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Biomedical subjects

T Sakai

Publications and source records attributed to T Sakai.

At least 397 records · Page 22Linked to original sources
PubMed1999

Purification and characterization of an endo-polygalacturonase from a mutant of Saccharomyces cerevisiae.

An extracellular endo-polygalacturonase (PGase) produced by a mutant of Saccharomyces cerevisiae was isolated. The enzyme was regarded, immunologically, as a PGase belonging to the Kluyveromyces marxianus group. The enzyme had properties similar to the PGase from K. marxianus in heat and pH stability, and N-terminal amino acid sequence. However, the enzyme showed different properties in optimum pH and temperature, molecular weight, and reactivity in antiserum against PGase from K. marxianus, indicating that the enzyme has a different molecular structure from the PGase from K. marxianus.

Antibodies, Monoclonal↗
PubMed1999

Cloning and sequencing of a bottle-nosed dolphin (Tursiops truncatus) interleukin-1alpha and -1beta complementary DNAs.

The bottle-nosed dolphin (Tursiops truncatus) IL-1alpha and IL-1beta cDNA were cloned from mitogen stimulated peripheral blood mononuclear cells (PBMC) RNA utilizing the reverse transcription-polymerase chain reaction (RT-PCR). The sequences of these cDNAs showed that dolphin IL-1alpha and IL-1beta clones contained open reading frames encoding 265 and 266 amino acids, respectively. Comparison of the deduced amino acid showed that dolphin IL-1alpha sequence shared 77, 77, 77, 74, 71, 65 and 57% similarity with the bovine, ovine, porcine, equine, feline, human and mouse IL-1alpha sequences, respectively. Similarly, the amino acid sequence showed that dolphin IL-1beta shared 77, 77, 74, 69, 65, 64 and 63% similarity with the bovine, ovine, porcine, equine, feline, human and mouse IL-1beta sequences, respectively. The relatedness of dolphin IL-1alpha and IL-1beta were relatively distant with 21% amino acid homology.

Amino Acid Sequence↗
PubMed1999

Cloning and sequencing of a bottle-nosed dolphin (Tursiops truncatus) interleukin-4-encoding cDNA.

Using polymerase chain reaction (PCR), a bottle-nosed dolphin (Tursiops truncatus) interleukin-4 (IL4) cDNA was cloned and sequenced. IL4 specific primers were based on the 5' and 3' untranslated regions of the human and murine IL4 gene. The dolphin IL4 cDNA is 528 base pairs in length and contains an open reading frame of 402 nucleotides coding an IL4 precursor of 133 amino acids, with the putative signal peptide of 24 amino acids. Analysis of the mature amino acid sequence shows three potential N-linked glycosylation sites and three disulfide bonds. Comparison of the predicted amino acid sequence shows that dolphin IL4 shares 77, 74, 58 and 41% identity with the bovine, ovine, human and mouse IL4s, respectively.

Amino Acid Sequence↗
PubMed1999

Cloning and sequencing of the bottle-nosed dolphin (Tursiops truncatus) interferon-gamma gene.

The bottle-nosed dolphin (Tursiops truncatus) interferon-gamma(IFN-gamma) cDNA was cloned from mitogen stimulated peripheral blood mononuclear cells (PBMC) RNA utilizing the reverse transcription-polymerase chain reaction (RT-PCR). The dolphin IFN-gammacDNA was 585 base pairs in length and contained an open reading frame of 498 nucleotides encoding an IFN-gammaprecursor of 166 amino acids, with cleavage of the putative signal peptide of 19 amino acids. Analysis of the mature amino acid sequences revealed two potential N-linked glycosylation sites. Comparison of the predicted amino acid sequence showed that dolphin IFN-(gamma)shares 86, 85, 63 and 42% similarity with the bovine, ovine, human and mouse IFN-gamma, respectively.

Amino Acid Sequence↗
PubMed1999

Point nucleotidic changes in both the RET proto-oncogene and the endothelin-B receptor gene in a Hirschsprung disease patient associated with Down syndrome.

