Cleavage of double helical DNA by Cu2+ ion in the presence of bisintercalator containing penta(ethylene glycol) connector chain

In designing new DNA recognizing and cleaving reagents, we introduce herein a bisacridine derivative (referred to as bisacridine) in which two acridine heterocycles are connected by a penta(ethylene glycol) bridging chain. This compound offers two possible functions: 1, stabilization of DNA bisacridine intercalator complex by metal ion. The penta(ethylene glycol) chain stabilizes metal ions binding to the phosphate site of DNA, where the penta(ethylene glycol) chain constitutes a part of a pseudomacrocyclic ligand for metal binding; and 2, enhancement of metal-assisted hydrolytic cleavage of DNA by means of a metal concentration effect by the pseudomacrocyclic ethereal chain. The binding isotherms of bisacridine with DNA in the presence of metal ions showed that the binding was mainly governed by the cation exchange reaction on the anionic DNA polymer chain, i.e., the exchange between metal ions and the cationic bisacridine. The bisacridine showed an increase DNA binding ability compared to quinacrine, the monoacridine counterpart, and caused an enhancement of DNA cleavage in the presence of Cu2+ ions. Additional experiments which included DNase 1 footprinting in the presence of bisacridine and the DNA cleavage by Cu2+/bisacridine using a 32P end-labelled DNA fragment, suggested that the Cu2(+)-assisted DNA cleavage sites in the presence of bisacridine were in reasonable overlap with the DNA binding sites of bisacridine.     

Sympathetic Tone Induced by High Acoustic Tempo Requires Fast Respiration

Many studies have revealed the influences of music, and particularly its tempo, on the autonomic nervous system (ANS) and respiration patterns. Since there is the interaction between the ANS and the respiratory system, namely sympatho-respiratory coupling, it is possible that the effect of musical tempo on the ANS is modulated by the respiratory system. Therefore, we investigated the effects of the relationship between musical tempo and respiratory rate on the ANS. Fifty-two healthy people aged 18–35 years participated in this study. Their respiratory rates were controlled by using a silent electronic metronome and they listened to simple drum sounds with a constant tempo. We varied the respiratory rate—acoustic tempo combination. The respiratory rate was controlled at 15 or 20 cycles per minute (CPM) and the acoustic tempo was 60 or 80 beats per minute (BPM) or the environment was silent. Electrocardiograms and an elastic chest band were used to measure the heart rate and respiratory rate, respectively. The mean heart rate and heart rate variability (HRV) were regarded as indices of ANS activity. We observed a significant increase in the mean heart rate and the low (0.04–0.15 Hz) to high (0.15–0.40 Hz) frequency ratio of HRV, only when the respiratory rate was controlled at 20 CPM and the acoustic tempo was 80 BPM. We suggest that the effect of acoustic tempo on the sympathetic tone is modulated by the respiratory system.     

Inhibition of ovulation in PMSG/hCG-treated immature rats by rotenone, a specific inhibitor of mitochondrial oxidation

Immature Wistar rats were induced to ovulate by treatment with PMSG and hCG. Control animals ovulated 43.5 +/- 0.36 ova/rat. Intraperitoneal injection of rotenone doses of 0.125, 0.25 and 0.50 mg/kg reduced the ovulation rate to 24.0 +/- 3.08, 8.0 +/- 0.88 and 1.5 +/- 0.44 ova/rat, respectively. The rotenone significantly reduced ovarian cytochrome oxidase activity and progesterone production, but not production of oestradiol or testosterone. Thyroxine treatment at a dose of 5 mg/kg s.c. reversed the rotenone inhibition of ovulation. The results suggest that an increase in mitochondrial respiration is an essential feature of the ovulation process in mammals.     

CD16+ lymphoblastic cell lines of crab-eating monkeys (Macaca fascicularis) shared U-5 antigen and expressed natural killer activity

The CD16+ lymphoblastic cell lines of crab-eating monkeys shared the U-5 antigen recognized by a monoclonal antibody. The CD16+U-5+ cell lines expressed high natural killer activity to K562 cells, whereas the CD16-U-5- control cell line had no significant natural killer activity. A possible involvement of the U-5 antigen in natural killer function was also suggested by reduction of the natural killer activity in peripheral blood mononuclear cells of Japanese monkeys after treatment with U-5 monoclonal antibody and complement.     

