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Biomedical subjects

M Furukawa

Publications and source records attributed to M Furukawa.

At least 235 records · Page 13Linked to original sources
PubMed1995

Expression of immunoreactive activin A in fetal rat pancreas.

Expression of activin A in fetal rat pancreas was studied immunohistochemically by using anti-activin A antibody. On embryonic day 12 (E12), cells in cap-like pancreatic anlage were stained with anti-activin A antibody. In these sections, no immunoreactive insulin or glucagon was observed. On E13.5, cells containing immunoreactive activin A were observed in pancreatic anlage. These cells were also stained by both anti-glucagon and anti-insulin antibodies. On E15, a cluster of cells could be recognized as a primitive islet. In the primitive islet, cells containing immunoreactive activin A were observed. Activin-positive cells were located mainly in the mantle of the primitive islet but some were located in the core of the primitive islet. These activin-positive cells also expressed glucagon. Among them, cells also containing insulin were observed. In addition to activin-positive cells, cells containing only insulin were detected in the core of the primitive islet. These results indicate that immunoreactive activin A is expressed in fetal pancreas. The expression of activin A is an early event during the development of pancreatic endocrine cells.

Activins↗
PubMed1995

Ectodermal dysplasia syndrome in siblings with true keloids, stenosis of the esophagus after operations for congenital achalasia and renovascular hypertension due to stenosis of renal artery.

Ectodermal dysplasia syndrome (EDS) is a rare hereditary disease, with symptoms brought about by dysplasia of ectodermal tissue (such as skin, teeth, nails, and hair). This report details the cases of two siblings (41 and 43 year old sisters) with autosomal recessive and hydrotic EDS complicated by esophageal achalasia, postoperative stenosis of esophagus, true keloids, renovascular hypertension, incomplete malrotation of the bowel, and demyelination of the brain.

Adult↗
PubMed1995

Development of high frequency vestibulo-ocular responses to active head shaking.

Computer aided active head shaking test has several advantages because it can be used clinical at frequencies higher than 2 Hz. In this study, VOR gain and phase were examined over age. For this experiment, we designed an original measurement system composed of EOG, an angular velocity sensor and a microcomputer. VOR gain was expressed by transfer function. Forty normal subjects ranging from 10 to 75 were examined for high frequency VOR responses to active head shaking. VOR gain at frequencies higher than 2 Hz attained the same value as that seen in children below the age of 10 years. The VOR gain was nearly 1 within 2 Hz, decreasing with frequencies above 4 Hz. The effect of aging was shown at frequencies of more than 4 Hz, and appeared in patients above 50 years of age. No obvious phase lag was observed within 5 Hz.

Adolescent↗
PubMed1995

Differentiation of the olfactory epithelium during development.

Maturation of the olfactory epithelium was studied in the rat. As a developmental index of the olfactory epithelium, quantitation was based on the thickness and the number of cell layers of the epithelium. Mean epithelial thicknesses were 84 microns on embryonic day (E) 19, 94 microns on postnatal day (P) 0, 98 microns on P10 and 57 microns in adult. Average numbers of cell layers were 7 (E19), 8 (P0), 10 (P10) and 7 (adult). Thus the olfactory epithelium progressively increased in thickness between P0-P10, and later decreased in thickness as well as in number of cell layers toward adult. To clarify the number of mature receptor cells sending their axons to the olfactory bulb, the percentages of receptor cell labeling (number of labeled cells/total number of receptor cells) were estimated with an aid of retrograde fluorescent tracer injected into the olfactory bulb. As a result, their percentages were 34% (P1-P3), 50% (P8-P10) and 78% (adult). The ablation experiment of the bulb on P1 pups and adult rats revealed that the percentages of receptor cell degeneration were 31% in neonates (P1) and 76% in adults, confirming the results obtained from the retrograde tracing. Thus the present study shows the substantial increase of mature receptor cells during development and may provide a morphological basis in understanding of the functional maturity of olfaction.

Animals↗
PubMed1995

Bulbar morphology and expression of bulbar dopamine and parvalbumin in experimentally-induced anosmic rats.

