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Biomedical subjects

K Kawaguchi

Publications and source records attributed to K Kawaguchi.

At least 37 records · Page 2Linked to original sources
PubMed2001

Pleomorphic leiomyosarcoma: clinicopathologic and immunohistochemical study with special emphasis on its distinction from ordinary leiomyosarcoma and malignant fibrous histiocytoma.

Pleomorphic leiomyosarcoma (PLMS) was recently described as a morphologic variant of leiomyosarcoma; however, its diagnostic criteria, as shown by morphologic features and biologic behavior, remain controversial. We describe 28 cases of pleomorphic sarcoma with pleomorphic areas in more than two thirds of the tumor and an ordinary leiomyosarcomatous fascicular area covering less than one third as PLMS. PLMS comprised 8.6% of all the leiomyosarcomas (322 cases) registered in our institute. Patients ranged in age from 31 to 89 years (average, 57.9 years). Seventeen patients (60.7%) were male and 11 were female. Tumor location was as follows: the extremities in 17 cases, the retroperitoneum or abdominal cavity in 7 cases, the chest/abdominal wall in 3 cases, and the scalp in 1 case. Histologically, all cases showed at least small foci of fascicles consisting of smooth muscle tumor cells, in addition to pleomorphic areas mimicking storiform-pleomorphic malignant fibrous histiocytoma. The border between pleomorphic and leiomyosarcomatous fascicular areas was sharp in 3 cases, gradual in 2 cases, and blending in 23 cases. Sixteen cases (57.1%) showed a typical storiform pattern, 6 cases revealed extensive stromal hyalinization, 6 cases showed a chronic inflammatory infiltrate, 2 cases had the foci of foamy xanthomatous cells, and 7 cases contained myxoid malignant fibrous histiocytoma-like areas covering less than 50% of the tumor. The tumors had a tendency to be of a morphologically higher grade (10 tumors were French Federation of Cancer Centers grade 2, 18 were grade 3). Five of 28 cases (18%) showed rhabdoid features. Immunohistochemically, all of the 28 tumors examined showed a positive reactivity for at least one smooth muscle marker (desmin, muscle-specific actin, and alpha-smooth muscle actin) in the leiomyosarcomatous fascicular areas. In the pleomorphic areas the expression of smooth muscle markers (desmin 10 of 28, muscle-specific actin 13 of 28, and alpha-smooth muscle actin 14 of 28) was significantly reduced, compared with that in leiomyosarcomatous fascicular area (desmin 18 of 28, muscle-specific actin 26 of 28, and alpha-smooth muscle actin 24 of 28). No significant difference was observed between the MIB-1 labeling index in the leiomyosarcomatous fascicular areas (26.10 on average) and that in the pleomorphic areas (26.17 on average). However, the MIB-1 labeling index in PLMS was significantly higher than that in ordinary leiomyosarcoma (n = 20, 12.86 on average) or storiform-pleomorphic malignant fibrous histiocytoma (n = 16, 16.63 on average). In 23 patients follow-up data were available with a duration of 1-239 months. Eleven patients developed metastases, and lung accounted for the most common site of metastasis (9 cases). Fifteen of 23 patients (65.2%) died of disease. Our results indicate that PLMS should be differentiated from ordinary leiomyosarcoma because of its high proliferative activities and rather aggressive biologic behavior.

Adult↗
PubMed2001

Pituitary apoplexy caused by ruptured internal carotid artery aneurysm.

BACKGROUND AND PURPOSE: We report the first case of pituitary apoplexy caused by the rupture of an intracavernous carotid artery aneurysm embedded in a pituitary adenoma. CASE DESCRIPTION: A 46-year-old man presented with clinical and CT findings typical of pituitary apoplexy. MRI showed an unusual flow-void protrusion into the intratumoral hematoma, which, however, was not diagnosed as a ruptured aneurysm until severe intraoperative bleeding occurred. Angiography after surgery revealed an intracavernous carotid artery aneurysm. CONCLUSIONS: The possible association of adenoma and aneurysmal rupture should be kept in mind when assessing any case of pituitary apoplexy.

Aneurysm, Ruptured↗
PubMed2001

[Induction chemotherapy (cisplatin + vinorelbine) is found to be markedly effective for squamous cell lung carcinoma with sarcoidosis--a case report].

