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Biomedical subjects

H Ueno

Publications and source records attributed to H Ueno.

At least 19 recordsLinked to original sources
PubMed1992

The fms-like tyrosine kinase, a receptor for vascular endothelial growth factor.

The fms-like tyrosine kinase (Flt) is a transmembrane receptor in the tyrosine kinase family. Expression of flt complementary DNA in COS cells conferred specific, high-affinity binding of vascular endothelial growth factor, also known as vascular permeability factor (VEGF-VPF), a factor that induces vascular permeability when injected in the guinea pig skin and stimulates endothelial cell proliferation. Expression of Flt in Xenopus laevis oocytes caused the oocytes to release calcium in response to VEGF-VPF. These findings show that flt encodes a receptor for VEGF-VPF.

Animals↗
PubMed1992

A truncated form of fibroblast growth factor receptor 1 inhibits signal transduction by multiple types of fibroblast growth factor receptor.

A truncated form of the type 1 fibroblast growth factor receptor (FGFR1) lacking most of its cytoplasmic domain was tested for its ability to inhibit signal transduction by each of three different wild-type FGFRs (FGFR1, 2, and 3). When the truncated FGFR1 was expressed in Xenopus oocytes in excess of each wild-type FGFR, mobilization of intracellular calcium mediated by the wild-type FGFRs was completely blocked. The truncated FGFR did not inhibit signal transduction by the co-expressed platelet-derived growth factor beta-receptor. A form of truncated FGFR1 which lacked the first immunoglobulin-like domain also inhibited signal transduction by wild-type FGFRs. Truncated FGFR formed complexes with wild-type FGFR in the presence of basic FGF in intact cells. These observations were consistent with the hypothesis that the truncated FGFR interacted with wild-type FGFRs to form nonfunctional heterodimers, thus eliminating the signaling by the wild-type FGFRs. The observation that signaling by multiple types of FGFR can be blocked by a single type of truncated FGFR suggests that the different types of FGFR can interact with each other in ligand-mediated complexes. These findings provide a molecular basis for inhibiting the actions of FGFs in vivo.

Animals↗
PubMed1992

The functional, oxygen-linked chloride binding sites of hemoglobin are contiguous within a channel in the central cavity.

Chloride ion is a major allosteric regulator for many hemoglobins and particularly for bovine hemoglobin. A site-directed reagent for amino groups, methyl acetyl phosphate, when used for global rather than selective modification of R (oxy) and T (deoxy) state bovine hemoglobin, can acetylate those functional amino groups involved in binding of chloride; the extensively acetylated hemoglobin tetramer retains nearly full cooperativity. The chloride-induced decrease in the oxygen affinity parallels the acetylation of bovine hemoglobin (i.e., their effects are mutually exclusive), suggesting that methyl acetyl phosphate is a good probe for the functional chloride binding sites in hemoglobins. Studies on the overall alkaline Bohr effect indicates that the part of the contribution dependent on chloride and reduced by 60% after acetylation is due to amino groups, Val-1(alpha) and Lys-81(beta); the remaining 40% is contributed by the imidazole side chain of His-146(beta), which is not acetylated by methyl acetyl phosphate, and is not dependent on chloride. The five amino groups--Val-1(alpha), Lys-99(alpha), Met-1(beta), Lys-81(beta), and Lys-103(beta)--of bovine hemoglobin that are acetylated in an oxygen-linked fashion are considered functional chloride binding sites. Molecular modeling indicates that these functional chloride binding sites are contiguous from one end of the central cavity of hemoglobin to the other; some of them are aligned within a chloride channel connecting each end of the dyad axis.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylation↗
PubMed1992

Altered renal response to enhanced endogenous 5-hydroxytryptamine after tryptophan administration in essential hypertension.

1. To examine the pathophysiological significance of 5-hydroxytryptamine (serotonin) in essential hypertension, we compared the renal response to intrarenally formed 5-hydroxytryptamine by oral dosing with its precursor, L-tryptophan (2 g), in nine patients with essential hypertension and in six subjects with normotension. 2. Before tryptophan administration, urinary excretion of 5-hydroxytryptamine was significantly higher in the hypertensive group than in the normotensive group (66 +/- 8 versus 36 +/- 6 ng/min, P less than 0.05), whereas renal plasma flow and glomerular filtration rate did not differ between the two groups. After dosing with tryptophan, urinary excretion of 5-hydroxytryptamine significantly increased to the same plateau level in both groups (366 +/- 55 ng/min in the hypertensive group and 365 +/- 64 ng/min in the normotensive group). Significant and equivalent decreases in renal plasma flow were observed in the early phase after tryptophan administration in both groups (-8.5 +/- 3.4% in the hypertensive group and -8.2 +/- 1.7% in the normotensive group). Thereafter, renal plasma flow increased to above the baseline value in normotensive subjects, whereas this late vasodilatation was absent in the hypertensive group. Glomerular filtration rate significantly decreased at the time of the fall in renal plasma flow in the normotensive group (106.8 +/- 7.8 to 92.7 +/- 8.5 ml min-1 1.73 m-2, P less than 0.05), whereas it remained unchanged in the hypertensive group (108.2 +/- 6.2 to 110.4 +/- 6.3 ml min-1 1.73 m-2, not significant).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

Microcystic adnexal carcinoma: a case report with immunohistochemical and electron microscopical examinations.

