Biomedical subjects

J Yoshida

Publications and source records attributed to J Yoshida.

At least 163 records · Page 9Linked to original sources

PubMed1998

Flow cytometric analysis of DNA content and Ki-67-positive fractions in the diagnosis of salivary gland tumors.

To explore the utility of flow cytometry (FCM) for the diagnosis of histopathology of salivary gland tumors, fresh materials taken at surgery from 23 Warthin's tumors, 57 pleomorphic adenomas, and 14 malignant tumors were analyzed for DNA ploidy and proliferative cell activities, including S-phase fraction (SPF), G2- plus M-phase fraction (G2M), and Ki-67-positive fraction. To facilitate this study, glands were taken from all major salivary sites and minor glands in the head and neck. DNA aneuploidy was not detected in the benign tumors. Nine of 14 malignant tumors showed DNA aneuploidy. The percentage of SPF or G2M of the malignant tumors was significantly higher than those of the benign tumors. The percentage of Ki-67-positive fraction of pleomorphic adenomas was comparable to that of malignant tumors and was significantly higher than that of Warthin's tumors. Ki-67 of 20% as a cut-off had a sensitivity of 88%, specificity of 100%, and accuracy of 91% for differentiating pleomorphic adenomas from Warthin's tumors. In analyzing DNA content and proliferative activities by FCM, we could distinguish among the three major histopathologies of salivary gland tumors. Warthin's tumors showed low SPF + G2M with low Ki-67, pleomorphic adenomas had low SPF + G2M with high Ki-67, and malignant tumor showed high SPF + G2M with high Ki-67. The high percentage of the Ki-67-positive fraction seen in pleomorphic adenomas may reflect their potential biological aggressiveness manifested as tumor recurrence or malignant transformation.

Adenolymphoma↗

PubMed1998

Vector manometric study of the sphincter of Oddi in the dog: functional and morphological correlation.

The relationship between sphincter of Oddi pressure and the morphological structure of the sphincter was studied in eight dogs prepared with a duodenal cannula. Sphincter of Oddi manometry was performed in awake animals in three directions, ventral, left dorsal, and right dorsal, using a catheter with three radial side holes for recording at one level. The pressure in the ventral direction (26.6+/-1.06 mmHg) (mean+/-SEM) was significantly lower than that in the left and right dorsal directions (30.6+/-1.42 and 31.2+/-1.23 mmHg, respectively). This functional manometric difference in the three directions correlated closely with the morphological structure of the sphincter of Oddi; the sum of the thickness of the sphincter of Oddi muscle and duodenal proper muscle was greater on the dorsal than on the ventral side. To our knowledge, this is the first report of axial asymmetry in sphincter of Oddi pressure.

Analysis of Variance↗

PubMed1998

Isolated mediastinal Hodgkin's disease mimicking thymoma: report of a case.

Mediastinal Hodgkin's disease has rarely been reported in the literature in Japan; however, it is not uncommon in Europe and North America. A 32-year-old woman with isolated mediastinal Hodgkin's disease mimicking thymoma is herein described. A preoperative diagnosis of thymoma led to a combined resection of the mediastinal tumor together with the entire thymus, left innominate vein, and left phrenic nerve. The resected tumor was histologically diagnosed to be Hodgkin's disease of the nodular sclerosis type. Adjuvant 40 Gy irradiation of the mediastinum and neck was added postoperatively. The patient is doing well at present with no signs of recurrence 8 months after the operation.

Adult↗

PubMed1998

The development of extrahepatic portal obstruction after undergoing multiple operations for a congenital dilatation of the bile duct: report of a case.

As a long-term complication after undergoing a cystenterostomy for a congenital dilatation of the bile duct, liver cirrhosis due to stenosis of the anastomosis or reflux cholangitis has been reported in conjunction with subsequent portal hypertension. We treated a 48-year-old Japanese woman who developed both portal hypertension and pancytopenia after undergoing multiple operations for a congenital dilatation of the bile duct. She underwent a Hassab's operation in July 1994, when an occlusion of the extrahepatic portal vein, which resulted in portal hypertension, was first noted; the liver was microscopically normal. The etiology of the extrahepatic portal obstruction in our patient was most likely due to either repeated inflammation or adhesion at the hepatic hilus. Based on these findings, the differential diagnosis of portal hypertension after an operation for a congenital dilatation of the bile duct should therefore include an extrahepatic portal obstruction in addition to liver cirrhosis.

Anastomosis, Surgical↗

PubMed1998

Interleukin-6 and development of vasospasm after subarachnoid haemorrhage.

