Lithium-induced suicidal erythrocyte death

Lithium (Li+), an effective drug for treatment of bipolar disorders, is known to alter several Ca²+ transporting systems. Increased cellular Ca²+ has in turn been shown to stimulate eryptosis, the suicidal death of erythrocytes. Eryptosis is characterised by exposure of phosphatidylserine (PS) at the erythrocyte surface and by cell shrinkage. The present experiments explored whether Li+ influences eryptosis. In erythrocytes from healthy volunteers, cytosolic Ca²+ activity (Fluo-3 fluorescence), cell volume (forward scatter) and PS exposure (annexin V binding) were determined by fluorescence-activated cell sorting analysis. Exposure to Li+ (≥ 1 mM) did not significantly modify forward scatter but significantly increased cytosolic Ca²+ activity (within 3 h) and annexin binding (within 48 h). The effect was paralleled by increase of cellular adenosine triphosphate concentration. Glucose depletion (24 h) strongly increased PS exposure, an effect significantly enhanced in the presence of Li+ (≥ 1 mM). In conclusion, Li+ triggers suicidal erythrocyte death, an effect at least partially due to increase of cytosolic Ca²+ activity.

Akt2/PKBbeta-sensitive regulation of renal phosphate transport

AIM

The protein kinase B (PKB)/Akt is known to stimulate the cellular uptake of glucose and amino acids. The kinase is expressed in proximal renal tubules. The present study explored the influence of Akt/PKB on renal tubular phosphate transport.

METHODS

The renal phosphate transporter NaPi-IIa was expressed in Xenopus oocytes with or without PKB/Akt and Na(+) phosphate cotransport determined using dual electrode voltage clamp. Renal phosphate excretion was determined in Akt2/PKBbeta knockout mice (akt2(-/-)) and corresponding wild-type mice (akt2(+/+)). Transporter protein abundance was determined using Western blotting and phosphate transport by (32)P uptake into brush border membrane vesicles.

RESULTS

The phosphate-induced current in NaPi-IIa-expressing Xenopus oocytes was significantly increased by the coexpression of Akt/PKB. Phosphate excretion [micromol per 24 h per g BW] was higher by 91% in akt2(-/-) than in akt2(+/+) mice. The phosphaturia of akt2(-/-) mice occurred despite normal transport activity and expression of the renal phosphate transporters NaPi-IIa, NaPi-IIc and Pit2 in the brush border membrane, a significantly decreased plasma PTH concentration (by 46%) and a significantly enhanced plasma 1,25-dihydroxyvitamin D(3) concentration (by 46%). Moreover, fractional renal Ca(2+) excretion was significantly enhanced (by 53%) and bone density significantly reduced (by 11%) in akt2(-/-) mice.

CONCLUSIONS

Akt2/PKBbeta plays a role in the acute regulation of renal phosphate transport and thus contributes to the maintenance of phosphate balance and adequate mineralization of bone.

Cell volume regulatory mechanisms

Prerequisites for cell survival include avoidance of excessive alterations of cell volume. Cells counterbalance the osmolarity due to cellular accumulation of organic substances by uneven distribution of inorganic ions. They extrude Na(+) in exchange for K(+) by the Na(+) /K(+) ATPase. The cell membrane is less permeable to Na(+) than to K(+) . The K(+) exit generates a cell-negative potential difference across the cell membrane which drives the exit of anions such as Cl(-) thus decreasing intracellular osmolarity. Upon cell swelling, cells release ions through activation of K(+) channels and/or anion channels, KCl-cotransport, or parallel activation of K(+) /H(+) exchange and Cl(-) /HCO-3 exchange. Upon cell shrinkage, cells accumulate ions through activation of Na(+) , K(+) , 2Cl(-) cotransport, Na(+) /H(+) exchange in parallel to Cl(-) /HCO3- exchange, or Na(+) channels. Na(+) taken up is extruded by the Na(+) /K(+) ATPase in exchange for K(+) . Shrunken cells further accumulate organic osmolytes. They generate sorbitol and glycerophosphorylcholine and monomeric amino acids by altered metabolism and take up myoinositol (inositol), betaine, taurine and amino acids by Na(+) coupled transport. They release osmolytes during cell swelling.

