Intracardiac metastasis of gestational choriocarcinoma: a case report and literature review

INTRODUCTION

Gestational trophoblastic neoplasia (GTN) with intracardiac metastasis is rare, and here we reported a patient with intracardiac metastasis of high-risk and refractory gestational choriocarcinoma and reviewed relevant literatures.

CASE PRESENTATION

A 37-year-old woman presented with vaginal bleeding and high level of β-human chorionic gonadotropin (β-hCG) at 199,060 (mIU/mL). It was clinically diagnosed with gestational choriocarcinoma. The patient initially received eight cycles of chemotherapy but unsatisfactory response was observed, and the level of β-hCG still ranged between 5000 and 10,000. Then there was found intracardiac masses in the right atrium (2.6*1.7 cm), anterior chordae tendineae of the tricuspid valve (1.4*0.7 cm) and the right ventricle (4.1*2.9 cm) by ultrasonic cardiogram (UCG). PET/CT highly suspected the intracardiac metastasis of choriocarcinoma (SUVmax = 9.3) and no disease was found in the lung and pelvis. The patient undertook complete intracardiac masses resection. The pathology confirmed the intracardiac metastasis of disease. After a week of operation, the UCG found a 5.4*4.2 cm mass in the right atrium again. Considering the poor prognosis, the patient received palliative care and eventually died of disease progression.

CONCLUSION

Intracardiac metastasis of GTN is an aggressive sign of disease. Patients can benefit from chemotherapy and surgery. Future investigation of PD-1 immunotherapy combines with chemotherapy are expected to improve the prognosis in this group of patients.

B7-H4 Further Stratifies Patients With Endometrial Cancer Exhibiting a Nonspecific Molecular Profile

CONTEXT.—

Endometrial cancer is classified into 4 molecular subtypes: DNA polymerase epsilon ultramutated, mismatch repair deficient, p53 mutant, and nonspecific molecular profile (NSMP). Additional biomarkers are urgently needed to better characterize the NSMP subtype, the largest group with heterogeneous pathologic features and prognoses.

OBJECTIVE.—

To investigate the expression of B7 homolog 3 (B7-H3), B7 homolog 4 (B7-H4), and V-set and immunoglobulin domain containing 3 (VSIG-3, a ligand for B7-H5) in 833 patients with endometrial cancer and determine their associations with clinicopathologic and molecular features as well as survival outcomes.

DESIGN.—

Molecular classification was determined by polymerase epsilon sequencing and immunohistochemical staining for p53 and mismatch repair proteins. B7-H3, B7-H4, VSIG-3, and programmed death ligand-1 (PD-L1) were detected via immunohistochemistry.

RESULTS.—

The positivity rates for B7-H3 in each of the tumor and immune cells, B7-H4 (exclusively in tumor cells), and VSIG-3 (exclusively in tumor cells) were 89.0%, 42.3%, 71.5%, and 99.8%, respectively. B7-H3 and B7-H4 positivity in tumor cells was associated with favorable pathologic features and prognosis. In contrast, B7-H3 expression in immune cells was frequent in samples with unfavorable pathologic features; those with p53-mutant subtype, PD-L1 positivity, and a high density of CD8+ T cells; and in patients with poor prognoses. Positive B7-H4 expression was a predictor of improved survival in patients with the NSMP subtype independent of tumor stage or pathologic features.

CONCLUSIONS.—

The NSMP subgroup of endometrial cancer can be further stratified by B7-H4 status. Incorporating B7-H4 status into the molecular classification of NSMP could improve the ability to predict disease relapse.

Clinicopathological analysis of patients with molecularly confirmed stage I adult granulosa cell tumors and prediction of recurrence

OBJECTIVE

Adult granulosa cell tumors (AGCTs) are rare malignancies that accounts for approximately 1% of ovarian neoplasms. As there are currently no well-recognized models for predicting relapse-free survival (RFS), we performed a clinicopathological analysis to identify risk factors for AGCT recurrence.

METHODS

We investigated 130 patients with pathologically diagnosed AGCT as confirmed by the presence of the characteristic FOXL2 C402G mutation.

RESULTS

Most patients had International Federation of Gynecology and Obstetrics stage I disease (n = 122, 95.3%). The 10-year RFS rate was 31.4% (22/70) and mean 10-year RFS was 74.4 (95% CI, 65.2-83.7) months. Ten patients experienced recurrence beyond the 10-year follow-up period. Undergoing fertility sparing surgery, an estrogen receptor-α (ERα) score (>0.25), and a Ki-67 index >15% were independent risk factors for recurrence in patients with stage I disease (bias-corrected C-index: 0.776). We constructed a nomogram with well-fitting calibration plots; the areas under the curve (AUCs) for 5-, and 10-year RFS prediction were 0.883 and 0.906 respectively. A simplified model with 3 predictive factors (ERα score, Ki-67 index, and primary surgical procedure) and 2 risk stratification subgroups (low- and high-risk) was constructed; its AUCs for 5-, and 10-year RFS prediction were 0.825 and 0.850 respectively. Kaplan-Meier survival curves showed significant differences in 10-year RFS between the low- and high-risk groups (p < 0.001).

CONCLUSIONS

The type of primary surgical procedure, ERα score, and Ki-67 index are independent predictors of recurrence for patients with stage I AGCT. Our predictive model based on these factors showed good performance.

Solid Pseudopapillary Neoplasms of the Pancreas: Clinicopathologic Analysis and a Predictive Model

Solid pseudopapillary neoplasms (SPNs) of the pancreas are rare. They are considered low-grade malignancies, and a small percentage of patients experience recurrence or metastasis. It is critical to investigate associated biological behavior and identify patients at a risk of relapse. This was a retrospective study of 486 patients with SPNs who were diagnosed between 2000 and 2021. Their clinicopathologic features, including 23 parameters and prognoses were analyzed. Six patients (1.2%) presented with synchronous liver metastasis. A total of 21 patients experienced recurrence or metastasis postoperatively. The overall and disease-specific survival rates were 99.8% and 100%, respectively. The 5- and 10-year relapse-free survival (RFS) rates were 97.4% and 90.2%, respectively. Tumor size, lymphovascular invasion, and the Ki-67 index were independent predictors of relapse. Furthermore, a Peking Union Medical College Hospital-SPN risk model was built to evaluate the risk of relapse and compared it with the American Joint Committee on Cancer tumor staging system (eighth edition, 2017). Risk factors included 3 parameters: tumor size (>9 cm), lymphovascular invasion status (presence), and Ki-67 index (>1%). Risk grades were available for 345 patients, who were divided into 2 groups: (1) low risk (n = 124) and (2) high risk (n = 221). The group with no risk factors was designated as low risk and had a 10-year RFS of 100%. The group associated with 1 to 3 factors was designated as high risk, with a 10-year RFS of 75.3%. Receiver operating characteristic curves were generated, and the area under the curve was 0.791 for our model and 0.630 for the American Joint Committee on Cancer with respect to the cancer staging system. We validated our model in independent cohorts and demonstrated a sensitivity of 98.3%. In conclusion, SPNs are low-grade malignant neoplasms that rarely metastasize, and the 3 selected pathologic parameters can be used to predict their behavior. A novel Peking Union Medical College Hospital-SPN risk model was proposed for routine application to guide the patient counseling in clinical practice.

[Research progress in anti-reflux reconstructions and mechanism after proximal gastrectomy]

The electrophysiological activity of the gastrointestinal tract and the mechanical anti-reflux structure of the gastroesophageal junction are the basis of the anti-reflux function of the stomach. Proximal gastrectomy destroys the mechanical structure and normal electrophysiological channels of the anti-reflux. Therefore, the residual gastric function is disordered. Moreover, gastroesophageal reflux is one of the most serious complications. The emergence of various types of anti-reflux surgery through the mechanism of reconstructing mechanical anti-reflux barrier and establishing buffer zone, and the preservation of, the pacing area and vagus nerve of the stomach, the continuity of the jejunal bowel, the original gastroenteric electrophysiological activity of the gastrointestinal tract, and the physiological function of the pyloric sphincter, are all important measures for gastric conservative operations. There are many types of reconstructive approaches after proximal gastrectomy. The design based on the anti-reflux mechanism and the functional reconstruction of mechanical barrier, and the protection of gastrointestinal electrophysiological activities are important considerations for the selected of reconstructive approaches after proximal gastrectomy. In clinical practice, we should consider the principle of individualization and the safety of radical resection of tumor to select a rational reconstructive approaches after proximal gastrectomy.

Expression and Prognostic Value of B7 Family Immune Checkpoints in Pancreatic Neuroendocrine Tumors

CONTEXT.—

Pancreatic neuroendocrine tumors (PanNETs) are rare malignancies with heterogeneous clinical courses requiring novel prognosticators and therapies. B7 family molecules have an important role in various cancers; however, these have not been distinguished in PanNETs.

OBJECTIVE.—

To investigate the expression and clinical significance of programmed death ligand-1 (PD-L1), programmed death ligand-2 (PD-L2), B7 homolog 3 (B7-H3), B7 homolog 4 (B7-H4), and V-domain immunoglobulin suppressor of T-cell activation (VISTA) in 182 PanNETs (with a high proportion of functioning versus nonfunctioning PanNETs: 51% versus 49%).

DESIGN.—

Molecules were immunostained by using tissue microarrays from 182 patients with grade 1/2 PanNETs. VISTA-positive microvessel density (VISTA+ MVD) was evaluated in 4 high-power fields (HPFs) (×200) and mean count was calculated; immune cells with 1% or greater VISTA staining were considered positive. PD-L1 tumoral expression was considered positive in samples with 5% or more membranous staining. Tumoral VISTA, stromal PD-L1, PD-L2, B7-H3, and B7-H4 expression were deemed positive if any staining was observed.

