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1.
Elevated triglycerides (TG) contribute towards increased risk for cardiovascular disease. Lipoprotein lipase (LPL) is an enzyme that is responsible for the metabolism of core triglycerides of very-low density lipoproteins (VLDL) and chylomicrons in the vasculature. In this study, we explored the structure-activity relationships of our lead compound (C10d) that we have previously identified as an LPL agonist. We found that the cyclopropyl moiety of C10d is not absolutely necessary for LPL activity. Several substitutions were found to result in loss of LPL activity. The compound C10d was also tested in vivo for its lipid lowering activity. Mice were fed a high-fat diet (HFD) for four months, and treated for one week at 10 mg/kg. At this dose, C10d exhibited in vivo biological activity as indicated by lower TG and cholesterol levels as well as reduced body fat content as determined by ECHO-MRI. Furthermore, C10d also reduced the HFD induced fat accumulation in the liver. Our study has provided insights into the structural and functional characteristics of this novel LPL activator.  相似文献   

2.
BackgroundIn the last years, food grade antioxidants are used safely as an alternative to traditional fungicides to control fungal growth in several food and agricultural products.AimsIn this work, the effect of butylated hydroxyanisole (BHA) and propyl paraben (PP) on two hydrolytic enzyme activity (β-d-glucosidase and α-d-galactosidase) by Aspergillus section Nigri species under different water activity conditions (aW; 0.98, 0.95 and 0.93) and incubation time intervals (24, 48, 72 and 96 h) was evaluated on peanut-based medium.MethodsThe activity of two glycosidases, β-d-glucosidase and α-d-galactosidase, was assayed using as substrates 4-nitrophenyl-β-d-glucopyranosido and 4-nitrophenyl-α-d-galactopyranosido, respectively. The enzyme activity was determined by the increase in optical density at 405 nm caused by the liberation of p-nitrophenol by enzymatic hydrolysis of the substrate. Enzyme activity was expressed as micromoles of p-nitrophenol released per minute.ResultsThe major inhibition in β-d-glucosidase activity of A. carbonarius and A. niger was found with 20 mmol l−1 of BHA or PP at 0.98 and 0.95 aW, respectively, whereas for α-d-galactosidase activity a significant decrease in enzyme activity with respect to control was observed in A. carbonarius among 5 to 20 mmol l−1 of BHA or PP in all conditions assayed. Regarding A. niger, the highest percentages of enzyme inhibition activity were found with 20 mmol l−1 of BHA or PP at 0.95 aW and 96 h.ConclusionsThe results of this work provide information about the capacity of BHA and PP to inhibit in vitro conditions two of the most important hydrolytic enzymes produced by A. carbonarius and A. niger species.  相似文献   

3.
Semicarbazide (SEM) is a by-product of the blowing agent azodicarbonamide, present in glass jar-sealed foodstuffs mainly baby foods. The pleiotropic in vivo SEM toxicological effects suggested to explore its possible role as endocrine modulator. Endocrine effects of SEM were assessed in vivo in male and female rats after oral administration for 28 days at 0, 40, 75, 140 mg/kg bw pro die during the juvenile period. Vaginal opening and preputial separation were recorded. Concentration of sex steroid in blood, the ex vivo hepatic aromatase activity and testosterone catabolism were detected. The in vitro approach to test SEM role as (anti)estrogen or N-methyl-d-aspartate receptors (NMDARs)-(anti)agonist included different assays: yeast estrogenicity, MCF-7 proliferation, stimulation of the alkaline phosphatase activity in Ishikawa cells and LNCaP-based NMDAR interference assay. In vivo SEM-treated female rats showed delayed vaginal opening at all tested doses, whereas in males preputial separation was anticipated at SEM 40 and 75 mg/kg and delayed at 140 mg/kg, the latter effect probably due to the significantly decreased body weight gain seen at the higher dose in both sexes. Serum estrogen levels were dose-dependently reduced in treated females, whereas dehydrotestosterone serum levels were also decreased but a clear dose–response was not evidenced. Testosterone catabolism was altered in a gender-related way, aromatase activity was increased in treated males at 75 and 140 mg/kg and in females in all dose groups. In the three estradiol-competitive assays, SEM showed a weak anti-estrogenic activity, whereas in the LNCaP-based NMDAR interference assay SEM activity resembled MK-801 antagonist effect. SEM appeared to act as an endocrine disrupter showing multiple and gender specific mechanisms of action(s). A possible cascade-mechanism of SEM on reproductive signalling pathways may be hypothesized. Such in vivoin vitro approach appeared to be an useful tool to highlight SEM activity on endocrine homeostasis.  相似文献   

