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Biomedical subjects

N Sakura

Publications and source records attributed to N Sakura.

At least 109 records · Page 6Linked to original sources
PubMed1985

Inhibition by adenine of in vitro immunological functions of normal and adenine phosphoribosyltransferase-deficient human lymphocytes.

Exogenous adenine strongly inhibited mitogen-stimulated transformation, cytoplasmic immunoglobulin production, and natural killer activity of human mononuclear leukocytes at the high concentration of 1.0 mM. These inhibitions by adenine were not due to cytotoxicity, because the viability of cultured cells was not affected by adenine up to 1.0 mM. As the magnitude of inhibition by adenine of these in vitro immunological functions was similar in normal and adenine phosphoribosyltransferase-deficient cells, its inhibition was not mediated by corresponding nucleotides. Adenine at the concentration of 0.1 mM caused 50% inhibition of cytoplasmic immunoglobulin production without alternating cell proliferation or viability. This suggests that an appropriate concentration of adenine may inhibit the differentiation of B cells to plasma cells rather than affecting cell proliferation. Understanding the mechanisms of adenine inhibition may lead to new approaches for the regulation of immune responses.

Adenine↗
PubMed1984

Presumed BCG infection in a boy with chronic granulomatous disease. A report of a case and a review of the literature.

A male child with chronic granulomatous disease (CGD) developed protracted axillary lymphadenopathy with liquefaction following a bacille Calmettle-Guérin (BCG) immunization. Except for phagocytic dysfunctions characteristic of the underlying disease, immunological examinations were normal. The literature dealing with CGD cases with disseminated BCG infection was reviewed. It is concluded that the possibility of CGD should be considered in those who developed such adverse reactions to BCG immunization.

BCG Vaccine↗
PubMed1984

Favorable effect of dimethyl sulfoxide on secondary amyloidosis in juvenile rheumatoid arthritis.

A girl with secondary amyloidosis as a complication of juvenile rheumatoid arthritis was administered dimethyl sulfoxide by topical application to the skin. Her gastrointestinal symptoms and massive proteinuria improved. Decreased left ventricular function and creatinine clearance also improved remarkably. The favorable effect of dimethyl sulfoxide in this single patient deserves further study in a controlled trial.

Adolescent↗
PubMed1984

Complete deficiency of adenine phosphoribosyltransferase: a report of three cases and immunologic and phagocytic investigations.

The levels of adenine phosphoribosyltransferase (APRT:EC 2.4.2.7) were determined in red blood cells (RBCs), peripheral mononuclear cells (MNCs), and polymorphonuclear leukocytes (PMNLs) from normal controls and from two families with APRT deficiency. No APRT activity was demonstrated in MNCs and PMNLs of patients with complete deficiency of RBC-APRT. APRT deficiency occurs not only in RBCs but also in MNCs and PMNLs. Immunologic and phagocytic examinations showed normal hemogram and serum immunoglobulin levels, and normal E-rosette forming cells and surface immunoglobulin-bearing cells. Lymphocyte blastogenesis in response to phytohemagglutinin and lymphocyte differentiation to cytoplasmic immunoglobulin-producing cells induced by pokeweed mitogen were normal. No major defects were apparent in natural killer activity. Phagocytic functions were normal as tested by bactericidal activity, O2-consumption, chemotaxis, and chemiluminescence response.

Adenine Phosphoribosyltransferase↗
PubMed1983

Complete deficiency of adenine phosphoribosyl transferase: report of a new family.

We report a case of 2,8-dihydroxyadenine urinary lithiasis with complete deficiency of adenine phosphoribosyl transferase. Adenine phosphoribosyl transferase activities in the erythrocytes, lymphocytes and granulocytes of the patient's family also were determined. The propositus and her younger brother were homozygotes for adenine phosphoribosyl transferase deficiency and her parents were heterozygotes. This is the third family with this disease to be reported.

Adenine↗
PubMed1983

A case of immunodeficiency with decreased serum IgA levels and impaired polyclonal B cell differentiation in vitro.

We report a patient with low serum IgA levels and persistent pulmonary infection. In spite of the normal contents of serum IgG and IgM, the patient had a deficiency for plasma cell differentiation of all major classes of immunoglobulins (IgG, IgA and IgM). Cross culture systems between normal T or B cells and the patient's T or B cells showed a defect of both T and B cell function.

Adolescent↗
PubMed1983

Kinetic properties of placental aminopeptidase A: N-terminal degradation of angiotensin II.

Purified placental aminopeptidase A cleaved N-terminal aspartic acid of Angiotensin II, and it was inhibited by amastatin. Amastatin and various angiotensin analogs having N-terminal dicarboxylic acid were potent inhibitors of the enzyme. Kinetic analysis indicated that amastatin, angiotensin II, the N-terminal tripeptide of angiotensin II, and aspartic acid were competitive inhibitors, with Ki values 1.25 X 10(-7) M, 2.40 X 10(-5) M, 2.67 X 10(-4) M, and 1.2 X 10(-3)M respectively. The enzyme was also inhibited by transition metals, such as Zn2+, Cu2+, Cd2+ and Ni2+. Serum aminopeptidase A activity progressively increased during the course of normal pregnancy.

Amino Acids↗
PubMed1982

Stimulation of lymphocyte proliferation to monitor fractionation of thymus extracts.

Multi-step fractionations by solvent extractions, gel filtrations, ion-exchange chromatography, etc., of bovine thymus extracts were monitored by a standardized assay, in vitro, which led to the described peptides, thymones A, B and C. The assay uses spleen cells from neonatally thymectomized mice as tissue relevant to immunoregulation. Assay of incorporation of [3H]-thymidine into DNA located peaks of activities. Calf thymus outer fraction ("CTO") showed activity, but Fraction 5, synthetic thymosin alpha 1, [G1n1]-FTS, and glutathione, were inactive in this assay.

Animals↗
PubMed1981

A new approach to detection of heterozygotes for adenosine deaminase deficiency: a hypothetical method.

In a second and third families with ADA deficiency found in Japan, we tried a new approach to evaluate heterozygote detection. This is based on the hypothesis that ADA activity of red blood cell is the quantitative sum of the activities of ADA proteins expressed by two allelic genes at the ADA autosomal locus, and that these activities are not changed by the gene transmission from parents to children. We have detected red blood cell-ADA activities expressed by the one normal allelic gene in heterozygotes (including parents and paternal or maternal grandfather or grandmother) and from these values have determined combinations for the pair of ADA activities expressed by the two allelic genes of other family members. These combinations were consistently made in all relatives examined in the two families, and we conclude that several members of each family who were judged to have nil activity in the combinations were heterozygotes for ADA deficiency.

Adenosine Deaminase↗
PubMed1981

Synthetic study on human C-peptide and its related peptides.

Syntheses of eighteen peptides related to human C-peptide and the connecting peptide are described. The syntheses were performed exclusively by the azide fragment condensation method. The immunochemical results justified the utilization of these peptides for development of human C-peptide radioimmunoassay system. The synthetic peptide fragments may be extremely important substrates for assessment of specificity of human C-peptide antisera and thus usefulness of the antisera in practical measurement of blood levels of human C-peptide immunoreactivity.

Amino Acid Sequence↗