Magnetic stimulation F-responses

We used the 9 cm Cadwell magnetic coil, stimulating at the wrist, to obtain simultaneous median and ulnar nerve F-responses. Surface recording was performed from conventional thenar and hypothenar sites. It is known that with this type of coil it is difficult to accomplish selective supramaximal stimulation of the median or ulnar nerve individually. We found it possible, however, to record a compound muscle action potential of supramaximal or near supramaximal amplitude, as well as F-responses, in both thenar and hypothenar muscles simultaneously. We assessed this technique for F-response latency determination in controls and patients with carpal tunnel syndrome. In controls, there was no significant difference in the F-minimal latency or the F-minimum-maximum range obtained by the two methods. In patients with carpal tunnel syndrome, with median F-responses very delayed or absent on conventional testing, magnetically elicited thenar F-responses were of shorter latency, similar to F's recorded in the hypothenar muscles, suggesting they were recorded from ulnar innervated thenar muscles. Although magnetic stimulation allows simultaneous determination of median and ulnar F-latencies, sparing patients several painful stimuli, and shortening the electrophysiologic examination, magnetic stimulation in patients with carpal tunnel syndrome may elicit thenar recorded F-responses that are not of median origin. Use of this technique is limited by the lack of focality of the stimulus, which has been the major limiting factor in its use on peripheral nerves.     

Binding of dynorphin A and related peptides to kappa- and mu-opioid receptors: sensitivity to Na+ ions and Gpp(NH)p

We have examined the effects of Na+ ions and 5'-guanylyl imidodiphosphate (Gpp(NH)p) on the equilibrium binding of dynorphin A and of a series of related agonist and antagonist peptides to kappa- and mu-opioid receptors in guinea pig (kappa) and rabbit (mu) cerebellum membrane preparations. The binding to kappa sites of dynorphin A and of the peptides displaying agonist properties was strongly inhibited in the presence of 120 mM NaCl and 50 microM Gpp(NH)p. In contrast, a somewhat lower sensitivity to the inhibitory effect of the two allosteric effectors was observed for the analogues of the series showing antagonist properties. The same general behavior, but more marked, was observed at mu sites, at both mu- and kappa-opioid receptors. The peptides had biochemical properties (binding sensitivity vs. insensitivity to sodium ions and guanine nucleotides) that correlated well with their biological activities (agonist vs. antagonist) previously determined in in vitro pharmacological bioassays.     

Value of Tissucol in dentistry and maxillofacial surgery

Fibrinogen glue of human origin was used in 44 patients. Indications are of two types: as a glue mainly for dermoepidermoid grafts but also to assist mucosal suturing and bone obturation, and for hemostasis after extractions in patients with coagulation disorders (hemophilia, cirrhosis, leukemia). Positive results were obtained, particularly in hemophilic patients, the incidence and severity of secondary hemorrhage appearing to diminish.     

Evidence for multiple "Kappa" binding sites by use of opioid peptides in the guinea-pig lumbo-sacral spinal cord

Binding properties of [3H]-etorphine and [3H]-ethylketocyclazocine have been studied in the lumbo-sacral spinal cord of guinea-pig which does not contain mu or delta binding sites. [3H]-etorphine binds to a single class of high affinity sites, whereas [3H]-ethylketocyclazocine interacts with a high and a low affinity component. Using a discriminative procedure, 5 microM (D-Ala2, D-Leu5) enkephalin (DAL), the high affinity component of [3H]-ethylketocyclazocine can be resolved in two classes of sites, (D-Ala2, D-Leu5) enkephalin sensitive sites (DALS sites) and (D-Ala2, D-Leu5) enkephalin insensitive sites (DALI sites). In these conditions, there is a total loss of [3H]-etorphine sites, whose binding capacity and properties strictly correspond to the DALS sites labelled by [3H]-ethylketocyclazocine. Pharmacological investigations indicate that DALI sites for which dynorphin (1 leads to 17) is the best ligand, can be related to kappa sites previously described in guinea-pig brain, whereas DALS sites for which (Arg6, Phe7) Met-enkephalin possesses a good affinity, closely correspond to benzomorphan sites recently characterized in rat brain and spinal cord. [3H]-ethylketocyclazocine interacts additionally with "non opiate" low affinity sites, for which only benzomorphan drugs exhibit a good affinity, whereas morphine, naloxone, phencyclidine or endogenous opioid peptides do not present any affinity for them. On the basis of these data, a new subdivision of "kappa" sites is discussed.     

