Computer-aided diagnosis system for optical diagnosis of colorectal polyps under white light imaging

OBJECTIVES

This study presents a novel computer-aided diagnosis (CADx) designed for optically diagnosing colorectal polyps using white light imaging (WLI).We aimed to evaluate the effectiveness of the CADx and its auxiliary role among endoscopists with different levels of expertise.

METHODS

We collected 2,324 neoplastic and 3,735 nonneoplastic polyp WLI images for model training, and 838 colorectal polyp images from 740 patients for model validation. We compared the diagnostic accuracy of the CADx with that of 15 endoscopists under WLI and narrow band imaging (NBI). The auxiliary benefits of CADx for endoscopists of different experience levels and for identifying different types of colorectal polyps was also evaluated.

RESULTS

The CADx demonstrated an optical diagnostic accuracy of 84.49%, showing considerable superiority over all endoscopists, irrespective of whether WLI or NBI was used (P < 0.001). Assistance from the CADx significantly improved the diagnostic accuracy of the endoscopists from 68.84% to 77.49% (P = 0.001), with the most significant impact observed among novice endoscopists. Notably, novices using CADx-assisted WLI outperform junior and expert endoscopists without such assistance.

CONCLUSIONS

The CADx demonstrated a crucial role in substantially enhancing the precision of optical diagnosis for colorectal polyps under WLI and showed the greatest auxiliary benefits for novice endoscopists.

A novel self-inflatable balloon for treating refractory benign esophageal strictures: a prospective, single-arm, multicenter study

BACKGROUND AND AIM

Current treatments for refractory benign esophageal strictures (BESs) often take several years and have poor effects. The authors propose a novel method of self-help inflatable balloon (SHIB) and evaluate its efficacy and safety.

METHODS

A prospective, multicenter study was conducted from January 2019 to March 2022. All enrolled patients were diagnosed with refractory BESs and received SHIB. The primary endpoint was the clinical success rate at 12 months after removing SHIB. The secondary endpoints were the number of days of placing SHIB, and changes from baseline in BMI and health-related quality of life at 1, 3, 6, and 12 months.

RESULTS

The clinical success rate was 51.2% (21/41) with the median days of placing SHIB being 104.0 days (range: 62.0-134.5 days), which was higher in the endoscopic group compared to the caustic and surgery groups (63.3 vs. 28.6% vs. 0, P=0.025). All patients (100%) showed significant improvement in dysphagia scores during placing SHIB. Although 20 patients (48.8%) experienced recurrent stricture, the median stricture length was decreased (P<0.001) and the median intervention-free interval was prolonged (P<0.001). In all patients, the mean BMI at and health-related quality of life at 1, 3, 6, and 12 months were significantly increased compared with baseline (P<0.05). On multivariate analysis, stricture etiology and wearing time were independent predictors of recurrent stricture.

CONCLUSIONS

The SHIB has high efficacy and safety in treating refractory BESs of different origins, especially for endoscopic resection. Stricture etiology and wearing time were independent predictors of recurrent stricture.

Genetic Factors Associated With Adverse Pregnancy Outcomes in Chronic Pancreatitis

INTRODUCTION

The effects of genetic factors on pregnancy outcomes in chronic pancreatitis (CP) patients remain unclear. We evaluated the impacts of clinical features and mutations in main CP-susceptibility genes ( SPINK1 , PRSS1 , CTRC , and CFTR ) on pregnancy outcomes in Chinese CP patients.

METHODS

This was a prospective cohort study with 14-year follow-up. The sample comprised female CP patients with documented pregnancy and known genetic backgrounds. Adverse pregnancy outcomes were compared between patients with and without gene mutations. Univariate and multivariate analyses were performed to determine the impact factors for adverse pregnancy outcomes.

RESULTS

Totally, 160 female CP patients with a pregnancy history were enrolled; 59.4% of patients carried pathogenic mutations in CP-susceptibility genes. Adverse pregnancy outcomes occurred in 38 patients (23.8%); the prevalence of adverse outcomes was significantly higher in those harboring gene mutations than those without (30.5% vs 13.8%, P = 0.015). Notably, the rates of preterm delivery (12.6% vs 3.1%, P = 0.036) and abortion (17.9% vs 4.6%, P = 0.013) were remarkably higher in patients with gene mutations (especially SPINK1 mutations) than those without. In multivariate analyses, both CP-susceptibility gene mutations (odds ratio, 2.52; P = 0.033) and SPINK1 mutations (odds ratio, 2.60; P = 0.037) significantly increased the risk of adverse pregnancy outcomes. Acute pain attack during pregnancy was another risk factor for adverse pregnancy outcomes.

DISCUSSION

Pathogenic mutations in CP-susceptibility genes, especially SPINK1 , were independently related to adverse pregnancy outcomes in CP patients. Significant attention should be paid to pregnant females harboring CP-susceptibility gene mutations (ClinicalTrials.gov: NCT06055595).

Nicotinamide adenine dinucleotide phosphate oxidase in pancreatic diseases: Mechanisms and future perspectives

Pancreatitis and pancreatic cancer (PC) stand as the most worrisome ailments affecting the pancreas. Researchers have dedicated efforts to unraveling the mechanisms underlying these diseases, yet their true nature continues to elude their grasp. Within this realm, oxidative stress is often believed to play a causal and contributory role in the development of pancreatitis and PC. Excessive accumulation of reactive oxygen species (ROS) can cause oxidative stress, and the key enzyme responsible for inducing ROS production in cells is nicotinamide adenine dinucleotide phosphate hydrogen oxides (NOX). NOX contribute to pancreatic fibrosis and inflammation by generating ROS that injure acinar cells, activate pancreatic stellate cells, and mediate macrophage polarization. Excessive ROS production occurs during malignant transformation and pancreatic carcinogenesis, creating an oxidative microenvironment that can cause abnormal apoptosis, epithelial to mesenchymal transition and genomic instability. Therefore, understanding the role of NOX in pancreatic diseases contributes to a more in-depth exploration of the exact pathogenesis of these diseases. In this review, we aim to summarize the potential roles of NOX and its mechanism in pancreatic disorders, aiming to provide novel insights into understanding the mechanisms underlying these diseases.

The role of mitochondria-related lncRNAs in characterizing the immune landscape and supervising the prognosis of osteosarcoma

Mitochondrial damage is related to the functional properties of immune cells as well as to tumorigenesis and progression. Nevertheless, there is an absence concerning the systematic evaluation of mitochondria-associated lncRNAs (MALs) in the immune profile and tumor microenvironment of osteosarcoma patients. Based on transcriptomic and clinicopathological data from the TARGET database, MAL-related patterns were ascertained by consistent clustering, and gene set variation analysis of the different patterns was completed. Next, a MAL-derived scoring system was created using Cox and LASSO regression analyses and validated by Kaplan-Meier and ROC curves. The GSEA, ESTIMATE, and CIBERSORT algorithms were utilized to characterize the immune status and underlying biological functions in the different MAL score groups. MAL-derived risk scores were well stabilized and outperformed traditional clinicopathological features to reliably predict 5-year survival in osteosarcoma cohorts. Moreover, patients with increased MAL scores were observed to suffer from poorer prognosis, higher tumor purity, and an immunosuppressive microenvironment. Based on estimated half-maximal inhibitory concentrations, the low-MAL score group benefited more from gemcitabine and docetaxel, and less from thapsigargin and sunitinib compared to the high-MAL score group. Pan-cancer analysis demonstrated that six hub MALs were strongly correlated with clinical outcomes, immune subtypes, and tumor stemness indices in various common cancers. Finally, we verified the expression patterns of hub MALs in osteosarcoma with qRT-PCR. In summary, we identified the crosstalk between prognostic MALs and tumor-infiltrating immune cells in osteosarcoma, providing a potential strategy to ameliorate clinical stratification management.

