Propylene Glycol Group Research Articles

Effect of two treatment protocols for ketosis on the resolution, postpartum health, milk yield, and reproductive outcomes of dairy cows

We determined the effect of ketosis treatment with propylene glycol (PG) or PG plus l-carnitine and methionine (Metabolase®, Fatro, Bologna, Italy) on the resolution, postpartum health, milk yield, and reproductive performances of dairy cows. Blood from 475 Holstein cows was collected weekly until 4 weeks after calving to measure blood β-hydroxybutyrate (BHBA) concentrations. Cows with blood BHBA concentration ≥1.2 mmol/L were diagnosed with ketosis and were enrolled. One hundred and fifty cows diagnosed with ketosis were randomly assigned to three treatment groups (Day 0): (1) PG (300 g, PO) for 3 days (PG group, n = 50), (2) PG (300 g, PO) plus l-carnitine (1.25 g) plus methionine (5 g, IV) for 3 days (PG + CM group, n = 50), and (3) no treatment (control group, n = 50). On Day 3, blood was collected to evaluate whether the ketosis had resolved. Cows in the PG and PG + CM groups with blood BHBA ≥1.2 mmol/L were retreated for an additional 2 days, and then blood BHBA concentration was evaluated on Days 5 and 10. Blood glucose and haptoglobin concentrations, rumen fill score (RFS), and body condition score (BCS) were measured on Days 0, 3, 5, and 10. Postpartum complications, milk yield during the first 2 months, and reproductive outcomes were evaluated. The probability of resolution from ketosis was higher (P < 0.05) in the PG + CM group than in the control group on Days 3, 5, and 10 (odds ratio: 2.6–6.3). Blood BHBA in the PG + CM group was lower (P < 0.05) than that of the control group on Days 3 and 5, whereas blood glucose in the PG + CM group was higher (P < 0.05) than that of the control group on Days 3 and 5. RFS in the PG and PG + CM groups was higher than that of the control group on Day 10 (P < 0.01), while BCS loss from Day 0–10 in the control group was higher than those of the PG and PG + CM groups (P < 0.05). Milk yields on the 30th and 60th days postpartum were higher in the PG + CM group than the control and PG groups (P < 0.05). Postpartum complications and intervals between calving and first postpartum insemination or pregnancy did not differ among the groups (P > 0.05). In conclusion, treatment of dairy cows with PG plus l-carnitine and methionine improved the chances of resolution of ketosis and increased milk yield, while affecting neither the incidence of postpartum complications nor reproductive performance.

The Garcinia kola biflavonoid kolaviron attenuates experimental hepatotoxicity induced by diclofenac

This study sought to investigate the effects of kolaviron on diclofenac-induced hepatotoxicity in rats. Sixty male Wistar rats were divided into 6 groups of 10 rats each as follows: a control group that received oral propylene glycol and treatment groups that received diclofenac alone, diclofenac followed by Livolin Forte (a reference drug), or diclofenac followed by kolaviron at three different doses. At the end of the study period, five rats per group were sacrificed under ketamine hydrochloride anesthetic, 24h after treatment, while the other 5 rats in the group were allowed to recover for 2 weeks before being sacrificed. Liver enzyme activities, total bilirubin levels, and the concentrations of several pro-inflammatory cytokines were determined using plasma samples, while liver tissue samples were used for antioxidant analysis and histopathological examination.Compared with the control group, plasma liver enzyme activities, along with bilirubin levels, were higher in the groups that received diclofenac alone or diclofenac+the highest dose of kolaviron, respectively. These groups had higher plasma concentrations of pro-inflammatory cytokines than did the control group. However, the administration of Livolin Forte and kolaviron (at the lower doses) ameliorated diclofenac-induced hepatic injury by improving antioxidant status, preventing an increase in inflammatory mediators, decreasing malondialdehyde, and attenuating the adverse effect of diclofenac on hepatic tissues. In addition, there was a significant difference in the histological scores between the groups that received either diclofenac alone or diclofenac followed by the highest dose of kolaviron when compared with the other three groups (Livolin Forte or lower doses of kolaviron). In conclusion, kolaviron appears to be as effective as Livolin in attenuating DCLF-induced hepatotoxicity in rats. However, high doses of kolaviron seem to cause damage to the liver.

