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Journal of Biochemical and Molecular... Apr 2024The endocrine disruptor hexavalent chromium [Cr(VI)] is a proven reproductive toxicant. We recently demonstrated that prenatal Cr(VI) exposure causes testicular...
The endocrine disruptor hexavalent chromium [Cr(VI)] is a proven reproductive toxicant. We recently demonstrated that prenatal Cr(VI) exposure causes testicular resistance to gonadotropins, resulting in hypergonadotropic hypoandrogenism in F rats. However, the mechanism driving hypergonadotropism in F rats exposed to Cr(VI) prenatally remains an enigma. Therefore, we hypothesized that 'Prenatal Cr(VI) exposure may disrupt steroid hormones-mediated negative feedback regulation of the hypothalamic GnRH, and its receptor in the pituitary of F1 rats, leading to hypergonadotropism.' We administered potassium dichromate (50, 100, or 200 mg/L) to pregnant rats through drinking water between days 9 and 14, and their male F1 offspring were euthanized at 60 days of age. Prenatal Cr(VI) exposure in F rats resulted in the accumulation of Cr in the hypothalamus and pituitary. Western blot detected decreased hypothalamic GnRH, Kisspeptin1, and its receptor GPR54, along with diminished ERα, AR, aromatase, and 5α reductase, and GnRH regulatory transcription factors Pit-1 and GATA-4 proteins. Immunohistochemical studies revealed increased immunopositivity of GnRH receptor, AR, 5α reductase, ERα, ERβ, and aromatase proteins in the pituitary, whereas decreased Kisspeptin1, GPR54, and inhibin β. Our findings imply that Cr(VI) exposure during the prenatal period disrupts the hypothalamic Kisspeptin-GPR54-Pit-1/GATA4-GnRH network, boosting the pituitary GnRH receptor. We conclude that prenatal exposure to Cr(VI) alters GnRH expression in the hypothalamus and its receptor in the pituitary of F1 progeny through interfering with the negative feedback effect of androgens and estrogens.
Topics: Female; Pregnancy; Humans; Rats; Male; Animals; Receptors, LHRH; Estrogen Receptor alpha; Aromatase; Prenatal Exposure Delayed Effects; Hypothalamus; Gonadotropin-Releasing Hormone; Chromium
PubMed: 38532648
DOI: 10.1002/jbt.23699 -
Foods (Basel, Switzerland) Aug 2023Cultivating rice varieties with lower cellulose content in the bran layer has the potential to enhance both the nutritional value and texture of brown rice. This study...
Cultivating rice varieties with lower cellulose content in the bran layer has the potential to enhance both the nutritional value and texture of brown rice. This study aims to establish a rapid and accurate method to quantify cellulose content in the bran layer utilizing near-infrared spectroscopy (NIRS), thereby providing a technical foundation for the selection, screening, and breeding of rice germplasm cultivars characterized by a low cellulose content in the bran layer. To ensure the accuracy of the NIR spectroscopic analysis, the potassium dichromate oxidation (PDO) method was improved and then used as a reference method. Using 141 samples of rice bran layer (rice bran without germ), near-infrared diffuse reflectance (NIRdr) spectra, near-infrared diffuse transmittance (NIRdt) spectra, and fusion spectra of NIRdr and NIRdt were used to establish cellulose quantitative analysis models, followed by a comparative evaluation of these models' predictive performance. Results indicate that the optimized PDO method demonstrates superior precision compared to the original PDO method. Upon examining the established models, their predictive capabilities were ranked in the following order: the fusion model outperforms the NIRdt model, which in turn surpasses the NIRdr model. Of all the fusion models developed, the model exhibiting the highest predictive accuracy utilized fusion spectra (NIRdr-NIRdt (1st der)) derived from preprocessed (first derivative) diffuse reflectance and transmittance spectra. This model achieved an external predictive R of 0.903 and an RMSEP of 0.213%. Using this specific model, the rice mutant O2 was successfully identified, which displayed a cellulose content in the bran layer of 3.28%, representing a 0.86% decrease compared to the wild type (W7). The utilization of NIRS enables quantitative analysis of the cellulose content within the rice bran layer, thereby providing essential technical support for the selection of rice varieties characterized by lower cellulose content in the bran layer.
