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Biomedical subjects

R Kuroda

Publications and source records attributed to R Kuroda.

At least 91 records · Page 5Linked to original sources
PubMed1994

Altered expression of antithrombotic molecules in human glioma vessels.

A total of 14 surgical specimens, including 7 glioblastomas, 3 anaplastic astrocytomas, 2 brains adjacent to glioblastoma and 2 grossly normal brains, were investigated immunohistochemically for the expression of antithrombin III (AT-III), heparan sulfate proteoglycan (HSPG) and thrombomodulin (TM) in the endothelium of microvessels. The immunoreaction to AT-III was of moderate intensity in grossly normal brains, brains adjacent to glioblastoma, and anaplastic astrocytomas, but was only weak in glioblastomas, especially in the capillaries. The immunoreaction to HSPG was constantly intense in the microvessels in all the specimens. Although the immunoreaction to TM was negative or only faint in the microvessels in grossly normal brains, it was moderately to strongly intense in anaplastic astrocytomas and brains adjacent to glioblastoma. The intensity of immunoreaction to TM was variable, from faint to strong in the capillaries, and moderate to strong in larger microvessels in glioblastomas. The present study suggested that the alterations in the expression of those antithrombotic molecules could explain, at least in part, the tendencies for intratumoral hemorrhage as well as intravascular thrombosis in the different areas of malignant gliomas.

Antithrombin III↗
PubMed1994

Expression of thrombomodulin in astrocytomas of various malignancy and in gliotic and normal brains.

A total of 22 surgical specimens, 16 astrocytomas with various malignancy, 3 brains adjacent to tumor and 3 brains with non-neoplastic lesion, was investigated immunohistochemically for the expression of thrombomodulin (TM). This membrane protein is localized on the vascular endothelium of nearly every human tissue and plays a crucial role in the maintenance of antithrombotic property of the endothelial cells. Although the normal cerebral vessels were negative for TM, the tumor vessels were positive for TM. The increased expression of TM was, however, demonstrated not only in glioblastomas but also in low-grade astrocytomas. Furthermore, the vessels in the brains adjacent to tumor and gliotic brains were also positive for TM. Those observations suggested that the tendency of intratumoral bleeding, which is rather characteristic of glioblastomas, is not simply explained by the altered expression of vascular endothelial TM. In two cases of glioblastoma, not only the blood vessels but also the tumor cells were positive. Considering the mitogenic activity of thrombin, a ligand for TM, the increased expression of TM might be related to the tumor neovascularization and also the tumor growth.

Astrocytoma↗
PubMed1994

Remote subarachnoid haemorrhage in the posterior fossa following supratentorial surgery. Clinical observation of 6 cases.

Haemorrhage in regions remote from the site of following intracranial operations is rare, but they do occur. We performed supratentorial craniotomy on 639 patients between the time of introduction of computed tomography (CT) for clinical use in 1983 and June 1992; subarachnoid haemorrhage (SAH) in the posterior fossa occurred postoperatively in six of these cases. These included four patients with tumours in the sellar region, one with an arteriovenous malformation (AVM) and one who underwent superficial temporal artery (STA)-middle cerebral artery (MCA) anastomosis. The ages of the six patients ranged from 17-72 years. Haemorrhage occurred on the day of operation in one case and was detected on CT examination on the day following surgery in the remaining five cases. Of three patients with disturbance of consciousness, two underwent suboccipital craniectomy for reduction of intracranial pressure, while one received barbiturate therapy and later underwent cerebrospinal fluid (CSF) shunt surgery. No special treatment was necessary for the remaining three patients with less serious lesions. Five of the six patients ultimately recovered their pre-operative neurological status apart from the primary diseases. Factors inducing such haemorrhages seem likely to include displacement of the cerebellum by reduced CSF pressure during and after operations, and stretching and tearing of the veins and venules in the sulci of the tentorial surface of the cerebellum. Consideration should therefore be given to the maintenance of an appropriate CSF pressure during operation; this is particularly important in elderly patients and those with an atrophied cerebral cortex.

Adolescent↗
PubMed1994

Interstitial chemotherapy with biodegradable ACNU pellet for glioblastoma.

