Piglets vocally express the anticipation of pseudo-social contexts in their grunts.

Emotions not only arise in reaction to an event but also while anticipating it, making this context a means of accessing the emotional value of events. Before now, anticipatory studies have rarely considered whether vocalisations carry information about emotional states. We studied both the grunts of piglets and their spatial behaviour as they anticipated two (pseudo)social events known to elicit positive emotions of different intensity: arrival of familiar conspecifics and arrival of a familiar human. Piglets spatially anticipated both pseudo-social contexts, and the spectro temporal features of grunts differed according to the emotional context. Piglets produced low-frequency grunts at a higher rate when anticipating conspecifics compared to anticipating a human. Spectral noise increased when piglets expected conspecifics, whereas the duration and frequency range increased when expecting a human. When the arrival of conspecifics was delayed, the grunt duration increased, whereas when the arrival of the human was delayed, the spectral parameters were comparable to those during isolation. This shows that vocal expressions in piglets during anticipation are specific to the expected reward. Vocal expressions-both their temporal and spectral features- are thus a good way to explore the emotional state of piglets during the anticipation of challenging events.

[Naftidrofuryl in arterial obstructive disease: A systematic revue of the literature]. / Naftidrofuryl dans l'artériopathie oblitérante des membres inférieurs : une revue systématique de la littérature.

INTRODUCTION: Arterial obstructive disease is a disease affecting 11 % of the general population. This prevalence is constantly increasing. Nafronyl is still prescribed despite a decreasing reimbursement rate since 2005. The objective of this study was to summarize data from the scientific literature on the efficacy and safety of nafronyl used for the treatment of peripheral arterial obstructive disease. METHOD: A systematic review was made on EMBASE, MEDLINE and the Cochrane Library. Randomized controlled trials, systematic reviews and meta-analyses comparing naftidrofuryl with placebo were included. The main outcome was an improvement in the maximum walking distance or pain free walking distance. The quality of the reviews was analysed using a standardised reading grid. Only the best study was retained. RESULTS: Among 193articles, one meta-analyses were selected. Naftidrofuryl improved the initial pain free walking distance by 60 % at six months, without a demonstrated increase in the risk of adverse reactions. CONCLUSION: The efficacy of naftidrofuryl over the maximum walking distance in peripheral arterial obstructive disease appears similar to physical exercise or simvastatin.

The dental management of adult patients with haemophilia and other congenital bleeding disorders.

The management of adult dental patients with congenital bleeding disorders has caused a considerable number of problems to the dental profession. There is a need to simplify the process and identify what can be safely carried out on a 'shared care' basis in General Dental Practice or the Community Dental Service. Particular problems are discussed with special reference to those requiring hospital care. The Scottish Oral Health Group for Medically Compromised Patients has developed this clinical guidance in conjunction with the Scottish Haemophilia Directors. It is important that dental care is easily available for this group of patients, especially those living at some distance from the regional centres. The aim is to simplify planning dental care for this group of patients and remove a number of myths concerning their management. The hospital departments, both medical and dental, must be available for advice and to arrange for treatment that is inappropriate outside a specialist hospital.

The kinetic cycle of cardiac troponin C: calcium binding and dissociation at site II trigger slow conformational rearrangements.

