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Biomedical subjects

K Minami

Publications and source records attributed to K Minami.

At least 19 recordsLinked to original sources
PubMed2006

Unusual case of an 18-year-old heart transplant recipient with endocardial fibroelastosis.

An 18-year-old female Japanese patient who suffered from heart failure and severe pulmonary hypertension was referred to our clinic. The etiology of her cardiomyopathy was unclear. Inhaled prostacyclin therapy resulted in an improvement of pulmonary arterial pressure and allowed us to avoid lung transplantation. Heart transplantation resulted in a complete remission of her respiratory function. Autopsies of the explanted heart revealed massive endomyocardial fibroelastosis. We concluded that endomyocardial fibroelastosis has to be considered a cause of heart failure in young adults with unclear cardiomyopathy.

Adolescent↗
PubMed2006

C4d deposition and clearance in cardiac transplants correlates with alloantibody levels and rejection in rats.

Antibody-mediated rejection of human cardiac transplants is correlated with C4d deposits and macrophage infiltrates in capillaries of endomyocardial biopsies. We produced an antibody to rat C4d to study C4d deposition and clearance in Lewis rats that were sensitized with a blood transfusion from DA rats 7, 14 or 21 days before cardiac transplantation. Cyclosporin A (CsA) immunosuppression was initiated after transplantation at a dose that inhibited graft rejection, antibody production and C4d deposition in unsensitized recipients. Blood transfusion elicited high levels of circulating IgG alloantibodies, predominantly of the complement-activating IgG2b subclass, that peaked 14 days after transplantation. At this time, macrophages accumulated in capillaries, and C4d deposits were diffuse and intense on arteries, capillaries and veins. Grafts that survived 90 days in sensitized recipients still had deposits of C4d that were associated with increased interstitial fibrosis and vasculopathy in arteries. Clearance of C4d was determined by retransplanting DA cardiac allografts from Lewis recipients back to DA recipients. C4d deposits were decreased to minimal levels within 5 days after retransplantation. Thus, C4d deposition is not limited to the capillaries, but extends throughout the arterial tree, and despite formation of a covalent bond, C4d is cleared within days.

Animals↗
PubMed2006

[Small peripheral lung cancer incidentally detected by massive hemoptysis].

A 47-year-old man was admitted to our hospital for treatment of massive hemoptysis. He was intubated and underwent bronchial arterial embolization because of this deteriorating respiratory state and uncontrollable hemoptysis. Computed tomography (CT) of the chest showed a 1-cm nodular shadow in the peripheral apical lobe (S1) of the right lung. He underwent right upper lobectomy for the purpose of preventing re-hemorrhage as well as making the definitive diagnosis of nodular shadow in S1 of the right lung. Intraoperative pathological examination revealed the nodule as adenocarcinoma, and mediastinal lymphadenectomy was added to the right upper lobectomy. The patient recovered uneventfully, and there has been no sign of recurrence for 15 months after the operation.

Adenocarcinoma↗
PubMed2006

Unusual pacemaker implantation through a left sided superior vena cava via anonymous vein after heart transplantion.

We report the case of a 56-year-old male heart transplant recipient, who underwent postoperative pacemaker implantation through a left sided superior vena cava (LSVC) via anonymous vein. We describe our successful management of this case. We suggest that the specific anatomic conditions should be considered in all heart transplant recipients with LSVC if pacemaker implantation is necessary postoperatively.

Cardiac Surgical Procedures↗
PubMed2005

Giant coronary arteriovenous fistula. A case report and review of the literature.

Coronary artery fistulas are rare congenital anomalies. Although they constitute the most common form of hemodynamically significant coronary malformation, the incidence is around 0.002% in the general population. We report the successful surgical closure of a very large coronary artery fistula, originating from the left coronary artery and draining into the right atrium with left-to-right shunt of more than 50% and a review of the literature.

Adult↗
PubMed2005

Frequent detection of hepatitis B core antibodies in heart transplant recipients without preceding hepatitis B infection.

