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Biomedical subjects

T Kuroda

Publications and source records attributed to T Kuroda.

At least 199 records · Page 11Linked to original sources
PubMed1996

Cervical Castleman's disease associated with benign M-proteinemia: report of a case.

We report the unusual case of a 77-year-old man with cervical Castleman's disease associated with benign M-proteinemia. The patient was found to have an anterior cervical tumor during a follow-up examination after surgery for early gastric cancer, at which time blood biochemistry tests revealed M-proteinemia at the position of beta-globulin with a high level of IgG and low levels of IgA and IgM. Serum protein immunoelectrophoresis revealed M-protein consisting of the IgG-k chain, and urine protein immuno-electrophoresis demonstrated Bence Jones protein consisting of the chain. No abnormalities were noted in bone marrow aspiration or bone scintigram. The results of imaging and fine-needle aspiration biopsy of the tumor led to a pre-operative diagnosis of cervical malignant lymphoma with suspected M-proteinemia derived from this disease, and resection of the anterior cervical tumor with bilateral neck dissection was performed. Histopathological examination subsequently demonstrated four mixed-type tumors of Castleman's disease. The pathogenesis of Castleman's disease remains unknown; however, we speculate that the complication of benign M-proteinemia in this patient was not incidental, but caused by an underlying immunological abnormality of the B cells.

Aged↗
PubMed1996

Leiomyomatosis peritonealis disseminata occurring in a postmenopausal woman: report of a case.

Leiomyomatosis peritonealis disseminata (LPD) is a rare condition, reported to occur chiefly in premenopausal women. In fact only five cases of LPD in postmenopausal women have been documented in the English literature. We report herein a case of LPD occurring in a postmenopausal woman who had undergone a total hysterectomy 15 years earlier and received no subsequent hormonal therapy. At laparotomy, a cystic mass measuring 10.0 x 12.0 cm was found adhering to the jejunum. There were also innumerable tumor nodules ranging from 0.5 to 5.0 cm in diameter attached to the antimesenteric borders of the intestine and the parietal peritoneum. We resected the cystic main tumor together with 20 cm of jejunum to release the intestinal obstruction. Several daughter tumors were also resected as biopsies for histological examination. Histologically, the lesions were multiple and consisted of proliferating smooth muscle cells with rod-like nuclei showing extremely rare mitotic figures, confirming a diagnosis of LPD.

Abdominal Neoplasms↗
PubMed1996

Varioliform gastritis and duodenitis associated with protein-losing gastroenteropathy, treated with omeprazole.

A 44-year-old female with varioliform gastritis and duodenitis had gastrointestinal protein loss revealed by 111indium chloride scintigraphy. Treatment with omeprazole, a proton pump inhibitor, for 2 months, followed by famotidine, resulted in clinical improvement with resolution of the gastroduodenal lesions and protein loss. Colonization of the stomach with Helicobacter pylori was found before and after the treatment. The results in this patient suggest that omeprazole can be of value for the treatment of varioliform gastritis associated with protein-losing gastroenteropathy. The role of Helicobacter pylori in the pathogenesis of this disease is unclear.

Adult↗
PubMed1996

Overexpression of p53 protein and histologic grades of dysplasia in colorectal adenomas.

PURPOSE: To clarify the relation between tumor-suppressor gene p53 expression and histologic grades of dysplasia in colorectal adenomas, we performed immunohistochemical analysis in a series of 59 colorectal polyps and 40 advanced carcinomas. METHODS: Adenomatous polyps were stained by hematoxylin and eosin and classified into mild, moderate, and severe dysplasia (intramucosal carcinoma), according to the World Health Organization's classification. RESULTS: p53 was positive in 7.1 percent (2/28) of mild, 29.4 percent (5/17) of moderate, and 62.5 percent (5/8) of severe dysplasia. In submucosal and advanced carcinomas, positivity rates were 75 percent (3/4) and 47.5 percent (19/40), respectively. Different staining patterns were found, according to grades of dysplasia. In the adenomas with mild or moderate dysplasia, a few focal crypts showed localized p53-positive staining. Adenomas with severe dysplasia had two different staining types. One was a focal staining type as shown in mild or moderate dysplasia; the other was a diffuse staining type, in which glands with mild or moderate dysplasia, surrounding severe dysplasia area, were also stained. Submucosal and advanced carcinomas showed a strong positive staining in cancer cells only. CONCLUSIONS: Overexpression of p53 protein in adenomas with mild or moderate dysplasia and existence of two types of expression in adenomas with severe dysplasia were observed. These facts suggested the possible existence of different pathways in the adenoma to carcinoma progression.