RU486 Reverses Emotional Disorders by Influencing Astrocytes and Endoplasmic Reticulum Stress in Chronic Restraint Stress Challenged Rats

Aims: To investigate the effect of RU486 (mifepristone) on emotional disorders in chronic restraint stress-induced rats and to explore the mechanisms of that phenomenon. Methods: For this purpose, 80 healthy male Sprague Dawley rats were randomly divided into four groups: the normal group (Con group, The Con group members received no treatment, eating and drinking freely), the chronic restraint stress group (CRS group, normal Sprague Dawley rats treated with chronic restraint stress, 6 h/day for 21days), the propylene glycol group (CRS+propylene glycol) and the RU486 group (CRS+RU486). RU486 or propylene glycol was administered 30 mins before each CRS procedure. Twenty-four hours after CRS exposure, we investigated the effects of CRS on the anxiety-like behavior using an elevated plus-maze (EPM). To explore the mechanisms of RU486 on anxiety, we measured the expression of glial fibrillary acid protein (GFAP) and β-subunit of S100 (S100β) via immunohistochemistry and western blot analysis. Apoptosis was demonstrated by flow cytometry. In addition, endoplasmic reticulum (ER) stress markers, glucose regulated protein 78 (GRP78), C/EBP homologous protein (CHOP) and Cysteine aspartic acid specific protease-12 (Caspase-12), were detected by western blot analysis. Results: Compared to the control group, rats in the CRS and propylene glycol group showed decreased exploratory behavior on the open arms during EPM testing, and these reductions were accompanied by significantly reduced GFAP and S100β expression, increased apoptosis and GRP78, CHOP, and caspase-12 expression in the amygdala. However, RU486 increases the exploratory behavior and reverses the changes of GFAP, S100β, GRP78, CHOP, and caspase-12 and protects cells against apoptosis. Conclusions: Taken together, these data suggest that exposure to chronic restraint stress decreases the number of astrocytes and induces apoptosis and ER stress in the amygdala, which are possible causes for psychiatric disorders. RU486 can significantly ameliorate abnormal behaviors in CRS-induced anxiety model rats. The protective effects of RU486 could be attributed to its anti-ER stress, anti-apoptosis and astrocyte increasing effects.

Propylene glycol alginate (PGA) gelled foams: A systematic study of surface activity and gelling properties as a function of degree of esterification

A series of propylene glycol alginates (PGA) with degrees of esterification (D.E.) in the range of 32–93% were investigated with respect to surface activity and gelling potential. The surface tension measurements revealed increasing surface activity with increasing contents of propylene glycol groups. The rheological characterization of the PGA series calcium gels uncovered that the gelling potential of the PGAs was surprisingly well conserved even at intermediate degrees of esterification, assumed to reflect heterogeneity in the esterification pattern. For the PGAs of highest degree of esterification the assumed electrostatic point associations combined with hydrogen bonding lead to the rapid formation of weak gels. The rheological properties of high D.E. PGA solutions could be easily modified through the addition of sodium chloride and urea. Self-supporting, heterogeneous and stable PGA and PGA/unmodified alginate gelled foams were prepared applying the internal setting method and characterized with respect to mechanical properties and density. Increasing foamability and corresponding decrease in densities of the gelled foams and their mechanical strength was observed with increasing D.E..

Morphological assessment of sulfur mustard-induced acute lung injury in rats through different routes

To establish an animal model of sulfur mustard (SM)-induced acute lung injury in rats through different routes and compare the morphological changes in lung tissue and cells. One hundred and thirty-six male rats were selected and randomly divided into 5 groups, namely peritoneal cavity SM group (n=32), trachea SM group (n=32), peritoneal cavity propylene glycol group (n=32), trachea propylene glycol group (n=32), and normal control group (n=8). The rats in peritoneal cavity SM group were injected intraperitoneally with diluted SM (0.1 ml, 8 mg/kg), and the rats in trachea SM group were injected intratracheally with diluted SM (0.1 ml, 2 mg/kg). Once the rats were sacrificed at 6, 24, 48, and 72 h after SM treatment, morphological changes in lung tissue and cells were observed by light and electron microscopy. In the peritoneal cavity SM group, the epithelial cells of bronchioles maintained intact with increased exudate and bleeding in alveolar cavity and large areas of pulmonary consolidation under the light microscope. In the tracheal SM group, focal ulcer formed in the epithelial cells of bronchioles with increased exudate and bleeding in alveolar cavity, partial pulmonary consolidation, and compensatory emphysema in peripheral alveolar space under the light microscope. The alveolar interval areas were widened obviously in both groups in a time-dependent manner. Under the electron microscope, we observed local loss of cellular membrane in type I alveolar epithelium, broken or lost microvilli in cells of typeⅡalveolar epithelium and fuzzy mitochondrial crista as well as the appearance of ribosome detached from rough endoplasmic reticulum in both two groups. Compared with those in the trachea SM group and the control group, the ratio of the alveolar septum average area to the visual field area in the peritoneal cavity SM group at 6, 24, 48, and 72 h was significantly higher (P<0.05). The lung tissue injury through the intraperitoneal route is more severe than that through the tracheal route, while focal ulceration of bronchioles epithelial cells appears in the case of tracheal route. The degree of injury increases over time in both groups, and the cellular damage is approximately the same in both groups.

