Mannosylated liposomes bearing Amphotericin B for effective management of visceral Leishmaniasis

The cationic and mannosylated liposomes were prepared using the cast film method and compared for their antileishmaniasis activity. The surface of the Amphotericin B (Amp B)-bearing cationic multilamellar liposomes was covalently coupled with p-aminophenyl-α-D-mannoside using glutaraldehyde as a coupling agent, which was confirmed by agglutination of the vesicles with concanavalin A. The prepared liposomes were characterized for shape, size, percent drug entrapment, vesicle count, zeta potential, and in vitro drug release. Vesicle sizes of cationic and mannosylated liposomes were found to be 2.32?±?0.23 and 2.69?±?0.13?µm, respectively. Zeta potential of cationic liposomes was higher (30.38?±?0.3 mV), as compared to mannosylated liposomes (17.7?±?0.8 mV). Percentage drug release from cationic and mannose-coupled liposomes was found to be 45.7%?±?3.1 and 41.9%?±?2.8, respectively, after 24 hours. The in vivo antileishmanial activity was performed on Leishmania donovani–infected golden hamster, and results revealed that Amp B solution was reduced by 42.5?±?1.8% in the parasite load, whereas the placebo cationic liposomes and drug-containing cationic liposomes showed a reduced parasite load (i.e., 28.1?±?1.5 and 61.2?±?3.2%, respectively). The mannose-coupled liposomes showed a maximum reduction in parasite load (i.e., 78.8?±?3.9%). The biodistribution study clearly showed the higher uptake of mannosylated liposomes in the liver and spleen and hence the active targeting to the reticular endothelial system, which, in turn, would provide a direct attack of the drug to the site where the pathogen resides, rendering the other organs free and safe from the toxic manifestations of the drug.     

Cholesterol efflux from bovine sperm. I. Induction of the acrosome reaction with lysophosphatidylcholine after reducing sperm cholesterol

Methods were developed to quantitatively reduce the cholesterol (Chol)/phospholipid (PL) ratio of bovine sperm and to determine the effectiveness of this treatment in capacitating sperm. Washed sperm (2 × 10⁸) were incubated in 1.0 ml of modified Tyrode's solution (TS) containing unilamellar liposomes of phosphatidylcholine (PC), phosphatidylethanolamine (PE), and [¹⁴C]-Chol (35:35:30 molar ratio, 300 nmol total PL). [³H]-triolein was included as a nonexchangable marker. After 90 min at 39°C, a 13% net exchange of [¹⁴C]-Chol from liposomes to sperm was observed (n = 4), and sperm motility was 80%. Sperm were then washed and 50 × 10⁶ sperm were incubated as before with PC/PE liposomes containing no Chol. After 90 min, sperm were separated from liposomes by centrifugation. Measurement of [¹⁴C]-Chol in the liposomes (supernatant) and parallel gas chromatographic analysis of extracted, saponified liposomes (n = 4) indicated that 30% of sperm Chol was removed by this procedure. Chol efflux decreased percent motile sperm by less than 10% but reduced sperm velocity by more than 50%. Sperm incubated with no liposomes (control), with liposomes containing Chol ( + Chol), and with Chol-free liposomes (—Chol) were washed and resuspended in TS with 0.2% BSA and 30 μg lysophosphatidylcholine (LPC)/mg bovine serum albumin (BSA). Percent sperm undergoing the acrosome reaction (AR) upon incubation with LPC-BSA was used as a measure of sperm capacitation. After 60 min of exposure to LPC-BSA at 39°C, the mean (± SE) percent motile sperm for control, +Chol, and —Chol treatments was 57.0 ± 4.9, 60.0 ± 4.7, and 57.0 ± 6.8, respectively. Corresponding values for percent AR were 14.0 ± 3.4, 20.3 ± 4.4, and 39.7 ± 1.2. These results suggest that loss of Chol from bovine sperm may be an early step in sperm capacitation in this species.     

Liposomal hydrogel formulation for transdermal delivery of pirfenidone

Context: Pirfenidone (PFD) is an anti-fibrotic and anti-inflammatory agent indicated for the treatment of idiopathic pulmonary fibrosis (IPF). The current oral administration of PFD has several limitations including first pass metabolism and gastrointestinal irritation.

Objective: The aim of this study is to investigate the feasibility of transdermal delivery of PFD using liposomal carrier system.

