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1.
The purpose of this research was to compare three different methods for the aerodynamic assessment of (1) chloroflurocarbon
(CFC)-fluticasone propionate (Flovent), (2) CFC-sodium cromoglycate (Intal), and (3) hydrofluoroalkane (HFA)-beclomethasone
dipropionate (Qvar) delivered by pressurized metered dose inhaler. Particle size distributions were compared determining mass
median aerodynamic diameter (MMAD), geometric standard deviation (GSD), and fine particle fraction <4.7 μm aerodynamic diameter
(FPF<4.7 μm). Next Generation Pharmaceutical Impactor (NGI)-size distributions for Flovent comprised finer particles than determined
by Andersen 8-stage impactor (ACI) (MMAD=2.0±0.05 μm [NGI]; 2.8±0.07 μm [ACI]); however FPF<4.7 μm by both impactors was in the narrow range 88% to 93%. Size distribution agreement for Intal was better (MMAD=4.3±0.19 μm
(NGI), 4.2±0.13 μm (ACI), with FPF<4.7 μm ranging from 52% to 60%. The Aerodynamic Particle Sizer (APS) undersized aerosols produced with either formulation (MMAD=1.8±0.07
μm and 3.2±0.02 μm for Flovent and Intal, respectively), but values of FPF<4.7 μm from the single-stage impactor (SSI) located at the inlet to the APS (82.9%±2.1% [Flovent], 46.4%±2.4% [Intal]) were fairly
close to corresponding data from the multi-stage impactors. APS-measured size distributions for Qvar (MMAD=1.0±0.03 μm; FPF<4.7 μm=96.4% ±2.5%), were in fair agreement with both NGI (MMAD=0.9±0.03 μm; FPF<4.7 μm=96.7%±0.7%), and ACI (MMAD=1.2±0.02 μm, FPF<4.7 μm=98%±0.5%), but FPF<4.7 μm from the SSI (67.1%±4.1%) was lower than expected, based on equivalent data obtained by the other techniques. Particle bounce,
incomplete evaporation of volatile constituents and the presence of surfactant particles are factors that may be responsible
for discrepancies between the techniques. 相似文献
2.
This investigation was undertaken to evaluate practical feasibility of site specific pulmonary delivery of liposomal encapsulated
Dapsone (DS) dry powder inhaler for prolonged drug retention in lungs as an effective alternative in prevention of Pneumocystis carinii pneumonia (PCP) associated with immunocompromised patients. DS encapsulated liposomes were prepared by thin film evaporation
technique and resultant liposomal dispersion was passed through high pressure homogenizer. DS nano-liposomes (NLs) were separated
by ultra centrifugation and characterized. NLs were dispersed in phosphate buffer saline (PBS) pH 7.4 containing different
carriers like lactose, sucrose, and hydrolyzed gelatin, and 15% l-leucine as antiadherent. The resultant dispersion was spray dried and spray dried formulation were characterized to ascertain
its performance. In vitro pulmonary deposition was assessed using Andersen Cascade Impactor as per USP. NLs were found to have average size of 137 ± 15 nm,
95.17 ± 3.43% drug entrapment, and zeta potential of 0.8314 ± 0.0827 mV. Hydrolyzed gelatin based formulation was found to
have low density, good flowability, particle size of 7.9 ± 1.1 μm, maximum fine particle fraction (FPF) of 75.6 ± 1.6%, mean
mass aerodynamic diameter (MMAD) 2.2 ± 0.1 μm, and geometric standard deviation (GSD) 2.3 ± 0.1. Developed formulations were
found to have in vitro prolonged drug release up to 16 h, and obeys Higuchi's Controlled Release model. The investigation provides a practical approach
for direct delivery of DS encapsulated in NLs for site specific controlled and prolonged release behavior at the site of action
and hence, may play a promising role in prevention of PCP. 相似文献
3.
Oze H Hirao M Ebina K Shi K Kawato Y Kaneshiro S Yoshikawa H Hashimoto J 《In vitro cellular & developmental biology. Animal》2012,48(2):123-130
Previous studies have demonstrated that oxygen environment is an important determinate factor of cell phenotypes and differentiation,
although factors which affect pericellular oxygen concentration (POC) in murine chondrogenic cell culture remain unidentified.
