Maintenance treatment of immunotherapy after microwave ablation plus drug-eluting bead bronchial arterial chemoembolization for advanced non-small cell lung cancer: a retrospective single-center cohort study

Background

The combination therapy of immunotherapy and drug-eluting bead bronchial artery chemoembolization (DEB-BACE) or microwave ablation (MWA) has been attempted as an effective and safe approach for advanced non-small cell lung cancer (NSCLC). However, the outcomes of immunotherapy plus multiple interventional techniques for advanced NSCLC remain unclear. This retrospective study thus aimed to investigate the effectiveness and safety of the maintenance treatment of programmed cell death protein 1 (PD-1) blockade after MWA plus DEB-BACE for advanced NSCLC.

Methods

This retrospective cohort study consists of 95 patients with advanced NSCLC who were treated with DEB-BACE between April 2017 and October 2022 and who were allocated to three groups: group A (MWA + DEB-BACE + PD-1 blockade; n=15), group B (MWA + DEB-BACE; n=25), and group C (DEB-BACE alone; n=55). The adverse events (AEs) were compared between the three groups. The outcomes were compared via Kaplan-Meier methods, including median progression-free survival (PFS) and overall survival (OS). Survival analyses were performed via the univariate and multivariate analyses to investigate the prognostic predictors.

Results

The overall incidence of AEs in the groups A-C was 53.3% (8/15), 36.0% (9/25), and 32.7% (18/55), respectively, which did not represent a significant difference (P=0.42). No severe AEs (SAEs) occurred. Group A, compared with group B and group C, had a significantly longer estimated median PFS (33.0 vs. 7.0 vs. 3.0 months; P<0.001) and OS (33.0 vs. 13.0 vs. 6.0 months; P=0.002). PD-1 blockade (P=0.006), tumor number (P=0.01), and DEB-BACE/bronchial artery infusion (BAI) chemotherapy cycles (P=0.04) were identified as the predictors of PFS, while the predictors of OS were PD-1 blockade (P<0.001), number of metastases (P<0.001), tumor diameter (P<0.001), and DEB-BACE/BAI cycles (P=0.02).

Conclusions

Compared with that of advanced NSCLC treated with MWA plus DEB-BACE or DEB-BACE alone, the maintenance treatment of immunotherapy after MWA plus DEB-BACE might provide a superior prognosis without increasing the risk of AEs.

Comparing the oncologic outcomes of local tumor destruction vs. local tumor excision vs. partial nephrectomy in T1a solid renal masses: a population-based cohort study from the SEER database

BACKGROUND

There are few large-scale analyses comparing local tumor destruction (LTD) or local tumor enucleation/excision (LTE) relative to partial nephrectomy (PN) for patients with T1a renal masses in terms of cancer-specific survival (CSS) and overall survival (OS). We aimed to compare CSS and OS after LTD versus LTE versus PN.

MATERIALS AND METHODS

Within the Surveillance, Epidemiology, and End Results (SEER) database (2000-2019), we identified patients with clinical T1a renal masses and histologically confirmed kidney cancer treated with LTD, LTE or PN. After 1:1 ratio propensity score matching (PSM), comparisons between the groups were conducted. Kaplan-Meier analysis and log-rank tests were used to compare survival in the matched population.

RESULTS

In the overall cohort of 3717 LTD patients versus 1993 LTE patients versus 26935 PN patients, 77.3% of LTD-treated patients and 74.4% of LTE-treated patients were over 60 years old, while only 50.3% of PN-treated patients were over 60 years old. PN was more strongly associated with CSS (hazard ratio (HR)=1.276, P<0.001) and OS (HR=1.112, P<0.001)) than was LTD, while PN was less strongly associated with CSS (HR=1.040, P=0.230) and OS (HR=0.888, P=0.002) than was LTE, not only in the PSM cohort but also in the subgroups of patients with a tumor size ≤3 cm and patients with a tumor size of 3.1-4 cm.

CONCLUSIONS

In clinical T1a solid renal mass patients, LTD was associated with lower CSS and OS than LTE and PN, while LTE demonstrated noninferior CSS and superior OS to PN regardless of tumor size.