RESULTS.—

VISTA+ MVD was high (≥10.8/HPF) in 45 patients (25%), while VISTA stained positively on immune and tumor cells in 121 (66%) and 0 patients, respectively. Positive PD-L1 tumoral and stromal expression was observed in 23 (13%) and 0 patients, with positive B7-H3 expression in 76 (42%) and 98 (54%) patients, respectively, in these cells; PD-L2 and B7-H4 were not detected. PD-L1 positivity rate was high in functioning PanNETs. Stromal B7-H3 and high VISTA+ MVD correlated with unfavorable clinicopathologic features. Moreover, high VISTA+ MVD was an independent predictor of shorter progression-free survival.

CONCLUSIONS.—

VISTA may serve as a prognosticator and immunotherapeutic target for patients with pancreatic neuroendocrine tumor (PanNET).

Incorporating Molecular Classification When Stratifying the Survival Risk of Patients with High-Grade Endometrial Carcinomas

Assessing survival risk in patients with high-grade endometrial carcinomas has remained challenging. We aimed to investigate the distribution of molecular subtypes and assess their prognostic role in a large cohort of 355 patients with high-grade endometrial carcinoma. Molecular classification was determined using DNA polymerase epsilon (POLE) sequencing as well as immunohistochemical staining for p53 and mismatch repair (MMR) proteins. Endometrial carcinomas were stratified into four subtypes: POLE ultramutated, MMR-deficient, non-specific molecular profile (NSMP), and p53-mutant. This study included 177 and 178 patients with endometrioid and non-endometrioid carcinomas, respectively. Forty-two patients (11.8%) were categorized as POLE ultramutated, 106 (29.9%) as MMR-deficient, 128 (36.1%) as p53-mutant, and 79 (22.2%) as NSMP. Patients of different molecular subtypes had distinct survival times; molecular classification, but not histotype, was significantly associated with survival outcomes. When incorporating molecular classification into the stratification model, 52 patients (15.5%) switched risk groups, with 40 (11.9%) shifting to a lower risk for having a POLE mutation and 12 (3.6%) shifting to a higher risk owing to p53-mutant status. Molecular classification may provide more accurate prognostic information among patients with high-grade endometrial carcinomas and improve their stratification for purposes of clinical management.

Expression of the immune targets in tumor-infiltrating immunocytes of gestational trophoblastic neoplasia

Objectives: To evaluate the expression of emerging immune targets in the tumor-infiltrating immunocytes (TIIs) of human gestational trophoblastic neoplasia (GTN) specimens, and to analyze the correlation between the expression patterns and prognosis of GTN patients. Methods: Between January 2008 and December 2017, patients who were diagnosed histologically with GTN were included in this study. The expression densities of LAG-3, TIM-3, GAL-9, PD-1, CD68, CD8, and FOXP3 in the TIIs were assessed independently by two pathologists blinded to clinical outcomes. The expression patterns and correlation with patient outcomes were analyzed to identify prognostic factors. Results: We identified 108 patients with GTN, including 67 with choriocarcinoma, 32 with placental site trophoblastic tumor (PSTT), and 9 with epithelioid trophoblastic tumor (ETT). Almost all GTN patients showed expression of GAL-9, TIM-3, and PD-1 in TIIs (100%, 92.6%, and 90.7%, respectively); LAG-3 was expressed in 77.8% of the samples. The expression densities of CD68 and GAL-9 were significantly higher in choriocarcinoma than that in PSTT and ETT. The TIM-3 expression density in choriocarcinoma was higher than that in PSTT. In addition, the expression density of LAG-3 in the TIIs of choriocarcinoma and PSTT was higher than that in ETT. There was no statistical difference in the expression pattern of PD-1 among different pathological subtypes. The positive expression of LAG-3 in tumor TIIs was a prognostic factor for disease recurrence, and patients with positive expression of LAG-3 in the TIIs had poorer disease-free survival (p = 0.026). Conclusion: Our study evaluated the expression of immune targets PD-1, TIM-3, LAG-3, and GAL-9 in the TIIs of GTN patients and found that they were widely expressed but not associated with patients' prognoses, excepting the positive expression of LAG-3 was a prognostic factor for disease recurrence.

Expression of B7 family checkpoint proteins in cervical cancer

The role of programmed cell death-ligand 1 (PD-L1) in cervical cancer has been widely investigated; however, the influences of other inhibitory B7 family members are poorly understood. We investigated the expression of PD-L1, B7 homolog 3 (B7-H3), B7-H4, and V-domain Ig suppressor of T-cell activation (VISTA) and their association with the clinicopathological features and outcomes of a large cohort of 673 patients with squamous cell carcinoma or adenocarcinoma of the uterine cervix. The positivity rates for PD-L1 (combined positive score ≥1), B7-H3 in tumor cells (TCs), B7-H4 (exclusively in TCs), VISTA in immune cells (ICs), and VISTA in TCs were 57.9%, 62.8%, 44.8%, 92.6%, and 4.8%, respectively, in 606 primary cervical cancer samples. Co-expression of PD-L1 with B7-H3 in TCs and with B7-H4 and VISTA in ICs was observed in 38.8%, 25.4%, and 57.9% of samples, respectively. B7-H3 in TCs and B7-H4 and VISTA in ICs were observed in 58.1%, 46.6%, and 83.1% of PD-L1-negative samples, respectively. These proteins were observed more frequently in squamous cell carcinomas and in moderately to poorly differentiated carcinomas. VISTA (in ICs) and B7-H4 were more frequent in primary tumors than in recurrent counterparts and correlated with improved survival; in contrast, B7-H3 positivity in TCs was less frequent in primary tumors and correlated with short disease-specific survival. Co-expression of B7-H4 and VISTA in ICs was an independent predictor of favorable outcomes overall and among patients with PD-L1-negative tumors. These data indicate that B7 family proteins exhibit differing expression patterns, distributions, and prognostic implications in cervical cancer. Furthermore, the co-expression of PD-L1 with other checkpoint proteins suggests that PD-1/PD-L1 blockade combined with modulating other immune checkpoints may present a novel therapeutic approach for cervical cancer. Future studies are needed to validate prognostic values of B7 family proteins and explore their biological roles in this malignancy.

[History and present situation of seromuscular flap anastomosis in proximal gastrectomy]

With the increasing detection rate of early upper gastric cancer and adenocarcinoma of esophagogastric junction, the safety of proximal gastrectomy with clear indications has been verified, and function-preserving proximal gastrectomy has been widely used. However, proximal gastrectomy destructs the normal anatomical structure of esophagogastric junction, resulting in severe postoperative gastroesophageal reflux symptoms and seriously affecting the quality of life. Among various anti-reflux surgery methods, reconstruction of "cardiac valve" has always been the focus of relevant scholars because its similarity with the mechanism of normal anti-reflux. After years of development, evolution and optimization, the designed seromuscular flap anastomosis includes tunnel muscle flap anastomosis, Hatafuku valvuloplasty, single muscle flap anastomosis and double muscle flap anastomosis. The double muscle flap anastomosis has become a research hotspot because it shows good anti-reflux effect in clinical application. This paper reviews the history, research status and hot issues of seromuscular flap anastomosis of esophageal remnant stomach at home and abroad.

[Current status and progress in the standardized surgical management of specimens after radical gastric cancer surgery]

Standardized surgical management of postoperative specimens of gastric cancer is an important part of the standardized diagnosis and treatment of gastric cancer. It can reflect the accurate number and detailed distribution of lymph nodes in the specimen and lay the foundation for accurate and standardized pathological reports after surgery. Meanwhile, it can evaluate the scope of intraoperative lymph node dissection, the safety of cutting edge, and the standardization of surgery (principle of en-bloc dissection), which is an important means of surgical quality control. It also provides accurate research samples for further research and is an important way for young surgeons to train their clinical skills. The surgical management of postoperative specimens for gastric cancer needs to be standardized, including specimen processing personnel, processing flow, resection margin examination, lymph node sorting, measurement after specimen dissection, storage of biological specimens, documentation of recorded data, etc. The promotion of standardized surgical management of specimens after radical gastrectomy can promote the homogenization of gastric cancer surgical diagnosis and treatment in medical institutions and further promote the high-quality development of gastric cancer surgery in China.

A Novel Signature Based on m6A RNA Methylation Regulators Reveals Distinct Prognostic Subgroups and Associates with Tumor Immunity of Patients with Pancreatic Neuroendocrine Neoplasms

INTRODUCTION

The RNA N6-methyladenosine (m6A) regulators play a crucial role in tumorigenesis and could be indicators of prognosis and therapeutic targets in various cancers. However, the expression status and prognostic value of m6A regulators have not been studied in pancreatic neuroendocrine neoplasms (PanNENs). We aimed to investigate the expression patterns and prognostic value of m6A regulators and assess their correlations with immune checkpoints and infiltrates in PanNENs.

METHODS

Immunohistochemistry was performed for 15 m6A regulators and immune markers using tissue microarrays obtained from 183 patients with PanNENs. The correlation between m6A protein expression and clinicopathological parameters with recurrence-free survival (RFS) was examined using a random survival forest, Cox regression model, and survival tree analysis.