Developmental neuroethology: changes in escape and defensive behavior during growth of the lobster

The changes in relative efficacy of two incompatible behaviors was investigated during growth of the lobster, Homarus americanus. In larval and early juvenile stages, physiological and morphological factors favor use of the escape response over defensive behavior. In large animals, defensive behavior is preferred almost exclusively to escape behavior unless the claws are lost. The interaction of escape and defensive behavior is modified by neural and morphological factors, which are dependent on the stage in the life cycle of the organism.

[Preliminary comparative study of the personality disorder evaluation DIP instrument with the semi-structured SCID-II interview]

INTRODUCTION

This work deals with the comparative study of two standardised instruments, which can be used to diagnose personality disorders (PD): the SCID-II and the DIP. Each instrument used as a self-questionnaire followed by a semi-structured interview by the same clinician was applied to 21 patients suffering from PD. The DIP (DSM-IV and ICD-10 Personality), which is a recent instrument, consists of a self-questionnaire (DIP-Q) and a semi-structured interview (DIP-I), created by Bodlund and Ottosson. It makes it possible to evaluate PD from criteria based on the DSM-IV as well as the ICD-10. We translated it into French then evaluated it in comparison with another instrument, the Structured Clinical Interview for DSM-IV Axis II PD (SCID-II) whose validity was demonstrated by Bouvard.

METHOD

For the self-questionnaire (SCID-auto), we used CUNGI'S computerised version. The present version of the semi-structured interview SCID-E (French translation by Bouvard et al.) evaluates the 10 PD of the DSM-IV, the depressive personality and the passive-aggressive personality, included in the DSM-IV appendix B. The DIP-Q questionnaire is made up of 140 right/wrong items referring to the 10 PD of the DSM-IV and the eight disorders of the ICD-10. The DIP-I is the self-structured interview created by Ottosson et al. and it is built on the same pattern as the SCID-II. It provides diagnoses for all DSM-IV and/or ICD-10 PD as well as the schizotypic disorder. The DIP-I is usually preceded by a general "scan" interview in order to assess an existing personality disorder corresponding to Axis I of the DSM-IV or the ICD-10. In our study, we substituted a Mini International Neuropsychiatric Interview (MINI) questionnaire for this interview. Twenty-four patients suffering from one or several PD were chosen among ambulatory or out-patients by clinicians from the Saint-Etienne Psychiatric University Hospital Center. The diagnosis was not revealed to the examiner during the study. The subjects filled in the DIP-I and the SCID-II self-questionnaires. The answers to each test were first processed through a computer, then the patients were seen over the following weeks for the DIP-I and SCID-II semi-structured interviews. For both questionnaires, we only explored the diagnostic categories reaching pathological level (as was recommended by the authors). Considering the small number of patients involved, we used nonparametric tests: Wilcoxon test, Mac Nemar test and the Kappa.

