Biomedical subjects

J Hirota

Publications and source records attributed to J Hirota.

At least 73 records · Page 4Linked to original sources

PubMed1993

[Functional evaluation of skeletal muscle ventricles for circulatory assist].

Skeletal muscle has a potential power for cardiac assist. Two approaches have been used to harvest this power: dynamic cardiomyoplasty, which involves the application of muscle directly to the heart to support cardiac contractile function; and the construction of skeletal muscle pouches or ventricles, which are used as separate pumps working either in parallel or in series with the heart. In this study, we evaluated the function of the skeletal muscle ventricles (SMVs) for circulatory assist. In six dogs (18.5 +/- 2.3 kg, mean +/- S.E.M.), SMVs were constructed from the right latissimus dorsi muscle, and placed in the right hemithorax. After a 3-week vascular delay period, the SMVs were preconditioned electrically by 2 Hz continuous stimulation for six weeks. Nine weeks later, SMVs were connected to a mock circulation device for functional evaluation. As right-sided pumps, at a preload of 10 mmHg, SMVs generated stroke work of 0.63 +/- 0.04 x 10(6) ergs with 25 Hz and 0.80 +/- 0.06 x 10(6) ergs with 85 Hz, which exceeded that of the native right ventricle. As left sided pumps, also at a preload of 10 mmHg, SMV stroke work was 0.49 +/- 0.13 x 10(6) with 25 Hz 0.90 +/- 0.09 x 10(6) ergs, which was roughly half that of the left ventricle. These results demonstrate that SMVs have the potential to function as left or right heart assist devices.

Animals↗

PubMed1993

[An arch and ascending replacement for aortic arch dissection by "separate hypothermia" retrograde cerebral perfusion].

We have developed a new technique of cerebral perfusion during operations on the aortic arch. The concept of this technique is as follows. A retrograde cerebral perfusion provides a relative long time to perform the distal aortic repair, and simplifies the operation. To avoid the disadvantages by deep hypothermia, we perfused from SVC cannula with blood cooled at 10-15 degrees C, from femoral artery with blood cooled at 20-26 degrees C. A successful case using this method is as follows. A 68-year-old man was referred to our hospital for aortic arch dissection. He underwent an operation 4 weeks after onset. Graft replacement of ascending aorta and aortic arch was performed under this method. We perfused blood from SVC cannula at an internal jugular vein pressure of 30 cmH2O, and SVC perfusion flow was 600 cc/min. By this separate hypothermia perfusion, the nasopharyngeal temperature is maintained about 15 degrees C, the rectal temperature is maintained 22-24 degrees C. The duration of cerebral perfusion from SVC cannula was 125 min, but prolonged emergence from anesthesia and neurological deficit were not seen.

Aged↗

PubMed1993

[A right internal thoracic artery graft to the left anterior descending artery].

From 1987 to 1991, 48 patients received a right internal thoracic artery (RITA) to the left anterior descending artery (LAD). No operative death occurred, but two patients (4.2%) died during hospitalization due to graft versus host disease, and congestive heart failure. Graft patency of the RITA was 100%. After a 17.2 month mean follow-up, the 4 year actuarial survival rate (including all causes of death) was 85.3%, and the 4 year cumulative cardiac event free rate (including all cardiac deaths, myocardial infarction, reoperation, and PTCA) was 87.6%. The length of the RITA graft to the LAD, 15.6 +/- 1.1 cm, was significantly longer than that of the left internal thoracic artery (LITA) to the LAD, 12.9 +/- 1.1 cm. However, the flow of the RITA-LAD graft, 42.3 +/- 21.1 ml/min, was same as the flow of the LITA to the LAD, 42.1 +/- 19.6 ml/min. These findings justify wider use of the RITA to the LAD as a second arterial graft.

Adult↗

PubMed1993

[A case report of surgical treatment for aortic valve papillary fibroelastoma].

A 71-year-old woman was referred to our hospital for aortic valve replacement because of the vegetation of aortic valve. She had transient right arm weakness and aphasia in November 1991. On two-dimensional echocardiogram, she was found to have a mobile, pedunculated mass attached to the non-coronary cusp of the aortic valve. At operation, multiple frond-like tumor measuring 7*7 mm was found attached to the free-edge of the non-coronary cusp of the aortic valve. The aortic valve with this tumor was excised and replaced with a 21-mm Carpentier-Edwards prosthesis. Microscopic sections revealed the typical findings of a papillary fibroelastoma. The patient's postoperative course was unremarkable.