A short-segment Hirschsprung disease (HSCR) patient associated with 21 trisomy showing point nucleotidic changes in both the receptor tyrosine kinase (RET) proto-oncogene and the endothelin-B receptor (EDNRB) gene is reported. A T to A heterozygous transition at the splicing donor site of the intron 10 in the RET proto-oncogene, and a G to A heterozygous substitution in non-coding region in the exon 1 of the EDNRB gene were observed. The familial analysis with these genes revealed that the origin of the former mutation was de novo and the latter one was maternal. No patient has been reported with two points mutations in different pathogenetically susceptible loci for HSCR. There is genetic evidence that the RET and EDNRB genes may interact in their susceptibility leading to HSCR.

Down Syndrome↗
PubMed1999

A controlled trial of combined therapy for newly diagnosed severe childhood IgA nephropathy. The Japanese Pediatric IgA Nephropathy Treatment Study Group.

The most appropriate treatment for patients with IgA nephropathy is controversial. Treatment with prednisolone, azathioprine, heparin-warfarin, and dipyridamole early in the course of disease may prevent immunologic renal injury in children with severe IgA nephropathy. To determine whether similar results can be obtained with a combination of just heparin-warfarin and dipyridamole, the effects of such treatment were compared to those of treatment with prednisolone, azathioprine, heparin-warfarin, and dipyridamole in 78 children with newly diagnosed IgA nephropathy showing diffuse mesangial proliferation. The patients were randomly assigned to receive either prednisolone, azathioprine, heparin-warfarin, and dipyridamole for 2 yr (group 1) or heparin-warfarin and dipyridamole for 2 yr (group 2). All of the 40 patients in group 1 and 34 of the 38 patients in group 2 completed the trial. The mean urinary protein excretion fell in group 1 patients (P < 0.0001), but remained unchanged in group 2 patients. The mean serum IgA concentration was reduced in group 1 patients (P = 0.0002), but was unchanged in group 2 patients. BP and creatinine clearance were normal at the end of the trial in all but one group 2 patient, who developed chronic renal insufficiency. The percentage of glomeruli showing sclerosis was unchanged in group 1 patients, but increased in group 2 patients (P = 0.006). The intensity of mesangial IgA deposits decreased in group 1 patients (P = 0.02), but remained unchanged in group 2 patients. In conclusion, the present study shows that treatment of children with severe IgA nephropathy with prednisolone, azathioprine, heparin-warfarin, and dipyridamole for 2 yr early in the course of disease reduces immunologic renal injury and prevents increase of sclerosed glomeruli.

Adolescent↗
PubMed1999

Age-dependent changes in the distribution of BrdU- and TUNEL-positive cells in the murine gingival tissue.

BACKGROUND: Age-dependent morphological and cell kinetic changes of the gingival tissue seem to be related to the occurrence of periodontal disease. The purpose of this study was to investigate the age-dependent changes in the distribution of BrdU- and TUNEL-positive cells in murine gingival tissue. METHODS: Gingival tissue of the lower first molar region of 2-, 3-, 5-, 7-, 10-, 15-, 20-, 30-, 40-, 50-, 60-, 70- and 80-week-old mice was used in this study. BrdU- and TUNEL-positive cells were evaluated at the following 4 sites: 1) gingival epithelium (GE); 2) junctional epithelium (JE); 3) submucosal connective tissue of the gingival epithelium (GECT); and 4) submucosal connective tissue of the junctional epithelium (JECT). RESULTS: No significant differences in the mean number of BrdU-positive cells at each site were demonstrated among the various age groups. No significant change in the mean number of TUNEL-positive cells was demonstrated in either the GE or JE groups among the various age groups. Meanwhile, a significant increase in the TUNEL-positive cells was observed in the GECT of mice 40 weeks or older, and in the JECT of mice 20 weeks or older. CONCLUSIONS: These results indicate that no age-dependent change in the cell proliferation or cell death occurred in the gingival and junctional epithelial layers as well as in the cell proliferation in the submucosal connective tissue. Meanwhile, a significant decrease in the cellular component of the submucosal connective tissue of both gingival and junctional epithelial layers caused by apoptosis occurred with aging. The decreased cellular component in the submucosal connective tissue thus seems to be related to either gingival recession or to the apical migration of the JE with aging. These morphological changes with aging possibly occur in humans and may be related to the susceptibility to periodontal disease in aged individuals.

Aging↗
PubMed1999

Hemolytic uremic syndrome associated with immunoglobulin A nephropathy: a case report and review of cases of hemolytic uremic syndrome with glomerular disease.