PubMed: 37627996
DOI: 10.3390/foods12162997 -
Marine Drugs Jun 2024Ichthyotoxic red tide is a problem that the world is facing and needs to solve. The use of antialgal compounds from marine macroalgae to suppress ichthyotoxic red tide...
Ichthyotoxic red tide is a problem that the world is facing and needs to solve. The use of antialgal compounds from marine macroalgae to suppress ichthyotoxic red tide is considered a promising biological control method. Antialgal substances were screened and isolated from , , , , , , and sp. to obtain new materials for the development of algaecides against ichthyotoxic red tide microalgae using bioactivity-guided isolation methods. The fractions of seven macroalgae exhibited selective inhibitory activities against and , of which the ethyl acetate fractions had the strongest and broadest antialgal activities for the two tested red tide microalgae. Their inhibitory effects on . and . were even stronger than that of potassium dichromate, such as ethyl acetate fractions of . , . , and sp. Thin-layer chromatography and ultraviolet spectroscopy were further carried out to screen the ethyl acetate fraction of sp. Finally, a new glycolipid derivative, 2--eicosanoyl-3--(6-amino-6-deoxy)--D-glucopyranosyl-glycerol, was isolated and identified from sp., and it was isolated for the first time from marine macroalgae. The significant antialgal effects of 2--eicosanoyl-3--(6-amino-6-deoxy)--D-glucopyranosyl-glycerol on . and . were determined.
Topics: Seaweed; Glycolipids; Harmful Algal Bloom; Microalgae; Dinoflagellida
PubMed: 38921590
DOI: 10.3390/md22060279 -
Comparative Biochemistry and... Nov 2023In fish, the skin is directly exposed to multiple environmental stressors and provides the first line of defense against harmful external factors. It turned out that...
In fish, the skin is directly exposed to multiple environmental stressors and provides the first line of defense against harmful external factors. It turned out that cortisol and melatonin (Mel) are involved in fish cutaneous stress response system (CSRS) similar to mammalian. This study investigates the mode of action of CSRS in two teleost species of different biology and skin characteristics, the three-spined stickleback and the European flounder, after exposure to oxidative stress induced by a potassium dichromate solution. The cutaneous stress response system presents different ways of action in two studied species: Mel concentration increases in the skin of both species, but cortisol concentration increases in the skin only in sticklebacks. Data suggest that stickleback skin cells can produce cortisol. However, cortisol is not involved in the response to oxidative stress in flounders. In stickleback skin, two genes encoding AANAT and ASMT/HIOMT (enzymes involved in Mel synthesis), aanat1a and asmt2, are expressed, but in flounder skin, only one, asmtl. Because gene expression does not change in stickleback skin after exposure to stress, the source of increased Mel is probably outside the skin. A lack of expression of the gene encoding AANAT in flounder skin strongly suggests that Mel is transported to the skin by the bloodstream from other sites of synthesis. Pigment dispersion in the skin after exposure to oxidative stress is found only in sticklebacks.
Topics: Animals; Flounder; Hydrocortisone; Melatonin; Smegmamorpha; Fishes; Oxidative Stress; Arylalkylamine N-Acetyltransferase; Mammals
PubMed: 37541323
DOI: 10.1016/j.cbpa.2023.111493 -
JAAD International Sep 2024Psoriasis and allergic contact dermatitis are 2 very common dermatoses. The relationship between them has not yet been fully understood. Contact dermatitis can be an...
BACKGROUND
Psoriasis and allergic contact dermatitis are 2 very common dermatoses. The relationship between them has not yet been fully understood. Contact dermatitis can be an additional cause of epidermal disruption in psoriasis patients, resulting in poor management of the disease.
OBJECTIVE
To analyze the tendencies of contact sensitization in a cohort of psoriasis patients with suspected allergic contact dermatitis.
