Biomedical subjects

J Iwata

Publications and source records attributed to J Iwata.

At least 55 records · Page 3Linked to original sources

PubMed1996

Multilocular thymic cysts associated with thymoma. A case report.

The association of multilocular thymic cysts (MTC) with thymoma is exceedingly rare, and the pathogenesis of this combination is controversial. We describe the case of a 42-year-old man with an anterior mediastinal mass found to contain MTC and thymoma. A multilocular cystic mass, measuring 13 x 6.5 x 2 cm, was found in the right lobe of the thymus, and contained a 4.7 x 2 cm thymoma in its center. Microscopic thymomas, lipomatously involuted remaining thymic tissue, and lymphoid follicles with germinal centers were found in the walls of MTC as well as in the left thymic lobe. Non-specific chronic inflammation was also present in the walls. In addition, microcysts, which were only found at the periphery of the thymoma and covered with epithelium, might have been formed secondarily by dilatation of the perivascular spaces and of Hassall's corpuscles. These findings suggest that a chronic inflammatory process was responsible for the early formation and enlargement of this patient's MTC, and that while the cavities of the MTC expanded to various degrees, the thymoma, which originated from one of the microscopic thymomas in the walls of MTC, increased in size, and grew to involve the remaining thymic tissue.

Adult↗

PubMed1996

Desmoplastic malignant melanoma of the gingiva: case report and review of the literature.

A rare case of desmoplastic melanoma arising from the maxillary gingiva of a 66-year-old woman is reported. This tumour metastasised to the submandibular lymph node 5 years after extirpation, and local recurrence was observed 2 years later. The gingival tumour showed the histopathological characteristics of desmoplastic melanoma and the metastasised tumour cells were immunohistochemically positive for S-100 protein, neuron specific enolase, HMB-45 highly specific for conventional melanoma, and Fontana-Masson staining. The gingival tumour, originally regarded as benign clinically, was actually a desmoplastic melanoma.

Aged↗

PubMed1996

Granular cell tumor expressing myogenic markers in the prostate.

A granular cell tumor in the prostate of a 72 year old male is reported. The tumor nest was composed of large polygonal tumor cells, possessing cytoplasmic eosinophilic granules which were positive with PAS stain and resistant to diastase digestion. Immunohistochemically, most tumor cells were strongly positive with anti-alpha-smooth muscle actin and -neuron specific enolase antibodies. Only a few scattered tumor cells were reacted with anti-S-100 protein antibody. These findings might suggest smooth muscle differentiation of this case, and provide an additional insight into the histogenesis of granular cell tumors, especially in their heterogeneity.

Actins↗

PubMed1996

Lung squamous cell carcinoma producing both parathyroid hormone-related peptide and granulocyte colony stimulating factor.

An autopsy case of a 61 year old male with primary squamous cell carcinoma of the lung with associated marked leukocytosis and hypercalcemia is reported. High levels of serum parathyroid hormone-related peptide (PTHrP) and granulocyte colony stimulating factor (GCSF) were detected. The tumor cells distinctly showed positive cytoplasmic immunoreactions with anti-PTHrP and anti-GCSF antibodies. Marked granulocytosis and thin bony trabeculae lacking osteoblasts were observed in the vertebral bone. Calcium deposits were found in the proximal tubules of the kidneys. Infarcts were seen as a result of fibrin thrombosis of the splenic artery. The tumor was successfully transplanted into nude mice in which the high levels of serum PTHrP and GCSF were reproduced. These results indicate that the tumor simultaneously produced both PTHrP and GCSF causing the paraneoplastic syndromes of hypercalcemia and leukocytosis.

Animals↗

PubMed1996

Immunohistochemical characterization of a case of duodenal gangliocytic paraganglioma.