A sixty-one-year-old man was admitted to our hospital because of a right lung tumor shadow. He had been diagnosed as having sarcoidosis at the age of fifty-seven. He was newly diagnosed as having squamous cell carcinoma by trans bronchial biopsy. He was treated with an induction chemotherapy (cisplatin 80 mg/m2 + vinorelbine 20 mg/m2) followed by right middle and lower lobectomy with a mediastinal nodal dissection, because the stage of his carcinoma was cT2N2M0. Resected lung tissue showed the disappearance of cancer cells. Dissected mediastinal and hilar lymph nodes showed many sarcoid granulomas. Cisplatin combined with vinorelbine might be an effective chemotherapy for non-small cell lung carcinoma.

Antineoplastic Agents↗
PubMed2000

Total synthesis of the antitumor antibiotic (+/-)-fredericamycin A by a linear approach.

A linear approach to the total synthesis of racemic fredericamycin A (1) through the oxidative intramolecular [4 + 2] cycloaddition of a (phenylthio)acetylene-cobalt complex is described, which is applicable for the asymmetric total synthesis of naturally occuring 1. The highlight of this work is the aromatic Pummerer-type reaction with 1-ethoxyvinyl chloroacetate, which effects the introduction of the oxygen functional group to the internal B-ring of the highly functionalized, congested polyaromatic ABC-ring moiety.

Antibiotics, Antineoplastic↗
PubMed2000

Temporal and mosaic distribution of large ganglion cells in the retina of a daggertooth aulopiform deep-sea fish (Anotopterus pharao).

The daggertooth Anotopterus pharao (Aulopiformes: Anotopteridae) is a large, piscivorous predator that lives within the epipelagic zone at night. In this species, the distribution of retinal ganglion cells has been examined. An isodensity contour map of ganglion cells shows that the cells concentrate in a slightly ventral region of the temporal retina. The region of high ganglion cell density contains 4.07 x 10(3) cells mm(-2), and the resulting visual acuity is 3.5 cycles deg(-1). Outside the area centralis, conspicuously large ganglion cells (LGCs) are observed in the temporal margin of the retina. The LGCs are regularly arrayed, and displaced into the inner plexiform layer. Thick dendrites extend into the outer part (sublamina a) of the inner plexiform layer. In the retinal whole mount, the total number of LGCs is 1590 (90.7 cm specimen), and the mean size of the LGCs is about four times larger than that of the ordinary ganglion cells. The morphological appearance of the LGCs was similar to the off-type alpha cells of the cat retina. The function of these distinctive LGCs is discussed in relation to specific head-up feeding behaviour.

Animals↗
PubMed2000

Temperature dependence of force, velocity, and processivity of single kinesin molecules.

Using the bead assay in optical microscopy equipped with optical tweezers, we have examined the effect of temperature on the gliding velocity, force, and processivity of single kinesin molecules interacting with a microtubule between 15 and 35 degrees C. The gliding velocity increased with the Arrhenius activation energy of 50 kJ/mol, consistent with the temperature dependence of the microtubule-dependent ATPase activity. Also, the average run length, i.e., a measure of processivity of kinesin, increased on increasing temperature. On the other hand, the generated force was independent of temperature, 7.34 +/- 0.33 pN (average +/- S.D., n = 70). The gliding velocities decreased almost linearly with an increase in force irrespective of temperature, implying that the efficiency of mechano-chemical energy conversion is maintained constant in this temperature range. Thus, we suggest that the force generation is attributable to the temperature-insensitive nucleotide-binding state(s) and/or conformational change(s) of kinesin-microtubule complex, whereas the gliding velocity is determined by the ATPase rate.

Adenosine Triphosphate↗
PubMed2000

Identification of SH Deltav=1 Ro-vibrational Lines in R Andromedae.

We report the identification of SH Deltav=1 ro-vibrational lines in the published high-resolution infrared spectrum of the S-type star R Andromedae. This is the first astronomical detection of this molecule. The lines show inverse P Cygni profiles, indicating infall motion of the molecular layer due to stellar pulsation. A simple spherical shell model with a constant infall velocity is adopted to determine the condition of the layer. It is found that a single excitation temperature of 2200 K reproduces the observed line intensities satisfactorily. SH is located in a layer from 1.0 to approximately 1.1 stellar radii, which is moving inward with a velocity of 9 km s-1. These results are consistent with the previous measurements of CO Deltav=3 transitions. The estimated molecular abundance SH/H is 1x10-7, consistent with a thermal equilibrium calculation.

Journal Article↗
PubMed2000

Esophageal intramural pseudodiverticulosis associated with esophageal perforation.

