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Biomedical subjects

J Yoshida

Publications and source records attributed to J Yoshida.

At least 127 records · Page 7Linked to original sources
PubMed1999

Postoperative mediastinal chyloma.

Anterior mediastinal mass developed in a 69-year-old woman who had undergone right upper lobectomy and systematic lymph node dissection. The mass was diagnosed to be a mediastinal chyloma and surgical intervention was necessary to resolve the compression to the superior vena cava. Although posttraumatic mediastinal chyloma is not rare, postoperative mediastinal chyloma has not been reported in the literature. However, it should be noted as a differential diagnosis for a postoperative mediastinal mass.

Adenocarcinoma↗
PubMed1999

The prognosis of surgically resected N2 non-small cell lung cancer: the importance of clinical N status.

BACKGROUND: Clinical trials dealing with multimodal strategy for N2 non-small cell lung cancer are now being watched with keen interest, and the feasibility of this strategy is to be confirmed. N2 lung cancer, however, is composed of several subgroups with different prognoses. The prognostic factors still remain controversial. METHODS: Between January 1986 and July 1997, 222 patients with lung cancer underwent surgical intervention at our institute; these patients were eventually given a diagnosis of metastasis to ipsilateral mediastinal lymph nodes. All patients underwent mediastinal lymph node dissection or sampling. Sixteen clinicopathologic factors were investigated by univariable and multivariable analyses to identify significant prognostic factors among resected N2 disease. Clinical N status was evaluated by computed tomographic scan. RESULTS: The overall 5-year survival was 27%. Multivariable analyses among overall patients revealed 4 significant prognostic factors (P <.05): clinical N2 status, incomplete resection, larger tumor size, and multiple diseased N2 nodes. Based on the result, 32 patients with both clinical N2 status and pathologic multiple N2 nodes showed a 5-year survival of 5%, whereas 76 patients with neither of the factors showed a 5-year survival of 57% (P <.001). CONCLUSION: The prognosis of surgically resected N2 disease varies tremendously according to the 4 significant prognostic factors. These factors should be clearly described in reporting clinical trials on N2 lung cancer. Clinical N status evaluated by computed tomographic scan should be 1 criterion to perform a clinical trial for N2 disease among a homogeneous population with respect to prognosis.

Adult↗
PubMed1999

Clinical predictors of N2 disease in the setting of a negative computed tomographic scan in patients with lung cancer.

OBJECTIVES: Although preoperative cervical mediastinoscopy is absolutely indicated for patients with lung cancer in whom computed tomography demonstrates mediastinal nodal enlargement, the indications when the computed tomographic scan is negative are controversial. To determine the indications in patients with negative computed tomographic scans, we retrospectively studied patients with surgically resected lung cancer. METHODS: Between 1992 and 1997, 379 patients with lung cancer who had clinical N0-1 disease underwent surgical resection of lung cancer. Mediastinal lymph nodes were pathologically examined for metastasis in all the patients. A clinical diagnosis of nodal involvement was determined on the basis of preoperative computed tomographic findings: that is, mediastinal or hilar lymph nodes 1.0 cm or larger in the shortest axis were diagnosed as metastatic. Univariate and multivariate analyses were performed to determine the relationships between 9 clinical factors and pathologically proven N2 disease. RESULTS: Among the patients with clinical N0-1 disease, 68 (17.9%) had pathologic N2 disease. Adenocarcinoma histology, large tumor dimension, and high serum carcinoembryonic antigen levels were significant predictors of pathologic N2 disease on the basis of multivariate analyses (P <.05). When these factors were combined, 43% of adenocarcinomas larger than 2.0 cm with high serum carcinoembryonic antigen levels (P <.001), 34.7% of adenocarcinomas with high serum carcinoembryonic antigen levels (P <.001), 25.6% of adenocarcinomas larger than 2.0 cm (P =.009), and 31.1% of patients with high serum carcinoembryonic antigen levels and large tumor dimension (P <.001) had pathologic N2 disease. CONCLUSION: Preoperative cervical mediastinoscopy should be considered in patients in whom computed tomography is negative for lung cancer and who have some pathologic N2 predictive factors.

Adenocarcinoma↗
PubMed1999

A dural arteriovenous fistula of the tentorium successfully treated by intravascular embolization.