Safety and efficacy of CT-guided percutaneous microwave ablation for stage I non-small cell lung cancer in patients with comorbid idiopathic pulmonary fibrosis

OBJECTIVES

To evaluate the safety and efficacy of microwave ablation (MWA) for stage I non-small cell lung cancer (NSCLC) in patients with idiopathic pulmonary fibrosis (IPF).

MATERIALS AND METHODS

A retrospective single-center cohort study was conducted in patients with clinical stage I NSCLC who underwent CT-guided MWA from Nov 2016 to Oct 2021. The patients were divided into the IPF group and the non-IPF group. The primary endpoints were 90-day adverse events and hospital length of stay (HLOS). The secondary endpoints included overall survival (OS) and progression-free survival (PFS).

RESULTS

A total of 107 patients (27 with IPF and 80 without IPF) were finally included for analysis. No procedure-related acute exacerbation of IPF or death occurred post-MWA. The rates of adverse events were similar between the groups (48.6% vs. 47.7%; p = 0.998). The incidence of grade 3 adverse events in the IPF group was higher than that in the non-IPF group without a significant difference (13.5% vs. 4.6%; p = 0.123). Median HLOS was 5 days in both groups without a significant difference (p = 0.078). The 1-year and 3-year OS were 85.2%/51.6% in the IPF group, and 97.5%/86.4% in the non-IPF group. The survival of patients with IPF was significantly poorer than the survival of patients without IPF (p < 0.001). There was no significant difference for PFS (p = 0.271).

CONCLUSION

MWA was feasible in the treatment of stage I NSCLC in patients with IPF. IPF had an adverse effect on the survival of stage I NSCLC treated with MWA.

CLINICAL RELEVANCE STATEMENT

CT-guided microwave ablation is a well-tolerated and effective potential alternative treatment for stage I non-small cell lung cancer in patients with idiopathic pulmonary fibrosis.

KEY POINTS

• Microwave ablation for stage I non-small cell lung cancer was well-tolerated without procedure-related acute exacerbation of idiopathic pulmonary fibrosis and death in patients with idiopathic pulmonary fibrosis. • No differences were observed in the incidence of adverse events between patients with idiopathic pulmonary fibrosis and those without idiopathic pulmonary fibrosis after microwave ablation (48.6% vs. 47.7%; p = 0.998). • The 1-year and 3-year overall survival rates (85.2%/51.6%) in the idiopathic pulmonary fibrosis group were worse than those in the non- idiopathic pulmonary fibrosis group (97.5%/86.4%) (p < 0.001).

Microwave Ablation for Inoperable Stage I Non-Small Cell Lung Cancer in Patients Aged ≥70 Years: A Prospective, Single-Center Study

PURPOSE

To evaluate the safety and survival outcomes of computed tomography-guided microwave ablation (MWA) for medically inoperable Stage I non-small cell lung cancer (NSCLC) in patients aged ≥70 years.

MATERIALS AND METHODS

This study was a prospective, single-arm, single-center clinical trial. The MWA clinical trial enrolled patients aged ≥70 years with medically inoperable Stage I NSCLC from January 2021 to October 2021. All patients received biopsy and MWA synchronously with the coaxial technique. The primary endpoints were 1-year overall survival (OS) and progression-free survival (PFS). The secondary endpoint was adverse events.

RESULTS

A total of 103 patients were enrolled. Ninety-seven patients were eligible and analyzed. The median age was 75 years (range, 70-91 years). The median diameter of tumors was 16 mm (range, 6-33 mm). Adenocarcinoma (87.6%) was the most common histologic finding. With a median follow-up of 16.0 months, the 1-year OS and PFS rates were 99.0% and 93.7%, respectively. There were no procedure-related deaths in any patient within 30 days after MWA. Most of the adverse events were minor.

CONCLUSION

MWA is an effective and safe treatment for patients aged ≥70 years with medically inoperable Stage I NSCLC.

