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Biomedical subjects

Y Mizukami

Publications and source records attributed to Y Mizukami.

At least 217 records · Page 12Linked to original sources
PubMed1988

Histologic features of thyroid gland in a patient with bromide-induced hypothyroidism.

A case of a 22-year-old woman with bromide-induced hypothyroidism is presented. There have been no reports dealing with changes in thyroid function and thyroid morphologic characteristics associated with bromide intoxication. The characteristic histologic features of the affected thyroid gland included a marked hyperplasia of follicles lined by tall columnar follicular cells with foci of papillary proliferation and a loss of colloid materials in the follicular lumen. Ultrastructurally, thyroid follicular cells showed a marked dilatation of rough endoplasmic reticulum containing no electron-dense materials. X-ray microanalysis of the thyroid follicular cells revealed the presence of significant amounts of bromide and an absence of iodine. These indicated that severe hypothyroidism in this patient might be related to the accumulation of bromide in the thyroid follicular cells.

Adult↗
PubMed1988

Pseudolymphoma of the thyroid.

An unusual case of pseudolymphoma of the thyroid is reported. The tumor was histologically characterized by good demarcation, mature lymphocytes with prominent follicle formation and germinal centers, and mature plasma cells. Immunohistochemical staining revealed a similar distribution of T- and B-cells to reactive lymph nodes and a polyclonal nature of the plasma cell infiltrate. These findings are closely related to the entity, pseudolymphoma in other organs. Differential diagnosis from follicular lymphoma or ectopic thymic tissue is discussed.

Female↗
PubMed1988

Simultaneous detection of epidermal growth factor receptor (EGF-R), epidermal growth factor (EGF) and ras p21 in cholangiocarcinoma by an immunocytochemical method.

Expression of the epidermal growth factor (EGF), EGF receptor (EGF-R) and ras oncogene product p21 was simultaneously examined in 37 cases with intrahepatic cholangiocarcinoma (CC) by means of an immunocytochemical method. While normal livers were all negative for any of the antigens at the concentration of the antibodies used, EGF-R was positive in 12 (32.4%) CCs, EGF in 22 (59.5%), and ras p21 in 33 (89.2%). The positive incidence of the three antigens was not different among the histologic subtypes of the tumor. However, the number of EGF-R- and ras p21-positive tumor cells decreased with progressing histologic tumor grade, but the expression of EGF was not associated with the tumor grade. Expression of the three antigens was not related to the degree of metastatic spread of the tumor. Simultaneous expression of the three antigens was seen only in 4 CCs, and that of EGF-R and EGF in 4, EGF-R and ras p21 in 12, and EGF and ras p21 in 20. These data suggest that the expression of EGF, EGF-R and ras p21 on CC cells is not related to the tumor aggressiveness, and the activation of each respective gene is independent. Furthermore, the data also indicate that an autocrine model for tumor growth, as suggested by a combination of EGF and EGF-R, may be applicable only to very limited cases of CCs.

Adenoma, Bile Duct↗
PubMed1988

[Ultrastructural changes in the jejunal mucosa of the dog after dissection of the cranial mesenteric plexus].

Ultrastructural change was investigated in the small intestinal mucosa of dogs after experimental dissection of the cranial mesenteric plexus and/or obstruction of the lymphatics. In group with a combination of dissection of the plexus and obstruction of the lymphatics (Group A): Marked mucosal edema and dilatation of intercellular spaces of epithelial cell were observed after the 6th postoperative hours (POH), and numerous pinocytotic vesicles appeared after 24th POH. After the 5th postoperative days, rough glycocalyx and irregular microvilli were recognized in epithelial cells. As a characteristic change, pinocytotic vesicles fused together and formed a complex. However, no lipid droplet were accumulated in epithelial cells. In group with obstruction of lymphatics (Group B): Epithelial cells were full in lipid droplets. Based on these evidences, it was suggested that diarrhea and nutritional disorder were mainly caused by the disturbance of absorption and water transport in epithelial cells, involving severe pathological changes in their ultrastructure.

Animals↗
PubMed1988

Prediction of steady-state plasma theophylline concentration by Bayesian algorithm.

