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Biomedical subjects

T Nakada

Publications and source records attributed to T Nakada.

At least 19 recordsLinked to original sources

Elevated levels of telomerase activity in malignant pheochromocytoma.

BACKGROUND: Although malignant pheochromocytoma is a life-threatening illness, there is no excretory profile that is predictive of malignancy. Reliable prediction of malignant behavior on the basis of histopathology is also notoriously difficult. Although DNA ploidy can be a helpful indicator, aneuploidy per se is not considered to be a specific marker of malignancy. Mutations in p53 have been reported to occur frequently in cases of benign pheochromocytoma. Thus, molecular analysis of this protein is not a useful diagnostic tool. The authors analyzed telomerase activity in benign and malignant pheochromocytomas and assessed its utility as a prognostic marker. METHODS: Telomerase activity was estimated in 16 benign pheochromocytomas, 3 malignant pheochromocytomas, and 16 normal adrenal medullae by the fluorescence-based telomeric repeat amplification protocol. The telomerase activities of each group of samples were compared. RESULTS: No telomerase activity was detected in any of the normal adrenal medullae or the benign pheochromocytomas. By contrast, all of the three malignant pheochromocytomas had elevated telomerase activity. The telomerase activity in each tumor was determined to be 87.6 units, 71.2 units, and 180.3 units, respectively. CONCLUSIONS: The expression of telomerase activity in pheochromocytoma clearly suggests the malignant behavior of the component cells. Analysis of telomerase activity appears to be a powerful tool for the diagnosis of malignant pheochromocytoma.

Adrenal Gland Neoplasms

Serum level of carboxyterminal propeptide of type I procollagen in haemodialysis patients.

Serum concentrations of carboxyterminal propeptide of type I procollagen (PICP) and carboxyterminal parathyroid hormone (C-PTH) were measured in 33 haemodialysis patients. Serum levels of PICP and C-PTH in the haemodialysis group were significantly higher than those in the controls. Although there was no correlation between serum C-PTH and creatinine, a positive correlation was found between PICP and creatinine. This indicates that the measurement of PICP in serum is useful for monitoring metabolic bone diseases in haemodialysis patients.

Adult

Endocrinological and pathological entities of the pre-Cushing's syndrome.

The purpose of the study was to clarify the disease entity of pre-Cushing's syndrome. The authors report on the pathological findings and contents of various steroids in the adenomas of three cases of pre-Cushing's syndrome. Oncocytes were found in one adenoma and others were pure clear cell dominant adenomas. All the adenomas contained higher concentrations of precursor steroids than those of five cases of Cushing's syndrome. However, the patterns of increased precursors were quite different among the three cases. Pre-Cushing's syndrome appeared to include several different kinds of disease entities.

Adrenal Cortex

The effect of triathlon on urinary excretion of enzymes and proteins.

In order to investigate the effect of triathlon and renal function of normal subjects, we evaluated the excretion of urinary enzymes and proteins before and after triathlon. From 6 subjects samples were obtained 24 hours after the first urine collection. We performed quantification of urinary total protein, beta2-microglobulin (beta2-M), N-acetyl-beta-D-glucosaminidase activity (NAG), and concentration of urinary creatinine from each participant. There was a significant increase in urinary total protein excretion immediately after triathlon (p<0.01). The urinary beta2-M and NAG excretions after triathlon were higher than the initial values. Post-exercise proteinuria in one subject persisted until the next morning, whereas the increased excretion of urinary beta2-M and NAG returned to the pre-exercise level at least 24 hours after triathlon. It appears to be reasonable to presume that glomerular damage may persist in some subjects who do heavy exercise.

Acetylglucosaminidase

Schwannoma of the penis: report of a case and review of the literature.

A case of schwannoma located in the penile shaft in a 65-year-old male is described. Special stain using S-100 immunoperoxidase was useful in establishing the diagnosis in this case. We reviewed the literature on penile schwannoma and focussed on the diagnosis of this rare ailment.

Aged

Pericentric inversion of chromosome 9 in infertile men.

Reproductive condition was studied in 6 infertile men with pericentric inversion of chromosome 9. Semen analyses revealed one azoospermia, one oligozoospermia, three asthenozoospermias and one normozoospermia. Four cases showed normal levels of plasma gonadotropins and testosterone. The response of plasma testosterone to human chorionic gonadotropin was within the normal range in all cases. However, the administration of LH-RH resulted in abnormal response of plasma gonadotropin in all patients. These results indicate that infertile males with pericentric inversion of chromosome 9 have an abnormality in the hypothalamic-pituitary-testicular axis.

Adult

Hepatocyte growth factor stimulates DNA synthesis in rat preneoplastic hepatocytes but not in liver carcinoma cells.

