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Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 55 records · Page 3Linked to original sources
PubMed1991

FTZ-F1, a steroid hormone receptor-like protein implicated in the activation of fushi tarazu.

The Drosophila homeobox segmentation gene fushi tarazu (ftz) is expressed in a seven-stripe pattern during early embryogenesis. This characteristic pattern is largely specified by the zebra element located immediately upstream of the ftz transcriptional start site. The FTZ-F1 protein, one of multiple DNA binding factors that interacts with the zebra element, is implicated in the activation of ftz transcription, especially in stripes 1, 2, 3, and 6. An FTZ-F1 complementary DNA has been cloned by recognition site screening of a Drosophila expression library. The identity of the FTZ-F1 complementary DNA clone was confirmed by immunological cross-reaction with antibodies to FTZ-F1 and by sequence analysis of peptides from purified FTZ-F1 protein. The predicted amino acid sequence of FTZ-F1 revealed that the protein is a member of the nuclear hormone receptor superfamily. This finding raises the possibility that a hormonal ligand affects the expression of a homeobox segmentation gene early in embryonic development.

Amino Acid Sequence↗
PubMed1991

Combination of Trp and Glu residues for recognition of mRNA cap structure. Analysis of m7G base recognition site of human cap binding protein (IF-4E) by site-directed mutagenesis.

Four mutants of the human cap binding protein (hCBP), in which Trp-102, Glu-103, Asp-104 or Glu-105 was changed to the aliphatic Leu or Ala, were prepared, and their cap binding abilities were examined. Cap binding abilities of two mutants, W102L (Trp-102----Leu) and E105A (Glu-105----Ala), were significantly decreased in comparison with the wild-type hCBP. This result suggests that Trp-102 and Glu-105 are both necessary for the cap binding, and the most probable binding mode with the m7G of cap structure is the combination of the stacking by Trp-102 and the hydrogen-bond pairing by Glu-105, as was already proposed from the model studies.

Amino Acid Sequence↗
PubMed1991

Repression of the Drosophila fushi tarazu (ftz) segmentation gene.

The striped expression of the Drosophila segmentation gene fushi tarazu in alternate parasegments of the early embryo is controlled by the 740 bp zebra element. Among multiple protein factors that bind to the zebra element, FTZ-F2 behaves as a transcriptional repressor of ftz. Point mutations in the zebra element which disrupt FTZ-F2 binding to DNA cause ectopic expression of zebra-lacZ activity in transformed embryos. The mutant constructs are expressed from the zygotic genome in preblastoderm embryos as early as the third nuclear division cycle. This unprecedented early transcription suggests that ftz requires active repression during initial nuclear division cycles, a novel type of embryonic gene regulation. A putative FTZ-F2 cDNA clone isolated by recognition site screening of an expression library was found to be identical in sequence with the zinc finger protein tramtrack (Harrison and Travers, 1990).

Animals↗
PubMed1991

Immunogold electron microscopic localization of antigenic sites in the outer dense fiber region of rat sperm tail obtained by using antisera to two Sertoli cell secretory proteins.

Polyclonal antisera raised against polypeptide components of two rat Sertoli cell secretory proteins, designated protein S70 and S45-S35 heterodimeric protein on the basis of cell origin and estimated molecular weight, were used to identify antigenic sites in 1) rat testis, 2) cultured Sertoli cells, 3) developing spermatids (collected from spermatogenic stage-specific seminiferous tubular segments), and 4) epididymal sperm. Indirect immunofluorescence, immunoperoxidase, and immunogold electron microscopy (single and double labeling) were used. Immunocytochemical techniques have detected antigenic sites in 1) the cytoplasm of Sertoli cells in the intact seminiferous tubule and in culture in the form of a punctuate, granular-like pattern, and 2) the acrosome (but not the Golgi region) and tail of developing spermatids and sperm. In developing spermatids, the principal piece of the tail displays a characteristic apical-to-distal immunoreactive banding pattern that correlates both temporally and spatially with the reported multistep assembly of outer dense fibers along the axoneme. The immunoreactivity of the acrosome, connecting piece, and outer dense fibers of the sperm tail was confirmed by immunogold electron microscopy. A precise identification of the component(s) of the outer dense fiber region responsible for the antigenic homology with Sertoli cell secretory proteins is under investigation.

