Photoemission spectroscopy study of the lanthanum lutetium oxide/silicon interface.

Rare earth oxides are promising candidates for future integration into nano-electronics. A key property of these oxides is their ability to form silicates in order to replace the interfacial layer in Si-based complementary metal-oxide field effect transistors. In this work a detailed study of lanthanum lutetium oxide based gate stacks is presented. Special attention is given to the silicate formation at temperatures typical for CMOS processing. The experimental analysis is based on hard x-ray photoemission spectroscopy complemented by standard laboratory experiments as Rutherford backscattering spectrometry and high-resolution transmission electron microscopy. Homogenously distributed La silicate and Lu silicate at the Si interface are proven to form already during gate oxide deposition. During the thermal treatment Si atoms diffuse through the oxide layer towards the TiN metal gate. This mechanism is identified to be promoted via Lu-O bonds, whereby the diffusion of La was found to be less important.

Response properties from turtle auditory hair cell afferent fibers suggest spike generation is driven by synchronized release both between and within synapses.

Inner ear hair cell afferent fiber synapses are capable of transferring information at high rates for long periods of time with extraordinary fidelity. As at other sensory synapses, hair cells rely on graded receptor potentials and unique vesicle trafficking and release properties of ribbon synapses to relay intensity information. Postsynaptic recordings from afferent fibers of the turtle auditory papilla identified excitatory postsynaptic currents (EPSCs) that were fast AMPA receptor-based responses with rapid onset and decay times. EPSCs varied in amplitude by ≈ 15× per fiber, with kinetics that showed a tendency to slow at larger amplitudes. Complex EPSCs were produced by temporal summation of single events, likely across synapses. Complex EPSCs were more efficient at generating action potentials than single EPSCs. Potassium-evoked release increased the frequency of EPSCs, in particular complex events, but did not increase EPSC amplitudes. Temporal summation of EPSCs across synapses may underlie action potential generation at these synapses. Broad amplitude histograms were probed for mechanisms of multivesicular release with reduced external Ca(2+) or the introduction of Cd(2+) or Sr(2+) to uncouple release. The results are consistent with broad amplitude histograms being generated by a combination of the variability in synaptic vesicle size and coordinated release of these vesicles. It is posited that multivesicular release plays less of a role in multisynaptic ribbon synapses than in single synaptic afferent fibers.

[Health locus of control of patients in disease management programmes]. / Gesundheitliche Kontrollüberzeugungen von Patienten in Disease Management Programmen.

Health locus of control beliefs plays a major role in improving self-management skills of the chronically ill - a main goal in disease management programmes (DMP). This study aims at characterising participants in disease management regarding their health locus of control. Data are based on 4 cross-sectional postal surveys between spring and autumn of 2006 and 2007 within the Health Care Monitor of the Bertelsmann Foundation. Among the 6 285 respondents, 1 266 are chronically ill and not enrolled in a DMP and 327 are participating in a DMP. A high internal locus of control (HLC) occurs significantly less often in DMP patients than in normal chronically ill patients (and healthy people) controlling for age, gender and social class. With increasing age, a high internal locus of control is also significantly less likely. When comparing healthy people, the chronically ill and the DMP participants a social gradient of a high internal locus of control belief can be observed. The weaker internal and higher doctor-related external locus of control of DMP participants should be carefully observed by the physician when trying to strengthen the patients' self-management skills. Evaluators of DMP should take into account the different baselines of DMP patients and relevant control groups and incorporate these differences into the evaluation.

Permeation properties of the hair cell mechanotransducer channel provide insight into its molecular structure.

Mechanoelectric transducer (MET) channels, located near stereocilia tips, are opened by deflecting the hair bundle of sensory hair cells. Defects in this process result in deafness. Despite this critical function, the molecular identity of MET channels remains a mystery. Inherent channel properties, particularly those associated with permeation, provide the backbone for the molecular identification of ion channels. Here, a novel channel rectification mechanism is identified, resulting in a reduced pore size at positive potentials. The apparent difference in pore dimensions results from Ca(2+) binding within the pore, occluding permeation. Driving force for permeation at hyperpolarized potentials is increased because Ca(2+) can more easily be removed from binding within the pore due to the presence of an electronegative external vestibule that dehydrates and concentrates permeating ions. Alterations in Ca(2+) binding may underlie tonotopic and Ca(2+)-dependent variations in channel conductance. This Ca(2+)-dependent rectification provides targets for identifying the molecular components of the MET channel.

The natural history of hereditary pancreatitis: a national series.

