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Toxicology Reports 2020Rats were exposed 3 times a week during 6 weeks to repeated intraperitoneal injections of lead acetate solution in water (Pb) and/or benzo(а)pyrene solution in...
Rats were exposed 3 times a week during 6 weeks to repeated intraperitoneal injections of lead acetate solution in water (Pb) and/or benzo(а)pyrene solution in petrolatum oil (B(а)P) in various dose ratios. Towards the end of the period, the animals developed a moderate subchronic intoxication having some features characteristic of lead effects. The type of combined toxicity estimated with the help of isoboles constructed by the Response Surface Methodology was found to be varied depending on a particular effect, its level, and dose ratio. However, Pb and B(a)P in combination often displayed an additive or even superadditive action. In the group exposed to this combination compared with the group of rats exposed to B(a)P alone, its concentration in the organism was increased while the concentration of some B(a)P oxidative metabolism products was reduced. Such inhibition of B(a)P biotransformation, assumingly associated with impaired heme and, thus, cytochrome P450 synthesis induced by lead intoxication, can serve as an explanation for certain enhancement of the genotoxic effect of B(a)P. This effect was not present in the same combined intoxication if a complex of antitoxic bioprotectors was being administered in the background.
PubMed: 32874921
DOI: 10.1016/j.toxrep.2020.08.004 -
PloS One 2023Many animals display innate preferences for some odors, but the physiological mechanisms underlying these preferences are poorly understood. Here, with behavioral tests,...
Many animals display innate preferences for some odors, but the physiological mechanisms underlying these preferences are poorly understood. Here, with behavioral tests, we establish a model system well suited to investigating olfactory mechanisms, the locust Schistocerca americana. We conducted open field tests in an arena designed to provide only olfactory cues to guide navigation choices. We found that newly hatched locusts navigated toward, and spent more time near, the odor of wheat grass than humidified air. In similar tests, we found that hatchlings avoided moderate concentrations of major individual components of the food blend odor, 1-hexanol (1% v/v) and hexanal (0.9% v/v) diluted in mineral oil relative to control presentations of unscented mineral oil. Hatchlings were neither attracted nor repelled by a lower concentration (0.1% v/v) of 1-hexanol but were moderately attracted to a low concentration (0.225% v/v) of hexanal. We quantified the behavior of the animals by tracking their positions with the Argos software toolkit. Our results establish that hatchlings have a strong, innate preference for food odor blend, but the valence of the blend's individual components may be different and may change depending on the concentration. Our results provide a useful entry point for an analysis of physiological mechanisms underlying innate sensory preferences.
Topics: Animals; Odorants; Mineral Oil; Smell
PubMed: 37428771
DOI: 10.1371/journal.pone.0284641 -
Scientific Reports Jun 2021Prolonged use of tight-fitting PPE, e.g., by COVID-19 healthcare workers leads to skin injuries. An important contributor is the shear exerted on the skin due to static...
Prolonged use of tight-fitting PPE, e.g., by COVID-19 healthcare workers leads to skin injuries. An important contributor is the shear exerted on the skin due to static friction at the skin-PPE interface. This study aims to develop an optimised wax-oil lubricant that reduces the friction, or shear, in the skin-PPE contact for up to four hours. Lubricants with different wax-oil combinations were prepared using beeswax, paraffin wax, olive oil, and mineral oil. In-vivo friction measurements involving seven participants were conducted by sliding a polydimethylsiloxane ball against the volar forearms to simulate the skin-PPE interface. The maximum static coefficient of friction was measured immediately and four hours after lubricant application. It was found that the coefficient of friction of wax-oil lubricants is mainly governed by the ratio of wax to oil and the thermal stability and morphology of the wax. To maintain long-term lubricity, it is crucial to consider the absorption of oil into the PPE material. The best performing lubricant is a mixture of 20 wt% beeswax, 40 wt% olive oil, and 40 wt% mineral oil, which compared to unlubricated skin, provides 87% (P = 0.0006) and 59% (P = 0.0015) reduction in instantaneous and 4-h coefficient of friction, respectively.
