Search PubMed⌕ Search

Biomedical subjects

H Shima

Publications and source records attributed to H Shima.

At least 181 records · Page 10Linked to original sources

Contrasting effects of phorbol esters on serotonin- and vasopressin-evoked contractions in rat aorta and small mesenteric artery.

Phorbol esters, which activate protein kinase C, modulate vasoconstrictor-induced tension in vascular smooth muscle. We examined the effects of phorbol esters (phorbol 12,13-dibutyrate [PDBu] and 12-O-tetradecanoylphorbol 13-acetate [TPA]) on receptor agonist (serotonin [5-HT] and arginine vasopressin [AVP])-, high K(+)-, and caffeine-induced contractions in rings of rat aorta and a small (second-order) branch of the superior mesenteric artery (SMA). PDBu and TPA significantly augmented agonist-evoked contractions in aorta but diminished those in SMA. For example, 30 nM PDBu increased 5-HT- and AVP-evoked contractions 2.0-2.5-fold in aorta (p less than 0.01) but decreased 5-HT- and AVP-induced contractions by 40-60% in SMA (p less than 0.01). In contrast, PDBu and TPA amplified high K(+)- and 10 mM caffeine-induced contractions in both aorta and SMA. Augmentation of agonist-induced contractions by PDBu was greater in endothelium-denuded aorta than in intact aorta. Two protein kinase C antagonists, H-7 and staurosporine, inhibited 5-HT-evoked contractions in the absence as well as in the presence of PDBu in both types of arteries. The augmentation of contractile responses to caffeine and K+ by phorbol esters in both types of arteries suggests that the phorbols increase the sensitivity of the contractile apparatus to Ca2+, probably by activating protein kinase C. However, the inhibitory effects of phorbols on 5-HT- and AVP-evoked responses in SMA suggest that under these conditions the dominant effect of the phorbols is a marked reduction in the availability of Ca2+ in the SMA but not in the aorta.

Animals↗

Effect of human recombinant mullerian inhibiting substance on isolated epithelial and mesenchymal cells during mullerian duct regression in the rat.

The effect of human recombinant Mullerian Inhibiting Substance (MIS) on the regression of the Mullerian duct (MD) of female rat fetuses was examined in vitro to determine whether MIS acts on MD epithelium and/or mesenchyme at the critical periods of sexual differentiation. Urogenital ridges (URs) of female rat fetuses at 14.5- to 18.5-days of gestation (plug day = 0) were cultured for 3 days with or without recombinant human MIS in CMRL 1066 medium with 10% female fetal calf serum. In URs from 14.5- and 15.5-day-old fetuses, the cranial portion of the MD regressed almost completely during the 3-day culture period in the presence of MIS, whereas the caudal half to third of the MD remained intact but tapered to a fine point cranially. MDs survived in URs from 16.5-day-old fetuses cultured in the presence of MIS except that the cranial portion of the MDs was deformed. MIS did not elicit regression of MDs in URs obtained from 17.5- and 18.5-day-old fetuses, but instead caused the MD epithelium to form bulges projecting into the mesenchyme. MD epithelium at 15.5-days of gestation was separated from the surrounding UR mesenchyme, and both components (MD epithelium and mesenchyme) were cultured separately for 3 days in the presence or absence of MIS. Both epithelial and mesenchymal cells survived in the presence or absence of MIS. MD epithelium formed typical epithelial colonies, whereas UR mesenchyme spread as fibroblastic cells. Analysis of labeling index after incorporation of [3H] thymidine demonstrated that MD epithelial DNA synthesis was not influenced by MIS. In contrast, mesenchymal labeling index was reduced significantly by MIS. This effect of MIS on UR mesenchyme in conjunction with earlier histological observations of mesenchymal condensation during MD regression and an absence of direct effects of MIS on the epithelium suggests that MIS elicits its effect on the MD epithelium via the surrounding mesenchyme.

Animals↗

Construction of an alpha-amylase/glucoamylase fusion gene and its expression in Saccharomyces cerevisiae.