BACKGROUND AND AIMS: The prevalence and natural history of hereditary pancreatitis (HP) remain poorly documented. The aims of this study were to assess genetic, epidemiological, clinical and morphological characteristics of HP in an extensive national survey. METHODS: A cohort comprising all HP patients was constituted by contacting all gastroenterologists and paediatricians (response rate 84%) and genetics laboratories (response rate 100%) in France (60,200,000 inhabitants). Inclusion criteria were the presence of mutation in the cationic trypsingen gene (PRSS1 gene), or chronic pancreatitis in at least two first-degree relatives, or three second-degree relatives, in the absence of precipitating factors for pancreatitis. RESULTS: 78 families and 200 patients were included (181 alive, 6673 person-years, males 53%, alcoholism 5%, smoking 34%). The prevalence was 0.3/100,000 inhabitants. PRSS1 mutations were detected in 68% (R122H 78%, N29I 12%, others 10%). Penetrance was 93%. Median age at first symptom, diagnosis and date of last news, were 10 (range 1-73), 19 (1-80) and 30 (1-84) years, respectively. HP was responsible for pancreatic pain (83%), acute pancreatitis (69%), pseudocysts (23%), cholestasis (3%), pancreatic calcifications (61%), exocrine pancreatic insufficiency (34%, median age of occurrence 29 years), diabetes mellitus (26%, median age of occurrence 38 years) and pancreatic adenocarcinoma (5%, median age 55 years). No differences in clinical and morphological data according to genetic status were observed. 19 patients died, including 10 directly from HP (8 from pancreatic adenocarcinoma). CONCLUSION: The prevalence of HP in France is at least 0.3/100,000. PRSS1 gene mutations are found in 2/3 with a 93% penetrance. Mutation type is not correlated with clinical/morphological expression. Pancreatic adenocarcinoma is the cause of nearly half the deaths.

Auditory hair cell-afferent fiber synapses are specialized to operate at their best frequencies.

Auditory afferent fiber activity is driven by high-fidelity information transfer from the sensory hair cell. Presynaptic specializations, posited to maintain fidelity, are investigated at synapses with characteristic frequencies of 120 Hz and 320 Hz. Morphological data indicate that high-frequency cells have more synapses and higher vesicle density near dense bodies (DBs). Tracking vesicular release via capacitance changes identified three overlapping kinetic components of release corresponding to morphologically identified vesicle pools. High-frequency cells released faster; however, when normalized to release site number, low-frequency cells released faster, likely due to a greater Ca2+ load per synapse. The Ca(2+)-dependence of release was nonsaturating and independent of frequency, suggesting that release, not refilling, was rate limiting. A model of release derived from vesicle equilibration between morphologically defined pools reproduced the capacitance data, supporting a critical role in vesicle trafficking for DBs. The model suggests that presynaptic specializations enable synapses to operate most efficiently at their characteristic frequencies.

[Shared decision making]. / Shared Decision Making. Gemeinsame Entscheidungsfindung aus Patientenperspektive.

BACKGROUND AND OBJECTIVE: The demand for integration of patients in medical decisions becomes more and more obvious. Little is known about whether patients are willing and ready to share therapeutic decisions. So far information is lacking, whether existing communication skills of both -- patients and physicians -- are sufficient for shared decision making (SDM). This paper presents new data on patients perspectives regarding SDM. METHODS: Standardized survey of 3058 German speaking people (1565 females, 1493 males), aged 18-79 years, a population based random sample of an access panel (pool of german households available for specific surveys) regarding the following topics: medical decision making in practice, communication skills and behaviour of physicians. RESULTS: A majority of patients approved the model of SDM. However, some subgroups of patients, especially older patients, were less interested in the concept of SDM. Necessary communication skills which may help patients to participate in decision making were used rather scarcely. Patients who approved the model of SDM more often experienced a common and trustful exchange of information. CONCLUSION: Most patients favour the concept of SDM. The communication skills necessary for this process are to be promoted and extended. Research on patients' preferences and their participation in health care reform should be intensified. Academic and continuous medical education should focus on knowledge transfer to patients.

Biophysical and pharmacological characterization of voltage-gated calcium currents in turtle auditory hair cells.

