Removal of239Pu from mice with 3,4,3 LICAM(C) or N,N′, N″, N‴-tetra-(2,3-dihydroxybenzoyl)-spermine

Summary Male mice SAS/4 were injected i.v. with²³⁹Pu citr(IV) 0.27 µCikg^–1–9.99 kBqkg^–1. After 1 h 30 µmol kg^–1 of 3,4,3 LICAM(C), N, N, N, N-tetra-(2,3-dihydroxybenzoyl)-spermine or Na₃CaDTPA as a reference compound was given intraperitoneally. After 4 days the animals were sacrified and the Pu content in livers, kidneys, femurs and carcasses was determined by the liquid scintillation method. It was found that, as compared with the control, 3,4,3 LICAM(C) removed 83% of the Pu activity deposited in the liver, 71% of that in the femur and 79% of the Pu in the whole body. The Pu content in the kidneys exceeded the control value by about 50%. Na₃CaDTPA removed 96, 86, 40 and 72% of plutonium from the liver, kidneys, femurs and carcasses respectively.Tetra-DHB-spermine caused the excretion of 50, 57 and 39% of Pu from liver, bone and whole body respectively. The retention of Pu in the kidneys was increased to 400% of the control value.     

Completion total thyroidectomy in children with differentiated thyroid cancer

INTRODUCTION: The optimal surgical treatment of children with differentiated thyroid cancer remains an important point of discussion. Especially the need for completion operation is questioned in young patients. Our objective was to examine the rate of residual neoplastic disease after non radical initial operation. MATERIAL AND METHODS: From the 235 children diagnosed with differentiated thyroid cancer, 131 (56%) needed completion operation due to incomplete primary surgery. Completion operation involved thyroid bed, lymph nodes or both respectively in 91 (39%), 13 (6%) and 27 (11%) cases. Risk factors responsible for residual disease were evaluated by means of logistic regression analysis. RESULTS: Residual disease was detected in 46 (35%) of reoperated children (25% in thyroid bed and 85% in lymph node of lateral neck compartment). Sex and age did not influence the risk of residual disease in thyroid bed or lymph nodes. Papillary type of cancer and multifocality increased risk of residual disease in thyroid bed respectively by the factor of 15 (95% CI: 2-125) and 2.3 (95% CI: 1.2-4.4). Infiltration of thyroid capsule did not correlate with the risk of residual disease. Lymph node metastases in primary operation increased risk of residual disease by the factor of 16 (95% CI: 1.2-245). Histopathology, multifocality of primary tumour or infiltration of lymph node capsule did not influence the risk of residual disease in lymph nodes of lateral neck compartment. CONCLUSIONS: In children with differentiated thyroid cancer residual disease is diagnosed in about 1/3 of non radically operated cases. This high incidence justifies completion operations. The risk of residual disease is significantly increased in papillary thyroid cancer, multifocal tumours and cases with lymph node metastases.     

Aging: all in the head?

Global reduction in insulin signaling has been linked to extended life span in a range of organisms. New work on mice with brain-specific or whole-body reductions in insulin receptor substrate 2 (IRS2) (Taguchi et al., 2007) points to a role for insulin/IGF-1 signaling in the central control of mammalian aging.     

Assessment of prolactin secretion in children: a profile of circadian prolactin secretion and the principles for interpreting it

INTRODUCTION: Prolactin (Prl) is secreted in a circadian pattern, although no method of interpreting it has yet been established. The aim of the study was to assess Prl secretion in children on the basis of the Prl circadian profile and to establish principles for the interpretation of the results obtained by this method. MATERIAL AND METHODS: The analysis comprised 41 healthy short children (25 boys); aged 5.2-16.3 years, in whom hormonal disorders and chronic diseases had been excluded. The children were divided into prepubertal or pubertal subgroups. Serum Prl concentrations were measured every 3 hours for 24 hours. To assess the rhythm the parameters of macroscopic analysis were calculated and receiver operating characteristic (ROC) analysis was performed. The group for comparison consisted of 30 children aged 8.9-17.2 years with hyperprolactinaemia. RESULTS: In each subgroup significantly higher Prl concentrations were observed at night than by day. No statistical differences were noticed between the groups regarding Prl concentrations at particular time points or parameter values during circadian Prl rhythm evaluation. In the group analysed weak correlations were found between age and Prl peak and trough levels. On the basis of ROC analysis criteria for the existence of normal circadian Prl rhythm in children were established. CONCLUSIONS: 1. The presence of normal circadian Prl rhythm is observed if at least one of the following three criteria is fulfilled: amplitude >1.8779; X(n)/X(d) ratio >1.685; regression index <-0.4107. 2. No interpretation in relation to sex, age and stage of puberty is necessary for the circadian prolactin secretion rhythm in children.     