Per-oral endoscopic myotomy is safe and effective for pediatric patients with achalasia: A long-term follow-up study

BACKGROUND

Per-oral endoscopic myotomy (POEM) is emerging as a prefer treatment option for pediatric achalasia. However, data are limited on the long-term efficacy of POEM in children and adolescents with achalasia.

AIM

To evaluate the safety and long-term efficacy of POEM for pediatric patients with achalasia and compare those outcomes with adult patients.

METHODS

This retrospective cohort study was conducted in patients with achalasia who underwent POEM. Patients aged under 18 years were included in the pediatric group; patients aged between 18 to 65 years who underwent POEM in the same period were assigned to the control group. For investigation of long-term follow-up, the pediatric group were matched with patients from the control group in a 1:1 ratio. The procedure-related parameters, adverse events, clinical success, gastroesophageal reflux disease (GERD) after POEM, and quality of life (QoL) were evaluated.

RESULTS

From January 2012 to March 2020, POEM was performed in 1025 patients aged under 65 years old (48 in the pediatric group, 1025 in the control group). No significant differences were observed in the occurrence of POEM complications between the two groups (14.6% vs 14.6%; P = 0.99). Among the 34 pediatric patients (70.8%) who underwent follow-up for 5.7 years (range 2.6-10.6 years), clinical success was achieved in 35 patients (35/36; 97.2%). No differences were observed in post-POEM GERD occurrence (17.6% vs 35.3%; P = 0.10). QoL was significantly improved in both groups after POEM.

CONCLUSION

POEM is safe and effective for pediatric patients with achalasia. It can achieve significant symptoms relief and improve QoL.

A modified exposed endoscopic full-thickness resection: traction-assisted resection while defect closing

AIMS

Exposed endoscopic full-thickness resection (Eo-EFTR) has been proven to be effective and economical for patients with gastric submucosal tumors (SMTs), showing great prospects. However, the poor operational field of view, the risk of tumors falling into the peritoneal cavity, and especially the difficulties in defect closure limited its widespread applicability. Herein, we described a modified traction-assisted Eo-EFTR technique, aiming to simplify both the dissection and defect closure procedures.

METHODS

There were 19 patients who underwent the modified Eo-EFTR for SMTs in Chinese PLA General Hospital enrolled in the study. Following a two-thirds circumferential full-thickness incision, a clip with dental floss was anchored to the resected part of the tumor surface. With the dental floss traction, the gastric defect was reshaped as a "V"-shape which facilitated the deployment of clips to close the defect. The defect closing and tumor dissecting procedures were then performed alternately. Patients' demographics, tumor characteristics, and therapeutic outcomes were evaluated retrospectively.

RESULTS

All tumors had an R0 resection. The median procedure time was 43 min (range 28-89min). No severe adverse events occured. Two patients experienced transient fever and three patients complained of mild abdominal pain on the first day after operation. All patients recovered on the next day with conservative management. No residual lesion or recurrence was reported during the follow-up period.

CONCLUSIONS

The safety and practicability of the modified technique might provide the possibility for wide clinical applications of Eo-EFTR in gastric SMTs. This article is protected by copyright. All rights reserved.

Comprehensive multi-omics analysis reveals m7G-related signature for evaluating prognosis and immunotherapy efficacy in osteosarcoma

Background

Osteosarcoma is one of the most prevalent bone malignancies with a poor prognosis. The N7-methylguanosine (m7G) modification facilitates the modification of RNA structure and function tightly associated with cancer. Nonetheless, there is a lack of joint exploration of the relationship between m7G methylation and immune status in osteosarcoma.

Methods

With the support of TARGET and GEO databases, we performed consensus clustering to characterize molecular subtypes based on m7G regulators in all osteosarcoma patients. The least absolute shrinkage and selection operator (LASSO) method, Cox regression, and receiver operating characteristic (ROC) curves were employed to construct and validate m7G-related prognostic features and derived risk scores. In addition, GSVA, ssGSEA, CIBERSORT, ESTIMATE, and gene set enrichment analysis were conducted to characterize biological pathways and immune landscapes. We explored the relationship between risk scores and drug sensitivity, immune checkpoints, and human leukocyte antigens by correlation analysis. Finally, the roles of EIF4E3 in cell function were verified through external experiments.

Results

Two molecular isoforms based on regulator genes were identified, which presented significant discrepancies in terms of survival and activated pathways. Moreover, the six m7G regulators most associated with prognosis in osteosarcoma patients were identified as independent predictors for the construction of prognostic signature. The model was well stabilized and outperformed traditional clinicopathological features to reliably predict 3-year (AUC = 0.787) and 5-year (AUC = 0.790) survival in osteosarcoma cohorts. Patients with increased risk scores had a poorer prognosis, higher tumor purity, lower checkpoint gene expression, and were in an immunosuppressive microenvironment. Furthermore, enhanced expression of EIF4E3 indicated a favorable prognosis and affected the biological behavior of osteosarcoma cells.

Conclusions

We identified six prognostic relevant m7G modulators that may provide valuable indicators for the estimation of overall survival and the corresponding immune landscape in patients with osteosarcoma.

The correlation of sacral table angle to spinopelvic sagittal alignment in healthy adults

BACKGROUND

The sacrum plays an important role in sagittal balance of the spine, whereas the exact association between sacral parameters, specifically the sacral table angle (STA) and spinopelvic parameters has been only scarcely assessed. It aims to investigate the correlations between the sacral parameters and spinopelvic sagittal alignment parameters in healthy adults.

METHODS

A cohort of 142 Northern Chinese healthy adults between 18 and 45 years old were recruited between April 2019 and March 2021. Full-spine standing X-ray films were performed for every volunteer. The sacral parameters were measured: sacral table angle (STA), sacral inclination (SI) and sacral slope (SS). The spinopelvic sagittal alignment parameters included: pelvic incidence (PI), pelvic tilt (PT), lumbar lordosis (LL), thoracic kyphosis and the apex of lumbar lordosis (LLA). The correlations analysis, as well as the linear regression analysis, were performed between STA, SI and the spinopelvic parameters.

RESULTS

An equation 'STA = SI + 90 - SS' was revealed to represent the interrelationships between STA, SI and SS. STA was statistically correlated with PI (r_s = - 0.693), PT (r_s = - 0.342), SS (r_s = - 0.530), LL (r_s = 0.454), and LLA (r_s = 0.438). SI correlated with STA (r_s = 0.329), PT (r_s =  - 0.562), SS (r_s =  - 0.612) and LL (r_s = 0.476). Simple linear regression analysis also verified the correlation between STA and PI (y = - 1.047x + 149.4), SS (y = - 0.631x + 96.9), LL (y = 0.660x - 117.7), LLA (y = 0.032x + 0.535), and SI (y = 0.359x + 8.23).