Clinical significance of circulating tumor DNA in localized non-small cell lung cancer: a systematic review and meta-analysis

Circulating tumor DNA (ctDNA) detection holds promise for genetic analyses and quantitative assessment of tumor burden. A systematic review and meta-analysis were conducted to investigate the clinical relevance of ctDNA among patients with localized non-small cell lung cancer (NSCLC). PubMed, EMBASE, and the Cochrane Library were searched for eligible studies published from January 2001 to April 2022. After quality assessments and data extraction, diagnostic accuracy variables and prognostic data were calculated and analyzed by Meta-Disc 1.4, Review Manager 5.4.1, and STATA 17.0. Eight prospective studies and one retrospective study including 784 patients with localized NSCLC were used in our meta-analysis. The pooled sensitivity and specificity of ctDNA for minimal residual disease (MRD) detection were 0.58 and 0.93, respectively. The pooled positive and negative likelihood ratios were 7.57 (95% confidence interval (CI) 2.84-20.20) and 0.45 (95% CI 0.37-0.55), respectively. The area under the summary receiver operating characteristic curve was 0.8967, and the diagnostic odds ratio was 32.26 (95% CI 14.63-71.12). In addition, both precurative-treatment and postcurative-treatment ctDNA positivity was associated with worse recurrence-free survival (hazard ratio (HR), 3.82 and 8.32, respectively) and worse overall survival (HR, 3.82 and 4.73, respectively). The findings suggested that ctDNA detection has beneficial utility regarding MRD detection specificity; moreover, positive ctDNA was associated with poor prognosis in patients with localized NSCLC.

Diagnostic performance and safety of percutaneous fine-needle aspiration immediately before microwave ablation for pulmonary ground-glass nodules

Background

This study sought to evaluate the safety and diagnostic performance of computed tomography (CT)-guided fine-needle aspiration (FNA) immediately before microwave ablation (MWA) for pulmonary ground-glass nodules (GGNs).

Methods

This retrospective study analyzed the synchronous CT-guided biopsy and MWA data of 92 GGNs (male to female ratio 37:55; age 60.4±12.5 years; size 1.4±0.6 cm). FNA was performed in all patients, and sequential core-needle biopsy (CNB) was performed in 62 patients. The positive diagnosis rate was determined. The diagnostic yield was compared on the basis of the biopsy methods (FNA, CNB, or both), the nodule diameter (<1.5 and ≥1.5 cm), and the lesion component (pure GGN or part-solid GGN). The procedure-related complications were recorded.

Results

The technical success rate was 100%. The positive rates of FNA and CNB were 70.7% and 72.6% respectively, but did not differ significantly (P=0.8). Sequential FNA and CNB showed better diagnostic performance (88.7%) than did either alone (P=0.008 and P=0.023, respectively). The diagnostic yield of CNB for pure GGNs was significantly lower than that for part-solid GGNs (P=0.016). The diagnostic yield was lower for smaller nodules (78.3% vs. 87.5%; P=0.28), but the differences were not significant. Grade 1 pulmonary hemorrhages were observed in 10 (10.9%) sessions after FNA, including 8 cases of hemorrhage along the needle track and 2 cases of perilesional hemorrhage, but these hemorrhages did not hamper the accuracy of the antenna placement.

Conclusions

FNA immediately before MWA is a reliable technique for the diagnosis of GGNs that does not alter the accuracy of the antenna placement. Sequential FNA and CNB improves the diagnostic ability of GGNs compared to either method used alone.

Effects of tract embolization on pneumothorax rate after percutaneous pulmonary microwave ablation: a rabbit study

PURPOSE

To determine the effects of tract embolization with gelatin sponge particles on the prevention of pneumothorax after percutaneous microwave ablation (MWA) in rabbit lungs.

MATERIALS AND METHODS

Twenty-four New Zealand white rabbits were randomly divided into Group A (MWA followed by tract embolization with gelatin sponge particles, n = 12) and Group B (MWA without tract embolization, n = 12). For each group, CT images were reviewed for the occurrence of pneumothorax within 30 min after MWA. The rate of pneumothorax was compared by Chi-square Test. Lung tissue around the needle tract was harvested after the rabbits were euthanized, and histopathological examinations were performed and studied with hematoxylin and eosin stains.