Microcystic adnexal carcinoma (MAC) is an unusual cutaneous neoplasm comprised of pilar and sweat duct structures. We report here a 66-year-old Japanese woman with MAC on her left nasolabial fold with more prominent calcified keratinous cysts than ductal differentiated structures which stained positively for carcinoembryonic antigen (CEA). The clinical appearance and statistical characteristics of MAC are reported to be different from those of other adnexal tumors. Desmoplastic trichoepithelioma (DTE) is the most difficult tumor to differentiate from MAC, unless positive reactivity for CEA in differentiated ductal structures in MAC can be demonstrated. We compare the differences between the clinical, histological, immunohistochemical, and electron microscopical features of DTE and MAC. It seems probable that these differences could be explained by biological differences in the characteristics of the cells from which these tumors originate, hair follicle cells and eccrine sweat cells, respectively.

Aged↗
PubMed1992

Superficial epithelioma with sebaceous differentiation.

In 1980, Rothko, Farmer, and Zeligman first described the disease entity "Superficial epithelioma with sebaceous differentiation" as a histologically distinct, rare, benign lesion. We report here the first Japanese case fitting this description. The patient is a 38-year-old Japanese woman, who had a small, yellow, flat-topped, well-defined plaque on her right upper eyelid. Histologically, the lesion was a multilobular, superficial, dermal tumor with numerous broad attachments to the overlying epidermis. The overall configuration was a plate-like proliferation of tumor cells with well-defined borders. The tumor cells were basically uniform basaloid cells with single or clustered sebocytes in the upper part of the tumor and multiple well differentiated sebaceous lobules in the middle and lower parts of the tumor. Multiple cystic spaces were formed in the lobules. Differential diagnosis of several tumors with sebaceous differentiation is discussed.

Adult↗
PubMed1992

Clear cell hidradenoma: a tumor with basaliomatous changes in the overlying epidermis and follicular infundibula of surrounding skin.

We report a clear cell hidradenoma on the cheek of a Japanese man. We performed the primary operation on the flesh-colored tumor, which had surface telangiectasia. The histopathologic features of the tumor, which indicated an intradermal nodular hidradenoma, consisted mainly of typical clear cells with small numbers of eosinophilic fusiform cells. Most clear cells reacted negatively for CEA, EMA, S-100 protein and KL-1 keratin, but those in and around the cystic and ductal structures reacted positively for CEA, EMA and KL-1 keratin. Ultrastructurally, these clear cells had numerous microvillus processes, abundant intracytoplasmic glycogen granules, and numerous mitochondria. In addition, buds of hyperpigmented keratinocytes hung from the overlying epidermis and thin cords of hyperpigmented keratinocytes proliferated around the follicular infundibula beside the tumor. Within two months of the primary operation, growth of the tumor into the overlying epidermis recurred rapidly. We discuss the histological features of the combination of clear cell hidradenoma with basaliomatous changes of the overlying and surrounding skin and the highly aggressive recurrence of this type of tumor after primary treatment.

Adenoma, Sweat Gland↗
PubMed1992

Eccrine hidrocystoma: two cases of Robinson and Smith types.

Two cases of eccrine hidrocystoma, one of which is a "classic" Robinson type and the other a Smith type, were reported. The walls of both cysts consisted mainly of two layers of flat or low cuboidal epithelial cells with eosinophilic cytoplasm. Immunostaining for S-100 protein was negative in the cells of the cyst wall of the Robinson type and only weakly positive in the inner luminal layer of the Smith type. Electron microscopically, the Smith type showed double-layered cuboidal lining and cell membrane interdigitations as junctions of neighboring cells without any characteristics of the secretory segment of sweat glands, indicating substantial similarity to those of the intradermal portion of the eccrine sweat duct.

Facial Neoplasms↗
PubMed1992

Localized basaloid follicular hamartoma.

