Protective effect of fluvastatin on degradation of apolipoprotein B by a radical reaction in human plasma

Fluvastatin, which is a synthetic 3-hydroxy-3-methylglutaryl coenzyme (HMG-CoA) reductase inhibitor, its metabolites (M2, M3 and M4) and trolox all inhibited the decrease of apolipoprotein B-100 (apoB) and alpha-tocopherol in a radical reaction of human plasma initiated by Cu2+. The concentrations of fluvastatin, M2, M3, M4 and trolox for 50% inhibition (IC50) of apoB fragmentation were 405, 8.55, 1.75, 305, and 43.4 microM, respectively. The IC50 value of pravastatin, which is another HMG-CoA reductase inhibitor, was 2880 microM, showing that pravastatin is not an effective antioxidant. Although fluvastatin, its metabolites and trolox inhibited the decrease of alpha-tocopherol in a similar manner to that of apoB, pravastatin did not significantly inhibit the decrease of alpha-tocopherol. Since oxidation of low density lipopotein (LDL) is an important step in the initiation and progression of atherosclerosis, fluvastatin may reduce the risk of atherosclerosis not only by lowering plasma cholesterol but also by protecting LDL from oxidation.

A patient with severe palindromic rheumatism and frequent episodes of pain

A 44-year-old man began to experience episodes of joint pain with erythema in his knees, elbows, shoulders, and hands in April 1996. He was diagnosed as having palindromic rheumatism. Due to the increasing frequency and severity of these episodes, he was admitted to our hospital in May 1999. Heat therapy to the affected area produced a rapid improvement in symptoms. In addition, the continued use of physical therapy during symptom-free periods tended to reduce the frequency and severity of pain attacks. We present this case and discuss treatment options in patients with palindromic rheumatism.

Efficacy of galectins in the amelioration of nephrotoxic serum nephritis in Wistar Kyoto rats

BACKGROUND

Galectins are characterized by specific affinity for beta-galactoside sugars, and they play a role in diverse biological processes, including cell adhesion, cell proliferation, and apoptosis. Galectin-1, -3, and -9 have been implicated in modulating the immune response.

METHODS

Nephrotoxic serum nephritis, which is characterized by crescent formation and glomerular influx of CD8+ cells into glomerular capillaries, was induced in Wistar Kyoto (WKY) rats by injecting rabbit antiglomerular basement membrane serum. Following induction, the rats were treated either with phosphate-buffered saline or dexamethasone, galectin-1, galectin-3, or galectin-9 on alternate days and were sacrificed at day 14. At day 8, splenic lymphocytes were isolated and employed for terminal deoxytransferase-mediated uridine triphosphate nick end-labeling (TUNEL) assay to assess the degree of apoptosis, and the kidneys were utilized to determine the extent of influx of CD4(+) and CD8(+) cells and glomerular damage.

RESULTS

Dexamethasone induced a marked apoptosis of splenic CD4(+) and CD8(+) cells, and it inhibited the production of anti-rabbit IgG and the influx of CD8+ cells and macrophages into the renal glomeruli. Crescent formation and excretion of urinary proteins were also reduced. Galectin-9 failed to induce apoptosis in the CD4(+) cells; however, it induced apoptosis in the CD8(+) cells and inhibited the infiltration of CD8(+) cells. Although galectin-1 and -3 did not induce the apoptosis in the T cells, they inhibited the accumulation of macrophages in the renal glomeruli. Like dexamethasone, the galectins also reduced the crescentic formation, proliferation of glomerular cells, and excretion of urinary proteins.

CONCLUSIONS

Galectin-9 selectively induces apoptosis of the activated CD8(+) cells, while the macrophage influx into the kidney is modulated by all three galectins. This finding raises an interesting possibility for the utility of galectins in the modulation of macrophages that are involved in immune-mediated glomerular diseases.

