Lactate Buffer Research Articles

Stability and compatibility of intraperitoneal antimicrobials in peritoneal dialysate solutions.

To optimise antimicrobial administration in patients with peritoneal dialysis (PD)-related peritonitis, healthcare providers need literature-based information to develop patient-centred pharmacotherapeutic plans. Traditional PD solutions promote osmosis using dextrose or icodextrin with a lactate buffer. Newer PD solutions have modified the osmotic vehicle and buffer. Knowledge of antimicrobial compatibility and stability with newer PD solutions will assist with determining the route of antimicrobial administration as compatible and stable solutions could be delivered directly to the peritoneum using intraperitoneal administration. This review updates the compatibility and stability of antimicrobial additives in newer PD solutions for PD-related peritonitis.

Rapid, Direct, Noninvasive Method to Determine the Amount of Immobilized Protein.

Protein immobilization is of utmost importance in many areas, where various proteins are used for selective detection of target compounds. Despite the importance given to determine the amount of immobilized protein, there is no simple method that allows direct, noninvasive detection. In this work, a method based on pH transition, occurring during change of solution ionic strength, was developed. The method utilized the ionic character of the immobilized protein while implementing biologically compatible buffers. Five different proteins, namely, glucose oxidase, horseradish peroxidase, bovine serum albumin, lysozyme, and protein A, were immobilized in different amounts on a porous polymeric matrix, and their pH transition was measured using lactate buffer of various concentrations and pH values. A linear correlation was found between the amount of immobilized protein and the amplitude of the pH transition, allowing the detection down to 2 nmol of immobilized protein. By changing the buffer concentration and pH, the sensitivity of the method could be tailored. Criteria based on the symmetry of the pH transition peak have been developed to determine if a particular measurement is within a linear range. In addition, a mathematical model was developed enabling prediction of pH transition profiles based solely on the protein amino acid sequence, the buffer pKa value(s), and the amount of immobilized protein.Hence, it can be used to design pH transition method experiments to achieve the required sensitivity for a target sample. Since the proposed method is noninvasive, it can be routinely applied during optimization of the immobilization protocol, for quality control, and also as an in-process monitoring tool.

Effect of acidic solutions present in the diet on the surface roughness of microhybrid composite resins

The objective of this study was to evaluate in vitro the roughness and surface morphology of composite resins (CRs) stored for 180 days in acidic solutions present in the diet. Three micro-hybrid composite resins were used in this study (Charisma, Opallis, and Esthet-X). Fifty-one specimens were made of each material with 4 mm in diameter and 2 mm thick with the aid of an elastomer matrix. After photoactivation for 40 seconds (Elipar Free-Light / 3M ESPE), the specimens were stored in distilled water for 24 hours at 37ºC for subsequent surface polishing with Soft Lex / 3M ESPE discs in fine and extra-fine granulation. Then, the specimens were dried with absorbent paper and the surface roughness was measured using a rugosimeter. The specimens were then randomly divided into five groups (n=10) according to the tested solutions: DW - Distilled water (pH 5.30); RW - Red Wine / Trapiche Syha Ind. Argentina red wine (pH 3.68); CK – Coke / Coca Cola Co. (pH 2.73), OJ - Orange juice / Purity Cocamar (pH 3.58) and LBS - lactate buffer solution (pH 2.74). The tested solutions were changed daily. The surface roughness test was repeated after 15, 90 and 180 days of immersion. The average values of surface roughness were submitted to LSmeans analysis and Tukey-Kramer test, at a significance level of 5%. The results of surface roughness revealed that all CRs showed a significant increase in the roughness values over time for all tested solutions.

Noninvasive method for determination of immobilized protein A

The pH transition method, developed for the determination of the ion-exchange group density on chromatographic stationary phase, was used for the quantification of immobilized protein A. Monolithic epoxy polyHIPE and particulate CNBr-Sepharose supports were used for immobilization. A lactate buffer was selected, having a buffer capacity peak approximately 0.5 pH units below the maximum buffer capacity of protein A. The pH transition measurements were performed at pH 4.3, where protein A exhibits maximum buffer capacity, with a lactate buffer concentration of 1 mM for protein A immobilized on polyHIPE monoliths and of 5 mM for protein A immobilized on CNBr-Sepharose. The pH transition height and full width at half maximum for the particulate support and the height for the polyHIPE matrix, showed a linear correlation with the amount of immobilized protein A determined from the absorbance difference before and after immobilization for both supports. The developed method allows a simple, non-invasive on-line determination of immobilized protein A using biological buffers, even for chromatographic columns with an amount of immobilized protein A as low as 0.25 mg. In addition, its sensitivity and duration can be easily adjusted by varying the buffer concentration and pH.

