GABA(B) receptors couple directly to the transcription factor ATF4

The inhibitory neurotransmitter gamma-aminobutyric acid (GABA), acts at ionotropic (GABA(A) and GABA(C)) and metabotropic (GABA(B)) receptors. Functional GABA(B) receptors are heterodimers of GABA(B(1)) and GABA(B(2)) subunits. Here we show a robust, direct, and specific interaction between the coiled-coil domain present in the C-terminus of the GABA(B(1)) subunit and the transcription factor ATF4 (also known as CREB2). ATF4 and GABA(B(2)) binding to the GABA(B(1)) subunit were mutually exclusive. In rat hippocampal neurons native GABA(B(1)) showed surprisingly little similarity to GABA(B(2)) in its subcellular distribution. GABA(B(1)) and ATF4, however, were highly colocalized throughout the cell and displayed a punctate distribution within the dendrites. Activation of GABA(B) receptors in hippocampal neurons caused a dramatic translocation of ATF4 out of the nucleus into the cytoplasm. These data suggest a novel neuronal signaling pathway that could regulate the functional expression of GABA(B) receptors and/or modulate gene transcription.

[Laparoscopic splenectomy in thrombotic thrombocytopenic purpura. Surgical and hematological results in 2 patients]

HISTORY

Case 1. Thrombotic-thrombocytopenic purpura (TTP, Moschkowitz' disease) in a 57-year-old woman had for one year been treated conservatively. But when daily plasmapheresis was temporarily discontinued she developed behavioural changes and impaired speech, providing an indication for splenectomy. Case 2. A 53-year-old woman with TTP had been similarly treated for one month. Splenectomy was indicated when neurological symptoms rapidly developed.

INVESTIGATIONS

At admission, creatinine 110 mg/d, white cell count (WBC) 12.4 G/l haemoglobin 10.1 g/dl, haematocrit 0.29, platelets 91 G/l. Prothrombin time (PTT) and thromboplastin time were normal. Patient 2. At admission, platelet count was below 10 G/l and she had various neurological abnormalities. Haemoglobin was 9.0 f/dl, haematocrit 0.27. Platelet count, PTT, thromboplastin time and renal functions were normal.

TREATMENT AND COURSE

Case 1. After plasmapheresis and administration of cryoprecipitate-free fresh frozen plasma (FFP) excess, laparoscopic splenectomy was performed. On the third postoperative day WBC count was 11.5 G/l, haemoglobin level was unchanged, but platelet count was now normal, as were PTT and thromboplastin time and renal functions. 8 and 32 months after the operation WBC count, haemoglobin, haematocrit and platelets were all normal. There were no neurological abnormalities postoperatively. Case 2. Laparoscopic splenectomy was performed after intensive haematological preparation. The pre- and postoperative course was uneventful and she was discharged on the 8th postoperative day, at which time her haemoglobin was 8.4 g/dl, haematocrit 0.25, while platelets, PTT, thromboplastin time and renal functions were all normal and remained so at follow-up 11 months later. There have been no neurological symptoms after the splenectomy.

CONCLUSION

Laparoscopic splenectomy is a haematologically and surgically safe treatment of TTP and should be considered for all cases of TTP that fail to respond to conservative management.

Screening for an AIRE-1 mutation in patients with Addison's disease, type 1 diabetes, Graves' disease and Hashimoto's thyroiditis as well as in APECED syndrome

OBJECTIVE

Autoimmune polyendocrinopathy-candidiasis-ectodermal dystrophy (APECED) is a rare systemic autoimmune disorder of monogenic and autosomal-recessive inheritance. To date, 29 APECED causing mutations have been identified in the responsible gene AIRE-1, coding for a regulator of transcription. The aim of this study was to examine whether mutations in AIRE-1, in their heterozygous form, predispose to the more common isolated autoimmune endocrinopathies Addison's disease, type 1 diabetes mellitus, Graves' disease and Hashimoto's thyroiditis.

DESIGN

Patients with isolated autoimmune endocrine disorders as well as healthy controls were analysed for two of the most common AIRE-1 mutations, mutation R257X in exon 6 and a 13-bp deletion in exon 8. Mutations were detected by polymerase chain reaction based techniques.

