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Biomedical subjects

T Katsumata

Publications and source records attributed to T Katsumata.

At least 127 records · Page 7Linked to original sources

[Combined operations of coronary artery bypass grafting using the right gastro-epiploic artery and other abdominal operation].

We carried out combined operation of coronary artery bypass grafting using the right gastro-epiploic artery (GEA) and other abdominal operation in four patients. The abdominal operation were one total gastrectomy for double early gastric cancer, one bypass with Y-shaped graft for arteriosclerosis obliterans in iliac region and two peritoneal dialysis for chronic renal failure. There were no early death. The postoperative course was uneventful without any mediastinitis or other infectious events. Doing careful maneuver, we can use the GEA for grafts in such cases.

Aged↗

[Curative report of post sternotomy mediastinitis due to bacterofungal infection].

We describe a 72-year-old patient with mediastinitis caused by Methicillin-resistant Staphylococcus aureus (MRSA) and Candida albicans after median sternotomy who was successfully treated with wound closure with pectoral musculocutaneous flap and closed continuous mediastinal irrigation. The irrigation device consisted of two pairs of irrigation and suction tubes which placed upper and lower half of mediastinum respectively, in which high rate irrigation technique (200 ml/h) was employed using 0.01% of Vancomycin hydrochloride as a base agent and additional 0.1% of Povidone-iodine in early phase and 0.01% of Fluconazole in late phase. After 12-days irrigation, the drainage culture turned negative and the wound was healed and tomographically granulated. High rate irrigation with sufficient concentration of antimicrobial agents selected according to each organism sensitivity could eliminate redundant irrigation and contribute to avoid antimicrobial toxication. We experienced also another four cases (two caused by MRSA, two caused by Serratia liquefaciens) treated successfully with this technique. These results led us to believe that continuous mediastinal irrigation technique could be carried out with safe and effectiveness so far as high rate irrigation with low concentration of Povidone-iodine is employed.

Aged↗

Effect of substituting fluorine for hydrogen at C-26 and C-27 on the side chain of 1,25-dihydroxyvitamin D3.

Previous reports have demonstrated that introduction of fluorine atoms at C-26 and C-27 of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) results in the potentiation of various aspects of some biological activities. The higher biological activities of 26,26,26,27,27,27-hexafluoro- 1,25-dihydroxyvitamin D3 (26,27-F6-1,25-(OH)2D3) were accounted for in part by a decrease in metabolic inactivation via the 26- and 27-hydroxylation pathways. In addition to 26,27-F6-1,25-(OH)2D3 not being hydroxylated in the 26 and 27 positions, it did not undergo 24-hydroxylation despite a significant induction by 26,27-F6-1,25-(OH)2D3 of 24-hydroxylase activity in the HL-60 cell system. Another fluorinated vitamin D3 analog, 26,26,26,27,27,27-hexafluoro-1 alpha-hydroxyvitamin D3 (26,27-F6-1 alpha-OH-D3) may not undergo 25-hydroxylation as efficiently as 1 alpha-OH-D3 in vivo because a rise in serum 26,27-F6-1,25-(OH)2D3 levels after injection of 26,27-F6-1 alpha-OH-D3 was delayed significantly with a much smaller amplitude. Furthermore, 26,26,26,27,27,27-hexafluoro-1,23(S),25-trihydroxyvitamin D3 retained full activity in the induction of HL-60 cell differentiation even after 23(S)-hydroxylation, in contrast to 1,23(S),25-(OH)3D3. These data suggested that substitution of fluorines for hydrogens at C-26 and at C-27 positions may result in alteration in chemical reactivity and/or conformation of C-23, C-24 and C-25 positions of the 1,25-(OH)2D3 molecule.

Animals↗

Erythropoietin receptor binds to Friend virus gp55 through other membrane components.

Direct interactions of Friend spleen focus-forming virus glycoprotein gp55 with either erythropoietin receptor (EpoR) or interleukin (IL)2 receptor beta chain (IL2R) (but not with IL3 receptor) have been reported to induce factor-independent prolonged proliferation of erythroid or lymphoid cells. In order to clarify the molecular mechanism by which EpoR-gp55 complex transmits an aberrant growth signal in the absence of erythropoietin, various chimeric receptors constituted with IL2R, EpoR or IL3 receptor were constructed. It was found that coexpression of gp55 and the chimeric receptors containing the cytoplasmic domains of EpoR and the extracellular domains of IL3 (or IL2) receptor in IL3-dependent Ba/F3 cells results in factor-independent growth. Since gp55 in cell membrane has only a two amino acid tail in the cytoplasmic domains and thus cannot interact with EpoR in cytoplasm, our data suggest that gp55 does not bind EpoR directly but interacts with EpoR through third membrane component(s).

Animals↗

Intra-arterial aortoinfundibuloplasty: hemodynamic and anatomical study of a new method for the enlargement of a small aortic annulus.

