Oral Vancomycin Followed by Fecal Transplantation Versus Tapering Oral Vancomycin Treatment for Recurrent Clostridium difficile Infection: An Open-Label, Randomized Controlled Trial.

Background: Fecal transplantation (FT) is a promising treatment for recurrent Clostridium difficile infection (CDI), but its true effectiveness remains unknown. We compared 14 days of oral vancomycin followed by a single FT by enema with oral vancomycin taper (standard of care) in adult patients experiencing acute recurrence of CDI.

Methods: In a phase 2/3, single-center, open-label trial, participants from Ontario, Canada, experiencing recurrence of CDI were randomly assigned in a 1:1 ratio to 14 days of oral vancomycin treatment followed by a single 500-mL FT by enema, or a 6-week taper of oral vancomycin.

Primary bilateral corneal nerve sheath neoplasm in a dog.

A 15-year-old, neutered male, Shih Tzu cross developed progressive corneal stromal thickening and vascularization of the right eye, and 5 months later, of the left eye. Both eyes became blind due to extensive corneal opacification and were enucleated. Light microscopic examination revealed a diffuse corneal infiltrate of neoplastic mesenchymal cells, and immunohistochemistry revealed diffuse cytoplasmic vimentin immunoreactivity and variable cytoplasmic and nuclear immunoreactivity for S100 in the neoplastic cells.

Low awareness but positive attitudes toward fecal transplantation in Ontario physicians.

Background: Despite mounting evidence supporting fecal transplantation (FT) as a treatment for recurrent Clostridium difficile infection (CDI), adoption into clinical practice has been slow.

Objective: To determine the health literacy and attitudes of academic physicians in Toronto and infectious disease physicians in Ontario toward FT as a treatment for recurrent CDI, and to determine whether these are significant barriers to adoption.

Methods: Surveys were distributed to 253 general internists, infectious diseases specialists, gastroenterologists and family physicians.

Intravenous iron and recombinant erythropoietin for the treatment of postoperative anemia.

Purpose: To determine if early recovery from severe post-operative anemia is accelerated by iv iron therapy alone or in combination with recombinant erythropoietin (EPO).

Methods: In this double-blinded, placebo-controlled randomized study, consenting adult patients without preoperative anemia whose hemoglobin concentration (Hb) was 70 to 90 g x L(-1) on the first day after cardiac or orthopedic surgery (POD 1) were assigned to one of three groups: control, iv iron alone (200 mg of iron sucrose on POD 1, 2, and 3) or in combination with EPO (600 U x kg(-1) on POD 1 and 3). The primary outcome was increase in Hb (adjusted for red blood cell transfusions) from POD 1 to 7.

A triple-blinded randomized trial comparing the hemostatic effects of large-dose 10% hydroxyethyl starch 264/0.45 versus 5% albumin during major reconstructive surgery.

In Canada, hydroxyethyl starch 264/0.45 (HES 264/0.45; molar weight 264 kDa, molar substitution 0.

Transients in acetylcholine receptor site density and degradation during reinnervation of mouse sternomastoid muscle.

The degradation rates of acetylcholine receptors (AchRs) were evaluated at the neuromuscular junction during and just after reinnervation of denervated muscles. When mouse sternomastoid muscles are denervated by multiple nerve crush, reinnervation begins 2-4 days later and is complete by day 7-9 after the last crush. In fully innervated muscles, the AChR degradation rate is stable and slow (t1/2 approximately 10 days), whereas after denervation the newly inserted receptors degrade rapidly (t1/2 approximately 1.

Two distinct effects on neurotransmission in a temperature-sensitive SNAP-25 mutant.

Vesicle fusion in eukaryotic cells is mediated by SNAREs (soluble N-ethylmaleimide-sensitive factor attachment protein receptors). In neurons, the t-SNARE SNAP-25 is essential for synaptic vesicle fusion but its exact role in this process is unknown. We have isolated a SNAP-25 temperature-sensitive paralytic mutant in Drosophila, SNAP-25(ts).

Rate constants of acetylcholine receptor internalization and degradation in mouse muscles.

The rate constants for internalization and subsequent extrusion of acetylcholine receptors (AChRs) during degradation in adult innervated and denervated mouse diaphragm muscles were determined using proteinase K (PK) digestion. This procedure separated (125)I-alpha-bungarotoxin (Bgt)-labeled AChRs into PK-sensitive and PK-resistant compartments. The time course of the residual radioactivity in these two compartments suggested that they represented surface membrane and internalized compartments, respectively.

