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Biomedical subjects

S Takano

Publications and source records attributed to S Takano.

At least 109 records · Page 6Linked to original sources
PubMed1996

Synthetic studies of vitamin D analogs. XXII. Synthesis and antiproliferation activity of putative metabolites of 1 alpha, 25-dihydroxy-22-oxavitamin D3.

As putative metabolites of 1 alpha,25-dihydroxy-22-oxavitamin D3 (OCT), 24-hydroxylated OCT in 24(R) and 24(S) forms, 24-ketoOCT, 26-hydroxylated OCT in 25(S) and 25(R) forms, pentanorOCT and pentanor-ketoOCT were synthesized from the steroidal 20(S)-alcohol. Their antiproliferation activities towards human promyelocytic leukemia cells (HL-60 cells) are also reported. Oxidized derivatives at the C-24 position, 24-ketoOCT, 24(R)-hydroxylated OCT and 24(S)-hydroxylated OCT, showed activities comparable to or slightly weaker than that of OCT, while 26-hydroxylated OCT was less active than OCT. Truncated OCT, pentanor OCT and pentanor-ketoOCT, were inactive at 10(-7)-10(-10) M.

Animals↗
PubMed1996

The influence of work loads on regional differences in sweating rates.

The influence of work loads (20, 40 and 60% VO2max) on regional differences in sweating rates was investigated in six healthy male students. The ratios of local sweating rate (msw) on the chest and back to estimated total sweating rate (mean msw of four sites examined x body surface area) at 20% work load were significantly greater than those on the forearm and forehead, whereas the ratio on the forehead at 60% work load was greater than at the other sites. The ratios on the forearm at 40 and 60% work loads were significantly greater than at 20% work load. The regional differences in sweating rates change with the increase in work load as seen by the greater variation in the ratios of msw on each site at 20% work load compared with 40 and 60% work loads. The results indicate that redistribution of this sweat activity to whole body or head with the rise in work load induces favorable conditions for evaporation and controlling brain temperature.

Adult↗
PubMed1996

Low grade astrocytoma in the medial part of the frontal lobe manifesting as paroxysmal speech disturbance--case report.

A right-handed 48-year-old female had clustered groups of seizures characterized by speech disturbance (attacks of verbal repetition and speech arrest) over a period of 7 years. Later, speech arrest was accompanied by perioral focal seizures. Magnetic resonance imaging and surgery found a low grade astrocytoma, centered in the left supplementary motor area. Postoperatively, no seizures or speech disturbances occurred for 3 years. This case confirms the main function of the supplementary motor area of the dominant hemisphere is connected with the initiation of speech and the setting into motion of the mechanism of speech.

Astrocytoma↗
PubMed1996

Correlation of histopathological factor of brain tumor and high thallium-201 uptake in single photon emission computed tomography.

This study was undertaken to investigate the relationship between several histological features and the degree of TI-201 uptake in brain tumors. T1-201 SPECT was performed on 52 patients with intracranial lesions. Histological examinations were carried out to determine the gradation of tumor cell density, vascularization, small-cell density, and matrix loosening, and the presence of necrosis, atypia, mitoses, and endothelial proliferation. The histological findings were classified into three categories. While the early uptake of T1-201 depended on the degree of necrosis of glial tumor, the delayed T1-201 uptake was closely related to the degree of necrosis, tumor cell density, and small-cell density, and may thus be of value for estimating the viability and degree of malignancy of glial tumors. In the non-glial tumors, the early and delayed T1-201 uptakes were closely related to all histological parameters, with the increase of necrosis and vascularization in the tumor tissue being particularly closely related to high uptake levels.

Astrocytoma↗
PubMed1996

Immediate tonsillectomy for peritonsillar abscess.

The usual treatment for peritonsillar abscess (PTAs) in Japan is antibiotic therapy, drainage and incision followed by tonsillectomy several weeks later. This is a retrospective study of cases treated by immediate tonsillectomy (IT) for PTAs between January 1990 and February 1995 in our hospital. There were 119 cases, 94 male and 25 female, ranging in age from 14 to 76 years (average: 36.6). In all cases, we performed CT scan, which is the most reliable diagnostic method for PTAs. Five of the 119 cases were treated by IT under general anesthesia. All five were male and their ages ranged from 50 to 62 years (average: 56.2). Two patients had diabetes mellitus. Bacteriological study revealed alpha-Streptcoccus in 1 case, but the others showed no remarkable findings. Anaerobacteria were not found in any patient. IT under general anesthesia is preferable for advanced PTAs.

