Diversified Adversarial Attacks based on Conjugate Gradient Method

Deep learning models are vulnerable to adversarial examples, and adversarial attacks used to generate such examples have attracted considerable research interest. Although existing methods based on the steepest descent have achieved high attack success rates, ill-conditioned problems occasionally reduce their performance. To address this limitation, we utilize the conjugate gradient (CG) method, which is effective for this type of problem, and propose a novel attack algorithm inspired by the CG method, named the Auto Conjugate Gradient (ACG) attack. The results of large-scale evaluation experiments conducted on the latest robust models show that, for most models, ACG was able to find more adversarial examples with fewer iterations than the existing SOTA algorithm Auto-PGD (APGD). We investigated the difference in search performance between ACG and APGD in terms of diversification and intensification, and define a measure called Diversity Index (DI) to quantify the degree of diversity. From the analysis of the diversity using this index, we show that the more diverse search of the proposed method remarkably improves its attack success rate.Comment: Proceedings of the 39th International Conference on Machine Learning (ICML 2022

Role of neurosteroid allopregnanolone on age-related differences in exercise-induced hypoalgesia in rats

The beneficial effects of physical activity for pain are denominated exercise-induced hypoalgesia (EIH). Here, we examined the age-related change and potential role of the neurosteroid allopregnanolone (ALLO) on EIH in rats. Adult and aged rats were randomly divided into one of three groups; non-exercise control, Low-exercise, and High-exercise. The animals in the Low- and High-exercise groups were subjected to a 10-minute treadmill workout at 40% and 80% maximum oxygen intake intensity, respectively. In the Low-exercise groups, a significant EIH response was observed in aged but not in adult rats. The pre-treatment with ALLO synthesis inhibitor finasteride, but not opioid-receptor antagonist naloxone, inhibited the Low-exercise induced EIH response in aged rats. Furthermore, the Low-exercise increased brain ALLO levels in aged animals compared with controls, which was correlated with the mechanical pain sensitivity. On the other hand, High-exercise could induce EIH response in both adult and aged animals, but it was more effective in adult rats. The pre-treatment with naloxone, but not finasteride, reduced the EIH observed after High-exercise in both adult and aged rats. Our findings demonstrated that effective EIH can be achieved even by mild-intensity exercise in aged animals via an increase of the brain ALLO levels

Resveratrol-loaded nanoemulsion prevents cognitive decline after abdominal surgery in aged rats

The maladaptive response of aged microglia to surgery and consequent neuroinflammation plays a key pathogenic role in postoperative cognitive dysfunction (POCD). Here, we assessed the preventive effect of resveratrol (RESV) for POCD in aged rats. The emulsified form of RESV (e-RESV) was selected to improve its oral and brain bioavailability. Animals were assigned to one of four groups: e-RESV (80 mg/kg) versus vehicle treatment by abdominal surgery versus isoflurane anesthesia alone (n = 8 in each group). The dose-dependent effects of e-RESV were also assessed in dose range of 0e60 mg/kg. Either vehicle or e-RESV was administered intragastrically 24 h before surgery. Seven days after procedure, cognitive function was evaluated using a novel object recognition test, followed by measurement of hippocampal pro-inflammatory cytokine levels. Our results showed that pre-treatment with e-RESV attenuated the surgery-induced cognitive impairment and related hippocampal neuroinflammation at 40 mg/kg or higher doses. Additionally, the ex-vivo experiments revealed that the preemptive e-RESV regimen reduced the hippocampal microglial immune reactivity to lipopolysaccharide. Furthermore, e-RESV induced neuroprotective benefits were inhibited by the concomitant administration of sirtinol, a specific SIRT1 inhibitor. Our findings imply the preventive potential of e-RESV for POCD via the SIRT1 signaling pathway

Comparison of Clinical and Radiological Results of Posterolateral Fusion and Posterior Lumbar Interbody Fusion in the Treatment of L4 Degenerative Lumbar Spondylolisthesis

