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Biomedical subjects

S Sakurai

Publications and source records attributed to S Sakurai.

At least 19 recordsLinked to original sources
PubMed1996

Bombyxin gene expression in tissues other than brain detected by reverse transcription-polymerase chain reaction (RT-PCR) and in situ hybridization.

Bombyxin is a 5 kDa insulin-related peptide produced in four pairs of medial neurosecretory cells in the brain of the silkmoth Bombyx mori. We demonstrate here the presence of bombyxin mRNA in tissues other than brain: ganglia, epidermis, testis, ovary, fat body, silk gland, Malpighian tubule, midgut, and hindgut of the Bombyx fifth instar larvae. Bombyxin mRNA was detected by Oligotex reverse transcription-polymerase chain reaction (RT-PCR), a rapid and simple procedure of reverse transcription-PCR, and in situ hybridization. The Oligotex RT-PCR method effectively eliminated the contaminating DNA in RNA samples and amplified bombyxin mRNA efficiently. In situ hybridization of the Bombyx ovary clearly demonstrated the localization of the bombyxin mRNA in the ovariole. The present study is the first demonstration of expression of brain neurosecretory peptide in tissues other than the central nervous system in insects at RNA level.

Animals↗
PubMed1996

Hypertrophic neuritis due to chronic inflammatory demyelinating polyradiculoneuropathy (CIDP): a postmortem pathological study.

A postmortem pathological study of a 65-year-old woman with hypertrophic neuritis associated with hand tremor and limb ataxia is described. There were many onion bulbs and loss of myelinated nerve fibers in the peripheral nerves, including the facial and subserosal visceral nerves. The hypertrophic neuritis was caused by chronic inflammatory demyelinating neuropathy (CIDP), in which interstitial amorphous substances in the endoneurium and onion bulb formation might contribute to nerve swelling. We speculate that visceral autonomic nerves as well as somatic peripheral nerves are involved in patients with a long clinical CIDP course and that peripheral nerve pathology in this disorder shows more heterogeneous changes than previously recognized.

Aged↗
PubMed1996

Variations in ribosomal DNA and mitochondrial DNA among chromosomal species of subterranean mole rats.

Restriction site variations in nuclear ribosomal DNA (rDNA) spacers and mitochondrial DNA (mtDNA) were examined in several populations of mole rats with variable numbers of chromosomes, which represented the two superspecies Spalax leucodon (2n = 38, 54, or 62) and Spalax ehrenbergi (2n = 52, 54, 58, or 60). Sequence divergence of rDNA spacers between the members of the superspecies was approximately 8%, while the variation within each superspecies was 4% on average. The intrasuperspecies differentiation of rDNA spacers was generally associated with changes in the diploid number of chromosomes. However, substantial divergence (approximately 1.5%) was also detected among populations with the same diploid number of chromosomes. The sequence divergence of mtDNA among haplotypes of S. ehrenbergi was 10% or higher and among haplotypes of S. leucodon it was approximately 12%. By contrast, the range of sequence divergence between superspecies was 7.4%-12%. The large divergence of mtDNAs within each superspecies of mole rats may be explained by the preservation of ancient mtDNA polymorphisms.

Animals↗
PubMed1996

Association of restriction fragment-length polymorphisms in the alcohol dehydrogenase 2 gene with alcoholic brain atrophy.

Alcohol abuse can induce brain atrophy, but it only occurs in some alcoholics. To investigate whether genetic polymorphism of alcohol-metabolizing enzymes [including alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH)] was related to alcoholic brain atrophy, we determined restriction fragment-length polymorphisms of the ADH2 and ALDH2 genes in 77 male alcoholics. Computed tomography was used to determine the severity of brain atrophy. Digestion with MaeIII and MboII after polymerase chain reaction amplification showed that the ADH2(1) gene frequency was significantly higher in patients with brain atrophy than in those without brain atrophy (chi 2 = 9.274, p < 0.01), whereas no significant association was observed between brain atrophy and the ALDH2 gene Multivariate analysis (including age, total alcohol intake, liver cirrhosis, and ADH2 genotype) showed that the ADH2(1)/ADH2(1) genotype was associated with alcoholic brain atrophy. These findings suggest that the ADH2(1) allele may be associated with alcoholic brain atrophy.

