Ml Of Phosphate Research Articles

386 Pregnancy supportive metabolites are enhanced in Brahman cows on day 15 of the estrous cycle

Abstract Bos indicus-influenced cattle are more resilient to pregnancy loss while receiving a restricted nutrient diet compared with Bos taurus cattle, but the mechanism behind this resilience is still unknown. To undercover this mechanism, the present study was designed with Angus (Bos taurus), Brangus (Bos indicus-influenced), and Brahman (Bos indicus) cows randomly assigned (d -30) to either a 100% maintenance diet (n = 22), or a 70% maintenance diet (n = 23) for 45 d. All cows were submitted to a 5-d CO-Synch + CIDR synchronization protocol on d -7 with ovulation induction representing d 0. A cervically navigated foley catheter was placed in the uterine horn ipsilateral to the corpus luteum on d 15 of the estrous cycle. Approximately 50 mL of phosphate buffered saline was infused into the uterus then recovered for uterine flush analysis. Recovered uterine fluid was subjected to metabolomic analysis by ultra-high performance liquid chromatography - high resolution mass spectrometry. A significant breed by metabolite interaction occurred (P < 0.001). A treatment by metabolite interaction was also observed (P = 0.015) in which maintenance and restricted cows clustered within their respective treatment when plotted in an orthogonal PCA graph. Of the 101 metabolites analyzed, 7 metabolites (aspartate, glutamate, hydroxyphenylacetate, taurine, uric acid, uridine, and xanthine) differed (P < 0.05) among breeds. Brahman cows had the greatest value of all 7 metabolites (P < 0.05) except hydroxyphenylacetate (P > 0.10). Angus and Brangus metabolomic values were similar for aspartate, taurine, and uridine (P > 0.10) but differed for glutamate, hydroxyphenylacetate, uric acid, and xanthine (P < 0.05). Two metabolites that were greatest in Brahman cows (aspartate and glutamate) contribute significantly to the Kreb Cycle, indicating that Brahman cows have the ability to maintain proper amounts of substrates for energy production compared with Angus cows. Both glutamate and aspartate also aid in the removal of toxic ammonium as they are substrates for a-ketoglutarate and oxaloacetate, respectively, which both consume ammonium in their respective reactions. Furthermore, uric acid (which has a precursor of xanthine) was also greatest in Brahman cows and is a potent antioxidant with strong capabilities of scattering reactive oxygen species. Finally, aspartate also aids in the detoxification of ammonium within the urea cycle. Taken together, these four metabolites (aspartate, glutamate, uric acid, and xanthine) are working together but separately with the overall goal to provide more functional energy, while removing unnecessary toxins which may be two mechanisms in how Bos indicus-influenced cows are better able to sustain optimal reproductive efficiency than Angus cows.

Effects of rumen-protected niacin on inflammatory response to repeated intramammary lipopolysaccharide challenges

Nutritional strategies that improve an animal's resilience to various challenges may improve animal health and welfare. One such nutrient is niacin which has reduced inflammation in mice, humans, and swine; however, niacin's anti-inflammatory effects have not been investigated in cattle. Our objective was to determine whether rumen-protected niacin (RPN) alters lactating dairy cows' inflammatory response to intramammary lipopolysaccharide (LPS) challenges, whether RPN resulted in any carry-over effects, and whether repeated LPS challenges result in signs of immune tolerance or innate immune training. Twenty healthy, late-lactation Holstein cows (232 ± 65 d in milk; 39 ± 5.8 kg/d of milk) were enrolled in a randomized complete block experiment which lasted 70 d. Cows received 26 g/d of RPN or no top-dress (CON) for the first 42 d of the experiment. During the final milking of d 27 and 55, cows were challenged in their rear-right mammary gland (RR) with 100 µg of LPS suspended in 5 mL of phosphate buffered saline. Milk yield, milk conductivity, and feed intake were measured daily. Milk composition was measured on d 14, 23, 24, 30, 37, 45, and 52. Blood samples were collected at 0, 8, 12, 24, 48, 72, 96, and 120 h after each LPS challenge, whereas RR quarter milk samples were collected at 0, 8, 16, 24, 48, 72, 96, 120, 144, and 168 h after each LPS challenge. Body temperature was measured continuously during each challenge with an intravaginal thermometer. Linear mixed models with repeated measures were used to analyze the results. Before LPS challenge, RPN did not affect feed intake or milk production, but it reduced SCS (1.24 ± 0.41 vs. 0.05 ± 0.45). After challenge, RPN did not affect feed intake, milk production, milk composition, SCS, body temperature, plasma glucose, or plasma insulin concentrations. Our results suggest RPN reduced peak plasma haptoglobin and lipopolysaccharide binding protein (LBP) during the 1st LPS challenge. Plasma haptoglobin tended to be less after the 2nd challenge for cows previously supplemented RPN while LBP was similar for each treatment group after the 2nd challenge. The 2nd LPS challenge resulted in decreased plasma haptoglobin compared with the 1st LPS challenge, suggestive of tolerance but it also induced a greater peak SCS than the 1st LPS challenge. Our results suggest that repeated LPS challenges promote a systemic tolerance but heightened local response to LPS-induced mastitis. Feeding RPN reduced SCS before challenge and reduced plasma acute phase proteins after challenge suggesting that RPN may reduce systemic inflammation without altering the local inflammatory responses.