Animals↗
PubMed1991

Temporal profile of serum albumin extravasation following cerebral ischemia in a newly established reproducible gerbil model for vasogenic brain edema: a combined immunohistochemical and dye tracer analysis.

We investigated the temporal profile of the extravasation of serum albumin in a reproducible gerbil model of unilateral cerebral ischemia, using immunohistochemical and dye-tracer techniques to evaluate albumin accumulation and the occurrence of active extravasation, respectively. After 30 min of cerebral ischemia and subsequent reperfusion, immunostaining for albumin became visible in the lateral part of the thalamus during the first 3 h, and then expanded to other brain regions up to 24 h. At both 24 h and 3 days after reperfusion, massive extravasation of albumin was noted in the whole ischemic hemisphere, and this had decreased again by 7 days after reperfusion. The extent and the degree of albumin immunopositivity were almost the same in all animals examined at each period after reperfusion. The extravasation of Evans blue, which was allowed to circulate for 30 min before death, was limited to the lateral part of the thalamus during the first 6 h of reperfusion. In the circumscribed area of massive albumin extravasation, many neurons were immunopositive for albumin; most of these neurons appeared to be intact and also showed immunostaining for microtubule-associated protein 2. The current investigation clearly demonstrated that (1) albumin extravasation was produced with reliable reproducibility in this model, (2) the lateral part of the thalamus was the region most vulnerable to ischemic blood-brain barrier damage, and (3) many apparently intact neurons in the ischemic region were positive for albumin.

Animals↗
PubMed1991

A histochemical method for the demonstration of unsaturated lipids.

A method has been developed for the histochemical demonstration of unsaturated lipids in light microscopy. It is a peracetic acid-thiocarbohydrazide-silver protein sequence followed by a physical development procedure. In the present study on paraffin and cryostat sections of liver, brain and ovary, unsaturated lipids were visualized as distinct reaction products coloured various shades of brown and black. The reaction products are easier to see and the method is more efficient than the peracetic acid-Schiff method.

Animals↗
PubMed1991

Influence of immunotherapy on the cellular immunity of unexplained recurrent aborters.

Changes in lymphocyte subsets in whole blood were analyzed sequentially by flow cytometry with an automated leukocyte differential system in 15 patients with unexplained recurrent spontaneous abortions, each of whom underwent vaccination(s) with her husband's lymphocytes. Mitogen responses of peripheral blood lymphocytes (PBL) were also examined in these patients. The reactivity of PBL against mitogens revealed no significant change in each patient before and after vaccination(s) with her husband's lymphocytes. The CD4:8 ratio was observed to decrease significantly during 22 and 28 days after the first vaccination with a significant increase in the percentage of T suppressor-cytotoxic (CD8) cells. This change was also observed after the second vaccination. The percentages of other subsets did not change significantly after vaccination(s). In 11 patients out of 15, the pregnancy continued successfully and correlated with a predominance of Ts/c (CD8) over TH/I (CD4) cells in the first trimester. These changes in lymphocyte subsets may indicate the induction of immune enhancing mechanisms and it is suggested that continuation of the predominance of Ts/c cells induced by immunotherapy might be important for the successful maintenance of pregnancy.

Abortion, Habitual↗
PubMed1991

A comparison of central nervous lesions directly induced by Escherichia coli lipopolysaccharide in piglets, calves, rabbits and mice.

To evaluate the role of endotoxin during Gram-negative bacterial meningitis, the nervous lesions of piglets, calves, rabbits and mice were compared by direct inoculation of Escherichia coli lipopolysaccharide into the central nervous system. Suppurative leptomeningitis was induced in piglets by small doses of lipopolysaccharide. Mice also had a mild suppurative inflammation in the leptomeninges. In contrast, calves showed suppurative pachymeningitis, but no lesions in the leptomeninges. Leptomeningeal inflammation was not induced in rabbits. Induction of the leptomeningitis by endotoxin was compared with sensitivity to intravenous or intraperitoneal endotoxin in these species.

Animals↗
PubMed1991

Predominant Paneth cell differentiation in an intestinal type gastric cancer.