BACKGROUND: Dural arteriovenous fistulas of the tentorium are rare lesions that often present with intracranial hemorrhage. Definitive treatment is therefore necessary, but transarterial embolization has rarely been curative. CASE DESCRIPTION: A 59-year-old man presenting with sudden onset of severe headache had subarachnoid hemorrhage demonstrated by computed tomography. Left carotid angiography showed a tentorial dural arteriovenous fistula fed by a tentorial branch from the internal carotid artery and by a middle meningeal artery; the fistula drained to the marginal sinus via a dilated varicosity. Transarterial embolization successfully obliterated the fistula, and the patient was discharged with no neurologic deficit. CONCLUSION: This tentorial fistula, that showed extremely rare angiographic features, particularly venous drainage, was embolized successfully. The literature concerning tentorial dural arteriovenous fistulas is discussed in terms of effective therapeutic choice.

Arteriovenous Fistula↗
PubMed1999

Antitumor effect and cellular immunity activation by murine interferon-beta gene transfer against intracerebral glioma in mouse.

Cationic liposomes containing the human interferon-beta (IFN-beta) gene induce marked growth inhibition in human glioma cells. In vivo experiments using an human glioma implanted into the brains of nude mice have demonstrated a definite growth-inhibitory effect, achieving complete tumor regression with multiple intratumoral injections of the gene. However, nude mouse studies are inadequate to evaluate antitumor effects fully, especially those related to activation of the host immune response. This article aimed to investigate antitumor effects and immune response activation by murine IFN-beta gene transfer in syngeneic mice. In vitro experiments demonstrated a stronger growth-inhibitory effect of liposomes containing the murine IFN-beta gene on a GL261 mouse glioma cell line than exogenously added murine IFN-beta. In in vivo experiments, intratumoral administration of liposomes containing the murine IFN-beta gene resulted in a 16-fold reduction in the mean volume of residual gliomas in the brains of C57BL/6 mice and massive infiltration of cytotoxic T lymphocytes (CTL) within the residual tumor, while few CTL were infiltrated in controls including murine IFN-beta, empty liposomes, naked plasmid expressing murine IFN-beta, and liposomes containing beta-galactosidase gene. In addition, 40% of mice treated with liposomes containing the murine IFN-beta gene were completely cured. These findings indicated that activation of cellular immunity participates in antitumor effects in vivo together with direct effects of the IFN-beta gene.

Animals↗
PubMed1999

Use of the free medialis pedis flap in orofacial reconstruction: report of two cases.

The medialis pedis flap is a fasciocutaneous flap based on a branch of the medial plantar artery. The authors have used this flap in the reconstruction of skin defects of the hands and fingers because its skin is very similar in texture, color, and thickness. Because of its characteristics, this flap can also be applicable for orofacial reconstruction, when small or thin skin coverage is needed. Two cases are reported in which free medialis pedis flaps were used to reconstruct the eye socket in one patient and the alveolar ridge in the other. The authors concluded that the skin of the medialis pedis flap is not flexible enough and thus less suitable than the radial forearm flap for reconstruction of defects in which flexible skin is required, such as eye-socket reconstruction. However, reduced flexibility of the medialis pedis flap may provide an advantage in reconstruction of the gingiva and palate, where thin and rigid coverage is necessary.

Adult↗
PubMed1999

Recovery of olfactory function after an anterior craniofacial approach.

We assessed recovery of olfactory function in five consecutive patients who underwent surgical resection of midline skull base tumors using an anterior craniofacial approach in which the cribriform plate was mobilized with the dura. Olfactory function was evaluated before and after surgery using an intravenous olfactory test with prosultiamine and also a standard olfactory acuity test. Before surgery, one patient showed anosmia attributable to obstruction of the nasal cavity and olfactory cleft, and four patients showed normal olfactory function. After surgery, one patient was irreversibly anosmic, probably because of intradural dissection of the olfactory tracts. The other four patients, including the patient showing anosmia preoperatively, reported subjective recovery of olfaction 3 to 8 weeks after surgery. Intravenous and standard olfactory acuity tests indicated recovery of olfaction to the normal range in three patients and decreased olfactory function in one. With careful preservation of the olfactory system and of the integrity of the nasal cavity, olfactory function was found to recover after skull base resections via the anterior craniofacial approach.

Journal Article↗
PubMed1999

Ki-67 positive fractions in benign and malignant thyroid tumours: application of flow cytometry.