PATIENTS

In total, 726 individuals were investigated for mutation R257X. Subjects comprised patients with Addison's disease, IDDM, Graves' disease and Hashimoto's thyroiditis. With regard to the 13 bp deletion we could screen 91 patients with Addison's disease. In addition, six patients with the APECED syndrome including one family were analysed for both mutations.

RESULTS

Out of the 12 alleles in APECED patients six contained either mutation R257X or the 13 bp deletion, confirming that these mutations prevail in Europe. R257X was found in one subject with Hashimoto's thyroiditis in its heterozygous form. The 13 bp deletion was not detected in any subject with Addison's disease.

CONCLUSIONS

The two studied AIRE-1 mutations are so rare in the general population that they can not contribute to susceptibility for the more common isolated autoimmune disorders.

Thermal decomposition of (NH4)2[PdCl6] studied by in situ X-ray absorption spectroscopy

In situ X-ray absorption near edge structure (XANES) investigations were carried out at chlorine K edge and palladium L3 edge to study the mechanism of the thermal decomposition of ammonium hexachloropalladate. The spectra show a characteristic feature for the initial step that might be explained as the formation of the precursor via ligand exchange (Cl --> NH3). Multiple scattering calculations (Feff 8) for the Cl K, Pd and Rh L3 edges were successful in simulating the XANES spectra of the precursor as well as the reference compounds (NH4)2 [PdCl4] and (NH4)3[RhCl6].

Glycoprotein C of bovine herpesvirus 5 (BHV-5) confers a distinct heparin-binding phenotype to BHV-1

Bovine herpesvirus type 1 (BHV-1) causes respiratory and genital diseases in cattle, whereas the closely related BHV-5 can induce severe meningoencephalitis in calves. To characterize BHV-5 glycoprotein C (gC5) within the backbone of BHV-1, three consecutive recombinant viruses were constructed: A deletion mutant (rBHV-1delta gC blue) with gC replaced by the lacZ gene, an exchange mutant (rBHV-1gC5) with the lacZ of BHV-1delta gC blue exchanged by gC5, and a rescue mutant (rescue BHV-1) from rBHV-1gC5 with an additional XbaI site in gC1. The recombinant and wildtype viruses were characterized on MDBK cells. Although no significant differences were observed in growth behaviour and entry kinetics, rBHV-1gC5 showed a distinct phenotype in a heparin blocking assay. The gC5 was able to transfer the heparin binding phenotype of BHV-5 to BHV-1. This indicates that gC1 and gC5 differ in their receptor binding qualities, which might modulate the ability of the viruses to spread within the central nervous system.

Federal efforts to improve quality of care: the Quality Interagency Coordination Task Force (QuIC)

FORMATION OF THE QUIC: The Quality Interagency Coordination Task Force (QuIC) was established in 1998 to enable the participating federal agencies to coordinate their activities to study, measure, and improve the quality of care delivered by federal health programs; provide people with information to help them in making more informed choices about their care; and develop the research base and infrastructure needed to improve the health care system, including knowledgeable and empowered workers, well-designed systems of care, and useful information systems. STUDY, MEASURE, AND IMPROVE CARE: The QuIC's initial efforts to improve the care delivered in federal health care programs have focused on diabetes, depression, and the effect of working conditions on quality of care. More recently, patient safety efforts are under way to establish a coordinating center that will enable those who are testing methods of reducing errors to share information across their projects and with experts in error reduction. DEVELOP A RESEARCH BASE AND INFRASTRUCTURE: The QuIC has coordinated efforts in credentialing, information on measures of quality, a taxonomy of quality improvement methods, and errors data collection. PROVIDE INFORMATION TO AMERICANS ABOUT HEALTH CARE QUALITY: The QuIC agencies are developing products that will enhance their ability to communicate with the American people about their health care choices: improved gateways for consumer information available from federal agencies, a glossary of commonly used terms, and guidance for producing report cards on quality of care. MOVING THE QUALITY IMPROVEMENT AGENDA FORWARD: Federal efforts to improve quality of care are moving forward in a more integrated fashion on a wide number of fronts.