RESULTS

Twenty-four animals underwent 47 sessions of MWA (24 sessions in Group A and 23 sessions in Group B). Group A had a statistically lower rate of pneumothorax than Group B (25.0 vs. 56.5%; p = 0.028). The pathological examinations of both groups demonstrated thermal injury of the needle tract characterized by a rim of the coagulated lung parenchyma, which might be responsible for pneumothorax after MWA. Gelatin sponge particles could be arranged in irregular flakes densely to effectively seal the needle tract, thus reducing the occurrence of pneumothorax. The gelatin sponge particles could be almost completely absorbed about 14 days later.

CONCLUSION

Results of the present study showed needle tract embolization with gelatin sponge particles after CT-guided pulmonary MWA can significantly reduce the incidence of pneumothorax. Gelatin sponge particles can effectively seal the needle tract after ablation and can be completely absorbed in the body with good safety.

Microwave ablation combined with anti-PD-1/CTLA-4 therapy induces an antitumor immune response to renal cell carcinoma in a murine model

The study was designed to evaluate the efficiency of microwave ablation (MWA) in combination with anti-programmed death receptor 1 (anti-PD-1)/cytotoxic T lymphocyte-associated antigen 4 (CTLA-4) in renal cell carcinoma (RCC) treatment. After tumors were established on C57/BL6 mice, MWA treatment and/or immune checkpoint inhibitor (ICI) treatment to the mice were performed. Tumor volume was recorded every 7 days. A rechallenge test was conducted on mice with tumors in the left kidney to explore the systemic establishment of antitumor immunity on day 7. In this study, during the 21-day observation period, tumors were continued to grow in all groups. However, compared with the tumor growth rate in MWA or control group, the rate in the ICI or MWA+ICI groups was decreased. Moreover, the population of CD8+T-cells was increased only in the MWA+ICI group, while that of regulatory T cells was decreased in the MWA, ICI, and MWA+ICI groups. Additionally, the MWA+ICI group had the highest interferon-γ level among all groups. Furthermore, histopathological examination revealed that CTLA-4 expression in distant tumors was reduced in the ICI and MWA + ICI groups. MWA treatment increased PD-L1/PD-1 expression; however, after the combination treatment with ICI, PD-L1/PD-1 expression was decreased. According to the rechallenge test, mice (16.7%) in the MWA group, ICI group (50%), and MWA+ICI group (66.7%) exhibited successful tumor rejection, whereas no mice in the control group exhibited the capability of tumor rejection. Overall, the systemic antitumor immunity induced by MWA was boosted when combined with anti-PD-1/CTLA-4 treatment in an RCC murine model.

Computed tomography-guided microwave ablation for non-small cell lung cancer patients on antithrombotic therapy: a retrospective cohort study

BACKGROUND

For non-small cell lung cancer (NSCLC) patients on antithrombotic therapy who are treated with microwave ablation (MWA), the transient interruption of antithrombotic agents may increase the risk of thromboembolism, and continuation of antithrombotic agents may increase the risk of intraprocedural hemorrhage. This retrospective cohort study aimed to explore the safety of MWA in patients with NSCLC on antithrombotic therapy.

METHODS

A total of 572 patients with NSCLC (antithrombotic therapy group: n=84, Group A; control group: n=488, Group B) who received MWA were included. Antithrombotic agent use was suspended before MWA and resumed as soon as possible after MWA. Hemorrhagic (hemothorax and hemoptysis) and thromboembolic complications (pulmonary embolism, cerebral infarction, and angina) were compared. Logistic regression analyses were used to investigate the predictors of hemorrhagic complications after MWA.

