Acid suppressant use in association with incidence and severe outcomes of COVID-19: a systematic review and meta-analysis.

PURPOSE: Several observational studies have presented conflicting results on the association between the use of proton pump inhibitors (PPIs) or histamine H2 receptor antagonist (H2RA) and the risk of coronavirus disease 2019 (COVID-19). This systematic review and meta-analysis aimed to examine this association. METHODS: In July 2021, PubMed, Embase, Cochrane Central Register of Controlled Trials, and Web of Science were searched for articles investigating the relationship between the two main acid suppressants and COVID-19. Studies showing the effect estimates as hazard ratio (HR) for severe outcomes or incidence of COVID-19 were evaluated using a random-effects model. RESULTS: A total of 15 retrospective cohort studies with 18,109 COVID-19 cases were included in the current meta-analysis. PPI use was significantly associated with severe outcomes of COVID-19 (hazard ratio [HR] = 1.53; 95% confidence interval [CI]: 1.20-1.95) but not with the incidence of COVID-19, whereas H2RA use was significantly associated with decreased incidence (HR = 0.86, 95% CI: 0.76-0.97). For subgroup analyses of PPIs, increased severe outcomes of COVID-19 were observed in < 60 years, active use, in-hospital use, and Asians. For subgroup analyses of H2RAs, decreased severe outcomes of COVID-19 were observed in > 60 years, while in-hospital use and use in Asia were associated with higher disease severity. CONCLUSIONS: Close observation can be considered for COVID-19 patients who use PPIs to prevent severe outcomes. However, caution should be taken because of substantial heterogeneity and plausible protopathic bias.

Sunlight exposure in association with risk of lymphoid malignancy: a meta-analysis of observational studies.

PURPOSE: Several observational studies have shown contradictory results regarding the association between sunlight exposure and the risk of malignant lymphoma. Thus, we aimed to systematically determine the association between sunlight exposure and lymphoid malignancy risk through a meta-analysis. METHODS: A thorough search of four electronic databases (PubMed, Embase, Web of Science, and Scopus) was performed to identify eligible studies until 13 August 2020. A random-effects model was used to calculate risk estimates of sunlight exposure. The main outcome measure was the risk of lymphoid malignancy subtypes with odds ratios (ORs) and 95% confidence intervals (CIs) according to various forms of solar ultraviolet radiation. RESULTS: In total, 17 case-control studies and 9 cohort studies including 216,285 non-Hodgkin lymphoma (NHL) and 23,017 Hodgkin's lymphoma (HL) patients were included in the final analysis. Personal sunlight exposure was significantly associated with a decreased risk of HL (OR 0.77; 95% CI 0.68-0.87) and NHL (OR 0.81; 95% CI 0.71-0.92), including all subtypes except T-cell lymphoma. Ambient sunlight exposure at residence was associated with a reduced risk of HL (OR 0.88; 95% CI 0.81-0.95) and all NHL subtypes (OR 0.84; 95% CI 0.73-0.96), except for chronic lymphocytic leukemia/small lymphocytic lymphoma. As the number of sunburns and sunbaths increased, the risk of NHL tended to decrease. CONCLUSION: While there was an observed protective effect both from case-control and prospective studies, substantial heterogeneity was found in the current study. Thus, more evidence is required to confirm that promoting sunlight exposure can prevent the development of lymphoid neoplasia.

Association between sunlight exposure and risk of prostate cancer: a systematic review and meta-analysis.

