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Biomedical subjects

H Harasaki

Publications and source records attributed to H Harasaki.

At least 109 records · Page 6Linked to original sources
PubMed1978

Immunological studies on myasthenia gravis: operative indication and cell-mediated immunity.

An important aspect of the management of patients with myasthenia gravis is the decision to recommend thymectomy. Hitherto, many investigators have reported the relationship between the operative effects and such factors as age, sex, duration of symptoms, or degree of germinal center proliferation in the myasthenic thymus. However, these reports are not practical aids in deciding the indication for thymectomy in an individual myasthenic patient. The currently accepted indications of thymectomy for myasthenic patients are (1) the thymomatous patient, especially those with malignancy, and (2) the nonthymomatous patients who are resistant to medical treatment. From our present data we would add the following as an indication of the operation: (3) patients who have high T-cell subpopulation levels with highly blastogenic activities and strong skin test reactivities. In order to assure good operative results in myasthenic patients, surgeons should examine their patients' preoperative immunological states.

Adolescent↗
PubMed1977

Accumulation of phosphoenolpyruvate in red cells incubated with the phosphate ester in an acidified isotonic sucrose medium.

Accumulation of exogenous phosphoenolpyruvate against the concentration gradient was observed when human red cells were incubated in an acidified isotonic sucrose medium. Fluoride increased the apparent accumulation by inhibition of the intracellular metabolic interconversion of the phosphate compound. The accumulation appeared to be specific for phosphoenolpyruvate and the accumulation rate for 3-phosphoglycerate, which has a molecular size and pKa similar to those of phosphoenolpyruvate, was less than one-tenth of the rate of phosphoenolpyruvate. Red cells incubated in the acidified sucrose medium tended to adhere to each other when examined with a scanning electron microscope.

Biological Transport, Active↗
PubMed1976

Immunotherapy of cancer patients with Bacillus Calmette-Guérin: summary of four years of experience in Japan.

Active immunotherapy with living BCG was conducted on 98 patients with various types of cancer. The candidates for this therapy were patients with residual or inoperable cancer of the colorectum, liver, breast, biliary tract, lung, and other organs with a follow-up of 4-58 months. Eleven of the 98 (11%) were able to survive for as long as 37-58 months (mean survival time 42.5 months) because of this treatment and are still living. Another 11 patients are also alive more than 24 months after starting treatment. Thirty-seven patients, however, succumbed within 12 months despite BCG immunotherapy. On the other hand, 37 patients in the control group, who shared the same clinical status and did not receive BCG therapy during this period, underwent unhappy courses for 2-12 months (mean survival time 8.7 months). The pretreatment immunoresponsiveness of these 98 patients was suppressed, as measured by the following immunologic parameters: T-cell subpopulation in the peripheral blood, stimulation index of PHA, and skin tests to DNCB, KLH, PPD, and PHA. All of these parameters improved shortly after initiation of BCG injections in 22 patients who survived more than 24 months. In contrast, in patients who died within 12 months, immunoresponsiveness remained suppressed throughout the course. This result has suggested that there was an apparent correlation between the effectiveness of BCG and immunoresponsiveness. In addition, a good correlation was observed between the duration of inflammatory reactions at BCG injection sites and clinical prognoses. Moreover, it was shown that a relatively high amount of BCG (20-80 mg as an initial dosage) and repeated injections of living BCG were necessary to obtain a sufficient enhancing effect on the immunocompetency of these late-stage cancer patients. The most conventional criterion used to determine an optimal time for booster injections of BCG was measurement of the PPD-evoked skin reaction at the BCG injection site, that is, Koch's phenomenon. When a marked flare-up reaction of more than 2.5 X 2.5 cm in size was observed, the effect of BCG was considered to be continuing, and no additional booster injection was needed. The mean interval between the first and second BCG injections was 6.2+/-1.1 months in patients who survived more than 2 years. In contrast, the duration of this reaction was only transient in ineffective cases. The most frequent side effects of this therapy were fever and malaise; these complications occurred in 62% of the cases. No severe side effects, such as dissemination, anaphylactic shock, or granulomatous hepatitis, have been experienced throughout this study, even in patients to whom a total dosage of more than 200 mg of living BCG were injected.

Adult↗
PubMed1975

Ultrastructure research of the endocardial endothelium of monkeys.

The surface structure of the endocardial endothelium of normal monkeys (Macaca fuscata and M. irus) was studied using scanning and transmission electron microscopy. The endocardium was covered by a layer of endothelial cells, each of which was recognized by the presence of nuclear bulge and marginal folds. The free cell surface was covered by a number of microvilli. The size of the endothelial cell and its surface morphology varied considerably in the different portions of the heart. The endothelial cells were packed more densely along the free margin of the valves especially at the noduli valvularum semilunarum. The microvilli over the cell surface were denser and longer on the ventricular side of the mitral valve and on the aortic valve, where the marginal folds were not "folds" but were formed by an array of numerous microvillous projections. These cytoplasmic projections had a topographical correlation with micro- and macro-pinocytotic vesicles, thus suggesting their role in the interaction with circulating biologically active substances.

Animals↗
PubMedDate not supplied

Intravascular endoprostheses. Effect of surface geometry on restenosis and side branch patency.

To investigate the effects of gaps between the wire pitches of a shape memory Nitinol alloy intravascular endoprosthesis (IVEP), 42 stents with and without gaps were implanted transluminally into the infrarenal abdominal aortae of 11 normal and 10 atherosclerotic rabbits. Digital subtraction angiography was done every 4 weeks to examine the restenosis rate and major side branch patency. Restenosis rates within IVEPs with gaps were significantly lower than in stents without gaps in both normal and atherosclerotic rabbits. The side branch patency rate was significantly higher with IVEPs having gaps. These results suggest that the placement of gaps between wire pitches reduced the restenosis rate within IVEPs, and prevented the obstruction of major side branches.

Angioplasty, Balloon↗