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Biomedical subjects

A Ohno

Publications and source records attributed to A Ohno.

At least 163 records · Page 9Linked to original sources

Importance of collateral circulation for prevention of left ventricular aneurysm formation in acute myocardial infarction.

The effect of preexistent coronary collateral perfusion on the prevention of left ventricular aneurysm formation was examined in 47 patients undergoing an intracoronary thrombolysis within 6 hours after the onset of a first acute anterior myocardial infarction. Left ventricular aneurysm formation and wall motion were analyzed with cineventriculography. A left ventricular aneurysm was determined as well-defined demarcation of the infarcted segment from normally contracting myocardium. In 25 patients with successful thrombolysis (group A), a left ventricular aneurysm was observed in one patient (4%) during the chronic stage of infarction. In 10 patients who had a significant collateral circulation to the infarct-related coronary artery and unsuccessful reperfusion (group B), the left ventricular aneurysm was observed in only one patient (10%). In the remaining 12 patients with unsuccessful recanalization in the absence of a significant collateral perfusion (group C), there was a higher incidence (seven of 12, 58%) of left ventricular aneurysm formation than in groups A and B (p less than 0.05). In group A, both the global ejection fraction and regional wall motion in the infarct areas improved significantly (p less than 0.05) between the acute and chronic stages of infarction. By contrast, in groups B and C, these indexes on the ventricular function did not change significantly during the convalescent period. Thus, although the collateral perfusion existing at the onset of acute myocardial infarction may not improve ventricular function, it exerts a beneficial effect on the prevention of left ventricular aneurysm formation.

Adult↗

Functional characteristics of nonischemic region during pacing-induced myocardial ischemia in angina pectoris.

To investigate the details of the hyperfunction of nonischemic area during acute ischemia, the regional myocardial function at rest and immediately after rapid cardiac pacing was compared using cineventriculography in 12 patients with stable effort angina. Three left ventricular boundaries at the time of end-diastole, aortic valve opening and end-systole were superimposed, and 128 radial grids were drawn from the center of gravity of end-diastolic frame to the endocardial margin. The changes in the length of each radial grid provided quantitative description of segmental systolic function. In the ischemic area, the percent of total segment shortening decreased from 36 +/- 6% (mean +/- standard error of the mean) to 24 +/- 8% (p less than 0.05) in patients with a significant narrowing of left anterior descending coronary artery (LAD), and from 42 +/- 6% to 20 +/- 4% (p less than 0.05) in those with right coronary artery (RCA) involvement. In the nonischemic area, the percent of total segment shortening increased from 33 +/- 7% to 44 +/- 7% (p less than 0.05) in LAD disease, while it was unchanged in RCA involvement (40 +/- 5% vs 41 +/- 7%). The percentage of isovolumic segment shortening increased from 1 +/- 4% to 7 +/- 3% (p less than 0.05) and from 1 +/- 1% to 5 +/- 2% (p less than 0.05) in LAD and RCA involvement, respectively. Meanwhile, ejection phase shortening did not change significantly (33 +/- 6% vs 40 +/- 7% in LAD involvement, and 39 +/- 6% vs 38 +/- 7% in RCA involvement).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Significance of pre-infarction angina for occurrence of post-infarction angina.

We evaluated the factors determining the occurrence of post-infarction angina in 41 patients who had intra-coronary thrombolysis within 6 h of the onset of acute myocardial infarction. Pre-infarction angina was considered to be present if it occurred more than one week before acute myocardial infarction. Post-infarction angina was defined as typical chest pain occurring within 10 days following the infarction. Collateral flow to the infarct zone was determined to be present if any portion of the infarct-related epicardial artery or side branches was visualized. In cases of successful thrombolysis, the prevalence of post-infarction angina was not significantly influenced by pre-infarction angina and the extent of collateral circulation. However, in patients without recanalization, pre-infarction angina and collateral blood flow supply to the area at risk caused a high prevalence of angina after infarction. It is concluded that pre-infarction angina indicative of myocardial ischemia is associated with post-infarction angina especially in patients with conventional therapy, because the jeopardized myocardium is salvaged substantially by collateral circulation with a limited flow reserve.

Adult↗

Improvement of treadmill capacity and collateral circulation as a result of exercise with heparin pretreatment in patients with effort angina.

