Oxalate: From the Environment to Kidney Stones Brzica, Hrvoje; Breljak, Davorka; Burckhardt, Birgitta C ...
Arhiv za higijenu rada i toksikologiju,
12/2013, Letnik:
64, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Oxalate urolithiasis (nephrolithiasis) is the most frequent type of kidney stone disease. Epidemiological research has shown that urolithiasis is approximately twice as common in men as in women, but ...the underlying mechanism of this sex-related prevalence is unclear. Oxalate in the organism partially originate from food (exogenous oxalate) and largely as a metabolic end-product from numerous precursors generated mainly in the liver (endogenous oxalate). Oxalate concentrations in plasma and urine can be modified by various foodstuffs, which can interact in positively or negatively by affecting oxalate absorption, excretion, and/or its metabolic pathways. Oxalate is mostly removed from blood by kidneys and partially via bile and intestinal excretion. In the kidneys, after reaching certain conditions, such as high tubular concentration and damaged integrity of the tubule epithelium, oxalate can precipitate and initiate the formation of stones. Recent studies have indicated the importance of the SoLute Carrier 26 (SLC26) family of membrane transporters for handling oxalate. Two members of this family Sulfate Anion Transporter 1 (SAT-1; SLC26A1) and Chloride/Formate EXchanger (CFEX; SLC26A6) may contribute to oxalate transport in the intestine, liver, and kidneys. Malfunction or absence of SAT-1 or CFEX has been associated with hyperoxaluria and urolithiasis. However, numerous questions regarding their roles in oxalate transport in the respective organs and male-prevalent urolithiasis, as well as the role of sex hormones in the expression of these transporters at the level of mRNA and protein, still remain to be answered.
Oksalatna urolitijaza (nefrolitijaza) najučestaliji je tip bolesti bubrežnih kamenaca. Rezultati epidemioloških istraživanja pokazali su da je urolitijaza približno dvostruko učestalija u muškaraca nego u žena, ali osnovni mehanizam nastanka ove spolno-ovisne prevalencije nije razjašnjen. Oksalat u organizmu dijelom potječe iz hrane (egzogeni oksalat), a glavninom nastaje kao konačni produkt metabolizma raznih preteča u jetrima (endogeni oksalat). Na koncentraciju oksalata u plazmi i urinu utječu razne tvari iz hrane, koje mogu pozitivno ili negativno djelovati na apsorpciju, metaboličke puteve i/ili izlučivanje oksalata. Oksalat se iz organizma izlučuje u manjem obimu putem žuči u crijevo, a glavninom bubrezima. U bubrezima, pri odgovarajućim uvjetima kao što su visoka koncentracija oksalata i oštećenje epitela bubrežnih kanalića, oksalat može precipitirati i time potaknuti stvaranje kamenaca. Rezultati novih istraživanja upućuju na važnost membranskih prijenosnika otopljenih tvari (SoLute Carriers) iz obitelji 26 (SLC26) za prijenos oksalata u specifičnim organima. Smatra se da dva člana ove obitelji: prijenosnik sulfatnog aniona (Sulfate Anion Transporter 1; SAT-1; SLC26A1) i izmjenjivač klora i mravlje kiseline (Chloride/Formate EXchanger; CFEX; SLC26A6), imaju značajnu ulogu u prijenosu oksalata u crijevima, jetrima i bubrezima; hiperoksalurija i nefrolitijaza utvrđeni su pri slaboj aktivnosti ili nedostatku SAT-1 i CFEX proteina. Međutim, još uvijek postoje brojne nejasnoće glede prijenosa oksalata u navedenim organima, mehanizma nastanka spolnih razlika u nefrolitijazi i utjecaja spolnih hormona na ekspresiju proteina i mRNA za navedene prijenosnike.
Oksalat – od okoliša do bubrežnih kamenaca Brzica, Hrvoje; Breljak, Davorka; Burckhardt, Birgitta C ...