CONCLUSION

The equation 'STA = SI + 90 - SS' indicates the exact geometric relationship between STA, SI and SS. The sacral parameters, both STA and SI, correlate to the spinopelvic sagittal alignment parameters in healthy adults. The linear regression analysis results also give predictive models for spinopelvic sagittal alignment parameters based on the invariant parameter STA, which are helpful for surgeons in designing an ideal therapeutic plan.

Anatomic feasibility of a modified 3-distal site anesthesia injection method for impacted mandibular third molar extraction using cone-beam computed tomography

Background

Various injection methods have been used to improve the success rate of inferior alveolar nerve (IAN) block and reduce the pain and complications. But these methods also have their advantages and disadvantages. A modified 3-distal site anesthesia injection method proposed in 2015 was used clinically with satisfactory results at some dental clinics in China. This study aimed to determine the feasibility of this modified 3-distal site anesthesia injection method for extraction of an impacted mandibular third molar from an anatomical point of view.

Methods

Three-dimensional (3D) reconstruction and analysis of the mandibles was performed using cone-beam computed tomography (CBCT) scanning to measure the simulated needle insertion depth, infiltration distance, and other important parameters. These parameters were compared with an actual depth of 20 mm and a theoretic infiltration distance of 10 mm. The main parameters were compared between males and females.

Results

Sixty-three CBCT datasets were imported into Simplant OMS software for 3D reconstruction. The left simulated insertion depth did not differ from 20 mm, while right insertion depth was >20 mm (P<0.05). The bilateral infiltration distances were <10 mm (P<0.05) and articaine blocked the IAN. The widths of the mandibular rami were greater than the syringe length (21 mm), thus it was not possible for the syringe to reach the distal edge of the mandible. There was no difference in the simulated needle insertion depth and infiltration distance between the left and right (P>0.05). The bilateral simulated insertion depths, infiltration distances, widths of the mandibular rami, and height of the left mandibular foramen in females were less than in males (P<0.05), while there was no difference in the height of the right mandibular foramen and bilateral insertion angles (P>0.05).

Conclusions

The modified 3-distal site anesthesia injection method was shown to block the IAN based on anatomic evidence derived from 3D analysis on the measurements by CBCT.

The Impacts of Genetic and Environmental Factors on the Progression of Chronic Pancreatitis

BACKGROUND & AIMS

Both environmental factors, such as alcohol consumption and smoking, and genetic factors are strongly associated with the risk of developing chronic pancreatitis (CP). However, comprehensive understanding of their impacts on the progression of CP remains elusive.

METHODS

A prospective cohort study was performed on a large cohort of CP patients with known genetic backgrounds. The cumulative incidence of pancreatic insufficiency after the onset of CP was analyzed using Kaplan-Meier survival curves. Multivariate Cox proportional hazards regression analysis also was performed.

RESULTS

A total of 798 patients were enrolled in the study and followed up for 10.5 years. Rare pathogenic genotypes in the SPINK1, PRSS1, CTRC, or CFTR genes were identified in 410 (51.4%) patients. The development of pancreatic insufficiency was significantly earlier in patients with a history of smoking and/or alcohol consumption in both the positive (P < .001) and negative (P = .001) gene mutation groups. However, the development of pancreatic insufficiency did not differ significantly between patients with and without gene mutations despite alcohol and/or smoking status, with P values of .064 and .115, respectively. Multivariate Cox regression analysis showed that age at onset of CP (hazard ratio, [HR], 1.02; P < .001) and alcohol consumption (HR, 1.86; P < .001) were independent risk factors for the development of diabetes, while male sex (HR, 1.84; P = .022) and smoking (HR, 1.56; P = .028) were predictors of steatorrhea.

CONCLUSIONS

Although rare pathogenic mutations in the 4 major susceptibility genes for CP were not correlated significantly with the development of pancreatic insufficiency, environmental factors (either alcohol consumption or smoking) significantly accelerated disease progression (ClinicalTrials.gov: NCT04574297).

Varied Low Back Pain Induced by Different Spinal Tissues in Percutaneous Endoscopic Lumbar Discectomy: A Retrospective Study

BACKGROUND

Percutaneous endoscopic lumbar discectomy (PELD) has become a mature and mainstream minimally invasive surgical technique for treating lumbar disc herniation (LDH). During PELD, various spinal structures, such as ligamentum flavum, dural sac, nerve root, posterior longitudinal ligament, annulus fibrosus, and endplate, were exposed, removed, and decompressed. When we used different endoscopic instruments to touch, remove, and excise different spinal structures, the patient will experience varying degrees of low back pain (LBP). To the best of our knowledge, the differences of the LBP have not been investigated in detail.

OBJECTIVES

To evaluate the spinal structures pain variability during PELD.

STUDY DESIGN

A retrospective study.

SETTING

All data were collected from Shandong Provincial Hospital Affiliated to Shandong First Medical University.

METHODS

From February 2017 to May 2021, 1,100 patients with LDH underwent PELD surgery. During the operation, the Visual Analog Scale (VAS) was used to assess the pain intensity of each patient, generated by physical stimuli of different endoscopic instruments (i.e., nucleus pulposus forceps, punch forceps, and radiofrequency bipolar coagulator) in different tissue (i.e., posterior longitudinal ligament, nerve root /dural sac, endplate, and ligamentum flavum). Data were analyzed by analysis of variance with Bonferroni post hoc tests.

RESULTS

As for the VAS for LBP among different spinal tissues, the degree of LBP was reduced in each group in the following order (decreasing from most severe to mildest): posterior longitudinal ligament, nerve root/dural sac, endplate, ligamentum flavum, annulus fibrosus (P < 0.01). As for the VAS for LBP caused by different endoscopic instruments, we found the most intense LBP always caused by nucleus pulposus forceps, next by punch forceps, then by radiofrequency bipolar coagulator (P < 0.01).

LIMITATIONS

The retrospective nature of data collection and the educational discrepancies among the trial population may affect data collection to some extent.

CONCLUSIONS

During PELD, varied LBP will generate when different spinal tissues are manipulated by different endoscopic instruments, the most severe LBP always came from the posterior longitudinal ligament and nerve root /dural sac. Moreover, compared to incision and thermal stimulus, traction could provoke more severe LBP.

Sacral anatomical parameters varies in different Roussouly sagittal shapes as well as their relations to lumbopelvic parameters

PURPOSE

To study the normal variations in sacral anatomical parameters in different Roussouly sagittal shapes and the association between sacral anatomical parameters and lumbopelvic parameters in healthy adults.

METHODS

A cohort of 239 healthy volunteers between 18 and 45 years old was enrolled in this study. A full-spine, standing X-ray was taken for each volunteer. The following parameters were measured: the sacral table angle (STA), sacral kyphosis (SK), pelvic incidence (PI), pelvic tilt (PT), sacral slope (SS), lumbar lordosis (LL), and lumbar lordosis apex (LLA). Two hundred and thirty-nine volunteers were classified into five groups according to the Roussouly classification. The differences in sagittal parameters among the five groups were evaluated by one-way analysis of variance. The correlations between lumbopelvic parameters and sacral anatomical parameters were analyzed, and simple linear regressions were simultaneously constructed.