Development of a series of monoclonal antibodies recognizing leukocyte differentiation antigens of Japanese monkeys (Macaca fuscata)

Six monoclonal antibodies to Japanese monkey leukocytes were developed. These monoclonal antibodies, designated the U series, cover most kinds of leukocytes (pan T cells, CD8+ cells, CD8+ subset and granulocytes, CD16+ cells, monocytes/macrophages), and should be useful in the immunological analysis of primate models, such as tissue transplants and virus-related diseases, in particular, acquired immune deficiency syndrome (AIDS).     

Plasma thyroxine-binding proteins and thyroid hormone levels in primate species; is callithricidae thyroid hormone resistant?

Thyroxine(T4)-binding to serum proteins in primates; catarrhini, prosimiae, and platyrrhini were studied by polyacrylamide gel electrophoresis T4 binding analysis. From the electrophoretic analysis, it was shown that thyroxine-binding proteins similar to human thyroxine-binding globulin (TBG) and thyroxine-binding prealbumin (TBPA) were present in catarrhini and prosimiae species, but not in platyrrhini (callithricidae and cebidae). T4-binding analysis also revealed that catarrhini and prosimiae have a high affinity T4-binding protein similar to human TBG. The association constant (Ka) for T4 of the plasma proteins in these species was approximately 2.0 X 10(10) M-1. On the other hand, it was unable to demonstrate a high affinity binding site for T4 in the plasma of platyrrhini species. Both the total and free thyroid hormone concentrations in catarrhini and prosimiae were similar to those in human. Total T4 in cebidae, one of the platyrrhini species, was extremely low. Among 8 animals examined, T4 in 6 was undetectable by radioimmunoassay and the mean T4 of the other two was 2.8 micrograms/dl. However, free thyroid hormone concentrations were similar to those in human. In callithricidae, another platyrrhini species, T4 in plasma was 6.90 +/- 2.11, which is comparable to the level in normal human subjects. However, in this species, high-affinity T4-binding protein was lacking and free thyroid hormone concentrations were extremely high (most were higher than the assay limit). Although the thyroid function of callithricidae remains to be studied, it will be interesting if callithricidae is resistant to thyroid hormone action.     

Changes in membrane constituents and chemiluminescence in vitamin E-deficient red blood cells induced by the xanthine oxidase reaction

The oxidation of vitamin E-deficient rat red blood cells (RBCs) induced by the hypoxanthine-xanthine oxidase (HX-XOD) system has been performed in an aqueous suspension. The generation of chemiluminescence and the accumulation of thiobarbituric acid-reactive substances (TBARS) were observed initially and were followed by hemolysis. Interestingly, the total counts of chemiluminescence were closely related to the amount of TBARS. The predominant change of membrane proteins induced by the reaction was the depletion of spectrin bands in gel electrophoresis. When RBC ghosts were oxidized with HX-XOD, the sulfhydryl (SH) groups of membrane proteins decreased at an early stage of the incubation, which was coincident with the above protein alteration. Membrane alpha-tocopherol suppressed not only the formation of TBARS but also chemiluminescence and hemolysis; nevertheless, it did not inhibit the protein damage and the loss of SH groups. Moreover, it was concluded that the chemiluminescence observed during the oxidation of RBC membranes was associated mainly with the peroxidation of lipids and only to a minor extent with the oxidation of proteins.     

Monoclonal antibodies to human germ cell tumors from "routine" paraffin-embedded pathological specimens

We have established a method for monoclonal antibody (MoAb) preparation from routine paraffin-embedded tissue of human seminoma as an immunogen. Three 40-microns thick sections were deparaffinized and rehydrated. An eight-week-old BALB/c mouse was immunized intraperitoneally with this extract, which showed no detectable protein bands on sodium laurylsulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Five monoclonal antibodies (MoAbs) with different characteristics were obtained; one reacted with the nucleus, two with the cytoplasm, and two with the cytoplasmic membrane. One of the MoAbs 5G9 reacted with spermatogonia in normal human tissues and with seminoma, embryonal carcinoma and choriocarcinoma in the testicular tumors.     

Establishment of primate lymphoblastic cell lines by coculture with a simian T-cell leukemia virus-1 positive, hypoxanthine-guanine-phosphoribosyltransferase negative Japanese macaque cell line

A cell line (JAMH17+) resistant to 8-azaguanine was established from a human T-cell leukemia virus type 1 related virus (simian T-cell leukemia virus-1) positive Japanese macaque cell line. Lymphoblastic cell lines were established from the peripheral blood mononuclear cells of humans, hominoids, and several species of macaques by coculture with JAMH17+ in hypoxanthine-aminopterin-thymidine medium. HTLV-1 specific antigen was detected in some of the established cell lines. Phenotypic analysis showed that several cell lines of crab-eating macaques expressed Leu11a antigen, which is a marker of human natural killer cells.