Physicochemical Characteristics of Arginine Enriched NaF Varnish: An In Vitro Study.

The in vitro study objectives were to investigate the effect of arginine (Arg) incorporation in a 5% sodium fluoride (NaF) varnish on its physical and chemical properties including F/Arg release. Six experimental formulations were prepared with L-arginine (L-Arg) and L-arginine monohydrochloride at 2%, 4%, and 8% w/v in a 5% NaF varnish, which served as a control. The varnishes were subjected to assessments for adhesion, viscosity, and NaF extraction. Molecular dynamics were simulated to identify post-dynamics total energy for NaF=Arg/Arg>NaF/Arg<NaF concentrations. The Arg/F varnish release profiles were determined in polyacrylic lactate buffer (pH-4.5; 7 days) and artificial saliva (pH-7; 1 h, 24 h, and 12 weeks). Incorporation of L-Arg in NaF varnish significantly influences physical properties ameliorating retention (p < 0.001). L-Arg in NaF varnish institutes the Arg-F complex. Molecular dynamics suggests that NaF>Arg concentration denotes the stabilized environment compared to NaF<Arg (p < 0.001). The 2% Arg-NaF exhibits periodic perennial Arg/F release and shows significantly higher integrated mean F release than NaF (p < 0.001). Incorporating 2% L-arginine in 5% NaF varnish improves its physical properties and renders a stable matrix with enduring higher F/Arg release than control.

Attention to the details: childbirth without stress and aggression

Background. Perinatal obstetrics involves the interests of both the mother and the fetus. The main sections of perinatal obstetrics are prenatal diagnosis, intensive care during pregnancy and childbirth, choice of optimal delivery way, resuscitation and care of the newborn. WHO experts believe that the comfort of the mother, psychological support of relatives, adequate analgesia, lack of aggressive delivery (unreasonable opening of the amniotic sac or unreasonable labor stimulation), monitoring of the childbirth dynamics and even the pose of the woman during labor are extremely important.&#x0D; Objective. To describe the modern views on childbirth.&#x0D; Materials and methods. Analysis of literature data on this issue.&#x0D; Results and discussion. Current trends in childbirth include the increase of the average weight of the fetus, of the number of high-risk mothers, of childbirth duration, of the incidence of traumatic injuries of the birth canal, of the frequency of surgical interventions. Obstructive labor is often accompanied by the aggressive management: hyperactive actions of obstetricians and gynecologists, uncontrolled use of oxytocin, any action in immature cervix. In obstructive labor, the obstetric situation should be assessed by vaginal examination and/or transabdominal ultrasound (US). If the latter does not show the middle structures of the head, one can combine transabdominal and transperitoneal US. With regard to birth injuries, their prevention should begin several weeks before the expected date of birth to reduce the risk of episiotomy and spontaneous perineal rupture. To do this, there are special vaginal hydrogels that reduce friction during childbirth. The composition of the hydrogel Ginodek (“Yuria-Pharm”) includes an antiseptic component (decamethoxine 0.02 %), a regenerating component (hyaluronic acid 0.5 %) and a component that regulates the vaginal pH (lactate buffer). Decamethoxine has bactericidal, viricidal, fungicidal, anti-inflammatory, desensitizing and antispasmodic action. Lactate buffer eliminates the symptoms of acid-base imbalance, helps to moisturize the vaginal mucosa and to maintain normal microflora. Hyaluronic acid restores the water balance of cells, promotes the entry of nutrients into the cells and the excretion of metabolic products, stimulates regeneration. Indications for the use of Ginodek include the prevention of infectious complications in obstetrics and gynecology before surgery, minor diagnostic operations, abortion, childbirth, intrauterine device insertion, as well as treatment of genital infections and conditions accompanied by dryness and atrophy of the vaginal mucous membrane.&#x0D; Conclusions. 1. When conducting childbirth in a natural way, the comfortable condition of the woman in labor, psychological support of relatives, adequate anesthesia, and the absence of aggressive assistment are of great importance. 2. There are vaginal hydrogels that prevent birth injuries via reducing the friction during childbirth. 3. Ginodek hydrogel, which contains decamethoxine, hyaluronic acid and lactate buffer, helps to reduce the number of birth injuries.

