Clonal analysis of metachronous double biliary tract cancers.

The molecular mechanisms underpinning the development of metachronous tumors in the remnant bile duct following surgical resection of primary biliary tract carcinomas (BTCs) are unknown. This study aimed to elucidate these mechanisms by evaluating the clinicopathologic features of BTCs, the alterations to 31 BTC-related genes on targeted sequencing, and the aberrant expression of p53, p16, SMAD4, ARID1A and ß-catenin on immunohistochemistry. Twelve consecutive patients who underwent resection of metachronous BTCs following primary BTC resection with negative bile duct margins were enrolled. Among the 12 metachronous tumors, six exhibited anterograde growth in the lower portion and six exhibited retrograde growth in the upper portion of the biliary tree. Surgical resection of metachronous BTCs resulted in recurrence-free survival in seven, local recurrence in five, and death in two patients. Nine achieved 5-year overall survival after primary surgery. Molecular analyses revealed that recurrently altered genes were: TP53, SMAD4, CDKN2A, ELF3, ARID1A, GNAS, NF1, STK11, RNF43, KMT2D and ERBB3. Each of these was altered in at least three cases. A comparison of the molecular features between 12 paired primary and metachronous BTCs indicated that 10 (83%) metachronous tumors developed in clonal association with corresponding primary tumors either successionally or phylogenically. The remaining two (17%) developed distinctly. The successional tumors consisted of direct or evolved primary tumor clones that spread along the bile duct. The phylogenic tumors consisted of genetically unstable clones and conferred a poor prognosis. Metachronous tumors distinct from their primaries harbored fewer mutations than successional and phylogenic tumors. In conclusion, over 80% of metachronous BTCs that develop following primary BTC resection are probably molecularly associated with their primaries in either a successional or a phylogenetic manner. Comparison between the molecular features of a metachronous tumor and those of a preceding tumor may provide effective therapeutic clues for the treatment of metachronous BTC. © 2024 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Gene Rearrangement and Expression of PRKACA and PRKACB Govern Morphobiology of Pancreatobiliary Oncocytic Neoplasms.

Intraductal oncocytic papillary neoplasms (IOPNs) are distinct from intraductal papillary mucinous neoplasms based on characteristic morphologic and genetic features represented by fusion genes involving PRKACA or PRKACB (PRKACA/B). However, pancreatic and biliary tumors with partial oncocytic features are often encountered clinically, and their molecular features are yet to be clarified. This study included 80 intraductal papillary neoplasms: 32 tumors with mature IOPN morphology (typical), 28 with partial or subclonal oncocytic features (atypical), and 20 without oncocytic features (control). We analyzed PRKACA/B fusion genes, including ATP1B1::PRKACA, DNAJB1::PRKACA, and ATP1B1::PRKACB, by reverse-transcription PCR; mRNA expression of fusion genes and nonrearranged PRKACA/B genes by quantitative reverse-transcription PCR; mutations in KRAS, BRAF, and GNAS by targeted sequencing or droplet digital PCR; and the expression of cyclic adenosine monophosphate (cAMP)-dependent protein kinase catalytic subunits α (PRKACA) and ß (PRKACB), phosphorylated cAMP response element-binding protein, and aberrations of p16, p53, SMAD4, STK11, and ß-catenin by immunohistochemistry. PRKACA/B fusion genes were detected in 100% (32/32) of typical, 46% (13/28) of atypical, and 0% (0/20) of control (P < .05). Expression of PRKACA, PRKACB, and phosphorylated cAMP response element-binding protein was upregulated in neoplasms with PRKACA/B fusion genes (P < .05). mRNA expression of the PRKACA/B fusion genes and protein expression of PRKACA or PRKACB tended to be higher in typical than in atypical cases (mRNA, P = .002; protein expression, P = .054). In some atypical neoplasms with mixed subtypes, PRKACA/B fusion genes were superimposed exclusively on oncocytic components. Typical IOPNs harbored fewer KRAS and GNAS mutations than control samples and fewer alterations in p53 and STK11 than atypical samples (P < .05). In conclusion, PRKACA/B fusion genes not only are the characteristic drivers of IOPNs but also play a crucial role in the development of subclonal oncocytic neoplasms. Moreover, oncocytic morphology is strongly associated with upregulation of PRKACA/B, which may provide clues for potential therapeutic options.

Comprehensive characterization of intraductal oncocytic papillary neoplasm (IOPN) of the pancreas: a systematic and critical review.

