Evaluation of serum levels of neurotrophin 4 and brain-derived nerve growth factor in uremic pruritus patients.

BACKGROUND: Pruritus is a common symptom in end-stage renal failure. Many patients suffer from this severe distressing symptom. Although several factors have been postulated to explain uremic pruritus, there is not any conclusive evidence for one of these factors. OBJECTIVES: We aimed to evaluate serum levels of brain-derived nerve growth factor (BDNF), neurotrophin-4 (NT-4), serum calcium, phosphors and parathyroid hormone in uremic patients with pruritus and without pruritus compared to control subjects. METHODS: One hundred twenty patients suffering from renal failure and 60 healthy subjects were included in the study. Serum BDNF and NT4 levels were determined by ELISA. The serum calcium, phosphorus, parathyroid hormone and hemoglobin were also evaluated. RESULTS: Serum BDNF was significantly higher in uremic patients with pruritus (P=0.0026) and uremic patients without pruritus (P=0.0294) than control subjects. In addition, NT-4 levels were significantly elevated in uremic patients with pruritus (P<0.0001) and uremic patients without pruritus than control subjects (P=0.0016). There was no significant difference of serum level of BDNF between uremic patients with pruritus and uremic patients without pruritus (P=0.1215). However, serum NT-4 was higher in uremic patients with pruritus vs nonpruritic uremic patients with a significant difference (P=0.0026). There was a positive significant correlation between serum level of NT-4 and severity of pruritus (P=0.024). CONCLUSION: The present study shows that NT-4 level is increased in the serum of uremic patients with pruritus and there was a significant correlation between NT-4 and severity of pruritus suggesting that NT-4 may have a role in uremic pruritus.

Endometrial Injury May Increase the Pregnancy Rate in Patients Undergoing Intrauterine Insemination: An Interventional Randomized Clinical Trial.

OBJECTIVE: This study aimed to investigate the effect of endometrial injury using Pipelle catheter in the follicular phase (cycle day 5, 6, or 7) of the stimulation cycle on pregnancy rates in patients undergoing intrauterine insemination. METHODS: This prospective randomized controlled study was carried out in the Assisted Reproductive Technology Unit of Ain Shams University Maternity Hospital, Cairo, Egypt, from July 1, 2013 to August 31, 2015. Three hundred sixty women, 20 to 35 years of age, with patent fallopian tubes, mild male factor infertility, or unexplained infertility were recruited. Participants were allocated randomly into 2 groups: experimental arm and control arm. Women in the experimental arm underwent endometrial biopsy using a Pipelle catheter on day 5, 6, or 7 of the stimulation cycle combined with intrauterine insemination. Women in the control group underwent intrauterine insemination with no endometrial biopsy done. The primary outcomes were the clinical and chemical pregnancy rates. RESULTS: Data of 344 participants were statistically analyzed. The chemical pregnancy rate was 23.66% in the experimental arm and 10.85% in the control arm (P = .002). The clinical pregnancy rate was 18.93% in the experimental arm and 7.42% in the control arm (P = .003). CONCLUSION: Endometrial injury using a Pipelle catheter in the stimulation cycle may improve pregnancy rates in women undergoing intrauterine insemination.

Hybrid carbon nanoparticles modified core-shell silica: a high efficiency carbon-based phase for hydrophilic interaction liquid chromatography.

Hydrophilic interaction liquid chromatography (HILIC) is a fast growing separation technique for hydrophilic and polar analytes. In this work, we combine the unique selectivity of carbon surfaces with the high efficiency of core-shell silica. First, 5 µm core-shell silica is electrostatically coated with 105 nm cationic latex bearing quaternary ammonium groups. Then 50 nm anionic carbon nanoparticles are anchored onto the surface of the latex coated core-shell silica particles to produce a hybrid carbon-silica phase. The hybrid phase shows different selectivity than ten previously classified HILIC column chemistries and 36 stationary phases. The hybrid HILIC phase has shape selectivity for positional isomeric pairs (phthalic/isophthalic and 1-naphthoic/2-naphthoic acids). Fast and high efficiency HILIC separations of biologically important carboxylates, phenols and pharmaceuticals are reported with efficiencies up to 85,000 plates m(-1). Reduced plate height of 1.9 (95,000 plates m(-1)) can be achieved. The hybrid phase is stable for at least 3 months of usage and storage under typical HILIC eluents.

