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Biomedical subjects

H Uno

Publications and source records attributed to H Uno.

At least 127 records · Page 7Linked to original sources
PubMed1993

Pathology of preneoplastic and neoplastic renal tubular lesions induced in F-344 rats by sodium barbital, a nongenotoxic renal carcinogen and nephrotoxin.

Sodium barbital (NaBB), a long-duration sedative/hypnotic barbiturate, is a nongenotoxic nephrotoxin and induces chronic persistent increases in rates of cell proliferation in renal cortical tubules of male F-344/NCr rats. In 5 of our 2-stage carcinogenesis experiments with NaBB at doses of 500, 1,000, or 4,000 ppm for periods of up to 106 wk of age, renal tubular cell tumors were found in incidences of up to 25% in rats receiving only NaBB while fewer than 1% of controls had renal epithelial tumors. We reviewed renal tubular proliferative lesions found in these studies and classified the lesions based on morphology, histogenesis, and immunohistochemical findings. Renal dysplastic tubules (DTs; atypical hyperplasia), putative preneoplastic lesions rarely seen in controls, were found in the renal cortex of more than 50% of the NaBB-exposed rats. DTs were classified into grades 1-3, based on lesion size and growth patterns. All renal adenomas were usually of the basophilic phenotype, and 70% of basophilic adenomas displayed solid patterns, while tumors with papillary, cystic, or tubular patterns were seen less commonly. By serial or step sectioning of the DTs and tumors, evidence was found indicating that the high grades (grade 2 or 3) of DTs, some of which arose in the P1 or P2 segment of the proximal tubules, were sometimes connected to the adenomas. Vimentin expression was demonstrated immunohistochemically in NaBB-induced renal tubular adenomas but not in normal tubules. Tumors were usually not immunoreactive for glutathione S-transferase, placental form, but heterogeneous immunoreactivity was also seen in some tumors. Lysozyme was absent in preneoplastic and neoplastic lesions induced by NaBB, while some intact normal proximal convoluted tubules were immunoreactive. The common tumor phenotype induced by NaBB, the basophilic solid adenoma, was similar to the most common type of spontaneous renal tumor found in untreated aging F-344 rats. NaBB may promote naturally occurring renal preneoplastic or neoplastic tubular lesions of this unique phenotype, but it is also possible that it may induce these lesions de novo.

Adenoma↗
PubMed1993

Immunohistochemistry and morphology of reactive lesions in lymph nodes and spleen from rats and mice.

The use of immunohistochemistry with anatomical and systematized classifications of nonneoplastic lesions in hematopoietic pathology of lymph nodes and spleens from rats and mice is described. Polyclonal antisera and monoclonal antibodies to leukocyte and other antigens can be used with frozen or fixed tissue sections to identify changes in cell populations in these tissues in response to tissue injury and aging. A classification for reactive lesions of lymph nodes and spleen is proposed that can be utilized for computerized pathology and toxicology data systems. These classifications are based on a systematized anatomic distribution of the lesions with the aid of immunohistochemistry. The association of some lesions with early leukemia or lymphoma of rats and mice is also discussed.

Aging↗
PubMed1993

Cell proliferation not associated with carcinogenesis in rodents and humans.

Cell proliferation has often been found to be associated with carcinogenesis in rodents and humans at different stages of the multistage carcinogenesis process. The multistage process includes initiation, promotion, and progression phases. At each phase, increasing the normal level of cell turnover of target cells may enhance carcinogenesis. However, we present evidence that normal levels of cell turnover, or increasing the rate of cell turnover at these different stages, do not necessarily lead to enhanced carcinogenesis. In normal tissues, the length of the cell cycle depends on the age of the host and varies from tissue to tissue. Tissues with normal short cell cycles, such as intestine and bone marrow, do not show a high rate of spontaneous tumors in most species. Cells with higher turnover should be more susceptible to carcinogens at the initiation stage of carcinogenesis if cell proliferation per se causes cancer and if these cells or their progeny survive. Cancer in humans is more often associated with specific etiological factors rather than with the natural proliferative rate of specific tissues. For many tissues of humans and rodents, age-related diseases develop in a progressive, irreversible manner. Often, naturally occurring chronic degenerative and inflammatory changes in a tissue (e.g., kidney, liver, heart, reproductive tract) lead to chronic regeneration of the damaged tissue. Yet, cancer is rarely found in these tissues. In rodent carcinogenesis experiments, chronic toxic lesions, accompanied by increases in normal levels of cell turnover, have sometimes been observed in target organs of nongenotoxic carcinogens. More often, however, organ-specific nongenotoxic toxins are not carcinogens. These toxins include compounds toxic for the liver, kidney, and nasal cavity. In 19 inhalation bioassays conducted by the National Toxicology Program, 5/5 nasal carcinogens and 12/14 nasal noncarcinogens caused nasal lesions usually associated with chronic cell proliferation. Although cell proliferation may contribute to multistage carcinogenesis, cell proliferation is not necessarily a tumor promoter or cocarcinogen.

