The pathological mechanism responsible for cerebral white matter lesions, frequently observed in elderly individuals, is supposed to be chronic cerebral hypoperfusion. Vascular risk factors such as hypertension and carotid artery stenosis are usually involved in these lesions. The objective of this study was to elucidate the role of hypertension in white matter changes using a bilateral carotid artery stenosis model.
To induce cerebral hypoperfusion, chronic stenosis was produced by placing a 3 mm long polyethylene cuff around the bilateral carotid arteries of normotensive Wistar rats (Wistar) and spontaneously hypertensive rats (SHR). Two different diameters of tube, PE-50 (inside diameter 0.58 mm) and PE-60 (inside 0.76 mm). were used to induce different degrees of stenosis. The rats were divided into three groups, sham group, PE-50 group, and PE-60 group (each group included 15 Wistar and 15 SHR).
At 1, 2, and 4 weeks after the operation, pathological changes in white matter were observed in the corpus callosum, and the degree of lesions was assessed using the Vacuole Index. PaO₂, PaCO₂, pH and mean arterial blood pressure (MABP) were measured prior to and immediately after carotid stenosis.
MABP in SHR was significantly higher than in Wistar in all groups (p<0.05). Other physiological data did not differ significantly between Wistar and SHR. There was no difference in white matter changes between the Wistar sham and SHR sham groups at any time point. There was only a small degree of white matter lesions in the Wistar PE-50 and -60 groups after 4 weeks stenosis, and they did not differ significantly from the sham. In both the SHR PE-50 and -60 groups, however, white matter lesions were slightly apparent at 1 week, and were clearly visible at 4 weeks. The degree of lesions in the SHR PE-50 was significantly higher at 1 week than in the sham (p<0.01), and both the sham and the Wistar PE-50 at 2 and 4 weeks (p<0.01), and the SHR PE-60 at 4 weeks (p<0.01). The SHR PE-60 also had significantly more lesions than the sham at 2 weeks (p<0.05), and both the sham and the Wistar PE-60 at 4 weeks (p<0.01). These findings indicate that both hypertension and chronic hypoperfusion play important roles in the development of white matter lesions. (J Nippon Med Sch 1998; 65: 450-458)

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DNA bend sites in the promoter region of the human estrogen receptor a gene were determined by the circular permutation assay. Among a total of five sites (ERB-4 to -1, and ERB+1) mapped in the 3 kb region, three matched with the positions of the predicted periodicity while the other two did not. Most of the sites were accompanied by the short poly (dA) -poly (dT) tracts including the potential bend core sequence A₂N₈A₂N₈A₂ (A/A/A). Fine mapping of the ERB-2 site indicated that this A/A/A and the immediate franking sequences contained motifs for the estrogen response element. This region had a higher affinity for the nuclear scaffold and was included in the core region of the nucleosome structure. However, binding of the nuclear factor(s) to the motifs and disruption of nucleosome structure occurred without ATP. These results suggest that a class of periodic bent DNA could act as a site of multiple interactions among the nuclear scaffold, core histones and nuclear factors. ( J Nippon Med Sch 1998; 65 : 459-470)

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To elucidate the presence and distribution of Endothelin-1 (ET-1) in tissues of human salivary glands, we performed an immunohistochemical analysis of ET-1 in 15 normal salivary glands, 8 adenolymphomas, 13 pleomorphic adenomas and 5 carcinomas, using the mouse monoclonal antibody against human ET-1. In normal glands, immunoreactivity for ET-1 was observed in the striated duct cells. In adenolymphomas, the columnar cells of the granular epithelium showed strong intracytoplasmic immunoreactivity. In carcinomas, moderate or strong immunoreactivity was observed in the tumor cells, whereas in pleomorphic adenomas, weak immunoreactivity was observed. A good relation was detected between the size of pleomorphic adenoma and ET-1 immunoreactivity, as well as between the duration of tumor in carcinoma and ET-1 immunoreactivity. The presence and distribution of ET-1 in salivary glands and salivary gland tumors suggests a possible role for ET-1 in the regulation of electrolytes and water transport in salivary glands, and as a growth-promoting factor for tumors. (J Nippon Med Sch 1998; 65 : 471-477)

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Laparoscopic cholecystectomy (LC) is a safe and less traumatic procedure for benign cholecystic disease. However there have been some complications peculiar to LC. Here we report a case with postoperative subcapsular hematoma of the liver after LC. A 78-year-old woman was admitted with acute cholecystitis due to cholecystolithiasis. She underwent LC and liver dysfunction was noted after the operation. Ultrasonography (US) and computed tomography (CT) showed subcapsular hematoma of the liver. It was supposed that it had happened to occur during the operation, but we could not make the cause clear. The patient was improved with only conservative therapy and discharged. It is important to handle the forceps carefully close to the liver in the laparoscopic surgery in order to prevent this complication. We report a case with subcapsular hematoma of the liver following LC with a review of the literature. (J Nippon Med Sch 1998 ; 65: 478-480)

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