Aged↗

PubMed1992

Midline malignant B-cell lymphoma with leukemic transformation.

This article presents a case of lethal midline granuloma on the palate of a 44-year-old woman, which had been identified histologically as B-cell lymphoma with leukemic transformation in the terminal stages. At the first visit, physical and laboratory examinations showed no remarkable findings except for a necrotizing ulcer of the palate, and the biopsy specimens only showed massive inflammatory cell infiltration and necrosis of the granulation tissue. There was a short-term resolution after treatment with cyclophosphamide and prednisolone, but the disease reactivated and the necrotic ulcerative lesion progressively advanced into the nasal cavity. Specimens from the third biopsy exhibited histologic features that were consistent with malignant lymphoma of the diffuse, mixed B-cell type. Chemotherapy with the regimen of cyclophosphamide, doxorubicin, vincristine, and prednisolone was adopted but was interrupted after a short time because of bone marrow suppression. Subsequently, large numbers of enlarged abnormal lymphocytes with a few vacuoles in the cytoplasm appeared in the circulating blood, indicating leukemic transformation of the midline lymphoma. The patient died on the seventh day after the initiation of chemotherapy. In the presentation of this case, the authors mention clinically important matters regarding midline lethal lymphoma and briefly discuss the pathophysiology and pathogenesis.

Adult↗

PubMed1992

Electron microscopic study on cell-to-cell interactions in oral lichen planus.

Ultrastructural analysis of oral lichen planus was performed in 18 cases, focusing on cell-to-cell interactions. In the peripheral portion of the lesion, the most consistent findings were a widening of intercellular spaces, separation of the basement membrane (BM) from basal cells and scarce inflammatory cells. In the central portion of the lesions basal cells and BM showed severe damage and numerous inflammatory cells infiltrated into both the epithelium and subepithelial stroma. The infiltrates predominantly consisted of T-lymphocytes, a few Langerhans cells (LC) and macrophages. Most lymphocytes were large and positive for CD45RO. Dendritic LC and macrophages with cytoplasm containing abundant organelles were seen in the epithelium and subepithelial stroma, respectively. Close contacts of lymphocytes with LCs, macrophages and also with keratinocytes were sometimes observed in the central portion. In the subepithelial stroma, some lymphocytes contacted an HLA-DR+ dendritic cell, which was possibly a macrophage, forming a rosette-like arrangement. Conjugations between CD4 cells and dendritic cells (possibly LC) and also between CD8 cells and basal cells were observed in the epithelium. These T cells were large in size, and the CD8 cells which made contact with degenerated keratinocytes possessed cytoplasm containing numerous polarized organelles and a nucleus toward and contrary to the contact side, respectively. These lymphocytes expressed LFA-1 on the cell surface, and many basal cells exhibited ICAM-1. These findings indicate that T cells may receive information from LC and macrophages concerning degenerative keratinocytes, and that informed T cells attack perhaps the keratinocytes.

Basement Membrane↗

PubMed1992

Changes in the Ki-67 labeling rates of head and neck squamous cell carcinomas during preoperative radiation therapy.

Immunostaining with Ki-67 monoclonal antibody was performed on frozen sections of biopsy specimens obtained before and during preoperative radiation therapy from 21 patients with head and neck squamous cell carcinoma. The Ki-67 labeling rates before radiation therapy and at radiation doses of 10 and 20 Gy ranged from 21 to 71% (mean: 35.0%), from 7 to 49% (mean: 25.8%) and from 1 to 44% (mean: 14.8%), respectively. One of the 2 patients whose tumors showing Ki-67 labeling rates of greater than 48% (mean +1 SD) before radiation therapy suffered local relapse shortly after the treatment. Moreover, tumors with rapidly decreased Ki-67 labeling rates (lower than 3%) at radiation doses of 20 Gy were related to poor clinical outcome: 4 out of 6 patients whose tumors showed Ki-67 labeling rates below 3% (mean -1 SD) at 20 Gy of irradiation had local relapses or showed distant metastases. These findings indicate that immunostaining with Ki-67 monoclonal antibody of biopsy specimens of head and neck squamous cell carcinoma, before and during radiation therapy, is very useful in assessing the clinical outcome of the patients.

Adult↗

PubMed1992

[Long-term results in 1,400 patients with coronary artery bypass grafting: saphenous vein vs arterial grafts].

