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Biomedical subjects

Y Takemoto

Publications and source records attributed to Y Takemoto.

At least 235 records · Page 13Linked to original sources

[Extracorporeal shock-wave lithotripsy for radiolucent calculi in the upper urinary tract].

Eight years have passed since extracorporeal shock-wave lithotripsy (ESWL) was used clinically for the first time, and now its usefulness is recognized all over the world. At first, variable cases were considered to be contra-indicative, one of which was the radiolucent calculi. This time for two cases of the radiolucent calculi we performed ESWL under retrograde pyelography. Using this technique, we brought the filling defect of RP into the focus of the shock waves. The stones were effectively disintegrated and these patients became stone-free in five weeks.

Humans↗

Coagulation disorders following acute head injury.

Coagulation disorders following acute head injury were investigated in 100 patients: 81 patients survived and 19 patients died. Disseminated intravascular coagulation (DIC) was seen in 24%, and occurred most frequently in acute subdural haematoma, followed by contusional haematoma and contusion. Mortality rate of the patients with DIC was 58%. Level of serum fibrin-fibrinogen degradation product (FDP) was correlated with the amount of damaged tissue. The factors which influenced the prognosis for life were evaluated by multivariate analysis: in 100 patients, activated partial thromboplastin time (APTT) was most closely correlated with the prognosis for life, but in 24 patients with DIC, level of serum fibrinogen was most closely correlated with it.

Brain Injuries↗

Characterization of a mammalian mutant with a camptothecin-resistant DNA topoisomerase I.

DNA topoisomerase I was purified to near homogeneity from a clonal line of human lymphoblastic leukemia cells, RPMI 8402, that is resistant to camptothecin, a cytotoxic alkaloid from Camptotheca acuminata, and compared with that of the parent wild-type cells. As assayed by relaxation of the supercoiled plasmid DNA and by formation of enzyme-linked DNA breaks, the purified enzyme from the resistant cells was shown to be greater than 125-fold as resistant to camptothecin as the wild-type enzyme, comparable to a cellular resistance index of about 300. Therefore, the cellular resistance appears to be due to the resistance of the enzyme. The amount of the immunoreactive enzyme protein in whole extract appeared to be reduced to less than half that of the wild-type enzyme. These results establish that DNA topoisomerase I is the cellular target of camptothecin and that DNA topoisomerase I is essential for the survival of mammalian cells.

Camptothecin↗

Redistribution of cardiac output during grooming of the rat.

Changes in blood flow in the carotid, superior mesenteric, or renal artery or terminal aorta during grooming were measured in the conscious rat with a chronically implanted electromagnetic flow probe. Arterial pressure was measured simultaneously with an indwelling catheter. During grooming, carotid flow almost doubled and arterial pressure rose slightly, while hindquarter (terminal aortic) flow decreased by an average of about 20%. Superior mesenteric flow decreased occasionally and renal flow remained almost unchanged. Heart rate increased by an average of about 10%. An increase in carotid flow during grooming was similarly observed after cervical sympathectomy. After ganglion blockade with hexamethonium, grooming did not decrease hindquarter flow any more. These findings suggest that during grooming a substantial amount of blood flow is switched from the hindquarters to the carotid areas, to achieve a redistribution of cardiac output largely by excitation of the respective regional sympathetic and parasympathetic fibers and that sympathetic vasoconstrictor fibers supplying different vascular areas are controlled by separate pathways from separate neuron groups.

Animals↗

Studies on the effects of primary therapy for DIC following circulatory arrest.

Comparative studies in early treatment for DIC caused by circulatory arrest were carried out on three groups of dogs during 300 min from the recovery of circulatory arrest: a heparin group, a FOY (gabexate mesilate) group, and a FUT-175 (nafamostat mesilate) group. The parameters employed were platelet count, prothrombin time (PT), activated partial prothrombin time (APTT), fibrinogen, antithrombin-III (AT-III), and fibrin or fibrinogen degradation products (FDP). In the heparin group, there was less of a drop in the platelet count and the level of AT-III than in the control group, but the FDP levels were the same as in the control group. The PT and APTT remained within normal limits in the FOY group and no decrease was observed in either platelet count or AT-III levels. In addition, FDP levels were kept within normal limits. In the FUT-175 group, prolongation of APTT, no decline in the platelet count and AT-III levels, and normal levels of FDP were observed. The results of these experiments indicate the importance of early treatment for DIC. Judging from the parameters, better results were obtained in the FOY and FUT-175 group than in the heparin group.

Animals↗

Disseminated Trichosporon beigelii infection in a patient with malignant histiocytosis.

A case of disseminated Trichosporon beigelii infection is reported. Trichosporon inhabits the soil, but may also be present in the human skin and mouth as a normal flora. Occasionally it causes superficial mycotic infection, but it is rarely invasive. A review of literature disclosed 21 reported cases of invasive Trichosporon beigelii infection, to date. Of these, two cases were from Japan. The scarcity of reports on this invasive infection may be due to a lack of awareness of the organism. Histologically, it should be carefully differentiated from Candida.

Adult↗

The effect of prophylactic heparinization on DIC arising from transitory circulatory arrest in dogs.

To evaluate the beneficial effect of heparin administration on the prevention of disseminated intravascular coagulation (DIC) which appears following circulatory arrest, experimental studies were carried out with one group of dogs during circulatory arrest (control group) and compared to a group of dogs that received heparinization (heparinized group) soon after termination of circulatory arrest. Dogs of the control group were subjected to transitory circulatory arrest with occlusion balloons in the aorta and the femoral vein for a period of 8 minutes and allowed to recover without further treatment. Dogs of the heparinized group were given continuous infusions of 20 units/kg/hour of heparin as soon as circulatory arrest was started. The control group developed DIC 5 hours after circulatory arrest; however, the heparinized group demonstrated reduced platelet counts and low levels of antithrombin III (AT-III) 2 to 3 hours subsequently to circulatory arrest, but these changes were not serious, and normal levels of platelet count and AT-III were restored rapidly thereafter. Prophylactic heparin therapy is, accordingly, recommended as a useful measure of preventing the occurrence of DIC in circulatory arrest and the subsequent detrimental consequences.

Animals↗

[Disturbance of the coagulatory system in patients with head injury in acute phase].

The coagulation and fibrinolytic function of 100 cases (male 75, female 25) of trauma limited to the head was evaluated in acute phase. The coagulation and fibrinolytic function was evaluated by 6 parameters, consisting of platelet counts, PT, APTT, fibrinogen, serum FDP, and protamine sulfate test. Head injury was categorized into 5 groups according to CT findings: subdural hematoma (SDH: 13 cases), cerebral contusion (CC: 46 cases), epidural hematoma (EDH: 21 cases), skull fracture only (Fr: 14 cases), and cerebral concussion (Co: 6 cases). The results were as follows, in 19 dead cases, severe coagulopathy was observed. In intracerebral injury group (SDH + CC), serum FDP level was markedly elevated. The incidence of disseminated intravascular coagulation (DIC) following head injury was 24% (in dead cases 73.7% in survival cases 12.3%) of all cases, and mortality of cases with DIC was exceedingly high (58.3%). In 14 dead cases with DIC, the patients did not recover from DIC, and their mean survival time was only 89.2 hours. In 10 survival cases with DIC, the patients recovered from DIC. APTT was the most important to estimate the mortality of head injury. Thus, the evaluation of coagulation and fibrinolytic function in head injury in acute phase is not only important to know the occurrence of DIC, but also useful to predict the severity and prognosis of head injury.

Acute Disease↗