Effects of two combinations of cryoprotectants on the in vitro developmental capacity of vitrified immature porcine oocytes

This study evaluated two cryoprotectant (CPA) combinations, ethylene glycol (EG) + DMSO and EG + propylene glycol (PG), used for the vitrification of germinal vesicle (GV) porcine oocytes. In experiment 1, the equilibration of GV with the two CPA combinations increased (P < 0.05) the percentage of oocytes that degenerated after IVM (18.1 ± 2.3% and 19.4 ± 2.6% for EG + DMSO and EG + PG groups, respectively) compared with control oocytes (7.6 ± 1.3%). However, CPAs did not affect the fertilization or developmental parameters of the embryos. In experiment 2, the percentages of live vitrified–warmed GV oocytes at 2 hours after warming (EG + DMSO: 67.0 ± 2.3% and EG + PG: 57.6 ± 2.3%) were lower than those of fresh control GV oocytes (97.3 ± 0.7%). The percentage of degenerated oocytes after IVM was higher (P < 0.001) in vitrified–warmed oocytes (EG + DMSO: 59.8 ± 2.3% and EG + PG: 56.2 ± 2.6%) than in the control (1.6 ± 1.3). Fertilization efficiency was higher (P < 0.05) in the EG + PG (39.6 ± 2.4%) and control (42.0 ± 2.2%) groups than in the EG + DMSO (26.3 ± 7.7%) group. The cleavage and blastocyst formation rates of the EG + DMSO (25.9 ± 3.5% and 6.6 ± 2.5%, respectively) and EG + PG (20.2 ± 5.4% and 4.7 ± 1.6%, respectively) vitrification groups were lower (P < 0.001) than those observed in the control oocytes (53.4 ± 2.7% and 31.9 ± 1.7%, respectively). In conclusion, in the absence of vitrification, the toxic effects of both CPA combinations on the GV oocytes were minimal. Vitrification resulted in important losses in viability at each step of the in vitro embryo production procedure. However, the surviving oocytes were able to mature and be fertilized, although the fertilization efficiency in the EG + DMSO group was lower. Blastocysts formation was similar for both CPA combinations.

Carica papaya Latex Accelerates Wound Healing in Diabetic Wistar Rats

Aim: The wound healing ability of Carica papaya latex in excisional wound of alloxan induced diabetic wistar rats was investigated. Methodology: The excisional wounds of 24 diabetic rats in four equal groups were dressed respectively with latex (LD), gentamicin (GD), normal saline (ND) and propylene glycol (PD). A composite four nondiabetic (control) groups were also established (LC, GC, NC, and PC). All the eight groups had daily dressing till healed. Wound dimensions were taken at an interval of four days and obtained values were used to calculate wound contraction rates for specific period. Granulation tissue biopsies taken on day 4, 8 and 12 were processed for light microscopy. The healed scars were also processed for light microscopy. Results: The latex control (LC) group had the shortest healing period (16 days) while the longest period of 32 days was recorded by the diabetic normal saline (ND) and diabetic propylene glycol (PD) groups. The differences in the healing duration amongst the groups were significant (P < 0.001). Original Research Article Ajani and Ogunbiyi; EJMP, 9(3): 1-12, 2015; Article no.EJMP.17758 2 Comparison of highest and lowest wound contraction rates within the same period The LC group had highest mean wound contraction rate of 21.56±7.04% on day 4 with the PD group being the lowest (6.45±2.32%). Similar pattern was observed on day 8; (LC: 55.71±4.87%) and (ND: 18.98±12.13%). For day 12, the results were LC: 84.86±5.11% and GD: 35.36±17.80%. All these paired values were of statistical significance. Intra and intergroup comparisons of contraction rates On day 4, LC had significantly higher contraction rate than LD (21.58±7.04; 11.06±2.82 respectively with P< 0.001). Also results for the same parameter on day 8 and day 12 were significant in LD vs GD (47.48±8.9 vs 21.06±5.83; P<0.001); LD vs ND (47.48±8.94 vs 18.98±12.13; P<0.001); LD vs PD (47.48±8.9 vs 23.12±5.77; P< 0.001) and GC vs GD (42.56±8.61 vs 21.06±5.83; P< 0.001). Light microscopy of the granulation tissue from all the control groups showed more cellular infiltration than the respective diabetic group which might be due to hyperglycemia. Conclusion: The study had been able to demonstrate that Carica papaya latex promotes wound healing in diabetic wistar rats. Possible mechanisms through which this was achieved include amelioration of the inhibitory effect of diabetes mellitus on wound healing, increased rapidity of wound contraction and reduction in the duration of healing. From the results of this study, the latex of Carica papaya appeared superior to gentamicin, normal saline and propylene glycol as materials for wound management in diabetic wistar rats. Latex is naturally occurring and its source (Carica papaya) is easily cultivated, readily available, affordable and cannot be adulterated. It may thus be considered as an alternative to the synthetic materials in the current management of wounds in patients with diabetes mellitus.

