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Biomedical subjects

M Hata

Publications and source records attributed to M Hata.

At least 73 records · Page 4Linked to original sources
PubMed1999

Histologic effects of ruby laser hair removal in Japanese patients.

BACKGROUND AND OBJECTIVE: Hair removal by lasers has recently become a popular method to remove unwanted hair. However, histologic changes in human skin before and after exposure to lasers have not been thoroughly investigated. The aim of this study was to clarify the differences that occur immediately after laser exposure and 1 month after laser exposure. STUDY DESIGN/MATERIALS AND METHODS: Eight adult Japanese volunteers were recruited for this study. They were treated with a long pulsed ruby laser at 20 J/cm(2). A single 3-mm punch biopsy of the laser-treated sites was obtained immediately after laser irradiation and at the 1-month follow-up visit, and they were analyzed using hematoxylin and eosin, PAM, and immunohistological staining. RESULTS: Immediately after laser exposure, hair follicles were very damaged and had extensive eosinophilic degeneration. One month after laser therapy, one type of hair follicle showed cystlike formations with negative proliferating cell nuclear antigen reactions (PCNA). Another type of hair follicle showed follicular mitotic figures with cytoplasmic halos. Early anagen hair follicles were apparently not treated effectively by ruby laser. CONCLUSION: Ruby laser leads to extensive follicular damage, and hair follicles considered to be at early anagen phase were not effectively treated. This may be the reason several courses of laser therapy are required to obtain satisfactory results.

Adult↗
PubMed1999

Cardioprotective effect of orally administered angiotensin-converting enzyme inhibitor against ischemia. Reperfusion injury in the isolated rat heart.

Angiotensin-converting enzyme inhibitors are reported to be cardioprotective against ischemia/reperfusion injury. Few studies have been made, however, on the cardioprotectiveness of orally administered angiotensin-conrerting enzyne inhibitors. Wistar rats were pretreated with oral delapril--30 mg/kg/day in the low-dose group and 90 mg/kg/day in the high-dose group--for one week. Cardiac function recovery was assessed after ischemia/reperfusion in the isolated working heart model. Rat hearts in the high-dose group were also reperfused with a solution containing nitro-L-arginine methyl ester, a nitric-oxide synthase inhibitor. Oral pretreatment of delapril did not affect baseline cardiac function. The percentage of cardiac output recovery for controls was 22 +/- 4.5%, for the low-dose group 44 +/- 6.5% (P < 0.05 versus controls), and for the high-dose group 76 +/- 5.3% (P < 0.001 versus controls and low-dose). Although coronary vascular resistance at the end of reperfusion showed no difference, mean coronary vascular resistance early after reperfusion was significantly lower (P < 0.0001) in both delapril groups than in control. In the high-dose group, reperfusion with L-NAME significantly increased coronary vascular resistance after ischemia/reperfusion and attenuated the cardioprotectiveness of delapril (P < 0.05 versus without nitro-L-arginine methyl ester). We thus found that oral administration of delapril was cardioprotective dose-dependently against ischemia/reperfusion injury. Nitric oxide appeared to be involved in the mechanism behind this cardioprotective effect.

Administration, Oral↗
PubMed1999

Tumor angiogenesis predicts recurrence with normal serum carcinoembryonic antigen in advanced rectal carcinoma patients.

Many studies have established the usefulness of serum carcinoembryonic antigen (CEA) oriented serial monitoring for predicting recurrence and prognosis; however, few studies have so far investigated serum CEA-negative recurrence. The aim of this study was to elucidate the nature of CEA-negative recurrence regarding tumor angiogenesis. Fifty-seven patients with T3/T4 rectal cancer were divided into the two groups according to the serum CEA status. Angiogenesis was defined as the intratumoral vessel count by immunohistochemical staining using CD31. The CD31 count was significantly higher in the recurrent patients in both groups and the ratio of nodal involvement was significantly higher in the recurrent patients of the CEA-negative group. Local recurrence mainly developed in the CEA-negative group; however, the CD31 count did not predict the sites of recurrence nor the relapse period in the both groups. A multivariate analysis showed a high CD31 count >26) to be a prognostic factor not only for recurrence but also for survival (P = 0.001, 0.043, respectively). These results suggest that a high degree of tumor angiogenesis in sections of T3/T4 rectal cancer may therefore be an important predictor for CEA-negative recurrence.

Adenocarcinoma↗
PubMed1999

Ab initio study of the role of lysine 16 for the molecular switching mechanism of Ras protein p21.

