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Biomedical subjects

T Morikawa

Publications and source records attributed to T Morikawa.

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

Allelotype analysis of gallbladder carcinoma associated with anomalous junction of pancreaticobiliary duct.

Anomalous junction of pancreaticobiliary duct (AJPBD) patients has an increased risk of gallbladder and bile duct carcinomas. However, the relevance of carcinoma with AJPBD is not fully clarified. We performed analysis of loss of heterozygosity (LOH) at p53 locus and immunohistochemistry of p53 and K-ras gene mutation in five cases of gallbladder carcinoma associated with AJPBD. LOH of p53 locus and overexpression of p53 were detected in two out of five (40%) and five out of five (100%), respectively, in the present study. K-ras gene mutation at codon 12 and 13 was not detected (0%, 0/5). These results suggest that aberrations of p53 are involved in carcinogenesis of gallbladder carcinoma associated with AJPBD. Next, in order to find the genetic events besides K-ras mutation and overexpression of mutant p53 in this disease, LOH analysis was performed using 72 microsatellite markers. High frequency of allelic loss (> 50%) was found on 2p (81.8%), 4p (50%), 4q (50%), 8q (60%), 9q (50%), 10p (50%), 14p (60%), 14q (50%), 16p (60%), 19p (50%), 21p (50%) and Xp (66.6%). The highest deletion regions on chromosome 2p24 (3/3, 100%), 14q22 (3/4, 75%) and 21q22 (3/4, 75%) were found. The present study suggests that gallbladder carcinoma associated with AJPBD has high frequent allelic loss and has two new regions which may harbor putative tumor suppressor genes.

Aged↗
PubMed2001

X-ray-excited optical luminescence of impurity atom in semiconductor.

We observed the x-ray-excited optical luminescence (XEOL) of erbium-doped silicon (Si:Er) thin films to make a site-selective x-ray absorption fine structure (XAFS) measurement of an optically active Er atom. The undulator beam was used for the increment of the electron population in the excited state, and following XEOL at an infrared wavelength of 1.54 microm with minimum absorption loss in the host Si was detected. The edge-jump and XAFS oscillation were successfully obtained at the Er L(III)-edge. This spectrum originated from inner-shell excitation and relaxation of only the optically active Er atom, indicating that site-selectivity at an atomic level was achieved.

Journal Article↗
PubMed2001

Analysis of predictive factors for recurrence after hepatectomy for colorectal liver metastases.

Hepatectomy for liver metastases from colorectal cancer has recently received general acceptance as a safe, potentially curative treatment. Most patients, however, die of recurrent disease after hepatectomy. The predictive factors for recurrence after first resection of liver metastases have not yet been clarified. The authors aimed to determine the factors that can predict recurrence, especially hepatic-only recurrence after hepatectomy for colorectal liver metastases. Seventy-six patients who underwent liver resection of colorectal metastases were studied retrospectively. Forty-seven (61.8%) of the patients had a recurrence. The patients' disease-free survival after first hepatectomy and the second recurrence sites were univariately and multivariately analyzed using 16 clinicopathologic variables. Wall invasion, lymph node metastases, lymphatic invasion, venous invasion of the primary tumor, 24 months or longer disease-free interval after resection of the primary colorectal cancer, and bilateral liver metastases significantly influenced the disease-free survival (log-rank test: p < 0.05). The multivariate analysis revealed that venous invasion of the primary tumor and bilateral hepatic metastases were independent risk factors for recurrence after hepatectomy. The liver was the only site of second recurrence in 23 patients. Patients with lymph node metastases and venous invasion of the primary tumor had a significant difference between hepatic-only and extrahepatic recurrence after first hepatectomy (chi-square test or Fishers' exact test: p < 0.05). Recurrence after hepatectomy was influenced more by factors associated with the primary colorectal cancer than factors surrounding the first liver metastases. Venous invasion of the primary colorectal cancer was the most important predictable factor for hepatic-only second recurrence.

