Twenty-Four-Hour Variations in the Sensitivity of Rat Aorta to Vasoactive Agents

The presence of time-dependent variations in the in vitro sensitivity of aorta preparations to either vasoconstricting or relaxing agents was investigated in rats maintained in light from 08: 00 to 20: 00 and in darkness from 20: 00 to 08: 00. Rat thoracic aorta rings were obtained from animals sacrificed at four different times of the day. The rat aorta was found to be more sensitive to the constricting effect of phenylephrine at 15: 00, and of 5-hydroxytryptamine at 21: 00. On the other hand, both endothelium-dependent and -independent relaxations were more remarkable at 03: 00 than at other times of the day. These variations represented significant circadian rhythms when analyzed by analysis of variance. Different in vitro responsiveness to these agents might reflect changes in the sensitivity and/or number of related receptors in vascular preparations. In conclusion, the circadian time of animal sacrifice to obtain vascular preparations constitutes an important aspect of the research method and a key determinant of findings. (Chronobiology International, 13(6), 465-475, 1996)     

A new Cephalaria species (Dipsacaceae) from the European part of Turkey

A new species, Cephalaria tuteliana, (Dipsacaceae) from the European part of Turkey is described and illustrated. The characteristics of the new species, and its relationships with Cephalaria tenuiloba is discussed.     

The Long-Term Dynamics of Mortality Benefits from Improved Water and Sanitation in Less Developed Countries

The problem of inadequate access to water, sanitation and hygiene (WASH) in less-developed nations has received much attention over the last several decades (most recently in the Millennium Development Goals), largely because diseases associated with such conditions contribute substantially to mortality in poor countries. We present country-level projections for WASH coverage and for WASH-related mortality in developing regions over a long time horizon (1975–2050) and provide dynamic estimates of the economic value of potential reductions in this WASH-related mortality, which go beyond the static results found in previous work. Over the historical period leading up to the present, our analysis shows steady and substantial improvements in WASH coverage and declining mortality rates across many developing regions, namely East Asia and the Pacific, Latin America and the Caribbean, Eastern Europe and the Middle East. The economic value of potential health gains from eliminating mortality attributable to poor water and sanitation has decreased substantially, and in the future will therefore be modest in these regions. Where WASH-related deaths remain high (in parts of South Asia and much of Sub-Saharan Africa), if current trends continue, it will be several decades before economic development and investments in improved water and sanitation will result in the capture of these economic benefits. The fact that health losses will likely remain high in these two regions over the medium term suggests that accelerated efforts are needed to improve access to water and sanitation, though the costs and benefits of such efforts in specific locations should be carefully assessed.     

Alterations of Red Cell Membrane Properties in Nneuroacanthocytosis

Neuroacanthocytosis (NA) refers to a group of heterogenous, rare genetic disorders, namely chorea acanthocytosis (ChAc), McLeod syndrome (MLS), Huntington’s disease-like 2 (HDL2) and pantothenate kinase associated neurodegeneration (PKAN), that mainly affect the basal ganglia and are associated with similar neurological symptoms. PKAN is also assigned to a group of rare neurodegenerative diseases, known as NBIA (neurodegeneration with brain iron accumulation), associated with iron accumulation in the basal ganglia and progressive movement disorder. Acanthocytosis, the occurrence of misshaped erythrocytes with thorny protrusions, is frequently observed in ChAc and MLS patients but less prevalent in PKAN (about 10%) and HDL2 patients. The pathological factors that lead to the formation of the acanthocytic red blood cell shape are currently unknown. The aim of this study was to determine whether NA/NBIA acanthocytes differ in their functionality from normal erythrocytes. Several flow-cytometry-based assays were applied to test the physiological responses of the plasma membrane, namely drug-induced endocytosis, phosphatidylserine exposure and calcium uptake upon treatment with lysophosphatidic acid. ChAc red cell samples clearly showed a reduced response in drug-induced endovesiculation, lysophosphatidic acid-induced phosphatidylserine exposure, and calcium uptake. Impaired responses were also observed in acanthocyte-positive NBIA (PKAN) red cells but not in patient cells without shape abnormalities. These data suggest an “acanthocytic state” of the red cell where alterations in functional and interdependent membrane properties arise together with an acanthocytic cell shape. Further elucidation of the aberrant molecular mechanisms that cause this acanthocytic state may possibly help to evaluate the pathological pathways leading to neurodegeneration.     

ICAM1 K469E and E-selectin S128R polymorphisms could predispose to increased autoantibody production and TSH suppression in Graves’ disease

