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Biomedical subjects

K Naruse

Publications and source records attributed to K Naruse.

268 records · Page 15Linked to original sources

Immunohistochemical localization of renin in luteinizing hormone-producing cells of rat pituitary.

The location of renin (EC 3.4.99.19) in rat pituitary was determined by the peroxidase-antiperoxidase immunohistochemical technique. By using antisera prepared with purified rat renal renin, an immunoreactive substance was localized within ovoid cells scattered throughout the anterior pituitary. These cells were shown to be luteinizing hormone-producing cells by staining with anti-luteinizing hormone antisera in adjacent sections. By using the double staining method, the renin-containing cells were differentiated from cells containing corticotropin, thyrotropin, growth hormone (somatotropin), and prolactin (mammotropin). These results suggest a possible local role for renin in the anterior pituitary.

Adrenocorticotropic Hormone↗

A case of histiocytosis X associated with panhypopituitarism and hyperimmunoglobulinemia G and E.

A 43 year old man with diabetes insipidus who showed panhypopituitarism and marked hypergammaglobulinemia due to histiocytosis X is reported. His low basal plasma adrenocorticotropin (ACTH) and growth hormone (GH) failed to respond to insulin-induced hypoglycemia. His basal serum thyroid hormone level was below normal and normal basal plasma thyrotropin (TSH) showed a delayed response with normal peak value to TSH-releasing hormone (TRH). Normal basal plasma pituitary gonadotropin also showed a delayed response with normal peak value to luteinizing hormone-releasing hormone (LH-RH). Suppression of plasma prolactin (PRL) by levodopa (l-dopa) was impaired and elevation of basal plasma PRL was noted at the second admission. These results, combined with diabetes insipidus, suggested that the panhypopituitarism in these patients was hypothalamic in origin. The polyclonal hypergammaglobulinemia was characterized by elevated serum IgG and IgE levels which returned to normal after corticosteroid treatment with concomitant clinical improvement. Elevated serum IgE levels, tissue and peripheral eosinophilia, and the effectiveness of corticosteroid therapy support the hypothesis that some allergic mechanism may be involved in the pathogenesis of this disease.

Adrenocorticotropic Hormone↗

Immunoreactive alpha-human atrial natriuretic polypeptide in human plasma.

A radioimmunoassay (RIA) has been developed for the determination of alpha-human atrial natriuretic polypeptide (alpha-hANP) in human plasma. Antibodies generated in rabbits recognized alpha-hANP-related peptides containing the subsequence flanked by two cysteine residues at position 7 and 23 equally. Radiolabelled tracer prepared by iodination with chloramine-T method was purified by high performance liquid chromatography. Immunoreactive (ir-) alpha-hANP was extracted from human plasma by Sep-Pak C18 column. The plasma ir-alpha-hANP concentrations in normal, healthy adults were 178 +/- 16 pg/ml in male and 182 +/- 18 pg/ml in female, respectively. Plasma ir-alpha-hANP increased significantly after acute intravenous administration of isotonic saline. Plasma levels were elevated in patients with various disease states accompanying increased body fluid volume, whereas those in patients with idiopathic edema were decreased despite excessive salt and water retention. These results suggest that alpha-hANP plays an important role in the regulation of body fluids and may have primary or secondary pathophysiological significance in various disease states.

Adolescent↗

Atrial natriuretic peptide correlates with pulmonary arterial pressure and cardiac output.

Correlations between plasma atrial natriuretic polypeptide (ANP) levels and hemodynamic parameters were studied in the central circulation of 12 patients with angina pectoris. The average plasma ANP level determined in the aorta was found to be 619 +/- 140 pg/ml. The plasma ANP levels showed a significant positive correlation with mean pulmonary arterial (PA) pressure, right ventricular pressure, and with cardiac index. In contrast, there was no significant correlation between plasma ANP levels and other hemodynamic variables including atrial pressure. These results suggest that hemodynamics other than the atrial pressure may have some role in modulating ANP secretion in certain pathological states.

Adult↗

In vitro function of porcine hepatocyte spheroids in 100% human plasma.

To assess their functional stability, porcine hepatocyte spheroids, which have great potential in bioartificial liver systems and/or xenogeneic liver transplantation, were cultured in vitro in 100% human plasma, and their ammonium detoxification capacity was measured. In a short-term functional study, collagen-gel entrapped and rotationally cultured porcine hepatocyte spheroids showed almost the same functional expression, which was approximately twice that of monolayers. No significant functional deterioration was observed up to day 10 as compared with those in a synthesized medium without collagen gel entrapment. In a longer term study (4 wk) using rotational culture, morphological and functional deterioration presumably due to immunorejection involving complement proteins and natural antibodies progressed gradually with culture time. On the termination of the culture, the detoxification ability for the residual cells was approximately two-thirds that on day 2.

Animals↗

Short-term hypothermic preservation of porcine hepatocyte spheroids using UW solution.

The feasibility of University of Wisconsin (UW) solution in short-term hypothermic preservation of porcine hepatocyte spheroids was investigated, because they have great potential in bioartificial liver (BAL) systems. Porcine hepatocyte spheroids preserved for 3 days expressed almost comparable levels of albumin secretion as those without preservation, during 8 subsequent days of recultivation in continuous rotational culture, whereas isolated single cells did not reorganize into spheroids and completely lost their function in recultivation. Although for 3-day-preserved spheroids, the albumin secretion was lowered immediately after recultivation (Days 0-2), it was completely restored to that of nonpreserved ones. The function was completely lost in recultivation for 7-day-preserved ones. These results demonstrate that reorganization into spheroids is effective in preventing the functional loss of porcine hepatocytes occurring in hypothermic preservation, and that spheroid formation should precede the preservation as long as spheroid culture is finally used in BAL systems. Also, porcine hepatocyte spheroids are shown to be satisfactory stored in UW solution up to 3 days without significant cellular or functional loss.

