Nitrosative stress parameters and the level of oxidized DNA bases in patients with multiple sclerosis

Multiple sclerosis (MS) is a neurodegenerative disease with various factors affecting its etiology. Overproduction of nitric oxide and subsequent lesions of biopolymers are some of the possible causes of the disease. This study aimed to measure the most relevant nitrosative and oxidative stress biomarkers and the level of modified DNA bases in patients with MS. Each parameter was assayed in 25 patients with MS and 25 healthy controls. This study involved detecting blood plasma and serum nitric oxide metabolites by chemiluminescence detector Sievers NOA-280i, malondialdehyde (MDA) measurements with thiobarbituric acid reactive substance (TBARS) assay, detection of oxidized purines and pyrimidines with the enzyme-modified comet assay. Statistical analysis of the results was performed by one-way analysis of variance (ANOVA) and unpaired t test for the comparison of less than three data sets. DNA single-strand breaks, levels of modified purines and pyrimidines, as well as nitrite and nitrate levels in plasma and serum samples, were significantly higher in patients with MS than in healthy controls. On the contrary, MDA levels appeared to be lower in patients with MS.

     

Sensory receptor organs of the human nasal respiratory mucosa

Human nasal respiratory mucosa has a limited capacity for localization of stimuli and discrimination of sensory modalities. In order to obtain morphological data on its receptor organs, histochmeical and electron microscopical studies were undertaken in six individuals ranging in age from 18 to 39 years. It was found that the nasal respiratory mucosa was supplied by non-myelinated nerves which approached the mucosa in fascicles containing up to 200 axons. These fascicles were devoid of perineurial sheaths. They ramified repeatedly producing only one type of receptor organ — a simple terminal arborization. The finest terminal fascicles of the plexus ended either in the cell free zone of the lamina propria or in the spaces between the epithelial cells next to the basement membrane. The axons in the fascicles and in the endings were only partly insulated from one another by Schwann cell folds. The axoplasm of the terminal and preterminal nerve fibers contained accumulations of fine vesicles, simple granules and clusters of mitochondria. All nerve fibers gave a positive acetyl- and a negative butyro-cholinesterase reaction. The plexiform endings of the nasal respiratory mucosa are different from any receptor organ of the adult human skin. They are reminiscent of the transitory, yet functional plexiform endings of the fetal skin which are found prior to the formation of the definitive receptor organs.     

Innervation of human nasal glands

Summary The innervation of human nasal glands was investigated with the electron microscope in 14 males and 11 females using osmium and permangante fixed material. Acetylcholinesterase activity was localized electron microscopically in formalin fixed tissues.It was found that the tubuloalveolar glands possessed myoepithelial cells which extended over the basal surfaces of the secretory cells and were attached to them by desmosomes. The glands were supplied by fenestrated capillaries. Periacinar and intraepithelial nerves of the glands exhibited high positive acetylcholinesterase and negative butyrocholinesterase activity. The reaction product was localized in the interval between the axolemma and the cell membranes of the secretory, myoepithelial or Schwann cells, respectively. The axon varicosities of the periacinar nerves and the intraepithelial endings contained accumulations of agranular vesicles in preparations fixed with osmic acid, formalin or permanganate solutions, signifying cholinergic nerves. The blood vessels of the nasal glands were supplied by cholinergic and adrenergic nerves.     

Putative role of nitric oxide synthase isoforms in the changes of nitric oxide concentration in rat brain cortex and cerebellum following sevoflurane and isoflurane anaesthesia

