Small bowel intramural hematoma caused by warfarin: case report and literature review

BACKGROUND

Intramural hematoma of the small bowel is a rare yet acute gastrointestinal condition typically linked with impaired coagulation function, often posing diagnostic challenges. It is principally encountered in patients undergoing prolonged anticoagulant therapy, specifically warfarin.

CASE PRESENTATION

We reported a case of intramural hematoma associated with warfarin use. The patient was admitted to hospital with abdominal pain and had received anticoagulant therapy with warfarin 2.5 mg/day for 4 years. Laboratory examination showed decreased coagulation function, abdominal CT showed obvious thickening and swelling of part of the jejunal wall, and abdominal puncture found no gastroenteric fluid or purulent fluid. We treated the patient with vitamin K and fresh frozen plasma. The patient was discharged after the recovery of coagulation function. Then we undertaook a comprehensive review of relevant case reports to extract shared clinical features and effective therapeutic strategies.

CONCLUSION

Our analysis highlights that hematoma in the small intestinal wall caused by warfarin overdose often presents as sudden and intense abdominal pain, laboratory tests suggest reduced coagulation capacity, and imaging often shows thickening of the intestinal wall. Intravenous vitamin K and plasma supplementation are effective non-surgical strategies. Nevertheless, in instances of severe obstruction and unresponsive hemostasis, surgical resection of necrotic intestinal segments may be necessary. In the cases we reported, we avoided surgery by closely monitoring the coagulation function. Therefore, we suggest that identifying and correcting the impaired coagulation status of patient is essential for timely and appropriate treatment.

Uncut Roux-en-Y reconstruction after distal gastrectomy for gastric cancer

BACKGROUND

Choosing an optimal reconstruction method is pivotal for patients with gastric cancer undergoing distal gastrectomy. The uncut Roux-en-Y reconstruction, a variant of the conventional Roux-en-Y approach (or variant of the Billroth II reconstruction), employs uncut devices to occlude the afferent loop of the jejunum. This modification is designed to mitigate postgastrectomy syndrome and enhance long-term functional outcomes. However, the comparative benefits and potential harms of this approach compared to other reconstruction techniques remain a topic of debate.

OBJECTIVES

To assess the benefits and harms of uncut Roux-en-Y reconstruction after distal gastrectomy in patients with gastric cancer.

SEARCH METHODS

We searched CENTRAL, PubMed, Embase, WanFang Data, China National Knowledge Infrastructure, and clinical trial registries for published and unpublished trials up to November 2023. We also manually reviewed references from relevant systematic reviews identified by our search. We did not impose any language restrictions.

SELECTION CRITERIA

We included randomised controlled trials (RCTs) and quasi-RCTs comparing uncut Roux-en-Y reconstruction versus other reconstructions after distal gastrectomy for gastric cancer. The comparison groups encompassed other reconstructions such as Billroth I, Billroth II (with or without Braun anastomosis), and Roux-en-Y reconstruction.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures. The critical outcomes included health-related quality of life at least six months after surgery, major postoperative complications within 30 days after surgery according to the Clavien-Dindo Classification (grades III to V), anastomotic leakage within 30 days, changes in body weight (kg) at least six months after surgery, and incidence of bile reflux, remnant gastritis, and oesophagitis at least six months after surgery. We used the GRADE approach to evaluate the certainty of the evidence.

MAIN RESULTS

We identified eight trials, including 1167 participants, which contributed data to our meta-analyses. These trials were exclusively conducted in East Asian countries, predominantly in China. The studies varied in the types of uncut devices used, ranging from 2- to 6-row linear staplers to suture lines. The follow-up periods for long-term outcomes spanned from 3 months to 42 months, with most studies focusing on a 6- to 12-month range. We rated the certainty of evidence from low to very low. Uncut Roux-en-Y reconstruction versus Billroth II reconstruction In the realm of surgical complications, very low-certainty evidence suggests that uncut Roux-en-Y reconstruction compared with Billroth II reconstruction may make little to no difference to major postoperative complications (risk ratio (RR) 0.98, 95% confidence interval (CI) 0.24 to 4.05; I² = 0%; risk difference (RD) 0.00, 95% CI -0.04 to 0.04; I² = 0%; 2 studies, 282 participants; very low-certainty evidence) and incidence of anastomotic leakage (RR 0.64, 95% CI 0.29 to 1.44; I² not applicable; RD -0.00, 95% CI -0.03 to 0.02; I² = 32%; 3 studies, 615 participants; very low-certainty evidence). We are very uncertain about these results. Focusing on long-term outcomes, low- to very low-certainty evidence suggests that uncut Roux-en-Y reconstruction compared with Billroth II reconstruction may make little to no difference to changes in body weight (mean difference (MD) 0.04 kg, 95% CI -0.84 to 0.92 kg; I² = 0%; 2 studies, 233 participants; low-certainty evidence), may reduce the incidence of bile reflux into the remnant stomach (RR 0.67, 95% CI 0.55 to 0.83; RD -0.29, 95% CI -0.43 to -0.16; number needed to treat for an additional beneficial outcome (NNTB) 4, 95% CI 3 to 7; 1 study, 141 participants; low-certainty evidence), and may have little or no effect on the incidence of remnant gastritis (RR 0.27, 95% CI 0.01 to 5.06; I2 = 78%; RD -0.15, 95% CI -0.23 to -0.07; I2 = 0%; NNTB 7, 95% CI 5 to 15; 2 studies, 265 participants; very low-certainty evidence). No studies reported on quality of life or the incidence of oesophagitis. Uncut Roux-en-Y reconstruction versus Roux-en-Y reconstruction In the realm of surgical complications, very low-certainty evidence suggests that uncut Roux-en-Y reconstruction compared with Roux-en-Y reconstruction may make little to no difference to major postoperative complications (RR 4.74, 95% CI 0.23 to 97.08; I² not applicable; RD 0.01, 95% CI -0.02 to 0.04; I² = 0%; 2 studies, 256 participants; very low-certainty evidence) and incidence of anastomotic leakage (RR 0.34, 95% CI 0.05 to 2.08; I² = 0%; RD -0.02, 95% CI -0.06 to 0.02; I² = 0%; 2 studies, 213 participants; very low-certainty evidence). We are very uncertain about these results. Focusing on long-term outcomes, very low-certainty evidence suggests that uncut Roux-en-Y reconstruction compared with Roux-en-Y reconstruction may increase the incidence of bile reflux into the remnant stomach (RR 10.74, 95% CI 3.52 to 32.76; RD 0.57, 95% CI 0.43 to 0.71; NNT for an additional harmful outcome (NNTH) 2, 95% CI 2 to 3; 1 study, 108 participants; very low-certainty evidence) and may make little to no difference to the incidence of remnant gastritis (RR 1.18, 95% CI 0.69 to 2.01; I² = 60%; RD 0.03, 95% CI -0.03 to 0.08; I² = 0%; 3 studies, 361 participants; very low-certainty evidence) and incidence of oesophagitis (RR 0.82, 95% CI 0.53 to 1.26; I² = 0%; RD -0.02, 95% CI -0.07 to 0.03; I² = 0%; 3 studies, 361 participants; very low-certainty evidence). We are very uncertain about these results. Data were insufficient to assess the impact on quality of life and changes in body weight.

AUTHORS' CONCLUSIONS

Given the predominance of low- to very low-certainty evidence, this Cochrane review faces challenges in providing definitive clinical guidance. We found the majority of critical outcomes may be comparable between the uncut Roux-en-Y reconstruction and other methods, but we are very uncertain about most of these results. Nevertheless, it indicates that uncut Roux-en-Y reconstruction may reduce the incidence of bile reflux compared to Billroth-II reconstruction, albeit with low certainty. In contrast, compared to Roux-en-Y reconstruction, uncut Roux-en-Y may increase bile reflux incidence, based on very low-certainty evidence. To strengthen the evidence base, further rigorous and long-term trials are needed. Additionally, these studies should explore variations in surgical procedures, particularly regarding uncut devices and methods to prevent recanalisation. Future research may potentially alter the conclusions of this review.

[Epidemiological characteristics of human respiratory syncytial virus (HRSV) among acute respiratory infection (ARI) cases in 16 provinces of China from 2009 to 2023]

Objective: To understand the epidemiological characteristics of human respiratory syncytial virus (HRSV) among acute respiratory infection (ARI) cases in 16 provinces of China from 2009 to 2023. Methods: The data of this study were collected from the ARI surveillance data from 16 provinces in China from 2009 to 2023, with a total of 28 278 ARI cases included in the study. The clinical specimens from ARI cases were screened for HRSV nucleic acid from 2009 to 2023, and differences in virus detection rates among cases of different age groups, regions, and months were analyzed. Results: A total of 28 278 ARI cases were enrolled from January 2009 to September 2023. The age of the cases ranged from<1 month to 112 years, and the age M (Q1, Q3) was 3 years (1 year, 9 years). Among them, 3 062 cases were positive for HRSV nucleic acid, with a total detection rate of 10.83%. From 2009 to 2019, the detection rate of HRSV was 9.33%, and the virus was mainly prevalent in winter and spring. During the Corona Virus Disease 2019 (COVID-19) pandemic, the detection rate of HRSV fluctuated between 6.32% and 18.67%. There was no traditional winter epidemic peak of HRSV from the end of 2022 to the beginning of 2023, and an anti-seasonal epidemic of HRSV occurred from April to May 2023. About 87.95% (2 693/3 062) of positive cases were children under 5 years old, and the difference in the detection rate of HRSV among different age groups was statistically significant (P<0.001), showing a decreasing trend of HRSV detection rate with the increase of age (P<0.001). Among them, the HRSV detection rate (25.69%) was highest in children under 6 months. Compared with 2009-2019, the ranking of HRSV detection rates in different age groups changed from high to low between 2020 and 2023, with the age M (Q1, Q3) of HRSV positive cases increasing from 1 year (6 months, 3 years) to 2 years (11 months, 3 years). Conclusion: Through 15 years of continuous HRSV surveillance analysis, children under 5 years old, especially infants under 6 months old, are the main high-risk population for HRSV infection. During the COVID-19 pandemic, the prevalence and patterns of HRSV in China have changed.