RESULTS

Hemorrhagic complications occurred in 8 participants (9.5%) from Group A and 33 participants (6.8%) from Group B, and no statistically significant difference was found (P=0.365). There were 3 participants (0.5%) who developed thromboembolic complications, including 1 case (1.2%, 1/84) of pulmonary embolism in Group A, and 2 cases (0.4%, 2/488) of cerebral infarction or angina in Group B; no significant difference was found (P=0.923). In the subgroup analyses of Group A, no statistically significant difference of hemorrhagic (P>0.999) or thromboembolic complications (P>0.999) was found between patients who received and did not receive bridging anticoagulation with heparin. Logistic regression analyses revealed that direct contact of a tumor with vessels ≥2 mm was a predictor of hemorrhagic complications [hazard ratio (HR) =2.318; 95% confidence interval (CI): 1.215-4.420; P=0.011], while antithrombotic therapy was irrelevant.

CONCLUSIONS

With the appropriate cessation and resumption of antithrombotic agents, patients with NSCLC on antithrombotic therapy have comparable incidence rates of hemorrhagic and thromboembolic complications after MWA to those of patients who are not on antithrombotic therapy. Therefore, with appropriate cessation, MWA appears to generally be safe for NSCLC patients on antithrombotic therapy.

Drug-Eluting Bead Bronchial Arterial Chemoembolization With and Without Microwave Ablation for the Treatment of Advanced and Standard Treatment-Refractory/Ineligible Non-Small Cell Lung Cancer: A Comparative Study

Purpose

To compare the outcomes of drug-eluting bead bronchial arterial chemoembolization (DEB-BACE) with and without microwave ablation (MWA) for the treatment of advanced and standard treatment-refractory/ineligible non-small cell lung cancer (ASTRI-NSCLC).

Materials and Methods

A total of 77 ASTRI-NSCLC patients who received DEB-BACE combined with MWA (group A; n = 28) or DEB-BACE alone (group B; n = 49) were included. Clinical outcomes were compared between groups A and B. Kaplan–Meier methods were used to compare the median progression-free survival (PFS) or overall survival (OS) between the two groups. Univariate and multivariate Cox proportional hazards analyses were used to investigate the predictors of OS for ASTRI-NSCLC treated with DEB-BACE.

Results

No severe adverse event was found in both groups. Pneumothorax was the predominant MWA-related complication in group A, with an incidence rate of 32.1% (9/28). Meanwhile, no significant difference was found in DEB-BACE-related complications between groups A and B. The overall disease control rate (DCR) was 61.0% (47/77), with a significantly higher DCR in group A (85.7% vs. 46.9%, P = 0.002). The median PFS in groups A and B was 7.0 and 4.0 months, respectively, with a significant difference (P = 0.037). The median OS in groups A and B was both 8.0 months, with no significant difference (P = 0.318). The 6-month PFS and OS rates in groups A and B were 75.0% and 78.6%, 22.4% and 59.2%, respectively, while the 12-month PFS and OS rates in groups A and B were 17.9% and 28.6%, 14.3% and 22.4%, respectively. Of these, a significantly higher 6-month PFS rate was found in group A (75.0% vs. 22.4%; P < 0.001). The cycles of DEB-BACE/bronchial artery infusion chemotherapy [hazard ratio (HR): 0.363; 95% confidence interval (CI): 0.202–0.655; P = 0.001] and postoperative immunotherapy (HR: 0.219; 95% CI: 0.085–0.561; P = 0.002) were identified as the predictors of OS in ASTRI-NSCLC treated with DEB-BACE.

Conclusion

MWA sequentially combined with DEB-BACE was superior to DEB-BACE alone in the local control of ASTRI-NSCLC. Although the combination therapy reveals a trend of prolonging the OS, long-term prognosis warrants an investigation with a longer follow-up.

Synchronous microwave ablation followed by core-needle biopsy via a coaxial cannula for highly suspected malignant lung ground-glass opacities: A single-center, single-arm retrospective study

Background

This study aimed to retrospectively explore the safety and feasibility of computed tomography (CT)‐guided synchronous microwave ablation (MWA) followed by core‐needle biopsy (CNB) via a coaxial cannula for highly suspected malignant lung ground‐glass opacities (GGOs).