It is unclear whether heart donors positive for hepatitis B core antibodies (anti-HBc) can transfer hepatitis B virus (HBV) infection to immunosuppressed heart recipients, or whether passive transfer of anti-HBc simulates a hepatitis B infection. Therefore, we performed a case-controlled study in 46 heart recipients who all tested negative for hepatitis B antigen (HbsAg), antiHBc, and hepatitis B surface antibodies before heart transplantation. Twenty-three patients (group 1) received hearts from anti-HBc-positive donors, while 23 other patients (group 2) received hearts from anti-HBc-negative donors. After heart transplantation, anti-HBc were present in 65.0% of blood samples among group 1 and 47.8% of the blood samples among group 2 (P > .05). HbsAg was undetectable in blood samples of all patients of both study groups. The immunoglobulin preparation that we regularly use for immune suppression immediately after heart transplantation contained a relatively high concentration of anti-Hbc antibodies. The nearly identical presence of anti-HBc in both study groups indicated that passive transfer via immunoglobulin preparations rather than HBV infection is the cause for the anti-HBc detected in heart recipients. Since only a small volume of blood is transferred with the donor heart, it seems to be rather unlikely that the donor heart might be the source of anti-HBc. In summary, we observed no evidence for HBV infection in those heart recipients who received organs from anti-HBc-positive donors. Moreover, our data demonstrated that the presence of anti-HBc in heart recipients frequently occurs but does not necessarily indicate a preceding HBV infection.

Adult↗
PubMed2005

Anterolateral right thoracotomy for mitral valve procedure after previous coronary artery bypass grafting with functioning internal mammary artery grafts.

AIM: Mitral valve procedure after previous coronary artery bypass grafting (CABG) with functioning internal mammary artery (IMA) grafts has high risk. Especially, internal mammary artery grafts injury may be fatal. The anterolateral right thoracotomy affords easy access to the right atrium with minimal dissection, and minimizes the risk of injury to the IMA grafts. We reviewed our operative technique and outcome after mitral valve procedure after previous CABG with functioning IMA grafts. METHODS: Thirteen patients (11 male and 2 female, mean age of 67.7+/-8.5 years, range 54 to 80 years) underwent mitral valve replacement after previous CABG with functioning IMA grafts from march 1993 to september 2002. The mean interval between the previous CABG and the mitral valve procedure was 3.8 years (range 9 months to 8 years). Four patients had simultaneous mitral valve procedures at initial CABG (2 repairs and 2 replacements). The operation has performed through the anterolateral right thoracotomy, under ventricular fibrillation with moderate hypothermia and without cardioplesia. RESULTS: Mitral valve repair was performed in 3 patients, mitral valve replacement in 10 patients. The mean coronary bypass time was 69.1+/-16.2 min (range 45 to 98 min). The operation time was 159.3+/-29.4 min (range 120 to 219 min). Intensive care unit stay days was 1.9+/-1.6 days (range 1 to 5 days). Peak CK/CK-MB values were 555.1+/-290.4 IU/16.6+/-10.7 IU (range 176 to 924 IU/7 to 44 IU). Peak troponin I value was 9.5+/-5.2 pg/mL (range 4 to 17.8 pg/mL). There was no IMA injury and no early death. Other complications were newly arrhythmia in 3 patients, renal insufficiency in 1 patient, reoperation for bleeding in 1 patient. CONCLUSIONS: Anterolateral right thoracotomy approach, ventricular fibrillation with moderate hypothermia without cardioplesia were a safe and good method for mitral valve operation after previous CABG with functioning IMA graft.

Aged↗
PubMed2004

Range of validity of the Rayleigh hypothesis.

The parameter range over which the Rayleigh hypothesis (RH) for optical gratings might be validly applied to analysis of high power backward wave oscillators has been investigated numerically. It had been pointed out that from a rigorous mathematical viewpoint, RH was only valid for a shallow corrugation of slow wave structure (SWS) such that h K0 <0.448; here, h and K0 are, respectively, the amplitude and wave number of the periodicity in a sinusoidal planar grating. We numerically analyze the electromagnetic fields in the axisymmetric SWS with and without use of RH. The field patterns and eigenfrequency for the SWS are solved numerically for a given k(z) by using the code HIDM (higher order implicit difference method) that is free from the RH. It is found that, for a deep corrugation, h K0 =5 x 0.448, using RH is still valid for obtaining the dispersion relation, although the Floquet harmonic expansion (FHE) fails to correctly represent the field patterns inside the corrugation. Accordingly, there exists a discrepancy between the validity of using RH for obtaining dispersion relations and for an exact convergence of FHE everywhere in the SWS.

Journal Article↗
PubMed2004

Organs from donors with primary brain malignancy: the fate of cardiac allograft recipients.

BACKGROUND: The phenomenon of malignancy transmission from donors with primary brain malignancy (PBM) which is relatively well documented in renal or liver transplant recipients, has not been analyzed in cardiac allograft recipients. METHODS: We reviewed the medical records of 32 cardiac allograft recipients who were transplanted with organs from donors suffering from primary brain malignancies from 1989 to 2003. RESULTS: No case of donor-transmitted malignancy has been reported with a mean follow-up of 80.6 months. CONCLUSIONS: In our experience as well as according to a review of the literature, the risk of tumor transmission from donors with primary brain malignancy to cardiac allograft recipients seems to be extremely low. In the context of the increased donor shortage, we recommend to accept all suitable cardiac allografts harvested from donors with primary brain malignancy provided there are no detectable remote metastases.