Topics: Adult; COVID-19; Female; Forearm; Humans; Lubricants; Male; Mineral Oil; Olive Oil; Personal Protective Equipment; Skin; Time Factors; Waxes
PubMed: 34078980
DOI: 10.1038/s41598-021-91119-0 -
Journal of Assisted Reproduction and... Aug 2019To investigate the stability of osmolality in non-humidified and humidified incubators for assisted reproductive technologies (ART).
PURPOSE
To investigate the stability of osmolality in non-humidified and humidified incubators for assisted reproductive technologies (ART).
METHODS
Drops of three single-step culture media (media A, B, and C) were incubated for 5 or 6 days covered with four different mineral oils (oils A, B, C, and D) in non-humidified incubator A, non-humidified incubator B, or humidified incubator C to investigate the effects of incubator environment (humidification), drop volume, culture media, and mineral oil on the stability of osmolality in microdrops.
RESULTS
A significant and linear increase was shown in the osmolality of 50-μL and 200-μL microdrops covered with mineral oil during 5 days incubation in non-humidified benchtop incubators. The maximum increase was 20 mOsm/kg, and the extent of the increase was affected by microdrop volume and possibly by the type of mineral oil used to cover the drops. In contrast, the osmolality of 50-μL and 200-μL microdrops did not change during 5 days incubation in a humidified benchtop incubator.
CONCLUSIONS
Mineral oil alone may not adequately prevent gradual changes in the osmolality of low-volume microdrops during extended in vitro culture of human embryos in non-humidified incubators. As a result, the osmolality may increase to high enough levels to stress some human embryos and adversely affect clinical outcomes. We therefore recommend that the stability of osmolality should be given more consideration to ensure optimal culture conditions for ART.
Topics: Culture Media; Embryo Culture Techniques; Embryo, Mammalian; Embryonic Development; Female; Fertilization in Vitro; Humans; Humidity; Incubators; Mineral Oil; Osmolar Concentration
PubMed: 31267335
DOI: 10.1007/s10815-019-01515-9 -
Integrated Pharmacy Research & Practice 2022Skin diseases are among the major contributors of disease burden in Ethiopia affecting individuals of all age. Extemporaneous compounding of topical medications serves...
BACKGROUND
Skin diseases are among the major contributors of disease burden in Ethiopia affecting individuals of all age. Extemporaneous compounding of topical medications serves as a necessary option to treat skin diseases when manufactured medications could not meet specific patient needs. Different classes of drugs are commonly used for the treatment of dermatologic diseases. Failure to periodically assess the prescribing pattern and patient needs may lead to inappropriate planning and implementation that ultimately compromise the service. Periodic prescription analysis for compounded medications helps to monitor the prescription pattern with respect to medication selection, disease condition, dosage form types and other relevant parameters. The current study was conducted to analyze the pattern of compounding prescriptions for dermatologicals in ALERT hospital.
METHODS
A cross-sectional design was conducted by retrospectively evaluating compounding prescription records of January and July, 2021. A total of 460 prescriptions in the hospital community pharmacy were systematically selected. Data related to disease pattern, product selection and dosage form type were extracted and analyzed. Data analysis was done using software for the statistical package for social science version 25.0.
RESULTS
A total of 441 prescriptions containing dermatological products for compounding were analyzed. Most patients were female (62.8%) and aged 30-64 years (44.0%). Psoriasis (36.2%), acne vulgaris (15.3%), and rosacea (13.4%) were the top 3 skin diseases for which the compounding preparations were prescribed. Salicylic acid (38.0%) was the most frequently prescribed drug followed by betamethasone (20.2%); while white petrolatum (47.2%) was the most common diluting agent used for compounding.
CONCLUSION
Psoriasis was the major dermatologic disease for compounding prescriptions and salicylic acid was the most frequent product used in compounding for treatment of the prescribed skin diseases.
PubMed: 35024353
DOI: 10.2147/IPRP.S346395 -
Skin Pharmacology and Physiology 2023Dry skin is a hallmark of impaired skin barrier function. Moisturizers are a mainstay of treatment to help the skin retain moisture, and there is a high consumer demand...
