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Biomedical subjects

S Yamazaki

Publications and source records attributed to S Yamazaki.

At least 307 records · Page 17Linked to original sources
PubMed1994

[Blind duplication of the ureter. Apropos of a case].

The authors report on a case of a 24 year-old man with a double-blind duplication of the ureter, which was diagnosed in the workup of a microscopic hematuria. The patient who had no symptoms and a normal renal function has been followed up at regular intervals. The diagnosis of this malformation is difficult as long as it is asymptomatic and does not affect the excretory function.

Adult↗
PubMed1994

General pharmacological properties of the human corticotropin-releasing hormone corticorelin (human).

General pharmacological effects of the human corticotropin-releasing hormone, corticorelin (human) (CAS 86784-80-7), on the central nervous system, somatic nervous system, autonomic nervous system and smooth muscle, respiratory and circulatory system, digestive system and miscellaneous organs were investigated. 1. The central nervous system: Corticorelin (human) had little effect on hexobarbital-induced sleeping-time, maximal electroshock-induced convulsion, acetic acid-induced writhing, rota-rod performance. Corticorelin (human) at doses of more than 10 micrograms/kg i.v. induced flush of skin and pilo-erection, at doses of more than 30 micrograms/kg i.v. decreased body temperature, delayed expression of perphenazine-induced catalepsy and indicated hunched posture, and at the dose of 100 micrograms/kg i.v. induced the rise of awake-level and decrease of the total power of EEG, and decreased the spontaneous motor activity. 2. The somatic nervous system: Corticorelin (human) did not cause muscle relaxation in mice and had little effect on neuromuscular transmission in rats. No local anesthetic activity of corticorelin (human) was exhibited through inhibition of the corneal reflex in guinea pigs. 3. The autonomic nervous system and smooth muscle: Corticorelin (human) had no effect on the contraction of isolated ileum of guinea pigs induced by histamine and acetylcholine, and on the contraction of isolated trachea of guinea pigs induced by histamine, and the pupil diameter of rabbits. Corticorelin (human) at doses more than 30 micrograms/kg i.v. decreased spontaneous motility and contractile force of uterus of non-pregnant rabbits. 4. The respiratory and circulatory system: Corticorelin (human) had no effect on the contraction of isolated aorta of rats induced by norepinephrine. Corticorelin (human) at doses of more than 3 micrograms/kg i.v. decreased the blood pressure, increased heart rates and slightly increased the number of respiration in dogs. However, corticorelin (human) had no effect on ECG and femoral blood flow in dogs. 5. The digestive system: Corticorelin (human) at doses of more than 0.3 microgram/kg i.v. increased duodenal motility and contractile force, at doses of more than 1 microgram/kg i.v. increased colonic contractile force transiently and increased antral motility. Corticorelin (human) at doses of more than 3 micrograms/kg i.v. caused diarrhea and at doses of more than 30 micrograms/kg i.v. inhibited small intestinal propulsion in mice. Corticorelin (human) at dose of 100 micrograms/kg i.v. showed an inhibition of the gastric juice secretion and decreased the excretion of Na+, Cl- and H+ in rats. Corticorelin (human) produced slight gastric damages only at the highest dose of 100 micrograms/kg i.v.(ABSTRACT TRUNCATED AT 400 WORDS)

Animals↗
PubMed1994

[Ventricular endoaneurysmorrhaphy for the left ventricular aneurysm after myocardial infarction: technique and left ventricular function].

A 54-year-old male with a left ventricular aneurysm and angina after myocardial infarction underwent Cooley's ventricular endoaneurysmorrhaphy with single coronary artery bypass grafting. On cardiopulmonary bypass, an elliptial Dacron felt patch was fashioned to replace the diseased area in the left ventricular cavity, restoring normal shape, contour and volume to the ventricule and stabilizing the still viable and functioning myocardium, and sutured to transition zone between viable myocardium and the fibrotic scarred area. At this time, single coronary bypass grafting (LITA to diagonal branch) was done. His post operative course was uneventful. The left ventricular systolic and diastolic function improved significantly in each variable measured on left ventriculogram analysis.

Cardiac Surgical Procedures↗
PubMed1993

Serotonin in the raphe nuclei: regulation by light and an endogenous pacemaker.

Temporal changes of serotonin (5-HT) content in the median (MRN) and dorsal (DRN) raphe nuclei were measured in rats kept under various lighting conditions. Serotonin content in the MRN and DRN under light-dark (LD) condition showed diurnal rhythmicity, with a peak during early light phase and a trough during the dark phase. In constant dark (DD) condition, a single peak was observed and was out of phase to the 5-HT peak found under LD condition. Animals exposed to constant light (LL) after 2 days in DD showed marked increase in 5-HT after lights on. These results suggest that changes in 5-HT in the MRN and DRN are regulated by an endogenous pacemaker and by light.

