Biomedical subjects

M Hosono

Publications and source records attributed to M Hosono.

At least 37 records · Page 2Linked to original sources

PubMed2000

Early surgery for active infective endocarditis.

OBJECTIVE: The timing of surgery for active infective endocarditis remains controversial. In this report, we have reviewed 26 patients who underwent surgery for active infective native-valve endocarditis between April 1992 and December 1998. PATIENTS AND METHOD: There were 19 male and 7 female patients (mean age 45 years). The aortic valve was involved in 8 patients, the mitral valve in 6 patients, tricuspid valve in 2 patients, both aortic and mitral valves in 7 patients, both aortic and tricuspid valve in 2 patients, and both mitral and tricuspid valve in one patient. The most common microorganisms were streptococcal species. Preoperative high New York Heart Association functional class (III and IV) was presented in 20 patients (77%). Progressive heart failure and the echocardiographic findings of vegetation (larger than 1 cm) were the main operative indications. Emergency or urgent surgery was required in 18 patients (70%). All patients underwent valve replacement, involving 25 mechanical prosthesis and 8 bioprosthesis. RESULTS: The operative mortality was 7.8% (n = 2). In the two patients who died, the infection had extended to the deep cardiac tissue and to the cerebral artery. The mean follow-up of the 24 survivors was 33 months (range from 6 to 82 months). There was no late death and no recurrence of infective endocarditis. CONCLUSION: In case of active infective endocarditis, early surgical intervention is recommended in patients with rapidly progressive cardiac deterioration or vegetation seen on echocardiography.

Adolescent↗

PubMed2000

Granular cell tumor of the male breast: report of a case.

We treated a 35-year-old male with a granular cell tumor in the right breast. Physical examination revealed a solid, flattened, round 3.2 x 2.5-cm mass with an irregular surface, covering skin fixation and right axillary lymphadenopathy. Mammography revealed a well-demarcated high-density mass with a minimal starburst appearance. Ultrasonography revealed a hypoechoic, nonhomogeneous mass with an acoustic shadow. Several enlarged lymph nodes in the right axilla were removed at the time of breast tumor excision. Histologically, the tumor featured nests of round or polygonal cells with abundant eosinophilic cytoplasmic granules and small round nuclei, and the enlarged lymph nodes in the right axilla exhibited no metastasis. Immunohistochemically, there was positive staining for S-100 protein, neuron-specific enolase, and vimentin. The tumor also stained for macrophage CD-68, alpha1-antichymotrypsin, and myoglobin. These immunohistochemical findings suggested the tumor cells to be undifferentiated mesenchymal cells which demonstrated the properties of neurogenic cells and histiocytes.

Adenocarcinoma↗

PubMed2000

Failure to remove autoreactive Vbeta6+ T cells in Mls-1 newborn mice attributed to the delayed development of B cells in the thymus.

Clonal deletion of autoreactive T cells in the thymus is one of the major mechanisms for establishing tolerance to self-antigens, and self-reactive T cells bearing Vbeta6 T-cell receptors are usually deleted before their maturation in Mls-1a mice. However, these T cells develop transiently in the neonatal thymus, and migrate to the periphery. In order to understand the mechanisms which permit these potentially auto-toxic T cells to generate, we investigated in vivo the physiological or functional properties of the elements involved, such as neonatal T cells, antigens and antigen-presenting cells (APC). Confirming the previous findings that each of these elements per se is already completed in function in neonates, we investigated the possibility of the absence or immaturity of particular APC with Mls antigens of their own products in the neonatal thymus. In the search for the cellular and histological changes occurring in the newborn thymus, we found that the elimination of Vbeta6+ T cells progressed in parallel with the development of thymic B cells. Involvement of B cells in purging the autoreactive T cells from the newborn thymus was shown by prevention of the deletion of Vbeta6+ T cells after the removal of B cells by the treatment of neonates with anti-immunoglobulin M antibodies. The restricted and stable expression of CD5 on the thymic B cells, but not on the splenic cells, suggests that these B cells are not postnatal immigrants from the periphery. Finally, it is concluded that the deficiency in the deletion of self-reactive T cells in the thymus of Mls-1a neonates is due to the delayed development of B cells.

