Search PubMed⌕ Search

Biomedical subjects

H Handa

Publications and source records attributed to H Handa.

At least 415 records · Page 23Linked to original sources
PubMed1983

Effects of a transfusion with a blood substitute (Fluosol-DA, 20%). Part II: Human cerebral blood flow.

In 24 patients suffering from cerebrovascular diseases, alteration of the cerebral blood flow was investigated by means of the 133Xe clearance technique before and after the intravenous infusion of perfluorochemical suspension (Fluosol-DA, 20%, 10 ml/kg). Since perfluorochemicals exhibit high solubilities for not only oxygen but other kinds of gases, the partition coefficient of Xe (lambda tb) is considered to change depending on the amount of perfluorochemicals contained in the blood (Fct). The solubilities of Xe in the perfluorochemicals contained in the solution were then measured by gas chromatography to obtain an equation for lambda tb: lambda tb = 1.50/(Hct/100 + 12.48Fct/100 + 0.95). The cerebral blood flow was found to increase significantly by 10.1% in the lesional hemisphere and by 10.8% in the healthy one. The cortical small artery with a diameter between 0.1 and 0.2 mm appeared to dilate by 13% after its administration. From these results, the decrease of blood viscosity and some vasodilating effect of the solution might be responsible for the increase of the cerebral blood flow.

Blood Substitutes↗
PubMed1983

Superimposition of Krypton-81m single photon emission CT and X-ray CT images for cerebral blood flow evaluation.

Selective arteriographic infusion of krypton-81m was used to obtain cerebral single photon emission computed tomograms. These were then superimposed on X-ray computed tomograms to assess topographically the perfusion of the entire brain. This method enhances the detecting capability for abnormal perfusion areas and has been used in 21 patients with various brain diseases.

Carotid Artery Thrombosis↗
PubMed1983

Epidural hematomas of the posterior fossa in children.

The authors report 3 cases of epidural hematoma of the posterior fossa in children. The clinical signs and symptoms are discussed. Onset of symptoms is not necessarily acute. The radiological findings are discussed. Epidural hematomas of the posterior fossa in children have a tendency to liquefy earlier than supratentorial hematomas. We emphasize the value of computed tomography for the diagnosis of epidural hematoma of the posterior fossa. One should keep in mind the possibility of the presence of an epidural hematoma of the posterior fossa in the treatment of head injury in children, even in the case of a minor head injury.

Cerebral Angiography↗
PubMed1983

Intra-arterial ACNU therapy for malignant brain tumors. Experimental studies and preliminary clinical results.

The authors examined the growth rate of mouse 203 glioma cells in vitro and found it to be markedly inhibited after exposure to ACNU for 5 minutes at a drug concentration of 100 micrograms/ml. Rats that had undergone intracranial implantation of T1 neurogenic tumor were treated by 5 mg/kg of ACNU administered either intravenously or intra-arterially. The median survival times for the control animals and the animals undergoing intravenous or intracarotid administration of ACNU were 23, 29, and 46 days, respectively. The difference in survival time between the intravenous and intracarotid administration groups was statistically significant (p less than 0.01) when examined by the Cox-Mantel test. In a clinical trial, 17 patients with glioblastoma were treated by ACNU, eight intravenously and nine by the intra-arterial route. The drug was given in doses of 2 to 3 mg/kg at least twice before and twice after a course of postoperative radiotherapy. Intra-arterial administration was performed over a period of 5 minutes under local anesthesia. The median postoperative survival time for the patients in the intra-arterial group was 12.5 months, compared with 9.0 months for those in the intravenous group. The survival rate for the intra-arterial group was slightly higher, although statistically not significant, probably because the number of cases was small. The degree of thrombocytopenia due to ACNU tended to be less marked in the intra-arterially treated patients. The theoretical advantages of the intra-arterial administration of ACNU are discussed.

Adult↗
PubMed1983

[Suppressor mechanism in tumor immunology: characteristics of suppressor T-cells in glioma-bearing mice].

Suppressor T cells in syngeneic tumor-bearing mice that inhibited in vitro generation of tumor antigen-specific cytotoxic T lymphocytes were characterized with respect to the kinetics, the nature and the target specificity, using murine malignant glioma (a methylcholanthrene-induced malignant ependymoblastoma, 203-glioma). Suppressor cell activity was assessed by the inhibition of tumor cell killing activity of cytotoxic T lymphocytes, which were prepared from splenic T enriched lymphocytes of mice immunized with 1 X 10(6) mitomycin C (50 micrograms/ml, 45 minutes)-treated 203-glioma cells twice at an interval of 7 days. It was confirmed that suppressor T cells were generated in 203-glioma-bearing mice, and they were tumor antigen-specific as evidenced by the fact that sensitized splenic T lymphocytes from mice bearing other syngeneic EL4 thymoma or allogeneic P 815 mastocytoma or YAC-1 T cell lymphoma did not exhibit the inhibition of the cytotoxic T lymphocyte activity against 203-glioma cells. Significant suppressor cell activity was detected in spleen cells 1 to 5 days after the subcutaneous inoculation of 203-glioma cells with the peak activity on day 3 and it disappeared as early as on day 7, suggesting strongly that the turn-over of suppressor T cells is very quick. Surface markers of suppressor T cells in 203-glioma-bearing mice were checked on day 3 with the results that the suppressor cell activity was eliminated by the treatment with anti-Lyt-2 monoclonal antibody and complement, indicating that the phenotype of suppressor T cells is Lyt-1-.2.3+.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1983

[Effects of interferons on syngeneic murine malignant glioma-specific killer T cell].

The effects of IFN (interferon) on the activation and differentiation of syngeneic murine malignant glioma-specific killer T cell were investigated in C57BL/6 adult mice in order to clarify the potential usefulness for anti-tumor local immunotherapy. It was confirmed that the specific killer T cell against 20-methylcholanthrene-induced 203-glioma was generated in mice after intracranial and subcutaneous inoculation of the tumor cells. The cytotoxic activities of splenic cells obtained from intracranial and subcutaneous tumor-bearing mice were assessed on MLTC (mixed lymphocyte-tumor cell culture) for 18 hours by microcytotoxicity assay modified Takasugi and Klein's method. The addition of IFN to MLTC resulted in a similar 1.5- to 2.0-fold increase of generated cytotoxic activities. Prior treatment of sensitized splenic cells with IFN resulted in an enhancement of the specific cytotoxic activity for the target tumor cells. IFN enhanced cytotoxic activities in MLTC only in the first 3 hours. These cytotoxic activities were eliminated by the treatment of sensitized lymphocytes with anti-Thy-1 antibody and complement before adding IFN. Therefore, it was found that IFN was able to enhance killer T cell activity of sensitized lymphocytes. Normal lymphocytes did not exhibit any cytotoxic activity even after the treatment with IFN. On the other hand, IFN had a cytostatic effect on the growth of 203-glioma cells. This effect of IFN on 203-glioma cells was not observed when IFN was removed from the suspension (by washing 203-glioma cells).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