Biomedical subjects

T Sano

Publications and source records attributed to T Sano.

At least 973 records · Page 54Linked to original sources

PubMedDate not supplied

Paraganglioma of the cauda equina: an ultrastructural and immunohistochemical study of two cases.

The ultrastructural and immunohistochemical features of 2 paragangliomas arising in the cauda equina are described. In both cases the tumor cells were arranged in small nests or cords and contained characteristic neurosecretory granules, lamellar stacks of rough endoplasmic reticulum (RER), and some well-developed Golgi apparatuses in their cytoplasm. The cells varied in electron density; the darker cells, occasionally resembling sustentacular cells, were probably dehydrated light cells because they contained a few neurosecretory granules. Sustentacular cells were difficult to identify by electron microscopy, but irregularly distributed S-100 protein and glial fibrillary acidic protein (GFAP) were found in these cells by immunostaining. Many tumor cells contained abundant neurofilaments. Curiously, a few cytokeratin-positive cells were found in 1 case. On microscopic examination, a small area of ganglioneuroma was found associated with the paraganglioma in 1 case. Ganglionic differentiation was concluded to be frequent in paragangliomas of the cauda equina region as in duodenal paragangliomas.

Adult↗

PubMedDate not supplied

Pulmonary blastoma: an ultrastructural and immunohistochemical study with special reference to nuclear filament aggregation.

A case is presented of pulmonary blastoma occurring in the right upper lobe of a 25-year-old man without distinct clinical features and laboratory abnormality. Light microscopic analysis revealed that the tumor was composed of branching glands and morulae embedded in a primitive but bland mesenchyme. Immunohistochemically the epithelial cells were immunoreactive for cytokeratins, S-100 protein, protein gene product 9.5, chromogranin A, calcitonin, and Ki-67 (MIB-1); the mesenchymal cells were immunoreactive for vimentin, actin, cytokeratins, and Ki-67; and all the tumor cells were negative for p53, estrogen receptor protein, and human chorionic gonadotropin beta. Characteristically, many epithelial cells contained optically clear nuclei which were immunoreactive for biotin (M743). Electron microscopic analysis revealed that the optically clearing change was due to replacement of the central area of the nuclei by a mass of parallel-arranged 7- to 10-nm filaments, and biotin-immunoreactive products were mainly localized in the nuclear matrix. Additionally, spherical bodies were identified in the cytoplasm of the nuclear filament-aggregated cells, suggestive of an intimate pathogenetic association of the two morphological abnormalities. The similarity of the aggregated nuclear filaments to those observed in gestational endometrium and ovarian endometrioid carcinoma implies that a similar mechanism plays a role in the pathogenesis of these abnormalities.

Adult↗

PubMedDate not supplied

Atypical glomus tumor in the mediastinum: a case report with immunohistochemical and ultrastructural studies.

A case is reported of atypical glomus tumor occurring in the posterior inferior mediastinum of a 26-year-old woman complaining of severe back pain. The tumor was composed of atypical small, round tumor cells with scattered mitotic figures. In addition to sheet-like, diffuse proliferation of the tumor cells, some areas of the tumor contained small "glomoid" cells arranged in organoid and hemangiopericytomalike patterns. Immunohistochemically, many tumor cells were positive for muscle-type actins and a few cells were focally positive for desmin. Ultrastructural studies revealed smooth muscle features of tumor cells, that is, pinocytotic vesicles, external laminas, dense plaques, and occasional thin filaments with dense bodies. The patient remained well for 5 years and 4 months after the operation without additional radiation and chemotherapy. The tumor was diagnosed as an atypical, or low-grade malignant, glomus tumor morphologically. It seems important to recognize the presence of this type of tumor in sites other than extremities and to differentiate it from other malignant small, round cell tumors.

Actin Cytoskeleton↗

PubMedDate not supplied

Phagocytosis of microcapsules by guinea-pig polymorphonuclear leucocytes.

