Biomedical subjects

T Sakamoto

Publications and source records attributed to T Sakamoto.

1,433 records · Page 80Linked to original sources

PubMedDate not supplied

Two cases of primary isolated chylopericardium diagnosed by oral administration of 131I-triolein.

Two cases of isolated chylopericardium, one idiopathic and the other secondary to the lymphangioma of the pericardium are reported here. In both cases, correct diagnosis was made by radionuclide imaging techniques. When imaging the cardiac pool using 99mTc-in vivo, labeled RBC, a large separation between the heart and surrounding organs was demonstrated; this suggested a presence of massive pericardial effusion. On pericardial imaging taken 24 hours after oral administration of 131I-triolein, a donut-like shape was clearly produced, situated in a gap between the separation, suggesting chylous effusion within the pericardial space. On operating, isolated chylopericardium was confirmed in both cases. To our knowledge, this is the first report of preoperative noninvasive diagnosis of chylopericardium in Japan.

Administration, Oral↗

PubMedDate not supplied

Sonographic diagnosis of biliary ascariasis.

Real-time sonographic imaging can clearly represent the biliary ascarid as a longitudinal double linear echo. We call this representation an intraductal tubular image. Such imaging allows easy differentiation of the biliary parasite from calcification and other foreign bodies in the biliary tracts.

Ascariasis↗

PubMedDate not supplied

Opportunistic esophagitis caused by Aspergillus fumigatus.

The authors report on a 59-year-old man with opportunistic esophagitis caused by Aspergillus fumigatus. Although the patient had no underlying disease, esophagitis occurred after a short course of antibiotic therapy. A double contrast esophagogram showed multiple nodular or vertical plaque-like projections. Endoscopy provided pathological conformation of Aspergillus infection.

Anti-Bacterial Agents↗

PubMedDate not supplied

Successful surgical management of a dissecting aneurysm of the ascending and transverse aorta with heart failure due to sudden, severe aortic valve insufficiency.

A dissecting aneurysm of the ascending and transverse aorta with heart failure due to sudden severe arotic valve insufficiency in a 47-year-old man has been treated successfully. Vasodilator therapy was done preoperatively, and then hemodynamics was improved markedly. A selective perfusion technique by using separate pumps at pre-determined flow-rates with hypothermia was utilized. The replacement of both the aortic valve and the ascending and transverse aorta involving brachiocephalic artery with a prosthetic valve and expanded polytetra-fluoroethylene coated woven Dacron grafts was performed.

Aortic Dissection↗

PubMedDate not supplied

Surgical treatment of syphilitic coronary ostial stenosis with aortic regurgitation.

Syphilitic aortitis leads to involvement of the coronary ostia, aortic annulus and valve leaflets. Aortic valve replacement (AVR) with restoration of coronary blood flow is an essential therapeutic objective. Three different approaches were used for the treatment of syphilitic aortic regurgitation with coronary ostial stenosis; Case 1. AVR and endarterectomy, Case 2. AVR and aorto-coronary saphenous vein bypass graft and Case 3. AVR and endarterectomy using Fogarty catheter and Scanlan Aorta Punch. Special emphasis was given to the technique used in Case 3 as a therapeutic adjunct in the treatment of syphilitic coronary ostial stenosis.

Aortic Valve Insufficiency↗

PubMedDate not supplied

Postoperative hemolysis and its prevention in corrective surgery of truncus arteriosus.

Two cases of truncus arteriosus type I associated with truncal valve insufficiency were operated upon with the Rastelli's procedure. The first case of 3-year-old boy died from severe hemolysis which was caused by the regurgitant jet from the truncal valve running against the rough-surfaced Dacron patch for the VSD. The second case of 12-month-old girl was treated with a Dacron patch lined with an autologous pericardial pedicle. Her postoperative course was uneventful. The authors discuss the potential risk and prevention of postoperative hemolysis in corrective surgery of the truncus arteriosus with truncal valve insufficiency.

Child, Preschool↗

PubMedDate not supplied

New algorithm of intra aortic balloon pumping in patients with atrial fibrillation.

Intra aortic balloon pumps have been operated inaccurately when used in patients with atrial fibrillation. In 36 pre-operative cardiac surgical patients with atrial fibrillation, the interval between the R wave of the electrocardiogram and the dicrotic notch (R-DCN interval) of the aortic pressure waveform showed significant correlation with the preceding R-R interval by second degree polynomial curves (0.53 < r2 < 0.74, p < 0.01). Based on these results a new algorithm for atrial fibrillation was designed. During brief off periods of the intra-aortic balloon pump in atrial fibrillation, electrocardiograms and aortic pressure waveforms were simultaneously recorded and analyzed to obtain a second degree polynomial curve between the preceding R-R and R-DCN intervals. The precise timing of balloon inflation was controlled using the equation in response to the preceding R-R interval. This new algorithm showed the smallest time lags (SD = 8.5 msec) when compared to other existing algorithms (the Kontron model-10, 53.49 msec; the Aries Medical model-700, 43.69 msec; the Datascope system-90, 25.98 msec; the Mansfield 3000, 19.65 msec; and the Kontron K-2000, 14.89 msec) in mock simulation driving using data obtained from clinically recorded waveforms.