A new method for prosthetic valve replacement in a small aortic annulus is described. An anatomical examination showed that the intra-arterial approach via the main pulmonary artery made it feasible to incise the aortopulmonary septum at the middle point of both coronary ostia and also to relieve left ventricular outflow tract obstruction with a two-dimensional patch. The pressure study in three mongrel dogs demonstrated that 6-mm augmentation of the host aortic annulus with this procedure made no significant difference in the pressure gradient between the right ventricle and the main pulmonary artery before and after operation. The right ventricular end-diastolic pressure did not show any significant change with respect to hemodynamics. It is expected from these results that our procedure could be used for the treatment of various types of left ventricular outflow tract stenosis without affecting the hemodynamics and, especially, right ventricular function.

Animals↗

Health problems among Vietnamese refugees resettled in Japan.

A medical examination of 932 Vietnamese refugees was conducted within 1 month of their resettlement in Japan between 1989 and 1991. A variety of abnormalities were detected, including parasitic disease (78% prevalence), anemia (12%), HBsAg positive state (14%), liver dysfunction (10%), hypertension (0.8%), active pulmonary tuberculosis (2%) and syphilis (0.7%). These rates were still as high as the prevalence in previous studies of earlier immigrants from Vietnam. The high frequency of infectious diseases in recent Vietnamese refugees compared with the Japanese community leads to a recommendation for continuing medical examinations and treatment for new Vietnamese refugees.

Adolescent↗

[A case report of malignant mesothelioma].

A case of successful surgical removal of a primary malignant pericardial mesothelioma was reported. The patient was a 79-year-old man with a complaint of dyspnea at rest. Chest X-ray study showed enlargement of upper mediastinum. Echocardiogram, computed tomography and MRI revealed a giant mass occupying the pericardial space anterior to the heart with marked pericardial effusion. The right ventricle was severely compressed with this tumor. Total resection of the tumor was achieved because the tumor was localized without invading surrounding tissue. The tumor was 17 x 12 x 10 cm in size and 900 g in weight. Rare growth fashion as a distinct isolated mass was a key of successful outcome.

Aged↗

[A case report of BWG syndrome in an elderly patient performed with mitral valve replacement 11 years after single CABG].

A 46-year-old female who had undergone single CABG for BWG syndrome 11 years ago was referred to our hospital for paroxysmal atrial fibrillation. The roentgenogram showed slightly cardiomegaly and the enlargement of LA. Ischemic changes of ECG appeared at I, aVL, V5, V6, as inverted T wave, and low voltage R wave at V1-V4, but non Q wave. The thallium-201 emission computed tomogram at exercise revealed poor perfusion at apical region without redistribution pattern. Catheterization showed mitral regurgitation (grade III), big right coronary artery (RCA) arising from aorta, rich collateral to poor left coronary artery (LCA), and bypass graft was obstructed. The proximal end of LCA was closed, and didn't arise from both pulmonary artery and ascending aorta. In this cases, MVR only without re-CABG to LCA was selected and performed. Postoperative course was uneventful. The result of this case suggested that MVR was an effective surgical procedure for MR of BWG syndrome in the adult case and it was better to add CABG to LCA as much as possible if the ischemic region was large.

Coronary Artery Bypass↗

[Late malfunction of the Björk-Shiley valve prosthesis due to Delrin disc defacement].

A 55-year-old woman eighteen years after mitral valvular replacement with Delrin disc Björk-Shiley valve prosthesis underwent a reoperation of prosthetic valve replacement for the prosthetic malfunction due to disc defacement. The patient suffered from faintness and vertigo at rest. An echocardiographic examination showed a moderate mitral insufficiency with a normal disc movement. Precise examination on the removed prosthesis revealed accelerated defacement of disc margin which made the ring-disc clearance up to 0.35 mm and strut-shaped groove formation on the inlet surface of the disc occluder. These findings suggested a pronouncedly earlier disc wear than predicted by Björk and co-workers. We concluded, therefore, that a patient undergone a valve replacement with Delrin disc Björk-Shiley valve should be examined periodically by echocardiography even though being without any symptoms.

Female↗

[Scintigraphic comparison of graft patency between the left internal thoracic artery and saphenous vein graft after coronary bypass surgery].