4.
PurposeAt our institute, a transit back-projection algorithm is used clinically to reconstruct in vivo patient and in phantom 3D dose distributions using EPID measurements behind a patient or a polystyrene slab phantom, respectively. In this study, an extension to this algorithm is presented whereby in air EPID measurements are used in combination with CT data to reconstruct ‘virtual’ 3D dose distributions. By combining virtual and in vivo patient verification data for the same treatment, patient-related errors can be separated from machine, planning and model errors.Methods and materialsThe virtual back-projection algorithm is described and verified against the transit algorithm with measurements made behind a slab phantom, against dose measurements made with an ionization chamber and with the OCTAVIUS 4D system, as well as against TPS patient data. Virtual and in vivo patient dose verification results are also compared.ResultsVirtual dose reconstructions agree within 1% with ionization chamber measurements. The average γ-pass rate values (3% global dose/3 mm) in the 3D dose comparison with the OCTAVIUS 4D system and the TPS patient data are 98.5 ± 1.9%(1SD) and 97.1 ± 2.9%(1SD), respectively. For virtual patient dose reconstructions, the differences with the TPS in median dose to the PTV remain within 4%.ConclusionsVirtual patient dose reconstruction makes pre-treatment verification based on deviations of DVH parameters feasible and eliminates the need for phantom positioning and re-planning. Virtual patient dose reconstructions have additional value in the inspection of in vivo deviations, particularly in situations where CBCT data is not available (or not conclusive).  相似文献   

5.
ProjectBeside its useful functions at very low concentrations, selenium including supplementary Se sources pose a potential toxicological risk. The toxicity of selenium species was tested in HaCaT cell culture and related nephrotoxicity in mice.ProcedureThe apoptotic shrinkage and necrotic expansion of cells were measured by time-lapse image microscopy. Acute nephrotoxicity was estimated upon administration of various selenium species to mice for two weeks. To confirm or to refute the accumulation of Se in the kidney and its potential chronic effect, Se concentration in kidney tissue and histopathlology were tested.ResultsThe comparison of selenium species showed that organic lactomicroSe did not affect cell growth at 5 ppm, but inorganic nanoSe severely hampered it at lower concentration (1 ppm). The in vivo Se treatment (0.5, 5, 50 ppm, corresponding to 4, 40 and 400 μg/kg) was misleading as it did neither affect the outward appearance nor the weight of the kidney. Se accumulation was observed after selenate, selenite, SelPlex, selenite and nanoSe administration, while lactomicroSe caused no traceable accumulation. In vivo, ex vivo and in vitro experiments reflected this order of selenium toxicity: selenate > selenite > SelPlex = nanoSe > lactomicroSe.ConclusionWithin the tested species lactomicroSe was the only non-nephrotoxic selenium source recommended for nutritional Se supplementation.  相似文献   