Methods

The clinical data of 66 patients (66 GGOs) treated with CT‐guided synchronous MWA followed by CNB via a coaxial cannula from January 2019 to January 2021 were included in this study. The technical success rate, curative effect, and complications were evaluated.

Results

Technical success rates were 100%. The pneumothorax rate was 36.4% (24/66). 72.7% (48/66) patients had the bronchopulmonary hemorrhage, 81.3% of hemorrhage was attributable to CNB. 24.2% (16/66) patients had varying degrees of pleural effusion. The pathological results were adenocarcinomas (n = 44), atypical adenomatous hyperplasia (n = 2), chronic inflammation (n = 3) and indeterminate pathological diagnosis (n = 17) with a 69.7% (46/66) positive diagnosis rate. The therapeutic response rate was 100.0% (66/66).

Conclusions

Synchronous MWA followed by CNB via a coaxial cannula has a satisfactory ablation effectiveness and an acceptable biopsy positive rate, which is an alternative treatment for highly suspected malignant GGOs.

Influence of cyclophilin D protein expression level on endothelial cell oxidative damage resistance

We examined the influence of cyclophilin-D (CypD) protein expression level on endothelial cell oxidative damage resistance. A model of CypD protein expression or high expression in endothelial cells was established through gene silencing or cloning. The comparable groups were normal endothelial cells cultured in phosphate-buffered solution in liquid handling cells containing 500 mM H2O2 for 90 or 120 min, and then the medium was replaced with common nutrient solution and cultured again for 24 h. The apoptosis rate and nitric oxide (NO) levels of each group were tested. The cell apoptosis rate of the CyPD low expression group (32.51 ± 6.6 %) was significantly lower than that of the control group (52.57 ± 5.84%, P = 0.001), and total NO production was 24.06 ± 3 and 13.03 ± 3.55 μM. The apoptosis rate of the CyPD high expression group (24.24 + 3.08%) was significantly higher than that of the control group (7.7 + 0.68%, P < 0.001); total NO production was 3.55 ± 1.53 and 8.46 ± 0.77 μM, which was significantly different (P = 0.008). CypD protein could increase oxidative stress and cause endothelial cell injury and apoptosis.

Voluntary weight loss: systematic review of early phase body composition changes

Weight loss follows when adult humans enter a phase of negative energy balance brought about by reducing energy intake and/or increasing energy expenditure. The weight loss period is usually viewed as a continuous process, ending when energy equilibrium is achieved at a lower weight or with death following depletion of fuel stores. However, growing evidence supports the expanded view that induction of negative energy balance leads to well-defined physiological effects characterized by three discrete phases (I-III). At present there are no comprehensive reviews of the 'early' phase of weight loss, a gap highlighted by recent interest in rapidly testing new treatments with short-term protocols. Herein we show from earlier reports and with new data that weight loss during phase I is: mathematically quantifiable with a t(1/2) < 1-week and 4- to 6-week duration; includes well-defined rapidly evolving body composition and energy expenditure changes; and is moderated by multiple factors including subject sex and activity level, nutrients ingested at baseline and during the negative energy balance period, and hormone and pharmacologic treatments. Our in depth review collectively characterizes phase I as a distinct weight loss period while revealing important knowledge gaps that can be filled with appropriately designed future studies.

Eradication of Helicobacter pylori infection reverses E-cadherin promoter hypermethylation

BACKGROUND

E-cadherin methylation is important in gastric carcinogenesis. Reversing hypermethylation may halt the carcinogenic process. We have previously reported that Helicobacter pylori infection is associated with E-cadherin methylation in chronic gastritis patients.

AIM

To examine if eradication of H pylori could reverse E-cadherin methylation.

METHODS

Patients with dyspepsia and positive for H pylori infection, with a mucosal biopsy showing chronic active gastritis, were randomised to receive H pylori eradication therapy (group 1, n = 41) or no treatment (group 2, n = 40), and were followed up prospectively. Gastric mucosae were taken for methylation assay at week 0 (before treatment) and week 6 (after treatment). Archived specimens of intestinal metaplasia with H pylori infection (n = 22) and without (n = 19) were retrieved for methylation analysis. Methylation was assessed using methylation specific polymerase chain reaction and sequencing.