Algorithms↗

PubMedDate not supplied

Modification of T-lymphocyte subsets in peripheral blood, the liver, and the spleen during liver regeneration after partial hepatectomy of mice.

Flow cytometry analysis was performed to investigate the modifications to the T lymphocytes in peripheral blood, the spleen, and two intrahepatic lymphocyte fractions--the intrahepatic lymphocyte fraction 1 (IHL Fr.1), which is easily washed out from the liver by perfusion of collagenase solution, and the intrahepatic lymphocyte fraction 2 (IHL Fr.2), which remains in the liver after the perfusion--occurring in the liver regeneration process after partial hepatectomy of mice. The following findings were obtained: 1) The nontreated murine liver contains Thy 1.2+ cells, alpha beta TCR+ cells, gamma delta TCR+ cells, CD4+ cells, and CD8+ cells. 2) The percentage of each T-cell subset in IHL Fr.1 shows an intermediate value between that in the peripheral blood lymphocytes (PBL) and that in the IHL Fr.2. 3) One day after partial hepatectomy, the Thy 1.2+ cells, alpha beta TCR+ whole cells, and CD4+ cells in IHL Fr.2 all showed a transient, yet significant, decrease, but did not reveal any major change in the other fractions. 4) Both the alpha beta TCR dull+ cells and the CD8+ cells showed practically no change after partial hepatectomy in any of the fractions. This indicates that the alpha beta TCR dull+ cell/alpha beta TCR+ whole cell and the CD8+ cell/CD4+ cell ratios show a significant increase 1 day after partial hepatectomy only in the IHL Fr.2. Double-positive cells, which were scarcely found in the spleen of nontreated mice, appeared in the spleen after partial hepatectomy.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMedDate not supplied

Evaluation of prodrugs ability to induce effective ablation of cells transduced with viral thymidine kinase gene.

Transduction of the herpes simplex virus thymidine kinase (HSV-tk) gene into tumor cells followed by treatment with prodrugs is one of the most promising approaches for gene therapy in cancer. The choice of prodrugs is important in order to obtain maximum anticancer effects with minimum adverse reactions. We retrovirally transduced the HSV-tk gene into murine and rat hepatocellular carcinoma (HCC) cells, and investigated their sensitivity to ganciclovir and acyclovir. Retrovirally-mediated HSV-tk transduction did not affect cell proliferation, but led to both ganciclovir- and acyclovir-dependent cytotoxicity in the HCC cells. Ganciclovir exhibited much stronger cytotoxicity on HSV-tk transduced cells than acyclovir. Importantly, HSV-tk transduced cells were completely abrogated at a ganciclovir concentration which was lower than the minimum plasma level achieved in the clinical usage of ganciclovir. Furthermore, HSV-tk transduced cells induced stronger killing of neighboring untransduced cells in the presence of ganciclovir than acyclovir. Ganciclovir may be preferable to acyclovir in the HSV-tk transduction system.

Acyclovir↗

PubMedDate not supplied

Aortitis syndrome due to Takayasu's disease. A guideline for the surgical indication.

Seven cases of aortitis syndrome were surgically treated with good results: Abdominal aortic aneurysm 1, atypical coarctation of aorta 2, aortic valve insufficiency 2, renovascular hypertension 2. Several attentions were paid as following: 1. Operation should be avoided during acute phase of aortitis. 2. Synthetic graft material should be avoided if possible. Autogenous vein is advisable for reconstruction of small-sized artery. 3. Surgical intervention should be performed before the loss of organ function. 4. Hematological consideration is worthwhile to prevent hypercoagulopathy due to aortitis.

Adult↗

PubMedDate not supplied

Bystander effect caused by cytosine deaminase gene and 5-fluorocytosine in vitro is substantially mediated by generated 5-fluorouracil.

Because it appears impossible to transfer toxic genes to all the cells of a cancer, the bystander effect is critical to induce effective antitumor effects. In the present study, possible in vitro mechanisms of the bystander effect by the cytosine deaminase (CD) gene and 5-fluorocytosine (5-FC) were investigated. CD-transduced cancer cells exhibited much higher sensitivity to 5-FC compared to parental cells. CD-transduced cells caused killing of neighboring parental cells in the presence of 5-FC, irrespective of direct cell-to-cell contact. Media conditioned by CD-transduced cells and 5-FC contained considerable amounts of 5-fluorouracil (5-FU) and exhibited profound cytotoxicity on parental cells. Furthermore, this killing ability of conditioned media correlated well with 5-FU levels converted from 5-FC by CD-transduced cells. CD was shown not to be secreted into media from cells. These results indicate that diffusible 5-FU plays the substantially causative role in the in vitro bystander effect caused by the CD/5-FC system.

Animals↗