RESULT

The sacral anatomical parameters vary in different Roussouly sagittal shapes. Correlation analysis revealed that the significant correlations between sacral anatomical parameters and lumbopelvic parameters. The STA correlated with PI (r = -.690, P <.001), PT (r = -.216, P = .001), SS (r = -.631, P <.001), LL (r = -.491, P <.001), and LLA (r = 0.515, P <.001). The corresponding regression formulae were as follows: PI = -0.991*STA + 143(R 2 = .476), LL = 0.870*STA-135.1(R 2 = .242), and LLA = 0.039*STA -0.087(R 2 = .265). The SK correlated with PI (r = .471, P <.001), PT (r = .445, P = .001), SS (r = .533, P <.001), LL (r = .438, P <.001), and the LLA (r = -.265, P <.001). The corresponding regression formulae were as follows: PI = 0.38*SK + 27.22(R 2 = .396), LL = -0.35*SK - 35.99(R 2 = .192), and LLA = -0.01*SK + 4.25(R 2 = .201).

CONCLUSIONS

The sacral anatomical parameters vary in different Roussouly sagittal shapes and have strong correlations with lumbopelvic parameters, which demonstrates that the specific lumbar shape can be affected by the sacral morphology. Moreover, the predictive models of lumbopelvic parameters based on SK and STA have been provided, which demonstrates constant sacral anatomical parameters could serve as good supplementary index of PI to predict ideal lumbar parameters.

Prevalence and Risk Factors for Osteopathy in Chronic Pancreatitis

BACKGROUND AND AIMS

The high incidence of osteopathy among patients with chronic pancreatitis (CP) has garnered increased attention over recent years. The aims of this study were to assess the prevalence and risk factors for osteopathy in Chinese patients with CP.

METHODS

This was a cross-sectional study of CP patients from a large center in China; patients were recruited between 31 January 2017 and 31 January 2018. Bone density and laboratory tests, including bone-related biochemical, inflammatory, and hormone parameters, were assessed prospectively. Differences between patients with and without osteopathy were analyzed. Logistic regression analysis was used to investigate associations between variables.

RESULTS

In total, 104 CP patients were enrolled in this study (68.3% idiopathic and 31.7% alcoholic). According to the M-ANNHEIM classification, 87.5% of the patients were at an early stage (0-II). Osteopenia was diagnosed in 30.8% of patients and osteoporosis in 5.8%; thus, a total of 36.5% of patients presented with osteopathy. In multivariate analysis, the independent risk factors for osteopathy in CP patients were age (OR = 1.04; 95% CI = 1.00-1.08; P = 0.030), BMI (OR = 0.72; 95% CI = 0.58-0.89; P = 0.003), and PTH (OR = 0.96; 95% CI = 0.93-1.00; P = 0.022).

CONCLUSIONS

This study is the first to report the prevalence of osteopathy in Chinese patients with CP. It found that age and low BMI are significant risk factors for osteopathy. Low PTH (but within the normal range) showed a weak association with osteopathy, which warrants further exploration.

Factors associated with prior acute pancreatitis episodes among patients with chronic pancreatitis

BACKGROUND

The relationship between chronic pancreatitis (CP) and acute pancreatitis (AP) is complex and not well understood. CP could be preceded by antecedent episodes of AP.

AIMS

The aim of this study was to explore both genetic and environmental factors associated with AP episodes before the diagnosis of CP.

METHODS

This was a cross-sectional study including 1022 patients. Detailed demographic, genetic, and clinical data were collected. Based on the presence of AP episode(s) before diagnosis of CP, patients were divided into AP group (further classified into single episode of AP group and recurrent AP group) and non-AP group. Related factors among these groups were assessed using multivariate logistic regression model.

RESULTS

Before diagnosis of CP, 737 patients (72.1%) had a history of AP. Smoking(P = 0.005) and heavy alcohol consumption(P = 0.002) were risk factors for AP while age at CP onset(P < 0.001), harboring the SPINK1 mutation(P < 0.001), diabetes(P < 0.001) and steatorrhea(P < 0.001) were protective factors. Further, alcoholic CP(P = 0.019) was the only independent risk factor for recurrent AP attacks while age at onset of CP(P < 0.001), pancreatic stones(P = 0.024). and pseudocysts(P = 0.018) served as protective factors.

CONCLUSIONS

SPINK1 mutations served as protective factor for AP episodes, suggesting SPINK1 mutation might play a pathogenic role in CP occurrence with occult clinical manifestations.

SPINK1 mutations and risk of pancreatic cancer in a Chinese cohort

OBJECTIVE

The relationship between SPINK1 and pancreatic cancer (PC) remains controversial. The current study aimed to determine the effect of SPINK1 mutations on PC development among patients with chronic pancreatitis (CP).

METHODS

This is a prospective observational study including a large cohort of 965 CP patients with 11-year follow-up. Patients' demographic characteristics and clinical CP outcomes were documented in detail. Genetic testing was performed. The effect of SPINK1 mutations on the clinical development of PC was explored using Cox proportional hazards regression. Subgroup analyses conducted included the consideration of gender, onset age of CP (early- and late-onset), etiologies of CP, smoking, and alcoholic drinking status.

RESULTS

PC was diagnosed in 2.5% (24/965) of patients, and the cumulative incidence rates were 0.2%, 0.8%, and 1.5% at 3, 5, and 10 years since the onset of CP, respectively. In this cohort, SPINK1 c.194+2T > C was the most common variant with a proportion of 39.1%. And the risk of PC development varied marginally between patients with and without SPINK1 mutations (Cox HR 0.39(0.14-1.04), P = 0.059). In the subgroup analyses, patients carrying SPINK1 mutations had a significantly lower risk of PC (Cox HR 0.18(0.04-0.80), P = 0.025) in the non-smoking group. SPINK1 mutations showed no significant effect in the other subgroups considered.

CONCLUSIONS

CP patients harboring SPINK1 mutations do not have an elevated risk of PC development compared to mutation-negative CP patients. On the contrary, SPINK1 mutations may be a protective factor in non-smoking patients with CP.

Post-ESWL and post-ERCP pancreatitis in patients with chronic pancreatitis: Do they share the same risks?

BACKGROUND

Endoscopic intervention combined with extracorporeal shock wave lithotripsy (ESWL) is recommended as the first line therapy for large pancreatic stones, yet both can cause adverse events. The aim of the study was to identify the risk factors for post-procedural pancreatitis.

METHODS

Consecutive patients with chronic pancreatitis and pancreatic stones treated with both ESWL and subsequent endoscopic retrograde cholangiopancreatography (ERCP) from October 2016 to December 2019 were prospectively enrolled. Multivariate logistic analyses were performed to detect risk factors for post-ESWL and post-ERCP pancreatitis (PEP).

RESULTS

A total of 714 patients (507 males, 45.60 ± 12.52 years) were included in this study. A total of 80 patients (11.2%) developed post-ESWL pancreatitis,while 33 patients (4.6%) suffered from PEP. Steatorrhea (P = .018), multiple stones (P = .043), and stones located at the head combined with the body or tail of the pancreas (P = .015) were identified as independent protective factors for post-ESWL pancreatitis. The history of acute exacerbations (P = .013), post-ESWL pancreatitis (P < .001) and stricture dilation during ERCP (P = .002) were identified as risk factors for PEP.