Adult↗
PubMed1996

Nitric oxide induction by pertussis toxin in mouse spleen cells via gamma interferon.

We examined the major pathogenic substances of Bordetella pertussis for the ability to induce nitric oxide, and important biological function of macrophages, via gamma interferon in spleen cells. B. pertussis, which produces a variety of pathogenic substances, including pertussis toxin and filamentous hemagglutinin, causes a severe respiratory disease. Nitric oxide was detected in the culture fluid of spleen cells stimulated with pertussis toxin or its B oligomer but not in the culture fluid of spleen cells stimulated with the A protomer of pertussis toxin or with filamentous hemagglutinin. Incubation of the peritoneal exudate macrophages with pertussis toxin, B oligomer, A protomer, or filamentous hemagglutinin induced little nitric oxide, whereas incubation with gamma interferon induced a significant amount of nitric oxide. The induction of nitric oxide in spleen cells stimulated with pertussis toxin was completely inhibited by anti-gamma interferon antibody. The treatment of spleen cells with anti-Thy-1.2 antibody plus complement followed by stimulation with pertussis toxin decreased the secretion of gamma interferon and nitric oxide. These results suggest that gamma interferon from T lymphocytes stimulated with pertussis toxin induces nitric oxide.

Animals↗
PubMed1996

Rat 5S rDNA spacer sequences and chromosomal assignment of the genes to the extreme terminal region of chromosome 19.

Fragments of the spacer region of genes for rat 5S ribosomal RNA (rDNA), which are tandemly repeated, were amplified by PCR with primers specific to the two ends of the coding region for 5S rRNA. Two amplified fragments of approximately 1.6 kb were subcloned and sequenced. The spacer sequences showed a high degree of sequence identity to each other (99.2%) but substantial divergence from those of analogous mouse clones. The homologous regions in the mouse clones were interrupted by the duplication or deletion of small segments of DNA. A 12-mer, 5'-GGCTCTTGGGGC-3', thought to be responsible for efficient transcription, was located from position -33 to position -22 in the rat -5S clones. The genes were mapped by fluorescence in situ hybridization with cloned fragments of rat 5S rDNA as probe. The genes were localized exclusively in a single telomeric region of chromosome 19.

Animals↗
PubMed1996

Synthesis of [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives containing pyridyl or imidazolyl groups and their thromboxane A2 receptor antagonistic and thromboxane A2 synthase inhibitory activities.

As part of our search for a dual inhibitor possessing both thromboxane A2 (TXA2) receptor antagonistic and TXA2 synthase inhibitory activities, some [[(benzenesulfonamido)alkyl]phenyl]alkanoic acid derivatives possessing a pyridyl or imidazolyl group were synthesized. Their TXA2 receptor antagonistic and TXA2 synthase inhibitory activities were evaluated in terms of the inhibitory effects on U-46619-induced guinea-pig platelet aggregation and on thromboxane B2 (TXB2) production in human platelets, respectively. It was found that 3-[4-[2-(1-imidazolyl)-1-(4-chlorobenzenesulfonamido)ethyl]phenyl] propionic acid (22a), containing an imidazolyl group, is a well-balanced dual inhibitor having both TXA2 receptor antagonistic activity (IC50 = 0.31 microM) and TXA2 synthase inhibitory activity (IC50 = 0.39 microM).

Animals↗
PubMed1996

Synthesis and thromboxane A2 antagonistic activity of [[1-aryl(or benzyl)-1-(benzenesulfonamido)methyl]phenyl]alkanoic acid derivatives.

In order to find new antiasthmatic and antithrombotic agents, various [[1-aryl(or benzyl)-1-(benzenesulfonamido)methyl]phenyl]alkanoic acid derivatives were synthesized. Evaluation of these compounds for thromboxane A2 (TXA2) antagonistic activities indicated that 4-[4-[(4-chlorobenzenesulfonamido)phenylmethyl]phenyl]butyric acid (6h) ,4-[4-[1-(4-chlorobenzenesulfonamido)-2-phenylethyl]phenyl]butyric acid (6y) and many other compounds have potent inhibitory effects on U-46619-induced guinea-pig platelet aggregation. No significant difference in the inhibitory effect between (+)-6h and its antipode could be detected, although (+)-6h and its antipode could be detected, although (+)-6y was about 10 times more potent than (-)6y. The pKb values of 6h and 6y were estimated to be 8.9 and 10, respectively on U-46619-induced contraction of guinea-pig trachea as a pharmacological measure of TXA2 antagonistic activity. These compounds also showed potent inhibitory effects on U-46619-induced bronchoconstriction in guinea-pig after oral administration in vivo. They were also evaluated for other related pharmacological effects involving the arachidonic acid cascade. It was found that these compounds possess TXA2 synthase inhibitory activity together with TXA2 antagonistic activity, and 6h also possesses weak leukotriene D4 (LTD4) antagonistic activity. Structure-activity relationships for TXA2 antagonistic activity of these derivatives are discussed.

