A surgical resection case of myxoma arising from the posterior wall of the left atrium complicated with complete atrioventricular block.

An 80-year-old female was referred to our institution due to transient right upper limb weakness. Transthoracic and transesophageal echocardiography revealed a tumor in the left atrium. The tumor was attached to the posterior wall of the left atrium near the atrioventricular node. Intraoperative pathological examination revealed that the tumor was a myxoma, and complete resection was successfully performed. However, she experienced persistent complete atrioventricular block postoperatively and required pacemaker implantation.

Use of amlodipine in the treatment of cats with systemic hypertension in Japan.

An increase in systemic blood pressure causes bleeding and ischemia owing to peripheral vascular breakdown, leading to various forms of organ damage. The brain, eyes, kidneys, and cardiovascular system are known target organs for hypertension. To our knowledge, no reports in Japan describe, in detail, the types of antihypertensive drugs used to treat hypertension in cats or its underlying causes. Therefore, we aimed to investigate the use of antihypertensive drugs in domestic cats with hypertension in Japan, the causes of hypertension, and the vital prognosis of these patients. In the present survey, we found that amlodipine was used alone (60/80 cats) or concomitantly (20/80 cats) in all cat patients with hypertension in Japan. We also determined that blood pressure measurements were not yet routinely performed on cats at veterinary clinics in Japan. Furthermore, we have new information suggesting that amlodipine administration in cats with hypertension, which lowers systolic arterial pressure levels to within the normal range (<140 mmHg), may have a negative impact on their survival. Routine blood pressure measurements for cats during their regular health checkups can help identify hypertension, and proper interpretation of blood pressure readings can facilitate suitable treatment measures.

A case of a dog with paragonimiasis after consumption of raw deer meat.

A 6-year-old castrated male Cavalier King Charles Spaniel was referred to the Animal Medical Center, Tokyo University of Agriculture and Technology, for examination and treatment of recurrent pneumothorax. Chest radiography and computed tomography showed multiple cavitary lesions in the caudal right posterior lobe. These lesions were surgically excised via thoracotomy. Subsequent histopathological examination revealed paragonimiasis. In the postoperative review, we found that the owner had fed raw deer meat to the dog four months earlier. Deer meat has attracted attention as a source of Paragonimus in humans. To our knowledge, this is the first report of Paragonimus infection in a dog due to deer meat consumption.

Mid-Term Outcomes of Late Open Conversion with Endograft Preservation for Sac Enlargement after Endovascular Abdominal Aortic Aneurysm Repair.

BACKGROUND: Late open conversion has sometimes been required for sac enlargement after endovascular aneurysm repair (EVAR) for abdominal aortic aneurysm. Though the open repair with endograft preservation is considered less invasive compared to endograft removal, the mid-term outcomes are still unclear. The aim of this study is to evaluate the mid-term outcomes of late open conversion with endograft preservation after EVAR. METHODS: We reviewed patients who underwent late open conversion with endograft preservation for sac enlargement or rupture in our institution from May 2007 to December 2020. The open repair mainly consisted of ligation of lumber arteries or the median sacral artery and sacotomy. We additionally performed wrapping of plicated aneurysm with equine pericardium as much as possible. Patients were followed-up by a computed tomography scan and duplex ultrasound 1 and 6 months postoperatively, and each year thereafter. RESULTS: Of the 1,087 patients who underwent EVAR, 23 patients with a mean age of 81.5 years were included in this study. The mean duration post-EVAR was 35.6 months. Sac wrapping with equine pericardium was performed in 14 patients (60.9%). We additionally performed wrapping of the endograft junction by a Dacron knitted fabric in 1 case with type III endoleak and aortic neck banding in 4 cases with type I endoleak. The 30-day mortality was 0% and the rate of major complications was 4%. All-cause mortality was 21.7% which included 1 aneurysm-related death during a mean follow-up of 38.5 months. Sac re-enlargement was observed in 4 patients without the wrapping method. At 3 years, the aneurysmal diameter in the nonwrapping group significantly increased, compared with the wrapping group (P = 0.011). CONCLUSIONS: Late open conversion with endograft preservation is a feasible treatment; however, at times re-enlargement of the sac aneurysm occurs. The wrapping method has the potential to prevent sac re-enlargement after open conversion.

