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Biomedical subjects

M Hatori

Publications and source records attributed to M Hatori.

At least 73 records · Page 4Linked to original sources
PubMed1995

A rapid and ultrasensitive method for measurement of DNA, calcium and protein content, and alkaline phosphatase activity of chondrocyte cultures.

Most investigators are cognizant of the problems inherent in counting cells embedded in a complex and abundant extracellular matrix. To overcome these obstacles, we developed a new method of isolating nucleic acids from chondrocytes which facilitates measurement of cell number by DNA analysis. Chondrocytes were isolated from chick embryo sterna and grown continuously without subculturing for 2-3 weeks in monolayer. The cells were treated with triton X-100 and the nucleic acid content of the extract was determined by measuring DNA fluorescence in the presence of Hoechst dye 33258. To minimize background fluorescence due to the triton, we precipitated the DNA with alcohol and then solubilized the nucleic acids in EDTA. This simple procedure removed the detergent and substantially increased the sensitivity of the method. Thus, we could measure with high precision and high recovery, the DNA content of cultures of 10,000-50,000 cells. In a single well containing 0.5-1.0 million cells, sufficient material remained for subsequent measurements of alkaline phosphatase activity and protein and calcium content. As the mineral present in the triton-treated samples was soluble in EDTA, we experienced no problems in measuring the calcium content of the culture. In addition, as triton X-100 is a nonionic detergent, we were able to measure cell and matrix proteins; moreover, the presence of the triton maintained the catalytic state of alkaline phosphatase. We conclude that this procedure provides a simple and rapid approach to measuring major indicators of chondrocyte maturation and function.

Alkaline Phosphatase↗
PubMed1995

Effects of deferoximine on chondrocyte alkaline phosphatase activity: proxidant role of deferoximine in thalassemia.

The homozygous form of beta-thalassemia, the most common single gene disorder, is treated by red cell transfusion therapy. Following transfusion, the chelator, deferoximine, is administered to patients to remove excess iron. However, when this drug is given to young children, metaphyseal dysplasia and abnormalities of linear growth are frequently observed. To explore the notion that deferoximine interferes with endochondral growth by chelating zinc, we examined the effect of the drug on chondrocytes maintained in long-term culture. We found that deferoximine caused a dose-dependent inhibition of a wide range of functions including cell proliferation, protein synthesis (and possibly under-hydroxylation of type X collagen), and mineral deposition. Directly relevant to the mineralization process was the observation that the drug dramatically lowered the activity of alkaline phosphatase, a zinc-requiring enzyme. To test the hypothesis that enzyme inhibition was due to chelation of zinc by deferoximine, the cell culture medium was supplemented with excess zinc. However, this treatment did not overcome the deferoximine-dependent change in enzyme activity. We next examined the possibility that deferoximine, in the presence of ascorbate, could form a free radical system that would serve to inactivate the enzyme. Using alkaline phosphatase extracted from chick cartilage, we noted that the activity of the phosphatase was markedly reduced in the presence of deferoximine and ascorbate. These effects were consistant with the notion that deferoximine and ascorbate can act as a prooxidant couple. This conclusion was confirmed when we measured the oxidative activities of the system using nitrobule tetrazolium and cytochrome c. Indeed, we noted that deferoximine markedly activates the autocatalytic oxidation of ascorbate.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaline Phosphatase↗
PubMed1995

Reduced expression of neurofibromin in the soft tissue tumours obtained from patients with neurofibromatosis type I.

1. We analysed the expression of neurofibromin mRNAs, encoded by the gene responsible for neurofibromatosis type 1, and of neurofibromin protein in nine soft tissue tumours by S1 nuclease mapping and Western blot analyses. Four tumours were obtained from patients with neurofibromatosis type 1, comprising two neurofibromas, one fibrolipoma and one malignant schwannoma, and five neurogenic tumours were obtained from non-neurofibromatosis type 1 patients. 2. All tumours, except for a malignant schwannoma, similarly expressed three species of mRNA encoding neurofibromin, an isoform with the insertion of 21 amino acids in the domain related to ras GTPase-activating protein, and an N-terminal isoform lacking this domain. 3. Western blot analysis demonstrated deficiency of neurofibromin in the tumours derived from three out of the four neurofibromatosis type 1 patients: a fibrolipoma, a malignant schwannoma and a neurofibroma. In contrast, reduction in neurofibromin was not detected in the five tumours obtained from non-neurofibromatosis type 1 patients. Furthermore, the expression of ras GTPase-activating protein was detected in all nine tumours examined. 4. The undetectable or reduced level of neurofibromin in the tumours obtained from neurofibromatosis type 1 patients suggests that this deficiency is closely related to their tumourigenesis.