The authors characterized the role of interleukins in the cerebrospinal fluid (CSF) in the development of vasospasm after subarachnoid haemorrhage (SAH), particularly interleukin-6 (IL-6). Concentrations of interleukin-1 beta (IL-1 beta), IL-6, and interleukin-8 (IL-8) were measured serially in CSF of 24 patients and in serum of 9 patients with SAH and correlated clinically. Additionally, the effects of the same cytokines on the cerebral arteries of dogs were analyzed on angiograms after intracisternal injection. Changes in levels of eicosanoids, angiogenic factors, and soluble cell adhesion molecules were investigated in the CSF of injected dogs. CSF concentrations of IL-6 and IL-8 were elevated significantly above control levels from the acute stage of SAH until the chronic stage. Patients with symptomatic vasospasm had significantly higher levels of IL-6 as well as IL-8 in CSF on days 5 and 7. Intracisternal injection of IL-6 induced long-lasting vasoconstriction in five out of eight dogs, while IL-8 did not. The diameter of canine basilar artery after IL-6 was reduced 29 +/- 5% from pretreatment diameter at 8 hours. Prostaglandins E2 and I2 were elevated in CSF for the first 4.5 hour of this IL-6-induced vasospasm. Neither angiogenic factors such as platelet-derived growth factor-AB and vascular endothelial growth factor nor soluble cell adhesion molecules were significantly elevated in CSF. IL-6, which increases to very high concentrations in CSF after SAH, may be important in inducing vasospasm, as IL-6 produced long-lasting vasoconstriction in the canine cerebral artery, which may be partly related to activation of the prostaglandin cascade.

Animals↗

PubMed1998

Anterior cervical decompression and fusion for cervical spondylosis using vertebral grafts obtained from the fusion site. Technical advantages and follow-up results.

A retrospective analysis was done in 60 consecutive patients who underwent anterior cervical fusion using vertebral grafts obtained from the fusion site at the Nagoya University and its affiliated hospitals by a single surgeon (MT). Follow-up results and technical advantages are reported. The average follow-up period was 33 months (range 6 to 55 months). Sufficient decompression of the anterior cervical pathology was performed successfully via a wider operative field. The symptoms and neurological score improved significantly without any new deficits in all patients except in one with a three-level fusion who needed re-operation for further decompression. No major graft complications such as graft extrusion or pseudoarthrosis occurred. Graft fracture was noted in five cases. However, good bony fusion was observed in all these cases without any further treatment. Normal cervical lordosis was preserved in most cases except in four, who lost lordotic alignment but did not show kyphosis. Major advantages of this method are a wider operative field, excellent graft fusion rate, and no need for an additional incision to obtain autogenous bone graft. These benefits seem have to contributed to satisfactory surgical results in this series.

Adult↗

PubMed1998

Characterization of a streptococcal antitumor glycoprotein (SAGP).

An acidic antitumor glycoprotein (SAGP) was purified from a crude extract of Streptococcus pyogenes, Su strain. Intraperitoneal injection with SAGP (20 mg protein/kg/day for 4 consecutive days) prolonged the life span of mice inoculated i.p. with Ehrlich ascite carcinoma cells and methylcholanthrene-induced fibrosarcoma cells (Meth A) up to 244% and 169% of that of the control mice, respectively. These in vivo antitumor effects were reduced in immunosuppressed mice. The effector spleen cells from the Meth A-inoculated and SAGP-injected mice showed a considerable cytostatic activity on Meth A cells in vitro, and immunosuppression studies suggested that carrageenan-sensitive and/or asialo-GM1 positive spleen cells are responsible for the in vivo antitumor effect of SAGP. SAGP inhibited the cell growth of cultured cell lines including transformed hamster embryonic lung cells, murine leukemia L 1210, Meth A and human promyelocytic leukemia HL60 cells. The IC50s for the cell growth of these cells were all below 0.1 microg protein/ml. SAGP inhibited the incorporation of nucleic acid precursors into Meth A cells. It seems that sulfhydryl groups of the SAGP molecule are essential for the expression of the antitumor action of SAGP. The cell growth-inhibitory activity of SAGP was diminished in Meth A cells preincubated with pertussis toxin (IAP), whereas it was augmented in the cells preincubated with cholera toxin (CTX), suggesting the involvement of toxin-sensitive GTP (G)-proteins in the SAGP-action. IAP and CTX-catalyzed ADP ribosylation assays confirmed that SAGP augmented the activity of IAP-sensitive G-protein. In addition, this augmentation was detected neither in Meth A cells incubated with heat-inactivated SAGP nor in SAGP-insensitive L929 cells. SAGP induced apoptosis in Meth A and HL60 cells as assessed by DNA fragmentation. A single dose injection of SAGP (100 mg protein/kg, i.v., s.c., or i.p.) into mice produced no toxic signs except occasional pain responses observed for one week after the injection. Thus, SAGP is a low toxic substance that shows in vivo antitumor activity by modulating immune responses of the host, and also exhibits in vitro cell-growth inhibition through IAP-sensitive G-protein.