Graft patency after coronary bypass surgery (CABG) was evaluated with stress 201-thallium scintigraphy (stress 201Tl) in 26 cases, including 13 cases using the left internal thoracic artery (LITA group) in situ and 13 cases with saphenous vein graft (SVG group). All of them had effort or unstable angina caused by LAD lesion without apparent infarction. Stress 201Tl using a symptom-limited, graded bicycle exercise test was performed before CABG and 1 month, 6 months to 1 year, 1 year to 1.5 years after surgery. Five tomographic images including the apical side of the area fed by the bypass anastomosed to LAD in short axial sections were picked out and piled up. Fan-shaped ROI was made on this area and % Tl uptake was calculated using the following formula. 201Tl counts in ROI--Background counts/Maximum counts--Background counts x 100 (%) The normal % Tl uptake calculated in the control group (n = 11) in this ROI was 68.2 +/- 4.8%. Preoperative % Tl uptake showed 49.3 +/- 0.2% in the LITA group and 54.3 +/- 13.2% in the SVG group. % Tl uptake of the SVG group 1 month after CABG was slightly higher than that of the LITA group, (62.0 +/- 7.0% vs. 56.3 +/- 7.6%). However 6 months to 1 year after, % Tl uptake of the LITA group increased to 60.8 +/- 6.4%, inspite of a tendency on the decrease of that in the SVG group, (59.0 +/- 8.5%), and further more, 1 year to 1.5 years after CABG, increased to 62.3 +/- 5.1% near the normal % Tl uptake of the control group and the SVG group decreased to 58.8 +/- 6.8%. This result suggested that arterial in situ bypass graft might have an auto-regulation and "growing property" corresponding to flow demand, and this helps the excellent long-term patency of arterial bypass grafts.

Adult↗

[Efficacy of myocardial preservation using GIK solution for prolonged ischemic heart].

The efficacy of myocardial preservation using GIK solution combined with continuous cold blood perfusion was assessed in patients with prolonged ischemia. Fifteen patients receiving more than 4 hours' ischemia were divided into two groups. In Group A, seven patients were associated with severe aortic regurgitation and showed increased left ventricular volume of more than 60 mm in LVDd and 45 mm in LVDs. In Group B, eight patients had a normal left ventricular volume of less than 60 mm in LVDd and 45 mm in LVDs echocardiographically. There was no significant difference in ischemic time, or preoperative hemodynamic parameters between the two groups. The postoperative cardiac index was 2.93 +/- 0.87 in Group A and 4.3 +/- 0.8 in Group B (p < 0.01). The postoperative shortening fraction was 0.17 +/- 0.01 in Group A, 0.43 +/- 0.12 in Group B (p < 0.01). These parameters significantly deteriorated in Group A compared to Group B. Released enzymes (GOT, CK-MB) were significantly increased in Group A with prolonged ischemic time. In conclusion, postoperative cardiac function after 4 hours' ischemia using GIK solution deteriorated in the patients with a dilated heart due to aortic regurgitation.

Aortic Valve Insufficiency↗

[Newly-developed catheter for cardio-renal assist during intraaortic balloon counterpulsation].

A new catheter was developed for the cardio-renal assist during intra-aortic balloon counterpulsation. The catheter consists of both a large balloon of conventional IAB (TMP balloon) located at the distal end of the catheter and an additional small balloon 10 cm distant from the large balloon with common lumen and single shaft. Experimental study was carried out in the mock circulatory system simulating the descending aorta employing a conventional IAB catheter as a control. It was demonstrated that the flow in the mid portion between both balloons could be increased maximally by as much as 28% of that of the control under the continuous flow and 214% under the pulsatile flow. The double balloon catheter was considered to improve the renal perfusion as well as the coronary perfusion.

Assisted Circulation↗

[Efficacy of myocardial preservation using HTK solution in continuous 120 min cross-clamping method--a comparative study with GIK method].

The aim of this study is to investigate the efficacy of HTK solution in the 120 minutes cross-clamping method in comparison with conventional intermittent cardioplegia using GIK solution. Fifty-four open heart surgery were performed with cardioplegic solution using either HTK solution (HTK) or GIK solution (GIK). In the HTK, HTK (3L) was infused for the initial dose and 1L was added every 60 min after 120 min of cross-clamping. In GIK, 1L of GIK solution was intermittently infused initially and then every 30 min together with continuous cold blood perfusion. The effect of two cardioplegic solution was evaluated by postoperative cardiac function (CI, %SF), released enzymes (CPK), histology and dosage of catecholamine. Postoperative CI was 3.67 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). % SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 0.76 in HTK, and 4.34 +/- 1.04 in GIK (NS). %SF was 26.0 +/- 5.26 in HTK and 25.6 +/- 9.2 in GIK (NS). The CK-MB (IU/dl) level after reperfusion was significantly decreased in HTK at 60 and 180 min after reperfusion. Histology at 60 min of ischemia revealed a significant increase of edema of mitochondria in GIK. Postoperative catecholamine dose was 2.65 +/- 1.3 in HTK and 10.3 +/- 3.4 in GIK (p < -0.01). PH of myocardium was well maintained around 7.4 during cross-clamping in HTK, however, it was decreased in GIK. In conclusion, The HTK method offers a reliable cardiac protection due to effective buffering using Histidine in comparison with GIK.

Cardioplegic Solutions↗