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Biomedical subjects

K Fujimoto

Publications and source records attributed to K Fujimoto.

At least 487 records · Page 27Linked to original sources
PubMed1994

Effect of aging on plasma 1,5-anhydroglucitol levels in humans and rats.

Since normal reference values change with age in some clinical parameters, we measured the plasma levels of 1,5-anhydroglucitol (AG), a new marker of glycemic control in diabetes mellitus, in healthy subjects and in rats. Our results showed a significantly negative correlation of the marker with age in humans and that the plasma AG levels of older rats were markedly lower than those of younger counterparts. This remarkable reduction of AG in the older rat group can be partially explained by our finding that aged animals excreted AG more rapidly in the urine than younger ones, besides a decrease in food intake. We therefore suggest that normal clinical reference values for plasma AG levels should be modified according to age.

Adolescent↗
PubMed1994

Role of proprioceptors in the mylohyoid muscle.

Afferent discharges of the mylohyoid muscle branch during respiration were studied electrophysiologically in the rat. Afferent discharges from the mylohyoid muscle branch of the mylohyoid nerve were found to be synchronized with respiration. Stretching of the mylohyoid muscle elicited afferent discharges of the mylohyoid muscle branch, suggesting that lengthening of the mylohyoid muscle caused electrical activity in the proprioceptors. When the central cut end of the mylohyoid muscle branch was stimulated electrically, reflex discharges were recorded from the EMG lead at the sternohyoid muscle where it is innervated by the cervical nerve. The latency between the electrical stimulation and the action potential in the sternohyoid muscle was 3-4 ms. Therefore, the mylohyoid muscle branch may transmit information to the sternohyoid muscle regarding the stretching actions of the mylohyoid muscle resulting from movements of the hyoid bone.

Afferent Pathways↗
PubMed1994

In vivo experimental analysis of silicone implants used with titanium grommets.

This study evaluated the titanium grommets recommended to reduce breakage by protecting hinge implants from bone edges. Silastic HP-100 (Dow Corning Wright, Arlington, TN) flexible finger implants (size 5) were used to replace one knee of 10 rabbits, and implants plus titanium grommets were used in another 10. X-ray films were taken monthly; deaths from each group were 1 animal at 2 and 4 months, 2 animals at 6, and 3 each at 12 and 16 months. X-ray films revealed that 4 of 10 implants from each group had fractured. Silicone fractures occurred identically at the proximal stem-hinge junction in both groups, destruction was always most pronounced at the dorsal surface of the proximal stems. The time from surgery to x-ray film evidence of implant fracture without grommets was an average of 9 months and with grommets 13 months. Although grommets delayed x-ray film evidence of fracture onset, after 14 months all implants in both groups of animals fractured. These findings do not support the hypothesis that grommets prevent silicone hinge implant wear or fracture in this experimental model.

Animals↗
PubMed1994

Expression and characterization of the bovine histamine H1 receptor in cDNA-transfected C6 astroglioma cells.

Rat C6 astroglioma cells (C6-bH1R cells) expressing cloned bovine histamine H1 receptors were established by transfection with a vector (pEF-BOS-bH1R) which carried a 2.7-kbp EcoRI fragment of the bovine H1 receptor cDNA [Yamashita, M. et al. (1991) Proc. Natl. Acad. Sci. USA 88, 11515-11519]. The cloned bovine H1 receptor in C6-bH1R cells was characterized by three established criteria: the [3H]mepyramine binding assay, the accumulation of inositol phosphates induced by histamine, and histamine-induced elevation of intracellular Ca2+ concentration ([Ca2+]i). The accumulation of inositol phosphates induced by histamine was time- and dose-dependent. The accumulation of inositol trisphosphate was biphasic with a prompt increase to the maximal level, followed by a sustained submaximal level. The histamine-induced accumulation of inositol phosphates was suppressed by phorbol ester, but not by pertussis toxin. Results from the [3H]-mepyramine binding assay and histamine-induced elevation of [Ca2+]i were characteristic of H1 receptors. Several compounds among tricyclic antidepressants, neuroleptics, and serotonin antagonists showed affinities to the cloned bovine H1 receptor with Ki values similar to reported values. Histamine neither induced cAMP accumulation nor attenuated forskolin-induced cAMP accumulation in C6-bH1R cells. C6-bH1R cells are particularly useful for studying the H1 receptor-mediated astroglial cell functions.

Animals↗
PubMed1994

Spatial distribution of thoron and radon concentrations in the indoor air of a traditional Japanese wooden house.