In vitro and in vivo antiviral effects of CLEVir-X against porcine reproductive and respiratory syndrome virus

The aim of this study was to investigate the in vitro and in vivo antiviral effects of CLEVir-X, against porcine reproductive and respiratory syndrome virus (PRRSV). CLEVir-X is a nucleoside analogue and a dialdehyde form of xanthosine. CLEVir-X demonstrated antiviral action during the in vitro portion of this experiment with its inosine monophosphate dehydrogenase (IMPDH) inhibition against PRRSV. The anti-PRRSV effect of CLEVir-X was recovered through supplementation with guanosine. This suggests that PRRSV replication may be regulated through IMPDH and its guanosine biosynthetic pathway. CLEVir-X treatment in cultures resulted in mutation frequency increase of up to 7.8-fold within the viral genomes (e.g. ORF6) compared to their parallel, untreated cultures. The incorporation of CLEVir-X into the viral genome causes lethal mutagenesis and subsequent decrease in specific infectivity. During the in vivo antiviral experiment, 21-day-old pigs began oral administration of 5 mL of phosphate buffered saline containing CLEVir-X (with purity of 68 % and dosage of 40 mg/kg body weight). This treatment was provided twice daily at 9:00AM and 5:00PM for 14 days. Pigs were simultaneously intranasally inoculated with PRRSV at the beginning of CLEVir-X treatment (21 days of age). Several beneficial effects from the oral administration of CLEVir-X were observed including reduction of body temperature, alleviation of respiratory clinical signs, decreased PRRSV load in both blood and lung tissues, and mitigation of lung interstitial pneumonia lesions. The results of the present study demonstrated that CLEVir-X has mutagenic and nonmutagenic modes of antiviral action against PRRSV based on both in vitro and in vivo antiviral experiments.

Effect of ribose incubation on physical, chemical, and mechanical properties of human cortical bone

Raman spectroscopy (RS) is sensitive to the accumulation of advanced glycation end-products (AGEs), and it measures matrix-sensitive properties that correlate with the fracture toughness of human cortical bone. However, it is unclear whether sugar-mediated accumulation of AGEs affects the fracture toughness of human cortical bone in a manner that is consistent with the negative correlations between amide I sub-peak ratios and fracture toughness. Upon machining 64 single-edge notched beam (SENB) specimens from cadaveric femurs (8 male and 7 female donors between 46 years and 61 years of age), pairs of SENB specimens were incubated in 15 mL of phosphate buffered saline with or without 0.1 M ribose for 4 weeks at 37 °C. After acquiring 10 Raman spectra per bone specimen (n = 32 per incubation group), paired SENB specimens were loaded in three-point bending at a quasi-static or a high loading rate approximating 10−4 s−1 or 10−2 s−1, respectively (n = 16 per incubation group per loading rate). While 2 amide I sub-peak ratios, I1670/I1640 and I1670/I1610, decreased by 3–5% with a 100% increase in AGE content, as confirmed by fluorescence measurements, the ribose incubation to accumulate AGEs in bone did not affect linear elastic (KIc) nor non-linear elastic (KJc) measurements of bone's ability to resist crack growth. Moreover, AGE accumulation did not affect the change in these properties when the loading rate changed. Increasing the loading rate increased KIc but decreased KJc. Ribose incubation did not affect mineral-related RS properties such as mineral-to-matrix ratios, Type B carbonate substitutions, and crystallinity. It did however increase the thermal stability of demineralized bone (differential scanning calorimetry), without affecting the network connectivity of the organic matrix (i.e., maximum slope during a hydrothermal isometric tension test of demineralized bone). In conclusion, RS is sensitive to AGE accumulation via the amide I band (plus the hydroxyproline-to-proline ratio), but the increase in AGE content due to ribose incubation was not sufficient to affect the fracture toughness of human cortical bone.