The goal of this study is to characterize the kinetic mechanism of Ca2+ activation and inactivation of cardiac troponin C (cTnC), the Ca2+ signaling protein which triggers heart muscle contraction. Previous studies have shown that IAANS covalently coupled to Cys84 of wild-type cTnC is sensitive to conformational change caused by Ca2+ binding to the regulatory site II; the present study also utilizes the C35S mutant, in which Cys84 is the lone cysteine, to ensure the specificity of IAANS labeling. Site II Ca2+ affinities for cTnC-wt, cTnC-C35S, cTnC-wt-IAANS2, and cTnC-C35S-IAANS were similar (KD = 2-5 microM at 25 degrees C; KD = 2-8 microM at 4 degrees C), indicating that neither the IAANS label nor the C35S mutation strongly perturbs site II Ca2+ affinity. To directly determine the rate of Ca2+ dissociation from site II, the Ca2+-loaded protein was rapidly mixed with a spectroscopically sensitive chelator in a stopped flow spectrometer. The resulting site II Ca2+ off-rates were k(off) = 700-800 s(-1) (4 degrees C) for both cTnC-wt and cTnC-C35S, yielding calculated macroscopic site II Ca2+ on-rates of k(on) = k(off)/KD = 2-4 x 10(8) M(-1) s(-1) (4 degrees C). As observed for Ca2+ affinities, neither the C35S mutation nor IAANS labeling significantly altered the Ca2+ on- and off-rates. Using IAANS fluorescence as a monitor of the protein conformational state, the intramolecular conformational changes (delta) induced by Ca2+ binding and release at site II were found to be significantly slower than the Ca2+ on- and off-rates. The conformational rate constants measured for cTnC-wt-IAANS2 and cTnC-C35S-IAANS were k(delta on) = 120-210 s(-1) and k(delta off) = 90-260 s(-1) (4 degrees C) . Both conformational events were slowed in cTnC-wt-IAANS2 relative to cTnC-C35S-IAANS, presumably due to the bulky IAANS probe coupled to Cys35. Together, the results provide a nearly complete kinetic description of the Ca2+ activation cycle of isolated cTnC, revealing rapid Ca2+ binding and release at site II accompanied by slow conformational steps that are likely to be retained by the full troponin complex during heart muscle contraction and relaxation.

Mutagenesis of subunit delta from Escherichia coli F1F0-ATP synthase.

In Escherichia coli, the F1 sector of the F1F0-ATP synthase is connected to the membrane-embedded F0 sector by a narrow stalk, thought to be formed by subunits delta and b. Mutagenic analysis was used here to study the structure and function of subunit delta. First, random mutations in the protein were generated by bisulfite mutagenesis. Two single missense mutations causing impaired growth by oxidative phosphorylation were found, namely delta A149T and delta G150D. Both occur at the conserved C-terminal region, which has been suggested previously to be functionally important. Two techniques were applied to study the C-terminal region in greater detail. Cassette mutagenesis was used to randomly mutate the sequence from delta 145 to delta 167, and residues delta A149 and delta G150 were specifically mutated by site-directed mutagenesis to obtain multiple substitutions at each position. Fifteen of the residues between delta 145 and delta 167 were mutated. None was found to be absolutely essential for function. However, the properties of the mutants obtained, which included partial impairment of growth by oxidative phosphorylation, temperature sensitivity, and specific structural requirements at residues delta A149 and delta G150, confirmed that this region is important for enzyme function. Based on these studies, and on secondary and tertiary structure predictions, a model for subunit delta and its orientation in F1F0-ATP synthase is proposed.

Defective energy coupling in delta-subunit mutants of Escherichia coli F1F0-ATP synthase.

Membrane vesicles from 13 strains carrying mutations in the C-terminal region of the delta-subunit of Escherichia coli F1F0-ATP synthase were characterized in respect to ATPase activity, ATP-driven proton-pumping, dicyclohexylcarbodiimide sensitivity of ATPase, and oxidative phosphorylation. The salient finding was that energy-coupling between F1 and F0 sectors of the enzyme is impaired by several of the mutations. The delta G150N mutant appeared completely uncoupled in vitro. The data emphasize the role of the C-terminal region of delta-subunit in integration of the proton conduction machinery in F0 with the three F1 catalytic sites. It is suggested that the C-terminal region of delta-subunit, speculatively located in the central region of the alpha 3 beta 3 hexagon, acts functionally at the interface between the helical domain of the stalk and the F1 subunits to relay conformational signals which alter the affinities of the catalytic sites for substrates and products.

Direct determination of macromolecular charge by equilibrium electrophoresis.

Charge is a fundamental property of macromolecules in solution. However, estimation of the apparent charge on polyions has confounded science for decades. Presented here is a general method to determine directly the apparent charge on a polyion, regardless of its size or shape. This new method uses equilibrium electrophoresis, a procedure in which opposing solute flows from electrophoresis and from diffusion balance everywhere as the system reaches a steady-state distribution. The method uses only small quantities of materials, is nondestructive, and requires only simple, inexpensive instrumentation. Here we describe a prototype apparatus, demonstrate the phenomenon, and present experimental examples of the procedure.