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Biomedical subjects

Y Segawa

Publications and source records attributed to Y Segawa.

At least 73 records · Page 4Linked to original sources
PubMed1996

Primary lung cancer associated with diffuse granulomatous lesions in the pulmonary parenchyma.

A 60-year-old man was admitted to our hospital for productive cough. Chest roentgenography and CT scan disclosed a left hilar tumor invading the mediastinum, with mediastinal lymphadenopathy and diffuse micronodular shadows in both lung fields. A biopsied sample of the tumor revealed squamous cell carcinoma, while noncaseating epithelioid cell granulomas were observed in the samples obtained by transbronchial lung biopsy. The granulomas in the pulmonary parenchyma were determined to be sarcoid reactions secondary to lung cancer, since there was no evidence of sarcoidosis. Combination chemotherapy was effective for the tumor, and the granulomas disappeared after completion of the chemotherapy. These findings suggest the presence of a relationship between sarcoid reactions and lung cancer in this case.

Carcinoma, Squamous Cell↗
PubMed1996

Clinical usefulness of serum cytokeratin 19 fragment as a tumor marker for lung cancer.

Serum soluble cytokeratin 19 fragment (CYFRA) levels were measured in 251 patients with lung cancer and 139 patients with benign lung diseases to determine the clinical usefulness of CYFRA level determination in the diagnosis and monitoring of lung cancer. Serum levels of CYFRA were measured by a 2-step sandwich ELISA method. When the cut-off value was defined as 3.5 ng/ml, which was associated with a specificity of 95% for benign lung diseases, CYFRA had a high sensitivity (53%) in all patients with lung cancer. Both the serum level of CYFRA and its sensitivity increased significantly with the increase in clinical stage. A comparison of areas under receiver operating characteristic curves showed that CYFRA had the most power of discrimination in the diagnosis of lung cancer among markers including carcinoembryonic antigen, squamous cell carcinoma antigen, carbohydrate antigen 19-9, and neuron-specific enolase. A good correlation was found between serial changes in serum CYFRA levels during therapy and clinical responses for 18 patients who underwent chemotherapy and/or radiotherapy. Our findings suggest that CYFRA may be a marker of choice for screening and monitoring of lung cancer, particularly squamous cell carcinoma.

Adenocarcinoma↗
PubMed1996

[Middle ear cholesteatoma caused by cannonball foreign bodies impacted in the bony eustachian tube: a case report].

We present a 76-year-old male patient with adhesive-type cholesteatoma and with metal foreign bodies which were shown to be located in the bony eustachian tube by computed tomography. He sustained a burn injury of the left tympanic membrane when he was struck by a bomb 52 years ago, during World War II. The cannonball fragments that entered the tympanic cavity were apparently transported to and stuck in the eustachian tube isthmus by mucociliary action after spontaneous closure of the tympanic membrane perforation. Persistent tubal obstruction due to the impacted foreign bodies and surrounding granulation tissue seems to have caused chronic adhesive otitis, leading to cholesteatoma which developed in the attic and mastoid antrum. No foreign bodies became visible after cholesteatoma removal by an intact canal wall technique in conjunction with anterior tympanotomy for wide exposure of the supratubal recess and the tympanic osteum of the eustachian tube. Therefore, anterior tympanotomy was further extended anteriorly to open the enlarged bony eustachian tube, allowing visualization and safe removal of two cannonball-fragments firmly impacted within it. We call this surgical approach to the bony eustachian tube "extended anterior tympanotomy". The transmastoidal accessibility of the bony eustachian tube produced by this technique should be assessed by preoperative computed tomography.

Aged↗
PubMed1995

Changes in urinary deoxypyridinoline level and vertebral bone mass in the development of adjuvant-induced arthritis in rats.