Carboxylate modified porous graphitic carbon: a new class of hydrophilic interaction liquid chromatography phases.

Stationary phases for hydrophilic interaction liquid chromatography (HILIC) are predominantly based on silica and polymer supports. We present porous graphitic carbon particles with covalently attached carboxylic acid groups (carboxylate-PGC) as a new HILIC stationary phase. PGC particles were modified by adsorbing the diazonium salt of 4-aminobenzoic acid onto the PGC, followed by reduction of the adsorbed salt with sodium borohydride. The newly developed carboxylate-PGC phase exhibits different selectivity than that of 35 HPLC columns, including bare silica, zwitterionic, amine, reversed, and unmodified PGC phases. Carboxylate-PGC is stable from pH 2.0 to 12.6, yielding reproducible retention even at pH 12.6. Characterization of the new phase is presented by X-ray photoelectron spectroscopy, thermogravimetry, zeta potentials, and elemental analysis. The chromatographic performance of carboxylate-PGC as a HILIC phase is illustrated by separations of carboxylic acids, nucleotides, phenols, and amino acids.

A validated HPLC method for the simultaneous determination of naftidrofuryl oxalate and its degradation product (metabolite), naftidrofuryl acid: applications to pharmaceutical tablets and biological samples.

A simple, sensitive, and selective reverse phase-high performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous determination of naftidrofuryl oxalate (NF) and its hydrolytic degradation product (metabolite), naftidrofuryl acid (NFA). Chromatographic separation was achieved on Spheri-5 RP-C8 (5 µm) (220 × 4.6 mm i.d.) column using a mobile phase composed of acetonitrile, 0.05 M sodium acetate and triethylamine (40 : 60 : 0.1, by volume) adjusted to pH 5.5 using glacial acetic acid. The mobile phase was pumped at flow rate 1.5 ml/min. The UV detector was set at 225 nm and quantification of the analytes was based on measuring the peak areas. The method was proved to be accurate and precise with linearity ranges of 0.1-25 and 0.2-25 µg ml(-1) for NF and NFA, respectively. The limits of detection were 0.03 and 0.04 µg ml(-1) for NF and NFA, respectively. The method was applied to serve three goals: (1) stability-indicating assay of the parent drug NF in its pharmaceutical formulation, (2) determination of the degradation product NFA down to a level of 0.005% in the presence of large excess of the parent drug, and (3) drug monitoring of naftidrofuryl and its metabolite, naftidrofuryl acid, in human plasma/urine samples taken from a healthy volunteer treated with 200 mg oral dose of naftidrofuryl oxalate. The proposed method proved to be accurate, precise, and reliable in all these application fields.

Mixed mode HILIC/anion exchange separations on latex coated silica monoliths.

Bare silica monoliths do not possess anion exchange sites hence they show low retention for anions. Moreover, bare silica monoliths show low retention in hydrophilic interaction liquid chromatography (HILIC). Coating the silica surface with cationic nanoparticles e.g. AS9-SC (latex A), AS12A (latex B) and DNApac (latex C) increases the thickness of the water layer on the Onyx silica monolith 8-10 times enabling HILIC retention when a high % acetonitrile (ACN) mobile phase is used. The formed water layer by itself is not sufficient to perform good separation of the studied anions (acetate, formate, nitrate, bromate, thiocyanate and iodide). On the other hand, the latex nanoparticles introduce positively charged sites, making anion exchange chromatography possible, with the anion exchange capacity varying with the latex adsorbed (44.1 ± 0.2, 4.4 ± 0.1 and 14.0 ± 0.7 µeq/column for latex A, B and C, respectively). Latex A nanoparticles which provided the highest ion exchange capacity separated all tested anions with reasonable resolution. Fast separation (2.5 min) of acetate, formate, nitrate, bromate, thiocyanate and iodide was performed using the latex A coated silica monolith. The obtained efficiencies are 13,000-50,000 plates/m at 3 mL/min with a minimum resolution of 0.85. Retention is mixed mode under HILIC conditions with HILIC dominating for the kosmotropic anions and ion exchange dominating for the chaotropic anions. The two different brands of silica monoliths (Merck Chromolith and Phenomenex Onyx) coated with the same latex A nanoparticles displayed similar water layer volumes, ion exchange capacity and selectivity.