Quantitative assessment of transforming growth factor-β1 release from dentin matrix upon conditioning with ethylene diamine tetra-acetate, doxycycline hydrochloride, and propolis: An in vitro study.

Transforming growth factor-beta 1 (TGF-β1) is a key morphogen in regenerative endodontics that plays a central role in regulating cellular functions. Various chelating agents have been shown to release this growth factor upon conditioning. The objective of the study was to evaluate TGF-β1 release from the dentin matrix upon conditioning with ethylene diamine tetra-acetate (EDTA), doxycycline hydrochloride, and propolis. Forty-two human 3rd molar teeth were collected and coronal portion of the teeth was sectioned to obtain dentin blocks with dimensions 2 mm × 2 mm × 2 mm. The blocks were then randomly divided into three groups depending on the conditioning agent used; Group 1: 17% EDTA, Group 2: doxycycline hydrochloride (100 mg/mL), and Group 3: propolis (250 μg/mL). Conditioned blocks were placed in 0.5 mL of phosphate buffered saline and incubated for 1 week for quantification. Highest TGF-β1 release was noted for propolis (0.21 ng/mL), followed by doxycycline hydrochloride (0.18 ng/mL) and 17% EDTA (0.14 ng/mL). Doxycycline hydrochloride and propolis significantly enhanced the release of TGF-β1 from the dentin matrix compared to EDTA (P < 0.05). No significant difference was observed between doxycycline hydrochloride and propolis (P > 0.05). Doxycycline and propolis can be used as effective alternatives to EDTA during regenerative endodontic procedures.

Serum cardiac troponin i and lactate as prognostic markers of Canine African Trypanosomiasis

The study was aimed at understanding the nature and pattern of serum lactate, cardiac troponin I changes associated with acute Trypanosoma brucei infection of dogs. It also seeks to investigate the usefulness of these biomarkers in monitoring disease progression and predicting mortality. Twenty healthy adult dogs of both sexes were used for the study. All the dogs were intra-peritoneally inoculated with 1ml of phosphate buffered saline diluted blood containing 1x106 of Lafenwa strain of T. brucei. The serum lactate, cardiac troponin I, potassium, sodium, chloride and bicarbonate were monitored before and at 16 and 24 days after infection. There was a progressive increase in serum values of lactate, cardiac troponin I and potassium at various days after infection. A significant association was found between lactate and heart rate, chloride and heart rate, potassium and cardiac troponin I. This result has shown that there could be myocardial damage due to hypoxia of anemia and hypo-perfusion in canine African trypanosomiasis. The progressive increase in serum lactate and cardiac troponin I could help in predicting severity and outcome of Canine African Trypanosomiasis. The Lactic acidosis may increase ventilation drive and consequently the heart rates of infected dogs.

A Three-Dimensional Bioprinted Copolymer Scaffold with Biocompatibility and Structural Integrity for Potential Tissue Regeneration Applications.

The present study was to investigate the rheological property, printability, and cell viability of alginate–gelatin composed hydrogels as a potential cell-laden bioink for three-dimensional (3D) bioprinting applications. The 2 g of sodium alginate dissolved in 50 mL of phosphate buffered saline solution was mixed with different concentrations (1% (0.5 g), 2% (1 g), 3% (1.5 g), and 4% (2 g)) of gelatin, denoted as GBH-1, GBH-2, GBH-3, and GBH-4, respectively. The properties of the investigated hydrogels were characterized by contact angle goniometer, rheometer, and bioprinter. In addition, the hydrogel with a proper concentration was adopted as a cell-laden bioink to conduct cell viability testing (before and after bioprinting) using Live/Dead assay and immunofluorescence staining with a human corneal fibroblast cell line. The analytical results indicated that the GBH-2 hydrogel exhibited the lowest loss rate of contact angle (28%) and similar rheological performance as compared with other investigated hydrogels and the control group. Printability results also showed that the average wire diameter of the GBH-2 bioink (0.84 ± 0.02 mm (*** p < 0.001)) post-printing was similar to that of the control group (0.79 ± 0.05 mm). Moreover, a cell scaffold could be fabricated from the GBH-2 bioink and retained its shape integrity for 24 h post-printing. For bioprinting evaluation, it demonstrated that the GBH-2 bioink possessed well viability (>70%) of the human corneal fibroblast cell after seven days of printing under an ideal printing parameter combination (0.4 mm of inner diameter needle, 0.8 bar of printing pressure, and 25 °C of printing temperature). Therefore, the present study suggests that the GBH-2 hydrogel could be developed as a potential cell-laden bioink to print a cell scaffold with biocompatibility and structural integrity for soft tissues such as skin, cornea, nerve, and blood vessel regeneration applications.