CONCLUSIONS

More attention should be paid to patients with post-ESWL pancreatitis, as well as a history of acute exacerbations and stricture dilation during ERCP to prevent PEP. (ClincialTrials.gov number, NCT04619511).

Systemic HDAC3 inhibition ameliorates impairments in synaptic plasticity caused by simulated galactic cosmic radiation exposure in male mice

Deep space travel presents a number of measurable risks including exposure to a spectrum of radiations of varying qualities, termed galactic cosmic radiation (GCR) that are capable of penetrating the spacecraft, traversing through the body and impacting brain function. Using rodents, studies have reported that exposure to simulated GCR leads to cognitive impairments associated with changes in hippocampus function that can persist as long as one-year post exposure with no sign of recovery. Whether memory can be updated to incorporate new information in mice exposed to GCR is unknown. Further, mechanisms underlying long lasting impairments in cognitive function as a result of GCR exposure have yet to be defined. Here, we examined whether whole body exposure to simulated GCR using 6 ions and doses of 5 or 30 cGy interfered with the ability to update an existing memory or impact hippocampal synaptic plasticity, a cellular mechanism believed to underlie memory processes, by examining long term potentiation (LTP) in acute hippocampal slices from middle aged male mice 3.5-5 months after radiation exposure. Using a modified version of the hippocampus-dependent object location memory task developed by our lab termed "Objects in Updated Locations" (OUL) task we find that GCR exposure impaired hippocampus-dependent memory updating and hippocampal LTP 3.5-5 months after exposure. Further, we find that impairments in LTP are reversed through one-time systemic subcutaneous injection of the histone deacetylase 3 inhibitor RGFP 966 (10 mg/kg), suggesting that long lasting impairments in cognitive function may be mediated at least in part, through epigenetic mechanisms.

Adverse events of video capsule endoscopy over the past two decades: a systematic review and proportion meta-analysis

BACKGROUND

A full spectrum of video capsule endoscopy (VCE) adverse events over the past two decades has not been evaluated. We aimed to determine pooled rates, predictors and temporal-trend of VCE adverse events over the past two decades.

METHODS

Systematic search of PubMed and EMBASE for English-language publications reporting VCE adverse events (January 1, 2000 to March 31, 2019). Data were extracted independently by two investigators. Pooled VCE adverse event rates were calculated using the random or fixed model as appropriate. Predictors and temporal-trend of each adverse event were performed by meta-regression analyses.

RESULTS

In total, 402 studies were identified, including 108,079 VCE procedures. Rate of retention, swallow disorder, aspiration, technical failure, and procedural adverse events were 0.73% (95% confidence interval [CI] 0.59-0.89%), 0.75% (95% CI 0.43-1.13%), 0.00% (95% CI 0.00-0.00%), 0.94% (95% CI 0.65-1.28%), 0.67% (95% CI 0.32-1.10%), respectively; incomplete examination rate of esophagus, stomach, small bowel, and colon were 9.05%, 7.69%, 12.08%, 19.19%, respectively. Patency capsule reduced retention rate by 5.04%, whereas known inflammatory bowel disease increased retention rate by 4.29%. Elder was the risk and protective factor for small bowel incomplete examination (0.30%) and swallow disorder (- 0.72%), respectively. Rates of retention and small bowel incomplete examination significantly declined over time (P = .0006 and P < .0001)..

CONCLUSIONS

VCE adverse event rates were generally low, and retention and small bowel incomplete examination rates declined over the past two decades. Patients with known inflammatory bowel disease or elder should be alerted to high risk of retention or small bowel incomplete examination (PROSPERO: CRD42019139595).

Risk factors for sinistral portal hypertension and related variceal bleeding in patients with chronic pancreatitis

OBJECTIVES

Sinistral portal hypertension (SPH) is an uncommon complication of chronic pancreatitis (CP) and can result in severe gastrointestinal bleeding. The aim of this study was to determine the prevalence and the potential risk factors for SPH and related gastrointestinal variceal bleeding in patients with CP.

METHODS

We retrospectively reviewed all patients with SPH due to CP admitted to our hospital from July 2014 to June 2019 in this case-control study. Patients with CP without SPH were randomly selected as controls during the study period (case: control  =  1:2). The characteristics, medical history, course of CP, characteristics associated with SPH, and follow-up evaluations of the patients were documented in detail. The prevalence rate of SPH in patients with CP and related gastrointestinal bleeding was calculated. Risk factors for SPH and related variceal bleeding were analyzed using univariate or multivariate logistic regression analysis.

RESULTS

The prevalence of SPH was 2.7% (89/3358) in patients with CP. Independent risk factors for SPH included alcohol consumption (P = 0.030), history of acute pancreatitis (P = 0.010), diabetes mellitus (P < 0.001), and pseudocysts (P < 0.001). Overall 17 (19.1%) patients suffered from related gastrointestinal bleeding. Between the bleeding and non-bleeding groups, there were significant differences in the types of CP, existence of stones, gastric varices diagnosed before bleeding, splenomegaly and hypersplenism by univariate analysis.

CONCLUSION

SPH is a rare complication of CP that is associated with a relatively low risk of variceal bleeding.

Meta-analysis of the impact of the SPINK1 c.194 + 2T > C variant in chronic pancreatitis

BACKGROUND AND AIMS

The SPINK1 c.194 + 2T > C variant has been increasingly recognized as an important risk factor for chronic pancreatitis (CP). However, there is no clear agreement on its contribution to different ethnicities and CP etiologies. To address this issue, a meta-analysis of literature was performed.

METHODS

Studies addressing the presence of the SPINK1 c.194 + 2T > C variant in CP patients and controls were retrieved from the PubMed, EMBASE and Cochrane databases. Initial analysis included all CP patients, followed by subgroup analyses for East Asian and non-East Asian patients, and for idiopathic CP (ICP) and non-ICP.

RESULTS

A total of 13 studies were retrieved for analysis, comprising 2097 cases and 4019 controls. There were 126 cases (10.01%) carrying the SPINK1 c.194 + 2T > C variant in cases, while only two controls were carriers (0.05%). Overall, the variant was significantly associated with an increased risk of CP (OR = 25.73). In the subgroup, the variant was significantly associated with increased risk of CP in East Asians (OR = 73.16), and in non-East Asians (OR = 10.21). Further, the contribution of the variant in ICP (OR = 35.31) was found to be higher than in non-ICP (25.75).

CONCLUSIONS

The SPINK1 c.194 + 2T > C variant is a strong risk factor for CP, especially in East Asian patients with ICP.

Microarchitecture and Biomechanical Evaluation of BoneCeramic Grafted Alveolar Defects during Tooth Movement in Rat

OBJECTIVE

BoneCeramic can regenerate bone in alveolar defects, but it remains unknown whether it is feasible to move a tooth through BoneCeramic grafting sites. The objective of this study was to investigate three-dimensional real-time bone responses and micromechanical properties in the grafting sites during orthodontic tooth movement.

METHODS

Sixty 5-week-old rats were randomly assigned into three groups to receive BoneCeramic, natural bovine cancellous bone particles (Bio-Oss), and no graft, respectively, after the extraction of the left maxillary first molar. After 4 weeks, the maxillary left second molar was moved into the extraction for 28 days. Dynamic bone microstructures and root resorption were evaluated using in vivo micro-computed tomography and histology. Stress distribution of tooth roots and biomechanical properties of corresponding bone tissue were examined by finite element methods and nanoindentation. Mixed-model analysis of variance was performed to compare the difference among time points with Bonferroni post hoc tests at the significance level of P < .05.