6.
BackgroundThe balance between osteoblastic and osteoclastic activity is critical in orthodontic tooth movement (OTM). Mesenchymal stem cells (MSCs) play an important role in maintaining bone homeostasis, and periodontal ligament stem cells (PDLSCs) are tissue-specific MSCs in the periodontal ligament. However, whether PDLSCs are required for periodontal tissue remodeling during OTM is not fully understood.MethodsHere, we used PDGFRα and Nestin to trace PDLSCs during OTM in rats. We treat human PDLSCs with 100 kpa static pressure for 1 h or 12 h in vitro, and examined the phenotypic changes and expression of RANKL and OPG in these cells.ResultsIn vivo, we found that positive signals of PDGFRα and Nestin in the PDL gradually increased and then decreased on the pressure side to which pressure was applied. In vitro, the osteogenic differentiation of PDLSCs was significantly increased after force treatment for 1 h relative to 12 h. In contrast, the expression ratio of RANKL/OPG was reduced at 1 h and significantly increased at 12 h. Furthermore, we found that the Wnt/β-catenin pathway was dynamically activated in the PDL and in PDLSCs after mechanical stimulation. Importantly, the canonical Wnt pathway inhibitor DKK1 blocked the osteogenesis effect and rescued the ratio of RANKL/OPG in PDLSCs under force treatment for 1 h.ConclusionsOur findings reveal that PDLSCs participate in OTM and that the Wnt/β-catenin pathway maintains bone homeostasis during tooth movement by regulating the balance between osteoblastic and osteoclastic activity.General significanceWe describe a novel potential mechanism related to tooth movement.  相似文献   

7.
This communication explains the biosynthesis of stable silver nanoparticles (AgNPs) from Melia azedarach and its cytotoxicity against in vitro HeLa cells and in vivo Dalton's ascites lymphoma (DAL) mice model. The AgNPs synthesis was determined by UV–visible spectrum and it was further characterized by scanning electron microscopy (SEM), dynamic light scattering (DLS) and X-ray diffraction (XRD) analysis. Zeta potential analysis revealed stable AgNPs at ?24.9 mV. UV visible spectrum indicated an absorption peak at 436 nm which reflects its specific Surface Plasmon Resonance (SPR). Biosynthesized AgNPs were predominantly cubical and spherical with an average particle size of 78 nm approximately as observed through SEM and DLS analysis, respectively. Cytotoxicity of biosynthesized AgNPs against in vitro Human epithelial carcinoma cell line (HeLa) showed a dose–response activity. Lethal dose (LD50) value was found to be 300 μg/mL of AgNPs against HeLa cell line. Cytotoxicity against normal continuous cell line human breast lactating, donor 100 (HBL 100) was found only in increased concentration of both AgNPs and 5-FU. In addition, in vivo DAL mice model showed significant increase in life span, induction of apoptosis was evidenced by acridine orange and ethidium bromide (AO and EB) staining.  相似文献   

8.
《Phytomedicine》2014,21(6):830-837
The aim of the study was to investigate the anti-rheumatoid arthritic activity of four flavonoids from Daphne genkwa (FFD) in vivo and in vitro. Flavonoids of D. genkwa were extracted by refluxing with ethanol and purified by polyamide resin. An in vivo carrageenan-induced paw edema model, tampon-granuloma model and Freund's complete adjuvant (FCA)-induced arthritis mouse model were used to evaluate the anti-rheumatoid arthritic activities of FFD. Moreover, nitric oxide (NO) release and neutral red uptake (NRU) in lipopolysaccharide (LPS)-induced murine macrophage RAW264.7 cells were used to evaluate the anti-inflammatory effect in vitro. In addition, antioxidant effect of FFD was determined using the 2,2-diphenyl-1-picrylhydrazyl (DPPH) method. A high dose of FFD significantly reduced the degree of acute inflammatory paw edema in mice as a response to carrageenan administration (p < 0.01). FFD displayed a dose-dependent inhibition of granuloma formation in mice (p < 0.05). FFD also inhibited chronic inflammation in adjuvant-induced arthritis rats when administered orally at the dose of 50 mg/kg/day (p < 0.001). In addition, FFD suppressed the production of NO and exhibited immunoregulatory function in LPS-activated RAW264.7 cells in a dose-related manner. Simultaneously, FFD revealed conspicuous antioxidant activity with IC50 values of 18.20 μg/ml. FFD possesses significant anti-inflammatory and antioxidant activity, which could be a potential therapeutic agent for chronic inflammatory disorders such as rheumatoid arthritis.  相似文献   