Comparative evaluation of the efficacy of aloe vera juice, amla juice, and milk as storage media in maintaining the periodontal ligament cell viability

Background: Tooth avulsion implies total displacement of the tooth out of its socket. Many storage media such as milk, saliva, Hank’s Balanced Salt Solution (HBSS), propolis, Viaspan, have been studied as storage medias for preserving PDL cell viability. Amongst these, HBSS has been proposed as the storage medium of choice for treatment of avulsed teeth by the American Associations of Endodontists. However, the major disadvantage is that it is not easily available at places where these traumatic injuries occur. Aim: To evaluate and compare the efficacy of aloe vera juice, amla juice, milk and water in maintaining the periodontal ligament cell viability of avulsed teeth. Study Design: Forty premolars extracted for orthodontic therapeutic purposes were randomly and equally divided into four groups based on storage media used [Group I: aloe vera juice; Group II: amla juice; Group III: milk; Group IV: water. Following extractions, the teeth were dried for 30 mins and were placed in one of the four different storage media for 45 minutes, following which the scrapings of the PDL from these teeth were collected in Falcon tubes containing collagenase enzyme in 2.5 mL of phosphate buffered saline.

Comparative evaluation of periodontal ligament cell viability of permanent teeth in five different storage media followed by simulated avulsion injury

Aim: To evaluate and compare the viability of periodontal ligament cells of avulsed teeth in five different storage media followed by simulated avulsion injury. Settings and Design: Seventy-five premolars extracted for orthodontic therapeutic purposes were randomly and equally ivided into five groups based on storage media used [A: HBSS (control), B: Milk (experimental), C: Aloe Vera (experimental), D: Egg white (experimental), E: Coconut water (experimental)].Methods and Material: Following extractions, the teeth were placed in one of the five different storage media for 60 minutes, following which the scrapings of the PDL were collected in Falcon tubes which already contained collagenase enzyme in 2.5 mL of Phosphate buffered saline. The tubes were subsequently incubated and centrifuged. Then acquired PDL cells were stained with Trypan Blue dye and were counted under an optical microscope. Statistical Analysis Used: Results were subjected to statistical analysis using ANOVA test and Post Hoc Tukey test. p-value &lt; 0.05 is considered to be significant. Results: HBSS showed the highest percentage of viable cells (80.14%), followed by Egg white (74.01%) and Aloe Vera (73.68%). Milk and Coconut water showed the least percent of viable cells 63.20%, 63.58% respectively.

Uptake and release of polyhexamethylene biguanide (PHMB) from hydrogel and silicone hydrogel contact lenses using a radiolabel methodology

PurposeThe purpose of this study was to evaluate the uptake and release of radiolabelled polyhexamethylene biguanide (PHMB) on reusable daily wear contact lenses (CLs) over 7 days. MethodsThree silicone hydrogel (SH) contact lens materials (lotrafilcon B, balafilcon A, senofilcon A) and two conventional hydrogel (CH) materials (etafilcon A, omafilcon A) were examined. In experiment 1 (1-day study), CLs were soaked in 2 mL of phosphate buffered solution (PBS) containing radiolabelled 14C PHMB (1 µg/mL) for 8 h. The release kinetics of 14C PHMB from the CLs was measured at t = 0.25, 0.5, 1, 2, 4, 8, and 24 h in fresh 2 mL PBS. In experiment 2 (7-day study), the CLs were soaked in the 14C PHMB (1 µg/mL) solution for 8 h followed by a 16-hour release in 2 mL PBS. The lens cycle was repeated daily for 7 days. After both experiments, the residual amount of PHMB remaining within the lenses was extracted to determine the total uptake of PHMB. ResultsIn experiment 1, the total uptake of PHMB for etafilcon A was significantly greater than senofilcon A (p = 0.01). There were no significant differences in total uptake of PHMB between other lens materials (p > 0.05). Etafilcon A released more PHMB compared to all other lens types over a 24-hr period (p < 0.001). In experiment 2, all CL materials continued to sorb more PHMB over time (p < 0.001). By day 7, the amount of PHMB sorbed by etafilcon A was significantly greater than senofilcon A (p = 0.02). After day 2, the CH materials released significantly more PHMB than the SH materials (p < 0.01). ConclusionThe CL materials continued to sorb PHMB with no signs of saturation after 7 days. All lens materials released a consistent amount of PHMB each day. Radioactive labelling provides a sensitive method of assessing the uptake and release of PHMB from CL materials.

