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.     

Arrhythmogenic right ventricular cardiomyopathy coincided with the cardiac fibrosis in the inner muscle layer of the left ventricular wall in a boxer dog

A 7-year-old female boxer dog died suddenly without any clinical signs. It was suspected that the dog had arrhythmogenic right ventricular cardiomyopathy (ARVC) due to ventricular premature complexes and ventricular tachycardia at 3 years of age. The final diagnosis of ARVC was confirmed by histological characteristics, such as loss of cardiocytes and fibrofatty replacement, occurring in the right and left ventricular walls. In the cardiocytes, non-lipid vacuoles were observed. Cardiac fibrosis and intimal thickening of the small arteries occurred without fatty replacement in the inner muscle layer including the papillary muscles of the left ventricular wall. This paper describes the pathomorphological details of an ARVC case with coincidental cardiac fibrosis in the inner muscle layer of the left ventricular wall.     

Establishing conditions for the storage and elution of rabies virus RNA using FTA? cards

The Flinders Technology Associates filter paper cards (FTA^® cards) can be used to store nucleic acid from various samples and are easily portable. However, RNA is physicochemically unstable compared with DNA, and appropriate methods have not been established for storage and extraction of RNA from FTA^® cards. The present study investigated the optimum conditions for storage and elution of viral RNA (vRNA) using rabies virus (RABV) applied to FTA^® cards. When TE buffer was used, the elution rates of vRNA increased with the length of the elution time. When the cards were stored at −80°C or −20°C, vRNA was stable over 3 months. Degradation of vRNAs occurred following storage at 4°C and room temperature, suggesting that RNA should be extracted from cards as soon as possible if no freezer is available. When we tried to amplify vRNA from RABV-infected animal brains applied to FTA^® cards and stored at −80°C for 6 months, we did not detect any amplified products with the primer set for 964 bp of RABV N gene. However, we were able to detect amplified products by increasing the elution time of vRNA from FTA^® cards from 30 min to 24 hr or by changing the primer sets to amplify 290 bp of N gene. Thus, we recommend extending the elution time for damaged or low concentration samples in FTA^® cards.     

Antihypertensive effect of heshiko, a fermented mackerel product, on spontaneously hypertensive rats

ABSTRACT:   During the processing of heshiko , a fermented mackerel product, a rapid increase in peptide content in the extract and a remarkable decrease in the IC₅₀ (the inhibitor concentration to inhibit 50% of enzyme activity) as an index of the angiotensin I-converting enzyme (ACE) inhibitory activity were observed. Systolic blood pressure (SBP) in spontaneously hypertensive rats (SHR) decreased between 2 and 4 h after single oral administration of heshiko extract at a dose of 10 mg/kg as a peptide, and SBP recovered its initial level by 8 h. For single doses of extract at three different levels (5, 10 and 50 mg/kg), SBP similarly decreased after between 2 and 4 h. The decreased SBP at 50 mg/kg was almost equal to that at 10 mg/kg, indicating a low dose dependency for heshiko extract. Through successive administration of heshiko extract or its desalted extract at 10 mg/kg for 10 days, SBP decreased 7 days after the start of administration and it recovered its initial level 5 days after stopping administration. During these periods, the change in ACE activity in blood plasma from SHR administered the extract roughly corresponded to that of SBP, suggesting that ACE inhibition was related to a decrease in SBP. For long-term administration of the extract to 5-week-old SHR for 70 days, SBP decreased 28 days after the start of administration. The decreased SBP remained low for 28 days after stopping administration, whereas the decreased ACE activity recovered its initial level. These results suggest that heshiko extract influences not only ACE inhibition, but also other systems that regulate blood pressure.