Aging↗

PubMed2000

Neointimal formation at the sites of anastomosis of the internal thoracic artery grafts after coronary artery bypass grafting in human subjects: an immunohistochemical analysis.

OBJECTIVES: The aim of this study was to evaluate the cellular composition and cell proliferative activity of neointimal tissue in human internal thoracic artery grafts and to characterize the differentiation state of neointimal smooth muscle cells at early stages after coronary artery bypass grafting. METHODS: The anastomotic sites and body segments of 7 patent grafts were obtained at autopsy from 7 patients who died within 92 days after operation. Serial sections were examined by immunohistochemical techniques to identify macrophages, endothelial cells, smooth muscle cell phenotype, and proliferating cells. For the identification of the cell types that show cell proliferative activity, immunodouble staining was also performed. RESULTS: In all body segments the luminal surface was completely covered by endothelial cells, and no areas showed thrombus formation or neointimal proliferation after grafting. In contrast, in the anastomotic segments endothelial denudation and focal disruption of the internal elastic lamina with adherence of fibrin-platelet thrombus and infiltration of macrophages were observed in the earliest stage after grafting. At these sites of injury, early neointimal tissue response had occurred, and cell proliferative activity was detected in macrophages and dedifferentiated smooth muscle cells. During the evolution of neointimal thickening, redifferentiation of neointimal smooth muscle cells occurred associated with the decline in proliferative activity. CONCLUSIONS: These observations strongly support the concept that excessive neointimal proliferation, which may occur at the site of anastomosis because of extensive damage to the arterial wall, could be one of the possible causes of failure of the internal thoracic artery graft in human beings.

Aged↗

PubMed2000

Induction of hepatocellular carcinoma with high metastatic potential in WS/Shi rats: discovery of an inbred strain highly susceptible to the liver carcinogen N-nitrosomorpholine.

We investigated the susceptibility of three inbred strains of rats to the hepatocarcinogen, N-nitrosomorpholine (NNM), to establish a spontaneous metastatic model of hepatocellular carcinoma (HCC). WS/Shi. SD/gShi, and F344/DuCrj rats were given 0.02% NNM in drinking water for 8 weeks and thereafter left without any treatment. The experiment ceased at week 20, because mortality markedly increased after this time point in WS/Shi rats. Liver weight was highest in WS/Shi rats among the three strains examined. The incidence of HCC was 15/15 (100%) in WS/Shi rats, 1/16 (6%) in SD/gShi rats, and 13/16 (81%) in F344/DuCrj rats surviving after NNM treatment. Metastasis to the lung was observed in HCC-bearing rats at an incidence of 13/15 (87%) in WS/Shi, 1/1 in SD/gShi, and 6/13 (46%) in F344/DuCrj. Four-week administration of NNM resulted in a significantly higher BrdU-labeling index of hepatocytes in WS/Shi rats than in the other strains. These findings indicated that WS/Shi is the most sensitive strain to NNM and may be the most suitable strain for use as a spontaneous metastatic model of HCC among the strains of rats examined in the present study.

Animals↗

PubMed2000

[A case of tricuspid infective endocarditis in a drug addict].

This report describes a successful operative case of tricuspid infective endocarditis in a drug addict. A 24-year-old man with a history of drug addiction (6 months) complained of general fatigue and high fever. Echocardiography showed a large vegetation attached to the tricuspid valve and severe tricuspid regurgitation. Blood cultures revealed septicemia due to methicillin sensitive Staphylococcus aureus. He was treated for about 1 week with intravenous antibiotics. However, subsequent severe heart failure necessitated emergency operation. The tricuspid valve was replaced with Carpentier-Edwards bioprosthesis because of severe destruction of the tricuspid valve. The postoperative course was uneventful and he has remained free from endocarditis for 15 months after surgery.