RESULTS

Among the 15 m6A proteins, high expression of YTHDF2 (p < 0.001) and HNRNPC (p = 0.006) was found to be significantly associated with recurrence and served as independent risk factors in multivariate analysis. High YTHDF2 expression was associated with higher number of CD3+ T cells (p = 0.003), whereas high HNRNPC expression was significantly correlated with the expression of PD-L1 (p = 0.039). A YTHDF2-based signature was determined, including five patterns from survival tree analysis: patients with the LNnegYTHDF2high signature had a 5-year RFS rate of 92.1%, whereas patients with LNposTumorSize＜2.5 cm signature had the worst 5-year RFS rate of 0% (p < 0.001). The area under receiver operating characteristic curve was 0.870 (95% confidence interval: 0.762-0.915) for the YTHDF2-based signature. The C-index was 0.978, suggesting good discrimination ability; moreover, the risk score of recurrence served as an independent prognostic factor indicating shorter RFS.

CONCLUSIONS

YTHDF2 appears to serve as a promising prognostic biomarker and therapeutic target. A YTHDF2-based signature can identify distinct subgroups, which may be helpful to strategize personalized postoperative monitoring.

Clinicopathological and molecular characterization of high-grade endometrial carcinoma with POLE mutation: a single center study

Objective

The molecular classification system of endometrial carcinoma (EC) in ‘The Cancer Genome Atlas’ is widely acknowledged for its prognostic utility. Subsequently, more simplified classification system that incorporate DNA polymerase epsilon (POLE) exonuclease domain mutations, mismatch repair deficiencies (MMRd), and abnormal p53 (P53abn) has also demonstrated its clinical utility. These classifications helped identifying a ‘POLE ultramutated’ (POLEmut) category of patients, most of whom show excellent prognoses despite having high-grade ECs. We aimed to investigate the clinicopathological and molecular characteristics of high-grade ECs with POLEmut.

Methods

We investigated 414 patients with high-grade ECs (including endometrioid carcinomas grade 3, serous carcinomas, clear cell carcinomas, mixed carcinomas, undifferentiated and dedifferentiated carcinomas, and carcinosarcomas) by sequencing and immunohistochemical staining.

Results

Forty-three tumors (10.4%) were classified as POLEmut, including 2 with new, possibly pathogenic POLE mutations at P286C and L424V. These patients had very good prognoses except for 1 with stage IV disease and residual tumor. Eleven patients in this group also had P53abn and 4 had MMRd; molecular analysis revealed that patients with synchronous POLE pathogenic mutation and other mutations had a POLEmut or MMRd phenotype; survival analysis found no difference in prognosis between these patient categories. The prognoses of patients in the POLEmut EC group were not significantly influenced by treatment or risk category.

Conclusions

Patients with high-grade EC exhibiting POLEmut have very good clinical outcomes, and should be identified urgently in daily work owing to their conflicting morphology. Our findings also provide guidance on subclassifying ECs with poor histological appearance.

We investigated patients with high-grade endometrial carcinoma (EC) exhibiting POLEmut. We identified 2 new POLE mutations that are possibly pathogenic. All our 43 patients except for the one with stage IV disease had good prognoses. The prognoses of patients with POLEmut EC were not significantly influenced by treatment or risk level.

High Mast Cell Density Predicts a Favorable Prognosis in Patients with Pancreatic Neuroendocrine Neoplasms

INTRODUCTION

Mast cells are involved in allergic diseases, immune regulation, and tumor microenvironment modulation, with both pro- and anti-tumorigenic functions, and could serve as a prognostic factor in various cancers. However, their potential role in pancreatic neuroendocrine neoplasms (PanNENs) is largely unknown. Here, our aim was to investigate the presence of mast cells in PanNENs and evaluate their association with clinicopathological parameters and other common tumor-infiltrating immune cells.

METHODS

Tissue microarrays containing PanNEN samples from 187 patients were constructed and stained immunohistochemically for CD117, CD15, CD68, CD3, CD4, and CD8. Immune cells were counted from four high-power fields (HPFs; ×400) at maximal concentrations, and the mean counts were calculated per HPF. The cutoff values were set by X-tile.

RESULTS

The median (interquartile range) counts of CD117+ mast cells, CD15+ neutrophils, CD68+ macrophages, CD3+ T cells, and CD4+ T cells were 3.5 (2.0-6.0), 3.0 (1.3-6), 3.8 (2.5-5.8), 13 (8.0-24.0), and 2.0 (1.0-4.0)/HPF, respectively. CD8+ T cells were not detected. The cutoff values for these immune cells were 1.5/HPF, 6/HPF, 4.8/HPF, 32.5/HPF, and 2/HPF, respectively. Low mast cell density was correlated with higher grades, noninsulinoma, and advanced stages. Moreover, high mast cell infiltration was associated with elevated CD4+ T cell and CD15+ neutrophil counts. Multivariate analysis revealed that high mast cell density was an independent predictor of prolonged progression-free survival in the entire cohort; in pancreatic neuroendocrine tumors; and in intermediate-grade, noninsulinoma, and advanced stage subgroups.

CONCLUSIONS

These findings suggest a protective role of mast cells in PanNENs.

Camrelizumab plus apatinib in patients with high-risk chemorefractory or relapsed gestational trophoblastic neoplasia (CAP 01): a single-arm, open-label, phase 2 trial

BACKGROUND

Treatment options for patients with high-risk chemorefractory or relapsed gestational trophoblastic neoplasia are scarce. The synergistic antitumour effect of immunotherapy and antiangiogenic drugs has been shown in many solid tumours. This phase 2 trial evaluated the activity and safety of camrelizumab (PD-1 inhibitor) plus apatinib (VEGF receptor inhibitor) in patients with high-risk chemorefractory or relapsed gestational trophoblastic neoplasia.

METHODS

This was a single-arm, open-label, phase 2 trial, done at a single tertiary health-care centre in Beijing, China. Women (18-70 years) with high-risk (International Federation of Gynecology and Obstetrics score ≥7) chemorefractory or relapsed gestational trophoblastic neoplasia who had received at least two lines of previously unsuccessful multidrug chemotherapy regimens and had an Eastern Cooperative Oncology Group performance status of 0-2 were eligible for inclusion. Patients received 4-week cycles of intravenous camrelizumab 200 mg every 2 weeks plus oral apatinib 250 mg once per day until disease progression or unacceptable toxicity. The primary endpoint was objective response rate assessed according to serum human chorionic gonadotrophin concentration. Activity and safety were analysed in all patients who received at least one dose of study drug. The study is ongoing, but recruitment is complete. The study is registered with ClinicalTrials.gov, NCT04047017.

FINDINGS

Between Aug 7, 2019, and March 18, 2020, 20 patients enrolled; 19 (95%) were diagnosed with choriocarcinoma and one (5%) had placental site trophoblastic tumour. The median follow-up duration was 18·5 months (IQR 14·6-20·9). The objective response rate was 55% (95% CI 32-77); ten (50%; 95% CI 27-73) patients had complete response. The most common grade 3 treatment-related adverse events were hypertension (five [25%] patients), rash (four [20%] patients), neutropenia (two [10%]), leukocytopenia (two [10%]), and aspartate aminotransferase increase (two [10%]). One patient had a treatment-related serious adverse event (aspartate aminotransferase 19-times higher than the upper limit of normal). No grade 4 or 5 treatment-related adverse events were reported.

INTERPRETATION

Camrelizumab plus apatinib showed promising antitumour activity and acceptable toxicity and could be a salvage therapy option for the treatment of high-risk chemorefractory or relapsed gestational trophoblastic neoplasia. Immune checkpoint inhibitors combined with chemotherapy for heavily-treated patients and upfront use of camrelizumab plus apatinib for patients with high-risk gestational trophoblastic neoplasia are under investigation in phase 2 trials.

FUNDING

National Natural Science Foundation of China, Jiangsu Hengrui Pharmaceuticals.

[Application of modified Kamikawa anastomosis in digestive tract reconstruction after proximal gastrectomy]

Objective: Traditional Kamikawa anastomosis in digestive tract reconstruction after proximal gastrectomy can greatly decrease the anastomosis-related complications and reduce the incidence of reflux esophagitis, but its complexity limits the wide application. To decrease the complexity of Kamikawa anastomosis, the surgical team of Changzhi People's Hospital of Shanxi Changzhi Medical College improved this technique by using novel notion and reduced surgical procedures. This study aims to evaluate the efficacy and safety of modified Kamikawa anastomosis in digestive tract reconstruction after proximal gastrectomy. Methods: A descriptive cohort study was carried out. Case enrollment criteria: (1) upper gastric carcinoma or esophagogastric junction carcinoma without distant metastasis was confirmed by preoperative gastroscopic biopsy and imaging examination; (2) tumor diameter was less than 4 cm; (3) preoperative clinical staging was cT1-3N1M0. Exclusion criteria: (1) patients received preoperative neoadjuvant chemotherapy; (2) patients had severe heart or lung disease, or poor nutritional status so that they could not tolerate surgery. Clinical data of 25 patients with upper gastric carcinoma or esophagogastric junction carcinoma who underwent modified Kamikawa anastomosis in digestive tract reconstruction in Heji Hospital (8 cases) and Changzhi People's Hospital (17 cases) from April 2019 to December 2020 were retrospectively collected. Of 25 patients, 21 were male and 4 were female, with mean age of 63.0 (49 to 78) years; 3 underwent open surgery and 22 underwent laparoscopic surgery. The modified Kamikawa anastomosis was as follows: (1) the novel notion of total mesangial resection of the esophagogastric junction was applied to facilitate the thorough removal of lymph nodes and facilitate hand-sewn anastomosis and embedding; (2) the diameter of the anastomotic stoma was selected according to the diameter of the esophageal stump, between 2.5 and 3.5 cm, to reduce the occurrence of anastomotic stenosis; (3) an ultrasonic scalpel was used to incise the esophageal stump, which could not only prevent bleeding of the esophageal stump, but also closely seal the esophageal mucosa, muscle layer and serosa to prevent esophageal mucosa retraction; (4) barbed suture was used to suture the remnant stomach fundus and esophagus to fix the stomach fundus in order to reduce the cumbersome and difficult intermittent sutures in a small space; (5) two barbed sutures were used to continuously suture the front and back walls of the anastomosis and complete the suture and fixation of the muscle flap. Relevant indicators of surgical safety, postoperative complications (using the Clavien-Dindo classification), esophageal reflux symptoms and the occurrence of esophagitis (using Los Angeles classification) were analyzed. The gastroesophageal reflux disease (GERD) score, gastroscopy, multi-position digestive tract radiography during postoperative follow-up were used to evaluate the residual gastric motility and anti-reflux efficacy. Results: Modified Kamikawa anastomosis in digestive tract reconstruction after proximal gastrectomy was successfully performed in 25 patients. The surgical time was (5.8±1.8) hours, the intraoperative blood loss was (89.2±11.8) ml, and the average hospital stay was (13.8±2.9) days. Three cases (12.0%) developed postoperative anastomotic stenosis as Clavien-Dindo grade III and were healed after endoscopic dilation treatment. Postoperative upper gastrointestinal radiography showed 1 case (4.0%) with reflux symptoms as Clavien-Dindo grade I. Gastroscopy showed no signs of reflux esophagitis, and its Los Angeles classification was A grade. No anastomotic bleeding, local infection and death were found in all the patients. At postoperative 6-month of follow-up, GERD score showed no significant difference compared to pre-operation (2.7±0.6 vs. 2.4±1.0, t=-1.495, P=0.148). Conclusion: Modified Kamikawa anastomosis in digestive tract reconstruction after proximal gastrectomy is safe and feasible with good anti-reflux efficacy.