Intraductal oncocytic papillary neoplasm (IOPN) of the pancreas is a recently recognized pancreatic tumor. Here, we aimed to determine the most essential features with the systematic review tool. PubMed, SCOPUS, and Embase were searched for studies reporting data on pancreatic IOPN. The clinicopathological, immunohistochemical, and molecular data were extracted and summarized. Then, a comparative analysis of the molecular alterations of IOPN with those of pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm from reference cohorts (including The Cancer Genome Atlas) was conducted. The key findings from 414 IOPNs were as follows: 1) Clinicopathological Features: Male-to-female ratio was 1,5:1. Pancreatic head was the most common site (131/237, 55.3%), but a diffuse tumor extension involving more than one pancreatic segment was described in about 1/5 of cases (49/237, 20.6%). The mean size was 45.5 mm. An associated invasive carcinoma was present in 50% of cases (168/336). In those cases, most tumors were pT1/pT2 and pN0 (>80%), and vascular invasion was uncommon (20.6%). Regarding survival, more than 90% of patients were alive after surgical resection. 2) Immunohistochemical and Molecular Features: The most expressed mucins were MUC5AC (110/112, 98.2%) and MUC6 (78/84, 92.8%). Compared with pancreatic ductal adenocarcinoma and intraductal papillary mucinous neoplasm, the classic pancreatic drivers KRAS, TP53, CDKN2A, SMAD4, and GNAS were less altered in IOPN (p<0.01). Moreover, fusions involving PRKACA or PRKACB genes were detected in all of 68 cases examined, with PRKACB::ATP1B1 as the most common (27/68 cases, 39.7%). These genomic events emerged as an entity-defining molecular alteration of IOPN (p<0.01). Thus, such fusions represent a promising biomarker for diagnostic purposes. Recent evidence also suggests their role in influencing the acquisition of oncocytic morphology. IOPN is a distinct pancreatic neoplasm with specific clinicopathological and molecular features. Considering the clinical/prognostic implications, its recognition is essential for pathologists and, ultimately, patients' management.

Prognostic performance of microscopic size measurements in small invasive carcinomas arising in intraductal papillary mucinous neoplasms of the pancreas.

AIMS: Small invasive carcinomas arising in intraductal papillary mucinous neoplasms (IPMNs) of the pancreas can present as multiple, small foci. In such cases, there is no clear optimal measurement method for determining the invasive size for tumour staging and prognostication. METHODS: In all, 117 small invasive IPMNs (size of largest invasive component ≤2 cm) from seven institutions (2000-2016) were reviewed, and all individual foci of invasive carcinoma were measured. T stages (AJCC 8th edition) based on the largest single focus size (LS), average size of all foci (AS), and total sum of all foci (TS) were examined in association with clinicopathologic parameters and patient outcomes. RESULTS: The cohort comprised IPMNs with invasive tubular-type (n = 82, 70%) and colloid-type (n = 35, 30%) carcinomas. The mean LS, AS, and TS were 0.86, 0.71, and 1.32 cm, respectively. Based on the LS, AS, and TS, respectively, 48, 65, and 39 cases were classified as pT1a; 22, 18, and 11 cases as pT1b; and 47, 34, and 50 cases as pT1c. Higher pT stages based on all measurements were significantly associated with small vessel, large vessel, and perineural invasion (P < 0.05). LS-, AS-, and TS-based pT stages were not significantly associated with recurrence-free survival (RFS) or overall survival (OS) by univariate or multivariate analyses. However, among tubular-type carcinomas, higher LS-, AS-, and TS-based pT stages trended with lower RFS (based on 1-, 3-, and 5-year survival rates). All microscopic measurement methods were most predictive of RFS and OS using a 1.5-cm cutoff, with LS significantly associated with both RFS and OS by univariate and multivariate analysis. CONCLUSIONS: For invasive tubular-type carcinomas arising in IPMN, microscopic size-based AJCC pT stages were not significant predictors of patient outcomes. However, for LS, a size threshold of 1.5 cm was optimal for stratifying both RFS and OS. The AJCC 8th ed. may not be applicable for stratifying small invasive IPMNs with colloid-type histology that generally portend a more favourable prognosis.

Serine/Threonine Kinase 11 Plays a Canonical Role in Malignant Progression of KRAS -Mutant and GNAS -Wild-Type Intraductal Papillary Mucinous Neoplasms of the Pancreas.