Human Treated Dentin Matrix Hydrogel as a Drug Delivery Scaffold for Regenerative Endodontics.

The objective of the current study was to develop a human treated dentin matrix (hTDM) hydrogel for use as a scaffold to allow the controlled release of an antimicrobial agent for regenerative endodontics. Human extracted teeth were treated via chemical demineralization using ethylene diamine tetra-acetic acid solution to produce hTDM powder. Fourier transform infrared spectroscopy (FTIR) was conducted to determine the functional groups of hTDM, scanning electron microscopy (SEM) was used to define the morphology/particle size of hTDM, and energy dispersive X-ray analysis was performed to identify the superficial apatite groups. Prepared hTDM powder was added to the amoxicillin-clavulanate mixture with a mass ratio of 1:1. Then, the combination was dripped into a 5% (w/v) calcium chloride solution. Antibiotic release profiles were evaluated for 14 days via high performance liquid chromatography (HPLC). Hydrogel degradation properties were studied for 14 days using 10 mL of phosphate buffered saline (PBS). Encapsulation efficiency was determined by HPLC, while minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of amoxicillin-clavulanate were determined against Enterococcus faecalis (E. faecalis). The antibacterial activity of amoxicillin-clavulanate against E. faecalis was investigated for 14 days via agar diffusion test. Statistical analysis was performed with the Shapiro-Wilk test (P=0.05). hTDM showed statistically a significant difference for percentage weight change (P=0.1). The encapsulation efficiencies for hTDM hydrogel with antibiotic and hydrogel with antibiotic was 96.08%±0.02 and 94.62%±0.11, respectively. MIC and MBC values of amoxicillin-clavulanate against E. faecalis were 2.4 µg/mL and 9.6 µg/mL, respectively. The antibacterial activity of antibiotic loaded hTDM hydrogels was significantly greater than loaded hydrogels alone by 31% after 4 days and 100% at 14 days, respectively (P≤0.001). This in vitro study showed antibiotic-loaded injectable hTDM hydrogel could be an alternative system to transfer antibiotic-based intracanal medicaments for use in regenerative endodontics.

7 - Method for Detecting Calcium Phosphate Mineralization on Dental Composites

The purpose of the study is to develop a procedure for determining the in-vitro calcium phosphate mineralization potential of dental composites. A dental material containing Methacrylate-Functionalized Calcium Phosphate (MCP), was studied to determine a procedure to identify and quantify its capacity to create calcium phosphate mineralization. This study used Activa Presto, a dental composite containing 3 wt.% MCP (3MCP), and a control with the same chemical formulation as Presto, but without MCP (0MCP). Using ISO 23317:2007 as a guideline, six cylindrical samples were created with an approximate diameter of 9.5 mm and height of 4 mm. Each sample was fabricated with an embedded nylon thread, which was used to suspend each sample in 25 mL of phosphate buffered saline (PBS) in individual plastic bottles. The samples were stored in a 37 C incubator for time periods of one, two and four weeks, and the PBS solution was replaced twice weekly. Once the designated time period elapsed, the samples were removed from the solution, placed back in the 37 C incubator and desiccated for scanning electron microscopy (SEM) with energy dispersive spectroscopy (EDS) evaluation. The SEM of the 0MCP sample was uniform throughout. At 3000x magnification the surface was granular and showed no sign of crystal formation. All the SEMs of the 3MCP samples had areas of crystal formation and areas where crystals had not yet formed (nucleation areas). The nucleation areas on the 3MCP sample looked granular, like the control, but EDS revealed a different surface composition. The EDS shows that the 0MCP sample had minimal calcium and phosphorus, elements essential for mineralization. This sample had a high amount of silicon, which comes from the silica inherent in dental composites. The nucleation area of the 3MCP sample had over five times the amount of calcium and phosphorus compared to the control, which indicates that there is an increase in potential for mineralization. The crystal area of the 3MCP sample shows about three times the amount of calcium and phosphorus when compared to the nucleation area, these values confirm the surface has been mineralized. Additionally, silicon was not detectable in this area, which suggests that the crystals are dense, and completely cover the underlying silica in the composite. The results of this study confirm that this procedure is suitable to determine the in-vitro mineralization potential of dental composites.Download : Download high-res image (307KB)Download : Download full-size image

