Search PubMed⌕ Search

Biomedical subjects

Y Kameda

Publications and source records attributed to Y Kameda.

At least 199 records · Page 11Linked to original sources
PubMed1982

C-cell follicles of canine thyroid glands studied by PAS reaction and electron microscopy.

Small follicles composed solely of C cells were occasionally observed in large C cell groups of dog thyroid glands. The lumina of C-cell follicles were filled with, or contained peripheral depositions of PAS-positive amorphous material, which was similar in ultrastructural features to thyroglobulin-containing colloid in typical thyroid follicles. This indicates that C cells, in addition to secreting calcitonin, produce a glycoprotein that can be stored in the lumina of the follicles.

Animals↗
PubMed1982

The cysts in C cell complexes of dog thyroids studied by immunoperoxidase staining and autoradiography.

The C cell complexes in the dog thyroid are the remnants of ultimobranchial bodies which retain fetal characteristics, and contain cyst structures showing various sizes, shapes and liminal contents. This study deals with these cysts with regard to their morphology, immunoperoxidase reactions to anti-calcitonin, anti-19S thyroglobulin and anti-C-thyroglobulin antisera, and ability to incorporate radioiodine. Small cysts lined by densely packed small cells are devoid of a stainable substance in their lumina and show no reaction to any of the antisera. They are regarded as immature structures. The large cysts, covered mainly by a single layer of cuboidal cells, store varying amounts of secretory products in their lumina. The secretory products showing colloid-like, flocculent, or granular features are intensely stained with the anti-19S thyroglobulin and anti-C-thyroglobulin antisera. However, they scarcely accumulate silver grains after injection of Na125I. C cells are distributed in the cyst epithelium but the cystic contents reveal no immunoreaction for calcitonin. In conclusion, the present study indicates that the cyst structures in C cell complexes synthesize and store a thyroglobulin-like glycoprotein but are not directly involved in thyroid hormone synthesis.

Animals↗
PubMed1982

Asparenomycins A, B and C, new carbapenem antibiotics. IV. Antibacterial activity.

Asparenomycins (ASM) A, B and C, new members of the carbapenem family of antibiotics, are broad spectrum antibiotics with activity against Gram-positive and Gram-negative bacteria. ASM A was bactericidal to both aerobic and anaerobic bacteria, although morphological alterations of ASM A exposed cells differed significantly between Escherichia coli and Bacteroides fragilis; with the former ovoidal forms were produced while with the latter elongated forms were seen. Synergistic activities were observed with a combination of ASM A and ampicillin (ABPC) against various ABPC-resistant bacteria presumably as a result of the inhibition by ASM A of beta-lactamases. ASM A showed relatively weak therapeutic activity against E. coli infected mice, because of instability in body fluids, a common property of the carbapenem family of antibiotics.

Animals↗
PubMed1981

Uptake of radioiodine in follicles of dog C-cell complexes studied by autoradiograph and immunoperoxidase staining.

C-cell complexes are special cell groups consisting of a mass of C-cells associated with other epithelial elements and cysts. They are remnants of ultimobranchial bodies retaining fetal characteristics. In the C-cell complexes there are follicular cells in various stages of differentiation, i.e., the cell clusters not yet organized into follicles, primordial follicles with small lumens and comparatively enlarged follicles storing plentiful amounts of colloid. They have a morphology similar to follicular cells of fetal thyroid glands and react to antiserum to 19S thyroglobulin. In order to determine whether or not the follicles in these complexes have the ability to incorporate radioiodine, autoradiography after a single injection of 125I was combined with immunoperoxidase staining using specific anti-calcitonin, anti-C-thyroglobulin, and anti-19S thyroglobulin antisera. The 19S-positive cells not yet organized into follicles did not take up radioiodine. Primordial follicles showed a heavy accumulation of silver grains over their follicular lumens storing new 19S thyroglobulin as colloid. Comparatively enlarged follicles revealed a strong autoradiographic reaction and their labeling patterns were identical with those of typical thyroid follicles. These results confirm that the follicles in C-cell complexes, as well as thyroid follicles, can incorporate radioiodine and are related to thyroid hormone synthesis. That is, functional thyroid follicles can arise from the ultimobranchial bodies.