It has been demonstrated in animal experiments that heparin accelerates the coronary collateral development induced by repeated coronary occlusion. We used this effect of heparin for the treatment of patients with stable effort angina. In 10 patients, treadmill exercise was performed according to standard Bruce protocol twice a day for 10 days. A single intravenous dose of heparin (5000 IU) was given 10 to 20 min before each exercise period. Exercise with heparin pretreatment increased the total exercise duration from 6.3 +/- 1.9 (SD) to 9.1 +/- 2.2 min (p less than .001) and the maximal double product (DP) from 18,900 +/- 5100 to 25,500 +/- 6800 mm Hg.beats/min (p less than .001). The DP at the onset of angina was also increased by 35% (p less than .01) and the DP at which ST depression (0.1 mV) first appeared was 19% (p less than .05) greater after treatment. Repeat coronary cineangiography revealed an increase in the extent of opacification of collaterals to the jeopardized myocardium. In an additional six patients, treadmill exercise was performed with no medication twice a day for 10 days. All of the above-mentioned variables of treadmill capacity remained unchanged, despite 20 exercise periods without heparin pretreatment. Thus, heparin accelerates exercise-induced coronary collateral development by promoting angiogenesis. The development of such a therapeutic modality will open a new field for the treatment of patients with ischemia.

Angina Pectoris↗

[The efficacy of combined use of 1 alpha-hydroxyvitamin D3 with calcium supplements in the treatment of osteoporosis].

Synthetic analogue of active vitamin D metabolite, 1 alpha (OH) D3, has been widely used in the treatment of osteoporosis. However, the most effective method of treatment is yet to be established. Importance of calcium supplement to improve the calcium metabolism in osteoporosis is also reported by many authors. We have studied the combined effects of 1 alpha (OH)D3 with calcium supplement in preventing progressive decrease of bone mass in patients with osteoporosis. Sixty-six cases of postmenopausal and senile osteoporosis were divided into two groups: one treated with calcium alone 1,000 mg a day and the other treated with calcium 1,000 mg and 1 alpha (OH)D3 0.5 microgram a day, and both groups were followed for 24 months. Bone mass was evaluated by microdensitometry of the roentgenograms of the second metacarpal bone. The results revealed that the combined use of 1 alpha (OH)D3 with calcium has a significantly more favorable effect than the use of calcium alone in preventing bone loss. Therefore, 1 alpha (OH)D3 with calcium is useful in the treatment of osteoporosis. The conclusion would be further confirmed with longer term study and a more accurate method of measuring bone mass.

Aged↗

[A histomorphometric study of normal iliac trabecular bones. Part I: Age related changes and the values of tissue-leveled static parameters].

Trans-iliac bone biopsies were performed on 142 normal Japanese subjects (55 males, 87 females, mean age: 44.8 years) and were evaluated particularly for the indices of tissue-leveled static parameters: volume and thickness of bone/osteoid, and surface measurement of formation, resorption and inert surface. The results were in general agreement with previous studies, but some discrepancies were found regarding osteoid indices: 1) The osteoid (formation) surface, especially osteoblastic osteoid surfaces, increased significantly at the ages from 50 to 60 years in females, 2) osteoid volume and relative osteoid volume were also found to have increased at this age range in females, 3) osteoid thickness decreased or had a rather constant value in females, and 4) the values of these 3 parameters decreased in males with the advance of age after young adulthood. From these results, at least at tissue level, the bone formation rate seemed to increase from the 6th to the 7th decade of life in women making a clear contrast to men in whom the formation rate appeared to decrease within the same age range.

Adolescent↗

[A histomorphometric study of normal iliac trabecular bones. Part II: Age changes and the values of MWT and related parameters].

The Mean Wall Thickness (MWT) of the trabecular packet and other related indices: number of osteocytic lacunae (N-0) and maximum number of birefringent lamellae (N-1) in the packet were measured in 142 normal Japanese subjects (male 55, female 87, mean age 44.8 yrs). MWT was obtained by the equation MWT = 2S/L, where S and L designate area and perimeter, respectively. The MWT, S, and L of the packets all decreased significantly after young adulthood. N-0 and N-1 also decreased significantly with age. In contrast, S/(N-0), which is the measure of the volume of the matrix being formed by a single osteoblast, did not change with age. Therefore, it may be concluded that BMU-leveled bone formation decreases with age probably due to the decreased number of osteoblasts which participate in forming a trabecular packet.

Adolescent↗

Acute retinal necrosis syndrome following chickenpox in pregnant woman.

A pregnant woman presented with acute retinal necrosis syndrome (ARNS) involving both eyes. She had had varicella eruption one month before the onset of the disease. Antibody titer to the varicella-zoster virus was elevated in the aqueous humor of both eyes. To our knowledge, this is the first report which showed apparent association of varicella eruption with ARNS caused by varicella-zoster virus.

Acyclovir↗

Importance of coronary collateral circulation for kinetics of serum creatine kinase in acute myocardial infarction.