Effects of the Starch Types and the Grafting Conditions on the In Vitro Mucoadhesiveness of the Starch‐graft‐Poly(Methacrylic Acid) Hydrogels

AbstractIn the present study, grafting of poly(methacrylic acid) (PMAA) onto various types of starches (maize; rice; wheat; potato) is realized in the aqueous media for the first time using methacrylic acid as monomer and ammonium cerium‐IV‐nitrate as initiator system. The effects of the gelatinization pretreatment and the use of a crosslinker in the grafting reactions are investigated. The formation of the starch‐graft‐poly(methacrylic acid) (S‐g‐PMAA) is confirmed by Fourier transform infrared spectroscopy analysis. The grafting amounts (GA%) of the S‐g‐PMAAs are determined. The swelling and the erosion characteristics of the S‐g‐PMAAs are examined in deionized water and pH = 5 lactate buffer solution as an in vitro vaginal medium. Mechanical and in vitro mucoadhesiveness of the S‐g‐PMAAs are also investigated using ewe vaginal mucosa. The results demonstrate that the gelatinization pretreatment and crosslinking significantly affect the GA% values, swelling, erosion, mechanical, and mucoadhesive characteristics of the S‐g‐PMAAs depending on the types of starches. S‐g‐PMAAs with different mechanical and reasonable mucoadhesiveness can be obtained by manipulating the grafting conditions and using various types of starches. It is concluded that S‐g‐PMAAs could be appropriate candidates for applications as vaginal drug delivery systems.

Protective effect and mechanism of Ribociclib on sepsis induced-acute kidney injury

To investigate the role of Ribociclib in sepsis induced-acute kidney injury (AKI) and its possible mechanisms. (1) Twenty adult male C57BL/6 mice were divided into sham operation group (Sham group; only open the abdomen without ligating or perforating the cecum, administered with sodium lactate buffer 12 hours before the sham operation), Ribociclib control group (administered with 150 mg/kg Ribociclib), cecal ligation and puncture (CLP) group (sepsis model induced by CLP; lactate buffer was given by intragastric administration 12 hours before CLP), and Ribociclib pretreatment group (administered with 150 mg/kg Ribociclib 12 hours before CLP) according to random number table, with 5 mice in each group. Kidneys were harvested 12 hours after the operation. Pathological changes in kidney were observed by hematoxylin-eosin (HE) staining. Tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) levels in mice kidney homogenate were measured by enzyme linked immunosorbent assay (ELISA). Western Blot was used to detect the expression of cell cycle-related protein phosphorylate retinoblastoma protein (p-Rb), apoptosis-related protein Bcl-2 and Bax. (2) Mouse renal tubular epithelial (TCMK-1) cell line was used for in vitro experiment. The cells were divided into control group, Ribociclib group (treated with 5 μmol/L Ribociclib for 24 hours), lipopolysaccharide (LPS) group (treated with 200 mg/L LPS for 6 hours), Ribociclib+LPS group (replaced with the medium containing 5 μmol/L Ribociclib and 200 mg/L LPS for 6 hours after exposing with 5 μmol/L Ribociclib for 18 hours). Inflammatory cytokines in cell culture medium were detected by ELISA. The expression of p-Rb, Bcl-2 and Bax, autophagy-related proteins microtubule associated protein 1 light chain LC3b (LC3b II, LC3b I) and p62, phosphate protein kinase B (p-AKT), phosphorylated mammalian target of rapamycin (p-mTOR) were measured by Western Blot. (1) Animal experiments showed that, compared with the Sham group, the kidney tissue of mice were significantly damaged, the levels of TNF-α and IL-6 were increased, the expressions of p-Rb and Bcl-2/Bax ratio were decreased in kidney tissue in CLP group; but there was no significant difference in indexes between Ribociclib control group and Sham group. Compared with the CLP group, kidney injury in mice pretreated with Ribociclib was significantly ameliorated, the pathological score was significantly decreased (1.48±0.16 vs. 2.68±0.16, P < 0.01), the levels of TNF-α and IL-6 in kidney homogenate were significantly decreased [TNF-α (ng/g): 340.55±34.96 vs. 745.08±58.86, IL-6 (mg/g): 17.33±1.01 vs. 114.20±20.49, both P < 0.01], the expression of p-Rb was furtherly decreased (p-Rb/β-tubulin: 0.14±0.01 vs. 0.73±0.06, P < 0.01), Bcl-2/Bax ratio was increased (0.89±0.06 vs. 0.62±0.10, P < 0.01). (2) In vitro experiments showed that, compared with the control group, the releases of TNF-α and IL-6 were increased, the expression of p-Rb was decreased, the ratios of Bcl-2/Bax and LC3b II/I were decreased, the expressions of p62, p-AKT and p-mTOR were increased in LPS group; the expression of p-Rb was decreased after Ribociclib treatment in TCMK-1 cells. Compared with the LPS group, TNF-α and IL-6 were decreased [TNF-α (ng/L): 2.73±0.23 vs. 4.96±0.10, IL-6 (ng/L): 36.05±5.83 vs. 53.78±24.08, both P < 0.01], the expression of p-Rb was furtherly decreased (p-Rb/β-tubulin: 0.25±0.05 vs. 0.65±0.05, P < 0.01), the ratios of Bcl-2/Bax and LC3b II/I were increased (Bcl-2/Bax: 1.01±0.07 vs. 0.73±0.05, LC3b II/I: 2.08±0.31 vs. 1.04±0.01, both P < 0.05), the expressions of p62, p-AKT and p-mTOR were decreased (p62/β-tubulin: 0.59±0.01 vs. 1.09±0.08, p-AKT/β-tubulin: 0.61±0.03 vs. 1.20±0.06, p-mTOR/β-tubulin: 0.50±0.05 vs. 1.15±0.08, all P < 0.01) in the Ribociclib+LPS group. Ribociclib pretreatment ameliorated sepsis-induced AKI and AKT/mTOR pathway may be involved in the protective role of Ribociclib on kidney.