OBJECTIVE: We aimed to elucidate the clinicopathobiological significance of Serine/Threonine Kinase 11 (STK11) in pancreatic intraductal papillary mucinous neoplasms (IPMNs). BACKGROUND: STK11 is a tumor suppressor involved in certain IPMNs; however, its significance is not well known. METHODS: In 184 IPMNs without Peutz-Jeghers syndrome, we analyzed expression of STK11 and phosphorylated-AMPKa in all cases, and p16, p53, SMAD4, and ß-catenin in 140 cases by immunohistochemistry; and we analyzed mutations in 37 genes, including whole coding exons of STK11, CDKN2A, TP53, and SMAD4, and hotspots of KRAS, BRAF, and GNAS in 64 cases by targeted sequencing. KRAS and GNAS were additionally analyzed in 86 STK11-normal IPMNs using digital-PCR. RESULTS: Consistent loss or reduction of STK11 expression was observed in 26 of 184 (14%) IPMNs. These STK11-aberrant IPMNs were 17 of 45 (38%) pancreatobiliary, 8 of 27 (30%) oncocytic, 1 of 54 (2%) gastric, and 0 of 58 (0%) intestinal subtypes ( P = 8.5E-11), and 20 of 66 (30%) invasive, 6 of 74 (8%) high-grade, and 0 of 44 (0%) low-grade ( P = 3.9E-06). Sixteen somatic STK11 mutations (5 frameshift, 6 nonsense, 1 splicing, and 4 missense) were detected in 15/26 STK11-aberrant IPMNs ( P = 4.1E-06). All STK11-aberrantIPMNs were GNAS -wild-type and 96% of them were KRAS or BRAF -mutant.Morphologically, STK11-aberrant IPMNs presented "fern-like" arborizing papillae with thin fibrovascular core. Phosphorylated-AMPKa was down-regulated in STK11-aberrant IPMNs (92%, P = 6.8E-11). Patients with STK11-aberrant IPMNs showed poorer survival than patients with STK11-normal IPMNs ( P = 3.6E-04 overall; P = 6.1E-04 disease-free). CONCLUSION: STK11 may play a canonical role in malignant progression and poor survival of patients with IPMNs. Aberrant STK11-driven phosphorylated AMPK downregulation may provide therapeutic opportunities with mTOR inhibitors/AMPK activators.

GATA6 and CK5 Stratify the Survival of Patients With Pancreatic Cancer Undergoing Neoadjuvant Chemotherapy.

Relevant protein expression of GATA6, CK5, vimentin, and mucins using immunohistochemistry was assessed for predicting the prognosis of and chemotherapy efficacy in patients with pancreatic cancers (PCs). The protein expression was examined in 159 PCs resected after neoadjuvant chemotherapy (NAC-PCs) and compared with that of 120 matched biopsy specimens taken before NAC. KRAS mutations were assessed by digital PCR. NAC-PCs were classified by GATA6 expression initially and CK5 expression subsequently into 4 types: classical-type (n = 22) with GATA6-high (≥50%)/CK5-low (<10%) PCs; hybrid-type (n = 45) with GATA6-high/CK5-high (≥10%) PCs; basal-like-type (n = 53) with GATA6-low (<50%)/CK5-high (≥30%) PCs; and null-type (n = 39) with GATA6-low/CK5-low (<30%) PCs, which resulted in clear stratification of patient prognosis. The classical-type was associated with the most favorable prognosis, whereas the null-type was associated with the worst prognosis (multivariate hazard ratio: 3.56; 95% CI, 1.63-7.77; P = .0015). The hybrid and basal-like types correlated with in-between levels of prognosis. The risk of hepatic recurrence was lower in the classical-type than in null (multivariate odds ratio [mOR]: 0.18; 95% CI, 0.04-0.96; P = .0449) and basal-like (mOR: 0.24; 95% CI, 0.05-1.16; P =.0750) types. By contrast, the risk of locoregional recurrence was higher in the classical-type than in the basal-like-type (mOR: 5.03; 95% CI, 1.20-21.1; P = .0272). The hybrid-type was subclassified into transition and coexpression patterns with different gastric mucin expression levels. High levels of vimentin (≥10%, n = 30) in pre-NAC-PC tissues was associated with poor prognosis (P = .0256). Phenotypic transitions between pre-NAC and post-NAC-PCs were common (73/120; 61%). PCs with NAC regression grades 2 and 3 showed a transition to poorer prognostic phenotypes (P = .0497). KRAS mutations were not associated with these phenotypes. In conclusion, GATA6 and CK5 immunohistochemical expression phenotypes may stratify the survival of patients with NAC-PCs and reflect post-NAC phenotypic transitions associated with poor prognosis. Prompt evaluation of immunohistochemical phenotypes may contribute to designing a precision therapeutic strategy for patients with PCs.