Efficacy of cilostazol in canine bradyarrhythmia.

Recently, cilostazol, a phosphodiesterase III inhibitor, has been described as alternative medical treatment for canine bradyarrhythmia in cases for which pacemaker implantation was not indicated or available. In this retrospective study, we investigated the use and efficacy of cilostazol in dogs with bradyarrhythmia in Japan. Dogs that had been brought to the Tokyo University of Agriculture and Technology Animal Medical Center and 23 veterinary hospitals in Japan and been treated with cilostazol initially as the only therapeutic strategy for bradyarrhythmia between January 2010 and August 2021 were included in this study. Survival analyses were performed using Cox proportional hazards analysis, the log-rank test, and the generalized Wilcoxon test to evaluate the efficacy of cilostazol. Fifty-nine privately owned dogs were included in this study. In the survival time analysis, the risk of death was significantly lower and the survival rate was higher in cases in which cilostazol was administered at 10 mg/kg or more per dose. A third-degree atrioventricular block also significantly increased the risk of death and was associated with a lower survival rate. However, in some patients with a third-degree atrioventricular block, there was an increase in the ventricular rate and improvement in clinical symptoms without disappearance or decrease of the atrioventricular block. This study had several important findings that have not previously been reported concerning the use of cilostazol for canine bradyarrhythmia, including the appropriate dose in a clinical setting and the efficacy and prognosis according to the type of bradyarrhythmia.

Protective Effect on Pancreatic Acinar Cell by Maintaining Cardiac Output in Canine Heart Failure Model With Decreased Pancreatic Blood Flow.

Heart failure cause hypoperfusion-induced damage to abdominal organs due to decreased cardiac output (CO). Using a model dog with heart failure caused by rapid ventricular pacing (RVP), we have previously demonstrated that a decrease in CO reduces pancreatic blood flow (PBF). Furthermore, we have revealed that pancreatic acinar cell atrophy, which is a change in the pre-stage of pancreatitis was caused. However, the mechanism by which pancreatic acinar cell atrophy was caused in RVP dogs remains unknown. This study aimed to clarify the association between cardiac function, PBF, and histopathological changes in pancreatic acinar cells by administrating pimobendan, which increase CO, to RVP dogs. RVP dogs were divided into the control group (no medication, n = 5) and the pimobendan group (pimobendan at 0.25 mg/kg BID, n = 5). Non-invasive blood pressure measurement, echocardiography, and contrast-enhanced ultrasonography for PBF measurement were performed before initiating RVP and at 4 weeks after initiating RVP (4 weeks). At 4 weeks, the decreases in CO, mean blood pressure and PBF due to RVP were suppressed in pimobendan group. Furthermore, histopathological examination showed no changes in pancreatic acinar cells in the pimobendan group. Overall, it was clarified that the decrease in PBF due to cardiac dysfunction was a direct cause of pancreatic acinar cell atrophy. This suggests that maintaining PBF is clinically important for treating dogs with heart failure. In addition, these findings offer a reliable basis for developing new therapeutic strategies for heart failure in dogs, that is, pancreatic protection.

Evaluation of the Safety and Feasibility of Apheresis in Dogs: For Application in Metastatic Cancer Research.

In patients with solid tumors, circulating tumor cells (CTCs) spread in their blood and function as a seed for metastases. However, the study of CTCs has been limited by their rarity, low frequency, and heterogeneity. The efficient collection of CTCs will contribute to further research of metastatic cancers. Apheresis is a process in which the whole blood of an individual is passed through a machine that isolates a particular constituent and returns the remainder to the circulation. In the present study, we investigated the safety and feasibility of apheresis to separate peripheral blood monocytes (PBMCs), whose density is closely similar to that of CTCs, and to capture intravenously administered human breast cancer cells, MCF7s, from the dogs. No life-threatening events were observed in dogs during the apheresis process. The changes in the hemogram were transient and recovered gradually within a few days after apheresis. During apheresis, 50 mL of PBMCs could be collected from each dog. Notably, a thrombus was formed along the circuit wall during apheresis, which decreased the blood collection pressure. MCF7 cells were successfully captured by the apheresis machine. The captured cells were regrown in vitro and characterized compared with the original cells. In conclusion, apheresis could be safely performed in dogs to isolate CTCs with precautions to maintain hemodynamic stability.