A case of duodenal gangliocytic paraganglioma (DGP) arising in the ampulla of Vater of an 84 year old male is reported. The present case shows the typical histological features with a mixture of epitheliold, ganglion-like and spindle cells. Immunohistochemically, the spindle cells were positive with antibodies to neuron specific enorse, S-100 protein and neurofilament (NF), but negative for anti-glial fibrillary acidic protein (GFAP), synaptophysin and myelin basic protein (MBP). Both anti-Leu-7 and -chromogranin A antibodies gave positive reactions with a fine granular pattern in the epithelioid cells. Most ganglion-like cells showed the cytoplasmic immunoreaction with GFAP and a few with NF and synaptophysin. In these three tumor components, no reactivity was detected in the antibodies to the neurohormonal peptides tested. The present data are fundamentally in keeping with those previously reported, but add the immunohistochemical positivity of ganglion-like cells for GFAP, suggesting different neuroglial differentiation.

Aged↗

PubMed1996

Immunohistochemical study of epithelioid hemangioendothelioma in the leg: a case report.

Epithelioid hemangioendothelioma is a relatively rare lesion. Although its histogenesis has been well described, its immunohistochemical characteristics remain controversial. A case of epithelioid hemangioendothelioma of the soft tissue of the right leg in a 67-year-old Chinese woman is reported. Histologic findings of intracytoplasmic lumina in the tumor cells and positive immunostaining for vimentin, factor VIII-related antigen. CD34 and Ulex europaeus agglutinin 1 (UEA-1) were obtained, demonstrating differentiation of the tumor cells to endothelial cells, although staining for antibodies to cytokeratins AE1/AE3 and CAM5.2 was weak. CD34 as well as Factor VIII-related antigen is a useful marker of endothelial differentiation in this tumor. A review of the literature is also presented.

Aged↗

PubMed1996

Effects of the new calcium antagonist efonidipine hydrochloride on resting and exercise hemodynamics in patients with stable effort angina.

The action of efonidipine hydrochloride ((+/-)-2-[benzyl(phenyl)-amino]ethyl 1,4-dihydro-2,6-dimethyl-5-(5,5-dimethyl-2-oxo-1, 3,2-dioxaphosphorinan-2-yl)-4-(3-nitrophenyl)-3-pyridinecarboxy late hydrochloride ethanol, CAS 1110011-76-8, NZ-105) a new dihydropyridine calcium antagonist, on cardiac hemodynamics at rest and during exercise as well as plasma concentration and pharmacokinetic parameters were studied in 9 patients with angina pectoris. NZ-105 was administered 40 mg once daily for a week and cardiac hemodynamics parameters were measured at rest and during exercise using a bicycle ergometer before and after treatment. All patients showed anginal symptoms during exercise before treatment, while only 4 showed anginal symptoms during exercise after treatment. Improvement on electrocardiograms (ECG) (> 0.1 treatment mV) was detected in 4 out of 9, and NZ-105 was recognized to have an anti-anginal action. The mean plasma concentration of NZ-105 at the time was 14.5 ng/ml. At rest, reduction in blood pressure and decrease in total peripheral vascular resistance were observed, however, NZ-105 showed no effect on heart rate, cardiac index, pulmonary arterial pressure and central venous pressure. During maximum exercise, a decrease in total peripheral vascular resistance, reduction in pulmonary arterial pressure and central venous pressure, increasing tendency of left ventricular ejection fraction, and increase in cardiac index were observed. However, NZ-105 showed no effect on heart rate and blood pressure. Based on the results mentioned above, cardiac hemodynamics of NZ-105 during exercise, featured primarily, reduction of afterload and improvement of cardiac functional deterioration due to exercise. In conclusion, NZ-105 is useful in patients with ischemic cardiac diseases by improving hemodynamics and ECG findings during exercise in patients with effort angina.

Angina Pectoris↗

PubMed1996

[Hyperuricemia in hematological disorders].

Hyperuricemia is a common manifestation in various hematological disorders such as hemolytic anemias, megaloblastic anemia malignant lymphomas and leukemias. Tumor lysis syndrome (TLS) is a serious complication consists of hyperuricemia, hyperkalemia, hyperphosphatemia and hypocalcemia due to massive cell lysis, which occurs shortly after the onset of chemotherapy or radiotherapy for acute leukemias and malignant lymphomas. Acute renal failure may develop due to uric acid nephropathy. The risk factors of TLS are heavy tumor cell burden, rapid cell turn over rate and renal involvement of neoplastic cells. To prevent and control TLS, adequate intravenous hydration to keep patient's urine volume, alkalization of urine by sodium bicarbonate and inhibition of uric acid production by high dose allopurinol is recommended.