Adult↗
PubMed1995

Calcific bursitis in a three-year-old boy: a case report.

This is a case report of calcific bursitis adjacent to the first metatarsophalangeal (MP) joint in a 3-year-old boy. The patient had two attacks of pain on the medial side of the first MP joint, resembling an acute gouty attack. Roentgenograms showed calcified opacity adjacent to the medial side of the first MP joint. Surgical removal of the calcified bursa was performed. X-ray analyses revealed that this calcified deposit was hydroxyapatite.

Bursitis↗
PubMed1994

Retinoic acid induces a shift in the energetic state of hypertrophic chondrocytes.

In the epiphyseal growth plate, chondrocyte maturation is accompanied by dramatic alterations in energy metabolism. To explore the relationship between these two events, we used retinoic acid (RA) to promote chondrocyte maturation in culture. The specific question that was addressed was, does RA treatment of cultured chondrocytes in vitro induce a change in energy status similar to that seen in hypertrophic chondrocytes in vivo. Maturing chondrocytes isolated from the cephalic region of day 18 chick embryo sterna were allowed to grow for 7-14 days in monolayer until confluent and then treated with 10-300 nM RA. Immature chondrocytes from the caudal region of sternum were grown in parallel and served as control cells for the study. We found that in maturing cephalic cell cultures, RA had a rapid and profound effect on oxidative metabolism. The retinoid caused a reduction in the energy charge ratio (ECR) and the ATP/ADP ratio and a sharp decrease in cell ATP levels. Maximum inhibition was observed when the RA concentration was 10-35 nM. Compared with the adenine nucleotides, creatine phosphate levels were decreased to a lesser extent by RA, although there was substantial inhibition of creatine kinase activity. We expected to find a compensatory elevation in glycolytic activities; however, the lactate levels in the medium of the treated cells indicated that anaerobic glycolysis was depressed. In contrast to the cephalic chondrocytes, when caudal cell cultures were treated with RA, lactate formation was stimulated and there were minimal effects on oxidative metabolism. To determine the mechanism of inhibition of glycolysis, we measured the activity of pyruvate kinase in RA-treated cephalic cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adenosine Triphosphate↗
PubMed1994

A severe outbreak of haemorrhagic colitis and haemolytic uraemic syndrome associated with Escherichia coli O157:H7 in Japan.

UNLABELLED: In 1990, an outbreak of Escherichia coli O157:H7 infection occurred in 174 children in a nursery school in Saitama, Japan. The organism was isolated from tap water supplied from the well in the school. Clinical manifestations varied from asymptomatic infection to non-bloody diarrhoea, haemorrhagic colitis, haemolytic uraemic syndrome (HUS) and death. Among culture-confirmed 42 cases of E. coli O157:H7, 7 children were asymptomatic, 21 children had only diarrhoea, and 14 children developed HUS. Bloody diarrhoea with abdominal pain following initial frequent diarrhoea appeared to be associated with subsequent HUS. In patients with HUS, both leucocyte count and lactate dehydrogenase activity continued to increase in the early phase of the disease, and on day 3 of illness attained markedly higher levels than in patients without HUS. These two parameters seemed to be important as predictors of the development of HUS. CONCLUSION: E. coli O157:H7 is a common pathogen causing colitis. It should be kept in mind in paediatric practice and public health.

Child↗
PubMed1994

Ossification of the Achilles tendon: a case report.

Ossification of the Achilles tendon is a rare condition. We recently treated a patient with ossification of bilateral Achilles tendons. The patient was a 50 year old male whose chief complaint was discomfort around the Achilles tendon. He had a previous history of treatment of bilateral club feet. On the roentgenograms, the length of the bony mass in the Achilles tendon was 5.5 cm on the right side and 1.5 cm on the left side. The left side was treated by surgical removal of a bony mass and suture of the tendon. Microscopic examination of the extirpated specimen revealed bone formation through enchondral and intramembranous ossification in the Achilles tendon.

Achilles Tendon↗
PubMed1993

The effects of walking at the anaerobic threshold level on vertebral bone loss in postmenopausal women.