Arhiv za higijenu rada i toksikologiju,
12/2013, Letnik:
64, Številka:
4
Journal Article
Recenzirano
Odprti dostop
Oksalatna urolitijaza (nefrolitijaza) najučestaliji je tip bolesti bubrežnih kamenaca. Rezultati epidemioloških istraživanja pokazali su da je urolitijaza približno dvostruko učestalija u muškaraca ...nego u žena, ali osnovni mehanizam nastanka ove spolno-ovisne prevalencije nije razjašnjen. Oksalat u organizmu dijelom potječe iz hrane (egzogeni oksalat), a glavninom nastaje kao konačni produkt metabolizma raznih preteča u jetrima (endogeni oksalat). Na koncentraciju oksalata u plazmi i urinu utječu razne tvari iz hrane, koje mogu pozitivno ili negativno djelovati na apsorpciju, metaboličke puteve i/ili izlučivanje oksalata. Oksalat se iz organizma izlučuje u manjem obimu putem žuči u crijevo, a glavninom bubrezima. U bubrezima, pri odgovarajućim uvjetima kao što su visoka koncentracija oksalata i oštećenje epitela bubrežnih kanalića, oksalat može precipitirati i time potaknuti stvaranje kamenaca. Rezultati novih istraživanja upućuju na važnost membranskih prijenosnika otopljenih tvari (SoLute Carriers) iz obitelji 26 (SLC26) za prijenos oksalata u specifičnim organima. Smatra se da dva člana ove obitelji: prijenosnik sulfatnog aniona (Sulfate Anion Transporter 1; SAT-1; SLC26A1) i izmjenjivač klora i mravlje kiseline (Chloride/Formate EXchanger; CFEX; SLC26A6), imaju značajnu ulogu u prijenosu oksalata u crijevima, jetrima i bubrezima; hiperoksalurija i nefrolitijaza utvrđeni su pri slaboj aktivnosti ili nedostatku SAT-1 i CFEX proteina. Međutim, još uvijek postoje brojne nejasnoće glede prijenosa oksalata u navedenim organima, mehanizma nastanka spolnih razlika u nefrolitijazi i utjecaja spolnih hormona na ekspresiju proteina i mRNA za navedene prijenosnike.
This article compares the sorption behaviour of 2,4,6-trichlorophenol, 2,3,4,6-tetrachlorophenol, pentachlorophenol, chlorotriazine atrazine, methylthiotriazine ametryn, methoxytriazine atratone, ...hydroxyatrazine, and didelakylated atrazine in a topsoil and an aquifer sediment before and after removal of sorbent organic matter and in humic acid. Freundlich isotherm coefficients Kf and 1/n and free energy change (δG°) were calculated for all compounds in all sorbents. According to sorbent pH values, chlorophenolate anions and uncharged triazine species dominated in all sorption experiments with topsoil and aquifer sediment. In experiments with humic acid, chlorophenols, atrazine, and didealkylated atrazine existed almost completely as neutral species, whereas protonated species dominated for hydroxyatrazine, atratone, and ametryn. In addition to a hydrophobic partition, sorption of all compounds in native soil and sediment sorbents includes specific, more polar interactions, which greatly depend on sorbate acidity/basicity, specific properties of the sorbent organic matter and of mineral surface, as well as on the system pH. A significantly greater sorption intensity of all compounds in "organic-free" than in the native aquifer sediment confirmed the importance and possible dominance of mineral surface in the sorption process. Sorption intensity of chlorophenol and triazine compounds in humic acid was closely related to compound hydrophobicity. Greater sorption of almost completely protonated hydroxyatrazine than of the more hydropohobic but uncharged atrazine indicated different humic acid reaction sites for two compounds and consequently different sorption mechanisms.
Uspoređena je sorpcija 2,4,6-triklorfenola, 2,3,4,6-tetraklorfenola i pentaklorfenola te različito supstituiranih triazinskih spojeva - klortriazina atrazina, metiltiotriazina ametrina, metoksitriazina atratona i razgradnih produkata atrazina hidroksiatrazina i didealkiliranog atrazina — u površinskom tlu i sedimentu vodonosnika prije i nakon uklanjanja organske tvari te u huminskoj kiselini. Izračunani su koeficijenti Freundlichove izoterme Kf i 1/n te izmjena slobodne energije (δG°) za sve spojeve i sorbense. U skladu s pH-vrijednostima sorbensa u svim su sorpcijskim pokusima s nativnim tlom i sedimentom prevladavali klorfenolatni anioni i neutralni triazinski spojevi. U pokusima s huminskom kiselinom klorfenoli, atrazin i didealkilirani atrazin postojali su kao neutralne vrste, dok su hidroksiatrazin, atraton i ametrin bili većim dijelom protonirani. Sorpcija svih spojeva u prirodnom tlu i sedimentu uključuje uz hidrofobnu particiju i specifične polarnije interakcije ovisne o kiselosti/bazičnosti sorbata, specifičnim svojstvima organske tvari i mineralne površine sorbensa te o pH-vrijednosti sustava. Intenzitet sorpcije svih spojeva u sedimentu iz kojeg je uklonjena organska tvar bio je značajno veći od sorpcije u prirodnom sedimentu, što potvrđuje važnost i moguću dominantnu ulogu mineralne površine u sorpcijskom procesu. Intenzitet sorpcije klorfenola te klortriazina, metiltiotriazina i metoksitriazina u huminskoj kiselini korelirao je s hidrofobnosti spojeva. Veća sorpcija gotovo potpuno protoniranog hidroksiatrazina od hidrofobnijeg, ali neutralnog atrazina upućuje na različita reakcijska mjesta za ova dva spoja, a time i na različite mehanizme sorpcije u huminskoj kiselini.