For patients with nonresectable glioblastoma (GB) or recurrent GB, we have recently been using an interstitial chemotherapy with biodegradable polylactic acid pellets containing nimustine chloride (ACNU), in combination with superselective arterial ACNU injection, routine irradiation and chemotherapy. The ACNU pellets are prepared by mixing polylactic acid powder and ACNU, and then melting the mixture at low temperature and moulding it into a thin pellet. Pharmacological anticancer activity was experimentally demonstrated by the finding that a region of suppression was present surrounding an ACNU pellet placed in a B6 melanoma cell culture disc, but that no such suppression was present around a control pellet. In order to determine the spatial and temporal distribution of ACNU, a small pellet (ACNU: 0.6 mg) was implanted in the frontal lobe of rats. ACNU concentration determined by HPLC was 61.0 micrograms/g brain tissue on day 1. 22.5 on day 3, and 5.5 on day 7; small amounts of ACNU were in fact released for at least 4 weeks after implantation. This pellet was used for the clinical treatment of 11 GB patients. Four patients had several pieces of pellets implanted immediately after CT-guided stereotactic biopsy, and the other 7 had pellets placed in residual tumor after partial removal at craniotomy. No ACNU was detectable in serum. CT studies obtained at subsequent appropriate intervals disclosed gas formation around the pellets, a slight increase in edema, and necrosis or decrease in CT enhancement of tumor beginning around day 12 after implantation. Bone marrow suppression did not occur, since ACNU was administered interstitially and in the range of 50-200 mg (average: 126 mg) per patient.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

[Early detection of breast cancer by mass screening using mammography].

A mass screening trial for breast cancer using mammography was carried out in Tokushima Prefecture, either itinerant screening in the communities or center screening at the workplace. Craniocaudal and lateral oblique imagings of the breast using two-view film mammography were performed at the first stage of screening. In addition, physical examination of the breast was also performed on subjects independently. A total of 8 cases with breast cancer were found in these trials by mammography alone, and no cases with breast cancer were detected by physical examination. The detection rates were 0.19% in itinerant screening, and 0.92% in center screening, respectively. This was much higher than the level (0.10%) obtained by mass screening using physical examination alone in Japan. Moreover, in elderly patients (age over 50 years), the detection rates were higher (0.54%, 1.21%). The number of clinical stage for cases with breast cancer detected by these screening were 5 cases in TIS and 3 in stage I. Thus, all cases were patients with early-stage breast cancer. From these results, mass screening using mammography should be mandatory for elderly women (over 50 years) with asymptomatic breasts.

Adult↗
PubMed1994

[Long survival after removal of a huge brain tumor which had metastasized from a lung cancer: case report].

Patients with large metastatic brain tumors are considered to have poor prognosis. We report a case of a patient with more than 33 months survival after complete resection of a huge temporal tumor which had metastasized from a lung cancer. A 57-year-old woman presented left hemiparesis and disturbance of consciousness. Magnetic resonance images revealed a huge cystic mass lesion in the right temporal lobe. After a macroscopically complete excision of the tumor, she received radiation therapy (whole brain 50 Gray). She had received lung surgery for the primary lung cancer, 2 years prior to brain metastasis. Histological examination showed papillary tubular adenocarcinoma which was similar to the previously resected lung cancer. Thirty three months after the resection of the intracranial tumor, she has no neurological deficits and no signs of recurrence of either brain tumor or lung tumor. We discuss the size of metastatic brain tumor and the postoperative prognosis of patients with metastatic brain tumor.

Adenocarcinoma, Papillary↗
PubMed1993

Two-step procedure for early neonatal surgery of fetal hydrocephalus.

This retrospective study analyzed the diagnosis and treatment of 36 infants with central nervous system anomalies diagnosed antenatally by ultrasonographic studies between December, 1987 and December, 1990. Magnetic resonance imaging of the fetuses without maternal or fetal sedation/anesthesia was very useful, as the fetal ventricular system was depicted clearly. Twenty-three infants with hydrocephalus underwent early postnatal surgical emplacement of a miniature Ommaya's reservoir. Continuous cerebrospinal fluid aspiration was combined with intracranial pressure monitoring. Observation of the ventricular size used ultrasonography through the anterior fontanelle. This technique controlled the intracranial pressure during the early neonatal period without serious complications. A ventriculoperitoneal shunt was emplaced 1 month later as the second, more permanent treatment. This two-step procedure achieves brain reconstitution and prevents irreversible neurological damages. Clinical and radiographic findings are presented to illustrate the effectiveness of this approach.

Brain↗
PubMed1993

Treatment of severe localized cerebral vasospasm following recurrent hemorrhage from middle cerebral artery aneurysm--case report.