Oxygen concentrations in vivo were measured in rabbit musculoskeletal tissues, which were by far hypoxic compared to 20% O2 (ranging from 2.29 ± 1.16 to 4.36 ± 0.51%). Oxygen concentrations in murine chondrogenic cell (C3H10T1/2) culture medium
were monitored in different oxygen concentrations (20% or 5%) in the incubator and in different medium volumes (3,700 or 7,400 μl)
within 25-cm2 flasks. Chondrogenic differentiation was assessed by glycosaminoglycan production with quantitative evaluation of Alcian
blue staining in 12-well culture dishes. Expression of chondrogenic genes, aggrecan, and type II collagen α1, was examined
by quantitative real-time polymerase chain reaction. Oxygen concentrations in medium decreased accordingly with the depth
from medium surface, and POC at Day 6 was 18.99 ± 0.81% in 3,700-μl medium (1,480-μm depth) and 13.26 ± 0.23% in 7,400-μl
medium (2,960-μm depth) at 20% O2 in the incubator, which was 4.96 ± 0.08% (1,480-μm depth) and 2.83 ± 0.42% (2,960-μm depth) at 5% O2, respectively. The differences of POC compared by medium volume were statistically significant (p = 0.0003 at 20% and p = 0.001 at 5%). Glycosaminoglycan production and aggrecan gene expression were most promoted when cultured in moderately
low POC, 1,000 μl (2,960-μm depth) at 20% O2 and 500 μl (1,480-μm depth) at 5% O2 in 12-well culture dishes. We demonstrate that medium volume and oxygen concentration in the incubator affect not only POC
but also chondrogenic differentiation. 相似文献
4.
Morphological and Genetic Characterization of <Emphasis Type="Italic">Saimiri boliviensis</Emphasis>
Eliana Ruth Steinberg Mariela Nieves Marina Sofía Ascunce Ana María Palermo Marta Dolores Mudry 《International journal of primatology》2009,30(1):29-41
The taxonomy of Saimiri is controversial because morphological characteristics, traditionally used for identification, are insufficient to distinguish
species and subspecies. Genetic studies of specimens become relevant for captive management, especially considering their
frequently unknown geographical origin. We analyzed phenotypic and genetic parameters in Saimiri spp. in Argentinean zoological gardens and biological stations to provide a more accurate taxonomic identification. We studied
27 males and 19 females of Saimiri spp. The cytogenetic analysis in mitotic metaphases corroborated a modal number of 2N = 44, XX/XY, and FN = 75 for males
and FN = 76 for females. G- and C-bands, fluorescence in situ hybridization (FISH) and the pelage coloration pattern of all the specimens corresponded to Saimiri boliviensis boliviensis. We characterized for the first time the sperm cell morphology and morphometry (mean ± SE): total length: 71.39 ± 5.40 μm;
head length: 5.71 ± 0.81 μm; head width: 3.76 ± 0.70 μm; acrosome length: 3.70 ± 0.82 μm; midpiece length: 12.20 ± 2.22 μm.
Researchers can use the characterization of the sperm morphology as another parameter for taxonomic identification that, together
with cytogenetic and molecular ones, would allow a more precise identification of individual Saimiri boliviensis boliviensis. 相似文献
5.
Daisuke Sugimori 《Applied microbiology and biotechnology》2009,82(2):351-357
To develop a microbial treatment of edible oil-contaminated wastewater, microorganisms capable of rapidly degrading edible
oil were screened. The screening study yielded a yeast coculture comprising Rhodotorula pacifica strain ST3411 and Cryptococcus laurentii strain ST3412. The coculture was able to degrade efficiently even at low contents of nitrogen ([NH4–N] = 240 mg/L) and phosphorus sources ([PO4–P] = 90 mg/L). The 24-h degradation rate of 3,000 ppm mixed oils (salad oil/lard/beef tallow, 1:1 w/w) at 20°C was 39.8% ± 9.9% (means ± standard deviations of eight replicates). The highest degradation rate was observed at
20°C and pH 8. In a scaled-up experiment, the salad oil was rapidly degraded by the coculture from 671 ± 52.0 to 143 ± 96.7 ppm
in 24 h, and the degradation rate was 79.4% ± 13.8% (means ± standard deviations of three replicates). In addition, a repetitive
degradation was observed with the cell growth by only pH adjustment without addition of the cells. 相似文献
6.