Materials and methods: PFD-loaded liposomes were prepared using soy phosphatidylcholine (SPC) and sodium cholate (SC). Encapsulation efficiency (EE) of PFD in liposomes was optimized using different preparation techniques including thin film hydration (TFH) method, direct injection method (DIM) and drug encapsulation using freeze–thaw cycles. In vitro drug release study was performed using dialysis membrane method. The skin permeation studies were performed using excised porcine ear skin model in a Franz diffusion cell apparatus.

Results and discussion: The average particle size and zeta-potential of liposomes were 191?±?4.1?nm and ?40.4?±?4.5?mV, respectively. The liposomes prepared by TFH followed by 10 freeze–thaw cycles showed the greatest EE of 22.7?±?0.63%. The optimized liposome formulation was incorporated in hydroxypropyl methyl cellulose (HPMC) hydrogel containing different permeation enhancers including oleic acid (OA), isopropyl myristate (IPM) and propylene glycol (PG). PFD-loaded liposomes incorporated in hydrogel containing OA and IPM showed the greatest flux of 10.9?±?1.04?μg/cm²/h across skin, which was 5-fold greater compared with free PFD. The cumulative amount of PFD permeated was 344?±?28.8?μg/cm² with a lag time of 2.3?±?1.3?h.

Conclusion: The hydrogel formulation containing PFD-loaded liposomes can be developed as a potential transdermal delivery system.     

PEGylated liposomes of anastrozole for long-term treatment of breast cancer: in vitro and in vivo evaluation

The aim of present study was to develop conventional and PEGylated (long circulating), liposomes containing anastrozole (ANS) for effective treatment of breast cancer. ANS is a third-generation non-steroidal aromatase inhibitor of the triazole class used for the treatment of advanced and late-stage breast cancer in post-menopausal women. Under such disease conditions the median duration of therapy should be prolonged until tumor regression ends (>31 months). Liposomes were prepared by the thin film hydration method by using ANS and various lipids such as soyaphosphatidyl choline, cholesterol and methoxy polyethylene glycol distearoyl ethanolamine in different concentration ratios and evaluated for physical characteristics, in vitro drug release and stability. Optimized formulations of liposome were studied for in vitro cytotoxic activity against the BT-549 and MCF-7 cell lines and in vivo behavior in Wistar rats. Preformulation studies, both Fourier transform infrared study and differential scanning calorimetry analysis showed no interaction between the drug and the excipients used in the formulations. The optimized formulations AL-07 and AL-09 liposomes showed encapsulation efficiencies in the range 65.12?±?1.05% to 69.85?±?3.2% with desired mean particle size distribution of 101.1?±?5.9 and 120.2?±?2.8?nm and zeta potentials of ?43.7?±?4.7 and ?62.9?±?3.5 mV. All the optimized formulations followed Higuchi-matrix release kinetics and when plotted in accordance with the Korsemeyer–Peppas method, the n-value 0.5?n?in vitro cytotoxicity studies (p?(0–∞) values when compared to pure drug (p?相似文献   

Prostaglandin Endoperoxide H Synthase-2 (PGHS-2) Variants and Risk of Obesity and Microvascular Dysfunction Among Tunisians: Relevance of rs5277 (306G/C) and rs5275 (8473T/C) Genetic Markers