Abscess↗
PubMed1995

Reduced expression of kan-1 (encoding putative bile acid-CoA-amino acid N-acyltransferase) mRNA in livers of rats after partial hepatectomy and during sepsis.

We isolated a cDNA clone, kan-1, from a rat liver cDNA library using a reverse transcriptase PCR cloning method. The kan-1 cDNA encoded a polypeptide of 420 amino acids, and was 70 and 69% identical in nucleotide and amino acid sequences respectively with human liver bile acid-CoA-amino acid N-acyltransferase (BAT). Thus Kan-1 is probably a rat homologue of human BAT (rBAT). Kan-1/rBAT mRNA was mainly expressed in the livers of adult rats and rats immediately after, but not before, birth. It was expressed in the hepatocytes, the sinusoidal endothelial cells and the Kupffer cells of the liver. An anti-Kan-1/rBAT polyclonal antibody detected a protein of molecular mass 46 kDa in the liver. After partial hepatectomy, the levels of Kan-1/rBAT mRNA decreased at 6 and 12 h in the regenerating liver. In a sepsis model, hepatic expression of Kan-1/rBAT mRNA decreased at 6 and 12 h after caecal ligation and puncture. The kinetics of Kan-1/rBAT mRNA expression suggests that it may play a role in acute-phase reactions.

Acyltransferases↗
PubMed1995

A preadipocyte clonal line from bovine intramuscular adipose tissue: nonexpression of GLUT-4 protein during adipocyte differentiation.

A clonal bovine intramuscular preadipocyte (BIP) line has been established from the intramuscular white adipose tissue of the M. longissimus thoracis in each of three Japanese Black cattle. Exponentially growing BIP cells exhibited a fibroblastic appearance. Adipocyte differentiation was initiated by treating confluent BIP cells with differentiation medium containing insulin and dexamethasone. Small lipid droplets appeared 5-6 days after stimulation and occupied a large fraction of the cell volume at 10 days and beyond. During the adipose conversion, the incorporation of acetate to the cells gradually increased by 10-fold and reached a maximum at day 5. However, incorporation of glucose increased only 3-folds prior to this conversion, even though GLUT-1 level increased by 13-fold at day 7. GLUT-4, on the other hand, was not detected during the course of differentiation. These results suggested that adipose tissue metabolisms in ruminants were different from that of non-ruminants.

Acetates↗
PubMed1995

Presence of alternative 5' untranslated sequences and identification of cells expressing ctk transcripts in the brain and testis.

From a mouse brain cDNA library, two species of the Csk-type tyrosine kinase (ctk) gene containing different 5' untranslated sequences were cloned. Using the common as well as specific nucleotide sequences of the two clones as probes, we examined the expression of ctk in various mouse tissues by Northern blot analysis. The results indicated that both species of ctk were expressed in the brain, testis and bone marrow. By in situ histochemistry of the brain, ctk transcript was detected in neurons throughout the entire brain, especially those of the cortex, the hippocampus and the cerebellum. This distribution pattern is similar to that of the Src family kinases including Yes, Src, Fyn and Lyn. In the testis, the major transcript (0.7 kb) was shorter than that expressed in the brain and the bone marrow (2.0 kb). A subsequent Northern blot analysis of fractionated germ cell populations and in situ histochemistry revealed that the short and long transcripts were expressed in germ cells and somatic cells, respectively, and that the expression level was quantitatively regulated during germ cell development. These results suggest that Ctk is involved in the regulation of neural function and differentiation of male germ cells through interactions with member(s) of the Src family kinases.

Alternative Splicing↗
PubMed1995

The effect of diurnal variation on the regional differences in sweating and skin blood flow during exercise.

The aim of the present study was to examine changes in the control of heat-dissipation responses to exercise associated with the diurnal variation in core temperature from the viewpoint of the regional response patterns. We studied seven men during exercise on a cycle ergometer at 100 W for 40 min at 25 degrees C at 0630 (morning) 1630 (evening) hours on 2 separate days. Oesophageal temperature (T(oes)), local skin temperature, local sweating rate (msw) on the forehead, back, forearm and thigh, and skin blood flow by laser Doppler flowmeter (LDF) on the back and forearm were measured continuously. The T(oes) at rest was significantly higher in the evening than in the morning, the difference averaging approximately 0.4 degrees C (P < 0.05). The T(oes) thresholds for each site in msw and that for back in LDF were significantly different between the two times of day (P < 0.05). The change in T(oes) thresholds for sweating and vasodilatation for morning and evening were similar to T(oes) at rest. Although msw on the forehead was significantly higher in the morning than in the evening, msw on the back was significantly higher in the evening than in the morning (P < 0.05). Total local sweating rate (msw,tot) for each site during exercise was significantly higher on the forehead than on the forearm in the morning, and on the back than on the forearm in the evening, respectively (P < 0.05). The results would suggest that the diurnal variation of heat-dissipation responses to exercise is influenced not only by a central controlling mechanism but also by changes in the regional differences.

