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Biomedical subjects

H Akamatsu

Publications and source records attributed to H Akamatsu.

At least 73 records · Page 4Linked to original sources
PubMed1997

[Thoracoscopic resection of mediastinal parathyroid adenoma with cyst and hyperparathyroidism--a case report].

A 51-year-old woman was admitted because of general fatigue assumed to be due to climacteric disturbance. Laboratory examinations suggested a diagnosis of hyperparathyroidism based on high serum levels of Ca, intact PTH, and high-sensitivity PTH. No abnormalities were found in the cervix. Chest X-ray films and CT scans showed a mass measuring 4 cm in the right postero-upper mediastinum. The tumor was positive on a parathyroid scintigram, and was diagnosed as a mediastinal parathyroid adenoma with hyperparathyroidism. Operative findings showed a tumor surrounded by the superior vena cava, vagus nerve, azygos vein, and brachiocephalic artery. Careful resection of the hypervascular tumor from surrounding tissues was performed using a thoracoscopic technique alone. The postoperative course was uneventful. Serum values of Ca, intact PTH, and high-sensitivity PTH decreased to within normal ranges. after surgery. Pathohistological study confirmed the diagnosis of parathyroid adenoma including a cyst caused by degeneration of the tumor.

Adenoma↗
PubMed1996

Suppression of transformed phenotypes of human fibrosarcoma cells by overexpression of recombinant fibronectin.

Loss of fibronectin (FN) from the cell surface has been shown to be closely associated with malignant transformation of cells. To elucidate the role of the FN matrix in the modulation of malignant phenotypes, we overexpressed a full-length cDNA encoding plasma-type FN in HT1080 human fibrosarcoma cells. The cells overexpressing FN adopted a more flattened morphology and deposited a moderately developed FN matrix both in vitro and in vivo, although the level of expression of integrin alpha5beta1 remained unchanged. FN-overexpressing cells exhibited a reduced cell motility on the substratum and grew poorly when injected s.c. into nude mice. Overexpression of FN also suppressed the ability of the tumor cells to proliferate in soft agar, whereas the suppression was reversed by inclusion in soft agar of the Arg-Gly-Asp (RGD)-containing peptide and adhesion-blocking antibodies against the central cell-binding domain of FN. Neither cell motility nor growth potential was altered by overexpression of a truncated form of FN lacking the central cell-binding domain. These results, taken together, indicate that increased deposition of FN in the pericellular matrix per se can suppress the motility and growth potential of tumor cells through interaction with RGD-recognizing integrins, most likely alpha5beta1.

Animals↗
PubMed1996

Role of cytokines, tyrosine kinase, and protein kinase C on production of superoxide and induction of scavenging enzymes in human leukocytes.

We investigated the effects of proximal modulators of cytokines, tyrosine kinase (TK), and protein kinase C (PKC) on reactive oxygen species (ROS) generation and the induction of scavenging enzymes, superoxide dismutase (SOD), catalase, and glutathione peroxidase (GSH-Px) of human neutrophils and lymphocytes, by using IL1-alpha, TNF-alpha, and IFN-gamma and neutralizing antibodies to these cytokines. Inhibitors of TK (ST638 and herbimycin) or PKC (H-7, calphostin, and staurosporine) were also used. The results revealed that both (O2)- generation stimulated by five different agents (opsonized zymosan, A23187, PAF, PMA, and fMLP) and the inductions of all three scavenging enzymes were potentiated by priming with TNF-alpha. In contrast, both (O2)- generation and enzyme induction were attenuated by priming with IL1-alpha, with the exception of PMA-stimulated (O2)- generation. IFN-gamma decreased (O2)- generation but increased scavenging enzyme induction. Antibodies to all three cytokines and all the TK and PKC inhibitors decreased (O2)- stimulated by most agents, but markedly enhanced (O2)- levels stimulated by PAF. Induction of all three enzymes was enhanced equally by low concentrations of each of the three anticytokine antibodies, while each of the TK or PKC inhibitors decreased induction of SOD and GSH-Px and increased catalase induction. These results suggest that both ROS generation and scavenging enzyme induction are controlled in complex ways by the actions of these three proximal mediators. This supports our hypothesis that disturbances in the regulation of early events of cell activation can lead to oxidative tissue injury.

Adult↗
PubMed1996

Effects of right ventricular failure on renal function during pneumatic left ventricular assist.

