Inhibitory processes in normal and epileptic-like rat hippocampal slices: the role of GABAB receptors

The purpose of this study was to obtain more insight into the role of GABAB receptors in the rat hippocampus using the selective GABAB blocker phaclofen. In the CA1 region in normal slices, phaclofen (1 mM) had no effect on population spike amplitude. Moreover, phaclofen did not affect paired-pulse inhibition when the paired-pulses were delivered at short interpulse intervals (20-30 ms). At longer interpulse intervals (50-150 ms) phaclofen moderately reduced paired-pulse inhibition. In slices treated with submaximal concentrations of bicuculline methiodide or penicillin, the frequency and amplitude of electrically induced multiple population spikes were not affected by phaclofen. The GABAB agonist baclofen, however, attenuated paired-pulse inhibition and this effect was antagonized by phaclofen. In the CA3 region, phaclofen reduced the inhibitory effect of baclofen on penicillin-induced burst discharges. In conclusion, although phaclofen antagonized the effects of baclofen it did not show proconvulsant activity. Furthermore, phaclofen did not induce any pronounced signs of disinhibition of hippocampal pyramidal cells as is usually seen with the GABAA receptor-blocker bicuculline methiodide.     

An ethological model for the study of activation and interaction of pain, memory and defensive systems in the attacked mouse. Role of endogenous opioids

The present work reviews neurochemical, physiological and behavioral data recorded from the attacked mouse and integrates them into a model of coping mechanisms during social conflict. More specifically, the possible relationships between systems of pain, memory and defense are presented, with special emphasis on the role of endogenous opioid peptides (EOPs). In recipients of attack, decreased beta-endorphin-like immunoreactivity and changes in opiate and benzodiazepine binding characteristics are found in structures of the brain defensive system. EOPs mediate the social conflict-induced increase of dopamine synthesis in the periaqueductal grey and frontal cortex. Social conflict analgesia in attacked mice is under the control of central opioid and nonopioid (e.g., benzodiazepine, glutamate) mechanisms, and is modified by experience (e.g., long-term analgesic reaction; tolerance). EOPs and pain-inhibitory mechanisms participate in the organization of behavioral defense, recuperative behavior and the memory of attack experience. The data are considered in relation to the perceptual-defensive-recuperative model of fear and pain, forwarded by Bolles and Fanselow.     

Adolescent idiopathic scoliosis - to operate or not? A debate article

Adolescent idiopathic scoliosis (AIS) represents a rare condition with a potentially detrimental impact on young patients. Despite vast clinical research and published treatment guidelines and algorithms, the optimal therapeutic choice for these patients remains highly controversial. While advocates of early surgery emphasize the benefits of surgical deformity correction with regard to physical and psychological outcome, the opponents base their arguments on the high risk of complications and a lack of documented subjective long-term outcome. In the present paper, the authors were invited to debate the opposite positions of "pro" versus "contra" surgical treatment of AIS, based on the currently available evidence and published guidelines.     

Adolescent idiopathic scoliosis (AIS) - an indication for surgery? A systematic review of the literature

Purpose. Historically, the treatment options for AIS, the most common form of scoliosis are: Exercises, in-patient rehabilitation, braces and surgery. While there is evidence in the form of prospective controlled studies that Scoliosis Intensive Rehabilitation (SIR) and braces can alter the natural history of the condition, there is no review on prospective controlled trials for surgical treatment. The aim of this review was to perform a systematic search of the Pub Med literature to reveal the evidence on scoliosis surgery.

Methods. A systematic review has been performed using the Pub Med database. Literature has been searched for the outcome parameter; 'rate of progression' and only prospective controlled studies that have considered the treatment versus the natural history have been included.

Results. No controlled study, not in the short, mid or long term, searched within the review, has been found to reveal evidence to support the hypothesis that the effects of surgery as a treatment option for AIS is superior to natural history.

Conclusions. No evidence has been found in terms of prospective controlled studies to support surgical intervention from the medical point of view. In the light of the unknown long-term effects of surgery and in concluding on the lack of evidence already found that surgery might change the signs and symptoms of scoliosis, a randomized controlled trial (RCT) is long overdue. Until such a time that such evidence exists, there can be no medical indication for surgery. The indications for surgery are limited for cosmetic reasons in severe cases and only if the patient and the family agree with this.     

Compressibility and compactibility of powdered polymers: poly(vinyl chloride) powders

The present investigation is concerned with the possible effects of material-related properties (molecular mass, glass transition and melting temperatures, crystallinity, tacticity) and particle-related properties (shape, size, specific surface area) on the compression characteristics of the chosen model polymer powder: poly(vinyl chloride) (PVC). Four grades were selected known in literature for providing compacts of varied mechanical strength. The compression characteristics were determined using an instrumented single-punch tableting machine. The differences in tableting characteristics could not be ascribed to any of the material-related properties, but a direct relationship was observed between the compact strength and the specific surface area of the particles, as measured by nitrogen adsorption. The compact hardness was thus only dependent on the inter- and the intraparticulate contact area, which in turn is dictated by the very peculiar morphology of the grains of the PVC powders, whether prepared by emulsion or suspension polymerization.     

Long-term application of lepirudin on chronic haemodialysis over 34 months after heparin-induced thrombocytopenia.

Sir, The development of heparin-induced thrombocytopenia (HIT) isa well-known complication of heparin therapy. Once the syndromeoccurs and is recognized, it is essential to immediately avoidany sources of heparin. If anti-coagulation is still required,other anti-coagulants should be considered such as lepirudin,argatroban, danaparoid or fondaparinux in the acute phase usuallyfollowed by