A 35-year-old man with immunoglobulin A (IgA) nephropathy who developed hemolytic uremic syndrome (HUS) presented with transient elevation of serum creatinine, thrombocytopenia, and hemolytic anemia with fragmented red cells with nephrotic syndrome. Hemolytic anemia and the temporarily deteriorated renal function were improved after hemodialysis and plasma exchange. Histological findings were consistent with HUS and IgA nephropathy. Including this case, we reviewed the cases of HUS accompanied by glomerular diseases reported from 1969 to 1996. Surprisingly, most cases showed nephrotic syndrome at the onset of HUS. Several possible relationships between HUS and nephrotic syndrome are discussed.

Adult↗
PubMed1999

EM2487, a novel anti-HIV-1 antibiotic, produced by Streptomyces sp. Mer-2487: taxonomy, fermentation, biological properties, isolation and structure elucidation.

For the purpose of discovering novel agents that inhibit HIV-1 replication at the transcriptional level, we have established cell lines reflecting the HIV-1 long terminal repeat-driven gene expression. Using these cell lines, we have screened approximately 10,000 microorganism products and found that the culture supernatant of Streptomyces sp. Mer-2487 suppresses the HIV-1 Tat-induced gene expression without affecting the basal or tumor necrosis factor-alpha-induced transcription. The purified active component has a unique structure, as shown in Fig. 1. This compound has an inhibitory effect on HIV-1 replication in chronically infected cells as well as acutely infected cells, suggesting that the inhibition occurs at a postintegration step of HIV-1 proviral DNA in the HIV-1 replication cycle.

Anti-Bacterial Agents↗
PubMed1999

[Characteristics of anti-microbial agents and its clinical choice for H. pylori treatment].

Eradication of Helicobacter pylori (H. pylori) is now established as main treatment of upper-gastrointestinal diseases. Resistance to H. pylori and acid condition in the stomach were important factors which influenced H. pylori eradication. Recolonized H. pylori strains will be easily resistant to metronidazole and clarithromycin, whereas almost all of H. pylori strains are sensitive to amoxicillin. On the other hand, amoxicillin targets cell wall biosynthesis and clarithromycin inhibits protein synthesis of Helicobacter pylori mainly in the growth phase which induced high intragastric pH condition, however, metronidazole targets DNA and, therefore, is independent of the stationary or growth phase distribution. To established a optimal regimen for Helicobacter pylori treatment, several factors included them should be account according to the parmacokinetical standings.

Anti-Bacterial Agents↗
PubMed1999

[Expression of hepatocyte growth factor by activated eosinophiles in inflammatory lung tissue].

Hepatocyte growth factor (HGF) plays a multifunctional role in the regeneration of alveolar type-II and other epithelial cells. HGF is produced by various kinds of mesenchymal cells, including polymorphonuclear granulocytes. However, it was not evident that eosinophiles produce HGF. In this investigation, we utilized immunohistochemical techniques to show that Eol-1 cells, an eosinophilic leukemia cell line, as well as activated eosinophiles in inflammatory lung tissue, produce HGF. It was also shown that IL-5 induced the production of HGF by peripheral eosinophiles in vitro. These findings suggest that, in inflammatory lung diseases, eosinophiles activated in the presence of IL-5 produce not only tissue-injurious substances (e.g., eosinophilic cationic protein, major basic protein, and peroxidase) but also HGF; and that eosinophiles may play a role in the regeneration of injured lung tissue through the production of HGF.

Cells, Cultured↗
PubMed1999

[Expression of brain-derived neurotrophic factor gene in retina following vitreous tap].

PURPOSE: Mechanical injuries to the retina following vitreous tap are reported to protect photoreceptor cells in a rat model of the retinal degeneration and enhance the survival rate of retinal ganglion cells in the optic nerve transection. Neurotrophic factors are presumably involved in the protective mechanisms. In order to see whether neurotrophic factors are synthesized in the retina, we studied the expression of neurotrophic factors in the retina following vitreous tap in rats. MATERIALS AND METHODS: One eye each of 20 mature rats received transscleral vitreous taps at three points of entry and retinal injury. The retinas were removed and examined at day 0 to 14 of treatment. RESULTS: Following injury, the retina showed increased expression of glial fibrillary acidic protein (GFAP) mRNA and brain-derived neurotrophic factor (BDNF) mRNA. There was no enhancement of neurotrophin-3 (NT-3) mRNA when examined by reverse transcription-polymerase chain reaction (RT-PCR). CONCLUSIONS: Activated retinal glial cells may produce BDNF which prevents retinal neuronal cell damage following injury.