A radon-thoron discriminative passive dosimeter has been developed that can estimate both radon (222Rn) and thoron (220Rn) concentrations at the same time. Two polycarbonate films are installed as solid-state nuclear track detectors in the dosimeter housing. One film registers alpha tracks originating from predominantly thoron and its progeny together with a small contribution from radon, and the other film registers alpha tracks originating from radon and its progeny together with a negligible contribution from thoron. The lower detection limit is estimated to be 2.9 Bq m-3 for the radon concentration and 9.0 Bq m-3 for the thoron concentration for 2 mo exposure. Preliminary measurements from 1991-1992, in a traditional Japanese wooden house located in Kyoto, indicated that the indoor thoron concentration increases exponentially as the interior mud (or plaster-coated) wall is approached. A soil-based plaster commonly used in Japanese wooden houses to fill walls (or as a surface coating on the walls) is the probable source of the indoor thoron. Since thoron is not measured by the usual radon measurements, and the majority of Japanese houses are made of wood, attention should be paid to indoor thoron and its decay products, which may give a significant fraction of the total natural radiation exposure to the general public.

Air Pollutants, Radioactive↗
PubMed1994

Establishment of a human T-cell line with deficient surface expression of glycosylphosphatidylinositol (GPI)-anchored proteins from a patient with paroxysmal nocturnal haemoglobinuria.

A novel interleukin-2 dependent T-cell line, PMT-2Y, was established from the peripheral blood of a patient with paroxysmal nocturnal haemoglobinuria (PNH) by human T lymphotropic virus type I (HTLV-I)-mediated transformation. PMT-2Y cells are positive for CD2, CD3, CD4, CD25, T cell receptor alpha beta and HLA-DR, but negative for CD1, CD7, CD8, CD19 and CD20, indicating that the clone belongs to a helper/inducer subset of T cells. PMT-2Y cells have the monoclonal integration of HTLV-I proviral DNA, suggesting that they derived from a single clone. Moreover, they lack surface expression of complement regulatory proteins such as DAF (CD55) and CD59, that are the most important glycosylphosphatidylinositol (GPI)-anchored membrane proteins defective in haemopoietic cells of patients with PNH. Northern blot analysis, however, revealed the production of normal levels of DAF mRNAs. Thus, PMT-2Y is derived from a PNH T cell clone and may be a useful model to study PNH.

Antigens, CD↗
PubMed1994

Prevalence of IgE antibody to crude and purified allergens of Japanese cedar pollen among different troops of Japanese monkeys (Macaca fuscata).

We measured specific IgE antibodies to the crude allergen as well as two purified allergens (Cry j I and Cry j II) of Japanese cedar (Cryptomeria japonica--CJ) pollen in the serum of 276 Japanese monkeys in nine troops. Of 45 monkeys with CJ specific IgE in eight of nine troops, 23 (51%) were found to have IgE to both Cry j I and Cry j II, 21 (47%) only to Cry j I, and one (2.2%) only to Cry j II. The positive rate of specific IgE antibody to each allergen varied among the troops.

Allergens↗
PubMed1994

Induction of the conversion of xanthine dehydrogenase to oxidase in rabbit liver by Cu2+,Zn2+ and selenium ions.

Effects of Cu2+,Zn2+,Fe2+ and selenium ions on the conversion of xanthine dehydrogenase to oxidase in rabbit liver were examined. Under basal conditions, xanthine oxidase activity represented only 16% of the total xanthine oxidase plus dehydrogenase activity. Cu2+ (2-10 microM), Zn2+ (5-30 microM) and selenium ions (5-100 microM) brought about the conversion of xanthine dehydrogenase to oxidase in a dose-dependent manner. The concentrations of Cu2+,Zn2+ and selenium ions required for increasing xanthine oxidase activity by 50% was approximately 4, 10 and 20 microM, respectively. On the other hand, Fe2+ had no effect on the conversion of the enzyme up to 100 microM. These results suggest that Cu2+,Zn2+ and selenium ions have the potential to modulate the conversion of xanthine dehydrogenase to oxidase in rabbit liver.

Allopurinol↗
PubMed1994

Higher exercise performance and lower VO2max in Tibetan than Han residents at 4,700 m altitude.