Effects of propylene glycol on the metabolic status and milk production of dairy buffaloes.

The study was designed to investigate the effects of drenching with propylene glycol (PG) on body condition, serum metabolites and milk production during the transition period of dairy buffaloes. Animals were randomly allocated to a control group (n=5) and a PG group of 10 buffaloes that were drenched with 500 ml of propylene glycol once daily from 10 (9±3) days prepartum until 2 weeks postpartum. Ultrasound measurements of backfat thickness (BFT) were performed weekly, while blood samples were taken at -4, -2, 2, 4, 6, and 8 weeks from parturition for estimation of hematological and biochemical metabolites. At -4, -3, and -2 weeks from calving, BFT did not differ between the two groups, but decreased after calving and was higher for the control group than the PG group at weeks -1 and 1. Hematological analysis revealed insignificant changes between the two groups. Serum concentrations of non-esterified fatty acids (NEFA), β-hydroxybutyric acid (BHBA) and glucose did not differ between the two groups before parturition. At 2 and 4 weeks from parturition, NEFA was higher for the control group than the PG group. Serum concentrations of BHBA were higher at 2, 4, 6, and 8 weeks in control animals than in treated buffaloes. In contrast, the glucose level was significantly increased in PG group when compared to the control group at week 2 postpartum (p<0.05). Serum concentrations of total cholesterol, triglycerides, total proteins, albumin, and globulins did not differ significantly between the two groups (p>0.05). Serum enzyme activities of aspartate aminotransferase and γ-glutamyl transferase were significantly higher in the control than in the PG group. In treated buffaloes significantly (p<0.05) higher average 60-day milk yields were recorded (8.4±0.22 vs. 10.7±0.40 kg/day). Milk composition did not differ between the two groups. Drenching of dairy buffaloes with propylene glycol may reduce the risk of ketosis, improve the metabolic status, and increase the milk yield.

145 THE INFLUENCE OF PROPYLENE GLYCOL DRENCHING ON THE SUPEROVULATORY RESPONSE AND EMBRYO QUALITY IN HIGH-YIELDING DAIRY COWS

Genetic improvement of dairy cows increased markedly over the last decades; this has marked increased milk yield, which has been associated with reduced fertility parameters. The objective of this study was to determine the effects of feeding propylene glycol (PG) on superovulatory responses of 50 dairy cows and on their embryo quality and quantity. Starting at 1 week before the application of superovulatory regimen, each cow received once daily an oral dose of 150 g of PG (PG group) or water (control group). All cows were superovulated with a total dose of 400 mg of FSH administrated twice daily in decreasing doses over 4 consecutive days. Embryos were recovered nonsurgically 7.5 days after the onset of oestrus using a 2-way catheter. Evaluation of embryo quality was done according to the IETS manual based on 1 to 4 grades. Grade 1 embryos were transferred after freezing; grade 2 and 3 embryos were freshly transferred. The results showed that the number of total ova/embryos recovered, grade 1 embryos, and the number of transferable embryos were significantly higher (P = 0.048, 0.015, and 0.014, respectively) in the PG group (10.33 ± 1.9, 7.08 ± 1.7, and 7.92 ± 1.6, respectively) when compared with control group (6.09 ± 0.9, 2.11 ± 0.45, and 3.92 ± 1.25, respectively). Insignificant increase in grade 2 and grade 3 embryos was indicated in the control group (1.37 ± 0.3 and 0.51 ± 0.18, respectively) when compared with PG group (0.75 ± 0.28 and 0.25 ± 0.13, respectively). On the other hand, the results indicated that there was an increase in the number of degenerated embryos and unfertilized ovum in the PG group (2.33 ± 0.85) compared with control group (2.09 ± 0.6). In conclusion, these results suggested that administration of PG has the ability to positively improve the superovulatory response and embryo quality in high-yielding dairy cows.

Mechanistic insights of sulfur mustard-induced acute tracheal injury in rats.