Optimal reconstruction methods after distal gastrectomy for gastric cancer: a protocol for a systematic review and network meta-analysis update

BACKGROUND

Distal gastrectomy (DG) is a commonly used surgical procedure for gastric cancer (GC), with three reconstruction methods available: Billroth I, Billroth II, and Roux-en-Y. In 2018, our team published a systematic review to provide guidance for clinical practice on the optimal reconstruction method after DG for GC. However, since then, new evidence from several randomized controlled trials (RCTs) has emerged, prompting us to conduct an updated systematic review and network meta-analysis to provide the latest comparative estimates of the efficacy and safety of the three reconstruction methods after DG for GC.

METHOD

This systematic review and network meta-analysis update followed the PRISMA-P guidelines and will include a search of PubMed, Embase, and the Cochrane Library for RCTs comparing the outcomes of Billroth I, Billroth II, or Roux-en-Y reconstruction after DG for patients with GC. Two independent reviewers will screen the titles and abstracts based on predefined eligibility criteria, and two reviewers will assess the full texts of relevant studies. The Bayesian network meta-analysis will evaluate various outcomes, including quality of life after surgery, anastomotic leakage within 30 days after surgery, operation time, intraoperative blood loss, major postoperative complications within 30 days after surgery, incidence and severity of bile reflux, and loss of body weight from baseline.

ETHICS AND DISSEMINATION

The review does not require ethical approval. The findings of the review will be disseminated through publication in an academic journal, presentations at conferences, and various media outlets.

INPLASY REGISTRATION NUMBER

INPLASY2021100060.

The Global Burden of Vascular Intestinal Disorders in 204 Countries and Territories From 1990 to 2019: Global Burden of Diseases Study

Objectives: Assess the prevalence, mortality, and disability-adjusted life years (DALYs) of vascular intestinal disorders (VID) from 1990 to 2019. Methods: This study conducted a secondary data analysis utilizing the Global Burden of Diseases Study 2019. The prevalence, mortality and DALYs of VID were analyzed by sex, age and socio-demographic index (SDI), respectively. Analyses were performed by using R software. Results: Globally, the number of prevalent VID cases increased from 100,158 (95% uncertainty interval: 89,428-114,013) in 1,990-175,740 (157,941-198,969) in 2019. However, the age-standardized rates (ASR) of VID prevalence declined from 2.47 (95% uncertainty interval: 2.24-2.76) per 100,000 population to 2.21 (1.98-2.48) per 100,000 population between 1990 and 2019. Furthermore, the ASR of mortality also decreased from 1990 to 2019. Between 1990 and 2019, the regions with high and high-middle level exhibited the highest diseases burden. Conclusion: Globally, the diseases burden associated with VID demonstrated a decline from 1990 to 2019. However, concerted efforts are still required to enhance measures to combat VID within countries categorized as high and high-middle SDI.

Local excision and radical excision for rectal gastrointestinal stromal tumors: a meta-analysis protocol

Background

To date, several studies have compared the surgical and oncological outcomes of local excision (LE) and radical excision (RE) for rectal gastrointestinal stromal tumors (GISTs), but some have limited numbers of small series. This protocol outlines the planned scope and methods for a systematic review and meta-analysis that will compare the surgical and oncological outcomes of LE and RE in patients with rectal GISTs.

Methods

This protocol is presented in accordance with the PRISMA-P guideline. PubMed, Embase, Web of Science, Cochrane Library and Wanfang database will be systematically searched. Furthermore, reference lists of all included articles will be screened manually to add other eligible studies. We will include randomized controlled trials (RCTs) and non-randomized studies (NRS) in this study. The primary outcomes evaluated will be R0 resection rate and disease-free survival, while the secondary outcomes will contain overall survival, length of stay, tumor rupture rate and complications. Two reviewers will independently screen and select studies, extract data from the included studies, and assess the risk of bias of the included studies. Preplanned subgroup analyses and sensitivity analyses are detailed within this protocol. The strength of the body of evidence will be assessed using GRADE.

Discussion

This review and meta-analysis will provide a comprehensive evaluation of the current evidence concerning the application of LE and RE in patients with rectal GISTs. The findings from this review will serve as a foundation for future research and emphasize the implications for clinical practice.

Systematic review registration

PROSPERO (CRD42017078338), https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=387409, PROSPERO CRD42017078338.

Methodological quality of radiomic-based prognostic studies in gastric cancer: a cross-sectional study

Background

Machine learning radiomics models are increasingly being used to predict gastric cancer prognoses. However, the methodological quality of these models has not been evaluated. Therefore, this study aimed to evaluate the methodological quality of radiomics studies in predicting the prognosis of gastric cancer, summarize their methodological characteristics and performance.

Methods

The PubMed and Embase databases were searched for radiomics studies used to predict the prognosis of gastric cancer published in last 5 years. The characteristics of the studies and the performance of the models were extracted from the eligible full texts. The methodological quality, reporting completeness and risk of bias of the included studies were evaluated using the RQS, TRIPOD and PROBAST. The discrimination ability scores of the models were also compared.

Results

Out of 283 identified records, 22 studies met the inclusion criteria. The study endpoints included survival time, treatment response, and recurrence, with reported discriminations ranging between 0.610 and 0.878 in the validation dataset. The mean overall RQS value was 15.32 ± 3.20 (range: 9 to 21). The mean adhered items of the 35 item of TRIPOD checklist was 20.45 ± 1.83. The PROBAST showed all included studies were at high risk of bias.

Conclusion

The current methodological quality of gastric cancer radiomics studies is insufficient. Large and reasonable sample, prospective, multicenter and rigorously designed studies are required to improve the quality of radiomics models for gastric cancer prediction.

Study registration

This protocol was prospectively registered in the Open Science Framework Registry (https://osf.io/ja52b).

The necessity and safety of simultaneous cholecystectomy during gastric surgery for patients with asymptomatic cholelithiasis

OBJECTIVES

The incidence of cholelithiasis is higher among individuals who have undergone gastric surgery. The benefits of concomitant gallbladder removal in asymptomatic gallstone patients remain uncertain. The aim was to investigate the necessity and safety of simultaneous cholecystectomy in this particular patient population.

METHODS

We performed a systematic review and meta-analysis to assess the incidence of asymptomatic cholelithiasis converting to symptomatic after gastric surgery and the complication rate associated with simultaneous cholecystectomy. PubMed, Embase, and the Cochrane Library were searched for relevant articles published until 10 March 202210 March 2022.

RESULTS

Patients with asymptomatic cholelithiasis after gastric surgery were at a higher risk of developing symptomatic cholelithiasis compared to those without cholelithiasis (relative risk [RR] 2.28, 95% confidence interval [CI] 1.23-4.25) and those with unknown gallbladder conditions (RR 2.70, 95% CI 1.54-4.73). Additionally, patients who underwent simultaneous cholecystectomy did not face a higher risk of complications compared to those who only underwent gastric surgery (RR 0.86, 95% CI 0.48-1.53).

CONCLUSIONS

Simultaneous cholecystectomy is both necessary and safe for patients with asymptomatic cholelithiasis undergoing gastric surgery. It is crucial to assess the gallbladder's condition before gastric surgery, and if the gallbladder status is unknown, simultaneous cholecystectomy should be avoided.

Microbiology and prognostic prediction model of bloodstream infection in patients with hematological malignancies

Background

In recent years, with the continuous development of treatments for hematological malignancies (HMs), the remission and survival rates of patients with HMs have been significantly improved. However, because of severe immunosuppression and long-term recurrent neutropenia during treatment, the incidence and mortality of bloodstream infection (BSI) were all high in patients with HMs. Therefore, we analyzed pathogens' distribution and drug-resistance patterns and developed a nomogram for predicting 30-day mortality in patients with BSIs among HMs.

Methods

In this retrospective study, 362 patients with positive blood cultures in HMs were included from June 2015 to June 2020 at West China Hospital of Sichuan University. They were randomly divided into the training cohort (n = 253) and the validation cohort (n = 109) by 7:3. A nomogram for predicting 30-day mortality after BSIs in patients with HMs was established based on the results of univariate and multivariate logistic regression. C-index, calibration plots, and decision curve analysis were used to evaluate the nomogram.