Histopathological changes in the pancreas due to decreased pancreatic blood flow in a canine tachycardia-induced cardiomyopathy model.

In dogs, pancreatic acinar cell injury is thought to be caused by decreased pancreatic blood flow due to heart failure. In previous our report, it demonstrated that decreased heart function causes a significant decrease in pancreatic blood flow in heart failure dog model caused by rapid ventricular pacing (RVP). However, the types of histopathological changes remain unclear. We aimed to verify the types of histopathological changes occurring in the pancreatic tissue due to decreased heart function. After RVP for 4 weeks, atrophy of pancreatic acinar cells, characterized by a decrease in zymogen granules, was observed in all areas of the pancreas. In conclusion, the result of this study suggests that attention should be paid to ischemia/hypoperfusion injury in the pancreas.

Comparison of pancreatic and renal blood flow in a canine tachycardia-induced cardiomyopathy model.

The pancreas is believed to be vulnerable to hypoperfusion. In dogs with acute pancreatitis, pancreatic ischemia due to heart failure can worsen the condition. However, changes in pancreatic blood flow associated with decreased cardiac function have not been previously studied in dogs. Therefore, we aimed to identify and compare changes in pancreatic versus renal blood flow as a result of cardiac dysfunction. Seven dogs were subjected to rapid ventricular pacing to create heart failure models. Noninvasive blood pressure measurement, ultrasonic cardiography, contrast-enhanced ultrasonography for pancreatic blood flow measurement, and para-aminohippuric acid clearance for renal blood flow measurement were performed before starting and at 2 and 4 weeks after starting the pacing. Left ventricular cardiac output and mean blood pressure decreased at 2 and 4 weeks after starting the pacing, and pancreatic blood flow decreased at 2 and 4 weeks after starting the pacing. However, renal blood flow did not change at 2 weeks but decreased 4 weeks after starting the pacing. Overall, this study demonstrated that reduced pancreatic blood flow due to cardiac dysfunction occurs, similar to renal blood flow. This suggests that decreased pancreatic blood flow is not unusual and may frequently occur in dogs with heart failure. The results of this study support the speculation that heart failure can exacerbate acute pancreatitis. Additionally, this study provides useful basic information for designing further studies to study this association.

The effect of telmisartan on the ventricular systolic function in dogs with experimental supraventricular tachyarrhythmia.

Maintaining a good ventricular systolic function is important in the long-term therapy of dogs with supraventricular tachyarrhythmia (SVTA). The objective of this study was to evaluate the inhibitory effect of telmisartan on myocardial injury and the resulting ventricular systolic dysfunction in a canine model of SVTA. A total of 14 dogs were randomly assigned to a Telmisartan (oral telmisartan, 1.0 mg/kg daily, n=7) or a Control (no drug administration, n=7) group; the duration of rapid atrial pacing (RAP) was 3 weeks for both groups. The cardiac troponin I (cTnI) concentration in the Control group was significantly increased after 3 weeks compared to that before RAP initiation (baseline), but no significant difference was observed in the Telmisartan group. Moreover, the cTnI concentration at 3 weeks was significantly lower in the Telmisartan group than in the Control group. The left ventricular fractional shortening was significantly decreased at 3 weeks compared to that at baseline in both groups. However, fractional shortening at 3 weeks was significantly higher in the Telmisartan group than in the Control group. The cardiac output values in the Control group were significantly decreased at 3 weeks compared with those at baseline, but no significant difference was observed in the Telmisartan group. This study demonstrates that telmisartan inhibits the reduction in ventricular systolic function and prevents myocardial injury in a canine model of SVTA. Therefore, telmisartan is suggested as a novel treatment for canine SVTA.

Essential Roles of L-Type Amino Acid Transporter 1 in Syncytiotrophoblast Development by Presenting Fusogenic 4F2hc.

