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Biomedical subjects

T Okano

Publications and source records attributed to T Okano.

At least 145 records · Page 8Linked to original sources
PubMed1999

Amplitude and frequency spectrum of temporomandibular joint sounds from subjects with and without other signs/symptoms of temporomandibular disorders.

Temporomandibular joint (TMJ) sound is one of the most commonly recognized signs in patients with temporomandibular disorders (TMD) but is also frequently seen in asymptomatic individuals. Sound recording is therefore only meaningful if the sounds from a normal healthy joint can be differentiated from those in patients. In this study, the amplitude and power spectrum of the TMJ sounds from symptomatic patients and asymptomatic individuals were recorded and compared. The result showed that TMJ sounds from symptomatic patients had a larger amplitude than sounds from asymptomatic subjects. A significant proportion of sounds had frequencies between 2000 and 3000 Hz. It was concluded that the characteristic amplitude is worthy of further study as a sign of possible diagnostic value. Secondly, the bandwidth of the sensors used at electronic TMJ sound recording should not be less than 3000 Hz.

Acoustics↗
PubMed1999

Endocrinologically active retroperitoneal ganglioneuroma with positive iodine-131-metaiodobenzylguanidine scintigraphy.

BACKGROUND: A case of retroperitoneal ganglioneuroma incidentally found by ultrasonography in a 56-year old woman is presented. METHODS/RESULTS: Computed tomography revealed a solid round tumor 6 cm in diameter on the upper pole of the right kidney. Iodine-131-metaiodobenzylguanidine weakly accumulated in the tumor 24 and 48 h after the injection. Her serum catecholamines were within normal limits apart from slightly elevated norepinephrine at one of the two examinations. During the operation her serum epinephrine and dopamine levels were elevated to about 50 and 800 times higher than pre-operative values, respectively. CONCLUSION: This case is a rare ganglioneuroma in an adult patient that is endocrinologically active.

3-Iodobenzylguanidine↗
PubMed1999

A case of perirenal hemangioma mimicking renal cell carcinoma.

PURPOSE: We present a rare case of perirenal hemangioma that was detected incidentally. METHODS/RESULTS: Radiographic examinations revealed a 3.5 cm mass at the left renal hilum adjacent to the left renal parenchyma, which was difficult to differentially diagnose from renal cell carcinoma. Tumor resection was performed successfully. CONCLUSIONS: There was no recurrence observed 14 months after surgery.

Aged↗
PubMed1999

Growth factor and matrix molecules preserve cell function on thermally responsive culture surfaces.

Thermally-responsive culture surfaces were designed using copolymers of N-isopropylacrylamide, 4-(aminomethyl)styrene, and acrylic acid. These surfaces contained functional amine and carboxyl groups, which allowed biomolecules to be grafted by amide formation. Epidermal growth factor (EGF), and extracellular matrix (ECM) molecules (collagen type IV, and chondroitin sulfate) were investigated, as surface-grafted biomolecules, for their ability to stimulate cell attachment, proliferation, and function by signaling only from the basal side of cultured cells. Surface analysis of biomolecule-grafted porous inserts showed covalent binding of biomolecules to either amine or carboxyl groups. Multiple attachment to amine and/or carboxyl groups served as cross-linking points that made the polymer hydrogel permanently adherent to the culture surface. Immunofluorescence microscopy techniques gave positive identification of grafted biomolecules. Grafting of EGF improved cell proliferation versus that on nongrafted controls, or controls grafted only with ECM molecules. ECM grafting induced cell attachment on attachment-resistant surfaces. Analysis of trans-epithelial resistance, fluid transport, and polarized g-glutamyl transpeptidase activity indicated that simultaneous grafting of both EGF and ECM produced better polarized cell function than nongrafted controls, or controls grafted with only one type of biomolecule. Covalent grafting of biomolecules did not interfere with cells ability to detach from thermally responsive surfaces upon temperature decrease.

Amides↗
PubMed1999

Reduction of the side effects of an antitumor agent, KRN5500, by incorporation of the drug into polymeric micelles.

For intravenous (i.v.) injection of a water-insoluble antitumor drug, KRN5500, we have successfully incorporated KRN5500 into polymeric micelles. In the present study, in vitro and in vivo anti-tumor activity against several human tumor cell lines and toxicity in mice of polymeric micelles incorporating KRN5500 (KRN/m) were evaluated in comparison with those of the prototype KRN5500. KRN/m was found to express similar antitumor activity to KRN5500 in the in vitro and in vivo systems. However, the vascular damage and liver focal necrosis observed with KRN5500 i.v. injection were not seen when KRN/m was administered i.v. Therefore, we expect that KRN/m will be superior to KRN5500 for clinical use and that the methodology of polymeric micelle drug carrier systems can be applied to other water-insoluble drugs.