Trichomonas vaginalis Motility Is Blocked by Drug-Free Thermosensitive Hydrogel.

Trichomonas vaginalis motility in biological fluids plays a prominent, but understudied, role in parasite infectivity. In this study, the ability of a thermosensitive hydrogel (pluronic F127) to physically immobilize T. vaginalis was investigated. Blocking parasite motility could prevent its attachment to the mucosa, thus reducing the acquisition of the infection. The trajectory of individual parasites was monitored by multiple particle tracking. Mean square displacement, diffusivity, and velocity were calculated from x, y coordinates during time. Major results are that T. vaginalis exhibited different types of trajectories in a diluted solution composed of lactate buffer similar to "run-and-tumble" motion reported for flagellated bacteria. The fastest T. vaginalis specimen moves with a velocity of 19 μm/s. Observation of T. vaginalis movements showed that the cell body remains rigid during swimming and that the propulsive forces necessary to generate the movement are the result of flagellar beating. Parasite motility was partially slowed down using hydroxyethylcellulose hydrogel, used as a reference for the development of vaginal microbicides, while 100% of T. vaginalis were immobile in F127 hydrogel. Once completed by biological investigations on mice, this report suggests using drug-free formulation composed of F127 as a new strategy to prevent T. vaginalis attachment to the mucosa. The concept will be extended to other flagellated organisms where the motility is driven by cilia and flagella.

Is oxidative stress an issue in peritoneal dialysis?

During the last two decades, oxidative stress (OS) has emerged as a novel risk factor for a variety of adverse events, including atherosclerosis and mortality in chronic kidney disease (CKD) patients. Increased OS occurs even in early stages of the disease, progresses with deterioration of renal function and is further aggravated by hemodialysis (HD), due to the bioincompatibility of the method. Compared to HD, peritoneal dialysis (PD) is a more biocompatible dialysis modality, characterized by a significantly reduced, but still high, OS status. The culprit for OS in PD is mainly the composition of PD solutions (low pH, lactate buffer, increased osmolarity and high glucose concentration). After heat sterilization of PD solutions, formation of glucose degradation products (GDPs) and advanced glycation end-products (AGEs) trigger inflammation and enhance OS. Chronic exposure of the peritoneum to this toxic, hyperglycemic environment leads to OS-derived morphologic damage of peritoneal cells, loss of ultrafiltration capacity and decreased technique survival. Moreover, OS is linked with peritonitis, loss of residual renal function, inflammation, atherosclerosis, cardiovascular (CV) disease, and increased mortality. To ameliorate OS status in PD, a multitargeted approach is necessary that includes use of neutral pH, low GDP, low lactate and iso-ismolar PD solutions, strict glycemic control, optimal volume management and, probably supplementation with antioxidants, N-acetylcysteine being the most promising among them.