Expression of B7-H3 Correlates with PD-L1 and Poor Prognosis in Patients with Cervical Cancer

Purpose

The purpose of this study was to investigate B7 homolog 3 (B7-H3) expression patterns and define its associations with programmed cell-death ligand 1 (PD-L1), pathological features, and survival in patients with cervical cancer.

Patients and Methods

Immunohistochemical staining was used to investigate B7-H3 and PD-L1 expression in tissue microarrays from 552 patients with stage IB1 and IIA1 cervical cancer, including 406 with squamous cell carcinoma and 146 with endocervical adenocarcinoma.

Results

B7-H3 was expressed in the tumor cells (TCs) of 32.1% of the samples as well as in the stromal cells of 92.9% of the specimens. B7-H3 was co-expressed with PD-L1 in 21.0% of the samples, while only one or the other was expressed in 41.7% of the samples. B7-H3 expression in TCs was more frequent in squamous cell carcinoma, PD-L1-positive samples, and tissues from patients with lymph node metastasis; moreover, its expression was an independent predictor of shorter survival.

Conclusion

B7-H3 positivity in TCs is a promising prognostic biomarker, and targeting B7-H3 alone or in combination with PD-1/PD-L1 may be a potential immunotherapeutic strategy for patients with cervical cancer.

PD-L1 expression in tumor cells is associated with a favorable prognosis in patients with high-risk endometrial cancer

OBJECTIVE

To investigate programmed cell death ligand 1 (PD-L1) expression patterns and define the associations among PD-L1, molecular subtypes, pathological features, and survival in a cohort of 833 patients with endometrial cancer, of whom approximately half had high-risk disease.

METHODS

Using direct sequencing of the polymerase epsilon (POLE) exonuclease domain as well as immunohistochemistry for mismatch repair (MMR) proteins (MLH1, PMS2, MSH2, and MSH6) and p53, we stratified endometrial cancers into four molecular subtypes: POLE ultramutated, MMR-deficient, p53-mutant, and non-specific molecular profile (NSMP). PD-L1 was detected via immunohistochemistry and evaluated in tumor cells (TCs) and immune cells (ICs) individually and using the combined positive score (CPS).

RESULTS

Positive PD-L1 staining in TCs (≥1%), ICs (≥1%), and in combination (CPS ≥1) was detected in 14.0%, 37.3%, and 45.1% of the samples, respectively. PD-L1 positivity in TCs was more frequent in high-grade than in low-grade tumors, while that in ICs was associated with lymphovascular space invasion, non-endometrioid histology, and deep myometrial invasion. PD-L1 expression in both TCs and ICs was more frequent in POLE ultramutated and MMR-deficient subtypes than in p53-mutant and NSMP subtypes. PD-L1 positivity in TCs, but not in ICs or combined (CPS), was associated with a favorable prognosis in patients with high-risk endometrial cancer.

CONCLUSIONS

The distribution and prognostic significance of PD-L1 in TCs versus ICs differ in patients with endometrial cancer, indicating that the separate assessment of PD-L1 in these cells (rather than determining the CPS) may be more relevant to selecting patients eligible for endometrial cancer immunotherapy.

LncRNA LncOGD-1006 alleviates OGD-induced ischemic brain injury regulating apoptosis through miR-184-5p/CAAP1 axis

OBJECTIVE

This study aimed to explore the effect of long non-coding RNA (LncRNA) LncOGD-1006 to ischemic stroke and the possible mechanism.

MATERIALS AND METHODS

The primary brain microvascular endothelial cells (bEnd.3) of oxygen-glucose deprivation (OGD) was used as a mimic of ischemic stroke in vitro.

RESULTS

The results showed that LncOGD-1006 was upregulated in bEnd.3 after OGD-induced.

CONCLUSIONS

LncOGD-1006 might act as a ceRNA to inhibit apoptosis in bEnd.3 cells by targeting miR-184-5p/CAAP1 pathway.

[Current status of research on standardized management of specimens after radical gastrectomy for gastric cancer]

The quality control and standardization of procedures in radical gastrectomy for gastric cancer, especially the standardized processing of specimens after radical gastrectomy for gastric cancer, is very important. It is not only the basis of accurate pathological staging, but also the evidence of surgical quality and the original data of clinical research, which plays a pivotal role. The examination and classification of lymph nodes, specimens processing records, and data uploading and archiving after radical gastrectomy for gastric cancer are indispensable. It is necessary for surgeons to participate in the processing of surgical specimens. This article will combine the current research status and progress at home and abroad to review the standardized processing of specimens after radical gastrectomy for gastric cancer.

Upregulated MicroRNA-483-3p is an Early Event in Pancreatic Ductal Adenocarcinoma (PDAC) and as a Powerful Liquid Biopsy Biomarker in PDAC

Background

There is an urgent need for the development of effective noninvasive biomarkers for early pancreatic cancer diagnosis. MicroRNAs (miRNAs) are promising candidates that can be identified in peripheral blood and can act as "liquid biopsy" biomarkers. miR-483-3p is overexpressed in the tumor tissue of pancreatic duct adenocarcinoma, but its potential as noninvasive biomarker remains unknown.

Methods

We conducted locked nucleic acid in situ hybridization (LNA-ISH) for miR-483-3p in archival tissues of 107 patients with PDAC. We also used immunohistochemistry to evaluate SMAD4 expression, the putative miR-483-3p target gene. miR-483-3p expression level was also assessed using quantitative real-time PCR (qRT-PCR) in serum and serum exosome samples from 63 patients with PDAC and 22 healthy individuals.

Results

LNA-ISH showed that miR-483-3p was overexpressed in PDAC and PanIN tissues compared to normal pancreatic duct cells. miR-483-3p expression levels correlated with increases in PanIN lesion grade. miR-483-3p expression negatively correlated with Smad4 expression (γ=-0.770, p<0.0001) in PDAC and PanIN tissues. Circulating miR-483-3p levels were significantly elevated in the serum and serum exosomes of PDAC patients compared to healthy controls (p<0.0001 and p<0.01, respectively). Specifically, serum miR-483-3p levels were able to distinguish patients with early stage (≤2cm) PDAC from healthy controls with an AUC of 0.83 [95% CI, 0.70-0.96]. Higher serum exosomal miR-483-3p levels predicted worse survival in PDAC patients and serum exosomal miR-483-3p also proved to be an independent prognostic factor for PDAC (hazard ratio = 3.307; 95% CI=1.104 to 9.903; p=0.033). In vitro studies also showed that miR-483-3p promoted pancreatic cancer cell migration and invasion.

Conclusion

miR-483-3p overexpression occurs early in PDAC development and is present in premalignant PanIN lesions. Serum miR-483-3p may act as an early PDAC diagnostic biomarker and serum exosomal miR-483-3p may be a PDAC prognostic biomarker.

Operative and Oncological Outcomes Comparing Sentinel Node Mapping and Systematic Lymphadenectomy in Endometrial Cancer Staging: Meta-Analysis With Trial Sequential Analysis

Objective

To evaluate the utility of sentinel lymph node mapping (SLN) in endometrial cancer (EC) patients in comparison with lymphadenectomy (LND).

Methods

Comprehensive search was performed in MEDLINE, EMBASE, CENTRAL, OVID, Web of science databases, and three clinical trials registration websites, from the database inception to September 2020. The primary outcomes covered operative outcomes, nodal assessment, and oncological outcomes. Software Revman 5.3 was used. Trial sequential analysis (TSA) and Grading of Recommendations Assessment, Development, and Evaluation (GRADE) were performed.