Animals↗
PubMed1981

New forms of neonatal death dwarfism. Report of 3 cases.

The term Lethal Neonatal Dwarfism (Death Dwarfism) denotes bone dysplasias which always have a fatal outcome. Three different cases of "new" forms of death dwarfism are reported. A babygram should be a routine examination in all the cases of stillborn babies or those who die soon after the birth. If then the diagnosis cannot be established microscopic investigations of the growth cartilage should be performed.

Achondroplasia↗
PubMed1980

Immunohistochemical study of the C-cell complex of dog thyroid glands with reference to the reactions of calcitonin, C-thyroglobulin and 19S thyroglobulin.

Continued from the previous study in fetal animals (Kameda et al. 1980), the development and maturation of C-cell complexes in postnatal dogs from newborn to adult were investigated by use of an immunoperoxidase method using antisera to calcitonin, C-thyroglobulin (C-Tg) and 19S thyroglobulin, respectively. The younger the animals were, the more numerous were undifferentiated cells and high columnar epithelial cells in the complexes. With increasing age, the constituent elements of the complexes progressively differentiated. In one type of complex there are a large number of C-cells in various developmental stages, as well as undifferentiated cells and cysts. C-cell complexes composed mostly of mature C-cells were regarded as the more highly differentiated structures of this type. A second type contains follicular cells in various stages of differentiation in addition to undifferentiated cells and C-cells, i.e., 19S-positive cell masses not yet organized into follicles, primordial follicles with small lacunae and comparatively larger follicles. The follicular cells in the complexes were similar with respect to immunoreaction and folliculogenesis to the cells of fetal thyroids, but they developed very slowly. In conclusion, the present study indicates that follicular thyroid cells can differentiate within C-cell complexes, i.e., they develop from cells of ultimobranchial body origin.

Animals↗
PubMed1980

Immunohistochemical reactions of C-cell complexes in dogs after induced hypercalcemia, antithyroid drug treatment and hypophysectomy.

The C-cell complexes are remnants of ultimobranchial bodies retaining fetal characteristics. They contain C cells in various stages of differentiation, primordial follicles with small lacunae, follicular cell masses not yet forming follicles, and undifferentiated epithelial cells. By immunoperoxidase method using specific anti-calcitonin, anti-C-thyroglobulin and anti-19S thyroglobulin sera, the responses of C-cell complexes to hypercalcemia, thiourea, hypophysectomy and hypercalcemia after hypophysectomy were investigated systematically. These experimental conditions induced rapid differentiation and increased numbers of cells in the complexes. After chronic hypercalcemia, most of the complexes were occupied by mature C cells. The C cells in complexes similar to the cells in thyroid parenchyma presented increased mitotic activity, enlarged cell bodies and a marked decrease in materials immunoreactive for calcitonin and C-thyroglobulin. After prolonged administration of thiourea, follicular cell masses and small follicles, which underwent conspicuous hyperplasia and hypertrophy, markedly increased in the complexes and exceeded C cells in number. Typical undifferentiated cells were not recognized after hypercalcemia and treatment with thiourea, though they were unaffected by hypophysectomy. It is considered that undifferentiated cells develop into C cells after hypercalcemia and into follicular cells after treatment with thiourea; that is, undifferentiated cells seem to be the common precursor cell for both C cells and follicular cells.

Animals↗
PubMed1980

Development and cytodifferentiation of C cell complexes in dog fetal thyroids. An immunohistochemical study using anti-calcitonin, anti-C-thyroglobulin and anti-19S thyroglobulin antisera.

