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Biomedical subjects

T Takanashi

Publications and source records attributed to T Takanashi.

At least 37 records · Page 2Linked to original sources
PubMed1991

Quantitative analysis of lens changes after vitrectomy by fluorophotometry.

We measured the amount of autofluorescence in the lens to evaluate quantitatively lens changes after vitrectomy. Thirteen phakic patients, ranging in age from 12 to 75 years, were studied after unilateral vitrectomy, with a follow-up period of more than two years (range, 26 to 55 months). Autofluorescence in the lens was measured at the center along the ocular axis by fluorophotometry. Lens autofluorescence in the eyes that underwent vitrectomy was significantly higher than in the contralateral eyes that were not operated on (P = .0003). The increase of autofluorescence was correlated significantly with the age at time of vitrectomy (P = .0008). There was no correlation between the increase in autofluorescence and the length of postoperative follow-up or the use of air during vitrectomy. Based on these results, we believe that oxidation of lens proteins intraoperatively may be one of the causes of development of nuclear cataract after vitrectomy.

Adolescent↗
PubMed1990

Proliferative vitreoretinopathy shows predilection for the inferior fundus.

We reviewed 112 consecutive cases of retinal detachment associated with grade C-1 proliferative vitreoretinopathy (PVR) to assess the initial location of the full-thickness retinal folds. A total of 47 eyes had PVR preoperatively, and 65 eyes demonstrated PVR postoperatively. Of the eyes affected preoperatively, 29 (56%) developed PVR in the inferior retina, as did 58 (74%) of the eyes affected postoperatively for a total of 87 eyes (67%). Eyes treated with cryoretinopexy had a higher incidence of PVR in the inferior retina (87.5%) than did those undergoing diathermy (57.6%) or photocoagulation (80%). Our findings suggested that the location of PVR may be influenced clinically by gravity. This tendency was more apparent after surgery, especially after cryoretinopexy, than preoperatively.

Cryosurgery↗
PubMed1990

[Cell proliferation in a triple gastric cancer--a study using the isolated organ perfusion system].

So as to study the cell proliferation in a case with triple gastric cancers, we labeled an operated whole stomach with bromodeoxyuridine (BrdU) by the isolated organ perfusion system using artificial blood. Anti-BrdU immunohistochemical staining of sections from every part of the stomach was performed, and 3 separated cancerous lesions were all diagnosed as well differentiated adenocarcinomas. The labeling index (L.I.) of the cancerous lesions were found to differ from part to part. However, the L.I. tended to be higher in the superficial mucosal areas and in the cell-dense areas of the submucosa. In the almost normal fundic glands, the labeled zone was localized in the neck of the glands. The more metaplastic gastritis was advanced, the more the labeled zone shifted irregularly toward the bottom of the glands. Whenever the interstinal metaplasia was completed, the labeled zone was localized in the bottom of the glands. This method was found useful in studying the cell proliferation in the stomach without causing any harm to the human body.

Adenocarcinoma↗
PubMed1989

[Effect of breathing fluctuations on cerebral blood flow in demented patients and its correction method using end-tidal CO2 concentration].

During mouthpiece respiration of Xe-133 for a measurement of regional cerebral blood flow (rCBF), the breathing pattern of patients fluctuated and it caused a change of end-tidal CO2 concentration that had an excellent correlation with PaCO2 in patient without respiratory disease. The end-tidal CO2 concentration of demented patients varied within lower ranges than senile control group. The range of fluctuation on the end-tidal CO2 concentration was dependent on the type and the degree of dementia, and it fluctuated most widely at the middle stage of Alzheimer disease. Mean cerebral blood flow increased by 13.9% for each 1% increase in end-tidal CO2 concentration (3.6%/mmHg PaCO2) in the case of demented patients without cerebrovascular disease. To improve the reliability of rCBF in demented patients, especially in Alzheimer disease, the correction of rCBF data for end-tidal CO2 concentration should be performed.

Adult↗
PubMed1989

[Intra-arterial chemotherapy of malignant glioma after osmotic blood-brain barrier disruption].