Predictors of Long-Term Survival in Pancreatic Ductal Adenocarcinoma after Pancreatectomy: TP53 and SMAD4 Mutation Scoring in Combination with CA19-9.

BACKGROUND: Pancreatic ductal adenocarcinoma (PDA) is a fatal cancer for which even unfavorable clinicopathological factors occasionally fail to preclude long-term survival. We sought to establish a scoring system that utilizes measurable pre-intervention factors for predicting survival following surgical resection. METHODS: We retrospectively analyzed 34 patients who died from short-term recurrences and 32 long-term survivors among 310 consecutively resected patients with PDA. A logistic regression model was used to define factors related to clinical parameters, molecular profiles of 18 pancreatic cancer-associated genes, and aberrant expression of major tumor suppressors. RESULTS: Carbohydrate antigen 19-9 (CA19-9) had the best ability to classify patients with short-term recurrence and long-term survivors [odds ratio 21.04, 95% confidence interval (CI) 4.612-96.019], followed by SMAD4 and TP53 mutation scoring (odds ratio 41.322, 95% CI 3.156-541.035). Missense TP53 mutations were strongly associated with the nuclear expression of p53, whereas truncating mutations were associated with the absence of nuclear p53. The former subset was associated with a worse prognosis. The combination of aberrant SMAD4 and mutation types of TP53 exhibited a better resolution for distinguishing patients with short-term recurrences from long-term survivors (compared with the assessment of the number of mutated KRAS, CDKN2A, TP53, and SMAD4 genes). Calibration of mutation scores combined with CA19-9 in a logistic regression model setting demonstrated a practical effect in classifying long survivors and patients with early recurrence (c-statistic = 0.876). CONCLUSIONS: Genetic information, i.e., TP53 mutation types and SMAD4 abnormalities, combined with CA19-9, will be a valuable tool for improving surgical strategies for pancreatic cancer.

Case report of portal hepatic schwannoma: presentation of multimodality images.

BACKGROUND: Portal hepatic schwannoma is a rare benign tumor and difficult to diagnose preoperatively because of its rarity and imaging manifestations that mimic malignancy. We present a case of portal hepatic schwannoma that showed moderate contrast enhancement on computed tomography (CT), extension along the bile duct on T2-weighted imaging and magnetic resonance cholangiopancreatography (MRCP), and uptake of 18F-fluorodeoxyglucose (FDG) on positron emission tomography. CASE PRESENTATION: Ultrasonography at an annual health checkup identified a hepatic mass in a 38-year-old woman. CT showed a well-defined portal hepatic tumor with mild contrast enhancement. T2-weighted imaging and MRCP showed a clavate tumor extending along the intrahepatic bile ducts but no dilatation of the ducts. The tumor exhibited increased FDG uptake, such as maximum standardized uptake values of 5.0 and 6.5 in the early and late phases, respectively. Neither dilatation of intrahepatic bile ducts nor lymphadenopathy was identified, and the multimodality imaging suggested hepatic portal lymphoma, gastrointestinal tumor, or IgG4-related disease rather than cholangiocarcinoma. A needle biopsy via endoscopic ultrasonography was performed, and immunohistology confirmed the tumor as a schwannoma. CONCLUSIONS: The diagnosis of a portal hepatic schwannoma requires immunohistological examinations in addition to multimodality imaging studies to reflect fully the pathohistological characteristics of the tumor.

Intraductal papillary neoplasms of the bile duct consist of two distinct types specifically associated with clinicopathological features and molecular phenotypes.