We investigated the DNA ploidy pattern, cell cycle and the percentage of Ki-67 positive fractions in fresh surgical material from 17 benign and 33 malignant thyroid tumours using flow cytometry. DNA aneuploidy was not seen at all in benign tumours, but was seen in 3 out of 33 malignant tumours, suggesting that detection of DNA aneuploidy indicates malignancy, although the detection sensitivity was low. Regarding the cell cycle, there was no difference in the percentage of S-phase fractions (SPF) or G2 plus M phase fractions (G2M) between benign and malignant tumours. However, the percentage of Ki-67 positive fractions in malignant tumours (39.9 +/- 3.9%) was significantly higher than that in benign tumours (9.4 +/- 2.1%), indicating that malignant thyroid tumours contained a large population of G phase cells. When a cut-off value of 20%, was used for Ki-67 positive fractions, sensitivity was 82%, specificity was 88% and accuracy was 84% for the diagnosis of malignant tumours. Although this study was carried out on surgically derived materials, it is possible that flow cytometric analysis of fine needle aspiration-derived materials may have a place in preoperative histopathological assessment of thyroid tumours.

Adenocarcinoma, Follicular↗
PubMed1999

Cerebral blood flow regulation under activation of the primary somatosensory cortex during electrical stimulation of the forearm.

Coupling of neuronal activity to cerebral blood flow (CBF) is widely accepted, but the exact mechanism is still under investigation. We assessed the responses of CBF coupled with electrical activity over the primary somatosensory cortex (S-I) during electrical stimulation of the contralateral forearm in cats. CBF in S-I was monitored using laser-Doppler flowmetry (LDF), and electrical activity was recorded with a tungsten microelectrode. The effects of varying stimulus intensity and frequency were examined to assess the optimal stimulation parameters. CBF increased within 10 sec after onset of stimulation, sustained the plateau level, and returned to the pre-stimulus level after cessation of stimulation. The maximum response was obtained at 4 Hz under a constant intensity. Optimal stimulus intensity at 4 Hz ranged from 8 to 10 V. At intensity higher than 10 V, CBF increases reached a near-plateau level, while mean arterial blood pressure (MABP) decreased slightly. Electrical activity was recorded at the same restricted area where CBF increased. Low frequency components of the power spectrum of electrical activity increased as the CBF increase became greater. A tight coupling of CBF increases to neuronal activation is suggested, and CBF regulation may be affected by stimulation parameters.

Animals↗
PubMed1999

Signet ring cell adenoma of the thyroid with mucin predominance.

A 22-year-old male presented with a 1-year history of a right anterior neck mass. He did not have gastrointestinal cancer. Laboratory examination revealed an elevated serum thyroglobulin level of 120 ng/mL. The neck lesion showed poor uptake on 99mTc scan, but enhanced uptake on 201T1 scan. The patient underwent a hemithyroidectomy; the cut surface of the 7 x 3.5 cm lesion was solid and tanned orange. Postoperatively the serum thyroglobulin level decreased to 26 ng/mL. Microscopy of the tumor showed signet ring cells and microfollides, both of which were positive for mucicarmin and alcian Blue. A small percentage of the follicles were positive for thyroglobulin and periodic acid-Schiff. Our literature search detected 18 patients with signet ring cell lesions positive for thyroglobulin, but none had characteristics similar to ours showing predominance of mucin and poor staining for thyroglobulin.

Adenoma↗
PubMed1999

Surgical management of primary lung cancer in an elderly patient with preoperative empyema.

A 74-year-old man with primary lung cancer developed preoperative empyema but was successfully managed surgically. The patient was given a diagnosis of c-T2N1M0, stage IIB, moderately differentiated squamous cell carcinoma, but before surgery pneumothorax and empyema developed, resulting from rupture of the carcinoma. Thoracic drainage, lavage and systemic administration of antibiotics improved his empyema. As there were no malignant cells in the drainage fluid, right middle-lower bilobectomy, empyemal cavity resection and lymph node dissection were performed. The bronchial stump was covered with an intercostal muscle flap. Thoracic drainage, lavage and systemic administration of antibiotics were performed for 6 days following the operation. The patient was discharged on the 27th postoperative day without any complications having developed. The pathological diagnosis of the tumor was p-T4N2(#7)M0, stage IIIB, br(-), ly(+), v(+), p3(pleura), pm1 and d0. He died of recurrence at home 18 months after the operation. We believe the following to be the minimum requirements for surgical management of such patients: (1) immediate thoracic cavity drainage and lavage with systemic antibiotic therapy, aiming at infection control before surgery; (2) prophylactic lavage of the thoracic cavity during and after surgery and (3) coverage of the bronchial stump with an adequate flap. Six reported cases of primary lung cancer with preoperative empyema are also discussed.

