Elevation of cerebrospinal fluid sialic acid concentration in children with central nervous system leukemia

We studied sialic acid in the cerebrospinal fluid (CSF) of 52 children with leukemia and 51 children with non-leukemic diseases. The CSF sialic acid concentration in the children with central nervous system (CNS) leukemia was significantly higher than that in the children with acute lymphoblastic leukemia without CNS involvement, acute non-lymphocytic leukemia without CNS involvement, non-hemopoietic diseases, non-suppurative meningitis, epilepsy, and other neurologic diseases. Serial determinations revealed a rapid decline in the CSF sialic acid concentrations in the patients with CNS leukemia who responded well to the therapy and who were free from relapse of CNS leukemia. The simultaneously determined CSF beta 2 microglobulin concentration did not show any significant changes. These results suggest that the CSF sialic acid may be a good indicator of CNS leukemia.

The inhibition of neoplastic cell proliferation with human natural tumor necrosis factor

Purified human natural tumor necrosis factor (n-TNF) was prepared by stimulating human leukemic B cell line (BALL-1) with Sendai virus. The colony formations of all of 18 human cancer-derived abnormal cell lines were suppressed by 10(1)-10(6) U/ml of n-TNF, while n-TNF was nontoxic to all human normal fibroblast cells. This in vitro inhibition of cell growth was reversible. In breast adenocarcinoma MCF7 cells treated with n-TNF a specific decrease of DNA synthesis was observed, and DNA histograms showed a block at G1 in the cell cycle. In vivo studies revealed that n-TNF suppressed the tumor growth of murine Meth A sarcoma, human renal adenocarcinoma (ACHN), malignant melanoma (SK-MEL-28) and glioblastoma (U-373 MG). Isobologram analysis showed that n-TNF synergistically inhibited cell growth in combination with human natural interferon (IFN)-a. In vivo synergism of n-TNF and IFN-a was also found in the U-373 MG tumor model implanted into nude mice.

Mechanical efficiency in rowing

Five university oarsmen participated in a determination of mechanical efficiency when rowing in a tank. In the tank, water was circulated at 3 m X s-1 by a motor driven pump. The subjects rowed with the stepwise incremental loading, in which the intensity increased by 10% of the maximum force of rowing (maxFc) every 2 min. Power (WO) was calculated from the force applied to the oarlock pin (FC) and its angular displacement (theta H). Oxygen uptake and heart rate were measured every 30 s during rowing. Anaerobic threshold (AT) was determined from expired gas variables by Wasserman's method. AT of oarsmen was 74.6 +/- 6.01% as a percentage of VO2max. As the displacement of the handgrip in the stroke was independent of WO, the increment of WO was caused by the increase of both FC and stroke frequency. Gross efficiency without base-line correction (GE) increased with FC with low intensities of rowing. In the region of 124-182 W of WO GE was almost constant at 17.5%. Efficiency was 19.8 +/- 1.4%, with resting metabolism as base-line correction (net efficiency), and 27.5 +/- 2.9% when using the unloaded rowing as the base-line correction (work efficiency), and 22.8 +/- 2.2% when calculating the work rate as the base-line correction (delta efficiency).

[Effects of repeated administration of bromocriptine on ambulatory activity in mice, and changes in methamphetamine sensitivity in bromocriptine-experienced mice]

