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Biomedical subjects

K Akagi

Publications and source records attributed to K Akagi.

At least 163 records · Page 9Linked to original sources
PubMed1989

Alteration of FHR pattern and cerebral metabolic rate of glucose of the fetus measured by positron emission tomography during progress of acidemia. The significance of overshoot acceleration in FHR.

In order to investigate the significance of overshoot acceleration in FHR with acidosis induced by serial cord compression, cerebral glucose metabolic rate (CMRglc) was measured in four chronically instrumented fetuses before cord compression and immediately after appearance of the overshoot acceleration in FHR. The investigation of CMRglc was carried out using positron emission tomography to assess accumulation of cyclotron-produced F18-FDG in the fetal brain. CMRglc in the fetal brain in the nonacidemic condition was 1.73 mg/100 g/min. In acidemia, with fetal arterial pH near 7.15 in which FHR showed the characteristic pattern with overshoot acceleration, CMRglc was significantly decreased to 0.73 mg/100 g/min. We concluded that, to avoid neuronal damage, it is necessary to intervene when the fetal condition deteriorates to the extent that overshoot acceleration in FHR occurs.

Acidosis↗
PubMed1989

[Study of strengthening and stress distribution of porcelain jacket crowns constructed with twin foil technique. 2nd report].

McLean and Sced have reported (J Dent Res, 56: 1067-1069, 1977) a procedure for a reinforcement of the porcelain jacket crown, which improved the resistance to a fracture as a result of inhibiting the propagation of cracks into brittle materials, so called the twin foil technique. The purpose of this study is to evaluate the clinical application of this technique. The FEM analysis revealed that the same magnitude of surface tensile stress and no difference of the stress pattern were observed between porcelain jacket crowns constructed with a conventional and the twin foil technique. As the internal tensile stress concentrated in a platinum matrix of the twin foil technique, the stress distribution in a core layer reduced to about 20-35% compared to that of the conventional technique. This is explained by the mechanical and chemical bonds between a platinum matrix and a core porcelain and also by extreme high young's ratio of platinum. We can assume the similar finding from the fractography of the conventional porcelain jacket crown. But contrary above results, no significant differences of the strength were observed in both the presence and the absence of a platinum matrix in the fracture test. From the fact describe above, we may conclude that the tin coated platinum matrix contributes slightly to the strengthening of the porcelain jacket crown.

Crowns↗
PubMed1989

Pharmacologic modulation of spontaneous histamine release.

In a previous study from our laboratory (Akagi and Townley) we reported that basophils from asthmatic patients off medication show spontaneous histamine release (SHR) significantly higher than asthmatic patients on chronic medication. Both groups of asthmatics showed significantly higher SHR than normal subjects. These findings led us to test the in vitro effect of various therapeutic agents on SHR. Theophylline exerted the most pronounced inhibitory effect on SHR (P less than .005). The effects of isoproterenol and PGE1 were significant (P less than .005) but less than theophylline. These in vitro findings led us to evaluate the effect of a single dose, orally administered bronchodilator on in vitro SHR from asthmatic subjects. The effect of theophylline 250 mg and metaproterenol 20 mg on pulmonary function and SHR was evaluated on separate study days. Four of the eight asthmatic subjects showed greater than 10% SHR. The baseline value of SHR in the same individuals on two different study days showed significant correlation (r = .82). A single dose of metaproterenol or theophylline increased the pulmonary function but failed to influence the SHR. Although SHR occurs in asthmatic subjects, it is not influenced by single dose bronchodilation.

Adult↗
PubMed1989

[Study on adsorption of human serum protein to biomaterials].