The development of C-cell complexes was investigated in dog fetuses by an immunoperoxidase method with three specific antisera: anti-calcitonin, anti-C-thyroglobulin (C-Tg), and anti-19S thyroglobulin. Ultimobranchial bodies joined with the thyroid anlage and then dispersed into the parenchyma to form large C cell groups. Sparse reaction products of C-Tg initially appeared in C cells with small amounts of cytoplasm. Later at about day 39 of gestation, when the immunoreactivity of calcitonin and 19S thyroglobulin appeared weakly in C cells and follicular cells, C-cell complexes were identified as large cell masses containing numerous undifferentiated cells without no immunoreactivity for any of the antisera. As development proceeded, the undifferentiated cells developed progressively the morphology of C cells. In addition, the undifferentiated cells developed 19S thyroglobulin immunoreactivity, that is, within some of the complexes small clusters of cells filled with material immunoreactive for 19S thyroglobulin. They were not organized into follicles during the fetal period, and were very slow in development. Depending on the degree of development of the undifferentiated cells, several features of the complexes were noted. The present study indicates that not only C cells but also follicular thyroid cells appear to be derived from the ultimobranchial bodies.

Animals↗
PubMed1980

Morphological changes of the liver in uremic patients treated with chronic hemodialysis--laparoscopic observations and light- and electron-microscopic studies.

In order to clarify morphological changes of the liver in the uremic state, 16 uremic patients treated with chronic hemodialysis were studied. Biopsy was performed in 14 cases under laparoscopic observation and in two on the occasion of renal transplantation. One uremic patients not being treated with dialysis was also studied for comparison. All biopsy specimens were examined by light and electron microscopy. The liver usually appeared mildly or moderately swollen under laparoscopic observations, which was considered at least partially due to the enlargement of the hepatocytes. All patients had hepatocytes with an Orcein-negative "ground glass" appearance, in which marked proliferation of smooth endoplasmic reticulum (SER) was found by electron microscopy. Since the patient not being on dialysis also had such hepatocytes, this finding may be characteristic of uremia. With electron microscopy, in addition to proliferation of SER, alteration of mitochondria and rough endoplasmic reticulum (RER) and an increase in cytoplasmic lipid droplets were observed. Hypertrophy of the Golgi apparatus containing electron-dense particles (VLDL) was often found in patients associated with hypertriglyceridemia. Amorphous electron-dense inclusions in microbodies were occasionally observed. Siderosis was observed in nine patients including three having parenchymal siderosis. With electron microscopy, various siderosomes were seen in the cytoplasm of hepatocytes in patients with parencymal siderosis. Conclusively, these histological and ultrastructral features of hepatocytes are rather associated with several metabolic abnormalities in uremia.

Adolescent↗
PubMed1980

Moxalactam (6059-S), a novel 1-oxa-beta-lactam with an expanded antibacterial spectrum: laboratory evaluation.

Moxalactam (6059-S) {7beta-[2-carboxy-2-(4-hydroxyphenyl)acetamido]-7alpha-methoxy-3-[[(1-methyl-1H-tetrazol-5-yl)thio]-methyl]-1-oxa-1-dethia-3-cephem-4- carboxylic acid disodium salt} is a new semisynthetic 1-oxa-beta-lactam derivative for parenteral use. It was highly active against a broad range of gram-negative microorganisms, including those resistant to other cephalosporins. Moreover, it had widely expanded antibacterial spectra which included Haemophilus influenzae, indole-positive Proteus, Enterobacter, Serratia marcescens, Pseudomonas aeruginosa, and Bacteroides fragilis. When a large number of clinical isolates of the above-named bacilli were tested by the agar dilution method, using an inoculum size of one loopful of 10(6) or 10(8) organisms or both per ml, the 70% minimal inhibitory concentrations at the lower inoculum were 0.2, 0.2, 0.4, 0.8, 25, and 0.8 mug/ml, respectively. Its activity appeared to be independent of inoculum size and addition of serum. In these organisms, morphological response of the exposed cells revealed that the bacteriolytic effect of 6059-S was initiated by a concentration equivalent to the minimal inhibitory concentration. 6059-S was markedly bactericidal to both beta-lactamase-producing and -nonproducing strains of Escherichia coli; this was well reflected by its extraordinary stability to microbial beta-lactamase degradation. Administered subcutaneously in mice, 6059-S attained plasma levels and a half-life similar to those of cefazolin and exhibited potent protective efficacy against systemic infections; it also proved to be significantly more effective than either sulbenicillin or piperacillin against Pseudomonas aeruginosa and than either cefazolin or cefmetazole against a variety of other gram-negative bacteria.