The purpose of this study was to determine the impact of six PGHS-2 genetic variants on obesity development and microvascular dysfunction. The study included 305 Tunisian subjects (186 normal weights, 35 overweights and 84 obeses). PCR analyses were used for allelic discrimination between polymorphisms. Prostaglandin (PGE2, PGI2), leptin, and matrix metalloproteinase (MMP1, 2, 3, 9) levels were evaluated by ELISA. Fatty acid composition was performed by gas chromatography–mass spectrometry. Our results revealed that subjects carrying the PGHS-2 306CC (rs5277) and 8473CC (rs5275) genotypes present higher anthropometric values compared to wild-type genotypes (306GG, BMI (Kg/m²): 27.11?±?0.58; WC (cm): 93.09?±?1.58; 306CC, BMI: 33.83?±?2.46; WC: 109.93?±?5.41; 8473TT, BMI: 27.75?±?0.68; WC: 93.96?±?1.75; 8473CC, BMI: 33.72?±?2.2; WC: 117.89?±?2.94). A reduced microvascular reactivity and a higher PGE2 level were also found in individuals with the 306CC and 8473CC genotypes in comparison to 306GG and 8473TT carriers (306GG, Peak Ach-CVC (PU/mmHg): 0.46?±?0.03; PGE2 (pg/ml): 7933.1?±?702; 306CC, Peak Ach-CVC: 0.24?±?0.01; PGE2: 13,380.3?±?966.2; 8473TT, Peak Ach-CVC: 0.48?±?0.05; PGE2: 7086.41?±?700.31; 8473CC, Peak Ach-CVC: 0.23?±?0.01; PGE2: 13,175.7?±?1165.8). Fatty acid analysis showed a significant increase of palmitic acid (PA) (34.2?±?2.09 vs. 16.82%?±?1.76, P?<?0.001), stearic acid (SA) (25.76?±?3.29 vs. 9.05%?±?2.53, P?<?0.001), and linoleic acid (LA) (5.25?±?1.18 vs. 0.5%?±?0.09, P?<?0.001) levels in individuals carrying the PGHS-2 306CC genotype when compared to GG genotype individuals. Subjects with the 8473CC genotype showed also a significant increase of PA, SA ,and LA levels when compared to TT genotype carriers (PA: 38.02?±?1.51 vs. 12.65%?±?1.54, P?<?0.001; SA: 32.96?±?1.87 vs. 1.38%?±?0.56, P?<?0.001; LA: 26.84?±?2.09 vs. 3.7%?±?1.54, P?<?0.001). Logistic regression analysis revealed that PGHS-2 306CC and 8473CC variants are significantly associated with obesity status (OR 6.25, CI (1.8–21.6), P?=?0.004; OR 3.01, CI (1.13–8.52), P?=?0.03, respectively). Haplotypes containing the C₃₀₆:T₈₄₇₃ (OR 2.91; P?=?0.01) and G_306:C₈₄₇₃ (OR 5.25; P?=?0.002) combinations were associated with an enhanced risk for obesity development in the studied population. In conclusion, our results highlight that PGHS-2 306G/C and 8473T/C variants could be useful indicators of obesity development, inflammation, and microvascular dysfunction among Tunisians.

     

Topical delivery and in vivo antileishmanial activity of paromomycin-loaded liposomes for treatment of cutaneous leishmaniasis

The present study aimed to evaluate the potential of liposomes loaded with paromomycin (PA), an aminoglycoside antibiotic associated with poor skin penetration, for the topical treatment of cutaneous leishmaniasis (CL). Fluid liposomes were prepared and characterized for particle size, zeta potential, and drug entrapment. Permeation studies were performed with two in vitro models: intact and stripped skin. The antileishmanial activity of free and liposomal PA was evaluated in BALB/c mice infected by Leishmania (L.) major. Drug entrapment ranged from 10 to 14%, and the type of vesicle had little influence on this parameter. Particle size and polydispersity index of the vesicles composed by phosphatidylcholine (PC) and PC/cholesterol (Chol) ranged from of 516 to 362?nm and 0.7 to 0.4, respectively. PA permeation across intact skin was low, regardless of the formulation tested, while drug penetration into skin (percent of the applied dose) from PC (7.2?±?0.2%) and PC/Chol (4.8?±?0.2%) liposomes was higher than solution (1.9?±?0.1%). PA-loaded liposomes enhanced in vitro drug permeation across stripped skin and improved the in vivo antileishmanial activity in experimentally infected mice. Our findings suggest that the liposomes represent a promising alternative for the topical treatment of CL using PA.     

A comparison of native and non-urate Total Antioxidant Capacity of fasting plasma and saliva among middle-aged and older subjects

Objectives: As plasma and salivary total antioxidant capacity (TAC) is mainly contributed by uric acid (UA), the present study measures non-urate TAC (Nu-TAC). The aim of the study was to correlate plasma native TAC, Nu-TAC and UA with their salivary analogues, and compare the UA contribution in both body fluids using two different methods.

Methods: The study involved 55 middle-aged and older subjects (66.7?±?4.5 years). TAC was determined simultaneously with two methods (ferric reducing ability of plasma – FRAP, 2.2-diphenyl-1-picryl-hydrazyl – DPPH and countertypes for saliva – FRAS and DPPHS test), with and without UA (native TAC and Nu-TAC, respectively). Plasma UA and salivary UA (SUA) were assessed.