Phagocytosis of microcapsules by guinea-pig polymorphonuclear leucocytes (PMNs) was examined particularly considering the method of measurement and the effects of surface negative charges of the microcapsules and plasma proteins. Estimation of phagocytosis by oxygen consumption was found to correlate fairly well with the measured amount of the microcapsules phagocytosed. In the absence of plasma proteins, microcapsules having the same surface negative charge as that of the PMNs underwent less phagocytosis than those having surface negative charges different from those of the PMNs. The presence of plasma proteins was found to suppress phagocytosis.

Animals↗

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Increased heating efficiency of hyperthermia using an ultrasound contrast agent: a phantom study.

It is known that there are large temperature elevations in proximity to air bubbles during US (ultrasound) heating. The existence of tiny air bubbles in the target tissue may enhance the temperature elevation in US hyperthermia. To examine this hypothesis, phantom tissue experiments using an US contrast agent consisting of tiny air bubbles surrounded by a 5% (w/v) human albumin shell (Alb) were performed. As a phantom tissue, a 2 cm cube of beef was used. The phantom tissue was heated with or without the US contrast agent by an US hyperthermia device for 3 min. The heating device was operated at 1.5 MHz with the US intensity of 0.9 W/cm2. Physiological saline solution, iodized oil, and ethanol were used for control experiments. The effect of multiple needle punctures to the beef phantom was also examined. The temperature elevation rate (TER) was defined as the ratio of temperature elevation by heating with Alb or control materials to the temperature elevation by US heating alone. The TER of Alb was 1.7, whereas the TERs of the control materials and of the multiple needle punctures were approximately 1. The administration of Alb significantly increased the temperature in US hyperthermia. In addition, the heating efficiency of Alb was compared to the effect of an increase in the US intensity. Phantom tissue was heated at various US intensities. When the US intensity was increased from 0.9 to 1.8 W/cm2, the temperature elevated by approximately 1.7-fold. Thus, the effect of the administration of Alb was almost equivalent to the effect of increase in US power intensities from 0.9 to 1.8 W/cm2 in the present experimental settings. The results suggest that the US contrast agent can be a potential enhancer in US hyperthermia.

Hyperthermia, Induced↗

PubMedDate not supplied

Role of slow inward current on premature excitation in ventricular muscle.

Action potential durations in premature excitations showed paradoxical prolongation at the shorter coupling intervals; this was abolished by manganous ions. Voltage-clamp experiments also disclosed a transient increase of slow inward current in premature excitations. These results indicate that prolongation of action potential durations was mainly brought about by changes in slow inward current, especially in its characteristics of recovery from inactivation.

Action Potentials↗

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Effects of anoxia and metabolic inhibitors on reaction of the fast sodium system.

The effects of anoxia and metabolic inhibitors on inactivation and reactivation of the fast Na system of dog ventricular muscle fibers were studied by examining (dV/dt)max of the action potential upstroke. Anoxia for 60 min, dinitrophenol (DNP) (2.0 mM), and sodium azide (2.0 mM) depressed markedly steady-state (dV/dt)max at each membrane potential produced by changing [K]o. Anoxia tended to prolong recovery slightly, but DNP and azide changed little the time course of recovery of the (dV/dt)max, which was studied by applying double pulses to elicit action potential at different intervals. It is concluded that anoxia, DNP, and azide caused prominent depression of the maximum Na conductance but had less influence on its recovery kinetics.

Animals↗

PubMedDate not supplied

Advanced adenosquamous carcinoma of the gallbladder with bilio-biliary fistula: an uncommon case treated by hepatopancreatoduodenectomy.

A 70 year-old female, who presented with jaundice and abdominal pain, was found to have an advanced gallbladder cancer involving the liver parenchyma, duodenum, and transverse colon. This was complicated by a bilio-biliary fistula between the gallbladder and both the right and left hepatic ducts. After obtaining an accurate pre-operative diagnosis, the patient underwent hepatopancreatoduodenectomy (HPD) with lymph node dissection around the hepatic pedicle, celiac trunk, aorta, and inferior vena cava. Histologic examination revealed adenosquamous carcinoma. This rare variant accounts for 3.5% of gallbladder cancers, and is associated with a worse prognosis than adenocarcinoma. The patient is in good condition without any signs of recurrence 42 months after the HPD. In this case report, we discuss the histological type and internal biliary fistula with regard to the literature, and the usefulness of an aggressive surgical procedure such as HPD with extended lymph node dissection which can improve survival and quality of life in selected patients.