Adenoma↗
PubMed1996

Primary malignant melanoma of the rectum.

We present a case of primary malignant melanoma arising in the rectum of a 71-year-old woman who had presented with intermittent rectal bleeding following bowel movement 2 months previously. Digital and sigmoidoscopic examination of the rectum revealed a 3 x 2 x 1 cm exophytic tumor with a granular surface in the rectum 35 mm from the dentate line. No increased pigmentation was detected. Biopsy revealed degenerated mucosa accompanied by severe infiltration of inflammatory cells, but no malignant cells. The tumor and normal mucosa surrounding the tumor was excised 12 days after the biopsy. Light microscopy revealed the tumor to consist of malignant melanocytes and showed that the tumor was surrounded by normal mucosa. Immunohistochemical staining with antimelanoma antibody and HMB-45 substuntiated the diagnosis. Clinical and laboratory examination excluded the presence of melanoma at sites other than rectum. The patient refused an abdomino-perineal resection of the rectum and combination chemotherapy was performed. She died 18 months after the initial operation due to local recurrences and metastases to pelvic lymph nodes, liver, and lung.

Aged↗
PubMed1996

A histological study of the developing condylar cartilage of the fetal mouse mandible using coronal sections.

The first indication of cartilage formation was detected on day 14.5 of pregnancy in close connection to the ossifying mandible. A separated blastema was never observed. Thus the findings support the concept that the condylar cartilage develops from already differentiated cells, not from primary undifferentiated mesenchymal cells. Moreover, endochondral bone formation started on day 16 of pregnancy. Although the condylar cartilage basically undergoes the same processes of endochondral bone formation as the long bone, many hypertrophic chondrocytes may survive and are released into the primary spongiosa.

Animals↗
PubMed1996

Radioimmunoassay and gas chromatography/mass spectrometry for a novel antiglaucoma medication of a prostaglandin derivative, S-1033, in plasma.

A radioimmunoassay (RIA) and a gas chromatographic/mass spectrometric (GC/MS) method for a new antiglaucoma medicament, the prostaglandin derivative sodium (5Z, 9 alpha, 11 alpha, 13E)-9,11-dihydroxyprosta-5, 13-dienoate (S-1033), in human and rabbit plasma were investigated. For a competitive RIA, antisera from rabbit and radioiodine-labeled S-1033 were prepared by immunizing a conjugate of S-1033 with bovine serum albumin and by the Bolton and Hunter method, respectively. Pretreatment by C18 solid-phase extraction (SPE) for rabbit plasma sample and further purification by high-performance liquid chromatography (HPLC) for human plasma samples followed by the RIA (SPE/RIA and HPLC/RIA, respectively) were developed. The assay recoveries of SPE/RIA and HPLC/RIA were both excellent and the limits of quantitation were 320 and 10 pg ml-1, respectively. GC/MS for plasma samples after solid-phase extraction and thin-layer chromatographic purification was also developed using deuterium-labeled S-1033 as internal standard. The limit of quantitation was 100 pg ml-1 in human or rabbit plasma. Rabbit plasma samples after administration of this drug were measured by SPE/RIA and GC/MS and the assay results from both methods agreed well. The SPE/RIA, HPLC/RIA and GC/MS assay methods were suitable for measuring samples from preclinical studies, clinical studies and cross-validation, respectively.

Animals↗
PubMed1996

Relationship between severity of mitral regurgitation and prognosis of mitral valve prolapse: echocardiographic follow-up study.

