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Biomedical subjects

M Inomata

Publications and source records attributed to M Inomata.

14 recordsLinked to original sources

Slow axonal transport of soluble proteins and calpain in retinal ganglion cells of aged rabbits.

The rate of slow axonal transport of soluble proteins in retinal ganglion cells of the rabbit decreased with approximately 25% in aged (6 years) compared to previous estimates in adult (2 years) animals. Immunobinding of calpain to microtiter plates coated with a monoclonal antibody to mu-calpain was used to isolate labelled axonally transported mu-calpain from the nerve extracts. It was found that the distribution of labelled mu-calpain in the retrobulbar optic pathway was similar to the distribution profile of the slowly migrating phase of soluble proteins.

Aging

Primary anorectal malignant melanoma.

A case of primary anorectal malignant melanoma seen in a 46 year old woman is presented herein. Her most marked symptoms were bloody stools and anal pain. Endoscopic examination indicated a tumor with ulceration but without pigmentation in the anorectal region. Histologic examination of the biopsied specimens showed spindle-shaped cells with atypia proliferating in a bandlike arrangement, as in leiomyosarcoma. An abdominoperineal resection was done and detailed histological examination of the tumor confirmed the nature of the tumor to be malignant melanoma. The postoperative immunochemotherapy consisted of Dimetyl-Triazeno-Imidasole-Carboxamide (DTIC), Amino-Methyl-Pyrimidinyl-Methyl-Chlorethyl-Nitrosourea-Hydrochlori de (ACNU), Vincristine (VCR) and OK-432. The patient has been well without recurrence for fifteen months following her operation through the continuous administration of these agents.

Antineoplastic Agents

Calcium-activated neutral protease (CANP) in normal and dysmyelinating mutant paralytic tremor rabbit myelin.

Calcium-activated neutral protease (CANP) in normal and dysmyelinating mutant, paralytic tremor (PT) rabbit myelin and premyelin fractions was studied using immature (4-5 wk) or adult animals. The enzyme was estimated by determination of its catalytic activity as well as by using immunoblot analysis after SDS-PAGE separation. The presence of two forms of CANP--one activated by calcium in the micromolar concentration (mu CANP) range and the other exhibiting low calcium sensitivity in the millimolar concentration range (m-CANP)--was found in the myelin and premyelin fractions. The developmental pattern of the enzyme activity was different for each of these two enzyme isoforms depending on the fraction studied. The higher activity on CANP (both isoforms) found in PT myelin and premyelin could be related to delayed myelination and/or to the higher turnover rate of already formed myelin. These results suggest complex and specific roles for these isoenzymes during myelin formation as is discussed further in this article. Our results confirm the extensive degradation of myelin basic protein (MBP), proteolipid protein (PLP), and, to a lesser extent, the other myelin proteins by endo- and exogenous CANP. This degradation process was significantly elevated in PT rabbit myelin. Moreover as was shown by two-dimensional gel electrophoresis, calcium-controlled proteolysis in nonmutant rabbits affected the net-charge of MBP in a manner similar to that reported for PT myelin, suggesting the possible involvement of CANP in the generation of charge isomers of MBP.

Animals

Activation of intracellular calcium-activated neutral proteinase in erythrocytes and its inhibition by exogenously added inhibitors.

Intracellular calcium-activated neutral proteinase (CANP) in rabbit erythrocytes was activated by an influx of Ca2+ into the cells. The catalytic large subunit changed from the original 79 kDa from to the 77 kDa and 76 kDa forms on activation just in the same manner as occurs in the autolytic activation of purified CANP in vitro. The activation required both extracellular Ca2+ and A23187, and was accompanied by the degradation of some membrane proteins and morphological changes in erythrocyte shape from discocytes to echinodisks, echinocytes, and spherocytes. Exogenously added Cbz-Leu-Leu-Leu-aldehyde inhibited the activation of intracellular CANP as well as the degradation of membrane proteins and the morphological changes indicating that the latter two processes are due to the action of CANP. Leupeptin and E64d were without effect on intracellular CANP.

Amino Acid Sequence

Developmental and dietary induction of the 90K subunit of rat intestinal phytase.