[Necessity of permanent anticoagulant therapy for isolated mitral valve replacement with bioprosthetic heart valve to prevent the postoperative thromboembolic complications]

One hundred fifty four patients underwent isolated mitral valve replacement with bioprosthetic heart valve at Hyogo Medical College Hospital from November 1973 to December 1998. A porcine bioprosthetic valve was replaced in 82 patients (Hancock 43, Carpentier-Edwards 26, Hancock II 13) and pericardial bioprosthetic valve in 72 patients (Ionescue-Shiley 39, Carpentier-Edwards 33) with a mean follow-up of 1,410 patients-years. Their thromboembolism rates were also analyzed in linear and actuarial term over the 15-year period. The incidence of thromboembolism rate was 2.5%/pt.yr. Thromboembolic free rates for patients with anticoagulant therapy were significantly decreased for patients without therapy. Thromboembolic free rates for patients with atrial fibliration were also were significantly decreased for patients with sinus rhythm because the patients with sinus rhythm were not on anticoagulant therapy. In conclusion, it is necessary for the all patients to be on anticoagulant therapy after mitral valve replacement with bioprosthetic valves, even though patients with sinus rhythm.

Ratio of branched chain amino acid to tyrosine after hepatectomy

The roles of branched chain amino acids (BCAAs) and the tyrosine (Tyr) profile after liver resection were investigated using an inexpensive enzymatic method that was recently developed to quantify their concentrations. The preoperative BCAAs-to-Tyr ratio (BTR) was significantly correlated with the preoperative indocyanin green clearance ratio. The BTR decreased immediately after surgery in all patients, but it was significantly lower in those who had undergone major hepatectomies. After the infusion of BCAA-enriched amino acid solution, the BTR increased substantially, being significantly higher in patients who had not suffered an elevation in total bilirubin after liver resection. These findings indicate that this new enzymatic method to quantify the concentration of BCAAs and Tyr is useful to control the infusion of amino acids and to study the role of amino acid metabolization during the perioperative period.

Giant cell arteritis associated with rheumatoid arthritis monitored by magnetic resonance angiography

A 57-year-old Japanese woman with well controlled rheumatoid arthritis visited our hospital with a severe bitemporal headache and marked fatigue. Based on the classification criteria by the American College of Rheumatology, she was diagnosed as having giant cell arteritis. Magnetic resonance (MR) angiography was performed, from which stenotic changes in the bilateral superficial temporal arteries were strongly suspected. Corticosteroid therapy was quickly started. The patient followed an uneventful course with no complications. Therapeutic effect was confirmed by MR angiographic findings obtained 4 weeks after the initiation of therapy.

Anterior arthroscopic synovectomy plus capsuloplasty with a pedicle graft for the treatment of rheumatoid popliteal cysts

OBJECTIVE

To assess the value of arthroscopic synovectomy plus capsuloplasty with a pedicle graft in patients with rheumatoid cysts of the knee.

METHODS

We examined 31 rheumatoid knees in 9 men and 22 women with an average age of 52.5 years at time of operation. Postoperative clinical symptoms were investigated in comparison with each factor examined before the operation.

RESULTS

Postoperative results showed that 74% of the patients were grade 0 (no swelling or pain), 23% were grade 1 (swelling and slight discomfort after strenuous work or sports), and 3% were grade 2 (swelling and tenderness after normal activities). The improvement rate of the patients with arthroscopic synovectomy plus pedicle graft capsuloplasty was significantly higher than that of the untreated controls or patients with arthroscopic synovectomy or pedicle graft capsuloplasty. The preoperative degree of joint effusion, acceleration in the erythrocyte sedimentation rate, radiographic grades, and histological activity in the knee joint at the time of operation were correlated with the final clinical symptoms.

CONCLUSION

Our method may be useful for preventing recurrence of rheumatoid popliteal cysts.

Production of interleukin-7 and interleukin-15 by fibroblast-like synoviocytes from patients with rheumatoid arthritis

OBJECTIVE

To examine the ability of fibroblast-like synoviocytes in rheumatoid arthritis (RA) to produce interleukin-7 (IL-7) and IL-15, and the ability of these cytokines to induce the proliferation of synovium-infiltrating T cells.