A distinct morphological variant of a diffuse type adenocarcinoma of the stomach with Paneth cell differentiation is reported. The tumor was a Borrmann's Type III carcinoma measuring 6.0 x 5.5 cm at the body along the greater curvature. It was composed of Paneth cell- and endocrine cell differentiated cancer cells in addition to tubular and poorly differentiated adenocarcinoma cells. The Paneth cell differentiation was characterized histologically by cytoplasmic distinct coarse eosinophilic granules stained red with periodic acid-Schiff and Masson trichrome reagents and reddish brown with phosphotungstic acid hematoxylin, and electron microscopically by lysozyme in cytoplasmic electron dense granules. In addition, electron microscopy revealed acid mucin globules and various intermediate forms between Paneth granules and the mucin globules which might be regarded as abortive forms of Paneth granules presumably resulting from defective incorporation of lysozyme-positive mucosubstances into acid mucin. Endocrine differentiated cancer cells consisted of serotonin-, peptide YY-, and glucagon/glicentin-positive cells. The various cell phenotypes found in the present tumor could be explained on the basis of intestinal differentiation of gastric cancer.

Adenocarcinoma↗
PubMed1991

Novel cerebroprotective agents with central nervous system stimulating activity. 1. Synthesis and pharmacology of 1-amino-7-hydroxyindan derivatives.

To develop a novel cerebroprotective agent with central nervous system (CNS) stimulating activity, a series of 1-amino-7-hydroxyindan derivatives was synthesized, and their effects on the survival time of mice under hypoxic conditions were tested. CNS-stimulating activity was also evaluated by examining the promotional effect on the recovery from cerebral concussion induced coma in mice. Several compounds prolonged the survival time of mice in hypoxic conditions at a dose of 30 mg/kg (sc or ip) and 100 mg/kg (po). They also exhibited the promotional effects on recovery from coma at a dose of 100 mg/kg po. The three most potent compounds in both tests, 1-amino-7-hydroxy-6-(1-methylpropyl)indan, 1-amino-7-hydroxy-4, 6-dimethyl-2-phenylindan, and 1-amino-7-hydroxy-2,2,4,6-tetramethylindan were selected for further investigations. Structure-activity relationships were also discussed.

Animals↗
PubMed1991

Expression of a synthetic gene for human cap binding protein (human IF-4E) in Escherichia coli and fluorescence studies on interaction with mRNA cap structure analogues.

An artificial gene coding for the human cap binding protein (hCBP: human IF-4E) was chemically synthesized and expressed in Escherichia coli under the control of a trp promoter. The DNA duplex of 662 bp was designed and constructed from 44 oligodeoxynucleotide fragments of typically 30 nucleotides in length. Although the hCBP gene was not directly expressed in E. coli HB101, we succeeded in its high-level expression as a fusion protein connected with a portion of human growth hormone through a tetradecapeptide (Asp-Asp-Pro-Pro-Thr-Val-Glu-Leu-Gln-Gly-Leu-Val-Pro-Arg) that contains the recognition sequence for a site-specific protease alpha-thrombin. Upon induction with 3-indoleacrylic acid, the fusion protein accumulated with a yield of about 20% of the total proteins of the host cell. Upon the treatment of the fusion protein with alpha-thrombin, which recognizes the sequence "Val-Pro-Arg," specific proteolysis at the fused junction occurred efficiently. In this system, nonspecific digestion by alpha-thrombin was not marked. About 15 mg of recombinant hCBP was obtained from a 1-liter culture. Association constants between the recombinant hCBP and mRNA cap structure analogues were determined by fluorescence spectroscopy. The values obtained for the m7GpppA, m7GTP, and m7GMP were almost the same as those reported for the IF-4E isolated from human erythrocyte cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Amino Acid Sequence↗
PubMed1991

Synergy between cyclosporine and anti-IL-2 receptor monoclonal antibodies in rats. Functional studies of heart and kidney allografts.