To examine the hypothesis that the pathway of adaptation to high altitude in natives differs considerably from that in newcomers, we measured maximal O2 uptake (VO2max), minute ventilation, anaerobic threshold (AT), blood lactate, and blood gases during maximal exercise in 17 lifelong Tibetan residents and 14 acclimatized Han Chinese newcomers living at the altitude of 4,700 m. The two groups were similar in age, height, and weight, and the subjects were nonathletes. Although VO2max was significantly lower in the Tibetans than in the Hans (30.4 +/- 1.5 vs. 36.0 +/- 1.9 ml.min-1.kg-1 STPD; P < 0.05), at maximal exercise effort the exercise workload was greater (167.7 +/- 4.2 vs. 150.0 +/- 5.9 W; P < 0.05). The mean AT values (in % VO2max) in the Tibetan and Han subjects were 84.1 and 61.6%, respectively (P < 0.01). Minute ventilation at maximal exercise was significantly lower in the Tibetans than in the Hans (68.4 +/- 3.4 vs. 79.7 +/- 4.1 l/min BTPS; P < 0.05), whereas heart rate at maximal effort was equivalent in the two groups. The Tibetans showed lower blood lactate value than did the Hans both before and at the end of exercise. We conclude that the Tibetan natives have higher exercise performance and AT but lower VO2max and blood lactate concentration than do acclimatized Han newcomers. These results may reflect the effects of genetic or peripheral adaptation factors in the Tibetan natives.

Acclimatization↗
PubMed1994

Lysophosphatidylcholine in oxidized low-density lipoprotein increases endothelial susceptibility to polymorphonuclear leukocyte-induced endothelial dysfunction in porcine coronary arteries. Role of protein kinase C.

We have shown that transferred lysophosphatidylcholine (lysoPC) from oxidized low-density lipoprotein (Ox-LDL) to endothelial surface membrane activates protein kinase C (PKC) in endothelial cells, suggesting that Ox-LDL could alter endothelial functions through PKC activation. The purposes of the present study were to examine whether the endothelial susceptibility to polymorphonuclear leukocytes (PMNs) may be altered in Ox-LDL-treated coronary arteries, which have properties closely resembling those observed in atherosclerotic arteries, and to determine the mechanism(s) by which Ox-LDL may affect the endothelial susceptibility to PMNs. Isolated porcine coronary arteries were cannulated and perfused with oxygenated culture medium with or without LDLs or lipids at a constant flow (37 degrees C, pH 7.4). The treatment of porcine coronary arteries with Ox-LDL increased endothelial adhesiveness to PMNs and augmented PMN-induced impairment of endothelium-dependent arterial relaxation (EDR). Furthermore, Ox-LDL stimulated the expression of intercellular adhesion molecule-1 (ICAM-1) in the porcine coronary arterial endothelium. These effects of Ox-LDL were not mediated by the scavenger-receptor-mediated process but were attributed to lysoPC in Ox-LDL. Blocking of the PMN adherence to endothelium by using anti-CD18 monoclonal antibody abolished the PMN-induced impairment of EDR. Coincubation with staurosporine or calphostin C, inhibitors of PKC, during treatment of the arteries with Ox-LDL or lysoPC attenuated the augmentative effects of Ox-LDL and lysoPC on endothelial ICAM-1 expression, endothelial adhesiveness to PMNs, and PMN-induced EDR impairment. Treatment of the arteries with phorbol 12-myristate 13-acetate, a potent stimulator of PKC, induced ICAM-1 expression and enhanced the endothelial adhesiveness to PMNs and PMN-induced EDR impairment, mimicking the effects of Ox-LDL. These results suggest that lysoPC in Ox-LDL induces endothelial ICAM-1 expression, which facilitates PMN adherence to endothelium and the subsequent augmentation of PMN-induced EDR impairment. PKC activation in endothelial cells by lysoPC in Ox-LDL may at least in part be involved in these effects of Ox-LDL. LysoPC in Ox-LDL increases endothelial susceptibility to PMN-induced endothelial dysfunction.

Animals↗
PubMed1994

Preparation of DNA-carrying affinity latex and purification of transcription factors with the latex.

We have developed DNA-carrying latex particles for the separation and purification of transcription factors. These particles consist of styrene (St), glycidyl methacrylate (GMA) and divinylbenzene (DVB). It was confirmed that the ethanolamine-treated surface of these particles suffered no nonspecific adsorption of proteins. To the latex particles sequence-specific DNA oligomers were immobilized via covalent coupling. A transcription factor, E4TF3, was efficiently purified to homogeneity using the latext particles. In contrast, the purification using DNA-carrying Sepharose gel yielded poor results. Compared to DNA-carrying Sepharose gel, the latex particles exhibited several times higher efficiency in the purification of E4TF3 from the crude nuclear extract.

Adsorption↗
PubMed1994

Relationship between cytosolic Ca2+ level and contractile tension in canine basilar artery of chronic vasospasm.