This study was designed to determine the effect of bone resorption on the development of generalized osteopenia in adjuvant-induced arthritic rats. Thirty of a total of sixty male SD rats, 6 weeks of age, were injected with killed mycobacterium butyricum suspended in mineral oil into the right hind paw and assigned to six groups of 5 animals each. The other thirty animals served as the age-matched noninjected controls. Animals were sacrificed at 4, 7, 10, 14, 21, and 28 days post-injection after measuring the bilateral hind-paw volumes. Twenty-four-hour urinary samples were obtained before sacrifice and the levels of deoxypyridinoline (D-Pyr) and creatinine (CR) were measured. Plasma intact osteocalcin levels were measured by a sandwich enzyme immunoassay at the start, 14 and 28 days after injection. Bone mineral measurement and histomorphometrical analyses were performed on specimens of the third lumbar vertebral body. On the seventh day after injection, arthritic rats showed significant decreases in the values of bone mineral content (BMC) and density (BMD) when compared to controls. Urinary D-Pyr/Cr ratios, however, did not increase on the seventh day, showing a significant increase on the tenth day after injection. The serum osteocalcin level was significantly reduced on the fourteenth day. The trabecular bone volume (BV/TV) in the arthritic rats showed a significant decrease from the seventh day. The trabecular thickness (Tb.Th) value significantly decreased on the seventh day after injection.(ABSTRACT TRUNCATED AT 250 WORDS)

Absorptiometry, Photon↗
PubMed1995

White matter hyperintensity in neurologically asymptomatic subjects.

Recent advances in magnetic resonance imaging (MRI) technology have had a great impact on the delectability of minute, asymptomatic lesions of the central nervous system. The clinical significance and treatment modes of these lesions, such as white matter hyperintensity (WMH) lesions detected by T2 MRI, remain controversial. To address these problems, we retrospectively evaluated WMH lesions in relation to clinical parameters for 240 neurologically asymptomatic persons who had visited a hospital for a medical check-up of the brain. Proton and T2-weighted MRI were obtained using a 0.5 T superconducting MR imager using the spin echo technique with a repetition time (TR) of 2800 msec. An echo delay times (TE) of 40 msec was used for the proton MRI, and a TE of 100 msec was used for the T2-weighted MRI. The images were visually analyzed according to a four-point grading system. The MRI findings were correlated with clinical parameters including age, gender, presenting symptoms, and hypertension. The overall frequency of WMH increased with age. Grades 2 and 3 of WMH were more frequent in aged persons, whereas the occurrence of grade 1 WMH remained relatively constant across age groups. Based on multiple regression analysis, age was the most significant variable influencing the frequency of WMH, followed by hypertension. These results imply that WMH lesions may simply be a phenomenon of aging, or may be an indicator of prepathologic state in an ischemic brain.

Adolescent↗
PubMed1995

An outwardly rectifying K+ current active near resting potential in human retinal pigment epithelial cells.

Currents in freshly dissociated adult human retinal pigment epithelial (RPE) cells were studied using the perforated patch-clamp technique. The zero-current potential (V0) averaged -48.9 +/- 7.7 mV (n = 50). Depolarizing voltage pulses from -70 mV evoked an outward current that activated with first-order kinetics and that did not inactivate during prolonged depolarizations. Repolarizing the membrane potential produced tail currents that reversed near the K+ equilibrium potential, indicating that the sustained outward current was carried mainly by K+. The outwardly rectifying K+ conductance (gK) had an activation threshold voltage near -60 mV and was half-maximal at -37 mV. Approximately 25% of gK was active at the average V0. The K+ current was nearly completely blocked by 2 mM Ba2+ but was relatively insensitive to 20 mM tetraethylammonium. The kinetics, voltage dependence, and blocker sensitivity of this current clearly distinguish it from delayed rectifier K+ currents previously identified in RPE cells. We conclude that the sustained outward K+ current may help establish the resting potential of the apical and/or basolateral membranes and may also participate in K+ transport across the RPE.

Adult↗
PubMed1995

Effect of ZCR-2060, an antiallergic agent, on antigen-induced immediate- and late-phase increases in airway resistance in sensitized guinea pigs.

