Analysis of 8-hydroxydeoxyguanosine 5'-monophosphate (8-OH-dGMP) as a reliable marker of cellular oxidative DNA damage after gamma-irradiation

In order to improve 8-hydroxyguanine (8-OH-Gua) detection in DNA, we digested isolated DNA with nuclease P1 and analyzed for 8-hydroxydeoxyguanosine 5'-monophosphate (8-OH-dGMP) using a high-performance liquid chromatography system equipped with an electrochemical detector (HPLC-ECD). The amount of 8-OH-Gua in the DNA was expressed as the ratio of 8-OH-dGMP to deoxycytidine monophosphate (dCMP). Using this analysis, the background level of 8-OH-Gua in DNA from human lung carcinoma cells (A549) was several-fold lower than that obtained by a previous method. A549 cells were exposed to 20-60 Gy of gamma-radiation and an increase in 8-OH-Gua concentration was observed with increasing gamma-ray dose (0.3 residues per 10(7) dCMP per Gy). Moreover, by an immunohistochemical procedure using a commercial FITC-kit, 8-OH-Gua was clearly detected in A549 cells and the fluorescence intensity of cells with oxidative DNA damage increased with the doses of gamma-irradiation. Using an endonuclease nicking assay, we also found that gamma-rays decreased 8-OH-Gua repair activity. The results indicate that 8-OH-dGMP is a useful and sensitive marker for estimating oxidative damage in DNA.     

Cultures of human fetal pancreatic islet cells

Cultures of islets cells were obtained from the cadaveric pancreas of 16–25-week human fetuses. During culture two waves of mitotic activity were observed. An increase in the insulin concentration in the culture medium took place after a wave of mitotic activity.Department of Artificial Organs and Assisted Circulation, Laboratory of Pathomorphology, Scientific-Research Institute of Transplantation and Artificial Organs, Ministry of Health of the USSR. Laboratory of Biological Standardization of Hormones, Institute of Experimental Endocrinology and Hormone Chemistry, Academy of Medical Sciences of the USSR. Maternity Home No. 26, Moscow. Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 88, No. 8, pp. 202–204, August, 1979.     

Physiological Correlates of Mental Activity: Eye Movements, Alpha, and Heart Rate During Imagining, Suppression, Concentration, Search, and Choice

Rapid eye movements (REMs), EEG alpha, and tonic heart rate (HR) were measured during 6 types of cognitive tasks—imagining a liked person, suppressing thoughts of the person, searching one's mind for alternative solutions, arithmetic involving little concentration, problems involving high concentration, and choosing a preferred activity. The latter 3 required verbalization, the former 3 did not. Only suppression and search did not differ significantly from each other on at least one physiological variable. Imagining, suppression, and search yielded few REMs, high alpha, and low HR. High concentration yielded many REMs, low alpha, and high HR. Choice yielded many REMs, low alpha, and intermediate HR. Low concentration yielded few REMs, low alpha, and high HR. Suppression produced somewhat less alpha than imagining but did not differ significantly in REMs.     

Secretory immunoglobulin A and cardiovascular reactions to mental arithmetic, cold pressor, and exercise: effects of alpha-adrenergic blockade

The mechanism underlying acute changes in secretory immunoglobulin A (sIgA) remains to be determined. In this experiment, sIgA and cardiovascular activity were monitored at rest and while participants performed a mental arithmetic task, cold pressor, and submaximal cycle exercise following placebo or 1 mg of the alpha-adrenergic blocker, doxazosin. Under placebo, the tasks produced patterns of cardiovascular activity indicative of combined alpha- and beta-adrenergic, alpha-adrenergic, and beta-adrenergic activation, respectively. Doxazosin was associated with reduced blood pressure during cold pressor, but not during arithmetic or exercise. Mental arithmetic elicited increases in sIgA concentration and exercise produced increases in both sIgA concentration and secretion rate; these changes were unaffected by alpha blockade. In contrast, the cold pressor was associated with decreases in both sIgA concentration and secretion rate, which were blocked by doxazosin. These data suggest that acute decreases, but not increases, in sIgA are mediated by alpha-adrenergic mechanisms.     

Miltefosine (Impavido): the first oral treatment against leishmaniasis

Miltefosine is a novel antileishmanial drug that has significant selectivity in both in vitro and in vivo models. Clinical efficacy was demonstrated for the treatment of visceral leishmaniasis with the advantage of oral administration over the currently recommended antileishmanial drugs that require parenteral administration. Miltefosine produces high cure rates also in patients resistant to the standard antimonial therapy.     