METHODS

Messenger RNA (mRNA) and protein levels of IL-7 and IL-15 in synovial tissue cells and fibroblast cell lines were determined by reverse transcriptase-polymerase chain reaction and enzyme-linked immunosorbent assay, respectively. T cell-enriched populations from RA synovial tissues were isolated by deleting adherent cells after a 14-hour incubation in plastic dishes or by expanding T cells during a 14-day incubation of tissue cells with IL-2 alone, and their proliferative responses to IL-7, IL-15, and IL-2 were measured by 3H-thymidine incorporation.

RESULTS

Freshly isolated cells from RA synovial tissues more strongly expressed mRNA for both IL-7 and IL-15 compared with the cells from osteoarthritis tissues, and could spontaneously release greater amounts of these cytokine proteins in culture. Fibroblast cell lines prepared from RA patients were able to produce large amounts of IL-15 and small amounts of IL-7 at both the transcriptional and protein levels, and their cytokine production was significantly elevated when stimulated with IL-1 and tumor necrosis factor alpha. Purified synovial tissue macrophages spontaneously released IL-15 but not IL-7, and synovial T cells did not produce either cytokine. IL-7 and IL-15, similar to IL-2, stimulated the proliferation of synovial tissue T cells from RA patients; IL-7 was less potent than IL-15 or IL-2.

CONCLUSION

These results indicated that fibroblast-like synoviocytes are an important source of the cytokines with IL-2-like activity, IL-15 and IL-7, in RA joints, and that IL-15 may be mainly responsible for local T cell activation and expansion in the presence of deficient IL-2 production by T cells.

Stereoselective pharmacokinetics of RS-8359, a selective and reversible inhibitor of A-type monoamine oxidase, in rats, mice, dogs, and monkeys

RS-8359, (+/-)-4-(4-cyanoanilino)-5,6-dihydro-7-hydroxy-7H-cyclopenta[d]-py rimidine, inhibits, selectively and reversely, A-type monoamine oxidase (MAO-A). In order to clarify the stereoselective metabolism of this drug, plasma concentrations of the [R] and [S]-enantiomers of RS-8359 were determined by chiral column HPLC after oral administration of each enantiomer to rats, mice, dogs, and monkeys. After administration of the [R]-enantiomer, high levels were retained in all animal species studied. On the other hand, when the [S]-enantiomer was administered, plasma concentrations decreased rapidly in rats and mice, and extremely rapidly in dogs, while in monkeys, only a trace amount was detected immediately after dosing. Thus, it was found, as a common phenomenon in rats, mice, dogs, and monkeys, that plasma concentrations of the [S]-enantiomer were markedly lower than those of the [R]-enantiomer. Secondly, the [R]-enantiomer was observed in plasma after administration of the [S]-enantiomer, and the [S] to [R] chiral inversion rate was estimated from AUC([R] after [S])/AUC([R] after [R]). The percentage was 45.8% in rats, 3.8% in mice, 0.8% in dogs, and 4.2% in monkeys. Further, the [S]-enantiomer was detected in plasma of SD rats dosed with the [R]-enantiomer, suggesting [R] to [S] chiral inversion in rats. These results show marked species differences in the chiral inversion of the cyclopentanol group of RS-8359. A mechanism of chiral inversion is discussed based on experiments using isolated rat hepatocytes.

Diversity of thyrotropin-releasing hormone receptors in the pituitary and discrete brain regions of rats

In order to analyze the receptor properties of central nervous system (CNS)-stimulant thyrotropin-releasing hormone (L-pyroglutamyl-L-histidyl-L-prolinamide, TRH), we evaluated the binding of TRH and its analog taltirelin hydrate ((-)-N-[(S)-hexahydro-1-methyl-2,6-dioxo-4-pyrimidinylcarbonyl]-L- histidyl-L-prolinamide tetrahydrate; taltirelin, TA-0910) in rat anterior pituitary and several brain regions. There was a specific binding of [3H]methyl TRH (MeTRH) in the anterior pituitary, hypothalamus, brain stem, cerebral cortex and cerebellum with Kd values of 1.0-1.6 nM. The inhibition of [3H]MeTRH binding by TRH and taltirelin was monophasic in the anterior pituitary, hypothalamus and brain stem with Ki values of 6.3-8.0 nM and 145.5-170.4 nM for TRH and taltirelin, respectively. In contrast, the biphasic inhibition was revealed in the cerebral cortex and cerebellum. The Ki values for TRH and taltirelin were 4.1-4.3 nM and 67.8-73.4 nM for the high affinity binding site and 3.6-4.2 microM and 82.3-197.5 microM for the low affinity binding site, respectively. Addition of 100 microM GTP or its analog 5'-guanylylimidodiphosphate (Gpp[NH]p) affected neither the biphasic inhibition by TRH nor that by taltirelin. Thus the results suggest the presence of distinct high and low affinity TRH receptors in the CNS in contrast to the pituitary.