Bone Marrow↗

PubMed1995

Myolipoma of the round ligament: report of a case with a review of the English literature.

Tumours consisting of a mixture of mature adipose and smooth muscle tissues, including those designated lipoleiomyomas, fibrolipoleiomyomas and myolipomas, are exceedingly rare, but most often occur in the uterine corpus. We describe here a case of such a tumour arising in the right round ligament of a 44-year-old woman. The tumour, which measured approximately 20x15x10 cm, was well encapsulated and did not involve the intrapelvic organs. Intricate mixtures of adult adipose tissue and bland smooth muscle exhibited no cellular atypia or nuclear mitotic figures, and there was little vascular proliferation. We diagnosed the lesion as a myolipoma of soft tissue with dual differentiation, and have found only 13 cases of this tumour including our own in the English literature. The present tumour is the first reported in the round ligament. Although this tumour is rare, its recognition is important for the avoidance of erroneous diagnoses.

Adult↗

PubMed1995

Mucinous cholangiocarcinoma featuring a unique microcystic appearance.

An autopsy case is presented of a peculiar type of intrahepatic mucinous adenocarcinoma with microcyst formation arising in a 78 year old Japanese man who died of hepatic coma and renal failure 4 months after onset. Macroscopically, the cut surface of the lesion revealed a characteristic honeycomb-like appearance, consisting purely of microcysts, 0.2-0.4 cm in diameter, lined by prolific mucin-producing adenocarcinoma cells. The lesion did not have large cystic space, fibrous capsule, or benign cystadenomatous component other than neoplastic microcyst formation. The carcinoma cells showed various proliferating patterns, such as irregularly shaped nest-like, trabecular, papillary and tubular ones, directly invaded the hepatic parenchyma and portal tract with loose or thick fibrosis, and infiltrated extensively into both intrahepatic and extrahepatic stroma along the vascular structures. From these clinicopathological findings, we consider the present tumor to be a variant of mucinous cholangiocarcinoma with characteristic microcyst formation rather than a type of cystadenocarcinoma.

Aged↗

PubMed1995

Daily excretion levels of an unidentified ketosteroid in the urine of patients with Cushing's syndrome and healthy subjects measured by a new method.

We developed a new method for measuring an unidentified ketosteroid glucuronide (US-G) detected by the method of Iwata et al. for measuring 17-ketosteroid glucuronides by reversed phase HPLC on a Capcell-Pak C8 column with three kinds of mobile phase solutions (Iwata method; Clin Chem 35: 795-799, 1989). The Iwata method inadequately separated US-G and two hydroxy 17-ketosteroides, 11 beta-hydroxyetiocholanolone and 11 beta-hydroxyandrosterone, and it exhibits insufficient sensitivity for measuring traces of US-G in the urine of healthy subjects. We solved these problems by developing a new method which measures US-G in urine, as a free type by hydrolyzing the glucuronide type enzymatically, by normal phase HPLC on a Capcell-Pak Silica column with one kind of mobile phase solution. By this method, the levels of US excreted as a glucuronide in the urine of healthy subjects and of patients with Cushing's syndrome were determined as proportions of the levels of 11 beta-hydroxyandrosterone. The average daily urinary excretion of US was 971 micrograms (125-4,995 micrograms) in patients with Cushing's syndrome (n = 22: two males and 20 females aged 26 to 65 years), and 34 micrograms (0-141 micrograms) in healthy subjects (n = 63: 49 males, and 14 females aged 21 to 54 years), and the differences were clearly significant. However, there were no differences between the urinary US levels of patients with pituitary adenoma and patients with adrenal adenoma. Furthermore, no US was detected in the urine of patients with aldosteronism (two males and eight females aged 34 to 61 years).(ABSTRACT TRUNCATED AT 250 WORDS)

17-Ketosteroids↗

PubMed1995

[Sex cord/stromal tumor of the testis: a case report].