Conformational changes of single molecules induced by scanning tunneling microscopy manipulation: a route to molecular switching

A detailed experimental and theoretical investigation of the processes involved in the manipulation of individual specially designed porphyrin-based molecules by scanning tunneling microscopy at low temperature is presented. On a stepped Cu(211) surface, the interaction between tip and molecule was used to locally modify in a reversible way the internal configuration of a single molecule, thus drastically changing the tunneling current passing through it. Model calculations confirm that this manipulation realizes the principle of a conformational molecular switch.

Human and monkey fetal brain development of the supramammillary-hippocampal projections: a system involved in the regulation of theta activity

The supramammillary (SUM)-hippocampal pathway plays a central role in the regulation of theta rhythm frequency. We followed its prenatal development in eight Cynomolgus monkeys (Macaca fascicularis) from embryonic day E88 to postnatal day 12 (term 165 days) and in eight human fetuses from 17.5 to 40 gestational weeks, relying on neurochemical criteria established in the adult (Nitsch and Leranth [1993] Neuroscience 55:797-812). We found that 1) SUM afferents reached the dentate juxtagranular and CA2 pyramidal cell layers at midgestation in human fetuses, earlier than in monkeys (two-thirds of gestation [E109]). They co-expressed calretinin, substance P, and acetylcholinesterase but not gamma-aminobutyric acid (GABA) or glutamic acid decarboxylase (GAD); 2) the presumed parent neurons in the monkey SUM expressed calretinin or both calretinin and substance P; 3) most of them were surrounded by GAD-containing terminals that might correspond to the septo-SUM feedback pathway (Leranth et al. [1999] Neuroscience 88:701); and 4) in addition, a large band of calretinin-labeled terminals that did not co-express substance P, GAD, or acetylcholinesterase was present in the deepest one-third of the dentate molecular layer in both the Cynomolgus monkey and human fetuses. It persisted in the adult monkey but not in adult human hippocampus; it remains questionable whether it originates in the SUM. In conclusion, the early ingrowth of the excitatory SUM-hippocampal system in human and non-human primates may contribute to the prenatal activity-dependent development of the hippocampal formation. The possibility and the functional importance of an in utero generation of hippocampal theta-like activity should also be considered.

Ionic films on vicinal metal surfaces: enhanced binding due to charge modulation

NaCl films on Cu(311) exhibit a remarkably strong and localized binding between adlayer and substrate. The binding sites of the ions in the NaCl film with respect to the Cu surface are determined from atomically resolved scanning tunneling microscopy images. A new model is proposed in which the binding mechanism is controlled by the charge modulation of a regularly stepped surface due to the Smoluchowski effect. This model can be extended to explain the growth of ionic adlayers on regularly stepped and kinked metal surfaces in general.

Factors V leiden and II 20210A in patients with symptomatic pulmonary embolism and deep vein thrombosis

PURPOSE

Factor V Leiden and factor II 20210A are inherited disorders of the clotting system that occur frequently in patients with deep vein thrombosis. We conducted this study to determine whether these factors are also common in patients with pulmonary embolism.

SUBJECTS AND METHODS

We determined the prevalence of factor V Leiden and factor II 20210A in 773 consecutive patients with objectively documented symptomatic deep vein thrombosis or symptomatic pulmonary embolism, or with a combination of these disorders.

RESULTS

Isolated symptomatic deep vein thrombosis occurred in 345 patients; isolated symptomatic pulmonary embolism occurred in 236; and both anomalies occurred in 192. Factor V Leiden was present in 21 (9%) of the patients with isolated symptomatic pulmonary embolism, in 30 (16%) with both manifestations, and in 63 (18%) with isolated symptomatic deep vein thrombosis (P = 0.007). Factor V Leiden was more common among patients with deep vein thrombosis (odds ratio [OR] = 2.1; 95% confidence interval [CI]: 1.2 to 3.7; P = 0.006) or both pulmonary embolism and deep vein thrombosis (OR = 1.8; 95% CI: 1.0 to 3.3; P = 0.07) than among patients with isolated pulmonary embolism. Factor V Leiden was less common in massive pulmonary embolism (5% [7 of 127]) than in submassive pulmonary embolism (13% [21 of 155], P = 0.03). We found no significant difference in the prevalence of factor II 20210A among the three groups.