In the present study attempt was made for preparation of isotretinoin-hydroxypropyl β cyclodextrin (HP-β-CD) inclusion complex
and encapsulate this complex in elastic liposomes to study the effect of dual carrier approach on skin targeting of isotretinoin.
The isotretinoin HP-β-CD complex was prepared by freeze-drying method and characterized by IR spectroscopy. The drug and drug-CD
complex loaded elastic liposomal formulation were prepared and characterized in vitro, ex-vivo and in vivo for shape, size, entrapment efficiency, no. of vesicles per cubic mm, in vitro skin permeation and deposition study, photodegradation and skin toxicity assay. The transdermal flux for different vesicular
formulations was observed between 10.5 ± 0.5 to 13.9 ± 1.6 μg/cm2/h. This is about 15-21 folds higher than that obtained from drug solution (0.7 ± 0.1 μg/cm2/h) and 4-5 folds higher than obtained with drug-CD complex solution (2.7 ± 0.1 μg/cm2/h). The amount of drug deposit was found to increase significantly (p < 0.05) by cyclodextrin complexation (30.1 ± 0.1 μg). The encapsulation of this complex in elastic liposomal formulation
further increases its skin deposition (262.2 ± 21 μg). The results of skin irritation study using Draize test also showed
the significant reduction in skin irritation potential of isotretinoin elastic liposomal formulation in comparison to free
drug. The results of the present study demonstrated that isotretinoin elastic liposomal formulation possesses great potential
for skin targeting, prolonging drug release, reduction of photodegradation, reducing skin irritation and improving topical
delivery of isotretinoin. 相似文献
7.
Species and material considerations in the formation and development of microalgal biofilms 总被引:2,自引:0,他引:2
The development of microalgal biofilms has received very limited study despite its relevance in the design of photobioreactors
where film growth may be advantageous for biomass separation or disadvantageous in fouling surfaces. Here, the effects of
species selection, species control, and substrate properties on biofilms of Scenedesmus obliquus and Chlorella vulgaris were investigated. Experiments were conducted in batch culture and in continuous culture modes in a flow cell. Cell growth
was monitored using confocal laser scanning microscopy and gravimetrically. Species selection and species control had significant
effects on biofilm development. On non-sterile wastewater, C. vulgaris shifted from primarily planktonic (23.7% attachment) to primarily sessile (79.8% attachment) growth. The biofilms that developed
in non-sterile conditions were thicker (52 ± 19 μm) than those grown in sterile conditions (7 ± 6 μm). By contrast, S. obliquus attained similar thicknesses (54 ± 31 and 53 ± 38 μm) in both sterile and non-sterile conditions. Neither species was able
to dominate a non-sterile biofilm. The effect of substrate surface properties was minimal. Both species grew films of similar
thickness (∼30 μm for S. obliquus, <10 μm for C. vulgaris) on materials ranging from hydrophilic (glass) to hydrophobic (polytetrafluoroethylene). Surface roughness created by micropatterning
the surface with 10 μm grooves did not translate into long-term increases in biofilm thickness. The results indicate that
species selection and control are more important than surface properties in the development of microalgal biofilms. 相似文献
8.
Selenium concentrations in the blood of 112 (56 females and 56 males) normal subjects, from different regions of the Punjab
(Pakistan), have been determined using the technique of inductively coupled plasma-mass spectrometry. The whole blood selenium
concentrations were found to be 452 ± 12 ppb (parts per billion or nano-gram of Se per gram freeze-dried blood or 96 ± 3 μg/L
), with 470 ± 16 ppb (or 100 ± 4 μg/L) in female and 435 ± 16 ppb (or 92 ± 4 μg/L) in male population. Compared with other
populations of the world, these levels are amongst the lowest. 相似文献
9.
