Proces budowy miasta odpornego na przykładzie Rotterdamu

Potrzeba zapewnienia odporności wynika z istniejących oraz powstających zagrożeń naturalnych i antropogenicznych. Dzięki odporności miasto jest przygotowane na niebezpieczeństwa i może dostosować się do nowych warunków. W artykule podjęto próbę stworzenia schematu budowy miasta odpornego oraz sprawdzono jego funkcjonowanie w praktyce. Za studium przypadku wybrano Rotterdam, lidera w budowaniu odporności na zagrożenia związane ze zmianami klimatycznymi. Przeanalizowano dyskurs miasta odpornego w dokumentach lokalnych oraz praktyczne wdrażanie koncepcji. Wykazano, że budowanie odporności jest złożonym procesem. Rozpoczyna się poprzez współpracę podmiotów, prowadzącą do budowy silnej struktury umożliwiającej przepływ wiedzy, informacji i innowacji. W efekcie powstają projekty, których realizacja może zapewnić miastu długoterminową odporność

Inactivation of aldehyde dehydrogenase by disulfiram in the presence and absence of lipoic acid or dihydrolipoic acid : an in vitro study

The inhibition of aldehyde dehydrogenase (ALDH) by disulfiram (DSF) in vitro can be prevented and/or reversed by dithiothreitol (DTT), which is a well-known low molecular weight non-physiological redox reagent commonly used in laboratory experiments. These observations inspired us to ask the question whether the inhibition of ALDH by DSF can be preserved or abolished also by dihydrolipoic acid (DHLA), which is the only currently known low molecular weight physiological dithiol in the body of humans and other animals. It can even be metaphorized that DHLA is an "endogenous DTT". Lipoic acid (LA) is the oxidized form of DHLA. We investigated the inactivation of ALDH derived from yeast and rat liver by DSF in the presence or absence of LA or DHLA. The results clearly show that DHLA is able both to restore and protect ALDH activity blocked by DSF. The proposed mechanism is discussed

The effect of lipoic acid administration on the urinary excretion of thiocyanate in rats exposed to potassium cyanide

The oxidation of cyanide (CN-) to a much less toxic thiocyanate (SCN-) is the main in vivo biochemical pathway for CN- detoxification. SCN- is excreted mainly in urine. This study was performed to investigate the effect of lipoic acid (LA) on the urinary excretion of thiocyanate (SCN- ; rhodanate) in rats. Groups of the animals were treated intraperitoneally (i.p.) as follows: group 1: potassium cyanide (KCN) (1 mg/kg); group 2: KCN (1 mg/kg) + LA (100 mg/kg). Urine was collected for 24 h and the pooled samples were examined for SCN- levels. The obtained results indicated that the treatment of animals with potassium cyanide and LA in combination significantly increased the urinary excretion of SCN- in comparison w ith the respective values in the KCN-alone-treated group. It indicates that LA increased the rate of CN- detoxification in rats

Is aldehyde dehydrogenase inhibited by sulfur compounds? In vitro and in vivo studies

Aldehyde dehydrogenase (ALDH) catalyzes the critical step of ethanol metabolism, i.e. transformation of toxic acetaldehyde to acetic acid. It is a redox sensitive protein with the key Cys in its active site. Recently, it has been documented that activity of some proteins can be modified by sulfur-containing molecules called reactive sulfur species leading to the formation of hydro- persulfides. The aim of the present study was to examine whether ALDH activity can be modified in this way. Studies were performed in vitro using yeast ALDH and various reactive sulfur species, including Na2S, GSSH, K2Sx, Na2S2O3, and garlic-derived allyl sulfides. The effect of garlic-derived trisulfide on ALDH activity was also studied in vivo in the rat liver. The obtained results clearly demonstrated that ALDH could be regulated by sulfur species which inhibited its enzymatic activity. The results also suggested that not H2S but polysulfides or hydropersulfides were the oxidizing species responsible for this modification. This process was easily reversible by reducing agents. After the treatment with polysulfides or hydropersulfides the level of protein-bound sulfur increased, while the activity of the enzyme dramatically decreased. Moreover, the study demonstrated that ALDH activity was inhibited in vivo in the rat liver after garlic-derived trisulfide administration. This is the first study reporting the regulation of ALDH activity by sulfane sulfur species and the results suggest that it leads to the inhibition of the enzyme

Performance and Health of Group-Housed Calves Kept in Igloo Calf Hutches and Calf Barn