RESULTS

The BoneCeramic group had the least amount of tooth movement and root resorption volume and craters, highest bone volume fraction, trabecular number, mean trabecular thickness, microhardness, and elastic modulus, followed by Bio-Oss and the control group. The highest stress accumulated in the cervical region of the mesial roots.

CONCLUSION

BoneCeramic has better osteoconductive potential and biomechanical properties and induces less root resorption compared with Bio-Oss grafting and naturally recovered extraction site.

WITHDRAWN: In vivo micro-computed tomography evaluation of BoneCeramic grafted alveolar defects during orthodontic tooth movement

Ahead of Print article withdrawn by publisher.

BoneCeramic graft regenerates alveolar defects but slows orthodontic tooth movement with less root resorption

INTRODUCTION

BoneCeramic (Straumann, Basel, Switzerland) can regenerate bone in alveolar defects after tooth extraction, but it is unknown whether it is feasible to move a tooth through BoneCeramic grafting sites. The objective of this study was to investigate 3-dimensional real-time root resorption and bone responses in grafted sites during orthodontic tooth movement.

METHODS

Sixty 5-week-old rats were randomly assigned to 3 groups to receive BoneCeramic, natural bovine cancellous bone particles (Bio-Oss; Geistlich Pharma, Wolhusen, Switzerland), or no graft, after the extraction of the maxillary left first molar. After 4 weeks, the maxillary left second molar was moved into the extraction site for 28 days. Dynamic bone microstructures and root resorption were evaluated using in-vivo microcomputed tomography. Stress distribution and corresponding tissue responses were examined by the finite element method and histology. Mixed model analysis of variance was performed to compare the differences among time points with Bonferroni post-hoc tests at the significance level of P <0.05.

RESULTS

The BoneCeramic group had the least amount of tooth movement and root resorption volumes and craters, and the highest bone volume fraction, trabecular number, and mean trabecular thickness, followed by the Bio-Oss and the control groups. The highest stress accumulated in the cervical region of the mesial roots.

CONCLUSIONS

BoneCeramic has better osteoconductive potential and induces less root resorption compared with Bio-Oss grafting and naturally recovered extraction sites.

Effect of odanacatib on root resorption and alveolar bone metabolism during orthodontic tooth movement

The aim of this study was to investigate the effect of local administration of odanacatib (ODN) on orthodontic root resorption and the status of alveolar bone metabolism in rat molars. All specimens were scanned using microcomputed tomography and then the raw images were reconstructed. The total volume of the root resorption craters of the 60 g-NS (normal saline) group was higher than in the 60 g-ODN group and the control group. In the 60 g-NS group, the bone volume fraction values of alveolar bone were significantly decreased compared with the other 2 groups. There were no significant differences in the bone volume fraction values of the tibiae among the 3 groups. The results of tartrate-resistant acid phosphatase-positive (TRAP+) numbers showed that there was no difference between the 60 g-NS group and the 60 g-ODN group. The expression of cathepsin K was decreased significantly in the 60 g-ODN group. These results indicate that ODN reduces orthodontics-induced external root resorption and increases alveolar bone metabolism. This may be because ODN inhibits the activity of odontoclasts, but maintains the quantity of odontoclasts and enhances bone formation. ODN promotes local alveolar bone metabolism, but does not affect systemic bone metabolism.

Peroxisome proliferator-activated receptor gamma regulates bone remodeling after midpalatal suture expansion in mice

PURPOSE

The effectiveness of rapid maxillary expansion is adversely affected by failure and relapse. It is important to identify key factors that increase new bone formation and improve bone remodeling of midpalatal sutures to improve the stability and effectiveness of this commonly used orthodontic procedure. Peroxisome proliferator-activated receptor gamma (PPARγ) plays an important role in modulating osteogenesis and bone resorption in long bones. This study was designed to explore the function of PPARγ in bone remodeling and tissue engineering of midpalatal sutures.

MATERIALS AND METHODS

Pioglitazone, a PPARγ agonist, and osteoclast PPARγ knockout mice were used to explore the impact of PPARγ activation and inactivation, respectively, on bone remodeling in a mouse model of midpalatal suture expansion (MSE). Histologic analysis including staining with hematoxylin-eosin, tartrate-resistant acid phosphatase, and alkaline phosphatase was used to evaluate tissue remodeling. Reverse-transcriptase quantitative polymerase chain reaction was used to measure gene expression.

RESULTS

Pioglitazone decreased new bone formation after MSE. This was accompanied by an increased amount of osteoclasts and expression of genes promoting osteoclastogenesis, as well as a decreased amount of osteoblasts and expression of genes promoting osteoblastogenesis in midpalatal sutures. Conversely, osteoclast PPARγ knockout mice increased new bone formation and decreased the amount of osteoclasts and expression of genes promoting osteoclastogenesis.

CONCLUSION

In the process of bone remodeling after MSE, PPARγ, particularly in osteoclasts, is an important regulator of osteoblast and osteoclast homeostasis and bone remodeling in midpalatal sutures. Blockade of PPARγ might be an effective strategy to improve stability and decrease relapse in the practice of rapid maxillary expansion.

In vivo microcomputed tomography evaluation of rat alveolar bone and root resorption during orthodontic tooth movement

OBJECTIVE

To observe the real-time microarchitecture changes of the alveolar bone and root resorption during orthodontic treatment.

MATERIALS AND METHODS

A 10 g force was delivered to move the maxillary left first molars mesially in twenty 10-week-old rats for 14 days. The first molar and adjacent alveolar bone were scanned using in vivo microcomputed tomography at the following time points: days 0, 3, 7, and 14. Microarchitecture parameters, including bone volume fraction, structure model index, trabecular thickness, trabecular number, and trabecular separation of alveolar bone, were measured on the compression and tension side. The total root volume was measured, and the resorption crater volume at each time point was calculated. Univariate repeated measures analysis of variance with Bonferroni corrections were performed to compare the differences in each parameter between time points with significance level at P < .05.

RESULTS

From day 3 to day 7, bone volume fraction, structure model index, trabecular thickness, and trabecular separation decreased significantly on the compression side, but the same parameters increased significantly on the tension side from day 7 to day 14. Root resorption volume of the mesial root increased significantly on day 7 of orthodontic loading.

CONCLUSIONS

Real-time root and bone resorption during orthodontic movement can be observed in 3 dimensions using in vivo micro-CT. Alveolar bone resorption and root resorption were observed mostly in the apical third on day 7 on the compression side; bone formation was observed on day 14 on the tension side during orthodontic tooth movement.

[Effect of orthodontic force on periodontal healing after autotransplantation: an experimental study]

OBJECTIVE

To investigate the effect of the continuous light force to the donor teeth on the periodontal healing after transplantation.

METHODS

Thirty-two maxillary and mandibular incisors in four 10-month-old male Beagle dogs were autotransplanted. The pulps were removed in all teeth. The teeth were divided into four groups, one control and three experimental groups. In control group (group 1), the teeth were unloaded. In the other three experimental groups, continuous force (0.49 N) was applied in the 1st (group 2), 2nd (group 3) and 4th (group 4) week, respectively. The dogs were sacrificed in the 8th week. The tissue blocks were demineralized and sectioned perpendicular to the long axis of the teeth. The histological analysis was made.