Anionic polymerization of N-methoxymethyl-N-isopropylacrylamide (1) was carried out with diphenylmethyllithium,-potassium and-cesium in the presence of diethylzinc in THF at-78°C
for 1-3 h. The ...resulting poly(1)s possessed the predicted molecular weights based on the molar ratios between monomer and initiators and the narrow molecular weight distributions (M
w
/M
n
= 1.1). The methoxymethyl protecting groups were completely hydrolyzed to afford a poly(N-isopropylacrylamide) (poly(NIPAM)), having well-defined chain structures by treatment with aqueous HCl in 1,4-dioxane
at room temperature for 12 h. Stereoregularity of the resulting poly(NIPAM) was strongly affected by the counterions of anionic initiator. From the
1
H-NMR measurement, the racemo dyad of poly(NIPAM)
obtained with diphenylmethyllithium, -potassium and -cesium in the presence of Et
2
Zn was found to be 75, 50 and 30%, respectively. The sequential copolymerization of styrene or isoprene with
1 and the subsequent deprotection quantitatively gave well-defined block copolymers containing poly(NIPAM) segments. The copolymers had the predicted molecular weights, compositions and the narrow molecular
weight distributions, and showed the typical amphiphilic character with regard to solubility.
Twenty-six multiparous Italian Holstein cows were used to compare two feeding strategies for the prepartum period. Cows were allocated to two dietary treatments on the basis of their parity (3.1 ± ...1.1) and mature equivalent production (11473 ± 1449 kg). From 20 ± 7 d precalving to the calving day, one group of 13 cows (parity = 3.1 ± 1.0; mature equivalent production = 11473 ± 1606 kg) was fed a Control diet made by mixing a 50:50 as fed combination of the far off dry ration and the lactation diet fed postpartum. The remaining cows (parity = 3.1 ± 1.1; mature equivalent production = 11473 ± 1338 kg) were fed a prepartum diet (Anionic) obtained by supplementing the far off dry ration with energy and protein sources plus calcium chloride. This diet had a lower dietary cation-anion difference than the Control diet (7.35 vs 26.66 meq/100 g DM; P<0.05) and it induced a significant decrease in the cows' urine pH (7.58 vs 7.95; P<0.01). Cows fed the Anionic diet had the lowest DM intake during the prepartum (12.0 vs 13.4 kg/d; P<0.01), but at parturition they showed a limited drop in plasma Ca reducing the incidence of subclinical hypocalcaemia in comparison with the Control group (8 vs 62%; P<0.01). No differences due to the prepartum diet were observed for the plasma levels of several indicators of hepatic function (aspartate-amino transferase, ϒ-glutamil transferase, creatin-kinase and bilirubine). After calving, all the cows were co-mingled and fed the same lactation ration and those that had received the Anionic diet during the prepartum showed a significant increase in milk yield with no changes in milk quality. Average production at the peak of lactation was 43.8 kg/d for Control cows while it raised up to 47.8 kg/d (P<0.05) for the animals fed the Anionic diet during the prepartum. This positive result was obtained with a lower loss in cows' body condition score measured at 30 and 60 days in milk and without any effect on the uterine involution process. The use of the Anionic diet has proven to be an effective alternative to the common practice of feeding close-up diets made by a partial replacement of the far off dry ration with the diet fed to the lactating cows. This strategy should be particularly recommended for dairy herds in which there is a great incidence of metabolic and health problems related to clinical or subclinical hypocalcaemia in the early postpartum.