Autopsy↗
PubMed2004

Intermittent aortic cross-clamping for isolated CABG can save lives and money: experience with 15307 patients.

BACKGROUND: The ideal myocardial protection during isolated CABG is still a matter of debate. Cardioplegia versus intermittent aortic cross-clamping (IACC) are the main opponents; the following article shows that IACC can be safe, efficient and might be cheaper than cardioplegia. METHODS: Demographics and co-morbidities of 15307 CABG only patients consecutively operated on between January 1993 and October 2001 in the Heart Center in Bad Oeynhausen were assessed by the German Quality Assurance data set and risk-stratified using the EuroSCORE. Outcome (30-day or in-hospital mortality) was compared to the expected EuroSCORE estimation. RESULTS: Expected mortality was 3.25 %, observed mortality was 1.3 %, being significantly lower in the low, medium as well as high risk patients subgroup. Complication rates increased steadily with expected mortality rates. Stroke and myocardial infarction rates for patients with peripheral vessel disease were not higher than in comparable studies. More than 1000000 EUR were saved by lower cardioplegia bills. CONCLUSION: Myocardial protection with intermittent aortic cross-clamping for isolated CABG can be safe, effective, and economically advantageous when compared to cardioplegic solutions.

Cardiopulmonary Bypass↗
PubMed2004

Home monitoring of patients after prosthetic valve surgery -- experimental background and first clinical attempts.

PURPOSE: The purpose of this study was to investigate whether: 1. sound phenomena may be used to detect prosthetic valve dysfunction; 2. clinical and experimental data permit conclusions about alterations in the functional state of mechanical valves; 3. patients can record and pass on signals via Internet. METHODS: 1. We implanted bi-leaflet valves in pigs. By gradually influencing the motion of the tilting discs prosthetic dysfunction could be generated. 2. Thrombosis and lysis of bi-leaflet valves was studied in sheep. This process was documented using echocardiography and acoustically by the Fast Fourier Transformation. 3. Thirty devices were set up and handed out to patients following mechanical valve replacement. All patients regularly sent data to the hospital via Internet, regardless of their location at the time. The data were evaluated by comparing them with the reference file. RESULTS: Animal experiments proved that changes in prosthetic function led to a significant change in sound phenomena. In contrast to echocardiography alterations at an early stage (onset of thrombosis) could be reliably verified. The sensitivity was greater than in echo-control analysis. All patients regularly recorded and passed on their signals. Surveys revealed high acceptance and easy handling of the devices. CONCLUSIONS: Online registration of sound phenomena seems to be suitable for the detection of changes in prosthetic function. This led to the development of the first hand-held device for home monitoring of valve function. Registration of flow, frequency spectrum, and ECG envisaged at the next level opens up potential applications for Internet-based, remote monitoring of cardiac patients.

Animals↗
PubMed2004

Aortoplasty with a bovine venous xenograft for pseudoaneurysm after heart transplantation.

The case was a 54-year-old man after orthotopic heart transplantation with infected pseudoaneurysm of the ascending aorta. The operation was performed with hypothermic circulatory arrest. Pseudoaneurysm was excised and aortoplasty was performed with a bovine venous xenograft patch. Six months after the operation, and 2 years after transplantation, the patient is doing well.

Aneurysm, False↗
PubMed2003

Locoregional immunotherapy of malignant effusion from colorectal cancer using the streptococcal preparation OK-432 plus interleukin-2: induction of autologous tumor-reactive CD4+ Th1 killer lymphocytes.