The activities of phytase and alkaline phosphatase in the intestine gradually increased in parallel during development of rats, but the 70K and 90K subunits were expressed differentially; only the 70K subunit was detected at birth, whereas the 90K subunit appeared at the weaning period (3 weeks after birth). When rats were forced to wean at 18 days old and fed laboratory chow, the enzyme activity increased markedly and the 90K subunit appeared within 1 day. These findings suggest that weaning is involved in the change in the subunit composition. Increases in the enzyme activity and amount of the 90K subunit were significantly delayed by feeding weanling animals on casein diet, but induced significantly by feeding them on casein diet supplemented with phytate. Thus induction of the 90K subunit seems to be accelerated by intake of phytic acid in the diet. The Km value of the enzyme from suckling rats for phytate was 5.25 mM, while that of adult rats was 0.213 mM. In contrast, the Km value for p-nitrophenyl phosphate (PNPP) was constant during development. The phytase activity of suckling rats did not show a distinct pH-dependence. These findings suggest that the 90K subunit may play some important roles in expressing an efficient phytase activity.

6-Phytase

Y/6 chromosome translocation in a male with triple primary cancers involving the breast.

Cytogenic studies were performed in a 72-year-old male patient with triple primary cancers including breast, skin and lung. Left breast cancer was diagnosed at the age of 46 and he received mastectomy and thoracic irradiation. Squamous cell carcinoma and Bowen's disease were diagnosed from two separated parts of a skin lesion at the age of 70. Small-cell lung cancer was diagnosed 1 year later, and he received chemotherapy and radiotherapy. Chromosome analysis was carried out on both peripheral lymphocyte and skin fibroblast cultures at the age of 72. Out of 30 fibroblast cells karyotyped at the second passage, 7 cells (23%) consistently showed a reciprocal translocation t(Y;6)(q12;p21). The same translocation was found in one of 200 cells from lymphocyte cultures. The findings suggest that the translocation t(Y;6) might be inherent in nature, and that the patient was a mosaic of 46,XY/46,X,t(Y;6)(q12;p21). These results highlight the constitutional chromosomal abnormality as one of the possible high-risk factors for multiple primary cancers.

Breast Neoplasms

Reversal of cisplatin resistance with amphotericin B in a non-small cell lung cancer cell line.

The potentiation of anticancer agents by non-anticancer drugs is one of the possible strategies for overcoming cellular resistance to chemotherapy. In order to overcome cis-diamminedichloroplatinum(II) (CDDP) resistance, we evaluated the sensitizing effect on CDDP-induced cytotoxicity of various non-anticancer agents which might alter membrane transport, by means of a colorimetric [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] (MTT) assay. Drugs which have previously been demonstrated to modify multidrug resistance did not show a sensitizing effect to cisplatin. Only amphotericin B (AmB) selectively conquered CDDP resistance in the CDDP-resistant cell line. A drug accumulation study done by the atomic absorption method demonstrated that the accumulation of CDDP in the resistant cell line recovered to the level of the parental cell line after treatment with AmB. Thus, AmB might overcome CDDP resistance by increasing the accumulation of CDDP.

Amphotericin B

Ability of young children to button and unbutton clothes.

From 2 years of age, children enjoy trying to button and unbutton their jacket. The clothing of the children at this stage should have the form which fits their motor skills so as to develop their interest in buttons and to help their study in manipulating buttons. We observed processes of dressing and actions of buttoning and unbuttoning at the nursery school, for children in the 3.3-5.9 year range. Also, we experimented about dressing mainly for children in 2 year range to observe the process of manipulating buttons. As factors of experiment, we took two buttonhole directions (vertical and across) and three sizes of buttons (1, 2, 3 cm). The direction of buttonholes was significant at the 5% level. We recognized that buttonholes in the vertical direction were easier for children to button. We came to the following conclusion: for an open front of children's clothing, buttons having a 2 cm diameter and buttonholes in the vertical direction were the best.

Age Factors

e antigen and anti-e in the serum of asymptomatic carrier mothers as indicators of positive and negative transmission of hepatitis B virus to their infants.

Testing of serum samples of 23 pregnant women who were asymptomatic carriers of hepatitis B surface antigen for e antigen and antibody to e with an immunodiffusion technic identified 10 mothers with e antigen and seven with e antibody. Their babies were tested for hepatitis B surface antigen in serum at intervals for more than 12 months. In all 10 babies born to e-antigen-positive mothers hepatitis B surface antigen developed and persisted through the observation period, and all 10 elder siblings of these newborn babies were found to be asymptomatic carriers. In remarkable contrast, all seven babies born to mothers positive for antibody to e escaped antigenemia, and none of their three elder siblings carried surface antigen. On the basis of these results, e antigen may be used as an indicator of transmission, and antibody to e as that of absence of transmission of hepatitis B virus from carrier mothers to children.

Carrier State