Diagnostic Value of Transabdominal Ultrasonography in Gastrointestinal Malignant Tumors.

Objective: To explore the application value of transabdominal ultrasonography in the diagnosis of gastrointestinal malignant tumors. Methods: This study retrospectively analyzed the transabdominal ultrasound imaging data of 284 patients with gastrointestinal tumors admitted to our hospital from April 2019 to March 2022 and assessed the accuracy of transabdominal ultrasound in diagnosing different types of gastrointestinal tumor diseases. The diagnostic accuracy of transabdominal ultrasonography for TNM staging of gastrointestinal malignancies was calculated. Results: The sensitivity and specificity of transabdominal ultrasonography in the diagnosis of gastric cancer were (82.40% and 83.72%, respectively), colon cancer (77.78% and 88.35%, respectively), gastric stromal tumor (95.45% and 93.65%, respectively), gastric lymphoma (72.22% and 94.66%, respectively), colorectal lymphoma (80.00% and 95.42%, respectively), gastric mucosal hypertrophy (85.71% and 96.69%, respectively), and pyloric hypertrophy (92.59% and 97.79%, respectively). Among the 284 patients included, 152 patients had malignant tumors, including 34 patients with stage I, 30 patients with stage II, 51 patients with stage III, and 37 patients with stage IV. The accuracy of transabdominal ultrasonography for TNM staging of gastrointestinal malignancies was 85.53% (130/152). Conclusion: Transabdominal ultrasonography shows promise as a diagnostic tool for gastrointestinal malignant tumors; however, it is recommended to be used in conjunction with other detection methods such as fibrous gastrointestinal tract examination to minimize the risk of missed diagnoses and misdiagnoses. The study highlights the potential of transabdominal ultrasonography as a non-invasive and accessible diagnostic method for gastrointestinal malignancies. Further research and advancements in imaging technologies are crucial for enhancing diagnostic capabilities and improving patient outcomes in the future.

New scaffolds for type II JAK2 inhibitors overcome the acquired G993A resistance mutation.

Recurrent JAK2 alterations are observed in myeloproliferative neoplasms, B-cell acute lymphoblastic leukemia, and other hematologic malignancies. Currently available type I JAK2 inhibitors have limited activity in these diseases. Preclinical data support the improved efficacy of type II JAK2 inhibitors, which lock the kinase in the inactive conformation. By screening small molecule libraries, we identified a lead compound with JAK2 selectivity. We highlight analogs with on-target biochemical and cellular activity and demonstrate in vivo activity using a mouse model of polycythemia vera. We present a co-crystal structure that confirms the type II binding mode of our compounds with the "DFG-out" conformation of the JAK2 activation loop. Finally, we identify a JAK2 G993A mutation that confers resistance to the type II JAK2 inhibitor CHZ868 but not to our analogs. These data provide a template for identifying novel type II kinase inhibitors and inform further development of agents targeting JAK2 that overcome resistance.

Functional reclassification of variants of uncertain significance in the HCN4 gene identified in sudden unexpected death.

The HCN4 gene encodes a subunit of the hyperpolarization-activated cyclic nucleotide-gated channel, type 4 that is essential for the proper generation of pacemaker potentials in the sinoatrial node. The HCN4 gene is often present in targeted genetic testing panels for various cardiac conduction system disorders and there are several reports of HCN4 variants associated with conduction disorders. Here, we report the in vitro functional characterization of four rare variants of uncertain significance (VUS) in HCN4, identified through testing a cohort of 296 sudden unexpected natural deaths. The variants are all missense alterations, leading to single amino acid changes: p.E66Q in the N-terminus, p.D546N in the C-linker domain, and both p.S935Y and p.R1044Q in the C-terminus distal to the CNBD. We also identified a likely benign variant, p. P1063T, which has a high minor allele frequency in the gnomAD, which is utilized here as a negative control. Three of the HCN4 VUS (p.E66Q, p.S935Y, and p.R1044Q) had electrophysiological characteristics similar to the wild-type channel, suggesting that these variants are benign. In contrast, the p.D546N variant in the C-linker domain exhibited a larger current density, slower activation, and was unresponsive to cyclic adenosine monophosphate (cAMP) compared to wild-type. With functional assays, we reclassified three rare HCN4 VUS to likely benign variants, eliminating the necessity for costly and time-consuming further study. Our studies also provide a new lead to investigate how a VUS located in the C-linker connecting the pore to the cAMP binding domain may affect the channel open state probability and cAMP response.

Molecular autopsy: using the discovery of a novel de novo pathogenic variant in the KCNH2 gene to inform healthcare of surviving family.

