Genomic Dissection of Travel-Associated Extended-Spectrum-Beta-Lactamase-Producing Salmonella enterica Serovar Typhi Isolates Originating from the Philippines: a One-Off Occurrence or a Threat to Effective Treatment of Typhoid Fever?

One unreported case of extended-spectrum-beta-lactamase (ESBL)-producing Salmonella enterica serovar Typhi was identified, whole-genome sequence typed, among other analyses, and compared to other available genomes of S. Typhi. The reported strain was similar to a previously published strain harboring bla_SHV-12 from the Philippines and likely part of an undetected outbreak, the first of ESBL-producing S. Typhi.     

Neurotransmitter-Mediated Changes in the Electrophysiological Properties of Pituicytes

Intracellular recordings were obtained from pituicytes in the neural lobe of the isolated rat pituitary. Like other glia, pituicytes lacked action potentials in response to depolarizing current injection, but they tended to have more positive resting membrane potentials and higher input resistances than astrocytes in other preparations. Dye-coupling typical of astrocytes was also demonstrated amongst pituicytes, and their morphologies were similar to those of pituicytes stained for glial fibrillary acidic protein. Action potentials, anode-break spikes or barium spikes were not observed in pituicytes, even under conditions that maximized the elicitation of Ca²⁺-dependent responses. This suggests that pituicytes either have no or a very low density of Ca²⁺ channels or Ca²⁺ currents that are too small to generate action potentials. Dynorphin A (1–13), a kappa-opioid agonist, produced long-lasting increases in pituicyte input resistance with no significant changes in resting membrane potential. Dynorphin's action was concentration-dependent and was blocked by the opioid antagonist naloxone. This is consistent with previous reports demonstrating kappa-opioid receptors on pituicytes in the neurohypophysis. The β-adrenergic agonist isoproterenol (100 μM) reversed the increases in pituicyte input resistance produced by opioid application, with no significant changes in resting membrane potential. The fact that pituicytes responded to neurotransmitters suggests a functional link between pituicytes and neurosecretory nerve fibres.     

The course of a case of Maffucci's syndrome

The syndrome of Maffucci is characterized by angioma association of the enchondromatose. It is a relatively rare syndrome. The lesions are evolutived. The treatment is surgical. His pronostic is marqued by high percentage of malign degenerescence.     

Large-scale functional reorganization in adult monkey cortex after peripheral nerve injury.

In adult monkeys, peripheral nerve injuries induce dramatic examples of neural plasticity in somatosensory cortex. It has been suggested that a cortical distance limit exists and that the amount of plasticity that is possible after injury is constrained by this limit. We have investigated this possibility by depriving a relatively large expanse of cortex by transecting and ligating both the median and the ulnar nerves to the hand. Electrophysiological recording in cortical areas 3b and 1 in three adult squirrel monkeys no less than 2 months after nerve transection has revealed that cutaneous responsiveness is regained throughout the deprived cortex and that a roughly normal topographic order is reestablished for the reorganized cortex.     

Variability in hand surface representations in areas 3b and 1 in adult owl and squirrel monkeys

Detailed microelectrode maps of the hand representation were derived in cortical areas 3b and 1 from a series of normal adult owl and squirrel monkeys. While overlap relationships were maintained, and all maps were internally topographic, many map features varied significantly when examined in detail. Variable features of the hand representations among different monkeys included a) the overall shapes and sizes of hand surface representations; b) the actual and proportional areas of representations of different skin surfaces and the cortical magnifications of representations of specific skin surfaces, which commonly varied severalfold in area 3b and manyfold in area 1; c) the topographic relationships among skin surface representations, with skin surfaces that were represented adjacently in some monkeys represented in locations many hundreds of microns apart in others; d) the internal orderliness of representations; e) the completeness of representations of the dorsal hand surfaces; and f) the skin surfaces represented along the borders of the hand representation. Owl monkey maps were, in general, internally more strictly topographic than squirrel monkey maps. In both species, area 3b was more strictly topographic and less variable than was area 1. The degree of individual variability revealed in these experiments is difficult to reconcile with the hypothesis that details of cortical maps are ontogenetically specified during a period in early life. Instead, we propose that differences in the details of cortical map structure are the consequence of individual differences in lifelong use of the hands. This conclusion is consistent with earlier studies of the consequences of peripheral nerve transection and digital amputation, which revealed that cortical maps are dynamically maintained and are alterable as a function of use or nerve injury in these monkeys (Merzenich et al., '83a,b, '84a; Merzenich, '86; Jenkins et al., '84; Jenkins and Merzenich, '87).     

Cloning and sequencing of putative acetylcholinesterase cDNAs from the American dog tick, Dermacentor variabilis, and the brown dog tick, Rhipicephalus sanguineus (Acari: Ixodidae)

Two putative cDNAs of acetylcholinesterase (AChE), one from Dermacentor variabilis, and the other from Rhipicephalus sanguineus, were amplified and sequenced. The deduced amino acid sequences have high amino acid identities (between 70 and 94%) to known tick AChE sequences deposited in GenBank. Furthermore, these two AChEs also possess common features in their primary AChE structure such as catalytic active sites. A 2,220-bp contiguous sequence, containing a 1,791-bp open reading frame encoding an AChE precursor with 596 amino acid residues, was obtained from D. variabilis. The deduced proteins of R. sanguineus are different in size by 6 amino acids because of alternative splicing at the 5' end. A gene tree deduced from phylogenetic analysis indicates that there are at least three lineages of AChE in arthropods.