We investigated the relation between the severity of mitral regurgitation and the development of complications and cardiac events by using two-dimensional and color Doppler echocardiography in 229 consecutive patients with mitral valve prolapse. The frequency of moderate and severe mitral regurgitation was significantly higher in patients with a prolapsed posterior leaflet (61%) than in patients with a prolapsed anterior leaflet (25%), and the older the patient, the greater the severity of mitral regurgitation. The occurrence of complications, such as atrial fibrillation, congestive heart failure, and chordal rupture, was significantly greater in prolapsed posterior leaflet cases than in prolapsed anterior leaflet cases, and the occurrence was closely associated with the degree of severity of mitral regurgitation. Multiple logistic regression analysis showed that the severity of mitral regurgitation is a strong prognostic indicator for developing complications. Furthermore in a subgroup of 49 patients tracked for a mean of 4.8 years, the new development of complications was significantly higher in patients who showed a progression in the severity of mitral regurgitation (52%) that in patients without progression in severity (8%). The initial severity of mitral regurgitation was related to the occurrence of cardiac events (mitral valve replacement, infective endocarditis, cerebral embolism and death). The data indicated that the progression of mitral regurgitation is closely associated with the development of complications and cardiac events and suggest that the severity of mitral regurgitation is an important prognostic indicator for the development of complications and cardiac events in patients with mitral valve prolapse.

Adolescent↗
PubMed1996

Three-dimensional dental cast analyzing system using laser scanning.

The purpose of this article is to introduce the outline of our newly developed three-dimensional dental cast analyzing system with laser scanning, and its preliminary clinical applications. The system is composed of a measuring device with a slit-ray laser projector and two sets of coupled charged devised video cameras, an image processing unit, a 16-bit personal computer as a controller, and an engineering workstation as a post processor. The dental cast is projected and scanned with a slit-ray laser beam. The raster coordinates of the target are determined with an image processor. Triangulation is applied to determine the location of each point. Generation of three-dimensional graphics of the dental cast takes approximately 40 minutes. About 90,000 sets of X, Y, Z coordinates are stored in the main memory of the microcomputer. The measurement error is less than 0.05 mm. Besides the conventional linear and angular measurements of the dental cast, we are also able to demonstrate the size of the palatal surface area and the volume of the oral cavity. The advantage of this system is that it facilitates the otherwise complicated and time-consuming mock surgery necessary for treatment planning in orthognathic surgery.

Computer Graphics↗
PubMed1996

Immunological and chemical types of reversible hypothyroidism; clinical characteristics and long-term prognosis.

OBJECTIVE: Spontaneous improvement occurs in about one-half of patients with primary hypothyroidism who reside in an iodine-sufficient area of Japan, but the pathogenetic factors related to reversible hypothyroidism are still not fully understood. We therefore investigated the clinical features and prognosis of patients with reversible hypothyroidism with or without iodine excess and antithyroid antibodies. DESIGN: Amelioration of hypothyroidism was diagnosed when the elevated serum TSH concentrations (serum TSH concentration > or = 40 mU/l) decreased by 50% or more during an iodine restriction period of 2-15 weeks without replacement therapy. Reversible hypothyroidism occurred in a post-partum group (n = 20) and a non-post-partum group (n = 91). The latter was then further classified into chemical (n = 28), immunological (n = 20), and mixed (n = 43) groups, according to the presence of iodine excess (serum non-hormonal iodine level > 50 micrograms/l or a history of excess iodine ingestion), antithyroid autoantibody, or both, respectively. MEASUREMENTS: Clinical characteristics and long-term prognosis were compared among the four groups. The rate at which hypothyroidism recovered was expressed as the number of days required for a 50% decrease in the serum TSH concentration. The level of thyroid echogenicity was measured by 10-MHz ultrasonography. RESULTS: In the chemical group, the mean age, male:female ratio, and serum non-hormonal iodine concentrations were all higher than those in the immunological group. The estimated rate at which hypothyroidism recovered was rapid (6.1 +/- 3.1 (mean +/- SD) days), the levels of thyroid echogenicity were near normal, and a histological examination (n = 7) revealed either colloid goitre or a normal thyroid in the chemical group. In the immunological and post-partum groups, the recovery rate was slow (16.8 +/- 9.6 days and 16.2 +/- 5.8 days, respectively). The levels of thyroid echogenicity were markedly reduced but increased after the spontaneous recovery of the thyroid function in both groups. Aspiration cytology suggested lymphocytic infiltration in all patients examined in the immunological (n = 6) and post-partum groups (n = 4). Relapse to overt hypothyroidism was observed more frequently in the immunological (38%) and mixed groups (35%) than in the chemical group (5%). CONCLUSION: Thyroid damage was more severe, recovery slower and the rate of relapse higher in the immunological than in the chemical type of reversible hypothyroidism.

