The incidence, the size and the relationship with mitral valvular disease of mitral ring calcification (MRC) were examined in a total of 600 consecutive autopsy cases of over 60 years of age. (1) The incidence of MRC was 10% (60 cases among 600), and the sex difference was statistically significant with 6.7% in male and 13.3% in female (p<0.01). The age was 82 years in average, and increase of its incidence with aging was significant only in female (p<0.005). (2) MRC was found in the annulus of the posterior mitral leaflet. The length of MRC was 12.5±10.3mm in male, and 31.8±23.5mm in female (p<0.01). Large MRC more than 30mm were found in 1 male and 19 females. (3) The relationship of the length and maximum diameter of the MRC showed a positive correlation (r=0.75). Three cases of mitral stenosis or combined stenosis and regurgitation belonged to the extremely large group. (4) There were 27 cases having systolic murmurs; 3 holosystolic and 24 of ejection type. Systolic murmurs were found in 70% and 33% (p<0.05), MRC extending to the anterior leaflet in 65% and 2.5% (p<0.005), moderate to severe calcification of the aortic valve in 40% and 20% (n.s.), in large and small MRC groups, respectively. (5) X-ray films were examined retrospectively, and large MRC was diagnosed in 85%, and incidence of calcification in the other soft tissues (trachea, bronchi, costal cartilage, aortic arch, thoracic and abdominal aorta) was higher in large MRC group than in the control group (87 cases) without MRC (p<0.005).
The response of plasma renin activity (PRA) to intravenous administration of Furosemide (Fsm) (0.5mg/Kg) was determined in 6 normotensive young adults (Group I), 14 normotensive aged subjects (Group II) and in 31 hypertensive aged subjects (Group III). PRA before Fsm administration were 1.49±0.97ng/ml/hr (M±SE) in Group I, 1.07±0.23 in Group II and 1.10±0.85 in Group III, respectively. No significant difference in PRA was noticed among the three groups. PRA of 20 minutes after Fsm administration were 6.76±1.1 in Group I, 1.46±0.3 in Group II and 1.43±0.97 in Group III respectively. PRA of Group I significantly exceeded those of Groups II and III. (P<0.01) PRA increases significantly (P<0.01) after Fsm administration in Group I, but not in Group II and III. In order to compare the diuretic effect of Fsm in young adults and aged subjects, 4 hours' urine volume, before and after Fsm administration, and urinary excretion of sodium for corresponding periods were compared between 6 young adults and 21 aged subjects. Urinary volume in young adults was 150.6±5.4ml/4hrs (M±SE) before Fsm and 1155.3±114.5 after Fsm. Urinary volume in aged subject was 269.0±36.0 and 770.0±80.8, respectively. The increase of sodium excretion with Fsm was also less in aged subjects than in young adults. The diuretic effect of Fsm in young adults was significantly larger than that in aged subjects (P<0.05). From these results, it was concluded that 1) PRA values at rest were not significantly different among normotensive young adults, normotensive and hypertensive aged subjects, 2) the response of PRA to Fsm in normotensive young adults was significantly larger than those in normotensive and hypertensive aged subjects and 3) the diuretic effect of Fsm in aged subjects was less marked than that in young adults.
A neuropathological Investigation was performed on the 44 cases of dementia among 220 autopsied brains of the aged. 37 cases among those dementics were classified as“cerebro-vascular”dementia (dementia of cerebrovascular origin). Most of them showed pathological changes in bilateral cerebral hemispheres, which consisted mainly of multiple small infarctions and lacunes in the basal ganglia and deep white matter, especially territory of the middle cerebral artery. In 8 cases there was a change of diffuse degeneration of the white matter, which is very similar pathological change to the Morbus Binswanger (progressive subcortical vascular encephalopathy). They had history of hypertension and showed clinical symptoms of pseudobulbar palsy, parkinsomism or hemiplegia, besides progressive dementia with/without psychiatric symptoms. It is noticeable that some of the dementics with cerebral arteriosclerosis in the aged are due to the progressive subcortical vascular encephalopathy. Mechanism of this change appeared in old age is discussed.