), higher detrital matter input and fresher water led to lower TOC values. Among these multiple factors, dilution condition was the major one that influences OM abundance and variation on the basis of sufficient organic matter input. Thus, OM enrichment models of O_y-1, O_y-2 and O_y-3 sub-members were established. The OM enrichment and quality in oil shale were controlled by the combined effect of bioproductivity, preservation, and dilution.

[Effects of prenatal nicotine exposure on enamel formation of offspring mice]

Objective: To investigate the effects of nicotine on the morphology, structure of offspring's dental germ, enamel organ and other dental tissues and the further potential epigenetic mechanisms by establishing prenatal nicotine exposure mouse model. Methods: Ten C57BL/6 pregnant mice were randomly divided into control group (physiological saline subcutaneous injection) and prenatal nicotine exposure (PNE) group (nicotine subcutaneous injection) by using a random number table. Postnatal day 0 (P0), postnatal day 14 (P14) and postnatal day 25 (P25) offspring mice were collected for subsequent experiments. The offspring mice were divided into offspring control group and offspring PNE group according to the maternal group respectively. Weights of P0 and P25 offspring mice were recorded. Micro-CT, scanning electron microscope (SEM) and Vickers hardness test were performed to analyze the related parameters of hard tissues including alveolar bones and mandibular incisors. Total RNAs were extracted from mandible tissues and the third generation of dental epithelial stem cells (DESC) in P25 mice. The relative expression levels of osteogenic and ameloblastic differentiation related genes were measured by real-time quantitative PCR (RT-qPCR). Immunohistochemical stainings of paraffin sections were then performed to observe the distribution and expression level of proliferating cell nuclear antigen (Pcna), amelogenin (Amelx), histone H3 trimethylated at lysine 27 (H3K27me3) and enhancer of zeste homolog 2 (Ezh2). Cell counting kit-8 (CCK-8) assays were used to detect the cell viabilities of DESCs after administrations of different concentrations of nicotine (0.01, 0.1, 1 mmol/L) and GSK126 (an inhibitor of histone methyltransferase Ezh2). Results: Compared with the control group, pregnant mice in PNE group were more likely to have adverse pregnancy outcomes, such as significantly lower offspring body weight [P0: offspring control (1.20±0.04) g, offspring PNE (0.99±0.02) g, P<0.001; P25: offspring control (15.26±1.70) g, offspring PNE (9.65±1.32) g, P<0.001] and increased stillbirths rate [offspring control (0), offspring PNE (46.40±9.30) %, P<0.001]. At P14 and P25, the distance parameters between the enamel mineralized deposits of mandibular incisors and the mesial surface of the first molar in offspring PNE group [P14: (-1 349±45) μm; P25: (-1 192±147) μm] was significantly decreased compared with the control group [P14: (-506±380) μm, P25: (504±198) μm] (P<0.05, P<0.001). The enamel column and enamel column stroma of incisors in offspring PNE group were blurred, arranged loosely and disorderly than those in the control group, while the microhardness of incisor enamel in offspring PNE group [(245.7±18.4) MPa] was significantly lower compared to the control group [(371.9±28.7) MPa] (P<0.001). HE staining showed disordered pre-ameloblast (Pre-Am) arrangement and delayed mineralization deposition point in offspring PNE group compared with the control group, while the length of transit-amplifying cell (TA) and Pre-Am region were prolonged as well. Immunohistochemical staining results displayed that the overall Pcna (P<0.05), H3K27me3 (P<0.01), Ezh2 (P<0.01) expression of labial cervical loop (LaCL) in PNE group were increased, while the positive signal of Amelx in ameloblast cytoplasm was impaired. In vitro, the addition of 1 mmol/L nicotine could significantly upregulate the expression level of Pcna (P<0.01) and downregulate the expression levels of B lymphoma Mo-MLV insertion region 1 (P<0.05), leucine rich repeats and immunoglobulin like domains 1 (P<0.05), Amelx (P<0.01). In addition, 1 mmol/L nicotine could also significantly enhance the proliferation activity of DESCs (P<0.001). Addition of 10 μmol/L GSK126, could rescue the proliferation activation effect of 1 mmol/L nicotine on DESCs. Conclusions: PNE may delay the process of enamel formation and lineage differentiation, leading to the abnormal proliferation of DESCs and changes of epigenetic modification state in H3K27me3, which affect the development of enamel in offspring mice,suggesting PNE might be one of risk environmental factor for tooth development.