METHODS
Psoriasis patients ( = 85) with suspected contact dermatitis underwent patch testing with European Baseline allergen series S-1000 in Vilnius University Hospital Santaros Klinikos Centre of Dermatovenereology from August 2020 to August 2021. Their results are presented in this study.
RESULTS
The patch test was positive in 43.5% ( = 37) of patients. Contact sensitization was more prevalent in patients with mild psoriasis, as characterized by Psoriasis Area Surface Index scores ≤10, compared to those with moderate-to-severe psoriasis ( < .05). Generalized psoriasis and nail involvement were more common among nonsensitized patients ( < .05). Most common contact allergens among sensitized patients were nickel (II) sulfate, formaldehyde, and potassium dichromate.
CONCLUSION
An inverse trend was observed between psoriasis severity and contact sensitization. Extended psoriatic involvement was uncommon in sensitized patients.
PubMed: 38774342
DOI: 10.1016/j.jdin.2024.02.015 -
Contact Dermatitis Jan 2024Footwear contact allergy is caused by exposure to allergens in shoes. The prevalence and common allergens vary by region and time due to differences in customs and...
BACKGROUND
Footwear contact allergy is caused by exposure to allergens in shoes. The prevalence and common allergens vary by region and time due to differences in customs and lifestyle.
OBJECTIVES
To determine the clinical characteristics and common allergens of patients with footwear-related allergic contact dermatitis (ACD) who attended Siriraj Hospital in Bangkok, Thailand, between 2001 and 2020.
METHODS
The medical records of 247 patients with clinically suspected footwear dermatitis who underwent patch testing were reviewed.
RESULTS
The prevalence of ACD to footwear was 1.8%. Females were predominant (71.6%). The three most common allergens were carba mix (7.7%), mercapto mix (6.9%) and potassium dichromate (6.9%). According to the allergens found, rubber (14.2%), adhesives (7.7%) and leathers (6.9%) were the three most common groups. Dorsal-limited skin lesions were significantly associated with footwear ACD.
CONCLUSION
Rubber and leather allergens were still the most common culprit allergens. Dermatologists should keep up-to-date on common allergens in footwear and emerging allergens to include in patch test series.
Topics: Female; Humans; Dermatitis, Allergic Contact; Allergens; Prevalence; Rubber; Thailand; Foot Dermatoses; Patch Tests; Retrospective Studies
PubMed: 37750414
DOI: 10.1111/cod.14428 -
Nanotechnology Jan 2024In this paper, a preparation method of superhydrophobic composites of oxidized multi-walled carbon nanotubes modified by stearic acid (SA) is proposed. Hydroxylated...
In this paper, a preparation method of superhydrophobic composites of oxidized multi-walled carbon nanotubes modified by stearic acid (SA) is proposed. Hydroxylated multi-walled carbon nanotubes (HMWCNTs) were obtained by oxidizing multi-walled carbon nanotubes with potassium dichromate to give them hydroxyl groups on the surface. Subsequently, the carboxyl group in the SA molecule was esterified with the hydroxyl group on the HMWCNTs. SA molecules were grafted onto the surface of multi-walled carbon nanotubes. SA modified oxidized multi-walled carbon nanotubes (SMWCNT) superhydrophobic composites were obtained. The results show that the water contact angle (WCA) of superhydrophobic composites can reach up to 174°. At the same time, the modified nanocomposites have good anti-icing and corrosion resistance. After low temperature delayed freezing test, the freezing extension time of the nanocomposite film is 30 times that of the smooth surface. Under strong acid and alkali conditions, the superhydrophobic nanocomposites still maintain good superhydrophobicity. The nanocomposites may have potential applications in the preparation of large-scale superhydrophobic coatings.
PubMed: 38215490
DOI: 10.1088/1361-6528/ad1df3 -
Huan Jing Ke Xue= Huanjing Kexue Sep 2023Chemical oxygen demand (COD) is an important index used to assess organic oxygen consumption pollution. To explore COD composition in the natural water in Baiyangdian...