CONCLUSION

Factors V Leiden and II 20210A vary in prevalence among patients with pulmonary embolism and deep vein thrombosis, suggesting that the risk of pulmonary embolization may vary among patients who have different causes of venous thromboses.

Reelin-immunoreactive neurons in the adult vertebrate pallium

Reelin, an extracellular matrix protein, plays a crucial role in cortical development. By using Reelin-immunohistochemistry in different vertebrates (fish, amphibians, reptiles, and mammals : insectivores, odontocetes, rodents, carnivores and man) we show here that Reelin is also expressed by a variety of neurons in the adult pallium. In the everted telencephalon of the zebrafish, Reelin-positive neurons are widely distributed over the dorsal pallium. In land vertebrates, the most consistent and evolutionary conserved location of Reelin-expressing neurons is in the cell-sparse molecular layer associated with laminated cortical organization. We describe an additional heterogeneous population of Reelin-positive neurons outside the molecular layer, the location and distribution of which are more variable, and which may reflect major evolutionary changes in cortical architecture. In squamate reptiles, the Reelin-negative main cell layer is flanked by a superficial and a deep plexiform layer which both contain Reelin-expressing neurons. In mammals, Reelin-positive interneurons are dispersed throughout layers II--VI; the human neocortex is particularly poor in Reelin-positive interneurons. Reelin is also expressed by large stellate and modified pyramidal neurons in layer II of the mammalian entorhinal cortex, and in the superficial lateral cortex of lizards. Examination of this cell population (layer II Pre-alpha) in human brains of different age groups points to a decrease in Reelin-expression in the course of adult life.

Inhibitors of the Cl-/HCO3- exchanger activate an anion channel with similar features in the epithelial cells of rabbit gallbladder: patch-clamp analysis

The stilbene- and dipyridamole-sensitive Cl-conductance (GCl), non-additively activated by some inhibitors of the Cl-/HCO3- exchanger (hydrochlorothiazide, phlorizin, phenylglyoxal) after the exchanger inhibition in the apical plasma membrane of rabbit gallbladder epithelium, has been investigated by patch-clamp technique with cell-attached and inside-out configurations. No Cl- channels were observed under basal conditions or after treatment with 2.5 x 10(-4) mol/l 8-Br-cAMP or hydrochlorothiazide (HCTZ) on the cytosolic side. Conversely, with 2.5 x 10(-4) mol/l HCTZ or 2 mmol/l phlorizin in the pipette, a non-rectifying Cl- channel with about 5 pS conductance and 0.3-0.4 voltage-independent open probability was observed; it was inhibited by 10(-4) - 5 x 10(-4) mol/l SITS, 10(-4) mol/l furosemide or 0.6 x 10(-4) mol/l dipyridamole; the effects of HCTZ and phlorizin were not additive. Open probability increased from 0 (after seal formation) to a maximum of 0.3-0.4 reached in 7-9 min. Similar results were obtained with both configurations. With the cell-attached configuration, HCTZ added to the bath did not activate Cl- channels in the patch. The channel was shown to exclude cations, to be selective for Cl-, but also conductive for gluconate (PGluc/PCl = 0.18). On this basis, it is concluded that: (1) GCl, activated either by HCTZ or phlorizin, has the same underlying anion channels, (2) the channels can be activated only on the external side of the membrane, also in the absence of cytoplasm, without cellular mediations or effects at a distance along the membrane, (3) the channels are inhibited by the same drugs which inhibit the very small intrinsic anion conductance of the exchanger, (4) they are either related to a slow conversion of inhibited exchangers into channels or, less probably, they are parallel to the exchanger and slowly activated by intra-membrane (or membrane-bound) mediators in their turn activated by near, inhibited exchangers.