The layers of the epithelial syncytium, i.e., syncytiotrophoblasts, differentiate from chorionic trophoblasts via cell fusion and separate maternal and fetal circulations in hemochorial placentas. L-type amino acid transporter 1 (LAT1) and its covalently linked ancillary subunit 4F2hc are colocalized on both maternal and fetal surfaces of syncytiotrophoblasts, implying their roles in amino acid transfer through the placental barrier. In this study, LAT1 knockout, in addition, revealed a novel role of LAT1 in syncytiotrophoblast development. LAT1 at midgestation was selectively expressed in trophoblastic lineages in the placenta, exclusively as a LAT1-4F2hc heterodimer. In LAT1 homozygous knockout mice, chorionic trophoblasts remained largely mononucleated, and the layers of syncytiotrophoblasts were almost completely absent. The amount of 4F2hc protein, which possesses a fusogenic function in trophoblastic cells, as well as in virus-infected cells, was drastically reduced by LAT1 knockout, with less affecting the mRNA level. Knockdown of LAT1 in trophoblastic BeWo cells also reduced 4F2hc protein and suppressed forskolin-induced cell fusion. These results demonstrate a novel fundamental role of LAT1 to support the protein expression of 4F2hc via a chaperone-like function in chorionic trophoblasts and to promote syncytiotrophoblast formation by contributing to cell fusion in the developing placenta.

A case of pulmonary hamartoma with distinctive histopathological features: a discussion of its differential diagnosis and histogenesis.

We herein describe a case of a benign pulmonary tumor with distinctive histopathological features. A 55-year-old Japanese male presented with a well-demarcated tumor in the left upper lobe of his lung, which gradually increased in size from 18 to 21 mm over 24 months. The resected tumor consisted of an epithelial component of compact irregular glands and mesenchymal component of fascicles between the glands. The differentiation of pneumocytes and smooth muscle cells was immunohistochemically detected in the epithelial component and the mesenchymal component, respectively. No mitosis, necrosis, bleeding, or invasion was observed. A histopathologic diagnosis of fibroleiomyomatous hamartoma was made. We also review previously reported tumors with similar histopathological features and discuss their differential diagnosis and histogenesis.

Insulin-like growth factor binding protein-4 gene silencing in lung adenocarcinomas.

Gene silencing by promoter hypermethylation plays an important role in molecular pathogenesis. We previously reported that insulin-like growth factor (IGF) binding protein-4 (IGFBP-4), which inhibits IGF-dependent growth, is expressed via early growth response-1 (EGR-1) and is often silenced in cultivated lung cancer cells. The purpose of the present study was to clarify clinicopathological factors associated with IGFBP-4 gene silencing in lung adenocarcinomas. Seventy-six surgically resected adenocarcinomas (20 well-, 35 moderately-, and 21 poorly-differentiated) were subjected to methylation-specific polymerase chain reaction (PCR) analysis for EGR-1-binding sites located in the IGFBP-4 promoter and immunohistochemistry for IGFBP-4, EGR-1, and Ki-67. Thirty-two adenocarcinomas (42%) revealed IGFBP-4 promoter hypermethylation, and the severity inversely correlated with the level of IGFBP-4 expression (P < 0.0001) and tumor differentiation (well versus poor, P = 0.0278; well/moderate versus poor, P = 0.0395). Furthermore, there was a negative correlation between Ki-67 labeling index and IGFBP-4 expression (P = 0.0361). These findings suggest that the expression of IGFBP-4 in adenocarcinoma cells in vivo is downregulated by epigenetic silencing in association with tumor differentiation, resulting in disruption of the mechanism of IGFBP-4-mediated growth inhibition.

Early growth response-1 induces and enhances vascular endothelial growth factor-A expression in lung cancer cells.

Vascular endothelial growth factor-A (VEGF-A) is crucial for angiogenesis, vascular permeability, and metastasis during tumor development. We demonstrate here that early growth response-1 (EGR-1), which is induced by the extracellular signal-regulated kinase (ERK) pathway activation, activates VEGF-A in lung cancer cells. Increased EGR-1 expression was found in adenocarcinoma cells carrying mutant K-RAS or EGFR genes. Hypoxic culture, siRNA experiment, luciferase assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and quantitative RT-PCR using EGR-1-inducible lung cancer cells demonstrated that EGR-1 binds to the proximal region of the VEGF-A promoter, activates VEGF-A expression, and enhances hypoxia inducible factor 1alpha (HIF-1alpha)-mediated VEGF-A expression. The EGR-1 modulator, NAB-2, was rapidly induced by increased levels of EGR-1. Pathology samples of human lung adenocarcinomas revealed correlations between EGR-1/HIF-1alpha and VEGF-A expressions and relative elevation of EGR-1 and VEGF-A expression in mutant K-RAS- or EGFR-carrying adenocarcinomas. Both EGR-1 and VEGF-A expression increased as tumors dedifferentiated, whereas HIF-1alpha expression did not. Although weak correlation was found between EGR-1 and NAB-2 expressions on the whole, NAB-2 expression decreased as tumors dedifferentiated, and inhibition of DNA methyltransferase/histone deacetylase increased NAB-2 expression in lung cancer cells despite no epigenetic alteration in the NAB-2 promoter. These findings suggest that EGR-1 plays important roles on VEGF-A expression in lung cancer cells, and epigenetic silencing of transactivator(s) associated with NAB-2 expression might also contribute to upregulate VEGF-A expression.

