Multicenter Evaluation of the C6 Lyme ELISA Kit for the Diagnosis of Lyme Disease.

Lyme disease (LD), caused by infection with , is the most common tick-borne infection in many regions of Eurasia. Antibody detection is the most frequently used laboratory test, favoring a two-step serodiagnostic algorithm; immunoenzymatic detection of antibodies to C6 has been shown to perform similarly to a standard two-step workflow. The aim of this study was the performance evaluation of the C6 Lyme ELISA kit compared to a standard two-step algorithm in three laboratories located in the northeastern region of Italy which cater to areas with different LD epidemiology.

Clinical staff work sampling in a neurorehabilitation hospital and its relationship to severity of disease.

Aim: Study aimed to analyse how rehabilitation staff spends working time on specific activities in a neurorehabilitation hospital and to determine the number of direct activities received by patients with different levels of disease severity.

Background: Few studies have investigated how clinical staff spends their time on activities in rehabilitation hospitals without considering at the same time all working categories and without reporting the number of direct activities received by patients with respect to their disease severity.

Design: Self-reported observational study.

Acute Perioperative Comparison of Patient-Specific Instrumentation versus Conventional Instrumentation Utilization during Bilateral Total Knee Arthroplasty.

Utilizing patient-specific instrumentation during total knee arthroplasty has gained popularity in recent years with theoretical advantages in blood loss, intraoperative time, length of stay, postoperative alignment, and functional outcome, amongst others. No study has compared acute perioperative measures between patient-specific instrumentation and conventional instrumentation in the bilateral total knee arthroplasty setting. We compared patient-specific instrumentation versus conventional instrumentation in the setting of bilateral total knee arthroplasty to determine any benefits in the immediate perioperative period including surgical time, blood loss, pain medication use, length of stay, and discharge disposition.

A Functional Analysis Of An Assistive Device Information Database in Flanders: A Qualitative Study.

Since 1989-1990, Vlibank is the Flemish AT information database managed by the Flemish government and aims to have a complete overview of AT devices in Flanders. The growing AT market increases the need for unbiased information on AT. However, maintaining and keeping a database up-to-date is a very challenging task.

A new technique for arthroscopic resection of a bucket handle tear.

The authors present a previously undescribed technique for excision of a bucket handle tear. The technique uses a Caspari suture punch to pass a suture through the meniscus and use the suture as a tool to maneuver the meniscus so that its posterior horn attachment can be cut. The technique is noteworthy in that it eliminates the need for establishing an additional portal.

Correlation between quantal secretion and vesicle loss at the frog neuromuscular junction.

1. We measured the rate of occurrence of miniature endplate potentials (MEPPs) at identified endplates in frog cutaneous pectoris muscles treated with crude black widow spider venom (BWSV) or purified alpha-latrotoxin (alpha-LTX) in calcium-free solutions, and we examined the relationship between the length of the nerve terminal and the total number of quanta secreted, and the relationship between the number of quanta secreted and the number of vesicles remaining at different times. 2.

Redistribution of synaptophysin and synapsin I during alpha-latrotoxin-induced release of neurotransmitter at the neuromuscular junction.

The distribution of two synaptic vesicle-specific phosphoproteins, synaptophysin and synapsin I, during intense quantal secretion was studied by applying an immunogold labeling technique to ultrathin frozen sections. In nerve-muscle preparations treated for 1 h with a low dose of alpha-latrotoxin in the absence of extracellular Ca2+ (a condition under which nerve terminals are depleted of both quanta of neurotransmitter and synaptic vesicles), the immunolabeling for both proteins was distributed along the axolemma. These findings indicate that, in the presence of a block of endocytosis, exocytosis leads to the permanent incorporation of the synaptic vesicle membrane into the axolemma and suggest that, under this condition, at least some of the synapsin I molecules remain associated with the vesicle membrane after fusion.

The effect of anions on bound acetylcholine in frog sartorius muscle.

1. Frog sartorius muscles were treated with an irreversible cholinesterase inhibitor and then incubated in isotonic potassium propionate solution (isotonic KPr). Total and bound, presumably vesicular, acetylcholine (ACh) in the tissue and ACh in the medium were assayed by mass fragmentography, miniature end-plate potentials (MEPPs) were recorded and the end-plates were investigated by electron microscopy.