Analysis of Variance↗
PubMed1993

Substance P-like immunoreactivity in the suprachiasmatic nucleus of the rat.

The content of substance P (SP)-like immunoreactivity (LI) within the suprachiasmatic nucleus (SCN) of rats was determined by enzyme immunoassay to evaluate the effect of light on SP-LI in the rat SCN. Male rats were kept under various lighting conditions: light-dark cycles, constant darkness, continuous light exposure for 24 h or light pulse interrupting constant darkness. Animals were also subjected to ocular enucleation. The present study showed that SP-LI in the SCN was unaffected by environmental lighting conditions or by bilateral ocular enucleation. Immunohistochemical studies also confirmed that SP immunoreactivity, which was found in the ventrolateral (VL) subdivision of the SCN, was not reduced significantly even after ocular enucleation. These results suggest that, in contrast to other neurotransmitters in the VL portion of the SCN such as vasoactive intestinal polypeptide (VIP), gastrin releasing peptide (GRP) and neuropeptide Y (NPY), SP level in the SCN is quite stable to light and arises from an area other than the retina.

Animals↗
PubMed1993

Independent introduction of two major HIV-1 genotypes into distinct high-risk populations in Thailand.

To investigate the genetic heterogeneity and epidemiological distribution of human immunodeficiency virus type 1 (HIV-1) in Thailand, we determined proviral sequences for 63 HIV-1-infected patients in various risk groups from all over the country between April and July, 1991. Two distinct genotypes of HIV-1, A and B, were found to segregate by mode of transmission. Of 29 sexually infected patients, 25 (86%) had HIV-1 of genotype A and 4 (14%) had genotype B. Among 29 injecting drug users, probably parenterally infected, only 7 (24%) had genotype A and 22 (76%) had genotype B. This segregation is unlikely to have arisen by chance (p < 0.001). No patient was found to have dual infection. Nucleotide divergence averaged 3.4% among genotype-A-infected patients and 3.5% among genotype-B-infected patients, but 22.0% between the genotypes. 37 of 40 isolates (both genotypes) had the GPGQ tetrapeptide at the tip of the V3 loop, which is common in African HIV-1 strains but rare in North American and European strains, where the GPGR motif predominates. These findings suggest that the waves of HIV-1 infection in injecting drug users and in sexually infected patients in Thailand may not be epidemiologically linked. The nucleotide divergence data point to the separate introductions of the two genotypes in Thailand. Further studies in Thailand and neighbouring countries will be useful in the design and selection of candidate HIV vaccines.

Amino Acid Sequence↗
PubMed1993

Effects of (S)-alpha-fluoromethylhistidine and (R)-alpha-methylhistamine on locomotion of W/Wv mice.

We studied the effects of inactivators of the central histaminergic neuron system, (R)-alpha-methylhistamine, a histamine H3 receptor agonist, and (S)-alpha-fluoromethylhistidine, a histamine synthesis inhibitor, on locomotor activity and brain histamine content of mast cell-deficient W/Wv mice using a recently developed high-performance liquid chromatography system coupled with a fluorometric detector. IP injection of (R)-alpha-methylhistamine (6-50 mg/kg) increased brain histamine content after 1 h but caused no significant change in locomotor activity. IP injection of (S)-alpha-fluoromethylhistidine decreased brain histamine content at doses of 6-50 mg/kg and locomotor activity at doses of 12.5-50 mg/kg. However, locomotor activity was decreased significantly (in Student's t-test) by sequential administrations of (S)-alpha-fluoromethylhistidine (6 mg/kg) and (R)-alpha-methylhistamine (12.5 or 25 mg/kg), but not by (S)-alpha-fluoromethylhistidine (6 mg/kg) and other doses of (R)-alpha-methylhistamine (6 or 50 mg/kg). These results support the hypothesis that the central histaminergic neuron system is involved in the control of spontaneous locomotion or alertness.

Animals↗
PubMed1993

Differentiation of mumps vaccine strains from wild viruses by single-strand conformation polymorphism of the P gene.

The DNA fragments amplified through the polymerase chain reaction from part of the P gene of four mumps vaccine strains (Urabe, Torii, Hoshino and Miyahara) were subjected to single-strand conformation polymorphism (SSCP) analysis. These four vaccine strains were differentiated from each other. Furthermore, twelve wild viruses and a laboratory strain (Enders strain) were also distinguished by this method. Viruses isolated from patients who developed aseptic meningitis 4 to 6 weeks after measles-mumps-rubella vaccination showed identical SSCP patterns with the vaccine strain used for immunization. These results were well correlated with sequence analysis of P-gene segments, indicating high applicability of the SSCP analysis for differentiation of mumps vaccine strains not only from each other but from wild viruses.