In this work two analytical methods, ion chromatography (IC) and molecular absorbance spectrophotometry (MAS) are compared in terms of linearity, detection and repeatability in anion quantitation ...(nitrites, nitrates and phosphates) in wastewater and drinking water samples. For the IC a Dionex chromatograph was used equipped with an AS4-SC anion column which allows, using the 10-micronS conductimetric scale, detection limits of 0.03 mg/l for nitrites, 0.04 mg/l for nitrates and 0.08 mg/l for phosphates and percent variation coefficients always lower than 3% to be obtained. AMS analyses were carried out using a Lange Cadas 505 spectrophotometer with bar-coded tubes and pre-dosed reagents; value obtained are 5%. Linearity as a function of dilution gave correlation coefficient values r0.999 for IC and from 0.938 to 0.999 for AMS. The results obtained by IC are higher than those of AMS; the latter technique, however, can be considered suitable for drinking water and wastewater routine analyses within the framework of the new rules in force
In questo lavoro sono messi a confronto due metodi analitici, la cromatografia ionica (CI) e la spettrofotometria in assorbimento molecolare (AMS), in termini di linearita', rivelabilita' e ripetibilita' nella determinazione quantitativa di anioni (nitriti, nitrati e fosfati) in campioni di acque di scarico e potabili. Per la CI e' stato utilizzato un cromatografo Dionex munito di colonna per anioni AS4-SC che permette di ottenere, con la scala conduttimetrica da 10 micronS, limiti di rivelabilita' di 0.03 mg/l per i nitriti, di 0.04 mg/l per i nitrati e di 0.08 mg/l per i fosfati e coefficienti di variazione percentuale sempre inferiori al 3%. Le analisi in AMS sono state condotte con spettrofotometro Lange Cadas 50S predisposto con provette munite di codice a barre e reattivi predosati; i CV% ottenuti sono 5%. La linearita' in funzione della diluizione ha fornito valori di coefficiente di correlazione r0.999 per la CI e valori da 0.938 a 0.999 per l'AMS. Le prestazioni ottenute con la CI sono superiori a quelle dell'AMS; tuttavia, quest'ultima tecnica puo' essere ritenuta adeguata per le analisi di routine delle acque potabili e di scarico nell'ambito delle normative vigenti
A simple method was developed to determine organic acids in beer using very common laboratory equipment and easy sample preparation. Four Italian brands of lager type beer were used. Beer samples ...were applied to an anion exchange resin and organic acids were released using 0.1 N HCl. HPLC separation was achieved using two C18 reverse phase columns in series. Acids were separated and quantified by isocratic analysis (0.8 ml/min in 30 min). Pyruvic, malic, lactic, acetic, citric, succinic, citramalic and fumaric anions in beer were detected using Refractive Index (RI) and Ultraviolet (UV) detectors. Use of the resin bed gave a good efficiency of recovery evaluated with the two detectors. Responses of the two detectors were also statistically comparable when the organic acid anion composition of the four different brands was evaluated. The RI detector was 10 times less sensitive than the UV detector, but still quite sufficient to detect the lowest concentration of organic acid anions in beer
L'obiettivo di questa ricerca e' stato quello di mettere a punto un metodo semplice per la determinazione degli anioni degli acidi organici contenuti nella birra, utilizzando apparecchiature comunemente presenti in laboratorio ed eseguendo una facile preparazione del campione. Sono stati impiegati quattro differenti marchi di birre italiane del tipo lager. I campioni di birra sono stati trattati su resina a scambio anionico e gli acidi organici sono stati rilasciati mediante desorbimento con HCl 0,1 N. La separazione mediante HPLC e' stata ottenuta utilizzando due colonne in fase inversa C18 poste in serie. Gli acidi sono stati separati e quantificati mediante analisi in isocratica (0,8 ml/min) dopo 30 min utilizzando i rivelatori IR e UV a 210 nm. E' stato possibile rivelare gli acidi piruvico, malico, lattico, acetico, citrico succinico, citramalico e fumarico, contenuti nella birra. Il passaggio su resina ha mostrato una buona efficienza nel recupero con entrambi i rivelatori utilizzati. I dati quantitativi ottenuti con i due rivelatori sono risultati statisticamente comparabili, per le quattro birre analizzate. Il rivelatore RI e' risultato 10 volte meno sensibile dell'UV, ma ampiamente sufficiente per rivelare anche la piu' bassa concentrazione anionica