Production and characterization of hydrophilic and hydrophobic sunflower protein isolate nanofibers by electrospinning method

In the present study, sunflower protein isolate (SPI) was extracted and applied for production of nanofiber using polyvinyl alcohol (PVA) in different SPI:PVA volume ratios (0:100, 20:80, 40:60, 60:40, 80:20 and 100:0) under two voltages (18 and 23 kV) and two flow rates (0.5 and 0.75 ml/h). Nanofibers with average diameters ranging from 304 to 400 nm were achieved. SPI:PVA volume ratio of 40:60 at voltage of 18 kV and flow rate of 0.75 ml/h were determined as the optimum conditions for electrospinning which produced bead-free and uniform nanofibers with average diameter of 398 nm. The effects of heating (150 °C, for 24 h) and calcium chloride (1% W/V) solution solely and together on nanofibers hydrophobicity were also examined. SEM images after 24 h soaking in lactate buffer (pH 5.5) showed that only heat treatment could make nanofibers hydrophobic, which was proved by contact angle data. FTIR analysis showed denaturation of protein and interactions between protein and PVA after heat treatment. Moreover, DSC and TGA results indicated miscibility of protein and PVA, and higher thermal stability of heat treated sample. This study showed the potential application of soy protein as a byproduct for production of both hydrophobic and hydrophilic nanofibers.

Оптимізація профілактики септичних ускладнень у роділь з високим інфекційним ризиком

Despite the introduction of modern diagnostic technologies, prophylaxis and treatment techniques in obstetrical practice, the incidence of postpartum purulent-septic complications (PPSC) remains rather high and is an important medical and social problem, as they take one of the leading places in the structure of maternal morbidity and mortality. The objective: to improve the management of parturient womenwith a perineal birth injury in anamnesis, as part of an effective prevention of purulent-septic complications of puerperium. Materials and methods. The study included 77parturient women. Main and comparative groups were formed by women with a violation of the integrity of the perineum in the previous labor and with a high risk of developing infectious complications in puerperium. Women of the main group (n = 24) during each vaginal examination in labor (and an additional injection in 15-30 minutes after the rupture of the membranes) and twice a dayat a dose of 5 ml for 5 days postpartum, an antiseptic agent in the form of a vaginal gel, which consists of: 0.02% decamethoxin (antiseptic component), 0.5% hyaluronic acid (regenerating component) and lactate buffer (regulatory component). The comparison group included 27 women, without using vaginal gel in laborand using traditional wound treatment techniques in the postpartum period. The control group consisted of 26 women with uncomplicated somatic status, physiological course of pregnancy and labor. The evaluation of the effectiveness of the prescribed treatment was based on subjective symptoms (pain, discomfort, burning in the region of the perineal sutures), clinical data (swelling, hyperemia, nature of suturing healing), generally accepted indicators in dynamics (bacterioscopy of vaginal contents, pH-metry of the vaginal environment). Results. At the background of the use of three-component vaginal gel in the main group, the level of injury of soft tissues of the birth canal in these deliveries was lower by 19.9% than in the comparison group, prevalence of the 1st degreeperineumruptures, decreased the need for repeated episio- and perineotomy, which reduced the duration stay at hospital and improved postpartum rehabilitation in relation to the comparison group. On the third day of puerperium, hyperemia and edema of the wound area in women of the main group were observed almost three times less compared with the comparison group. On the fifth day of the puerperium in the main group the complaints were insignificant and appeared on the average 5 times less often, the healing was by the primary tension without infectious complications. The use of vaginal gel reduced the number of leukocytes in wound secretions by shortening the time of wound epithelization (1.5 times faster than in the parous from the comparison group). On the fifth day of using vaginal gel, 2/3 of the patients observed normalization of the vaginal microflora, the restoration of pH was observed. The results indicate the benefits of early onset of prophylactic measures and high effectiveness of topical antiseptic therapy in women with high infectious risk. Conclusions.In order to prevent antibiotic resistance tactics of prevention of PPSC in the group of high-risk septic complications provides one of the elements of anintegrated approach to use local antiseptics. Inclusion of the latter into a complex of prophylactic and treatment measures in the management of a high-riskwomen in puerperium contributes to the reduction of traumatic and infectious complications and provides more favorable course of labor and the postpartum period. Key words: labor traumatism, postpartum purulent-septic complications, local antiseptic.

Effects of Fluoride on Two Chemical Models of Enamel Demineralization.

