Acute myocardial ischemia induces an increase in interstitial extracellular potassium ([K+]e ). In the present overview, we review the electrophysiologic and metabolic consequences of [K+]e during acute myocardial ischemia, based upon findings from myself and my colleagues. 1) Heterogeneous increases in [K+]e between the endocardial and epicardial ischemic zones, and between the ischemic and border zones were demonstrated. 2) Intramyocardial conduction delay of the ischemic myocardium could not be explained by the increased [K+]e alone. However, hypoxia, acidosis, and isoproterenol also contribute to the conduction delay. Action potential duration was decreased by hypoxia, and the increased [K+]e led to a decrease in the action potential duration. However, isoproterenol increased the duration of the action potential in the setting of hypoxia and the increased [K+]e . 3) Treatments with CoQ10, GIK-P, and OKY-046 were shown to attenuate the increased [K+]e during acute myocardial ischemia. 4) The calcium antagonists, verapamil and nicardipine, also attenuate the increased [K+]e during acute myocardial ischemia. However, the effects were more pronounced with verapamil. 5) While the positive inotropic agents, isoproterenol, amrinone, and dopamine exacerbated the increased [K+]e , ouabain did not affect the rise in [K+]e during acute myocardial ischemia. 5) The class 3 antiarrhythmic drugs, bretylium, sotalol and amiodarone did not affect the increased [K+]e during acute myocardial ischemia. Bretylium and sotalol suppressed the shortening of the effective refractory period of the ischemic myocardium without affecting the conduction delay. However, amiodarone increased the effective refractory period of the ischemic myocardium without affecting the conduction delay.
Background: As we have found a significant correlation between left atrial (LA) voltage during sinus rhythm (SR) and that during atrial fibrillation (AF), we hypothesized that the existence of low-voltage zones (LVZs) during AF can be used to identify LVZs during SR. Therefore, we conducted a study to test this hypothesis. Methods: In 8 patients, high-density bipolar voltage mapping (> 300 points) of the left atrium was performed with a 20-pole circular catheter with 4-4-4-mm interelectrode spacing. The left atrium was divided into 7 segments, and the mean LA bipolar voltages recorded over 5 seconds during SR and AF were determined by measurement of the peak-to-peak amplitudes. Results: LVZs identified at each segment were compared between SR and AF. LA bipolar voltages obtained during SR and AF correlated positively (r = 0.74, p < 0.0001). With the low voltage during SR defined as < 0.5 mV, the low voltage of < 0.2 mV during AF approximately matched the low LVZs mapped during SR. Conclusions: These findings indicate that LVZs of < 0.5 mV during SR could be predicted from LVZs identified during AF by designating a threshold AF voltage of 0.2 mV.
Infrared radiation at short wavelengths, in particular near- and mid-infrared, are valuable probes for investigating mutual reactions between light and molecules in living organisms. However, it remains controversial as to whether animals can see mid-infrared (3.30 μm) radiation. To investigate the ability of crayfish (Procambarus clarkii) compound eyes to detect mid-infrared radiation, we used a free-electron laser (FEL) as a light source. We found that the crayfish compound eye can respond to pulsed mid-infrared (3.17 μm) radiation from the FEL, which may be a novel mid-infrared response in the animals visual organ. These findings present positive evidence to resolve the long-running question about whether the vision organs in P. clarkii are responsive to mid-infrared radiation. This study opens new avenues of research, such as investigating how and when crayfish uses electrical signals evoked by mid-infrared radiation in their behavior.
Salter surgery is often selected for infancy acetabular dysplasia and residual subluxation of the hip. Therefore, we examined the volume of bleeding when this procedure was performed at our hospital. Eight cases of 8 hips were treated, with an average age of 5 years 0 months. In all cases Bikini line β-TCP was used instead of autografting bone from the pelvis. Bleeding time was determined before surgery and on postoperative days 2, 4, 7 and 14, and the surgery time, intraoperative bleeding volume, minimum hemoglobin (Hb) value, transfusion volume, postoperative reduction in the maximum Hb, estimated bleeding volume, and complications. The average operation time was 82 minutes, the average intraoperative bleeding volume was 82 ml, the average lowest Hb value was 10.3 g/dl, with 2 cases at their lowest on the 2nd postoperative day, and 6 cases at the lowest on the 4th day after the operation. The average Hb decrease was 36.89 g and the average estimated hemorrhage volume was 277.3 ml. There was no conclusion as to whether it was necessary to perform corrective surgery in early childhood, with the expectation of acetabular dysplasia and improvement of subarachnoid withdrawal, or whether to choose adult pelvic osteotomy. The estimated bleeding volume of this procedure was about 1/5 of the total blood volume. In addition, autologous blood transfusion and blood transfusion were not necessary, and invasion was not considered to be significant.