We report a rare case of esophageal intramural pseudodiverticulosis with lower esophageal stricture which perforated into the peritoneal cavity after the patient vomited. A 61-year-old man was admitted with severe chest and epigastric pain after dysphagia and vomiting. Under a diagnosis of upper gastrointestinal perforation, laparotomy was performed. The anterior wall of the abdominal esophagus was found to have ruptured, and proximal gastrectomy with abdominal esophagectomy was performed. Histological examination revealed esophageal intramural pseudodiverticulosis with esophageal stricture distal to the site of rupture, and postoperative endoscopy showed diffuse pseudodiverticulosis in the remaining esophagus. The patient is free of symptoms 5 years after the surgery. This case suggests that careful treatment may be indicated in patients with esophageal intramural pseudodiverticulosis with stricture and elevated intraluminal pressure, to minimize the possibility of severe complications such as esophageal perforation.

Diverticulum, Esophageal↗
PubMed2000

Temperature change does not affect force between single actin filaments and HMM from rabbit muscles.

The temperature dependence of sliding force, velocity, and unbinding force was studied on actin filaments when they were placed on heavy meromyosin (HMM) attached to a glass surface. A fluorescently labeled actin filament was attached to the gelsolin-coated surface of a 1-microm polystyrene bead. The bead was trapped by optical tweezers, and HMM-actin interaction was performed at 20-35 degrees C to examine whether force is altered by the temperature change. Our experiments demonstrate that sliding force increased moderately with temperature (Q(10) = 1.6 +/- 0.2, +/-SEM, n = 9), whereas the velocity increased significantly (Q(10) = 2.9 +/- 0.4, n = 10). The moderate increase in force is caused by the increased number of available cross-bridges for actin interaction, because the cross-bridge number similarly increased with temperature (Q(10) = 1. 5 +/- 0.2, n = 3) when measured during rigor induction. We further found that unbinding force measured during the rigor condition did not differ with temperature. These results indicate that the amount of force each cross-bridge generates is fixed, and it does not change with temperature. We found that the above generalization was not modified in the presence of 1 mM MgADP or 8 mM phosphate.

Actins↗
PubMed2000

Suppression of lethal toxicity of endotoxin by biscoclaurine alkaloid cepharanthin.

Suppressive effects of Cepharanthin (CE) on lipopolysaccharide (LPS)-induced tumor necrosis factor alpha (TNFalpha) production followed by liver injury were investigated. Pretreatment with CE reduced limulus activity of LPS. Intraperitoneal treatment with CE 10 min before an i.v. challenge of LPS resulted in protection from LPS lethality in D-galactosamine (GalN)-sensitized BALB/c but not in C57BL/6 and C57BL/10ScSn mice. Treatment with CE before the LPS challenge significantly reduced serum TNF levels in a dose-dependent manner. The suppression was most effective when CE was administered 10 min before the LPS challenge. Increased levels of enzymes released from hepatocytes into the circulation, as a result of LPS-induced liver injury, were reduced by CE administration. Histological evaluation demonstrated that massive cell infiltration after severe injury developed in liver of mice injected with LPS plus D-GalN unless they were pretreated with CE. Apoptotic cells decreased by treatment with CE. Treatment with CE retarded lethal shock induced by an infection with 10(8) CFU Salmonella typhimurium deltaaroA mutant. These results suggest that action of CE is initiated through suppression of LPS-induced TNF production.

Alanine Transaminase↗
PubMed2000

Selective transvenous liquid embolization of a Type 1 dural arteriovenous fistula at the junction of the transverse and sigmoid sinuses. Case report.

The authors describe the case of a 51-year-old man with a Type 1 dural arteriovenous fistula (AVF) located at the junction of the transverse and sigmoid sinuses. The dural AVF developed after the patient underwent a craniotomy for an acute extradural hematoma. The patient suffered pulsatile tinnitus 3 months after surgery. After several attempts at transarterial embolization (TAE), the venous channel located close to the skull fracture was accessed via a transfemoral-transvenous approach and was embolized by administering a liquid nonadhesive agent. Successful embolization of the dural AVF was achieved both clinically and radiologically without causing considerable hemodynamic alterations. This procedure, either alone or combined with TAE, would seem to be an alternative treatment for dural AVFs in this location, without causing compromise of flow within the affected sinuses, when selective venous access is available.