Adult↗

PubMed2000

[Successful aortic root replacement for prosthetic valve endocarditis using the freestyle stentless bioprosthesis: report of two cases].

We report two cases of prosthetic valve endocarditis which were successfully treated with aortic root replacement using the freestyle stentless bioprosthesis. Prosthetic valve endocarditis occurred in two patients after aortic valve replacement and modified Bentall operation, respectively. The aortic annulus was severely damaged and left ventriculo-aortic discontinuity was found in both cases. We used the freestyle stentless bioprosthesis, which fits well to the destroyed aortic annulus with left ventriculo-aortic discontinuity, because of its flexibility. Postoperative echocardiography revealed excellent hemodynamic results in both cases. Although the long-term results obtained with the freestyle stentless bioprosthesis, such as resistance to bacterial infection, have not been reported, this prosthesis appears to be very useful for treatment of prosthetic valve endocarditis. We expect that this prosthesis might be a option for PVE as an alternative to a homograft.

Adult↗

PubMed2000

[Clinical application of 133-Xe ventilation scintigraphy].

Xenon-133 ventilation scintigraphy provides three sets of scintigrams: wash-in, equilibrium, and washout images. Krypton-81m or 99mTc-Technegas can be used as alternatives depending on their physical characteristics and the purpose of scintigraphy. Xenon-133 scintigraphy is compatible with SPECT when a multi-detector gamma camera is used. Ventilation images are analyzed by the height/area method to calculate regional lung volume and the mean transit time of the posterior planar view. If perfusion scintigraphy is done during the same examination, a ventilation/perfusion ratio image is also obtained. Factor analysis is applicable to the washout phase and permits a more detailed depiction of uneven ventilation. Series of consecutive SPECT during washout (dynamic SPECT) visualize ventilation in cross section and provide three-dimensional images of regional lung volume and poorly ventilated areas. A major indication for 133Xe scintigraphy is acute pulmonary thromboembolism (PTE) when used in combination with perfusion scintigraphy. The scintigraphic diagnosis of PTE is not inferior to that of contrast-enhanced helical CT, although the latter was initially reported to have higher sensitivity and specificity than scintigraphy. Other important indications are differentiation between primary pulmonary hypertension and chronic pulmonary thromboembolism, and the prediction of postoperative pulmonary function. Ongoing trials are attempting to create functional images of ventilation by CT or MRI, both of which may become rivals of scintigraphy because of their higher image resolution.

Diagnosis, Differential↗

PubMed1999

Tandem repeat structure of rhamnose-binding lectin from catfish (Silurus asotus) eggs.

The primary structure of catfish (Silurus asotus) egg lectin (SAL) was determined. SAL cDNA contained 1448-bp nucleotides and 308 amino acid residues, deduced from open reading frame. The SAL mature protein composed of 285-amino acid residues was followed by a predicted signal sequence having 23 residues. The mRNA of SAL was found to be expressed in eggs, but not in liver. SAL is composed of three tandem repeat domain structures divided into exactly 95 amino acid residues each, and all cysteine positions of each domain were completely conserved. Sequence homologies between the three domains, termed D1 (1-95), D2 (96-190) and D3 (191-285), were as follows; D1-D2, 28%; D2-D3, 33%; D1-D3, 43%. Two conserved peptide motifs, -(AN)YGR(TD)S(T)XCS(TGR)P- and -DPCX(G)T(Y)KY(L)-, appear to exist at the N- and C-terminal regions of each domain, respectively. The kinetic parameters of SAL obtained by measuring surface plasmon resonance were as follows: K(a) (M(-1)) for neohesperidosyl-BSA, 7. 1 x 10(6); for melibiosyl-BSA, 4.9 x 10(6); and for lactosyl-BSA, 5. 2 x 10(5). These results show that RBLs including SAL comprise a family of alpha-galactosyl binding lectins having characteristic tandem repeat domain structures.