Hair cell calcium channels regulate membrane excitability and control synaptic transmission. The present investigations focused on determining whether calcium channels vary between hair cells of different characteristic frequencies or if multiple channel types exist within a hair cell, each serving a different function. To this end, turtle auditory hair cells from high- (317 +/- 27 Hz) and low-frequency (115 +/- 6 Hz) positions were voltage clamped using the whole-cell recording technique, and calcium currents were characterized based on activation, inactivation and pharmacological properties. Pharmacological sensitivity to dihydropyridines (nimodipine, Bay K 8644), benzothiazepines (diltiazem) and acetonitrile derivatives (verapamil, D600) and the insensitivity to non-L-type calcium channel antagonists support the conclusion that only L-type calcium channels were present. Fast activation rise times (< 0.5 ms), hyperpolarized half-activation potentials and a relative insensitivity to nimodipine suggest the channels were of the alpha1D (CaV1.3) variety. Although no pharmacological differences were found between calcium currents obtained from high- and low-frequency cells, low-frequency cells activated slightly faster and at hyperpolarized potentials, with half-activating voltages of -43 +/- 1 mV compared to -35 +/- 1 mV. Inactivation was observed in both high- and low-frequency cells. The time course of inactivation required three time constants for a fit. Long depolarizations could result in complete inactivation. The voltage of half-inactivation was -40 +/- 2 mV for high-frequency cells and -46 +/- 2 mV for low-frequency cells. Calcium channel inactivation did not significantly alter hair cell electrical resonant properties elicited from protocols where the membrane potential was hyperpolarized or depolarized prior to characterizing the resonance. A bell-shaped voltage dependence and modest sensitivities to intracellular calcium chelators and external barium ions suggest that inactivation was calcium dependent.

Percutaneous ethanol injection vs. resection in patients with small single hepatocellular carcinoma: a retrospective case-control study with cost analysis.

BACKGROUND: Percutaneous ethanol injection and hepatic resection are the most widely used curative therapeutic options for patients with compensated liver disease and small hepatocellular carcinoma. AIM: To compare percutaneous ethanol injection and hepatic resection in a selected group of consecutive French patients with a single hepatocellular carcinoma, smaller than or equal to 50 mm, in terms of survival, recurrence rate of malignancy and direct costs. METHODS: The analysis of two contemporary cohorts of Child-Pugh A or B patients with a single hepatocellular carcinoma of < or = 50 mm treated by percutaneous ethanol injection (n=55) or hepatic resection (n=50). RESULTS: Long-term survival was not significantly different between the two groups when the size of hepatocellular carcinoma was less than 30 mm. However, the survival of patients with hepatocellular carcinoma larger than 30 mm was higher after hepatic resection than after percutaneous ethanol injection (P=0.044). The cumulative direct costs were significantly higher in patients treated by hepatic resection than in those treated by percutaneous ethanol injection regardless of the tumour size. The calculated costs per month of survival in patients treated with percutaneous ethanol injection and hepatic resection were 999 vs. 3865 euros, respectively (P < 0.001). CONCLUSIONS: Percutaneous ethanol injection is more cost effective than hepatic resection in patients with a single hepatocellular carcinoma smaller than 30 mm. However, in patients with a larger tumour, long-term survival is higher after hepatic resection.

Selectivity of linopirdine (DuP 996), a neurotransmitter release enhancer, in blocking voltage-dependent and calcium-activated potassium currents in hippocampal neurons.

Linopirdine [DuP 996, 3, 3-bis(4-pyridinylmethyl)-1-phenylindolin-2-one], a putative cognition enhancing drug, increases acetylcholine release in rat brain tissue and improves performance in animal models of learning and memory. The mechanism whereby linopirdine enhances acetylcholine release has been proposed to involve inhibition of the M-type K+ current (IM). Our study examines the selectivity of linopirdine for IM by determining its effects on other ionic currents present in rat hippocampal CA1 neurons using patch clamp techniques. Linopirdine was found to block voltage-gated, calcium-activated and leak K+ currents in a dose-dependent manner. Of the seven currents measured, linopirdine was most selective for IM with an IC50 of 2.4 +/- 0.4 microM, followed by IC (measured as a medium afterhyperpolarization tail current, ImAHP) with an IC50 of 16.3 +/- 2.4 microM. Both IM and IC were completely suppressed by linopirdine. At a concentration of 100 microM, linopirdine weakly inhibited the K+ leak current, IL, the transient outward current, IA, the delayed rectifier, IK, and the slow component of IAHP, by 28 +/- 8, 37 +/- 10, 36 +/- 9 and 52 +/- 10 percent, respectively. The mixed Na+/K+ inward rectifying current, IQ, was essentially unaffected by linopirdine (IC50 >300 microM). These results indicate that linopirdine selectively blocks IM at concentrations

Effects of [3H]-BIDN, a novel bicyclic dinitrile radioligand for GABA-gated chloride channels of insects and vertebrates.

