Abrupt change of Antarctic moisture origin at the end of Termination II.

The deuterium excess of polar ice cores documents past changes in evaporation conditions and moisture origin. New data obtained from the European Project for Ice Coring in Antarctica Dome C East Antarctic ice core provide new insights on the sequence of events involved in Termination II, the transition between the penultimate glacial and interglacial periods. This termination is marked by a north-south seesaw behavior, with first a slow methane concentration rise associated with a strong Antarctic temperature warming and a slow deuterium excess rise. This first step is followed by an abrupt north Atlantic warming, an abrupt resumption of the East Asian summer monsoon, a sharp methane rise, and a CO(2) overshoot, which coincide within dating uncertainties with the end of Antarctic optimum. Here, we show that this second phase is marked by a very sharp Dome C centennial deuterium excess rise, revealing abrupt reorganization of atmospheric circulation in the southern Indian Ocean sector.

10Be evidence for the Matuyama-Brunhes geomagnetic reversal in the EPICA Dome C ice core.

An ice core drilled at Dome C, Antarctica, is the oldest ice core so far retrieved. On the basis of ice flow modelling and a comparison between the deuterium signal in the ice with climate records from marine sediment cores, the ice at a depth of 3,190 m in the Dome C core is believed to have been deposited around 800,000 years ago, offering a rare opportunity to study climatic and environmental conditions over this time period. However, an independent determination of this age is important because the deuterium profile below a depth of 3,190 m depth does not show the expected correlation with the marine record. Here we present evidence for enhanced 10Be deposition in the ice at 3,160-3,170 m, which we interpret as a result of the low dipole field strength during the Matuyama-Brunhes geomagnetic reversal, which occurred about 780,000 years ago. If correct, this provides a crucial tie point between ice cores, marine cores and a radiometric timescale.

Chloramphenicol influence on antioxidant enzymes with preliminary approach on microsomal CYP1A immunopositive-protein in Chamelea gallina.

Chloramphenicol (CA) is a largely used antibiotic and it is an inhibitor of protein synthesis that also induces ROS production. In this work there were investigated activities and expressions in the Adriatic bivalve Chamelea gallina of some antioxidant and detoxification proteins like superoxide dismutase (Mn-SOD, Cu/Zn-SOD), catalase (CAT) and Cytochrome P450 (CYP1A). Clams exposed to 5mgl(-1) of chloramphenicol were sampled 2, 4 and 8 days after treatment (CA2, CA4 and CA8). SODs, CAT, and CYP1A activity and/or expression were detected in pooled digestive glands by Western blotting and by spectrophotometrical analysis. Enzymes activities increase during the entire antibiotic exposure. With respect to the control Cu/Zn-SOD expression increases, while Mn-SOD expression decreases significantly after 4 days. Two CYP1A immunopositive-proteins (57.7 and 59.8kDa) were detected. The lower band significantly decreases in CA8, the upper one also in CA4 condition. High levels of Mn-SOD, CAT activity and Cu/Zn-SOD expression, indicate intense ROS production while Mn-SOD expression inhibition might be ascribable to mitochondrial alterations due to CA and indirectly to ROS. CYP1A1 action determines H2O2 production that would contribute to a CYP1A1 gene promoter down regulation, a response to oxidative stress with the antioxidant enzymes activation as a final result. This study highlights the close association, in C. gallina, in presence of chloramphenicol, between SOD/CAT and CYP system, and it appear particularly interesting to the lack of similar researches on mollusc species.

Effect of exposure to benzo[a]pyrene on SODs, CYP1A1/1A2- and CYP2E1 immunopositive proteins in the blood clam Scapharca inaequivalvis.