Amino Acid Sequence↗

PubMed1999

Effects of NKH477 on renal functions and cyclic AMP production in anesthetized dogs.

The present study was undertaken to evaluate the effects of an adenylate cyclase activator N,N-dimethyl-beta-alanine[3R-(3alpha, 4alphabeta, 5beta, 6beta, 6aalpha, 10alpha, 10abeta, 10balpha)]-5(acetyloxy)-3-ethenyldodecahydro-10, 10b-dihydroxy-3, 4a, 7, 7, 10a-pentamethyl-1-oxo-1H-naphtho [2,1-b] pyran-6-yl ester hydrochloride (NKH477) on renal functions and cyclic AMP production in the dog kidney. The intrarenal arterial infusion of NKH477 (30, 100 and 300 ng kg(-1) min(-1)) increased renal blood flow, glomerular filtration rate, urine flow rate, urinary Na+ and cyclic AMP excretion, fractional Na+ excretion and arterial and renal venous plasma cyclic AMP concentrations in a dose-dependent manner. The intrarenal arterial infusion of rolipram (0.3 microg kg(-1) min(-1)), a cyclic AMP-specific phosphodiesterase inhibitor, also caused the same renal responses as NKH477. The increasing effects of NKH477 on renal blood flow, fractional Na+ excretion and renal venous plasma cyclic AMP concentration were facilitated in the presence of rolipram. NKH477 reduced glomerular filtration rate and filtration fraction in the presence of rolipram. The increasing effects of NKH477 on urine flow rate and urinary Na+ excretion were not affected by rolipram. The present results suggest that NKH477 increases glomerular filtration and suppresses tubular sodium reabsorption through activation of cyclic AMP production, and thereby induces natriuresis. The results also demonstrate that renal cyclic AMP level during the activation of adenylate cyclase is regulated by phosphodiesterase IV in both the vascular and tubular sites.

Anesthesia↗

PubMed1999

Coagulofibrinolysis during heparin-coated cardiopulmonary bypass with reduced heparinization.

BACKGROUND: We examined the safety of reduced systemic heparinization during heparin-coated cardiopulmonary bypass by measuring coagulofibrinolitic indices, including fibrinopeptide A, which directly reflects fibrinogenesis. METHODS: Twenty-four patients who had elective cardiac operations were perfused using a circuit coated with covalently bonded heparin. Twelve patients received 300 U/kg of heparin and the remaining 12 patients received 150 U/kg. Blood was obtained for the measurement of thrombin-antithrombin III complexes, fibrinopeptide A, plasmin-alpha 2 plasmin inhibitor complexes, and D-dimer preoperatively; after heparin administration; 10, 60, and 90 minutes after the start of bypass; after protamine administration; and 1, 3, 6, 12, and 24 hours after the end of bypass. RESULTS: Preoperative, intraoperative, and postoperative variables including postoperative bleeding were not significantly different between the two groups. Further, there were no complications in either group. No significant differences between the two groups were noted for any hematologic index at any time point. CONCLUSIONS: Reduced systemic heparinization combined with a heparin-coated cardiopulmonary bypass circuit is biochemically and clinically safe but does not reduce postoperative bleeding.

Adult↗

PubMed1999

Hot water extract of bark of Nikko maple (Acer nikoense) induces apoptosis in leukemia cells.

In screening for antitumor constituents in traditional crude drugs, we used three cultured cell lines: mouse leukemia P388 cells, doxorubicin-resistant P388 cells and leczyme (catalytic lectin)-resistant P388 cells. The hot water extract (HWE) of the bark of Nikko maple (Acer nikoense) showed concentration-dependent inhibitory effects on the growth of these three cell lines. DNA fragmentation and morphological changes, accompanied by condensed and fragmented nuclei, were observed in the leukemia cell lines cultured with HWE of the bark of Nikko maple. Treatment with this HWE increased the expression of sialylated glycoconjugates on the apoptotic cells. These results suggest that HWE induces cell death via apoptosis in vitro.