Animals↗

PubMed1998

Sarcomatous transformation of pituitary adenoma after bromocriptine therapy.

We reported a case of sarcomatous transformation of pituitary adenoma occurring in a 21-year-old woman. She had previously undergone surgery for pituitary adenoma (prolactinoma) 5 years earlier. Since then, she had received only bromocriptine medication therapy. The operation was repeated because of a relapse of the tumors. Histologically, the tumors were composed of adenomatous epithelial nests and fibrosarcomatous spindle cell components intermingled with each other. lmmunohistochemically, adenomatous epithelial cells were stained positively with cytokeratin and prolactin. Fibrosarcomatous spindle cells were stained only with vimentin. The proliferation activity (Ki-67 expression) was much higher in the sarcomatous components than in common pituitary adenoma. p53 immunostaining was also positive in sarcomatous components. This was thought to be the first reported case of sarcomatous transformation of pituitary adenoma not associated with radiation therapy.

Adenoma↗

PubMed1998

Benign osteoblastoma of the odontoid process of the axis: a case report.

BACKGROUND: The majority of benign spinal osteoblastomas arise from the posterior elements of the spine; there have been no published reports of the tumor in the odontoid process of the axis. Accurate preoperative localization of the tumor is important for planning minimally invasive surgery on such benign tumors. However, the magnetic resonance imaging (MRI) findings may be misleading, because peritumoral changes may be confusing. CASE DESCRIPTION: We report the case of a 20-year-old man, who presented with a 4-year history of protracted left posterior neck pain. Preoperative computed tomography (CT) revealed a discrete mixed-density mass within the odontoid process. MRI showed diffusely abnormal signal intensity and enhancement both in the odontoid process and the body of the axis, including regions from which biopsy specimens were normal or had minimal inflammatory changes. Precise preoperative localization of the tumor margins using CT and biopsy allowed for successful resection of the tumor via a transoral approach with preservation of a part of the axis and the odontoid process. Consequently, stabilization of the spine was unnecessary, and the patient remained symptom-free for 3.5 years. CONCLUSION: We reported a rare case of benign osteoblastoma of the odontoid process of the axis. The tumor was successfully resected via a transoral approach, preserving a part of the axis and the odontoid process. We have emphasized an advantage of CT over MRI for accurate localization of the tumor.

Adult↗

PubMed1998

Synchronous double primary lung carcinomas associated with multiple atypical adenomatous hyperplasia.

A 71-year-old woman with synchronous bilateral primary lung carcinomas accompanied by multiple atypical adenomatous hyperplasias is described. The patient was found to have bilateral tumors during preoperative workup for the previously detected well differentiated adenocarcinoma of the right lung. Thoracoscopic wedge resection of the left upper lobe was performed to obtain a definitive diagnosis of the left lesion. Although intraoperative diagnosis was made by frozen section as atypical papillary lesion, postoperative diagnosis of this lesion was changed to well differentiated adenocarcinoma accompanied by surrounding atypical adenomatous hyperplasia (AAH). We diagnosed that the bilateral lesions were synchronous primary well differentiated adenocarcinomas independent to each other based on the criteria of Martini and Melamed and performed right upper and mediastinal lymph node dissection. The resected lobe contained not only the primary adenocarcinoma but also multiple small gray nodules which were diagnosed as AAHs. In summary, it was diagnosed that the patient had synchronous double primary lung adenocarcinomas of T1 N0 M0 pathological stage and 12 solitary atypical adenomatous hyperplasias. The patient is doing well with no signs of recurrence 24 months after the operation. This case might be an example of the adenoma-carcinoma sequence of lung cancer. A careful follow-up study is mandatory for this patient with special regard to the further development of lung carcinoma in the future.

Adenocarcinoma↗

PubMed1998

Pre-operative assessment of metastatic parotid tumors.