We report a 39-year-old Japanese woman with a 30 x 10 mm, skin-colored, soft, hairless, irregularly elevated plaque in the left retroauricular area. Histologically, it consistently showed features of atypical hair follicles; some showed immaturely developed basaloid epithelial islands invaginated with condensed stromal cells, and others were replaced or associated with solid strands, branching cords, or lace-like networks of undifferentiated basaloid cells. Although the clinical appearance of a typical localized basaloid follicular hamartoma is a plaque of alopecia, this case seems to be a variant, because the histological findings are so characteristic of the entity. The relationship of basaloid follicular hamartoma to other hair-follicle derived tumors is also considered.

Adult↗
PubMed1992

Two cases of plantar epidermal cyst associated with human papillomavirus.

HPV-associated epidermal cysts of the sole (HAECS) of the foot have been reported recently in Japan in which there is positive staining for papillomavirus antibody in the nuclei of the epithelial cells in the cyst wall and vacuoles in the stratified horny material inside the cysts. A causative association with a newly recognized HPV, HPV 60, has been recorded. The authors report two new cases. The possible mechanism of cyst formation in HPV 60-infected epithelium is discussed.

Adult↗
PubMed1992

Comparative study of IgA nephropathy with acute and insidious onset. Clinical, laboratory and pathological findings.

In order to clarify the difference of clinical and pathological features between the IgA nephropathy patients with acute and insidious onset, 427 patients were examined in this study. Seventy-eight patients with acute onset (group 1) were often associated with mucosal system infections at the abrupt onset. This group revealed macroscopic hematuria, more severe microscopic hematuria (more than 20/hpf), higher glomerular filtration rate (p less than 0.01) and lower serum levels of C3 (p less than 0.01). It had also a significantly higher incidence of exudative lesions (p less than 0.001). On the other hand, the onset of 349 patients (group 2) was noticed to be insidious without preceding infections. This group showed a more severe increase in mesangial cells (p less than 0.01) and a significantly higher incidence of adhesion, arterial sclerosis and tubulointerstitial changes. Deposition of Clq, C4 and IgM and detachment of visceral epithelium from the basement membrane were more frequently seen in group 2. Twenty-seven of 345 patients followed for at least 1 year after the biopsy were on maintenance hemodialysis: 1 patient was in group 1 and 26 were in group 2. These results clarified that there was a difference in clinical, laboratory and histopathological findings between the patients with IgA nephropathy with acute and insidious onset.

Acute Disease↗
PubMed1992

Structure of the human glucokinase gene and identification of a missense mutation in a Japanese patient with early-onset non-insulin-dependent diabetes mellitus.

Glucokinase is thought to play a glucose-sensor role in the pancreas, and abnormalities in its structure, function, and regulation can induce diabetes. We isolated the human glucokinase gene, and determined its genomic structure including exon-intron boundaries. Structure of the glucokinase gene in human was very similar to that in rat. Then, by screening Japanese diabetic patients using polymerase chain reaction--single strand conformation polymorphism (PCR-SSCP) and direct-sequencing strategies, we identified a missense mutation substituting arginine (AGG) for glycine (GGG) at position 261 in exon 7 of the glucokinase gene in a patient with early-onset non-insulin-dependent diabetes (NIDDM).

Base Sequence↗
PubMed1992

Malignant fibrous histiocytoma in the skull--case report.

A 45-year-old male presented with a large calvarial mass caused by a malignant fibrous histiocytoma arising primarily from the frontal bone and extending into the intracranial space. Magnetic resonance imaging revealed a well-demarcated, mottled enhanced bulky tumor with several low-signal separations. He underwent extensive tumor and bone removal, followed by radiation therapy. Histological examination showed pleomorphic spindle cells in a storiform pattern. The tissue stained positive for alpha-1-antitrypsin and alpha-1-antichymotrypsin by immunohistochemical techniques.

Frontal Bone↗
PubMed1992

[Clinical and echocardiographic evaluation of the effects of atrial defibrillation in patients with idiopathic cardiomyopathy].

To elucidate the effects of atrial defibrillation in patients with idiopathic cardiomyopathy, we clinically and echocardiographically assessed 6 patients with hypertrophic cardiomyopathy (HCM) and 7 patients with dilated cardiomyopathy (DCM). Their mean age was 57 +/- 14 years and the mean duration of their atrial fibrillation (Af) was 47 +/- 29 days. There were no differences in age and the duration of Af between the HCM and DCM groups. We assessed the effects of defibrillation on the NYHA functional classification, heart rate (HR), systolic blood pressure (S-BP), M-mode echocardiographic data (LVDd, LVDs, %FS, LAD) and transmitral pulsed Doppler echocardiographic findings (peak velocity, time-velocity integral of rapid and atrial filling waves). These indices were obtained before and 52 +/- 22 days after defibrillation, and were compared with each other. 1. HR decreased (HCM: 87 +/- 16-->58 +/- 7/min, DCM: 93 +/- 19-->70 +/- 14/min) and total left ventricular filling increased (HCM: 6 +/- 1-->11 +/- 4 cm, DCM: 6 +/- 1-->10 +/- 2 cm) after defibrillation, and the increment of %FS (HCM: 36 +/- 6-->41 +/- 6%, DCM: 16 +/- 6-->25 +/- 11%) was observed. Four of 6 HCM patients and 5 of 7 DCM patients also improved with regard to the NYHA classification. 2. After defibrillation, LVDd increased in HCM (42 +/- 4-->47 +/- 4 mm), but not in DCM. However, LVDs decreased in DCM (52 +/- 9-->44 +/- 12 mm), but not in HCM. We concluded that atrial defibrillation had a beneficial effect on the recovery of the left ventricular function both in HCM and DCM due to the reduction in HR and increase in left ventricular filling. The mode of LV functional improvement after defibrillation varied depending on the state of patient's basal pathophysiology .