RESULTS

As far as the self-questionnaire results are concerned, we noticed important differences for the schizoid and the schizotypic PD between the DIP-Q (ICD) and the DIP-Q (DSM). The most represented PDs are the paranoiac, borderline, avoiding and obsessional personalities. After the semi-structured interviews, it appears that only 30 to 50% of the diagnoses obtained through self-evaluation were confirmed (with the exception of the schizotypic personality and the antisocial personality for the SCID with perfect agreement between self and clinical evaluation). Globally, the agreement between diagnosis by self-evaluation and diagnosis by semi-structured interview is not very satisfactory. Finally, a cluster analysis of the results of the three semi-structured interviews put together reveals that five patients show at least one PD diagnosed in the three clusters, two have no diagnosis, six patients have one or several PDs in clusters B and C, three patients have some in clusters A and C, and five patients only have some in cluster C. Our results lead to several remarks: the size of our group is small, but it must be pointed out that the investigations for each patient took about three hours, which made it difficult for the patients to agree when the clinicians proposed the study; three patients originally included could not be evaluated because of suicidal behaviour. In their self-administered form, the SCID and the DSM version of the DIP-Q broadly diagnose a little more than three PDs per patient, whereas the ICD version of the DIP-Q diagnoses more than five. The administration of semi-structured interviews leads to an average of 1.3 diagnosis for the DIP-Q DSM-IV and 1.6 for the ICD against 1.9 PD for the SCID interview. These results correspond to the literature data. There are differences between the SCID and the DIP-I, as regards to the way they were used: the SCID-II makes it necessary to repeat the questions positively answered in the self-questionnaire, whereas the DIP-I explores all the criteria of the whole diagnosed PD, which may favour the inclusions. Concerning other instruments compared to the SCID-II in the international literature, our results with the DIP are globally satisfactory.

CONCLUSION

The results must be interpreted with some care, considering the small number of patients. Important discrepancies were noticed between the diagnoses obtained through self-evaluation and the semi-structured interview, mainly for the A and C personality clusters of the DSM-IV, showing the tests to be extremely sensitive, but not specific enough for detection. However, the agreement between both instruments referring to the DSM-IV is satisfactory. The main interest of our work was to make the first French translation of the DIP known and to compare it to another instrument, which has often been evaluated previously.

Participation of leukotriene C(4) in the regulation of suicidal erythrocyte death

Eryptosis, the suicidal death of erythrocytes, is characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine exposure at the erythrocyte surface. Eryptosis is triggered by increase in cytosolic Ca(2+) concentration upon energy depletion. The present study explored the involvement of leukotrienes. Western blotting was employed to detect the cysteinyl-leukotriene receptor cysLT1, competitive immune assay to determine leukotriene release from erythrocytes, Fluo3 fluorescence to estimate cytosolic Ca(2+) concentration, forward scatter to analyse cell volume and annexin V-binding to disclose phosphatidylserine exposure. As a result, erythrocytes expressed the leukotriene receptor CysLT1. Glucose depletion (24 hours) significantly increased the formation of the cysteinyl-leukotrienes C(4)/D(4)/E(4). Leukotriene C(4) (10 nM) increased Ca(2+) entry, decreased forward scatter, activated caspases 3 and 8, and stimulated annexin V-binding. Glucose depletion similarly increased annexin V-binding, an effect significantly blunted in the presence of the leukotriene receptor antagonist cinalukast (1 microM) or the 5-lipoxygenase inhibitor BW B70C (1 microM). In conclusion, upon energy depletion erythrocytes form leukotrienes, which in turn activate cation channels, leading to Ca(2+) entry, cell shrinkage and cell membrane scrambling. Cysteinyl-leukotrienes thus participate in the signaling of eryptosis during energy depletion.

Triggering of suicidal erythrocyte death by radiocontrast agents

BACKGROUND

According to in vitro observations, gadolinium-containing magnetic resonance (MRT) contrast agents stimulate suicidal cell death or apoptosis. Similar to nucleated cells, erythrocytes may undergo suicidal death or eryptosis, characterized by cell shrinkage and cell membrane scrambling with phosphatidylserine (PS) exposure at the erythrocyte surface. Eryptosis is triggered by increased cytosolic Ca2+-activity. This study explored whether gadolinium-containing MRT contrast agents stimulate eryptosis.

MATERIALS AND METHODS

Annexin V-binding reflecting PS exposure and forward scatter reflecting cell volume were determined in erythrocytes within freshly drawn blood from patients (8female symbol, 3male symbol, 29-72 years) prior to and 10 min after administration of gadoterate meglumine (0.1 mmol kg(-1) b.w. Dotarem; six patients) or gadobenate dimeglumine (0.05 mmol kg(-1) bw Multi Hance; five patients). In a separate series, eryptosis was determined prior to and following in vitro incubation of erythrocytes from 16 blood donors for 4 h with gadoterate meglumine (5 mM Dotarem) or gadobenate dimeglumine (5 mM Multi Hance). Finally, eryptosis and Fluo3 fluorescence reflecting cytosolic Ca2+ were determined in vitro following exposure to Gd3+. Data were analysed using paired t-test or anova with Tukey's test as post-test.