Chemical oxygen demand (COD) is an important index used to assess organic oxygen consumption pollution. To explore COD composition in the natural water in Baiyangdian Lake, the main composition, source, and influencing factors of oxygen-consuming organic substances in the water body were revealed through physical continuous classification, three-dimensional fluorescence, and other methods. The results showed that the COD of the two waters was affected by dissolved organic substances (protein-like and humus-like organic matters) with size of less than 220 nm (59%-93%), and inorganic substances had little effect on COD. The source of organic matter in overlying water was primarily affected by endophytic vegetation decomposition, sediment release (the release flux of TOC was in the range of 1.55-2.28 mg·(m·d)), and other endogenous sources (biological index>0.8), as well as by land-based sources such as reed platform and artificial pollution (1.4
potassium dichromate method would rapidly oxidize most RDOC within a short time, leading to the overestimation of the organic oxygen consumption pollution in Baiyangdian Lake. PubMed: 37699810
DOI: 10.13227/j.hjkx.202208155 -
Analytical Methods : Advancing Methods... Jan 2024Formaldehyde (FA) sensing in children's toys and water has great application prospects in the protection of home safety and the ecological environment. However, there...
Formaldehyde (FA) sensing in children's toys and water has great application prospects in the protection of home safety and the ecological environment. However, there has been no report heretofore addressing FA detection in children's toys. In this work, a fluorescent (FL) whitening agent (FWA), potassium dichromate, and sulfuric acid were proposed as an "off-on" probe (FPD) for FA sensing FL and visual FL (VFL) methods. The FL emission of the FWA at 435 nm was quenched by CrO because of the internal filtration effect. The effect was interrupted after the addition of FA because CrO was reduced to Cr, accompanying the recovery of the FL emission of the FWA. The detection limit of FPD for FA FL and VFL approaches was 2.03 and 85.5 μg L, respectively. The proposed probe was successfully utilized for FA detection in crawling mats and building blocks as well as environmental water (verified by the UV method), indicating good adaptability. The FPD-based FL method might be a potential approach for FA detection due to the merits of high selectivity, anti-interference ability, and stability.
PubMed: 38165784
DOI: 10.1039/d3ay01551c -
Environmental Pollution (Barking, Essex... Jul 2024Human exposure to chromium (Cr) is common but little is known about its adverse effects on pregnancy outcomes. This study aimed to explore the association between Cr...
Human exposure to chromium (Cr) is common but little is known about its adverse effects on pregnancy outcomes. This study aimed to explore the association between Cr exposure and the risk of neural tube defects (NTDs) and the underlying mechanisms of Cr-induced NTDs. 593 controls and 408 NTD cases with placentas were included in this study. Chromium trichloride (Cr(III)) and potassium dichromate (Cr(VI)) were intragastrically administered to pregnant mice and the number of NTDs was recorded. The odds ratio for total NTDs in the highest exposure group in placenta was 4.18 (95% confidence interval (CI), 1.97-8.84). The incidence of fetal NTDs in mice administered with Cr(III) showed a dose-response relationship. Cr(VI) didn't show teratogenicity of NTDs whereas increased the stillbirth rate. Prenatal exposure to Cr(III) increased levels of oxidative stress and apoptosis in fetal mice. RNA-sequencing results indicated significant enrichment of the MAPK pathway. RT-qPCR and Western blot analysis revealed that Cr(III) induced increased expression of p-JNK, p-P38, and Casp3. Toxicological effects can be partly antagonized by antioxidant supplementation. High chromium exposure was associated with increased human NTD risks. Excessive Cr(III) exposure can induce NTDs in fetal mice by increasing apoptosis through upgrading oxidative stress and then activating JNK/P38 MAPK signaling pathway.
Topics: Female; Neural Tube Defects; Animals; Pregnancy; Chromium; Mice; Placenta; Humans; Apoptosis; Oxidative Stress; Maternal Exposure
PubMed: 38735460
DOI: 10.1016/j.envpol.2024.124126