The use of Bayesian algorithm on theophylline pharmacokinetics was studied in asthmatic patients. Each patient received multiple oral doses of the sustained-release theophylline tablet formulation, Theo-Dur, in an amount of 200-400 mg as maintenance dose. Plasma theophylline concentration was measured by a commercially available substrate-labeled fluorescent immunoassay. The data were analyzed by applying a one-compartment model with both zero-order and first-order absorptions based on a nonlinear least squares method, Bayesian algorithm. The present study indicated that the zero-order absorption model provided better estimated pharmacokinetic parameters than the first-order absorption model. It was also found that prediction by the Bayesian method is dependent on number of sampling trials, but the best sampling time is still unknown. This may be due to the small peak-trough plasma concentration differences. From these findings, we suggest that parameters with larger variances should be chosen by considering the interindividual and intraindividual variabilities in order to improve the accuracy of population pharmacokinetics.

Absorption↗
PubMed1987

Immunohistochemical and ultrastructural study of subacute thyroiditis, with special reference to multinucleated giant cells.

Twenty-four cases of subacute thyroiditis were examined immunohistochemically and ultrastructurally, with special attention being directed to the multinucleated giant cells that characterize the lesions of this condition. Immunohistochemical study revealed that 99 per cent of the giant cells contained lysozyme, 82 per cent contained vimentin, 66 per cent contained alpha 1-antitrypsin, and 61 per cent contained thyroxine. Only 17 per cent contained thyroglobulin, 5 per cent contained keratin, 16 per cent contained epithelial membrane antigen, and 4 per cent contained leukocyte common antigen. Mononuclear cells infiltrating the follicular spaces showed a staining pattern similar to that of the multinucleated giant cells. Desquamated follicular epithelial cells were strongly positive for thyroglobulin and thyroxine, while regenerated epithelia that formed small follicles were positive for thyroglobulin but negative for thyroxine. Electron microscopic examination of cell ultrastructure revealed that most multinucleated giant cells had structures identical with those of infiltrating mononuclear cells, particularly with histiocytes, and that giant cells were formed by mononuclear cell fusion. These findings indicate the majority of multinucleated giant cells in subacute thyroiditis are derived from mononuclear-histiocyte cells.

Acute Disease↗
PubMed1987

Primary mucin-producing adenosquamous carcinoma of the thyroid gland.

A rare case of mucin-producing adenosquamous carcinoma of the thyroid gland is reported in a 57-year-old woman. Light microscopically, much of the tumor showed a feature of mucin-producing adenosquamous carcinoma; squamous cells and mucous signet ring cells. In the lower portion of the tumor, a calcified area containing small foci of follicular carcinoma and its squamous cell metaplasia was accompanied. Histochemically, neutral, non-sulphated and sulphated acid mucins were found in the mucous cells, and no thyroglobulin or calcitonin was detected in the tumor cells. Electron microscopically, some tonofibrils and mucin production were observed concomitantly in the tumor cells. These findings suggested the possibility that this mucin-producing adenosquamous carcinoma originated from squamous cell metaplasia of pre-existing follicular carcinoma.

Adenocarcinoma, Mucinous↗
PubMed1987

Amylase in thyroid tissues from normal and various thyroid diseases. Biochemical and immunohistochemical study.

Amylase activity was measured in thyroid tissues of various thyroid diseases and was analysed electrophoretically. Normal thyroid tissues contained significant amounts of amylase (mean +/- SD; 2.71 +/- 1.15 IU/g of tissue), and their amylase isozyme was composed of a majority of salivary type isoamylase and other peculiar isoamylase. The statistical decrease of amylase activities in tissues of Graves' disease under hyperthyroidism, thyroid carcinoma, and most of thyroid adenomas were found (Graves' disease; 1.04 +/- 0.41, carcinoma; 1.49 +/- 1.10, adenoma (except five cases with high activity); 0.88 +/- 0.49 IU/g tissue). Five of 18 cases of adenoma showed strikingly higher amylase activity in their tissues. Electrophoretical patterns of amylase isoenzymes in these five adenoma tissue were different from those of normal thyroid tissues. The cellular localization of amylase in the normal thyroid tissues and the adenoma tissues was also demonstrated immunohistochemically.

