Search PubMed⌕ Search

Biomedical subjects

H Uchida

Publications and source records attributed to H Uchida.

At least 487 records · Page 27Linked to original sources

An experimental study of a new sutureless intraluminal graft with an elastic ring that can attach itself to the vessel wall. A preliminary report.

A new sutureless intraluminal graft was developed with an elastic ring made of a flat spring. The diameter of the ring could be reversibly reduced by compression. The sutureless intraluminal graft with an elastic ring can attach itself to the vessel wall by elastic expansion of the ring. The elastic-ring graft was implanted in the descending thoracic aortas of nine dogs and was evaluated histologically and angiographically at different intervals from 18 to 150 days. No complication such as detachment of the ring, aortic rupture, stenosis, or aneurysmal dilatation was observed. With the new graft neither ligation nor posterior aortic wall dissection is necessary, and no anastomotic stenosis occurs. This graft is applicable even if the diameter of the aorta is small. Therefore the elastic-ring sutureless intraluminal graft promises theoretic advantages over sutureless methods that use tape ligation.

Animals↗

Clinical pharmacokinetics and tolerance of fleroxacin in healthy male volunteers.

The tolerance and pharmacokinetics of fleroxacin were studied in healthy male adult volunteers. The peak serum concentrations of unchanged fleroxacin were about 1.5, 3 and 5 mg/l at 1-2 h after single oral doses of 100, 200 and 400 mg, respectively. The apparent serum elimination half-life was about 10 h, independent of the dose. Fleroxacin, demethyl fleroxacin and fleroxacin N-oxide excreted in urine over 3 days accounted for about 75%, 5% and 5%, respectively, of the doses. The urine concentrations of unchanged drug were dose-related; the mean concentrations, sustained over 24 h, were about 50, 100 and 150 mg/l after 100, 200 and 400 mg doses, respectively. Food intake did not significantly influence the serum concentration and urinary excretion. Steady state serum concentrations were achieved from day 3 onwards by repeated doses of twice-a-day dosage regimen and were 2-4 and 5-9 mg/l after 200 and 400 mg bid, respectively. The mean concentrations of unchanged drug in urine were about 200 and 300 mg/l at the respective dosages. The pattern of urinary metabolites was not changed by repeated doses and 90% of repeat doses was recovered in urine, including metabolites. The serum protein binding of fleroxacin was 32%. The saliva concentration was 40% of the total serum concentration or 60% of the free serum concentration. The faecal recovery over 3 days was 3% of the dose following a single 200 mg dose after a meal. The unchanged drug concentrations in faeces during 400 mg repeated dosing were 100-150 mg/kg. No severe dose-related side-effects were observed during the study.

Adult↗

Comparison between fluctuating PEEP and conventional PEEP in dogs with lung injury induced by blood aspiration.

It has been documented that in some patients with acute hypoxic respiratory failure the application of positive end-expiratory pressure (PEEP) may produce no improvement or even a deterioration of pulmonary oxygenation due to an increase in ventilation-perfusion mismatching. Fluctuating PEEP (F-PEEP) is a newly developed PEEP in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with localized lung injury induced by the aspiration of non-heparinized blood (2 ml.kg body weight-1), F-PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at frequencies of 10 min, and conventional PEEP with 3 different fixed EEPs, 0.5, 1.0 and 1.5 kPa (C-PEEP0.5, C-PEEP1.0 and C-PEEP1.5) were each applied for 60 min. F-PEEP produced a periodical change in PaO2 and hemodynamic variables including cardiac output, and in comparison with C-PEEP0.5, C-PEEP1.0 and C-PEEP1.5, a significantly greater improvement of A-aDO2 and dynamic compliance with relatively large cardiac output in the low EEP phase. These results suggest that F-PEEP is a useful mode of artificial ventilation for treating some kinds of acute hypoxic respiratory failure due to increased ventilation-perfusion mismatching.

Animals↗

Fluctuating PEEP (F-PEEP) versus conventional PEEP in dogs with asymmetrical lung injury.

Fluctuating PEEP (F-PEEP) is a newly developed PEEP in which end-expiratory pressure (EEP) is periodically changed within a certain range. In a dog model with unilateral lung injury induced by the introduction of hydrochloric acid, F-PEEP in which the EEP was periodically changed from 0.5 to 1.5 kPa at periods of 6 min, and conventional PEEP (C-PEEP) with an optimized EEP of 1.0 kPa, were each applied for 30 min. F-PEEP produced a significantly greater improvement of PaO2 and intrapulmonary shunt (QS/QT) than C-PEEP, and at the low EEP phase, the greatest improvement accompanied by an increased dynamic compliance and a large cardiac output was obtained. These results suggest that F-PEEP provides a useful mode of artificial ventilation for the treatment of unilateral lung injury.