The effect of coronary collateral perfusion on the kinetics of creatine kinase (CK) was examined in 32 patients undergoing intracoronary thrombolysis within 6 hours after the onset of a first acute myocardial infarction (AMI). Blood sampling for CK was performed every 2 to 4 hours for a period of 72 hours after AMI. The cumulative CK release was determined using the integrated appearance function curve with the individual disappearance rate. In 19 patients in whom thrombolysis was successful (group A), time to peak CK level was 11 +/- 1 (standard error of the mean) hours after AMI and cumulative CK release was 2,599 +/- 424 U/liter. In 6 patients who had a significant collateral circulation to the infarct-related coronary artery and unsuccessful reperfusion (group B), the time to peak CK was 16 +/- 1 hours (p less than 0.05 compared with group A) and cumulative CK release was 1,897 +/- 478 U/liter (difference not significant compared with group A). In the remaining 7 patients, with neither recanalization nor significant collateral perfusion group C, time to peak CK was 21 +/- 1 hours and significantly (p less than 0.05) longer than groups A and B. Cumulative CK release (2,707 +/- 776 U/liter) was not significantly different from groups A and B. Thus, collateral perfusion is an important determinant of the CK time-activity curve during AMI. Early peaking of CK levels does not reliably identify spontaneous or drug-induced recanalization of the infarct-related coronary artery.

Collateral Circulation↗

Functional significance of coronary collateral perfusion in preserving myocardial integrity.

Coronary collateral perfusion to the completely obstructed coronary artery was evaluated by coronary cineangiography in 32 patients. In 13 patients, there was neither history of severe chest pain of longer than 30-min duration nor electrocardiographic evidence of a transmural myocardial infarction (Group I). Among patients undergoing intracoronary thrombolytic therapy for the completely occluded infarct-related coronary artery within 6 h after the onset of symptoms of the first acute myocardial infarction, 19 patients had a history of preinfarction angina (Group II). Collateral visualization (collateral index) was found to be significantly greater in Group I (2.5 +/- 0.5, SD) than in Group II (0.9 +/- 1.0) (p less than 0.01). Group I patients had a longer history of angina (25 +/- 25 months) than did Group II patients (17 +/- 18 months) (p = NS). These findings indicate that well-developed coronary collateral vessels preserve myocardial integrity upon acute coronary occlusion and that a long-standing angina indicative of myocardial ischemia may play an important role in developing collateral channels.

Adult↗

Cineangiographic evaluation of changes in regional left ventricular wall motion after acute myocardial infarction.

To evaluate the natural course of changes in regional left ventricular function after acute myocardial infarction, we compared cineventriculograms taken during the acute and chronic stages of myocardial infarction in ten patients who had sustained coronary occlusion despite intracoronary thrombolysis. Three ventricular silhouettes (end diastole, aortic valve opening, and closure) were superimposed using external reference markers, and 36 radial grids were drawn from the center of gravity of the end-diastolic silhouette to the endocardial margin of each silhouette. Measurement of the length of each radial grid provided quantitative details of segmental centripetal wall motion. In the infarcted area, percentage total systolic shortening (% delta LTOT), iso-volumic shortening (% delta LISO), and ejection phase shortening (% delta LEJ) remained unchanged. In the nonischemic area, % delta LTOT tended to increase from 34% +/- 6% to 41% +/- 6%. Although % delta LISO was unchanged (9% +/- 4% vs. 8% +/- 1%), % delta LEJ increased from 25% +/- 4% to 37% +/- 6% (P less than 0.05). Thus, progressive increases in ejection phase shortening in normal regions may contribute to the functional recovery of the left ventricle after myocardial infarction.

Adult↗

Importance of angina for development of collateral circulation.

The extent of collateral circulation in 46 patients who had intracoronary thrombolysis within six hours of the onset of acute myocardial infarction was evaluated. Patients who had had a previous myocardial infarction (4 cases) or who had spontaneously recanalized infarct related coronary arteries (5 cases) were excluded from the analysis. Collateral development was graded during coronary cineangiography according to the extent of opacification of the collateral and epicardial arteries distal to the site of occlusion (collateral index 0 to 3). Angina was considered to be present before myocardial infarction if it had occurred more than one week before acute myocardial infarction. Collateral channels were visible in only two of 19 patients without angina before infarction and nine of the 18 patients with angina before infarction. The prevalence of angina and the collateral index were not significantly influenced by the extent of coronary vessel disease. It is concluded that myocardial ischaemia is important in promoting collateral development in man as well as in laboratory animals.

Adult↗

[Treatment of oral carcinoma in elderly patients--case reports and associated problems].

Three very elderly patients (more than 90 years old) suffering from oral carcinoma are reported with a discussion concerning complications of treatment and safety of surgery. In all cases, pretreatment with chemotherapy and/or chemo- and radiotherapy could be uncomplicatedly followed by surgery to excise the primary lesion done neck dissection. In one case, however, surgery after potent therapy with PLM, 5-FU and irradiation for the recurrence at the primary site was complicated by any severe consequences. Based on the clinical course of the patients, surgical treatment seems to be rather beneficial in very elderly cancer victims with the aim of avoiding complications caused by the usual conservative therapies.

Aged↗