Group-reared calves are usually housed in common buildings, such as calf barns of all sorts; however, there are concerns about this practice due to problems such as an increased incidence of diseases and poor performance of the calves. Group calf rearing using igloo hutches may be a solution combining the benefits of individual and group housing systems. The aim of this study was to evaluate group-reared calves housed in Igloo-type hutches compared with those housed in common calf barns. The experiment was carried out on a large private dairy farm located in Vorpommern, Germany. A total of 90 Deutsche-Holstein bull calves were assigned to 2 treatment groups: the calf-barn group, with calves grouped in pens in a building, and the Igloo-hutch group, with calves housed in outdoor enclosures with an access to group igloo-style hutches. Calves entering the 84-day experiment were at an average age of about three weeks, with the mean initial body weight of about 50 kg. The calves housed in the group Igloo hutches attained higher daily weight gains compared to those housed in the calf barn (973 vs 721 g/day), consumed more solid feeds (concentrate, corn grain and maize silage): (1.79 vs 1.59 kg/day), and less milk replacer (5.51 vs 6.19 kg/day), had also a lower incidence of respiratory diseases (1.24 vs 3.57%) with a shorter persistence of the illness

Is the mechanism of nitroglycerin tolerance associated with aldehyde dehydrogenase activity? : a contribution to the ongoing discussion

The aim of the study presented here was an attempt to answer the question posed in the title: Is the mechanism of nitroglycerin tolerance associated with aldehyde dehydrogenase (ALDH) activity? Here, we investigated the effect of administration (separately or jointly) of lipoic acid (LA), nitroglycerin (GTN), and disulfiram (DSF; an irreversible in vivo inhibitor of all ALDH isozymes (including ALDH2)), on the development of tolerance to GTN. We also assessed the total activity of ALDH in the rat liver homogenates. Our data revealed that not only DSF and GTN inhibited the total ALDH activity in the rat liver, but LA also proved to be an inhibitor of this enzyme. At the same time, the obtained results demonstrated that the GTN tolerance did not develop in GTN, DSF and LA jointly treated rats, but did develop in GTN and DSF jointly treated rats. This means that the ability of LA to prevent GTN tolerance is not associated with the total ALDH activity in the rat liver. In this context, the fact that animals jointly receiving GTN and DSF developed tolerance to GTN, and in animals that in addition to GTN and DSF also received LA such tolerance did not develop, is - in our opinion - a sufficient premise to conclude that the nitrate tolerance certainly is not caused by a decrease in the activity of any of the ALDH isoenzymes present in the rat liver, including ALDH2. However, many questions still await an answer, including the basic one: What is the mechanism of tolerance to nitroglycerin

The effect of lipoic acid on cyanate toxicity in different structures of the rat brain

Cyanate is formed mostly during nonenzymatic urea biodegradation. Its active form isocyanate reacts with protein –NH(2) and –SH groups, which changes their structure and function. The present studies aimed to investigate the effect of cyanate on activity of the enzymes, which possess –SH groups in the active centers and are implicated in anaerobic cysteine transformation and cyanide detoxification, as well as on glutathione level and peroxidative processes in different brain structures of the rat: cortex, striatum, hippocampus, and substantia nigra. In addition, we examined whether a concomitant treatment with lipoate, a dithiol that may act as a target of S-carbamoylation, can prevent these changes. Cyanate-inhibited sulfurtransferase activities and lowered sulfide level, which was accompanied by a decrease in glutathione concentration and elevation of reactive oxygen species level in almost all rat brain structures. Lipoate administered in combination with cyanate was able to prevent the above-mentioned negative cyanate-induced changes in a majority of the examined brain structures. These observations can be promising for chronic renal failure patients since lipoate can play a double role in these patients contributing to efficient antioxidant defense and protection against cyanate and cyanide toxicity

The effects of different garlic-derived allyl sulfides on anaerobic sulfur metabolism in the mouse kidney

Diallyl sulfide (DAS), diallyl disulfide (DADS) and diallyl trisulfide (DATS) are major oil-soluble organosulfur compounds of garlic responsible for most of its pharmacological effects. The present study investigated the influence of repeated intraperitoneally (ip) administration of DAS, DADS and DATS on the total level of sulfane sulfur, bound sulfur (S-sulfhydration) and hydrogen sulfide (H2S) and on the activity of enzymes, which catalyze sulfane sulfur formation and transfer from a donor to an acceptor in the normal mouse kidney, i.e., γ-cystathionase (CSE) and rhodanese (TST). The activity of aldehyde dehydrogenase (ALDH), which is a redox-sensitive protein, containing an –SH group in its catalytic center, was also determined. The obtained results indicated that all tested compounds significantly increased the activity of TST. Moreover, DADS and DATS increased the total sulfane sulfur level and CSE activity in the normal mouse kidney. ALDH activity was inhibited in the kidney after DATS administration. The results indicated also that none of the studied allyl sulfides affected the level of bound sulfur or H2S. Thus, it can be concluded that garlic-derived DADS and DATS can be a source of sulfane sulfur for renal cells but they are not connected with persulfide formation