A fusion gene which encoded a polypeptide comprised of 1116 amino acids was constructed using the alpha-amylase and glucoamylase cDNAs of Aspergillus shirousamii. When the fusion gene was expressed in Saccharomyces cerevisiae using a yeast expression plasmid under the control of the yeast ADH1 promoter, a bifunctional fusion protein (145 kDa) having both alpha-amylase and glucoamylase activities was secreted into the culture medium. The fusion protein had higher raw-starch-digesting activity than those of the original alpha-amylase and glucoamylase, and adsorbed onto raw starch like the glucoamylase. It was suggested that the characteristics are a result of the raw-starch-affinity site in the glucoamylase domain of the fusion protein.

Alcohol Dehydrogenase↗

A case of Graves' disease and papillary thyroid carcinoma with predominant production of thyroid-stimulation-blocking antibodies (TSBAb) persisted after total thyroidectomy.

A 42-year-old female with Graves' disease and papillary thyroid carcinoma with lung metastasis was referred to our hospital. After treatment of thyrotoxicosis with methimazole and Lugol's solution, she underwent total thyroidectomy. She was then given 131I twice to treat lung metastasis. However, 131I uptake into the lung was not clear in the scintigram. Both thyroid-stimulating antibodies (TSAb) and thyroid-stimulation-blocking antibodies (TSBAb) were detected in her sera before and after the treatments. Compared with TSAb activities, TSBAb activities were extremely high. Changes in the titers of these two antibodies were not clear after total thyroidectomy. These results indicate that lymphocytes outside the thyroid gland are the major source of TSAb and TSBAb in this patient.

Adult↗

Non-suppressed thyroidal radioactive iodine uptake (RAIU) in thyrotoxic phase in a case of subacute thyroiditis with thyroid-stimulating antibodies (TSAb).

In this paper, we report a 49-year-old female with subacute thyroiditis who had thyroid-stimulating antibodies (TSAb) and thyroid-stimulation-blocking antibodies (TSBAb) in serum. Although she was in the thyrotoxic phase and TSH was suppressed in May, 1990, her radioactive iodine uptake (RAIU) was not suppressed (35.5%) and a thyroid scan disclosed a diffuse goiter with no defect. Serum assays revealed the presence of TSAb, but TSBAb were negative. In August, 1990, the right lobe became undetectable by thyroid scan when the RAIU was 20.7% with the TSH level remaining suppressed. At that time, TSAb were negative, while TSBAb were positive. When the RAIU was 31.1% in October, 1990, both thyroid lobes became visible and the TSH level was normalized. TSBAb became negative, and although TSAb reappeared it later became undetectable. These results indicate that the changes in the patient's thyroid scan and RAIU were attributable to the presence of TSAb.

Autoantibodies↗

[Complete testicular feminization syndrome associated with thermolabile androgen receptor].

Radioreceptor assay and thermostability test for the androgen receptor in two cases with complete testicular feminization syndrome were performed in regard to the fibroblasts cultured from genital skin on the basis of dispersed whole cell binding assay (Eil et al., 1980). No [3H]dihydrotestosterone binding to the androgen receptor was observed in case 1 (receptor negative), while maximum binding capacity and dissociation constant of androgen receptor for [3H]dihydrotestosterone in case 2 were 21000 sites per cell and 1.67 x 10(-10) M (receptor positive). The specific binding of [3H]dihydrotestosterone to the androgen receptor in case 2 decreased remarkably to 6.6% after high temperature (42 degrees C) incubation in comparison with that at 22 degrees C incubation. The specific binding of [3H]dihydrotestosterone to the androgen receptor in normal controls decreased down to 81.6% at high temperature incubation. Thermostability test was useful to demonstrate qualitative abnormality of androgen receptor in receptor positive testicular feminization syndrome.

Adult↗

[Mainz pouch with umbilical stoma].

Between March 1986 and May 1991 the Mainz pouch urinary diversion was performed in 23 patients with bladder cancer. In 12 of these 23 patients, stoma was constructed in the umbilicus. As the efferent stomal limb, the ileum was used in 10 cases and the appendix was used in 2 cases. The skin at the bottom of the umbilicus and the abdominal fascia under the umbilicus were excised round. The stomal limb was pulled through the fascial hole and the stomal margin was sutured to the skin. The cosmetic results of the umbilical stoma were satisfactory in these 12 patients. Pouch capacity ranged from 330 ml to 560 ml and good urinary continence without difficulty of self-catheterization was obtained in 11 patients. In 1 patient difficulty in catheterization occurred due to a pocket-formation in the stomal limb and the operative revision was performed. Stomal stenosis occurred in 1 patient. Acute renal failure followed by intestinal bleeding occurred in 1 patient who was cured with intensive care including hemodialysis. The results of our study show the superiority of the umbilical stoma in the Mainz pouch in regard to good cosmetic appearance, no need to use a Marlex collar, little bending of catheterization route and low incidence of complications such as parastomal hernia or nipple valve prolapse.

