Biomedical subjects

A Adachi

Publications and source records attributed to A Adachi.

At least 55 records · Page 3Linked to original sources

PubMed2000

Studies on defatted seed removal efficiency for organochlorine compounds.

Defatted seeds were evaluated for effective adsorption of organochlorine compounds such as chloroform, dichloromethane, and trichloroethylene. The amounts of these compounds adsorbed were plotted against the equilibrium concentration of substances in solution on a logarithmic scale. A linear relationship was obtained, indicating that the adsorption reactions were of the Freundlich type. The removal of these organochlorine compounds by defatted seed was attributed to the uptake by intracellular particles called spherosomes.

Dose-Response Relationship, Drug↗

PubMed2000

Mercury-induced nummular dermatitis.

We report 2 cases of relapsing nummular dermatitis according to mercury sensitivity, which was confirmed by patch testing. Removal of the amalgam from dental metal alloys markedly improved their skin eruptions. One of the patients, a dentist, experienced exacerbation of the eruptions on his lower legs after handling dental amalgam. Hypersensitivity to haptens such as metals is possibly involved in, at least in some patients, the pathogenesis of nummular dermatitis.

Adult↗

PubMed2000

Recombinant p51 as antigen in an immune complex transfer enzyme immunoassay of immunoglobulin G antibody to human immunodeficiency virus type 1.

An ultrasensitive enzyme immunoassay (immune complex transfer enzyme immunoassay) of antibody immunoglobulin G (IgG) to human immunodeficiency virus type 1 (HIV-1) has been developed using recombinant HIV-1 reverse transcriptase (rRT) as antigen. However, some disadvantages were noted in the use of rRT as antigen: rRT was produced only with low efficiency in widely used strains of Escherichia coli using a rather long DNA fragment (3,012 bp) of the whole HIV-1 pol gene, and it was impossible to produce fusion proteins of RT for simple purification, since rRT is a heterodimer of p66 and p51. In this study, recombinant HIV-1 p51 and p66 with Ser-Ser at the N termini (Ser-Ser-rp51 and Ser-Ser-rp66) were produced in E. coli as fusion proteins with maltose binding protein containing a factor Xa site between the two proteins and were purified after digestion with factor Xa. Ser-Ser-rp51 was produced in larger amounts and purified in higher yields with less polymerization than Ser-Ser-rp66. Polymerized Ser-Ser-rp66 tended to be precipitated on mercaptoacetylation for conjugation to beta-D-galactosidase (used as a label) and showed higher nonspecific and lower specific signals in an immune complex transfer enzyme immunoassay of antibody IgG to HIV-1 than Ser-Ser-rp51. The signals for serum samples of HIV-1-seropositive subjects by immune complex transfer enzyme immunoassay of antibody IgG to HIV-1 using Ser-Ser-rp51 as antigen (Y) were well correlated to those obtained using rRT as antigen (X) (log Y = 0.99 log X + 0.23; r = 0.99). Thus, the use of rp51 as antigen was advantageous over that of rp66 and rRT in an immune complex transfer enzyme immunoassay of antibody IgG to HIV-1.

Adult↗

PubMed2000

Cell-dependent requirement of human immunodeficiency virus type 1 gp41 cytoplasmic tail for Env incorporation into virions.

Growth kinetics in lymphocytic H9 and M8166 cells of two mutants of human immunodeficiency virus type 1 (HIV-1) with deleted gp41 cytoplasmic tails were examined. While the mutant viruses designated CTdel-44 and CTdel-144 were able to grow in M8166 cells, they were unable to grow in H9 cells. Transfection and single-round infectivity assays demonstrated that they are defective in the early phase of viral replication in H9 cells. Analysis of the mutant virions revealed drastically reduced incorporation of Env gp120 (compared with the incorporation of wild-type virions) in H9 cells but normal incorporation in M8166 cells. These results indicate that the HIV-1 cytoplasmic tail of gp41 determines virus infectivity in a cell-dependent manner by affecting incorporation of Env into virions and suggest the involvement of a host cell factor(s) in the Env incorporation.

