Virological characterization of the 2022 outbreak-causing monkeypox virus using human keratinocytes and colon organoids

ヒトiPS細胞由来大腸オルガノイドおよびヒトケラチノサイトを用いたmpoxウイルス2022年株の解析. 京都大学プレスリリース. 2023-06-07.The outbreak-causing monkeypox virus of 2022 (2022 MPXV) is classified as a clade IIb strain and phylogenetically distinct from prior endemic MPXV strains (clades I or IIa), suggesting that its virological properties may also differ. Here, we used human keratinocytes and induced pluripotent stem cell-derived colon organoids to examine the efficiency of viral growth in these cells and the MPXV infection-mediated host responses. MPXV replication was much more productive in keratinocytes than in colon organoids. We observed that MPXV infections, regardless of strain, caused cellular dysfunction and mitochondrial damage in keratinocytes. Notably, a significant increase in the expression of hypoxia-related genes was observed specifically in 2022 MPXV-infected keratinocytes. Our comparison of virological features between 2022 MPXV and prior endemic MPXV strains revealed signaling pathways potentially involved with the cellular damages caused by MPXV infections and highlights host vulnerabilities that could be utilized as protective therapeutic strategies against human mpox in the future

Neoadjuvant chemotherapy in locally advanced colorectal cancer: a Japanese multicenter study

Purpose: The impact of neoadjuvant chemotherapy for locally advanced colorectal cancer has not yet been investigated; thus, this study aimed to examine the safety, feasibility, and oncological effects of neoadjuvant chemotherapy for locally advanced colorectal cancer.Methods: In this multicenter study, we retrospectively reviewed the data of 83 locally advanced colorectal cancer patients (cT3/4 or N1/2) who received neoadjuvant chemotherapy followed by radical resection between April 2016 and September 2020. The NAC regimens were FOLFOX (5-fluorouracil, leucovorin, and oxaliplatin), XELOX (capecitabine and oxaliplatin), or SOX (S-1 and oxaliplatin). We evaluated the pathological responses as well as the short- and long-term outcomes.Results: A pathological complete response was achieved in 4 patients (4.8%). Tumor down-staging and nodal down-staging were achieved in 57 (68.7%) and 49 (59.0%) patients, respectively. One patient (1.2%) experienced progressive disease. Postoperative complications occurred in 21 patients (25.3%). Multivariate analysis revealed that the pathological N positive status (p = 0.015; odds ratio, 4.458; 95% confidence interval, 1.331 to 7.9300) was an independent predictive factor for relapse-free survival.Conclusion: Neoadjuvant chemotherapy for colorectal cancer could achieve good tumor control and down-staging without increasing the rate of complications. Appropriate preoperative treatment that can reduce the rate of the pathological nodepositive disease may improve oncological outcomes

Unanticipated adverse event of endoscopic submucosal dissection: Rectal perforation associated with injury of the cecum wall, Report of a case

Endoscopic submucosal dissection (ESD) is a standard treatment for early gastric cancer, but it is not generally used for colorectal lesions because of its high risk of adverse events. An unanticipated adverse event of rectal ESD is reported. A 71-year-old man was found to have a laterally spreading tumor at the upper rectum. ESD was performed. During the ESD, rectal perforation occurred, and emergency laparoscopic surgery was performed. At the operation, rectal perforation with retroperitoneal emphysema was detected. Surprisingly, an 8-cm-long, lacerated wound was found at the cecum wall. It was thought to have been caused by heat injury due to ESD. The perforated site was resected, and the laceration of the cecum was repaired by extracorporeal suture. In patients with perforation during ESD, it is essential to keep in mind that other organs might have heat-induced injury, and the patient should be more carefully followed

A case of acinar cell carcinoma of the pancreas

Background Acinar cell carcinoma (ACC) is a very rare malignancy and represents only 1% to 2% of pancreatic exocrine carcinomas. At the time of diagnosis, 75% of ACC are resectable. Reliable data concerning effective adjuvant chemotherapy has not been established.Case presentation A 30-mm tumor in the pancreatic tail was incidentally discovered by computed tomography in a 71-yearold man. Several swollen lymph nodes were seen around the main tumor. Endoscopic retrograde cholangiopancreatography (ERCP) revealed disruption of the main pancreatic duct. The patient underwent curative resection (R0) with distal pancreatectomy and node dissection. Histopathological examination revealed ACC with lymph node metastases; adjuvant chemotherapy was performed with gemcitabine after surgery. Twelve months later, the patient showed no sign of recurrence.Conclusion The prognosis of ACC is dismal, although compared to ductal adenocarcinoma, the mean survival appears to be longer. Patients with advanced-stage ACC might benefit from gemcitabine-based adjuvant chemotherapy

