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Biomedical subjects

Y Yamano

Publications and source records attributed to Y Yamano.

At least 19 recordsLinked to original sources
PubMed1992

Domains for G-protein coupling in angiotensin II receptor type I: studies by site-directed mutagenesis.

To delineate domains essential for G-protein coupling in angiotensin II type 1 receptor (AT1), we mutated the receptor cDNA in the putative cytosolic regions and determined consequent changes in the effect of GTP analogs on angiotensin II (Ang II) binding and in inositol trisphosphate production in response to Ang II. Polar residues in targeted areas were replaced by small neutral residues. Mutations in the second cytosolic loop, carboxy terminal region of the third cytosolic loop or deletional mutation in the carboxyl terminal tail simultaneously abolished both the GTP-induced shift to the low affinity form and Ang II-induced stimulation of inositol trisphosphate production. These results suggest that polar residues in the second cytosolic loop, the carboxy terminal region of the third cytosolic loop, and the carboxy terminal cytosolic tail are important for G-protein coupling of AT1 receptor.

Angiotensin II↗
PubMed1992

Identification of amino acid residues of rat angiotensin II receptor for ligand binding by site directed mutagenesis.

To determine the specific mechanism of ligand binding to angiotensin (Ang II) receptor AT1, mutagenized rat receptor cDNAs were expressed transiently in COS-7 cells and the effect of the mutations on the binding to peptidic and non-peptidic ligands was analyzed by Scatchard plots. Mutation of Lys199 to Gln in the intramembrane domain strongly reduced the affinity to both [125I] Ang II and [125I]-1Sar, 8Ile-Ang II whereas mutation of two other Lys had little effect, indicating involvement of Lys199 in binding ligands. Replacement of each of four Cys in the extracellular domain markedly reduced binding affinity, indicating the importance of two putative disulfide bridges in the formation of active receptor conformation. Substitution of Asp for Asn in N-glycosylation had no effect on ligand binding or expression of the receptor. These studies indicate mutated receptors are expressed in the plasma membrane and are amenable for further detailed studies.

Angiotensin II↗
PubMed1992

Heat-shock responsive elements in the induction of the multidrug resistance gene (MDR1).

The MDR1 gene, considered to be involved in multidrug resistance of cancer cells, is expressed in liver, kidney, small intestine and the blood-brain barrier. We investigated MDR1 gene expression in the well-differentiated hepatoma cell line HepG2 after exposure to several stresses and found that sodium arsenite treatment increased MDR1 gene expression 2.6-fold. Deletion analysis of the MDR1 promoter indicated that the transcriptional activation after exposure to arsenite depends on a 60-bp region containing two heat-shock responsive elements.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1992

Arthroplasty of the proximal interphalangeal joint using costal cartilage grafts.

Seven intra-articular fractures in five patients with partial bone loss at the PIP joint were reconstructed using a graft of costal cartilage. In all cases there were total or partial cartilagenous defects of the proximal phalangeal side of the joint. Early treatment of two joints, using only costal cartilage grafts, resulted in bony ankylosis due to necrosis of the grafted cartilage. In five joints the grafted cartilage included osseous portions using the costo-osteochondral junction, leading to an average range of movement of 64 degrees with satisfactory clinical results. The technique is a useful alternative to other forms of arthroplasty or arthrodesis, and can provide satisfactory functional results when there is a partial defect of the head of the proximal phalanx.

Adolescent↗
PubMed1992

Dangerous mixture of household detergents in an old-style toilet: a case report with simulation experiments of the working environment and warning of potential hazard relevant to the general environment.

A housewife cleaned toilet porcelain connected directly to a sewage storage tank with a mixture of cleaning agents; sodium hypochlorite (NaOCl) and hydrochloric acid (HCl) solutions. She complained of insomnia on the night after cleaning and suffered from severe metabolic acidosis with extremely low blood pH, PCO2 and bicarbonate values. She recovered from the acidosis after bicarbonate transfusion, plasmapheresis and plasma exchange. Permanent blindness ensued, however, from the third day after the event. These clinical symptoms suggested that the toxic substances responsible were chloramine and methyl chloride. Their generation was confirmed by in-vitro experiments, mixing NaOCl, HCl and pooled urine from normal people. In the simulation, the methyl chloride level far exceeded (100,000 ppm) the maximal allowable concentration recommended (ca 400 ppm) by the American Conference of Governmental Industrial Hygienists (ACGIH). Chloramine's toxic actions were confirmed using purified enzyme assay, and the inhibition of carbonic anhydrase and aldehyde dehydrogenase and the enhancement of superoxide dismutase activity were confirmed in neutral pH. The patient's clinical symptoms suggested that insomnia and permanent blindness seemed to be partly ascribable to chronic repetitive exposure to methyl chloride; catching a cold, drug intake and alcohol intake, in addition, precipitated the patient's visual loss. The possibility of this kind of intoxication with such a mixture of agents may lie latent in any situation where sewage or garbage are exposed to the open air.