BACKGROUND: The prevalence of prostate cancer (PC) is increasing worldwide. An association between sunlight exposure and PC risk has been described by a previously published meta-analysis, although the level of statistical significance was not reached. We have, therefore, performed an updated systematic review and meta-analysis to further elucidate this potential connection. METHODS: To identify relevant articles, we conducted an in-depth search of 4 electronic databases (PubMed, Embase, the Web of Science and Scopus) for manuscripts published prior to March 2021. A random-effects model was used to compute a meta-estimate of the effects of sunlight exposure on risk of PC. RESULTS: Of the 5680 articles that were initially identified in our search, 12 observational epidemiological studies encompassing 29 282 cases of PC were selected for inclusion in the qualitative systematic review. Of these, two case-control studies were excluded from the meta-analysis. Comparing highest-to-lowest exposure, personal sunlight exposure was significantly associated with a decreased risk of PC [odds ratio (OR) = 0.67, 95% CI: 0.57-0.78] in a random-effects meta-analysis; however, high heterogeneity was present (I2 = 85.9%). Comparing moderate-to-lowest exposure, there was a non-significant relationship between personal sunlight exposure and the risk of PC (OR = 0.87, 95% CI: 0.68-1.10; I2 = 74.0%). CONCLUSIONS: Our findings indicate that exposure to sunlight may protect against PC. The limitations of our research are occurrence of publication bias and a substantial heterogeneity due to a diversity of criteria for measuring sunlight exposure.

The association between aspirin use and depression: a systematic review and meta-analysis of observational studies.

PURPOSE: Many clinical trials and observational studies have been conducted under the premise that the anti-inflammatory effect of aspirin may prevent depression. These studies, however, showed inconsistent results. To inspect the association between aspirin use and depression, we conducted a meta-analysis of observational studies. METHODS: In August 2019, two authors independently searched PubMed, EMBASE, and PsycINFO to retrieve observational epidemiological studies presenting an association between aspirin use and depression. Case-control and cohort studies were included, and odds ratios (ORs) or relative risks (RRs) with 95% confidence intervals (CIs) for the risk of depression were estimated using a random-effects model. In addition, number needed to harm (NNH) was calculated to measure the rates of depression. RESULTS: In total, 12 observational studies-five case-control studies and seven prospective cohort studies-were included in this meta-analysis. The random-effects model demonstrated a significant association between aspirin use and depression (OR/RR 1.10; 95% CI: 1.05-1.16) with insignificant heterogeneity (I2 = 23.3%). The risk estimates of depression from prospective cohort studies were similar (RR 1.11; 95% CI: 1.08-1.14), and heterogeneity was not observed (I2 = 0.0%). In the subgroup meta-analysis, a duration of aspirin use ≥5 years and a dosage ≥500 mg daily were also associated with depression. The NNH for depression with aspirin use >5 years was 103 (95% CI 91-111) indicating that observed event is rare. CONCLUSIONS: Aspirin use was associated with depression in the present meta-analysis. One of the major limitations is the lack of detail and consistency with respect to exposure verification in the included papers. Another limitation is the lack of randomized controlled studies and prospective cohort studies.

Use of benzodiazepine and risk of cancer: A meta-analysis of observational studies.

Several observational epidemiological studies have reported inconsistent results on the association between the use of benzodiazepine and the risk of cancer. We investigated the association by using a meta-analysis. We searched PubMed, EMBASE, and the bibliographies of relevant articles to locate additional publications in January 2016. Three evaluators independently reviewed and selected eligible studies based on predetermined selection criteria. Of 796 articles meeting our initial criteria, a total of 22 observational epidemiological studies with 18 case-control studies and 4 cohort studies were included in the final analysis. Benzodiazepine use was significantly associated with an increased risk of cancer (odds ratio [OR] or relative risk [RR] 1.19; 95% confidence interval 1.16-1.21) in a random-effects meta-analysis of all studies. Subgroup meta-analyses by various factors such as study design, type of case-control study, study region, and methodological quality of study showed consistent findings. Also, a significant dose-response relationship was observed between the use of benzodiazepine and the risk of cancer (p for trend <0.01). The current meta-analysis of observational epidemiological studies suggests that benzodiazepine use is associated with an increased risk of cancer.

Longer Duration of Sleep and Risk of Cognitive Decline: A Meta-Analysis of Observational Studies.