Reversible transient osmotic blood-brain barrier disruption was used to increase drug delivery to the brain. The authors treated 10 cases of malignant gliomas with intra-arterial chemotherapy after osmotic blood-brain barrier disruption. Ten patients received intra-arterial anticancer drugs (5-FU, ACNU, IFN-beta) after intra-arterial infusion of 20% mannitol to open the blood-brain barrier at the tumor site. Clinical responses in 9 evaluable cases were 1 Complete Response, 3 Partial Responses, 5 No Change and no Progressive Disease in CT examination. Response rate was 44.4% (4/9). The most untoward effect of this method was myelosuppression. Platelet and leukocyte count diminished below 20,000 and 2,000, respectively in 3 cases, and 2 out of these 3 cases died of severe infection. The other complications were eye pain during mannitol infusion in all cases, when the selective catheterization of the internal carotid artery failed to pass the origin of the ophthalmic artery. Decreased activity was seen in 70%, nausea and vomiting in 50%, swelling of external decompression area in 33%, increased neurological deficit in 20%, but all these side effects were transient. This method was considered an effective treatment for malignant gliomas.

Aged↗
PubMed1988

Sensitivity and accuracy in recording His-Purkinje activity by surface-averaged electrocardiography.

A clinical evaluation of the surface-averaged ECG (SAE) to record His-Purkinje activity (HPA) was made on 70 patients who underwent His bundle electrograms (HBE). The recorded signals first judged as HPA in 43 patients by the noninvasive method alone were later verified in 37 patients by HBE; the accuracy of the HPA recordings (predictive value) was 86.0%. The HPA-V interval measured noninvasively had a high correlation with the HV interval by HBE (r = 0.89, p less than 0.01). The verified detection rate in all 70 patients was 52.9%: HPA was detected in 12 of 18 patients (66.7%) with sclerotic and hypertensive heart disease (Group I), five of 19 patients (26.3%) with rheumatic heart disease (Group II), 11 of 17 patients (64.7%) with congenital heart disease (Group III), and nine of 16 patients (56.2%) with miscellaneous conditions (Group IV). The detection rate was markedly lower in Group II than in other groups (Group II vs Group I or III, p less than 0.025). The PR segment was significantly longer in the patients in whom HPA was detected than in those in whom it was not detected (71.5 +/- 22.3 msec vs 43.9 +/- 19.5 msec, p less than 0.001). His-Purkinje activity (HPA) was detected in 32 of 52 recordings (61.5%) with sinus rhythm and seven of 20 recordings (35.0%) with atrial fibrillation, including two recordings in each of two cardioverted patients (p less than 0.05). We conclude that the surface-averaged ECG (SAE) has clinically acceptable sensitivity and accuracy except in patients with rheumatic heart disease, short PR segments or atrial fibrillations.

Atrial Fibrillation↗
PubMed1988

Assessment of demented patients by dynamic SPECT of inhaled xenon-133.

We studied the potential for using dynamic single photon emission computed tomography of inhaled xenon-133 (133Xe) gas in the assessment of demented patients. An advanced ring-type single photon emission computed tomography (SPECT) "HEADTOME" with improved spatial resolution [15 mm in full width at half maximum (FWHM)] was used for tomographic measurement of regional cerebral blood flow (rCBF). All 34 patients underwent a detailed psychiatric examination and x-ray computed tomography scan, and matched research criteria for Alzheimer's disease (n = 13), senile dementia of the Alzheimer type (n = 9), or multi-infarct dementia (n = 12). In comparison with a senile control group (n = 7), mean CBF of both the whole brain and the temporo-parietal region was significantly less in the Alzheimer's disease and senile dementia Alzheimer type groups, but no significant difference was seen between the senile control group and multi-infarct dementia group. The correlation was 0.72 (p less than 0.004) between the mean CBF of the whole brain and the score of Hasegawa's Dementia Scale, and 0.94 (p less than 0.0001) between rCBF of the temporo-parietal region and the scale in Alzheimer's disease. In the senile dementia Alzheimer type group, the correlations were 0.77 (p less than 0.01) and 0.83 (p less than 0.004) respectively. No significant correlations were found in the multi-infarct dementia group. A temporo-parietal reduction in the distribution of the rCBF characteristic in the Alzheimer's disease group and a patchy whole brain reduction characteristic in the multi-infarct dementia group was detected. The ability of our improved SPECT to provide both quantitative measurement of rCBF and characteristic rCBF distribution patterns, makes it a promising tool for research or routine examination of demented patients.

Adult↗
PubMed1987

Three-dimensional vectorcardiography (3-D VCG) by computer graphics in old myocardial infarction.