Results: Subjects with increased FRAP, DPPH and UA had higher FRAS, DPPHS and SUA, respectively (P?P?Discussion: Our findings suggest that saliva is a good predictor for native plasma TAC but not for Nu-TAC. UA level is comparably dominant in saliva and in plasma according to DPPH, but lower in plasma according to FRAP.     

Liposomes modulate docetaxel-induced lipid oxidization and membrane damage in human hepatoma cells

The aim of this study was to investigate the effect of liposomes on docetaxel-induced lipid oxidization and membrane damage in human hepatoma cells. Cytotoxicity of free docetaxel and docetaxel-containing liposomes was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium (MTT) assay in human hepatoma cell lines HepG2 and SMMC-7721. To the cell lines, blank liposomes prepared with soybean phosphatidylcholine (SPC), dimyristoylphosphocholine (DMPC), and dioleoylphosphocholine (DOPC) did not show any significant toxicity below a 0.02-mg/mL phospholipid concentration. On the other hand, free docetaxel showed IC₅₀ values of 9.13?×?10^?6?±?1.54?×?10^?5 and 1.58?×?10^?2?±?2.71?×?10^?2 mg/mL in HepG2 cells and SMMC-7721 cells, respectively, after of 24 hours of incubation. IC₅₀ values of docetaxel-encapsulating liposomes, measured in terms of total docetaxel concentration, were at least 1.5-fold higher than those of free docetaxel. SPC liposomes reduced cellular damage caused by free docetaxel, as evidenced by the attenuation of docetaxel-induced lactate dehydrogenase (LDH) leakage by over 11% after liposome encapsulation at each dosage. Docetaxel-induced oxidative membrane damage was monitored by the formation of the lipid peroxidation product, malondialdehyde (MDA), and the antioxidative property of SPC liposome was monitored by the suppression of superoxide dismutase (SOD). These data demonstrated that free docetaxel facilitated MDA formation and suppressed SOD, and that these membrane-damaging effects were reduced by SPC liposomes.     

Liposomal quercetin potentiates maxi-K channel openings in smooth muscles and restores its activity after oxidative stress

The effects of quercetin-loaded liposomes (PCL-Q) and their constituents, that is, free quercetin (Q) and ‘empty’ phosphatidylcholine vesicles (PCL), on maxi-K channel activity were studied in single mouse ileal myocytes before and after H₂O₂-induced oxidative stress. Macroscopic Maxi-K channel currents were recorded using whole-cell patch clamp techniques, while single BK_Ca channel currents were recorded in the cell-attached configuration. Bath application of PCL-Q (100?μg/ml of lipid and 3?μg/ml of quercetin) increased single Maxi-K channel activity more than threefold, from 0.010?±?0.003 to 0.034?±?0.004 (n?=?5; p?<?0.05), whereas single-channel conductance increased non-significantly from 138 to 146?pS. In the presence of PCL-Q multiple simultaneous channel openings were observed, with up to eight active channels in the membrane patch. Surprisingly, ‘empty’ PCL (100?μg/ml) also produced some channel activation, although it was less potent compared to PCL-Q, that is, these increased NPo from 0.010?±?0.003 to 0.019?±?0.003 (n?=?5; p?<?0.05) and did not affect single-channel conductance (139?pS). Application of PCL-Q restored macroscopic Maxi-K currents suppressed by H₂O₂-induced oxidative stress in ileal smooth muscle cells. We conclude that PCL-Q can activate Maxi-K channels in ileal myocytes mainly by increasing channel open probability, as well as maintain Maxi-K-mediated whole-cell current under the conditions of oxidative stress. While fusion of the ‘pure’ liposomes with the plasma membrane may indirectly activate Maxi-K channels by altering channel’s phospholipids environment, the additional potentiating action of quercetin may be due to its better bioavailability.     