Sulfur mustard (SM) is believed to be a major threat to civilian populations because of the persistent asymmetric threat by nonstate actors, such as terrorist groups, the ease of synthesis and handling, and the risk of theft from stockpiles. The purpose of this study was to establish mechanisms of acute tracheal injury in rats induced by SM using histopathologic, immunohistochemical, and biochemical parameters. Male rats (Sprague-Dawley) were anesthetized, intratracheally intubated, and exposed to 2 mg/kg of SM. Animals were euthanized 6-, 24-, 48-, and 72-hour postexposure, and intracavitary blood samples from the heart and tracheal tissues were collected. Exposure of rats to SM resulted in rapid tracheal injury, including tracheal epithelial cell shedding, focal ulceration, and abundant lymphocyte invasion of the submucosa. There was also evidence of a large number of apoptotic cells in the epithelium and submucosa, the serum levels of tumor necrosis factor α, interleukin 1β (IL) 1β, IL-6, and γ-glutamyl transferase peaked at 24 hours, and the serum levels of lactate dehydrogenase, glutathione peroxidase, and thiobarbituric acid reactive substance peaked at 6 hours. The SM exposure also resulted in a loss of the cellular membrane, leakage of cytoplasm, fuzzy mitochondrial cristae, medullary changes in ciliated and goblet cells, and the nuclear chromatin appeared marginated in basal cells and fibroblasts. The results in the propylene glycol group were the same as the control group. These data demonstrated the histologic changes, inflammatory reactions, apoptosis, oxidative stress, and DNA damage following SM (2 mg/kg)-induced acute tracheal injury; the severity of changes was time dependent.

Lipid nanocapsules for transdermal delivery of ropivacaine: in vitro and in vivo evaluation.

The objective of this research was to develop novel ropivacaine-loaded lipid nanocapsules (RPV-LNCs) and evaluate the potential of RPV-LNCs as external preparation for transdermal delivery. RPV-LNCs were prepared by phase inversion technique and optimized by response surface design. The permeation ability of RPV-LNCs was characterized both in vitro and in vivo. The results showed that the optimized RPV-LNCs represented typical core-shell structure with the mean diameter of 62.1±1.7 nm. The entrapment efficiency and drug loading were 92.6±1.3% and 1.35±0.20%, respectively. Moreover, the cumulative amount of RPV penetrated through excised skin from LNCs was 2.17 folds than that of the propylene glycol. In vivo, RPV-LNCs contributed a higher RPV concentration in plasma (5.743 μg/mL). The RPV retained within dermis was 27.9±5.2 μg/mL for LNCs, obviously remarkable than that of the propylene glycol group (15.6±3.9 μg/mL). The skin histopathology study and scanning electron microscope (SEM) showed that interaction between LNCs and skin surface changed the apparent morphology of stratumcorneum and broke the close conjugation of corneocyte layers. All the detailed evidence showed that LNCs could provide a promising tuning as a transdermal delivery system of ropivacaine.

An In-vitro Evaluation of the pH Change Through Root Dentin Using Different Calcium Hydroxide Preparations as an Intracanal Medicament.

The aim of the study was to evaluate the pH variation in the surrounding medium after the use of two different vehicles of Calcium hydroxide - Saline (aqueous), Propylene glycol (viscous) and Calcium hydroxide containing guttapercha points over a period of 7 days as an intracanal medicament. Sixty single rooted premolars were decoronated at the cementoenamel junction and cleaned and shaped uptil size 40 master apical file. External defects were made on the mesial surface in the coronal third of the roots and divided randomly into 4 groups. One control and three experimental. In the control - group I the root canals were left empty. In the experimental groups - group II was filled with Ca(OH)2 + saline, group III was filled with Ca(OH)2 + propylene glycol and group IV the root canals were filled with Calcium hydroxide points. The coronal accesses were sealed with 3mm of Cavit G and all the surfaces of the root except the defect were covered with 3 coats at Nail varnish. The samples were then placed in air tight vials containing 2ml of distilled water. The vials were kept in an incubator and the pH of the surrounding medium was measured using a digital pH meter after 1,3,5 and 7 days respectively. A statistically significant difference (p<0.05) existed between the experimental groups over the observation period. At day 1, a high pH was recorded by the calcium hydroxide points and saline groups and a lower pH by the propylene group. At day's 3 and 5, the maximum pH was recorded by the propylene glycol group and minimum by the calcium hydroxide points and saline groups. At day 7, the pH of all the groups had dropped, with propylene glycol recording the maximum pH followed by saline and lastly calcium hydroxide points. Within the limitations of this study, a viscous vehicle is better among other vehicles, calcium hydroxide paste of propylene glycol provided the highest 7 days release of hydroxyl ions.

Effect of secondary lymphoid tissue chemokine suppression on experimental ulcerative colitis in mice.