To analyze and compare the effects of saphenous vein grafts (SVG) and arterial grafts (AG) on the long-term results of the coronary artery bypass grafting (CABG), retrospective nonrandomized studies were performed in 1,400 consecutive patients with CABG in terms of reoperation, postoperative transluminal coronary angioplasty (PTCA) to the grafts, actuarial survival rate, and cumulative event free rate. AG was used frequently in recent cases in which more diffuse and multiple vessel disease were encountered. No statistically significant differences were noted in any of the reoperation free rate, actuarial survival rate, success rate of the PTCA, and cumulative event free rate between SVG and AG, because the long-term results of the SVG was apparently better than reported Caucasian's long-term results, while those of the AG were as good as Caucasian's. Reoperation and PTCA for the AG were performed less than one year after the CABG in most cases and restenosis after the PTCA was rare. In contrast, those for the SVG were mainly done late postoperative period, and the incidence of the restenosis after the PTCA was very high. These results indicated that the main cause of the graft failure in the AG was technic-related, and that of the SVG was graft's atherosclerosis. We conclude from this study that AG should be indicated more extensively than SVG, but proper indication and application of the AG in various situations and technical improvement to avoid stenosis at anastomosis are important to improve the long-term results of the CABG.

Adolescent↗

PubMed1991

Serum cytokine levels in patients with oral mucous membrane disorders.

Serum cytokine levels were examined in 18 oral squamous cell carcinoma (SCC), 26 lichen planus (OLP), 20 recurrent aphthous stomatitis (RAS), 8 herpetic gingivostomatitis (HGS), 16 pseudomembrane candidiasis (PMC) and 19 acute bacterial infection (ABI) cases. All SCC and most PMC patients possessed clear serum IL-3. No clear increase of IL-4 was observed in most cases though over 20 pg/ml were found in a few OLP, RAS and ABI. ABI exhibited the highest IL-6, and the cytokine level was lower in RAS, PMC, HGS and OLP in this order. Suppressed IL-6 activity was elevated with improvement of HGS lesion. TNF-alpha increased in 9 OLP, but the levels were below 100 pg/ml in all cases. Most SCC possessed higher GM-CSF activity than the controls. Increase of the cytokine corresponding with improvement of the oral lesion was seen in HGS, but not in OLP. From these results, each serum cytokine seems to reflect a characteristic pathophysiology of individual oral disorder.

Abscess↗

PubMed1991

[Para-esophageal anastomosis of left atrium in orthotopic heart transplantation in dogs: possibility for electrophysiologic examination of the transplanted heart with transesophageal atrial stimulation].

Para-esophageal anastomosis of left atrium was examined in orthotopic heart transplantation as a new surgical technique for transesophageal electrophysiologic study of the transplanted heart. Seven orthotopic heart transplantations were performed in mongrel dogs. Left atrial appendage of the donor heart was trimmed as a flap and the sinus venosus of right atrium was incised posteriorly. An upper midline incision was made in the posterior wall of left atrium of the recipient after native ventricles were resected. Left atrial appendage flap of the donor heart was anastomosed to the posterior incision of native left atrium, and the remains of left atrium were sutured continuously. Sinus venosus incision of the donor heart was anastomosed to the right atrium of recipient. Ascending aorta and pulmonary trunk were reconstructed in the standard fashion. Transesophageal atrial pacing was possible during and after weaning from cardiopulmonary bypass in all seven cases. The appendage flap was found to occupy one third of the posterior wall of left atrium at the time of sacrifice. It was suggested that para-esophageal anastomosis of left atrium would be an useful technique for transesophageal electrophysiologic study of the transplanted heart.

Anastomosis, Surgical↗

PubMed1990

Mucinous adenocarcinoma of the submandibular gland.

A rare tumor not easily classifiable among published histologic categories for salivary gland tumors is reported. The neoplasm developed within the submandibular gland of a 78-year-old woman with invasion of the mandible and metastasis to regional lymph nodes. Histopathologically, cuboidal cells possessing clear cytoplasm and displaced round nuclei proliferated and exhibited an adenomatous pattern. Many cystic spaces surrounded by tumor cell strands were seen, mucus substance filled in the cystic spaces, and the tumor cells seemed mucus-secreting, but neither epidermoid cells nor papillary appearance could be observed. Electromicroscopically, numerous mucous droplets of low electron density were prominent in the cytoplasm, and the tumor cells had sparse irregular microvilli on the luminal surface. Mucin histochemistry, including paradoxical concanavalin A staining, revealed that the tumor cells contained neutral and acid mucins, and these were identified as class II and III mucosubstances. No other neoplastic lesion, except recurrent metastatic neck nodes, has been detected 6 years after the first examination, and it seems that the tumor is a rare primary mucinous adenocarcinoma of the submandibular gland.