A simple graphical representation of selectivity in hydrophilic interaction liquid chromatography.

This paper uses the HILIC selectivity data of Dinh et al. (J. Chromatogr. A 1218 (2011) 5880) to yield simple and easy to understand plots analogous to Neue plots for selectivity in HILIC. The plots categorize 21 previously studied HILIC phases (data from Dinh et al.), 8 additional HILIC columns and 4 reversed phase columns (our data) using selected probes for specific interactions. The relative retention of cytosine vs. uracil is used to probe the "hydrophilicity" of the HILIC phases; adenosine vs. adenine is used to probe the ability of the stationary phase to participate in hydrogen bonding; and benzyltrimethylammonium (BTMA) vs. cytosine is used to probe the cation exchange and anion exchange character of the column. Plots of kBTMA/kcytosine vs. kcytosine/kuracil successfully classify silica, amide, zwitterionic, diol and reverse phase columns in terms of their HILIC behavior. Polymeric columns including polymer substrate and polymer coated columns show low ion exchange character, but vary widely in their hydrophilicity. Alternatively a HILIC-Phase Selectivity Chart, in analogy to the Neue plot, is constructed by plotting log(kBTMA/kcytosine) vs. log(kcytosine). This plot enables classification of HILIC columns that will yield similar or significantly different separations.

Agglomerated silica monolithic column for hydrophilic interaction LC.

Hydrophilic interaction LC (HILIC) has gained wide acceptance in recent years due to its ability to retain and separate polar compounds such as pharmaceuticals. Most commercial HILIC phases are particle based, which limit the speed with which HILIC separations can be performed. Herein, agglomerated silica monolithic columns are prepared by electrostatically attaching polyionic latex particles onto a silica monolith by simply flushing a suspension of the ionic latex through a silica monolith. Such phases retain the high efficiency and permeability of the native silica monolith, while the agglomerated phase is easy to introduce and provides excellent mass transfer. High %ACN in the mobile phase dramatically increases the efficiency and retention, consistent with HILIC behavior. Test analytes such as benzoates, nucleotides and amino acids are separated with plate heights of 25-110 microm. The high permeability of monoliths allows HILIC separations to be performed with baseline resolution in less than 15 s. Electrostatic repulsion-hydrophilic liquid interaction chromatographic retention behavior of the latex-coated monoliths is verified using amino acids as test analytes.

Spectrophotometric, spectrofluorimetric and voltammetric analyses of naftidrofuryl oxalate in its tablets.

THIS WORK DEALS WITH SEVERAL DIRECT AND INDIRECT SPECTROPHOTOMETRIC, SPECTROFLUORIMETRIC AND VOLTAMMETRIC ANALYSES OF THE VASODILATOR DRUG: naftidrofuryl oxalate (NF). For the derivative spectrophotometric measurement, NF was determined by measuring the peak to peak amplitude of (1)D263-299 and (2)D282-311 or the absolute peak height of (1)D237 and (2)D241, while its reaction product with concentrated sulfuric acid was determined by measuring the peak to peak amplitude of (2)D248-263 or the absolute peak height of (1)D275. For the spectrofluorimetric measurement, native NF fluorescence was measured in Britton-Robinson buffer (pH 5) at λem = 331 nm (λex = 277 nm), while the reaction product was measured in aqueous solution at λem = 385 nm (λex = 258 nm). All factors affecting these analyses were studied and optimized. This work also describes a differential pulse cathodic voltammetric determination of the NF reaction product with concentrated sulfuric acid at the hanging mercury drop electrode (HMDE) where the experimental conditions affecting analysis including buffer pH, pulse amplitude and scan rate were examined and optimized. The chemical structure of the reaction product with concentrated sulfuric acid was investigated using several spectroscopic methods. All the developed procedures were validated and satisfactorily applied for the determination of NF in its pharmaceutical tablets.