The secondary lymphoid tissue chemokine (CCL21) is closely associated with lymphoid homing and anti-tumor immune responses. CCL21 also has a chemotactic effect on intestinal lymphocytes. This study mainly focused on CCL21 expression in experimental ulcerative colitis and on the effects of CCL21 suppression on this disease in mice. The mouse colitis model was induced by dextran sulfate sodium (DSS) in 40 female BALB/c mice that were equally distributed into five groups: control, DSS, propylene glycol, triptolide (TL), and dexamethasone treatment groups. The disease activity index, general morphology score of the colon, and histological pathology score of colon tissues were evaluated. CCL21 expression was examined in colons of mice by immunohistochemistry, reverse transcription-polymerase chain reaction, and Western blotting analysis. CCL21 was upregulated in the mouse model of ulcerative colitis (control group vs DSS group/propylene glycol group, P<0.01). The TL and dexamethasone treatments improved colitis symptoms and decreased CCL21 expression (TL group/dexamethasone group vs DSS group/propylene glycol group, P<0.05). In conclusion, CCL21 was shown to be involved in the induction of ulcerative colitis. Suppression of CCL21 expression decreased damage induced from ulcerative colitis, indicating that CCL21 targeted therapy might be an effective treatment for this disease.

Comparison of Ethylene Glycol and Propylene Glycol for the Vitrification of Immature Porcine Oocytes

Our aim was to optimize a cryoprotectant treatment for vitrification of immature porcine cumulus-oocyte complexes (COCs). Immature COCs were vitrified either in 35% ethylene glycol (EG), 35% propylene glycol (PG) or a combination of 17.5% EG and 17.5% PG. After warming, the COCs were in vitro matured (IVM), and surviving oocytes were in vitro fertilized (IVF) and cultured. The mean survival rate of vitrified oocytes in 35% PG (73.9%) was higher (P<0.05) than that in 35% EG (27.8%). Oocyte maturation rates did not differ among vitrified and non-vitrified control groups. Blastocyst formation in the vitrified EG group (10.8%) was higher (P<0.05) than that in the vitrified PG group (2.0%) but was lower than that in the control group (25.0%). Treatment of oocytes with 35% of each cryoprotectant without vitrification revealed a higher toxicity of PG on subsequent blastocyst development compared with EG. The combination of EG and PG resulted in 42.6% survival after vitrification. The maturation and fertilization rates of the surviving oocytes were similar in the vitrified, control and toxicity control (TC; treated with EG+PG combination without cooling) groups. Blastocyst development in the vitrified group was lower (P<0.05) than that in the control and TC groups, which in turn had similar development rates (10.7%, 18.1% and 23.3%, respectively). In conclusion, 35% PG enabled a higher oocyte survival rate after vitrification compared with 35% EG. However, PG was greatly toxic to oocytes. The combination of 17.5% EG and 17.5% PG yielded reasonable survival rates without toxic effects on embryo development.

79 A COMBINATION OF ETHYLENE GLYCOL AND PROPYLENE GLYCOL IS SUPERIOR TO INDIVIDUAL CRYOPROTECTANTS FOR THE VITRIFICATION OF IMMATURE PORCINE OOCYTES