Aged↗

PubMedDate not supplied

Pre-operative angiography in gastric cancer surgery with extended lymphadenectomy.

BACKGROUND/AIMS: The value of pre-operative angiographic evaluation in patients undergoing gastric cancer surgery with extended lymphadenectomy was assessed in a prospective study comparing exposed and unexposed groups of patients. METHODOLOGY: During the period from July 1991 to October 1997, 76 patients (Group A--exposed) were pre-operatively submitted to a digital subtraction angiography (DSA) after informed consent. Concurrently, 94 patients (Group B--unexposed) were included as an unexposed reference group. All patients underwent total or subtotal gastrectomy with D2 lymphadenectomy according to the guidelines proposed by the Japanese Research Society for Gastric Cancer (JRSGC). RESULTS: In 34 (45%) exposed patients (Group A), DSA detected an atypical vascular anatomy. Major anatomical variations of the celiac axis, its branches and the superior mesenteric artery were discovered in 4 subjects (5%). Vascular anomalies affecting the surgical tactics of lymphadenectomy were detected in less than 8% of patients. Five post-operative deaths (6.6%) were registered between patients of the Group A, exposed to pre-operative angiography, 8 in the unexposed Group B (8.5%). Post-operative morbidity was significantly higher (P = 0.038) in the Group B (34%) in comparison to Group A (20%) but no difference in risk of individual complications was detected. CONCLUSIONS: Although useful in the presence of major vascular anomalies, it appears that pre-operative angiography did not significantly reduce intra- and post-operative complications associated with radical gastrectomy combined with extended lymphadenectomy. Arteriography is therefore not routinely recommendable but its use is mandatory in specific operations for gastric cancer.

Aged↗

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Asymptomatic portal vein obstruction after hepatobiliary resection: early detection by Doppler ultrasonography.

We report two different types of portal vein obstruction after liver resection: portal vein thrombosis due to steal phenomenon via a splenorenal shunt, and kinking of the skeletonized left portal vein after right hepatic lobectomy with caudate lobectomy. The two cases of portal vein obstruction were asymptomatic without any suggestive laboratory findings. Only routine Doppler ultrasonography detected portal vein obstruction which was successfully treated by emergency operation.

Aged↗

PubMedDate not supplied

Retrospective analysis of administration of a combination of docetaxel and carboplatin for advanced non-small cell lung cancer.

Retrospective analysis was performed for 60 patients with advanced non-small-cell lung cancer (NSCLC) who had been treated with combination therapy combining 60 mg/m2 of docetaxel with carboplatin in the range of 200 to 360 mg/m2 (average: 290 mg/m2) every 3 weeks. Considering the patients' performance status, the dose of carboplatin was lowered accordingly, being equivalent to AUC 1.9 to 6.1 (average: 3.26) by the Chatelut formula. The mean treatment cycle was 2.3 (range 1 to 7). Complete response and partial response were observed in 2 and 18 (37.0%) of the 54 evaluable patients, respectively, with a median survival time of 12.8 months and 1-year survival of 56.4%. The calculated AUC of carboplatin was not proportional to the response rate. Moderate myelosuppression was exhibited. The severity of leukopenia increased in relation to the AUC of carboplatin (R2=0.1093), whereas the relation between the platelet count and the AUC of carboplatin was relatively disproportional (R2=0.0553). Although gastrointestinal toxicity was slight, its severity increased dependent on the AUC of carboplatin. No occurrence of neurotoxicity was observed. Treatment with a combination of docetaxel and low-dose carboplatin seemed to be effective and safer in patients with advanced NSCLC.

Adult↗

PubMedDate not supplied