Morphological study was carried out in rats with olfactory dysfunction induced by deafferentation of serotonergic fibers in the olfactory bulb. With a computer capable of area measurements, olfactory bulbs of the anosmic rats were found to be decreased in size to 61% of control bulbs, and all bulbar layers were involved in the bulbar shrinkage. Given areas of each bulbar layer in control bulbs to be 100%, percentages of each bulbar layer in the anosmic rats were 23% in the olfactory nerve layer, 54% in the glomerular layer, 63% in the external plexiform layer, 83% in the internal plexiform layer and 81% in the granule cell layer. Dopamine-and parvalbumin-containing neurons were examined immunohistochemically in the experimentally-induced anosmic rats. As a result, immunoreactive neurons for these two chemical substances were significantly decreased in number (dopamine, 33% of control value; parvalbumin, 46% of control value). The present study, using an animal model of anosmia, provided quantitative data on the bulbar atrophy and showed effects of anosmia on expression of dopamine and parvalbumin in the bulb.

Animals↗
PubMed1995

Effect of endothelin-1 on the development of hemorrhagic pancreatitis in rats.

BACKGROUND: It has been hypothesized that microcirculatory disturbance plays an important role in the development of severe pancreatitis. In this study we investigated the effects of exogenous endothelin-1 on the development of severe pancreatitis in rats. METHODS: Acute pancreatitis was induced by two intraperitoneal injections of cerulein (10 micrograms/kg body weight). Endothelin-1 was administered via an abdominal aortic catheter as a bolus of 250-750 pmol/kg BW every hour for 4 h. RESULTS: Remarkable morphologic changes in the pancreas, including hemorrhage, and increases in serum amylase level and active elastase content in pancreatic tissue were observed in rats treated with cerulein plus endothelin-1 in a dose-dependent manner 5 h after the first cerulein injection. Local pancreatic blood flow decreased significantly, and microcirculatory disturbances in the pancreas were demonstrated. CONCLUSIONS: These results suggest that endothelin-1 causes pancreatic microcirculatory disturbance and might be a contributing factor in the aggravation of acute pancreatitis.

Acute Disease↗
PubMed1995

[A randomized crossover comparison of azasetron and granisetron in the prophylaxis of emesis induced by chemotherapy including cisplatin].

The clinical application of 5-HT3 receptor antagonists has enabled continuation of the course of chemotherapy including cisplatin, which induces strong nausea and vomiting, and to prevent the delay of curative treatment for cancer patients receiving neoadjuvant chemotherapy. However, with the development of basic research on the mechanisms of vomiting, each 5-HT3 receptor antagonist has appeared to have different pharmacological actions and, subsequently, the difference in the clinical efficacy of each drug has been reported in Europe and USA. In freshly advanced head and neck carcinoma cases, a randomised crossover study was performed to compare the efficacy and safety profile of a single intravenous dose for 7 days of azasetron (10 mg/day) or granisetron (3 mg/day) in the prophylaxis of nausea and vomiting induced by multi-drug chemotherapy including cisplatin (50 mg/m2 or 60 mg/m2). Anti-emetic effects were evaluated by the protective rates for nausea and vomiting for 7 days following the start of cisplatin administration. Both 5-HT3 receptor antagonists were highly effective in the prophylaxis of acute and delayed emesis induced by chemotherapy, whereas the efficacies of azasetron on day 3 and 4 were superior to those of granisetron. No adverse effect of either drug was observed in this study.

Aged↗
PubMed1995

[Induction and properties of nitric oxide synthase in rat retinal pigment epithelial cells in culture].

UNLABELLED: We investigated the production of nitric oxide (NO) and nitric oxide synthase (NOS) by rat retinal pigment epithelial cells (RPE) in culture. METHODS: RPE was isolated from the eyes of 7-10 day-old rats and cultured in Dulbecco's modified Eagle medium with 10% fetal calf serum. NO2- concentration in the culture medium was determined with the Griess reaction. NOS was assayed by measuring 3H citrulline as the reaction product. RT-PCR was performed on the isolated RNA fractions from RPE. RESULTS: Rat RPE produced NOS with the combined stimulation of the bacterial endotoxin and cytokines including interferon gamma. PCR experiments showed that stimulated RPE expressed a gene product corresponding to inducible-type NOS. The enzyme required arginine, NADPH, and tetrahydrobiopterin for the reaction. The specific activity of the crude RPE extract was approximately 270 pmol/min/mg. CONCLUSION: Like bovine RPE, rat RPE produced NOS by the immunological stimulation. Induced NOS and the product NO may play important roles in inflammation of the eye.

Amino Acid Oxidoreductases↗
PubMed1995

[Comparison of granisetron alone and granisetron plus dexamethasone or hydroxyzine hydrochloride for the prevention of nausea and vomiting during chemotherapy including cisplatin].