9.
《Phytomedicine》2014,21(2):148-154
This study investigated the hepatoprotective activity of saponarin, isolated from Gypsophila trichotoma Wend., using in vitro/in vivo hepatotoxicity model based on carbone tetrachloride (CCl4)-induced liver damage in male Wistar rats. The effect of saponarin was compared with those of silymarin. In vitro experiments were carried out in primary isolated rat hepatocytes. Cell incubation with CCl4 (86 μmol l−1) led to a significant decrease in cell viability, increased LDH leakage, decreased levels of cellular GSH and elevation in MDA quantity. Cell pre-incubation with saponarin (60–0.006 μg/ml) significantly ameliorated CCl4-induced hepatic damage in a concentration-dependent manner. These results were supported by the following in vivo study. Along with decreased MDA quantity and increased level of cell protector GSH, seven day pre-treatment of rats with saponarin (80 mg/kg bw; p.o.) also prevented CCl4 (10%, p.o.)-caused oxidative damage by increasing antioxidant enzyme activities (CAT, SOD, GST, GPx, GR). Biotransformation phase I enzymes were also assessed. Administered alone, saponarin decreased EMND and AH activities but not at the same extent as CCl4 did. However, pre-treatment with saponarin significantly increased enzyme activities in comparison to CCl4 only group. The observed biochemical changes were consistent with histopathological observations where the hepatoprotective effect of saponarin was comparative to the effects of the known hepatoprotecor silymarin. Our results suggest that saponarin, isolated from Gypsophila trichotoma Wend., showed in vitro and in vivo hepatoprotective and antioxidant activity against CCl4-induced liver damage.  相似文献   

10.
Diabetes mellitus is associated with dyslipidemia, which is a significant risk factor for cardiovascular complications. The present study was carried out to evaluate the effects of tetrahydrocurcumin (THC) and chlorogenic acid (CGA) alone and in combination on alterations in lipids, lipoproteins and enzymes involved in lipid metabolism in streptozotocin (STZ)–nicotinamide (NA)-induced type 2 diabetic rats. A significant (p < 0.05) increase in the concentrations of plasma and tissue (liver and kidney) lipids (cholesterol, triglycerides (TGs), free fatty acids (FFAs) and phospholipids (PLs)) and low density and very low-density lipoproteins (LDL and VLDL), and a decrease in the concentration of high-density lipoproteins (HDL) were noticed in STZ administered diabetic rats. In addition, the activity of 3-hydroxy 3-methylglutaryl coenzyme A (HMG-CoA) reductase increased significantly (p < 0.05) in the liver and kidney whereas the activities of lipoprotein lipase (LPL) and lecithin cholesterol acyl transferase (LCAT) were decreased significantly (p < 0.05) in the plasma of diabetic rats. Combined administration of CGA (5 mg/kg b.w.) and THC (80 mg/kg b.w.) for 45 days remarkably reduced the STZ-induced changes in lipids, lipoproteins and lipid metabolising enzymes when compared to the effects of CGA or THC alone in diabetic rats. These results indicate that combination of THC and CGA can potentially ameliorate lipid abnormalities in experimental type 2 diabetes.  相似文献   

11.
Thanatin was first discovered from the hemipteran insect Podisus maculiventris and showed a promising antimicrobial activity. Multidrug-resistant (MDR) clinical isolates of Klebsiella pneumoniae have developed resistance to current therapies. As an attempt to resolve this problem, the efficacy of thanatin and its analogues against clinical isolates of K. pneumoniae was studied in vitro and in vivo. S-thanatin showed an improved antimicrobial activity with the tested MIC values was 2–8-fold lower than those of other thanatin analogs. Antimicrobial assay indicated a high activity of S-thanatin against K. pneumoniae in vitro with MIC between 4 and 8 μg/ml. Its in vivo activity was evaluated using a K. pneumoniae-infected mice model. Adult male ICR mice were randomly grouped and given an intraperitoneal (i.p.) administration of 2 × 1010 colony-forming units of K. pneumoniae (CI 120204205). Afterwards, mouse groups were subjected to i.p. administration of saline or S-thanatin (5, 10, or 15 mg/kg). After an inspection of 72 h, the mice were finally sacrificed for analysis of in vivo bacterial growth and plasma endotoxin level. The results showed that S-thanatin administration apparently improved the survival rate and reduced the bacterial CFU from intra-abdominal fluid in mice. The plasma endotoxin level was improved as well. All above implied that S-thanatin, as an alternative, may provide a novel strategy for treating K. pneumoniae infection and other infections due to multidrug-resistant bacteria.  相似文献   