1. The radiolabelled bicyclic dinitrile, [3H]-3,3-bis-trifluoromethyl-bicyclo[2.2.1]heptane-2,2-dicarbonitrile ([3H]-BIDN), exhibited, specific binding of high affinity to membranes of the southern corn rootworm (Diabrotica undecimpunctata howardi) and other insects. A variety of gamma-aminobutyric acid (GABA) receptor convulsants, including the insecticides heptachlor (IC50, 35 +/- 3 nM) and dieldrin (IC50, 93 +/- 7 nM), displaced [3H]-BIDN from rootworm membranes. When tested at 100 microM, 1-(4-ethynylphenyl)-4-n-propyl-2,6,7-trioxabicyclo[2.2.2]oct ane(EBOB), 4-t-butyl-2,6,7-trioxa-1-phosphabicy-clo[2.2.2]octane-1-thio ne (TBPS), 1-phenyl-4-t-butyl-2,6,7-trioxabicyclo[2.2.2]octane (TBOB) and picrotoxin failed to displace 50% of [3H]-BIDN binding to rootworm membranes indicating that the bicyclic dinitrile radioligand probes a site distinct from those identified by other convulsant radioligands. 2. Dissociation studies showed that dieldrin, ketoendrin, toxaphene, heptachlor epoxide and alpha and beta endosulphan displace bound [3H]-BIDN from rootworm membranes by a competitive mechanism. 3. Rat brain membranes were also shown to possess a population of saturable, specific [3H]-BIDN binding sites, though of lower affinity than in rootworm and with a different pharmacological profile. Of the insecticidal GABAergic convulsants that displaced [3H]-BIDN from rootworm, cockroach (Periplaneta americana) and rat brain membranes, many were more effective in rootworm. 4. Functional GABA-gated chloride channels of rootworm nervous system and of cockroach nerve and muscle were blocked by BIDN, whereas cockroach neuronal GABA(B) receptors were unaffected. 5. Expression in Xenopus oocytes of either rat brain mRNA, or cDNA-derived RNA encoding a GABA receptor subunit (Rdl) that is expressed widely in the nervous system of Drosophila melanogaster resulted in functional, homo-oligomeric GABA receptors that were blocked by BIDN. Thus, BIDN probes a novel site on GABA-gated Cl- channels to which a number of insecticidally-active molecules bind.

Pharmacology of skeletal muscle GABA-gated chloride channels in the cockroach Periplaneta americana.

The pharmacology of -aminobutyric acid (GABA)-gated chloride channels of the coxal levator (182c,d) muscle of the cockroach Periplaneta americana has been investigated and the data compared with similar findings for the cell body of the cockroach fast coxal depressor motor neurone (Df). Muscle GABA receptors resembled those of the motor neurone cell body in their sensitivity to picrotoxinin and insensitivity to bicuculline. However, muscle GABA receptors were insensitive to the neuronal GABA receptor agonists isoguvacine (10(-4) mol l-1) and 3-aminopropane sulphonic acid (10(-3 )mol l-1). The benzodiazepine flunitrazepam, which at 10(-6 )mol l-1 greatly enhances the amplitude of the motor neurone GABA-induced responses, failed to affect muscle responses to GABA when tested at the same and at a higher (10(-4 )mol l-1) concentration. The convulsant t-butylbicyclophosphorothionate was a weak antagonist of cockroach muscle GABA receptors, whereas several cyclodienes were much more effective antagonists. Thus, studies using a benzodiazepine and several convulsant antagonists reveal differences in the pharmacology of muscle and neuronal GABA receptors of the cockroach Periplaneta americana.

An exceptional genealogy for hereditary chronic pancreatitis.

Nearly one hundred families affected with hereditary chronic pancreatitis (HCP) have been reported in the literature. However, the fact that the disease involved only a few members of each family limits the informativeness of these reports and accounts for the infrequency and disappointing results of pathogenetic and genetic research. Our study concerned an exceptional HCP genealogy which would seem to provide an ideal model for the detection of a genetic anomaly linked to the expression of the disease. We studied 249 members of a family (214 still alive), covering eight generations born between 1800 and 1993. According to the customary criteria, 63 had definite and 17 probable HCP. Fifty-eight members under 18 years of age were still susceptible to developing the disease. This series confirms the mode of autosomal dominant heredity with variable penetrance. The clinical features and disease course were typical, except that symptoms tended to appear earlier. The series represents the most extensive HCP genealogy compiled and is one of the largest families studied in the field of genetic disease, regardless of etiology. Blood samples were taken from 146 subjects to facilitate pathogenetic and genetic research.

The hereditary pancreatitis gene maps to long arm of chromosome 7.