Litterfall production, decomposition and nutrient use efficiency varies with tropical forest types in Xishuangbanna, SW China: a 10-year study

Litterfall production, decomposition and nutrient use efficiency in three different tropical forest ecosystems in SW China were studied for 10 years. Annual mean litterfall production in tropical seasonal forest (TSF) (9.47?±?1.65 Mg ha^?1) was similar to that in man-made tropical forest (MTF) (9.23?±?1.29 Mg ha^?1) (P?>?0.05) but both were significantly lower than that in secondary tropical forest (STF) (12.96?±?1.71 Mg ha^?1) (P?<?0.05). The annual variation of litterfall was greater in TSF (17.4%, P?<?0.05) than in MTF (14.0%) or STF (13.2%). The annual mean decomposition rate of litterfall increased followed the order of MTF (2.72)?<?TSF (3.15)?<?STF (3.50) (P?<?0.05), which was not correlated with annual precipitation or annual mean temperature, but was rather related to litter quality. The nutrient use efficiency was found to be element-dependent and to vary significantly among the three forest types (P?<?0.05). These results indicate that litterfall production and decomposition rates in different tropical forest systems are related to plant species composition and are influenced strongly by coexisting species and their life stage (age) but less so by the species richness. Constructing multi-species and multistory man-made tropical forest is an effective way to enhance biological productivity and maintain soil nutrients on degraded tropical land.     

Evening physical activity alters wrist temperature circadian rhythmicity

The adequate time to perform physical activity (PA) to maintain optimal circadian system health has not been defined. We studied the influence of morning and evening PA on circadian rhythmicity in 16 women with wrist temperature (WT). Participants performed controlled PA (45?min continuous-running) during 7 days in the morning (MPA) and evening (EPA) and results were compared with a no-exercise-week (C). EPA was characterized by a lower amplitude (evening: 0.028?±?0.01?°C versus control: 0.038?±?0.016?°C; p?<?0.05) less pronounced second-harmonic (power) (evening: 0.41?±?0.47 versus morning: 1.04?±?0.59); and achrophase delay (evening: 06:35?±?02:14?h versus morning: 04:51?±?01:11?h; p?<?0.05) as compared to MPA and C. Performing PA in the late evening might not be as beneficial as in the morning.     

Investigations on feasibility of in situ development of amphotericin B liposomes for industrial applications

Amphotericin B (AmB) liposome formulations are very successful in the treatment of fungal infections and leishmaniasis. But higher cost limits its widespread use among people in developing countries. Therefore, we have developed a modified ethanol-injection method for the preparation of AmB liposomes. Two liposomal formulations were developed with dimyristoyl phosphatidylcholine [F-1a] and soya phosphatidylcholine [F-2a], along with egg phosphatidyl glycerol and cholesterol. AmB was dissolved in acidified dimethyl acetamide and mixed with ethanolic lipid solution and rapidly injected in 5% dextrose to prepare liposomes. Liposomes were characterized on the basis of size (~100?nm), zeta (–43.3?±?2.8 mV) and percent entrapment efficiency (>95%). The in vitro release study showed an insignificant difference (P?≥?0.05) for 24-hour release between marketed AmB liposomes (AmBisome) and F-1a and F-2a. Proliposome concentrate, used for the preparation of in situ liposomes, was physically stable for more than 3 months at experimental conditions. Similarly, AmB showed no sign of degradation in reconstituted liposomes stored at 2–8°C for more than 3 months. IC₅₀ value of Ambisome (0.18 µg/mL) was comparatively similar to F-1a (0.17 µg/mL) and F-2a (0.16 µg/mL) against intramacrophagic amastigotes. Under experimental conditions, a novel modified method for AmB liposomes is a great success and generates interest for development as a platform technology for many therapeutic drug products.     

Development of an experimental laboratory fertilization protocol for the South African abalone,Haliotis midae (Linnaeus 1758)

In this study, effective gamete concentrations, egg viability, and fertilization volumes were evaluated for Haliotis midae (L.). Sperm concentrations between 5?×?10³ and 5?×?10⁴?mL^?1 (p?>?0.05) consistently resulted in high hatch-out rates (96?±?1%). At concentrations higher than 5?×?10⁵?mL^?1, hatch-out rates decreased to 69?±?7% (p??1 resulted in high fertilization rates, with 50?eggs?mL^?1 being the ideal concentration for fertilization in H. midae. Egg viability was consistently high up to 100?min post-spawning, with a decrease in hatch-out success, when eggs were fertilized 120?min post-spawning. Fertilization volumes did not affect successful hatch-out. The results from this study can be implemented by South African abalone farms to increase hatch-out rates and subsequent culture. It can also be used as basis for the development of fertilization protocols in other marine invertebrate species.     