We compared the feasibility of ethylene glycol (EG) and propylene glycol (PG) for the vitrification of immature porcine cumulus–oocyte complexes (COC). Porcine COC collected from 3- to 6-mm follicles of slaughterhouse-derived ovaries were subjected to solid-surface vitrification (Somfai et al. 2010 Theriogenology 73, 147–156) either in 35% (v/v) EG or 35% (v/v) PG or in the mixture of 17.5% (v/v) EG and 17.5% (v/v) PG. After warming, the COC were subjected to in vitro maturation, IVF, and embryo culture according to Kikuchi et al. (2002 Biol. Reprod. 66, 1033–1041). Oocyte survival and maturation rates were assessed after in vitro maturation by evaluating membrane integrity and the extrusion of the first polar body. All live oocytes were subjected to IVF and in vitro culture. Cleavage and blastocyst rates were calculated from the total number of oocytes subjected to IVF on Day 2 (Day 0 = IVF) and Day 7, respectively. Total-cell (blastomeres) numbers in blastocysts were recorded on Day 7 after staining with Hoechst 33342. In Experiment 1, competence parameters of oocytes vitrified either in EG-based (EG group; n = 310) or a PG-based (PG group; n = 265) vitrification media were compared with those in the nonvitrified control (n = 160). The experiment was replicated 4 times. In Experiment 2, the competence parameters of oocytes vitrified with the combination of 17.5% EG and 17.5% PG (EG+PG group; n = 397) were compared with those in nonvitrified control (n = 245) and toxicity control (TC, exposed to cryoprotectants without cooling; n = 245) groups. Five replications were performed. Results were analyzed by ANOVA. Differences with P &lt; 0.05 were considered significant. In Experiment 1, the mean survival rate of vitrified oocytes was significantly higher (P &lt; 0.05) in 35% PG compared with that in 35% EG (73.3 and 25.9%, respectively). Maturation rates of surviving oocytes did not differ among vitrified (PG and EG) and nonvitrified control groups (71.1, 62.4, and 64.0%, respectively). After IVF of surviving oocytes, blastocyst formation rate in the group vitrified in EG was higher (P &lt; 0.05) compared with that vitrified in PG but was lower (P &lt; 0.05) compared with control (10.8, 2.0, and 25.0%, respectively). Mean cell numbers in blastocysts did not differ among EG, PG, and control groups (50.5, 47.7, and 48.7, respectively). In Experiment 2, survival of immature oocytes in the EG+PG group was 42.6%. After IVF, 10.7% of oocytes developed to the blastocyst stage in the EG+PG group, which was lower (P &lt; 0.05) than those of the control (18.1%) and TC (23.3%) groups. Blastocyst rates in the control and TC groups were not statistically different. Mean cell numbers in blastocysts did not differ significantly among the EG+PG, control, and TC groups (61.6, 59.3, and 53.3, respectively). In conclusion, 35% PG provided a higher oocyte survival rate after vitrification compared with 35% EG. However, presumably due to toxic effects, 35% PG greatly reduced the development competence of oocytes. The combination of 17.5% EG and 17.5% PG yielded higher survival rates than did 35% EG, without any toxic effect on oocytes.

Effect of slow freeze versus vitrification on the oocyte: an animal model

To determine whether there is a deleterious effect on dynamic events in the nucleus and cytoplasm of oocytes by using different cryopreservation protocols in an animal model. Prospective study. University hospitals. Not applicable. Immunostaining and confocal laser scanning microscope techniques were used. The spindle and chromosomal configurations, as well as dynamic changes of the cortical granules (CGs) and mitochondria in different cryogroups. After thawing/warming of bovine oocytes, CGs became more dispersed in the cytoplasm, particularly in the DMSO group. A significant reduction in normal spindle and chromosomal configurations was observed in all three cryogroups, particularly in the propylene glycol (PROH) group, when compared with the fresh group. Global DNA methylation levels were significantly reduced in the slow and DMSO groups, as compared with the fresh group; however, methylation levels were significantly increased in the PROH group. The proportion of severely apoptotic oocytes was dramatically increased in all three cryogroups, compared with the fresh group. Overall, results demonstrate that using DMSO as the cryoprotectant is better for preserving the cellular and nuclear integrity of the oocyte. The PROH method makes the oocyte more vulnerable to increased DNA methylation, which may be associated with imprinting gene alteration. This study adds to the increasing body of evidence that cryopreservation protocols vary in their impact upon the oocyte.

Supplemental feeding with glycerol or propylene glycol of dairy cows in early lactation—Effects on metabolic status, body condition, and milk yield

The objective of this field study was to evaluate the effect of supplemental feeding with glycerol or propylene glycol to dairy cows in early lactation on metabolic status, body condition and milk yield. In total, 673 newly calved cows from 12 commercial Swedish dairy herds were randomized to daily supplementation with 450g of glycerol (GLY), 300g of propylene glycol (PG), or nothing (control, CON). Supplements were fed twice daily from 0 to 21 d in milk (DIM) as a top dress on concentrates. For each cow, data on parity, breed, calving date, monthly test-day milk yield, and cases of diseases were collected. Blood samples were taken at approximately 2, 5, and 8 wk postpartum (pp) and analyzed for glucose, β-hydroxybutyrate (BHBA), nonesterified fatty acids (NEFA), and insulin. Samples taken within 3 wk pp were also analyzed for insulin-like growth factor 1 (IGF-1). Measurements of body condition score (BCS) and heart girth (HG) were obtained at approximately 2 and 5 wk pp and at time of first insemination. The effects of supplemental feeding with GLY or PG on the plasma concentrations of glucose, NEFA, BHBA, insulin, and IGF-1, and BCS, HG, and occurrence of disease were analyzed. No differences in BCS or HG or in plasma concentrations of glucose, BHBA, NEFA, or IGF-1 were found between the control group and any of the treatment groups. Cows in the GLY group had lower plasma insulin concentrations during DIM 0 to 63 compared with group CON, but no difference in insulin was found between the PG group and the CON group. Cows supplemented with GLY had a higher milk yield (kg of milk and kg of energy-corrected milk) during the first 90 DIM. Cows in the PG group tended to yield more milk during the same period. No differences in the occurrence of diseases were seen between the groups. In conclusion, supplementation with GLY in early lactation did increase milk yield without a subsequent decrease of metabolic status, and supplementation with PG tended to do the same.