Animals↗
PubMed1999

Synthesis and swelling-deswelling kinetics of poly(N-isopropylacrylamide) hydrogels grafted with LCST modulated polymers.

Two types of thermo-responsive hydrogels are synthesized to obtain comb-type grafted gels with different lower critical solution temperatures (LCSTs) between graft chains and cross-linked backbone networks: these are poly(N-isopropylacrylamide) (PIPAAm) cross-linked hydrogels grafted with poly(N-isopropylacryl amide-co-N,N-dimethylacrylamide) (poly(IPAAm-co-DMAAm)) maintaining a freely mobile end and poly(IPAAm-co-DMAAm) cross-linked hydrogels grafted with PIPAAm chains. The effect of graft chain hydrophilic/hydrophobic balance as well as its mobility on deswelling kinetics of these grafted gels are investigated through the polymer LCST modulation and external temperature changes. The deswelling rate of poly(IPAAm-co-DMAAm)-grafted PIPAAm gel increases with increasing in temperature. This gel shows a discontinuous increase of the deswelling rate when the temperature is applied from below to above the graft chain LCST (37 degrees C). The deswelling rate of PIPAAm-grafted poly(IPAAm-co-DMAAm) gel increases continuously when the temperature is applied from below to above the graft chain LCST (31 degrees C). Due to the strong hydrophilicity of backbone network, the hydrophobic aggregation force weak. In contrast to the graft-type gels, normal-type poly(IPAAm-co-DMAAm) cross-linked gel without graft chains demonstrates the discontinuous decrease for the deswelling rate when the temperature is applied from below to above the polymer LCST (36 degrees C), entrapping water inside the gel due to the formation of an impermeable dense skin layer at the gel surface. These gel deswelling mechanisms are discussed in terms of gel structures.

Absorption↗
PubMed1999

Rapid control of transmembrane calcium influx by 1alpha,25-dihydroxyvitamin D3 and its analogues in rat osteoblast-like cells.

1alpha,25-Dihydroxyvitamin D3 [1alpha,25(OH)2D3] has been shown to exert both its nuclear vitamin D receptor (nVDR)-mediated genomic actions and membrane vitamin D receptor (mVDR)-mediated nongenomic actions. In this study, the effects of 1alpha,25(OH)2D3 and its analogues on transmembrane Ca2+ influx were examined in the growth phase of rat osteosarcoma ROS17/2.8 cells. Like BAYK8644 (2 x 10(-5)M), a well-known L-type Ca2+ channel agonist, 1alpha,25(OH)2D3 (10(-8)M) increased transmembrane influx of Ca2+ through voltage-dependent Ca2+ channels and increased intracellular Ca2+ concentration within 2 min of addition to the medium. The 1alpha,25(OH)2D3-induced Ca2+ influx was completely blocked by pre-treatment with nifedipine (2 x 10(-5)M), an L-type Ca2+ channel antagonist. Two vitamin D analogues, 22-oxa-1alpha,25(OH)2D3 (OCT, 10(-8) M) and 20-epi-22-oxa-24a, 26a,27a-trihomo-1alpha,25(OH)2D3 (KH1060, 10(-8)M), which were 3.8 and 3600-fold more active than 1alpha,25(OH)2D3 in stimulating differentiation on human promyelocytic leukemic HL-60 cells, respectively, also increased intracellular Ca2+ concentration, while their Ca2+ channeling activities were similar to or significantly weaker than that of 1alpha,25(OH)2D3. Furthermore, the enhanced transmembrane Ca2+ influx induced by 1alpha,25(OH)2D3 (10(-8)M) or OCT (10(-8)M) was completely blocked by pre-treatment with the respective 1beta epimer [1beta,25(OH)2D3 and 1beta-OCT] at equal concentration. These findings suggest that 1alpha,25(OH)2D3 and its analogues modulate transmembrane Ca2+ influx in osteoblast-like cells by opening L-type Ca2+ channels which can recognize 1alpha-hydroxy analogues as agonists and 1beta-hydroxy analogues as antagonists.

Animals↗
PubMed1999

Biological activity profiles of 1alpha,25-dihydroxyvitamin D2, D3, D4, D7, and 24-epi-1alpha,25-dihydroxyvitamin D2.