RESULTS

Histomophometric analysis revealed a significantly lower occurrence of replacement root resorption in the group 3 (2.1%) than in the control group (12.5%, P < 0.05). The significant lower incidence of replacement root resorption, and a higher surface and inflammatory root resorption were found in group 2 (6.3% and 68.8%) than in the control group (12.5% and 41.7%, P < 0.05). No significant difference was found between group 4 and control group (P > 0.05).

CONCLUSIONS

The orthodontic force promoted the regeneration of the periodontal ligament and prevented dentoalveolar ankylosis, whereas excessive initial force might cause root and bone resorption.

[Evaluation of periodontal tissue during orthodontic tooth movement in rats: a micro-computed tomography study]

OBJECTIVE

To observe the microstructure changes of rat alveolar bone around tooth root under orthodontic force loading.

METHODS

Ten 10-week-old rats were included in the study. Upper first molars were moved mesially with 0.196 N of force. The alveolar bone around the root of upper first molar was scanned by a micro-computed tomography scan system (SkyScan-1076) in different period after the initiation of orthodontic force loading (on the 3rd, 7th, 14th day after force loading) and analyzed by a specially-designed software to measure the microstructure parameters of alveolar bone (bone volume fraction, bone surface to volume ratio, structure model index, trabecular thickness, trabecular separation, trabecular number).

RESULTS

From the 7th day, bone volume fraction [(41 ± 14)%], structure model index (1.51 ± 0.52) and trabecular separation [(90 ± 30) µm] changed significantly in the compressive area compared with those [(64 ± 15)%, (0.51 ± 0.85), (56 ± 10) µm] on the 3rd day. From the 14th day, bone volume fraction [(78 ± 14)%], structure model index (0.28 ± 0.20) and trabecular separation [(29 ± 13) µm] changed significantly in the tension area compared with those [(67 ± 14)%, (0.40 ± 0.41), (48 ± 15) µm] on the 7th day. No difference on trabecular number was found between the compressive area and tension area (P > 0.05).

CONCLUSIONS

The significant resorption of the alveolar bone was observed on the 7th days in the compressive area and the deposition of the alveolar bone was observed on the 14th day in the compressive area after orthodontic force loading.

Transient electronic structure and melting of a charge density wave in TbTe3

Obtaining insight into microscopic cooperative effects is a fascinating topic in condensed matter research because, through self-coordination and collectivity, they can lead to instabilities with macroscopic impacts like phase transitions. We used femtosecond time- and angle-resolved photoelectron spectroscopy (trARPES) to optically pump and probe TbTe3, an excellent model system with which to study these effects. We drove a transient charge density wave melting, excited collective vibrations in TbTe3, and observed them through their time-, frequency-, and momentum-dependent influence on the electronic structure. We were able to identify the role of the observed collective vibration in the transition and to document the transition in real time. The information that we demonstrate as being accessible with trARPES will greatly enhance the understanding of all materials exhibiting collective phenomena.

STM studies of TbTe3: evidence for a fully incommensurate charge density wave

We observe unidirectional charge density wave (CDW) ordering on the quasi-2D material TbTe3 with a scanning tunneling microscope at approximately 6 K. Our analysis indicates that the CDW is fully incommensurate, with wave vector qCDW approximately 0.71x2pi/c. By imaging at various tip-sample voltages, we highlight effects of the subsurface layer and its effect on the CDW. We also observe an additional (possibly surface) dimerization and approximately 0.68x2pi/a ordering perpendicular to the CDW.

Pressure dependence of the charge-density-wave gap in rare-earth tritellurides

We investigate the pressure dependence of the optical properties of CeTe3, which exhibits an incommensurate charge-density-wave (CDW) state already at 300 K. Our data are collected in the midinfrared spectral range at room temperature and at pressures between 0 and 9 GPa. The energy for the single particle excitation across the CDW gap decreases upon increasing the applied pressure, similarly to the chemical pressure by rare-earth substitution. The broadening of the bands upon lattice compression removes the perfect nesting condition of the Fermi surface and therefore diminishes the impact of the CDW transition on the electronic properties of RTe3.

Fermi surface reconstruction in the CDW state of CeTe3 observed by photoemission

CeTe3 is a layered compound where an incommensurate charge density wave (CDW) opens a large gap ( approximately 400 meV) in optimally nested regions of the Fermi surface (FS), whereas other sections with poorer nesting remain ungapped. Through angle-resolved photoemission, we identify bands backfolded according to the CDW periodicity. They define FS pockets formed by the intersection of the original FS and its CDW replica. Such pockets illustrate very directly the role of nesting in the CDW formation but they could not be detected so far in a CDW system. We address the reasons for the weak intensity of the folded bands, by comparing different foldings coexisting in CeTe3.

DD3: a new prostate-specific gene, highly overexpressed in prostate cancer

Prostate cancer is the most commonly diagnosed malignancy and the second leading cause of cancer-related deaths in the Western male population. Despite the tremendous efforts that have been made to improve the early detection of this disease and to design new treatment modalities, there is still an urgent need for new markers and therapeutic targets for the management of prostate cancer patients. Using differential display analysis to compare the mRNA expression patterns of normal versus tumor tissue of the human prostate, we identified a cDNA, DD3, which is highly overexpressed in 53 of 56 prostatic tumors in comparison to nonneoplastic prostatic tissue of the same patients. Reverse transcription-PCR analysis using DD3-specific primers indicated that the expression of DD3 is very prostate specific because no product could be amplified in 18 different normal human tissues studied. Also, in a sampling of other tumor types and a large number of cell lines, no expression of DD3 could be detected. Molecular characterization of the DD3 transcription unit revealed that alternative splicing and alternative polyadenylation occur. The fact that no extensive open reading frame could be found suggests that DD3 may function as a noncoding RNA. The DD3 gene was mapped to chromosome 9q21-22, and no homology of DD3 to any gene present in the computer databases was found. Our data indicate that DD3 is one of the most prostate cancer-specific genes yet described, and this makes DD3 a promising marker for the early diagnosis of prostate cancer and provides a powerful tool for the development of new treatment strategies for prostate cancer patients.

Detection of p16 gene deletions in gliomas: a comparison of fluorescence in situ hybridization (FISH) versus quantitative PCR

The p16 protein plays a key role in cell cycle control by preventing CDK4 from inactivating the retinoblastoma protein (pRb). The corresponding tumor suppressor gene (p16/MTS1/CDKN2) has recently been implicated in malignant progression of astrocytomas and could potentially serve as an important marker for patient prognosis and for guiding specific therapeutic strategies. We have undertaken a study to evaluate 2 methods of detecting p16 deletion. Thirty diffuse gliomas were analyzed for p16 gene dosage. Dual color fluorescence in situ hybridization (FISH) was performed on cytologic preparations using paired centromeric (CEN) and locus-specific probes for CEN9/p16, CEN8/RB, and CEN12/CDK4. Quantitative PCR was performed using primers for p16, MTAP, and reference genes. Eleven cases were also studied using comparative genomic hybridization (CGH). Abnormalities of the p16-CDK4-RB pathway were identified in 21 (70%) cases by FISH and/or PCR. These included 15 (50%) with p16 deletion, 9 of which were detected by both techniques, 3 by FISH alone, and 3 by PCR alone (concordance rate = 81%). FISH analysis further revealed tetraploidy/aneuploidy in 14 (47%), RB deletion in 11 (37%) and CDK4 amplification in 1 (3.3%). There were 94% and 100% concordance rates between CGH and FISH or PCR, respectively. Quantitative PCR was noninformative in 4 cases. Although FISH and quantitative PCR are both reliable techniques, each has limitations. PCR is likely to miss p16 deletions when there is significant normal cell contamination or clonal heterogeneity, whereas the p16 YAC probe used for FISH analysis may miss small deletions. Replacement of the latter with a cosmid probe may improve the sensitivity of FISH in future experiments.