We herein report a case of sex cord/stromal tumor of the testis. A 28-year-old man was admitted to our hospital with the chief complaint of painless swelling of the left scrotal contents. On examination, gynecomastia or swelling of superficial lymph nodes was not observed. With a diagnosis of left testicular tumor, left high orchiectomy was performed. Gross examination of the specimen demonstrated a mass measuring 20 x 18 x 14 mm within the testis. On the cut surface, the tumor was gray and was associated with focal hemorrhage and necrosis. The spermatic cord and epididymis were not involved by the tumor. Microscopically, the tumor demonstrated a mixed pattern consisting of, we thought, areas of Leydig-like cells as well as areas of Sertoli-like cells showing mild atypia. Without further treatment, the patient has remained free from the disease for over fifteen months since the operation. Fifty eight cases of sex cord/stromal tumor of the testis have been reported in the Japanese literature, but sex cord/stromal tumors, other than pure Leydig cell tumor or Sertoli cell tumor, are very rare. Only 4 cases have been reported including our case.

Adult↗

PubMed1994

Periosteal osteosarcoma of the femur with bone marrow involvement: a case report.

Periosteal osteosarcoma is an exceedingly rare type of chondroblastic osteosarcoma, showing rather better prognosis, and secondary bone marrow involvement is unusual. A case of a 22 year old male with periosteal osteosarcoma of the right femur with an associated bone marrow lesion is presented. The juxtacortical tumor, 16 x 11 x 9 cm, was located on the bone cortex of the upper diaphysis and extended into the surrounding soft tissues. A minimal bone marrow lesion was present, although the bone cortex was quite intact. Microscopically, the tumor consisted exclusively of atypical chondroblastic cells with a small osteoblastic area. The bone marrow lesion, interestingly, contained both multiple nodules of well-differentiated chondrosarcomatous components and a few demarcated foci of atypical spindle cells producing a fine osteoid matrix. It was reasonable to conclude, therefore, that this tumor was a periosteal osteosarcoma with an unusual secondary bone marrow lesion rather than a conventional (central) chondroblastic osteosarcoma with soft tissue invasion. The patient's good prognosis with no tumor recurrence or metastasis during more than 7 years follow-up after surgery supports this conclusion.

Adult↗

PubMed1993

[Unidentified steroid hormone of Cushing's syndrome and disease].

A previously unknown HPLC peak was recently observed in urine samples from patients with Cushing's syndrome and disease. We analysed dansylated derivatives of 17keto steroid glucuronides in urine samples from patients with Cushing's syndrome, Cushing disease and from healthy subjects using high-performance liquid chromatography (HPLC) on reversed-phase Cap Cell PakC8. All urine samples from patients with Cushing's syndrome caused by adrenal adenoma and Cushing's disease showed an unknown large peak at the point between [110HE-G] and [110HA-G] peaks and at a retention time of 25.4 min. The same unknown peak was also observed in urine samples from a patient with asymptomatic cortisol-producing adrenal adenoma and two patients with ectopic ACTH-producing tumor, though the peak height was low for the former and one of the latter but high for the second of the two patients. In contrast, healthy male and female urine only showed a very small peak at the same retention time. Urine samples from a Cushing disease treated with op'DDD and Cushing's syndrome bilaterally adrenalectomized and treating with cortisol showed no such peak. The retention time of this unknown peak is clearly different from that of seven 17keto steroid standard glucuronide conjugates. The structure of this substance may be closely related to [110HE-G] or [110HA-G].

17-Ketosteroids↗

PubMed1993

Establishment and characterization of a new human clear-cell sarcoma cell-line, HS-MM.

We have established and morphologically characterized a new human clear-cell sarcoma cell-line, HS-MM, from the pleural effusion of a 39-year-old man with pulmonary metastasis derived from the primary popliteal tumour. The HS-MM cells were round or spindle-shaped, with round nuclei containing extremely prominent nucleoli. Light microscopically, the heterotransplanted nude mouse tumours showed essentially the same features as those of the original sarcoma, revealing an alveolar pattern of tumour cells with abundant clear cytoplasm. Both in vitro and in vivo, the cells reacted with anti-S-100 protein and melanoma-specific HMB 45 antibodies by immunohistochemistry. Ultrastructurally, the cells contained round euchromatin-rich nuclei with large nucleoli revealing conspicuous nucleolonema, and a large amount of glycogen and a few lysosomal dense bodies, but no premelanosomes in their cytoplasm. The HS-MM cell line was thus fully proven to exhibit the unique characteristics of a clear sarcoma both in vitro and in vivo, being also compatible with an amelanotic melanoma. This cell line will therefore be extremely useful for clinicopathological and histogenetic studies on clear cell sarcomas.