Results

Among 362 patients with BSIs in HMs, the most common HM was acute myeloid leukemia (48.1%), and the most common pathogen of BSI was gram-negative bacteria (70.4%). The final nomogram included the septic shock, relapsed/refractory HM, albumin <30g/l, platelets <30×10⁹/l before BSI, and inappropriate empiric antibiotic treatment. In the training and validation cohorts, the C-indexes (0.870 and 0.825) and the calibration plots indicated that the nomogram had a good performance. The decision curves in both cohorts showed that the nomogram model for predicting 30-day mortality after BSI was more beneficial than all patients with BSIs or none with BSIs.

Conclusion

In our study, gram-negative bacterial BSIs were predominant in patients with HMs. We developed and validated a nomogram with good predictive ability to help clinicians evaluate the prognosis of patients.

Correlation between primary family caregiver identity and maternal depression risk in poor rural China

INTRODUCTION

Prenatal and postpartum depression are important public health challenges because of their long-term adverse impacts on maternal and neonatal health. This study investigated the risk of maternal depression among pregnant and postpartum women in poor rural China, along with the correlation between primary family caregiver identity and maternal depression risk.

METHODS

Pregnant women and new mothers were randomly selected from poor rural villages in the Qinba Mountains area in Shaanxi. Basic demographic information was collected regarding the women and their primary family caregivers. The Edinburgh Postnatal Depression Scale was used to identify women at risk of depression, and the Perceived Social Support Scale was used to evaluate perceived family support.

RESULTS

This study included 220 pregnant women and 473 new mothers. The mean proportions of women at risk of prenatal and postpartum depression were 19.5% and 18.6%, respectively. Regression analysis showed that identification of the baby's grandmother as the primary family caregiver was negatively correlated with maternal depression risk (β=-0.979, 95% confidence interval [CI]=-1.946 to -0.012, P=0.047). However, the husband's involvement in that role was not significantly correlated with maternal depression risk (β=-0.499, 95% CI=-1.579 to 0.581, P=0.363). Identification of the baby's grandmother as the primary family caregiver was positively correlated with family support score (β=0.967, 95% CI=-0.062 to 1.996, P=0.065).

CONCLUSION

Prenatal and postpartum depression are prevalent in poor rural China. The involvement of the baby's grandmother as the primary family caregiver may reduce maternal depression risk, but the husband's involvement in that role has no effect.

Efficacy and safety of copanlisib in relapsed/refractory B-cell non-Hodgkin lymphoma: A meta-analysis of prospective clinical trials

BACKGROUND

Copanlisib is an intravenously administered pan-class I PI3K inhibitor that has been demonstrated to have appreciable effects in the treatment of patients with lymphoma. The purpose of this meta-analysis was to evaluate the efficacy and safety of copanlisib for treating patients with relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL).

METHODS

PubMed, Web of Science, EMBASE, and the Cochrane Central Register of Controlled Trials were searched for relevant studies published prior to July 2022. The efficacy evaluation included complete response rate (CR), partial response rate (PR), rate of stable disease (SDR), overall response rate (ORR), disease control rate (DCR), rate of progressive disease (PDR), median progression-free survival (PFS), and median overall survival (OS). Any grade adverse events (AEs) and grade ≥3 AEs were synthesized to assess its safety.

RESULTS

Eight studies with a total of 652 patients with R/R B-NHL were identified. The pooled CR, PR, ORR, SDR, DCR, and PDR from all 8 articles were 13%, 40%, 57%, 19%, 86%, and 9%, respectively. The CR and ORR of combination therapy with rituximab were higher than those with copanlisib monotherapy for R/R B-NHL (34% vs. 6%, p<0.01; 89% vs. 42%, p<0.01). For patients with R/R indolent B-NHL, CR and ORR were lower with copanlisib monotherapy than with combination therapy with rituximab (7% vs. 34%, p<0.01; 58% vs. 92%, p<0.01). In R/R B-NHL patients receiving copanlisib monotherapy and combination therapy with rituximab, the risk of any grade AEs was 99% and 96%, respectively, and the risk of grade ≥3 AEs was 84% and 91%, respectively. The common any grade AEs included hyperglycemia (66.75%), hypertension (48.57%), diarrhea (35.06%), nausea (34.98%) and fatigue (30.33%). The common grade ≥3 AEs included hyperglycemia (45.14%), hypertension (35.07%), and neutropenia (14.75%). The comparison of AEs between the copanlisib monotherapy and the combination therapy with rituximab showed that hyperglycemia of any grade (p<0.0001), hypertension of any grade (p=0.0368), fatigue of any grade (p<0.0001), grade ≥3 hypertension (p<0.0001) and grade ≥3 hyperglycemia (p=0.0074) were significantly different between the two groups.

CONCLUSION

Our meta-analysis demonstrated that the efficacy of both copanlisib monotherapy and combination therapy with rituximab in patients with R/R B-NHL was satisfactory, while treatment-related AEs were tolerable. Compared with copanlisib monotherapy, combination therapy with rituximab showed superior efficacy for treating R/R B-NHL, and its safety was manageable.

SYSTEMATIC REVIEW REGISTRATION

https://inplasy.com/inplasy-2022-10-0008/, identifier INPLASY2022100008.

[Research progress of C-X-C motif chemokine ligand 12 and its receptor signaling axis in the regulation of pulmonary fibrosis]

Pulmonary fibrosis is an irreversible interstitial lung disease characterized by lung parenchyma remodeling and collagen deposition. In recent years, the incidence and mortality of pulmonary fibrosis caused by unknown causes have risen. However, its pathogenesis is still unclear. C-X-C motif chemokine ligand 12 (CXCL12)/C-X-C chemokine receptor 4 (CXCR4)/CXCR7 signal axis plays a critical regulatory role in pulmonary fibrosis disease. In addition, the signal axis has been shown to regulate recruitment and migration of circulating fibrocytes, mesenchymal stem cells to the damage lung tissue, the migration of endothelial cells, the proliferation and differentiation of fibroblasts and endothelial cells, which further affects the occurrence and progression of pulmonary fibrosis. In this review, we summarized the pathogenesis and treatment research progress of CXCL12 and its receptor CXCR4/CXCR7 in the occurrence and progression of pulmonary fibrosis.

Open and minimally invasive surgery for gastrointestinal stromal tumours: a systematic review and network meta-analysis protocol

INTRODUCTION

Gastrointestinal stromal tumours (GISTs) are the most common mesenchymal tumours of the digestive system, and complete resection is the only way to provide a radical cure for resectable GISTs. Open surgery and minimally invasive approaches, including laparoscopy, robotic surgery and endoscopy, consist of the mainstream GIST resection. However, there is still a lack of evidence regarding which surgical outcomes and long-term prognosis would be better. Thus, we are planning to conduct a network meta-analysis and systematic review aiming to determine the comparative effectiveness among laparotomy, laparoscopy, endoscopy, robotic surgery, and laparoscopic and endoscopic cooperative surgery in GISTs.

METHOD AND ANALYSIS

PubMed, EMBASE, the Cochrane Library and Web of Science will be searched for published studies to identify the proper literature comparing open resection, laparoscopy, endoscopy, robotic surgery, and laparoscopic and endoscopic cooperative surgery for resecting GISTs from inception to February 2021. Randomised controlled trials (RCTs) and non-randomised studies comparing at least two different interventions for GIST resection will be included. RCTs and non-randomised studies will be synthesised and analysed separately. Bayesian network meta-analysis will be performed to compare the surgical outcomes and long-term prognosis among the resection methods above. The included studies will be divided into several subgroups according to tumour location and size for further analysis. Sensitivity analysis will be performed to identify and explain heterogeneity to make our results robust. Meta-regression will serve as a supplementary method if data are available. The quality of evidence will be evaluated by the Grading of Recommendations, Assessment, Development and Evaluation.

ETHICS AND DISSEMINATION

No ethical approval is required for this network meta-analysis, as it is based on already published data. The findings of the review will be published in a peer-reviewed journal.

PROSPERO REGISTRATION NUMBER

CRD42021237892.

Comparative efficacy and safety of anti-HGF/MET pathway agents plus chemotherapy versus chemotherapy alone as first-line treatment in advanced gastric cancer: a protocol for a systematic review and meta-analysis

INTRODUCTION

Phase I/II clinical trials suggested that the hepatocyte growth factor (HGF)/mesenchymal-epithelial transition (MET) pathway-targeted agents were active in suppression of gastric cancer (GC). Randomised controlled trials (RCTs) were undertaken assessing whether the addition of anti-HGF/MET agent (rilotumumab or onartuzumab) to chemotherapy improves survival outcomes of advanced GC, but conflict conclusions were reached. Therefore, we plan to perform this systematic review and meta-analysis to synthesise evidence concerning efficacy and safety of anti-HGF/MET agents combined with chemotherapy as the first-line treatment to advanced GC.