Residues of calcium hydroxide-based intracanal medication associated with different vehicles: A scanning electron microscopy evaluation

This study evaluated the presence of residues after removal of calcium hydroxide [Ca(OH)(2) ] associated with different vehicles. Thirty single-rooted teeth were instrumented to a master apical file #25 using 2.5% NaOCl as main irrigant and 17% trisodium EDTA (ethylenediaminetetraacetic acid) as final agent irrigant. Then, the root canals were dressed with Ca(OH)(2) associated with silicone oil (Group 1), 2% chlorhexidine gluconate (Group 2), or propylene glycol (Group 3). After coronal sealing, all teeth were kept in a moist environment at room temperature. After 7 days, the teeth were reopened and medicaments were removed using 5 mL of saline solution and instrumentation with master apical file followed by new irrigation with 5 mL of 2.5% NaOCl. Subsequently, teeth were split longitudinally and assessed by scanning electron microscopy. The wall cleanliness of the cervical and apical thirds of the roots were evaluated and scored by three blinded examiners. Statistical analysis was performed using Kruskal-Wallis and Wilcoxon tests at 5% level of significance. All roots had residues of Ca(OH)(2) on the canal walls. All experimental groups had similar results (P > 0.05) regardless of the third evaluated. There was significant difference between the apical and cervical thirds only in Group 3 (P < 0.05). Association of different vehicles to Ca(OH)(2) does not influence the persistence of residues on the root canal walls.

Microscopic cleanliness evaluation of the apical root canal after using calcium hydroxide mixed with chlorhexidine, propylene glycol, or antibiotic paste

This study evaluated cleaning of the dentinal wall after removal of different calcium hydroxide pastes. Sixty-eight single-rooted teeth were prepared using the step-back technique and randomly divided into 4 groups according to medication used: Ca(OH)2 with 0.2% chlorhexidine solution (Group 1), Ca(OH)2 with propylene glycol (Group 2), Ca(OH)2 with antibiotic paste (ciprofloxacin, metronidazole) and distilled water (Group 3), and Ca(OH)2 with antibiotic paste and propylene glycol (Group 4). The samples were stored at 37 °C and 100% relative humidity for 21 days. The medicaments were removed using 5 mL 1% NaOCl, instrumentation with master apical file, 5 mL 1% NaOCl, patency with the K-file #10, ultrasonic instrumentation, and 10 mL 17% EDTA-T. The specimens were analyzed using scanning electron microscopy and chemical analysis. The Kruskal-Wallis (α = 5%) test showed that were no differences between the experimental groups when comparing Ca(OH)2 removal (P = .0951). The chi-square test (α = 5%) indicated a predominance of Ca(OH)2 obstructing dental tubules in all groups. On the basis of the methodology applied, it was concluded that the apical dentine surface remained equally covered by Ca(OH)2, regardless of the vehicle used.

Effects of Propylene Glycol on Milk Production, Serum Metabolites and Reproductive Performance during the Transition Period of Dairy Cows

The objective of this study was to investigate the effects of an oral drench of propylene glycol (PG) on milk production, serum metabolites and reproductive performance during the transition period of animals. Twenty-four 2-3 multiparous Holstein cows (average body weight 565 kg, body condition score about 3.6, at the 9 th month of gestation) were selected, blocked, and then randomly assigned into a PG and a control group. The control and the PG group cows were orally drenched with water or 50 ml sugarcane molasses mixed with 500 ml PG from 7 days pre-partum to 30 days post-partum, respectively. Experimental results indicated that the oral drench PG had no effect on dry matter intake (DMI). The milk yield of the PG group was significantly higher than that of the control group (p<0.05), whereas milk fat content, milk protein and somatic cell counts (SCC) were not significantly different between groups. Concentration of plasma glucose in the PG group was significantly higher than that of the control group (p<0.05). Conversely, the concentrations of non-esterified fatty acids (NEFA), and blood urea nitrogen (BUN) in the PG group were lower than those of the control group (p<0.05). Concentrations of insulin and ketone bodies were not significantly difference between groups. Body condition score (BCS) in the PG group was significantly higher than that of the control group (p<0.05). In reproductive performance there was no difference between groups. The experimental results indicate that supplementation of PG during the transition period of dairy cows can supply energy rapidly, resulting in reduced catabolism of body tissue and increased milk yield.