A 52-year-old female presented with localized but severe cerebral vasospasm induced by recurrent aneurysmal subarachnoid hemorrhage. The middle cerebral artery (MCA) aneurysm was clipped and the subarachnoid hematoma evacuated 1 day after recurrent hemorrhage. The cerebral vasospasm, localized in a region near the MCA aneurysm, was reduced by papaverine and nicardipine vasodilating agents delivered via an Ommaya cerebrospinal fluid reservoir placed at craniotomy.

Brain↗
PubMed1993

[Clinical study on perforation of the tympanic membrane and discussion based on experimentally induced tympanic rupture].

UNLABELLED: Traumatic perforation of the tympanic membrane (TM) was clinically studied by analyzing photographs of 231 ears treated in the Department of Otolaryngology of Tokyo Women's Medical College from May 1983 to December 1991. The dynamic features of TM and the mechanism of perforation are discussed. RESULTS AND DISCUSSION: 1) Direct and indirect injuries of the TM through the external auditory canals were observed in 101 and 130 ears, respectively. One hundred and twenty-seven injured ears were seen in males and 104 in females. Subjects ages ranged from 1 to 64 years. One hundred and thirty ears were on the left side and 101 on the right. 2) Approximately 80% of the perforated regions were observed in the antero-inferior or postero-inferior quadrant. "Triangular-type" perforation was predominant among direct injuries and "slit type" among indirect injuries. 3) Approximately 80% of the cases had a TM defect area smaller than 20%. 4) One hundred and twenty of 127 ears which were treated within 7 days after injury were healed by conservative treatment. One hundred and four ears among these 120 ears healed spontaneously. The average healing period for these 104 ears was 25 days. 5) It was suggested that the age of patients and the defect area of TM were factors that delayed healing. 6) The minimum breakage stress of human normal TM (the right angle to the radial fibers of TM) was 13.7 gf/mm2. 7) It was presumed that the strain stress and shear stress of TM contributed to traumatic TM perforation in indirect injuries.

Adolescent↗
PubMed1993

Sequence specific interaction of DNA with water-soluble porphyrins.

Footprinting experiments and restriction enzyme inhibition work as well as affinity cleavage studies have been carried out to probe the sequence specific recognition of DNA by water-soluble free-base porphyrins and their metal complexes. Porphyrins lacking functional groups capable of forming hydrogen bonds exhibited high DNA sequence specificity. Induced circular dichroism (CD) spectroscopy was found useful in analyzing the complex DNA binding modes of these compounds.

Binding Sites↗
PubMed1993

[Antiemetic efficacy of granisetron in the treatment of pediatric cancer--(1). Clinical evaluation of granisetron at a dose of 40 micrograms/kg].

Seventeen children with various types of cancer were studied on the effectiveness of antiemetic drug, granisetron, by a crossover randomized trial; receiving granisetron (40 micrograms/kg; n = 53) or conventional antiemetics, during intensive chemotherapy. In the patients given granisetron nausea and vomiting were well controlled (83.0%), compared with 33.3% of conventional (non granisetron) group. The mean number of vomiting episodes for each 6h-period over 24h after chemotherapy was reduced markedly in the patients given granisetron, compared with conventional therapy. One patient developed paraesthesia of the hand after injection of granisetron as the adverse effect, which recovered to normal spontaneously after 3 hrs. Our data indicated that antiemetic effect of granisetron was superior to conventional antiemetic drugs, both in terms of clinical effectiveness and usefulness.

Adolescent↗
PubMed1993

[Antiemetic efficacy of granisetron in pediatric cancer treatment--(2). Comparison of granisetron and granisetron plus methylprednisolone as antiemetic prophylaxis].

A crossover clinical trial was carried out to compare the effectiveness and safety of granisetron alone (40 micrograms/kg) with that from a combination of granisetron plus methylprednisolone (MPL, 10 mg/kg) for control of emesis and vomiting induced by anticancer drugs in children with cancer. Complete control of emesis and vomiting were achieved in 95% (19/20 cases) of patients receiving the combination compared to 85% (17/20 cases) of patients receiving granisetron alone. There were no clinical toxicities or side effects in either treatment group. These data indicated that the combination of granisetron plus MPL was superior for control of emesis and vomiting in children receiving cytostatic anticancer drugs.

Adolescent↗
PubMed1992

Escherichia coli DNA gyrase: genetic analysis of gyrA and gyrB mutations responsible for thermosensitive enzyme activity.

