Markers of lipid oxidative damage in the exhaled breath condensate of nano TiO2 production workers

Nanoscale titanium dioxide (nanoTiO₂) is a commercially important nanomaterial. Animal studies have documented lung injury and inflammation, oxidative stress, cytotoxicity and genotoxicity. Yet, human health data are scarce and quantitative risk assessments and biomonitoring of exposure are lacking. NanoTiO₂ is classified by IARC as a group 2B, possible human carcinogen. In our earlier studies we documented an increase in markers of inflammation, as well as DNA and protein oxidative damage, in exhaled breath condensate (EBC) of workers exposed nanoTiO₂. This study focuses on biomarkers of lipid oxidation. Several established lipid oxidative markers (malondialdehyde, 4-hydroxy-trans-hexenal, 4-hydroxy-trans-nonenal, 8-isoProstaglandin F2α and aldehydes C₆–C₁₂) were studied in EBC and urine of 34 workers and 45 comparable controls. The median particle number concentration in the production line ranged from 1.98?×?10⁴ to 2.32?×?10⁴ particles/cm³ with ～80% of the particles?<100?nm in diameter. Mass concentration varied between 0.40 and 0.65?mg/m³. All 11 markers of lipid oxidation were elevated in production workers relative to the controls (p?2 and markers of lipid oxidation in the EBC. These markers were not elevated in the urine samples. Lipid oxidation in the EBC of workers exposed to (nano)TiO₂ complements our earlier findings on DNA and protein damage. These results are consistent with the oxidative stress hypothesis and suggest lung injury at the molecular level. Further studies should focus on clinical markers of potential disease progression. EBC has reemerged as a sensitive technique for noninvasive monitoring of workers exposed to engineered nanoparticles.     

Effect of nitric oxide and cyclic guanosine monophosphate on the desensitization of choline receptors in snail neurons

Desensitization of choline receptors is studied after pharmacological effects on the intracellular level of nitric oxide and cyclic guanosine monophosphate in snail neurons. It is shown that inhibitors of NO synthase do not alter desensitization, whereas an activator of guanylate cyclase as well as intracellular injection of guanosine monophosphate boost it. Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 121, No. 4, pp. 426–429, April, 1996 Presented by I. P. Ashmarin, Member of the Russian Academy of Medical Sciences     

Effects of chronic administration of atrial natriuretic polypeptide on glomerular lesions in spontaneously hypertensive rats

In order to investigate the effects of atrial natriuretic polypeptides (ANP) on hypertensive glomerular lesions, ANP was administered intravenously by osmotic minipumps to 20 15-week-old male spontaneously hypertensive rats (SHRs) in a sustained hypertensive stage. ANP was infused at the rate of 100 ng/hour/rat (the ANP group). Saline was similarly administered to 19 age-matched SHRs (the control group). The rats were sacrificed on the seventh day. Semiquantitative evaluation of the renal tissue revealed no significant difference in glomerular sclerosis between the 2 groups. However, segmental hyalinosis in glomeruli was more accentuated in the ANP group than in the control group. As it is suggested that hyalinosis in glomeruli is related to the elevated intracapillary pressure, the results of the present work were in accordance with reports that ANP increases glomerular capillary pressure by preglomerular vasodilation and postglomerular vasoconstriction. It should be determined whether endogenous ANP works as an aggravating factor for glomerular injuries in the natural course of hypertension.     

IKO-GM-1 monoclonal antibodies in the diagnosis of acute nonlymphoblastic leukemias

The paper deals with the analysis of the phenotype of blastic cells obtained from patients suffering various subtypes (FAB-classification) of acute nonlymphoblastic leukemia. The study used monoclonal IKO-GM-1 antibodies complementary to an antigen common to myeloid and macrophagal cells. Also, previously described monoclonal IKO-11, IKO-1, IKO-02 and IKO-10 antibodies were employed. Application of the above antibodies appeared to provide information necessary for differentiating between myeloblastic and monoblastic leukemia. Complex immunologic and cytochemical investigations are required for identifying leukemia subtypes.     

Homeostatic reactions of the blood of experimental rats after "Kosmos-1667" flight

Biochemical analysis of blood of rats sacrificed 4 to 8 hours after Cosmos-1667 flight revealed a significant increase of corticosterone, decrease of 11-dehydroxycortisol, testosterone, total and bound thyroxine, and increase of glucose, phosphate, creatinine, alanine aminotransferase and total antioxidative activity. Changes in hormonal concentrations, glucose content and stimulation of antioxidant defense system were associated with a moderate gravitational stress. Increases in the creatinine and inorganic phosphate concentrations can be viewed as specific effects of microgravity related to musculo-skeletal or fluid-electrolyte changes.     

Identification of cholinoreceptors on the soma of RPa3 and LPa3 neurons in Helix lucorum]

Selective cholinomimetics and cholinolytics were employed to identify cholinoreceptors on the somatic membrane in Helix lucorum RPa3 and LPa3 neurons using recording of transmembrane ionic currents. Agonists of nicotinic and muscarinic cholinoreceptors evoked reversible activation and following nonreversible inhibition of receptors (except carbamylcholine). Selective cholinomimetics were connected with the same membrane sites that were activated by acetylcholine. Nicotinic and muscarinic cholinolytics decreased the amplitude of inward current induced by acetylcholine (scopolamine and platyphylline had no effect). It is concluded that somatic membrane of RPa3 and LPa3 Helix neurons contains nicotinic and muscarinic cholinoreceptors. These receptors have several pharmacological peculiarities as compared with those of the vertebrates. Muscarinic cholinoreceptors of RPa3 and LPa3 neurons must be included into a special subtype that differs from well-known M1 and M2 subtypes.