Rahman A Azad MA Hossain I Qusar MM Bari W Begum F Huq SM Hasnat A 《Biological trace element research》2009,127(2):102-108
The purpose of the study was to determine the concentration of trace elements present in scalp hair sample of schizophrenic
patients and to find out the relationship between trace elements level and nutritional status or socioeconomic factors. The
study was conducted among 30 schizophrenic male patients and 30 healthy male volunteers. Patients were recruited from Bangabandhu
Sheikh Mujib Medical University by random sampling. Hair trace element concentrations were determined by flame atomic absorption
spectroscopy and analyzed by independent t test, Pearson’s correlation analysis, regression analysis, and analysis of variance (ANOVA). Mn, Zn, Ca, Cu, and Cd concentrations
of schizophrenic patients were 3.8 ± 2.31 μg/gm, 171.6 ± 59.04 μg/gm, 396.23 ± 157.83 μg/gm, 15.40 ± 5.68 μg/gm, and 1.14 ± 0.89 μg/gm
of hair sample, while those of control subjects were 4.4 ± 2.32 μg/gm, 199.16 ± 27.85 μg/gm, 620.9 ± 181.55 μg/gm, 12.23 ± 4.56 μg/gm,
and 0.47 ± 0.32 μg/gm of hair sample, respectively. The hair concentration of Zn and Ca decreased significantly (p = 0.024; p = 0.000, respectively) and the concentration of Cu and Cd increased significantly (p = 0.021; p = 0.000, respectively) in schizophrenic patients while the concentration of Mn (p = 0.321) remain unchanged. Socioeconomic data reveals that most of the patients were poor, middle-aged and divorced. Mean
body mass indices (BMIs) of the control group (22.26 ± 1.91 kg/m2) and the patient group (20.42 ± 3.16 kg/m2) were within the normal range (18.5−25.0 kg/m2). Pearson’s correlation analysis suggested that only Ca concentration of patients had a significant positive correlation
with the BMI (r = 0.597; p = 0.000) which was further justified from the regression analysis (R
2 = 44%; t = 3.59; p = 0.002) and one-way ANOVA test (F = 3.62; p = 0.015). A significant decrease in the hair concentration of Zn and Ca as well as a significant increase in the hair concentration
of Cu and Cd in schizophrenic patients than that of its control group was observed which may provide prognostic tool for the
diagnosis and treatment of this disease. However, further work with larger population is suggested to examine the exact correlation
between trace element level and the degree of disorder. 相似文献
10.
Alma R. López-Laredo Fanny D. Ramírez-Flores Gabriela Sepúlveda-Jiménez Gabriela Trejo-Tapia 《In vitro cellular & developmental biology. Plant》2009,45(5):550-558
Tecoma stans is a tropical plant from the Americas. Antioxidant activity and both phenolic compound and flavonoid total content were determined
for callus tissue of T. stans cultured in either a set photoperiod or in darkness. Callus lines from three explant types (hypocotyls, stem, and leaf) were
established on B5 culture medium supplemented with 0.5 μM 2,4-D and 5.0 μM kinetin. While leaf-derived callus grew slower
under a 16-h photoperiod (specific growth rate, μ = 0.179 d−1, t
D = 3.9 d) than in darkness (μ = 0.236 d−1, t
D = 2.9 d), it accumulated the highest amount (p < 0.05) of both phenolics (86.6 ± 0.01 mg gallic acid equivalents/g) and flavonoids (339.6 ± 0.06 mg catechin equivalents/g).
Similarly, antioxidant activity was significantly higher (p < 0.05) when callus was cultured in period light than when grown in extended darkness. Antioxidant activity measured with
a 2,20-azinobis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt (ABTS)-based assay was 350.5 ± 15.8 mmol Trolox/g
extract for callus cultured under a defined photoperiod compared to 129.1 ± 7.5 mmol Trolox/g extract from callus cultured
in darkness. Content of phenolic compounds and flavonoids was in agreement with a better antioxidant power (EC50 = 450 μg extract/mg 1,1-diphenyl-2-picrylhydrazyl) and antiradical efficiency. Results of the present study show that calli
of T. stans are a source of compounds with antioxidant activity that is favored by culture under a set photoperiod. 相似文献
11.