In our study of the interaction between dental implant materials and human serum proteins, a simple column chromatographic method to measure extraction of proteins by the biomaterials was developed. The method allows for subsequent analysis of the absorped proteins by two dimensional microelectrophoresis. A system to measure dyestained proteins on two-dimensional polyacrylamide gels employing a television camera for data acquisition and a micro computer for data analysis is described. It can be seen that elution from the hydroxyapatite columns are qualitatively similar, more protein eluting at 0.1 M phosphate. Less protein was adsorbed by the 1,250 degrees C and 1,400 degrees C hydroxyapatite ceramics, and equal amounts were eluted with 0.01 M and 0.1 M phosphate solutions. The 0.1 M phosphate eluates were subsequently analyzed by two-dimensional electrophoresis. The proteins adsorbed band eluted from the biomaterials, are estimated to be albumin, pl 4.7-4.9; transferin, pl 5.9 and IgG, pl 5.8-7.3. pl's were obtained from literature and tentative identifications made by comparison with the patterns of reference serum. The protein pattern from each biomaterial was reproducible. Albumin, IgG and transferin were obtained from non-treated hydroxyapatite. Different patterns were observed with eluates of 1,250 degrees C and 1,450 degrees C hydroxyapatite ceramics. The large spot, tentatively identified as albumin and a small amount of IgG, were the only proteins seen. We conclude that hydroxyapatite and hydroxyapatite ceramics can adsorbed of human serum protein. Selective adsorption of protein may occur a structure change of the material surface activated by sintered temperature.

Adsorption↗
PubMed1989

[Measurement of DNA content and analysis of chromosome using flow cytometry].

This include review of recent paper about sensitivity and effective of radiation therapy using flow cytometry. This paper discuss the prediction of tumor response. As predictor of response in cancer. It is DNA aneuploidy, growth fraction (% S fraction), chromosome changes, and monoclonal antibody by oncogene product protein. It is possible that the protocol of cancer treatment will be determined based on prediction data from an individual cancer. Flow cytometry would be a useful tool to get a predictor of radiation, drugs response on each cancer.

Aneuploidy↗
PubMed1989

[Intracranial hemorrhage associated with aplastic anemia].

Intracranial hemorrhage is a fatal complication associated with aplastic anemia. We have encountered four patients who experienced six episodes of intracranial hemorrhage (intracerebral hemorrhage; 3, subarachnoid hemorrhage; 2, and subdural hematoma; 1,). Intracranial hemorrhage occurred without traumatic episodes, and was followed by frequent hemorrhagic episodes in other parts of about one year duration. This disease is considered to recur after a short interval. The site, type and degree of intracranial hemorrhage varied, and therefore intracranial hemorrhage seemed to be caused not only by thrombocytopenia but also by multifactorial hemorrhagic tendency. Transfusion of platelet rich plasma, and administration of Glycerol and steroids produced good results for conservative therapy. Continuous spinal drainage for subarachnoid hemorrhage was a relatively safe and useful means of management. In the patients who showed precipitous deterioration, the CT scan findings indicated that the high-density-area was diffusely spread with an unclear border, just like "contusional hemorrhage". For such severe cases, blood evacuation with craniotomy and emergency splenectomy are considered to be valuable.

Adolescent↗
PubMed1989

["AB-Triple V" therapy of relapsed or refractory acute myelogenous leukemia].

Sixteen adults with acute myelogenous leukemia (AML) in relapse or refractory to conventional therapy were treated with AB-Triple V therapy. This regimen consists of aclarubicin, behenoyl cytosine arabinoside, etoposide, vincristine, and vinblastine or vindesine. Patients who obtained complete remission (CR) were then given monthly three courses of AB-Triple V therapy, and further courses of AB-triple V therapy every three months. Eleven of the 16 patients entered CR, three were no response, and two died early after initial AB-Triple V therapy. Among 11 patients who achieved CR, 7 are alive and in CR during 1 to 13 months, one died of hepatic failure, and three patients died of infection in CR. Systemic arthralgia following the administration of vinblastine were frequently observed. These results indicate that this salvage therapy are useful relapsed or refractory AML. Therefore, the role of this combination chemotherapy as a part of the initial post-remission therapy needs to be evaluated.

Aclarubicin↗
PubMed1988

The slope of fetal heart rate deceleration is predictive of fetal condition during repeated umbilical cord compression in sheep.