Adult↗

PubMed1993

Morphological characterization of a new human epithelioid sarcoma cell line, ES020488, in vitro and in vivo.

A new human epithelioid sarcoma cell line (ES020488) was established from a cutaneous metastasis in 26-year-old man, and was morphologically characterized in vitro and in vivo by comparison with the original tumor. The ES020488 cells showed a male karyotype ranging from 39 to 83 chromosomes, with various abnormalities but no specific pattern. The cells were round, polygonal or spindle-shaped with abundant cytoplasm and round nuclei containing prominent nucleoli; they proliferated in a sheet-like pattern. Tumors transplanted into nude mice revealed essentially the same features as the original tumor. Both in vitro and in vivo, the cells immunohistochemically expressed vimentin, cytokeratin, and EMA, but not desmin and S-100 protein. Ultrastructural study revealed irregular or round nuclei containing abundant euchromatin and prominent nucleoli, many intermediate filaments running irregularly or around the nucleus, and a number of filopodia-like processes. ES020488 cells were thus proven to retain and exhibit the unique morphological characteristics of an epithelioid sarcoma both in vitro and in vivo. These cells are possibly derived from synovioblastic mesenchyme.

Adult↗

PubMed1993

Cardiovascular response and red cell membrane sodium transport in hypertensive cardiac hypertrophy.

To investigate the involvement of the sympathetic nervous system and cell membrane sodium transport in hypertensive cardiac hypertrophy, we divided 51 middle-aged male patients with essential hypertension into cardiac hypertrophy and noncardiac hypertrophy groups. We then compared the plasma noradrenaline concentration after exercise, the cardiovascular response to exercise and sympathomimetic agents, and cell membrane sodium transport in the two groups. There were differences between the cardiac hypertrophy and noncardiac hypertrophy groups with regard to the pressor response to exercise and noradrenaline (i.e. the response to sympathetic alpha-receptor stimulation) as well as the intracellular sodium concentration and cell membrane sodium transport. We concluded that there were abnormalities of the pressor response to alpha-receptor stimulation and of intracellular sodium concentration and cell membrane sodium transport in patients with hypertension and cardiac hypertrophy. These abnormalities might play some role in the pathogenesis of hypertensive cardiac hypertrophy.

Biological Transport↗

PubMed1993

Bilateral uveitis in a rabbit experimentally infected with human T-lymphotropic virus type I.

BACKGROUND: Among the various diseases associated with human T-lymphotropic virus type I (HTLV-I) infection, HTLV-I-associated uveitis has been proposed as a distinct clinical entity. EXPERIMENTAL DESIGN: Four rabbits experimentally infected with HTLV-I by blood transfusion from an HTLV-I-infected rabbit were observed for development of disease more than 3.5 years. Ophthalmologic, pathologic, hematologic, and virologic studies were performed on a rabbit that developed signs of uveitis. RESULTS: One of four rabbits developed bilateral uveitis 3.5 years after infection with HTLV-I. Ophthalmologic examination revealed opacities of the anterior chamber, lens, and vitreous body, as well as ciliary injection. Histologic examination demonstrated marked thickening of Descemet's membrane with degeneration of the corneal endothelial cells and mononuclear cell infiltration in the iris and choroid. The normal structure of the retina was almost completely replaced by gliosis. Gene amplification of cells from the left anterior chamber by polymerase chain reaction using pX primers disclosed the presence of HTLV-I sequences and an HTLV-I producing cell line (UV-1) was established from cells of the right anterior chamber. CONCLUSIONS: This is the first indication that rabbits may serve as an animal model of HTLV-I-related uveitis.

Animals↗