Effects of repeated administration of bromocriptine, a long-acting dopamine agonist, as well as interaction between bromocriptine and methamphetamine were investigated by mean of ambulatory activity in mice. The ambulatory activity of each mouse was measured by a tilting-type activity cage for 6 and 3 hr after administration of bromocriptine and methamphetamine, respectively. The repeated 5 times administration of bromocriptine and of methamphetamine was at intervals of 7 days and of 3-4 days, respectively. Bromocriptine tended to suppress the activity at low doses (1 and 2mg/kg, ip), but increased the activity at high doses (8 and 16 mg/kg, ip), showing biphasic effects depending on the doses administered. Both the ambulation-suppressing and -increasing effects of bromocriptine were enhanced when the drug was repeatedly administered. The mice that experienced the repeated administration of low doses and high doses of bromocriptine exhibited a decrease and an increase, respectively, in the sensitivity to the ambulation-increasing effect of methamphetamine (2 mg/kg, sc). Repeated administration of methamphetamine (2 mg/kg, sc) elicited an increase in sensitivity not only to methamphetamine itself, showing reverse tolerance, but also to high doses of bromocriptine, showing cross reverse tolerance. However, the reverse tolerance to methamphetamine, once produced, was not affected by the repeated administration of low doses of bromocriptine.

[Rapid establishment of nicotine intravenous self-administration behavior in rats]

The reinforcing effect of nicotine was investigated using the intravenous self-administration method in rats. After forced iv injection of nicotine (3, 10 and 30 micrograms/kg/inj) at 1-hr intervals for 3 days in 3 dose-level groups, self-administration sessions under the continuous reinforcement schedule were carried out for 15 days. Rats initiated self-administration of nicotine rapidly in 10 and 30 micrograms/kg/inj groups. Daily self-administration responses by nicotine (30 micrograms/kg/inj) were 3-10 times the control levels. Total self-administration responses for 15 days increased in a dose dependent manner. When the fixed ratio was increased from 1 to 4 and 8 after the 15 days self-administration session in the nicotine (10 and 30 micrograms/kg/inj) groups, lever press responses increased only about 2 times, and self-administration responses decreased in the both groups. These findings suggest that nicotine becomes a reinforcer rapidly, but the magnitude of reinforcing effect is relatively week after the acquisition of nicotine for a short period.

[Basic study on interferon-beta: Part IV. Antitumor effect on nude mouse-transplanted human tumors]

The effects of human interferon-beta (IFN-beta, MR-21) on the growth of xenografted human tumors in nude mice were examined. IFN-beta was administered to mice with malignant melanoma (SK-MEL-28 and Sk-14) intratumorally at a dose of 1 X 10(5)-3 X 10(5) IU/mouse, with acute leukemia (CCRF-HSB-2) intratumorally at a dose of 3 X 10(5) IU/mouse, with glioblastoma (U-373 MG) intravenously or intratumorally at a dose of 1 X 10(5)-6 X 10(5) IU/mouse, or with uterine cervical tumor (HeLa S3) intravenously at a dose of 0.3 X 10(5)-1 X 10(5) IU/mouse. IFN-beta inhibited the growth of all of these tumors in a dose-dependent manner.

[Basic study on human interferon-beta: Part III. The mechanisms of its antitumor effect]

The mechanisms of the direct and indirect antitumor effects of human interferon-beta (IFN-beta, MR-21) were examined. IFN-beta suppressed DNA, RNA and protein synthesis in cells derived from human tumor. The expression of cellular oncogenes (c-Ha-ras and c-myc) in tumor-originated cells was also suppressed by IFN-beta. These results suggest that such suppression is one possible mechanism of the direct anticellular effect induced by IFN-beta. IFN-beta augmented NK cell activity and the ADCC activity of human peripheral blood lymphocytes. It is also suggested that these are two of the immune system-mediated mechanisms responsible for the indirect antitumor effect of IFN-beta in vivo.