Aging↗
PubMed1993

Spatiotemporal observation of guinea pig auditory cortex with optical recording.

The spatiotemporal characteristics of neural activity in the guinea pig auditory cortex were studied in order to clarify neural processing and coding mechanisms of complex sounds. We used a multi-channel optical recording system for a voltage-sensitive dye: RH795. The experimental results showed that a boomerang-shaped moving pattern of optical response appeared on the cortical surface in response to complex sounds (clicks) stimulation, but a rather fixed pattern appeared in response to tone burst stimulation. The tonotopical organization observed using microelectrode was not directly visible, but a similar topographic pattern was evidenced by selecting regions of a strong response evoked by tone-bursts. The correlative functions of regionwide responses may indicate a parallel and serial neural processing structure.

Acoustic Stimulation↗
PubMed1993

[Successful chronic daily administration of oral etoposide for a case of adult T cell leukemia].

A 54-year-old woman with leucocytosis and skin lesion was hospitalized and diagnosed as chronic type adult T cell leukemia (ATL) in August 1989. Since her ATL cell count and LDH level increased after hospitalization, oral administration of etoposide was started at a dose of 100 mg/day for seven days. The oral administration of etoposide induced another chronic state of ATL. After 10 months without medication, she was readmitted because of an acute ATL crisis. After daily administration of etoposide at a dose of 50 mg/day, the white blood cell count and serum LDH level decreased to the normal range, and abnormal lymphocytes of peripheral blood disappeared. The low-dose daily administration of etoposide at a dose of 25 approximately 50 mg/day could be maintained over six months. No severe side effects except for alopecia and mild myelosuppression were noted during the treatment. Chronic daily administration of oral etoposide is one candidate for the treatment of ATL in an outpatient clinic.

Administration, Oral↗
PubMed1992

Visualization of dopamine nerve terminals by positron tomography using [18F]fluoro-beta-fluoromethylene-m-tyrosine.

[18F]-6-Fluoro-beta-fluoromethylene-m-tyrosine ([18F]FFMMT) was evaluated as a potential imaging agent for dopamine nerve terminals using positron emission tomography (PET). Biodistribution and time course of this tracer in mice after i.p. injection was consistent with the distribution of dopamine. PET imaging studies involving rhesus macaques showed specific uptake in the dopamine-rich caudate-putamen region. This specific localization was blocked by inhibiting the enzyme L-aromatic amino acid decarboxylase and the transport of the tracer into brain was shown to be stereospecific. These results show the promise of L-[18F]FFMMT as a PET tracer in monitoring degeneration of the CNS dopamine system.

Animals↗
PubMed1992

Dynamic characteristics of the auditory cortex of guinea pigs observed with multichannel optical recording.

The spatiotemporal characteristics of neural activity in the guinea pig auditory cortex are investigated to determine their importance in neural processing and coding of the complex sounds. A multi-channel optical recording system has been developed for observing the cortical field of the mammalian brain in vivo. Using the voltage-sensitive dye: RH795, optical imaging was used to visualize neural activity in the guinea pig auditory cortex. Experimental results reveal a boomerang-shaped pattern of movement of activated neural cell regions for the evoked response to click as complex sounds. Parallel and sequential neural processing structure was observed. Although the exact frequency selectivities of single cells and tonotopical organization observed using microelectrode were not visible, the similar feature to the microelectrode evidences was imaged by extracting the strongly response field from the optical data.

Acoustic Stimulation↗
PubMed1992

Pseudo-adrenal incidentaloma: magnetic resonance imaging in a patient with para-adrenal Castleman's disease.

We report a case of para-adrenal angiofollicular lymph node hyperplasia (Castleman's disease) of the hyaline-vascular type. The mass could not be differentiated from an adrenal tumor by ultrasonography and computed axial tomography (CT). However, magnetic resonance imaging (MRI) suggested the possibility of an extra-adrenal origin of the mass. The intensity of the mass by MRI was homogeneous and of a higher intensity in the T2-weighted image than in the T1-weighted image, a finding similar to lymphadenopathy, lymphatic tumorous mass or metastatic tumor of the lymph node. Ultrasonography, CT and MRI may not be useful in characterizing Castleman's disease, but MRI was useful to distinguish asymptomatic para-adrenal masses from those of adrenal origin.