DNA, Single-Stranded↗
PubMed1993

Importance of the proline-rich region following signal-anchor sequence in the formation of correct conformation of microsomal cytochrome P-450s.

A proline-rich region is present following the signal-anchor sequence in the amino-terminal portion of all known microsomal cytochrome P-450s. To assess the functional significance of the proline residues in this region, we systematically altered these residues of cytochrome P450(M1) (P450 2C11); one, two, and three proline residues out of the five in the region were exchanged for alanine residues. The wild-type and the mutated proteins were expressed in the fission yeast Schizosaccharomyces pombe under the control of nmt1 promoter. The wild-type and the mutated proteins were all highly expressed in the yeast cells (5-9% of the total membrane protein). The expressed wild-type P450(M1) showed a typical carbon monoxide difference spectrum of P-450 and the activity of testosterone hydroxylation, whereas all the mutated proteins constructed in the present study showed no characteristic P-450 spectrum, suggesting that the substitution of the proline residues in this region resulted in a defect of proper heme incorporation. Furthermore, the mutated proteins in which more than one proline residues had been exchanged were more sensitive to trypsin digestion than the wild type. From these results, we propose that the proline residues in the proline-rich region are crucial for the formation of the correct conformation of microsomal P-450 molecules.

Amino Acid Sequence↗
PubMed1993

Acral ichthyosiform mucinosis in association with Sjögren's syndrome: a peculiar form of pretibial myxedema?

Two Japanese women developed well-demarcated ichthyosiform plaques on the lateral aspect of their lower legs. Deposition of mucin was demonstrated throughout the papillary dermis, unlike the site of mucin deposition seen in pretibial myxedema. Their thyroid function was normal. The condition of both women was complicated by Sjögren's syndrome. One of them who presented with positive anti-microsomal and anti-thyroglobulin antibodies had goiter, suggesting that her malady was also complicated by Hashimoto's thyroiditis. Their skin manifestations differed from those described in cutaneous mucinosis including pretibial myxedema, specifically with regard to the well-demarcated ichthyosiform appearance, the mucin deposition in the papillary dermis, and the association with Sjögren's syndrome. To the best of our knowledge, our cases may thus be considered to be a previously undescribed form of cutaneous mucinosis associated with Sjögren's syndrome.

Adult↗
PubMed1993

Linear lichen planus mimicking creeping eruption.

A 42-year-old woman was referred to our hospital with a linear eruption on her right flank of two months duration. Because she had eaten loach-fish a month before she noticed the eruption, a creeping eruption due to Gnathostoma spp. was initially suspected, but the histological findings of the biopsy specimens showed typical features of lichen planus. Linear lichen planus is discussed based on the cases accumulated in the literature regarding the distribution of Blaschko lines.

Adult↗
PubMed1993

Giant mucocele of oral cavity as a mucocutaneous manifestation of Sjögren syndrome.

Two cases of Sjögren syndrome who developed a giant mucocele on the floor of the oral cavity are reported. Histological analysis revealed the dense infiltration of lymph-plasmacytic infiltration around the dilated salivary duct. Similar findings were observed in the biopsied specimens of the labial salivary gland which were consistent with the grade 4 score proposed by Chisholm and Mason's criteria. Mucocele is a common mucocutaneous disease of unknown etiology except for traumatic origin and Sjögren syndrome might be one of the important underlying disease which causes giant mucocele, especially in elderly female patients.

Adult↗
PubMed1993

Japanese patients with chronic fatigue syndrome are negative for known retrovirus infections.

Although chronic fatigue syndrome (CFS) is known to be the syndrome that begins with an acute flu-like illness that may be due to the exposure to an infectious agent, there has been no convincing evidence on the causative agents. Recently, human T-lymphotropic virus type II (HTLV-II)-like virus has been reported to be associated with the CFS by using HTLV Western blot analysis and polymerase chain reaction. However, some investigators could not detect HTLV-II by indirect immunofluorescence analysis. Lately, CFS patients have been reported in Japan. We detected all 30 tested patients with CFS were seronegative for HTLV-II, HTLV-I and HIV by specific peptide ELISA and Western blot. Further, PCR analysis was negative for HTLV-II and retrovirus was not detected by coculture method with patients' PBMC. Thus, known human retrovirus infections do not cause a CFS in Japan.

Blotting, Western↗