Prostaglandin E2 induces ovulation in prepubertal mice

The objective of this study was to determine the ability of prostaglandin E2 (PGE2) to induce ovulation and expression of PGE2 receptor (EP2 and EP4) and COX genes (COX-1 and COX-2) in the ovary and pituitary of prepubertal mice. The positive control consisted of the application of 5 μg of gonadotropin-releasing hormone (GnRH, n = 29); the negative control applied 0.5 mL of phosphate buffered saline (PBS, n=31); the treatment tested the application of 250 μg of PGE2 (n = 29), making a total of 89 prepubertal mice (BALB/c). Mice were euthanized 14 to 15 h after treatments to detect ovulation and tissue collection. A Chi-square test was used to compare the proportion of animals ovulating. Gene expressions and number of ovulation were analyzed by one-way ANOVA and Tukey’s test was used to compare means among groups. A greater proportion of mice (P &lt; 0.001) ovulated after receiving GnRH (89.7%, 26/29) compared to PGE2 group (58.6%, 17/29). However, the proportion was higher compared to those treated with PBS (0%, 0/31). Ep2 gene expression in the pituitary was &gt; two-fold higher (P &lt; 0.05) in the PGE2 group compared to the PBS and GnRH groups. Further, PGE2 stimulated Cox1 (2.7 fold, P &lt; 0.05) while GnRH stimulated Cox2 expression (6.5 fold, P &lt; 0.05) in the pituitary when compared to the PBS group. In conclusion, our results support the hypothesis that PGE2 can induce ovulation in prepubertal mice with a concomitant increase in Ep2 and Cox1 gene expression in the pituitary gland.

Exploration of de novo‐ synthesized Zeolitic Imidazolate Framework‐8 (ZIF‐8) Nanoparticles as an Additive to Growth Media for Myoblasts

Skeletal muscle tissue engineering aims to repair a large area of damaged muscle caused by injuries or illness due to the difficulty of the cells naturally regenerating large tissue loss. Supplements help restore this loss via myoblast proliferation and maturation. Zinc excites the signal pathways for myogenesis, and as a supplement it should increase myoblast proliferation and maturation. The project goal was to synthesize nanoparticles that will stay suspended in cell media and allow the transfer of the zinc ion to increase muscle cell proliferation and maturation. Zeolitic imidazole framework-8 (ZIF-8) were created using a de novo synthesis, with the desired carboxaldehydes attached to the four imidazole rings surrounding a zinc ion core (Krishna et al. 2017). After synthesis, MP-AES, FT-IR, 13C-NMR, and 1H-NMR instruments were used to characterize the ZIF-8 nanoparticles. The synthesized product yields were 0.1098 g, 0.7400 g, and 0.1492 g, but the characterization data was inconsistent. 10 mg, 50 mg, and 100 mg of the synthesized products were then suspended in vials of 10 mL of phosphate buffered saline (PBS), sonicated for four, and six minutes with 20 seconds on and off, and the suspension time recorded. The 50 mg and 100 mg had the lowest suspension times (21 s to 162 s) while the 10 mg of product had higher suspension times (16 s to 384 s). In conclusion, the de novo ZIF-8 synthesis provided varying product yields; however, the suspendability times were too low. Ongoing research will focus on characterization, increasing the amount of zinc, and increasing the suspension time.

Comparative evaluation of retreatability of calcium silicate-based root canal sealers and epoxy resin-based root canal sealers in curved canals-An In-Vitro micro-CT analysis.

To compare and evaluate the retreatability of calcium silicate-based root canal sealers and epoxy resin-based root canal sealers in curved canals using micro-CT scanning. Forty-five maxillary molars with curved roots were selected after confirming with the Schneiders test. Teeth were decoronated near the cemento-enamel junction and moderate to severely curved canals were selected for the study using cone-beam computed tomography. All the samples were subjected to pre-operative micro-CT scanning. Cleaning and shaping were done using step-back preparation, obturation was done using lateral compaction technique, and homogeneous obturation was achieved. All the specimens were kept in 10 mL of phosphate buffered-saline solution at a pH of 8.4 for 48 h and transferred to a plastic container containing moistened foam with 10 mL of phosphate- buffered saline solution, and stored at 37 °C with 100% relative humidity for 4 months. Retreatment was performed for all the samples using Protaper universal retreatment files. Micro-CT scanning was performed to compare and evaluate the remaining sealer volume and resultant cracks formed in the root canal after retreatment. The volume of sealer remaining in the root canal and the length of a crack within the groups were analysed using kruskal-Wallis test and among the groups using post-hoc scheffe test showed that more sealer present in the Diaproseal sealer followed by MTA Fillapex and Bioroot RCS and more crack length was seen in Diaproseal sealer followed by MTA Fillapex and no visible cracks were seen in Bioroot RCS, which had statistically significant results with a P value of < 0.05. Within the limitations of the study it was concluded that in-terms of retrievability, Diaproseal sealer was the best among the tested groups followed by MTA Fillapex and Bioroot RCS.