Deficiencies in Cu, Se, and Zn impair one or more biochemical functions, and excess are associated with toxicity. Baseline
studies on the Ghanaian population are scanty. The study was undertaken to determine whether significant rural/urban differences
in the serum levels of Cu, Se, and Zn did exist. Forty males/60 females from rural and 50 males/50 females from urban Ghanaian
communities were sampled. Serum Cu, Se, and Zn were determined using flame atomic absorption spectrometry. Cu level for rural
and urban subjects was 997 ± 333 and 979 ± 290 μg/L, respectively (p = 0.68). However, Cu levels were significantly higher in the rural females (1,063 ± 367 μg/L) than the rural males (898 ± 249 μg/L;
p = 0.0085). Se levels for rural/urban subjects were 97 ± 36 and 87 ± 31 μg/L, respectively (p = 0.03). Zn levels in the rural/urban subjects were 312 ± 218 and 150 ± 102 μg/L, respectively (p = 0.002). Additionally, Zn was significantly higher in rural females (428 ± 204 μg/L) than the urban females (166 ± 103 μg/L;
p = 0.0002). Finally, Zn was significantly higher in rural females (428 ± 204 μg/L) than males (172 ± 116 μg/L; p = 0.0028). In conclusion, Cu, Se, and Zn were higher in the rural group compared to the urban group, and the generally low
Zn levels were confirmed in another cohort follow-up study. 相似文献
12.
In a co-culture of dissociated neurons of lumbar dorsal root ganglia (DRG) and spinal dorsal horn (DH) neurons of newborn
rats, we examined peculiarities of induction of long-term depression (LTD) of synaptic transmission through synapses formed
by primary afferents on DH neurons. Induction of LTD was provided by low-frequency (5 sec−1) microstimulation of single DRG neurons. Ion currents were simultaneously recorded in pre- and post-synaptic cells using
a dual whole-cell path-clamp technique. Parameters of evoked excitatory and inhibitory postsynaptic currents (eEPSCs and eIPSCs,
respectively) initiated in DH neurons by intracellular stimulation of DRG neurons were analyzed. Monosynaptic eEPSC mediated
by activation of AMPA receptors demonstrated no sensitivity to blockers of NMDA and kainate receptors (20 μM DL-AP5 and 10 μM SIM 2081, respectively), but were entirely blocked upon applications of 10 μM DNQX. Monosynaptic glycinergic
eIPSCs found in some of the DH neurons were blocked by 1 μM strychnine and were insensitive to 10 μM bicuculline and blockers
of glutamatergic neurotransmission, DL-AP5 and DNQX. Long-lasting (360 sec) low-frequency stimulation of DRG neurons did not affect the amplitude of glycineinduced
eIPSCs in DH neurons. At the same time, such stimulation of DRG neurons evoked a drop in the amplitude of AMPA-activated eEPSCs
in DH neurons to 41.6 ± 2.5%, on average, as compared with the analogous index in the control. This effect lasted at least
20 min after stimulation. Long-term depression of glutamatergic transmission in DH neurons was observed at the holding potential
of −70 mV and did not change after applications of 10 μM bicuculline and 1 μM strychnine. The LTD intensity depended on the
duration of low-frequency stimulation of primary afferent neurons. Sequential stimulation of DRG neurons lasting 120, 160,
200, and 240 sec resulted in decreases in the eEPSC amplitude in DH neurons to 85.6 ± 3.9, 62.7 ± 4.3, 51.8 ± 3.5, and 41.6
±2.5% with respect to control values. Our findings show that use-dependent induction of homosynaptic LTD of glutamatergic
transmission is possible at the level of a separate pair of synaptically connected DRG and DH neurons under co-culturing conditions.
Such LTD of glutamatergic synaptic transmission mostly mediated by activation of AMPA receptors depends on the duration of
activation of a presynaptic DRG neuron and does not need depolarization of a postsynaptic DH neuron. 相似文献
13.