Adenocarcinoma, Mucinous↗

PubMed1990

[Immunological investigation of lymph node metastasis in oral squamous cell carcinomas].

Oral squamous cell carcinomas were studied in regard to lymph node metastasis (LNM). Relations between LNM and the mode of cancer cell invasion, basement membrane (BM) deposition, epidermal growth factor-receptor (EGF-R) on tumor cells, stromal lymphocyte infiltrates, and immunologic parameters such as natural killer (NK) and interferon (IFN) activity were investigated. In 76 carcinomas, 26 cases (34.2%) exhibited LNM. LNM was rare in limiting invasion type (grade 1 and 2), but LNM was occasional in grade 3 invasion (11/29), and extremely prominent in diffusely invasive type of grade 4C and 4D (6/10 and 4/5, respectively). Tumors showing sufficient BM deposition were poorly metastatic (only 5 tumors had positive lymph nodes in 30 cases showing sufficient BM deposition which was immunohistochemically delineated with type IV collagen), while tumor having limited BM deposition were highly metastatic (12 in 16 tumors). Weakly infiltrated carcinomas with Leu 2a+ cells exhibited generally limited laminin existence in BM, and these carcinomas were more metastatic. Furthermore, EGF-R was more expressed on tumor cells with LNM than cells without LNM. There was no significant differences between NK activities of patients with LNM (32.9 +/- 18.3%) and without LNM (37.2 +/- 16.3%). Cases having activities of less than 17.2% (mean-2SD in healthy controls) were more frequent in metastatic group (7/19) when compared with non-metastatic group (4/33). IFN activities in sera were significantly different between metastatic group (4.2 +/- 3.1 IU/ml) and non-metastatic one (9.5 +/- 7.0 IU/ml. From the above, LNM may be more accurately diagnosed by these immunologic investigations.

Carcinoma, Squamous Cell↗

PubMed1990

Immunohistochemical staining of infiltrates in oral lichen planus.

Immunohistochemical examination of lymphocyte and accessory cell infiltrates was performed in 24 cases of oral lichen planus using a double staining technique. The major population of the superficial stromal lymphocytes was T cells which were mostly composed of dominant CD 4+Leu8- (helper T cells) and lesser numbers of CD 8+11b- cells (cytotoxic T cells). Contrarily, many more CD 8+11b- cells than CD 4+Leu8- cells had infiltrated the epithelium. Some infiltrated T cells expressed interleukin-2 receptor and about half of cytotoxic T cells expressed class II antigen. HLA-DR-positive monocytes were also observed in both the superficial stroma and the epithelium. A number of HLA-DR-bearing CD 1+ cells (Langerhans/dendritic cells) and CD 11c+ cells (macrophages) were observed in the lower layers of the epithelium which were sometimes degenerative. Having significant correlation with the infiltration intensities of subepithelial macrophages and epithelial CD 8+ cells (cytotoxic/suppressor T cells), epithelial Langerhans cells variably infiltrated. Superficial stromal CD 8+ cells correlated with epidermal CD 8+ and CD 4+ cell (helper/inducer T cells) infiltrates. These findings are consistent with the notion that Langerhans cells and macrophages play an important role in antigen presentation, and suggest that cellular immunity, mediated by cytotoxic T cells with helper T cells, may be related to the pathogenesis of oral lichen planus.

Antigens, CD↗

PubMed1990

Immunohistochemical study of jaw cysts: different existence of keratins in odontogenic and non-odontogenic epithelial linings.

Keratins and secretory component (SC) were immunohistochemically examined in fresh tissue samples from 45 odontogenic and 35 non-odontogenic cysts. Lining epithelia of almost all cases contained keratins which reacted with polyclonal antibodies (Dako, Bio-Science), and no difference could be found between the two groups of lesions. By staining with two monoclonal antibodies against keratins, i.e., RGE53 (Bio-Science) and RKSE60 (Bio-Science), it was revealed that the epithelia of non-odontogenic cysts, which were columnar epithelium in most cases, had fully and positively reacted with RGE53, while none of the cases was positive for RKSE60. In contrast, the squamous linings of odontogenic cysts except for two cases did not react with RGE53, and few cases possessed RKSE60-reactive keratin. SC was also contradictory. All non-odontogenic cysts exhibited SC. Regarding each pair of non-odontogenic and odontogenic cysts covered with RGE53 and SC-positive, and RKSE60-negative squamous epithelium, it seemed reasonable from the staining results to conclude that the squamous linings were metaplastic from the columnar epithelium. Based on the results, concomitant examinations of SC with keratins will be helpful in deciding the epithelial derivation of jaw cysts.