Fatty acid efficiency profile in uncoupling of <Emphasis Type="Italic">Acanthamoeba castellanii</Emphasis> mitochondria

A profile of free fatty acid (FFA) specificity in Acanthamoeba castellanii mitochondrial uncoupling is described. The FFA uncoupling specificity was observed as different abilities to stimulate resting respiration, to decrease resting membrane potential, and to decrease oxidative phosphorylation efficiency. Tested unsaturated FFA (C18–20) were more effective as uncouplers and protonophores when compared to tested saturated FFA (C8–18), with palmitic acid (C16:0) as the most active. As FFA efficiency in mitochondrial uncoupling is related to physiological changes of fatty acid composition (and thereby FFA availability) during growth of amoeba cells, it could be a way to regulate the activity of an uncoupling protein and thereby the efficiency of oxidative phosphorylation during a cell life of this unicellular organism. Aleksandra Swida and Małgorzata Czarna contributed equally to this work.     

DESCRIPTION OF A NEW NAVICULOID DIATOM GENUS MORENEIS GEN. NOV. (BACILLARIOPHYCEAE) FROM SAND FLATS IN KOREA1

This article describes a new diatom genus Moreneis from the Yellow Sea sand flats on the west coast of Korea. The new genus is characterized by a unique combination of morphological characteristics, including the shape of the plastids, which have not been previously observed in diatoms. The valve morphology resembles other genera belonging to Lyrellaceae, within which we place this genus. In terms of areolae structure, Moreneis resembles Petroneis and Placoneis; however, it differs from both genera with respect to the raphe system and plastid shape. Cells of Moreneis spp. have a single large plastid appressed to the girdle of the secondary side of the valve, with two lobes extended toward the primary side of the valve. Furthermore, the unique feature of Moreneis frustules is the raphe, which has both external central and apical endings bent in opposite directions. We differentiated four taxa, which we describe as new for science. However, based on our findings, several established species from Navicula should also be formally transferred to Moreneis, including N. alpha Cleve, N. besarensis Giffen, N. epsilon Cleve, N. menaiana Hendey, N. polae Heiden, and N. quadri‐undulata F. Meister. Analysis of published data revealed that species belonging to Moreneis are numerous in tropical marine littoral waters, and in moderate climate zones, especially in the western Pacific, with only a few species occurring in the Mediterranean and Atlantic.     

X-Ray-Radiation-Induced Cooperative Atomic Movements in Protein

X-rays interact with biological matter and cause damage. Proteins and other macromolecules are damaged primarily by ionizing X-ray photons and secondarily by reactive radiolytic chemical species. In particular, protein molecules are damaged during X-ray diffraction experiments with protein crystals, which is, in many cases, a serious hindrance to structure solution. The local X-ray-induced structural changes of the protein molecule have been studied using a number of model systems. However, it is still not well understood whether these local chemical changes lead to global structural changes in protein and what the mechanism is.We present experimental evidence at atomic resolution indicating the movement of large parts of the protein globule together with bound water molecules in the early stages of radiation damage to the protein crystal. The data were obtained from a crystal cryocooled to ~ 100 K and diffracting to 1 ?. The movement of the protein structural elements occurs simultaneously with the decarboxylation of several glutamate and aspartate residues that mediate contacts between moving protein structural elements and with the rearrangement of the water network. The analysis of the anisotropy of atomic displacement parameters reveals that the observed atomic movements occur at different rates in different unit cells of the crystal. Thus, the examination of the cooperative atomic movement enables us to better understand how radiation-induced local chemical and structural changes of the protein molecule eventually lead to disorder in protein crystals.     