METHODS AND ANALYSIS

Systematic searches of the PubMed, Embase and the Cochrane Central Register of Controlled Trials will be performed with no language restriction from inception to 31 January 2022 to identify RCTs exploring the comparative efficacy and safety of anti-HGF/MET agents plus chemotherapy as first-line treatment in advanced GC. The primary outcome will be the time-to-event progression-free survival and overall survival, and the secondary outcomes will be disease control rate, overall adverse events rate and grade 3-5 adverse events rate. Statistical heterogeneity will be assessed by visual inspection of forest plots and measured using the I² statistics. A fixed-effect model will be used when heterogeneity is low otherwise, a random-effect model will be chosen. Publication bias will be assessed by funnel plots; subgroup analysis and sensitivity analysis will be performed in the right context. For each outcome, we will perform data synthesis using Rev Man V.5.3 software, and compile 'summary of findings' tables using GRADEpro software.

ETHICS AND DISSEMINATION

There is no requirement for ethics approval because no individual data will be collected in this research. It is anticipated that the dissemination of results will take place at conferences and through publication in a peer-review journal, any adjustments from the protocol will be clearly documented and explained in its final report.

PROSPERO REGISTRATION NUMBER

CRD42020177404.

Surgical resection for patients with recurrent or metastatic gastrointestinal stromal tumors: a protocol for a systematic review and meta-analysis update

BACKGROUND

There are limited data on the clinical benefits of adding surgical resection in patients with recurrent or metastatic gastrointestinal stromal tumors (GISTs). This protocol outlines the planned scope and methods for a systematic review and meta-analysis update that will compare the clinical outcomes of surgical resection combined with tyrosine kinase inhibitor (TKI) with TKI treatment alone in patients with recurrent or metastatic GISTs.

METHODS

This review will update a previously published systematic review by our team. This protocol is presented in accordance with the PRISMA-P guideline. PubMed, Embase, and Cochrane Central Register of Controlled Trials will be systematically searched and supplemented by a secondary screening of the references of all included studies. We will include randomized controlled trials (RCTs) and non-randomized studies (NRS) in this review update. The outcomes evaluated will be overall survival and progression-free survival. Two reviewers will independently screen and select studies, extract data from the included studies, and assess the risk of bias of the included studies. Data extracted from RCTs and NRS will be analysed and reported separately. Preplanned subgroup analyses and sensitivity analyses are detailed within this protocol. The strength of the body of evidence will be assessed using GRADE.

DISCUSSION

This systematic review and meta-analysis update will provide a current assessment of the evidence for the role of surgery in patients with recurrent or metastatic advanced GISTs. These findings will be used by the Chinese Society of Clinical Oncology (CSCO) GIST guideline recommendations on surgical treatment for recurrent or metastatic advanced GIST patients in China.

SYSTEMATIC REVIEW REGISTRATION

This protocol was prospectively registered in the Open Science Framework Registry ( https://osf.io/xus7m ).

Primary retroperitoneal gastrointestinal stromal tumor mimicking adrenal mass: A case report

Gastrointestinal stromal tumor (GIST) which occurs outside of alimentary canal without any connection is called as extra gastrointestinal stromal tumor (EGIST). Primary retroperitoneal EGISTs are extremely uncommon with insufficient awareness for rare prevalence. In addition, so-called adrenal EGISTs were reported by few authors. Here we reported a rare and interesting case about primary retroperitoneal extra gastrointestinal stromal in the left adrenal region. The tumor was diagnosed as pheochromocytoma preoperatively due to symptoms, abnormal hormone levels and imaging features. Tumor resection was operated after preoperative preparation for pheochromocytoma. However, postoperative pathology verified as primary retroperitoneal EGIST without relation to the left adrenal region or digestive tract.

Impact of Surgical Margin Status on Survival in Gastric Cancer: A Systematic Review and Meta-Analysis

BACKGROUND

It is inconclusive whether R1 margin determined by postoperative pathological examination indicates worse long-term survival in gastric cancer (GC) patients after curative intent resection (CIR). Hence, we aimed to systematically pool the conflicting evidence to fill this gap.

METHODS

The present study was performed according to the published protocol and Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Published studies examining the impact of microscopic margin status on overall survival (OS) and 5-year OS rate in GC were systematically searched in PubMed, Embase, and Cochrane Library databases. RevMan 5.3 was used to conduct statistical analysis, and the Grading of Recommendations, Assessment, Development, and Evaluations approach was used to assess the certainty of evidence for each outcome.

RESULTS

Twenty-three retrospective cohort studies including 19 992 patients were analyzed. The pooled hazard ratio for OS of 14 studies was 2.06 (95% confidence interval [CI]: 1.61-2.65, low certainty), indicating that R1 margin predicted inferior OS. Subgroup and sensitivity analyses upheld the statistical stability of this finding. The pooled odds ratio (OR) of 14 studies was .21 (95% CI: .17-.26, moderate certainty), demonstrating that the presence of R1 margins was associated with a poorer 5-year OS rate. Sensitivity analyses and most of the subgroup analyses confirmed this finding, except the "esophagogastric junction (EGJ) cancers" subgroup, which included two studies with a pooled OR of .41 (95% CI: .10-1.61).

CONCLUSION

R1 margin detected by pathological examination might exhibit a high correlation with poorer OS and 5-year OS rate in GC (except EGJ cancers) patients who underwent CIR. To figure out the effect of R1 margin on survival of different stages and histological types need prospective studies with large sample sizes and standardized methods. What is the best treatment for R1 margin patients also need more in-depth and special research.

Comparative safety and tolerability of approved PARP inhibitors in cancer: A systematic review and network meta-analysis

BACKGROUND

We aimed to evaluate comparative safety and tolerability of the approved PARP inhibitors in people with cancer.

METHODS

Eligible studies included randomized controlled trials comparing an approved PARP inhibitor (fluzoparib, olaparib, rucaparib, niraparib, or talazoparib) with placebo or chemotherapy in cancer patients. Outcomes of interest included: serious adverse event (SAE), discontinuation due to adverse event (AE), interruption of treatment due to AE, dose reduction due to AE, and specific grade 1-5 AEs.

RESULTS

Ten trials including 3763 participants and six treatments (olaparib, rucaparib, niraparib, talazoparib, placebo, and protocol-specified single agent chemotherapy) were identified. SAE and discontinuation of treatment did not differ significantly among the four approved PARP inhibitors. Regarding interruption of treatment and dose reduction due to AE, statistically significant differences and statistically non-significant trend were observed. Talazoparib is associated with a higher risk of interruption of treatment and dose reduction (excluding rucaparib) due to AE as compared with the other drugs. Niraparib showed a trend of lower risk of AE related dose reduction as compared with the other drugs. Furthermore, there were significant differences in specific grade 1-5 AE among the four drugs.

CONCLUSION

The safety profile of the four approved PARP inhibitors is comparable in terms of SAE and AE-related discontinuation of treatment. Statistically significant differences in the AEs spectrum and AEs related dose interruption and dose reduction demonstrated the prompt identification of AE and dose personalization seem mandatory to obtain maximal benefit from PARP inhibitors.

Color Doppler ultrasound detection of hemodynamic changes in pregnant women with GDM and analysis of their influence on pregnancy outcomes

OBJECTIVE

To study the influence of color Doppler ultrasound on hemodynamic changes and pregnancy outcome of pregnant women with gestational diabetes mellitus (GDM).

METHODS

From October 2018 to October 2019, a total of 76 pregnant women with GDM treated in the obstetric outpatient department of our hospital were selected as the experimental group, and 76 healthy pregnant women were selected as the control group. The uterine artery (UA) hemodynamic parameters, fetal middle cerebral artery (MCA) hemodynamic parameters and umbilical artery (Ut-A) hemodynamic parameters of the two groups of pregnant women were examined by color Doppler ultrasound. The arterial blood flow of the two groups of pregnant women was evaluated, and the incidence of early diastolic notches and pregnancy outcome were counted. The correlation between blood flow index changes during pregnancy [peak systolic velocity/end-systolic blood flow velocity (S/D), resistance index (RI), pulsation index (PI)] and GDM was analyzed.

RESULTS

The arterial hemodynamic parameters and arterial blood flow scores of pregnant women in the experimental group were better than those in the control group (P < 0.05); the incidence of early diastolic notch in the experimental group was significantly higher than that in the control group (P < 0.05); the number of neonates with the Apgar score ≥ 7 points in the experimental group was significantly smaller than that in the control group (P < 0.05). PI, RI and S/D of arterial blood flow during pregnancy were positively correlated with the occurrence of GDM (P < 0.05).

CONCLUSION

Clinically, color Doppler ultrasound may be used to understand the abnormal blood glucose of GDM pregnant women, identify the cause of the abnormality through symptoms, and detect the maternal arterial blood flow indicators to achieve timely understanding of the abnormal condition of the fetus, and provide a basis for preventing adverse pregnancy outcomes.

Indirect neonatal hyperbilirubinemia in hospitalized neonates on the Thai-Myanmar border: a review of neonatal medical records from 2009 to 2014

BACKGROUND

Indirect neonatal hyperbilirubinemia (INH) is a common neonatal disorder worldwide which can remain benign if prompt management is available. However there is a higher morbidity and mortality risk in settings with limited access to diagnosis and care. The manuscript describes the characteristics of neonates with INH, the burden of severe INH and identifies factors associated with severity in a resource-constrained setting.