15-Hydroxy-11 alpha,9 alpha-(epoxymethano)prosta-5↗
PubMed1995

Gastric adenoma-carcinoma sequence with special reference to p53 and Ki-ras gene alterations.

With the aim of detecting the timing of p53 and Ki-ras gene alterations in the gastric adenoma-carcinoma sequence, 19 early gastric adenocarcinomas arising from adenomas were studied. Immunohistochemically, 5 adenocarcinomas were positive for p53; 3 focally and 2 diffusely. The p53 point mutations were detected in a focal area with p53 immunoreactivity in 2 of the 5 p53-positive adenocarcinomas. This indicated that p53 point mutations may play a less crucial part in malignant conversion of adenoma to adenocarcinoma in the stomach than in the colon. No Ki-ras gene mutations at codons 12 and 13 were detected in any lesion. These results suggest that the adenoma-carcinoma sequence in the stomach has a different mechanism from that in the colon.

Adenocarcinoma↗
PubMed1995

Association of a restriction fragment length polymorphism in the alcohol dehydrogenase 2 gene with Japanese alcoholic liver cirrhosis.

BACKGROUND/AIMS: The association of ADH2 polymorphisms with alcoholic liver cirrhosis has not been clearly demonstrated. METHODS: We investigated the association of two alleles in the ADH2 gene marked by restriction fragment length polymorphisms in patients with alcoholic liver cirrhosis. The ADH2 restriction fragment polymorphisms with Mae III were determined using the polymerase chain reaction on lymphocytes from 76 male Japanese alcoholics (non-cirrhotic patients; 34 cases, cirrhotic patients; 42 cases) and 60 healthy male subjects. RESULTS: The frequency of the ADH2(1)/ADH2(1) genotype was significantly higher in the alcoholics than in the healthy subjects p < 0.001). In the alcoholics, the genotype ADH2(2)/ADH2(2) was significantly more prevalent in the cirrhotic group than in the non-cirrhotic group (p < 0.05). CONCLUSIONS: These results suggest that the Mae III polymorphisms of the ADH2 gene may be associated not only with susceptibility to alcoholic liver cirrhosis, but also with the development of alcoholism in Japanese patients.

Adult↗
PubMed1995

Effects of systolic anterior motion of the mitral valve on haemodynamics. Evaluation by a direct method.

We evaluated the effects of systolic anterior motion systolic anterior motion of the mitral valve on cardiac haemodynamics. Seven adult mongrel dogs in which systolic anterior motion-septal contact was observed after dobutamine administration were used. To exclude the effects of left ventricular function and morphology, a stone removal basket catheter was placed in the left ventricular outflow tract, and haemodynamics were compared with the basket closed and opened. The basket was opened five times in three dogs not showing systolic anterior motion-septal contact, but the basket itself did not effect the haemodynamics. In the seven dogs that showed systolic anterior motion-septal contact without left ventricular hypertrophy, the basket was opened a total of 33 times in the presence of various degrees of systolic anterior motion-septal contact. After opening the basket, systolic anterior motion was reduced echocardiographically, and significant (P<0.01) changes were observed in the left ventricle-aorta pressure gradient (from 68 +/- 22 to 25 +/- 15 mm Hg), the systolic ejection period (from 146 +/- 19 to 135 +/- 16 ms), and the stroke volume (SV; from 9.4 +/- 2.9 to 10.1 +/- 3.3 ml). After basket inflation, aortic pressure and aortic flow waveforms changed but the peak pressure and flow velocity did not. The temporal distribution of left ventricular ejection also definitely changed after the basket was opened. No changes were observed in the peak dp/dt, peak negative dp/dt, time constant, left ventricular end-diastolic pressure, or left atrial pressure. These observations in this animal model of systolic anterior motion without left ventricular hypertrophy suggest that: (1) there is no potential for generation of an intra-cavity gradient in the absence of systolic anterior motion of the mitral valve, so that (2) systolic anterior motion narrowed the left ventricular outflow tract and, consequently, produced the systolic ejection period, and affected the left ventricular ejection dynamics, and that (3) the basket catheter is useful because it allows these assessments in the same heart with a nearly fixed left ventricular contractility, at least in our animal model.