Cell Line↗

PubMed2000

Nef-induced major histocompatibility complex class I down-regulation is functionally dissociated from its virion incorporation, enhancement of viral infectivity, and CD4 down-regulation.

The N-terminal alpha-helix domain of the human immunodeficiency virus type 1 (HIV-1) Nef protein plays important roles in enhancement of viral infectivity, virion incorporation of Nef, and the down-regulation of major histocompatibility complex class I (MHC-I) expression on cell surfaces. In this study, we demonstrated that Met 20 in the alpha-helix domain was indispensable for the ability of Nef to modulate MHC-I expression but not for other events. We also showed that Met 20 was unnecessary for the down-regulation of CD4. These findings indicate that the region governing MHC-I down-regulation is proximate in the alpha-helix domain but is dissociated functionally from that determining enhancement of viral infectivity, virion incorporation of Nef, and CD4 down-regulation.

Amino Acid Sequence↗

PubMed2000

A novel lantibiotic, nukacin ISK-1, of Staphylococcus warneri ISK-1: cloning of the structural gene and identification of the structure.

Staphylococcus warneri ISK-1, which we had previously reported as Pediococcus sp. ISK-1, produces a novel bacteriocin, nukacin ISK-1. Edman degradation of the chemically reduced nukacin ISK-1 produced a sequence of 27 amino acids, 7 of which were unidentified. Using single-specific-primer-PCR product as a probe, a 3.6-kb HindIII fragment containing the nukacin ISK-1 structural gene (nukA) was cloned and sequenced. The deduced amino acid sequence of nukacin ISK-1 had 57 amino acids, including a 30-amino acid leader region. The propeptide sequence showed significant similarity to those of lacticin-481 type lantibiotics. In the region upstream of nukA, a part of a long open reading frame (ORF), designated as nukM, encoding a putative modification enzyme was oriented in the opposite direction. In the region downstream of nukA, ORF1 was found in which the sequence of the putative translational product was similar to various response regulatory proteins.

Amino Acid Sequence↗

PubMed2000

The H9/M8166 tropism of various HIV-1 mutants is determined by distinct cellular factors (review).

We have previously shown that a number of human immunodeficiency virus type 1 (HIV-1) mutants generated in vitro display a replication-defect in a cell-dependent manner. Of the mutants of this category, those of gag, vif, and env mutants do not grow at all in lymphocytic H9 (non-permissive) cells, but quite well in M8166 (permissive) cells. To determine whether the cell-dependent growth of the mutants is functionally related to each other, a number of double mutants were constructed, and monitored for their replication and biochemical property in various cells. The results obtained have indicated that there are multiple cellular factors responsible for the growth phenotype. Together with our previous findings on the host cell-dependent mutants of HIV-1, it is concluded that number of distinct cellular factors are involved in the various steps in HIV-1 replication cycle.

Animals↗

PubMed2000

Mutational analysis of HIV-1 gag proteins (review).

The mature Gag proteins of human immunodeficiency virus type 1 (HIV-1) are major components of infectious virions, and thought to carry out numerous functions throughout the HIV-1 replication cycle. We have recently generated numerous gag gene mutants of HIV-1 to genetically study the functions of the Gag proteins. Through the biological and biochemical analyses, our HIV-1 gag mutants have been grouped into early (defective for uncoating/reverse transcription), late (defective for virion release/maturation), and early/late (defective for both steps) mutants. Many mutants are found to efficiently inhibit the replication of wild-type virus. Worthy of note, there are some early mutants which show host cell-dependent replication potential.

DNA Mutational Analysis↗

PubMed2000

MHC-I expression in HTLV-1-positive and -negative cells.