Synaptophysin (p38) at the frog neuromuscular junction: its incorporation into the axolemma and recycling after intense quantal secretion.

Recycling of synaptophysin (p38), a synaptic vesicle integral membrane protein, was studied by the use of antisera raised against the protein purified from frog brain. When frog cutaneous pectoris muscles were fixed at rest, a bright, specific immunofluorescent signal was observed in nerve-terminal regions only if their plasma membranes had been previously permeabilized. When muscles were fixed after they had been treated for 1 h with a low dose of alpha-latrotoxin in Ca2+-free medium, an equally intense fluorescence could be observed without previous permeabilization.

Differential effect of alpha-latrotoxin on exocytosis from small synaptic vesicles and from large dense-core vesicles containing calcitonin gene-related peptide at the frog neuromuscular junction.

The regulatory peptide called calcitonin gene-related peptide (CGRP) was detected by immunofluorescence in frog motor neurons and motor nerve terminals. In motor nerve terminals, CGRP-like immunoreactivity was found to be segregated within large dense-core vesicles. To determine whether exocytosis from acetylcholine-containing small synaptic vesicles and from CGRP-containing large dense-core vesicles can be independently stimulated, nerve-muscle preparations were exposed to alpha-latrotoxin.

Effect of alpha-latrotoxin on the frog neuromuscular junction at low temperature.

1. alpha-Latrotoxin (alpha-LTx) was applied to frog cutaneous pectoris muscles bathed at 1-3 degrees C in either Ringer solution, Ca2+-free Ringer solution with 1 mM-EGTA and 4 mM-Mg2+ or Ringer solution plus 4 mM-Mg2+, and its effects on miniature end-plate potential (MEPP) frequency, nerve terminal ultrastructure and uptake of horseradish peroxidase (HRP) were studied. 2.

The effect of potassium on exocytosis of transmitter at the frog neuromuscular junction.

1. Electrophysiology and morphology have been combined to investigate the time course of the exocytosis of quanta of neurotransmitter induced by elevated concentrations of K+ at the frog neuromuscular junction. 2.

Localization of synapsin I at the frog neuromuscular junction.

We report here the results of immunocytochemical and biochemical studies on the localization of synapsin I, a nerve terminal--specific phosphoprotein, at the frog neuromuscular junction. Our results show that in this in situ synapse synapsin I is concentrated in the presynaptic compartment, where it appears to be associated with the synaptic vesicle membrane. Double immunoprecipitated synapsin I from homogenates of frog cutaneous pectoris muscles could be phosphorylated by the catalytic subunit of cyclic adenosine 5'-monophosphate-dependent protein kinase after gel electrophoresis and blotting onto nitrocellulose and could be subsequently identified by an immunoperoxidase technique.

Coated vesicles and pits during enhanced quantal release of acetylcholine at the neuromuscular junction.

Frog neuromuscular junctions were stimulated by different methods to secrete quanta of ACh, and the attendant changes in the ultrastructure of the nerve terminal were assessed by morphometric analysis of electron micrographs. Secretion was stimulated by electrical stimulation at 2 Hz or by application of the secretagogues, lanthanum, ouabain or black widow spider venom, either in the presence or in the absence of extracellular Ca2+. The numbers of synaptic vesicles, coated vesicles and coated pits, and the length of axolemma and area of axoplasm were measured on the micrographs.

The phorbol ester, 12-O-tetradecanoyl-phorbol-13-acetate, enhances the evoked quanta release of acetylcholine at the frog neuromuscular junction.

The possible role of protein kinase C in the regulation of quantal transmitter release was studied at the frog neuromuscular junction by using the phorbol ester 12-O-tetradecanoyl-phorbol-13-acetate (TPA), a compound known to mimic the effects of the physiological activator of the enzyme, endogenous diacylglycerol. The main effect of the phorbol ester was to increase the quantal content, m, of the endplate potential. The initial values of m were adjusted over a wide range by changing the Ca2+ concentration of the extracellular medium, and the TPA-induced fractional increase in m was significantly greater at junctions with a lower initial quantal content.

A solid-phase assay for the phosphorylation of proteins blotted on nitrocellulose membrane filters.