The purpose of this study was to determine the optimal intensity of exercise necessary to prevent the postmenopausal bone loss on the basis of anaerobic threshold (AT). Thirty-three postmenopausal women were randomized to control (group C: n = 12) or two exercise groups (group H and group M). All women performed a treadmill exercise test, and the AT was measured by expired gas analysis. The exercise regimen consisted mainly of walking at a speed that kept the exercise heart rate above the AT (group H: n = 12) or below the AT (group M: n = 9). Exercise was performed for 30 minutes, three times a week for 7 months. The bone mineral density (BMD) of the lumbar vertebrae was measured using dual energy X-ray absorptiometry. The BMD level in group C decreased by 1.7 +/- 2.7%, but there was a significant increase of 1.1 +/- 2.9% in group H. In group M there was a decrease of 1.0 +/- 3.1% which did not differ from group C. In group C, serum osteocalcin and urinary hydroxyproline excretion were significantly increased, but no changes were seen in either of the exercise groups. Urinary calcium significantly decreased in the exercise groups. We conclude that short-term (7 months) exercise with intensity above the AT is safe and effective in preventing postmenopausal bone loss.

Absorptiometry, Photon↗
PubMed1993

Prolonged infection of the floor of the mouth in hyperimmunoglobulinemia E (Buckley's syndrome). Report of a case.

A case of prolonged infection of the floor of the mouth with a generalized eczematous dermatitis in a 13-year-old boy is described. Immunologic examination revealed markedly elevated serum concentration of immunoglobulin E (IgE) and impaired neutrophil chemotaxis. The disorder was diagnosed as the hyperimmunoglobulinemia E (Buckley's syndrome) and was successfully treated with high doses of antibiotics and human immunoglobulin.

Adolescent↗
PubMed1993

BMS-181184, a new pradimicin derivative. Screening, taxonomy, directed biosynthesis, isolation and characterization.

BMS-181184 is a new semisynthetic pradimicin derivative with a broad-spectrum antifungal activity. In a search for actinomycetes producing BMS-181184, 4 strains of Actinomadura sp. isolated from soil samples were found to produce the antibiotic under conditions of directed biosynthesis. Among them, Actinomadura sp. AB1236 proved most useful in the production of BMS-181184 when fermented in a medium containing D-serine and D-cycloserine. A minor product isolated from the broth of strain AB1236 was identified as the dexylosyl analog of BMS-181184, which was also obtained by acid hydrolysis of BMS-181184.

Actinomycetales↗
PubMed1993

Pradimicins L and FL: new pradimicin congeners from Actinomadura verrucosospora subsp. neohibisca.

Pradimicin L, a new congener of pradimicin A having the D-glucosyl-D-thomosamine moiety at the C-5 position, was isolated from Actinomadura verrucosospora subsp. neohibisca subsp. nov. The structure of pradimicin L was deduced to be N-[[(5S,6S)-5-O-[4,6-dideoxy-4-(methylamino)-3-O-(beta-D-glucopyranosyl) - beta-D-galactopyranosyl]-5,6,8,13-tetrahydro-1,5,6,9,14-pentahydroxy-11- methoxy-3-methyl-8,13-dioxobenzo[a]naphthacene-2-yl]carbonyl ]-D-alanine by MS and NMR spectrometry and degradation studies. Pradimicin FL which has the D-serine moiety instead of D-alanine was produced by directed biosynthesis in D-serine-supplemented medium. Pradimicins L and FL have a broad spectrum of in vitro antifungal activity. Pradimicin L was equiactive to pradimicin A and pradimicin FL was more active than pradimicin L.

Actinomycetaceae↗
PubMed1993

Pradimicin S, a new pradimicin analog. II. Isolation and structure elucidation.

Pradimicin S was isolated from the culture filtrate of Actinomadura spinosa AA0851. NMR and MS analyses proved that pradimicin S is the 3'-O-(3''-O-sulfo-beta-D-glucopyranosyl) analog of pradimicin A, a new member of the pradimicin family of antibiotics. Stereochemical assignment was made by correlating pradimicin S with pradimicin L.

Actinomycetaceae↗
PubMed1993

Biosynthesis of the pradimicin family of antibiotics. III. Biosynthetic pathway of both pradimicins and benanomicins.