Results

Overall, 5,820 EC patients from 15 studies were pooled in the meta-analysis: SLN group (N = 2,152, 37.0%), LND group (N = 3,668, 63.0%). In meta-analysis of blood loss, SLN offered advantage over LND in reducing operation bleeding (I² = 74%, P<0.01). Z-curve of blood loss crossed trial sequential monitoring boundaries though did not reach TSA sample size. There was no difference between SLN and LND in intra-operative complications (I² = 7%, P = 0.12). SLN was superior to LND in detecting positive pelvic nodes (P-LN) (I² = 36%, P<0.001), even in high risk patients (I² = 36%, P = 0.001). While no difference was observed in detection of positive para-aortic nodes (PA-LN) (I² = 47%, P = 0.76), even in high risk patients (I² = 62%, P = 0.34). Analysis showed no difference between two groups in the number of resected pelvic nodes (I² = 99%, P = 0.26). SLN was not associated with a statistically significant overall survival (I² = 79%, P = 0.94). There was no difference in progression-free survival between SLN and LND (I² = 52%, P = 0.31). No difference was observed in recurrence. Based on the GRADE assessment, we considered the quality of current evidence to be moderate for P-LN biopsy, low for items like blood loss, PA-LN positive.

Conclusion

The present meta-analysis underlines that SLN is capable of reducing blood loss during operation in regardless of surgical approach with firm evidence from TSA. SLN mapping is more targeted for less node dissection and more detection of positive lymph nodes even in high risk patients with conclusive evidence from TSA. Utility of SLN yields no survival detriment in EC patients.

Emerging Targets of Immunotherapy in Gynecologic Cancer

Although programmed cell death protein 1/programmed death-ligand 1 (PD-1/PD-L1) and cytotoxic T lymphocyte antigen-4 (CTLA-4) have been successfully applied in the treatment of tumors, their efficiency is still not high enough. New immune targets need to be identified in order to seek alternative treatment strategies for patients with refractory tumors. Immune targets can be divided into stimulating and inhibiting molecules according to their function after receptor-ligand binding. We herein present a compendious summary of emerging immune targets in gynecologic tumors. These targets included coinhibitory molecules, such as T cell immunoglobulin-3 (TIM-3), T cell immunoglobulin and ITIM domain (TIGIT), lymphocyte activation gene-3 (LAG-3), V-type immunoglobulin domain-containing suppressor of T cell activation (VISTA), and B7-H3 and B7-H4, and co-stimulatory molecules, such as CD27, OX40, 4-1BB, CD40, glucocorticoid-induced tumor necrosis factor receptor (GITR) and inducible co-stimulator (ICOS). In this review, the characteristics and preclinical/clinical progress of gynecological malignancies are briefly discussed. However, the potential mechanisms and interactions of immune targets need to be elucidated in further studies.

[Current status of anti-reflux surgery of proximal gastrectomy for esophagogastric junction tumor]

In recent years, the overall incidence of gastric cancer has been decreasing worldwide, while the incidence of the esophagogastric junction tumor is increasing year by year. With the progress of the diagnostic technology of upper gastrointestinal tumors and the gradual popularization of early cancer screening, the detection rate of early esophagogastric junction tumor keeps increasing. Therefore, in recent years, the clinical application of gastric function preserving surgery is gradually increasing. As an important part of the surgical treatment strategy of esophagogastric junction tumors, proximal gastrectomy has attracted more and more attention with the confirmation of oncological safety. Compared with total gastrectomy, patients after proximal gastrectomy have better nutritional status and quality of life. However, the high incidence of reflux esophagitis after traditional proximal gastrectomy has seriously affected the quality of life of patients, and also hindered the application of proximal gastrectomy in esophagogastric junction tumors. How to reduce the occurrence of reflux esophagitis after proximal gastrectomy by optimizing the method of digestive tract reconstruction has been a big challenge in clinical practice. This article reviews the current methods of anti-reflux surgery for proximal gastrectomy for esophagogastric junction tumors, aiming to provide a reference for choosing a reasonable anti-reflux surgery.

Genome-wide Analyses Identify a Novel Risk Locus for Nonsyndromic Cleft Palate

The 3 major subphenotypes observed in patients with nonsyndromic orofacial clefts (NSOFCs) are nonsyndromic cleft lip only (NSCLO), nonsyndromic cleft lip with palate (NSCLP), and nonsyndromic cleft palate only (NSCPO). However, the genetic architecture underlying NSCPO is largely unknown. Here we performed a 2-stage genome-wide association study (GWAS) on NSCPO and replication analyses of selected variants in other NSOFCs from the Chinese Han population. We identified a novel locus (15q24.3) and a known locus (1q32.2) where variants in or near the gene reached genome-wide significance (2.80 × 10^-13 < P < 1.72 × 10^-08) in a test for association with NSCPO in a case-control design. Although a variant from 15q24.3 was found to be significantly associated with both NSCPO and NSCLP, the direction of estimated effects on risk were opposite. Our functional annotation of the risk alleles within 15q24.3 coupled with previously established roles of the candidate genes within identified risk loci in periderm development, embryonic patterning, and/or regulation of cellular processes supports their involvement in palate development and the pathogenesis of cleft palate. Our study advances the understanding of the genetic basis of NSOFCs and provides novel insights into the pathogenesis of NSCPO.

Correction to: Expression of the immune checkpoint VISTA in breast cancer

The original version of this article unfortunately contained a mistake. The correct information is given below.

Management and risk factors of recurrent gestational trophoblastic neoplasia: An update from 2004 to 2017

OBJECTIVE

We investigated the clinical characteristics, treatments, and survival of patients with gestational trophoblastic neoplasia (GTN) who experienced recurrence. Factors predictive of recurrence were also investigated.

METHODS

Patients with GTN who recurred after completing chemotherapy at Peking Union Medical College Hospital Trophoblastic Disease Center were identified between January 2004 and December 2017. Logistic regression analysis was used to identify factors predictive of GTN recurrence.

RESULTS

A total of 1827 patients with GTN achieved complete remission (CR) at our center, of whom 118 (6.5%) experienced recurrence during follow-up. The recurrence rates for patients initially treated at our center and those referred to us were 2.7% and 14.6%, respectively. The majority of recurrent patients received floxuridine-based multiagent chemotherapy (n = 64). Patients who underwent surgery achieved a significantly higher CR rate than those who did not (88.6% vs 61.1%, P = .001). Although 94.1% of recurrent patients reachieved CR, 33.3% of them recurred for a second time. The 5-year survival rate of the entire cohort was 80.4%. An interval between antecedent pregnancy and chemotherapy >12 months (OR: 6.600, 95% CI [3.217-13.540], P < .001), and an interval from first chemotherapy to achieving β-human chorionic gonadotropin (β-hCG) normalization >14 weeks (OR: 2.226, 95% CI [1.080-4.588], P = .030) were predictors of recurrence.

CONCLUSIONS

Patients with recurrent GTN are prone to recurring for a second time. Surgery plays a beneficial role in the management of recurrent GTN. An interval between antecedent pregnancy and chemotherapy >12 months, and an interval from first chemotherapy to achieving β-hCG normalization >14 weeks were predictors of recurrence.

CD105 overexpression mediates drug-resistance in choriocarcinoma cells through BMP9/Smad pathway

Background: CD105 (endoglin, ENG) is a membranous protein that is overexpressed in tumor-associated endothelial cells and some actual tumor cells and is associated with poor prognosis. However, the association between CD105 and response to chemoresistance in choriocarcinoma cells has not been clearly defined. The present study aimed to investigate the effects of targeting CD105 in drug-resistant choriocarcinoma.

Methods: CD105 expression was evaluated in drug-resistant and parental choriocarcinoma cells by qRT-PCR, western blotting, and immunofluorescence. CD105 overexpressing and knockdown cells were established by lentiviral transfection. CCK8, transwell, and flow cytometric assays were used to measure changes in drug-sensitivity, invasion, migration, and apoptosis. Drug-sensitivity and Smad1/5/8, Smad2, and Smad3 expression were also detected after BMP9 treatment. Immunohistochemical staining for CD105 and BMP9 was performed on choriocarcinoma tissues and the relationships between clinical and pathological characteristics were analysed.

Results: Data demonstrated that CD105 overexpression could decrease drug sensitivity, promote invasion and migration, and inhibit apoptosis in choriocarcinoma cells, and this protein was confirmed to mediate drug resistance through the BMP9/Smad pathway. Further experiments showed that the expression of CD105 and BMP9 was consistent in choriocarcinoma tissues and significantly associated with disease recurrence.

Conclusions: This study provides evidence suggesting that CD105 is critical for the development of drug-resistance in choriocarcinoma and might serve as a therapeutic target for reversing chemoresistance in choriocarcinoma patients.

The tumor-stroma ratio is an independent predictor of survival in patients with 2018 FIGO stage IIIC squamous cell carcinoma of the cervix following primary radical surgery

OBJECTIVE

To determine the value of the tumor-stroma ratio (TSR) while identifying prognostic factors in patients with 2018 International Federation of Gynecology and Obstetrics (FIGO) stage IIIC squamous cell carcinoma of the cervix following primary radical surgery.

METHODS

Three hundred eighty-four patients with node-positive squamous cell carcinoma of the cervix (2018 FIGO stage IIIC) who underwent radical surgery between January 2005 and December 2016 were included in this retrospective study. The TSRs were assessed on hematoxylin and eosin-stained tumor slides and classified as stroma-low (<50% stroma) or stroma-high (≥50% stroma).

RESULTS

Sixty-seven patients were categorized as stroma-high; they had shorter disease-free survival (DFS) and overall survival (OS) periods than did their stroma-low counterparts. On multivariate analysis, a tumor size ≥4 cm, ≥3 metastatic lymph nodes, and stroma-high status were independent predictors of shorter DFS and OS. These factors were incorporated into a prognostic scoring system in which patients were categorized into low- (score 0), intermediate- (score 1), and high-risk (scores 2-3) groups. The scoring system differentiated DFS and OS well (C-index = 0.65, 95% confidence interval, 0.59-0.72; and C-index = 0.65, 95% confidence interval, 0.59-0.72, respectively).

