Microbialite-like structures in Cladophora sp. (Ulvophyceae) mats from a subtropical Andean basin: ecological implications / Estructuras de tipo microbialito en Cladophora sp. (Ulvophyceae) de una cuenca andina subtropical: implicaciones ecológicas

Abstract The solubility equilibrium of calcite is influenced by physicochemical, climatic and biological factors. Annual cycles of exceptionally prolonged drought, in conjunction with naturally occurring diffuse organic pollution, generate the unique conditions for the precipitation of lithified carbonate structures (microbialites). The aim of this article is to analyze the possible implications of calcite precipitation produced in mats of Cladophora sp. in an Andean subtropical basin, considering it is the first time this phenomenon is described for the region. We collected samples from selected sites at the Lules River Basin, in four sampling dates between the years 2003 and 2004, within a monitoring work of 15 years. Samples were analyzed using an electron microscope and X-ray diffraction analysis. We found that Gomphonema sp. attached to Cladophora sp. contributes to precipitation of calcite and formation of microbialite like structures, in the studied area. This work presents an initial discussion of the discovery of microbialites-like structures attached to Cladophora sp. mats in a subtropical Andean stream and the environmental conditions that lead to their production, as well as the possible ecological implications of these microbialites.(AU)

Resumen La fase sólida de las sales de los cuerpos de agua juega un papel importante en la concentración de los elementos mayoritarios. El equilibrio de solubilidad de la calcita está influenciado por factores fisicoquímicos, climáticos y biológicos. Los ciclos anuales de sequía excepcionalmente prolongada, junto con la contaminación orgánica difusa de origen natural, generan condiciones únicas para la precipitación de estructuras de carbonato litificado (microbialitos). El objetivo de este artículo es analizar las posibles implicaciones de la precipitación de calcita producida en Cladophora sp. en una cuenca subtropical andina, considerando que es la primera vez que se describe este fenómeno para la región. Recolectamos muestras en sitios seleccionados en la Cuenca del Río Lules, en cuatro fechas de muestreo entre 2003 y 2004, en el marco de un trabajo de monitoreo de quince años. Usamos red Surber para realizar los muestreos. Las muestras de algas, una vez libres de macroinvertebrados, se secaron y pesaron. Analizamos utilizando microscopía electrónica y difracción de rayos X. Encontramos que Gomphonema sp. unido a Cladophora contribuye a la precipitación de calcita y la formación de estructuras similares a microbialitos, en el área estudiada. Este trabajo presenta una discusión inicial sobre el descubrimiento de estructuras similares a microbialitos unidas a filamentos de Cladophora sp. en una cuenca andina subtropical y las condiciones ambientales que conducen a su producción, así como las posibles implicaciones ecológicas de lo mencionado anteriormente.(AU)

Optical analysis of lithium carbonate: towards the development of a portable lithium blood level analyzer for bipolar disorder patients.

Lithium medication is the gold standard of treatment in Bipolar Disorder patients, preventing and reducing mood swings and suicidality. However, despite its effectiveness, it is a potentially hazardous drug requiring regular monitoring of blood levels to ensure toxic levels are not reached. This paper describes the first steps towards developing a new portable device that can be used by Bipolar Disorder patients to facilitate the analysis of lithium blood levels at home. Solutions of lithium carbonate have been optically fingerprinted using a high-end spectrophotometer. Preliminary measurements indicate that while the visible to near infrared region of the absorption spectra fall heavily within the water band, measurements in the Ultraviolet region show a strong distinction between different lithium concentrations. The optical spectra of Lithium in the 220 nm to 230 nm region demonstrated the ability to differentiate between concentrations representing those found in patients.

Lithium in the public water supply and suicide mortality in Greece.

The purpose of the present study was to evaluate the association between lithium levels in the public water supply and prefecture-based suicide rates in Greece. Analyses were conducted with respect to lithium levels in 149 samples from 34 prefectures of Greece. The average lithium level was 11.10 µg/l (range 0.1 to 121 µg/l). The results indicate that there is a tendency for lower suicide rates in the prefectures with high levels of lithium in drinking water. Ecological studies explained by researchers Schrauzer and Shrestha have revealed the existence of statistically significant inverse associations between the lithium levels in drinking water and the incidence of suicides, homicides, rapes, possession of narcotic drugs, and in juveniles, the rates of runaway from home. Such a result of inverse relationship was not proven by Kabacs et al., most likely because the differences of the lithium levels in the selection of their case-control samples were not large enough. In addition, probably the selection of random regions in Japan and East England might have been biased. Thus, the addition of small amounts of lithium to the drinking water could provide an effective means to lower the incidence of these conditions in the general population. Furthermore, the nutritional importance of lithium in the form of the carbonate named lithium carbonate (Li2CO3) is currently still viewed primarily as a pharmacological agent. The study by Al-Chalabi et al. state that the therapeutic activity of lithium in amyotrophic lateral sclerosis (ALS) is worth investigating. Any drug that can be shown to slow the course of ALS in a clinically significant way and to be safe and well tolerated will be an important advance for patients with this disease.

The application of atomic absorption spectrometry for the determination of residual active pharmaceutical ingredients in cleaning validation samples.