We have synthesized several 1alpha,25-dihydroxyvitamin D [1alpha,25(OH)2D] derivatives and evaluated their biological activity in terms of their binding affinity for the vitamin D receptor (VDR) and vitamin D-binding protein (DBP), antiproliferative or differentiation-inducing effects on human promyelocytic leukemic HL-60 cells, and transcriptional activity on a rat 25-hydroxyvitamin D3-24-hydroxylase gene promoter, including two vitamin D-responsive elements (VDREs), and human osteocalcin gene promoter, including a VDRE in transfected human osteosarcoma MG-63 cells. Furthermore, human VDR- or retinoic acid X receptor alpha (RXR alpha)-mediated luciferase activities of the derivatives were also measured by a one-hybrid system in human epitheloid carcinoma, cervix HeLa cells and African green monkey kidney CV-1 cells. Binding affinity for VDR, bone-resorbing activity, antiproliferative and cell-differentiating effects, transactivation potencies on target genes and VDR- or RXR alpha-mediated gene regulations of 1alpha,25(OH)2D2 and 1alpha,25(OH)2D4 were almost comparable to the effects of 1alpha,25(OH)2D3 while 24-epi-1alpha,25(OH)2D2 and 1alpha,25(OH)2D7 were much less active than 1alpha,25(OH)2D3 in these respects. This is the first report concerning biological assessment of 1alpha,25(OH)2D2, 1alpha,25(OH)2D3, 1alpha,25(OH)2D4, 24-epi-1alpha,25(OH)2D2 and 1alpha,25(OH)2D7 at the molecular level, especially with regards to the structural differences at the 24R- or 24S-methyl group and a double bond between carbons 22 and 23 in the side chain of 1alpha,25(OH)2D derivatives.

Animals↗
PubMed1999

Prediction of the development of hepato-cellular-carcinoma in patients with liver cirrhosis by the serial determinations of serum alpha-L-fucosidase activity.

OBJECTIVE: Evaluation of the usefulness of the serial determinations of serum alpha-L-fucosidase (AFU) activity for prediction of the development of hepatocellular carcinoma (HCC) was performed. METHODS AND PATIENTS: Serum AFU activity was determined monthly for 42 months in 73 patients with liver cirrhosis (LC). RESULTS: HCC was diagnosed in 27 patients by means of ultrasonography during this observation period. In 23 (85%) of the 27 patients, serum AFU activity was found to exceed 700 nmole/ml/h during the LC stage. HCC developed within a few years in 23 (82%) of 28 LC patients with AFU activity exceeding 700 nmole/ml/h, in contrast, it developed in only 4 (9%) of 45 LC patients with AFU activity below 700 nmole/ml/h. AFU activity was already elevated in 23 (85%) of 27 patients at least 6 months before the detection of HCC by ultrasonography. CONCLUSION: It is conceivable that the development of HCC can be predicted by means of serial determinations of serum AFU activity in patients with LC.

Carcinoma, Hepatocellular↗
PubMed1999

Selective delivery of adriamycin to a solid tumor using a polymeric micelle carrier system.

The anticancer drug, adriamycin (ADR), was incorporated by physical entrapment into polymeric micelles for selective delivery to a murine solid tumor colon adenocarcinoma 26 (C 26). In vivo antitumor activity of ADR was greatly enhanced by this incorporation into polymeric micelles. Using one polymeric micelle delivery system, the tumor completely disappeared at two doses, while free ADR exhibited a fair inhibition effect on tumor growth only at the maximum tolerated dose. Biodistribution analysis revealed that the physically entrapped micellar ADR accumulated at tumor sites in a highly selective manner. These results indicate that these polymeric micelles are a promising system for delivering hydrophobic anticancer drugs selectively to solid tumor sites using a passive targeting mechanism.

Adenocarcinoma↗
PubMed1999

[Influence of nitric oxide on cerebral hemodynamics during endotoxemia in dogs].

The aim of this study is to clarify the influence of nitric oxide (NO) in cerebral circulation during endotoxemia. Two groups of 24 mongrel dogs (N = 12 each) received saline 1 ml.kg-1.h-1 or endotoxin (lipopolysaccharide, LPS) 500 ng.kg-1.h-1 for 3 hours. To determine changes of NO in the systemic and cerebral circulation, we measured NOx (NO2-/NO3-) in the femoral artery and superior sagittal sinus as metabolites of NO using the Griess method. We also measured the concentrations of cerebral oxyhemoglobin (HbO2), deoxyhemoglobin (Hb), total hemoglobin (total Hb) and cytochrome aa3 (Cytaa3) using near-infrared laser spectroscopy. Changes in cerebral blood volume were evaluated from the total Hb. NOx in systemic and cerebral circulation increased significantly after infusion of LPS. Therefore, the increased production of NO in cerebral circulation was consistent with increase of cerebral blood volume. In conclusion, it seems reasonable to assume that increased cerebral blood volume may result from increased production of cerebral NO during endotoxemia.