Adult↗
PubMed1995

Induction of CL100 protein tyrosine phosphatase following transient forebrain ischemia in the rat brain.

Protein tyrosine phosphorylation is thought to play an important role in the regulation of neural function. To elucidate the role that protein tyrosine phosphatases (PTPs) may play in the postischemic brain, PTPs expressed in regions of the rat brain vulnerable to transient forebrain ischemia were examined. With the reverse-transcriptase polymerase chain reaction using degenerate primers, three PTPs, STEP, PTP delta, and SH-PTP2, were identified. They were expressed in the hippocampus 12 h after transient ischemia for 20 min. During the reperfusion period, the mRNA levels of these PTPs were not different from those in sham-operated rats. In contrast, a fourfold increase in the mRNA level of CL100 (3CH134), a PTP that is inducible by oxidative stress, was detected by Northern blotting in the hippocampus and cerebral cortex 1 h after the onset of reperfusion. In situ hybridization histochemistry showed a slight increase in the level of CL100 mRNA in neuronal cells in the hippocampus and cortex of postischemic rats compared to control rats. These findings suggest that PTPs play a role in the normal function of the hippocampus and cerebral cortex and demonstrate that ischemia induced CL100 expression.

Amino Acid Sequence↗
PubMed1995

Cells transfected with the basic fibroblast growth factor gene fused to a signal sequence are invasive in vitro and in situ in the brain.

Invasiveness is a critical event in the development of malignancy in brain tumors. A potential molecular mediator is basic fibroblast growth factor (bFGF). NIH-3T3 cells transfected with the bFGF gene fused with a signal peptide sequence (signal peptide bFGF) acquire an invasive phenotype as measured by in vitro assays of invasion including: 1) the formation of branching networks on Matrigel; 2) invasiveness in a chemoinvasion assay; 3) migration in a cell spreading assay; 4) detection of an Mr 92,000 gelatinase; and 5) local invasion into the surrounding neuropil after injection in the athymic mouse brain. By contrast, cells transfected with only the native bFGF gene (wild-type bFGF): 1) formed discrete cell clusters on Matrigel; 2) were less invasive and migratory in vitro; 3) released minimal Mr 92,000 collagenase; and 4) in vivo formed a pseudocapsule that separated the tumor cells from the neuropil. Quantitation of bFGF in the conditioned serum-free medium of the cell lines by enzyme-linked immunosorbent assay demonstrated that the signal peptide-bFGF cell clone secreted bFGF. These findings suggest a role for bFGF-mediated pathways and collagenase as molecular determinants of invasiveness in the brain.

3T3 Cells↗
PubMed1995

[Pharmacokinetic study of intraperitoneal cisplatin chemotherapy for gastric cancer as an adjuvant setting].

The pharmacokinetic studies of intraperitoneal cisplatin (CDDP) for gastric cancer were discussed elsewhere, but those studies were investigated in patients with ascites. The purpose of this study is to compare the difference in pharmacokinetics between patients with malignant ascites and those curatively resected without ascites. One hundred mg of CDDP and 300 ml of saline were administered intraperitoneally for 9 curatively resected patients by catheter just after operation, and the same doses of CDDP were administered for 3 advanced or recurrent patients with ascites just after removal of whole fluid. Blood samples were corrected at 6 points after administration. Results were as follows: The 0-t area under the curve (AUC) and the Cmax of both total and free CDDP in the patients without ascites was higher than in the patients with ascites. The 0-infinity AUC and MRT of the ascites patients were higher than in the patients without ascites. These data suggest that intraperitoneal CDDP chemotherapy for gastric cancer as an adjuvant setting is more effective than chemotherapy for advanced malignant ascites patients.

Ascitic Fluid↗
PubMed1995

[Incidence of uveitis at Tokyo Medical College Hospital].

We reviewed the records of 980 patients with endogenous uveitis who were followed in the uveitis clinic of the Tokyo Medical College Hospital, Department of Ophthalmology. A group of 693 patients examined within a 5-year period from January, 1989 through December, 1993 (Group A) were compared to an earlier group of 287 patients examined within a 3-year period from January, 1982 through December, 1984 (Group B). The incidence of Behçet's disease, intermediate uveitis, and toxoplasmosis showed an apparent decrease. In contrast, the incidence of sarcoidosis and acute anterior uveitis increased. In comparison to Group B, Group A showed an increased number of patients with virus-associated uveitis, toxocariasis, and uveitis caused by fungal infection. The changes observed in the prevalence of certain uveitic diseases in the patient population we followed may be related to changing environment and/or life style, in addition to various advances in diagnostic testing. In the future, the classification of uveitis will become more varied according to the establishment of new concepts.