Escherichia coli gyrA43 and gyrB203 alleles conferring temperature-sensitive (ts) growth encoded Gly751-->Asp and Pro171-->Ser substitutions in the DNA gyrase A and B subunits, respectively. A plasmid-borne gyrA43 allele was genetically dominant over a chromosomal quinolone-resistant gyrA gene at 30 degrees C but not at 42 degrees C. These results and others confirm the ts phenotype of the mutation, the first to be identified in the C-terminal DNA binding/complex stabilizing domain of gyrase A protein. By contrast, the Pro171-->Ser mutation is located near the ATP-binding site of gyrase B protein and could interfere with energy coupling during DNA supercoiling. These data are discussed in regard to recently described gyrA(ts) mutations that affect the control of chromosome segregation.

Alleles↗
PubMed1992

Protective effect of NGF atelocollagen mini-pellet on the hippocampal delayed neuronal death in gerbils.

Very recently, contradictory results were presented as to the effects of exogenous nerve growth factor (NGF) on the hippocampal delayed neuronal necrosis following transient ischemia. In the present study, we administered a large amount of NGF with the atelocollagen mini-pellet system, measured the local NGF contents, and evaluated the effect of this neurotrophic factor on the postischemic hippocampal pyramidal cells in gerbils. We concluded that the exogenous NGF, when given continuously at sufficient concentrations, prevents pyramidal cell damage. The possible cause of discrepancy in previous studies is discussed.

Animals↗
PubMed1992

Structures of new DNA photocleaving agents: 3,6-bis(dimethylamino)-10- [6-(4-nitrobenzoyloxy)hexyl]acridinium chloride (I) and 9-([6-(4- nitrobenzoyloxy)-hexyl]amino)acridinium chloride monohydrate (II).

(I) C30H35N4O4+.Cl-, Mr = 551.07, triclinic, P1, a = 10.512 (2), b = 11.203 (2), c = 14.469 (2) A, alpha = 111.49 (1), beta = 105.74 (1), gamma = 95.82 (1) degrees, V = 1487.4 (4) A3, Z = 2, Dm = 1.23 (by flotation), Dx = 1.231 g cm-3, lambda(Cu K alpha) = 1.5418 A, mu = 14.68 cm-1, F(000) = 584, T = 296 K, R = 0.109 for 3100 unique reflections with I greater than 3 sigma(I). (II) C26H26N3O4+.Cl-.H2O, Mr = 497.98, triclinic, P1, a = 9.4810 (8), b = 14.495 (2), c = 9.255 (1) A, alpha = 95.48 (1), beta = 98.17 (1), gamma = 101.78 (1) degrees, V = 1222.3 (5) A3, Z = 2, Dm = 1.35 (by flotation), Dx = 1.353 g cm-3, lambda(Cu K alpha) = 1.5418 A, mu = 17.34 cm-1, F(000) = 524, T = 296 K, R = 0.052 for 3589 unique reflections with I greater than 3 sigma(I). The diffraction work confirmed the molecular structures of the newly synthesized DNA photocleaving compounds, in which the p-nitrophenyl group is nearly coplanar with the acridine moiety in (I), whereas the two planar groups form a dihedral angle of 98.7 degrees in (II). The flexibility of the methylene chain and the substantial stacking ability of the aromatic groups observed may be essential for binding to DNA and reaction with the deoxyribose H atoms.

Aminoacridines↗
PubMed1992

Experimental study on the indications for barbiturate therapy. Change in haemodynamics and the influence of dopamine.

The effect of barbiturates on the cerebral haemodynamics and the influence of dopamine on barbiturates were investigated using 20 cats, and clinical indication of barbiturate therapy is discussed. Cerebral blood flow, oxygen extraction fraction, and cerebro-vascular resistance as well as physiological variables were evaluated at various concentrations of barbiturates in the blood. Thiamylal caused simultaneous reduction of mean arterial blood pressure and cerebral blood flow. As the disruption of autoregulation proceeded, cerebro-vascular resistance and oxygen extraction fraction increased till the barbiturate-induced coma stage. Furthermore, cerebro-vascular resistance increased much more markedly by the combined use of dopamine. Clinically, our results indicate barbiturates would increase cerebral circulatory disturbances caused by vasospasm following subarachnoid haemorrhage because barbiturates further increase cerebro-vascular resistance. Then again, the combined use of dopamine is not preferable because of deterioration in vasospasm.

Animals↗