Adult↗
PubMed2001

Water drinking causes a biphasic change in blood composition in humans.

To investigate precisely the fluid shifts associated with water drinking in humans, we measured continuously blood density and plasma electrolyte concentrations using the mechanical oscillator technique and ion-selective electrodes, respectively, in healthy young volunteers before (10 min) and after (48 min) water drinking for a period of 2 min. Beat-by-beat blood pressure was also monitored throughout the experiment. Drinking 1 l tap water caused a transient increase in blood density immediately after the drinking episode (from 1051.1+/-0.5 g/l before drinking to 1051.8+/-0.5 g/l 4 min after the start of drinking, P<0.05), followed by a gradual reduction (1050.1+/-0.5 g/l at 31 min). This drinking-induced change paralleled those of haematocrit, plasma density and plasma volume. Plasma [Na+] and [Cl-] and osmolality decreased after drinking without transient increases and reached minima at about 30 min. A transient increase in mean arterial blood pressure was observed prior to the increase in blood density. These findings suggest that water drinking causes a biphasic change in plasma volume: initial haemoconcentration, probably due to sympathetic acceleration, followed by haemodilution due to the post-absorptive effect, and further suggest that the fluid shift associated with the initial haemoconcentration is isosmotic.

Adult↗
PubMed2001

Thymic carcinoid in a patient with multiple endocrine neoplasia type 1: report of a case.

We report herein the rare case of a 33-year-old man found to have a multiple endocrine neoplasia type 1 (MEN1)-associated carcinoid tumor in the thymus. A chest roentgenogram demonstrated an asymptomatic anterior mediastinal mass, 7 cm in diameter, and ultrasound-guided percutaneous Tru-Cut biopsy revealed a carcinoid tumor of the thymus. An extended thymectomy was performed through a median sternotomy and pathological examination confirmed the diagnosis of a thymic carcinoid tumor, which was mainly encapsulated with locally invasive growth into the pleura. Despite the absence of a family history of MEN1, he was treated for two pancreatic islet cell tumors, hyperparathyroidism, an adrenal tumor, and a retroperitoneal lipoma. MEN1 mutations were detected both in blood samples and pancreatic tumor tissues. He is now well without any evidence of tumor recurrence 27 months after the operation for the thymic carcinoid. MEN1 mutations were screened by direct nucleotide sequencing of all protein-coding regions of exons 2-10 of the MEN1 gene. Heterozygous germline mutation was detected in the blood sample analyses. Moreover, fresh-frozen pancreatic tumor tissues showed a loss of heterozygosity in the MEN1 region.

Adult↗
PubMed2001

Malignant pheochromocytoma with hepatic metastasis diagnosed 10 years after a resection of the primary incidentaloma adrenal lesion: report of a case.

A 40-year-old woman developed hepatic tumors 10 years after a resection of pheochromocytoma of the left adrenal gland. Computed tomography showed a round tumor measuring about 35mm in diameter at segment V of the liver (Couinaud's classification), and magnetic resonance imaging showed another tumor measuring about 5mm at segment V-VIII of the liver. The results of the endoscopic examination of her upper gastrointestinal tract and barium enema were normal. Owing to a suspected hepatic metastasis of malignant pheochromocytoma, a right lobectomy of the liver was performed. Postoperatively, [131I]metaiodobenzylguanidine scintigram and computed tomography showed no other residual tumors nor metastasis. The present case suggests that a long-term follow-up only by endocrinological examinations is insufficient to find newly developed metastatic foci, while routine diagnostic imaging at frequent intervals is necessary in cases of pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed2001

Distal stump of an occluded intracranial vertebral artery at the vertebrobasilar junction mimicking a basilar artery aneurysm.