This study evaluated the effects of fluoride on subsurface enamel demineralization induced by two commonly used chemical models. Forty-eight enamel blocks were demineralized at pH = 5.0 by an acetate buffer (Group 1), a lactate buffer (Group 2), an acetate buffer with 0.02 ppm fluoride (Group 3) and a lactate buffer with 0.02 ppm fluoride (Group 4) at 25 °C for 3 weeks. The surface destruction percentage (SDP), mineral loss and lesion depth of the blocks were studied using micro-computed tomography. An elemental analysis of the enamel surface was evaluated using an energy-dispersive X-ray spectroscopy. Surface micro-hardness was determined by the Knoop Hardness Test. The mean lesion depth of Groups 1 through 4 were 134.1 ± 27.2 μm, 96.1 ± 16.5 μm, 97.5 ± 22.4 μm and 91.1 ± 16.2 μm, respectively (p < 0.001; group 1 > 2, 3 > 4). The SDPs of groups 1 through 4 were 7.8 ± 8.93%, 0.71 ± 1.6%, 0.36 ± 1.70% and 1.36 ± 2.94% (p < 0.001; group 1 > 2, 3, 4). The fluoride in mean weight percentages of groups 1 through 4 were 1.12 ± 0.24%, 1.10 ± 0.20%, 1.45 ± 0.40% and 1.51 ± 0.51%, respectively (p < 0.001; group 3, 4 > 1, 2). The mean Knoop hardness values of groups 1 through 4 were 27.5 ± 13.3, 39.7 ± 19.3, 73.6 ± 44.2 and 91.0 ± 57.2, respectively (p < 0.001; group 4 > 3 > 2 > 1). The chemical model using an acetate buffer solution created significantly deeper zones of subsurface demineralization on enamel than the lactate buffer solution. An acetate buffer may damage the enamel surface, but the surface damage can be prevented by adding fluoride.

Improved selectivity and cytotoxic effects of irinotecan via liposomal delivery: A comparative study on Hs68 and HeLa cells

Irinotecan (CPT-11) is an effective chemotherapeutic agent widely used to treat different cancers. Otherwise, the liposomal delivery of anti-tumor agents has been shown to be a promising strategy. The aim of this study has been to analyze the effect of liposomal CPT-11 (CPT-11lip) on two human cell lines (Hs68 and HeLa) to establish the suitability of this CPT-11 nanocarrier. We have demonstrated the highest uptake of CPT-11lip in comparison with that of CPT-11sol, in lactate buffer, and that CPT-11lip was internalized in the cells through an endocytic process whereas CPT-11sol does so by passive diffusion. CPT-11lip was not cytotoxic to normal fibroblast Hs68 cells, but induced a massive apoptosis accompanied by cell senescence in HeLa cells. CPT-11lip treatment modified the morphology of HeLa cells, induced different cell cycle alterations and accumulated into lysosomes in both cell lines. In particular, CPT-11lip treatment showed that surviving HeLa cells remained in a state of senescence whereas only a temporal growth arrest was induced in Hs68 cells. Results of RT-PCR indicated that the different responses in Hs68 (survival) and HeLa cells (apoptotic death), seemed to be induced by a p53- and p53- independent mechanism, respectively. An analysis of DNA damage also determined that released CPT-11 from liposomes was able to reach the nucleus and exert a genotoxic effect in both cell lines, which was repaired in Hs68 but not in HeLa cells. All results indicate that phospholipid-cholesterol liposomes possess optimum properties for CPT-11 delivery, being biocompatible and selectively cytotoxic against HeLa tumorigenic cells.

Recovery after PILP remineralization of dentin lesions created with two cariogenic acids

ObjectivesAcetate and lactate are important cariogenic acids produced by oral bacteria. They produced different residual dentin structures in artificial lesions of similar depth. We evaluated if such lesions responded in the same way to a polymer-induced-liquid-precursor (PILP) remineralization. DesignDentin blocks obtained from human third molars, divided into 6 groups (n=3). Blocks were demineralized with acetate (66h) or lactate (168h) buffer at pH 5.0 to create 140μm target lesion depths. A-DEM and L-DEM groups received no remineralization. Other groups were remineralized for 14days. 100μg/mL polyaspartate was added into the remineralizing buffer for A-PIL and L-PIL, whereas A-CAP and L-CAP were treated with the same solution but without polyaspartate. Cross-sectioned blocks were examined for shrinkage and AFM-topography. Line profiles of reduced elastic modulus (Er) were obtained by AFM-based nanoindentation across the lesion. Ultrastructures were examined with TEM. ResultsA-PIL and L-PIL recovered in shrinkage to the original height of the dentin and it appeared normal with tubules, with increases in Er at both outer flat and inner sloped zones. At the sloped zone, acetate lesions lost more Er but recovery rate after PILP was not statistically different from lactate lesions. A-CAP and L-CAP showed surface precipitates, significantly less recovery in shrinkage or Er as compared to PILP groups. TEM-ultrastructure of PILP groups showed similar structural and mineral components in the sloped zone for lesions produced by either acid. ConclusionsThe PILP process provided significant recovery of both structure and mechanical properties for artificial lesions produced with acetate or lactate.