CONCLUSIONS

The TSR is an independent prognostic factor, and our prognostic scoring system that incorporates this parameter exhibits good discriminative ability for both recurrence and survival in patients with 2018 FIGO stage IIIC cervical cancer after radical surgery. The TSR is a potentially novel clinicopathological variable for predicting the prognoses of these patients contingent on the validation of our findings.

VISTA expression is associated with a favorable prognosis in patients with high-grade serous ovarian cancer

Blockading programmed death ligand 1 (PD-L1) shows promising results in patients with some cancers, but not in those with ovarian cancer. V-domain Ig suppressor of T cell activation (VISTA) is a recently discovered immune checkpoint protein that suppresses T cell activation. This study aimed to investigate the expression and clinical significance of VISTA in ovarian cancer as well as its relationship with PD-L1. VISTA and PD-L1 levels in 146 ovarian cancer samples were assessed using immunohistochemistry. We investigated the association between VISTA and other clinicopathological variables, including survival. The associations between the VISTA-encoding C10orf54 gene, other immune checkpoints, and survival were analyzed. VISTA was detected in 51.4% of all samples and 46.6% of PD-L1-negative samples; it was expressed in 28.8%, 35.6%, and 4.1% of tumor cells (TCs), immune cells (ICs), and endothelial cells, respectively. Furthermore, VISTA expression was associated with pathologic type and PD-L1 expression. Moreover, VISTA expression in TCs, but not in ICs, was associated with prolonged progression-free and overall survival in patients with high-grade serous ovarian cancer. The expression of C10orf54 mRNA was associated with prolonged overall survival and immune escape-modulating genes. These results showed that VISTA expression in ovarian tumor cells was associated with a favorable prognosis in patients with high-grade serous ovarian cancer; however, additional studies are required to better understand the expression and role of VISTA in ovarian cancer.

Diagnosis and Management of Mixed Gestational Trophoblastic Neoplasia: A Study of 16 Cases and a Review of the Literature

Objective: Mixed gestational trophoblastic neoplasia (GTN) is a rare occurrence that refers to the coexistence of choriocarcinoma and/or placental site trophoblastic tumor and/or epithelioid trophoblastic tumor. The diagnosis and management of mixed GTN are challenging. We investigated the clinicopathological characteristics, diagnoses, treatments, and outcomes of patients with mixed GTN.

Materials and Methods: The medical records and pathological sections of 16 patients with mixed GTN who were treated at Peking Union Medical College Hospital and The Second Xiangya Hospital of Central South University between January 2012 and December 2018 were reviewed.

Results: Pretreatment serum human chorionic gonadotropin (hCG) levels ranged from 180 to 625,024 IU/L, and were >10,000 IU/L in 14 of the 16 patients, none of whom were diagnosed correctly at initial presentation. Two patients were diagnosed with choriocarcinoma coexisting with intermediate trophoblastic tumor (ITT) through dilation and curettage (D&C) before treatment. Another 5 patients were histologically confirmed to have placental site trophoblastic tumor (PSTT) by D&C but final pathological findings showed mixed PSTT and choriocarcinoma at subsequent hysterectomy. Seven post-chemotherapy patients with an initial clinical diagnosis of choriocarcinoma underwent surgery because of chemoresistance and their pathological findings revealed coexisting ITT. The remaining 2 patients were found to have choriocarcinoma coexisting with ITT following cervical biopsy and pulmonary lobectomy. All patients received chemotherapy: 14 underwent surgery combined with chemotherapy and 2 received chemotherapy alone to preserve fertility. Other than 1 patient who died of disease progression, 15 patients (93.8%) achieved complete remission (CR) after treatment, although 5 (33.3%) relapsed. Of these 5 patients with relapse, 3 achieved CR after additional treatment, 1 was receiving an immune checkpoint inhibitor, and 1 was lost to follow-up after refusing further therapy.

Conclusion: Mixed GTN is difficult to diagnose on initial presentation. Overlap of the ITT component should be considered in refractory chemoresistant choriocarcinoma. Coexistence of choriocarcinoma should be suspected in ITT patients with high hCG levels. Surgery combined with chemotherapy is optimal treatment for choriocarcinoma mixed with ITT.

Oncological Outcomes and Safety of Ovarian Preservation for Early Stage Adenocarcinoma of Cervix: A Systematic Review and Meta-Analysis

Objectives: To evaluate the oncological outcomes and safety of ovarian preservation, and to review the prognostic factors for ovarian metastases in early stage cervical adenocarcinoma.

Methods: PubMed, Embase, and Cochrane databases were searched for publications up to January 2019. Two investigators independently screened the studies for eligibility and extracted specific data. The primary outcomes were overall survival (OS) and progression-free survival (PFS). Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were calculated using STATA statistical software version 19.0.

Results: A total of 68 unique manuscripts were identified through the search strategy, and 10 studies were included in the meta-analysis of the safety of ovarian preservation. Fixed-effects model was used because of moderate heterogeneity. Pooled results of the included studies showed that ovarian preservation is not associated with a statistically significant OS (OR 1.00, 95% CI 0.64–1.56, I² = 25.7%) or PFS (OR 0.98, 95% CI 0.57–1.66, I² = 0%) in early stage cervical adenocarcinoma. In addition, 19 studies were included in the review of prognostic factors for cervical adenocarcinoma and risk factors for ovarian metastases. The incidence of ovarian metastases was 0% in stage IA, 2.8% in stage IB, 3.4% in stage IIA, and 11.8% in stage IIB cervical adenocarcinoma. International Federation of Gynecology and Obstetrics (FIGO) stage, tumor size, deep stromal invasion (DSI), lymph node metastasis (LNM), and vaginal invasion were significantly related to poor prognosis. Risk factors associated with ovarian metastases included age, FIGO stage, tumor size, DSI, parametrial invasion, corpus uteri invasion, LNM, vaginal invasion, and blood vessel invasion.

Conclusions: Ovarian preservation in young patients with early stage cervical adenocarcinoma is safe and has no significant effect on OS or PFS. Preserving ovaries in patients with FIGO stage IIB seems not reasonable because of the high rate of ovarian metastasis.

PD-L1, B7-H3 and VISTA are highly expressed in gestational trophoblastic neoplasia

AIMS

The B7 family check-point molecules are potential therapeutic targets in cancer immunotherapy. However, their expression status in human gestational trophoblastic neoplasia (GTN) remains unknown. We investigated the expression profiles of the B7 family check-point proteins PD-L1, PD-L2, B7-H3, B7-H4, VISTA and B7-H6 in GTN and their clinical significance.

METHODS AND RESULTS

We identified 112 patients with GTN, including 68 with choriocarcinoma, 33 with placental-site trophoblastic tumour (PSTT) and 11 with epithelioid trophoblastic tumour (ETT). Immunohistochemical staining was performed on whole-tissue GTN sections using anti-B7 family antibodies. VISTA expression was immunohistochemically analysed using microarrays of normal human tissues and of 20 common cancers. PD-L1 and B7-H3 were highly expressed in all GTN tumours, while PD-L2 was expressed in 87.5% of the samples. B7-H4 and B7-H6 were negative in 100% and 98.2% of the samples, respectively. PD-L1, B7-H3 and VISTA levels were significantly higher in choriocarcinomas and PSTTs than in ETTs. There was no association between B7 family check-point expression in tumour cells and disease stage, prognostic score or patient outcomes (complete remission versus death). VISTA protein was widely overexpressed in 98.2% of all the GTN, but its expression varied in other cancer types and was negative in normal adult and fetal tissues except placental trophoblasts and splenic lymphocytes.

CONCLUSIONS

The GTN trophoblast cells show high expression of PD-L1, B7-H3 and VISTA in a manner that is independent of clinical outcomes. These proteins may be potential immunotherapeutic targets when treating GTN.

Carcinoma of the lower female genital tract in patients with genitourinary malformations: a clinicopathologic analysis of 36 cases

Background: Lower genital tract carcinomas that coexist with genitourinary malformations are rare. The aim of this study was to investigate the clinicopathologic characteristics and outcomes of patients with this rare joint condition. The aim of this study was to investigate the clinicopathologic characteristics and outcomes of these patients to analyze the associations among clinicopathologic features in this rare entity.

Methods: The medical records of patients with carcinoma of lower genital tract combined with genital tract malformations who were treated at Peking Union Medical College Hospital (Beijing, China) between January 1995 and December 2017 were retrospectively reviewed and a comprehensive literature review was performed. The correlations between variables were determined using Fisher's exact test.

Results: Thirty-six patients were identified, among whom 22 had cervical carcinoma, 10 had vaginal carcinoma, and two had carcinomas of both the cervix and vagina. The most common genital tract anomaly was uterus didelphys (n=17), and 63.9% of patients had with urinary tract malformations. Twenty-five (69.4%) had pathologically confirmed adenocarcinoma, 10 (27.8%) had squamous cell carcinoma (SCC), and 1 had adenosquamous carcinoma. Patients with urinary tract malformations developed adenocarcinoma more frequently than those without malformations (95.7% vs. 30.8% P<0.001). Compared with patients with SCC, patients with adenocarcinoma presented at a younger age (36.1 vs. 47.0 years, P=0.011), had more advanced stages disease (57.7% vs. 10.0% were in stage II-IV, P=0.022), and tended to have poorer five-year overall survival rates (75.6% vs. 100.0%, P=0.279).

Conclusions: Patients with simultaneous malformations of the genital and urinary tracts had a high probability of developing adenocarcinoma. It is recommended that rigorous gynecologic exams with Pap smears and imaging analyses be performed periodically in women with genital malformations, as they may be at a risk of genital malignancies.