Animals↗

PubMed1999

[Cardiovascular effects of colforsin daropate hydrochloride, a novel drug for the treatment of acute heart failure].

Colforsin daropate hydrochloride (COL) is a water-soluble forskolin derivative for the treatment of acute heart failure. COL, like forskolin, stimulated adenylate cyclase (AC) directly and produced pharmacologic activities accompanied by the increase in cellular cAMP. COL was different from forskolin in water-solubility, duration of action, BBB permeability, oral activity and AC-subtype selectivity. COL was a inodilator with positive inotropic and vasodilator effects and was effective on a beta-receptor desensitized-heart model in which the effects of beta-agonists and PDE inhibitors were attenuated. COL improved cardiac function in some heart failure models. In the clinical studies, COL improved hemodynamics, subjective and objective symptoms of heart failure patients, and was also effective in the catecholamine-resistant heart failure patients. COL is a first clinically available adenylate cyclase activator. Further information from the post-marketing-surveillance will provide information that will enable more adequate usage of this drug.

Adult↗

PubMed1999

Two-step targeting and dosimetry for small cell lung cancer xenograft with anti-NCAM/antihistamine bispecific antibody and radioiodinated bivalent hapten.

UNLABELLED: The "affinity enhancement system," a two-step targeting technique using bispecific antibody and radiolabeled bivalent hapten, has been reported to be useful for carcinoembryonic antigen-expressing tumors. The purpose of this study was to evaluate the efficacy of this method for targeting human small cell lung cancer using an antineural cell adhesion molecule antibody. METHODS: Antineural cell adhesion molecule/antihistamine bispecific antibody NK1NBL1-679 was prepared by coupling an equimolecular quantity of a Fab' fragment of NK1NBL1 to a Fab fragment of antihistamine 679. Athymic mice inoculated with NCI-H69 small cell lung cancer cells expressing neural cell adhesion molecule were administered bispecific antibody and then 48 h later 125I-labeled bivalent histamine hapten. 125I-labeled intact NK1NBL1 was injected into other groups of mice. Biodistributions were examined as a function of time. RESULTS: In mice of the two-step targeting, tumor uptake was 2.5 +/- 0.2, 3.2 +/- 0.4, 6.4 +/- 2.0, 7.2 +/- 2.7, 6.1 +/- 2.1 and 2.2 +/- 0.4 %ID/g at 5, 30 min, 5, 24, 48 and 96 h, and tumor-to-blood, tumor-to-liver and tumor-to-kidney ratios were 1.4 +/- 1.1, 10.8 +/- 13.2 and 4.6 +/- 4.7, respectively, at 5 h, whereas 125I-labeled NK1NBL1 showed a tumor uptake of 5.7 +/- 0.4 %ID/g and tumor-to-blood, tumor-to-liver and tumor-to-kidney ratios of 0.3 +/- 0.1, 1.1 +/- 0.2 and 0.9 +/- 0.1, respectively, at 5 h. These results were confirmed by autoradiographic studies, which demonstrated clear tumor-to-normal tissue contrast. Dosimetry showed that the affinity enhancement system could enhance the therapeutic potential of the antineural cell adhesion molecule antibody NK1NBL1. CONCLUSION: This two-step targeting method seems promising for the diagnosis and therapy of small cell lung cancer.

Animals↗

PubMed1999

Use of heparin-coated cardiopulmonary bypass circuit with low-dose heparin reduces postoperative bleeding.