The effects of water-borne exposure to benzo[a]pyrene (36 h; celite-bound 0.44 mg L(-1) B[a]P) on cytochrome P450 (CYP) and superoxide dismutases (SODs) were examined in digestive gland of the blood clam, Scapharca inaequivalvis. B[a]P accumulation and elimination were rapid, with maximum whole-body concentrations of 1.78 ng g(-1) wet wt after 12 h of treatment, followed by a progressive decline to 0.89 ng g(-1) at 36 h. The presence of B[a]P resulted in an increase in total CYP of digestive gland microsomes from 54+/-14 to 108+/-21 pmol/mg protein (mean+/-SD; p<0.05, 24 h). Increases were also seen in microsomal CYP1A1/1A2-immunopositive protein (50.5 kDa app. mol. wt; p<0.05), but not CYP2E1-immunopositive protein (49 kDa app. mol. wt.), indicating a specific response of the former isoform. Exposure to B[a]P produced a steady increase in Mn-SOD digestive gland activity (p<0.01; p<0.05) but no significant change in Cu/Zn-SOD activity. The respective proteins, measured by western blotting, were not significant induced after B[a]P exposure. Cu/Zn-SOD and Mn-SOD activities were correlated with total CYP levels (r=0.96 and 0.63, respectively), indicating a role for CYP in reactive oxygen species (ROS) production during exposure. Both 'NADPH-independent' and NADPH-dependent metabolism of B[a]P by digestive gland microsomes was seen, producing mainly 1,6-, 3,6- and 6,12-diones, with some phenols and 7,8-dihydrodiol; putative protein adducts were also formed. Redox cycling of the diones may also have contributed to ROS production, leading to the increased SOD activities.

ASP, DSP, NSP and PSP monitoring in 'mucilaginous aggregates' and in mussels in a coastal area of the Northern Adriatic Sea facing Emilia-Romagna in 1988, 1989 and 1991.

In this study, monitoring of marine biotoxins in "mucilaginous aggregates" and in mussels from coastal area of Emilia Romagna (Northern Adriatic Sea) in June-August 1988, 1989 and 1991, are reported. Both "mucilaginous aggregates" and mussels were analysed for NSP and PSP in 1988, and ASP, DSP, NSP, PSP in 1989, 1991. Concerning "mucilaginous aggregate" any presence of biotoxins was never detected. In the mussels it was possible to exclude the presence of PSP, ASP and NSP, but very high levels of DSP were shown in all the considered periods, in relation to the presence in the sea water of cells of the Dinophysis genus.

Cd-metallothionein in liver and kidney of goldfish (Carassius auratus): effects of temperature and salinity.

Treatment of goldfish with Cd, by intraperitoneal injection, resulted in Cd-metallothionein (Cd-MT) synthesis mainly in liver and kidney. The relative amount of Cd sequestered by liver metallothionein was always greater in fish maintained at 20 degrees C compared to those reared at 10 degrees C, indicating a temperature dependence of metallothionein biosynthesis; in the kidney this dependence was not so clearly evident. Changes in MT levels induced by adapting fish to different salinities did not correlate with the salinity change.

Effects of different levels of dietary zinc on the gilthead, Sparus aurata during the growing season.

Gilthead were fed three diets. Diet A was the control diet, whereas diets B and C were supplemented with 300 and 900 mg Zn/kg, respectively. Fish fed with diet C, at the end of the experiment, showed the lowest weight. Zinc concentrations presented the higher values in gills, liver, and kidney. Muscle and brain had the lower mean values and showed a tight control of zinc levels. These results reinforce the hypothesis that zinc in the CNS should be strictly controlled in order to maintain the functional role of the metal. Significant differences in tissue zinc concentrations were obtained between fish fed different amounts of zinc, the metal concentrations being higher in tissues of fish fed diet C. The tissue decrease of zinc, found at the end of the experiment, may depend on a lower feed consumption or on different zinc requirements during the cold season. These changes, even if not univocal among the three diets, may be associated with the life cycle of fish. Furthermore, copper concentrations were little affected by the different concentrations of zinc in the three diets; liver and kidney presented the highest concentrations; liver showed a significant decrease in copper content at the end of the experiment. We conclude that: zinc concentrations of the diet may affect the gilthead weights and the tissual metal content; and zinc concentrations in the diets, depending on the growth rate, may be varied depending on the season.