Autologous salvaged blood transfusion in spontaneous hemopneumothorax.

Spontaneous hemopneumothorax (SHP) is a rare clinical entity, and an emergent operation due to continuous bleeding or hypovolemic shock is at times necessary. Although allogeneic blood transfusions are urgently required for significant blood loss, autologous blood transfusions can also be considered in patients with SHP. We herein report two cases of successful autologous blood transfusions using blood in the pleural space, decreasing or obviating the need for allogeneic blood transfusion.

21-kDa polypeptide, a low-molecular-weight cyclophilin, is released from pollen of higher plants into the extracellular medium in vitro.

Calcium ions play a key role in the elongation and orientation of pollen tubes. We found that significant amounts of 21-kDa polypeptide were specifically released into the extracellular medium when pollen grains of lily, Lilium longiflorum Thunb., were incubated in the presence of EGTA or at low concentrations of Ca2+. This phenomenon was also dependent on pH and on the concentrations of MgCl2 in the medium; the release of 21-kDa polypeptide from pollen was suppressed by increasing the MgCl2 concentration and by lowering pH. Germination of pollen grains was inhibited in the medium into which the 21-kDa polypeptide had been released. This inhibition was irreversible; germination did not occur on transfer of the pollen grains into basal culture medium. Immuno-electron microscopy using an antibody against 21-kDa polypeptide showed that this polypeptide was present in the cytoplasm, vegetative nucleus and generative cell. When the pollen was treated with a medium containing EGTA, the density of 21-kDa polypeptide in the cytoplasm significantly decreased, but its density in vegetative nuclei and the generative cell did not, suggesting that only cytoplasmic 21-kDa polypeptide was released into the extracellular medium. The 21-kDa polypeptide was also present in the pollen of other higher-plant species, such as Tradescantia virginiana L., Nicotiana tabacum L. (angiosperms), and Cryptomeria japonica D. Don. (gymnosperm), and was also released into the medium in the presence of EGTA. In the case of C. japonica, however, it was released from pollen at alkaline pH above 8.5. The expression of 21-kDa polypeptide was not pollen-specific, because 21-kDa components immunoreactive with the anti-21-kDa polypeptide serum also existed in vegetative organs and cells of lily or tobacco. However, the 21-kDa polypeptide was not released into the extracellular medium from cultured tobacco BY-2 cells, even in the presence of EGTA. Amino acid sequences of two peptide fragments derived from 21-kDa polypeptide matched well those of low-molecular-weight cyclophilin (CyP). The antiserum against 21-kDa polypeptide recognized the CyP A from calf thymus and that in A431 carcinoma cells. The 21-kDa polypeptide fraction purified from lily pollen possessed peptidyl-prolyl cis- trans isomerase activity, which was suppressed by cyclosporin A (CsA), an inhibitor of enzyme activities of CyPs. From these results, we concluded that the 21-kDa polypeptide is a low-molecular-weight CyP. The present study showed that CyP in the pollen of higher plants is released into the extracellular matrix under unfavorable conditions.

Catamenial pneumothorax caused by endometriosis in the visceral pleura.

Catamenial pneumothorax is a rare clinical entity of unknown etiology. The most well known hypothesis is passage of air from the genital tract through endometrial fenestrations in the diaphragm. Although some reports are associated with diaphragmatic endometriosis, few have been confirmed endometrial implants in the visceral pleura. We describe a very rare case of catamenial pneumothorax caused by ectopic endometriosis in the visceral pleura confirmed histopathologically in a woman 1-year after hysterectomy.