Aged↗
PubMed1999

Delayed gastric emptying after Billroth I pylorus-preserving pancreatoduodenectomy: effect of postoperative time and cisapride.

OBJECTIVE: To study the recovery course of gastric emptying after Billroth I pylorus-preserving pancreatoduodenectomy (PPPD) and therapeutic effects of cisapride. METHODS: To examine gastric emptying, acetaminophen was given, admixed in a pasty liquid meal, to 16 patients undergoing PPPD before surgery and at 1, 3, 6, 9, and 12 months after surgery. Cisapride was given orally to 10 patients before they received the acetaminophen regimen. Electrogastrography was performed at 2 weeks to 1 month after surgery in eight patients and at 6 to 12 months after surgery in seven patients. RESULTS: Gastric emptying was delayed but returned to the preoperative level by 6 months after surgery. Pretreatment with cisapride accelerated gastric emptying during months 1 to 6 but not during months 6 to 12 after surgery. Electrogastrography frequently showed tachygastria 2 weeks to 1 month after surgery, but seldom 6 to 12 months after surgery. CONCLUSIONS: After Billroth I PPPD, gastric emptying is delayed but recovers by 6 months after surgery. Tachygastria may play a part in the pathogenesis of delayed gastric emptying, but it can be treated with cisapride.

Adult↗
PubMed1999

Osteoplastic anterolateral vertebrotomy without fusion for multilevel cervical ossification of the posterior longitudinal ligament.

OBJECTIVE: To introduce a new method for osteoplastic anterolateral vertebrotomy without fusion to resect multilevel cervical ossification of the posterior longitudinal ligament. METHODS: A multilevel vertebral column graft containing portions of the intervertebral discs is cut with a microsurgical saw from the anterolateral part of the vertebra via a thin lateral gutter placed in advance. A sufficiently wide oblique operative field is provided for resection of the ossified ligament with this method, and only a narrow bony defect remains after simple replacement of the vertebral graft. Postoperatively, patients are allowed to walk, usually within 2 to 3 days, wearing simple cervical collars. RESULTS: Twelve patients underwent resection of the ossified ligaments in two to five vertebral bodies. Clinical results were satisfactory except in one patient, who died as a result of a pulmonary embolism that occurred 10 days after surgery. In all of the other patients, the vertebral column grafts were fused within a few months, and there were no graft-related problems. Postoperative lateral radiographs revealed that cervical alignment was preserved, with intervertebral mobility at the operated segment in flexion-extension views. CONCLUSION: The osteoplastic anterolateral vertebrotomy method provided a sufficiently wide operative field for satisfactory resection of multilevel cervical ossification of the posterior longitudinal ligament, simplifying graft replacement and postoperative patient care. The cervical alignment was preserved.

Adult↗
PubMed1999

Idiopathic hypertrophic cranial pachymeningitis: clinicoradiological spectrum and therapeutic options.

OBJECTIVE: Idiopathic hypertrophic cranial pachymeningitis is a rare disease, of undetermined pathogenesis, that is characterized by inflammation and fibrosis of the dura mater. METHODS: We encountered six patients with idiopathic hypertrophic cranial pachymeningitis and analyzed their clinical presentations, radiological findings, and treatment. RESULTS: In the six patients, the main manifestations were cranial nerve palsies and headache. Three associations were present, namely optic neuropathy, Tolosa-Hunt syndrome, and diabetes insipidus. Gadolinium-enhanced magnetic resonance imaging was diagnostic, showing intense dural enhancement in a linear or nodular pattern. The responses to corticosteroid therapy were better for patients who exhibited linear, rather than nodular, dural enhancement. For one patient, surgical decompression of the superior orbital fissure provided lasting relief. The course of the disease followed one of three patterns, i.e., sustained remission, relapse with corticosteroid independence, or relapse with corticosteroid dependence. Pulse corticosteroid therapy provided significant relief, while reducing the daily corticosteroid requirement and avoiding side effects, for a corticosteroid-dependent relapsing patient. CONCLUSION: Idiopathic hypertrophic cranial pachymeningitis exhibits varied clinical courses. It is important to prevent irreversible cranial neuropathy during the active phase of the disease, using daily administration of corticosteroids, pulse corticosteroid therapy, or surgical decompression.