Adult↗
PubMed1992

[Ultrastructural, immunohistochemical and immunoelectron microscopic studies on the transitional part of the trabecular meshwork and the ciliary muscle in human and porcine eyes].

The authors demonstrated the ultrastructure of the transitional portion of the human trabecular meshwork (TM) of the ciliary muscle (CM) by transmission electron microscopy, together with the porcine TM and CM, which have not been reported so far. In the transitional portion of the human eye, bundles of smooth muscle cells showed tapering in the anterior portion, and long slender processes of TM cells covered the outside of muscle bundles occasionally, in association with intervening nerve fibers. In the human transitional portion, there were many stick-like or irregular-shaped structures consisted of collagen fibrils. In the porcine eye, although the fine structure of the TM was similar to that of human TM, the shape of each porcine CM cell was irregular and their cytoplasm were invaginated into the adjoining cells, like herniation. In the immunohistochemical study, the positive immunoreactions were found in TM cells for vimentin, Schwann cells for S-100 and S-100b, and the CM cells for muscle (m)-actin and desmin in both species by using each antibody. Only the porcine TM cells were positive for S-100 and S-100b. In the human eye, smooth muscle-like cells similar to TM cells in the transitional portion were detected, and these cells were positive for m-actin. Moreover, the cells covering Schlemm's canal were positive for factor VIII and UEA-1. These immune positivities were confirmed at the ultrastructural level. These immunohistochemical reactions may be useful tools to evaluate cell at the light and electron microscopic levels in human and porcine TM and CM regions.

Actins↗
PubMed1992

[Effect of GABA antagonists on the rat electroretinogram].

It has been shown that gamma-aminobutyric acid (GABA) is densely packed in the inner nuclear and plexiform layers in the rat retina, where it is mainly located within a subgroup of amacrine cells. This study examined the effects on the electroretinogram of GABA antagonists infused into the vitreous cavity of urethan-anesthetized rats. Infusions of the GABAA antagonist, bicuculline (0.1-10 mM, 3 microliters) significantly enhanced the b-wave amplitude and reduced the oscillatory potentials (OPs). Similar effects were also produced by infusions of the GABAB antagonist, phaclofen (10 mM, 3 microliters), although lower doses (0.1-1 mM, 3 microliters) had no effect. These results suggest that the actions of GABA, presumably released from amacrine cells, on both GABAA and GABAB receptors are involved in the normal generation of the b-wave and OPs.

Animals↗
PubMed1992

Cytosolic free calcium concentration in platelets in patients with renovascular hypertension and primary aldosteronism.

To investigate the role of cytosolic free calcium, [Ca2+]i, in secondary hypertension, the levels in platelets from 14 secondary hypertensives (7 renovascular hypertension, 7 primary aldosteronism) were compared with those from 21 essential hypertensives and 15 normotensives by means of the fluorescent indicator, quin-2. The mean BP was significantly higher in both the secondary hypertensives and essential hypertensives (122 +/- 8 and 124 +/- 12 mmHg) than in the normotensives (89 +/- 10 mmHg). Cytosolic free calcium in platelets was significantly higher in the essential hypertensives, but not in the secondary hypertensives, compared with the normotensives (182 +/- 34, 141 +/- 17, 138 +/- 15 nM respectively). There was no significant difference in platelet [Ca2+]i between renovascular hypertension and aldosteronism (142 +/- 19 versus 139 +/- 16 nM). There was no correlation between platelet [Ca2+]i and plasma renin activity, plasma aldosterone concentration or plasma noradrenaline concentration in the three groups. Thus, the increase in platelet [Ca2+]i seen in essential hypertension was not found in patients with secondary hypertension. Our results suggest that the cytosolic calcium handling of secondary hypertensive patients with renal artery stenosis or primary aldosteronism differs from that of essential hypertensives.

Adult↗