Transvenous Catheter Embolectomy

Transvenous pulmonary embolectomy was first described in 1969 by Greenfield and associates who designed a special catheter for the aspiration of thrombi in the pulmonary circulatory system. This technique was applied in 64 patients with massive pulmonary embolism (PE) with a 70 to 72% survival rate. However, it is difficult to implement and has not gained widespread acceptance. More recently, several other catheter devices have been used in patients with PE. The total number of patients reported does not exceed 100. Relative angiographic improvement varies between 10 and 49%, but hemodynamic improvement is not observed or not measured in most patients and mortality varies between 9 and 30%. Fibrinolysis was associated with mechanical thrombectomy in 54% of the patients, making the results difficult to interpret. Transvenous pulmonary embolectomy remains an experimental procedure and should been attempted only in the very few patients with PE, uncontrolled cardiogenic shock, and absolute contraindication to fibrinolytic treatment. Animal models are required to compare the different devices available.

The role of clinical informatics in the Agency for Healthcare Research and Quality's efforts to improve patient safety

In 1998, the Institute of Medicine (IOM) issued a report on medical errors, which estimated that up to 98,000 people die in U.S. hospitals each year from errors. This report raised concerns that medical errors have become a national public health problem that should be addressed in the same manner as other epidemics such as heart disease, diabetes, and obesity. In 2001, the IOM released a follow-up report encompassing a broader range of quality issues. They concluded that the U.S. healthcare system is outmoded and incapable of providing consistent, high-quality care. They outlined a strategy for redesigning U.S. healthcare delivery to achieve safe, dependable, high-quality care, which emphasizes information technology as an integral part of the solution. AHRQ's fiscal year 2001 appropriation included an increase of $50 million dollars for initiatives to reduce medical errors and improve patient safety. AHRQ responded to this mandate by developing a series of research solicitations that form an integrated set of activities to design and test best practices for reducing errors in multiple health care settings. This paper discusses the components of this program and the central role of medical informatics research in the Agency's efforts to improve the safety of medical care in America.

Structure and mesomorphism of neodymium(III) alkanoates

The structural and thermal behavior of all members of the homologous series of neodymium(III) alkanoates, ranging from neodymium(III) butyrate to neodymium(III) eicosanoate are described. Neodymium(III) butyrate monohydrate, Nd(C3H7COO)3.H2O crystallizes in space group P1 (No. 2), Z = 2. The lattice parameters are a = 9.824(2) A, b = 11.974(2) A, c = 14.633(2) A, alpha = 86.21(2) degrees, beta = 75.92(2) degrees, gamma = 77.97(2) degrees. The crystal structure consists of ionic layers of neodymium ions, separated by bilayers of butyrate anions. In the ionic layers, the neodymium ions are connected by bridging tridentate carboxylate groups to zigzag chains, whereas the chains are connected among themselves by bridging bidentate carboxylate groups. The two crystallographically different neodymium ions are both having coordination number 9, with a geometry close to a monocapped square antiprism. The structure of the higher homologues can be derived from the structure of neodymium butyrate by extending the alkyl chains. These compounds have a lamellar bilayer structure with planes of neodymium(III) ions coordinated to the carboxylate groups and with the alkyl chains in an all-trans conformation. All homologous compounds from neodymium(III) pentanoate to neodymium(III) pentadecanoate display a thermotropic mesophase, which was identified by high-temperature X-ray diffraction as a smectic A phase. For the series from neodymium(III) pentanoate to neodymium(III) undecanoate an additional high viscosity mesophase is present between the crystalline state and the smectic A mesophase.

Specific passive immunity reduces the excretion of glycoprotein E-negative bovine herpesvirus type 1 vaccine strain in calves

We investigated the excretion of either a glycoprotein E (gE)-negative bovine herpesvirus type 1 (BHV1) vaccine strain or a conventional modified-live vaccine strain in both naïve and passively immunised calves. The replication of gE-negative strain was considerably reduced in the maternally immunised calves, in comparison with the non-immune calves. On the other hand, the excretion of the gE-positive conventional vaccine strain was not reduced and even seemed to be prolonged in the presence of maternal antibodies. These results suggest that BHV1 gE may play a role in virus survival in the presence of antibodies.