In an experiment dog model of acute biventricular failure, the effects of left ventricular (LV) assist on renal hemodynamics and function were evaluated. After the induction of severe cardiac failure by multiple ligation of the coronary arteries, LV assist with a 40 ml pneumatic pulsatile pump was initiated, and the aortic flow was maintained at control values. The right atrial pressure (RAP) rose to 21.3 mm Hg with the appearance of profound right ventricular (RV) failure. Renal arterial blood flow (RAF) decreased to about 60% of the control value after 2 h of LV assist. The urine volume decreased and renal function deteriorated progressively. RV assist decreased the RAP to 4.8 mm Hg, and the reduced RAF recovered. After 3 h of RV assist, the RAF returned to initial values and the urine volume increased, but renal function did not recover. Advanced biventricular failure with elevated RAP during LV assist reduced renal perfusion and impaired renal function and may be an indication for early RV assist.

Animals↗
PubMed1996

Changes of intraaortic balloon volume during pumping in a mock circulation system.

The effects of hemodynamic changes on intraaortic balloon (IAB) volumes were studied experimentally using a helium tachometer in a mock circulatory system. The IAB volume decreased with increases in the heart rate and mean aortic pressure, but the degree of reduction in the IAB volume was different among 4 commercially available IAB drivers. Improvements in IAB consoles are needed to compliment the progress made in percutaneous techniques for IAB insertion resulting in smaller balloons.

Arrhythmias, Cardiac↗
PubMed1996

Staging of primary lung cancer by computed tomography-guided percutaneous needle cytology of mediastinal lymph nodes.

BACKGROUND: The necessity of an easy and noninvasive technique to evaluate mediastinal node status cytopathologically is considered. METHODS: Eighteen cases of clinical N2 primary lung cancer were examined. Under local anesthesia, the lymph node was punctured with a 19-gauge needle using intermittent computed tomographic monitoring, and samples were studied cytologically. Subcarinal (no. 7) nodes and lower paratracheal (no. 4) nodes were sampled using the paraspinal posterior approach. Anterior mediastinal (no. 6) nodes were sampled using the parasternal anterior approach. Node status was diagnosed pathologically at operation. RESULTS: Number 7 nodes were examined in 11 cases, no. 4 nodes in 5 cases, and no. 6 nodes in 2 cases. Malignant cells were detected in 14 cases. Fourteen cases were diagnosed as true positive, 2 cases as true negative, and 2 cases as false negative. The sensitivity, specificity, and accuracy of this method were 88%, 100%, and 89%, respectively. Pneumothorax developed in 4 cases (22%). CONCLUSIONS: Computed tomography-guided percutaneous needle cytology of mediastinal lymph nodes is useful for staging primary lung cancer. Because this is a small series, additional studies are necessary.

Adenocarcinoma↗
PubMed1996

[Selection of staple for closure of the lobar bronchus].

From January 1984 to October 1995, Stapling of lobar bronchus excluding middle lobe was investigated in 335 patients with lung cancer. We used routinely the 3.5 mm staple in the previous term and the 4.8 mm staple in the latter term. The stapling with 3.5 mm staple was performed in 220 patients. The stapling failed in the pressure proof test intraoperatively in 8 patients and bronchopleural fistula occurred postoperatively in 4 patients. The bronchus was cut or destroyed by the staple in most of them. The stapling with 4.8 mm staple was performed in 115 patients. The stapling failed in the pressure proof test intraoperatively in one patient because of loose closure of the bronchus. Bronchopleural fistula did not occur postoperatively. In conclusion, the 4.8 mm staple is a better choice for closure of the lobar bronchus except for a small woman or middle lobe.

Adult↗
PubMed1996

Antimicrobial effects of phototherapy and photochemotherapy in vivo and in vitro.