BACKGROUND: Previous observational epidemiological studies have reported inconsistent findings about the association between longer durations of sleep and the risk of cognitive impairment and dementia. To investigate the association between longer durations of sleep and the risk of cognitive decline, we performed a meta-analysis of observational studies. METHODS: We searched PubMed, EMBASE, and the bibliographies of relevant articles to retrieve additional studies in July 2015. A total of 53,942 participants (mean age 66.9 years) were included in the final analysis. Three evaluators independently reviewed and selected articles, based on pre-determined selection criteria. RESULTS: Among a total of 695 articles, 10 observational epidemiological studies with 3 case-control studies and 7 cohort studies were included in the final analysis. Compared to the average sleep duration, the odds ratio or relative risk of the longest sleep duration was 1.42 (95% CI 1.27-1.59) for cognitive decline in the fixed-effect meta-analysis, 1.38 for cognitive impairment (95% CI 1.23-1.56), and 1.42 for dementia (95% CI 1.15-1.77). Subgroup meta-analyses by various factors such as study design, type of cognitive decline, gender, region, age, and methodological quality of study showed consistent findings. CONCLUSION: The current meta-analysis found that longer duration of sleep is associated with an increased risk of cognitive decline.

Surgical outcome and cost comparison between total vaginal hysterectomy and laparoscopic hysterectomy for uteri weighing >500 g.

STUDY OBJECTIVE: To compare surgical outcomes and overall costs of less invasive methods of hysterectomy to treat benign disease including total vaginal hysterectomy (TVH) and total laparoscopic hysterectomy (TLH) in women with a uterus weighing >500 g. DESIGN: Retrospective review of medical records (Canadian Task Force classification III). SETTING: University-associated hospital. PATIENTS: One hundred three women with a uterus weighing >500 g who had undergone either total vaginal hysterectomy (TVH) (n = 52) or total laparoscopic hysterectomy (TLH) (n = 51). MEASUREMENTS AND MAIN RESULTS: Cost data were extracted from the hospital billing system. Patient characteristics, surgical outcomes, and hospital costs were compared between the 2 groups. Patient characteristics were similar in both groups except for a history of surgery (TVH 11.5%, and TLH 37.3%; p = .01). Insofar as surgical outcomes, mean (SD) operative time was shorter in the TVH group compared with the TLH group (110.00 [28.68] minutes vs 180.47 [51.32] minutes; p < .001), and hospital stay was longer (8.08 [0.68] days vs 7.45 [1.03] days; p < .001). Other surgical outcomes including estimated blood loss (p = .20) and decrease in hemoglobin (p = .12) did not differ between the 2 groups. Total hospital costs (converted from Korean won to US dollars) were significantly lower in the TVH group than in the TLH group ($2076.59 [$666.58] vs $2744.03 [$715.76]; p < .001). CONCLUSION: Our data suggest that TVH is a safe and economic procedure even in women with a uterus weighing >500 g. Skilled surgeons should preferentially consider TVH for treatment of benign uterine disease, regardless of uterine size.

Correlation analysis of cancer stem cell marker CD133 and human endogenous retrovirus (HERV)-K env in SKOV3 ovarian cancer cells.