Postoperative bleeding was examined in patients undergoing cardiopulmonary bypass with a heparin-coated circuit and low-dose heparin. Out of 150 patients who underwent cardiopulmonary bypass for longer than 90 minutes, 74 received a standard dose (300 IU/kg) of heparin with an uncoated circuit (group C) and 76 received a low-dose (150 IU/kg) of heparin with a heparin-coated circuit (group H). The coagulation and fibrinolytic systems were investigated in 24 patients. Re-opening of the chest due to bleeding was performed in 5 patients in group C (7%), but none of the patients in group H (p=0. 03). The median of blood loss in the first 12 hours after surgery was 292 ml in group C, and 216 ml in group H (p=0.006). There were no significant differences in the peak thrombin-antithrombin complex concentration between the two groups. The plasmin-alpha 2 plasmin inhibitor complex concentrations after protamine administration were 1.9 ng/ml (median) in group C and 1.1 ng/ml in group H (p=0.002). The use of heparin-coated cardiopulmonary bypass circuits with low-dose heparin suppressed the activation of fibrinolysis. This may explain the reduction in postoperative bleeding.

Adult↗

PubMed1999

Use of a retractor designed to harvest an internal thoracic artery graft during cardiac surgery for patients with a unilateral lung.

Adequate exposure of the heart is required for safe cardiac surgery. We performed open heart surgery for 2 patients with a unilateral lung. In one patient, coronary artery bypass grafting was performed 13 years after left pneumonectomy for lung cancer. Mitral valve replacement was performed in the other patient whose left lung was entirely collapsed due to tuberculosis. The heart was markedly deviated to the left in both patients. A retractor designed to harvest the internal thoracic artery was very useful to obtain a good operative view of the heart. The operations were uncomplicated, and postoperative recovery was uneventful in both patients.

Aged↗

PubMed1999

Cardiac surgery in patients with dialysis-dependent renal disease.

This study was designed to evaluate the operative outcome of dialysis patients undergoing cardiac surgery. A retrospective review was performed of 28 consecutive patients with end-stage renal disease dependent on maintenance hemodialysis (n = 26) or peritoneal dialysis (n = 2) who underwent cardiopulmonary bypass (CPB). The operations included isolated coronary artery bypass grafting (CABG) (n = 21), aortic valve replacement (n = 4) and CABG plus aortic valve replacement (n = 3). Seven operations were emergent or urgent. In 23 patients, a heparin-coated (HC) circuit with reduced systemic heparinization was used for CPB. The hospital mortality was 7.1%. Complications occurred in 13 patients (46%). Although thoracotomy for bleeding was required in 3 patients, only 1 had undergone CPB with an HC circuit. There were 7 late deaths. All survivors showed improvement in symptoms and overall functional status. The actuarial survival rates were 78% and 58% at 1 and 4 years, respectively. In the 10 patients with diabetes mellitus, the 4-year survival rate was 50%. In the patients who underwent non-elective surgery, the survival rate was 29%. Cardiac surgery can be performed with increased but acceptable mortality in dialysis patients. Good symptomatic relief can be expected. Surgery should be performed before the general condition deteriorates.

Actuarial Analysis↗

PubMed1999

Heparin-coated circuits prevent renal dysfunction after open heart surgery.

UNLABELLED: We examined whether heparin-coated (HC) circuits can improve the operative results in patients with chronic renal insufficiency. SUBJECTS AND METHODS: Elective cardiac surgery was performed in 24 patients with a serum creatinine (Cr) level of at least 1.5 mg/dl. Uncoated circuits were used in 12 patients, and HC circuits were used in 12 patients. The results of surgery were compared between the two groups. RESULTS: The mean preoperative Cr concentration was significantly higher in the HC group (2.3 vs 1.8 mg/dl). The heparin doses, protamine dose, and activated clotting times were significantly lower in the HC group. The mean blood loss was also less, although this difference was not significant. The postoperative increase in the Cr level was small in the HC group (2.3-->2.5 mg/dl) compared to that in the noncoated group (1.8-->2.3 mg/dl). Postoperative dialysis was not required in the 5 patients in the HC group with a preoperative Cr clearance less than 20 ml/min. CONCLUSION: HC circuits and low-dose heparin can be used to maintain renal function after cardiopulmonary bypass, even in patients with severe kidney disease.

Aged↗