The distal stump of an occluded intracranial vertebral artery (VA) can mimic a basilar artery aneurysm of the vertebrobasilar junction. Their differentiation is crucial to establishing the appropriate treatment. We report two cases with occlusion of the distal stump of the VA due to atherosclerosis and arterial dissection. Magnetic resonance images with three-dimensional constructive interference in steady state sequences are useful in revealing the occluded segment as a continuous anatomical structure from the proximal VA to the basilar artery. This information may prevent unnecessary exploratory surgery for a suspected basilar artery aneurysm.

Adult↗
PubMed2001

Tissue sealing.

The tissue adhesive property of fibrinogen was first described 60 years ago. However, it was not until the availability of concentrated plasma fibrinogen and bovine thrombin that the use of fibrin sealants in surgical practice became widespread. Today, fibrin sealants are used for tissue sealing across a range of surgical procedures, including cardiothoracic, gastrointestinal, neurosurgery, and vascular surgery. Tissue sealing with fibrin sealant reduces perioperative hemorrhage and controls blood loss from cut surfaces of tissues that are difficult to suture. The use of fibrin sealants can also reduce perioperative and postoperative complications by reducing fluid leakage, air leakage, and by preventing fistulae formation. Fibrin sealants have a unique physiologic action, and the resulting fibrin clot is fully degraded by the body's natural wound healing process. The range of surgeries and types of procedure that incorporate the use of fibrin sealants in tissue sealing is expanding. As commercially prepared fibrin sealants become more widely available, the number of patients and surgeons benefiting from improved surgical outcomes is also set to increase. This article reviews the areas of surgery within which fibrin sealants are currently used to assist tissue sealing and highlights the improved surgical outcomes, such as reduced blood loss, operative time, and postoperative complications.

Fibrin Tissue Adhesive↗
PubMed2001

Antioxidant constituents from rhubarb: structural requirements of stilbenes for the activity and structures of two new anthraquinone glucosides.

The methanolic extracts from five kinds of rhubarb were found to show scavenging activity for DPPH radical and .O2-. Two new anthraquinone glucosides were isolated from the rhizome of Rheum undulatum L. together with two anthraquinone glucosides, a naphthalene glucoside, and 10 stilbenes. In the screening test for radical scavenging activity of rhubarb constituents, stilbenes and a naphthalene glucoside showed activity, but anthraquinones and sennosides did not. In addition, most stilbenes inhibited lipid peroxidation of erythrocyte membrane by tert-butyl hydroperoxide. Detailed examination of the scavenging effect on various related compounds suggested the following structural requirements; 1) phenolic hydroxyl groups are essential to show the activity; 2) galloyl moiety enhances the activity; 3) glucoside moiety reduces the activity; 4) dihydrostilbene derivatives maintain the scavenging activity for the DPPH radical, but they show weak activity for .O2-. In addition, several stilbenes with both the 3-hydroxyl and 4'-methoxyl groups inhibited xanthine oxidase.

Animals↗
PubMed2001

Hepatoprotective constituents from zedoariae rhizoma: absolute stereostructures of three new carabrane-type sesquiterpenes, curcumenolactones A, B, and C.

New carabrane-type sesquiterpene lactones, curcumenolactones A, B, and C, were isolated from the 80% aqueous acetone extract of Zedoariae Rhizoma (Zingiberaceae), together with 41 sesquiterpenes and two diarylheptanoids. The absolute stereostructures of curcumenolactones A, B, and C were determined on the basis of physicochemical evidence, which included nuclear Overhauser effect (NOE) and circular dichroic (CD) spectroscopic analyses. Curcumenone, a principal carabrane-type sesquiterpene from Zedoariae Rhizoma, was found to show potent protective effect on D-galactosamine/lipopolysaccharide-induced acute liver injury in mice. In addition, curcumenolactones A and B and the other constituents showed protective effect on D-galactosamine-induced cytotoxicity in primary cultured rat hepatocytes.