Intraductal papillary neoplasm of the bile duct (IPNB) is a grossly visible papillary biliary neoplasm with morphological variations and occasional invasion. Recently a new classification of IPNB into type 1 and type 2 was proposed in which the type 1 IPNBs consist of fine papillary neoplastic glands and the type 2 IPNBs consist of complex branching glands, seldom with foci of solid-tubular components. However, clinicopathological and molecular characteristics of these types of IPNBs are yet to be identified. We aimed to uncover clinicopathological and molecular characteristics of the types of IPNBs. Thirty-six IPNBs were studied retrospectively. Clinicopathological features as well as molecular alterations of 31 genes were evaluated by means of targeted next-generation sequencing and immunohistochemical examination of expression of mucin and cancer-associated molecules. The 36 IPNBs were classified into 22 of type 1 and 14 of type 2. The type 1 IPNBs were associated with a non-invasive phenotype, intestinal and oncocytic subtypes, development in the intrahepatic bile duct, overt mucin production, and a relatively good prognosis. The type 2 IPNBs were associated with an invasive phenotype, the pancreatobiliary subtype, development within the extrahepatic bile duct, and worse prognosis compared with the type 1 IPNBs. In the molecular analysis, recurrent mutations were found in TP53 (34.3%), KRAS (31.4%), STK11 (25.7%), CTNNB1 (17.1%), APC (14.3%), SMAD4 (14.3%), GNAS (11.4%), PBRM1 (11.4%), ELF3 (8.6%), KMT2C (8.6%), NF1 (8.6%), PIK3CA (8.6%), ARID1A (5.7%), ARID2 (5.7%), BAP1 (5.7%), BRAF (5.7%), EPHA6 (5.7%), ERBB2 (5.7%), ERBB3 (5.7%), KMT2D (5.7%), and RNF43 (5.7%). Mutations in KRAS and GNAS were enriched in the type 1 IPNBs, whereas mutations in TP53, SMAD4, and KMT2C were enriched in the type 2 IPNBs. These results indicate that IPNBs consist of two distinct types of neoplasms specifically associated with clinicopathological features and molecular phenotypes. © 2020 Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Pathways of Progression From Intraductal Papillary Mucinous Neoplasm to Pancreatic Ductal Adenocarcinoma Based on Molecular Features.

BACKGROUND & AIMS: Intraductal papillary mucinous neoplasms (IPMNs) are regarded as precursors of pancreatic ductal adenocarcinomas (PDAs), but little is known about the mechanism of progression. This makes it challenging to assess cancer risk in patients with IPMNs. We investigated associations of IPMNs with concurrent PDAs by genetic and histologic analyses. METHODS: We obtained 30 pancreatic tissues with concurrent PDAs and IPMNs, and 168 lesions, including incipient foci, were mapped, microdissected, and analyzed for mutations in 18 pancreatic cancer-associated genes and expression of tumor suppressors. RESULTS: We determined the clonal relatedness of lesions, based on driver mutations shared by PDAs and concurrent IPMNs, and classified the lesions into 3 subtypes. Twelve PDAs contained driver mutations shared by all concurrent IPMNs, which we called the sequential subtype. This subset was characterized by less diversity in incipient foci with frequent GNAS mutations. Eleven PDAs contained some driver mutations that were shared with concurrent IPMNs, which we called the branch-off subtype. In this subtype, PDAs and IPMNs had identical KRAS mutations but different GNAS mutations, although the lesions were adjacent. Whole-exome sequencing and methylation analysis of these lesions indicated clonal origin with later divergence. Ten PDAs had driver mutations not found in concurrent IPMNs, called the de novo subtype. Expression profiles of TP53 and SMAD4 increased our ability to differentiate these subtypes compared with sequencing data alone. The branch-off and de novo subtypes had substantial heterogeneity among early clones, such as differences in KRAS mutations. Patients with PDAs of the branch-off subtype had a longer times of disease-free survival than patients with PDAs of the de novo or the sequential subtypes. CONCLUSIONS: Detailed histologic and genetic analysis of PDAs and concurrent IPMNs identified 3 different pathways by which IPMNs progress to PDAs-we call these the sequential, branch-off, and de novo subtypes. Subtypes might be associated with clinical and pathologic features and be used to select surveillance programs for patients with IPMNs.

Metachronous intraductal papillary mucinous neoplasms disseminate via the pancreatic duct following resection.