METHODS

We conducted a retrospective evaluation of anonymized records of neonates hospitalized on the Thai-Myanmar border. INH was defined according to the National Institute for Health and Care Excellence guidelines as 'moderate' if at least one serum bilirubin (SBR) value exceeded the phototherapy threshold and as 'severe' if above the exchange transfusion threshold.

RESULTS

Out of 2980 records reviewed, 1580 (53%) had INH within the first 14 days of life. INH was moderate in 87% (1368/1580) and severe in 13% (212/1580). From 2009 to 2011, the proportion of severe INH decreased from 37 to 15% and the mortality dropped from 10% (8/82) to 2% (7/449) coinciding with the implementation of standardized guidelines and light-emitting diode (LED) phototherapy. Severe INH was associated with: prematurity (< 32 weeks, Adjusted Odds Ratio (AOR) 3.3; 95% CI 1.6-6.6 and 32 to 37 weeks, AOR 2.2; 95% CI 1.6-3.1), Glucose-6-phosphate dehydrogenase deficiency (G6PD) (AOR 2.3; 95% CI 1.6-3.3), potential ABO incompatibility (AOR 1.5; 95% CI 1.0-2.2) and late presentation (AOR 1.8; 95% CI 1.3-2.6). The risk of developing severe INH and INH-related mortality significantly increased with each additional risk factor.

CONCLUSION

INH is an important cause of neonatal hospitalization on the Thai-Myanmar border. Risk factors for severity were similar to previous reports from Asia. Implementing standardized guidelines and appropriate treatment was successful in reducing mortality and severity. Accessing to basic neonatal care including SBR testing, LED phototherapy and G6PD screening can contribute to improve neonatal outcomes.

Genome-wide identification and expression analysis of CIPK genes in diploid cottons

Calcineurin B-like protein-interacting protein kinase (CIPK) plays a key regulatory role in the growth, development, and stress resistance of plants by combining with phosphatase B subunit-like protein. In the present study, CIPK genes were identified in the whole genomes of diploid cottons and their sequences were subjected to bioinformatic analyses. The results demonstrated that the CIPK gene family was unevenly distributed in two diploid cotton genomes. Forty-one CIPKs were identified in the D genome, mainly located on chromosomes 9 and 10, whereas thirty-nine CIPKs were identified in the A genome, mainly located on chromosomes 8 and 11. Based on the gene structures, CIPKs in cotton could be classified into two types: one that is intron-rich and the other that has few introns. Phylogenetic analysis revealed that the CIPK gene family members in cotton had close evolutionary relationships with those of the dicotyledonous plants, such as Arabidopsis thaliana and poplar. The analysis of transcriptome sequence data demonstrated that there were differences in gene expression in different tissues, indicating that the expression of the CIPKs in cotton had spatio-temporal specificity. The expression analysis of CIPKs under abiotic stresses (drought, salt, and low temperature) in different tissues at trefoil stage demonstrated that these stresses induced the expression of CIPKs.

[Correlation analysis on retrobulbar vascular hemodynamic characteristics and carotid artery color Doppler ultrasonographic features of amaurosis fugax]

OBJECTIVE

To investigate the correlation of amaurosis fugax and carotid stenosis as well as posterior ocular blood vessel hemodynamic changes.

METHODS

Case series studies. 32 patients (19 men and 13 women whose age were 50 to 80 years old and average age was 64.31 ± 8.15) who were diagnosed as amaurosis fugax with 32 eyes were enrolled from 2011.5-2012.12. During the same period 30 cases without posterior ocular ischemic diseases were collected as the control group. Their ophthalmic artery, central retinal artery and carotid artery were examinated by color Doppler ultrasound, to detect vascular peak systolic velocity, end diastolic velocity, resistance index, the degree of carotid stenosis, carotid artery plaque area and type. All data were analyzed by chi-square test and t-test.

RESULTS

PSV (25.95 ± 2.45) cm/s, EDV (6.01 ± 0.87) cm/s of the ophthalmic artery in AmF group were lower compared with the control group [PSV:(27.53 ± 1.41) cm/s, EDV: (6.89 ± 0.56) cm/s]. The differences were statistically significant (t = 3.087, 0.712, P = 0.003, 0.048). There was no statistical difference of RI between AmF and the control group (t = 0.188, P = 0.852) . PSV (7.13 ± 0.96) cm/s, EDV (1.78 ± 0.26) cm/s of the central retinal artery in AmF group were lower compared with the control group[PSV:(8.23 ± 0.92) cm/s, EDV:(2.13 ± 0.29) cm/s]. The differences were statistically significant (t = 4.648, 4.976, P = 0.000, 0.000). There was no statistical difference of RI between AmF and the control group (t = 0.180, P = 0.855). Detection rate of carotid artery moderately and severe stenosis (59.4%) was significantly higher compared with the control group (6.7%) . The difference was statistically significant (χ(2) = 19.205, P = 0.000).

CONCLUSIONS

The blood flow velocity of ophthalmic artery and central retinal artery in amaurosis fugax patients reduced significantly, while the resistance was normal. About 60% of the patients had carotid artery moderately and severe stenosis. There was significant correlation between amaurosis fugax and carotid artery stenosis.

Global fire emissions and the contribution of deforestation, savanna, forest, agricultural, and peat fires (1997–2009)

Abstract. New burned area datasets and top-down constraints from atmospheric concentration measurements of pyrogenic gases have decreased the large uncertainty in fire emissions estimates. However, significant gaps remain in our understanding of the contribution of deforestation, savanna, forest, agricultural waste, and peat fires to total global fire emissions. Here we used a revised version of the Carnegie-Ames-Stanford-Approach (CASA) biogeochemical model and improved satellite-derived estimates of area burned, fire activity, and plant productivity to calculate fire emissions for the 1997–2009 period on a 0.5° spatial resolution with a monthly time step. For November 2000 onwards, estimates were based on burned area, active fire detections, and plant productivity from the MODerate resolution Imaging Spectroradiometer (MODIS) sensor. For the partitioning we focused on the MODIS era. We used maps of burned area derived from the Tropical Rainfall Measuring Mission (TRMM) Visible and Infrared Scanner (VIRS) and Along-Track Scanning Radiometer (ATSR) active fire data prior to MODIS (1997–2000) and estimates of plant productivity derived from Advanced Very High Resolution Radiometer (AVHRR) observations during the same period. Average global fire carbon emissions according to this version 3 of the Global Fire Emissions Database (GFED3) were 2.0 Pg C year−1 with significant interannual variability during 1997–2001 (2.8 Pg C year−1 in 1998 and 1.6 Pg C year−1 in 2001). Globally, emissions during 2002–2007 were relatively constant (around 2.1 Pg C year−1) before declining in 2008 (1.7 Pg C year−1) and 2009 (1.5 Pg C year−1) partly due to lower deforestation fire emissions in South America and tropical Asia. On a regional basis, emissions were highly variable during 2002–2007 (e.g., boreal Asia, South America, and Indonesia), but these regional differences canceled out at a global level. During the MODIS era (2001–2009), most carbon emissions were from fires in grasslands and savannas (44%) with smaller contributions from tropical deforestation and degradation fires (20%), woodland fires (mostly confined to the tropics, 16%), forest fires (mostly in the extratropics, 15%), agricultural waste burning (3%), and tropical peat fires (3%). The contribution from agricultural waste fires was likely a lower bound because our approach for measuring burned area could not detect all of these relatively small fires. Total carbon emissions were on average 13% lower than in our previous (GFED2) work. For reduced trace gases such as CO and CH4, deforestation, degradation, and peat fires were more important contributors because of higher emissions of reduced trace gases per unit carbon combusted compared to savanna fires. Carbon emissions from tropical deforestation, degradation, and peatland fires were on average 0.5 Pg C year−1. The carbon emissions from these fires may not be balanced by regrowth following fire. Our results provide the first global assessment of the contribution of different sources to total global fire emissions for the past decade, and supply the community with an improved 13-year fire emissions time series.

[The structures elucidation of isodopharicin D and F]

Two new compounds were isolated from Isodon pharicus (Prain) Murata. Their structures were determined to be 3 alpha, 11 beta, 13 alpha-trihydroxy-entkaur-16-en-15-one (1), named isodopharicin D, and 11 beta, 13 alpha, 15 alpha-trihydroxy-entkaur-16-en-3 alpha-beta-D-glucoside (2), named isodopharicin F by chemical and spectral evidence.