A Comparative Study of Drug Delivery Methods Targeted to the Mouse Inner Ear: Bullostomy &lt;em&gt;Versus&lt;/em&gt; Transtympanic Injection

We present two minimally invasive microsurgical techniques in rodents for specific drug delivery into the middle ear so that it may reach the inner ear. The first procedure consists of perforation of the tympanic bulla, termed bullostomy; the second one is a transtympanic injection. Both emulate human clinical intratympanic procedures. Chitosan-glycerophosphate (CGP) and Ringer´s Lactate buffer (RL) were used as biocompatible vehicles for local drug delivery. CGP is a nontoxic biodegradable polymer widely used in pharmaceutical applications. It is a viscous liquid at RT but it congeals to a semi solid phase at body temperature. RL is an isotonic solution used for intravenous administrations in humans. A small volume of this vehicle is precisely placed on the Round Window (RW) niche by means of a bullostomy. A transtympanic injection fills the middle ear and allows less control but broader access to the inner ear. The safety profiles of both techniques were studied and compared by using functional and morphological tests. Hearing was evaluated by registering the Auditory Brainstem Response (ABR) before and several times after microsurgery. The cytoarchitecture and preservation level of cochlear structures were studied by conventional histological techniques in paraformaldehyde-fixed and decalcified cochlear samples. In parallel, unfixed cochlear samples were taken and immediately frozen to analyze gene expression profiles of inflammatory markers by quantitative Reverse Transcriptase Polymerase Chain Reaction (qRT-PCR). Both procedures are suitable as drug delivery methods into the mouse middle ear, although transtympanic injection proved to be less invasive compared to bullostomy.

A new peritoneal dialysis fluid for Japanese patients: a randomized non-inferiority clinical trial of safety and efficacy

BackgroundWe report here two new peritoneal dialysis fluids (PDFs) for Japan [BLR 250, BLR 350 (Baxter Limited, Japan)]. The PDFs use two-chamber systems, and have bicarbonate and lactate buffer to a total of 35 mmol/L. In separate trials, the new PDFs were compared to two “standard” systems [PD-4, PD-2 (Baxter Limited, Japan)]. The trials aimed to demonstrate non-inferiority of peritoneal creatinine clearance (pCcr), peritoneal urea clearance (pCurea) and ultrafiltration volume (UF), and compare acid–base and electrolyte balance.MethodsWe performed randomized, multicenter, parallel group, controlled, open-label clinical trials in stable continuous ambulatory peritoneal dialysis (CAPD) patients. The primary endpoints were pCcr and UF. The secondary endpoints were serum bicarbonate and peritoneal urea clearance. The active phase was 8 weeks. These trials were performed as non-inferiority studies, with the lower limit of non-inferiority for pCcr and UF set at 3.2 L/week/1.73 m2 and 0.12 L/day, respectively.Results108 patients (28 centers) and 103 patients (29 centers) took part in the two trials. Groups were well balanced at baseline. The investigative PDFs were non-inferior to the “standard” ones in terms of primary endpoints, comparable in terms of pCurea, and superior in terms acid–base balance, especially correcting those with over-alkalinization at baseline.ConclusionsWe demonstrated fundamental functionality of two new PDFs and showed superior acid–base balance. Given the propensity of Japanese CAPD patients for alkalosis, it is important to avoid metabolic alkalosis which is associated with increased cardiovascular mortality risk and accelerated vascular calcification. The new PDFs are important progress of CAPD treatment for Japanese patients.