Although cyclosporine has improved results of organ transplantation, treatment regimens using multiple agents are being evaluated both experimentally and clinically in attempts to diminish its often profound nephrotoxicity; some therapies act synergistically by differential inhibition of distinct steps of the rejection cascade. The effects on graft function of a full dose or a subclinical dose of CsA, ART-18, a monoclonal antibody (mAb) directed against the IL-2 receptor expressed on activated host cells, and a combination of low-dose CsA and ART-18, have been tested in rat recipients of both heart and kidney allografts. Renal graft function was assessed by several classic techniques; heart function by isolated perfusion methods. Full-dose CsA and combination treatment were most effective in both organ graft systems, with at least one-third of grafts surviving indefinitely. At seven days after transplantation, glomerular filtration rates and renal plasma flow of all grafted recipients were decreased as compared with normal; at 14 days, function in the best treatment groups had improved toward that of isografts. Similarly, cardiac output and stroke work index of best treatment groups were comparable to that of isografts. These functional studies complement previously reported immunological and immunohistological findings stressing that synergy occurs between subclinical doses of CsA and anti-IL-2-R mAb in two rat organ graft systems.

Animals↗
PubMed1991

A case of idiopathic vulvar calcinosis: the first in Japan.

Idiopathic calcinosis of the scrotum is a rare condition of unknown etiology. As counterparts of this male disorder, only two female cases have been reported. We report a third case, the first of its kind, in Japan. Histochemical stains revealed acid mucopolysaccharide (acid-MPS) within the calcinosis and many infiltrated mast cells near it; these might histogenese the calcium deposition. Immunohistochemically, polyclonal carcinoembryonic antigen (CEA) and keratin stains revealed no positive cells near the calcium depositions.

Calcinosis↗
PubMed1991

L-arginine induces relaxation of rat aorta possibly through non-endothelial nitric oxide formation.

1. The relaxation of rings of rat thoracic aorta induced by L-arginine and its derivatives was investigated. 2. L-Arginine (0.3-100 microM), but not D-arginine, induced relaxation of the arteries, which was detectable after 2 h and maximal after 4-6 h on its repeated application; it was endothelium-independent. 3. L-Arginine methyl ester, N alpha-benzoyl L-arginine and L-homo-arginine had essentially similar effects to those of L-arginine. 4. NG-nitro L-arginine methyl ester (L-NAME, 3 microM), NG-nitro L-arginine (L-NNA, 1 microM) and NG-monomethyl L-arginine (L-NMMA, 10 microM), inhibitors of nitric oxide (NO) formation from L-arginine, inhibited or reversed the L-arginine-induced relaxation, irrespective of the presence or absence of the endothelium. In contrast, NG-nitro D-arginine was without effect. 5. Haemoglobin (Hb, 10 nM) and methylene blue (MB, 0.3 microM) inhibited or reversed the L-arginine-induced relaxation. 6. L-Arginine (1-100 microM), but not D-arginine, increased guanosine 3':5'-cyclic monophosphate (cyclic GMP) levels in the tissues that relaxed in response to L-arginine. This effect of L-arginine was suppressed by Hb (3 microM), MB (1 microM) and L-NAME (100 microM). Removal of the endothelium did not significantly alter the L-arginine-induced cyclic GMP production. 7. These results suggest that L-arginine itself caused a slowly developing relaxation of rat aorta, possibly via formation of NO by an endothelium-independent mechanism.

Animals↗
PubMed1991

Protein-secretory patterns of normal and abnormal human placentas with special reference to human chorionic gonadotropin.

[35S]Methionine-labeled protein-secretory patterns resolved by two-dimensional polyacrylamide gel electrophoresis in abnormal hydatidiform-mole placentas were compared with those in normal full-term placentas with special reference to human chorionic gonadotropin (hCG) by means of immunoblotting and immunoelectron-microscopic techniques. Although basic protein-secretory patterns of both placentas were similar to each other, four polypeptide spots appeared and one spot disappeared in the hydatidiform-mole samples. Among four newly synthesized and secreted spots, three were immunoreacted with anti-hCG serum by an immunoblotting experiment. Ultrastructural localization of hCG showed that the labeling intensity of anti-hCG serum in hydatidiform-mole placentas was much heavier than that in full-terms ones. Particularly, the Golgi apparatus, middle-sized granules and large bodies were highly immunoreactive. The present study reveals that hydatidiform-mole placentas have different protein-secretory functions especially in hCG synthesis and secretion from those of normal pregnancy.

Autoradiography↗