Study DesignMulticenter analysis of two groups of patients surgically treated for degenerative L4 unstable spondylolisthesis.PurposeTo compare the clinical and radiographic outcomes of posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) for degenerative L4 unstable spondylolisthesis.Overview of LiteratureSurgery for lumbar degenerative spondylolisthesis is widely performed. However, few reports have compared the outcome of PLF to that of PLIF for degenerative L4 unstable spondylolisthesis.MethodsPatients with L4 unstable spondylolisthesis with Meyerding grade II or more, slip of >10° or >4 mm upon maximum flexion and extension bending, and posterior opening of >5 degree upon flexion bending were studied. Patients were treated from January 2008 to January 2010. Patients who underwent PLF (n=12) and PLIF (n=19) were followed-up for >2 years. Radiographic findings and clinical outcomes evaluated by the Japanese Orthopaedic Association (JOA) score were compared between the two groups. Radiographic evaluation included slip angle, translation, slip angle and translation during maximum flexion and extension bending, intervertebral disc height, lumbar lordotic angle, and fusion rate.ResultsJOA scores of the PLF group before surgery and at final follow-up were 12.3±4.8 and 24.1±3.7, respectively; those of the PLIF group were 14.7±4.8 and 24.2±7.8, respectively, with no significant difference between the two groups. Correction of slip estimated from postoperative slip angle, translation, and maintenance of intervertebral disc height in the PLIF group was significantly (p<0.05) better than those in the PLF group. However, there was no significant difference in lumbar lordotic angle, slip angle and translation angle upon maximum flexion, or extension bending. Fusion rates of the PLIF and PLF groups had no significant difference.ConclusionsThe L4–L5 level posterior instrumented fusion for unstable spondylolisthesis using both PLF and PLIF could ameliorate clinical symptoms when local stability is achieved

The effect of a prostaglandin E-1 derivative on the symptoms and quality of life of patients with lumbar spinal stenosis

Quality of life (QOL) is a concern for patients with lumbar spinal stenosis (LSS). In this study, QOL was examined using the 5-item EuroQol (EQ-5D). QOL and activities of daily living (ADL) were surveyed for 91 patients who visited 18 medical institutions in our prefecture and were diagnosed with LSS-associated intermittent claudication. A second survey was performed after a parts per thousand yen6 weeks for 79 of the subjects to evaluate therapy with limaprost (an oral prostaglandin E1 derivative) or etodolac (an NSAID). Symptoms, maximum walking time, QOL, ADL items, and relationships among these variables were investigated for all 91 patients. Leg pain, leg numbness, and low back pain while walking were surveyed by use of VAS scores (0-100). Leg pain, leg numbness, and low back pain while walking (VAS a parts per thousand yen25) were present in 83.5, 62.6, and 54.9 % of the patients in the first survey, and approximately half of the patients had a maximum walking time 30 min, showing that maximum walking time affected health-related QOL. Of the 79 patients who completed the second survey, 56 had taken limaprost and 23 (control group) had received etodolac. Limaprost improved possible walking time, reduced ADL interference, and significantly increased the EQ-5D utility score, whereas no significant changes occurred in the control group. Maximum walking time was prolonged by a parts per thousand yen10 min and the EQ-5D utility value was improved by a parts per thousand yen0.1 points in significantly more patients in the limaprost group than in the control group. According to the findings of this survey, at an average of 8 weeks after administration limaprost improved symptoms, QOL, and ADL in LSS patients whereas treatment with an NSAID reduced pain but did not have any other effects.ArticleJOURNAL OF ORTHOPAEDIC SCIENCE. 18(2):208-215 (2013)journal articl

Bleeding sites and treatment strategies for cardiac tamponade by catheter ablation requiring thoracotomy: risks of catheter ablation in patients with left atrial diverticulum

Abstract Background There is insufficient information regarding the bleeding sites and surgical strategies of cardiac tamponade during catheter ablation for atrial fibrillation (AF). Case presentation Of the five patients with cardiac tamponade, three required surgical intervention and two required pericardiocentesis. In the first case of three cardiac tamponades requiring surgical intervention, considering that the peripheral route was used, the catecholamines did not reach the heart, and due to unstable vital signs, venoarterial extracorporeal membrane oxygenation (VA-ECMO) was inserted. No bleeding point was identified, but a thrombus had spread around the left atrium (LA) with diverticulum. Hemostasis was achieved with adhesives placed around the LA under on-pump beating. In the second case, pericardiocentesis was performed, but the patient showed heavy bleeding and unstable vital signs. Thus, VA-ECMO was inserted. Heavy bleeding was expected, and safety was enhanced by attaching a reservoir to the VA-ECMO. The bleeding point was found between the left upper pulmonary artery and LA under cardiac arrest to obtain a good surgical view for suturing repair. In the third case, the LA diverticulum was damaged. Pericardiocentesis resulted in stable vitals, but sustained bleeding was present. A bleeding point was found at the LA diverticulum, and suture repair under on-pump beating was performed. Conclusions When cardiac tamponade occured in any patient with LA diverticulum, treatment could not be completed with pericardiocentesis alone, and thoracotomy was likely to be necessary. If the bleeding point could be confirmed, suturing technique is a more reliable surgical strategy than adhesive alone that leads to pseudoaneurysm. If the bleeding point is unclear, it is important to confirm the occurrence of LA diverticulum using a preoperative CT, and if confirmed, cover it with adhesive due to a high possibility of diverticulum bleeding. The necessity of CPB should be determined based on whether these operations can be completed while maintaining vital stability