Orbital and millennial Antarctic climate variability over the past 800,000 years.

A high-resolution deuterium profile is now available along the entire European Project for Ice Coring in Antarctica Dome C ice core, extending this climate record back to marine isotope stage 20.2, approximately 800,000 years ago. Experiments performed with an atmospheric general circulation model including water isotopes support its temperature interpretation. We assessed the general correspondence between Dansgaard-Oeschger events and their smoothed Antarctic counterparts for this Dome C record, which reveals the presence of such features with similar amplitudes during previous glacial periods. We suggest that the interplay between obliquity and precession accounts for the variable intensity of interglacial periods in ice core records.

Superoxide dismutase in gastric adenocarcinoma: is it a clinical biomarker in the development of cancer?

Gastric cancer is the second most common cancer worldwide. The involvement of reactive oxygen species (ROS) in the pathogenesis of gastric malignancies is well known. Many human tumours have shown significant changes in the activity and expression of superoxide dismutase (SOD), which might be correlated with clinical-pathological parameters for the prognosis of human carcinoma. The aim of this study is the detection of MnSOD and CuZnSOD activity and their expression in gastric adenocarcinoma and healthy tissues. Gastric samples (adenocarcinoma and healthy tissues) harvested during endoscopy or resected during surgery were used to determine MnSOD and CuZnSOD activity and expression by spectrophotometric and Western blotting assays. The total SOD activity was significantly higher (p<0.05) in healthy mucosa with respect to gastric adenocarcinomas. No differences were found in MnSOD activity and, on the contrary, CuZnSOD activity was significantly lower (p<0.001) in cancer samples with respect to normal mucosa. The rate of MnSOD/CuZnSOD activity in adenocarcinoma was over ninefold higher than that registered in healthy tissues (p<0.05). Moreover, in adenocarcinoma MnSOD activity represented the 83% of total SOD with respect to healthy tissues where the ratio was 52% (p<0.001). On the contrary, in cancer tissues, CuZnSOD activity accounted for only 17% of the total SOD (p<0.001 if compared with the values recorded in normal mucosa). After immunoblotting, MnSOD was more expressed in adenocarcinoma with respect to normal mucosa (p<0.001), while CuZnSOD was similarly expressed in adenocarcinoma and healthy tissues. The SOD activity assay might provide a specific and sensitive method of analysis that allows the differentiation of healthy tissue from tumour tissue. The MnSOD to CuZnSOD activity ratio, and the ratio between these two isoforms and total SOD, presented in this preliminary study might be considered in the identification of cancerous from healthy control tissue.

[Dehalogenation of pp'DDT to pp'DDD in the liver microsomal fraction of Mugil cephalus]. / Dealogenazione di pp'DDT in pp'DDD nella frazione microsomiale nel fegato di Mugil cephalus.

pp'DDT was converted to DDD 1-1 dichloro-2,2 bis (p-chlorophenyl) ethane, by treated 12 000 x g supernatant preparations from grey mullet livers. The anaerobic reductive dechlorination occurs whether or not exogenous NADPH and riboflavin is added after a heat pretreatment, otherwise the dechlorination is lowered when the cofactors are not added.

[Hg, Pb and Cd in zooplankton from an area of the Adriatic opposite the Romagna coast line]. / Hg, Pb e Cd in zooplancton di un'area dell'Adriatico antistante il litorale Romagnolo.

The concentrations of heavy metals Hg, Pb and Cd found in zooplankton samples collected in two stations off Cesenatico (Northern Adriatic Sea) from March 1978 to January 1979, have been reported. The Hg, Pb and Cd concentrations showed large variations which did not seem to be correlated with taxonomic composition. The detected levels of metals were higher at the offshore than the nearshore station, accordingly with the sediment pattern. The high concentration of Hg were apparently associated with sources of local industrial pollution.