By using computer graphics we rotated the vector loop and three coordinate axes to find the viewpoint where the infarctional changes are maximally exposed and demonstrated the advantage of the "3-D VCG" over the conventional VCG by defining the quantitative "MI index." The orthogonal electrocardiogram recorded by the Frank lead system was digitally measured and processed by a microcomputer. The loops and axes were rotated about the X axis (X-rot) and the Y axis (Y-rot). The spatial vector loop and orthogonal coordinates can be presented as viewed from any spheric direction. Eight quadrants were illustrated with four colors and red circles. The subjects consisted of 30 patients with old anterior myocardial infarction (MI) and 15 patients with old inferior MI. We measured the area of "Bite" in anterior MI and superior displacement in inferior MI. The MI index was defined and averaged in 361 directions. In anterior MI, the maximum mean index was obtained when X-rot is +90 degrees and Y-rot -40 degrees, viewed from upward and leftward, whereas in inferior MI it was obtained when X-rot is -50 degrees and Y-rot -80 degrees, viewed from downward and leftward. These values were significantly higher than those in conventional VCG projections, substantiating superior diagnostic sensitivity of 3-D VCG.

Adult↗
PubMed1986

Iron status in low birth weight infants on breast and formula feeding.

Iron status in 15 low birth weight infants, 1000-2499 g, on breast feeding was studied longitudinally for the first 6 months of age, and the findings compared to those of 30 low birth weight infants receiving a proprietary iron-fortified formula. The two groups received no iron supplement until they developed iron deficiency. The incidence of iron deficiency at 6 months was significantly greater in the breast-fed group than in the formula-fed group (86% v 33%). The breast-fed group had significantly lower serum ferritin and hemoglobin values after 4 months of age. The findings indicate that breast-fed low birth weight infants have a higher risk of developing iron deficiency and should receive iron supplementation from 2 months of age.

Age Factors↗
PubMed1985

[Functional reserve of the ischemic left ventricle with ventricular aneurysm to afterload stress: digital subtraction angiographic assessments].

Digital subtraction angiography (DSA) has been confirmed to be an accurate method for determining left ventricular function. It is a relatively non-invasive technique without inducing premature ventricular complexes. The response of left ventricular function to afterload stress was assessed using DSA for eight patients with old anterior myocardial infarction and ventricular aneurysm including that of the anterior wall (averaging 30.3 months after the acute episodes). Their ages ranged from 36 to 65 years and one patient was a woman. Prior to the investigation, we confirmed that a single DSA procedure did not alter left ventricular function in a pilot study of one patient (No. 8). After initial DSA in the basal state, methoxamine was infused intravenously (1 to 2 mg/min). When aortic systolic blood pressure increased by 30 to 50 mmHg, a second DSA was performed for each patient. Left ventricular volumes and ejection fractions were calculated by the area-length method, and regional wall motion was assessed by the visual method according to the AHA classification and the curvature radius of the apical ventricular aneurysm was calculated. Methoxamine induced neither acute heart failure nor angina pectoris in the present series. The heart rates decreased, and there were a significant increase in end-systolic volumes (p less than 0.05), end-systolic radii (p less than 0.05), and a significant decrease in ejection fractions (p less than 0.02) after methoxamine infusion. In 32 of 40 segments, regional wall motion was unchanged by methoxamine as assessed by the visual method; whereas, in the other eight, there was a deterioration.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

An altered distribution and elimination of digoxin in anemic patients and experimentally induced anemic rats.

Digoxin was administered orally to eight anemic patients in their anemic and convalescent stages, and serum digoxin concentration was determined by radioimmunoassay. In the anemic patients a significantly lower level of serum digoxin concentration was observed in anemic state compared with convalescent stage at 72 hours after the drug administration (p less than 0.01). In usual clinical use, a full digoxin effect is expected to be attained as 72 hours. Tritiated digoxin was administered intravenously to anemic and control rats and the tritium in samples of the blood, myocardium and urine were counted in a liquid scintillation counter. The anemic rats showed significantly lower level of serum 3H-digoxin at 6 hours (p less than 0.01) and lower myocardial concentration at 24 hours (p less than 0.01). Larger amount of urinary excretion of 3H-digoxin was observed in the anemic rats 6 hours after the drug administration. No significant difference in fecal excretion of 3H-digoxin was found between the anemic and control rats.

Anemia, Hypochromic↗