Dentigerous Cyst↗

PubMed1990

[Sensorineural hearing loss following the decompression of the facial nerve].

This study aims to ascertain whether sensorineural hearing loss occurs after the decompression of the facial nerve. Nine patients have undergone decompression of the facial nerve (limited to the vertical segment) by the transmastoid approach were selected as the subjects of this study because the influence of disinfectants and surgical trauma on the inner ear seems to be less severe in this operation than in tympanoplasty. Additionally, this approach seems to be more suitable for judgement of the effect of the drilling noise induced acoustic trauma on the inner ear than tympanoplasty. Though high tone abrupt sensorineural hearing loss was occurred in the operated ear in seven patients, no changes in hearing level were found in the contralateral side ear. Bekesy audiometry performed in only one case revealed Jerger II which suggested some disorder in the cochlea. Not only acoustic trauma induced by the drilling noise but also labyrinthitis occurred via the opened facial canal and the internal ear canal seemed to be the cause of sensorineural hearing loss following the decompression of the facial nerve.

Adult↗

PubMed1990

Histochemical studies on irradiated and obstructive human submandibular glands. Protein distribution and lectin-binding in the degenerative glands.

Immunohistochemical protein distribution of alpha-amylase (Am), lysozyme (Ly), cytokeratinin (CK), S-100 protein (S-100) and secretory component (SC), and lectin-binding (SBA and UEA-I) profiles were studied in 10 obstructive and 20 irradiated human submandibular glands which were surgically extirpated. Degenerative intensity of the glands was graded as I, II and III based on the order of severity. All proteins generally existed in serous acinic cells of the intact glands. The proteins immunoreactivities became weak even in mildly inflamed glands (grade I), and nearly disappeared from the moderately damaged glands (grade II). Duct cells had clear CK and some cells reacted with the anti-SC antibody, but other proteins were not observed on the ducts. Mucous cells possessed none of the proteins, and their lectin-binding was only traceable in some glands. Compared with immunoreactivities in the proteins, lectin-binding profiles were different. SBA and UEA-I bound somewhat similarly to both acinic and duct cells, and the binding was hardly affected even by severe degeneration (grade III). Between obstructive and irradiated glands, no obvious difference was observed in either protein distribution or lectin-binding. From the above, it seems that some proteins are more affective to the degeneration and that lectin-binding sugar residues are non-affective against the degenerative changes of the tissues.

Histocytochemistry↗

PubMed1990

[Clinical evaluation of tumor markers in head and neck squamous cell carcinomas].

The serum levels of the carcinoembryonic antigen (CEA) and the beta 2-microglobulin (beta 2M) have been examined in 55 patients with a head and neck squamous cell carcinoma, and the squamous cell carcinoma-related antigen (SCC) levels were also detected in 36 of these subjects. With the advancement of the T-stage, an elevation in both the original SCC and the beta 2M levels was seen, though the level of the CEA did not relate with the T-stage. In three markers, the SCC clearly changed, in relation to the clinical conditions. About two-thirds (63%) of the advanced tumors (T 3 + 4) had a higher SCC level than the cut-off value (1.5 ng/ml), while levels in most early carcinomas did not reach the border line. In cases that were successfully treated, elevated SCC levels were lowered to below 1.5 ng/ml without exception, whereas the SCC values of cases with a bad prognosis remained at a high level. Further, the consecutive elevation of the beta 2M levels was observed even after the treatments. From these results, it seems that SCC combined with CEA appears useful for the diagnosis and monitoring of head and neck squamous cell carcinomas.

Antigens, Neoplasm↗

PubMed1989

Angiomyoma of the upper lip: report of a case with electron microscopic and immunohistochemical observation.

Immunohistochemical and electron microscopic observations of a vascular leiomyoma of the upper lip are presented. Tumour cells were positive for desmin, vimentin and neuron specific enolase but not for S-100 protein. Factor VIII was detected in the endothelium of blood vessels. Ultramicroscopically, the spindle-shaped tumour cells had elongated nuclei and cytoplasm containing abundant myofilaments and pinocytotic vesicles. Emphasis is placed on the fact that an immunohistochemical approach using appropriate antibodies can be used in identifying this tumour.

Adult↗