Federico A. Gutiérrez-Miceli Lourdes Arias Nicolás Juarez-Rodríguez Miguel Abud-Archila Aldo Amaro-Reyes Luc Dendooven 《In vitro cellular & developmental biology. Plant》2010,46(1):57-63
This paper reports on the optimum concentrations of naphthalene acetic acid (NAA) and 6-benzyladenine (BA) to stimulate callus
growth and NAA; kinetin and silver nitrate (AgNO3) for callus redifferentiation in Dianthus caryophyllus L. Meristems were excised and placed in MS medium with 30 g l−1 sucrose and 9.0 μM 2,4-d. Callus clusters were transferred to MS medium containing NAA (0, 1.7, 3.3, and 5.0 μM) and BA (0, 1.7, 3.3, and 5.0 μM)
for proliferation and to MS medium with 30 g l−1 sucrose, 2.5 g l−1 phytagel, kinetin (0, 33, and 66 μM); NAA (0, 7.95, and 15.9 μM) and AgNO3 (0, 23.54 and 47.08 μM) for shoot and root induction. Treatments were applied according to a Box–Behnken design. After callus
growth and redifferentiation, plants were incubated in the greenhouse at 18 ± 2°C for 4 wk and at 20–26°C for 4 wk. Finally,
plants were changed to near-commercial greenhouse conditions with different day (30–35°C) and night (16–24°C) temperatures.
Results showed better callus growth at higher NAA concentrations. A maximum callus weight was found with 5.0 μM NAA but without
BA. A maximum of 78% calluses with shoots was obtained with 15.9 μM NAA, 47.08 μM AgNO3, and 0.74 μM kinetin and 58% with roots with 15.7 μM NAA and 47.08 μM AgNO3, but without kinetin. The shoots obtained showed little hyperhydricity. Vigorous plants were obtained after gradual acclimatization
with an 80% survival rate under nursery conditions. 相似文献
14.
Molybdenum Content of Canadian and US Infant Formulas 总被引:1,自引:0,他引:1
Molybdenum is an essential trace nutrient in the human diet. Our purpose was to provide a comprehensive analysis of Mo content
of various types of powdered infant formulas across Canada and the USA. All infant formulas, available on the day of sampling,
were purchased from random supermarkets in Grand Forks, ND, USA; San Diego, CA, USA; Washington, DC, USA; and Winnipeg, MB,
Canada. Reference powdered milk, human milk (HM), and formula samples were weighed and acid-digested prior to analysis by
graphite furnace atomic absorption spectroscopy. Mo content in all formulas ranged from 15.4 to 80.3 μg/L (mean ± SE, 37.7 ± 1.7 μg/L).
HM Mo concentration ranged from 1.5 to 9.5 μg/L (5.09 ± 0.81 μg/L). Formulas intended for full-term or for premature infants
feeding contained, on average, more Mo than HM. Formulas intended for infants with special needs contained similar mean Mo
levels to HM. No significant differences were detected between mean Mo values of formulas of a same type purchased from different
brands and/or at different locations. High Mo intake may pose health risks, despite lower bioavailability of Mo from formula
compared with HM. 相似文献
15.
Riddhika Kalle Tharmalingam Ramesh Qamar Qureshi Kalyanasundaram Sankar 《Acta theriologica》2011,56(4):335-342
Density of tiger Panthera tigris and leopard Panthera pardus was estimated using photographic capture–recapture sampling in a tropical deciduous forest of Mudumalai Tiger Reserve, southern
India, from November 2008 to February 2009. A total of 2,000 camera trap nights for 100 days yielded 19 tigers and 29 leopards
within an intensive sampling area of 107 km2. Population size of tiger from closed population estimator model Mb Zippin was 19 tigers (SE = ±0.9) and for leopards Mh Jackknife estimated 53 (SE = ±11) individuals. Spatially explicit maximum likelihood and Bayesian model estimates were 8.31
(SE = ±2.73) and 8.9 (SE = ±2.56) per 100 km2 for tigers and 13.17 (SE = ±3.15) and 13.01 (SE = ±2.31) per 100 km2 for leopards, respectively. Tiger density for MMDM models ranged from 6.07 (SE = ±1.74) to 9.72 (SE = ±2.94) per 100 km2 and leopard density ranged from 13.41 (SE = ±2.67) to 28.91 (SE = ±7.22) per 100 km2. Spatially explicit models were more appropriate as they handle information at capture locations in a more specific manner
than some generalizations assumed in the classical approach. Results revealed high density of tiger and leopard in Mudumalai
which is unusual for other high density tiger areas. The tiger population in Mudumalai is a part of the largest population
at present in India and a source for the surrounding Reserved Forest. 相似文献
16.