Hereditary pancreatitis (HP) is an autosomal dominant disorder with incomplete penetrance characterized by recurring episodes of severe abdominal pain often presenting in childhood. Although this disorder has only been recently described, about 100 families have been documented worldwide. The pathophysiology of this disorder is unknown. Here, a large French family of 147 individuals (47 of whom were affected) from a four-generation kindred with HP has been examined and a genome segregation analysis of highly informative microsatellite markers has been performed. Linkage has been found between HP and six chromosome 7q markers. Maximal two point lod scores between HP and D7S 640, D7S 495, D7S 684, D7S 661, D7S 676 and D7S 688 were 4.00 (theta = 0.143), 5.85 (theta = 0.143), 4.91 (theta = 0.156), 8.58 (theta = 0.077), 8.28 (theta = 0.060), 4.40 (theta = 0.169), respectively. Multipoint linkage data combined with recombinant haplotype analysis indicated that the most likely order is: D7S 640-D7S 495-D7S 684-D7S 661-D7S 676-D7S 688, with the HP gene situated in the underlined region. As in all families reported in the literature, the clinical presentation of the disease is identical to the presentation of sporadic cases, one could expect that the knowledge of the HP gene could be a clue to pancreatitis in general. Based on its map position, this is the first step towards the positional cloning of the Hereditary Pancreatitis Gene (HPG).

High-risk coronary angioplasty assisted by active hemoperfusion. A feasibility study.

We assessed the effectiveness of distal hemoperfusion support during gradual, prolonged balloon inflation during percutaneous transluminal coronary angioplasty in high-risk patients. The patients were identified as having a poor left ventricular ejection fraction ( < 35%), > 50% of viable myocardium at risk percutaneous coronary balloon angioplasty, or both. A total of 64 procedures were performed in 61 patients. Angiographic success was achieved in 83 of 86 (96.5%) lesions treated with hemoperfusion support. Hospital complications included 1 patient who had a non-Q-wave infarction, 1 who had to undergo redo percutaneous coronary balloon angioplasty, and 5 who required coronary artery bypass operations. The hospital mortality was 7.8% (5 patients). This preliminary study indicates that hemoperfusion support can enable expeditious, simple, economical, and effective percutaneous transluminal coronary balloon angioplasty in a subset of labile patients in whom procedural failure frequently leads to sudden death.

Left ventricular outflow tract obstruction and hemolytic anemia after mitral valve repair with a Duran ring.

We report a case of mitral valve repair with a Duran ring that was complicated by left ventricular outflow tract obstruction, mitral regurgitation, and hemolytic anemia. A 59-year-old man with severe mitral valve regurgitation underwent mitral valve repair, including a Duran ring annuloplasty. Postoperatively, left ventricular outflow tract obstruction developed and echocardiography revealed severe systolic anterior motion of the mitral valve. The patient then underwent mitral valve replacement with a 29-mm St. Jude valve.

Involvement of small intestinal motility in blood glucose response to dietary fibre in man.

Three dietary fibres with different physicochemical properties were studied in healthy humans for their effects on small intestinal motility and postprandial hyperglycaemia. Duodeno-jejunal motor activity was evaluated electromyographically for 180 min in six subjects who had ingested a test meal composed of glucose alone or glucose with 15 g of wheat bran (WB), sugar beet (SB) or ispaghula (I) fibres. Glucose and insulin concentrations were determined during the same period. Each subject received each of the four test meals randomly during a 4 d period. Addition of SB or I to the glucose meal altered duodeno-jejunal motility. Both of these fibres inhibited stationary contractile activity and increased the propagation length and velocity of propagated activity, whereas addition of WB had no effect. These results could reflect the high water-holding capacity of SB and I. Blood glycaemic response to the glucose meal was reduced by SB and I but remained unchanged with WB. Postprandial blood glucose levels were significantly correlated with the total motility index (r 0.82) and stationary activity (r 0.79). Taken together, these observations suggest that the contractile activity induced by dietary fibre in the small intestine probably plays a major role in delayed glucose absorption.

Isolation and identification of a new diuretic peptide from the tobacco hornworm, Manduca sexta.

A 30-amino acid diuretic peptide was isolated from the corpora cardiaca-corpora allata complexes and, separately, from medial neurosecretory cells of the Sphingid moth, Manduca sexta. The peptide was found to have the following sequence, determined by automated Edman degradation and mass spectrometry: SFSVNPAVDILQHRYMEKV AQNNRNFLNRV-NH2. We have named the peptide Mas-DP II. The peptide was synthesized and shown to possess diuretic activity in decapitated moths. Mas-DP II is related by sequence homology to a 41-amino acid diuretic peptide identified previously from M. sexta, and it belongs to the family of corticotropin releasing factor-like peptides.