BACKGROUND & AIMS: It is not well clarified whether hepatocyte growth factor (HGF) stimulates the growth of preneoplastic hepatocytes and liver carcinoma cells in vivo. The effect of HGF on in vivo DNA synthesis in these cells and also its effect on tyrosine phosphorylation of the HGF receptor protein (c-Met) in liver carcinoma were examined. METHODS: Lesions were induced in rats using 3'-methyl-4-dimethylaminoazobenzene (3'-Me-DAB). The rats were given intravenous recombinant human HGF or vehicle, and DNA synthesis was assessed by the 5-bromo-2'-deoxyuridine labeling index. Tyrosine phosphorylation of c-Met by HGF was analyzed by Western blot. RESULTS: The labeling indices were significantly higher in the HGF group than in the vehicle control group in altered foci and hyperplastic nodules (preneoplastic hepatic lesions). No significant differences in the labeling indices were observed between the two groups with carcinoma. Tyrosine phosphorylation of c-Met in carcinoma cells was unaffected by HGF administration. CONCLUSIONS: HGF promotes the growth of preneoplastic hepatocytes but does not affect the growth of liver carcinoma cells in 3'-Me-DAB-treated rats.

Animals

Pulmonary and systemic arteriovenous fistulas in patients with left isomerism.

Hepatic venous blood has been thought to play some role as a vasoactive agent in the development of pulmonary arteriovenous fistulas in patients with congenital heart disease. During the last 15 years, we have observed pulmonary arteriovenous fistulas in 3, and systemic arteriovenous fistulas in 2, patients from our 16 cases of left isomerism. During the same period, neither pulmonary nor systemic arteriovenous fistulas were detected among 50 patients with right isomerism. Pulmonary arteriovenous fistulas had developed in the absence of surgery in 1 of the patients. Both pulmonary and systemic fistulas were detected in an another patient, in whom the hepatic venous blood bypassed the pulmonary circulation. The level of somatostatin, which is known to reduce splanchnic blood flow, was high in the systemic venous blood of this patient. Although the mechanism of development of the fistulas has yet to be clarified, we should be aware that not only pulmonary, but also systemic arteriovenous fistulas can be found in patients with left isomerism, even prior to any surgical intervention.

Angiography

Prurigo pigmentosa (Nagashima) associated with anorexia nervosa.

Prurigo pigmentosa (Nagashima), which is not rare in Japan, is an inflammatory disease of unknown aetiology. The characteristic lesions are pruritic red papules, superseded by reticular hyperpigmentation, characteristically on the back, neck, and chest. We now report a case of prurgio pigmentosa associated with anorexia nervosa. These findings suggest that the ketosis produced by anorexia nervosa may well contribute to the pathogenesis of prurigo pigmentosa.

Adult

Correlations between urethral elastance and histological architecture in patients with benign prostatic hyperplasia.

To investigate whether the properties of the flow-controlling zone (FCZ) in obstructive benign prostatic hyperplasia (BPH) would be affected by differences in the histological architecture of the prostate, we evaluated relationships between morphometric and urodynamic data. BPH specimens from 14 patients undergoing transurethral surgery were analysed by quantitative morphometry. The cross-sectional area and mean elastance of FCZ, together with other parameters, were calculated on a preoperative pressure-flow study. Correlations between these parameters and tissue composition were determined. Our study group comprised men with clinical and urodynamic evidence of infravesical obstruction secondary to BPH. No correlations were found between the area density or total volume of each histological element and the cross-sectional area of FCZ at peak flow rate. Neither area density nor total volume of each element correlated with the mean urethral elastance. Our results indicate that the histological architecture of the prostate in patients with obstructive BPH cannot predict the urethral elastance.

Aged

Juxtaglomerular cell tumor without hypertension.

Juxtaglomerular cell tumors are rare. This report presents a case of juxtaglomerular cell tumor without hypertension. All previously reported cases showed marked hypertension, whereas this is the first case of juxtaglomerular cell tumor without hypertension. The immunohistochemistry and ultrastructure of this case are discussed.

Adenocarcinoma

Eyeglass allergic contact dermatitis.

A literature review is presented of allergic contact dermatitis from eyeglasses. Causes are grouped into metals, plastics, plasticizers, solvents, UV stabilizers, antioxidants, dyes, and waxes. Plasticizers and UV stabilizers are currently the most common allergens.

Allergens

Nickel content of standard patch test materials.

The nickel sulfate content in standard patch test materials currently used in the US, Europe and Japan was determined by inductively-coupled plasma atomic emission spectroscopy, a state-of-the-art microanalytical method which allows nickel detection to levels of 7 ppb (microg/l). In 2 materials with a nominal concentration of 5% nickel sulfate hexahydrate in pet., the range (calculated averages of triplicate analyses of 3 different batches) was from 4.72 to 4.87% and 4.97 to 5.39%, respectively. In 1 material with a 2.5% nominal concentration in pet., the values ranged from 2.41 to 2.48%. The range seen in a 5% NiSO4 hexahydrate aq. material was 4.95 to 5.03%. The range for 2.5% NiSO4 anh. in pet. was 2.39 to 2.49%. This data suggest a significant improvement in quality control compared to our previously published data.

Allergens