Effect of leukocytapheresis therapy using a leukocyte removal filter in Crohn's disease

Eighteen patients with active Crohn's disease were treated with one leukocytapheresis session per week for a five-week intensive therapy, decreasing to one leukocytapheresis session per month for five sessions of initial maintenance therapy. Nutritional indices, inflammatory reactions, flow cytometry profiles, and cytokine production were also assessed before and after the intensive and initial maintenance therapy. Nine of the patients (50%) attained remission at the end of the intensive therapy. The nine non-remission patients had exhibited longer periods of suffering and more severely affected sites prior to the therapy. In 14 of 18 patients (77.8%), the nutritional indices, Internal Organization of Inflammatory Bowel Disease (IOIBD) score and Crohn's Disease Activity Index (CDAI) improved from the pretherapy levels, but only the remission group (50%) showed improvement in C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR). The remission group showed significantly higher pretherapy CD4+ CD45+ cell ratios and interleukin-2 (IL-2) production than the non-remission group, and significantly lower activated cells.

Alpha1-antitrypsin deficiency and toxic shock: a Japanese autopsy case

A 74-year-old Japanese female presented with the sudden appearance of hemorrhagic purpuric ecchymoses on her lower extremities and with fever and chills, and died on the fifth day of hospitalization. A diagnosis of alpha1-antitrypsin (AT) deficiency was made postmortem. The liver weighed 1260 g. Histological sections from the liver revealed rather severe fatty changes of the hepatocytic parenchyma and partial loss of the normal hepatic architecture with fibrosis. The hepatocytes contained periodic acid-Schiff (PAS)-positive, diastase-resistant and alpha1-AT-positive intracytoplasmic globules. There was markedly increased inflammatory infiltration with severe edema and congestion, accompanied by fibrous, thickened pulmonary alveolar walls with fibrin deposition in the lungs (right, 410 g; left, 280 g), which suggest findings similar to those seen in multiple organ failure. Mild pulmonary emphysema was also present in the upper lobes of the lungs. Histological sections from the hemorrhagic necrotic ecchymoses of the skin showed marked neutrophil infiltration over the subcutaneous tissue with bleeding and blistering. A finding of thrombophlebitis was also found in the subcutaneous tissue. No bacteria were detected in the ecchymoses, the urine or the blood. Plasma protein analysis revealed a lower level (9.5 micromol/L) of alpha1-AT and a higher level (330 U) of anti-streptolysin O (ASO). These findings suggest that the patient died of toxic shock-like syndrome and that alpha1-AT deficiency might have facilitated the development of the toxic shock. To our knowledge, this is the first case of toxic shock associated with alpha1-AT deficiency.

Peripheral blood neutrophils of germ-free rats modified by in vivo granulocyte-colony-stimulating factor and exposure to natural environment

Peripheral blood neutrophils from germ-free (GF), specific-pathogen-free (SPF) and conventional (CV) rats were compared. Besides neutropenia and impaired superoxide anion generation as previously reported, it was found that GF rats had lower phagocytic function (70%) and generated less nitric oxide than the other rats. GF and SPF rats were injected with recombinant human granulocyte-colony-stimulating factor (rhG-CSF), or were transferred to natural environment. It was found that total number, phagocytosis, intracellular killing, ratio of phagocytosis versus killing (killing efficiency) and nitric oxide production induced by recombinant rat interferon-gamma (rrIFN-gamma) were normalized upon injection of rhG-CSF. These results indicate that rhG-CSF may stimulate neutrophil production and induce the expression of neutrophil receptors for phagocytosis and nitric oxide production in GF rats. Although lower than in CV rats, the level of superoxide produced was sufficient for normal neutrophil-killing efficiency in SPF and GF rats. In SPF rats, this could be amended by exposure to natural environment. However, neither rhG-CSF injection nor transfer to natural environment could increase the generation of superoxide anion in GF rats.