Patterns of spontaneous unitary discharge in thalamic ventro-basal complex during wakefulness and sleep

Summary Influences of the wake-sleep states on spontaneous activity of thalamic ventro-basal neurons have been studied in the chronic cat using the following analyses for cell discharges: mean firing rate, interspike histogram and joint interval histogram (J.I.H.). While slow wave sleep is accompagnied by a characteristic firing pattern it is more difficult to compare spontaneous unit activity during wakefulness (W) and desynchronised sleep (D).A detailed analysis (especially of the J.I.H.) of the same neuron during the three states indicates marked differences between W and D; on the contrary, the intraburst pattern shows definite similarities between D and S. The greatest stability in the firing pattern of a given neuron is found during S on long recording. During D the variability in the firing pattern is mainly due to phasic activity but may also be related to tonic changes.     

Anti-microbial active composite nanoparticles with magnetic core and photocatalytic shell: TiO2-NiFe2O4 biomaterial system

Reverse micelle and chemical hydrolysis techniques have been successfully combined to synthesize composite nanoparticles consisting of a photocatalytic shell of titania and a magnetic core of nickel ferrite. The nature of titania shell, i.e. anatase or brookite, depends on the TiO₂ and NiFe₂O₄ molar ratio. The work presented here describes the photocatalytic and anti-microbial activity of the composite nanoparticles together with the magnetic characteristics of the nickel ferrite core. The TiO₂-coated NiFe₂O₄ nanoparticles retain the magnetic characteristics of uncoated nanocrystalline nickel ferrites (superparamagnetism; absence of hysteresis, remanence and coercivity at 300 K) encouraging their application as removable anti-microbial photocatalyst nanoparticles that can be extracted from the sprayed surface (human body or environment) after exposure.     

Stress-induced impairment of inhibitory avoidance learning in female neuromedin B receptor-deficient mice

Neuromedin B (NMB) is a mammalian bombesin (BN)-like peptide that exerts its function via the neuromedin B receptor (NMB-R). The NMB/NMB-R system is involved in stress response, and therefore we examined behavioral properties in female mice lacking NMB-R using a restraint-induced stress paradigm. Thirty minutes of restraint in a wire mesh cage constituted a sufficient stress stimulus for mice as evidenced by elevated blood glucose concentrations in stressed wild-type and NMB-R-deficient mice. Using a one-trial passive avoidance test, stressed NMB-R-deficient mice exhibited a marked reduction in memory performance. NMB-R-deficient mice exhibited elevated spontaneous activity in a novel environment compared to non-stressed mutant mice after 30-min stress, and a similar difference was also observed between stressed/non-stressed wild-type mice. An elevated plus maze test showed that the stress stimulus had no effect on anxiety in either wild-type or NMB-R-deficient mice. Furthermore, pain response of wild-type and NMB-R-deficient mice induced by electric foot shock was not affected under either stressed or non-stressed conditions. These results indicate that impaired memory performance in stressed NMB-R-deficient mice is not a consequence of changes in spontaneous activity, anxiety, or pain response, and suggest that the NMB/NMB-R pathway may play a role in regulating the stress response via the neural system that controls learning and memory.     

Viral hemagglutinin augments peptide-specific cytotoxic T cell responses

In attempt to increase the induction of peptide-specific cytolytic T cells (CTL) we investigated the effect of the Newcastle disease virus (NDV) hemagglutinin-neuraminidase (HN) gene product on the activation of peptide-specific CTL. Spleen cells of CH3 mice immunized against the influenza nucleoprotein peptide 50–63 (NP 50–63) were restimulated in vitro (i) with peptide-pulsed syngeneic fibroblast cells (Ltk^?) as antigen-presenting cells, which were in addition (ii) infected with NDV or (iii) stably transfected with the HN cDN A of NDV. A greater than sixfold increase in peptide-specific CTL responses was observed in cultures restimulated with peptide-pulsed Ltk^? cells which co-expressed viral hemagglutinin due to either infection or transfection. A similar augmentation was seen in CTL responses against other types of antigen (major histocompatibility complex alloantigens, minor histocompatibility antigens or tumor antigens) when suboptimal cultures were stimulated with the respective antigen-presenting cells modified by NDV infection. These findings suggest that NDV or viral HN expressed on antigen-presenting cells or tumor cells can exert a T cell co-stimulatory function.