Animals↗
PubMed2001

Inhibitors from rhubarb on lipopolysaccharide-induced nitric oxide production in macrophages: structural requirements of stilbenes for the activity.

By bioassay-guided separation, three stilbenes (rhapontigenin, piceatannol, and resveratrol), two stilbene glucoside gallates (rhaponticin 2"-O-gallate and rhaponticin 6"-O-gallate), and a naphthalene glucoside (torachrysone 8-O-beta-D-glucopyranoside) with inhibitory activity against nitric oxide (NO) production in lipopolysaccharide-activated macrophages were isolated (IC(50)=11--69 microM). The oxygen functions (-OH, -OCH(3)) of stilbenes at the benzene ring were essential for the activity. The glucoside moiety reduced the activity, while the alpha,beta-double bond had no effect. Furthermore, the active stilbenes (rhapontigenin, piceatannol, and resveratrol) did not inhibit inducible NO synthase activity, but they inhibited nuclear factor-kappa B activation following expression of inducible NO synthase.

Lipopolysaccharides↗
PubMed2001

Hypovolemic intolerance to lower body negative pressure in female runners.

PURPOSE: An attenuated baroreflex response and orthostatic intolerance have been reported in endurance-trained male athletes; however, it is still unknown whether this occurs also in females. The purpose of the present study was to examine whether endurance exercise-trained women had a predisposition to orthostatic compromise, and if so, what causative factor(s) may induce orthostatic intolerance. METHODS: We studied cardiovascular and hormonal responses to graded lower body negative pressure (LBNP) (0 to -60 mm Hg) in 26 middle-distance female runners (18.6 +/- 0.1 yr) as the exercise-trained (ET) subjects and 23 age-matched untrained (UT) control subjects. On the basis of the occurrence of syncope episodes during LBNP, ET and UT subjects were further allocated to two groups; ET with presyncope (ET+syncope) and without presyncope (ET-syncope) and UT with presyncope (UT+syncope) and without presyncope (UT-syncope). RESULTS: Occurrence of presyncope episodes during LBNP was higher in ET (65.4%, P < 0.05) than that for UT (34.8%). Leg compliance was higher (P < 0.05) in ET than in UT. LBNP reduced stroke volume (SV) more (P < 0.05), increased heart rate (HR) higher (P < 0.05), and increased forearm vascular resistance (FVR) more in ET+syncope as compared with the other groups. Response of vasoactive hormones to LBNP was higher in ET+syncope (P < 0.05) than that of the other groups except for norepinephrine (NE); high in both ET+syncope and UT+syncope. The relationship between SV and NE, an index of sympathetic neuronal response, had no training-related changes during LBNP. CONCLUSION: We conclude that exercise-trained females have a high incidence of orthostatic intolerance during LBNP, with a greater reduction of SV independent of changes in baroreflex and neurohumoral function. A lower incidence of LBNP intolerance in UT may be accounted for by a lower reduction of SV during LBNP. An increase in leg compliance in the exercise-trained females may play an important role in inducing pronounced reduction of SV and hence the intolerance to LBNP.

Adolescent↗
PubMed2001

A rare case of bronchial glomus tumor.

A 48-year-old man was admitted because of bloody sputum in whom a chest computed tomography (CT) scan and fiberoptic bronchoscopy demonstrated a polypoid tumor in the left main bronchus. The tumor was surgically resected, and the pathological and immunohistochemical findings led to diagnosis of the tumor as a bronchial glomus tumor.

Biopsy, Needle↗
PubMed2001

Sodium sensitivity of blood pressure appearing before hypertension and related to histological damage in immunoglobulin a nephropathy.