BACKGROUND: Human endogenous retrovirus (HERV)-K is a type of retrovirus that is present in the human genome, and its expression is usually silenced in healthy tissues. The precise mechanism by which HERV-K env influences cancer stemness is not fully understood, but it has been suggested that HERV-K env may activate various signaling pathways that promote stemness traits in cancer cells. OBJECTIVE: To establish the connection between HERV-K env expression and cancer stemness in ovarian cancer cells, we carried out correlation analyses between HERV-K env and the cancer stem cell (CSC) marker known as the cluster of differentiation 133 (CD133) gene in SKOV3 ovarian cancer cells. METHOD: To perform correlation analysis between HERV-K env and CSCs, ovarian cancer cells were cultured in a medium designed for cancer stem cell induction. The expression of HERV-K env and CD133 genes was verified using quantitative real-time polymerase chain reaction (RT-qPCR) and Western blot analyses. Additionally, the expression of stemness-related markers, such as OCT-4 and Nanog, was also confirmed using RT-qPCR. RESULTS: In the stem cell induction medium, the number of tumorsphere-type SKOV3 cells increased, and the expression of CD133 and HERV-K env genes was up-regulated. Additionally, other stemness-related markers like OCT-4 and Nanog also exhibited increased expression when cultured in the cancer stem cell induction medium. However, when HERV-K env knockout (KO) SKOV3 cells were cultured in the same cancer stem cell induction medium, there was a significant decrease in the number of tumorsphere-type cells compared to mock SKOV3 cells subjected to the same conditions. Furthermore, the expression of CD133, Nanog, and OCT-4 did not show a significant increase in HERV-K env KO SKOV3 cells compared to mock SKOV3 cells cultured in the same cancer stem cell induction medium. CONCLUSION: These findings indicate that the expression of HERV-K env increased in SKOV3 cells when cultured in cancer stem cell induction media, and cancer stem cell induction was inhibited by KO of HERV-K env in SKOV3 cells. These results suggest a strong association between HERV-K env and stemness in SKOV3 ovarian cancer cells.

Changes of apoptosis in tumor tissues with time after irreversible electroporation.

Irreversible electroporation is a novel method of ablating living tissues through its non-thermal effects, unlike radiofrequency ablation which has a severe problem of heat sink. It is due to high-energy direct current which leads to permanent disruption of lipid bilayer integrity in terms of exchanges between intra- and extracellular components via nano-sized pores. That finally causes irreversible damage to cellular homeostasis. Irreversibly damaged cells may undergo apoptosis followed by necrosis with time after electroporation. This damage can make it possible to monitor the ablated area with time post-IRE through MR imaging and an ultrasound system. Most previous studies have investigated the immediate response of undesired tissue to IRE. In our study, we showed changes of tumor tissues with time post-IRE by histological analysis and MR imaging. Tissues under IRE ablation showed a peak apoptotic rate at 24 h after IRE ablation with viable tissues at the peripheral rim of treated tissues in histological analysis. This phenomenon was also observed with no enhancement on contrast-enhanced MR images due to devascularization of IRE ablated zones.

Association of metabolic syndrome and its components with the risk of depressive symptoms: A systematic review and meta-analysis of cohort studies.

BACKGROUND: The purpose of this meta-analysis was to quantitatively analyze the association between metabolic syndrome (MetS) and the risk of depressive symptoms. METHODS: Three electronic databases (PubMed, Embase, and PsycINFO) were searched for articles published through February 15, 2022. Cohort studies evaluating the association between MetS and depressive symptoms were selected for inclusion in this study. A random-effects model was used to evaluate the pooled estimates of MetS, including each of its components, associated with depressive symptoms. RESULTS: A total of 11 cohort studies were selected including >2.65 million participants. There was a significant association between MetS and depressive symptoms risk, albeit with a high degree of heterogeneity (relative risk = 1.29, 95 % confidence interval: 1.12-1.48; I2 = 79.3 %). This association was consistently significant in Western countries, but it was not significant in Asian countries. When stratified by sex, age, and geographical region, MetS and its components exhibited varying degrees of association with depressive symptoms. CONCLUSIONS: MetS is a risk factor for depressive symptoms. Further large-scale prospective cohort studies are required to confirm our findings.

Impact of sarcopenia and phase angle on mortality of the very elderly.

