Negative Effects of Cyclic Palmitate Treatment on Glucose Responsiveness and Insulin Production in Mouse Insulinoma Min6 Cells Are Reversible

Pancreatic β-cell failure is characterized by compromised insulin secretion in response to glucose, which ultimately results in hyperglycemia, the clinical hallmark of type 2 diabetes mellitus (T2DM). Acute exposure to plasma free fatty acids (FFAs) potentiates glucose stimulated insulin secretion (GSIS), while chronic exposure impairs GSIS, and the latter has been associated with the mechanism of β cell failure in obesity linked T2DM. By contrast, growth hormone (GH) signaling has been linked positively to GSIS in β cells. Numerous studies have examined chronic exposure of β cells to elevated FFAs both with in vivo cohorts and in vitro models. Little attention, however, has been given to the fluctuation of plasma FFA levels due to rhythmic effects that are affected by daily diet and fat intake. Mouse insulinoma Min6 cells were exposed to cyclic/daily palmitate treatment over 2 and 3 days to assess effects on GSIS. Cyclic/daily palmitate treatment with a period of recovery negatively affected GSIS in a dose-dependent manner. Removal of palmitate after two cycles/day resulted in reversal of the effect on GSIS, which was also reflected by relative gene expression involved in insulin biosynthesis (Ins1, Ins2, Pdx1, and MafA) and GSIS (glucose 2 transporter and glucokinase). Modest positive effects on GSIS and glucokinase transcript levels were also observed when Min6 cells were cotreated with human GH and palmitate. These observations indicate that like continuous palmitate treatment, cyclic exposure to palmitate can acutely impair GSIS over 48 and 72 h. However, they also suggest that the negative effects of short periods of exposure to FFAs on β cell function remain reversible.

Impact of iron overload in hematopoietic stem cell transplantation

Iron overload (IOL) is a common condition in patients with hematological malignancies(HMs) undergoing hematopoietic stem cell transplantation (HSCT). Pathophysiologically, IOL results in iron-induced toxicity in HSCT by producing reactive oxygen species (ROS), which leads to detrimental effects on hematopoiesis, clonal evolution, and immunosuppression. IOL, therefore, may have a negative impact on the clinical outcomes of HSCT. For patients at a higher risk of developing IOL before HSCT, it is necessary to monitor red blood cell transfusion units, serum ferritin (SF) levels and MRI image of organs, and initiate iron removal therapy as soon as possible. Iron chelating therapy (ICT) might be safe and efficient in the post-HSCT period. We provide an overview of results from experimental and clinical evidence on the current understanding of IOL in patients with HMs undergoing HSCT, involving the underlying pathophysiological and clinical impact of IOL, as well as the significance of iron reduction therapy.

[Analysis of rRNA gene restriction fragments length polymorphism of Leptospira in China]

Sixty-four Leptospira international and domestic reference strains, which belonging to fifty-four serovars, and twenty-seven field strains were examined by using EcoR I restriction endonuclease analysis of genomic DNA and restriction fragments length polymorphism of rRNA gene, fifty-six Leptospiral ribotypes(RTs) were described. Most serovars gave specific patterns. Serovars in the same serogroup possess common core-segments, but we found RTs of reference strains from China and other countries are different. Most field strains have RTs with correspond of reference strains, only a few bands were shown different if RTs were different. A notable result was that the field strains of serovar pomona have the same Rt as the international reference strain but different from the domestic reference strain.

[Production of phage-displayed single chain variable fragments of monoclonal antibody MGb1]

OBJECTIVE

To lay a foundation for obtaining a tumor-targeting vehicle for in vivo study on diagnosis and treatment of gastric carcinoma by generating single chain variable fragments (ScFv) of monoclonal antibody MGb1 directed against the cancer.

METHODS

mRNA was isolated from MGb1-producing mouse hybridoma cell line, and the variable regions of heavy and light chain cDNAs were amplified separately and assembled into ScFv DNAs with a specially constructed linker DNA by PCR. The ScFv DNAs were ligated into the phagemid vector pCANTAB5E and the ligated sample was transformed into competent E. coli TG1. The transformed cells were infected with M13KO7 helper phage to yield recombinant phage, which display ScFv fragments as a fusion with gene 3 protein on the tips of the phage M13. After two rounds of panning with gastric carcinoma cell line KATO III highly expressing MGb1-binding antigen, the phage clones displayed ScFv fragments of the antibody were selected by enzyme-linked immunosorbent assay (ELISA) from the enriched phages. The affinity of the positive phage clones was detected by competition ELISA.

