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Biomedical subjects

M Fukuda

Publications and source records attributed to M Fukuda.

At least 559 records · Page 31Linked to original sources
PubMed1996

Event-related potential correlates of functional hearing loss: reduced P3 amplitude with preserved N1 and N2 components in a unilateral case.

A female patient exhibiting functional hearing loss in her left ear demonstrated reduced amplitude of P3 component in event-related potentials (ERP) to left monaural stimulation, with preserved N1 and N2 components to stimulation of either ear. This result suggested that stimuli in the affected ear were conducted successfully up to the auditory cortex but that further processing in higher brain regions was 'repressed'. Event-related potential examination for such hysterical disorders could be useful in clarifying their brain mechanism and offer a useful diagnostic clue to its nature.

Adult↗
PubMed1996

Effect of pituitary and ovarian hormones on human melanocytes in vitro.

Normal human melanocytes in culture became enlarged and dendritic after a 2-day incubation with either the pituitary (beta-MSH, a potent analog of alpha-MSH, ACTH, FSH and LH) or the ovarian (estradiol, estriol and progesterone) hormones. Under the same experimental conditions, pituitary hormones also increased both the tyrosinase activity and tyrosinase-related protein-1 (TRP-1) while ovarian hormones increased TRP-1 but not tyrosinase activity. The results suggest that pituitary and ovarian hormones possibly induce hyperpigmentation of the skin by stimulating the melanogenesis in epidermal melanocytes, and that estradiol and progesterone may be involved in the pathogenesis of melasma (chloasma) usually developing between early adulthood and menopause in which a high concentration of serum ovarian hormones was maintained.

Adrenocorticotropic Hormone↗
PubMed1996

Levels of recombinant human granulocyte colony-stimulating factor in serum are inversely correlated with circulating neutrophil counts.

Recombinant human granulocyte colony-stimulating factor (rhG-CSF) is effective in countering chemotherapy-induced neutropenia. However, serum rhG-CSF levels cannot be maintained throughout the course of rhG-CSF therapy. The drop in serum rhG-CSF levels may vary with the duration of rhG-CSF administration or with the circulating neutrophil counts. We investigated the relationship between serum G-CSF levels and circulating neutrophil counts and the pharmacokinetics of rhG-CSF for patients with lung cancer who had been treated with myelosuppressive chemotherapy and then with subcutaneous rhG-CSF (lenograstim, 2 micrograms per kg of body weight per day). Twelve patients were randomly assigned to four groups with different rhG-CSF therapy schedules. Serum G-CSF levels were measured by an enzyme immunoassay method. Serum G-CSF levels during the rhG-CSF therapy greatly exceeded endogenous G-CSF levels and were mainly due to the presence of exogenous rhG-CSF rather than increased levels of endogenous G-CSF. Despite the duration of rhG-CSF administration, serum G-CSF levels during rhG-CSF therapy were inversely correlated with circulating neutrophil counts (r2 = 0.73, P < 0.0001). The value for the area under the concentration-time curve of rhG-CSF on the day of neutrophilia was lower than that on the day of neutropenia (P < 0.05). Our results suggest that the fall in serum G-CSF levels during rhG-CSF therapy may result from increased clearance and/or decreased absorption of rhG-CSF, two processes related to circulating neutrophil counts.

Aged↗
PubMed1996

Identification of an alternative 2,3-dihydroxybiphenyl 1,2-dioxygenase in Rhodococcus sp. strain RHA1 and cloning of the gene.

Gram-positive Rhodococcus sp. strain RHA1 possesses strong polychlorinated biphenyl-degrading capabilities. An RHA1 bphC gene mutant, strain RDC1, had been previously constructed (E. Masai, A. Yamada, J. M. Healy, T. Hatta, K. Kimbara, M. Fukuda, and K. Yano, Appl. Environ. Microbiol. 61:2079-2085, 1995). An alternative 2,3-dihydroxybiphenyl 1,2-dioxygenase (2,3-DHBD), designated EtbC, was identified in RDC1 cells grown on ethylbenzene. EtbC contained the broadest substrate specificity of any meta cleavage dioxygenase identified in a Rhodococcus strain to date, including RHA1 BphC. EtbC was purified to near homogeneity from RDC1 cells grown on ethylbenzene, and a 58-amino-acid NH2-terminal sequence was determined. The NH2-terminal amino acid sequence was used for the identification of the etbC gene from an RDC1 chromosomal DNA 2,3-DHBD expression library. The etbC gene was successfully cloned, and we report here the determination of its nucleotide sequence. The substrate specificity patterns of cell extract and native nondenaturing polyacrylamide gel electrophoresis analysis identified the coexpression of two 2,3-DHBDs (BphC and EtbC) in RHA1 cells grown on either biphenyl or ethylbenzene. The possible implication of coexpressed BphC extradiol dioxygenases in the strong polychlorinated-biphenyl degradation activity of RHA1 was suggested.