Chromosome 5 suppresses tumorigenicity of PC3 prostate cancer cells: correlation with re-expression of alpha-catenin and restoration of E-cadherin function

Considerable evidence now exists to support an important role for the E-cadherin-mediated cell-cell adhesion pathway as a suppressor of the invasive phenotype in adenocarcinoma cells. Previous studies have found that this pathway is frequently aberrant in prostate cancers, particularly those that are likely to metastasize. In this study, we report on the effects of re-establishment of this pathway in a prostate cancer cell line, PC-3, in which this adhesion system is dysfunctional by virtue of a deletion of the gene that codes for alpha-catenin, an E-cadherin-associated protein necessary for normal E-cadherin function. Re-expression of alpha-catenin was accomplished either by transfection of PC-3 cells with a copy of the alpha-catenin cDNA under the control of a heterologous promoter or by microcell-mediated transfer of chromosome 5, which contains the alpha-catenin gene and its normal regulatory elements. In both cases, re-expression of alpha-catenin is associated with a similar, dramatic alteration in cell morphology, whereby extensive cell-cell contact is observed. In the case of transfection of the cDNA, this expression is only transient, because the transfected cells either cease to proliferate or, more commonly, revert to the parental phenotype with concomitant cessation of alpha-catenin expression. In contrast, cells containing one or more copies of microcell-transferred chromosome 5 express alpha-catenin in a stable manner and continue to proliferate. Upon injection into nude mice, these latter cells are no longer tumorigenic, or form only slowly growing tumors with greatly extended doubling times when compared to the parental PC-3 cells. During passage in culture, clones that contain only one transferred copy of chromosome 5 reproducibly revert to the parental phenotype. This reversion is associated with loss of the chromosome 5 region containing the alpha-catenin gene and consequent loss of alpha-catenin expression, as well as re-emergence of tumorigenicity. Transfer of chromosome 5 into prostate cancer cells that are E-cadherin negative does not result in either morphological transformation or suppression of tumorigenicity, suggesting that these effects of alpha-catenin expression are dependent upon concomitant expression of E-cadherin. These data demonstrate the tumor suppressive ability of chromosome 5 in the PC-3 prostate cancer cells and suggest that re-expression of alpha-catenin with resultant restoration of E-cadherin function plays a critical role in this process.

Differential suppression of mammary and prostate cancer metastasis by human chromosomes 17 and 11

Metastasis suppressor activities have previously been mapped to human chromosomes 17 and 11. Decreased expression of the metastasis suppressor gene NM23, which is located on chromosome 17, has been correlated with increased metastatic potential in mammary cancers. A region on human chromosome 11, from 11p11.2-p13, has been shown to suppress metastasis in rat prostatic carcinoma cells. In both cases the metastasis suppressor activity had no effect on tumorigenicity or tumor growth rate, demonstrating that the encoded activities are distinct from effects of tumor suppression. To determine whether these human chromosomes encode general or tissue-specific metastasis suppressor activities, a truncated human chromosome 17 (i.e., pter-q23) and a full-length human chromosome 11 were separately transferred into highly metastatic rat mammary and prostate cancer cell lines and tested for their ability to suppress spontaneous metastasis in vivo. These studies demonstrated that when the pter-q23 region of human chromosome 17 is retained by the microcell hybrids, the metastatic ability of both mammary and prostatic cancer cells is suppressed. In contrast, when the pter-q14 region of human chromosome 11 is retained, only the metastatic ability of prostatic cancer cells is suppressed. Additional studies demonstrated that the metastasis suppressor activity encoded by the chromosome 17 pter-q23 region is p53-independent and not due to enhanced expression of NM23 protein.

A phase II study of carboplatin in children with recurrent or progressive solid tumors. A report from the Childrens Cancer Group

BACKGROUND

Carboplatin is an analogue of cisplatin with less nonhematologic toxicity than the parent compound. It has been demonstrated previously to have activity against a spectrum of pediatric brain tumors. This Phase II study was undertaken to assess the activity of carboplatin in children with various solid tumors.

METHODS

Between October 1985 and March 1988, the Childrens Cancer Group entered 117 patients with drug-resistant, recurrent lymphomas and solid tumors, excluding primary central nervous system tumors, into a Phase II trial of carboplatin given intravenously at a dosage of 560 mg/m2 over 1 hour every 4 weeks.

RESULTS

A complete response was seen in 1 of 15 evaluable patients with Ewing's sarcoma. Partial responses were seen in 2 of 17 evaluable patients with neuroblastoma, 1 of 16 with soft tissue sarcoma, 2 of 5 with Wilms' tumor, and 1 with an endodermal sinus tumor of the testis. Objective responses were not seen in patients with malignant lymphoma, osteosarcoma, or hepatoma. Four of 7 patients who responded to carboplatin had previously received cisplatin. Sixty-two percent of patients had a platelet count nadir of less than 50,000/mm3, and 41% had an absolute neutrophil count nadir of less than 1,000/mm3. Ototoxicity, nephrotoxicity, hypomagnesemia, hypertransaminasemia, and nausea and vomiting each were seen in fewer than 10% of patients.

CONCLUSIONS

Carboplatin has some activity against Wilms' tumor, Ewing's sarcoma, neuroblastoma, soft tissue sarcoma, and endodermal sinus tumor of the testis. Activity was not demonstrated against osteosarcoma, malignant lymphoma, hepatoma, and miscellaneous other tumors. Myelosuppression was seen commonly, and nonhematologic toxicity was infrequent.

A phase II study of diaziquone in children with recurrent or progressive primary brain tumors: a report from the Childrens Cancer Study Group

Seventy-five children with recurrent, progressive or metastatic primary brain tumors were treated with aziridinylbenzoquinone (AZQ; Diaziquone) at 9 mg/m2/day by 30-minute intravenous infusion for five days every three weeks. Sixty-six patients were evaluable for response by imaging studies. There were five partial responses and one complete response for a combined response rate of 9%. A complete response lasting for 35+ months occurred in one of twelve patients with metastatic or locally recurrent ependymoma. Objective responses were also seen in patients with primitive neuroectodermal tumors (PNET) (1/8), low-grade glioma (1/6), and primary central nervous system lymphoma (1/1). Stable disease of greater than six months duration was seen in patients with ependymoma, PNET and medulloblastoma. Profound and prolonged myelo-suppression was the significant toxicity observed. As administered in this study, AZQ has marginal activity and severe toxicity.