[An evaluation of efficacy of minocycline as an anti-rheumatic drug in patients with active and refractory rheumatoid arthritis]

The efficacy and safety of minocycline was investigated in Japanese patients with rheumatoid arthritis (RA) who had already received more than three disease modifying anti-rheumatic drugs (DMARDs). Minocycline was administered at 100 mg twice a day to fifteen patients with active RA. The drug efficacy was evaluated by the clinical variables including the number of painful and/or swollen joints, the duration of morning stiffness, grip strength, the erythrocyte sedimentation rate, serum concentrations of C-reactive protein, and the titer of rheumatoid factor. Three patients experienced adverse effects such as dizziness and abdominal pain or discomfort, but only one patient with abdominal pain and dizziness was discontinued. Fourteen RA patients, who had taken minocycline for at least 6 months, were subjected to the clinical evaluation. Among them, 8 patients (54%) showed a significant improvement of clinical valuables for disease activity, beginning even at 4 weeks of the therapy. The continued effects were observed in 8 patients with over 1 year-minocycline therapy. Intriguingly, an active patient with a history of multiple DMARDs-resistancy showed a marked favorable response to this drug. The present study indicates that minocycline may be an effective DMARD with highly safe performance for patients with active and refractory RA. This is the first demonstration of the benefit of minocycline in the Japanese patients.

Presence of HSV-1 DNA in semen and menstrual blood

Using a specifically designed diagnostic PCR assay with nested primers the following could be achieved: (1) a group of 22 clinically indistinguishable women attending an infertility clinic, 18 with repeated embryo transfer failure, and asymptomatic for HSV-1 could be divided into two subgroups after testing their menstrual blood. An HSV-DNA positive (50%) and HSV-DNA negative group (50%) could be distinguished. None of the four controls were positive; (2) semen from 154 infertile and 24 fertile men was tested in relation to infertility. In the group of infertile men 37 (24%) were HSV-DNA positive but none of the fertile control (0%) was positive; (3) treatment of both partners with an antiviral drug resulted in two pregnancies; (4) HLA data on four of the couples in which the wife's menstrual blood was HSV positive was compared to seven HSV negative couples and 22 infertile, as well as 22 fertile couples. Clustering of class I HLA (B61 and Cw3) was found with a significant increase in Cw3 in both partners.

Increased type 2 cytokine expression by both CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells in blood circulation is associated with high serum IgE but not with atopic dermatitis

Type 2 cytokines, such as interleukin-4 (IL-4) and IL-13, are associated with immunoglobulin E (IgE) production. This association has also been observed in CD8+ T cells from patients infected with leprosy and human immunodeficiency virus (HIV). Using intracellular cytokine staining and flow cytometry, the cytokine profile [IL-2, IL-4, IL-10, IL-13, and interferon (IFN)-gamma] of both CD4+ and CD8+ memory/effector T cells circulating in atopic dermatitis (AD) patients was investigated at the single cell level. The levels of type 2 cytokines in CD4+ T cells or CD8+ T cells in AD patients with high levels of serum IgE (AD-H), low levels of serum IgE (AD-L), and healthy controls were compared. Increased production of IL-4 and IL-13 in both CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells after 4 h in vitro stimulation with phorbol 12-myristate 13-acetate and ionomycin, was more prominent in AD-H patients than in AD-L patients or healthy controls, whereas IFN-gamma-producing CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells were relatively diminished in AD-H patients. CD4+ T cells and CD8 + T cells from AD-H patients, cultured for 48 h with phorbol 12-myristate 13-acetate and ionomycin, released larger amounts of IL-4 and IL-13 but smaller amounts of IFN-gamma than both types of cells from AD-L patients or healthy controls. In addition, when stimulated with immobilized anti-CD3 monoclonal antibody (MoAb) and anti-CD28 MoAb, CD4+ CD45RO+ T cells and CD8+ CD45RO+ T cells from AD-H patients contained more IL-4-producing cells but fewer IFN-gamma-producing cells compared with healthy controls. Finally, spontaneous mRNA expression of IL-4 in blood CD8+ CD45RO+ T cells isolated from AD-H patients was increased, as determined by reverse transcriptase-polymerase chain reaction. Therefore, in AD patients with high IgE levels, type 2 cytokine (IL-4 and IL-13) expression is associated with IgE production, in both CD4+ CD45RO+ T cell and CD8+ CD45RO+ T cell subsets.