We have previously observed an increase in nitric oxide (NO) content in rat brain cortex following halothane, sevoflurane or isoflurane anaesthesia. This study was undertaken in order to determine whether isoform-specific nitric oxide synthase (NOS) inhibitors and inducers could modify these increases in NO contents. Rats were subjected to isoflurane and sevoflurane anaesthesia with concomitant administration of neuronal nitric oxide synthase (nNOS) inhibitor 7-Nitro-indazole (7-NI), inducible nitric oxide synthase (iNOS) inhibitor 2-amino-5,6-dihydro-6-methyl-4H-1,3-thiazine (AMT) or lipopolysaccharide. NO concentration in different organs was measured by electron paramagnetic resonance (EPR) spectroscopy. 7-NI significantly decreased NO concentration in cerebellum but not in brain cortex, whereas AMT decreased NO in all the organs studied. Anaesthesia significantly increased NO concentration in brain cortex and decreased that in cerebellum. AMT abolished the NO increase in brain cortex. Anaesthesia enhanced the drastic increase in NO concentration in brain cortex after intraventricular lipopolysaccharide administration. Isoflurane was found to inhibit recombinant nNOS and iNOS activities at high concentrations (EC50=20 mM). Our data suggest a putative role for iNOS in the increase in NO levels produced by isoflurane and sevoflurane, whereas nNOS activity is probably inhibited during anaesthesia.     

Role of the nuclear matrix proteins in malignant transformation and cancer diagnosis

The nuclear matrix (NM) is the structural framework of the nucleus that consists of the peripheral lamins and pore complexes, an internal ribonucleic protein network, and residual nucleoli. Differences between the nuclear matrix protein (NMP) composition of transformed cells and their normal homologues were detected in numerous cases. Actually several tumor-specific nuclear matrix proteins (NMPs) are proposed for diagnostic of bladder, breast, colon and some other cancers. According to the role of NMPs in development and phenotype of a given neoplasms the tumors can be classified as follows: I. Tumors bearing mutations in the genes encoding NMPs. The group consists of following subgroups: 1) hereditary cancer syndromes with mutations in the NM-attached oncoproteins or tumor suppressor genes; 2) sporadic tumors with somatic mutations in the NM-attached oncoproteins, tumor suppressor genes or replication enzymes; 3) leukemias with fused NMPs. II. Tumors with phenotypic quantitative or qualitative changes of the NMP spectrum.     

Mildronate: an antiischemic drug for neurological indications

Mildronate (3-(2,2,2-trimethylhydrazinium)propionate; MET-88; meldonium, quaterine) is an antiischemic drug developed at the Latvian Institute of Organic Synthesis. Mildronate was designed to inhibit carnitine biosynthesis in order to prevent accumulation of cytotoxic intermediate products of fatty acid beta-oxidation in ischemic tissues and to block this highly oxygen-consuming process. Mildronate is efficient in the treatment of heart ischemia and its consequences. Extensive evaluation of pharmacological activities of mildronate revealed its beneficial effect on cerebral circulation disorders and central nervous system (CNS) functions. The drug is used in neurological clinics for the treatment of brain circulation disorders. It appears to improve patients' mood; they become more active, their motor dysfunction decreases, and asthenia, dizziness and nausea become less pronounced. Since the brain does not utilize fatty acids as fuel other mechanisms of action of mildronate in CNS should be considered. Several reports indicate the possible existence of an alternative, non-carnitine dependent mechanism of action of mildronate. Our recent findings suggest that CNS effects of mildronate could be mediated by stimulation of the nitric oxide production in the vascular endothelium by modification of the gamma-butyrobetaine and its esters pools. It is hypothesized that mildronate may increase the formation of the gamma-butyrobetaine esters. The latter are potent cholinomimetics and may activate eNOS via acetylcholine receptors or specific gamma-butyrobetaine ester receptors. This article summarizes known pharmacological effects of mildronate, its pharmacokinetics, toxicology, as well as the proposed mechanisms of action.     