Cervical cancer in women aged 25 years or younger: a retrospective study

Purpose

The incidence of cervical cancer in young women is increasing. This study aimed to analyze the clinicopathological characteristics, treatment, and prognoses of women aged ≤25 years with cervical cancer.

Patients and methods

Medical record data of 60 cervical cancer patients aged ≤25 years treated at Peking Union Medical College Hospital between January 1986 and December 2017 were reviewed. The overall survival rate was estimated using the Kaplan–Meier method. Prognosis-related risk factors were analyzed using univariate and multivariate analyses.

Results

Among the 60 patients, 44 (73.3%) were diagnosed with cervical carcinoma and 16 (26.7%) with cervical sarcoma. In the cervical carcinoma group, the most common histology was squamous cell carcinoma (n=22, 50.0%) followed by adenocarcinoma (n=18, 40.9%). Notably, clear cell carcinoma dominated cervical adenocarcinomas at 61.1% (11/18). In the cervical sarcoma group, embryonal rhabdomyosarcoma comprised 50% of the cases (8/16). A total of eleven patients with cervical carcinoma underwent fertility-sparing surgeries, and the live birth rate approached 66.7%. The estimated 5-year overall survival rate of the entire cohort was 79.8% with no statistically significant difference between the carcinoma and sarcoma groups (74.3% vs 93.3%, P=0.14). Stage (RR 6.71, 95% CI 1.366–32.970, P=0.019) and lymph node metastasis (RR 9.09, 95% CI 1.050–78.732, P=0.045) were independent risk factors for poor prognosis in those young patients with cervical carcinoma.

Conclusion

Adenocarcinoma and sarcoma of the cervix comprise the majority of cervical cancer in young women; their overall prognoses are not worse than older patients; the survival rates tend to vary widely according to histologic subtypes.

Epithelioid Trophoblastic Tumors: Treatments, Outcomes, and Potential Therapeutic Targets

Background: Epithelioid trophoblastic tumors (ETTs) are the rarest type of gestational trophoblastic neoplasias. We investigated the clinical features, treatments, outcomes, and prognostic factors in patients with ETT, and explored potential therapeutic targets. Methods: We retrospectively analyzed the clinical features, treatments, survival, and prognostic factors of 21 ETT patients treated at our institution between January 2002 and December 2017. Expression levels of programmed cell death 1 (PD-1), PD-1 ligands (PD-L1and PD-L2), B7 family ligands (B7-H3, B7-H4, V-domain Ig suppressor of T cell activation [VISTA], and B7-H6), and CD105 expression were assessed by immunohistochemistry. Results: Fourteen patients with ETT (66.7%) presented with irregular vaginal bleeding. Three stage I patients (14.3%) with normal β-human chorionic gonadotropin (β- hCG) levels underwent hysterectomy alone. Of the remaining 18 patients who had elevated β-hCG levels (85.7%), 1 received chemotherapy and 17 underwent surgery and multi-agent chemotherapy. After treatment, 17 patients (81.0%) achieved complete remission (2 of whom [11.8%] later relapsed) and 4 (19.0%) with stage IV died of their disease. On univariate and multivariate analyses, stage IV disease was an independent prognostic factor for overall and disease-free survival (P < 0.001). PD-L1, B7-H3, and CD105 were detected in 100% of samples, PD-L2 and VISTA in 82%, B7-H6 in 18%, and B7-H4 was undetectable in ETT cells. Conclusions: Hysterectomy and metastatic lesion resection are essential for controlling ETT. Surgery plus chemotherapy are recommended for patients with abnormal β-hCG levels and metastatic disease. PD-L1, PD-L2, B7-H3, VISTA and CD105 are potential therapeutic targets for metastatic ETT.

Roles of B7-H3 in Cervical Cancer and Its Prognostic Value

B7-H3, which has been reported to be a co-regulatory ligand of the B7 family, can suppress T cell-mediated immunity and has also been reported to be expressed in many malignancies. In this study, we found that B7-H3 was primarily expressed in the cytoplasm of cervical cancer cells and was associated with deep stromal invasion (P=0.0013). The disease-free survival data showed that cervical cancer patients whose tumours were positive for B7-H3 expression had higher mortality rates compared with patients whose tumours lacked B7-H3 expression (P=0.0317), representing an advantage over P16 (P=0.3486). In contrast, the level of serum B7-H3 was low in cases of cervical intraepithelial neoplasia and cervical cancer. The silencing of B7-H3 in the SiHa, CaSki and H8 cell lines inhibited cell proliferation and enhanced apoptosis, while the over-expression of B7-H3 in HeLa cells showed inverse changes. These changes were partially due to the regulation of cell cycle- and apoptosis-related proteins, such as E2F, P21, P16, PARP-1, Caspase-8, Bax, Bcl-2 and Bcl-xl. The results of in vivo experiments revealed that the knockdown of B7-H3 in tumour cells suppressed SiHa cell growth in nude mice. Overall, B7-H3 is involved in the development and progression of cervical intraepithelial neoplasia and cervical cancer through its effects on the cell cycle and apoptosis, which are mediated via the E7/Rb pathway. B7-H3 also has the potential to be a useful prognostic marker for patients with cervical cancer.

Management and prognosis of patients with liver metastases from gestational trophoblastic neoplasia: a retrospective cohort study

Purpose

The aims of this study were to analyze the clinical features, identify prognostic factors, and evaluate the survival outcomes of gestational trophoblastic neoplasia (GTN) patients with liver metastases.

Patients and methods

Forty patients with liver metastases arising from GTNs, who were treated at the Peking Union Medical College Hospital (Beijing, People’s Republic of China) between January 1999 and December 2015, were recruited from the institutional database, and their medical records were reviewed. Univariate and multivariate analyses were performed to identify independent risk factors for survival.

Results

Twenty-seven patients (67.5%) achieved complete remission after multidrug chemotherapy treatment. The remaining 13 patients (32.5%) had disease progression. Eighteen patients (45.0%) died during treatment or follow-up. A history of failed multidrug chemotherapy was an independent risk factor for survival (OR: 5.57, 95% CI: 1.42–21.86, P=0.014). Moreover, patients with an International Federation of Gynecology and Obstetrics (FIGO) score of >16 had a significantly poorer survival than those with a score of ≤16 (P<0.001).

Conclusion

GTN with liver metastasis is a very rare disease with a relatively poor prognosis. Patients with a history of failed multidrug chemotherapy and a FIGO score of >16 have poorer survival outcomes. Multidrug chemotherapy is the key to the management of GTN patients with liver metastases.

Acquired uterine arteriovenous fistula due to a previous cornual pregnancy with placenta accreta: A case report

The present report describes a case of an acquired uterine arteriovenous fistula, which, following surgery and postoperative pathological analysis, was confirmed as a previous cornual pregnancy with placenta accreta. The patient was a 37-year-old woman (gravida 3; para 2) who had previously delivered two children via cesarean section (in 2004 and 2010, respectively) and also had a spontaneous abortion (2008). She had experienced continuous menstrual bleeding for ~20 days and had a history of prolonged (~30 days) vaginal bleeding 13 months earlier. Other pregnancy-related diseases were excluded following a negative serum human chorionic gonadotropin test, and the diagnosis was confirmed by Doppler ultrasonography. An emergency hysterectomy was subsequently performed due to the large amount of vaginal bleeding. Postoperative pathology confirmed the uterine arteriovenous malformation and demonstrated that the cause was a previous cornual pregnancy with placental implantation. The patient successfully recovered following the surgery.

[Clinical research of differences of volume of pharyngeal cavity between normal healthy subjects and patients with severe obstructive sleep apnea hypopnea syndrome]

Objective:To investigate the differences of volume of pharyngeal cavity between normal healthy subjects and patients with severe obstructive sleep apnea hypopnea syndrome(OSAHS)before and after surgery and its application value in assessment of surgical curative effect.Method:Forty-four healthy male adults were included in normal group.Thirty-eight patients with severe OSAHS diagnosed by polysomnography were included in experimental group(OSAHS group). Volume of pharyngeal cavity, oropharynx and laryngopharynx measured by acoustic pharyngealmetry and AHI, obstructive apnea frequency and the lowest oxygen saturation recorded by PSG monitor were all obtained in normal groups and experimental groups before and 3 months after the surgery. All the data are statistically analyzed. Result:Volume of pharyngeal cavity,AHI,obstructive apnea frequency and lowest oxygen saturation of patients in experimental group were all improved after surgery compared with pre-operation(P<0.01). Conclusion: The measurement of pharyngeal cavity volume is helpful to the quantitative analysis of upper airway structure and determine the stenosis location, it is also useful to guide surgery and evaluate the curative effect of the surgery.

High frequency of OTOF mutations in Chinese infants with congenital auditory neuropathy spectrum disorder

Auditory neuropathy spectrum disorder (ANSD) is one of the most common diseases leading to hearing and speech communication barriers in infants and young children. The OTOF gene is the first gene identified for autosomal recessive non-syndromic ANSD, and patients with OTOF mutations have shown marked improvement of auditory functions from the cochlear implantation, but the true involvement of OTOF mutations in Chinese ANSD patients is still unknown which precludes the effective management of this disease. Here, we investigated the contribution of OTOF mutations to congenital ANSD patients in China. In all, 37 infants and young Children with ANSD were screened for all the exons of OTOF gene, of them 34 patients had no neonatal risk factors who were considered as congenital ANSD. The clinical manifestation and audiometric features were also investigated and compared in patients with and without OTOF mutations. In all, 14 of these subjects were shown to carry two or three mutant alleles of OTOF with the high frequency of 41.2% in congenital ANSD patients. In total, 15 novel pathogenic mutations and 10 reported mutations were identified. Our results confirmed that mutations in OTOF gene were a major cause of congenital ANSD in China. Identification of OTOF mutations can facilitate diagnosis, clinical intervention and counseling for congenital ANSD.