Metachronous development of intraductal papillary mucinous neoplasms in the remnant pancreas following resection is a significant clinical burden. Our aim was to characterize the clinicopathological and molecular features of the patients with metachronous tumor development to identify predictive factors and the possible route(s) of dissemination. Seventy-four patients who underwent resection of intraductal papillary mucinous neoplasms with no invasive compartment or associated carcinoma were retrospectively analyzed. In patients with metachronous tumor development, targeted sequencing of 18 genes associated with pancreatic tumorigenesis and immunohistochemical detection of four proteins (p53, SMAD4, p16, and ß-catenin) were performed on both primary and metachronous tumors. The distributions of microscopic neoplastic lesions were examined at surgical margins and in apparently normal tissue apart from the primary tumor. During the median follow-up period of 52 months, 9 patients (12%) developed metachronous tumors in the remnant pancreas. Primary tumors located in the body/tail of the pancreas (odds ratio, 15; 95% confidence interval, 1.6-131) and of the pancreatobiliary type (odds ratio, 6.1; 95% confidence interval, 1.1-35.7) were identified as significant risk factors for subsequent metachronous tumor development. Eight of the nine patients shared molecular aberrations between their primary and metachronous tumors, suggesting migrations from the primary tumor to the pancreatic duct as the cause of metachronous tumor development. Our data suggest that these post-resection metachronous tumors develop by skip dissemination of the primary tumor, potentially via the pancreatic duct. The development of strategies to better predict and prevent this form of tumor progression is necessary.

Detection of Myocardial Tissue Alterations in Hypertrophic Cardiomyopathy Using Texture Analysis of T2-Weighted Short Inversion Time Inversion Recovery Magnetic Resonance Imaging.

OBJECTIVE: The aim of this study was to evaluate the usefulness of texture analysis of T2-weighted short inversion time inversion recovery (T2-STIR) for detecting myocardial tissue alterations in hypertrophic cardiomyopathy (HCM). METHODS: Twenty patients with HCM and 11 controls were examined. Texture analysis was performed for the hypertrophied regions with and without and abnormal hyperintensity (AHI) and for the interventricular septum of the controls on T2-STIR. T2 mapping was performed to measure myocardial T2 values. RESULTS: A gray-level nonuniformity value of 64.7 was the best discriminator between patients and controls with an area under the curve of 0.93 on a receiver operating characteristic curve. T2 values did not differ between them. The gray-level nonuniformity was significantly smaller in AHI regions than in the hypertrophied regions without AHI in HCM patients. CONCLUSIONS: Texture analysis is useful for quantitatively detecting myocardial tissue altenations, including AHI, associated with HCM on T2-STIR.

[Pancreatic Leiomyosarcoma with a Difficult Preoperative Diagnosis-A Case Report].

A 43-year-old man was referred to our hospital for examination of a pancreatic tumor. Imaging revealed a mass-like lesion with a cyst in the pancreatic tail. Histological examination by EUS-FNA showed a low grade spindle cell lesion for which laparoscopic distal pancreatectomy was performed. The neoplasm was histologically diagnosed as pancreatic leiomyosarcoma. The postoperative course was uneventful and no signs of recurrence at 8 months after the surgery. Pancreatic leiomyosarcoma is very rare. Only 7 previous cases were reported in Japan. In tumors with diameters exceeding 50 mm, bleeding and necrosis occur inside the tumor and a cyst-like form often develops, which is considered a characteristic imaging finding. Therefore, imaging is important for preoperative differential diagnosis of the disease.

Successful treatment of uterine artery pseudoaneurysm with laparoscopic temporary clamping of bilateral uterine arteries, followed by hysteroscopic surgery.

Surgical strategies for the treatment of uterine artery pseudoaneurysm (UAP) include transarterial embolization and ultrasound-guided low-dose thrombin injection. Such strategies, however, have limitations and include the risk of ischemic damage to the uterus. We report a case of UAP treated with a new hysteroscopic and laparoscopic technique. A 29-year-old G1P0 woman with spontaneous abortion was transferred to the present institution because of hemorrhagic shock. We diagnosed ruptured UAP on transvaginal ultrasound with color Doppler. Emergency laparoscopic temporary clamping of the bilateral uterine arteries was done to reduce the bleeding, and transcervical resection to stop the hemorrhaging and to collect the pseudoaneurysm tissue. After surgery, blood flow to the myometrium was monitored on ultrasound. By postoperative day 48, normal menstruation had restarted, and no intrauterine adhesions were observed. On pathology of the UAP, a dilated spiral artery without its characteristic elastic fibers was identified. This surgical approach may help preserve fertility and allow for pathological diagnosis of UAP.

Abundance and distribution of dimethylsulfoniopropionate degradation genes and the corresponding bacterial community structure at dimethyl sulfide hot spots in the tropical and subtropical pacific ocean.