Animals↗

Fluctuating PEEP versus conventional PEEP in diffuse and unilateral lung injury induced by oleic acid.

Effects of fluctuating positive end-expiratory pressure (F-PEEP), in which end-expiratory pressure (EEP) was periodically changed from 0.5 to 1.5 kPa with a periodic time of 6 min, and conventional PEEP (C-PEEP) with a fixed EEP of 1.0 kPa, were comparatively studied in diffuse (Group I) and unilaterally dominant lung injury (Group II). Although F-PEEP produced cyclic alterations of PaO2 in both groups, PaO2 changed in proportion to EEP in Group I and in reciprocal proportion to EEP in Group II. There was no significant difference between PaO2 and QS/QT during F-PEEP and those during C-PEEP in Group I, whereas in Group II, F-PEEP produced a significantly greater improvement of pulmonary oxygenation at the low EEP phase than C-PEEP. In both groups, the degree of hemodynamic depression was proportional to EEP. These results suggest that F-PEEP should be indicated for acute hypoxic respiratory failure with uneven distribution of lung injury.

Animals↗

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region.

An autopsy case of malignant rhabdoid tumor arising from soft parts in the left inguinal region of a 31-year-old Japanese male is reported. The tumor grew rapidly and appeared as a large mass measuring 21.5 X 16.5 cm located in the subcutaneous tissues of the lower abdominal wall. Histologically the tumor was composed of small round cells resembling rhabdomyoblasts, which showed a diffuse or alveolar arrangement. The cytoplasm of the tumor cells was eosinophilic and frequently contained round inclusion bodies, each consisting of an aggregation of globular filaments by electron microscopy. Immunohistochemistry showed the tumor cells to be positive for vimentin and keratin in the cytoplasm, but negative for actin, myoglobin and myosin. At autopsy, extensive metastatic or invasive tumors were observed mainly in the retroperitoneum and pelvic organs. The patient showed hypercalcemia which disappeared for only short periods just after surgery.

Abdominal Muscles↗

Results of a dental fear survey in Japan: implications for dental public health in Asia.

The purpose of this investigation was to initiate the study of dental fear in Japan. 415 college students, aged 18-22 yr were surveyed. A standardized questionnaire which has been used in the United States was translated into Japanese and was administered to the students. More than 80% of those surveyed reported some dental fear. Six to 14% of the students reported extreme fear of the dentist. The majority of the subjects admitted that they delayed making dental appointments due to fear. Muscle tension was the most common physiological symptom reported. The dental drill and needle were the most fear-provoking stimuli.

Adolescent↗

In vivo effects of deoxyspergualin (NKT-01) on lymphocyte activation in response to alloantigens.

We studied the effects of deoxyspergualin (NKT-01) on the events of lymphocyte activation in vivo by inoculating mice in the footpad with allogeneic spleen cells, and compared the effects with those of cyclosporin A (CyA). The administration of NKT-01 increased the numbers of cells recovered from the popliteal lymph node (PLN) 7 days after inoculation, but inhibited the proliferation of these cells in the presence of exogenous interleukin 2 (IL-2). NKT-01 enhanced IL-2 production, but suppressed the production of macrophage activating factor (MAF) in the mixed lymphocyte reaction between the PLN cells and allogeneic spleen cells treated with mitomycin C. CyA decreased the numbers of PLN cells little, and suppressed the response to exogenous IL-2 and the production of both IL-2 and MAF. Results with tumor cells used as allogeneic cells suggested that there was a close relationship between the suppression of MAF production by NKT-01 and its inhibition of allograft rejection. The findings showed that NKT-01 inhibited both the MAF production by and the response to IL-2 of PLN cells, and that these effects were involved in the suppression of allograft rejection by NKT-01.

Animals↗

[Surgical treatment and result of high aortic occlusion].