Clinicopathological Parameters Associated with Surgical Site Infections in Patients who Underwent Pancreatic Resection

Background/Aims: To clarify parameters associated with postoperative surgical site infection (SSI) after pancreatectomy, we examined clinicopathological and surgical records in 186 patients who underwent pancreatectomy at a single academic institute. Methodology: Patient demographics, liver functional parameters, histological findings, surgical records and post-hepatectomy outcomes during hospitalization were compared between the non-SSI and SSI group, in which SSIs included superficial and deep SSIs. Results: The prevalence of SSI (29-35%) has not changed over an 18-year period. With respect to patient demographics and laboratory data, no parameters were associated with postoperative SSI. In surgical records, the operating time in the SSI group tended to be longer in comparison with that in the non-SSI group (618 vs. 553 minutes, respectively) but not significantly different (p=0.070). With respect to postoperative outcomes, time to oral intake in the SSI group was significantly longer than that in the non-SSI group (21.2 vs. 13.7 days, respectively) (p<0.01). Incidences of pancreatic fistula, postoperative bleeding, long-term ascites and re-operation were significantly more frequent in the SSI group in comparison with the non-SSI group (p<0.05). Decrease of body weight after surgery in the SSI group was significantly greater than that in the non-SSI group (-4.1 vs. -2.7kg, respectively) (p<0.05). Period of hospital stay in the SSI group was significantly longer than that in the non-SSI group (37 vs. 25 days) (p<0.05). Multivariate analysis showed that only postoperative pancreatic fistula was significantly associated with SSI (p<0.01). Conclusions: SSI is an important risk factor of longer hospital stay after pancreatectomy and prevention of pancreatic fistula through the future improvement of surgical procedures is necessary to decrease SSI rates

Virological characteristics of the SARS-CoV-2 Omicron BA.2.75 variant

SARS-CoV-2オミクロンBA.2.75株（通称ケンタウロス）のウイルス学的性状の解明. 京都大学プレスリリース. 2022-10-12.The SARS-CoV-2 Omicron BA.2.75 variant emerged in May 2022. BA.2.75 is a BA.2 descendant but is phylogenetically distinct from BA.5, the currently predominant BA.2 descendant. Here, we show that BA.2.75 has a greater effective reproduction number and different immunogenicity profile than BA.5. We determined the sensitivity of BA.2.75 to vaccinee and convalescent sera as well as a panel of clinically available antiviral drugs and antibodies. Antiviral drugs largely retained potency but antibody sensitivity varied depending on several key BA.2.75-specific substitutions. The BA.2.75 spike exhibited a profoundly higher affinity for its human receptor, ACE2. Additionally, the fusogenicity, growth efficiency in human alveolar epithelial cells, and intrinsic pathogenicity in hamsters of BA.2.75 were greater than those of BA.2. Our multilevel investigations suggest that BA.2.75 acquired virological properties independent of BA.5, and the potential risk of BA.2.75 to global health is greater than that of BA.5

Early stage signet ring cell carcinoma of the colon examined by magnifying endoscopy with narrow-band imaging: a case report

Background: Signet ring cell carcinoma of the colon and rectum is rare, and most cases are detected at an advanced stage. We present a case of primary signet ring cell carcinoma detected at an early stage by magnifying endoscopy with narrow-band imaging (NBI) and crystal violet staining. Case presentation: A 73-year-old man visited our hospital for screening colonoscopy. Six years previously, he had undergone endoscopic submucosal dissection (ESD) for early gastric cancer. The pathological diagnosis was a well-differentiated adenocarcinoma, invading into the mucosa without lymphovascular invasion. Colonoscopy revealed a flat elevated lesion with a slightly depressed area, 20 mm in diameter, in the cecum. Further, magnifying endoscopy with NBI revealed that the surface pattern was slightly irregular and microvessels had a regular diameter and distribution in the margin of the lesion, but in the central part of the lesion, irregularity in the tumor surface pattern and form as well as in the diameter and distribution of microvessels was noted. Additionally, due to mucus, avascular areas were also observed. Magnifying endoscopy combined with 0.05 % crystal violet staining showed IIIL and VI pit patterns in the margin of the lesion, and a VI pit pattern in the central part of the lesion; however, due to mucus exudate, this finding could not be established with certainty. The lesion was successfully removed en bloc using ESD without complications. The tumor was composed mainly of signet ring cell carcinoma, partially mixed with moderately differentiated (tub2) and well-differentiated (tub1) adenocarcinomas. The tumor cells infiltrated 250 μm into the submucosal layer and involved lymphatic vessels. Therefore, the patient underwent an additional laparoscopic ileocecal resection, and the resected specimen revealed no residual carcinoma or lymph node metastasis. Conclusion: In this case report, we present a case of primary signet ring cell carcinoma detected at an early stage and identified by magnifying endoscopy with NBI and crystal violet staining