Increased apoptosis in acquired sideroblastic anaemia

Idiopathic acquired sideroblastic anaemias (IASAs) form a subgroup of the myelodysplastic syndromes and are characterized by mitochondrial iron accumulation, bone marrow erythroid hyperplasia and decreased peripheral red blood cell counts. Increased intramedullary apoptosis of erythroid precursors is presumed to constitute the pathophysiological mechanism explaining this ineffective erythropoiesis, but if and how mitochondrial dysfunction is implicated in this process is currently unknown. We therefore studied bone marrow precursor cells obtained from nine patients with IASA for (i) caspase 3 activity, (ii) numbers of Annexin V- and 7-amino-actinomycin-positive cells, (iii) numbers of cells with diminished mitochondrial membrane potential, Delta Psi(m), and (iv) numbers of cells producing reactive oxygen species (ROS), and we compared the results with those of five normal bone marrow samples. Compared with controls, we found increased caspase 3 activity in all IASA samples, which correlated with increased numbers of Annexin-V-positive cells (r = 0.7). Analysis of different subpopulations showed increased apoptosis in erythroid populations compared with myeloid and/or lymphoid populations in five out of nine cases, and increased apoptosis in the last two populations in four out of nine cases. As evidence of mitochondrial dysfunction, Delta Psi(m) was found to be diminished in the erythroid subpopulations of all cases of IASA (66.6 +/- 17% vs. 34.6 +/- 12% in normals). Delta Psi(m) decrease was correlated to Annexin V positivity (r = 0.7). Astonishingly, no difference was found between IASA and normal bone marrows with regard to the number of ROS-producing cells. In fact, both groups exhibited a similar low proportion of ROS production (10.3 +/- 7% in normals vs. 6.8 +/- 5% in IASA). Taken together, our results show that mitochondria are clearly implicated in the apoptotic process in IASA patients. Whether this is a result of an intramitochondrial defect (e.g. Fe accumulation, secondary to mitochondrial or nuclear DNA mutations) or is secondary to an extracellular stimulus [e.g. tumour necrosis factor (TNF), Fas ligand (FasL)] remains to be determined.

Casino gambling increases heart rate and salivary cortisol in regular gamblers

BACKGROUND

Although the effects of gambling on cardiovascular parameters have been documented, no data exists describing the effect of gambling on stress hormone secretion. Our study investigated the effect of gambling on heart rate and salivary cortisol in a casino environment.

METHODS

Ten male gamblers participated in both an experimental and control session. In the experimental session, gamblers played a game of blackjack using their own money. Gamblers played cards in the same setting during the control condition; however, the game was played for accumulation of points rather than money. Heart rate and endocrine parameters were recorded at baseline, 30 min, and 60 min following commencement of each session, and again at completion of the game.

RESULTS

Heart rate increased significantly from baseline to 30 min in the experimental session and remained elevated for the remainder of the recording period. Salivary cortisol was raised at 30 min and further elevated at 60 min during gambling, then returned to control levels following completion of the game.

CONCLUSIONS

These data indicate that gambling in a "real life" situation produces increases in salivary cortisol levels that accompany increased cardiovascular activity. Such effects may contribute to the development of gambling addiction.

Production of bovine herpesvirus type 1-seronegative latent carriers by administration of a live-attenuated vaccine in passively immunized calves

The consequences of the vaccination of neonatal calves with the widely used live-attenuated temperature-sensitive (ts) bovine herpesvirus type 1 (BHV-1) were investigated. The ts strain established acute and latent infections in all vaccinated calves either with or without passive immunity. Four of seven calves vaccinated under passive immunity became clearly BHV-1 seronegative by different serological tests, as did uninfected control calves after the disappearance of maternal antibodies, and they remained so for long periods. A cell-mediated immune response was detected by a BHV-1 gamma interferon assay, but this test failed to detect the seronegative latent carriers (SNLCs). While they are not detected, SNLCs represent a threat for BHV-1-free herds or countries. This study demonstrates that SNLCs can be easily obtained by inoculation with a live-attenuated BHV-1 under passive immunity and that latent carrier animals without any antibody do exist. Consequently, this situation could represent a good model to experimentally produce SNLCs.