Humans↗

[BEP (bleomycin, etoposide, cisplatin) therapy for testicular tumors].

We describe our experience with BEP (bleomycin, etoposide, cisplatin) therapy as chemotherapy for testicular tumors in 11 patients. Eight were non-seminomatous testicular cancer patients and 3 were seminoma patients. Three of 8 non-seminomatous testicular cancer patients had no evident metastasis and BEP therapy was performed for prophylaxis of recurrence. Other 5 non-seminomatous testicular cancer patients and 3 seminoma patients had metastatic lesions and BEP therapy was performed to cure these metastatic lesions. Ten of our 11 patients are living and disease-free. One non-seminomatous testicular cancer patient who had brain, lung, eye and bladder metastases and had an extremely elevated human chorionic gonadotropin (hCG) level responded only partially and died later due to disease progression. Side effects in most patients were nausea, vomiting, alopecia and leucopenia and all these side effects were reversible. Neuromuscular toxicity such as paresthesia or abdominal cramp that is sometimes encountered in PVB (cisplatin, vinblastine, bleomycin) therapy was not seen in our patients. Our results support the concept that BEP therapy is better than PVB therapy as an initial chemotherapy for testicular tumors.

Adolescent↗

The role of endogenous Na+, K(+)-adenosine triphosphatase inhibitory factor in the regulation of membrane fluidity of erythrocytes in essential hypertension.

OBJECTIVE: To investigate the regulatory mechanisms of membrane functions in hypertension, we examined the relationship between endogenous Na+, K(+)-adenosine triphosphatase (ATPase) inhibitor (digitalis-like factor; DLF) and erythrocyte membrane fluidity in essential hypertension by means of an electron spin resonance (ESR) and spin labelling methods. DESIGN AND METHODS: Erythrocytes were obtained from patients with essential hypertension and normotensive subjects, and the ESR spectra for a fatty acid spin label agent (5-nitroxide stearate) incorporated into the erythrocyte membranes were studied. The DLF content in plasma was expressed as the inhibitory potency of dog kidney Na+, K(+)-ATPase activity in vitro. RESULTS: The values of outer hyperfine splitting and of order parameter in ESR spectra were significantly higher in hypertensive patients than in normotensive subjects. This finding shows that the erythrocyte membrane fluidity may be decreased in essential hypertension. The level of plasma DLF content was greater in hypertensive patients than in normotensive subjects and was significantly correlated with the decrease in erythrocyte membrane fluidity. CONCLUSIONS: These results suggest that the decrease in erythrocyte membrane fluidity may be partially dependent upon the increased plasma DLF content.

Blood Proteins↗

[Prader-Willi syndrome associated with chromosomal aberration: report of a case].

A male case of Prader-Willi syndrome (2.8 years in age) with an interstitial deletion of a chromosome affecting 15q 11-12 region is reported. The chief complaints were hypoplastic scrotum and defect of bilateral scrotal content. The clinical features were short stature, obesity, delayed mental development, bilateral cryptorchidism, hypogenitalism, hypopigmentation, and bilateral moderate vesicoureteral reflux with a history of muscular hypotonia. Bilateral orchidopexy was done. Endocrinologically both base values of luteinizing hormone (LH) and follicle stimulating hormone (FSH) were normal although LH reserve function was impaired on gonadotropin releasing hormone (GnRH) test. Testosterone response was normal by the stimulation of human chorionic gonadotropin. An interstitial deletion of proximal 15q, and pituitary-gonadal axis in Prader-Willi syndrome are discussed in relation to the clinical features and therapy.

Child, Preschool↗

[Ectopic ureter opening to vestibule without urinary incontinence: a case report].