Patients with renal parenchymal disease exhibit sodium-sensitive hypertension. We examined patients with immunoglobulin A (IgA) nephropathy to determine whether this sensitivity appears before hypertension begins and whether this sensitivity is related to histological damage. Thirty-eight patients with IgA nephropathy followed a diet with an ordinary sodium level for 1 week and a sodium-restricted diet for 1 week, in random order, and were divided into 3 groups by their systemic blood pressure on the diet with an ordinary sodium level (optimal, <120/<80 mm Hg, n=15; normal to high-normal, 120 to 139/80 to 89 mm Hg, n=18; hypertensive, >/=140/>/=90 mm Hg, n=5). The sodium sensitivity index was calculated as the reciprocal of the slope of the pressure-natriuresis curve drawn by linkage of 2 datum points obtained during the different diets. The scores for glomerulosclerosis and tubulointerstitial damage were evaluated semiquantitatively. The sensitivity index, glomerulosclerosis score, and score for tubulointerstitial damage were higher in patients with normal to high-normal blood pressure or hypertension than in patients with optimal pressure. The sensitivity index was significantly correlated with glomerulosclerosis (P=0.001) and tubulointerstitial damage (P=0.002). In patients with normal to high-normal pressure, sodium restriction lowered blood pressure to the optimal range and decreased proteinuria. In patients with IgA nephropathy, sodium sensitivity of blood pressure related to renal histological damage appears before hypertension.

Adult↗
PubMed2001

Design and synthesis of carboxylate inhibitors for matrix metalloproteinases.

A series of carboxylate compounds were prepared from N(alpha)-substituted 2,3-diaminopropionic acid and were tested for efficacy as matrix metalloproteinase (MMP) inhibitors. During modeling of the initial compound 10a, we utilized three-dimensional structure modeling software (InsightII/Discover Ver. 2.98). Some of the prepared carboxylate derivatives, such as carbamate compounds (12c,d, 22) and sulfonamide compounds (14b,c), proved to be effective MMP-1 inhibitors (with IC50 values of a 10(-6) M order), depending on the substituent at the N(alpha)-position of 2,3-diaminopropionic acid. Some of them were also evaluated for inhibition of stromelysin-1 (MMP-3), and the sulfonamide compound 14c exceeded the lead compound 5b in its MMP-3 inhibitory potency. For the carbamate compounds, we investigated the minimum molecular size at which the MMP-1 inhibitory potency was maintained, and found that this was P3-P1' compound 10b.

Carboxylic Acids↗
PubMed2001

Medicinal foodstuffs. XXVII. Saponin constituents of gotu kola (2): structures of new ursane- and oleanane-type triterpene oligoglycosides, centellasaponins B, C, and D, from Centella asiatica cultivated in Sri Lanka.

Ursane- and oleanane-type triterpene oligoglycosides, centellasaponins B, C, and D, were isolated from the aerial parts of Centella asiatica (L.) Urban cultivated in Sri Lanka together with madecassoside, asiaticoside, asiaticoside B, and sceffoleoside A. The chemical structures of centellasaponins B, C, and D were determined on the basis of chemical and physicochemical evidence to be madecassic acid 28-O-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside, madasiatic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside, and 3beta,6beta,23-trihydroxyolean-12-en-28-oic acid 28-O-alpha-L-rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->6)-beta-D-glucopyranoside, respectively.

Carbohydrate Sequence↗
PubMed2001

Bioactive saponins and glycosides. XIX. Notoginseng (3): immunological adjuvant activity of notoginsenosides and related saponins: structures of notoginsenosides-L, -M, and -N from the roots of Panax notoginseng (Burk.) F. H. Chen.

New dammarane-type triterpene saponins, notoginsenosides-L, -M, and -N, were isolated from the glycosidic fraction of the dried roots of Panax notoginseng (Burk.) F. H. Chen. Their structures were elucidated on the basis of chemical and physicochemical evidence. Immunological adjuvant activities of the principal notoginsenosides and related dammarane-type triterpene saponins were examined and notoginsenosides-D, -G, -H, and -K were found to increase the serum IgG level in mice sensitized with ovalbumin.

Adjuvants, Immunologic↗