The effect of 2-[2-[4-(diphenylmethyl)-1-piperadinyl]ethoxy] benzoic acid maleate (ZCR-2060) on passive systemic anaphylaxis (PSA) and antigen-induced immediate- and late-phase increase in airway resistance (Rrs) in either passively or actively sensitized guinea pigs were investigated. ZCR-2060 inhibited PSA in guinea pigs. ID50 values of ZCR-2060, ketotifen, terfenadine and cetirizine on PSA were 0.03, 0.02, 0.8 and 0.3 mg/kg, respectively, when administered orally 1 h before the antigen challenge. The protective effect of ZCR-2060 was observed until 12 h before the antigen challenge. Aeroantigen-induce immediate increase in Rrs in passively sensitized guinea pigs with and without metyrapone treatment was inhibited by ZCR-2060, ketotifen, terfenadine and cetirizine. In contrast, prednisolone did not affect the aeroantigen-induced immediate increase in Rrs in animals not treated with metyrapone, but significantly inhibited the metyrapone-induced enhanced immediate response. In actively sensitized animals, the immediate- and late-phase increases in Rrs were observed within 30 min and between 3 and 8 h after the aeroantigen challenge. Pretreatment with metyrapone accelerated both antigen-induced responses. ZCR-2060 (1 mg/kg) significantly inhibited both responses. Ketotifen (1 mg/kg), terfenadine (10 mg/kg) and prednisolone (10 mg/kg) significantly the inhibited the late-phase response, but did not affect the immediate-phase response. In contrast, Cetirizine (10 mg/kg) did not affect either response. The effect of ZCR-2060 on late-phase response was stronger than that of ketotifen, terfenadine and cetirizine, and was almost the same as that of prednisolone. These results suggest that ZCR-2060 has a potent protective effect on immediate- and late-phase increases in Rrs.

Airway Resistance↗
PubMed1995

[Postoperative MRI findings after cholesteatoma surgery].

This study was designed to show MRI findings of postoperative middle ear pathologies and to discuss the usefulness of Gadolinium-enhanced MRI in evaluating the postoperative state of cholesteatoma. Thirty-eight ears which underwent intact canal wall tympanoplasty for cholesteatoma were examined. Recurrent cholesteatoma was detected as an iso-intensity area on T1-weighted images with negative enhancement. Notably, residual cholesteatoma were generally depicted as a round iso-intensity area with negative enhancement. Residual cholesteatoma less than 5mm in diameter were, however, not generally detectable with our MRI scanner. Granulation tissue can be separated from cholesteatoma as an area with positive enhancement. Cholesterol granuloma shows a characteristic high signal pattern on both T1 and T2-weighted images. Hypovascular fibrous tissue and fluid collection may be depicted as a pattern similar to that of cholesteatoma. However, the signal is usually more homogeneous than that of cholesteatoma. We conclude that Gadolinium-enhanced MRI is useful for detecting postoperative cholesteatoma and avoiding unnecessary second-look operations after cholesteatoma surgery, by the canal-up procedure.

Adolescent↗
PubMed1995

[Induction chemotherapy followed by adjuvant surgery (IC-AS) in patients with stage I-II small cell lung cancer (SCLC)].

Ten patients with stage I-II SCLC received IC-AS between 1984 and 1993. As induction chemotherapy, COMP-VAN alternating chemotherapy and CAV-PVP hybrid chemotherapy were administered. The former consisted of a 4-drug combination of cyclophosphamide (CPA), vincristine (VCR), methotrexate (MTX) and procarbazine alternated with a 3-drug combination of etoposide (ETP), adriamycin (ADM) and nimustine every 4 weeks. In the latter, a 3-drug combination of CPA, ADM and VCR given on day 1, and a 2-drug combination of ETP and cisplatin on day 8, were repeated every 4 weeks. All the patients had an objective response, including one complete response by induction chemotherapy. Post-operative pathology revealed SCLC in 4 patients, adenocarcinoma in 2 and no tumor (pathological CR) in 4. Four patients relapsed, and a intrathoracic relapse was experienced in only 2 patients. Six patients have died: 3 from relapsing SCLC, 2 from stomach cancer, and 1 from squamous lung cancer, who was salvaged from relapsing SCLC. The median survival time was 27.5 months, and the 3-year survival rate 37.5%. These results indicate that IC-AS is highly effective for stage I-II SCLC and warrant additional studies comparing IC-AS with chemo-radiotherapy.

Aged↗
PubMed1994

Properties of the inwardly rectifying K+ conductance in the toad retinal pigment epithelium.