Amino Acid Sequence↗
PubMed1996

Absorption, distribution and excretion of beta-cyclodextrin and glucosyl-beta-cyclodextrin in rats.

The absorption, distribution and excretion of intravenously and orally administered beta-cyclodextrin (beta-CD) and glucosyl (G)-beta-CD in rats were studied using HPLC with pulsed amperometric detection. Within 10 h after intravenous administration, unchanged beta-CD and G-beta-CD recovered in urine were about 90% of each dose. The nephritic accumulation of G-beta-CD after the intravenous administration of G-beta-CD was slightly lower than that of beta-CD using the same treatment. The maximum plasma concentrations of beta-CD and G-beta-CD after the oral administration of CDs (500 mg/kg) were observed within 40 min. After oral administration, 0.6% of beta-CD and 0.3% of G-beta-CD were excreted in urine. The pharmacokinetic behaviour of both CDs after the intravenous administration of CDs (50 mg/kg) was almost the same. Furthermore, the inclusion complexes of estriol and betamethasone with CDs were prepared, and their absorption was evaluated after oral administration in rats. The plasma concentrations of CDs after oral administration of drug-CD complexes were significantly decreased in comparison with those after the oral administration of CDs alone. On the other hand, the plasma concentrations of drugs after the oral administration of drug-CD complexes were higher than those after the administration of drugs alone.

Absorption↗
PubMed1996

Chronic bronchial foreign body mimicking peripheral lung tumor.

We describe a case with chronic bronchial foreign body presenting with recurrent hemoptysis mimicking a peripheral lung tumor, and the outcome of surgical resection. A 61-year-old female with recurrent hemoptysis had a peripheral nodule in the right lower lobe. A right bronchial arteriogram showed dilatation and hypervascularity in the nodule. Surgical removal of the nodule contained a small branch of a white cedar. Chronic bronchial foreign body, while rare in adults, should be considered in the differential diagnosis of peripheral lung tumors associated with recurrent hemoptysis.

Angiography↗
PubMed1996

A prospective study of bronchoscopy for endotracheobronchial tuberculosis.

To clarify the role of bronchoscopy for endotracheobronchial tuberculosis (EBTB), we performed a prospective study in 45 patients with active pulmonary tuberculosis, in 15 (33%) of whom bronchoscopic findings related to EBTB were seen. The findings were classified into six types:edematous hyperemic, submucosal nodule, ulcerative (shallow and deep), polypoid, cicatrical, and compression type. Each of these types was related to the healing process and outcome after antituberculosis chemotherapy. Serial bronchoscopy revealed that lesions less advanced than the deep ulcerative type responded to chemotherapy; the deep ulcerative and polypoid types progressed to cicatrical bronchostenosis despite chemotherapy. In the follow-up of patients with lesions of the deep ulcerative and polypoid types, serial bronchoscopy after chemotherapy is recommended; these patients also require adjunctive therapy to prevent cicatrical bronchostenosis.

Biopsy↗
PubMed1996

Content and characteristics of vitamin B12 in some seaweeds.

The vitamin B12 (B12) content in seven species of seaweed that are consumed frequently in Hokkaido, Japan, was microbiologically measured using Escherichia coli 215. Asakusanori (Porphyra tenera), maruba-amanori (Porphyra suborbiculata) and akaba-gin-nansou (rhodo-glossum pulcherum) showed higher B12 content than the other species, although the content varied greatly among samples in the same species. A bioautography on a thin-layer plate holding a mixture of silica gel and cellulose, differentiation of B12 and its analogues using a binding specificity of intrinsic factor and haptocorrin, and comparison of the B12 concentration determined by the radioisotope dilution assay method using the intrinsic factor as the B12-binding protein with that by the bioassay method, predominantly showed B12 in maruba-amanori and B12 analogues in wakame (Undaria pinnatifida) and akaba-gin-nansou. The B12 uptake of akaba-gin-nansou from artificial seawater was similar to that of asakusanori that contained only B12.