Animals↗
PubMed1979

Immunochemical and immunohistochemical studies on the 27 S iodoprotein of dog thyroid with reference to thyroglobulin-like reaction of the parafollicular cells.

Our earlier finding that the thyroglobulin-like material responsible for the immunoreaction of parafollicular cells obtained in peak I fraction of Bio-Gel A-5m was followed up in the present study by an investigation of the immunochemical and immunohistochemical reactions of 27 S iodoprotein which was the most prominent material in the peak I fraction. The antibody was raised against completely purified 27 S iodoprotein which was obtained as follows: Thyroglobulin was extracted from dog thyroids and chromatographed initially on Bio-Gel A-5m and then on Bio-Gel A-50m. The area of 27 S migrated as a single bank on polyacrylamide gel slab electrophoresis. This was cut and eluted. Anti-27 S antiserum showed the same immunochemical patterns to 27 S and 19 S as anti-19 S antiserum with three different immunochemical methods: double diffusion test, one dimensional and two dimensional immunoelectrophoresis. The immunoperoxidase reactions of the anti-27 S antiserum and anti-19 S antiserum were restricted to follicular cells and luminal colloids. No reaction of the parafollicular cells was obtained by these antisera. Thus, 27 S iodoprotein shared common immunochemical and immunohistochemical properties with 19 S thyroglobulin. It was concluded that 27 S iodoprotein was not responsible for the thyroglobulin-like reaction of the parafollicular cells.

Animals↗
PubMed1979

C cell (parafollicular cell) -- immunoreactive thyroglobulin: purification, identification and immunological characterization.

In relation to our earlier finding that the thyroglobulin-like material responsible for the cytochemical immunoreaction of C cells was obtained in the peak I fraction of Bio-Gel A-5 m, which included faster sedimenting components of thyroglobulin, the present study has identified the positive reacting component and clarified its immunochemical and immunohistochemical properties. 1. The peak I fraction of dog and hog thyroglobulin was chromatographed on a Bio-Gel A-50 m column. Antiserum to the faster eluted peak I'1 only immunoreacted with C cells. The peak I'1 was then refiltered on Bio-Gel A-150 m column. Antiserum to peak I''1 fraction of both species which was eluted in the first part had high immune specificity for C cells. 2. When 4-30% and 2-16% continuous gradient gels of polyacrylamide were employed, peak I''1 represented a single electrophoretic band corresponding to the component with the largest molecular weight in thyroglobulin. The protein was named C-thyroglobulin. The molecular weight was approximately 2,600,000, four times as large as 19 S, as calculated by relative mobility on the 2-16% gradient gel. 3. In double diffusion tests, anti-peak I''1 antiserum produced two immunoprecipitin lines with its own antigen. The reaction was different from that of anti-19 S antiserum which formed a single line. 4. On immunoperoxidase staining, anti-peak I''1 antiserum reacted to C cells in exactly the same way as anti-calcitonin antiserum. 5. When anti-peak I''1 antiserum was absorbed with calcitonin, the subsequent reaction of the C cells was greatly decreased. The absorption of anti-calcitonin antiserum with increased amounts of peak I''1 abolished the C cell reaction. On the basis of these observations, the possibility that C-thyroglobulin is a biosynthetic precursor of calcitonin exists.

Animals↗