Adenosine↗

A new bioartificial liver using porcine hepatocyte spheroids in high-cell-density suspension perfusion culture: in vitro performance in synthesized culture medium and in 100% human plasma.

A prototype of a bioartificial liver (BAL) based on suspension perfusion culture of porcine hepatocyte spheroids was developed at 150 ml scale. About 2% (4 x 10(9) cells) of whole human liver cells was immobilized. The cell density in the bioreactor was 2.7 x 10(7) cells/ml, which was almost comparable to that of presently developed packed-bed-type BALs. The bioreactor was perfused with culture medium while retaining spheroids. This was done using a rotating stainless filter (pore size 50 microm). In vitro 8-h perfusion experiments utilizing both synthesized culture medium and 100% human plasma demonstrated the spheroids in the bioreactor had almost the same functions on a unit/cell basis as those in small-scale rotational culture. This indicated that the functional deterioration often associated with scaling up had been minimized. Rapid spheroid aggregation and dysfunction in specific human plasma pool must be eliminated before clinical application, although this phenomenon seemed to be inherent to porcine hepatocyte-based BALs. This prototype shows promise in meeting present clinical demands by achieving maximal metabolic activities even in the short term.

Animals↗

Myofibroblasts at the tumor border of invasive gastric carcinomas: with special reference to histological type and tumor depth.

In order to elucidate the role of alpha-smooth muscle actin (ASMA)-positive stromal cells, namely myofibroblasts (MFs), in invasive growth of gastric carcinomas (GCs), we examined the number of MFs at the deep border (DB) of GCs. In total 78 invasive GCs (48 intestinal type GCs and 30 diffuse type GCs) were examined immunohistochemically, and analyzed from the view point of tumor depth and histological type. In the intestinal type GCs examined, both the GCs confined to the submucosa and muscularis propria had none or a small number of MFs at the tumor border facing the submucosa (smDB) and muscularis propria (mpDB), respectively; whereas the GCs invading the subserosa had a moderate or large number of MFs at the tumor border facing the subserosa (ssDB) (p<0. 05). Regardless of tumor depth, the diffuse type GCs examined generally had none or a small number of MFs at the smDB, mpDB and ssDB, respectively. There is a possibility that intestinal type GCs invading the subserosa showing tubular and papillary structure may induce myofibroblastic transformation of gastric subserosal stromal fibroblastic cells.

Actins↗

The complementary role of beta-catenin in diagnosing various subtypes of renal cell carcinomas and its up-regulation in conventional renal cell carcinomas with high nuclear grades.

beta-catenin is a kind of cytoplasmic protein involved in cell adhesion and signal transduction. This study investigated its expression in various subtypes of renal cell carcinomas (RCCs) using an immunohistochemical staining method. beta-catenin expression was assessed from staining frequency and staining score. Staining score was performed by evaluating both staining percentage and intensity. All subtypes of RCCs reacted positively with beta-catenin. However, the positive frequency and staining score in papillary and chromophobe RCCs were significantly higher than those in conventional RCCs (p < 0.05). In addition, in conventional RCCs, the positive frequency and staining score of beta-catenin showed a significant difference between nuclear grades I/II and grade III (p < 0.05). Therefore, it may indicate that beta-catenin can serve as a complementary tool to distinguish conventional RCCs from chromophobe RCCs. In conventional RCCs with low nuclear grades, beta-catenin expression is generally down-regulated, while it appears to be preserved in those with high nuclear grades.

Adult↗

Immunoreactive renin in mouse adrenal gland. Localization in the inner cortical region.

The existence of renin in the adrenal gland of the mouse was determined by its enzymatic activity and by immunohistochemical techniques using monospecific antibodies to mouse submandibular gland renin. The adrenal gland of mouse was found to contain a very high level of renin significantly greater than other mouse tissues except for the kidney and submandibular gland. Also, the renin level in mouse adrenal was significantly higher than that in adrenals of other species. This renin activity was distinct from the nonspecific renin-like activity of acid proteases in that its activity was optimal at neutral pH and specifically inhibited by antirenin antibody. Adrenal renin increased upon nephrectomy indicating that it is not derived from the kidney. Immunohistochemical studies localized the renin-immunoreactive substance to cells in the inner region of the cortex. The intensity of staining was highest in the innermost region and decreased in cells in outer layers.

Adrenal Cortex↗

Immunohistochemical evidence that angiotensins I and II are formed by intracellular mechanism in juxtaglomerular cells.

The existence of angiotensin II (AII) immunoreactivity in juxtaglomerular (JG) cells of rat kidney, which has been demonstrated previously by immunohistochemical studies, can be explained either as the product of intracellular synthesis or by the internalization of receptor-bound AII originating in plasma. To resolve these two alternative mechanisms, attempts were made to identify AI in JG cells of rat kidney by immunohistochemical staining using specific antibodies to AI. Although AI-like immunoreactivity was not detected in normal rat kidney, rats treated with the angiotensin-converting enzyme inhibitors, MK-421 or captopril, showed AI-like immunoreactivity in JG cells. The presence of renin and AII-like immunoreactivity was demonstrated in the same cells by specific antibodies to respective antigens used on adjacent serial sections. These findings support an intracellular mechanism of the formation of AII and suggest an intracellular renin angiotensin system, presumably separate from the extracellular system.

Angiotensin I↗