Effects of in situ-liming on chemical and biological properties of a forest soil in Northern Italy subjected to a natural acid deposition have been investigated for three years after liming. Soil ...chemical (pH; CEC; PBS; LR; available cations and anions) and biochemical (MBC and MBN; enzymatic activities; soil respiration) properties were tested. The first two years showed significant differences in most chemical and biochemical parameters of limed soils, while in the third year an evident and significant re-acidification process was detected. Climatic and ecological conditions of the research area and the reduced effect of CaCO3 during the last year contributed to the soil natural original acidic state
Per tre anni, dopo calcitazione, sono stati studiati gli effetti della calcitazione in situ sulle proprieta' chimiche e biologiche di un suolo forestale dell'Italia Settentrionale soggetto a una deposizione acida naturale. Sono state determinate le proprieta' chimiche (pH; CSC; SBP; FC; cationi e anioni disponibili) e biochimiche (BMC e BMC; attivita' enzimatiche; respirazione del terreno). Nei primi due anni sono state messe in evidenza differenze significative nella maggior parte dei parametri chimici e biochimici dei terreni sottoposti a calcitazione, mentre nel terzo anno e' stato riscontrato un processo evidente e significativo di riacidificazione. Le condizioni climatiche ed ecologiche dell'area in cui e' stata effettuata la ricerca e l'effetto ridotto del CaCO3 nel corso dell'ultimo anno hanno contribuito a ripristinare la condizione originale di acidita' naturale del terreno
Lemon and mandarin juices and their corresponding second pressure liquids were analysed by ion chromatography equipped with both UV and conductivity detectors. Inorganic (chloride, sulphate, ...phosphate) and organic (galacturonate, malate, citrate, isocitrate) anions were determined simultaneously using this technique. An unidentified peak at 210 nm, which was previously observed in second pressure concentrates of orange but not in their juices, was present in juices and second pressure liquids of lemon and mandarin. However, the peak-areas of the juices were remarkably lower, thus allowing the juices to be distinguished from their second pressure extracts
Mediante cromatografia ionica con eluizione in gradiente e rivelazione contemporanea, sia per conducibilita', sia per UV, sono stati analizzati e messi a confronto i succhi di limone e mandarino ed i corrispondenti liquidi di seconda pressione. In una singola analisi sono stati determinati gli anioni inorganici (cloruri, fosfati, solfati) e gli anioni organici (galatturonato, malato, citrato, isocitrato). Un picco non identificato, rivelato in UV a 210 nm e gia' riscontrato per l'arancia soltanto nei liquidi di seconda pressione, per limone e mandarino e', invece, presente sia nei torchiati, sia nei corrispondenti succhi. Tuttavia, le aree del picco relative a questi ultimi sono notevolmente inferiori, permettendo comunque una differenziazione tra i succhi ed i liquidi di seconda pressione allo studio
One hundred and ninety samples of fresh tomatoes (40% elongated, 60% round) grown in different areas of the Apulia region and harvested at different times during the 1998 season were analysed for ...nitrates, nitrites, chlorides, sulphates, phosphates, copper, soluble solids, pH and acidity. In addition, the acidity/soluble solids ratio was determined. In no sample were nitrites found, not even at the trace level. Average concentrations of nitrates, chlorides, sulphates, phosphates and copper (mg/kg) were, respectively: 12.9 +- 5.6; 534.4 +- 77.5; 316.9 +- 43.4; 451.8 +- 82.0; 0.60 +- 0.24. pH, % soluble solids content, acidity and acidity/soluble solids ratio were, respectively.- 4.41 +- 0.11; 4.69 +- 0.50; 0.37 +- 0.06; 8.06 +- 1.41. Fruit shape, harvesting date and production area had no significant effects on the examined parameters
190 campioni di pomodoro fresco (40% di forma allungato, 60% di forma tonda), coltivati in diverse zone della Puglia e raccolti in diversi periodi della campagna 1998, sono stati sottoposti alle seguenti analisi: nitrati, nitriti, cloruri, solfati, fosfati, rame, residuo secco solubile, pH, acidita' e rapporto acidita'/solidi solubili. In nessun campione e' stata riscontrata la presenza di nitriti, neppure a livello di tracce. Le concentrazioni medie di nitrati, cloruri, solfati, fosfati e rame (mg/kg) erano, rispettivamente, le seguenti: 12,9 +- 5,6; 534,4 +- 77,5; 316,9 +- 43,4; 451,8 +- 82,0; 0,60 0,24. Il pH, il contenuto di solidi solubili %, l'acidita' ed il rapporto acidita'/solidi solubili erano, rispettivamente, pari a: 4,41 +- 0,11; 4,69 +- 0,50; 0,37 +- 0,06; 8,06 +- 1,41. Per tutti i parametri esaminati non ci sono significative differenze in funzione della forma dei frutti, del periodo di raccolta e della zona di produzione
PDF