A case of a 2-year-old female with right ectopic ureter opening in vestibule vaginae and without urinary incontinence is reported. Excretory urogram showed mild dilatation of the upper right segment with bilateral complete duplication. Right ectopic ureter some functioning upper segment of the kidney was reimplanted into the bladder to avoid surgical intervention for heminephrectomy. According to the retrograde ureterogram of ectopic ureter the running courses and shapes of the dilated distal portions of ureters were compared between two groups, ectopic ureter with incontinence and that without incontinence. We suppose the continence mechanism of ectopic ureter is kept when the running course of the ureter through some portion of the urethral sphincter musculature.

Anastomosis, Surgical↗

[Chromosome abnormalities in hypospadias? An analysis of 131 patients].

We performed chromosome studies in 131 patients presenting with hypospadias, with the aim of detecting any causal connections between chromosomal abnormalities and the induction of hypospadias. Autosomal abnormalities were revealed in 6 and sex chromosomal abnormalities in 10 patients. Although a significant causal relationship between the occurrence of hypospadias and chromosomal abnormalities was seen in this study in only two cases of mixed gonadal dysgenesis (45,X/46,XY and streak gonad), the high incidence of chromosomal abnormalities observed (12.2%) seems noteworthy compared with the incidence of only 0.61% in the normal male population.

Adolescent↗

[Prognostic parameters of scar progression, new scar formation and maturation in primary vesico-ureteral-renal reflux].

We analysed the data recorded for 901 children (1357 kidneys) treated for primary vesicoureteral reflux between 1973 and 1988 at our institution. The retrospective study showed a rate of 7.3% for new renal scarring and progression; analysis by reflux grade revealed progression and new scarring in reflux, 10.9% of cases with grade IV and 16.5% of cases with grade V whereas low grades (I and II) were followed by no scarring at all. A close correlation of new scarring with urinary tract infection and bladder function was demonstrated. Spontaneous resolution of reflux was observed in 33.6% of all patients and in only 2.6% of patients with grade V reflux, as against a 85.5% resolution rate in patients with grade I or II reflux. A different sex distribution was revealed in the age group under 1 year, in which 80% of the patients were boys and the resolution rate was higher than in any other age group.

Adolescent↗

Detection of phosphorylated retTPC oncogene product in cytoplasm.

The product of the retTPC oncogene, an activated form of the ret proto-oncogene found in human papillary thyroid carcinomas, was identified as a 57-kDa protein (p57retTPC) by Western blotting with a polyclonal antibody raised by an oligopeptide corresponding to the carboxy-terminal region of the ret proto-oncogene product. Subcellular fractionation experiments using NIH3T3 cell transformants induced by the retTPC cDNA showed that p57retTPC was localized in a soluble cytoplasmic fraction, whereas the ret proto-oncogene products expressed in a neuroblastoma cell line were present in a membrane fraction. Immunostaining also demonstrated that p57retTPC is localized in the cytoplasm. Immunoprecipitation with anti-phosphotyrosine antibody followed by Western blotting revealed that p57retTPC is constitutively phosphorylated, whereas the ret proto-oncogene products are not. These findings suggest that p57retTPC has an aberrant tyrosine kinase activity resulting in autophosphorylation associated with change in its location.

Amino Acid Sequence↗

Identification of the promoter region of the rat protein phosphatase 2A alpha gene.

We have cloned a genomic fragment containing the promoter region of the rat protein phosphatase 2A alpha gene (PP-2A alpha). A 1.6 kb fragment of the 5' flanking region was sequenced. Three major transcriptional initiation sites were identified by the primer extension method using rat liver mRNA and found to be located 225, 222 and 220 bases upstream of the translational initiation site, respectively. Bacterial chloramphenicol acetyltransferase (CAT) assay revealed that a 503 bp SmaI fragment containing the transcriptional initiation sites had promoter activity, which was stronger than that of the SV40 early promoter on the pSV2CAT plasmid when introduced into NIH3T3 cells. Deletion of a 119 bp SacII fragment decreased its promoter activity considerably. The promoter region has an extremely high GC content and does not contain either a 'TATA box' or a 'CAAT box' suggesting that this promoter can be classified as that of a 'house keeping' gene, although there is only one typical GC-box (GGGCGG) immediately preceding the transcriptional initiation sites. There is a 10 base pair palindrome, 5'-GTGACGTCAC-3', 26 base pairs upstream of the +1 transcriptional initiation site, which is highly conserved in many other genes, whose expression is regulated by cAMP. The promoter activity was shown to be increased by forskolin treatment (10 microM) in NIH3T3 cells.

Amino Acid Sequence↗