Cd-metallothionein and metal-enzymes interactions in the goldfish Carassius auratus.

Goldfish injected with cadmium chloride synthesized metallothionein. Ten days after the first injection, cadmium reached a maximum in the metallothionein peak (2 micrograms/ml) obtained after gel filtration of liver cytosol. Pyruvate kinase activity was inhibited from the beginning of the experiment; after the fourth day, the enzyme activity again started to increase but did not reach the control level. Alkaline phosphatase and fructose biphosphatase did not show any apparent inhibition. From the results here reported, a detoxifying role of metallothionein could be suggested.

Diabetes insípida en pediatría: serie clínica y revisión de la literatura / Diabetes insipidus in pediatrics

Introduction: Diabetes insipidus (DI) is a syndrome characterized by polyuria and polydipsia secondary to a decreased secretion or action of the antidiuretic hormone (ADH). An early diagnosis is essential. Diagnosis is made by measuring plasma and urinary osmolarity and their changes under water deprivation and after DDAVP administration. Objective: Lo describe the clinical, radiological characteristics as well as the initial treatment of eight children with DI, 3 of them nephrogenic DI (DIN) and 5 with central DI. Methods: A Retrospective, descriptive study in DI patients under control at the Catholic University of Chile and Sotero del Rio Hospital between 1998-2008 is presented. Clinical files were evaluated collecting clinical, epidemiologic, biochemical and image data. Serum (Sosm) and urinary osmolarity (Uosm) were registered. DI was diagnosed with a Sosm > 300 and Usm < 600 mOsm/L. Central DI was defined as the inability to reach a Uosm > 600 or a 50 percent-increase after DDAVP treatment. Otherwise DI was classified as DIN. Results: Eight patients (5 males) were studied. Chief complaints were polydipsia/polyuria (5/8), hyperthermia (2/8), and failure to grow (1/8). MRI showed endocraneal lesion in all patients with Central DI. All of these utilized oral or inhalatory DDAVP treatment. Patients with Nephrogenic DI were trated with Hydrochlrothiazide. Conclusion: Polydipsia, polyuria, hyperthermia with hypernatremia are suggestive of DI in the first year of life. Water deprivation test is diagnostic in differentiating Central and Nephrogenic DI. MRI is an essential diagnostic tool in CDI. Manegement should be multidisciplinary, including a pediatician, nephrologist, endocrinologist and nutricionist.

Introducción: La diabetes insípida (DI) se caracteriza por poliuria y polidipsia, secundario a una disminución de la secreción o acción de la hormona antidiurética. Su diagnóstico precoz es fundamental. Objetivo: Describir las características clínicas, radiológicas y tratamiento inicial de una serie de ocho pacientes con DI. Diseño: Estudio descriptivo-restrospectivo. Universo: Pacientes con DI evaluados en la Universidad Católica de Chile y Hospital Dr. Sótero del Río entre 1998-2008. Pacientes y Métodos: Desde la ficha clínica se analizaron variables clínicas, epidemiológicas, bioquímicas e imágenes. Se determinó Osmolaridad sérica (OsmS) y urinaria (OsmU). Se consideró DI sí la OsmS > 300 mOsm con OsmU < 600 mOsm, Di-central (DIC) sí posterior a DDAVP la OsmU aumento > 50 por ciento ó > 600 mOsm, de los contrario se clasificó como nefrogénica (DIN). Resultados: Se reclutaron ocho pacientes con DI (5 varones), fueron DIN 3/8. El motivo de consulta fue: polidipsia-poliuria (5/8), hipertermia (2/8) y talla baja (1/8). La RNM mostró lesión intracraneana en todos los pacientes con DIC: nodulo hipofisiario, aracnoidocele selar, Histiocitosis X, germinoma y un paciente sin se±al de neurohipófisis. Los sujetos con DIC usaron DDAVP inhalatoria (4) y oral (1). Los sujetos con DIN usaron hidroclorotiazida. Conclusión: Polidipsia, poliuria, hipertermia con hipernatremia y falla de medro en lactantes son sugerentes de DI. La prueba de deprivación hídrica es fundamental en la diferenciación de DIC y DIN. La RNM cerebral es una herramienta diagnóstica imprescindible en la DIC. El tratamiento de estos pacientes debe ser multidiciplinario interactuando pediatra, nefrólogo, endocrinólogo y nutricionista.