Adolescent↗
PubMed1995

Incidence of hepatocellular carcinoma in chronic hepatitis B and C: a prospective study of 251 patients.

The incidence of hepatocellular carcinoma (HCC) was prospectively studied in 251 chronic hepatitis patients, and was compared between the 127 cases of hepatitis B and 124 cases of hepatitis C. All patients were diagnosed by needle biopsy on entering the study, and the cases consisted of chronic persistent hepatitis (CPH), chronic active hepatitis (CAH)2a, and CAH2b (cirrhosis was not included). Of the cases of chronic hepatitis B, 5 cases of HCC (3.9%) were detected; among the chronic hepatitis C cases, 13 cases (10.4%) were detected. Thus, although the mean follow-up periods were in the same range, the incidence of hepatocellular carcinoma was 2.7 times higher in hepatitis C than in hepatitis B (chi 2 = 3.116, P < .05). Using the Kaplan-Meier method, the incidence of HCC was significantly higher in chronic hepatitis C (P = .0194, generalized Wilcoxon test). In hepatitis C, the incubation period until HCC was detected was shorter when the liver disease was more advanced. Such a tendency was not observed in hepatitis B. In the 13 cases of HCC occurring in chronic hepatitis C, noncirrhotic liver was seen in only 1 case (7.7%), whereas 2 of the 5 cases of HCC (40%) in chronic hepatitis B were noncirrhotic. The prevalence of hepatitis C virus (HCV) genotypes II and III was the same in the total followed cases and HCC cases.

Adult↗
PubMed1994

Structure, expression and chromosomal localization of human p80-coilin gene.

Coiled bodies (CBs) are non-capsular nuclear bodies with a diameter of 0.3-1 micron and appear to be composed of coiled fibrils. Human autoantibodies to CBs recognize an 80-kD nuclear protein highly enriched in CBs, and this protein has been named p80-coilin. CBs are known to assemble and disassemble during the cell cycle, with the highest number of CBs occurring at mid to late G1 where p80-coilin is assembled into several small nuclear body-like structures. In S and G2 phases, CBs become larger and their number decreases and often they are undetectable during mitosis. Using a human autoantibody as a probe for expression cloning, we initially isolated a partial cDNA encoding p80-coilin. In this report, the 5' end of the complete cDNA for p80-coilin was obtained using the 5'-RACE (rapid amplification of cDNA ends) methodology. The size of the reconstructed full-length cDNA corresponds to the 2.7-kb mRNA detected in Northern blot analysis. The complete p80-coilin protein consists of 576 amino acids with a predicted molecular mass of 62,608. A putative p80-coilin pseudogene was also detected during the rescreening of p80-coilin cDNA. To confirm the validity of the cDNA sequence, three overlapping genomic DNA clones representing the human p80-coilin gene were selected for further analysis. The complete gene for p80-coilin contains 7 exons spanning approximately 25kb. Sequence analysis of exons 1 and 2 in genomic DNA clones confirmed the accuracy of the 5' cDNA sequence derived from the 5'-RACE procedure. Furthermore, the human p80-coilin gene was localized to chromosome 17q22-23 by fluorescence in situ hybridization.

Amino Acid Sequence↗
PubMed1994

Genetic diagnosis identifies occult lymph node metastases undetectable by the histopathological method.

The mutant allele-specific amplification (MASA) method is capable of detecting one tumor cell containing genetic changes in a sample containing thousands of normal cells. To investigate whether MASA can be applied to sensitive detection of lymph node metastasis, we screened 22 colorectal cancers for K-ras and p53 mutations and examined corresponding regional lymph node at the genetic level by the MASA method. Six of the primary tumors were found to certain K-ras mutations, and nine exhibited mutations of the p53 gene. In seven of the 14 cases in which genetic alterations were identified (mutations in both genes were found in one tumor), we found discrepancies between the genetic and the histopathological diagnoses with respect to the presence or absence of cancer cells in lymph nodes, in that these patients were histologically diagnosed lymph node negative, hn(-) but genetically diagnosed lymph node positive, gn(+). Because disease recurs in 20-30% of cancer patients whose lymph nodes are histopathologically negative after surgery, genetic evaluation of lymph nodes for metastasis may become a useful prognostic indicator.

Adult↗