Adult↗
PubMed1996

Reversible primary hypothyroidism with blocking or stimulating type TSH binding inhibitor immunoglobulin following recombinant interferon-alpha therapy in patients with pre-existing thyroid disorders.

OBJECTIVE: Treatment with recombinant interferon-alpha (rIFN-alpha) may induce autoimmunity. We have evaluated the effect of rIFN-alpha on pre-existing thyroid disease with special reference to changes in TSH receptor antibody. DESIGN AND PATIENTS: Five patients, who had a history of autoimmune thyroid disease diagnosed between 2 and 16 years earlier (three patients had Graves' disease while two had Hashimoto's thyroiditis), were treated with rIFN-alpha for chronic hepatitis C. Before, during and after rIFN-alpha therapy, we determined thyroid function, antithyroid antibody, thyroid echogenicity and the surface phenotype of the peripheral and intrathyroidal lymphocytes. RESULTS: Four of the patients developed overt hypothyroidism after 4-7 months of rIFN-alpha therapy, and two of them had a preceding history of low-uptake thyrotoxicosis. Recovery of thyroid function was observed in all four patients. Strongly positive blocking type TSH receptor antibody was detected and an increase in the percentage of CD19 positive cells in the intrathyroidal lymphocytes was also observed in three of the patients even though the goitre size increased in two of them. One of the patients became thyrotoxic later when stimulating type TSH receptor antibody became positive. Another patient suffered from reversible hypothyroidism although stimulating type TSH receptor antibody remained strongly positive throughout the clinical course. CONCLUSIONS: Our data thus indicated a high incidence of an unusual type of reversible hypothyroidism with TSH receptor antibodies in patients with chronic hepatitis C and pre-existing autoimmune thyroid disease after recombinant interferon-alpha therapy through a mechanism involving both the humoral and cellular immune systems.

Adult↗
PubMed1996

Determination of IgA- and IgM-rheumatoid factors in patients with rheumatoid arthritis with and without nephropathy.

OBJECTIVE: To clarify the characteristics and pathogenesis of renal disorders in patients with rheumatoid arthritis (RA). METHODS: In this study, 143 patients with RA were included, from whom 43 with urinary abnormalities were biopsied. Serum rheumatoid factor (RF) concentrations of IgA and IgM isotypes were also measured in these patients by enzyme linked immunosorbent assay. RESULTS: Light microscopy of renal biopsy specimens showed minor glomerular abnormalities in six patients, mesangial proliferative glomerulonephritis (GN) in 21, membranous nephropathy in seven, renal amyloidosis in seven, and tubulointerstitial nephritis in two. Twelve patients with mesangial proliferative GN and one with minor glomerular abnormalities were found by immunofluorescence microscopy to have abnormalities consistent with IgA GN. Although the concentrations of IgA-RF in patients with IgA GN were slightly raised compared with those with glomerulopathy established by biopsy but not associated with IgA GN, the concentrations of IgA-RF were higher in patients with RA with vasculitis or interstitial pneumonia than those with RA complicated by IgA GN. CONCLUSIONS: Mesangial proliferative GN, including IgA GN, may be a frequent renal lesion in Japanese patients with RA. IgA-RF may play little pathogenetic part in the development of IgA GN in RA.

Adult↗
PubMed1996

Characteristics of the insulin resistance syndrome in a Japanese population. The Jichi Medical School Cohort Study.