Retinol-binding protein 4 (RBP-4) levels do not change after oral glucose tolerance test and after dexamethasone, but correlate with some indices of insulin resistance in humans

Introduction: Secretory products from adipocytes may contribute to deterioration in glycaemic control and increased insulin resistance (IR). Retinol-binding protein 4 (RBP-4) may increase IR in mice, with elevated levels in insulin-resistant mice and humans with obesity and type 2 diabetes. However, the mechanisms regulating RBP-4 synthesis remain not fully understood. It is not clear whether short-term glucose-induced hyperglycaemia and hyperinsulinaemia as well as glucocorticosteroid-induced increase in IR might be reflected in alterations in serum RBP-4 levels in humans. In order to investigate this, we measured serum RBP-4, glucose and insulin concentrations during 75.0 gram oral glucose tolerance test (OGTT) - Study 1, as well as before and after oral administration of dexamethasone - Study 2. Material and methods: Both studies included 35 subjects (8 males), age (mean +/- SD) 39.1 +/- 15.6 years, BMI 35.8 +/- 8.7 kg/m(2). Twenty-four of those subjects (5 males), age 38.7 +/- 15.1 years, BMI 34.4 +/- 8.3 kg/m(2), had 75 gram oral glucose tolerance test (OGTT) - Study 1. Blood samples were taken before (0 minutes), and at 60 and 120 minutes of OGTT. 17 subjects (3 males, 4 subjects with type 2 diabetes), age 43.1 +/- 18.1 years, BMI 36.7 +/- 9.0 kg/m(2) underwent screening for Cushing's disease/syndrome (Study 2). Dexamethasone was administered in a dose of 0.5 mg every 6 hours for 48 hours. Fasting serum concentrations of RBP-4, glucose and insulin were assessed before (D0) and after 48 hours of dexamethasone administration (D2). IR was assessed by HOMA in all non-diabetic subjects and in subjects participating in study 1 also by Insulin Resistance Index (IRI), which takes into account glucose and insulin levels during OGTT. Results: Glucose administration resulted in significant increases in insulin and glucose (p < 0.0001). There was, however, no change in RBP-4 concentrations (124.1 +/- 32 mg/ml at 0 minutes, 123 +/- 35 mg/ml at 60 minutes and 126.5 +/- 37.5 mg/ml at 120 minutes of OGTT, p = ns). All subjects in Study 2 achieved suppression of cortisol below 50 nmo/l. Dexamethasone administration resulted in an increase in fasting insulin (from 11.6 +/- 6.8 to 17.1 +/- 7.2 muU/ml; p = 0.003), and an increase in HOMA (from 2.73 +/- 1.74 to 4.02 +/- 2.27; p = 0.015), although without a significant change in RBP-4 levels (119 +/- 26.8 vs. 117.5 +/- 24.8 mg/ml, p = ns). RBP-4 correlated with fasting insulin (r = 0.40, p = 0.025), fasting glucose (r = 0.41, p = 0.02) and HOMA (r = 0.43, p = 0.015), but not with IRI (r = 0.19, p = 0.31). There was, however, only a moderate correlation between HOMA and IRI (r = 0.49 [r(2) = 0.24]; p = 0.006, Spearman rank correlation), while the best correlation was obtained between the product of glucose and insulin levels at 60 min of OGTT and IRI in a non-linear model (r = 0.94 [r(2) = 0.88]; p<0.00001). In subjects who received dexamethasone, a positive correlation between RBP-4 and HOMA (p = 0.01) was lost after two days of dexamethasone administration (p = 0.61). Conclusions: RBP-4 levels do not change during oral glucose tolerance test or after a dexamethasone-induced increase in insulin resistance. This implies that it is highly unlikely that RBP-4 is involved in short-term regulation of glucose homeostasis in humans and that it responds to short-term changes in insulin resistance. A moderate correlation between RBP-4 and some insulin resistance indices (HOMA) does not exclude the fact that RBP-4 might be one of many factors that can influence insulin sensitivity in humans.