The ex vivo production of ammonia predicts l-asparaginase biological activity in children with acute lymphoblastic leukemia

Patients with acute lymphoblastic leukemia (ALL), who develop antiasparaginase antibodies without clinical allergic reactions (“silent inactivation”) during l-asparaginase (l-Asp) treatment, have poor outcomes. Ammonia is produced by hydrolysis of asparagine by l-Asp. We postulated that plasma ammonia level might reflect the biological activity of l-Asp. Five children with ALL treated according to the Tokyo Children’s Cancer Study Group (TCCSG) protocol were enrolled. Plasma ammonia levels were analyzed immediately and 1 h after incubation at room temperature and “ex vivo ammonia production” was defined as increase in ammonia concentration. Ex vivo ammonia production well correlated with l-Asp activity (r = 0.882, P < 0.01, n = 23). It always exceeded 170 μg/dL (170–345 μg/dL) in induction therapy. We found 3 patients whose ammonia production was negligible during later phases of therapy. Antiasparaginase antibody was detected and l-Asp activity decreased in these patients. Ex vivo ammonia production is a surrogate marker of l-Asp biological activity.     

Posttreatment nadir M-protein level is a stronger discriminator of survival following plateau attainment than is percent reduction in M-protein in patients with IgG myeloma

We conducted a retrospective study of patients with IgG or IgA myeloma who attained plateau to evaluate the relationships between survival and posttreatment nadir M-protein levels and between survival and the response to treatment evaluated by the percent reduction in M-protein. Of the 127 patients comprising 92 IgG and 35 IgA myeloma patients with disease stages II or III, 51 (40.2%) attained plateau. For IgG myeloma patients who attained plateau, survival time was not affected by the percent reduction in M-protein (median survival, 59.5 months for responding patients versus 54.4 months for nonresponding patients, P = .6910). Posttreatment nadir M-protein level, however, did affect survival time (median survival, 61.2 months for <3000 mg/dL versus 25.7 months for >3000 mg/dL, P = .0439). These findings suggest that the posttreatment nadir M-protein level is a stronger discriminator of survival following plateau attainment than the percent reduction of M-protein in patients with IgG myeloma.     

Functional expression of a Delta12 fatty acid desaturase gene from spinach in transgenic pigs

Linoleic acid (18:2n-6) and alpha-linolenic acid (18:3n-3) are polyunsaturated fatty acids that are essential for mammalian nutrition, because mammals lack the desaturases required for synthesis of Delta12 (n-6) and n-3 fatty acids. Many plants can synthesize these fatty acids and, therefore, to examine the effects of a plant desaturase in mammals, we generated transgenic pigs that carried the fatty acid desaturation 2 gene for a Delta12 fatty acid desaturase from spinach. Levels of linoleic acid (18:2n-6) in adipocytes that had differentiated in vitro from cells derived from the transgenic pigs were approximately 10 times higher than those from wild-type pigs. In addition, the white adipose tissue of transgenic pigs contained approximately 20% more linoleic acid (18:2n-6) than that of wild-type pigs. These results demonstrate the functional expression of a plant gene for a fatty acid desaturase in mammals, opening up the possibility of modifying the fatty acid composition of products from domestic animals by transgenic technology, using plant genes for fatty acid desaturases.     

Risk factors in the pregnancy of patients with systemic lupus erythematosus: association of hypocomplementaemia with poor prognosis.

Fetal wastage is still high in the pregnancies of patients with systemic lupus erythematosus (SLE). We examined retrospectively the cases of 38 patients with inactive SLE in whom pregnancy was either desired or had already been obtained. The prevalence of antiphospholipid antibodies in the group with fetal loss was high. The antibodies were, however, also detected in five of 14 patients who had had a live birth. It was noted that low levels of serum complement activity (CH50 less than 25 U/ml) occurred in five of six patients with fetal loss, but in only two of 22 with a live birth. Serial studies also confirmed a close association between decreased serum complement activity and poor fetal prognosis in lupus pregnancy. Treatment with increased doses of prednisolone may help to achieve successful live births. Thus hypocomplementaemia may be associated with a worse prognosis for the fetus in the pregnancies of some patients with SLE in remission.     

Difference in changes of membrane fluidity of polymorphonuclear leukocytes stimulated with phorbol myristate acetate and formyl-methionyl-leucyl-phenylalanine: role of excited oxygen species

Polymorphonuclear leukocytes (PMN) were stimulated with phorbol myristate acetate (PMA) and N-formyl-methionyl-leucyl phenylalanine (FMLP) to clarify the role of excited oxygen species in inducing changes of membrane fluidity. Membrane fluidity was assessed by the excimer-forming lipid technique using pyrenedecanoic acid and flow cytometry. Membrane fluidity of PMN decreased following stimulation with PMA, and the extent of decrease was both time- and dose-dependent. FMLP at 10(-5) M induced a decrease, while FMLP at 10(-7) M induced a rapid increase. On stimulation with 10(-7) M FMLP as well as in a resting condition, the change of membrane fluidity of PMN from patients with chronic granulomatous disease (CGD) was similar to that of normal PMN. However, on stimulation with PMA or 10(-5) M FMLP, CGD PMN did not show a significant decrease. In addition, normal PMN incubated with catalase inhibited the decrease. These findings suggest that the generation of excited oxygen species, particularly of H2O2, is important in inducing a decrease of PMN membrane fluidity.     