Adenoma↗
PubMed1987

Primary T-cell lymphoma of the thyroid.

A rare case of non-Hodgkin's malignant T-cell lymphoma of the thyroid in a 79-year-old woman is reported. Light microscopically, the tumor showed diffuse proliferation of lymphoid cells, revealing prominent nuclear irregularity and occasional multilobulated nuclei, and was diagnosed as a diffuse lymphoma of medium-sized cell type. Electron microscopically, the tumor cells were seen to possess irregularly indented nuclei. Immunologic surface marker studies showed that the lymphoma cells were positive for T-lymphocyte-lineage antigens, OKT4 and OKT11, and did not react with B-lymphocyte-associated antigens. These findings indicated that the lymphoma had a T-cell phenotype.

Aged↗
PubMed1987

Immunohistochemical detection of ras oncogene p21 product in liver cirrhosis and hepatocellular carcinoma.

Expression of the ras oncogene p21 product by hepatocytes of cirrhotic liver with hepatocellular carcinoma (HCC) was examined immunohistochemically using mouse monoclonal antibody RAP-5. At the concentration of antibody used, histologically normal liver tissues were negative for p21 antigen, whereas hepatocytes of cirrhotic nodules from 80 of 92 HCC patients (87.4%), and 10 of 32 patients without HCC (59.4%) were positive. This difference was statistically significant (p less than 0.05). The incidence of p21 expression by hepatocytes was significantly higher in macronodular cirrhotic patients than in those with micronodular cirrhosis (p less than 0.05) and tended to be higher in those positive for hepatic hepatitis B virus markers than in those that were negative (p less than 0.1). All 16 patients with liver cell dysplasia, and 17 of 18 with adenomatous hyperplasias showed increased expression of p21 antigen. In HCC it was detected on tumor cells of 63 of 101 patients (62.4%). Characteristically, its expression in well-differentiated HCC was mild and uniformly diffuse, and in moderately differentiated tumors was markedly heterogeneous in both intensity and distribution, whereas no expression was observed in cells of poorly differentiated HCC. These observations suggest that elevated ras p21 antigen expression is important in the development of both cirrhotic nodules and HCC, but that after tumor development, its sustained elevation is no longer necessary for cell proliferation and progression through the grades of anaplasia.

Antibodies, Monoclonal↗
PubMed1987

Absorption of theophylline from a sustained-release theophylline tablet formulation, Theo-Dur.

The absorption kinetics of theophylline after single oral administration of a sustained-release theophylline tablet formulation, Theo-Dur, were studied in healthy volunteers. The pharmacokinetic parameters were estimated by utilizing a one-compartment model with zero-order or first-order absorption according to the procedure "Praxis". The release of theophylline from the formulation in the in vitro dissolution study was shown to be an apparent zero-order process. The in vivo studies demonstrated that the time required to reach maximum plasma concentration of theophylline was about 8 h. The mean residence time in vivo, MRT, was 18.6 h. The present study also showed that the formulation was good sustained-release properties with adequate bioavailability and that the in vitro sustained-release characteristic was confirmed to be reflected in the plasma concentration-time profile of theophylline in the in vivo. The computer-predicted concentrations of theophylline based on the zero-order absorption model fitted to the observed data points better than those based on the first-order absorption model. The regression curves obtained by nonlinear least squares method based on the first-order absorption model underestimate the maximum observed plasma concentrations of theophylline. There was a highly significant relationship between observed and calculated around the maximum plasma concentration data based on the zero-order absorption model. These results show that the drug absorption from the formulation is best described by an apparent zero-order rather than a first-order absorption model.

Absorption↗
PubMed1986

The nucleotide sequences of the heterologous region between the genomes of Bacillus phages M2 and Nf that indicate the two phages are originally identical.

It has been suggested that the heterologous population of Bacillus phage M2 is derived from an original clone, which is identical with phage Nf, by the deletion on a particular region of the genome. We have determined the nucleotide sequence of this region of M2 subclones and Nf genomes. The results clearly indicate that the homologous recombination through the short direct repeated sequence is the main cause of the varied deletions found in the genomes of M2 subclones.

Bacillus↗