The biosynthetic pathway of the pradimicin-benanomicin family of antibiotics was investigated by using sinefungin and blocked mutants derived from Actinomadura verrucosospora subsp. neohibisca E-40 (a high pradimicin producer) or Actinomadura sp. AB1236 (a benanomicin producer). Addition of sinefungin to strain E-40, pradimicin A aglycone-producing mutant or strain AB1236 inhibited the formation of 11-O-demethyl-7-methoxypradinone II (11dM-7M-PN II), resulting in the accumulation of 11-O-demethylpradimicinone II and pradimicinone II. By feeding pradimicin A aglycone and its analogs to mutants blocked early in pradimicin or benanomicin biosynthesis, the following results were obtained: 11-O-demethylpradinone II, 11dM-7M-PN II 11-O-demethylpradinone I, 11-O-demethylpradimicinone I and pradimicinone I were converted to pradimicin A or benanomicin A; the remaining 6 aglycone analogs were not incorporated into the antibiotics. Pradimicin B, dexylosylpradimicin C and dexylosylbenanomicin A were converted to pradimicin A, pradimicin C and benanomicin A, respectively. A biosynthetic pathway for the antibiotics is proposed.

Actinomycetales↗
PubMed1993

Pradimicins T1 and T2, new antifungal antibiotics produced by an actinomycete. II. Structures and biosynthesis.

Pradimicins T1 and T2 are new members of the pradimicin family of antibiotics produced by an actinomycete strain AA3798. Pradimicins T1 and T2 are dihydrobenzo[a]naphthacenequinones substituted with 3 and 2 sugar moieties, respectively. The salient feature in their structures is an L-xylose attached to the phenolic hydroxyl group at C-11. Bioconversion experiments using a blocked mutant B-54 of strain AA3798 not only explored a plausible biosynthetic pathway of pradimicins T1 and T2, but also provided evidence of 5S,6S configuration.

Actinomycetaceae↗
PubMed1992

Evaluation of trismus after treatment of mandibular fractures.

This retrospective study examines the effects of treatment modalities and other contributing factors on the duration of trismus following mandibular fractures. Under a strict protocol, 80 cases involving a total of 120 fractures and their treatment modalities were reviewed. An investigation of duration of trismus was carried out in several ways. Although a relationship was established between age, initial interincisal distance, and duration of trismus, no relationship was found with the number or location of fractures, or reduction method. However, after examining the fixation methods separately, it was found that those cases in which Champy plates were used experienced a shorter duration of trismus compared with those using closed reduction with maxillomandibular fixation.

Adolescent↗
PubMed1992

Tissue distribution of 125I-labeled fetal thyroid hormone in nude mice xenografted with Ewing sarcoma.

Biodistribution of fetal thyroid hormone (RT3) was studied in nude mice with Ewing's sarcoma xenografts. At 30 min and 1, 2, 4, 8, and 12 hr after injection, blood, tumor and normal organs were measured to determine the amount of radioactivity per gram of tissue. The amount of radioactivity in the blood of tumor-bearing mice decreased sharply from 7.64% of injected dose per gram of tissue (% ID/g) at 30 min after inoculation to 0.45%/ID/g at 12 hr. The % of injected dose per gram for 125I-labeled RT3 in the tumor reached 1.92 at 1 hr after injection and decreased to 0.22 at 12 hr. The radiolocalization indices for tumor to other organs at 12 hr ranged from 1.35 to 4.43. This study suggests increased localization of RT3 in the Ewing's sarcoma as compared to other tissues in the nude mouse.

Animals↗
PubMed1992

[Significance of prostatic specific antigen in the mass screening for prostate cancer].

The significance of prostatic specific antigen (PSA) was investigated in the subjects examined by the mass screening for prostate cancer from 1985 to 1990. All subjects was examined by digital rectal examination (DRE) and with prostatic acid phosphatase (PAP) and the subjects in whom prostate cancer (Pca) was suspected from abnormal DRE and/or elevated PAP were recommended to receive the secondary screening to confirm the presence of Pca. PSA was measured by radioimmunoassay using Ball-Elsa-PSA-kit. 1,600 serum samples were obtained from our serum bank. The relationship among PSA, prostate size estimated by DRE and age was investigated. PSA was increased with age and the prostate size, PSA being more closely related with the latter. Therefore, we estimated that PSA has an ability to detect benign prostatic hypertrophy (BPH) in the mass screening. This estimation should be confirmed by using an ultrasound tomography because the prostate size obtained by DRE is inaccurate as compared with that obtained by ultrasound tomography. The cut off level of PSA was determined by control which was composed from the subjects with normal size prostate and one with BPH. When the cut off level was 8.6 ng/ml, the sensitivity, specificity and efficiency as Pca marker was 73.9%, 97.4% and 97.1%, respectively. PSA was more than 8.6 ng/ml in all of Pca with elevated PAP. PSA was expected to improve the Pca detection rate in our mass screening system.

Aged↗