The expression level of major histocompatibility class I (MHC-I) and the extent of down-regulation of MHC-I after an anti-MHC-I antibody treatment in numerous human T-cell leukemia virus type 1 (HTLV-1)-positive and -negative lymphocytic cell lines were examined. While there was no clear correlation between the expression level of MHC-I and the presence of HTLV-1 genome, a relatively low level of MHC-I down-regulation was generally induced in HTLV-1-positive cells by the antibody. The results may suggest the potential involvement of MHC-I in HTLV-1 leukemogenesis.

Antibodies, Monoclonal↗

PubMed2000

[Clinical evaluation of hepatic blood flow and oxygen metabolism during thoracoabdominal aortic surgery using pulse dye-densitometry combined with hepatic venous oxygen saturation].

OBJECTIVE: There has been no report that pulse dye-densitometry (PDD), a novel non-invasive modality for monitoring hepatic blood flow (HBF), was applied during cardio-pulmonary bypass (CPB). We investigated weather PDD was useful to measure HBF during thoracoabdominal aortic surgery using partial CPB. Furthermore, HBF and hepatic metabolism were assessed during selective visceral perfusion or shunt using PDD, hepatic venous oxygen saturation (ShO2), and analysis of hepatic metabolic products. METHODS: A prospective study was carried out in eight patients who underwent thoracoabdominal aortic surgery from April 1998 to October 1999. Operative adjuncts were partial CPB with mild hypothermia in six (femoral veno-arterial bypass: FF group) and deep hypothermic circulatory arrest in two (DHCA group). Measurements were performed at following five time points; just before initiating CPB, just after establishing CPB, during selective visceral perfusion, during selective visceral shunt, and just after weaning CPB. RESULTS: Plasma clearance rate of indocyanine green measured by PDD well correlated with that obtained by in vitro spectrophotometry (p < 0.0001, R2 = 0.644). PDD demonstrated that decreased IIBF during selective visceral perfusion or shunt was well compensated by increased hepatic oxygen extraction rate in FF group and reduced oxygen consumption in DHCA group. Lactic acid extraction ratio and arterial ketone body ratio also decreased during this period. ShO2 during selective visceral shunt correlated with systemic systolic arterial pressure (SAP), and it showed a marked decrease under 20% when SAP was below 80 mmHg. Postoperative time course of serum total bilirubin and alanine aminotransferase of almost patients were within acceptable limits except the patient who required large amount of homologous blood transfusion. CONCLUSIONS: PDD proved to be a useful modality that enabled non-invasive monitoring of HBF even during partial CPB. Decreased HBF during selective visceral perfusion or shunt in thoracoabdominal aortic surgery was within physiological compensation, which led us conclude that it might be effective adjuncts, for visceral organ protection.

Adult↗

PubMed2000

Preparations of recombinant HIV-1 p66 antigen to improve the specificity of immune complex transfer enzyme immunoassay of antibody IgG to HIV-1 reverse transcriptase.

Recombinant HIV-1 p66 (rp66, a subunit of reverse transcriptase (RT), a heterodimer of p66 and p51) was produced in Escherichia coli in three different ways. First, rp66 was produced as a part of the fusion protein of lacZ protein and HIV-1 pol protein consisting of three components: protease (p10), RT (p51/p66), and integrase (p31), and was released from the fusion protein by the protease (pol-rp66). Second, rp66 with Ser-Ser at the N-terminus was produced as a fusion protein with maltose-binding protein containing a factor Xa site between the two proteins (MBP-Ser-Ser-rp66) and was released from the fusion protein by factor Xa (Ser-Ser-rp66). Third, rp66 with Met-Gly at the N-terminus was produced in transformed cells (Met-Gly-rp66). The recombinant proteins were purified from sonic extracts of transformed cells by ammonium sulfate fractionation and various column chromatographies. MBP-Ser-Ser-rp66 and Met-Gly-rp66 were readily purified in sufficient amounts for labeling with 2, 4-dinitrophenyl groups and beta-D-galactosidase from E. coli, but pol-rp66 and Ser-Ser-rp66 were not for enzyme-labeling. Ser-Ser-rp66 was not only polymerized but also degraded to considerable extents. The purified preparations were labeled with 2,4-dinitrophenyl groups and beta-D-galactosidase and were tested in immune complex transfer enzyme immunoassay of antibody IgG to HIV-1 RT using serum samples from 600 HIV-1 seronegative and 30 HIV-1 seropositive subjects. Among various combined uses of the two labeled preparations, the uses of 2,4-dinitrophenylated MBP-Ser-Ser-rp66 and pol-rp66 with beta-D-galactosidase-labeled Met-Gly-rp66 showed the highest (99.8%) and the second highest (99.5%) specificities, which were higher than that with the labeled preparations used in the previous study (98. 0%).