Acute Disease↗
PubMed2000

[Detection of pyrogenic exotoxin SpeA, SpeB and SpeC genes in Chilean streptococci isolates and their association with clinical manifestations].

BACKGROUND: The virulence of Streptococcus pyogenes is determined by a variety of structural molecules, toxins and complex enzymes. Pyrogenic exotoxins cause fever, erythematous reactions, cytotoxic and immunological effects. AIM: To assess the frequency of speA, SpeB and SpeC genes in Chilean Streptococcus pyogenes strains and their association with the invasiveness of infections. MATERIAL AND METHODS: The genes for pyrogenic exotoxins SpeA, SpeB and SpeC were determined by polymerase chain reactions in 114 strains of group A Streptococcus pyogenes isolated from Chilean patients with invasive or non invasive infections. RESULTS: The gene for SpeA was present in 30.7% of isolates, the gene for SpeB was present in 69.3% and the gen for SpeC in 44.7% of isolates. The gene for SpeA was present in 20 of 33 invasive infections and in 15 of 81 non invasive infections (p < 0.0001). On the contrary, the gene for SpeC was present in 11 of 33 invasive infections and in 41 of 81 non invasive infections (p < 0.05). The frequency of speB was similar in invasive and non invasive infections. CONCLUSIONS: There is a clear relationship between the presence of SpeA genes and the severity of infections caused by Streptococcus pyogenes.

Bacterial Proteins↗
PubMed2000

Retinal changes after retinal translocation surgery with scleral imbrication in dog eyes.

PURPOSE: To examine retinal changes induced by scleral imbrication during retinal translocation surgery in dog eyes. METHODS: Fifteen dogs were anesthetized and underwent retinal translocation surgery. After lensectomy and vitrectomy, an intentional retinal detachment was created, and the upper temporal sclera around the equator was imbricated with five mattress sutures. Translocated distances were calculated by pre- and postoperative photographs. At 1, 2, and 4 weeks after the surgery, the retina was studied by TdT-dNTP terminal nick-end labeling (TUNEL) and immunohistochemistry of peanut agglutinin (PNA) lectin and glial fibrillary acidic protein (GFAP). RESULTS: The retina was translocated by a mean distance of 0.53 +/- 0.30 disc diameters or 959 +/- 543 micrometer. Retinal folds were created around the optic disc in all eyes. Histologic examination of the retinal folds 1 week after the surgery showed many TUNEL-positive cells in the outer nuclear layer, loss of photoreceptor cells, and shortening of the outer and inner segments. A strong immunoreactivity to GFAP was detected in the folds of the retina. CONCLUSIONS: . The results demonstrated that retinal translocation surgery by scleral imbrication inevitably caused retinal folds as a postoperative complication, and the retina within the folds showed extensive loss of photoreceptor cells. It is recommended that the foveal translocation surgery be planned to avoid involving the fovea in the retinal folds.

Animals↗
PubMed2000

The main factor causing prolonged reaction time on force producing process following anterior cruciate ligament reconstruction.

This study investigated the electromechanical properties of atrophied human quadriceps femoris muscle during a voluntarily elicited maximal isometric contraction (MVC) and a peripherally stimulated twitch contraction. Nineteen patients were recruited 2-3 months following a unilateral anterior cruciate ligament (ACL) reconstruction. Both the involved leg as well as the uninvolved leg were studied. Maximal twitch response was elicited and surface electromyograms (EMG) were recorded from the vastus lateralis. Total reaction time (TRT) for both MVC and twitch on involved leg was prolonged (251.47 msec, 26.01 msec). This prolongation suggests an extended lag in avoiding injury such as during sports. Pre-motor time during both MVC and twitch (PMTmvc, PMTtwitch) did not differ between both groups. Electromechanical delay during MVC (EMDmvc) was prolonged on involved leg (53.42 msec), and also evoked twitch EMD (EMDtwitch) (20.04 msec) as compared to the opposite side. Prolonged EMDtwitch may be due to a decrease in stiffness of the series elastic component, changes of peripheral muscle composition to containing more slow type muscle fibers, or a decrease in function of the excitation-contraction (E-C) coupling process. A prolonged EMDtwitch can also explain the prolonged EMDmvc. These findings also suggested that prolonged TRTmvc to visual stimulus during MVC in atrophied human quadriceps femoris muscle after disuse was principally due to prolongation of EMDmvc. Prolonged EMDmvc may have resulted from decreased muscle stiffness, which was evident in the prolongation of the EMDtwitch.

Anterior Cruciate Ligament↗