We investigated the antimicrobial effects of phototherapy and photochemotherapy in vivo and in vitro. First, Staphylococcus aureus samples were obtained using stamp agar medium from inflammatory lesions of 29 adult patients with atopic dermatitis before and after a single photochemotherapy. Therapy was oral PUVA (30 mg 8-methoxypsoralen, 8MOP plus 5J/cm2 UVA), topical PUVA (0.3% 8MOP plus 200 mJ/cm2 UVA) or UVB (80 mJ/cm2) irradiation. The number of S. aureus on the lesions was significantly reduced, even after a single treatment with all therapies. Reductions (mean +/- SD) were 69.3 +/- 26.9%, 76.3 +/- 31.3% and 83.8 +/- 18.5%, respectively. Secondly, we investigated the effect of PUVA (0.001% 8MOP plus 10, 20, 30, 40, or 50 mJ/cm2 UVA) and UVB (10, 30, 50, or 100 mJ/cm2) irradiation on the proliferation of S. aureus in vitro. PUVA and UVB treatment markedly inhibited the proliferation in a dose-dependent manner. These results seem to indicate the possibility that the antimicrobial effect of UV radiation contributes to successful photochemotherapy in patients with atopic dermatitis.

Adult↗
PubMed1995

Activity of eight fluoroquinolones against both methicillin-susceptible and -resistant Staphylococcus aureus isolated from skin infections.

The in vitro susceptibility of Staphylococcus aureus to eight fluoroquinolones, norfloxacin, ofloxacin, enoxacin, ciprofloxacin, lomefloxacin, tosufloxacin, sparfloxacin, and nadifloxacin was established by agar dilution tests, 71 isolates of methicillin-susceptible (MSSA) and 74 isolates of -resistant S. aureus (MRSA) isolated from skin infections. Among all of the fluoroquinolones, nadifloxacin exhibited the lowest MIC for both MSSA and MRSA. In addition, there were no resistant S. aureus, neither MSSA and MRSA, to nadifloxacin. With the exception of nadifloxacin, the incidence of MRSA resistant to fluoroquinolones has gradually increased in recent years. Over half of the MRSA strains were resistant to norfloxacin, ofloxacin, enoxacin, ciprofloxacin, and lomefloxacin.

Anti-Infective Agents↗
PubMed1995

[Two cases underwent patch closure and mitral annuloplasty for ventricular septal perforation and mitral regurgitation caused by acute inferior myocardial infarction].

Two cases underwent successful operation for the ventricular septal perforation (VSP) and mitral regurgitation (MR) caused by acute myocardial infarction (AMI) are reported. Patch closure of VSP and mitral annuloplasty (MAP) by Kay-Suzuki method were performed. Location of VSP were posterior ventricular septum and moderate MR were detected in both cases. Case 1 was a 74-year-old man. Four weeks after AMI, patch closure of VSP through right ventricular approach and MAP through trans-atrial approach and also aorto-coronary bypass to left anterior descending artery were performed. Doppler echocardiography was effective to evaluate the severity of VSP and MR. Case 2 was a 69-year-old man. Eight days after AMI, patch closure of VSP and MAP were performed through biventricular approach. Postoperative examination revealed the disappearance of left-to-right shunt and MR in both cases. These cases operated successfully were thought to be rare.

Aged↗
PubMed1995

[Resection of lung cancer complicated by pleural empyema].

In a 53-year-old man, carcinoma of the lung was resected and was complicated by pleural empyema. Two days after fiberoptic bronchoscopy, he developed a high fever and was found to have pleural empyema. After thoracic drainage and other palliative treatment, the right lower lobe and empyema cavity were resected. The postoperative course was uneventful and he was discharged 3 weeks after the operation, but he died of cervical and intrathoracic lymph node recurrence 5 months later. Surgical treatment of malignant lung cancer complicated by pleural empyema has been reported 10 times, including 3 reports from Japan. According to those reports, post-operative complications are rare, and long survival is possible. Therefore, surgical resection is indicated in some cases.

Carcinoma, Squamous Cell↗
PubMed1995

[Neoadjuvant chemotherapy with tegafur suppository for rectal cancer--effects of tegafur on nuclear DNA content of cancer cells--Tochigi Colorectal Cancer Study Group].

To assess the significance of neoadjuvant chemotherapy for large bowel cancer, we investigated an effect of tegafur on cancer cell kinetics by DNA content flow cytometric analysis. The pathologic specimens analyzed in this study were obtained from 28 patients with rectal cancer who had received tegafur suppositories prior to surgery. Mean cumulative doses administered were 13.4 g, and mean duration was 12.7 days. In 24 of the 28 specimens, the DNA ploidy and DNA index of the cancer cells were essentially unchanged after the chemotherapy, and DNA aneuploidy was present in 67%. The proportion of cells in S-phase in DNA aneuploid tumors was significantly higher than in DNA diploid tumors. The proportion of cells in G0G1-phase was inversely correlated to that in S-phase. After the chemotherapy, the proportions of cells in S-phase increased both in DNA diploid and aneuploid tumors, although a significantly higher mean value was found only for the latter (p < 0.05). In the DNA aneuploid tumors, there was a higher frequency of responders confirmed by histological evaluation (44%) as compared to the DNA diploid tumors (25%), and a tendency for increases in S-phase fraction of the responders to be greater than in non-responders. These results suggest that DNA flow cytometry-derived parameters may conceivably be useful in predicting the antitumor effect of 5-FU and its derivatives against large bowel cancer.