12.
Two series of new thiazolidin-4-one derivatives 4ac and 8ae were designed and prepared. All the synthesized compounds were evaluated for their in vitro COX-2 selectivity and anti-inflammatory activity in vivo. Compounds 8c and 8d showed the best overall in vitro COX-2 selectivity (selectivity indexes of 4.56 and 5.68 respectively) and in vivo activities (edema inhibition % = 61.8 and 67 after 3 h, respectively) in comparison with the reference drug celecoxib (S.I. = 7.29, edema inhibition % = 60 after 3 h). In addition, 8c and 8d were evaluated for their mean effective anti-inflammatory doses (ED50 = 27.7 and 18.1 μmol/kg respectively, celecoxib ED50 = 28.2 μmol/kg) and ulcerogenic liability (reduction in ulcerogenic potential versus celecoxib = 85%, 92% respectively. Molecular docking studies were performed and the results were in agreement with that obtained from the in vitro COX inhibition assays.  相似文献   

13.
The effects of acute stress on immune status and its regulation by cortisol/corticosteroid receptors have received little attention in percids. To address that question, we investigated the physiological and immune responses of Eurasian perch, Perca fluviatilis to acute stress. We exposed immature perch to an 1-min exondation and measured at 1 h, 6 h, 24 h and 72 h post-stress: (1) stress-related parameters including plasma cortisol and glucose levels, (2) immune parameters in the plasma and in the spleen (complement, respiratory burst and lysozyme activity, total immunoglobulins; gene expression of lysozyme, complement unit 3, apolipoprotein A1 and 14 kDa, hepcidin and chemotaxin) (3) the corticosteroid receptors gene expression in the spleen after having cloned them. In addition, the in vitro effects of cortisol on the spleen immune parameters were also investigated.Plasma cortisol and glucose levels increased markedly 1 h post-stress and returned at basal levels after 24 h. P. fluviatilis mineralocorticoid receptor, but not glucocorticoid receptors, was significantly up-regulated both in vivo after the stress and in vitro by cortisol at a physiological concentration (100 ng/ml). The plasma immune parameters were not significantly affected by the stress. In contrast, spleno-somatic index, spleen lysozyme activity, lysozyme and hepcidin gene expression were depleted and total immunoglobulins increased along the whole time-course (1–72 h). But, these immune parameters were not regulated in vitro by cortisol at physiological or supra-physiological doses.Our results indicate that handling stress may affect spleen antibacterial defences without clear effects on circulating immune compounds and that the elevation of plasma cortisol after handling stress may not be related to the regulation of this splenic response.  相似文献   

14.
BackgroundSilver nanoparticles (Ag-NPs) are widely used nowadays in a variety of commercial applications including medical, health care, textiles and household supplies.ObjectivesThe current study was designed to determine the median lethal dose (LC50) of Ag-NPs on Oreochromis niloticus and Tilapia zillii.MethodsAcute and sub-acute toxicity study of the Ag-NPs on brain tissues was carried out using different concentrations of the NPs at 2 mg L and 4 mg L. These concentrations were dispersed in deionized water with the exception of the control groups in the experiments. Biochemical and molecular analysis were conducted on tissue homogenates in order to evaluate the potential effects of NPs on the antioxidant system.ResultsThe Ag-NP acute toxicity (96 h LC50) values of 19.5 ± 2 and 20 ± 2.4 mg/L were reported for O. niloticus and T. zillii respectively. Fish exposed to 2 mg/L Ag-NPs did not show any significant change in the levels of reduced glutathione (GSH), total glutathione (tGSH) levels, superoxide dismutase (SOD), catalase (CAT), glutathione reductase (GR), glutathione peroxidase (GPx) and glutathione-S-transferase (GST) activity or genes expression and malondialdehyde (MDA) level. In contrary, a dose of 4 mg/L showed a significant reduction in the levels all the above-mentioned parameters except in MDA level where it was significantly induced.ConclusionResults indicate that exposure of O. niloticus and T. zillii to Ag-NPs (4 mg/L) has deleterious effects on brain antioxidant system, whereas a dose of 2 mg/L has no effects.  相似文献   