INTRODUCTION
Dry skin is a hallmark of impaired skin barrier function. Moisturizers are a mainstay of treatment to help the skin retain moisture, and there is a high consumer demand for effective products. However, the development and optimization of new formulations are hampered due to lack of reliable efficacy measures using in vitro models.
METHODS
In this study, a microscopy-based barrier functional assay was developed using an in vitro skin model of chemically induced barrier damage to evaluate the occlusive activity of moisturizers.
RESULTS
The assay was validated by demonstrating the different effects on barrier function between humectant (glycerol) and occlusive (petrolatum). Significant changes in barrier function were observed upon tissue disruption, which was ameliorated by commercial moisturizing products.
CONCLUSION
This newly developed experimental method may be helpful to develop new and improved occlusive moisturizers for the treatment of dry skin conditions.
Topics: Humans; Emollients; Skin; Petrolatum; Skin Diseases; Skin Absorption
PubMed: 36863326
DOI: 10.1159/000529630 -
European Journal of Pharmaceutical... Jun 2021We investigated the effects of mineral oil on statin pharmacokinetics and inflammatory markers in animal models. A new synthesis strategy produced regioisomers that...
We investigated the effects of mineral oil on statin pharmacokinetics and inflammatory markers in animal models. A new synthesis strategy produced regioisomers that facilitated the characterization of the main metabolite (M1) of atorvastatin, a lipophilic statin, in C57BL/6NCrl mice. The chemical structure of M1 in mice was confirmed as ortho-hydroxy β-oxidized atorvastatin. Atorvastatin and M1 pharmacokinetics and inflammatory markers were assessed in C57BL6/J mice given atorvastatin 5 mg/kg/day or 10 mg/kg/day, as a single dose or for 21 days, with or without 10 µL or 30 µL mineral oil. No consistent differences in plasma exposure of atorvastatin or M1 were observed in mice after single or repeat dosing of atorvastatin with or without mineral oil. However, mice administered atorvastatin 10 mg/kg with 30 µL mineral oil for 21 days had significantly increased plasma levels of serum amyloid A (mean 9.6 µg/mL vs 7.9 µg/mL without mineral oil; p < 0.01) and significantly increased proportions of C62L B cells (mean 18% vs 12% without mineral oil; p = 0.04). There were no statistically significant differences for other inflammatory markers assessed. In dogs, pharmacokinetics of atorvastatin, its two hydroxy metabolites and pravastatin (a hydrophilic statin) were evaluated after single administration of atorvastatin 10 mg plus pravastatin 40 mg with or without 2 g mineral oil. Pharmacokinetics of atorvastatin, hydroxylated atorvastatin metabolites or pravastatin were not significantly different after single dosing with or without mineral oil in dogs. Collectively, the results in mice and dogs indicate that mineral oil does not affect atorvastatin or pravastatin pharmacokinetics, but could cause low-grade inflammation with chronic oral administration, which warrants further investigation.
Topics: Animals; Atorvastatin; Dogs; Heptanoic Acids; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Mice; Mice, Inbred C57BL; Mineral Oil; Pravastatin; Pyrroles
PubMed: 33667667
DOI: 10.1016/j.ejps.2021.105776 -
International Journal of Environmental... Dec 2022Excipients are used as vehicles for topical treatments; however, there are not many studies that evaluate the impact of different excipients themselves. The aim of this...
Excipients are used as vehicles for topical treatments; however, there are not many studies that evaluate the impact of different excipients themselves. The aim of this research is to assess skin homeostasis changes in healthy individuals after using water/oil (W/O), oil/water (O/W), Beeler base, foam and Vaseline excipients. A within-person randomized trial was conducted that included healthy individuals without previous skin diseases. Skin barrier function parameters, including stratum corneum hydration (SCH), transepidermal water loss (TEWL), pH, temperature, erythema, melanin and elasticity (R0, R2, R5 and R7), were measured on the volar forearm before and after using each excipient. Sixty participants were included in the study, with a mean age of 32 years. After applying w/o excipient erythema decreased by 25 AU, ( < 0.001) and elasticity increased by 6%. After using the o/w excipient, erythema decreased by 39.36 AU ( < 0.001) and SCH increased by 6.85 AU ( = 0.009). When applying the Beeler excipient, erythema decreased by 41.23 AU ( < 0.001) and SCH increased by 15.92 AU ( < 0.001). Foam and Vaseline decreased TEWL and erythema. Excipients have a different impact on skin barrier function. Knowing the effect of excipients on the skin could help to develop new topical treatments and help specialists to choose the best excipient according to the pathology.