Adrenal Cortex Hormones↗
PubMed1999

Perforating branches from offending arteries in hemifacial spasm: anatomical correlation with vertebrobasilar configuration.

OBJECTIVE: In microvascular decompression for hemifacial spasm, the perforating branches around the facial nerve root exit zone occasionally complicate facial nerve decompression. In this context, the vertebrobasilar configuration was retrospectively correlated with the perforating branches. METHODS: Based on vertebral angiography, magnetic resonance angiography, and three dimensional computed tomographic angiography, 69 patients were divided into three groups, according to the anatomy of the vertebrobasilar system. In patients with the type I configuration, the vertebral artery on the affected side was dominant and had a sigmoidal course. The type II patients had the basilar artery curving mainly towards the affected side. The type III patients showed the basilar artery either running straight or curving toward the unaffected side. The relation of the anatomical configuration of these vessels with the perforating branches around the facial nerve exit zone was investigated. RESULTS: The posterior inferior cerebellar artery in type I patients (n=33) and the anterior inferior cerebellar artery in type II (n=5) and type III (n=31) patients were the most common offending arteries. More than half of the type I patients (n=20) showed no perforating branches around the facial nerve exit zone. However, the type II (n=3) and III patients (n=23) often showed one or more perforating branches around that region. CONCLUSIONS: The configuration of the vertebrobasilar system has a significant correlation with the presence of perforating branches near the site of microvascular decompression. These perforating vessels are often responsible for the difficulty encountered in mobilising the offending artery during the procedure.

Adult↗
PubMed1999

Abundance of low molecular weight phosphotyrosine protein phosphatase in the nerve-ending fraction in the brain.

The distribution of low molecular weight phosphotyrosine protein phosphatase (LMW-PTP) in subcellular fractions of rat brain tissue was investigated by immunoblotting analysis using anti-LMW-PTP antibody. The enzyme was detected in the 105000 g precipitate in addition to the supernatant of brain homogenate, even after the precipitate was extensively washed, and was abundant in the particulate fraction of nerve endings. Nerve ending LMW-PTP was effectively solubilized by 1% Triton X-100 or 1% deoxycholate, though the enzyme was solubilized by thorough sonication. Two forms of LMW-PTP, designated as LMW-PTP-I and -II, were separated from the nerve ending-rich fraction by chromatofocusing. Nerve endings PTP-I and -II were different in molecular weight, isoelectric point and susceptibility to activators and inhibitors. The properties of nerve endings LMW-PTP-I and -II were similar to those of cytosolic LMW-PTP-I and -II. The abundance of LMW-PTP in nerve endings as well as in the cytosol suggests that this enzyme plays an important role in synaptic function.

Animals↗
PubMed1999

Inhibition of neutrophil migration by a protein kinase inhibitor for the treatment of ischemic brain infarction.

This study investigated the therapeutic potential of agents that inhibited neutrophil infiltration in cerebral ischemic infarction. The migration of neutrophils elicited by N-formyl-methionyl-leucyl-phenylalanine, tumor necrosis factor, C5a or platelet-activating factor was potently inhibited by fasudil, an inhibitor of protein kinases including rho kinase, protein kinase C and myosin light chain kinase, and hydroxy fasudil, a metabolite of fasudil, in vitro. In a microembolism model in rats, myeloperoxidase-quantified neutrophil accumulation in the ischemic brain was observed 24 hr after embolization. Intravenous administration of fasudil prevented the accumulation of neutrophils. In rats given fasudil, myeloperoxidase activity in the ipsilateral hemisphere (0.04+/-0.01 unit/g wet tissue) was significantly lower than that in ischemic rats (0.11+/-0.02 unit/g wet tissue). Fasudil also significantly reduced the size of the infarct area and improved neurological functions. These results suggest that neutrophil infiltration into the ischemic brain is involved in the pathogenesis of ischemic injury and that inhibiting neutrophil infiltration may provide an effective therapeutic intervention to reduce ischemic injury.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