RESULTS

The MRT contrast agents such as gadoterate meglumine (Dotarem) and gadobenate dimeglumine (Multi Hance) significantly increased the percentage of eryptotic cells. Moreover, in vitro exposure to gadoterate meglumine (5 mM), gadobenate dimeglumine (5 mM) or Gd3+ (1.9 microM) stimulated eryptosis in vitro. The effect of Gd3+ was paralleled by increase in cytosolic Ca2+-activity.

CONCLUSIONS

MRT contrast agents may stimulate suicidal erythrocyte death or eryptosis in vitro and in vivo.

PKC(alpha) and PKC(epsilon) differentially regulate Legionella pneumophila-induced GM-CSF

Legionella pneumophila is an important causative agent of severe pneumonia in humans. The human alveolar epithelium is an effective barrier for inhaled microorganisms and actively participates in the initiation of innate host defense. Although secretion of granulocyte-macrophage colony-stimulating factor (GM-CSF) is essential for the elimination of invading Legionella spp., mechanisms of Legionella pneumophila-induced release of this cytokine are widely unknown. In this study, we have demonstrated a toll-like receptor (TLR)2- and TLR5-dependent release of GM-CSF in L. pneumophila-infected human alveolar epithelial cells. GM-CSF secretion was not dependent on the bacteria type II or type IV secretion system. Furthermore, an increase in protein kinase C (PKC) activity, particularly PKC(alpha) and PKC(epsilon), was noted. Blocking of PKC(alpha) and PKC(epsilon) activity or expression, but not of PKC(beta), PKC(delta), PKC(eta), PKC(theta), and PKC(zeta), significantly reduced the synthesis of GM-CSF in infected cells. While PKC(alpha) was critical for the initiation of a nuclear factor-kappaB-mediated GM-CSF expression, PKC(epsilon) regulated GM-CSF production via activator protein 1. Thus, differential regulation of GM-CSF, production by PKC isoforms, contributes to the host response in Legionnaires' disease.

Determination of the conversion factor for silymarin - a solution for the problems associated with new assay methods in the pharmacopoeia

In pharmacopoeial monographs for herbal drugs and herbal preparations, conventional assay methods such as colorimetry or spectophotometric assays are often replaced by modern, more specific and reliable methods, e.g. liquid chromatography (LC). However, existing dosage recommendations in the monographs on efficacy and safety of herbal medicinal products which are an important basis for licensing procedures do not refer to the mandatory new methods but to the existing photometric methods. The laboratory comparison of the determination of silymarin of Milk Thistle extract shows that a conversion factor can be calculated which allows a correlation between the new and the existing method. It is suggested that this factor should be included in the Ph. Eur. monograph on Milk Thistle extract, allowing reference to dosages given in official monographs (e.g. ESCOP, HMPC). The solution to use a conversion factor should also be applied to other herbal drugs and herbal preparations, especially for standardised extracts.

Ultracold triplet molecules in the rovibrational ground state

We report here on the production of an ultracold gas of tightly bound Rb2 triplet molecules in the rovibrational ground state, close to quantum degeneracy. This is achieved by optically transferring weakly bound Rb2 molecules to the absolute lowest level of the ground triplet potential with a transfer efficiency of about 90%. The transfer takes place in a 3D optical lattice which traps a sizeable fraction of the tightly bound molecules with a lifetime exceeding 200 ms.

Evaluation of clinician-operated sonography and fine-needle aspiration in the assessment of salivary gland tumours

OBJECTIVES

To evaluate the combination of ultrasound (US) + fine-needle aspiration (FNA) in the assessment of salivary gland tumours in the hands of the otolaryngologist.

DESIGN

A retrospective review of case notes was performed.