Acidosis↗
PubMed1992

Primary papillary adenocarcinoma in the third portion of the duodenum.

We herein report a rare case of papillary adenocarcinoma which occurred in the third portion of the duodenum. The patient was a 62-year-old Japanese male who was admitted due to vomiting and right lower abdominal pain. No abnormal findings were found in the laboratory examinations. After a diagnosis of primary duodenal carcinoma was made by radiologic, endoscopic and ultrasonographic studies, a pancreatoduodenectomy was performed. The histology of the resected specimen revealed papillary adenocarcinoma, with invasion reaching to the pancreatic body. Some characteristic features of the disease are also reviewed.

Adenocarcinoma, Papillary↗
PubMed1992

[A case of Fitz-Hugh-Curtis syndrome confirmed by laparoscopy].

A 25-year-old Japanese female was admitted to the Department of Surgery in Kyushu Koseinenkin Hospital because of serious right hypochondralgia. Gastrofiberscopy, abdominal ultrasonography, intravenous pyelography and irrigoscopy did not reveal the origin of the pain, and she was introduced to the Department of Internal Medicine. Because enzyme immunoassay of the uterine cervical specimen in the Department of Urology showed positive chlamydial antigen, we suspected her of perihepatitis induced by Chlamydia trachomatis (Fitz-Hugh-Curtis syndrome). Laparoscopy revealed typical violin string adhesions between the anterior surface of the liver and the corresponding parietal peritoneum, and the diagnosis was confirmed. After an administration of Ofloxacin was started, the symptom disappeared completely. It is considered to be important to remember this syndrome when examining a young women with right hypochondralgia.

Adult↗
PubMed1992

[Five cases of Crow-Fukase syndrome].

We presented five cases of Crow-Fukase syndrome. Plasma cell hyperplasia or dyscrasia in bone marrow were recognized in all cases and localized bone lesion was seen in three cases. Thyroid dysfunction was seen in three cases; hyperthyroidism in one case and hypothyroidism in two cases, which was considered to be one of the characteristics though it has seldom been described in this disease. Two of four cases treated with prednisolone had good responses but two cases treated with interferon had no effect.

Adult↗
PubMed1992

[An experience of laser therapy of lung cancer complicated with hemophilia A].

We applied an endoscopic Nd-YAG laser therapy for an early hilar lung cancer complicated with hemophilia A in a patient of 62-year-old male. Abnormality was pointed out by means of sputum cytology. But, no shadow of tumor was observed by chest x-ray films and computed tomogram. By a bronchoscopy, a mild irregular mucomembrane and stenosis without tumor were exhibited. By means of cytological diagnosis of an abrasive-washing specimen of that region, the presence of squamous cell carcinoma was proved. Also, he was diagnosed as factor VIII deficient hemophilia A. So we performed him a laser therapy in place of the operation and with an intrabronchial arterial infusion. After the laser treatment, the conditions progressed better without any recurrence but about one and a half years later, an intrapulmonary metastasis occurred. Then, radiation and chemotherapy have been applied and at present, the patient is in a good state although under the tumor-bearing condition.

Carcinoma, Squamous Cell↗
PubMed1991

Rat angiotensin II receptor: cDNA sequence and regulation of the gene expression.

The nucleotide and amino acid sequences for rat type I angiotensin II receptor were deduced through molecular cloning and sequence analysis of its complementary DNAs. The rat angiotensin II receptor consists of 359 amino acid residues and has a sequence similar to G protein-coupled receptors. The expression of this receptor gene was detected in the adrenal, liver and kidney by Northern blotting. Sodium deprivation positively modulated the expression of the receptor gene in the adrenal. No detectable change was observed in the expression levels of this receptor gene between spontaneously hypertensive rats and Wistar-Kyoto rats in the tissues examined including the adrenal, brain, kidney and liver. Interestingly the expression of this receptor gene was developmentally regulated.