Analysis of myosmine,cotinine and nicotine in human toenail,plasma and saliva

Myosmine is a minor tobacco alkaloid with widespread occurrence in the human diet. Myosmine is genotoxic in human cells and is readily nitrosated and peroxidated yielding reactive intermediates with carcinogenic potential. For biomonitoring of short-term and long-term exposure, analytical methods were established for determination of myosmine together with nicotine and cotinine in plasma, saliva and toenail by gas chromatography–mass spectrometry (GC/MS). Validation of the method with samples of 14 smokers and 10 non-smokers showed smoking-dependent differences of myosmine in toenails (66?±?56 vs 21?±?15?ng?g^?1, p?<0.01) as well as saliva (2.54?±?2.68 vs 0.73?±?0.65?ng ml^?1, p <0.01). However, these differences were much smaller than those with nicotine (1971?±?818 vs 132?±?82?ng g^?1, p <0.0001) and cotinine (1237?±?818 vs <35?ng?g^?1) in toenail and those of cotinine (97.43?±?84.54 vs 1.85?±?4.50?ng ml^?1, p <0.0001) in saliva. These results were confirmed in plasma samples from 84 patients undergoing gastro-oesophageal endoscopy. Differences between 25 smokers and 59 non-smokers are again much lower for myosmine (0.30?±?0.35 vs 0.16?±?0.18?ng?ml^?1, p <0.05) than for cotinine (54.67?±?29.63 vs 0.61?±?1.82?ng ml^?1, p <0.0001). In conclusion, sources other than tobacco contribute considerably to the human body burden of myosmine.     

Effect of time of day on soccer specific skills in children: psychological and physiological responses

The aim of this study was to examine the effect of time of day on soccer-specific skills and physiological and psychological parameters in children. Ten male children soccer players (age: 14.6?±?0.8 years; height: 1.63?±?0.4 m; body mass: 52.5?±?4.9 kg) performed two shooting accuracy tests before and after a 10?×?20-m dribbling sprint test with 20-s of passive recovery between repetitions. The measurements were taken at 08:00 h, 13:00 h, and 17:00 h in a randomized order. Mean heart rate (HR) was monitored during the dribbling test. At the beginning of each test session, blood pressure and intra-aural temperature were measured. Likewise, children were asked to complete the profile of mood state (POMS) and the Hooper Index questionnaires. Lactate concentration ([La]) was recorded at rest, post-fifth recovery periods and post-second accuracy test. Moreover, they indicate their rating of perceived exertion (RPE) score immediately at the end of each test session. The results of this study showed that dribbling performance was higher at 13:00 h and 17:00 h in comparison with 08:00 h (p?p?r?=?0.6, p?相似文献   

Mechanistic studies on human N-acetylgalactosamine kinase

N-Acetylgalactosamine kinase (GALK2) is a small molecule kinase from the GHMP family which phosphorylates N-acetylgalactosamine at the expense of ATP. Recombinant GALK2 expressed in, and purified from, Escherichia coli was shown to be active with the following kinetic parameters: Michaelis constant for ATP, 14?±?3?μM; Michaelis constant for N-acetylgalactosamine, 40?±?14?μM; and turnover number, 1.0?±?0.1?s^?1. The combination of substrate inhibition by N-acetylgalactosamine and α-methylgalactopyranoside acting as an uncompetitive inhibitor with respect to ATP suggested that the enzyme has an ordered ternary complex mechanism in which ATP is the first substrate to bind. The effects of pH on the kinetic parameters provided evidence for ionizable residues playing a role in substrate binding and catalysis. These results are discussed in the context of the mechanisms of the GHMP kinases.     

Effects of traditional insecticides on Habrobracon hebetor (Hymenoptera: Braconidae): bioassay and life-table assays