Metastatic disease to the parotid gland is rare and its diagnosing procedures are not established. We assessed several parameters, including the prior history of malignancy, fine needle aspiration cytology (FNAC) and magnetic resonance (MR) imaging and determined the most useful combinations for diagnosing metastatic parotid tumors. The primary tumors were squamous cell carcinomas of the eyelid, larynx, tonsil and of unknown origin, malignant melanoma of the auricle and small cell lung carcinoma. In three of four patients with parotid lymph node metastasis who underwent MR imaging, rim enhancement of the tumor was observed on gadolinium (Gd)-enhanced fat-suppressed T1-weighted MR images (sensitivity 75%). In the histopathologic examinations, the tumor was encapsulated and massive infiltration of normal lymphocytes was found peripheral to the capsule. These were not seen in the patients with metastasis to the parotid parenchyma via hematogeneous dissemination or with advanced-stage parotid node metastasis. The FNAC diagnosis accorded with the tumor histology in five of six patients (sensitivity 83%). Three of the six patients had a prior history of malignancy in other sites (sensitivity 50%). The triad of FNAC, prior history of malignancy and enhanced MR images was identified as the combination most useful in the diagnosis of metastatic parotid tumors (sensitivity 100%).

Aged↗

PubMed1998

Primary thyroid lymphoma associated with metastatic thyroid tumor: discrimination with US.

We surgically treated a 75-year-old man who suffered from metastatic adenocarcinoma from the colon associated with primary thyroid lymphoma measuring 1 cm maximum in diameter. Radiologic findings were correlated with histopathology of excised specimens. Ultrasonography could discriminate between these two tumors based on the margin characteristics and the lesion echogenicity: the metastatic tumor was shown as an ill-defined hypo to iso echoic mass, while the malignant lymphoma was detected as a well-defined markedly hypoechoic mass. In addition, we could confirm that early-stage primary thyroid lymphoma even as small as 1 cm shows the same radiologic appearance as that of a bulky lymphoma.

Adenocarcinoma↗

PubMed1998

The effects of gonadotropin-releasing hormone agonist on androstenedione production and follicular development during controlled ovarian hyperstimulation.

PURPOSE: We performed a prospective randomized study to assess the effects of a GnRH agonist (GnRH-a) on follicular development and steroidogenesis during controlled ovarian hyperstimulation (COH). METHODS: Patients undergoing in vitro fertilization (IVF) for tubal infertility received human menopausal gonadotropin (hMG) stimulation with or without the GnRH-a, buserelin, beginning in the midluteal phase of the prior cycle. We analyzed serum hormone levels, follicular development, and outcome of IVF. RESULTS: The mean number of retrieved oocytes was significantly greater, and the implantation rate per embryo was significantly higher, in the GnRH-a/hMG group (n = 101) than in the hMG-only group (n = 97). The concentration of androstenedione (A) and the A/estradiol ratio in the serum were significantly lower in the GnRH-a treatment group throughout the follicular phase. CONCLUSIONS: The concomitant use of GnRH-a during COH prevents atretic change of the follicles and enhances follicular development by reducing androgen accumulation, resulting in a higher developmental competence of the oocytes.

Adult↗

PubMed1998

Primary unknown cancer in pulmonary hilar lymph node with spontaneous transient regression: report of a case.

A 69-year-old man was referred to our hospital in December 1993 because an abnormal mass had been detected in the right pulmonary hilum. Computed tomography (CT) of the chest revealed a swollen hilar lymph node between the right middle and lower lobe bronchi, and an adherent tumor in the right ventrobasal segment (S8). Chest roentgenogram in February 1994, however, showed no evident tumor in the right lung field. In March 1996, the mass in the right pulmonary hilum reappeared on chest roentgenogram. Chest CT revealed a swollen hilar lymph node between the right middle and lower lobe bronchi, but there was no tumor in right S8. The patient underwent video-assisted thoracoscopy on 17 May 1996. Intraoperative needle biopsy of the node revealed cancer cells. We performed right middle and lower bilobectomy with mediastinal dissection. Histological diagnosis revealed a large cell carcinoma almost completely occupying a hilar lymph node. The resected middle and lower lobes showed no tumors, except for a coagulation necrosis measuring 1.5 cm in diameter in S8b, corresponding to the site where a tumor shadow had been depicted on the CT image in December 1993. We concluded that the coagulation necrosis might have been the primary site of the tumor, which had spontaneously regressed and then appeared in the metastatic interlobar node.

Aged↗

PubMed1998

Neural activation of the brain with hemodynamic insufficiency.