Amino Acid Sequence↗

PubMed2000

Relationship between chromosomal instability and intratumoral regional DNA ploidy heterogeneity in primary gastric cancers.

The purpose of this study was to elucidate the relationship between intratumoral regional heterogeneity in DNA ploidy and chromosomal instability (CIN) in primary gastric adenocarcinomas. In 45 sporadic gastric adenocarcinomas, we measured DNA ploidy and numerical aberrations for chromosomes 7, 11, 17, and 18 by laser scanning cytometry and fluorescence in situ hybridization, respectively, in small tissue specimens taken from 2 to 6 (on the average 4) different portions of the same tumor. A total of 231 specimens including 45 normal control specimens were examined. All 98 tumor specimens with DNA aneuploidy (DNA index > or = 1.2) showed large intercellular variations in chromosome copy number, indicating CIN. In contrast, 85 tumor specimens with (near) diploidy (1.0 < or = DNA index < 1.2) exhibited much small intercellular variations in chromosome copy number as compared with aneuploid specimens (P < 0.0001). The relationship between DNA ploidy and intercellular variation in chromosome copy number was true for tumors consisting of a mixture of (near) diploid and aneuploid subpopulations. These data indicate that DNA aneuploidy is associated with CIN but that (near) diploidy is not. Intratumoral regional DNA ploidy heterogeneity was conspicuous in 33 (92%) of 36 tumors with regions of DNA aneuploidy, and all aneuploid specimens showed great intercellular variation in chromosome copy number. Diploid regions were predominant in early stage cancers (intramucosal and submucosal cancers), and five of eight early cancers contained only diploid population. In contrast, all tumors without (near) diploid regions were advanced cancers. These observations suggest that CIN is a necessary prerequisite for developing intratumoral DNA ploidy heterogeneity with DNA aneuploidy.

Adenocarcinoma↗

PubMed2000

[Thoracoscopic resection for benign solitary fibrous tumor of the parietal pleura].

We have experienced thoracoscopic surgery for benign solitary fibrous tumor of the parietal pleura. A 46-year-old woman was admitted to our hospital because of chest abnormal shadow. Under thoracoscopy the tumor that was connected to the parietal pleura with a wide pedicle was completely resected with combined parietal resection of the pleura. Pathological diagnosis was a benign solitary fibrous tumor developed from the connective tissues under the parietal pleura. Thoracoscopic surgery is well indicated for a solitary fibrous tumor and wide excision of the tumor with combined resection of the pleura is important to prevent a local recurrence.

Female↗

PubMed2000

Concomitant abdominal aortic aneurysm repair and cholecystectomy. Combination of retroperitoneal aortic reconstruction and gassless laparoscopic cholecystectomy.

The coexistence of cholelithiasis and abdominal aortic aneurysm is not uncommon. However, cholecystectomy at the time of abdominal aortic reconstruction has generally been delayed because of the potential contamination of the graft. The case described here had concomitant cholelithiasis and abdominal aortic aneurysm, both of which were required to be treated, and was successfully treated with a combination of retroperitoneal abdominal aortic reconstruction and gasless laparoscopic cholecystectomy.