We investigated the relationships between hyperinsulinemia (a major indicator of the insulin resistance syndrome), blood pressure, dyslipidemia, and coagulation factors in 2606 community-dwelling Japanese individuals as part of the Jichi Medical School Cohort Study. An age-related decrease of the fasting insulin level was found in men but not in women. Body mass index, systolic and diastolic blood pressure, triglyceride and fasting glucose levels, and factor VII activity all increased in both sexes as the insulin level became higher, while the HDL cholesterol level decreased. In addition, total cholesterol and LDL cholesterol levels increased as the insulin level became higher and lipoprotein(a) levels decreased in the men. Fibrinogen levels were not related to the insulin level in either sex. Multiple logistic regression analysis revealed that fasting insulin levels were positively correlated with body mass index and fasting glucose and factor VII activity levels, whereas they were negatively correlated with HDL cholesterol in both sexes. In addition, fasting insulin levels were positively correlated with LDL cholesterol levels in men and with triglyceride levels in women. Our results indicate that hyperinsulinemia is associated with high factor VII activity in a general Japanese population as well as with high blood pressure and dyslipidemia. The accumulation of these cardiovascular risk factors in hyperinsulinemic subjects appears to contribute to cardiovascular events in the Japanese as well as in westerners.

Adult↗
PubMed1996

Acute exacerbation of masked hyperthyroidism after iodine restriction followed by thyrotoxic atrial fibrillation and cerebral embolism. A case report.

The authors present a seventy-two-year-old woman complaining of diffuse and firm goiter. At the first visit, she looked almost euthyroid with regular pulse rate of 78 per minute. After iodine restriction, however, she became severely thyrotoxic and developed cerebral embolism associated with atrial fibrillation due to Graves' hyperthyroidism. In conclusion, sudden withdrawal of dietary iodine might lead to exacerbation of Graves' hyperthyroidism resulting in serious cardiovascular or cerebrovascular complications, especially in elderly patients.

Aged↗
PubMed1996

Risk factors for brain infarction in patients with Cushing's disease. Case reports.

Two women aged 51 and 52 years old, respectively, developed a brain infarction before and after undergoing treatment for Cushing's disease. A biochemical remission was obtained more than ten years after the onset of signs or symptoms of Cushing's disease. The arteriosclerotic changes of the cerebral vessels progressed even during replacement therapy for posttreatment hypopituitarism after they underwent either ablative surgery or radiotherapy. One patient, who showed the signs of Nelson's syndrome, demonstrated severe progressive cerebrovascular sclerotic changes, especially around the irradiated site. It is thus suggested that hypercortisolemia, external pituitary irradiation, and posttreatment hypopituitarism may be risk factors for brain infarction. The early diagnosis and adequate treatment are therefore important to prevent cerebrovascular complications in patients with Cushing's disease.

Cerebral Infarction↗
PubMed1996

Tuna muscle peptide, PTHIKWGD, inhibits leukocyte-mediated injury and leukocyte adhesion to cultured endothelial cells.

Tuna muscle-derived angiotensin-converting enzyme inhibitory peptide, PTHIKWGD, inhibited the injury of bovine aorta endothelial cells (BAECs) induced by N-formyl-methionyl-leucyl-phenylalanine-activated polymorphonuclear leukocytes and the adhesion of a leukemia cell line, THP-1 cells, to BAECs stimulated by lipopolysaccharides. It is possible that this peptide directly affects BAECs, protecting them from activated leukocytes.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1996

Effect of pulse on iontophoretic delivery of desmopressin acetate in rats.

The effect of pulse parameters (duty and frequency) in a constant direct current iontophoresis on the antidiuretic response (elevation in rat urinary osmotic pressure) of desmopressin acetate (DDAVP) was examined in diabetes insipidus rats. Although antidiuretic response was not affected by frequency, it was induced by a duty of more than 26% and prolonged with increasing duty. A positively relationship between dose and AUC, the area under the osmotic pressure-time curve, was confirmed by intravenous administration of DDAVP, and the AUC induced by the iontophoretic delivery increased with increasing duty. The voltage across rat skin required to maintain a constant current density was investigated. A higher voltage was initially applied rat skin in a higher duty. This was related the prolonged pharmacological response induced by iontophoresis.

Animals↗