Selective in vitro and in vivo binding of [(125)I]ADAM to serotonin transporters in rat brain

An improved iodinated tracer, ADAM (2-((2-((dimethylamino)methyl)- phenyl)thio)-5-iodophenylamine) for imaging serotonin transporters (SERT) with single photon emission computerized tomography (SPECT), was prepared and characterized. Scatchard analysis of saturation binding of [(125)I]ADAM to rat frontal cortical membrane homogenates gave a K(d) value of 0.15 +/- 0.03 nM and a B(max) value of 194 +/- 65 fmol/mg protein. Biodistribution of [(125)I]ADAM in rat brain after an iv injection showed a high specific binding in the regions of hypothalamus, cortex, striatum, and hippocampus, where SERT are concentrated and the specific binding peaked at 120-240 min postinjection [(hypothalamus-cerebellum)/cerebellum = 4.3 at 120 min post-iv injection]. Moreover, the specific hypothalamic uptake was blocked by pretreatment with SERT selective competing drugs, such as paroxetine and (+)McN5652, while other noncompeting drugs, such as ketanserin, raclopride, and methylphenidate, showed no effect. The radioactive material recovered from rat brain homogenates at 120 min after [(125)I]ADAM injection showed primarily the original compound (>90%), a good indication of in vivo stability in the brain tissues. Both male and female rats showed similar and comparable organ distribution pattern and regional brain uptakes. Ex vivo autoradiograms of rat brain sections (120 min after iv injection of [(125)I]ADAM) showed intense labeling in several regions (olfactory tubercle, lateral septal nucleus, hypothalamic and thalamic nuclei, globus pallidus, central gray, superior colliculus, substantia nigra, interpeduncular nucleus, dorsal and median raphes, and locus coerulus), which parallel known SERT density. These results strongly suggest that the novel tracer ADAM is superior to the congers (i.e., IDAM) reported previously. When labeled with I-123, ADAM will be an improved and useful SPECT imaging agent for SERT in the brain.

2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine (ADAM): an improved serotonin transporter ligand

Serotonin transporters (SERT) are target-sites for commonly used antidepressants, such as fluoxetine, paroxetine, sertraline, and so on. Imaging of these sites in the living human brain may provide an important tool to evaluate the mechanisms of action as well as to monitor the treatment of depressed patients. Synthesis and characterization of an improved SERT imaging agent, ADAM (2-((2-((dimethylamino)methyl)phenyl)thio)-5-iodophenylamine)(7) was achieved. The new compound, ADAM(7), displayed an extremely potent binding affinity toward SERT ( K(i)=0.013 nM, in membrane preparations of LLC-PK(1)-cloned cell lines expressing the specific monoamine transporter). ADAM(7) also showed more than 1,000-fold selectivity for SERT over norepinephrine transporter (NET) and dopamine transporter (DAT) ( K(i)=699 and 840 nM, for NET and DAT, respectively). The radiolabeled compound [(125)I]ADAM(7) showed an excellent brain uptake in rats (1.41% dose at 2 min post intravenous [IV] injection), and consistently displayed the highest uptake (between 60-240 min post IV injection) in hypothalamus, a region with the highest density of SERT. The specific uptake of [(125)I]ADAM(7) in the hypothalamus exhibited the highest target-to-nontarget ratio ([hypothalamus - cerebellum]/cerebellum was 3.97 at 120 min post IV injection). The preliminary imaging study of [(123)I]ADAM in the brain of a baboon by single photon emission computed tomography (SPECT) at 180-240 min post IV injection indicated a specific uptake in midbrain region rich in SERT. These data suggest that the new ligand [(123)I]ADAM(7) may be useful for SPECT imaging of SERT binding sites in the human brain.

A novel serotonin transporter ligand: (5-iodo-2-(2-dimethylaminomethylphenoxy)-benzyl alcohol

The serotonin transporters (SERT) are the primary binding sites for selective serotonin reuptake inhibitors, commonly used antidepressants such as fluoxetine, sertraline, and paroxetine. Imaging of SERT with positron emission tomography and single photon emission computed tomography in humans would provide a useful tool for understanding how alterations of this system are related to depressive illnesses and other psychiatric disorders. In this article the synthesis and characterization of [(125)I]ODAM [(5-iodo-2-(2-dimethylaminomethylphenoxy)-benzyl alcohol, 9)] as an imaging agent in the evaluation of central nervous system SERT are reported. A new reaction scheme was developed for the preparation of compound 9, ODAM, and the corresponding tri-n-butyltin derivative 10. Upon reacting 10 with hydrogen peroxide and sodium[(125)I]iodide, the radiolabeled [(125)95%). In an initial binding study using cortical membrane homogenates of rat brain, ODAM displayed a good binding affinity with a value of K(i) = 2.8 +/- 0.88 nM. Using LLC-PK(1) cells specifically expressing the individual transporter (i.e. dopamine [DAT], norepinephrine [NET], and SERT, respectively), ODAM showed a strong inhibition on SERT (K(i) = 0.12 +/- 0.02 nM). Inhibition constants for the other two transporters were lower (K(i) = 3.9 +/- 0.7 microM and 20.0 +/- 1.9 nM for DAT and NET, respectively). Initial biodistribution study in rats after an intravenous (IV) injection of [(125)I]ODAM showed a rapid brain uptake and washout (2.03, 1.49, 0.79, 0.27, and 0.07% dose/organ at 2, 30, 60, 120, and 240 min, respectively). The hypothalamus region where the serotonin neurons are located exhibited a high specific uptake. Ratios of hypothalamus-cerebellum/cerebellum based on percent dose per gram of these two regions showed values of 0.35, 0. 86, 0.86, 0.63, and 0.34 at 2, 30, 60, 120, and 240 min, post-IV injection, respectively. The specific uptake in hypothalamus can be effectively blocked by pretreatment of known SERT ligands. The results suggest that this novel ligand displays desirable in vitro and in vivo properties as a potential SERT imaging agent.

A simplified method to determine [99mTc]TRODAT-1 in human plasma

[99mTc]TRODAT-1 is a useful imaging agent in evaluating changes in presynaptic dopamine transporters (DAT) for Parkinson's disease and other central nervous system (CNS) neurodegenerative diseases, for which a reduction of dopamine neurons is indicated. As part of an effort to establish a quantitative single-photon emission tomography (SPECT) procedure for imaging CNS DAT, measurement of nonmetabolized [99mTc]TRODAT-1 in human plasma was investigated. After an intravenous injection of [99mTc]TRODAT-1, there are three possible radioactive components in human plasma: hydrophilic compounds (pertechnetate, etc.), lipophilic metabolite(s), and unchanged [99mTc]TRODAT-1. Based on the differences in lipophilicity of [99mTc]TRODAT-1 and its lipophilic metabolite [99mTc]BAT, a new quantitative method for measuring [99mTc]TRODAT-1 with a simple solvent extraction method was developed. Various organic solvents or mixtures of solvents were tested, among which cyclohexane gave the best extraction yield for [99mTc]TRODAT-1 (76.06 +/- 3.32%) with a low extraction for [99mTc]BAT (2.43 +/- 0.82%). Extractions of [99mTc]TRODAT-1 and [99mTc]BAT mixtures in different predetermined ratios to simulate the actual human plasma samples with cyclohexane from phosphate buffer (5 mM, pH 8.0) were evaluated. The experimentally obtained ratios were in good agreement with the theoretical ratios. To investigate further the possibility of replacing the previously established high performance liquid chromatography (HPLC) method with the new solvent extraction method for the clinical application, both HPLC and extraction methods were used side by side to determine the unchanged [99mTc]TRODAT-1 in human plasma samples during [99mTc]TRODAT-1/SPECT imaging studies. The results from four human subjects showed that both methods consistently produced similar values for unchanged [99mTc]TRODAT-1 in the plasma samples. This improved solvent extraction method provides an easy and reliable technique to quantify unchanged [99mTc]TRODAT-1 in human plasma, thus making the clinical application of this agent readily available for quantitation of the DAT binding sites in the brain by SPECT imaging.

Single-photon emission tomography imaging of serotonin transporters in the nonhuman primate brain with [(123)I]ODAM

We have described previously a selective serotonin transporter (SERT) radioligand, [(123)I]IDAM. We now report a similarly potent, but more stable IDAM derivative, 5-iodo-2-[2-[(dimethylamino)methyl]phenoxy]benzyl alcohol ([(123)I]ODAM). The imaging characteristics of this radioligand were studied and compared against [(123)I]IDAM. Dynamic sequences of single-photon emission tomography (SPET) scans were obtained on three female baboons after injection of 375 MBq of [(123)I]ODAM. Displacing doses (1 mg/kg) of the selective SERT ligand (+)McN5652 were administered 120 min after injection of [(123)I]ODAM. Total integrated brain uptake of [(123)I]ODAM was about 30% higher than [(123)I]IDAM. After 60-120 min, the regional distribution of tracer within the brain reflected the characteristic distribution of SERT. Peak specific binding in the midbrain occurred 120 min after injection, with an equilibrium midbrain to cerebellar ratio of 1. 50+/-0.08, which was slightly lower than the value for [(123)I]IDAM (1.80+/- 0.13). Both the binding kinetics and the metabolism of [(123)I]ODAM were slower than those of [(123)I]IDAM. Following injection of a competing SERT ligand, (+)McN5652, the tracer exhibited washout from areas with high concentrations of SERT, with a dissociation kinetic rate constant k(off)=0.0085+/-0.0028 min(-1) in the midbrain. Similar studies using nisoxetine and methylphenidate showed no displacement, consistent with its low binding affinity to norepinephrine and dopamine transporters, respectively. These results suggest that [(123)I]ODAM is suitable for selective SPET imaging of SERT in the primate brain, with higher uptake and slower kinetics and metabolism than [(123)I]IDAM, but also a slightly lower selectivity for SERT.