SETTING

Two university teaching hospitals in Switzerland.

PARTICIPANTS

One hundred and three patients with a total of 106 focal masses of the salivary glands were included. Clinician-operated US + FNA were the first line of investigation for these lesions. All patients underwent surgical excision of the lesion, which allowed for confirmation of diagnosis by histopathology in 104 lesions and by laboratory testing in two lesions.

MAIN OUTCOME MEASURES

Primary--diagnostic accuracy in identifying true salivary gland neoplasms and detecting malignancy. Secondary--predicting an approximate and specific diagnosis in these tumours.

RESULTS

The combination of US + FNA achieved a diagnostic accuracy of 99% in identifying and differentiating true salivary gland neoplasms from tumour-like lesions. In detecting malignancy, this combination permitted an accuracy of 98%. An approximate diagnosis was possible in 89%, and a specific diagnosis in 69% of our patients.

CONCLUSIONS

Due to economic factors and a high diagnostic accuracy, the combination of US + FNA represents the investigation method of choice for most salivary gland tumours. We suggest that the otolaryngologist be employed in carrying out these procedures, as is already the rule in other medical specialties, while computed tomography and magnetic resonance imaging should be reserved to those few lesions, which cannot be delineated completely by sonography.

Evaluation of clinician-operated sonography and fine-needle aspiration in the assessment of salivary gland tumours

OBJECTIVES

To evaluate the combination of ultrasound (US) + fine-needle aspiration (FNA) in the assessment of salivary gland tumours in the hands of the otolaryngologist.

DESIGN

A retrospective review of case notes was performed.

SETTING

Two university teaching hospitals in Switzerland.

PARTICIPANTS

One hundred and three patients with a total of 106 focal masses of the salivary glands were included. Clinician-operated US + FNA were the first line of investigation for these lesions. All patients underwent surgical excision of the lesion, which allowed for confirmation of diagnosis by histopathology in 104 lesions and by laboratory testing in two lesions.

MAIN OUTCOME MEASURES

Primary--diagnostic accuracy in identifying true salivary gland neoplasms and detecting malignancy. Secondary--predicting an approximate and specific diagnosis in these tumours.

RESULTS

The combination of US + FNA achieved a diagnostic accuracy of 99% in identifying and differentiating true salivary gland neoplasms from tumour-like lesions. In detecting malignancy, this combination permitted an accuracy of 98%. An approximate diagnosis was possible in 89%, and a specific diagnosis in 69% of our patients.

CONCLUSIONS

Due to economic factors and a high diagnostic accuracy, the combination of US + FNA represents the investigation method of choice for most salivary gland tumours. We suggest that the otolaryngologist be employed in carrying out these procedures, as is already the rule in other medical specialties, while computed tomography and magnetic resonance imaging should be reserved to those few lesions, which cannot be delineated completely by sonography.

Evaluation of clinician-operated sonography and fine-needle aspiration in the assessment of salivary gland tumours

OBJECTIVES

To evaluate the combination of ultrasound (US) + fine-needle aspiration (FNA) in the assessment of salivary gland tumours in the hands of the otolaryngologist.

DESIGN

A retrospective review of case notes was performed.

SETTING

Two university teaching hospitals in Switzerland.

PARTICIPANTS

One hundred and three patients with a total of 106 focal masses of the salivary glands were included. Clinician-operated US + FNA were the first line of investigation for these lesions. All patients underwent surgical excision of the lesion, which allowed for confirmation of diagnosis by histopathology in 104 lesions and by laboratory testing in two lesions.

MAIN OUTCOME MEASURES

Primary--diagnostic accuracy in identifying true salivary gland neoplasms and detecting malignancy. Secondary--predicting an approximate and specific diagnosis in these tumours.

RESULTS

The combination of US + FNA achieved a diagnostic accuracy of 99% in identifying and differentiating true salivary gland neoplasms from tumour-like lesions. In detecting malignancy, this combination permitted an accuracy of 98%. An approximate diagnosis was possible in 89%, and a specific diagnosis in 69% of our patients.