Does preoperative patient’s estimated acceptable pain affect the satisfaction with postoperative pain management?

Abstract Background Patient satisfaction with postoperative pain management is an important quality indicator in patient health care, but its determinants are poorly understood. Here, we examined the contribution of the discrepancy between an individual’s estimated acceptable and actual postoperative pain scores to the overall satisfaction with pain treatment. Findings A total of 93 surgical patients were included in this study. Preoperatively, the subjects were asked to rate their estimated acceptable postoperative pain using a numerical rating scale (NRS). One day after the surgery, the patients were again asked to give NRS ratings of the overall actual pain intensity they had experienced, as well as their satisfaction with the provided pain treatment. The median estimated acceptable and actual NRS values for postoperative pain were 4.0 (3.0–5.0) and 4.0 (2.0–5.0), respectively. Although there was no correlation between the degree of patient satisfaction and preoperative estimated acceptable pain intensity, there was a significant negative correlation between the degree of patient satisfaction and postoperative actual pain intensity. When the preoperative estimated acceptable NRS value was compared with the postoperative actual value for each individual, postoperative NRS was greater in 34 cases (36.6%), less in 43 cases (46.2%), and equal in 16 cases (17.2%). The degree of patient satisfaction was not significantly correlated with the magnitude of difference between preoperative estimated acceptable NRS and postoperative actual NRS. Conclusions Our findings suggest that inquiring about the estimated acceptable pain before surgery may not help anesthesiologists to understand the patient’s goal of pain management for improving patient satisfaction

General anesthesia in a patient with asymptomatic second-degree two-to-one atrioventricular block

Abstract Background The major perioperative concern in patients with second-degree atrioventricular (AV) block is the progression to complete AV block. Therefore, the prophylactic implantation of a temporary pacemaker prior to surgery is recommended, especially in symptomatic patients. However, as no quantitative preoperative risk assessment from progression to complete AV block is available, there is currently no established indication for preoperative prophylactic pacemaker implantation. Here, we present a case of progression from asymptomatic second-degree two-to-one (2:1) AV block to complete AV block following the induction of general anesthesia. Case presentation A 69-year-old female with degenerative spinal stenosis was scheduled for transforaminal lumbar interbody fusion surgery under general anesthesia. She had no cardiac symptoms, but routine preoperative resting 12-lead electrocardiogram revealed second-degree 2:1 AV block. After discussion with the surgeon and referring cardiologist, we scheduled the surgery without implantation of a temporary pacemaker before surgery for the following reasons: (1) asymptomatic, (2) no evidence of underlying cardiac disease, and (3) a narrow QRS complex. On the day of surgery, general anesthesia was induced with 150 mg of intravenous thiamylal and 25 μg of fentanyl, followed by intravenous administration of 50 mg of rocuronium to facilitate endotracheal intubation. Sevoflurane (1.0–2.0%) was used to maintain anesthesia. A few minutes after induction, the 2:1 AV block progressively converted to complete AV block, and the surgery was postponed. During emergence from anesthesia, the third-degree AV block recovered to 2:1 AV block, similar with the preoperative pattern. The patient was monitored in the intensive care unit for 2 days and then transferred to the normal orthopedic ward uneventfully. One month later, the surgery was rescheduled with preoperative implantation of a temporary pacemaker. A slow mask induction using sevoflurane with oxygen was started. Upon loss of consciousness during the inhalation of initial sevoflurane, complete AV block developed and temporary pacing was immediately initiated. Subsequent anesthesia and surgery were uneventful. The patient made an uncomplicated recovery from surgery with stable hemodynamics. The temporary pacemaker was not required after surgery, and the pacemaker catheter was removed 1 day after surgery. Conclusions The present case indicates that a prophylactic pacemaker should be implanted preoperatively in patients who have 2:1 AV block even without symptoms