Aged↗
PubMed1995

[Successful treatment of hemopneumothorax with intrapleural OK432 in pulmonary metastases of cutaneous angiosarcoma].

An 80-year-old woman with angiosarcoma of the scalp was treated with radiation and interleukin 2. The patient experienced dyspnea one month later because of pulmonary metastases, and underwent video-assisted thoracoscopic surgery for a right pneumothorax. Right hemopneumothorax recurred 3 weeks after the surgery and left hemopneumothorax occurred 4 months later. Both were successfully treated with intrapleural OK432 and drainage. As of March 1995 the patient had been alive and well for one year since the right pneumothorax developed.

Aged↗
PubMed1994

Long-term follow-up study of changes in lipid peroxide levels and the activity of superoxide dismutase, catalase and glutathione peroxidase in mouse skin after acute and chronic UV irradiation.

Lipid peroxide levels, the activities of superoxide dismutase (SOD), catalase and glutathione peroxidase (GSH-Px), and the development of tanning in the skin of C57 BL/6 mice were assessed for long periods, from very early to late stages, after acute or chronic UVB irradiation. Acute UVB irradiation produced an increase in lipid peroxide levels that peaked 18 h after irradiation, after which the levels declined to a minimum 2-3 days after irradiation and then gradually rose to baseline. Chronic irradiation caused the lipid peroxide level to fall to a minimum at 0.5-1.0 weeks, after which it gradually returned to baseline by the third week. SOD and GSH-Px activities decreased sharply after acute irradiation, reaching a minimum 18 h after irradiation. Following chronic irradiation, these enzyme levels peaked after 0.5 weeks, and thereafter declined gradually to the original levels 3 weeks after irradiation. In contrast, catalase activity did not change significantly. Tanning began to increase at 1.5 weeks after irradiation, with an accelerated rate of increase from the third week.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Response of right ventricular systolic function to exercise stress: effects of pulmonary vascular resistance on right ventricular systolic function.

To elucidate factors influencing responses of right ventricular systolic function to exercise stress, we evaluated the right ventricular ejection fraction and peak ejection rate with two different loading conditions, atrial septal defect and mitral stenosis, at rest and during exercise by means of gated equilibrium blood pool radionuclide ventriculography. In both atrial septal defect and mitral stenosis, strong correlations between changes in the right ventricular ejection fraction with exercise and pulmonary vascular resistance at rest (r = -0.97, p < 0.001; r = -0.86, p < 0.005: respectively) were found. Significant correlations between changes in the right ventricular peak ejection rate with exercise and pulmonary vascular resistance at rest (r = -0.85, p < 0.05; r = -0.75, p < 0.01: respectively) were found in atrial septal defect and mitral stenosis. Both the right ventricular ejection fraction and peak ejection rate were lower during exercise than at rest when pulmonary vascular resistance at rest was more than 200 dynes.sec.cm-5.m2 in both atrial septal defect and mitral stenosis. In conclusion, right ventricular systolic function responding to exercise stress was influenced by the pulmonary vascular resistance in both atrial septal defect and mitral stenosis.

Adult↗
PubMed1994

Primary chylopericardium.

To evaluate the surgical treatment of primary chylopericardium, 2 cases of primary chylopericardium are described and previous case reports are reviewed. Enhanced computed tomography combined with lymphangiography is a very reliable diagnostic tool for identifying abnormalities of the thoracic duct and its lymphatic channels connecting to the pericardium. When the course of the thoracic duct was identified exactly, ligation and resection of the thoracic duct with establishment of a pericardial window proved to be the most effective surgical procedure. Because the thoracic duct and the pericardium can be exposed easily, left thoracotomy seems to be the most preferable approach for the operation.

Adolescent↗