In total, 16 patients with cytologically proven malignant effusion from colorectal cancer were treated by locoregional administration of the streptococcal preparation OK-432 alone or OK-432 plus the T-cell growth factor interleukin (IL)-2, and the action mechanism of the treatment was studied. A positive clinical response, showing a cytologic disappearance of cancer cells and decrease of effusion, was observed in nine of 11 (82%) patients treated with OK-432 alone and in all five patients treated with OK-432 plus IL-2. Flow cytometric analysis revealed that OK-432 plus IL-2 locally induced acute inflammation-like responses, including serial cellular infiltrations of granulocyte migration within a matter of hours, and activation of macrophages and T lymphocyte involvement within the following days, and that a predominant expansion of CD3+CD4+ lymphocytes (CD: cluster of differentiation) was induced by in vitro stimulation with IL-2 of locoregional cells after the OK-432 administration (OK/IL-2AK cells). The OK/IL-2AK cells produced tumour necrosis factor-alpha and interferon-gamma, but these cells did not produce IL-4 and IL-6. The OK/IL-2AK cells expressed potent killing activity against autologous tumour cells. This activity was abrogated by treatment of the lymphocytes with anti-CD3, -CD4, -TCRalphabeta antibody, and by the treatment of target cells with anti-human leukocyte antigen (HLA)-DR antibody. The OK/IL-2AK cells expressed Fas-L gene, and flow cytometric analysis demonstrated HLA-DR expression in approximately 75% of CEA+ or cytokeratin+ effusion cells. TCRVbeta gene analysis of the OK/IL-2AK cells showed an oligoclonal usage of TCRbeta20, which was also involved in the cytotoxic mechanism of the OK/IL-2AK cells. Single-strand conformational polymorphism analysis demonstrated the clonotypes for the TCRVbeta20 gene, and the CDR3s of the gene were sequenced. The clonotypic PCR using the TCRVbeta20-CDR3 sequences could detect the CDR3-identical TCRs in effusion lymphocytes from the other patients. Taken together, it is suggested that locoregional administration of OK-432 plus IL-2 is highly effective for the management of malignant effusion from colorectal cancer. OK-432 plus IL-2 induces autologous tumour-reactive CD4+ Th1 killer lymphocytes, which recognise tumour antigen(s) presented with HLA class II molecules on effusion tumour cells by means of preferential usage of TCRVbeta20. The clonotypic PCR using the TCRVbeta20-CDR3 sequences may be informative for treating malignant effusion from colorectal cancer using OK-432 plus IL-2.

Adult↗
PubMed2003

INR self-management permits lower anticoagulation levels after mechanical heart valve replacement.

BACKGROUND: The Early Self Controlled Anticoagulation Trial (ESCAT I) showed that anticoagulation self-management after mechanical heart valve replacement decreased complication rates by maintaining INR levels closer to the target range than International Normalized Ratio (INR) home doctor management. The therapeutic range for the INR in that study was between 2.5 and 4.5 for all positions of prosthetic valves. ESCAT II should find out whether lowering the target range for INR self-management would further reduce complication rates. METHODS: ESCAT II is a prospective controlled randomized (valves: St. Jude Medical Standard or Medtronic Hall, treatment: conventional/low-dose) multicenter study with 3,300 patients. We present interim results of 1,818 patients. 908 were categorized as having a low-dose target range, which was INR 1.8 to 2.8 for prostheses in aortic position and 2.5 to 3.5 for prostheses in mitral position or in combined valve replacement. The control group (conventional group) with 910 patients aimed at an INR of 2.5 to 4.5 for all valve positions. RESULTS: In the conventional group, 74% of INR values measured were within the therapeutic range. In the low-dose group, 72% of the values were within that range. The linearized thromboembolism rate (% per patient year) was 0.21% for both groups. The bleeding complication rate was 0.56% in the low-dose regimen group versus 0.91% in the conventional group. CONCLUSIONS: Early onset INR self-management under oral anticoagulation after mechanical heart valve replacement enables patients to keep within a lower and smaller INR target range. The reduced anticoagulation level resulted in fewer grade III bleeding complications without increasing thromboembolic event rates.

Anticoagulants↗
PubMed2003

S-allyl-L-cysteine selectively protects cultured rat hippocampal neurons from amyloid beta-protein- and tunicamycin-induced neuronal death.

S-allyl-L-cysteine (SAC), one of the organosulfur compounds found in aged garlic extract, has been shown to possess various biological effects including neurotrophic activity. In our previous experiments, we found that SAC could protect against amyloid beta-protein (Abeta)- and tunicamycin-induced cell death in differentiated PC12 cells. In the study described here, we characterized the neuronal death induced by Abeta, 4-hydroxynonenal (HNE), tunicamycin, and trophic factor deprivation, and investigated whether and how SAC could prevent this in cultured rat hippocampal neurons. Treatment with SAC protected these cells against Abeta- and tunicamycin-induced neuronal death, which is mediated predominantly through caspase-12-dependent pathway in a concentration-dependent manner. In contrast, it afforded no protection against HNE- and trophic factor-deprivation-induced cell death, which has been shown to be mediated by caspase-3-dependent pathway. SAC also attenuated the Abeta-induced increase of intracellular reactive oxygen species in hippocampal neurons. SAC had no effect on Abeta-induced cell death in cultured cerebellar granule neurons, which was prevented by a caspase-3 inhibitor. These results suggest that SAC could protect against the neuronal cell death that is triggered by ER dysfunction in the hippocampus, and that it has no effect on neuronal cell death that is dependent upon the caspase-3 mediated pathway.

Amyloid beta-Peptides↗