BACKGROUND: Sarcopenia is a major component of geriatric syndrome and associated with poor clinical outcomes and mortality. However, diagnosing sarcopenia in the very elderly is difficult, and data on its epidemiology and devastating effects in this group are scarce. Phase angle (PA) is measured using bioimpedance spectroscopy and known to reflect cellular integrity and health. This study aimed to clarify the impact of sarcopenia and PA on mortality risk in very elderly people living in long-term care facilities. METHODS: This prospective cohort study enrolled elderly residents living in nine long-term care facilities. We collected the participants' data, such as body mass index (BMI), comorbidities and laboratory data, from September to October 2017 and mortality data until October 2019. Nutritional status was evaluated using the Mini Nutritional Assessment (MNA) score, and multifrequency bioimpedance spectroscopy was used to assess body composition including PA. Appendicular skeletal muscle mass was calculated using the body composition monitor-derived equation of Taiwan's researchers. Sarcopenia was diagnosed using the European Working Group on Sarcopenia in Older People 2 (EWGSOP2) definition (sarcopenia vs. normal group). We divided the participants into two groups according to the median PA value of 3.65° (high vs. low group) and performed multivariate regression analyses to verify the association with mortality risk according to sarcopenia diagnosis or PA group. RESULTS: A total of 279 elderly participants were enrolled; of them, 238 (85.3%) were diagnosed with sarcopenia according to EWGSOP2 guidelines. The median patient age was 83 years, 211 (75.6%) were female and the median BMI was 20.4 kg/m2 . The sarcopenia group was older than the normal group (84 vs. 81 years; P = 0.002), had a lower mean BMI (19.8 vs. 26.6 kg/m2 , P < 0.001) and had a lower MNA score (9 vs. 12 points, P < 0.001). Sarcopenia was associated with a higher mortality risk after the adjustment for age, sex and diabetes mellitus (hazard ratio [HR], 3.744; 95% confidence interval [CI], 1.155-12.134; P = 0.028). A low PA was associated with sarcopenia, older age, female sex, low MNA score and overhydration volume; it was also a significant predictor of mortality after the adjustment for age, sex, diabetes mellitus and MNA score (HR, 0.593; 95% CI, 0.420-0.837; P = 0.003). CONCLUSIONS: Sarcopenia is prevalent among the very elderly patients in long-term care facilities. Sarcopenia and low PA are significantly associated with higher mortality risk.

When do we need to perform laparotomy for benign uterine disease? Factors involved with conversion in vaginal hysterectomy.

AIM: To identify the preoperative risk factors affecting the conversion to laparotomy during vaginal hysterectomy (VH) for benign uterine conditions. MATERIAL AND METHODS: The charts were reviewed for all patients who underwent VH between 1 January 2003 and 31 December 2008 at Hallym University Hospital, Seoul. RESULTS: The rate of conversion to laparotomy was 3.7% (32 cases). Factors that were independently associated with the risk of conversion to laparotomy were found to be low parity (conversion 1.43 vs VH 1.92, P=0.021), previous abdominal surgery (conversion 0.71 vs, VH 0.26, P=0.012), pelvic adhesion (conversion 1.25 vs VH 0.04, P=0.000), and large uterine weight (conversion 345.15g vs VH 222.38g, P=0.005). In the conversion group, the operative time was longer (conversion 144.84min vs VH 77.67min, P=0.000), and estimated blood loss was also greater (conversion 656.25mL vs VH 358.47mL, P=0.00). Postoperative hemoglobin change (conversion 1.65g/dL vs VH 1.23g/dL, P=0.046) and transfusion rate were also greater in the conversion group (conversion 0.75 vs VH 0.01, P=0.001). CONCLUSION: VH is the main procedure for benign uterine disease and is successfully performed in most cases. But several factors, including low parity, previous abdominal surgery, pelvic adhesion and large uterine weight can affect the risk of conversion to laparotomy.

Prophylactic adnexectomy along with vaginal hysterectomy for benign pathology.

OBJECTIVE: This study was designed to evaluate the safety and feasibility of prophylactic adnexectomy during vaginal hysterectomy for benign pathology. METHODS: We retrospectively reviewed medical records of all patients who underwent vaginal hysterectomy (VH) between 2008 and 2010. Clinical comparison of patients who underwent VH with adnexectomy (n = 92) and VH only (n = 686) was performed. Clinical characteristics (age, parity, body mass index, and previous pelvic surgery), surgical outcomes (uterine weight, operative time, estimated blood loss, pelvic adhesion, hemoglobin change and hospital stay) and intra- and postoperative complications (transfusion, bladder injury and fever) were evaluated. RESULTS: Clinical characteristics except for age (45.44 years for VH only vs. 47.15 years for VH with adnexectomy, P = 0.007) were not different between the two groups. Similarly, surgical outcomes and complication rates were not different between the two groups. CONCLUSION: Prophylactic bilateral adnexectomy can be performed safely during VH.

