Brain Tractography in Diabetes Mellitus and Cognitive Impairments

Neuroscience and Behavioral Physiology - Objective. To assess the characteristics of the conducting pathways in the white matter in patients with types 1 and 2 diabetes mellitus (DM) with and...     

Impaired presynaptic cytosolic and mitochondrial calcium dynamics in aged compared to young adult hippocampal CA1 synapses ameliorated by calcium chelation

Impaired regulation of presynaptic intracellular calcium is thought to adversely affect synaptic plasticity and cognition in the aged brain. We studied presynaptic cytosolic and mitochondrial calcium (Ca) dynamics using axonally loaded Calcium Green-AM and Rhod-2 AM fluorescence respectively in young (2–3 months) and aged (23–26 months) CA3 to CA1 Schaffer collateral excitatory synapses in hippocampal brain slices from Fisher 344 rats. After a tetanus (100 Hz, 200 ms), the presynaptic cytosolic Ca peaked at ∼10 s in the young and ∼12 s in the aged synapses. Administration of the membrane permeant Ca chelator, bis (O-aminophenoxy)-ethane-N,N,N,N-tetraacetic acid (BAPTA-AM), significantly attenuated the Ca response in the aged slices, but not in the young slices. The presynaptic mitochondrial Ca signal was much slower, peaking at ∼90 s in both young and aged synapses, returning to baseline by 300 s. BAPTA-AM significantly attenuated the mitochondrial calcium signal only in the young synapses. Uncoupling mitochondrial respiration by carbonyl cyanide m-chlorophenylhydrazone (CCCP) application evoked a massive intracellular cytosolic Ca increase and a significant drop of mitochondrial Ca, especially in aged slices wherein the cytosolic Ca signal disappeared after ∼150 s of washout and the mitochondrial Ca signal disappeared after 25 s of washout. These signals were preserved in aged slices by BAPTA-AM. Five minutes of oxygen glucose deprivation (OGD) was associated with a significant increase in cytosolic Ca in both young and aged synapses, which was irreversible in the aged synapses. These responses were significantly attenuated by BAPTA-AM in both the young and aged synapses. These results support the hypothesis that increasing intracellular calcium neuronal buffering in aged rats ameliorates age-related impaired presynaptic Ca regulation.     

Features of the association of Helicobacter pylori infection and ulcer in Europeans and Mongoloids in Siberia

AIM: To study association between Helicobacter Pylori infection in ulcer in native population and migrants in Siberia. MATERIALS AND METHODS: Epidemiological survey of ulcer has been performed in Northern (Evenkia, Yakutia) and Southern (Khakasia) regions of Siberia. Clinical examination covered 3908 Europeoids (Russians, Ukrainians) and 1999 Mongoloids (Evenks, Evens, Khakases). Endoscopic examination was made in 2144 patients. Light microscopy has detected Helicobacter pylori (HP) in 453 patients (215 migrants and 238 natives). RESULTS: Prevalence of ulcer in the South of Siberia was 6.1 and 1.5% for migrants and natives, respectively. In the North--8.9 and 0.6%, respectively. HP was diagnosed in 83.7% of Mongoloids and 69.2% of Europeoids in the South and 92.2 and 100%, respectively, in the North. HP index, contamination and adhesion in migrants were higher than in native population. CONCLUSION: Siberial Europeoids and Mongoloids have specific ethnic features of ulcer occurrence and its association with HP. Native population is protected better from the pathogenic bacteria. Further study of the causes of virulent bacterial properties and mechanisms maintaining long persistance of HP in the stomach is necessary.     

Peculiarities of relationship between atrophic gastritis and stomach cancer in the population of Eastern Siberia

The authors studied the prevalence of atrophic gastritis, H.pylori strains carrying the CagA gene, seeding and apoptosis indices of gastric mucosa in indigenous and newcomer residents of Evenkia. A total of 136 Evenks and 159 newcomers were examined using fibrogastroscopy and biopsy of antral gastric mucosa. Morphological study included light microscopy of hematoxylin and eosin-stained biopsies and their analysis using a visual-analog scale to reveal signs of inflammation, apoptosis, intestinal metaplasia and the degree of insemination by P. pylori. Urease and morphological tests were used to identify H. pylori and the TUNEL technique (Mebstain Apoptosis kit direct, France) to determine apoptosis index; serum anti-Helicobacter and CagA antibodies were detected by an immunoenzyme assay in 22 Evenks and 24 newcomers with chronic H. pylori-associated gastritis. The prevalence of atrophic gastritis in these groups was estimated at 13.2 and 23.9% respectively, seeding density 45.37 +/- 2.01 and 214 +/- 8.75 (p < 0.001). H. pylori strains carrying the CagA gene were identified in 59.6 and 43.6% of the newcomers and Evenks (p = 0.01), total apoptosis index in greater curvature mucosa was 4.99 +/- 0.23 and 3.19 +/- 0.28 (p < 0.01) respectively. These ethnic difference in the prevalence of atrophic gastritis appear to be attributable to different intensity of apoptosis in greater curvature mucosa.     

The mechanism of reverse cholesterol transport and cholelithiasis in Northern ethnic groups

The aim of the study was to investigate metabolic factors that protect the human organism from cholelithiasis and coronary artery disease (CAD). An epidemiological study was carried out to determine the prevalence of cholelithiasis and CAD in eight settlements of Yakutia and Evenkia. The subjects were 1154 Evens and Evenks, and 1591 Europoids. The parameters under study were the lipid composition and bile acid (BA) spectrum as well as the level of lipids, the spectrum of lipoproteins, neutral lipids, and phospholipids in the serum and blood plasma. Among Europoids, the prevalence of cholelithiasis was 8.8%, and the prevalence of CAD was 18.8%, while among Mongoloids they were 1.5% (p < 0.001) and 10.2% (p < 0.001), respectively. Serum levels of total cholesterol (CH) were significantly higher in Europoids than in Evens and Evenks, whereas CH, BA, and primary cholates prevailed in bile of Mongoloids. The levels of main LCHAT-reactive substrates evidence a significantly higher efficiency of CH esterification in Evens and Evenks vs. Europoids. Highly effective mechanism of CH return transport, an important component of which is active BA synthesis and transport of sterins into bile should be considered the leading factor that protects high latitude Mongoloids from cholelithiasis and CAD.     

Prevalence of Helicobacter pylori CaGa strains and peptic ulcer in the population of Eastern Siberia

AIM: To study prevalence of Helicobacter pylori (Hp) CagA strains and ulcer disease in native population of eastern Siberia and migrants. MATERIAL AND METHODS: Epidemiological screening of Hp CagA strains and ulcer disease was performed by cross-sectional method in population of Evenkia, Khakassia, Tuva. Fibrogastroduodenoscopy was made in 3602 examinees; IgG of CagA Hp was detected in the sera of 2472 patients with entyme immunoassay. RESULTS: Prevalence of ulcer was higher in Europeans than in Mongoloids. Detectability of CagA Hp was 36.5% among khakas population, 43.8% among evenks, 60.1% among tyvin population, 59.8% among European population. In khakas and tyva population with ulcer CagA Hp incidence was higher than in healthy subjects. CONCLUSION. CagA HP is associated with ulcer in mongoloid population. This was not confirmed for European populatioin of the Eastern Siberia.