RESULTS

The VH, VL and ScFv DNAs were about 340 bp, 320 bp and 750 bp respectively. 17 phage clones displayed ScFv of MGb1 were selected from 40 enriched phage clones. 4 out of the 17 phage clones could strongly compete with the original hybridoma antibody MGb1 for binding to the antigen expressed on KATOIII cells.

CONCLUSION

The phage-displayed ScFv fragments of monoclonal antibody MGb1 are successfully produced by phage antibody technology, which may be useful to widen the range of application of the antibody.

An augmented magnetic navigation system for Transcatheter Aortic Valve Implantation

This research proposes an augmented magnetic navigation system for Transcatheter Aortic Valve Implantation (TAVI) employing a magnetic tracking system (MTS) combined with a dynamic aortic model and intra-operative ultrasound (US) images. The dynamic 3D aortic model is constructed based on the preoperative 4D computed tomography (CT), which is animated according to the real time electrocardiograph (ECG) input of patient. And a preoperative planning is performed to determine the target position of the aortic valve prosthesis. The temporal alignment is performed to synchronize the ECG signals, intra-operative US image and tracking information. Afterwards, with the assistance of synchronized ECG signals, the contour of aortic root automatic extracted from short axis US image is registered to the dynamic aortic model by a feature based registration intra-operatively. Then the augmented MTS guides the interventionist to confidently position and deploy the aortic valve prosthesis to target. The system was validated by animal studies on three porcine subjects, the deployment and tilting errors of which are 3.17 ± 0.91 mm and 7.40 ± 2.89° respectively.

Line shapes of photon-gated persistent spectral hole burning in polarization spectroscopy

We introduce a method of polarization spectroscopy into photon-gated persistent spectral hole burning, which results in considerable improvement in the signal-to-background ratio. Fifty multiple spectral holes burnt into meso-phenyl-tetrabenzoporphyrinato-zinc/aromatic cyanide/poly(methyl methacrylate) were clearly detected by this measurement technique. We developed a simplified model to account for the hole shapes. Background birefringence combined with refractive dispersion is thought to play a key role in the generation of asymmetric line shapes.

Surface and interfacial study of atomic layer deposited Al2O3 on MoTe2 and WTe2

The atomic layer deposition (ALD) of high-k dielectrics could build an efficient barrier against moisture and O₂ adsorption. Such a barrier is highly needed for MoTe₂ and WTe₂ transition metal dichalcogenides because of the poor structural stability and the fast oxidization in ambient air. In situ x-ray photoelectron spectroscopy and ex situ atomic force microscopy and scanning transmission electron microscopy were employed to report a comparative study between the growth of Al₂O₃ on MoTe₂ and WTe₂ by means of traditional thermal ALD and plasma-enhanced ALD (PEALD). Similar to what has been observed on other 2D materials such as MoS₂ and Graphene, the thermal ALD results in an islanding growth of Al₂O₃ on MoTe₂ due to the dearth of dangling bonds, whereas, a uniform coverage of Al₂O₃ on WTe₂ is observed and likely contributed to the high concentration of intrinsic structural defects. The PEALD behavior is consistent between MoTe₂ and WTe₂ providing a conformal and linear growth rate (∼0.08 nm/cycle), which correlates with the creation of Te-O and metal-O nucleation sites. However, a thin layer of interfacial Mo or W oxides gradually forms, resulting from the plasma-induced damage in the topmost (1-2) layers. Attempts to enhance the Al₂O₃/MoTe₂ interfacial quality by physically evaporating an Al₂O₃ seed layer are investigated as well. However, the evaporated Al₂O₃ process causes thermal damage on MoTe₂, necessitating a more 'gentle' ALD technique for the surface passivation.

Identifying protected areas in biodiversity hotspots at risk from climate and human-induced compound events for conserving threatened species

Anthropogenic pressure in areas of biodiversity importance erodes the integrity of the ecosystems they harbour, making features of biodiversity less buffered against extreme climatic events. We define the combination of these disturbances as compound events. We assessed compound event risk in protected areas (PAs) applying a spatial framework guided by criteria and quantitative thresholds associated with exposure to cyclones, drought, and intense human pressure. This assessment was used in a relational matrix to classify PAs with different risk of compound event occurrence. We identified PAs of higher conservation concern by quantifying the extent of human pressure in their surrounding landscape while harbouring large numbers of threatened vertebrate species. Of the 39,694 PAs assessed, very high risk of compound events was determined for 6965 PAs (17.5 %) related to cyclones and human pressure (mainly island hotspots), 6367 PAs (16 %) related to droughts and human pressure (island and continental hotspots), and 2031 PAs (5 %) to cyclones, drought and human pressure (mainly in island hotspots). From the subset of 2031 PAs assessed at very high risk, we identified 239 PAs of higher conservation concern distributed predominantly in the Caribbean Islands, Japan, North America Coastal Plain, Philippines, and Southwest Australia. Our work highlights PAs in the biodiversity hotspots where high risk of compound event occurrence poses a greater threat to species. We encourage researchers to adapt and apply this framework across other globally significant sites for conserving biodiversity to identify high risk-prone areas, and prevent further biodiversity decline.