Aortic Aneurysm, Abdominal↗

PubMed2000

Arterial thoracic outlet syndrome with embolic cerebral infarction. Report of a case.

Cerebral embolism is a very rare but recognized manifestation of arterial complications of thoracic outlet syndrome, and is associated with retrograde embolization in the cerebral arteries. We herein report a case of embolic brain infarction due to arterial thoracic outlet syndrome while discussing the etiology, diagnosis, and surgery.

Cerebral Infarction↗

PubMed1999

High expression of cyclooxygenase-2 in macrophages of human colonic adenoma.

Cyclooxygenase (COX)-2 is a possible molecular target for suppression of colon carcinogenesis by non-steroidal anti-inflammatory drugs (NSAIDs). However, the expression of COX-2 in human colonic tumors during the adenoma-carcinoma sequence has not been elucidated. In the present study, we examined immuno-histochemically the expression and localization of the COX-2 protein in human colonic adenomas and cancers. Twelve human colonic adenomas and 9 advanced cancers were studied. Immunoreactive COX-2 was predominantly and strongly expressed in sub-epithelial interstitial cells broadly present in the surface area of adenomas. The staining pattern of macrophages was similar to that observed for COX-2 in adenomas. Adjacent normal colonic mucosa was negative for COX-2 expression. In contrast, COX-2 was relatively weakly expressed in both tumor cells and interstitial cells in advanced colon cancers. In conclusion, the target of NSAIDs in preventing colon carcinogenesis may be the COX-2 expressed in interstitial cells, possibly macrophages, of colonic adenomas.

Adenoma↗

PubMed1999

Small amino acid changes in the V3 loop of human immunodeficiency virus type 2 determines the coreceptor usage for CXCR4 and CCR5.

HIV-2 GH-1 is a molecular clone derived from an AIDS patient from Ghana. In contrast to the prototypic molecular clone ROD, GH-1 exhibits a narrow range of target cell specificity. By an infectious assay using HeLa-CD4 cells stably transfected with an HIV-1 LTR-beta-galactosidase reporter gene and transiently expressing various cloned chemokine receptors, we have examined the coreceptor usage of GH-1. In contrast to ROD, which uses principally CXCR4, GH-1 was found to use mainly if not exclusively CCR5 but not CXCR4. The distinct coreceptor usage of these two molecular clones allowed us to further map the region of gp120 that is important for the coreceptor specificity. By constructing a series of chimeric viruses between GH-1 and ROD, we have demonstrated that the C-terminal half of the V3 loop region of gp120 determines the differential coreceptor usage between GH-1 and ROD, and only a few amino acid differences in this region appear to be able to shift the specificity between CCR5 and CXCR4. Notably, the shift in the coreceptor usage from CCR5 to CXCR4 is associated with an increase in the net positive charge in the V3 region.

Acquired Immunodeficiency Syndrome↗

PubMed1999

Induction of apoptosis in Herpesvirus saimiri-immortalized T lymphocytes by blocking interaction of CD28 with CD80/CD86.

We have previously shown that Herpesvirus saimiri (HVS) immortalizes primary macaque monkey T lymphocytes. In this study, we examined the characteristics of the immortalized T cells. The cells showed the phenotype of activated T lymphoblasts (CD3(+) CD25(+) CD69(+) MHC-IIDR(+)) and produced no infectious virus while viral DNA was detected in the Hirt DNA. Interestingly, both a major costimulatory molecule, CD28, and its ligands, CD80/CD86, were coexpressed on the immortalized T cells. The treatment of the cells with a neutralizing monoclonal antibody against CD28, which blocks interaction of CD28 with CD80/CD86, resulted in retarded cell growth and in induction of apoptosis. The effect of the antibody treatment was not overcome by exogenous interleukin-2 treatment. These findings demonstrate the requirement of interaction of CD28 with CD80/CD86 for the optimal growth of HVS-immortalized T cells.

Animals↗