Adrenal Gland Neoplasms↗
PubMed1992

Differential expression of the alpha 2 and beta messenger RNAs of Na,K-ATPase in developing brine shrimp as measured by in situ hybridization.

We used in situ hybridization histochemistry with synthetic oligonucleotide probes to localize the mRNAs encoding the alpha 2- and beta-mRNAs of Na,K-ATPase during development of the brine shrimp Artemia. The mRNAs of the alpha 2- and beta-subunit were of low abundance in the cysts; in addition, less mRNA of the beta-subunit was localized. During emergence (12 hr), there was an increase in alpha 2-subunit mRNA in the gut mucosa, but there was a burst in beta-subunit mRNA throughout. As development progressed, the mRNAs of both the alpha 2- and beta-subunits showed a distinct pattern of expression in which the mRNA in the salt gland was of greatest abundance, followed by epidermal cells and gut mucosa. After 36 hr the alpha 2-subunit mRNA began to decrease in all positive cells but still remained highest in the salt gland and the brain region, while the mRNA of the beta-subunit kept increasing in the gut mucosa. Finally, the greatest abundance of the beta-subunit mRNA shifted from the salt gland to the antenna gland and the epidermal cells in the tail region, but the alpha 2-subunit mRNA did not. The more widespread distribution of the beta-mRNA than alpha 2-mRNA at certain stages (e.g., there was no alpha 2-mRNA in the antenna gland at the adult stage) is in all likelihood due to the marked drop in the alpha 2-subunit and a rise in alpha 1-subunit previously seen by Peterson et al. on polyacrylamide gel electrophoresis, as development progresses.

Animals↗
PubMed1992

Vimentin metaplasia in renal cortical tubules of preneoplastic, neoplastic, aging, and regenerative lesions of rats and humans.

Vimentin expression was studied immunohistochemically in renal cortical tubules of untreated male rats of various ages, rats exposed to toxins (barbital sodium, folic acid) and carcinogens (streptozotocin, N-bis(2-hydroxypropyl)nitrosamine, barbital sodium, and in humans of various ages with or without renal epithelial tumors. Fetal, neonatal, and young adult rats did not express vimentin in renal cortical tubules. Regenerative renal tubular lesions from rats with aging nephropathy and from rats with toxic nephropathy both expressed vimentin. Mitogenic lesions induced by folic acid at 24 hours, however, were not immunoreactive for vimentin. Carcinogen-induced preneoplastic renal cortical tubular lesions in rats were most often focally immunoreactive whereas strong vimentin expression was found in almost all induced renal tumors. In kidneys of three children (younger than 2 years of age), vimentin was not found in renal cortical tubular cells except in rare individual cells in one case. Vimentin was abundant in basophilic regenerative tubules in kidneys of aged individuals, however. Most (7/10) human renal carcinomas and latent preneoplastic or neoplastic renal tubular lesions found incidentally at autopsy (2/4) showed vimentin expression. The authors suggest that the switching to vimentin expression in phenotypically normal renal cortical tubular cells in rats and humans, which do not usually express the intermediate filament protein vimentin, should be considered vimentin metaplasia. Vimentin expression is dissociated from increased cell proliferation in hyperplastic and neoplastic lesions, however. Instead the degree of dedifferentiation of the tubule cells and changes in phenotype were associated with vimentin expression.

Age Factors↗
PubMed1992

[Evaluation of halothane induced HPV inhibition with analysis of pressure-flow curve].

We investigated the effect of halothane on the hypoxic pulmonary vasoconstriction using in vivo measurement of the pressure-flow curve of the left lower lobe in the dog. With hypoxic ventilation of the left lower lobe, the pressure-flow curve shifted to the right and the slope of the curve became flatter. Although inhalation of 1 MAC halothane by the left lower lobe during hypoxic ventilation had no effect on the pressure-flow curve configuration, inhalation of 3, 5 MAC made the slope steeper. We analyzed these changes by the distensibility model proposed by W. Mitzner et al, and our data support the hypothesis that hypoxic ventilation decreases the small pulmonary vessels of 1-4 orders and also increases the compliance of the orders of vessel where the constriction has occurred, and halothane antagonizes the HPV response by further increasing the compliance of the constricted vessels. The inhibitory effect of halothane on HPV was weaker in in vivo preparation compared with the effect in in vitro preparation. Some humoral factors in the perfusate could contribute to this effect.

Animals↗
PubMed1992

[Acute lymphocytic leukemia (L1) preceded by hypercalcemia].