An inwardly rectifying K+ current was analysed in isolated toad retinal pigment epithelial (RPE) cells using the perforated-patch clamp technique. The zero-current potential (Vo) of RPE cells averaged -71 mV when the extracellular K+ concentration ([K+]o) was 2 mM. Increasing [K+]o from 0.5 to 5 mM shifted V0 by +43 mV, indicating a relative K+ conductance (TK) of 0.74. At [K+]o greater than 5 mM, TK decreased to 0.53. Currents were larger in response to hyperpolarizing voltage pulses than depolarizing pulses, indicating an inwardly rectifying conductance. Currents were time independent except in response to voltage pulses to potentials positive to 0 mV, where the outward current decayed with an exponential time course. Both the inwardly rectifying current and the transient outward current were eliminated by the addition of 0.5 mM Ba2+, 5 mM Cs+ or 2 mM Rb+ to the extracellular solution. The current blocked by these ions reversed near the K+ equilibrium potential (EK) over a wide range of [K+]o, indicating a highly selective K+ channel. The current-voltage relationship of the isolated K+ current exhibited mild inward rectification at voltages negative to -20 mV and a negative slope conductance at voltages positive to -20 mV. The Cs(+)- and Ba(2+)-induced blocks of the K+ current were concentration dependent but voltage independent. The apparent dissociation constants were 0.8 mM for Cs+ and 40 microM for Ba2+. The K+ conductance decreased when extracellular Na+ was removed. Increasing [K+]o decreased the K+ chord conductance (gK) at negative membrane potentials. In the physiological voltage range, increasing [K+]o from 2 to 5 mM caused gK to decrease by approximately 25%. We conclude that the inwardly rectifying K+ conductance represents the resting K+ conductance of the toad RPE apical membrane. The unusual properties of this conductance may enhance the ability of the RPE to buffer [K+]o changes that take place in the subretinal space at the transition between dark and light.

Animals↗
PubMed1994

Waveform changes of compound muscle action potential (CMAP) with muscle length.

Changes in finger positions influence the waveform of CMAP recorded from the muscle that moves that finger. The present study suggested that the muscle length, dependent on the finger position, was a main factor affecting the waveform. On shortening the muscle length, the amplitude of CMAP increased with concomitant reduction in the duration, and on lengthening, the amplitude decreased with concomitant increase in the duration. These changes are considered due to changes in propagation velocities of muscle fibers dependent on the muscle length. In nerve conduction studies, it is important to carefully monitor the finger position to distinguish the waveform changes with muscle length from those due to nerve lesions.

Action Potentials↗
PubMed1994

Effects of ZCR-2060 on allergic airway inflammation and cell activation in guinea-pigs.

The effects of 2-(2-(4-(diphenylmethyl)-1-piperadinyl) ethoxy) benzoic acid malate (ZCR-2060) on allergic airway inflammation and inflammatory cell activation in guinea-pigs were studied. Allergic airway inflammation was induced by inhalation of antigen into actively-sensitized animals and the increase in inflammatory cells into bronchoalveolar lavage fluid (BALF) was measured. Aeroantigen-induced infiltration of inflammatory cells, especially eosinophils and neutrophils, in BALF gradually increased, and reached a peak at 6 or 9 h after the challenge. ZCR-2060 (1 mg kg-1 p.o.) clearly inhibited the increase of eosinophil numbers in BALF. Moreover, the effect of ZCR-2060 on inflammatory cell activation in terms of chemotaxis and superoxide generation in-vitro was studied. ZCR-2060 (10(-6)-10(-4) M) inhibited the platelet-activating factor (PAF)-induced chemotaxis of eosinophils and neutrophils, but did not inhibit the leukotriene B4-induced chemotaxis of eosinophils and the formyl-Met-Leu-Phe-induced chemotaxis of neutrophils. PAF-induced superoxide anion generation by eosinophils, neutrophils and alveolar macrophages was inhibited by ZCR-2060 (10(-6)-10(-4) M). However, ZCR-2060 did not affect phorbol myristate acetate-induced superoxide anion generation by eosinophils, neutrophils and alveolar macrophages. These results indicate that ZCR-2060 inhibits allergic airway inflammation, and PAF-induced inflammatory cell activation in guinea-pigs. ZCR-2060 may prove useful for the treatment of allergic airway inflammation or allergic disorders, especially inflammatory cell infiltration and activation.

Animals↗