Efficacy of antibacterial sealant to prevent microlekage at the implant superstructure interface – An in vivo study

Objective: The aim of this study is to evaluate the efficacy of antibacterial sealants to prevent microleakage at the implant superstructure interface. Materials and Methods: Around twenty patients were selected after a thorough investigation with lower missing teeth (1st and 2nd premolars 1st and 2nd molars) by inclusion criteria. The patients were divided into two groups Group A (10 patients)– Control group and Group B (10 patients)-test group. The implants were placed with proper surgical protocol in all the patients except that in the test group antibacterial sealant was used before putting the coverscrew. The implants were allowed to osseointegrate for 3 months after which swabs were collected from the interior of the implant once the cover screw was removed. The swabs collected from all the patients were immediately transported to the microbiology laboratory by placing in 1 ml of phosphate buffered saline. The swabs were inoculated on brain heart infusion and McKonkeys medium and processed for routine culture and sensitivity. The identification of the isolates was done by standard microbiological methods. The data thus obtained were subjected to statistical analysis using t-tests for equality. Results: Microbial growth was found in both the groups, but lesser variation in colony-forming units was observed in the test group where antibacterial sealant was used. Conclusions: It was concluded that in spite of using antibacterial sealants; some amount of microleakage was still observed.

Determination of unbound fraction of dorzagliatin in human plasma by equilibrium dialysis and LC-MS/MS and its application to a clinical pharmacokinetic study

Dorzagliatin, a novel glucokinase (GK) activator targeting both pancreatic and hepatic GK, is currently in late-stage clinical development for treatment of type 2 diabetes (T2D). For the optimization of dosing regimens to ensure adequate safety and efficacy, it is critical to have a deep understanding of pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the drug in various targeting patient populations, considering the fact that T2D adversely affects a vast patient population who often times also suffer from a wide range of comorbidities including severe liver and/or kidney damage. Since drug efficacy seems to be closely related to unbound drug concentrations at the site of action, therefore, the determination of plasma unbound concentrations/fractions of dorzagliatin is of crucial importance, especially when performing the PK/PD assessment in those special populations. In the current study, a method was developed and validated for determining the unbound fraction (fu) of dorzagliatin in human plasma by using equilibrium dialysis for the separation of the bound and unbound drug, and LC–MS/MS for subsequent quantification. We have successfully addressed two widely recognized challenges for determination of the fu, i.e., the lack of knowledge on the “true fu” and the difficulty in assessing the accuracy and reproducibility of the measurement. Using this method, a 0.2 mL aliquot of human plasma samples were first dialyzed against 0.35 mL of phosphate buffered saline buffer at 37 °C for 5 h in the equilibrium dialysis device to separate the unbound dorzagliatin. Afterwards, post-dialysis samples were extracted by protein precipitation using acetonitrile. Separation of dorzagliatin and potential interferences were achieved using a Gemini C18 column coupled with gradient elution. Subsequent detection was carried out on tandem mass spectrometer operated by multiple reaction monitoring in positive mode using electrospray ionization. The standard curve over the concentration range of 0.125−250 ng/mL exhibits good linearity. The method was fully validated meeting the requirements in current bioanalytical guidance and was successfully applied in a clinical PK study of dorzagliatin in healthy volunteers and patients with renal function impairment. Method reproducibility was demonstrated in incurred sample reanalysis. With demonstrated accuracy, stability and reproducibility, reliable analytical results were obtained from clinical samples for PK/PD interpretation, providing valuable insight for the development of dorzagliatin.

Child hand contamination is associated with subsequent pediatric diarrhea in rural Democratic Republic of the Congo (REDUCE Program).