Pharmaceutical development of novel lactate-based 6-fluoro-l-DOPA formulations

6-[18F]fluoro-l-dihydroxyphenylalanine (18F–DOPA) is a diagnostic positron emission tomography (PET) agent, which has been used for decades in imaging the loss of dopaminergic neurons in Parkinson's disease, and more recently to detect, stage and restage neuroendocrine tumors (NETs) and to search for recurrence of viable glioma tissue. The commercially available 18F–DOPA PET radiopharmaceutical for diagnostic use in European Union countries, is formulated in an aqueous solution of acetic acid (1.05mg/mL) and has the disadvantages that, immediately before injection, the pH must be adjusted to 4.0–5.0 by the addition of a sterile solution of sodium bicarbonate (84mg/mL) causing a light and transient burning sensation at the injection site. To overcome these drawbacks, preformulation studies were accomplished to confirm that F-DOPA degradation was affected by pH. Hence, two formulations of F-DOPA, namely ND1 and ND2, were prepared maintaining the pH=5.0 using 1mM l-(+)-lactate buffer, excluding oxygen, and incorporating in the formula the chelating agent Na2EDTA (1mM). F-DOPA oxygen exposure, the presence of free metal cations in formulation and high pH values seem to promote F-DOPA degradation. The resulting formulations proved to guarantee the chemical stability of F-DOPA in solution at pH5.0, value also compatible with the direct infusion. In vitro cell viability tests on mouse skeletal muscle fibers, renal tsa201 and neuronal SH-SY5Y cell lines, and in vivo studies in rats reported elsewhere, showed cell tolerability to the new F-DOPA formulations providing the basis for their further in vivo evaluation.

CD101, a novel echinocandin with exceptional stability properties and enhanced aqueous solubility

The echinocandins are an important class of antifungal agents. However, instability and, in some cases, lack of solubility have restricted their use to situations in which daily infusions are acceptable. CD101 is a novel echinocandin in development for topical and weekly i.v. administration that exhibits prolonged stability in plasma and aqueous solutions up to 40 °C. After incubation for 44 h in rat, dog, monkey and human plasma at 37 °C, the percent of CD101 remaining (91%, 79%, 94% and 93%, respectively) was consistently greater than that of anidulafungin (7%, 15%, 14% and 7%, respectively). Similarly, after incubation in phosphate-buffered saline at 37 °C, the CD101 remaining (96%) was greater than that of anidulafungin (42%). CD101 exhibited <2% degradation after long-term storage at 40 °C as a lyophilized powder (9 months) and at room temperature in 5% dextrose (15 months), 0.9% saline (12 months) and sterile water (18 months). Degradation was <7% at 40 °C in acetate and lactate buffers (6 to 9 months at pH 4.5–5.5). The chemical stability and solubility of CD101 contribute to dosing, pharmacokinetic, formulation and safety advantages over other echinocandins and should expand utility beyond daily i.v. therapy.

The effect of cinnamon, oregano and thyme essential oils in marinade on the microbial shelf life of fish and meat products

Fresh and minimally processed fish and meat are easy targets for microbial spoilage. The demand for natural alternatives to synthetic additives increases. In this study essential oil (EOs) in marinades were used on fish and meat and the effect on the microbial growth during storage was assessed. EOs from Oreganum compactum (oregano), Cinnamomum zeylanicum (cinnamon), and Thymus zygis ct. Thymol (thyme) were chosen. The marinade was composed of water, Na-lactate/lactic acid buffer (2 w/w %), NaCl (10 w/w %), and EO emulsified with Tween 80 and with a pH of 4.5. The necessary Tween 80 to emulsify the EOs in the marinade depended on the EO type and was increased more than tenfold by the NaCl and lactate buffer. The treatment consisted of immersion of meat (pork filet, pork bacon, chicken filets, chicken skin), salmon or scampi for 2 min in marinade solution. The samples were stored at 4 °C in air. Samples were analyzed for microbial counts (dependent on matrix: total coliforms, Escherichia coli, lactic acid bacteria, yeasts and molds, total aerobic psychrotrophs). Growth inhibition was achieved with some EO + marinade treatments but marinade itself did not slow down the microbial growth. Most notably, the growth of yeasts and molds was inhibited by immersion of all food matrices in 1 w/w % cinnamon EO. Use of (1 w/w % for all EO) cinnamon EO (+marinade) led to microbial shelf life increase of all matrices (except the chicken matrices as the end of the shelf life was not reached during the experimental duration), oregano EO to shelf life increase of pork filet and salmon, and thyme EO of pork filet and scampi. Sensorial analysis on pork filet and salmon showed that immersion in 3% EO (resulting in 0.09 g EO/100 g pork filet and 0.05 g EO/100 g salmon) resulted in an acceptable odor after 24 h of storage. The results in this study show that the sensorial properties of the meat/fish are inevitably affected when the necessary EO concentrations to extend the microbial shelf life are applied.