Amino Acid Sequence↗
PubMed1991

Cloning and expression of a complementary DNA encoding a bovine adrenal angiotensin II type-1 receptor.

Angiotensin II elicits different responses which affect cardiovascular, neuronal and electrolyte transport regulation. To understand the mechanisms responsible for its various actions, the receptor for angiotensin II has long been sought, but numerous attempts to purify the receptor have been unsuccessful owing to its instability and low concentration. We report here the expression cloning of a complementary DNA encoding a bovine angiotensin II receptor to overcome these difficulties. The receptor cDNA encodes a protein of 359 amino-acid residues with a transmembrane topology similar to that of other G protein-coupled receptors. COS-7 cells transfected with the cDNA expressed specific and high-affinity binding sites for angiotensin II, angiotensin II antagonist and a non-peptide specific antagonist for type-1 receptor. Dithiothreitol inhibited ligand binding. The concentration of intracellular Ca2+ and of inositol-1,4,5-trisphosphate increased in the transfected COS-7 cells in response to angiotensin II or angiotensin III, indicating that this receptor is the type-1 receptor for angiotensin II. Northern blot analysis revealed that the messenger RNA for this receptor is expressed in bovine adrenal medulla, cortex and kidney.

Adrenal Cortex↗
PubMed1991

A case of prominent hepatic cholestasis developing to hepatic failure in lambda-AL amyloidosis.

We report a case of lambda-AL amyloidosis which manifested prominent hepatic cholestasis. The patient was a 71-year-old Japanese male who was admitted to our hospital because of abdominal distension and jaundice. Laboratory examination revealed a marked deterioration of liver function with cholestasis. Gastric biopsy revealed amyloid deposition. Under a diagnosis of primary amyloidosis he was treated with corticosteroid and dimethylsulfoxide. However, jaundice progressed, renal function deteriorated rapidly, and he died two weeks after admission. Autopsy revealed a profound deposition of lambda-AL amyloid not only in the liver but also in the kidneys, spleen, lungs, heart and intestine.

Aged↗
PubMed1991

Giant metastatic VIPoma in the liver.

A case of giant metastatic liver VIPoma manifesting WDHA syndrome is described. The patient was a 33-year-old Japanese male who was admitted because of persisting watery diarrhea and weight loss. Laboratory examinations revealed marked hypokalemia, mild hypercalcemia and highly elevated plasma vasoactive intestinal peptide (VIP) and glucagon levels. Intensive imaging examinations disclosed two large tumors in the liver but not in other organs, including the pancreas. Laparoscopy disclosed a slightly elevated purplish-colored large tumor on the surface of the apparently normal liver. At operation, however, a small hard nodule was observed in the tail of the pancreas. Histologically, it was revealed to be a VIPoma resembling a carcinoid or an islet cell tumor, and was identical to the liver tumors. Thus, this neoplasm was considered to be a VIPoma of pancreatic origin, with metastatic lesions in the liver.

Adult↗
PubMed1991

[Subjective symptoms and blood findings in painters exposed to organic solvents].

Subjective symptoms and blood findings were studied in 16 construction workers and 30 vehicle repairmen using organic solvent and compared to 30 workers who were not exposed to organic solvents. A statistically significant increase was observed in the prevalence of subjective symptoms, serum phospholipid, lipoprotein fraction and IgE in construction workers and vehicle repairmen. A statistically significant decrease in neutrophils function was observed in construction workers.

Adolescent↗
PubMed1991

Structural analysis of repetitive DNA sequences in the goat growth hormone gene region.

Two clones that contain goat growth hormone (gGH) genes were isolated from goat genomic library using goat growth hormone cDNA as a probe. One clone CgGH contained gGH1 gene, and another clone, EgGH, contained gGH2 and gGH3 genes. The clone EgGH contained 491 bp inserted sequence, just upstream of the gGH3 gene, which was not present in the clone CgGH. From the sequencing data of the flanking regions of these gGH genes, short interspersed repetitive sequences (SINES) were found. Four SINES's existed in the CgGH clone and eight SINES's existed in the EgGH clone. The number of the repetitive DNA sequences in the goat genome was estimated about 10(2) copies from the analysis of the reassociation rate. As the number of gGH genes (gGH1, gGH2, and gGH3) per genome was different among individual goats, DNA fragments containing gGH1 gene, and that containing gGH2 and gGH3 genes, were estimated to be allelic on the goat chromosome.

Animals↗