Topics: Humans; Adult; Excipients; Skin; Petrolatum; Administration, Topical; Erythema
PubMed: 36554558
DOI: 10.3390/ijerph192416678 -
Molecular Immunology Sep 2022In this pre-clinical study, we designed a candidate vaccine based on severe acute respiratory syndrome-related -coronavirus 2 (SARS-CoV-2) antigens and evaluated its...
Preclinical study of formulated recombinant nucleocapsid protein, the receptor binding domain of the spike protein, and truncated spike (S1) protein as vaccine candidates against COVID-19 in animal models.
BACKGROUND
In this pre-clinical study, we designed a candidate vaccine based on severe acute respiratory syndrome-related -coronavirus 2 (SARS-CoV-2) antigens and evaluated its safety and immunogenicity.
METHODS
SARS-CoV-2 recombinant protein antigens, including truncated spike protein (SS1, lacking the N-terminal domain of S1), receptor-binding domain (RBD), and nucleoprotein (N) were used. Immunization program was performed via injection of RBD, SS1 +RBD, and SS1 +N along with different adjuvants, Alum, AS03, and Montanide at doses of 0, 40, 80, and 120 μg at three-time points in mice, rabbits, and primates. The humoral and cellular immunity were analyzed by ELISA, VNT, splenocyte cytokine assay, and flow cytometry.
RESULTS
The candidate vaccine produced strong IgG antibody titers at doses of 80 and 120 μg on days 35 and 42. Even though AS03 and Montanide produced high-titer antibodies compared to Alum adjuvant, these sera did not neutralize the virus. Strong virus neutralization was recorded during immunization with SS1 +RBD and RBD with Alum. AS03 and Montanide showed a strong humoral and cellular immunity; however, Alum showed mild to moderate cellular responses. Ultimately, no cytotoxicity and pathologic change were observed.
CONCLUSION
These findings strongly suggest that RBD with Alum adjuvant is highly immunogenic as a potential vaccine.
Topics: Animals; Antibodies, Neutralizing; Antibodies, Viral; Antigens, Viral; COVID-19; Mice; Mineral Oil; Models, Animal; Nucleocapsid Proteins; Rabbits; Recombinant Proteins; SARS-CoV-2; Spike Glycoprotein, Coronavirus; Viral Vaccines
PubMed: 35802999
DOI: 10.1016/j.molimm.2022.06.007 -
Planta Mar 2022Using petrolatum gel as an antitranspirant on the flowers of California poppy and giant bindweed, we show that transpiration provides a large contribution to floral...
Using petrolatum gel as an antitranspirant on the flowers of California poppy and giant bindweed, we show that transpiration provides a large contribution to floral humidity generation. Floral humidity, an area of elevated humidity in the headspace of flowers, is believed to be produced predominantly through a combination of evaporation of liquid nectar and transpirational water loss from the flower. However, the role of transpiration in floral humidity generation has not been directly tested and is largely inferred by continued humidity production when nectar is removed from flowers. We test whether transpiration contributes to the floral humidity generation of two species previously identified to produce elevated floral humidity, Calystegia silvatica and Eschscholzia californica. Floral humidity production of flowers that underwent an antitranspirant treatment, petrolatum gel which blocks transpiration from treated tissues, is compared to flowers that did not receive such treatments. Gel treatments reduced floral humidity production to approximately a third of that produced by untreated flowers in C. silvatica, and half of that in E. californica. This confirms the previously untested inferences that transpiration has a large contribution to floral humidity generation and that this contribution may vary between species.
Topics: Biological Transport; Flowers; Humidity; Plant Nectar; Pollination
PubMed: 35246754
DOI: 10.1007/s00425-022-03864-9