The objective of this work was the development and validation of atomic absorption spectrometric (AAS) methods for the determination of residual active pharmaceutical ingredients (API) in rinse samples for cleaning validation. AAS as an indirect method for the determination of API in rinse samples can be applied when it is in the form of salt with metal ions or when the metal ion is a part of the API's structure. The electrothermal AAS methods (aqueous and ethanol medium) for the determination of magnesium in esomeprazole magnesium and the flame AAS method for the determination of lithium in lithium carbonate in rinse samples were developed. Various combinations of solvents were tested and a combination of 1% aqueous or ethanol solution of nitric acid for esomeprazole magnesium and 0.1% aqueous solution of nitric acid for lithium carbonate were found to be the most suitable. The atomization conditions in the graphite furnace and in the flame were carefully studied to avoid losses of analyte and to achieve suitable sensitivity. The cleaning verification methods were validated with respect to accuracy, precision, linearity, limit of detection, and quantification. In all the cases, the limits of detection were at the microgram level. The methods were successfully applied for the determination of esomeprazole magnesium and lithium carbonate in rinse samples from cleaning procedures.

New guidelines for delta13C measurements.

Consistency of delta13C measurements can be improved 39-47% by anchoring the delta13C scale with two isotopic reference materials differing substantially in 13C/12C. It is recommended that delta13C values of both organic and inorganic materials be measured and expressed relative to VPDB (Vienna Peedee belemnite) on a scale normalized by assigning consensus values of -46.6 per thousand to L-SVEC lithium carbonate and +1.95 per thousand to NBS 19 calcium carbonate. Uncertainties of other reference material values on this scale are improved by factors up to two or more, and the values of some have been notably shifted: the delta13C of NBS 22 oil is -30.03 per thousand.

Efficiency of the Genius batch hemodialysis system with low serum solute concentrations: the case of lithium intoxication therapy.

BACKGROUND: The Genius batch system consists of a 90-L closed reservoir, from which fresh dialysate is extracted at the top and to which spent dialysate is returned at the bottom. It was shown in long-term hemodialysis patients that almost the entire amount of unspent dialysate can be used before contamination of fresh with spent dialysate occurs. Separation is caused by differences in density, partly because of the presence of uremic solutes in spent dialysate. The question is raised whether this separation can be maintained during dialysis of patients who experience an intoxication without renal failure. METHODS: A patient intoxicated with lithium was dialyzed using the Genius system, prepared at 37 degrees C, during 300 minutes. With dialysate flow set at 300 mL/min (5 mL/s) and in the absence of mixing, urea is not expected at the inlet dialysate tubing before minute 300. RESULTS: In the dialysate inlet tubing, an abrupt increase in lithium and urea concentrations was observed 210 minutes after the start of the session, reflecting contamination of fresh with spent dialysate. At minute 210, only 60.9 L of 90 L of dialysate had crossed the dialyzer. In a control dialysis treatment in a patient with marked renal failure, this mixing occurred only at 300 minutes. CONCLUSION: In the present observation, it is shown that during Genius dialysis in a patient without renal failure, an earlier contamination of fresh with spent dialysate can occur, compared to conditions of renal failure.

Lithium clearance measurements during recombinant interleukin 2 treatment: tubular dysfunction in man.

Renal tubular function was evaluated in nine patients undergoing recombinant interleukin 2 (rIL2) treatment for metastatic colorectal carcinoma. A lithium clearance technique was used and the activities of the lysosomal enzyme N N-acetyl-beta-D-glucosaminidase were also measured in the patients' urine, before treatment, during treatment, and then 2 days and 23 days after rIL2 therapy had finished. Significant reductions in clearances of creatinine, sodium, and lithium were observed. The fractional excretions of sodium and lithium were also reduced. Twenty-three days following cessation of rIL2 treatment, there was still a significant reduction in creatinine clearance compared with pretreatment values (p < .01). The clearances of sodium and lithium were also reduced compared with pretreatment values although this did not achieve significance. The fractional reabsorption of sodium and water by the proximal nephron increased during rIL2 treatment, from 0.707 +/- 0.030 (pretreatment) to 0.793 +/- 0.043. This increased reabsorption of sodium and water persisted, rising to 0.849 +/- 0.029, 2 days following cessation of treatment (p < .001, means +/- SEM). Twenty-three days later this had returned toward the pretreatment value, being 0.781 +/- 0.036. The fractional reabsorption of sodium by the distal nephron was also significantly elevated, both during and 2 days after completing rIL2 treatment. Twenty-three days after cessation of rIL2, this value had returned to the pretreatment value. However, in contrast, the fractional reabsorption of water by the distal nephron demonstrated no change during rIL2 treatment, but 2 days posttreatment was significantly reduced and remained low for a further 3 weeks.

[The possibility of replacing blood serum with sputum for monitoring of therapy with lithium carbonate]. / Mozliwosc zastapienia surowicy slina w monitorowaniu leczenia weglanem litowym.

Lithium concentration was determined in both sputum and blood serum of 31 patients treated with lithium carbonate. It was found that lithium concentration rate in the sputum/blood serum is 2.17 +/- 0.16, and is constant in all patients, except one, for a long time. A high correlation index between lithium concentration in the sputum and blood serum (r = 0.9025, and without two assays in the above mentioned patient r = 0.9858) as well as stability of sputum/serum lithium levels enable -- in the opinion of the authors -- to control lithium concentration in the body, using sputum for the assays. These assays are easy to perform with the aid of the kit called "Salivette" (Sarstedt, Germany). Its principle was discussed, too.