RESULTS

Methylation at E-cadherin was detected in 46% (19/41) and 17% (7/41) of patients at weeks 0 and 6, respectively, in group 1 (p = 0.004); 78.9% (15/19) of specimens were unmethylated after eradication of H pylori. Mucosal biopsy showed chronic inactive gastritis in 35 patients, intestinal metaplasia in one, and normal mucosa in five at week 6. Methylation was detected in 47.5% (19/40) and 52.5% (21/40) of patients at weeks 0 and 6, respectively, in group 2 (P = 0.5). Gastric mucosal biopsy showed persistent chronic active gastritis in all cases. Methylation frequency did not differ in H pylori positive or negative intestinal metaplastic specimens (72.7% v 63%; p = 0.5).

CONCLUSION

H pylori eradication therapy could reverse methylation in patients with chronic gastritis. This demonstrates an environmental effect on methylation.

Effect of Helicobacter pylori on apoptosis and apoptosis related genes in gastric cancer cells

BACKGROUND/AIMS

Helicobacter pylori induces the apoptosis of gastric epithelial cells in vivo and in vitro. However, the molecular mechanism has not been clarified. The aim of this study was to investigate the effect of H pylori on the apoptosis of gastric epithelial cells and the expression of apoptosis related genes in vitro.

METHODS

Human gastric adenocarcinoma SGC-7901 cells were co-cultured with a cytotoxic H pylori strain, NCTC 11637, at various densities ranging from 3.2 x 10(4) to 1.0 x 10(8) colony forming units (CFU)/ml for 48 hours. Apoptosis in gastric cells was determined by transmission electron microscopy, Hoechst 33258 fluorochrome staining, and flow cytometry. The expression of apoptosis related proteins, Bcl-2, Bax, and c-Myc, was measured by an immunohistochemical method, and c-Myc mRNA expression was determined by the reverse transcription-polymerase chain reaction.

RESULTS

Helicobacter pylori induces morphological changes typical of apoptosis. Both fluorochrome staining and flow cytometry showed that the apoptotic index began to increase when H pylori were at a density of > 1.6 x 10(4) CFU/ml, and in a density dependent manner (p < 0.01; one way ANOVA). The expression of the Bax and c-Myc proteins and of c-Myc mRNA was increased, whereas Bcl-2 expression was decreased after co-culture for 48 hours.

CONCLUSIONS

Helicobacter pylori induced apoptosis in gastric epithelial cells is mediated by altered expression of the products of the Bcl-2, Bax, and c-Myc genes.

[Cardiovascular effects of lateral intracerebroventricular injection of L-securinine]

To investigate cardiovascular effects of changed GABAergic tonic activation in periventricular forebrain, arterial pressure (AP), heart rate (HR) and renal sympathetic nerve discharge (RSND) were recorded in anesthetized rats when L-securinine (L-Sec) was administered into the lateral intracerebroventricle. L-Sec elicited dose-dependent increases in RSND, AP and HR, which were much weaker than those of bicuculline. L-Sec antagonized the sympatho-inhibitory and depressor effects evoked by both muscimol and baclofen. These results indicate that GABAergic inhibition originating from periventricular forebrain may suppress tonically sympathetic outflow to cardiovascular system which is disinhibited by L-Sec, and L-Sec is likely an unselective GABA receptor antagonist.

Effect of intracerebral injection of pirenzepine on electroencephalography and convulsions in conscious rabbits

Intracerebroventricular (icv) injection of pirenzepine (Pir) 2 mg.kg-1 caused EEG spike discharges, which first appeared in amygdala or hippocampus and then in midbrain reticular formation and cortex. After that rabbits developed clonic convulsions. Injection (300 micrograms) into amygdala or hippocampus also produced EEG spike discharges Hemicholinium 3 (HC-3) 50-150 micrograms.kg-1 icv inhibited the EEG spike and seizure discharges in varying degrees produced by Pir. It is suggested that Pir has a central stimulatory action which is related to cholinergic mechanism.