15.
PurposeThree MOSkins dosimeters were assembled over a rectal probe and used to perform in vivo dosimetry during HDR brachytherapy treatments of vaginal cancer. The purpose of this study was to verify the applicability of the developed tool to evaluate discrepancies between planned and measured doses to the rectal wall.Materials and methodsMOSkin dosimeters from the Centre for Medical Radiation Physics are particularly suitable for brachytherapy procedures for their ability to be easily incorporated into treatment instrumentation. In this study, 26 treatment sessions of HDR vaginal brachytherapy were monitored using three MOSkin mounted on a rectal probe. A total of 78 measurements were collected and compared to doses determined by the treatment planning system.ResultsMean dose discrepancy was determined as 2.2 ± 6.9%, with 44.6% of the measurements within ±5%, 89.2% within ±10% and 10.8% higher than ±10%. When dose discrepancies were grouped according to the time elapsed between imaging and treatment (i.e., group 1: ≤90 min; group 2: >90 min), mean discrepancies resulted in 4.7 ± 3.6% and 7.1 ± 5.0% for groups 1 and 2, respectively. Furthermore, the position of the dosimeter on the rectal catheter was found to affect uncertainty, where highest uncertainties were observed for the dosimeter furthest inside the rectum.ConclusionsThis study has verified MOSkin applicability to in-patient dose monitoring in gynecological brachytherapy procedures, demonstrating the dosimetric rectal probe setup as an accurate and convenient IVD instrument for rectal wall dose verification. Furthermore, the study demonstrates that the delivered dose discrepancy may be affected by the duration of treatment planning.  相似文献   

16.
《Phytomedicine》2014,21(5):579-585
BackgroundDiabetes mellitus is associated with oxidative stress which impairs the platelet function. Phyllanthus emblica extract a rich source of vitamin C plays an important role in scavenging free radicals. The effect of vitamin C on platelet aggregation in healthy and coronary artery disease patients has been demonstrated. The present study attempts to study the pharmacodynamic interactions of P. emblica extract with clopidogrel and ecosprin.Materials and methodsThis was a randomized open label crossover study of 10 type II diabetic patients. The dosage schedules were either single dose of 500 mg P. emblica extract or 75 mg clopidogrel or 75 mg ecosprin or 500 mg P. emblica + 75 mg clopidogrel or 500 mg P. emblica + 75 mg ecosprin. After single dose study and washout period, patients received either 500 mg P. emblica extract twice daily or 75 mg clopidogrel or 75 mg ecosprin once daily or combinations for 10 days. Platelet aggregation was measured at baseline and at 4 h of treatment after single and multiple dose study along with recording of bleeding and clotting time.ResultsAfter single and multiple dose administration of the three treatments and with combinations there was statistically significant decrease of platelet aggregation compared to baseline. Further, the mean percent inhibition of platelet aggregation was significant, when compared between single and multiple doses of P. emblica. The bleeding and clotting time was prolonged with single and multiple dose administration of all treatments compared to baseline. All treatments were well tolerated.ConclusionP. emblica extract demonstrated significant antiplatelet activity with both single and multiple dose administration.  相似文献   