The reaction of thiolates with 2,3-dibromo-1-propanol revisited: application to the synthesis of bis(fattyalkylthio)propanols

This work compares two reaction schemes for preparing 2,3-bis(fattyalkylthio)-1-propanols for further synthetic adaptation as hydrophobic analogs of lung surfactant phosphatidylcholines. An attempt to prepare 2,3-bis(fattyalkylthio)-1-propanols based on the previously published methods of Bell and co-workers (B.R. Ganong, C.R. Loomis, Y.A. Hannun, R.M. Bell, 1986. Proc. Natl. Acad. Sci. USA 83, 1184-1188; B.R. Ganong, R.M. Bell, 1987. Methods Enzymol. 141, 313-320; J.P. Walsh, L. Fahrner, R.M. Bell, 1990. J. Biol. Chem. 265, 4374-4381) was found to give the rearranged 1,3-bis(fattyalkylthio)-2-propanols as major products. As a reliable alternative, the reaction of ethyl 2,3-dibromopropionate with 2 equivalents of long chain sodium n-alkanethioates gave the corresponding ethyl 2,3-bis(n-alkylthio)propionates, which were then reduced with LiAlH4 to yield the desired 2,3-bis(fattyalkylthio)-1-propanols. Both 13C and 1H NMR spectroscopy were used to differentiate the two possible 1,3- and 2,3-dithio substituted alcohol products and to rigorously assign their structures.

Characterization of [(123)I]IDAM as a novel single-photon emission tomography tracer for serotonin transporters

Development of selective serotonin transporter (SERT) tracers for single-photon emission tomography (SPET) is important for studying the underlying pharmacology and interaction of specific serotonin reuptake site inhibitors, commonly used antidepressants, at the SERT sites in the human brain. In search of a new tracer for imaging SERT, IDAM (5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol) was developed. In vitro characterization of IDAM was carried out with binding studies in cell lines and rat tissue homogenates. In vivo binding of [(125)I]IDAM was evaluated in rats by comparing the uptakes in different brain regions through tissue dissections and ex vivo autoradiography. In vitro binding study showed that IDAM displayed an excellent affinity to SERT sites (K(i)=0.097 nM, using membrane preparations of LLC-PK(1) cells expressing the specific transporter) and showed more than 1000-fold of selectivity for SERT over norepinehrine and dopamine (expressed in the same LLC-PK(1) cells). Scatchard analysis of [(125)I]IDAM binding to frontal cortical membrane homogenates prepared from control or p-chloroamphetamine (PCA)-treated rats was evaluated. As expected, the control membranes showed a K(d) value of 0.25 nM+/-0.05 nM and a B(max) value of 272+/-30 fmol/ mg protein, while the PCA-lesioned membranes displayed a similar K(d), but with a reduced B(max) (20+/-7 fmol/ mg protein). Biodistribution of [(125)I]IDAM (partition coefficient =473; 1-octanol/buffer) in the rat brain showed a high initial uptake (2.44%dose at 2 min after i.v. injection) with the specific binding peaked at 60 min postinjection (hypothalamus-cerebellum/cerebellum =1.75). Ex vivo autoradiographs of rat brain sections (60 min after i.v. injection of [(125)I]IDAM) showed intense labeling in several regions (olfactory tubercle, lateral septal nucleus, hypothalamic and thalamic nuclei, globus pallidus, central gray, superior colliculus, substantia nigra, interpeduncular nucleus, dorsal and median raphes and locus coeruleus), which parallel known SERT density. This novel tracer has excellent characteristics for in vivo SPET imaging of SERT in the brain.

Single-photon emission tomography imaging of serotonin transporters in the non-human primate brain with the selective radioligand [(123)I]IDAM

A new radioligand, 5-iodo-2-[[2-2-[(dimethylamino)methyl]phenyl]thio]benzyl alcohol ([(123)I]IDAM), has been developed for selective single-photon emission tomography (SPET) imaging of SERT. In vitro binding studies suggest a high selectivity of IDAM for SERT (K(i)=0.097 nM), with considerably lower affinities for norepinephrine and dopamine transporters (NET K(i)= 234 nM and DAT K(i)>10 microM, respectively). In this study the biodistribution of SERT in the baboon brain was investigated in vivo using [(123)I]IDAM and SPET imaging. Dynamic sequences of SPET scans were performed on three female baboons (Papio anubis) after injection of 555 MBq of [(123)I]IDAM. Displacing doses (1 mg/kg) of the selective SERT ligand (+)McN5652 were administered 90-120 min after injection of [(123)I]IDAM. Similar studies were performed using a NET inhibitor, nisoxetine, and a DAT blocker, methylphenidate. After 60-120 min, the regional distribution of tracer within the brain reflected the characteristic distribution of SERT, with the highest uptake in the midbrain area (hypothalamus, raphe nucleus, substantia nigra), and the lowest uptake in the cerebellum (an area presumed free of SERT). Peak specific binding in the midbrain occurred at 120 min, with a ratio to the cerebellum of 1.80+/-0.13. At 30 min, 85% of the radioactivity in the blood was metabolite. Following injection of a competing SERT ligand, (+)McN5652, the tracer exhibited rapid washout from areas with high concentrations of SERT (dissociation rate constant in the midbrain, averaged over three baboons, k(off)=0. 025+/-0.002 min(-1)), while the cerebellar activity distribution was undisturbed (washout rate 0.0059+/- 0.0003 min(-1)). Calculation of tracer washout rate pixel-by-pixel enabled the generation of parametric images of the dissociation rate constant. Similar studies using nisoxetine and methylphenidate had no effect on the distribution of [(123)I]IDAM in the brain. These results suggest that [(123)I]IDAM is suitable for selective SPET imaging of SERT in the primate brain, with high contrast, favorable kinetics, and negligible binding to either NET or DAT.

Simultaneous SPECT studies of pre- and postsynaptic dopamine binding sites in baboons

The central nervous system dopamine transporters (DATs) and dopamine D2/D3 receptors are implicated in a variety of neurological disorders. Both sites are also targets for drug treatment. With the successful development of [99mTc]TRODAT-1, single-isotope imaging studies using this ligand for DAT imaging can be complemented by additional use of 123I-labeled D2/D3 receptor ligand co-injected to assess both pre- and postsynaptic sites of the dopaminergic system simultaneously.

METHODS

Twelve SPECT scans of the brain were obtained in two baboons after intravenous administration of 740 MBq (20 mCi) [99mTc]-TRODAT-1 (technetium, [2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3,2,1]oct-2-yl]methyl ](2-mercaptoethyl) amino]ethyl]-amino]ethanethiolato (3-)]- oxo-[1R-(exo-exo)]) and 185 MBq (5 mCi) [123I]iodobenzamide or [123I]iodobenzofuran. SPECT data were acquired by a triple-head gamma camera equipped with ultra-high-resolution fanbeam collimators (scan duration = 210 min). Two sets of SPECT data were obtained using energy windows of 15% centered on 140 keV for 99mTc and 10% asymmetric with a lower bound at 159 keV for 123I. After coregistration with MRI, region-of-interest analysis was performed using predefined templates from coregistered MRI. In blocking studies, baboons were pretreated with N-methyl-2beta-carbomethoxy-3beta-(4-fluorophenyl)tropane (CFT, 14 mg) or raclopride (14 mg) to block DAT or D2/D3 binding site, respectively.

RESULTS

Image quality of dual-isotope studies was similar to that obtained from single-isotope studies. When one site was blocked with CFT or raclopride, the binding of the respective ligand to the other site was not affected.

CONCLUSION

This is the first example that clearly demonstrates the feasibility of simultaneous imaging of both pre- and postsynaptic sites of the dopaminergic system in baboons with dual-isotope SPECT studies. With or without corrections for cross-contamination of 123I into the 99mTc window, striatum-to-cerebellum ratios (target-to-nontarget) of dual-isotope experiments did not differ significantly from single-isotope experiments. This method may be a valuable and cost-effective tool for gaining comprehensive information about the dopaminergic system in one SPECT imaging session.

99mTc-labeled MIBG derivatives: novel 99mTc complexes as myocardial imaging agents for sympathetic neurons

Radioactive-iodine-labeled meta-iodobenzylguanidine (MIBG) is currently being used as an in vivo imaging agent to evaluate neuroendocrine tumors as well as the myocardial sympathetic nervous system in patients with myocardial infarct and cardiomyopathy. It is generally accepted that MIBG is an analogue of norepinephrine and its uptake in the heart corresponds to the distribution of norepinephrine and the density of sympathetic neurons. A series of MIBG derivatives containing suitable chelating functional groups N2S2 for the formation of [TcvO]3+N2S2 complex was successfully synthesized, and the 99mTc-labeled complexes were prepared and tested in rats. One of the compounds, [99mTc]2, tested showed significant, albeit lower, heart uptakes post iv injection in rats (0.21% dose/g at 4 h) as compared to [125I]MIBG (1.7% dose/g at 4 h). The heart uptake of the 99mTc-labeled complex appears to be specific and can be reduced by co-injection with nonradioactive MIBG or by pretreatment with desipramine, a selective norepinephrine transporter inhibitor. Further evaluation of the in vitro uptake of [99mTc]2 in cultured neuroblastoma cells displayed consistently lower, but measurable uptake (approximately 10% of that for [125I]MIBG). These preliminary results suggested that the mechanisms of heart uptake of [99mTc]2 may be related to those for [125I]MIBG uptake. If suitable 99mTc-labeled MIBG derivatives can be further developed, the prevalent availability of 99mTc in nuclear medicine clinics will allow them to be readily available for widespread application.