Lack of Pulse and Surge Modes and Glutamatergic Stimulation of Luteinising Hormone Release in Kiss1 Knockout Rats

Kisspeptin, encoded by the Kiss1 gene, has attracted attention as a key candidate neuropeptide in controlling puberty and reproduction via regulation of gonadotrophin‐releasing hormone (GnRH) secretion in mammals. Pioneer studies with Kiss1 or its cognate receptor Gpr54 knockout (KO) mice showed the indispensable role of kisspeptin‐GPR54 signalling in the control of animal reproduction, although detailed analyses of gonadotrophin secretion, especially pulsatile and surge‐mode of luteinising hormone (LH) secretion, were limited. Thus, in the present study, we have generated Kiss1 KO rats aiming to evaluate a key role of kisspeptin in governing reproduction via pulse and surge modes of GnRH/LH secretion. Kiss1 KO male and female rats showed a complete suppression of pulsatile LH secretion, which is responsible for folliculogenesis and spermatogenesis, and an absence of puberty and atrophic gonads. Kiss1 KO female rats showed no spontaneous LH/follicle‐stimulating hormone surge and an oestrogen‐induced LH surge, suggesting that the GnRH surge generation system, which is responsible for ovulation, does not function without kisspeptin. Furthermore, challenge of major stimulatory neurotransmitters, such as monosodium glutamate, NMDA and norepinephrine, failed to stimulate LH secretion in Kiss1 KO rats, albeit they stimulated LH release in wild‐type controls. Taken together, the results of the present study confirm that kisspeptin plays an indispensable role in generating two modes (pulse and surge) of GnRH/gonadotrophin secretion to regulate puberty onset and normal reproductive performance. In addition, the present study suggests that kisspeptin neurones play a critical role as a hub integrating major stimulatory neural inputs to GnRH neurones, using newly established Kiss1 KO rats, which serve as a useful model for detailed analysis of hormonal profiles.     

7-Nitroindazole attenuates nitrotyrosine formation in the early phase of cerebral ischemia-reperfusion in mice.

The purpose of this study was to evaluate the role of neuronal nitric oxide synthase (nNOS) in nitrotyrosine (NO2-Tyr) formation in the early phase of ischemia-reperfusion in mouse brain. Using a hydrolysis/high pressure liquid chromatography (HPLC) procedure (0.6 microM detection limit), we measured %NO2-Tyr (ratio of NO2-Tyr to total tyrosine) in 23 male C57Black/6J mice subjected to 2-h middle cerebral artery occlusion followed by 0.5-h reperfusion, in the presence (25 or 50 mg/kg) and absence of 7-nitroindazole (7-NI), a relatively specific nNOS inhibitor. At 25 mg/kg, 7-NI reduced NO2-Tyr formation to about a half of that in the vehicle-treated group (0.10 +/- 0.07 vs. 0.18 +/- 0.05%), while 50 mg/kg suppressed NO2-Tyr formation to below the limit of detection, indicating that nNOS is responsible for most of the NO2-Tyr formation in the early phase after reperfusion.     

Lack of CD4+CD25+FOXP3+ regulatory T cells is associated with resistance to intravenous immunoglobulin therapy in patients with Kawasaki disease

The aim of this study was to investigate changes in CD4⁺CD25⁺FOXP3⁺ regulatory T cells (Tregs) throughout the clinical course of Kawasaki disease (KD) and correlations with response to intravenous immunoglobulin (IVIg) therapy. Participants comprised 18 patients who fulfilled the diagnostic criteria for KD and 20 healthy subjects. Expressions of CD25 and FOXP3 among all CD4⁺ T cells in peripheral blood mononuclear cells were analyzed by flow cytometry before and 7 and 30 days after IVIg therapy. Before treatment, percentages of CD4⁺CD25⁺FOXP3⁺ Tregs among total CD4⁺ Tregs were significantly lower among KD patients (4.19 %; range, 0.16–8.11 %) than among healthy subjects (7.32 %; 4.18–13.42 %; P?=?0.0001). Both percentages and absolute numbers of CD4⁺CD25⁺FOXP3⁺ Tregs on day?7 after IVIg therapy were significantly increased compared with values before treatment (8.02 % (range, 0.51–12.6 %) vs. 4.19 % (range, 0.16–8.11 %), P?=?0.0005; 93.25/?μL (range, 6.67–258.05) vs. 41.85/?μL (range, 0.44–160.62), P?<?0.0001, respectively). Moreover, percentages and absolute numbers of CD4⁺CD25⁺FOXP3⁺ Tregs before treatment were significantly lower in the IVIg-resistant group than in the IVIg-sensitive group (0.18 % (range, 0.16–3.34 %) vs. 4.52 % (range, 2.8–8.11 %), P?=?0.0022; 0.68/μL (range, 0.44–53.81) vs. 51.66/μL (range, 2.88–160.62), P?=?0.0098, respectively). The frequency of CD4⁺CD25⁺FOXP3⁺ Tregs in four of the five IVIg-resistant patients at diagnosis was more than 3 standard deviations below that in healthy subjects. Two of these four patients displayed coronary abnormalities, and one of these two patients developed coronary aneurysm. Conclusion: Lack of CD4⁺CD25⁺FOXP3⁺ Tregs before treatment may predict resistance to IVIg therapy in patients with KD.     

Comparison of time trends in colorectal cancer incidence (1973-97) in East Asia, Europe and USA, from Cancer Incidence in Five Continents Vol. IV-VIII

Time trends of age-standardized rate (ASR) of colorectal cancerincidence (ICD-10: colon (C18), rectal and anal canal (C19–C21)) were compared among 18 selected cancer registries and ethnic/racialgroups in Asia, Europe and USA. Data source was the Cancer Incidencein Five Continents Vol. IV–VIII (years at diagnosis: 1973–77,1978–82, 1983–87, 1988–92 and