17.
《Cytokine》2013,63(3):360-368
BackgroundInterleukin (IL)-19, a member of the IL-10 cytokine family, is involved in keratinocyte proliferation in psoriasis.ObjectivesWe investigated the role of IL-19 in the wound-healing process in vivo and in vitro.MethodsTwo full-thickness circular wounds (4 mm in diameter) were punched into the skin of BALB/C mice. IL-19 and keratinocyte growth factor (KGF) mRNA in wounded skin were determined using real-time PCR. The wounds were treated with PBS, vehicle, IL-19 (400 ng/mL), or IL-20 (400 ng/mL) (n = 6 in each group) twice daily and the percentage of wound healing was measured daily for 7 days. In vitro, human skin fibroblast CCD966-SK cells and keratinocyte HaCaT cells were treated with IL-19 or KGF. Cell proliferation and migration were determined using bromodeoxyuridine (BrdU) and transwell assays, respectively. The expression of IL-19 and KGF mRNA was also analyzed.ResultsIn wounded mouse skin, IL-19 mRNA was upregulated at 12 h, and KGF at 24 h after the injury. Both increases in gene expression declined 72 h after the skin had been wounded. The percentage of wound healing in IL-19-treated mice was higher than in control mice. In vitro, IL-19 upregulated KGF expression in the CCD966-SK cells; IL-19 was upregulated in KGF-treated HaCaT cells. KGF but not IL-19 promoted HaCaT cell proliferation. However, IL-19 significantly increased the migration of HaCaT cells. HaCaT cells treated with the cultured supernatants of IL-19-stimulated CCD966-SK cells showed significantly more proliferation than in controls.ConclusionsIL-19 is important for cutaneous wound healing because it upregulates KGF expression.  相似文献   

18.
A subcutaneous exenatide delivery system was developed and characterized in vitro and in vivo. The results clearly showed that the exenatide loaded PLGA microspheres prepared by using a non-aqueous processing medium had low burst release and high drug encapsulation efficiency. Exenatide loaded in the microspheres preserved its bioactivity. The pharmacokinetics parameters were determined after subcutaneous administration of microspheres to SD rats. The plasma concentration of the single dose of the sustained-release microspheres attained Cmax of 108.19 ± 14.92 ng/ml at tmax of 1.33 ± 0.58 h and the t1/2 was 120.65 ± 44.18 h. There was a linear correlation between the in vitro and in vivo release behavior (R2 = 0.888). Exenatide loaded microspheres may prove to have great potential for clinical use.  相似文献   

19.
Biological dosimetry provides information on the absorbed dose and its distribution in the body for an early assessment of irradiation consequences in exposed individuals. In this study, an effort has been made to see the applicability of biological dosimetry using micronuclei assay for dose estimation in therapeutic irradiation of cancer patients in acute high dose partial body irradiation. Dose estimation in partial body irradiations was done on the basis of Dolphin's contaminated Poisson method, using the in vitro dose response calibration curve. The equivalent whole body dose and the dose to the irradiated part of the body were estimated to be 1.8 ± 0.1 Gy and 6.4 ± 0.3 Gy, respectively. The estimated percentage of irradiated blood and the fraction of cells exposed were 41.5 ± 1.6% and 10.4 ± 0.8%, respectively. The estimated fraction of irradiated cells was comparable with the actual volume of irradiation.  相似文献   

20.
PurposeTo analyse the correlations between the eye lens dose estimates performed with dosimeters placed next to the eyes of paediatric interventional cardiologists working with a biplane system, the personal dose equivalent measured on the thorax and the patient dose.MethodsThe eye lens dose was estimated in terms of Hp(0.07) on a monthly basis, placing optically stimulated luminescence dosimeters (OSLDs) on goggles. The Hp(0.07) personal dose equivalent was measured over aprons with whole-body OSLDs. Data on patient dose as recorded by the kerma-area product (PKA) were collected using an automatic dose management system. The 2 paediatric cardiologists working in the facility were involved in the study, and 222 interventions in a 1-year period were evaluated. The ceiling-suspended screen was often disregarded during interventions.ResultsThe annual eye lens doses estimated on goggles were 4.13 ± 0.93 and 4.98 ± 1.28 mSv. Over the aprons, the doses obtained were 10.83 ± 0.99 and 11.97 ± 1.44 mSv. The correlation between the goggles and the apron dose was R2 = 0.89, with a ratio of 0.38. The correlation with the patient dose was R2 = 0.40, with a ratio of 1.79 μSv Gy−1 cm−2. The dose per procedure obtained over the aprons was 102 ± 16 μSv, and on goggles 40 ± 9 μSv. The eye lens dose normalized to PKA was 2.21 ± 0.58 μSv Gy−1 cm−2.ConclusionsMeasurements of personal dose equivalent over the paediatric cardiologist’s apron are useful to estimate eye lens dose levels if no radiation protection devices are typically used.  相似文献   

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