Dimethylsulfoniopropionate (DMSP) is mainly produced by marine phytoplankton but is released into the microbial food web and degraded by marine bacteria to dimethyl sulfide (DMS) and other products. To reveal the abundance and distribution of bacterial DMSP degradation genes and the corresponding bacterial communities in relation to DMS and DMSP concentrations in seawater, we collected surface seawater samples from DMS hot spot sites during a cruise across the Pacific Ocean. We analyzed the genes encoding DMSP lyase (dddP) and DMSP demethylase (dmdA), which are responsible for the transformation of DMSP to DMS and DMSP assimilation, respectively. The averaged abundance (±standard deviation) of these DMSP degradation genes relative to that of the 16S rRNA genes was 33% ± 12%. The abundances of these genes showed large spatial variations. dddP genes showed more variation in abundances than dmdA genes. Multidimensional analysis based on the abundances of DMSP degradation genes and environmental factors revealed that the distribution pattern of these genes was influenced by chlorophyll a concentrations and temperatures. dddP genes, dmdA subclade C/2 genes, and dmdA subclade D genes exhibited significant correlations with the marine Roseobacter clade, SAR11 subgroup Ib, and SAR11 subgroup Ia, respectively. SAR11 subgroups Ia and Ib, which possessed dmdA genes, were suggested to be the main potential DMSP consumers. The Roseobacter clade members possessing dddP genes in oligotrophic subtropical regions were possible DMS producers. These results suggest that DMSP degradation genes are abundant and widely distributed in the surface seawater and that the marine bacteria possessing these genes influence the degradation of DMSP and regulate the emissions of DMS in subtropical gyres of the Pacific Ocean.

Measurement of air-sea exchange of dimethyl sulfide and acetone by PTR-MS coupled with gradient flux technique.

We developed a new method for in situ measurement of air-sea fluxes of multiple volatile organic compounds (VOCs) by combining proton transfer reaction-mass spectrometry (PTR-MS) and gradient flux (GF) technique. The PTR-MS/GF system was first deployed to determine the air-sea flux of VOCs in the open ocean of the western Pacific, in addition to carbon dioxide and water vapor. Each profiling at seven heights from the ocean surface up to 14 m took 7 min. In total, 34 vertical profiles of VOCs in the marine atmosphere just above the ocean surface were obtained. The vertical gradient observed was significant for dimethyl sulfide (DMS) and acetone with the best-fit curves on quasi-logarithmic relationship. The mean fluxes of DMS and acetone were 5.5 ± 1.5 and 2.7 ± 1.3 µmol/m(2)/day, respectively. These fluxes are in general in accordance with those reported by previous expeditions.

Evaluating production rates of particulate organic hydrogen by marine phytoplankton for estimating phytoplanktonic productivity of organically bound tritium.

To estimate the production potential of organically bound tritium (OBT) by phytoplankton from tritiated water in coastal areas adjacent to the Fukushima Daiichi Nuclear Power Plant (FDNPP), phytoplanktonic production rates of particulate organic hydrogen (POH) were evaluated in laboratory and field experiments using stable isotope tracers (2H and 13C). In the laboratory experiment, the production rate of POH was evaluated for five types of phytoplankton cultivated cultures (two diatoms, Haptophyceae, Chlorophyceae, and Cryptophyceae) at two temperatures (15 °C and 25 °C) and two 2H concentrations in the medium (1 and 5%). Additionally, the production rate of POH was especially focused on non-exchangeable POH (NE-POH) which is the chemical form of hydrogen connected tightly to organic matter. The production rates of NE-POH in the laboratory experiment varied (0.10 to 36 µmol L-1 d-1 µg-Chl a-1) with the productivity of particulate organic carbon, phytoplankton species, and temperature, with negligible influence of 2H concentrations. In the field experiment, in situ incubation of coastal seawater at water depths of 1 and 20 m with isotope tracers under light and dark conditions, respectively, was performed thrice (November 2021, May 2022, and October 2022) on the Pacific coastal ocean approximately 2 km from the land of northeast Japan. We observed variation in the production rate of POH (0.21 to 3.1 µmol L-1 d-1 µg-Chl a-1), which was theoretically explained by the data in the laboratory experiment. Using the phytoplanktonic production rate of POH obtained in this study, OBT production by phytoplankton and the subsequent accumulation potential of OBT in sediments in the coastal area adjacent to FDNPP were tentatively estimated, results of which suggested this potential to be small.