[Effect of octreotide on intragastric pH in patients with duodenal ulcer bleeding]

OBJECTIVE

To evaluate the effect of octreotide on the intragastric pH of patients with duodenal ulcer bleeding during the period of 24 hours and to observe if it can advance the effect of hemostasis by endoscopic injection of epinephrine.

METHODS

Twenty-four patients with duodenal ulcer bleeding were randomly divided into three groups, eight in each. Patients in group 1 received an intravenous injection of 0.1 mg of octreotide followed by continuous intravenous drip of octreotide at a constant speed of 25 microg/h for 24 hours. The patients in group 2 received an intravenous injection of 0.1 mg of octreotide followed by continuous intravenous drip of octreotide at a constant speed of 42 microg/h for 24 hours. The patients in group 3 received an intravenous injection of 40 mg of omeprazole followed by continuous intravenous drip of omeprazole at a constant speed of 8 mg/h for 24 hours. Intragastric pH was continuously recorded with a pH meter. The patients with active ulcer bleeding was treated with injection of epinephrine via endoscope and then received intravenous drip of octreotide (with the same dosage as in group 1, n = 42) or omeprazole (with the same dosage as in group 3, n = 54) for 72 hours and were given omeprazole (20 mg Bid).

RESULTS

The mean and median intragastric pH values among the patients in group 2 treated by a larger dosage of octreotide (6.7 +/- 0.5 and 6.9 +/- 0.4) were similar to those in the group 3 treated by omeprazole (6.8 +/- 0.4 and 7.0 +/- 0.4). There was no statistically significant difference between these two groups in percentage of intragastric pH above 4, 6, and 7 The mean and median of intragastric pH among the patients in group 1 treated by a smaller dosage of octreotide were statistically significantly smaller (5.2 +/- 0.5 and 5.4 +/- 0.4) than those in the omeprazole group. There was no statistically significant difference between octreotide treatment and omeprazole treatment in terms of volume of blood transfusion (0.7 +/- 0.5 vs. 0.6 +/- 0.4 L), rebleeding rate (11.6% vs. 12.9%), emergency operation rate (7.1% vs. 3.7%), and mortality (2.3% vs. 3.7%).

CONCLUSION

Octreotide effectively inhibits the secretion of gastric acid. However, the dosage in common use clinically fails to increase the intragastric pH to the best situation needed for effective hemostasis. Only a large dosage (1.10 mg/d) works.

Profiling the epigenetic interplay of lncRNA RUNXOR and oncogenic RUNX1 in breast cancer cells by gene in situ cis-activation

RUNX1 is frequently mutated as chromosomal translocations in a variety of hematological malignancies. Recent studies show that RUNX1 is also mutated somatically in many solid tumors. We have recently identified a 260 kb un-spliced intragenic overlapping long noncoding RNA RUNXOR in the RUNX1 locus, yet its role as an epigenetic regulator in tumors remains to be characterized. To delineate this RUNXOR-RUNX1 regulatory interplay in breast cancer cells, we devised a novel "gene in situ cis-activation" approach to activate the endogenous RUNXOR gene. We found that the in situ activation of RUNXOR lncRNA upregulated RUNX1 in cis from the P1 promoter. The preferred activation of the P1 promoter caused a shift to the RUNX1c isoform expression. Using a chromatin conformation capture (3C) approach, we showed that RUNXOR lncRNA epigenetically activated the RUNX1 P1 promoter in cis by altering the local chromatin structure. The binding of RUNXOR lncRNA triggered DNA demethylation and induced active histone modification markers in the P1 CpG island. Changes in RUNX1 isoform composition correlated with a trend to cell cycle arrest at G0/G1, although cell proliferation rate, apoptosis, and migration ability were not significantly changed. Our results reveal an underlying epigenetic mechanism by which the lncRNA regulates in cis the RUNX1 promoter usage in breast cancer cells, thereby shedding light on potential genetic therapies in malignancies in which RUNX1 loss-of-function mutations frequently occur.