Comparison of two bipolar systems in laparoscopic hysterectomy.

OBJECTIVE: To compare the efficacy of 2 bipolar systems during total laparoscopic hysterectomy (TLH): the pulsed bipolar system (PlasmaKinetic; Olympus, Japan) vs. conventional bipolar electrosurgery (Kleppinger bipolar forceps; Richard Wolf Instruments, Vernon Hills, IL). METHODS: We retrospectively reviewed medical records of 80 women who underwent TLH for benign gynecologic disease between 2009 and 2010. Forty women received TLH using the conventional bipolar system and another 40 using the pulsed bipolar system. The clinical outcomes and complications were compared between the 2 groups. RESULTS: No significant differences between the 2 groups were observed in terms of age, body mass index, and hospital stay. However, the blood loss was greater (515.3 ± 41.2mL vs. 467.9 ± 33.4mL, P < .05) and the operation time was longer (173.4 ± 33.4min vs. 157.3 ± 21.3min, P < .05) in the conventional group. Additionally, the uterine weight was lighter in the conventional group (218.5 ± 23.4g vs. 299.4 ± 41.1g, P < .05). None of the surgeries were required to be converted to laparotomy. No significant differences were found in intraoperative or postoperative complications between the groups. CONCLUSION: The pulsed bipolar system has some advantages over the conventional system, and therefore, may offer an alternative option for patients undergoing TLH.

Resting Heart Rate and Cognitive Decline: A Meta-Analysis of Prospective Cohort Studies.

BACKGROUND AND PURPOSE: Several previous meta-analyses have identified an association between cognitive decline and heart rate variability, which reflects autonomic nerve activity. This systematic review and meta-analysis investigated the impact of increased resting heart rate (RHR) on the incidence of cognitive decline, including dementia. METHODS: The PubMed, Embase, and PsycInfo databases were searched for relevant prospective cohort studies published before April 18, 2022. A methodological quality assessment of the included studies was conducted using the Newcastle-Ottawa Scale. Summary estimates of the incidence of cognitive decline, including dementia, were generated using a random-effects model. Potential publication bias was evaluated using Begg's funnel plots and Egger's regression tests. RESULTS: The meta-analysis included 7 prospective cohort studies comprising 53,621 participants. A weak significant association was observed between RHR and the risk of cognitive decline, although the analysis indicated high heterogeneity among the studies (relative risk=1.18, 95% confidence interval=1.04-1.33, I²=82.5%). Significant associations were determined between RHR and all combined types of dementia except for Alzheimer's disease and mild cognitive impairment. There was also a dose-response association between increased RHR and cognitive decline. The meta-estimate of the cognitive decline risk associated with a 10 beat-per-minute increase in RHR was 1.06, and it was 1.10 for dementia. CONCLUSIONS: This study found that a higher RHR was associated with an increased cognitive decline risk. Due to study limitations such as publication bias and high heterogeneity, additional studies are required to validate this finding. SYSTEMATIC REVIEW REGISTRATION: PROSPERO registration number CRD42021282912.

Effect of human endogenous retrovirus-K env gene knockout on proliferation of ovarian cancer cells.