The lethal and sublethal effects of the insecticides chlorpyriphos and fenpropathrine, which are overused in tomato production, were evaluated on the larval, pupal and adult stages of the parasitoid Habrobracon hebetor in the laboratory. Dose-response bioassays were carried out on immature and adult stages by using dipping and contact residue methods, respectively. The LC₅₀ of chlorpyriphos varied from 40 to 2000 times less than the recommended field rate and 10–100 times less for fenpropathrine treatments on the different life-history stages. To assess the sublethal effects, all life-history stages were exposed to LC₂₅ equivalent concentration of each insecticide and the demographic parameters of surviving parasitoids were studied. In LC₂₅ tests on adult stage, mean longevity and fecundity showed significant differences between chlorpyriphos (15.93?±?1.37 d and 128.20?±?20.20 eggs) and fenpropathrine (12.76?±?0.78 d and 124.00?±?12.27 eggs) as compared with the control (20.41?±?0.72 d and 281.00?±?12.95 eggs). In addition, net reproductive rate and intrinsic rate of increase indicated significant differences between chlorpyriphos (22.89?±?6.43 and 0.19?±?0.02) and fenpropathrine (14.44?±?3.58 and 0.17?±?0.02) as compared with the control (55.55?±?12.54 and 0.24?±?0.02). Briefly, we can conclude that both insecticides had negative effects on H. hebetor. However, the negative effect of fenpropathrine on r_m was higher than that of chlorpyriphos. In conclusion, field studies are recommended to determine the total effects of these insecticides on H. hebetor.     

Comparison of sensory tests and neuronal quantity of peripheral nerves between streptozotocin (STZ)-induced diabetic rats and paclitaxel (PAC)-treated rats

Although diabetic peripheral neuropathy (DPN) and chemotherapy-induced peripheral neuropathy (CIPN) are different disease entities, they share similar neuropathic symptoms that impede quality of life for these patients. Despite having very similar downstream effects, there have been no direct comparisons between DPN and CIPN with respect to symptom severity and therapeutic responses. We compared peripheral nerve damage due to hyperglycemia with that caused by paclitaxel (PAC) treatment as represented by biochemical parameters, diverse sensory tests, and immunohistochemistry of cutaneous and sciatic nerves. The therapeutic effects of alpha-lipoic acid and DA-9801 were also compared in the two models. Animals were divided into seven groups (n?=?7–10) as follows: normal, diabetes (DM), DM?+?alpha-lipoic acid 100?mg/kg (ALA), DM?+?DA-9801 (100?mg/kg), paclitaxel-treated rat (PAC), PAC?+?ALA (100?mg/kg), and PAC?+?DA-9801 (100?mg/kg). The sensory thresholds of animals to mechanical, heat, and pressure stimuli were altered by both hyperglycemia and PAC when compared with controls, and the responses to sensory tests were different between both groups. There were no significant differences in the biochemical markers of blood glutathione between DM and PAC groups (p?>?.05). Quantitative comparisons of peripheral nerves by intraepidermal nerve fiber density (IENFD) analysis indicated that the DM and PAC groups were similar (6.18?±?1.03 vs. 5.01?±?2.57). IENFD was significantly improved after ALA and DA-9801 treatment in diabetic animals (7.6?±?1.28, 7.7?±?1.28, respectively, p?p?>?.05). Sciatic nerves were less damaged in the PAC-treated groups compared with the DM groups with respect to axonal diameter and area (8.60?±?1.14?μm vs. 6.66?±?1.07?μm, and 59.04?±?15.16?μm² vs. 35.71?±?11.2?μm², respectively, p?相似文献   

Effects of Long-Term Fixed Orthodontic Treatment on Salivary Nickel and Chromium Levels: a 1-Year Prospective Cohort Study

Effect of long-term orthodontic treatment on salivary nickel and chromium has not been quite assessed except in few retrospective studies with controversial results. The aim of this prospective study was to measure salivary levels of these ions during 1?year of orthodontic treatment. Saliva samples were collected from 20 orthodontic patients, before treatment (control) and 6 and 12?months later. Nickel and chromium concentrations were determined using atomic absorption spectrophotometry. Data were analyzed using one- and two-way repeated-measures ANOVA, Bonferroni, Friedman (???=?0.05), and Wilcoxon signed-ranks tests (???=?0.016). Average nickel level changed from 9.75?±?5.02 to 10.37?±?6.94 and then to 8.32?±?4.36???g/L in 1?year. Average chromium concentration changed from 3.86?±?1.34 to 4.6?±?6.11 and then to 2.04?±?1.66???g/L. Alterations in nickel values were not statistically significant [P?=?0.468 (ANOVA)], but fluctuations in chromium levels were [P?=?0.021 (Friedman)]. The decrease in chromium concentration after 12?months was significant compared to the control [P?=?0.004 (Wilcoxon)]. Although slightly increased after 6?months, the concentration of both ions dropped to levels slightly lower than the control groups after 12?months.