Phenomics-assisted genetic dissection and molecular design of drought resistance in rice

Dissecting the mechanism of drought resistance (DR) and designing drought-resistant rice varieties are promising strategies to address the challenge of climate change. Here, we selected a typical drought-avoidant (DA) variety, IRAT109, and a drought-tolerant (DT) variety, Hanhui15, as parents to develop a stable recombinant inbred line (RIL) population (F8, 1262 lines). The de novo assembled genomes of both parents were released. By resequencing of the RIL population, a set of 1 189 216 reliable SNPs were obtained and used to construct a dense genetic map. Using above- and belowground phenomic platforms and multimodal cameras, we captured 139 040 image-based traits (i-traits) of whole-plant phenotypes in response to drought stress throughout the entire rice growth period and identified 32 586 drought-responsive quantitative trait loci (QTLs), including 2097 unique QTLs. QTLs associated with panicle i-traits occurred more than 600 times on the middle of chromosome 8, and QTLs associated with leaf i-traits occurred more than 800 times on the 5' end of chromosome 3, indicating the potential effects of these QTLs on plant phenotypes. We selected three candidate genes (OsMADS50, OsGhd8, OsSAUR11) related to leaf, panicle, and root traits, respectively, and verified their functions in DR. OsMADS50 was found to negatively regulate DR by modulating leaf dehydration, grain size, and downward root growth. A total of 18 and 21 composite QTLs significantly related to grain weight and plant biomass were also screened from 597 lines in the RIL population under drought conditions in field experiments, and the composite QTL regions showed substantial overlap (76.9%) with known DR gene regions. Based on three candidate DR genes, we proposed a haplotype design suitable for different environments and breeding objectives. This study provides a valuable reference for multimodal and time-series phenomic analyses, deciphers the genetic mechanisms of DA and DT rice varieties, and offers a molecular navigation map for breeding of DR varieties.

[Two years clinical observation of a kind of castable ceramic--IPS Empress]

We used this material in clinic since 1995.

OBJECTIVE

Discussion on the prosthetic effects of the above-mentioned material to spreat it clinically.

METHODS

Through half to two years clinical observations to evaluate the effect of IPS Empress crowns in anterior teeth and inlays in posteriors.

RESULTS

and

CONCLUSION

Prosthesis made of this kind of material IPS Empress is one kind of excellent all-ceramic prosthetic material. IPS Empress also could be used in post crowns and the clinical effect was satisfactory.

Pluripotency exit is guided by the Peln1-mediated disruption of intrachromosomal architecture

The molecular circuitry that causes stem cells to exit from pluripotency remains largely uncharacterized. Using chromatin RNA in situ reverse transcription sequencing, we identified Peln1 as a novel chromatin RNA component in the promoter complex of Oct4, a stem cell master transcription factor gene. Peln1 was negatively associated with pluripotent status during somatic reprogramming. Peln1 overexpression caused E14 cells to exit from pluripotency, while Peln1 downregulation induced robust reprogramming. Mechanistically, we discovered that Peln1 interacted with the Oct4 promoter and recruited the DNA methyltransferase DNMT3A. By de novo altering the epigenotype in the Oct4 promoter, Peln1 dismantled the intrachromosomal loop that is required for the maintenance of pluripotency. Using RNA reverse transcription-associated trap sequencing, we showed that Peln1 targets multiple pathway genes that are associated with stem cell self-renewal. These findings demonstrate that Peln1 can act as a new epigenetic player and use a trans mechanism to induce an exit from the pluripotent state in stem cells.

Excessive free fatty acid sensing in pituitary lactotrophs elicits steatotic liver disease by decreasing prolactin levels

The pituitary is the central endocrine gland with effects on metabolic dysfunction-associated steatotic liver disease (MASLD). However, it is not clear whether the pituitary responds to free fatty acid (FFA) toxicity, thus dysregulating hepatic lipid metabolism. Here, we demonstrate that decreased prolactin (PRL) levels are involved in the association between FFA and MASLD based on a liver biospecimen-based cohort. Moreover, overloaded FFAs decrease serum PRL levels, thus promoting liver steatosis in mice with both dynamic diet intervention and stereotactic pituitary FFA injection. Mechanistic studies show that excessive FFA sensing in pituitary lactotrophs inhibits the synthesis and secretion of PRL in a cell-autonomous manner. Notably, inhibiting excessive lipid uptake using pituitary stereotaxic virus injection or a specific drug delivery system effectively ameliorates hepatic lipid accumulation by improving PRL levels. Targeted inhibition of pituitary FFA sensing may be a potential therapeutic target for liver steatosis.