Enfermedad de Basedow Graves en pacientes pediátricos / Graves-Basedow disease in pediatric patients

Objective: Determine differences in the epidemiology, clinical features and diagnosis of Graves-Basedow disease (GBD) in prepubertal and pubertal patients. Method: Retrospective study analyzing medical records of 38 patients with GBD at Pontificia Universidad Católica de Chile between 1992-2007. Statistical analysis was performed with non parametric test of Mann-Whitney U and proportions difference with Fisher Test (SPSS 10.0 for Windows and Graphpad Prism 4). Results: 21 patients were prepubertal and 17 were pubertal, with ages between 3 and 15,9 years. There were more girls than boys in both groups (5:2 and 15:2, respectively; p = 0.2). The most common clinical presentations were diffuse goiter, hyperactivity, frequent bowel movements, insomnia and heat intolerance. The prepubertal group had a taller stature (+2.4 SDS) compared with the pubertal group (+0.2 SDS; p = 0.03) and the most frequent ocular manifestation was exophthalmus in both groups. Conclusions: We did not find any differences in the clinical presentations of Graves-Basedow disease among prepubertal and pubertal patients. Neuropsychiatric symptoms such as hyperactivity and insomnia, together with tall stature are common features in children with GBD.

Objetivo: Determinar si existen diferencias en las características epidemiológicas y clínicas al momento del diagnóstico de hipertiroidismo por Basedow Graves (BG) en sujetos pre-púberes y púberes. Pacientes y Método: Estudio descriptivo y retrospectivo. Universo: Pacientes con diagnóstico de BG en control en endocrinología pediátrica en la Pontificia Universidad Católica de Chile, entre 1991 y abril 2007 (n = 38). Se registraron los hallazgos clínicos y de laboratorio. Se evaluó las diferencias entre los grupos con pruebas no paramétricas (Mann-Whitney U), las diferencias de proporciones con la Prueba de Fisher (SPSS 10.0 para Windows y graphpad Prism 4). Resultados: El rango de edad fue 3 a 15,9 años. Veintiún sujetos eran pre-púberes y 17 eran púberes; hubo más mujeres que hombres (5: 2 y 15: 2, respectivamente; p = 0,2). Los síntomas y signos más frecuentes fueron bocio difuso, hiperactividad, polidefecación, insomnio e irradiación de calor. No hubo diferencias entre los pre-púberes y púberes. El grupo pre-púber tenía talla más alta que su carga genética (+2,4 DS) comparados con los púberes (+0,2 SDS; p = 0,03). El compromiso ocular más frecuente fue el exoftalmo. Conclusión: No encontramos diferencias en la forma de presentación del BG entre los niños pre-púberes y púberes. Los síntomas neuropsiquiátricos tales como hiperactividad e insomnio, y una talla mayor a la esperada para la diana familiar, fueron hallazgos frecuentes en los niños con BG.

Insuficiencia suprarrenal primaria de etiología autoinmune: dos casos clínicos / Autoimmune primary adrenal failure: 2 cases report

Introducción: La insuficiencia suprarrenal primaria (ISRP) es producida por diversas etiologías, congénitas o adquiridas. Su sintomatología es poco específica, exigiendo un alto índice de sospecha. Objetivo: Presentación de dos casos clínicos y revisión de ISRP. Casos Clínicos: Dos niños de 9 y 6 años, ambos con astenia y adinamia, dolor abdominal, baja de peso y vómitos, con avidez por la sal, con mal estado general, lipotimia, hiperpigmentación de piel y mucosas. Se confirmó el diagnóstico de ISRP con compromiso en la secreción de cortisol, y mineralocorticoides. Ambos tuvieron anticuerpos antiadrenales positivos. Conclusiones: La ISRP es poco frecuente en pediatría, sin embargo, es potencialmente de riesgo vital, de manera que reconocer precozmente sus síntomas permitirá realizar un diagnóstico y tratamiento oportuno.