Neutral and stereospecific Tc-99m complexes: [99mTc]N-benzyl-3,4-di-(N-2-mercaptoethyl)-amino-pyrrolidines (P-BAT)

Technetium-99m-labeled radiopharmaceuticals are currently the most commonly used agents in nuclear medicine. To prepare binding site-specific small molecules containing a Tc-99m complexing core, it is important to consider a ligand system, which selectively forms only one stereoisomer. A novel series of bisaminoethanethiol (BAT) derivatives as a model system were prepared. Stereoisomers of N-benzyl-3,4-di(N-2-mercaptoethyl)-amino pyrrolidines (P-BAT): (3R,4R)-P-BAT (R,R-4) and (3,4)meso-P-BAT (8), the trans and meso isomer, respectively, as a chelating group were prepared successfully. The desired Tc-99m P-BAT complexes were obtained by using Sn(II)/glucoheptonate as the reducing agent for [99mTc]pertechnetate. As predicted, after complexation with [99mTc]Tc'O, the trans isomer, (3R,4R)-P-BAT (R,R-4), showed only one isomer; whereas the corresponding meso isomer, (3,4)meso-P-BAT (8), produced two distinctive complexes isolated readily by high performance liquid chromatography (HPLC). The [99mTc](R,S) meso-P-BAT (8) isomers showed a different lipophilicity (partition coefficient [P.C.] = 54.3 and 55.4 for peak A and peak B, respectively), as compared with that of the corresponding [99mTc](3R,4R)-P-BAT (R,R-4), trans isomer (P.C. = 163). Results of the biodistribution study in rats of these isomers show different heart and brain uptake, suggesting that the intrinsic differences in biodistribution are due to structural and stereospecific factors. Examples in this report confirm that it is possible to design stereospecific Tc-99m complexes based on the bisaminoethanethiol (N2S2, BAT) ligand system. Consideration on stereoselectivity of site-specific agents labeled with Tc-99m is likely an essential requirement on developing binding-site specific radiopharmaceuticals.

Kinetic modeling of [99mTc]TRODAT-1: a dopamine transporter imaging agent

[99mTc]Technetium[2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo [3.2.1] oct-2-yl]-methyl] (2-mercaptoethyl) amino] ethyl] amino] ethane-thiolato(3-)-N2,N2',S2,S2']oxo-[1R-(exo-exo)] ([99mTc] TRODAT-1) is a useful imaging agent for central nervous system dopamine transporters. The purpose of this study was to characterize the in vivo binding potential and kinetic rate constants of this agent in nonhuman primates.

METHODS

A series of four SPECT scans were performed on each of two female baboons with a bolus injection of [99mTc]TRODAT-1 (717+/-78 MBq; 19.38+/-2.12 mCi). Dynamic images of the brain were acquired over 4 h using a triple-head camera equipped with fan-beam collimators. Arterial and venous blood were sampled frequently using a peristaltic pump throughout the duration of the study. Regions of interest were drawn on the corresponding MRI scan to which each functional image was coregistered. Using analytical solutions to the three-compartment model with the Levenberg-Marquardt minimization technique, each study was individually fitted to a kinetic parameter vector (method I). Additionally, within each subject, three corresponding intrasubject studies were fitted simultaneously to a single parameter vector by constraining the binding potential, distribution volume and dissociation rate constant to improve the identifiability of the parameter estimates (method II).

RESULTS

The results clearly indicated that [99mTc] TRODAT-1 localized in the striatum with slower washout rate than other brain regions. A maximal target/nontarget ratio of 3.5 between striatum and cerebellum was obtained. SPECT image analysis of the striatum yielded unconstrained k3/k4 values of 3.4+/-1.4, 2.4+/-0.7, 3.0+/-1.5, and 4.0+/-10.3, with respective constrained (fixed k4) values of 2.9 +/- 0.4, 2.4 +/- 0.4, 1.7+/-0.4 and 1.8+/-0.4 in one baboon using method I. With method II, the corresponding simultaneously fitted values were 2.1+/-0.3 using no constraints and 2.2+/-0.2 using a fixed k4. The second baboon had similar results.

CONCLUSION

These findings suggest that the binding potential and corresponding kinetic rate constants can be reliably estimated in nonhuman primates with dynamic SPECT imaging of the dopamine transporter using a technetium-based tropane analogue. Furthermore, method II parameter vectors compare favorably to those produced using method I based on SEEs.

NCS-MPP (4-(2'-methoxy-phenyl)-1-[2'-(N-2"-pyridyl)-p-isothiocyanobenz amido]-ethyl-piperazine): a high affinity and irreversible 5-HT1A receptor ligand

A novel irreversible 5-HT1A receptor binding ligand, NCS-MPP (4-(2'- methoxy-phenyl)-1-[2'-(N-2"-pyridyl)-p-isothiocyanobenzamido]- ethyl-piperazine), based on the new 5-HT1A receptor antagonist p-MPPI (4-(2'-methoxy-phenyl)-1-[2'-(N-2"-pyridyl)-p-iodobenzamido]-ethyl -piperazine ), was synthesized, and its binding characteristics were evaluated using in vitro homogenate binding with rat hippocampal membranes. The Ki value of NCS-MPP was estimated to be 1.8 +_ 0.2 nM using analysis of concentration-dependent inhibition for the binding of [125I]p-MPPI to 5-HT1A receptors. NovaScreen of NCS-MPP showed low to moderate binding affinities to alpha-1, alpha-2-adrenergic and 5-HT2 receptors, with Ki values of 350, 420, and 103 nM, respectively. These data strongly suggest that the ligand bound to 5-HT1A receptors with high affinity and high selectivity. Irreversible inhibition of [125I]p-MPPI binding by NCS-MPP following a 5 min incubation at room temperature was concentration dependent; the inhibition increased to 50% at a concentration less than 10 nM, and became more pronounced (90%) at 400 nM. Under similar assay conditions, NCS-MPP was significantly less efficient in irreversibly inhibiting agonist ligand [125I]8-OH-PIPAT binding to 5-HT1A receptors at lower concentrations (<10nM). After pretreatment of membranes with a low concentration of NCS-MPP (2nM), there was an apparent loss of [125I]p-MPPI binding sites, as expected, but no change in the binding affinity (Kd) was observed. However, the significant increase in Kd at a higher concentration of NCS-MPP (50 nM) indicated that there may be a secondary alkylation site, which may not be directly involved in p-MPPI binding to receptors; nevertheless, it would lead to an increased Kd value. The availability of an irreversible ligand, NCS-MPP, may provide a useful tool for studies of 5-HT1A receptors in the central nervous system.

Specificity of diastereomers of [99mTc]TRODAT-1 as dopamine transporter imaging agents

Recently, we reported the first human study of [99mTc]TRODAT-1, technetium, 2-[[2-[[[3-(4-chlorophenyl)-8-methyl-8-azabicyclo[3.2.1]oct-2- yl]methyl](2-mercaptoethyl)amino]ethyl]amino]-ethanethiolato(3-)-o xo- [1R-(exo-exo)]-, as an imaging agent of central nervous system (CNS) dopamine transporters. Due to the existence of several chiral centers on this molecule, upon the formation of [99mTc]TRODAT-1 complex (2) several diastereomers could be created. Two major diastereomers of [99mTc]TRODAT-1 (2), designated as peak A (2A) and peak B (2B), were separated by HPLC. Biodistribution of the purified diastereomers 2A,B was evaluated in rats. It appears that 2A displayed a higher lipophilicity than 2B (PC = 305 and 229, respectively), and a similar trend was observed for the initial brain uptake at 2 min postinjection (0.50% and 0.28% dose/organ for 2A,B, respectively). At 60 min post-iv-injection, the specific uptakes, as measured by [striatum - cerebellum]/cerebellum ([ST-CB]/CB) ratio, were 1.72 and 2.79 for 2A,B, respectively. The higher [ST-CB]/CB ratio observed for 2B was corroborated by the results of an in vitro binding assay. Higher binding affinity for dopamine transporters was observed for 3B (Ki = 13.87 and 8.42 nM for the analogous rhenium complexes 3A,B, respectively). The structure of the [99mTc]TRODAT-1 complexes was deduced using nonradioactive rhenium as a surrogate for radioactive technetium complex. Reacting free TRODAT-1 ligand with [Bu4N][ReOCl4] yielded two major complexes: Re-TRODAT-1A (3A) and Re-TRODAT-1B (3B) (corresponding with peaks A and B of [99mTc]TRODAT-1, respectively), whose structures were determined by X-ray analysis. The X-ray structures show that both complexes have a pseudo-square-pyramidal structure of [RevO]3+N2S2 core with oxygen occupying the apical position and the N-alkyl substitution in syn-configuration to the oxo-rhenium bond. In conclusion, TRODAT-1 formed at least two diastereomers after complexing with a metal(V)-oxo (M = 99mTc, Re) center core. The two isomers display different binding affinities toward dopamine transporters and distinct properties of localization in the striatum area of the brain where the transporters are located.