Quantum chemical computations using the ab initio molecular orbital (MO) method have been performed to investigate the molecular switching mechanism of Ras protein p21, which has an important role in intracellular signal cascades. Lys(16) was demonstrated to be crucial to the function of Ras p21, and the hydrolysis of GTP to GDP was found to be an one-step reaction. The potential energy barrier of this hydrolysis reaction from GTP to (GDP + P) was calculated to be approximately 42 kcal/mol. The role of GAP (GTPase-activating protein) was also discussed in terms of the delivery of the water molecules required for the hydrolysis.

Animals↗
PubMed1999

Endovascular repair of a descending thoracic aortic aneurysm: a tip for systemic pressure reduction.

A proposed technique for systemic pressure reduction during deployment of a stent graft was studied. A 67-year-old man, who had a descending thoracic aneurysm, was successfully treated with an endovascular procedure. An occluding balloon was introduced into the inferior vena cava (IVC) through the femoral vein. The balloon volume was manipulated with carbon dioxide gas to reduce the venous return, resulting in a transient and well-controlled hypotension. This IVC-occluding technique for systemic pressure reduction may be safe and convenient to minimize distal migration of stent grafts.

Aged↗
PubMed1999

Major organ function under mechanical support: comparative studies of pulsatile and nonpulsatile circulation.

We examined a major organ function during 3 h biventricular assisted circulation after acute myocardial infarction model in the pig. In left ventricular circulation, the outflow cannula was placed in the ascending aorta and an inflow cannula through the mitral valve in the left ventricle. A pump (pulsatile group, Zeon Medical, Inc., Tokyo, Japan and nonpulsatile group, Nikkiso HPM-15, Nikkiso, Inc., Tokyo, Japan) was connected to each cannula. In right ventricular circulation, the outflow cannula was placed in the pulmonary artery and an inflow cannula in the right ventricle. The right ventricular circulation was supported by a nonpulsatile pump (Nikkiso HPM-15). The items measured were the regional blood flows of the cortex and medulla in the kidney, white matter and gray mater in brain, and liver; renal arterial flow; carotid arterial flow; portal vein flow; common hepatic arterial flow; arterial ketone body ratio (AKBR); and lactate/pyrubic acid (L/P). In the pulsatile group, the renal cortical blood flow increased, and the medulla blood flow decreased. On the other hand, in the nonpulsatile group, both regional blood flows decreased. That means that in the pulsatile assisted group intrarenal redistribution improved rather than in the nonpulsatile assisted group. In addition the liver regional blood flow, AKBR, and L/P showed significant differences between the pulsatile and nonpulsatile groups. On the other hand, the white matter and gray matter regional blood flows and carotid arterial flow did not show significant differences between the groups. The results of our study indicated that pulsatile circulation produced superior circulation in the kidney and liver, and microcirculation on the cell level was superior as well in early treatment of acute heart failure.

Animals↗
PubMed1999

Cytokine and endothelial damage in pulsatile and nonpulsatile cardiopulmonary bypass.

Recently, several types of centrifugal pumps have been widely used as the main pumps for cardiopulmonary bypass (CPB). However, according to the results of our experimental studies, after cardiogenic shock, pulsatile flow was effective in maintaining the functions and microcirculations of end organs, especially those of the liver and kidney. To estimate the effectiveness of pulsatility during CPB, cytokine and endothelin and other metabolic parameters were measured in clinical pulsatile and nonpulsatile CPB cases. From March to May 1997, CPB was performed in 18 elective cases (14 ischemic and 4 valvular disease). In 9 cases, pulsatile perfusion was achieved by the Jostra HL20, which is a newly developed CPB pump (Group P). A nonpulsatile centrifugal pump was used in 9 patients (Group NP). In both groups, as chemical and metabolic mediators, interleukin-8 (IL-8), endothelin-1 (ET-1), and plasma free hemoglobin were measured before and during CPB, and 0.5, 3, 6, 9, 18 h after weaning from CPB. This pulsatile CPB pump could be very simply and easily controlled and could easily produce pulsatile flow. There were no significant differences in CPB time (CPBT), aortic cross clamp time (ACCT), mean aortic pressure, or pump flow during CPB between the both groups. The ET-1 level of Group P was significantly (p < 0.05) lower than that of Group NP 9 h after CPB weaning. The IL-8 level of Group P also showed a lower value than that of Group NP. As for plasma free hemoglobin, there were no significant differences between the groups. These results suggested that even in conventional CPB, pulsatility was effective to reduce endothelial damage and suppress cytokine activation. It may play a important role in maintaining the functions and microcirculations of end organs during CPB.

Aged↗
PubMed1999

Effects of phosphodiesterase inhibitors after coronary artery bypass grafting.