Chromatography, Thin Layer↗
PubMed1996

Release and uptake of vitamin B12 by asakusanori (Porphyra tenera) seaweed.

When asakusanori was incubated in artificial seawater, it released a significant amount of vitamin B12. The rate of release was very high at the beginning of incubation and steeply decreased. Four-fifths of the released B12 was a macromolecule-bound form and the rest was free form, of which some were taken up by the asakusanori tissue. Asakusanori took up the free form B12 from the incubation medium by concentration- and temperature-dependent processes. The amount of uptake increased with the time of incubation and did not attain a plateau after 4 h. The capacity was retained even after storage in frozen state for 11 months.

Diffusion↗
PubMed1996

Fibronectin in the tear film.

PURPOSE: Fibronectin plays an important role in corneal healing and has been detected previously in the tear film. To investigate the levels of fibronectin in normal human tears, the authors measured and compared fibronectin concentration in open-eye, closed-eye, and reflex tear fluid. The origin of fibronectin in the tear film was investigated by comparing fibronectin concentration in sequentially collected reflex tear samples with the concentrations of total protein and albumin in the same samples. METHODS: Open-eye and closed-eye tears were collected from 11 noncontact lens wearers. From 7 subjects, 20 uninterrupted reflex tear samples (10 microliters each) subsequently were collected, using the sneeze reflex method of stimulation, followed by an additional 10 nonstimulated tear samples (3 microliters each) immediately after cessation of stimulus. Enzyme-linked immunosorbent assays were used to determine fibronectin and albumin concentrations, and bicinchoninic acid protein assays were used to determine total protein concentration in each sample. RESULTS: Fibronectin concentration in open-eye tears (19 +/- 24 eta g/ml, range 3 to 78 eta g/ml) was significantly different (P = 0.004) from that in closed-eyes tears (4127 +/- 3222 eta g/ml, range 1177 to 11384 eta g/ml). In the first 50 microliters of reflex tears, fibronectin concentrations were low (10 +/- 23 eta g/ml), but they increased significantly (P = 0.028) after 100 microliters of reflex tears had been collected (220 +/- 126 eta g/ml). There was a further marked transient increase (767 +/- 946 eta g/ml) after cessation of stimulus. Total protein concentration in the same samples decreased significantly during reflex tear collection compared to open-eye tears, and it increased gradually after cessation of stimulus. Albumin concentration in the same samples, analyzed for two subjects only, showed a pattern similar to that for fibronectin. Dilation of conjunctival blood vessels was noted in all subjects after reflex tear collection. Administration of a topical vasoconstrictor in two subjects eliminated the increase in fibronectin concentration during reflex tearing but did not affect total protein concentration. Under reducing conditions, the molecular mass of fibronectin in open-eye and reflex tears was 240 kDa, identical to commercially available purified plasma fibronectin, whereas fibronectin in closed-eye tears was degraded into small molecular mass fragments. CONCLUSIONS: These findings suggest that fibronectin in tear fluid is derived from plasma and that the increase in concentration in closed-eye and reflex tear fluid is caused by leakage from dilated conjunctival blood vessels.

Adult↗
PubMed1996

Arbutin: mechanism of its depigmenting action in human melanocyte culture.

Arbutin, a naturally occurring beta-D-glucopyranoside of hydroquinone, is effective in the topical treatment of various cutaneous hyperpigmentations characterized by hyperactive melanocyte function. We examined the mechanism of its depigmenting action in human melanocyte cultures. Arbutin inhibited the tyrosinase activity of cultured human melanocytes at noncytotoxic concentrations. It did not affect the expression of tyrosinase mRNA. Melanin production was inhibited significantly by arbutin, as determined by measuring eumelanin radicals with an electron spin resonance spectrometer. The study of the kinetics and mechanism for inhibition of tyrosinase confirms the reversibility of arbutin as a competitive inhibitor of this enzyme. The utilization of L-tyrosine or L-dopa as the substrate suggests a mechanism involving competition with arbutin for the L-tyrosine binding site at the active site of tyrosinase. These results suggest that the depigmenting mechanism of arbutin in humans involves inhibition of melanosomal tyrosinase activity, rather than suppression of the expression and synthesis of tyrosinase.