The relationship between components of fetal heart rate deceleration and fetal arterial blood gas values or plasma catecholamine concentrations was investigated by repeated complete umbilical cord compression in chronically instrumented fetal lamb. Fetal arterial pH and bicarbonate levels decreased, while plasma norepinephrine and epinephrine concentrations increased more than tenfold. The slope of the descending limb of the fetal heart rate deceleration curve decreased and correlated strongly with fetal arterial pH, bicarbonate, and logarithmic plasma norepinephrine and epinephrine concentrations. Fetal arterial pH and bicarbonate levels were significantly lower in the group with lower fetal heart rate deceleration slope, and a greater plasma catecholamine concentration in this group suggested a redistribution of blood flow to vital organs. Therefore, during repeated umbilical cord compression, the fetal acid-base and hormonal state was predicted by the fetal heart rate deceleration slope. This relationship may be applicable to human fetuses in the diagnosis of fetal distress caused by umbilical cord compression during labor.

Acidosis↗
PubMed1988

Regional differences in inhibition and recovery of protein synthesis after transient hindbrain ischaemia of gerbils.

Regional protein synthesis was estimated autoradiographically in a model of transient hindbrain ischaemia of gerbils. In studies of 5 min ischaemia followed by 5 min recirculation, incorporation of [14C]valine into the TCA-insoluble protein fraction was not affected. In studies of 15 min ischaemia followed by 5 min recirculation, incorporation of the tracer into the protein fraction was severely depressed in the ischaemic lesion of the brain stem and cerebellum. However, the granular layer of the cerebellar cortex had partially preserved protein synthesis. When recirculation time was extended to 2 h after 30 min ischaemia, protein synthesis of the cerebellar cortex almost recovered to the full level of the control. However, in the pontine grey matter, inferior colliculus and vestibular nucleus, a significant reduction in protein synthesis persisted. These results indicate that protein synthesis in the pontine grey matter, inferior colliculus and vestibular nucleus are selectively inhibited by ischaemia. Further its recovery after recirculation is slow. The cerebellar cortex is less vulnerable to ischaemia, and recovery is relatively fast. The regional heterogeneity of protein synthesis is neither due to the degree of ischaemia in this model nor the extent of postischaemic hypoperfusion. Factors that influence protein synthesis in this ischaemic model are discussed.

Animals↗
PubMed1988

Three cases of fetal ascites with successful outcome and seven year evaluation of NIHF: 1981-1987.

Three pregnant women with fetal ascites were admitted to our hospital at 30, 32 and 33 weeks of gestation on diagnosis by sonogram. On sonogram, all the fetuses were initially with marked ascites but without any pleural or pericardial effusion or subcutaneous edema. Under observation by sonogram and cardiotocogram, obstetrical intervention was performed by cesarean section in all 3 cases; at 31 weeks of gestation due to notably increased ascites, at 32 weeks due to fetal distress and at 35 weeks due to development of subcutaneous edema, respectively, and the subsequent courses were uneventful. On the other hand, in our precious experience with 21 cases of NIHF over a period of 7 years, only 2 babies with NIHF have been born alive. We think fetal ascites should be considered an initial sign of NIHF and the successful outcome of these three cases were due to early diagnosis by frequent sonographic examination.

Adult↗
PubMed1988

Gastroduodenal lesions after transcatheter arterial chemo-embolization in patients with hepatocellular carcinoma.

We investigated the incidence and endoscopic features of gastroduodenal lesions which appeared after transcatheter arterial chemo-embolization (TACE), performed 29 times in 25 patients with inoperative hepatocellular carcinoma. The new development or exacerbation of the gastroduodenal lesions after TACE was evident in 13 of the 29 (45%). The side of the lesions ranged from the gastric body to the second portion of the duodenum, and the lesions that developed were multiple ulcers in four, and multiple erosions with white coat in nine. The development of these gastroduodenal lesions may be due to mucosal ischemia caused by embolic materials, the toxic effect of antineoplastic drugs infuse, or to stress. In light of these events, upper gastrointestinal endoscopy should be added to the usual examinations done for patients undergoing TACE.

Adult↗