Resistencia a hormonas tiroideas no asociada a mutación de la isoforma beta del receptor de hormonas tiroideas: caso clínico / Thyroid hormone resistance not associated to mutation on the beta isoform of the thyroid hormone receptor: report of one case

Thyroid hormone resistance (RTH) is inherited as an autosomal dominant trait, with variable clinical presentations. The hallmark of the syndrome is a variable degree of resistance to thyroid hormones, with high levels of circulating thyroid hormones, inappropriately normal or elevated TSH values and a clinical pattern of mixed hypothyroidism and hyperthyroidism. RTH is related in more than 85 percent of cases to thyroid hormone beta receptor mutations. We report a 11 years female with a history of treatment with propylthiouracil (PTU) for hyperthyroidism, presenting with a progressive goiter. Thyroidectomy was performed, removing 233 grams of thyroid tissue showing follicular hyperplasia. After surgery, a fast growth of the remnant thyroid gland was observed along with tachycardia. Laboratory showed a TSH of 38 mU/mL a triiodothyronine level of 300 ng/dL a thyroxin level of 14.8 ug/dL and a free thyroxin of 3.19 ng/dL, suggesting the diagnosis of RTH. The molecular study was negative for mutation of the beta isoform of thyroid hormone receptor. The possible theories that can explain these findings are discussed.

Cáncer medular de tiroides esporádico de curso agresivo, en un adolescente varón / Madullary thyroid cancer in a 14 years old male: case report

Medullary thyroid cancer can appear sporadically or as part of a multiple endocrine neoplasia type 2A or 2B. In both conditions, it is associated with mutations of proto oncogene RET (rearranged during transfection). We report a 14 years old male presenting with a bone lesion in the skull followed by a hard cevical mass. A CAT scan showed an invasive thyroid nodule with involvement of regional lymph nodes , osteolytic lesions in skull, spine and ribs and liver metastases. Serum calcitonin was markedly elevated (9752 pg/ml, normal below 14 pg/ml). Fine needle biopsy showed a medullary thyroid carcinoma and the patient was subjected to a total thyroidectomy and radical cervical dissection. In the postoperative period the patient required calcium and vitamin D supplementation. Serum calcitonin 15 days after surgery was 11.692 pg/ml. Palliative radiotherapy was indicated for spine pain. A percutaneous gastrostomy was indication for nutritional support. The molecular study did not detect mutations of RET gene between exons 10 and 16.

Hiperinsulinismo neonatal persistente: análisis del diagnóstico diferencial a propósito de dos casos clínicos / Persistent neonatal hyperinsulinism: report of two cases

Persistent neonatal hyperinsulinism is the most common cause of refractory hypoglycemia during the first year of life. Inadequate insulin secretion is associated to mutations of four different genes, that can be diagnosed to orient patient management. We report two patients: a female newborn that presented a hypoglycemia of 16 mg/dl two hours after birth, was subjected to a subtotal pancreatectomy that did not correct hypoglycemia, requiring a total pancreatectomy. Pathological study of the pancreas showed a focal adenomatous hyperplasia. At the present time, she is three years of age and maintains euglycemia with fractionated feeding. A male newborn that had seizures at 28 hours of life and a hypoglycemia of 15 mg/dl was detected. He was also subjected to a subtotal pancreatectomy, that did not correct hypoglycemia and had to be extended to a total pancreatectomy. At the present time, he is 3 years and 11 months of age and has a normal psychomotor development (Rev Méd Chile 2004; 132: 995-1000).