Animals↗
PubMed1995

Superantigenic exotoxin production by isolates of Staphylococcus aureus from the Kawasaki syndrome patients and age-matched control children.

Nineteen strains of Staphylococcus aureus were isolated from the throat or the tooth surfaces of 19 cases amongst 127 patients with Kawasaki syndrome (KS) during the acute phases and 11 S. aureus isolates were obtained from five of 17 diseased controls and six healthy controls. The production of exotoxins, particularly superantigenic toxic shock syndrome toxin-1 (TSST-1), coagulase serotype, pigment production, haemolytic activity and tryptophan auxotrophy of these isolates were compared. Among 10 KS S. aureus strains isolated in 1990-1991, five (50%) secreted TSST-1, a higher frequency than two (18%) of 11 control isolates. In contrast, none of the nine KS strains collected in 1984 produced TSST-1. Four of five TSST-1-secreting KS strains produced white or white to golden pigmentation, whereas the two control strains capable of TSST-1 production formed golden colonies. There were no noticeable differences between S. aureus strains from KS patients and control children in the production of staphylococcal exotoxins A-E, coagulase serotype, haemolysis of sheep erythrocytes and tryptophan auxotrophy. The pathological or aetiological role of a new TSST-1-secreting S. aureus clone in patients with KS was not confirmed.

Bacterial Toxins↗
PubMed1995

Rapid identification by polymerase chain reaction of staphylococcal exfoliative toxin serotype A and B genes.

A new system was designed to detect staphylococcal exfoliative toxin A (ETA) and B (ETB) genes by the polymerase chain reaction (PCR). The primer pairs for the ETA gene (eta) were 20 and 20-mer, and its PCR product was a 741-bp eta fragment, while the primer pairs for the ETB gene (etb) were also 20 and 20-mer, and its PCR product was a 629-bp etb fragment. When these primers were simultaneously used in the PCR, the two types of ET were clearly detected as two bands in an ETA and ETB double-producer using only one colony within 3 hr. We examined 66 strains of Staphylococcus aureus isolated from patients with staphylococcal scalded skin syndrome (SSSS) and compared the results obtained by ELISA and PCR. The same results were obtained for 56 of the strains, i.e., 30 strains were ETA producers, 20 strains were ETB producers, and 6 strains were double-producers. However, positive results were obtained for 5 of the 10 non-ET-producing strains. Two of these strains were judged by PCR as ETA producers and three as ETB producers. Thus, PCR is very sensitive and rapid in detecting ETA and ETB gene fragments in colonies isolated from patients with SSSS.

Base Sequence↗
PubMed1995

Prognosis of epilepsy withdrawn from antiepileptic drugs.

Antiepileptic drugs (AED) were discontinued in 55 epileptics who had been free from seizures treated with AED, in accordance with the following criteria and procedures. (i) A reduction in AED commences when patients have been free from seizures for at least 2 years and epileptic discharges have also disappeared in repeated electroencephalogram (EEG) recordings during that period. (ii) AED are gradually reduced if no relapse is seen in clinical seizures and epileptic discharges in EEG. (iii) As a rule at least 2 years are required as the interval from the onset of a reduction to the withdrawal of AED. Forty-three patients were followed up by a questionnaire and/or by telephone and the follow-up period from the withdrawal of AED to the survey ranged from 0.9 to 8.8 years; in 38 patients (88.4%) the period was longer than 2 years. No relapse of seizures was found in any of the 43 patients. The severity of epilepsy judged by the total number of frequency of seizures, the presence of neuropsychiatric complications, the combination of different types of seizures, and the duration of epilepsy from the seizure onset to the last seizure appeared not to be risk factors for the recurrence of seizure. Normal EEG was, however, considered to be an important prerequisite for a good prognosis.

Adolescent↗