The comparative study among granisetron alone and granisetron combined with hydroxyzine hydrochloride or dexamethasone was undertaken for the prevention of nausea and vomiting during chemotherapy including cisplatin in patients with advanced head and neck carcinomas. The results indicated that the combination antiemetic therapies were more effective than granisetron alone for acute nausea and vomiting, whereas a significant difference was not observed among these three groups in the acute adverse effects. Otherwhile, there were statistically significant improvements in the prevention of delayed nausea and vomiting for patients receiving granisetron combined with the other antiemetic drugs, especially the combination antiemetic therapy with dexamethasone. These results confirm the antiemetic activity of granisetron in acute nausea and vomiting induced by cisplatin and show that it has an additive effect in combination with dexamethasone.

Adult↗
PubMed1995

Platelet-activating factor. Role in fetal lung development and relationship to normal and premature labor.

In this overview on the role of PAF in reproductive biology, we have emphasized its relationship to fetal lung maturation and the initiation and maintenance of parturition. In addition, we have discussed the role of this autacoid in certain complications of premature delivery. It should be pointed out, however, that it is our view that other mediators and cytokines also play a role in these processes. In the past, many investigators have suggested a central role for one of these mediators that serves as the "trigger" of these biologic events. It is our view that these systems are regulated by a number of effectors, among which PAF may play an important role.

Cytokines↗
PubMed1995

An interactive consultation multimedia software for orthodontic patients.

Presentation of diagnosis and treatment planning for orthodontic problems by orthodontists is often a hurdle and a nuisance to most patients. The reasons are that it has much content which may be hard to understand without having expert knowledge related to the temporal change in dentofacial structures known as the growth, development and physiological aspects of masticatory apparatus. To complement this, we have developed an interactive consultation multimedia software for orthodontic patients. he design concept of the current software has three aspects. Firstly, since the software is operated by orthodontic patients themselves or by their parents, it enhances the operational feasibility. Secondly, it helps the patients choose the information in which they are interested. Thirdly, it emphasizes audio-visual understanding of orthodontic practice, including terminology. e used a hypertext machine with a 240MB hard disk drive, an 8MB RAM and a 13 inch color monitor. In developing the current software, we also used a video camera, a video color board, a microphone, and an image scanner together with an image recorder, a movie and sound data editing system, image scanning and editing, an image changer, a spread sheet and mathematical software. he current software consists of various multimedia such as images, sounds, characters, and biosignals. The "stack" of the software consists of three parts: a) "General Understanding of Occlusion" b) "Understanding Specific Types of Occlusion Exhibited by the Patient" c) "Orthodontic Terminology" When card A is selected the patient can choose either "Good Occlusion" or "Malocclusion." If "Malocclusion" is chosen, respective occlusal types are shown. The next card provides pathological conditions caused by respective malocclusion, e.g., gingivitis. After selecting card B which asks the patient, "What do your teeth look like?" the following buttons are provided: "Maxillary Protrusion," "Reversed Occlusion," "Crowding," "Open Bite," and "Spaced Arch." After selecting one of these, the card with an explanation of the respective malocclusion is shown according to the patient's physiological age. Finally, after card C is selected, a new card which has a list of orthodontic terminology is presented. Patients can search any term according to their choice to open a new card which gives a detailed explanation. e confirmed that the current consultation multimedia software can provide a comfortable environment to the patients and their families to learn where the orthodontic problems lie and how they could be solved.

Audiovisual Aids↗
PubMed1994

Distinct effects of human herpesvirus 6 and human herpesvirus 7 on surface molecule expression and function of CD4+ T cells.

This study was undertaken to investigate the effects of newly isolated T lymphotropic viruses, human herpesvirus (HHV)-6 and HHV-7, on CD4+ T cells. We first examined changes in surface molecule expression on CD4+ T cells after infection with HHV-6 or HHV-7 by flow cytometry. Among surface molecules examined, CD3 expression appeared to decline markedly after infection with HHV-6 variant A (strain U1102) but the decreased level of CD3 expression after infection with HHV-6 variant B (strain Z29) was slight. Impairment of surface CD3 expression on HHV-6 variant A-infected cells was also demonstrated by measuring intracellular free Ca2+ concentration in response to anti-CD3 mAb. In contrast, HHV-7 infection induced a marked loss of surface CD4 expression, but the decline of CD3 expression was slight. Cytotoxic activity of virus-specific CD4+ CTL clones decreased after infection with both HHV-6 variant A or HHV-7 but the degree of reduction of cytotoxicity by HHV-6 variant B was not significant. Addition of lectin restored the cytotoxicity of HHV-7-infected CTL but not that of HHV-6 variant A-infected CTL. Northern blot analysis and immunoprecipitation showed that infection with HHV-6 and HHV-7 did not affect the transcription and protein synthesis of CD3 and CD4. These findings suggest that both HHV-6 and HHV-7 may directly cause T cell immunodeficiency but that the mechanisms of CD4+ T cell dysfunction mediated by HHV-6 and HHV-7 are different.