1,4-dihydropyridine Derivatives Increase mRNA Expression of Psma3, Psmb5, and Psmc6 in Rats

The ubiquitin-proteasome system modifies different cellular and protein functions. Its dysregulation may lead to disrupted proteostasis associated with multiple pathologies and aging. Pharmacological regulation of proteasome functions is already an important part of the treatment of several diseases. 1,4-dihydropyridine (1,4-DHP) derivatives possess different pharmacological activities, including antiaging and neuroprotective. The aim of this study was to investigate the effects of several 1,4-DHP derivatives on mRNA expression levels of proteasomal genes Psma3, Psmb5, and Psmc6 in several organs of rats. Rats were treated with metcarbatone, etcarbatone, glutapyrone, styrylcarbatone, AV-153-Na, or AV-153-Ca per os for three days. mRNA expression levels were determined with real-time polymerase chain reaction (PCR). For AV-153-Na and AV-153-Ca, we also determined the expression of the Psma6 gene. In the kidney, metcarbatone, etcarbatone, styrylcarbatone, and AV-153-Na increased the expression of all analysed genes. Glutapyrone increased the expression of Psmb5 and Psmc6 but did not affect the expression of Psma3. In the blood, glutapyrone increased Psmb5 expression. In the liver, AV-153-Na increased the expression of Psma6 and Psmc6 but lowered the expression of Psmb5, while AV-153-Ca only increased Psma6 expression. The ability of 1,4-DHP derivatives to increase the expression of proteasome subunit genes might hold a therapeutic potential in conditions associated with impaired proteasomal functions, but further research is needed.Key words: AV-153-Ca, AV-153-Na, etcarbatone, gene expression, glutapyrone, impaired proteasomal functions, metcarbatone, pharmacological activities, proteasome subunits, styrylcarbatone, ubiquitin-proteasome system     

The fine structure of the arteriovenous anastomosis and its nerve supply in the human nasal respiratory mucosa

The fine structure of the arteriovenous anastomosis was investigated in the normal human nasal mucosa. The tissues were fixed in 2% osmic acid solution, embedded in Epon and stained with uranyl acetate and lead citrate solutions. It was found that the endothelial basement membrane of the arterial segment of the anastomosis was discontinuous. The anastomosing artery possessed subendothelial cushions of longitudinal smooth musculature which expanded into a thick uniform layer before the artery joined the vein. The fine morphology of these muscle cells did not show epitheloid modification. An elastic membrane of a peculiar structure separated the subendothelial musculature from that of the tunica media. The membrane was continuous with the internal elastic membrane of the proximal artery and with the adventitial elastic mesh of the vein. The anastomosis was supplied by a non-myelinated periarterial nerve plexus which contained cholinergic and adrenergic axons characterized by agranular and fine granular vesicles respectively. The wall of the vein was devoid of musculature and nerves. It mainly consisted of elastic meshes interspersed with bundles of collagen fibers and occasional fibrocytes. It was suggested that the musculature of the tunica media of the artery was controlled by the cholinergic and adrenergic nerves of the autonomic system, and by the sensory nerves in the form of axons reflexes. The subendothelial musculature was controlled by agents carried in blood and was not influenced by the adventitial nerves.     

Receptor activator of NF-κB ligand promotes proliferation of a putative mammary stem cell unique to the lactating epithelium

In mice, CD49f(hi) mammary stem cells (MaSCs) asymmetrically divide to generate CD49f(+) committed progenitor cells that differentiate into CD49f(-) phenotypes of the milk-secreting tissue at the onset of pregnancy. We show CD49f(+) primary mammary epithelial cells (PMECs) isolated from lactating tissue uniquely respond to pregnancy-associated hormones (PAH) compared with CD49f(+) cells from nonlactating tissue. Differentiation of CD49f(+) PMEC in extracellular matrix produces CD49f(-) luminal cells to form differentiated alveoli. The PAH prolactin and placental lactogen specifically stimulate division of CD49f(-) luminal cells, while receptor activator of nuclear factor (NF)-κB ligand (RANKL) specifically stimulates division of basal CD49f(+) cells. In nondifferentiating conditions, we observed a greater proportion of multipotent self-renewing cells, and RANKL treatment activated the RANK pathway in these cultures. Furthermore, we observed the deposition of calcium nodules in a proportion of these cells. These data imply that a MaSC unique to the lactating breast exists in humans, which generates progeny with discrete lineages and distinct response to PAH.