BACKGROUND: Molecular testing of the deceased (Molecular Autopsy) is an overlooked area in the United States healthcare system and is not covered by medical insurance, leading to ineffective care for surviving families of thousands of sudden unexpected natural deaths each year. We demonstrated the precision management of surviving family members through the discovery of a novel de novo pathogenic variant in a decedent. METHODS: Forensic investigation and molecular autopsy were performed on an 18-year-old female who died suddenly and unexpectedly. Co-segregation family study of the first-degree relatives and functional characterization of the variant were conducted. FINDINGS: We identified a novel nonsense variant, NP_000229.1:p.Gln1068Ter, in the long QT syndrome type II gene KCNH2 in the decedent. This finding correlated with her ante-mortem electrocardiograms. Patch clamp functional studies using transfected COS-7 cells show that hERG-ΔQ1068 has a mixed phenotype, with both gain- (negative voltage shift of steady-state activation curve, the positive shift of the steady-state inactivation curve, and accelerated activation) and loss-of function (reduced current density, reduced surface expression and accelerated deactivation) hallmarks. Loss of cumulative activation during rapid pacing demonstrates that the loss-of-function phenotype predominates. The wild-type channel did not rescue the hERG-ΔQ1068 defects, demonstrating haploinsufficiency of the heterozygous state. Targeted variant testing in the family showed that the variant in KCNH2 arose de novo, which eliminated the need for exhaustive genome testing and annual cardiac follow-up for the parents and four siblings. INTERPRETATION: Molecular testing enables accurate determination of natural causes of death and precision care of the surviving family members in a time and cost-saving manner. We advocate for molecular autopsy being included under the healthcare coverage in US.

Cyclic nucleotide-gated channel 18 is an essential Ca2+ channel in pollen tube tips for pollen tube guidance to ovules in Arabidopsis.

In flowering plants, pollen tubes are guided into ovules by multiple attractants from female gametophytes to release paired sperm cells for double fertilization. It has been well-established that Ca(2+) gradients in the pollen tube tips are essential for pollen tube guidance and that plasma membrane Ca(2+) channels in pollen tube tips are core components that regulate Ca(2+) gradients by mediating and regulating external Ca(2+) influx. Therefore, Ca(2+) channels are the core components for pollen tube guidance. However, there is still no genetic evidence for the identification of the putative Ca(2+) channels essential for pollen tube guidance. Here, we report that the point mutations R491Q or R578K in cyclic nucleotide-gated channel 18 (CNGC18) resulted in abnormal Ca(2+) gradients and strong pollen tube guidance defects by impairing the activation of CNGC18 in Arabidopsis. The pollen tube guidance defects of cngc18-17 (R491Q) and of the transfer DNA (T-DNA) insertion mutant cngc18-1 (+/-) were completely rescued by CNGC18. Furthermore, domain-swapping experiments showed that CNGC18's transmembrane domains are indispensable for pollen tube guidance. Additionally, we found that, among eight Ca(2+) channels (including six CNGCs and two glutamate receptor-like channels), CNGC18 was the only one essential for pollen tube guidance. Thus, CNGC18 is the long-sought essential Ca(2+) channel for pollen tube guidance in Arabidopsis.

Effects of long axis in-plane vs short axis out-of-plane techniques during ultrasound-guided vascular access.

BACKGROUND: Currently, whether long-axis in-plane (LA-IP) is superior to short-axis out-of-plane (SA-OOP) during ultrasound-guided vascular access remains inconclusive. We, therefore, conducted a meta-analysis of randomized controlled trials to compare the effects of LA-IP vs SA-OOP techniques in patients undergoing ultrasound-guided vascular access (USGVA). METHODS: A computer-based literature search of PubMed, Embase, and the Cochrane Library (up to October 2015) was performed to identify randomized controlled trials that evaluated the effects of LA-IP compared with SA-OOP in patients undergoing USGVA. The primary end point was the first-pass success rate. Secondary end points included mean time to success, mean attempts to success, and incidence of the complication of hematoma. Weighted mean differences (WMDs) and relative risks (RRs) with 95% confidence intervals (CIs) were calculated by random-effects model. RESULTS: Five eligible studies with a total of 470 patients satisfied the inclusion criteria. There was no significant difference for the first-pass success rate (RR, 1.06; 95% CI, 0.91-1.23; P = .44), mean time to success (WMD, 4.78seconds; 95% CI, -4.43 to 13.99; P = .31), mean attempts to success (WMD, 0.06 times; 95% CI, -0.23 to 0.35; P = .69), and incidence of the complication of hematoma (RR, 2.86; 95% CI, 0.32-25.42; P = .35) between the LA-IP and SA-OOP groups. CONCLUSIONS: There is insufficient evidence to definitively choose either LA-IP or SA-OOP in patients undergoing USGVA. Further robustly well-designed trials are warranted to investigate the appropriate technique in patients receiving USGVA.

V2 protein encoded by Tomato yellow leaf curl China virus is an RNA silencing suppressor.

The V2 protein of Tomato yellow leaf curl China virus (TYLCCNV) was identified as an RNA silencing suppressor by Agrobacterium-mediated co-infiltration. The V2 protein could inhibit local RNA silencing, systemic RNA silencing of the green fluorescent protein (GFP) gene and the spread of a systemic GFP RNA silencing signal. However, the V2 could not interfere with the cell-to-cell spread of RNA silencing. Subcellular localization assay indicated that the V2 protein was distributed in the cytoplasm of Nicotiana benthamiana cells, and accumulated in irregular cytoplasmic bodies. The V2 bound 21nt and 24nt small interfering RNA (siRNA) duplexes and 24nt single-stranded (ss)-siRNA but not 21nt ss-siRNA in electrophoresis mobility shift assays. Expression of the V2 protein via the Potato virus X (PVX) vectors heterogenous system induced severe symptoms in N. benthamiana. In a yeast two-hybrid system, TYLCCNV V2 could interact with itself, but not with SlSGS3, which is known to been involved in RNA silencing pathway and to interact with a closely related Tomato yellow leaf curl virus (TYLCV) V2. These results indicate that TYLCCNV V2 is an RNA silencing suppressor, possibly through sequestering siRNA molecules.