Influences of low intensity exercise on body composition, food intake and aerobic power of sedentary young females

The present study was designed to investigate the influences of aerobic training on the body composition, aerobic power and food intake of sedentary young females in relation to the initial levels of these variables. Thirty one untrained college females (age = 19.8 +/- 0.2 yr, stature = 154.4 +/- 0.8 cm, body mass = 53.3 +/- 1.2 kg, mean +/- SEM) participated in an exercise regimen consisting of 40% of maximum oxygen uptake (VO2max) for 30 minutes per day on a bicycle ergometer 5 times a week in a training period of 12 weeks. Food consumption was ad libitum but the content of daily food intake was recorded accurately throughout the whole training period and analyzed weekly. The average body mass index (BMI) and fat mass relative to body mass (% FM), estimated from the data of skinfold thickness, decreased significantly after the 12 wk training. There were significant negative correlations between the relative changes (% delta s) and initial levels of both body mass (r = -0.447, p < 0.05) and fat mass (r = -0.638, p < 0.05), but the corresponding correlation for lean body mass (LBM) was not significant (r = 0.186, p > 0.05). While the energy intake during the training period did not differ significantly from that during the control period on the average, the % delta value in energy intake between the two periods was negatively correlated to the energy intake during the control period (r = -0.604, p < 0.05). In addition, there were low but significant negative correlations between both the initial levels of BMI and %FM and % delta in energy intake; r = -0.413 (p < 0.05) for BMI and r = -0.393 (p < 0.05) for %FM. However, no significant correlations were found between % delta in energy intake and those in body composition variables (r = 0.116 to 0.237, p > 0.05). On the average VO2max relative to body mass (VO2max/BM) increased significantly, but VO2max relative to LBM (VO2max/LBM) did not. However, not only VO2max/BM but also VO2max/LBM was negatively correlated to the initial level; r = -0.671 (p < 0.05) for VO2max/BM and r = -0.625 for VO2max/LBM. Thus, the present results indicate that whether the body composition, food intake and aerobic power of sedentary young females can be modified by the exercise regimen eliciting 40% of VO2max depends on their initial levels.

Flow cytometric single-cell analysis of cytokine production by CD4+ T cells in synovial tissue and peripheral blood from patients with rheumatoid arthritis

OBJECTIVE

To determine the cytokine profile of CD4+ T cells in the synovial tissue (ST) of rheumatoid arthritis (RA) patients at the single-cell level.

METHODS

Unseparated ST cells and paired CD4+ T cells separated from the peripheral blood (PB) and ST of RA patients were stimulated for 4 hours with phorbol myristate acetate (PMA) plus calcium ionophore A23187, or for 6 hours with immobilized anti-CD3 plus anti-CD28, in the presence of brefeldin A. Cells were stained for intracellular cytokines such as interferon-gamma (IFNgamma), interleukin-2 (IL-2), IL-4, IL-10, and IL-13, in combination with cell surface markers. The percentages of cytokine-producing T cells were analyzed by flow cytometry.

RESULTS

When ST cells were stimulated with PMA plus A23187 in bulk culture, IFNgamma-producing T cells were more frequently detected in the CD8+ subset, but cells producing other cytokines were found in the CD4+ subset. Purified ST CD4+ T cells, after stimulation with PMA plus A23187, were able to produce higher levels of IFNgamma but lower levels of IL-4 and IL-13, by analysis at the single-cell level, as compared with the PB CD4+, CD45RO+ T cells. The majority of IL-4- or IL-13-producing ST CD4+ cells produced IFNgamma, although PB CD4+ T cells rarely showed this cytokine pattern. IL-10-producing CD4+ T cells were more frequently found in the ST than in the PB. Of interest, most of the IL-10-producing ST CD4+ T cells were able to produce IFNgamma. IL-2-producing CD4+ T cells were similarly present in both compartments. Similar intracellular cytokine patterns were observed with anti-CD3 plus anti-CD28 stimulation, although the number of detected cells was lower.