The aim of this study was to estimate the postoperative effects of phosphodiesterase (PDE) inhibitors (milrinone and olprinone) after coronary artery bypass grafting (CABG). To prevent hypotension caused by the PDE inhibitors, low dose of catecholamines were used concomitantly. A total of 34 elective CABG cases were tested. In 12 cases, 0.25 microg kg(-1) min(-1) of milrinone, 3 microg kg(-1) min(-1) of dobutamine (DOB) and dopamine (DOA) were used concomitantly (Group-M). In another 10 patients, 0.1 microg kg(-1) min(-1) of olprinone and the same doses of the catecholamines were infused (Group-O). As a control, the same doses of DOA and DOB only were administered in 12 patients (Group-C). When the pump flow of the cardiopulmonary bypass (CPB) decreased to half, these drugs were given in all groups. Hemodynamics were recorded before CPB, just after the operation, and 3, 6, 12, 24, 48 and 72 h after the operation. Both milrinone and olprinone increased the cardiac index and decreased systemic vascular resistance to almost the same degree. Olprinone decreased mean aortic and pulmonary artery pressures, and also significantly reduced the preload of both right and left heart compared with milrinone. Significant hypotension was not detected due to the concomitant usage of low-dose catecholamines. This concomitant usage of PDE inhibitors and catecholamines allowed easy weaning from CPB, demonstrating excellent hemodynamics after CABG. Good oxygen demand and supply balance were maintained in peripheral tissue. These results suggest that these new PDE inhibitors may be effective not only for weaning from CPB but also for post-cardiotomy cardiogenic shock.

Aged↗
PubMed1999

Should use of the internal thoracic artery be avoided under conditions of low free flow? Postoperative hemodynamic assessment using pulsed Doppler echocardiography.

There are cases in which it is thought advisable to avoid the use of the left internal thoracic artery (LITA) in coronary artery bypass grafting (CABG) due to its low free flow (FF). However, even though the LITA flow is very low, anastomosis without any further maneuvers intraluminally is recommended. The present study investigated the clinical results of CABG, using a LITA with low FF. The 60 cases of CABG were divided into 2 groups: (i) Group L (n = 23), in which LITA FF was less than 20 ml/min; and (ii) Group H (n = 37) in which it was more than 20 ml/min. A comparative study on the basis of coronary angiography and pulsed Doppler echocardiography was performed. In both groups, no LITA graft occlusion was identified, and the 'string sign' was also absent. In the LITA blood waveform, all cases exhibited a biphasic pattern with a higher mid-diastolic and a lower end-systolic component. There were no significant differences in the LITA flow diastolic peak velocity, velocity time integrals and the diastolic/systolic peak velocity ratios. These results suggest that the LITA can be used for CABG even when the free flow is less than 20 ml/min.

Aged↗
PubMed1999

Doppler features of occlusion of the internal thoracic artery due to preoperative branch embolization.

A 61-year-old male was referred to the surgical ward by cardiologists because of a diagnosis of unstable angina with 3-vessel disease. On preoperative left internal thoracic arteriography, a large first intercostal branch was found at the proximal portion. Selective arterial embolization of the branch of the left internal thoracic artery (LITA) was carried out preoperatively. At 2 days after embolization, the Doppler peak flow velocity and diameter of the LITA were increased and enlarged compared with before the procedure. However, a large reverse wave following after the first systolic peak flow of the LITA was newly detected after embolization. Upon operation, the LITA was found to be occluded at the 2nd intercostal space due to thrombus formation. Therefore, the right internal thoracic artery was anastomosed to the left anterior descending artery and coronary reversed saphenous vein grafts were joined to segment 4PD of the right coronary artery. The postoperative course was uneventful. There has been no previous report of an LITA branch being embolized preoperatively. It was possible to diagnose the graft problem by detecting the altered Doppler wave form of the LITA.

Angina Pectoris↗
PubMed1999

Sildenafil induced priapism.

A 53 year-old Japanese man was referred to our hospital for persistent priapism, which had been induced by 200 mg (usual dose 25-50 mg) of sildenafil citrate (Viagra) three days earlier. He had a history of erectile dysfunction and had undergone penile injection therapy elsewhere; however, he had not used injection therapy this time. He obtained sildenafil personally without a doctor's prescription. He had not taken any other drugs that affect the metabolism of sildenafil, nor did he have any medical complications that might induce priapism. Since needle aspiration and irrigation were ineffective as first line therapy, surgical treatment was indicated to relieve the condition; a incision of tunica albuginea of both corpora cavernosa was made, and vigorous irrigation of saline washed out the blood clots. This is the first case report of priapism induced by sildenafil. Although this drug can be obtained through private commerce, it should be used under professional guidance as its abuse may lead to severe morbidity.

Humans↗
PubMed1999

[The use of predeposited autologous blood transfusion for radical prostatectomy and total cystectomy].