Environmental conditions regulate the impact of plants on cloud formation

The terrestrial vegetation emits large amounts of volatile organic compounds (VOC) into the atmosphere, which on oxidation produce secondary organic aerosol (SOA). By acting as cloud condensation nuclei (CCN), SOA influences cloud formation and climate. In a warming climate, changes in environmental factors can cause stresses to plants, inducing changes of the emitted VOC. These can modify particle size and composition. Here we report how induced emissions eventually affect CCN activity of SOA, a key parameter in cloud formation. For boreal forest tree species, insect infestation by aphids causes additional VOC emissions which modifies SOA composition thus hygroscopicity and CCN activity. Moderate heat increases the total amount of constitutive VOC, which has a minor effect on hygroscopicity, but affects CCN activity by increasing the particles' size. The coupling of plant stresses, VOC composition and CCN activity points to an important impact of induced plant emissions on cloud formation and climate.

Volatile organic compounds (VOC) emitted by vegetation influence cloud formation, yet the impact of environmental stresses remains little known. Here, manipulation experiments reveal insect infestation and heat stress are linked to induced VOC and constitutive VOC emissions shifts, respectively.

Establishment of an animal model of biliary ischemic stenosis with clamping in mice

OBJECTIVE

The objective of this study was to explore a method to establish biliary ischemic stenosis in mice.

METHODS

After the optimal time of biliary ischemia was determined, 20 Kunming mice were equally divided into 2 groups. In the experimental group a 0.4-cm length of common bile duct was clamped for 90 minutes with 2 micro-vessel clamps (width = 0.1 cm). The common bile duct was not clamped in the control group. Twenty-one days later, biliary tract visualization was performed in all mice. Blood samples were collected from the inferior vena cava to determine the serum levels of total bilirubin (TBIL) and alanine aminotransferase (ALT). Meanwhile, samples of the common bile duct and liver tissue were extracted for microscopic examination to observe morphological changes.

RESULTS

In the experimental group, obvious dilatation of the common bile duct appeared over the clamp site. There was no dilatation of the common bile duct in the control group. Twenty-one days later, serum levels of TBIL and ALT were significantly higher among the experimental compared with the control group. Microscopic examination showed that the part of common bile duct at the clamp site was significantly expanded, with a smaller or occluded bile duct lumen necrotic mucosa with determination, and tubular wall with fibrosis and excrustation. A few dead liver cells and many inflammatory cells were observed in liver tissue samples.

CONCLUSIONS

A biliary ischemic stenosis model was established using a clamping method in mice, which may provide a reliable technique for basic and clinical research into mechanisms of biliary ischemic stenosis after liver transplantation.

Purification of avian circulating primordial germ cells by nycodenz density gradient centrifugation

1. Primordial germ cells (PGCs) are the progenitor cells for gametes. In aves, PGCs show a unique migration pathway, that is, they circulate temporarily through the bloodstream during early development. 2. In this study we developed a method to purify circulating primordial germ cells (cPGCs) in quail and chicks by Nycodenz density gradient centrifugation. 3. The process consisted of primary and secondary purification. In primary purification, cPGCs were enriched at the interface of 8 and 12% Nycodenz fractions. In secondary purification, cPGCs were harvested from 8% Nycodenz fraction at a purity of 90% and from 10% Nycodenz fraction at a purity of 70%. The recovery rate of cPGCs was over 70%. 4. This method would facilitate research on cPGCs' culture and the production of transgenic birds using cPGCs.

[Study of the effects of using uterine stimulants on milk secretion during delivery]

The effects of two uterotonics, Oxytocin and Ergotocin, on postpartum lactation were observed and compared in this study. 30 puerperants were given Oxytocin and another 30 puerperants were given Ergotocin during delivery. The result showed that the time of lactation for the Oxytocin group was earlier than that of the Ergotocin group. The amount of lactation of the Oxytocin group was also much more than that of the Ergotocin group. This study indicated that the rate of breast-feeding may increase if the uterotonics are used properly during delivery.

Epitope analysis of an HLA-B27-derived synthetic peptide: a possible approach to analyzing HLA class I antigens

A monoclonal antibody, F3H7, was generated by immunizing mice with a synthetic peptide corresponding to residues 63-84 of the B*2705 allele of the HLA-B27 antigens. The reactive epitope and the contact residues on the peptide were localized by ELISA using a large panel of overlapping peptides as well as peptides with substituted amino acids. Residues corresponding to R75, D77 and L78 on the HLA-B27 protein appeared to be critical. The clarity of these results indicate that this is a potentially useful approach to the study of HLA class I epitopes.