[Correlation between the inhibition of renin-angiotensin system and antihypertensive effect of MK-421 and captopril in 2-kidney, 1-clip renal hypertensive rats after single and repeated oral administration of MK-421 or captopril]

The angiotensin converting enzyme (ACE) activity in tissues and plasma renin activity (PRA) were measured in 2-kidney, 1-clip renal hypertensive rats (2K-RHR) and normotensive rats after a single and 3-weeks oral administrations of ACE inhibitors such as MK-421 and captopril. In the single dose study, MK-421 (1 and 3 mg/kg) and captopril (3 and 10 mg/kg) inhibited the ACE activities in kidney, aorta and plasma in a dose-dependent fashion. The inhibition of ACE activity in kidney or aorta was observed for a longer time than that in plasma. PRA took a time course reversal to that of plasma ACE activity. In the 3-weeks repeated dose study, the ACE activity in kidney and aorta was strongly inhibited after the administration of each ACE inhibitor, while there was no significant change in lung ACE activity at any time point examined. The plasma ACE activity markedly elevated after the administration of each agent. PRA significantly increased after the administration of either agent, while the plasma angiotensin II level was significantly inhibited. These results indicate that the inhibition of the ACE activity in blood vessel or kidney correlate well with the antihypertensive activity in 2K-RHR after a single and repeated administration of both ACE inhibitors, but not well with the inhibition of plasma ACE activity.

[Effects of single and repeated oral administration of MK-421 and captopril on blood pressures in normotensive and experimental hypertensive rats]

In the single dose study, the aortic blood pressure in conscious normotensive rats, 2-kidney, 1-clip renal hypertensive rats (2K-RHR), 1-kidney, 1-clip renal hypertensive rats (1K-RHR) or DOCA hypertensive rats was measured for 24 hr after the oral administration of angiotensin converting enzyme (ACE) inhibitors such as MK-421 or captopril. MK-421 at 3 mg/kg and captopril at 10 mg/kg markedly lowered the blood pressure of 2K-RHR. MK-421 at 10 mg/kg and captopril at 30 mg/kg only modestly lowered the blood pressure of 1K-RHR. In contrast, both ACE inhibitors failed to reduce blood pressure in DOCA and normotensive rats. In the repeated dose study, the systolic blood pressures in normotensive rats, 2K-RHR or spontaneously hypertensive rats (SHR) were measured twice a week for 3 weeks treatment of either MK-421 at 3 mg/kg or captopril at 10 mg/kg. Both ACE inhibitors produced significant antihypertensive effects in these model rats, and the effects were sustained throughout the treatment period. The antihypertensive effects in 2K-RHR were greater than those in SHR and normotensive rats. These results indicate that MK-421 and captopril cause the most significant antihypertensive effect in 2K-RHR in which the renin-angiotensin system played a dominant role in blood pressure regulation. The antihypertensive effect of MK-421 was approximately 3 times as potent as that of captopril in these hypertensive models.

Elevated serum and urine sialic acid levels in renal diseases of childhood

Serum and urine sialic acid levels were measured in various renal diseases of childhood. Serum sialic acid levels were found to be elevated in patients with idiopathic nephrotic syndrome (INS) at onsets and relapses, acute poststreptococcal glomerulonephritis (PSGN) and chronic glomerulonephritis (CGN) found by chance proteinuria and/or hematuria. A large amount of bound sialic acids were excreted in the urine in INS at onsets and relapses, although the serum sialic acid levels were increased. Sephadex G-200 column chromatography revealed three separate peaks with sialoglycoproteins in a patient with INS at onset, but only two peaks in a normal control subject. These results suggest that some sialoglycoproteins are involved in the development of INS, PSGN and CGN.

Pericentric inversion of chromosome No. 8

Chromosome studies of an infant with multiple malformations were made by means of the trypsin-Giemsa banding as well as conventional Giemsa staining methods. The propositus showed 46, XY +3, -C, and it was indicated that the abnormal metacentric chromosome was induced by the pericentric inversion of chromosome No. 8, in which chromosomal breakage had occurred most likely at the bands 8p23 and 8q23. The probable formula of the inversion is 46, XY, inv (8) (p23q23). Karyotypic analyses of the parents revealed no abnormalities, and the inversion therefore occurred spontaneously. Clinical features of the porpositus are postulated to be caused by a loss of very small portions of the chromosomal material with the occurrence of the pericentric inversion.