CD3 Complex↗
PubMed1994

Amplification and overexpression of the cyclin D1 gene in aggressive human hepatocellular carcinoma.

We analyzed the genetic alterations of the cyclin D1 and INT-2 genes in hepatocellular carcinomas (HCCs) from 45 patients. Among these, expression of the cyclin D1 mRNA was also analyzed in 18 of them by Northern blotting. The cyclin D1 gene was amplified 3-16 fold in five HCCs (11%); among these, the INT-2 gene was also amplified 2-10 fold in four HCCs. We analyzed the mRNA of cyclin D1 in four HCCs with gene amplifications, and 6-10 fold overexpressions were detected in all of them. Because the cyclin D1 gene was amplified in patients at an advanced stage of HCC with rapid tumor growth, it appeared to be associated with the aggressive behavior of tumors. Studies on loss of heterozygosity on chromosome 13q, where the retinoblastoma (RB) gene is located, indicated that all HCCs with an amplified cyclin D1 gene retained heterozygosity on chromosome 13q. These results suggest that amplification and overexpression of the cyclin D1 gene result in the rapid growth of a subset of HCC, even though the function of the RB gene is retained.

Carcinoma, Hepatocellular↗
PubMed1994

Alcoholysis of epsilon-decalactone with polyethylene glycol-modified lipase in 1,1,1-trichloroethane.

Lipase from Pseudomonas cepacia was modified with 2,4-bis[O-methoxypoly(ethylene glycol)]-6-chloro-s-triazine, activated PEG2, to form PEG-lipase. The PEG-lipase is soluble and active in organic solvents. It catalyzes alcoholysis of racemic epsilon-decalactone with ethanol in 1,1,1-trichloroethane to form (R)-hydroxydecanoic acid ethyl ester. No alcoholysis of (S)-decalactone takes place. These results were discussed in relation to carbon number of n-alcohol, optimum temperature and comparison with modified and non-modified lipases.

Ethylene Glycols↗
PubMed1994

Regulatory mechanism of human factor IX gene: protein binding at the Leyden-specific region.

Hemophilia B-Leyden is characterized by the gradual amelioration of bleeding after the onset of puberty. All Leyden phenotype mutations found to date lie within the Leyden-specific region, which spans roughly nt-40 to +20 in the 5' end of the human factor IX gene. With HepG2 cell nuclear extracts, the Leyden-specific region and its immediate neighboring region of the normal factor IX gene showed five DNase I footprints: FP-I (nt +4 to +19), FP-II (nt -16 to -3), FP-III (nt -27 to -19), FP-IV (nt -67 to -49), and FP-V (nt -99 to -77). Protein binding affinities of short oligonucleotides containing sequences of FP-I, FP-II, or FP-III were substantially reduced in the presence of Leyden phenotype mutations in these areas, correlating well with the negative effects of these mutations on factor IX gene expression. A Leyden phenotype mutation at nt -20 (T to A) caused a loss of both footprints FP-III and FP-II but generated a new footprint, FP-III' (nt -34 to -23), partially overlapping with FP-III, indicating mutation-dependent competitive protein binding at these sites. Although the FP-III' area contains an androgen responsive element-like sequence, the nuclear protein that binds at FP-III' is not androgen receptor. The protein was not recognized by anti-androgen receptor antibody and, furthermore, was present not only in liver but also in both androgen receptor-positive and androgen receptor-negative cells in electrophoretic mobility shift assays. The nuclear concentration of this protein increased significantly upon treatment of the HepG2 cells with testosterone. Its binding affinity to an oligonucleotide (-32sub) containing the FP-III' sequence was greatly reduced in the presence of exogenous androgen receptor, suggesting a possible interaction of this protein with androgen receptor. The affinities of both this protein and a protein which binds to FP-III (presumably HNF-4) to -32sub with a mutation at nt -26 were grossly lowered. These findings suggest that the amelioration of hemophilia B-Leyden with a mutation at nt -20 after puberty involves binding of a specific non-androgen receptor nuclear protein at FP-III' and it is able to substitute for the function of a protein bound at FP-III in the normal gene optimally through its elevated interaction with androgen receptor upon a surge of testosterone.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