The temperature sensitivity of miniature endplate currents is mostly governed by channel gating: evidence from optimized recordings and Monte Carlo simulations.

The temperature dependence of miniature endplate current (MEPC) amplitude (A(c)), 20-80% rise time (t(r)), and 90-33% fall-time (t(f)) was determined for lizard (Anolis carolinensis) intercostal muscle using broadband extracellular (EC) and voltage clamp (VC) recordings. Voltage clamp methods were optimized for the fast MEPC rising phase using custom electronics. From 0-43 degrees C, A(c) increased by approximately 4.

125I-labeled fasciculin 2: a new tool for quantitation of acetylcholinesterase densities at synaptic sites by EM-autoradiography.

Radio-iodinated fasciculin 2 (Fas2), a polypeptide anticholinesterase toxin from Mamba venom, was used as a new probe for localizing and quantifying acetylcholinesterase (AChE) at mouse neuromuscular junctions (NMJs) by quantitative electron microscope autoradiography. We demonstrate that 125I-Fas2 binds very specifically to the NMJs of mouse sternomastoid muscles, with very little binding to other regions in the muscles. Junctional AChE-site densities obtained from the autoradiograms were similar to those previously obtained for the same muscles using 3H-DFP.

Epsilon subunit-containing acetylcholine receptors in myotubes belong to the slowly degrading population.

Two types of muscle acetylcholine receptors (AChRs) can be distinguished on the basis of their degradation rates and sensitivities to innervation, muscle activity, and agents elevating intracellular cAMP. The first type (Rs), is present in a stable form (degradation t1/2 = approximately 10 d) at the adult innervated neuromuscular junctions (NMJs). Rs can also exist in a less stable form (called accelerated Rs; t1/2 = approximately 3-5 d) at denervated NMJs and in aneurally cultured myotubes; agents that increase intracellular cAMP reversibly modulate Rs stability.

Acetylcholine receptors in innervated muscles of dystrophic mdx mice degrade as after denervation.

Acetylcholine receptors (AChRs) are present at the top of the postsynaptic membrane of the neuromuscular junction (NMJ) at very high density, possibly anchored to cytoskeletal elements. The present study investigated whether AChR degradation is affected in animals lacking dystrophin, a protein that is an integral part of the cytoskeletal complex and is missing in Duchenne muscular dystrophy. The animal model for Duchenne muscular dystrophy, the mutant mdx mouse, was used to determine whether disruption of the cytoskeleton, caused by the absence of dystrophin, affects AChR degradation.

Stabilization of acetylcholine receptors by exogenous ATP and its reversal by cAMP and calcium.

Innervation of the neuromuscular junction (nmj) affects the stability of acetylcholine receptors (AChRs). A neural factor that could affect AChR stabilization was studied using cultured muscle cells since they express two distinct populations of AChRs similar to those seen at the nmjs of denervated muscle. These two AChR populations are (in a ratio of 9 to 1) a rapidly degrading population (Rr) with a degradation half-life of approximately 1 d and a slowly degrading population (Rs) that can alternate between an accelerated form (half-life approximately 3-5 d) and a stabilized form (half-life approximately 10 d), depending upon the state of innervation of the muscle.

Absence of nerve-dependent conversion of rapidly degrading to stable acetylcholine receptors at adult innervated endplates.

It has been suggested that acetylcholine receptors newly inserted into adult innervated endplates have a rapid degradation rate, but are normally converted to a stable, slowly degrading form in a nerve-dependent fashion. Denervation therefore should eliminate conversion and cause pre-existing unconverted receptors to continue degrading rapidly. We tested this model of nerve-dependent conversion in mouse sternomastoid muscle, using quantitative electron microscopic autoradiography in order to specifically examine degradation of receptors at identified endplate membrane.

Miniature endplate current rise times less than 100 microseconds from improved dual recordings can be modeled with passive acetylcholine diffusion from a synaptic vesicle.

We recorded miniature endplate currents (mEPCs) using simultaneous voltage clamp and extracellular methods, allowing correction for time course measurement errors. We obtained a 20-80% rise time (tr) of approximately 80 micros at 22 degrees C, shorter than any previously reported values, and tr variability (SD) with an upper limit of 25-30 micros. Extracellular electrode pressure can increase tr and its variability by 2- to 3-fold.

Protein kinase A regulates the degradation rate of Rs acetylcholine receptors.