Little is known about how ischemia affects hemodynamic responses to neural activation in the brain. We compare the effects of a motor activation task and a cerebral vasodilating agent, acetazolamide (ACZ), on regional cerebral blood flow (rCBF) in primary sensorimotor cortex (PSM) in six patients with major cerebral artery steno-occlusive lesions without paresis of the upper extremities. Quantitative rCBF was measured in all patients using H2(15)O autoradiographic method and positron emission tomography. The CBF was determined at rest, during a bimanual motor activation task, and 10 minutes after ACZ administration. With bimanual motor activation, rCBF increased significantly in both PSM compared with at rest (P < 0.01 on lesion side, and P < 0.02 on contralateral side). However, rCBF did not increase after ACZ injection in the PSM on the lesion side, whereas rCBF increased significantly in the contralateral PSM after ACZ injection compared with the level at rest. This result suggests that despite a decreased hemodynamic reserve, there is a nearly normal flow response to neural activation, indicating that the mechanism of vasodilation responsible for perfusion change is different for acetazolamide and neural activation. The relations among neural activation, hemodynamic status, and cerebral metabolism in the ischemic stroke patients are discussed.

Acetazolamide↗

PubMed1998

Experimental creation of fusiform carotid artery aneurysms using vein grafts in rats.

OBJECTIVE: We developed an in vivo model of growing fusiform aneurysms, using vein grafts to the rat carotid artery. This aneurysm model might demonstrate the pathological features of the development and growth of aneurysms to become giant aneurysms. METHODS: Placement of an interposed femoral vein graft to restore carotid artery flow was performed in Wistar rats. On Day 21, 75% of the grafts (mean diameter, 1.6 mm) were found to be dilated to resemble fusiform aneurysms (mean diameter, 5.82 mm), and 53% of these were giant. Quantitative analysis of the histological findings was performed using image-analyzing software. RESULTS: Histological findings were similar to those for human intracranial giant aneurysms. The average length of the initial grafts in the aneurysm group was 9.1+/-1.9 mm, and grafts were significantly longer and more tortuous than in the normal graft group (6.4+/-0.8 mm) (P = 0.01). Cross-sectional areas of the aneurysms (mean, 18.9 mm2) were significantly correlated with the following: 1) the area of intra-aneurysmal thrombosis (mean, 11.1 mm2) (P < 0.0001); 2) the number of intrathrombotic vascular channels (P = 0.005); and 3) the area of dissection, with hemorrhage, between the thrombus and the wall of the aneurysm (mean, 0.72 mm2) (P = 0.0013). Scanning electron microscopic examination showed evidence of endothelial damage associated with growth of the aneurysms. CONCLUSION: Recurrent hemorrhaging from intrathrombotic vascular channels caused dissection between the thrombus and the aneurysm wall, which led to growth of the experimental aneurysms to giant aneurysms. With this model, we demonstrated the growth mechanism of giant fusiform aneurysms.

Aortic Dissection↗

PubMed1998

Adeno-associated virus vector containing the herpes simplex virus thymidine kinase gene causes complete regression of intracerebrally implanted human gliomas in mice, in conjunction with ganciclovir administration.

Adeno-associated virus (AAV) has attracted considerable interest as a potential vector for gene therapy because of its wide host range, high transduction efficiency, and lack of cytopathogenicity. In this experiment, we evaluated the efficacy of AAV vector containing the herpes simplex virus thymidine kinase (HSV-tk) gene on human gliomas transplanted into the brain of nude mice. Complete regression of the tumors was observed after multiple AAV-tk injections followed by intraperitoneal ganciclovir (GCV) administration, and the survival of mice treated with AAV-tk vector and GCV administration was markedly prolonged. These results suggest that AAV-tk vectors may be useful for gene therapy against malignant gliomas in humans.

Animals↗

PubMed1998

Improvement of transduction efficiency of recombinant adeno-associated virus vector by entrapment in multilamellar liposomes.

Recombinant adeno-associated virus (AAV) has attracted considerable interest as a potential vector for human gene therapy, but its transduction efficiency is quite low. The present study demonstrated AAV vector-associated liposomes to be more effective for in vitro gene transfer to human glioma cells than are liposomes containing plasmid DNA. Using vector-associated liposomes increased the transduction efficiency more than 10-fold compared to liposomes containing plasmid DNA and more than 6-fold compared to AAV alone. From these results, AAV vector-associated liposomes appear to be a good candidate for in vivo gene delivery to human gliomas.

DNA, Viral↗