A new procedure for the phosphorylation and assay of phosphoproteins is described. Proteins are solubilized from tissue samples, separated by polyacrylamide gel electrophoresis, transferred onto nitrocellulose membrane filters, and the blotted polypeptides are phosphorylated with the catalytic subunit of cyclic AMP (adenosine 3':5'-monophosphate)-dependent protein kinase. The method was developed for the assay of dephosphosynapsin I, but it has also proven suitable for the phosphorylation of other proteins.

Effects of black widow spider venom and Ca2+ on quantal secretion at the frog neuromuscular junction.

A modification of the classical procedure of fluctuation analysis is used to measure the waveform, w(t), mean amplitude, (h), and mean rate of occurrence, (r), of miniature endplate potentials (MEPPs) at frog cutaneous pectoris neuromuscular junctions treated with black widow spider venom (BWSV). MEPP parameters are determined from the power spectrum of the fluctuating potential and the second (variance), third (skew), and fourth semi-invariants (cumulants) of high-pass-filtered records of the potential. The method gives valid results even when the mean potential undergoes slow changes unrelated to MEPPs and when the MEPP rate is not stationary; it detects changes in the distribution of MEPP amplitudes and corrects for the nonlinear summation of MEPPs.

Measurement of quantal secretion induced by ouabain and its correlation with depletion of synaptic vesicles.

Ouabain (0.1 and 0.05 mM) was applied to frog cutaneous pectoris nerve-muscle preparations bathed in modified Ringer's solution containing either 1.

Temporal coincidence between synaptic vesicle fusion and quantal secretion of acetylcholine.

We applied the quick-freezing technique to investigate the precise temporal coincidence between the onset of quantal secretion and the appearance of fusions of synaptic vesicles with the prejunctional membrane. Frog cutaneous pectoris nerve-muscle preparations were soaked in modified Ringer's solution with 1 mM 4-aminopyridine, 10 mM Ca2+, and 10(-4) M d-Tubocurarine and quick-frozen 1-10 ms after a single supramaximal shock. The frozen muscles were then either freeze-fractured or cryosubstituted in acetone with 13% OsO4 and processed for thin section electron microscopy.

Miniature endplate potential frequency and amplitude determined by an extension of Campbell's theorem.

A method based upon an extension of Campbell's theorem is used to measure the amplitude, waveform, and frequency of occurrence of miniature endplate potentials (mepps) at rapidly secreting neuromuscular junctions of frog cutaneous pectoris muscles. Measurements of the variance, skew, and power spectrum of the fluctuations in membrane potential are used to deduce the mepp parameters. These estimates of mepp amplitude and frequency are insensitive to slow drifts in membrane potential that preclude the conventional application of Campbell's theorem, which uses the mean and variance.

Specific localization of the alpha-latrotoxin receptor in the nerve terminal plasma membrane.

The receptor for alpha-latrotoxin, the major protein component of the black widow spider venom, was investigated by the use of the purified toxin and of polyclonal, monospecific anti-alpha-latrotoxin antibodies. Experiments on rat brain synaptosomes (where the existence of alpha-latrotoxin receptors was known from previous studies) demonstrated that the toxin-receptor complex is made stable by glutaraldehyde fixation. At saturation, each such complex was found to bind on the average five antitoxin antibody molecules.

The effects of Bothrops jararacussu venom and its components on frog nerve-muscle preparation.

The effect of Bothrops jararacussu venom was studied in cutaneous pectoris nerve muscle preparations and in the desheathed sciatic nerve of the frog. The venom rapidly inhibited muscle twitch--tension, evoked either directly or indirectly through the motor nerve and abolished the compound action potential of the muscle and of the sciatic nerve. After fractionation of the venom by Sephadex G-50 column chromatography, all the activity was recovered in a fraction containing 30% of the total venom protein and highly enriched in two polypeptides with apparent Mr of 13-15,000, as revealed by two-dimensional polyacrylamide gel electrophoresis.

Exocytosis and membrane recycling.

Exocytosis implies the fusion of the membrane of secretion granules with, and the insertion into, the plasmalemma. In non-growing systems such an insertion is temporary in that the inserted membrane is eventually removed. Turnover results indicate that the removed membrane is not destroyed but recycled within the cell and reused.