BACKGROUND: Among various human endogenous retroviruses (HERVs), the HERV-K (HML-2) group has been reported to be highly related to cancer. In pancreatic cancer cells, shRNA-mediated downregulation of HERV-K env RNA decreases cell proliferation and tumor growth through the RAS-ERK-RSK pathway; in colorectal cancer, CRISPR-Cas9 knockout (KO) of the HERV-K env gene affects tumorigenic characteristics through the nupr-1 gene. OBJECTIVE: The effect of HERV-K env KO has not been studied in ovarian cancer cell lines. In this study, we analyzed the tumorigenic characteristics of ovarian cancer cell lines, including cell proliferation, migration, and invasion, and the expression patterns of related proteins after CRISPR-Cas9 KO of the HERV-K env gene. METHODS: The HERV-K env gene KO was achieved using the CRISPR-Cas9 system in ovarian cancer cell lines SKOV3 and OVCAR3. Tumorigenic characteristics including cell proliferation, migration, and invasion were analyzed, and related protein expression was investigated by western blot analysis. RESULTS: The expression of the HERV-K env gene in KO cells was significantly reduced at RNA and protein levels, and tumorigenic characteristics including cell proliferation, migration, and invasion were significantly reduced. In HERV-K env KO SKOV3 cells, the expression of the RB protein was significantly up-regulated and the cyclin B1 protein level was significantly reduced. In contrast, in HERV-K env KO OVCAR3 cells, the level of phospho-RB protein was significantly reduced, but other protein levels were not changed. CONCLUSION: The results of this study showed that HERV-K env gene KO affects cell proliferation, invasion, and migration of ovarian cells through RB and Cyclin B1 proteins, but the specific regulation pattern can differ by cell line.

Stent-based electrode for radiofrequency ablation in the rat esophagus: a preliminary study.

Endoluminal radiofrequency (RF) ablation has been widely used as a safe and effective treatment for Barrett's esophagus. However, inadequate RF ablation may occur due to insufficient contact between the electrode and target tissues. Herein, a stent-based monopolar RF electrode (SE) was developed to evenly deliver RF energy to the inner wall of the rat esophagus. The optimal RF parameters were evaluated in the exposed rat esophagus. The temperature in the rat esophagus reached 70 â„ƒ in 89 s at 30 W, 59 s at 40 W, and 34 s at 50 W. The technical feasibility and efficacy of RF ablation using SE were evaluated based on changes in histological transformation and immunohistochemical parameters of tissues compared at immediately, 1 and 2 weeks after the procedure. The degrees of inflammatory cell infiltration, fibrotic changes, TUNEL, and HSP70 in the RF-ablated rat esophagus were significantly higher than compared with sham control (all p < 0.05). TUNEL-positive deposition gradually decreased, but HSP 70-positive deposition maintained a similar level for 2 weeks. The stent-based RF ablation was technically feasible and effective in evenly inducing thermal damages to the rat esophagus. The RF ablation system using the SE may represent a promising treatment for endoluminal malignancies.

High-Frequency Pulsed Electric Field Ablation in Beagle Model for Treatment of Prostate Cancer.

Conventional irreversible electroporation (IRE) with low-frequency pulsed electric field (LF-PEF) is used to induce cell death; however, it has several disadvantages including a long procedure time and severe muscle contraction due to high-voltage electric field. This study investigates a novel IRE protocol with high-frequency pulsed electric field (HF-PEF) of 500 Hz repetition to ablate the prostate tissue in beagles for treatment of prostate cancer. A finite element analysis was performed to validate optimal electrical field strength for the procedure. In total, 12 beagles received HF-PEF of 500 Hz and were sacrificed at 4 h, 4 days, and 28 days (3 each). The remaining three beagles underwent sham procedure. The outcomes of HF-PEF were assessed by histological responses. HF-PEF successfully decellularized the prostate tissues 4 h after the treatment. The prostate glands, duct, and urethra were well preserved after IRE with HF-PEF. The ablated prostatic tissues were gradually regenerated and appeared similar to the original tissues 28 d after IRE with HF-PEF. Moreover, electrocardiography and hematology demonstrated that IRE with HF-PEF did not seriously affect the cardiac tissue. HF-PEF was effective and safe in the beagle prostate and effectively induced the ablation and gradually recovered with cellular regeneration.