CONCLUSIONS

Due to economic factors and a high diagnostic accuracy, the combination of US + FNA represents the investigation method of choice for most salivary gland tumours. We suggest that the otolaryngologist be employed in carrying out these procedures, as is already the rule in other medical specialties, while computed tomography and magnetic resonance imaging should be reserved to those few lesions, which cannot be delineated completely by sonography.

Up-regulation of hypertonicity-activated myo-inositol transporter SMIT1 by the cell volume-sensitive protein kinase SGK1

Mechanisms of regulatory cell volume increase following cell shrinkage include accumulation of organic osmolytes such as betaine, taurine, sorbitol, glycerophosphorylcholine (GPC) and myo-inositol. Myo-inositol is taken up by the sodium-myo-inositol-transporter SMIT1 (SLC5A3) expressed in a wide variety of cell types. Hypertonicity induces the transcription of the SMIT1 gene upon binding of the transcription factor tonicity enhancer binding protein (TonEBP) to tonicity responsive enhancers (TonE) in the SMIT1 promoter region. However, little is known about post-translational regulation of the carrier protein. In this study we show that SMIT1 is modulated by the serum- and glucocorticoid-inducible kinase SGK1, a protein genomically up-regulated by hypertonicity. As demonstrated by two-electrode voltage-clamp in the Xenopus oocyte expression system, SMIT1-mediated myo-inositol-induced currents are up-regulated by coexpression of wild type SGK1 and constitutively active (S422D)SGK1 but not by inactive (K127N)SGK1. The increase in SMIT1 activity is due to an elevated cell surface expression of the carrier while its kinetic properties remain unaffected. According to the decay of SMIT1 activity in the presence of brefeldin A, SGK1 stabilizes the SMIT1 protein in the plasma membrane. The SGK isoforms SGK2, SGK3 and the closely related protein kinase B (PKB) are similarly capable of activating SMIT1 activity. SMIT1-mediated currents are decreased by coexpression of the ubiquitin-ligase Nedd4-2, an effect counteracted by additional coexpression of SGK1. In conclusion, the present observations disclose SGK isoforms and protein kinase B as novel regulators of SMIT1 activity.

Coherent optical transfer of Feshbach molecules to a lower vibrational state

Using the technique of stimulated Raman adiabatic passage (STIRAP) we have coherently transferred ultracold (87)Rb(2) Feshbach molecules into a more deeply bound vibrational quantum level. Our measurements indicate a high transfer efficiency of up to 87%. Because the molecules are held in an optical lattice with not more than a single molecule per lattice site, inelastic collisions between the molecules are suppressed and we observe long molecular lifetimes of about 1 s. Using STIRAP we have created quantum superpositions of the two molecular states and tested their coherence interferometrically. These results represent an important step towards Bose-Einstein condensation of molecules in the vibrational ground state.

Analysis of the monovalent ion fluxes in U937 cells under the balanced ion distribution: recognition of ion transporters responsible for changes in cell ion and water balance during apoptosis

Unidirectional (22)Na, Li(+) and Rb(+) fluxes and net fluxes of Na(+) and K(+) were measured in U937 human leukemic cells before and after induction of apoptosis by staurosporine (1 microM, 4 h) to answer the question which ion transporter(s) are responsible for changes in cell ion and water balance at apoptosis. The original version of the mathematical model of cell ion and water balance was used for analysis of the unidirectional ion fluxes under the balanced distribution of major monovalent ions across the cell membrane. The values of all major components of the Na(+) and K(+) efflux and influx, i.e. fluxes via the Na(+),K(+)-ATPase pump, Na(+) channels, K(+) channels, Na/Na exchanger and Na-Cl symport were determined. It is concluded that apoptotic cell shrinkage and changes in Na(+) and K(+) fluxes typical of apoptosis in U937 cells induced by staurosporine are caused by a complex decrease in the pump activity, Na-Cl symport and integral Na(+) channel permeability.