The present research work was aimed to formulate clotrimazole encapsulated Cavamax W7 composite ethosomes by injection method
for improved delivery across epidermis. 32 factorial design was used to design nine formulations (F1-F9) and compared with ethosomal formulations (F10-F12). F9 with
vesicle size of 202.8 ± 4.8 nm, highest zeta potential (−83.6 ± 0.96 mV) and %EE of 98.42 ± 0.15 was selected as optimized
composite ethosome and F12 as reference ethosomal formulation. As revealed by transmission electron microscopy F9 vesicles
were more condensed, uniformly spherical in shape than F12 vesicles. Vesicular stability studies indicated F9 to be more stable
as compared to F12. Both F9 and F12 were incorporated in carbopol 934 gel base to get G1–G8 gel formulations and evaluated
for in vitro skin permeability. Cavamax W7 composite ethosomal optimized gel (G5) showed higher in vitro percent cumulative drug permeation (88.53 ± 2.10%) in 8 h and steady state flux (J
ss) of 3.39 ± 1.45 μg/cm2/min against the J
ss of 1.57 ± 0.23 μg/cm2/min for ethosomal gel (G1) and 1.13 ± 0.06 μg/cm2/min for marketed formulation. The J
ss flux of G5 was independent of amount of drug applied/unit area of skin. In vivo confocal laser scanning microscopic study of G5 depicted uniform and deeper penetration of rhodamine B (marker) in epidermis
from Cavamax W7 composite ethosomal gel in comparison to G1. Finally, G5 demonstrated better (p < 0.05) antifungal activity against Candida albicans and Aspergillus niger than G1 thus, signifying that Cavamax W7 composite ethosomes present a superior stable and efficacious vesicular system than
ethosomal formulation for topical delivery of clotrimazole. 相似文献
17.
The purpose of this study was to develop and validate a rapid, sensitive, and specific reversed-phase high-performance liquid
chromatography method for the quantitative determination of native tenofovir (TNF) for various applications. Different analytical
performance parameters such as linearity, precision, accuracy, limit of quantification (LOQ), limit of detection (LOD), and
robustness were determined according to International Conference on Harmonization (ICH) guidelines. A Bridge™ C18 column (150 × 4.6 mm,
5 μm) was used as stationary phase. The retention time of TNF was 1.54 ± 0.03 min (n = 6). The assay was linear over the concentration range of 0.1–10 μg/mL. The proposed method was sensitive with LOD and LOQ
values equal to 50 and 100 ng/mL, respectively. The method was accurate with percent mean recovery from 95.41% to 102.90%
and precise as percent RSD (relative standard deviation) values for intra-day, and inter-day precision were less than 2%.
This method was utilized for the estimation of molar absorptivity of TNF at 259 nm (ε
259 = 12,518 L/mol/cm), calculated from linear regression analysis. The method was applied for determination of percentage of
encapsulation efficiency ( 22.93 ± 0.04%), drug loading (12.25 ± 1.03%), in vitro drug release profile in the presence of enzyme (43% release in the first 3 h) and purification analysis of hyaluronic acid-based
nanomedicine. 相似文献
18.
Codium fragile (Suringar) Hariot is an edible green alga farmed in Korea using seed stock produced from regeneration of isolated utricles
and medullary filaments. Experiments were conducted to reveal the optimal conditions for nursery culture and out-growing of
C. fragile. Sampling and measurement of underwater irradiance were carried out at farms cultivating C. fragile at Wando, on the southwestern coast of Korea, from October 2004 to August 2005. Growth of erect thalli and underwater irradiance
were measured over a range of depths for three culture stages. During the nursery cultivation stage (Stage I), growth rate
was greatest at 0.5 m depth (0.055 ± 0.032 mm day−1), where the average midday irradiance over 60 days was 924 ± 32 μmol photons m−2 s−1. During the pre-main cultivation stage (Stage II), the greatest growth rate occurred at a depth of 2 m (0.113 ± 0.003 mm day−1) with an average irradiance of 248 ± 116 μmol photons m−2 s−1. For the main cultivation stage (Stage III) of the alga, thalli achieved the greatest increase in biomass at 1 m depth (7.2 ± 1.0 kg
fresh wt m−1). These results suggest that optimal growth at each cultivation stages of C. fragile could be controlled by depth of cultivation rope. 相似文献
19.