Twenty-one patients with high aortic occlusion treated at our institution from 1967 to 1986 were reviewed. There were seventeen men aged from 39 to 78 (mean age: 61.0) underwent surgical intervention. All patients presented clinical manifestations of vascular insufficiency of the lower limbs; rest pain in eleven patients, intermittent claudication in nine and the others. Sexual impotence was present in eight patients. Renal artery involvement was seen in one case, and renovascular hypertension was observed in this patient. Hypertension and ischemic heart disease were present in twelve cases, cerebrovascular insufficiency in one case, diabetes mellitus in three cases. The following surgical treatments were performed; end-to-end Y-shaped Dacron graft implantations from the infrarenal abdominal aorta to the common femoral arteries in six patients, onlay V-shaped Dacron graft implantations in three patients, axillofemoral extra-anatomic bypass in four patients, and amputation only in one. The hospital mortality was 18% (3/17). Twelve patients discharged from the hospital are followed up (average period was 118 months), but the follow up was lost in two patients. There were two late deaths, which course was not related to operations. The prognosis of high aortic occlusion after anatomic bypass is good, thus it was concluded that anatomic bypass with Y-shaped or V-shaped Dacron graft was recommended and extra-anatomic bypass might be performed only in a high risk patient.

Adult↗

[Healing of an external velour warp-knit Dacron vascular prosthesis].

An external velour warp-knit Dacron vascular prosthesis (8mm in internal diameter, 6cm in length), whose porosity is 1200cc/cm2/min at 120mmHg, was implanted in the descending thoracic aorta of 30 mongrel dogs. The dogs were sacrificed at different intervals between 2 weeks and 6 months. All grafts were patent at sacrifice and no serious complication was observed. Thrombus free surface score was about 90%. Cell coverage on the flow surface was first observed near anastomoses in 1-month specimens and was almost completed in 2 months. Transinterstices healing was completed in 2 months. This excellent healing in a canine model would allow clinical availability of this graft.

Animals↗

[Diagnostic imaging of small liver tumors].

The recent introduction of the various imaging modalities including MRI has improved the diagnostic accuracy of metastatic liver tumor. Especially ultrasonography provides useful informations to demonstrate the relation of tumors to surrounding structures. However, at the same time it is still a fact that small lesions frequently escape detection and qualitative diagnosis is also rendered impossible in cases of small liver tumors. Repeated ultrasonographic examination combined with clinical informations is most important and qualitative diagnosis seems accomplishable by a combination of various imaging techniques including ultrasonically guided biopsy.

Angiography↗

[Response to antitumor agents of human transplantable glioma implanted into chorioallantoic membrane of chick embryo].

In case of chemotherapy against brain tumors, it is most important to choose suitable drugs for brain tumors, since human tumors have different drug sensitivity and growth. Heretofore, the nitrosourea-induced rat glioma cell, such as C6, or immunodeficient mice were usually used for predicting the drug sensitivity of brain tumors. We took notice of Murphy's system for the chemosensitivity test, in which a human tumor is transplanted into the chorioallantoic membrane (CAM) of a chick embryo. By modifying the conventional Murphy's system, we studied the efficiency of this system in predicting the drug sensitivity of brain tumors. First, we compared the result of a drug sensitivity test using CAM of a chick embryo with that using nude mice. Next we studied the effect of chemotherapeutic agents against brain metastasis of a chick embryo caused by the intravenous injection of mouse B16 melanoma cells. The tumor reduction rate of the sensitivity test using a chick embryo tended to agree with that using nude mice. In the drug sensitivity test against brain metastasis, ACNU was the most effective. This result supports the result of the clinical study. In conclusion, the drug sensitivity test using a chick embryo is thought to be useful and the advantages or disadvantages of this system are discussed.

Allantois↗

[A review of post-operative multiple organ failure in peripheral arterial diseases].

Two-hundred- and-fifty-one patients of peripheral arterial diseases underwent 281 operations for past 11 years in our institute, and multiple organ failure (MOF) occurred in 10 patients (4.0%). These patients were reviewed and were compared with in other diseases. Survival rate was 50% and all the patients with 4 or more organ disorders died. Incidence and survival rate were not significantly different from operative time, blood loss and blood transfusion. Significant difference was observed between elective operation (3.0%) and emergent operation (20.0%). Compared with other diseases, MOF occurred more rarely in peripheral arterial diseases than in aortic aneurysms, but occurred 1.4 times of digestive diseases. While the gastro-intestinal bleeding as the initial failure organ occurred more frequently in peripheral arterial diseases than in other diseases, heart and respiratory failures were rare. MOF occurred after peripheral arterial intervention as well as other abdominal and thoracic surgery. To avoid MOF it is important to avoid MOF that the emergent surgery should be kept out and that general status, especially the grade of diabetes mellitus should be evaluated sufficiently.

Adult↗