BACKGROUND: To avoid homologus blood transfusion, we performed the operation for intra-pelvic malignancy with predeposited autologus blood using recombinant human erythropoietin (rH-EPO). MATERIALS AND METHODS: The seven cases of radical prostatectomy and the 15 cases of total cystectomy were analyzed retrospectively. All cases were given ferrons sulfate/200 mg of iron orally every day to the day before the operation and treated with 24,000 unit of rH-EPO subcutaneously every week. The target volumes of preoperative autologus blood collection were 800 to 1,000 ml and 800 to 1,200 ml for radical prostatectomy and total cystectomy, respectively. For each case, 400 ml blood was collected once a week. RESULTS: In cases of radical prostatectomy, the preserved blood volume was 885.7 +/- 157.4 ml and 6 out of 7 operations were successfully performed without additional homologus blood transfusion (85.7%). In total cystectomy, the preserved blood volume was 1,033.3 +/- 167.6 ml and 14 out of 15 operations were successfully performed without additional homologus blood transfusion (93.3%). The bleeding volume during operation showed no significant difference compared to control group where used homologus blood transfusion. Postoperative courses were uneventful and there encountered no severe side effects and complications in all our procedures. CONCLUSIONS: Our study indicates that in cases of radical prostatectomy and total cystectomy, the operation with predeposited autologus blood using rH-EPO is possible to be performed in safe. The effect on long term prognosis of malignancy is not clear, however, this technique is helpful able to avoid hazardous issues related to homologus blood transfusion during the operation.

Aged↗
PubMed1999

Spontaneous recanalization of postoperative severe graft stenosis. What is the cause and prognosis of the "string sign" in the internal thoracic artery?

A 68-year-old female with unstable angina was treated surgically. She was referred to the surgical ward by cardiologists because of a diagnosis of unstable angina with three vessel disease. On a coronary angiogram (CAG), 90% stenoses were found in the left anterior descending coronary artery (LAD), circumflex (CX), and right coronary artery (RCA). She received elective coronary artery bypass grafting (CABG), in which the left internal thoracic artery (LITA) was anastomosed to the LAD and reversed saphenous vein grafts (SVG) were made to segment 12 of the CX, and segment 4PD of the RCA, respectively. The postoperative course was uneventful, but postoperative early graftgraphy revealed distal narrowing of the LITA graft as the so-called "string sign". However, one year post surgery, the LITA string sign was not found and its patency had markedly improved on the second graftgram. It is reported that the LITA "string sign" might cause late graft occlusion. However, this LITA graft evidently enlarged the size and increased the flow of the artery in proportion to myocardial blood demand. To our knowledge, it has not been reported that an in situ LITA string sign on postoperative early graftgram has disappeared in the late phase. We hypothesize that the LITA string sign might be caused by several different factors such as flow competition, spasm, and/or technical problems. In any event, the LITA string sign does not cause graft occlusion in the late postoperative period in every case.

Aged↗
PubMed1999

[Effectiveness of low dose continuous infusion of alpha-hANP from the start of cardiopulmonary bypass].

In this study, we used alpha-human atrial natriuretic peptide (hANP) from staring on cardiopulmonary bypass and evaluated for the hemodynamics, ANP, renin activity, aldosterone, urine volume, glomerular filtration rate (GFR) and so on. The hANP decreased renin activity, aldosterone, systemic vascular resistance and increased urine volume, GFR and use of furosemide and KCL were decreased. We concluded that hANP was effective for hemodynamics, renal function and hormonal release on intra and post-operation in cardiac surgery, and low dose continuous infusion of alpha-hANP from staring on cardiopulmonary bypass will be expected as a newly application.

Aldosterone↗
PubMed1999

Surgical treatment of 22 cardiac myxomas: A review.

Twenty-two cases of cardiac myxomas were reviewed. The patients were 8 men and 14 women ranging in age from 12 to 73 (mean: 50.8 +/- 16. 6) at operation. They suffered from dyspnea, palpitation, and cough, similar to mitral disease symptoms, and cerebral emboli in 6 patients (30%) with left atrial myxomas. Echocardiography, especially transesophageal, was useful in diagnosing cardiac tumors and location. In 20 cases, tumors were at the left atrium and at the right in 2. Left atrial myxomas were approached through a septal incision in 17 cases; a large circular incision of the biatrium was used in 3 patients with large tumors or mitral regurgitation. Left atrial myxomas were attached to the atrial septum in 17 cases, the posterior wall of the left atrium in 2, and near the posterior commissure of the mitral valve in 1. Right atrial myxomas were attached to the atrial septum in 1 and posterior wall beside the inferior vena cava in 1. Resected myxomas weighed from 10 to 90 (mean: 39.1 +/- 19.1) g. No correlation was seen between features such as neurologic symptoms, feeding artery on coronary angiography, or functional status and tumor weight. No recurrence was seen.

Adolescent↗