SUMMARY: Ultrastructural changes in gill chloride cells during smoltification were examined in wild and hatchery‐reared masu salmon. On the filament, two types of chloride cells (α and β) and accessory cells were observed in wild fish from January (parr) to May (full‐smolt), while only α and accessory cells (α‐a cells) were observed in hatchery‐reared fish from March (pre‐smolt) to May (full‐smolt). Among α‐a cells of both types of fish, development of rough endoplasmic reticulum (ER) and Golgi apparatus was detected in pre‐smolt before full‐smolt. However, ultrastructural changes were not revealed in β cells of wild fish during smoltification. During smoltification, the α‐a cell number increased and β cell number decreased. On the lamella, only one type of chloride cell was observed in both wild and hatchery‐reared fish during smoltification. Their ultrastructural changes were almost the same as those in filament α‐a cells, and their number declined during smoltification. Although there was almost no difference between changes in ultrastructure or in the number of chloride cells in both wild and hatchery‐reared fish during smoltification, the chloride cell number of hatchery‐reared fish varied widely in comparison to that in wild fish. The present study is the first report for wild salmonids of ultrastructural changes in gill chloride cells during smoltification, and indicated that there were some ultrastructural differences between gill chloride cells of wild masu salmon and hatchery‐reared fish.

The effects of adjacent large blood vessels, fibroelastic membrane, and parenchyma on pressure-diameter (P-D) behavior of intrapulmonary bronchi were studied in five dog lung lobes. Central lobar airways were inflated separately by blocking all branches with beads and inflating the distal lobar air spaces via pleural capsules. After bronchial P-D curves were obtained at fixed pleural pressures (Ppl) of -30, -10, and -5 cmH2O, the P-D properties of the isolated bronchi were measured in each of four stages of dissection: 1) lobar artery and vein were left attached to the bronchus, but parenchyma was removed to within 1-2 mm of the limiting membranes; 2) all remaining parenchyma was carefully removed; 3) the large vessels were removed, leaving the bronchial fibroelastic membrane intact; and 4) the fibroelastic membrane was peeled from the bronchus. From stage 1 it was deduced that in the intact lobes, peak peribronchial parenchymal stress (Px) averaged -29.2 cmH2O at Ppl = -30 cmH2O). In stage 2 bronchial recoil was reduced only approximately 5%. The major decrease (approximately 35%) occurred in stage 3, indicating that interaction between vessels and bronchi contributed significantly to bronchial stiffness. A final decrease of approximately 10% was seen in stage 4. We conclude that Px in the intact state is similar to Ppl at a transpulmonary pressure of 30 cmH2O and that stages 1 or 2 may provide a better basis for estimating Px than the commonly employed bronchus free of vessels and tissue.

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Metastatic cardiac liposarcoma is extremely rare, with only 2 cases previously reported, to our knowledge; of those, only 5 involved surgical resection of right ventricular liposarcoma. The first such case in Japan involved a 61-year-old woman with metastatic liposarcoma of the right ventricle. Despite emergency resection, the patient died of severe congestive heart failure 6 days after operation. Her history included surgery for liposarcoma in the right knee 11 years previously, although it is very difficult to predict that metastasis would proceed thereafter to the cardiac cavity. This rare case suggests, however, that follow-up including examination for cardiac lesions is necessary long after resection of the primary lesion.

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