D-Pro10]-dynorphin(1-11) is a kappa-selective opioid analgesic in mice

The synthetic opioid agonist [D-Pro10]-dynorphin(1-11) (DPDYN) binds kappa receptors with both high affinity and selectivity in vitro. We have examined the in vivo characteristics (i.e., analgesic properties) of the peptide in mice. The analgesic effects of i.c.v. administered DPDYN were determined in two nociceptive tests, involving thermal cutaneous (tail-flick) and chemical visceral (AcOH-induced writhing) stimuli, in which mu and kappa receptors are known to be activated differentially. The antinociceptive action of DPDYN was compared with that of 1) morphine and U-50,488H, which are, respectively, the prototypical mu and kappa agonists, 2) dynorphin A which is the endogenous parent peptide and 3) Leu-enkephalin, which represents the N-terminal sequence of DPDYN. DPDYN did not show any activity against thermal stimulus but, in contrast, produced a dose-related effect against chemical pain. In the AcOH-writhing test, there was no significant cross-tolerance between morphine and DPDYN in mice made tolerant to morphine. Pretreatment with low doses of s.c. naloxone (less than 1 mg/kg) antagonized completely the antinociceptive action of morphine but only partially reversed the analgesic action of DPDYN. In gastrointestinal studies, DPDYN as well as U-50,488H were ineffective (maximum effect lower than 25%) in inhibiting intestinal transit in mice, in contrast to morphine which produced a dose-related antitransit effect reaching 100%. These data indicate that the in vivo properties, and particularly analgesia, of i.c.v. administered DPDYN are mediated by a "non-mu" (presumably kappa) opioid receptor at the supraspinal level of the opioid system of the mouse.     

Routine identification of Mycobacterium tuberculosis complex isolates by automated hybridization.

Methodologies for biochemical identification of mycobacteria isolated from clinical samples are still cumbersome, taking skilled technicians 3 to 6 weeks. We describe here a 2-h identification system for mycobacterial isolates belonging to the Mycobacterium tuberculosis complex using a DNA probe. After 30 min of hands-off sample preparation, the 1.5-h hybridization test is totally automated in the newly developed VIDAS system (bioMérieux, Marcyl'Etoile, France), which performs solid-phase specific hybridization of 16S rRNA at 37 degrees C. The strain collection of actinomycetes tested was composed of 662 isolates from 27 species: 461 members of the M. tuberculosis complex (443 M. tuberculosis, 10 M. bovis, and 8 M. bovis BCG isolates) and 201 isolates of other species, including 55 M. avium-intracellulare isolates). They were identified by traditional methods: growth rate, colonial morphology, pigmentation, and biochemical profiles. The automated probe assay displayed an excellent correlation with the reference results. The four members of the Nocardia and Rhodococcus genera tested did not cross-hybridize. This flexible random-access and automated technology was shown to suit the routine context of the laboratory by rapidly delivering the results.     

Possibilities and limitations for the correction of bony, dental and mucosal tissue loss in children using a maxillofacial prosthesis

The maxillofacial prosthesis for surgical treatment of loss of bony, dental or mucosal substance in children has the advantage of allowing postponement of therapy until growth is terminated or any other favorable period. In addition, the temporary reconstitutions possible by their use often provide, apart from esthetic results, an effective action physically and mentally on the mainly labile growth.     

Relapsing bilateral brachial plexopathy during pregnancy. Report of a case

We describe a case of relapsing bilateral brachial plexopathy occurring during pregnancy and the postpartum period. This condition is known to occur with a familial predilection, but it has not been previously reported on a sporadic basis. The outcome was poor and associated with several psychosocial consequences.     

Trafficking of viral genomic RNA into and out of the nucleus: influenza,Thogoto and Borna disease viruses

Most RNA viruses that lack a DNA phase replicate in the cytoplasm. However, several negative-stranded RNA viruses such as influenza, Thogoto, and Borna disease viruses replicate their RNAs in the nucleus, taking advantage of the host cell's nuclear machinery. A challenge faced by these viruses is the trafficking of viral components into and out of the nucleus through the nuclear membrane. The genomic RNAs of these viruses associate with proteins to form large complexes called viral ribonucleoproteins (vRNPs), which exceed the size limit for passive diffusion through the nuclear pore complex (NPC). To insure efficient transport across the nuclear membrane, these viruses use nuclear import and export signals exposed on the vRNPs. These signals recruit the cellular import and export complexes, which are responsible for the translocation of the vRNPs through the NPC. The ability to control the direction of vRNP trafficking throughout the viral life cycle is critical. Various mechanisms, ranging from simple post-translational modification to complex, sequential masking-and-exposure of localization signals, are used to insure the proper movement of the vRNPs.