Bergman O Haber M Mayzel B Anderson MA Shpigel M Hill RT Ilan M 《Marine biotechnology (New York, N.Y.)》2011,13(6):1169-1182
Marine organisms including sponges (Porifera) contain many structurally diverse bioactive compounds, frequently in a low concentration that hampers their commercial production.
Two solutions to this problem are: culturing sponge explants for harvesting the desired compound and cultivation of sponge-associated
bacteria. These bacteria (often considered the source of the desired compounds) include the Actinobacteria, from which many
novel drugs were developed. In a long-term experiment (lasting 767 days), we evaluated the culture amenability of the sponge
Diacarnus erythraenus in a mariculture system, placed at 10- and 20-m depths. The growth and survival rates of sponge fragments were monitored.
Wild and maricultured sponges from both depths and their larvae were sampled at different time intervals for denaturing gradient
gel electrophoresis (DGGE) profiling of the bacterial community residing within them. 16S rRNA gene sequences of both cultured
bacterial isolates and clone libraries of unculturable bacteria were composed and compared, focusing on Actinobacteria. Sponges
from both depths did not differ significantly either in mean growth rates (percent weight change year−1 ± S.E.) (64.5% ± 21% at 10 m and 79.3% ± 19.1% at 20 m) or in seasonal growth rates. Survival was also very similar (72%
at 10 m and 70% at 20 m). There were 88 isolates identified from adults and 40 from their larvae. The isolates and clone libraries
showed diverse bacterial communities. The DGGE profiles of wild and maricultured sponges differed only slightly, without a
significant effect of depths or dates of sampling. This long-term experiment suggests that D. erythraenus probably remained healthy and indicates its mariculture suitability. 相似文献
20.
Tumor cells have a high tolerance for acidic and hypoxic microenvironments, also producing abundant lactic acid through accelerated
glycolysis in the presence or absence of O2. While the accumulation of lactate is thought to be a major contributor to the reduction of pH-circumscribing aggressive
tumors, it is not known if other endogenous metabolic products contribute this acidity. Furthermore, anaerobic metabolism
in cancer cells bears similarity to homo-fermentative lactic acid bacteria, however very little is known about an alternative
pathway that may drive adenosine triphosphate (ATP) production independent of glycolysis. In this study, we quantify over
40 end-products (amines, acids, alcohols, aldehydes, or ketones) produced by malignant neuroblastoma under accelerated glycolysis
(+glucose (GLU) supply 1–10 mM) ± mitochondrial toxin; 1-methyl-4-phenylpyridinium (MPP+) to abate aerobic respiration to delineate differences between anaerobic vs. aerobic cell required metabolic pathways. The
data show that an acceleration of anaerobic glycolysis prompts an expected reduction in extracellular pH (pHex) from neutral to 6.7 ± 0.006. Diverse metabolic acids associated with this drop in acidity were quantified by ionic exchange
liquid chromatography (LC), showing concomitant rise in lactate (Ctrls 7.5 ± 0.5 mM; +GLU 12.35 ± 1.3 mM; +GLU + MPP 18.1 ± 1.8 mM),
acetate (Ctrl 0.84 ± 0.13 mM: +GLU 1.3 ± 0.15 mM; +GLU + MPP 2.7 ± 0.4 mM), fumarate, and a-ketoglutarate (<10 μM) while a
range of other metabolic organic acids remained undetected. Amino acids quantified by o-phthalaldehyde precolumn derivatization/electrochemical detection–LC show accumulation of l-alanine (1.6 ± .052 mM), l-glutamate (285 ± 9.7 μM), l-asparagine (202 ± 2.1 μM), and l-aspartate (84.2 ± 4.9 μM) produced during routine metabolism, while other amino acids remain undetected. In contrast, the
data show no evidence for accumulation of acetaldehyde, aldehydes, or ketones (Purpald/2,4-dinitrophenylhydrazine—Brady's
reagent), acetoin (Voges–Proskauer test), or alcohols (NAD+-linked alcohol dehydrogenase). In conclusion, these results provide preliminary evidence to suggest the existence of an active
pyruvate–alanine transaminase or phosphotransacetylase/acetyl-CoA synthetase pathway to be involved with anaerobic energy
metabolism of cancer cells. 相似文献