Arabidopsis HDA6 Regulates Locus-Directed Heterochromatin Silencing in Cooperation with MET1

Heterochromatin silencing is pivotal for genome stability in eukaryotes. In Arabidopsis, a plant-specific mechanism called RNA–directed DNA methylation (RdDM) is involved in heterochromatin silencing. Histone deacetylase HDA6 has been identified as a component of such machineries; however, its endogenous targets and the silencing mechanisms have not been analyzed globally. In this study, we investigated the silencing mechanism mediated by HDA6. Genome-wide transcript profiling revealed that the loci silenced by HDA6 carried sequences corresponding to the RDR2-dependent 24-nt siRNAs, however their transcript levels were mostly unaffected in the rdr2 mutant. Strikingly, we observed significant overlap of genes silenced by HDA6 to those by the CG DNA methyltransferase MET1. Furthermore, regardless of dependence on RdDM pathway, HDA6 deficiency resulted in loss of heterochromatic epigenetic marks and aberrant enrichment for euchromatic marks at HDA6 direct targets, along with ectopic expression of these loci. Acetylation levels increased significantly in the hda6 mutant at all of the lysine residues in the H3 and H4 N-tails, except H4K16. Interestingly, we observed two different CG methylation statuses in the hda6 mutant. CG methylation was sustained in the hda6 mutant at some HDA6 target loci that were surrounded by flanking DNA–methylated regions. In contrast, complete loss of CG methylation occurred in the hda6 mutant at the HDA6 target loci that were isolated from flanking DNA methylation. Regardless of CG methylation status, CHG and CHH methylation were lost and transcriptional derepression occurred in the hda6 mutant. Furthermore, we show that HDA6 binds only to its target loci, not the flanking methylated DNA, indicating the profound target specificity of HDA6. We propose that HDA6 regulates locus-directed heterochromatin silencing in cooperation with MET1, possibly recruiting MET1 to specific loci, thus forming the foundation of silent chromatin structure for subsequent non-CG methylation

Convergent evolution of SARS-CoV-2 Omicron subvariants leading to the emergence of BQ.1.1 variant

In late 2022, various Omicron subvariants emerged and cocirculated worldwide. These variants convergently acquired amino acid substitutions at critical residues in the spike protein, including residues R346, K444, L452, N460, and F486. Here, we characterize the convergent evolution of Omicron subvariants and the properties of one recent lineage of concern, BQ.1.1. Our phylogenetic analysis suggests that these five substitutions are recurrently acquired, particularly in younger Omicron lineages. Epidemic dynamics modelling suggests that the five substitutions increase viral fitness, and a large proportion of the fitness variation within Omicron lineages can be explained by these substitutions. Compared to BA.5, BQ.1.1 evades breakthrough BA.2 and BA.5 infection sera more efficiently, as demonstrated by neutralization assays. The pathogenicity of BQ.1.1 in hamsters is lower than that of BA.5. Our multiscale investigations illuminate the evolutionary rules governing the convergent evolution for known Omicron lineages as of 2022

Virological characteristics of the SARS-CoV-2 XBB variant derived from recombination of two Omicron subvariants

In late 2022, SARS-CoV-2 Omicron subvariants have become highly diversified, and XBB is spreading rapidly around the world. Our phylogenetic analyses suggested that XBB emerged through the recombination of two cocirculating BA.2 lineages, BJ.1 and BM.1.1.1 (a progeny of BA.2.75), during the summer of 2022. XBB.1 is the variant most profoundly resistant to BA.2/5 breakthrough infection sera to date and is more fusogenic than BA.2.75. The recombination breakpoint is located in the receptor-binding domain of spike, and each region of the recombinant spike confers immune evasion and increases fusogenicity. We further provide the structural basis for the interaction between XBB.1 spike and human ACE2. Finally, the intrinsic pathogenicity of XBB.1 in male hamsters is comparable to or even lower than that of BA.2.75. Our multiscale investigation provides evidence suggesting that XBB is the first observed SARS-CoV-2 variant to increase its fitness through recombination rather than substitutions