Animals↗
PubMed1999

[The effectiveness of glaucomatous visual field test using a size I stimulus].

PURPOSE: Perimetry using size I and III targets was conducted on glaucoma patients. The detectability of the visual field defects using a size I target and abnormal spatial summation was investigated. SUBJECTS & METHODS: Subjects were 14 eyes of 11 glaucoma patients with mild to moderate visual field defects and 11 eyes of 11 normal persons. Program 24-2 of the Humphrey Field Analyzer was applied to each subject. Based on the mean sensitivity and standard deviation at each coordinate in normal persons, the Z-score was calculated in the visual fields of glaucoma patients (absolute scotomas were excluded). RESULTS: The mean Z-score of retinal sensitivity, was less for size III than for size I in abnormal lesions, and less for size I than for size III in normal lesions (paired t-test, p < 0.01). Pathological spatial summation was found more frequently in normal lesions than in abnormal lesions. CONCLUSIONS: In mild visual field defects, size I detects abnormalities with greater sensitivity than size III. Perimetry using the size I target can be effective as a supplementary diagnostic method to detect and follow the early glaucomatous visual field.

Glaucoma↗
PubMed1999

[Clinical characteristics of acute non A to G hepatitis caring TTV-DNA].

We measured TTV-DNA using polymerase chain reaction method in twenty seven patients with acute non A to G hepatitis and 139 patients with known types of acute hepatitis. TTV-DNA was detected in 40.7% in the former and in 36.7% in the latter, which was not significantly different. In acute non A to G hepatitis, TTV-DNA was more common in the male and in patient with more advanced age, however, no remarkable difference was noted concerning clinical characteristics according to the existence of TTV. Therefore TTV does not seem to play a causative role in pathogenesis of acute non A to G hepatitis.

Acute Disease↗
PubMed1999

[Penile carcinoma with humoral hypercalcemia of malignancy (HHM): a case report].

A 57-year-old male, with 1.5 cm tumor in his prepuce, was admitted to our institute in Feb. 1990. Circumcision and inguinal lymph node dissection was performed under the diagnosis of T1 disease of penile carcinoma. Pathological evaluation revealed well-differentiated squamous cell carcinoma (SCC). In April 1996, the patient revealed recurrence of the disease in the right inguinal lymph nodes and the lower abdomen, that was diagnosed to be poorly differentiated SCC. Laboratory findings showed elevation of serum calcium, parathyroid hormone-related protein (PTHrP) levels. Immunohistochemical staining confirmed production of PTHrP in the tumor tissue. This is the first case report of penile carcinoma that caused humoral hypercalcemia of malignancy in Japan.

Carcinoma, Squamous Cell↗
PubMed1999

[High-dose chemotherapy with peripheral blood stem cell autotransplantation for patients with poor-risk testicular germ cell tumors--pilot study of the Japan Blood Cell Transplantation Study Group].

The efficacy and toxicity of a single cycle of high-dose chemotherapy with peripheral blood stem cell autotransplantation (PBSCT) in patients with poor-risk testicular germ cell tumors (GCT) enrolled in the Japan Blood Cell Transplantation Study Group was investigated. Previously untreated poor-risk testicular GCT patients were treated with BEP therapy (cisplatin, etoposide and bleomycin) with or without high-dose chemotherapy (carboplatin, etoposide and ifosphamide) followed by PBSCT. Patients were qualified for a change to high-dose chemotherapy if elevated serum tumor markers (human chorionic gonadotropin-beta, alpha-fetoprotein and lactate dehydrogenase) was observed after 3 cycles of BEP therapy. Eighteen patients were treated with BEP therapy alone and 16 with BEP and high-dose chemotherapy. At the completion of high-dose chemotherapy, all tumor markers had returned to normal in 6 patients. Among them, 1 had only teratoma found at resection and 5 had carcinoma resected. Nine patients who had persistent elevation of any tumor marker were treated with high-dose chemotherapy or another anticancer drug. Thirteen are alive (81%) and 9 (56%) are continuously disease-free at a median follow up of 11 months. The median time from PBSCT to a granulocyte count > 500/microL was 9.5 days and to a platelet count > 50,000/microL was 13 days.

Adolescent↗