Arbutin↗
PubMed1996

[Usefulness and limitation of serum tumor markers in diagnosis of lung cancer].

In the clinical practice of lung cancer, serum tumor markers are important laboratory tests and their use is wide spread. Among the various markers for lung cancer, the usefulness of CEA, SLX, SCC and NSE has been firmly established. These markers cannot be used routinely to screen for lung cancer but may be used as complementary tools for diagnosing the tumor. Elevated levels of these markers also appear to be useful for monitoring the response to therapy and tumor progression. CYFRA21-1 and ProGRP, new tumor markers with relatively high sensitivity and specificity to lung cancer, were recently developed. These tumor markers may be useful tools for early detection of lung cancer.

Antigens, Neoplasm↗
PubMed1996

Two deficiency cases of disputed paternity: sibling or half-sibling?

We report briefly the results of DNA analysis in two cases of disputed paternity where the alleged father and the mother were dead and only the children were available. In one case, half-sibship was established by minisatellite typing with a multi-locus probe and microsatellite FGA typing. In the other case, Y27H39 typing revealed that the fathers of the two male children were different. DNA polymorphisms, especially at microsatellite loci, provide useful information to solve such paternity cases.

Base Sequence↗
PubMed1996

Microsatellite typing in a paternity case against a deceased man whose two brothers were available for testing.

To resolve a deficiency case of disputed paternity, we examined the mother, child, and two sibs of the deceased alleged father. In all of the 11 conventional marker systems and three microsatellite systems (ACTBP2, FGA, and D11S488) applied, the child and the paternal sibs had alleles is common. We deduced first the possible ACTBP2 genotypes of the deceased parents of the two sibs from their test results. Next, from all the combinations of the deduced genotypes, we estimated the frequencies of the possible genotypes of the alleged father and, with Bayes' theorem, calculated the probabilities of the alleged father having the genotypes compatible with paternity. Using these probabilities, we worked out the probability of the child's genotype resulting from the mating of the mother with the alleged father. Meanwhile, we calculated the probability of the child's genotype being expected of the mating of the mother with an unrelated random man. Finally, applying Bayes' theorem again, we obtained a probability of paternity of 0.992 for the ACTBP2 locus alone. Inclusion of the FGA locus in the probability calculations brought the overall probability of paternity to 0.998. The present study demonstrates that testing for hypervariable microsatellite loci greatly facilitates the solution of a deficiency case that would be difficult or time-consuming to solve by conventional marker typing.

Female↗
PubMed1996

Quintuplex PCR-amplification of microsatellites.

We tested the potential usefulness of quintuplex PCR-amplification of STRs (D16S537, D8S320, FGA, D11S554 and THO1) for paternity testing, first by constructing 20 false family trios, each with a non-biological father, to estimate the actual exclusion rate, and next by a retrospective study of 20 paternity cases which had been previously tested by RFLP analysis and typing of conventional genetic markers. The five STR loci have a combined average exclusion power of 99.8%. The forensic efficiency values for four of the five STRs were based on typing of a Japanese population of 300 individuals. The observed rate of exclusion was in close agreement with the expected rate for the Japanese population. In 12 of the 20 cases, paternity was not excludable by any of the loci. The probability of paternity calculated for the alleged father was > 99% in the inclusion cases. In the remaining 8 cases, paternity was excluded by at least 2 of the STR loci. The results of STR typing agreed with the data from RFLP analysis and conventional genetic typing. Taking advantage of five STRs sharing AA in the tetranucleotide repeats (AAAG or AATG), we detected PCR products simultaneously with a digoxigenin-labeled (AAAG)6 oligonucleotide probe after sequencing-gel electrophoresis. The quintuplex PCR-amplification of STRs is a rapid and efficient method for paternity testing and individual identification.

Base Sequence↗