Study of the propagation centre in the anionic polymerization of acrylic monomers, 1. Spectroscopic study of methyl 2-lithioisobutyrate,an initiator for the anionic polymerization of acrylic monomers

As the simplest model for the propagation centre in the anionic polymerization of methyl methacrylate, the solution of methyl 2-lithioisobutyrate ( 1 ) in tetrahydrofuran was studied by means of ¹H, ⁶Li, ⁷Li and ¹³C nuclear magnetic resonance (NMR), and Raman spectroscopy at various concentrations and temperatures. A system of equilibria of differently solvated dimeric, tetrameric and two isomeric trimeric aggregates was found and their thermodynamic constants were established. On the basis of the analysis of NMR chemical shifts, heteronuclear nuclear Overhauser effect correlation spectroscopy (NOESY) spectra and relaxation data, structures of the aggregates are suggested. The kinetics of the exchange between the aggregates and the lifetime of individual aggregates was established. The results suggest that the aggregation can interfere with initiation in the early steps of anionic polymerization of acrylics.     

Gastric lipoma presenting as upper gastrointestinal obstruction

A 61-year-old man presented with an upper gastrointestinal obstruction caused by a submucosal gastric lipoma in the prepyloric area. The diagnosis was made coincidentally during his admission for another disease. Gastric resection was performed because of a large lipoma combined with florid gastric ulcers. The frequency of gastric lipoma, its differential diagnosis, means of diagnosis, and treatment are discussed. Received Oct. 28, 1997; accepted Feb. 27, 1998     

Learning facts during aging: the benefits of curiosity

Background/study context: Recent studies have shown that young adults better remember factual information they are curious about. It is not entirely clear, however, whether this effect is retained during aging. Here, the authors investigated curiosity-driven memory benefits in young and elderly individuals.

Methods: In two experiments, young (age range 18–26) and older (age range 65–89) adults read trivia questions and rated their curiosity to find out the answer. They also attended to task-irrelevant faces presented between the trivia question and the answer. The authors then administered a surprise memory test to assess recall accuracy for trivia answers and recognition memory performance for the incidentally learned faces.

Results: In both young and elderly adults, recall performance was higher for answers to questions that elicited high levels of curiosity. In Experiment 1, the authors also found that faces presented in temporal proximity to curiosity-eliciting trivia questions were better recognized, indicating that the beneficial effects of curiosity extended to the encoding of task-irrelevant material.

Conclusions: These findings show that elderly individuals benefit from the memory-enhancing effects of curiosity. This may lead to the implementation of learning strategies that target and stimulate curiosity in aging.     

Interventional management of neuropathic pain: NeuPSIG recommendations

Neuropathic pain (NP) is often refractory to pharmacologic and noninterventional treatment. On behalf of the International Association for the Study of Pain Neuropathic Pain Special Interest Group, the authors evaluated systematic reviews, clinical trials, and existing guidelines for the interventional management of NP. Evidence is summarized and presented for neural blockade, spinal cord stimulation (SCS), intrathecal medication, and neurosurgical interventions in patients with the following peripheral and central NP conditions: herpes zoster and postherpetic neuralgia (PHN); painful diabetic and other peripheral neuropathies; spinal cord injury NP; central poststroke pain; radiculopathy and failed back surgery syndrome (FBSS); complex regional pain syndrome (CRPS); and trigeminal neuralgia and neuropathy. Due to the paucity of high-quality clinical trials, no strong recommendations can be made. Four weak recommendations based on the amount and consistency of evidence, including degree of efficacy and safety, are: 1) epidural injections for herpes zoster; 2) steroid injections for radiculopathy; 3) SCS for FBSS; and 4) SCS for CRPS type 1. Based on the available data, we recommend not to use sympathetic blocks for PHN nor radiofrequency lesions for radiculopathy. No other conclusive recommendations can be made due to the poor quality of available data. Whenever possible, these interventions should either be part of randomized clinical trials or documented in pain registries. Priorities for future research include randomized clinical trials, long-term studies, and head-to-head comparisons among different interventional and noninterventional treatments.     

Limits of Stability in Persons With Transtibial Amputation With Respect to Prosthetic Alignment Alterations

Objectives

To evaluate the limits of stability (LOS) in persons with transtibial amputation (TTA), and to determine the effects of prosthetic alignment alterations on motor control strategies.

Design

Before-and-after trial.

Setting

A kinesiology laboratory at a university hospital.

Participants

Male patients with TTA (n=10) and controls (n=17).

Interventions

Prosthetic alignment.

Main Outcome Measures

For the LOS test, the maximum excursion, endpoint excursion, direction control, movement velocity, and reaction time with inclination in the forward direction, toward the amputated leg/right leg, and in the backward direction, and toward the nonamputated leg/left leg. Measurements were performed using the following 5 prosthetic alignments: the optimal alignment, with the prosthesis shorter by 1cm, with the prosthesis longer by 1cm, and with the prosthetic foot in 5° of extra plantar flexion and 5° of extra dorsiflexion.

Results

Compared with the control group, maximum excursion and direction control were lower (P<.05) in patients with TTA with backward body inclination for all tested prosthetic alignments. Direction control in backward inclination was reduced (P<.05) compared with other tested directions for all assessed prosthetic alignments. Differences between the tested alignments were not significant in any of the tested directions.

Conclusions

Patients with TTA have decreased voluntary body inclination backward within the LOS for all tested prosthetic alignments. Compared with controls, changes in prosthetic foot settings by means of rotation in the sagittal plane had a larger impact on movement strategy in patients with TTA than did changes to the length of the prosthesis.     

Rehabilitation medicine in countries of Central/Eastern Europe

Purpose.?To describe attributes of rehabilitation medicine common to the five countries of Central Eastern Europe (CEE) and their implications for future challenges.

Methods.?Critical collection and study of pertinent data on evolvement and present state of rehabilitation medicine in CEE countries by a coordinated team of rehabilitation experts from each of the relevant countries.

Results.?CEE countries are similar in their need for rehabilitation medicine, its evolvement, present state and current practice. Settings largely emerged without strategic planning on the national level and lagged behind those in Central and Western Europe both in time and content.

Conclusion.?The framework that evolved in all except Slovenia is not appropriate to needs. In order to meet future challenges all five CEE countries need the incorporation of inpatient, outpatient and community-based rehabilitation into one system.     

Dynamics of Coumarin Production in Leaves of Diploid and Tetraploid Matricaria chamomilla.

ABSTRACT

The content of herniarin, (Z.)- and (E.)-2-β.-D-glucopyranosyloxy-4-methoxycinnamic acid, umbelliferone, chlorogenic acid, and (Z.)- and (E.)-ene-yne-dicycloether was evaluated in Matricaria chamomilla.L. leaf rosette in relation to the leaf age. Developmental changes of the herniarin quantity in diploid and tetraploid cultivar were similar. The highest content of (E.)-2-β.-D-glucopyranosyloxy-4-methoxycinnamic acid was found in the youngest leaves. The amount of umbelliferone and chlorogenic acid increased with the leaf age. Differences in amount of (Z.)- and (E.)-ene-yne-dicycloether between tetraploid and diploid plants were significant in all leaf pairs. However, their content during the leaf development was not considerably changed, contrary to coumarins.