CONCLUSION

These data indicate that CD4+ T cells present within the inflamed synovium have apparently distinct cytokine profiles from those of memory CD4+ T cells in the PB, as typified by their ability to secrete both IFNgamma and IL-10.

Induction of DNA fragmentation by nicotine in human myelogenous leukemic cell lines

The effect of nicotine, a component of tobacco, on the cytokine production and cell growth of various cultured cells was investigated. Nicotine did not stimulate, but rather inhibited the tumor necrosis factor production by human peripheral blood mononuclear cells at higher doses. Cytotoxic concentrations of nicotine did not induce the monocytic and granulocytic differentiation of human myelogenous leukemic cell lines (HL-60, ML-1). Nicotine induced internucleosomal DNA cleavage in these leukemic cell lines but not in human peripheral blood lymphocytes and polymorphonuclear cells. The fragmentation-inducing activity of nicotine was not prevented by simultaneous addition of ascorbic acid. Flow cytometry showed a slight increase in the number of G2 + M phase cells, before the appearance of the apoptosis peak. Nicotine transiently increased the intracellular calcium concentration to higher levels in leukemic cells than in normal leukocytes. These data suggest that the induction of DNA fragmentation requires elevation of intracellular calcium concentration above a certain threshold level.

Calcium mobilization during nicotine-induced cell death in human glioma and glioblastoma cell lines

Nicotine dose-dependently induced cytotoxicity in human glioma (KG-1-C) and glioblastoma (GBS-1, T98G) cell lines, but could not induce internucleosomal DNA cleavage, in contrast to apoptosing human myelogenous leukemic cell lines. Human glioma/glioblastoma cell lines thus might have a chromatin structure resistant to endonuclease digestion. Nicotine induced a rapid increase in the intracellular calcium concentration. Confocal experiments with Fluo-3 fluorescence revealed that nicotine elevated the free Ca2+ concentration in both nuclear and cytoplasmic regions of the cells, and the elevation of Ca2+ in the nuclear region was more pronounced than that of the cytoplasmic region. The present study suggests that nuclear accumulation of Ca2+ is an important initial step for cell death induction by nicotine.

Effects of taltirelin hydrate (TA-0910), a novel thyrotropin-releasing hormone analog, on in vivo dopamine release and turnover in rat brain

Effects of taltirelin hydrate (CAS 103300-74-9, TA-0910), a novel thyrotropin-releasing hormone (TRH) analog, on the cerebral monoamine systems, especially the release and turnover of dopamine (DA) in rat brain were compared with those of TRH by intraperitoneal administration. Taltirelin hydrate (1-10 mg/kg) increased the extracellular levels of DA and its metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) in the nucleus accumbens and corpus striatum for 3 h in a microdialysis study. TRH (30 mg/kg) also increased the levels of these substances, the potency of TRH being the same as that of taltirelin hydrate at doses of 1-3 mg/kg. Taltirelin hydrate (10 mg/kg) also caused an increase in 3-methoxytyramine (3-MT: DA metabolite) until 6 h after the treatment and L-3-dihydroxyphenylalanine (DOPA: precursor of DA and noradrenaline). Taltirelin hydrate also increased the 3-methoxy-4-hydroxyphenylglycol (MHPG: noradrenaline metabolite) level in the frontal cortex and hypothalamus, and 5-hydroxytryptophan (5-HTP: serotonin precursor) accumulation and 5-hydroxyindoleacetic acid (5-HIAA: serotonin metabolite) level in the nucleus accumbens or corpus striatum. These results suggest that taltirelin hydrate possesses not only an enhancing effect on DA release, but also a stimulating effect on the monoamine system. Moreover, these actions were 10-30 times stronger and also longer-lasting than those of TRH. In addition, the mechanisms of DA release induced by these drugs were different from those induced by methamphetamine.