The etiopathogenesis of Graves’ disease (GD) has not been clearly elucidated although the role of chronical inflammation and endothelial dysfunction has been established. Adhesion molecules such as intercellular adhesion molecule 1 (ICAM1), vascular cell adhesion molecule 1 (VCAM1), and E-selectin are secreted from vascular endothelium and promote accummulation of leukocytes in damaged endothelial areas. This study examined the possible association of ICAM1 (G241R and K469E), VCAM1 (T-1591C and T-833C), and E-selectin (S128R) single nucleotide polymorphisms (SNPs) with the occurence of GD. ICAM1 (G241R and K469E), VCAM1 (T-1591C and T-833C), and E-selectin (S128R) SNPs in DNA from peripheral blood leukocytes of 171 patients with GD and 259 healthy controls were investigated by real-time PCR combined with melting curve analysis using fluorescence-labeled hybridization probes. We did not find significant differences in the distributions of studied polymorphisms, nor in the haplotype frequencies between patients with GD and healthy control. However, the anti-TPO levels in E-selectin 128R allele carrying subjects (SR + RR) were higher than S128S genotype (p < 0.05). In addition, the decline of TSH levels was more prominent in ICAM1 469 E carrying subjects (KE + EE) in comparison with wild homozygotes (p < 0.05). Although there is not assosiation between ICAM1 (G241R and K469E), VCAM1 (T-1591C and T-833C), and E-selectin (S128R) SNPs and susceptibility to GD, higher anti-TPO in E-selectin 128 SR + RR, and lower TSH in ICAM1 469 KE + EE subjects suspect that these genotypes are prone to increased antithyroid autoantibody production with more accentuated TSH suppression in GD. Further studies with a larger cohort, analyzing other polymorphisms in ICAM, VCAM1 and E-selectin genes are necessary to support our observations.     

Lithium-Induced Hypothyroidism: Oxidative Stress and Osmotic Fragility Status in Rats

The present study was conducted to explore the possible effects of different doses of lithium carbonate on thyroid functions, erythrocyte oxidant–antioxidant status, and osmotic fragility. Twenty-four Wistar-type male rats were equally divided into three groups: groups I and II received 0.1 and0.2 % lithium carbonate in their drinking water, respectively, for 30 days. The rats in group III served as controls, drinking tap water without added lithium. At the end of the experimental period, the erythrocyte osmotic fragility and the levels of triiodothyronine (T₃), thyroxine (T₄), thyroid-stimulating hormone (TSH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione (GSH) were measured in blood samples. Compared to controls, there was a statistically significant increase of TSH but decreases of the T₃ and T₄ levels in group II. Both experimental groups showed a statistically significant increase of the maximum osmotic fragility limit. The minimum osmotic fragility values of the animals in group II were statistically higher than those of controls. The standard hemolytic increment curve of both experimental groups was shifted to the right when compared to the curve obtained from the controls. Also, relative to controls, the activities of MDA and SOD were significantly higher and the GSH level lower in group II, but not so in group I. The results of the present study show that treatment with lithium carbonate may result in thyroid function abnormalities, increased oxidative damage, and possible compromise of the erythrocyte membrane integrity resulting from increased osmotic fragility.     

Carbonic anhydrase inhibitors. Benzenesulfonamides incorporating cyanoacrylamide moieties strongly inhibit Saccharomyces cerevisiae β-carbonic anhydrase

A series of benzenesulfonamides incorporating cyanoacrylamide moieties (tyrphostine analogs) were assayed as inhibitors of the β-carbonic anhydrase (CA, EC 4.2.1.1) from Saccharomyces cerevisiae, ScCA. Some of these compounds were low nanomolar or subnanomolar ScCA inhibitors and showed selectivity ratios in the range of 4.91–69.86 for inhibiting the yeast enzyme over the offtarget human (h) isoforms hCA I and of 6.46–13.52 for inhibiting ScCA over hCA II. The model organism S. cerevisiae and this particular enzyme may be useful for detecting antifungals with a novel mechanism of action compared to the classical azole drugs to which significant drug resistance emerged. Indeed, some of these sulfonamides inhibited the growth of the yeast with CC₅₀-s in the range of 0.73–6.54 μM.     

Facile synthesis and characterization of novel pyrazole-sulfonamides and their inhibition effects on human carbonic anhydrase isoenzymes

In the current study, a series of pyrazole-sulfonamide derivatives (2–14) were synthesized, characterized, and the inhibition effects of the derivatives on human carbonic anhydrases (hCA I and hCA II) were investigated as in vitro. Structures of these sulfonamides were confirmed by FT-IR, ¹H NMR, ¹³C NMR and LC–MS analysis. ¹H NMR and ¹³C NMR revealed the tautomeric structures. hCA I and hCA II isozymes were purified from human erythrocytes and inhibitory effects of newly synthesized sulfonamides on esterase activities of these isoenzymes have been studied. The K_i values of compounds were 0.062–1.278 μM for hCA I and 0.012–0.379 μM for hCA II. The inhibition effects of 7 for hCA I and 4 for hCA II isozymes were almost in nanomolar concentration range.     

Kinetic and docking studies of cytosolic/tumor-associated carbonic anhydrase isozymes I,II and IX with some hydroxylic compounds

A series of hydroxylic compounds (1–10, NK-154 and NK-168) have been assayed for the inhibition of three physiologically relevant carbonic anhydrase isozymes, the cytosolic isozymes I, II and tumor-associated isozyme IX. The investigated compounds showed inhibition constants in the range of 0.068–4003, 0.012–9.9 and 0.025–115?μm at the hCA I, hCA II and hCA IX enzymes, respectively. In order to investigate the binding mechanisms of these inhibitors, in silico studies were also applied. Molecular docking scores of the studied compounds are calculated using scoring algorithms, namely Glide/induced fit docking. The inhibitory potencies of the novel compounds were analyzed at the human isoforms hCA I, hCA II and hCA IX as targets and the K_I values were calculated.