A 37-year-old female with hypercalcemia presented with lumbago, nausea and vomiting. Peripheral blood (PB) and bone marrow (BM) smears revealed no lymphoblasts on the first admission. The value of parathyroid hormone related protein (PTHrP) was increased and osteoporosis was found in the lumbar vertebrae. After 5 months, diagnosis of acute lymphocytic leukemia (ALL) was made on the evidence that lymphoblasts were found in PB (1%) and in BM (98%). Treatment with vincristine, daunorubicin, prednisolone and L-asparaginase achieved complete remission (CR) and the serum calcium level returned to the normal range. She has maintained CR, and is currently treated with consolidation therapy by cyclophosphamide and methotrexate. Acute leukemia is known to be rarely accompanied with hypercalcemia. This rare case was accompanied with hypercalcemia in acute leukemia. Hypercalcemia appeared to be attributable to the increased bone absorption by PTHrP derived from tumor cells. This important case will help understanding the etiology of hypercalcemia associated with ALL.

Adult↗
PubMed1991

Hereditary hypotrichosis of the scalp.

Hypotrichosis of the scalp was found in 4 individuals of a 6-generation Caucasian family. This congenital phenomenon is a rather rare subtype of hereditary hypotrichosis and affects only scalp hair. The hairs of the scalp were generally sparse and short vellus type from childhood and thinned progressively with age. Morphologic studies showed poor imbrication of cuticles and dysplastic bulbar structure of the anagen follicles. The density of hair follicles per/cm2 area was comparatively lower than that of normal individuals. The genealogical study and histomorphometrical findings of this autosomal dominant trait are discussed along with previously reported causes of hypotrichosis.

Adult↗
PubMed1991

A new class of calcium antagonists. Synthesis and biological activity of 11-[(omega-aminoalkanoyl)amino]-6,6a,7,8,9,10,10a,11-octahydrodibenzo [b,e]thiepin derivatives.

A series of 11-[(omega-aminoalkanoyl)amino]-6,6a,7,8,9,10,10a,11- octahydrodibenzo[b,e]thiepin derivatives were prepared and found to be a structurally new class of calcium antagonists. The structure-activity relationship studies indicated that the optimum was (6aR*,10aR*,11R*)-11-[[4-[4-(4-fluorophenyl)-1- piperazinyl]butyryl] amino]-6,6a,7,8,9,10,10a,11-octahydrodibenzo[b,e]thiepin (31,pA2 8.16), which was superior to diltiazem (pA2 7.42) in calcium antagonistic activity. Compound 31 showed antihypertensive activity in anesthetized rats, without a significant effect on the heart rate. It had also antianginal effects in vasopressin-induced ST-depression and methacholine-induced ST-elevation testings in rats. These potencies of 31 were essentially equal to those of diltiazem.

Animals↗
PubMed1991

A new class of calcium antagonists. 2. Synthesis and biological activity of 11-[[4-[4-(4-fluorophenyl)-1-piperazinyl]butyryl]amino]-6,11- dihydrodibenzo[b,e]-thiepin maleate and related compounds.

A series of [(epsilon-aminoalkanoyl)amino]-6,11- dihydrodibenzo[b,e]thiepins and -5H-dibenzo[a,d]cycloheptenes and related compounds were synthesized and evaluated for calcium antagonistic activity by calcium-induced constriction of potassium-depolarized rat aorta. Semiempirical molecular orbital calculations of the dibenzotricyclic systems indicated that calcium antagonistic activity increased with a decrease of the angle between the planes of the two phenyl rings. AM1 net charge calculations showed that a neutral or positive charge distribution in the bridge portion was necessary for activity. 11-[[4-[4-(4-Fluorophenyl)-1- piperazinyl]butyryl]amino]-6,11-dihydrodibenzo[b,e]thiepin maleate (16, AJ-2615) showed a more gradual and longer lasting antihypertensive effect than diltiazem and nifedipine in spontaneously hypertensive rats (SHR) administered orally. Compound 16 also possessed antianginal effects in methacholine-induced ST elevation and vasopressin-induced ST depression tests in rats. The alteration of the dibenzotricyclic system of 16 to 5H-dibenzo[a,d]cycloheptene (19, 5-[[4-[4-(4-fluorophenyl)-1-piperazinyl]-butyryl]amino]-5H- dibenzo[a,d]cycloheptene) resulted in selectivity for cardiac tissue over vascular tissue, thereby conferring antianginal activity without an effect on blood pressure. Antianginal potencies of 16 and 19 were equal to or somewhat more potent than those of diltiazem.

Animals↗