In order to study the role of the Ca2+/calmodulin/myosin light chain kinase system in the development of chronic vasospasm caused by subarachnoid hemorrhage, the cytosolic Ca2+ level ([Ca2+]i), measured with fura-2, a fluorescent Ca2+ indicator, and contractile tension were measured simultaneously, and their quantitative correlation was examined in basilar arterial tissue obtained from the canine "two-hemorrhage" model. Sixteen adult mongrel dogs were divided into two groups, control (n = 8) and vasospasm (n = 8), and were killed 7 days after the first experimental subarachnoid hemorrhage. In basilar arterial tissue loaded with fura-2, 1) [Ca2+]i in the resting condition was not significantly different between the two groups; 2) the increment in [Ca2+]i induced by 40 mmol/L K+ stimulation was significantly smaller in vasospastic tissue (P < 0.01); and 3) 40 mmol/L K(+)-induced tension development per cross-sectional area for a fixed increment in [Ca2+]i was significantly greater in vasospastic tissue (P < 0.01). In tissue not loaded with fura-2, active myogenic tone, which was tentatively represented by the ratio of tonus relaxed with 10(-4) mol/L papaverine to initial resting tone, was significantly greater in vasospastic tissue (P < 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Tacrine increases stimulation-evoked acetylcholine release from rat hippocampal slices.

We examined the effects of tacrine (9-amino-1,2,3,4-tetrahydroacridine) on endogenous acetylcholine (ACh) release from rat hippocampal slices. Tacrine (more than 1 microM) increased the measurable amount of basal ACh release. On the other hand, in the presence of physostigmine (50 microM; under this condition, cholinesterase activity was inhibited), tacrine did not enhance the basal ACh release. Tacrine at more than 100 microM increased the submaximal electrical stimulation-evoked release of ACh in both the absence and presence of physostigmine (50 microM). This effect of tacrine was abolished by a combination of atropine (100 mM) and physostigmine. These results indicate that a high-dose of tacrine increases cholinergic neurotransmission not only by inhibition of cholinesterase but also by increasing ACh release through an atropine-like effect, perhaps by blockade of part of the process of muscarinic autoinhibition.

Acetylcholine↗
PubMed1994

[Clinical study of scabies. The changes in the modes of transmission, and its diagnosis and treatment].

Scabies has become a common disease, not sexually transmitted but transmitted in households. Although it is also known to cause an epidemic in hospitals for the aged patients or residential homes, no effective treatment was taken for it at the present time. From January 1985 to December 1992, 424 patients with scabies (249 males and 175 females) visited the Dermatological clinic of Nippon Medical School Main Hospital. In these cases, only 13 patients (3.1%) were recognized as having STD. The sources of infestation were unclear in most cases where the disease was transmitted in households, which account for 38.5% of the patients. In 68 cases (16.0%), outbreaks of scabies in hospitals and residential homes affected the patients as well as the staffs and their families. The number of scabies cases which were infested in hospitals is increasing yearly. It is speculated that the hospitals for the aged patients and residential homes are becoming the main source of scabietic infestation. Only 16.6% of the patients were previously diagnosed or suspected to have scabies by their family doctors. It seems that the diagnosis of scabies is extremely difficult for the general practitioner. A considerable number of the patients who had been diagnosed or suspected to have scabies changed their doctor or stop visiting them. This is because an appropriate treatment is not available in most of medical facilities. At the time of the first visit to our clinic, 93.6% of the patients was diagnosed or suspected to have scabies, and the mite was demonstrated in 63.2% of the patients. It is suggested that careful inspection of scabietic burrows and the skillful technique to demonstrate the mite are essential to establish the diagnosis of scabies. Atopic dermatitis was the most common diagnosis of the patients who were misdiagnosed at the first time and later turned out to have scabies. These patients did have atopic dermatitis besides scabies. After the treatment with benzyl benzoate with crotamiton, 70.3% of the patients were cured and up to 94.9% of the patients were over improved. We compared the therapeutic effect of phenothrin to that of benzyl benzoate. Benzyl benzoate had more antipruritic effect and a little more improvement of skin lesion than phenothrin. However, there was no significant difference between benzyl benzoate and phenothrin in the period of time until the skin lesion cleared. Phenothrin is considered to have an adequate therapeutic effect for scabies.

Adult↗
PubMed1994

Hyperplastic polyps following treatment of acute gastric ulcers.

Although hyperplastic polyps are the most common polyps of the stomach, the etiology of these polyps is not completely understood. We report a 61-year-old woman who developed gastric hyperplastic polyps following acute gastric lesions. She was admitted for endoscopic injection sclerotherapy of esophageal varices. After the end of sclerotherapy, acute gastric lesions developed. For treatment of the lesions, omeprazole was used for 8 weeks followed by famotidine for 8 weeks. At the end of the treatment, she developed multiple gastric hyperplastic polyps, suggesting that acute gastric lesions and/or treatment of the gastric lesions are related to the development of hyperplastic polyps in the stomach.

Esophageal and Gastric Varices↗