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Barley α-amylase isozyme 1 (AMY1, EC 3.2.1.1) contains two surface binding sites, SBS1 and SBS2, involved in the degradation of starch granules. The distinct role of SBS1 and SBS2 remains to be fully understood. Mutational analysis of Tyr-380 situated at SBS2 previously revealed that Tyr-380 is required for binding of the amylose helix mimic, β-cyclodextrin. Also, mutant enzymes altered at position 380 displayed reduced binding to starch granules. Similarly, binding of wild type AMY1 to starch granules was suppressed in the presence of β-cyclodextrin. We investigated the role of SBS2 by comparing kinetic properties of the wild type AMY1 and the Y380A mutant enzyme in hydrolysis of amylopectin, amylose and β-limit dextrin, and the inhibition by β-cyclodextrin. Progress curves of the release of reducing ends revealed a bi-exponential hydrolysis of amylopectin and β-limit dextrin, whereas hydrolysis of amylose progressed mono-exponentially. β-Cyclodextrin, however, inhibited only one of the two reaction rates of amylopectin and β-limit dextrin hydrolysis, whereas hydrolysis of amylose was unaffected. The Y380A enzyme showed no detectable inhibition by β-cyclodextrin but displayed similar kinetics to the inhibited wild type AMY1. These results point to SBS2 as an important binding site in amylopectin depolymerization., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Determination of the thiol-disulfide status in biological systems is challenging as redox pools are easily perturbed during sample preparation. This is particularly pertinent under neutral to mildly alkaline conditions typically required for alkylation of thiols. Here we describe the synthesis and properties of a thiol-specific reagent, fluorescent cyclic activated disulfide (FCAD), which includes the fluorescein moiety as fluorophore and utilizes a variation of thiol-disulfide exchange chemistry. The leaving-group character of FCAD makes it reactive at pH 3, allowing modification at low pH, limiting thiol-disulfide exchange. Different applications are demonstrated including picomolar thiol detection, determination of redox potentials, and in-gel detection of labeled proteins., (Copyright © 2011 Elsevier Inc. All rights reserved.)

A microtiter plate format previously reported for the biochemical characterization of microorganisms was modified by adding agar to all of the different test media instead of using a combination of liquid and solid media. This modification, termed the Modified Microtiter Plate procedure (MMP), offered the same advantages of the original method (labor saving, inexpensive, and custom designed for special needs) as well as having the added advantages of longer term storage prior to use and ease of handling. In this study, 60 bacterial isolates (both Listeria suspects and known Listeria cultures) were biotyped using the MMP protocol and compared to results obtained using the classical tube-based US-FDA recommended protocol as the standard identification method and the BBL-Minitek system.

In 15 patients (ASA I-II) undergoing intraabdominal gynaecological surgery, muscle paralysis for tracheal intubation and surgery was achieved by a combined bolus and demand infusion of vecuronium. The initial loading dose of 67 micrograms kg-1 and the rate of subsequent infusion were determined by evaluation of the tactile twitch response to train-of-four (TOF) stimulation of the ulnar nerve while the neuromuscular blockade obtained was recorded blindly for control on the contralateral arm. A maintenance dose of 4.9 mg h-1 (2.0-7.6 mg h-1) produced a smooth course of blockade with minimum and maximum values of twitch height during infusion of 2% and 12%, respectively. A period of 15.9 min elapsed from the end of infusion to a TOF-ratio of 0.7, when neostigmine 2.5 mg was administered at the point of two palpable twitches to TOF-stimulation. Simple tactile evaluation of peripheral nerve stimulation is sufficient to determine the infusion rate of vecuronium required to produce stable and appropriate neuromuscular blockade during intra-abdominal surgery.

We studied 20 otherwise healthy women undergoing lower abdominal surgery. Immediately after wound closure, while still anaesthetized, they received either electroacupuncture (EA) or no further treatment. They were allowed pethidine for postoperative analgesia by patient-controlled infusion pump. Signs of postoperative distress (pain, nausea, drowsiness) were evaluated after 2 and 6 h by visual analogue scale scores. The group receiving EA consumed half the quantity of pethidine as that used used by the no treatment group. Two patients in the EA group had no postoperative analgesia in the first 2 h. There was no difference in the assessments of postoperative distress between groups. No patient was aware of having received EA or not.

In a double-blind study, 39 patients (ASA groups I-II,) were given either pancuronium or atracurium as an infusion during surgery. The drugs were given as an initial loading dose of 0.064 mg kg-1 or 0.30 mg kg-1, respectively, followed by an infusion, the rate of which was regulated to produce a constant 95% depression of the evoked twitch response throughout surgery. No significant difference in the number of corrections of the infusion rate per hour was found (4.6 v. 4.9). Mean infusion maintenance doses were 35 and 356 micrograms kg-1 h-1, respectively. The inter-individual variability of maintenance doses for the two drugs did not differ, the coefficients of variation being 0.32 and 0.24. On stopping the infusion, the patients given atracurium recovered to a 15% twitch faster than those given pancuronium. In addition neostigmine produced a quicker recovery in this group. Thus atracurium may be a more satisfactory drug for use by infusion.