Animals↗
PubMed1999

[Assessment of adrenal function on steroid using renal diseases in children using the modified original ACTH tolerance test: comparing nephrotic syndrome with non-nephrotic syndrome].

Steroid therapy occupies a very important position in various types of kidney diseases in children. The period of steroid therapy in kidney disease tends to extend over a long time and the amount of medication tends to be high. Inhibition of the adrenal function because of steroid therapy is one of the major side effects requiring considerable care. In the present investigation, we examined the inhibition of adrenal function in various pediatric renal diseases using synthetic ACTH. In this study, we checked the serum 11-OHCS and cortisol levels and found that in nephrotic syndrome, the inhibition already existed at sideration. In other diseases we found inhibition of adrenal function using steroid and improvement of the function on reduction of the steroid dose. Patients who used steroid every other day showed better improvement. Therefore, we suggest that in nephrotic syndrome, the inhibition of adrenal function may participate in sideration in the syndrome. It was also found that reduction of the steroid given every other day inhibited the adrenal function to a lesser extent. We found that our challenge test using ACTH is safe and very useful for determining adrenal function.

Adolescent↗
PubMed1999

[Postoperative recurrent laryngeal nerve palsy following a transesophageal echocardiography].

The postoperative recurrent laryngeal nerve palsy (RLNP) following transesophageal echocardiography (TEE) was retrospectively evaluated in 175 adult patients after cardiac surgery. The incidence of RLNP was not significantly different between TEE group and non TEE group, but the incidence in female TEE group was higher than that in female non TEE group. The mechanism of RLNP following TEE as well as the insertion of nasogastric tube may be compression injuries of the branches of the posterior division of the recurrent laryngeal nerves. The incidence of RLNP in female TEE group was higher because of the narrow female larynx. TEE is a useful monitor during cardiac surgery, but we must be careful about RLNP following TEE.

Aged↗
PubMed1999

Complete DNA sequence analysis for 16S ribosomal RNA gene of the leproma-derived, cultivable and nerve-invading mycobacterium HI-75.

The complete 1493 nucleotide sequence of the 16SrRNA gene of the leproma-derived and cultivable mycobacterium HI-75 strain was analyzed to elucidate the taxonomic characteristics by direct sequencing of the polymerase chain reaction (PCR) products. The results revealed that the sequence of mycobacterium HI-75 was mostly similar to that of Mycobacterium scrofulaceum with 5 bases differences in the sequenced 1493 bases (0.35%) of the 16SrRNA gene. M. leprae differed from the strain with 47 bases (3.3%). Sasaki and Hamit reported the nerve-invasive activity of the inoculated mycobacterium HI-75 in nude mice or the 131I-treated immunocompromised Swiss mice. The results indicate that mycobacterium HI-75 could be a mutant of M. scrofulaceum possessing the ability to invade the peripheral nerve in addition to developing leproma-like lesions.

Base Sequence↗
PubMed1999

[Emergency coronary artery bypass grafting for acute coronary syndrome].

Between 1987 and 1998, 22 patients underwent emergency coronary artery bypass grafting for the treatment of acute coronary syndrome. Overall hospital mortality was 22.7% (5/22) versus 1.8% (9/501) in patients operated on electively (p < 0.01). There were no hospital deaths in the unstable angina group. Three patients (37.5%) in the myocardial infarction group and two patients (40%) in the failed catheter intervention group died due to postoperative low cardiac output syndrome (LOS) or mediastinitis. As a complication of mechanical supports, lower extremity ischemia was a risk factor for mortality. Postoperatively six patients (27.3%) had LOS. Univariate analyses showed that age greater than 70 years, old myocardial infarction, poor ejection fraction, preoperative shock, and left main trunk or three vessel disease were significantly associated with increased LOS. To improve the surgical results, it is considered that improvement of intraoperative myocardial protection, effective combination with catheter interventional therapy and careful use of mechanical supports are needed for these compromised patients.

Adult↗