Acetylcholine receptors at the neuromuscular junction of innervated vertebrate muscle (called Rs AChRs) have a stable degradation rate (t1/2 approximately 8-12 days) which accelerates after denervation to a half-life of approximately 3 days, but can be restabilized by reinnervation or by cAMP. We examined the mechanism by which cAMP regulates the Rs degradation rate. When dibutyryl cAMP (DB-cAMP) was applied to denervated mouse diaphragms in organ culture, it stabilized the accelerated degradation rate of the Rs.

In situ hybridization and cytochemistry: localization of mRNA at stained neuromuscular junctions with 33P-labeled probes.

We modified the Karnovsky and Roots method of staining sites of acetylcholinesterase (AChE) activity at neuromuscular junctions (NMJs) to survive the lengthy, multiple steps of in situ hybridization and autoradiography. When the original method of Karnovsky and Roots is used to identify the muscle endplates, the stain does not survive the in situ hybridization procedures and association of mRNA to specific endplates can be inferred only indirectly. The successful modification involves secondary staining with diaminobenzidine (DAB) and H2O2 using the Karnovsky-Roots staining reaction product as a catalyst.

Mouse muscle epsilon- and gamma-containing acetylcholine receptors expressed in Xenopus laevis oocytes do not differ in their degradation half-lives.

Mouse acetylcholine receptors (AChRs) consisting of either the embryonic form (2 alpha, 1 beta, 1 delta and 1 gamma) or the adult form (2 alpha, 1 beta, 1 delta and 1 epsilon) were expressed in Xenopus laevis oocytes. As expected, the single channel conductance was approximately 52 pS and the exponential decay time constants were 2.2 and 8.

Acetylcholinesterase density and turnover number at frog neuromuscular junctions, with modeling of their role in synaptic function.

Acetylcholinesterase (AChE) density at the neuromuscular junction of frog cutaneous pectoris muscle was determined by electron microscope autoradiography and biochemistry to be approximately 600 sites micron-2 of postsynaptic area, approximately 4-fold lower than all previous reports (mouse), whereas the hydrolytic turnover number was 9,500 s-1, well within the range (2,000-16,000 s-1) for AChE from other species. Monte Carlo computer simulations of miniature endplate currents showed that for vertebrate neuromuscular junctions with different morphologies, an AChE density of only approximately 400 sites microns-2 and a turnover number of only approximately 1,000 s-1 are sufficient for normal quantal currents. Above these critical lower limits, miniature endplate currents were essentially insensitive to AChE density and turnover number values up to 5,000 sites microns-2 and 16,000 s-1, respectively.

Secreted collagen induced by ascorbic acid in L5 cloned muscle cultures does not affect acetylcholine receptor expression.

Previous studies have shown that ascorbic acid increases both the total surface acetylcholine receptor (AChR) expression and the mRNA for the alpha-subunit of this receptor in myotubes of cloned L5 muscle cultures. Since ascorbic acid increases collagen synthesis in fibroblasts, we studied the effect of ascorbic acid on collagen secretion in L5 muscle cells and investigated the possibility that the effects of ascorbic acid on collagen and AChR are related. We report that L5 muscle cells secrete collagen types I, III, and V, with collagen type I being the most abundant species, and that accumulation of secreted collagens increased in the medium approximately two- to ninefold within 3 h of ascorbic acid treatment.

Two populations of AChR in rat myotubes have different degradation rates and responses to cAMP.

Acetylcholine receptors (AChRs) of rat muscle cells grown in culture for 4 days were labeled with 125I-alpha-bungarotoxin and their degradation rate measured. Two AChR populations, a rapidly degrading one (Rr,t1/2 approximately 1 day) and a slowly degrading one (Rs, t1/2 approximately 4 days) were identified at a ratio of approximately 9 to 1. The degradation rate of the Rs was slowed to a t1/2 of approximately 10 days by cAMP while that of the Rr remained unchanged.

Degradation of two AChR populations at rat neuromuscular junctions: regulation in vivo by electrical stimulation.

The effect of electrical stimulation on the stability of junctional ACh receptors (AChR) on soleus muscles of Wistar rats was compared to that of denervation and reinnervation. Denervation causes the degradation rate of the slowly degrading AChRs (Rs) at the neuromuscular junction to accelerate and be replaced by rapidly degrading AChRs (Rr), while reinnervation restabilizes the accelerated Rs. Electrical stimulation initiated at the time of denervation prevented the acceleration of the Rs.