A 72-year-old man was admitted with the complaint of abdominal pain. Esophagogastroduodenoscopy demonstrated early gastric cancer and colonoscopy demonstrated carcinoma at the sigmoid colon and rectum. Chest CT showed a nodule and large cell carcinoma was confirmed by transbronchial tumor biopsy. We diagnosed the patient as having quadruple synchronous cancers of large cell carcinoma of the lung, rectal cancer, sigmoid colon cancer, and gastric cancer. We performed lower anterior resection for the colon and rectal cancer, endoscopic submucosal dissection for the gastric cancer, and upper lobectomy for the pulmonary large cell carcinoma, and the postoperative course was uneventful with no recurrence.
Background: There have been few practical reports of dietary intervention near the threshold of allergic reactions for food allergy. Herein, we report a case of a food allergic child who was successfully treated for egg and wheat allergy by oral food challenge (OFC) and dietary intervention, not oral immunotherapy. Case presentation: A 4-year-old boy who developed anaphylaxis at seven months of age. He showed high specific IgE values and was skin prick test-positive for egg, milk, and wheat. He was recommended to completely avoid these allergens by a previous doctor. He experienced six incidences of food-induced anaphylaxis to these allergens before visiting our hospital. We repeatedly instructed the patient in dietary management at the outpatient department. Consequently, he managed to avoid the restriction of wheat and egg and achieved a satisfactory diet menu. Conclusion: We concluded that the elimination of allergens is possible by gradually increasing the target dose of causative foods under evaluation by OFC.
Herein, we report a rare case of an invasive thymoma accompanied by central necrosis and venous invasion in a 76-year-old female patient. The tumor was resected with partial resection of the left upper lobe of the lung. Histopathological findings showed central necrosis surrounded by a well-circumscribed tumor nest of type AB thymoma. The Classification of Malignant Tumours (TNM) stage of the tumor was T1aN0M0 stage I. Elastica van Gieson’s staining showed venous invasion of the thymoma. Further investigation is necessary, because this type of growth is rare and the pathological significance for invasive thymoma remains unclear.
An 80-year-old man was diagnosed as having malignant lymphoma in 2011 and underwent chemotherapy, which led to complete remission (CR). After achieving CR, he had been treated with steroid for pulmonary fibrosis since 2015. On the most recent occasion he crashed, recurrence of the malignant lymphoma brain metastasis was found and he was hospitalized. Radiotherapy was performed for malignant lymphoma metastatic brain tumor. On the 30th day after hospitalization, he suddenly exhibited difficulty breathing, mediastinal emphysema and intraperitoneal free gas was detected in the upper abdomen by radiological imaging. In the absence of findings of perforation of the gastrointestinal tract, mediastinal emphysema and pneumoperitoneum related to pulmonary fibrosis were diagnosed. There are few case reports of pneumoperitoneum complicated with respiratory disease. Radiotherapy was administered with the diagnosis of malignant lymphoma metastatic brain tumor. Dyspnea appeared, mediastinal emphysema and intraperitoneal gas were confirmed by image examination, and pneumoperitoneum and pneumoperitoneum were diagnosed.
A 52-year-old man was admitted to our hospital with the complaints of chronic pain and swelling from the right shoulder to the precordial chest, which had started one month ago. He also exhibited cervical lymphadenopathy. Cervical lymph node biopsy revealed adenocarcinoma. Chest computed tomography (CT) showed a small nodule in the left upper lobe. Fluorodeoxyglucose positron emission tomography (FDG-PET) revealed multiple uptake of FDG in the right pectoralis major muscle, as well as the cervical, axillary, and thoracic lymph nodes. Based on these findings, we diagnosed the patient as having advanced lung adenocarcinoma with metastasis to the right pectoralis major muscle. The patient was treated with bevacizumab combination chemotherapy, which induced tumor regression and improved the symptoms. This is a rare case in which bevacizumab combination chemotherapy proved effective for lung adenocarcinoma metastasis to the skeletal muscles.