The Reducing Enteropathy, Undernutrition, and Contamination in the Environment (REDUCE) program focuses on identifying exposure pathways to faecal pathogens for young children in the Democratic Republic of the Congo (DRC) and on developing scalable interventions to reduce faecal contamination from these pathways. A prospective cohort study of 690 participants was conducted to investigate the association between hand, food, and environmental faecal contamination and diarrhoeal disease prevalence among young children in Walungu Territory, South Kivu, DRC. A total of 1923 hand rinse, soil, food, object, surface, stored water and water source samples were collected during unannounced spot checks after baseline enrolment and analysed for Escherichia coli. Caregiver reports of diarrhoea were obtained from children<5years at a 6-month follow-up. E.coli was detected in 73% of child and caregiver hand-rinse samples, 69% of soil samples from child play spaces, 54% of child food samples, 38% of objects and surfaces children were observed putting in their mouths, 74% of stored water samples, and 40% of source water samples. Children<5years with E. coli on their hands had significantly higher odds of diarrhoea at the 6-month follow-up (odds ratio: 2.03 (95% confidence interval: 1.05, 3.92)). The cohort study findings from the REDUCE program have shown that child hand contamination is associated with diarrhoeal disease in rural DRC, and that there is high faecal contamination in child plays spaces and food. These findings provide evidence demonstrating the urgent need to provide clean play spaces for young children and interventions targeting hand hygiene to reduce paediatric exposure to faecal pathogens.

Novel delivery of cellular therapy to reduce ischemia reperfusion injury in kidney transplantation.

Ex vivo normothermic machine perfusion (NMP) of donor kidneys prior to transplantation provides a platform for direct delivery of cellular therapeutics to optimize organ quality prior to transplantation. Multipotent Adult Progenitor Cells (MAPC® ) possess potent immunomodulatory properties that could minimize ischemia reperfusion injury. We investigated the potential capability of MAPC cells in kidney NMP. Pairs (5) of human kidneys, from the same donor, were simultaneously perfused for 7 hours. Kidneys were randomly allocated to receive MAPC treatment or control. Serial samples of perfusate, urine, and tissue biopsies were taken for comparison. MAPC-treated kidneys demonstrated improved urine output (P=.009), decreased expression of injury biomarker NGAL (P=.012), improved microvascular perfusion on contrast-enhanced ultrasound (cortex P=.019, medulla P=.001), downregulation of interleukin (IL)-1β (P=.050), and upregulation of IL-10 (P<.047) and Indolamine-2, 3-dioxygenase (P=.050). A chemotaxis model demonstrated decreased neutrophil recruitment when stimulated with perfusate from MAPC-treated kidneys (P<.001). Immunofluorescence revealed prelabeled MAPC cells in the perivascular space of kidneys during NMP. We report the first successful delivery of cellular therapy to a human kidney during NMP. Kidneys treated with MAPC cells demonstrate improvement in clinically relevant parameters and injury biomarkers. This novel method of cell therapy delivery provides an exciting opportunity to recondition organs prior to transplantation.

Uptake and Release of a Multipurpose Solution Biocide (MAP-D) From Hydrogel and Silicone Hydrogel Contact Lenses Using a Radiolabel Methodology.

The purpose of this study was to evaluate the uptake and release of radiolabelled myristamidopropyl dimethylamine (MAP-D) on reusable daily wear contact lenses (CLs) over 7 days. Three silicone hydrogel (SH) CL materials (lotrafilcon B, balafilcon A, senofilcon A) and two conventional hydrogel (CH) materials (etafilcon A, omafilcon A) were tested. A short-term (experiment 1, N=4) and a longer-term (experiment 2, N=3) study was conducted. In experiment 1, the CLs were incubated in 2 mL of phosphate buffered solution (PBS) containing 14C MAP-D (5 μg/mL) for 8 hrs. The release of 14C MAP-D was measured at t=0.25, 0.5, 1, 2, 4, 8, and 24 hr in PBS. In experiment 2, the CLs were incubated in the 14C MAP-D solution for 8 hrs followed by a 16-hr release in PBS. This cycle was repeated daily for 7 days. At the end of both experiments, lenses were extracted to determine the total uptake of MAP-D. The radioactivity was measured using a beta scintillation counter. In experiment 1, all three SH lenses sorbed similar amounts of MAP-D (P=0.99), all of which were higher than the two CH materials (P<0.01). However, the CH materials released a greater amount of MAP-D than the SH materials (P<0.01). In experiment 2, the uptake of MAP-D in SH materials increased over 7 days, whereas the amount of MAP-D remained constant in the CH materials (P=0.99). Similar to experiment 1, the CH lenses released more MAP-D than SH lenses after 7 days (P<0.01). The SH materials absorbed greater amounts of MAP-D compared to CH materials. However, the CH materials released the greatest amount of MAP-D. Radioactive labelling of MAP-D offers a highly sensitive method of assessing the uptake and release profiles of biocides to CL materials.