Connexin26 (GJB2) deficiency reduces active cochlear amplification leading to late-onset hearing loss

Connexin26 (Cx26, GJB2) mutations account for >50% of nonsyndromic hearing loss. The deafness is not always congenital. A large group of these patients (∼30%) demonstrate a late-onset hearing loss, starting in childhood. They have normal hearing early in life and are therefore good candidates for applying protective and therapeutic interventions. However, the underlying deafness mechanism is unclear. In this study, we used a time-controlled, inducible gene knockout technique to knockout Cx26 expression in the cochlea after birth. We found that deletion of Cx26 after postnatal day 5 (P5) in mice could lead to late-onset hearing loss. Similar to clinical observations, the mice demonstrated progressive, mild to moderate hearing loss. The hearing loss initiated at high frequencies and then extended to the middle- and low-frequency range. The cochlea showed normal development and had no apparent hair cell loss. However, distortion product otoacoustic emission (DPOAE) was reduced. The reduction was also progressive and large at high-frequencies. Consistent with DPOAE reduction, we found that outer hair cell electromotility-associated nonlinear capacitance was shifted to the right and the slope of voltage dependence was reduced. The endocochlear potential was reduced in Cx26 conditional knockout (cKO) mice but the reduction was not associated with progressive hearing loss. These data suggest that Cx26 deficiency may impair active cochlear amplification leading to late-onset hearing loss. Our study also helps develop newer protective and therapeutic interventions to this common nonsyndromic hearing loss.

Edaravone protects endotoxin-induced liver injury by inhibiting apoptosis and reducing proinflammatory cytokines

Studies have shown that edaravone may prevent liver injury. This study aimed to investigate the effects of edaravone on the liver injury induced by D-galactosamine (GalN) and lipopolysaccharide (LPS) in female BALB/c mice. Edaravone was injected into mice 30 min before and 4 h after GalN/LPS injection. The survival rate was determined within the first 24 h. Animals were killed 8 h after GalN/LPS injection, and liver injury was biochemically and histologically assessed. Hepatocyte apoptosis was measured by TUNEL staining; proinflammatory cytokines [tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6)] in the liver were assayed by ELISA; expression of caspase-8 and caspase-3 proteins was detected by Western blot assay; and caspase-3 activity was also determined. Results showed that GalN/LPS induced marked elevations in serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT). Edaravone significantly inhibited elevation of serum AST and ALT, accompanied by an improvement in histological findings. Edaravone lowered the levels of TNF-α and IL-6 and reduced the number of TUNEL-positive cells. In addition, 24 h after edaravone treatment, caspase-3 activity and mortality were reduced. Edaravone may effectively ameliorate GalN/LPS-induced liver injury in mice by reducing proinflammatory cytokines and inhibiting apoptosis.

Correlation between P53 expression and malignant risk of gastrointestinal stromal tumors: evidence from 9 studies

PURPOSE

The published data about p53 expression and its potential value in malignant risk of Gastrointestinal Stromal Tumors patients seemed inconclusive. To derive a more precise estimation of the relationship between p53 and Malignant risk of GIST, a meta-analysis was performed.

MATERIALS AND METHODS

Studies have been identified by searching PubMed and Embase. Inclusive criteria were GIST patients, evaluation of p53 expression and malignant risk. The odds ratio (OR) for positive rate of p53 in NIH very low risk group vs. NIH low risk group, the odds ratio (OR) for positive rate of p53 in NIH low risk group vs. NIH Intermediate risk group and the odds ratio (OR) for positive rate of p53 in NIH Intermediate group vs. NIH high risk group were calculated with 95% confidence interval (CI) for each study as an estimation of potential value of p53 in malignant risk of GIST.

RESULTS

A total of 9 studies including 768 patients were involved in this meta-analysis. The meta-analysis of positive rate of p53 in NIH VL group vs. NIH L group did not attain significant difference (OR 0.38 95% CI, 0.11-1.28; P = 0.12 P(heterogeneity) = 0.51). However the overall OR for positive rate of p53 in NIH L group vs. NIH I group revealed that significantly elevated risks of positive p53 in NIH I group were achieved (OR 0.44 95% CI, 0.24-0.82; P = 0.009 P(heterogeneity) = 0.32). The overall OR for NIH I group vs. NIH H group was 0.62 (95% CI, 0.37-1.02; P = 0.06 P(heterogeneity) = 0.25).

CONCLUSION

The results indicate p53 overexpression correlate with the malignant risk increasing of GIST and have a primary and closest relationship within the NIH I risk group of GIST.

Coding regions of INHBA, SFRP4 and HOXA10 are not implicated in familial endometriosis linked to chromosome 7p13-15

Endometriosis is a common, chronic gynaecological disease affecting up to 10% of women in their reproductive years. Its aetiology still remains unclear, but evidence indicates genetic factors play a role. We previously identified a region of significant linkage on chromosome 7 in 52 families comprising at least three affected women, stretching ∼6.4 Mb. We screened coding regions and parts of the regulatory regions of three candidate genes with a known role in endometrial development and function-INHBA, SFRP4 and HOXA10-located under or very near the linkage peak, for potential causal mutations using Sanger sequencing. Sequencing was conducted in 47 cases from the 15 families contributing most to the linkage signal (Z(mean) ≥ 1). Minor allele frequencies (MAFs) of observed variants were compared with MAFs from two publicly available reference populations of European ancestry: 60 individuals in HapMap and 150 individuals in the 1000 Genomes Project. A total of 11 variants were found, 5 (45%) of which were common (MAF > 0.05) among the 15 case families and the reference populations (P-values for MAF difference: 0.88-1.00). The remaining six were rare and unlikely to be individually or cumulatively responsible for the linkage signal. The results indicate that the coding regions of these three genes do not harbour mutations responsible for linkage to endometriosis in these families.

A distinct spectrum of SLC26A4 mutations in patients with enlarged vestibular aqueduct in China

There is a worldwide interest in studying SLC26A4 mutations that are responsible for enlarged vestibular aqueduct (EVA) in different ethnic background and populations. The spectrum of SLC26A4 mutations in Chinese population is yet to be fully characterized. In this study, all the 21 exons of SLC26A4 were screened in 107 Chinese patients with hearing loss associated with EVA or both EVA and Mondini dysplasia (MD), taken from six multiplex and 95 simplex families. The two types of control populations consisted of 84 normal-hearing subjects and 46 sensorineural hearing loss subjects without inner ear malformations. Biallelic mutations were found in 12 patients from multiplex families and 84 patients (88.4%) from the simplex families. In addition, monoallelic variant was detected in nine patients in the remaining 11 simplex families. Overall, up to 97.9% patients were found having at least one possible pathogenic variant in SLC26A4, with most having biallelic variants consistent with recessive inheritance of this disorder. A total of 40 mutations including 25 novel mutations were identified in the Chinese patients but were not detected in all the controls except for one normal subject. For the Chinese mutation spectrum of SLC26A4 gene, IVS 7-2A>G mutation was the most common form accounting for 57.63% (102/177) of all the mutant alleles.

A review of microwave-assisted polymer chemistry (MAPC)

As a relatively new source of processing energy, microwave energy offers many compelling advantages in materials processing over conventional heat sources. These advantages include greater flexibility, greater speed and energy savings, improved product quality and properties, and synthesis of new materials that cannot be produced by other heating methods. Studies of microwave processing of polymeric materials in the early 1960s led to a successful industrial application in the rubber industry. Since the mid-1980's, there has been a great deal of interest in microwave processing of polymeric materials worldwide. The discipline can be categorized in two major fields: microwave-assisted polymer physics (MAPP) and microwave assisted polymer chemistry (MAPC). This paper offers an overview of the state-of-the-art research on the field of MAPC, including polymer processing (curing of thermosets, processing of thermoplastics, and joining), polymer synthesis, plasma modification of polymer surfaces, plasma polymerization, polymer degradation, and production of nanomaterials. Most of these studies have focused on laboratory-scale, exploratory efforts. Challenges and possible future directions for the commercialization of microwave processing technologies are discussed.

[Influence of planting density and precipitation on N2O emission from a winter wheat field]

To investigate the impact of plant density on N2O emission from winter wheat field and the cause of seasonal variation in the emission, field experiment with four planting rates of 0, 90, 180 and 270 kg/ha was conducted at the Jiangning County near Nanjing during 1999-2000 winter wheat growing season. Data of the field measurements indicated that the N2O emission rates during the season from planting to overwintering were not influenced by the plant density, while the emission was positively correlated with the planting density during the season from turning green to maturity. The emissions from the field plots with planting rates of 0 and 90 kg/ha were not found to be significantly different. A further analysis suggested that the seasonal variation of N2O emission be mainly influenced by precipitation, which could be quantitatively described by an exponential function of a weighted average precipitation of 6-day period before measurement.

P[Switch], a system for spatial and temporal control of gene expression in Drosophila melanogaster

We have developed a method for turning on and off the expression of transgenes within Drosophila in both time and space. Two different enhancer detector elements carrying an RU486-inducible form of the yeast transcription factor GAL4 were constructed and used to generate enhancer detector lines. These lines were screened for RU486-inducible reporter gene expression in the adult head. We identified lines that exhibit inducible expression in many cell and tissue types, verifying that the elements respond to nearby enhancers. No expression was detected in the absence of the ligand. The P[Switch1] element responded to genomic enhancers less efficiently than P[Switch2] but produced more specific patterns of expression. Two P[Switch] lines were used to ablate fat body tissue in adult females through the induced expression of diphtheria toxin. These females were sterile, which correlates with fat body loss, and they died prematurely.